Journal articles: 'Vehicle center of Gravity'

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Zhao, Xin Tong, H. Z. Jiang, S. T. Zheng, and Jun Wei Han. "Precision Gravity Center Position Measurement System for Heavy Vehicles." Key Engineering Materials 315-316 (July 2006): 788–91. http://dx.doi.org/10.4028/www.scientific.net/kem.315-316.788.

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Knowledge of a vehicle’s inertial parameters is essential for safety research and accident reconstruction. A precision measure system is proposed to determine the weight and gravity center for heavy vehicles. Based on a static gravity measuring principle with three measuring points, a hydraulically driven 2-DOF motion platform is developed. The transfer function model is derived for the hydraulically driven system. By means of a degree-of-freedom control scheme, the platform can realize accurate positioning to construct two intersected planes and work out the three-dimensional coordinates of the vehicle gravity center. Experiments demonstrate that the system has less than 0.3% measurement error in weight, and is able to measure the gravity centre accurately with deviation ≤3mm in X and Y direction, and ≤5mm in Z direction.

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Zhou, Chen, Xin-Hui Liu, Wei Chen, Fei-Xiang Xu, and Bing-Wei Cao. "Distribution of driving force beneath wheeled vehicle with varying center of gravity." Advances in Mechanical Engineering 11, no. 1 (January 2019): 168781401982559. http://dx.doi.org/10.1177/1687814019825591.

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Driving force analysis is performed on the no-spin differential and full-time all-wheel-drive vehicle; this thesis takes an automatic loading mixing vehicle as an example to introduce the compositions and working principle of the driving system. Based on the tire-ground mechanics, the model of the dynamics and the kinematics is established under the walking straight and steering conditions. According to the theoretical model, the influence of the vehicle’s gravity center on the moving system is analyzed. Co-simulation based on LMS Imagine Lab AMESim and LMS Virtual Lab Motion is performed to build the hydraulic driving system and the multi-body dynamics system models. Based on the tire-ground load environment simulation model built by 1D + 3D, various positions of the gravity center of the model are set to compare with the theoretical analysis. Various weight blocks are also added to change the location of the gravity center in the practical experiment. The conclusions that different gravity center positions lead to the change of the driving torque distribution are proved by the simulation results and experimental data.

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FAN, Yuezhen, Chuanchao DU, and Qingchun WANG. "Study on the Influence of the Center of Gravity of Fuel Cell City Bus on its Handling Characteristics." Mechanics 26, no. 5 (October 20, 2020): 416–25. http://dx.doi.org/10.5755/j01.mech.26.5.23590.

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The vehicles driven by combustion engine leads to environmental problems because of fossil fuel consumption. In recent years, many policies have adopted to support the development of new energy vehicles, especially battery electric vehicles as the main strategy in China. For the battery electric vehicles, the position of the battery pack can change the centroid position of the vehicle because of its big mass, and it can also change the loading of each tire in the motion, which has important influence on the vehicle handing and stability performance. This article studies the relationship between handling characteristic and the change of centroid position on a fuel cell city bus, and then solves the suitable centroid position of this vehicle which makes the vehicle have satisfied steering characteristic.

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Kis, J., and L. Jánosi. "Improved handling characteristics of off-road vehicles by applying active control of steering wheel torque." International Journal Sustainable Construction & Design 2, no. 1 (November 6, 2011): 66–74. http://dx.doi.org/10.21825/scad.v2i1.20437.

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Driving speed of agricultural mobile machines have been increased in the recent years, raisingserious questions about vehicle handling characteristics considering the high center-of-gravity, multi-massconfiguration and rear-wheel-steering of these vehicles. The next generation of steering systems on offroad vehicles will incorporate a steering column mechatronic subsystem which will generate tactilefeedback for operator. This paper presents our research work to utilize steering wheel torque to improveoff-road vehicle handling characteristics.

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Dechjarern, Surangsee, and Piyapat Chuchuay. "Parametric Study of Influence of Assembly and Design on the Center of Gravity of Public Buses." Applied Mechanics and Materials 835 (May 2016): 609–14. http://dx.doi.org/10.4028/www.scientific.net/amm.835.609.

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The bus is a vehicle for transport the passenger to the destination safely. The bus manufacturing is produced directly from the company and the bus has been modifying from the bus garage. The Bus modify into popular use in the domestic because it is cheaper. The modified bus is also a safety issue because these vehicles to the tilted test 30 degrees most of the test is not passed. The center of gravity is influenced to the stability of the bus. Which the Company or modify bus garage can not know the position of the center of gravity in advance. When the bus is used to build a center of gravity located in improper placement. Hence, the test does not pass 30 degrees tilt.Which required costs to adjustment and test again. This paper was intended to study the variables that affect the center of gravity of the bus include engine placement, adjustment pressure into air suspension before build bus body, bending chassis, characterized by mounting to the chassis frame. Studies using instruments find the center of gravity of the bus used computer simulation center of gravity nearby real bus. The variable adjustment in order to design a bus with the appropriate center of gravity. Research has found that different variables adjustment engine placement characterized by mounting to the chassis frame have an affect to bending chassis relate to the center of gravity change, Therefore, the variables to be optimized, it is possible to design a bus safety.

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Lee, Jounghee, Dongyoon Hyun, Kyoungseok Han, and Seibum Choi. "Real-Time Longitudinal Location Estimation of Vehicle Center of Gravity." International Journal of Automotive Technology 19, no. 4 (June 21, 2018): 651–58. http://dx.doi.org/10.1007/s12239-018-0062-8.

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Skrúcaný, Tomáš, and Jozef Gnap. "The Effect of the Crosswinds on the Stability of the Moving Vehicles." Applied Mechanics and Materials 617 (August 2014): 296–301. http://dx.doi.org/10.4028/www.scientific.net/amm.617.296.

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The article describes the effect of the crosswinds on the moving heavy road vehicles. It gives mathematical descriptions of two extreme situations originated from the crosswinds – side deflection from the directness and the rollover of the vehicles. It also analyzes the factors affecting the rate of the wind, as a cornering tire stiffness, instantaneous vehicle weight, axle load, the position of the center of gravity of the vehicle. Both situations present a greater risk for empty vehicles with tarpaulin superstructure, so some types of them are dealt.

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Zhang, Li Jun, and Rui Wang. "Key Factors Effect on Vehicle Braking Performance Based on Nonlinear 3DOF Vehicle Dynamic Model." Key Engineering Materials 439-440 (June 2010): 950–55. http://dx.doi.org/10.4028/www.scientific.net/kem.439-440.950.

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3DOF nonlinear braking dynamic model considering tire-road adhesion characteristics was established, and non-dimensional equations were gained from the above mathematic models by using braking torque coefficient, front and rear axle equivalent inertia coefficients and braking force distribution coefficient. Based on the numerical calculation in Matlab-Simulink software, the effect of key factors, (including vehicle mass and vehicle gravity center position variation, frontal and rear braking force distribution coefficient, and frontal and rear axle inertial variation caused by driven mode) on vehicle braking performance, such as braking distance and wheel lockup status, was investigated and summarized. Several 3D visualizations of the simulation results show that variation of vehicle center of gravity, vehicle mass, braking moment distribution, wheel equivalent inertia due to driveline, can cause quite complex effect. It can be assumed that the gained results in this study can help to improve vehicle braking performance and enhance braking stability.

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Wasiwitono, Unggul, I. Nyoman Sutantra, Yohanes, and Yunarko Triwinarno. "Steady-State Cornering Modeling and Analysis of Three-Wheel Narrow Vehicle." Applied Mechanics and Materials 758 (April 2015): 173–78. http://dx.doi.org/10.4028/www.scientific.net/amm.758.173.

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Electric mobility seems to be an innovative alternative to future urban transport. In this study, a steady-state cornering model of a three-wheel narrow electric vehicle is derived. The steady-state cornering analysis is conducted by varying the location of the vehicle center of gravity, speed and tilt angle. From this analysis, the center of gravity location and tilt angle that gives better cornering characteristics can be obtained. Therefore, this analysis helps and can be used as starting point to design the chassis and the tilting control system of the three-wheel narrow electric vehicle.

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SAGOU, Yukinori, Ryosuke TASAKI, Yoshiyuki NODA, Kiyoaki KAKIHARA, and Kazuhiko TERASHIMA. "203 Development of gravity center position control system of parallel two-wheel vehicle with lower gravity center including passenger." Proceedings of the Symposium on sports and human dynamics 2012 (2012): 191–96. http://dx.doi.org/10.1299/jsmeshd.2012.191.

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Durisek, N. J., G. J. Heydinger, J. P. Chrstos, and D. A. Guenther. "Land Vehicle Roll/Yaw Product of Inertia Measurement." Journal of Dynamic Systems, Measurement, and Control 119, no. 2 (June 1, 1997): 212–16. http://dx.doi.org/10.1115/1.2801235.

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This paper focuses on the measurement of the roll/yaw product of inertia of a vehicle and describes a four-degree-of-freedom lumped-parameter ADAMS model used to simulate the test configuration. The measurement is performed by oscillating the vehicle in yaw and monitoring the resulting yaw acceleration and roll torque. The product of inertia is calculated from equations representing the motion of a rigid body relative to a nonmoving reference frame modified to accommodate for the misalignment of the vehicle center of gravity and the test apparatus yaw axis, and to approximate the compliant behavior between the test device and vehicle. The effects of the vehicle center of gravity misalignment from the test apparatus’ yaw axis and the compliance between the test vehicle and test device are studied. The measurement uncertainty is found using the law of propagation of uncertainty.

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Risby, M. S., Khalis Suhaimi, Tan Kean Sheng, Arif Syafiq M. S., and Mohd Hafizi N. "Heavy Military Land Vehicle Mass Properties Estimation Using Hoisting and Pendulum Motion Method." Defence Science Journal 69, no. 6 (December 13, 2019): 550–56. http://dx.doi.org/10.14429/dsj.69.13478.

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Mass properties such as the centre of gravity location, moments of inertia, and total mass are of great importance for vehicle stability studies and deployment. Certain parameters are required when these vehicles need to be arranged inside an aircraft for the carrier to achieve proper mass balance and stability during a flight. These parameters are also important for the design and modelling process of vehicle rollover crash studies. In this study, the mass properties of a military armoured vehicle were estimated using hoisting and pendulum method. The gross total weight, longitudinal and vertical measurements were recorded by lifting the vehicle using a mobile crane and the data were used to estimate the centre of gravity. The frequency of vehicle oscillation was measured by applying swing motion with a small angle of the vehicle as it is suspended on air. The centre of gravity and mass moment of inertia were calculated using the vector mechanics approach. The outcomes and limitations of the approach as discussed in details.

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Povaliaiev, Serhii, and Olexii Saraiev. "Mathematical model for estimation the stability of the vehicle's motion on overturning." Vehicle and electronics. Innovative technologies, no. 19 (May 19, 2021): 47–52. http://dx.doi.org/10.30977/veit.2021.19.0.47.

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Problem. During the reconstruction of the circumstances of road traffic accidents with vehicles overturning, difficulties arise with determining the parameters of vehicles in the process of their overturning. This is due to the fact that the recommended calculation methods are often simplified. The main focus of such techniques is to determine the minimum speed of vehicles, which leads to their overturning. In fact, the speed of vehicles before overturning can be significantly higher. Goal. This paper is dedicated to developing mathematical model of overturning vehicles that makes possible to determine not only the conditions for overturning vehicles, but also other parameters of the vehicle movement in the process of overturning. Methodology. The overturning of the vehicle occurs as a result of the action of inertial forces after collision with an immovable side obstacle. In this case, the moment from the force of gravity of the vehicle keeps it from overturning. In the process of overturning the vehicle, the moment from the force of gravity decreases due to the decrease in the arm of the force of gravity. To compile a mathematical model, the basic equation of dynamics during rotational motion was used. The mathematical model of a vehicle overturning is written in the form of a nonlinear homogeneous second order differential equation. An analytical solution of this equation is obtained. Results. Developed mathematical model makes possible to determine not only the conditions for overturning vehicles, but also other parameters of the vehicle movement from the moment the center of mass begins to rise to the moment of its maximum rise in the process of overturning. For a particular case, when the critical speed of a vehicle during its overturning is determined, the developed mathematical model fully corresponds to the mathematical model based on the law of conservation of energy. For a specific vehicle, numerical results were obtained that fully correspond to the physics of the overturning process.

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Hao, Wan Jun, Guo Qiang Wang, Jun Na Qu, and Xue Fei Li. "Study on Dynamic Roll Stability of Articulated Engineering Vehicle Based on Virtual Prototype." Applied Mechanics and Materials 365-366 (August 2013): 435–39. http://dx.doi.org/10.4028/www.scientific.net/amm.365-366.435.

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Most rollover accidents involve articulated engineering vehicle due to the center of gravity shift when steering. In this paper, a virtual prototype model of a loader as the typical articulated engineering vehicle is built using multi-body dynamics software. The dynamic simulation of steering characteristic under different slop and speed is made and the roll stability is analyzed. The stable working range of the loader obtained from the simulation results can give reference for the drivers selection of vehicle route and safe operation. This paper has a certain meaning for further study of articulated vehicles roll stability.

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Wong, J. Y., and J. Preston-Thomas. "Investigation into the Effects of Suspension Characteristics and Design Parameters on the Performance of Tracked Vehicles using an Advanced Computer Simulation Model." Proceedings of the Institution of Mechanical Engineers, Part D: Transport Engineering 202, no. 3 (July 1988): 143–61. http://dx.doi.org/10.1243/pime_proc_1988_202_169_02.

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This paper describes the results of an investigation into the effects of the characteristics of the suspension system, initial track tension, vehicle weight and location of the centre of gravity on the tractive performance of tracked vehicles over unprepared terrain. The investigation was carried out using a newly developed computer simulation model NTVPM-86. The results show that the suspension characteristics, initial track tension and vehicle weight have noticeable effects on the mobility of tracked vehicles over marginal terrain, while the location of the centre of gravity, within the normal range, has a less significant influence on the tractive performance. It is demonstrated that the simulation model NTVPM-86 can play a significant role in the optimization of tracked vehicle design or in the evaluation of vehicle candidates for a given mission and environment.

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Subramaniyam, Kesavan Valis, and Shankar C. Subramanian. "Analysis of cornering response and stability of electrified heavy commercial road vehicles with regenerative braking." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 6 (December 6, 2019): 1672–89. http://dx.doi.org/10.1177/0954407019890157.

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Additional powertrain components and regenerative braking are two important factors that may affect the performance and stability of electrified vehicle cornering. The location of additional components affects the vehicle’s center of gravity (CG) position and thereby the stability of the vehicle. As regenerative braking is possible only on driven wheels, the brake force distribution between front and rear wheels may not follow the ideal brake force distribution curve. Hence, applying maximum regenerative braking during cornering may affect vehicle stability, and this has motivated the analysis presented in this paper. The scope of this research work includes obtaining a model for the regenerative brake system, which was then used to analyze the heavy commercial road vehicle lateral dynamic response during combined cornering and regenerative braking. A sensitivity study was carried out regarding variations in center of gravity, longitudinal speed, and tire–road traction coefficient [Formula: see text]. The IPG TruckMaker® vehicle simulation software running in a hardware-in-loop experimental system was used to study the heavy road vehicle cornering performance. The results showed that applying braking on a constant radius path required correction in the steering input to follow the desired path. However, the amount of steering correction required during regenerative braking was higher than that with conventional friction braking. Moreover, applying maximum regenerative braking at higher longitudinal speeds on snowy roads and split- µ roads has a higher impact on vehicle cornering performance compared with that on dry roads. Furthermore, a co-operative braking strategy with an optimum brake force sharing between regenerative braking and friction braking was developed to improve the electrified heavy commercial road vehicle’s cornering stability and handling performance during cornering and braking.

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Gong, Cheng, and Bao-Feng Ma. "Aerodynamic evaluation of an unmanned aerial vehicle with variable sweep and span." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 13 (March 19, 2019): 4980–97. http://dx.doi.org/10.1177/0954410019836907.

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Morphing aircraft can achieve optimum performances at multiple flight conditions through large geometry deformations. However, to obtain the optimum configurations, optimization design studies are required. A study on aerodynamic optimization of a morphing aircraft was conducted to obtain corresponding optimal configurations at various flight speeds. Firstly, an optimization framework being suitable to a morphing aircraft with larger deformations was established by integrating existing codes, in which aerodynamic forces for the optimization are calculated by an Euler-based solver and friction/form drag estimation code. The solver is based on a Cartesian method in which configurations are modeled in terms of components of aircraft, hence large deformations of morphing aircraft can be performed during the optimization. A surrogate-based model was employed for fitting aerodynamic forces, thus reducing computational cost in a global optimization. A generic morphing aircraft with variable sweep and span was investigated at subsonic, transonic, and supersonic conditions through the optimization process. The target of optimization is to obtain maximum lift-to-drag ratios subject to lift, trim, and static stability constrains at each flight condition. The movement of center-of-gravity of the aircraft was also considered in optimization. The results indicate that the center-of-gravity has an important effect on the optimum configurations obtained, and the aerodynamic performance will be enhanced significantly if the center-of-gravity is moved backward at transonic and supersonic cases. In the case of movable center-of-gravity, the optimum sweep angles increase with the increase in flight speeds, and the optimum spans at transonic and supersonic speeds are smaller than the subsonic case.

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Zhang, Duo, Yinying Tang, Qiyuan Peng, Chunjiao Dong, and Yunguang Ye. "Effect of mass distribution on curving performance for a loaded wagon." Nonlinear Dynamics 104, no. 3 (March 25, 2021): 2259–73. http://dx.doi.org/10.1007/s11071-021-06386-3.

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AbstractThe location of wagon gravity center for a loaded wagon is underestimated in a vehicle–track coupled system. The asymmetric wheel load distribution due to loading offset significantly affects the wheel-rail contact state and seriously deteriorates the curving performance in conjunction with the height of gravity center and cant deficiency. Optimizing the location of gravity center and cruising velocity, therefore, is of interest to prevent the derailment and promote the transport capacity of railway wagons. This study aims to reveal the three-dimensional influencing mechanism of mass distribution on vehicle curving performance under different velocities. The wheel unloading ratio is regarded as the evaluation index. A simplified quasi-static model is established considering essential assumptions to highlight the influence of lateral and vertical offset on curving performance. For a more accurate description, the MBS models with various locations of wagon gravity center are built and then negotiate curves in different simulation cases. The simulation results reveal that the distribution of wheel unloading ratio determined by loading offset is like contour lines of ‘basin’. Based on the conclusions of quasi-static analysis and dynamics simulations, the regression equation is proposed and the fitting parameters are calculated for each simulation case. This paper demonstrates the necessity of optimizing the location of wagon gravity center according to the running condition and offers a novel strategy to load and transport the cargo by railway wagons.

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Wong, J. Y., and V. M. Asnani. "Study of the correlation between the performances of lunar vehicle wheels predicted by the Nepean wheeled vehicle performance model and test data." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 222, no. 11 (November 1, 2008): 1939–54. http://dx.doi.org/10.1243/09544070jauto811.

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This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in ‘Performance evaluation of wheels for lunar vehicles’, Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 4×4 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth's gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth's gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth's gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio ( P20/ W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable correlation between the predictions and experimental data. This indicates that the NWVPM has the potential as an engineering tool for evaluating wheel candidates for a future generation of extra-terrestrial vehicles, provided that appropriate input data are available.

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Chada, Jithendra Sai Raja, Venkat G. Sandeep, and Rajesh Chollaganti. "Analysis of hydraulic system for adjustable ground clearance mechanism." Journal of Mechanical and Energy Engineering 4, no. 3 (December 10, 2020): 203–8. http://dx.doi.org/10.30464/jmee.2020.4.3.203.

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The stability of a vehicle depends on many parameters.The Centre of Gravity is one of the most important in them. If the height of center of gravity from the ground decreases the stability of the vehicle increases. But when the ground clearance is too low it has a chance of collision vehicle and the ground while going on an uneven road or with speed brakes. So, to avoid the collision of a vehicle to ground and increase the stability a mechanism to adjust the ground clearance is to be attached. Also, the lift and drag forces can also be altered using this adjustable ground clearance mechanism. The designers usually fix ground clearance and they try to acquire this by the suspension system. The suspension system has tires, tire air, springs, shock absorber, and other parts to connect the vehicle with the wheels. The present paper describes the significance of using hydraulic oil as a working fluid in an adjustable ground clearance mechanism. Also describes the design and analysis of piston and cylinder rod.

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Wong, J. Y. "Optimization of the Tractive Performance of Articulated Tracked Vehicles Using an Advanced Computer Simulation Model." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 206, no. 1 (January 1992): 29–45. http://dx.doi.org/10.1243/pime_proc_1992_206_158_02.

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This paper describes the results of a study of the effects of articulation joint configuration, suspension characteristics, location of the centre of gravity and initial track tension on the mobility of a two-unit, articulated tracked vehicle. The study was carried out using a comprehensive computer simulation model known as NTVPM-86. The results show that suspension characteristics, location of the centre of gravity and initial track tension have noticeable effects on the mobility of articulated tracked vehicles over marginal terrain, while the articulation joint angle has a less significant influence on vehicle performance. Locking the articulation joint between the two units of an articulated tracked vehicle usually causes a degradation of tractive performance. The approach to the optimization of the design of articulated tracked vehicles is demonstrated. It is shown that the simulation model NTVPM-86 can play a significant role in the optimization of articulated tracked vehicle design or in the evaluation of vehicle candidates for a given mission and environment.

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Povalyaev, S., and O. Saraiev. "MODELING OF THE MECHANISM OF VEHICLE OVERTURNING IN THE PROCESS OF DEVELOPMENT OF ROAD TRAFFIC ACCIDENT." Theory and Practice of Forensic Science and Criminalistics 20, no. 2 (December 4, 2019): 320–28. http://dx.doi.org/10.32353/khrife.2.2019.24.

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The development of mathematical models of vehicle overturning has been given significant attention by many researchers because of the need to obtain reliable information on the circumstances of road traffic accidents. Research of road traffic accidents with the overturning of vehicles is related with the difficulty to determinate the mechanism of overturning, because expert calculation methods do not always use the adapted mathematical models. Most of the methods focus on determining the minimum (critical) speed of vehicles, which leads to its overturning. However, the real speed of vehicles before overturning can be much higher. In this paper, a mathematical model of the process of vehicle overturning after a collision with an immovable lateral obstacle is given. Thus the overturning moment caused by the inertia forces acts on the vehicle, and the moment from the gravity that holds the vehicle from overturning. It is necessary to mark that the shoulder of moment from gravity changes from a maximal value to 0 in the process of vehicle overturning. The mathematical model is based on the basic equation of dynamics for rotational motion. The developed mathematical model is a nonlinear homogeneous differential equation of second order. A solution of this equation is obtained that allows us to determine the conditions for the vehicles overturning and to investigate the basic parameters of the movement of vehicles in the process of overturning from the moment when the center of mass of the vehicle begins to rise until the moment of its maximum lifting. A comparison of the results of calculating the critical speed of vehicles with results obtained on the basis of the law of energy conservation was carried out. The results are fully agreed. The numerical results obtained using a mathematical model for a particular vehicle have been analyzed.

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Kinsey, James C., Maurice A. Tivey, and Dana R. Yoerger. "Dynamics and navigation of autonomous underwater vehicles for submarine gravity surveying." GEOPHYSICS 78, no. 3 (May 1, 2013): G55—G68. http://dx.doi.org/10.1190/geo2012-0181.1.

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We investigated the effect of autonomous underwater vehicle (AUV) dynamics and navigation on underway submarine gravimetry. Our research was motivated by the need to obtain spatially dense marine gravity measurements close to the source of subkilometer-scale geologic features in the shallow oceanic crust. Such measurements have been previously obtained, for instance, with piloted submarines and towed sleds; however, the high cost and, in the case of on-bottom measurements, poor spatial sampling preclude routine acquisition of these measurements. Continuous underway gravity surveys with AUVs is a compelling cost-effective option, but this method requires separating the AUV accelerations from the measured gravity. We show that AUVs with a large distance between the center of buoyancy and the center of gravity have lower vertical accelerations than torpedo-shaped AUVs and consequentially are better suited for underway gravity surveys. Furthermore state estimators, which combine sensor measurements and models of the vehicle’s motion, provide superior estimates of the vehicle’s vertical accelerations than methods used in previous underway submarine gravity surveys. We simulated the use of these navigation methods in detecting dike swarms at the East Pacific Rise. Analysis showed that we can shorten filters used in reducing gravity data and consequentially provide improved measurements of the free-water anomaly with a minimal detectable spatial wavelength approximately 65% lower than previously reported results.

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Ayers, Paul, John B. Conger, Rob Comer, and Paul Troutt. "Stability Analysis of Agricultural Off-Road Vehicles." Journal of Agricultural Safety and Health 24, no. 3 (2018): 167–82. http://dx.doi.org/10.13031/jash.12889.

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Abstract. Vehicle rollovers cause many agricultural work-related fatalities each year. Tractors, off-road utility vehicles (ORUVs), zero turn radius (ZTR) mowers, and all-terrain vehicles (ATVs) can all become involved in fatal rollovers. The rollover tendency of these vehicles was evaluated using static lateral and longitudinal stability angles. Center of gravity locations were measured with the lift axle method, and lateral and longitudinal stability angles were calculated for four ATVs, five ORUVs, four ZTR mowers, and four lawn tractors. Stability angles were calculated for loaded and unloaded vehicle conditions. Loading vehicles with ballast and operators can substantially decrease lateral and longitudinal stability angles. Stability angles for these vehicles and for five full-size agricultural tractors were compared. All loaded and unloaded, lateral and longitudinal stability angles determined met the appropriate ANSI requirements. Keywords: ATVs, Off-road utility vehicles, Stability angles, Tractors.

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Sasaki, Makiko, Naoto Yanagihara, Osamu Matsumoto, and Kiyoshi Komoriya. "Light Weight Personal Vehicle Operated by the Movement of Rider's Center-of-Gravity." Journal of the Robotics Society of Japan 24, no. 4 (2006): 533–42. http://dx.doi.org/10.7210/jrsj.24.533.

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TAKEMI, Hiroki, and Makoto YOKOYAMA. "1414 Reinforcement learning control of a vehicle robot with variable center of gravity." Proceedings of Conference of Hokuriku-Shinetsu Branch 2012.49 (2012): 141401–2. http://dx.doi.org/10.1299/jsmehs.2012.49.141401.

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Zhang, Ya Wei, and Ren Kai Ren. "Study on Key Issues of Two-Wheel Auto-Balance Vehicle Based on Magnetic Navigation." Applied Mechanics and Materials 437 (October 2013): 775–78. http://dx.doi.org/10.4028/www.scientific.net/amm.437.775.

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Considering the two-wheel auto-balance vehicle system is complex and difficult to control, study on control system and assembly way of the vehicle have been made. The control system can be divided into balance control, speed control and steering control, and solutions to key issues of control system are proposed. Based on rollover prevention, a two-wheel vehicle is designed with low center of gravity. The results indicate that the solutions have increased speed and stability of the vehicle.

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Oktay, Tugrul, Harun Celik, and Ilke Turkmen. "Maximizing autonomous performance of fixed-wing unmanned aerial vehicle to reduce motion blur in taken images." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 232, no. 7 (March 28, 2018): 857–68. http://dx.doi.org/10.1177/0959651818765027.

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In this study, reducing motion blur in images taken by our unmanned aerial vehicle is investigated. Since shakes of unmanned aerial vehicle cause motion blur in taken images, autonomous performance of our unmanned aerial vehicle is maximized to prevent it from shakes. In order to maximize autonomous performance of unmanned aerial vehicle (i.e. to reduce motion blur), initially, camera mounted unmanned aerial vehicle dynamics are obtained. Then, optimum location of unmanned aerial vehicle camera is estimated by considering unmanned aerial vehicle dynamics and autopilot parameters. After improving unmanned aerial vehicle by optimum camera location, dynamics and controller parameters, it is called as improved autonomous controlled unmanned aerial vehicle. Also, unmanned aerial vehicle with camera fixed at the closest point to center of gravity is called as standard autonomous controlled unmanned aerial vehicle. Both improved autonomous controlled and standard autonomous controlled unmanned aerial vehicles are performed in real time flights, and approximately same trajectories are tracked. In order to compare performance of improved autonomous controlled and standard autonomous controlled unmanned aerial vehicles in reducing motion blur, a motion blur kernel model which is derived using recorded roll, pitch and yaw angles of unmanned aerial vehicle is improved. Finally, taken images are simulated to examine effect of unmanned aerial vehicle shakes. In comparison with standard autonomous controlled flight, important improvements on reducing motion blur are demonstrated by improved autonomous controlled unmanned aerial vehicle.

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Wilhelm, Toni, Volker Dorsch, and Frank Gauterin. "Mass Data Measurement, Approximation and Influence on Vehicle Stability for Ultra-Light Human-Powered Vehicles." Applied Sciences 11, no. 12 (June 13, 2021): 5485. http://dx.doi.org/10.3390/app11125485.

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The mass properties of a vehicle play a decisive role in its dynamics and characteristics and are fundamental for vehicle dynamics models and controllers. These values are not yet known for the vehicle class of the ultra-light velomobiles and similar multi-track bicycle vehicles. In the future, however, such vehicles could play a role in reducing the CO2 emissions generated by individual transportation. As a basis for vehicle dynamics modeling, accident reconstruction, and controller development for this vehicle class, this paper investigated ranges of mass properties and their influence on vehicle stability considering driver influence. In total, 13 vehicles (10 velomobiles and 3 trikes) were examined using different experimental setups. It was shown that most vehicles exhibited understeering behavior based on the center of gravity position and calculations of the static stability factor showed significantly lower rollover stability compared with conventional vehicles. The measured moments of inertia were used to develop and examine different approximation approaches for the yaw moment of inertia using conventional approaches from the passenger car sector and stepwise regression. This created the basis for parameter estimation from easily measurable vehicle parameters and provided the possibility to generate realistic parameter sets for vehicle dynamic models. Existing tests do not consider the influence of driver movements, such as pedaling movements or possible inclination of the upper body. This offers the potential for further investigations of the dynamic influences on the investigated variables.

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House, Peggy. "Science and Mathematics in Balance." Mathematics Teaching in the Middle School 11, no. 9 (May 2006): 453–59. http://dx.doi.org/10.5951/mtms.11.9.0453.

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Have you ever attached a pair OF cardboard “feet” to an inflated balloon and tossed the balloon into the air? The balloon always lands on its “feet.” Why? The answer involves the scientific concepts of gravity and center of gravity as well as several important geometric principles. Many children's toys, based on these principles, can be the vehicle for valuable investigations linking science and mathematics.

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Carputo, Francesco, Danilo D’Andrea, Giacomo Risitano, Aleksandr Sakhnevych, Dario Santonocito, and Flavio Farroni. "A Neural-Network-Based Methodology for the Evaluation of the Center of Gravity of a Motorcycle Rider." Vehicles 3, no. 3 (July 15, 2021): 377–89. http://dx.doi.org/10.3390/vehicles3030023.

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A correct reproduction of a motorcycle rider’s movements during driving is a crucial and the most influential aspect of the entire motorcycle–rider system. The rider performs significant variations in terms of body configuration on the vehicle in order to optimize the management of the motorcycle in all the possible dynamic conditions, comprising cornering and braking phases. The aim of the work is to focus on the development of a technique to estimate the body configurations of a high-performance driver in completely different situations, starting from the publicly available videos, collecting them by means of image acquisition methods, and employing machine learning and deep learning techniques. The technique allows us to determine the calculation of the center of gravity (CoG) of the driver’s body in the video acquired and therefore the CoG of the entire driver–vehicle system, correlating it to commonly available vehicle dynamics data, so that the force distribution can be properly determined. As an additional feature, a specific function correlating the relative displacement of the driver’s CoG towards the vehicle body and the vehicle roll angle has been determined starting from the data acquired and processed with the machine and the deep learning techniques.

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Joubert, Nicolas, Maxime Boisvert, Carl Blanchette, Yves St-Amant, Alain Desrochers, and Denis Rancourt. "Frame loads accuracy assessment of semianalytical multibody dynamic simulation methods of a recreational vehicle." Multibody System Dynamics 50, no. 2 (July 27, 2020): 189–209. http://dx.doi.org/10.1007/s11044-020-09756-8.

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Abstract The design of a vehicle frame is largely dependent on the loads applied on the suspension and heavy parts mounting points. These loads can either be estimated through full analytical multibody dynamic simulations, or from semi-analytical simulations in which tire and road sub-models are not included and external vehicle loads, recorded during field testing, are used as inputs to the wheel hubs. Several semi-analytical methods exist, with various modeling architectures, yet, it is unclear how one method over another improves frame loads prediction accuracy. This study shows that a semi-analytical method that constrains the vehicle frame center of gravity movement along a recorded trajectory, using a control algorithm, leads to an accuracy within 1% for predicting frame loads, when compared to reference loads from a full analytical model. The control algorithm computes six degrees of freedom forces and moments applied at the vehicle center of gravity to closely follow the recorded vehicle trajectory. It is also shown that modeling the flexibility of the suspension arms and controlling wheel hub angular velocity both contribute in improving frame loads accuracy, while an acquisition frequency of 200 Hz appears to be sufficient to capture load dynamics for several maneuvers. Knowledge of these loads helps engineers perform appropriate dimensioning of vehicle structural components therefore ensuring their reliability under various driving conditions.

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Li, Shaohua, Jiangbo Chen, and Hongwei Huang. "Investigation on Emergency Brake Property of a Heavy-Duty Vehicle Based on Functional Virtual Prototyping Model." Open Mechanical Engineering Journal 8, no. 1 (December 31, 2014): 675–81. http://dx.doi.org/10.2174/1874155x01408010675.

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A Functional Virtual Prototyping full vehicle model for a tri-axial heavy-duty truck is built, and the non-linearity of suspension dampers and tires is also considered. With the trajectory of full vehicle gravity center, longitudinal tire force of front wheel, longitudinal acceleration, lateral acceleration, yaw rate and pitch angle as the evaluation indexes of brake property, the influences of system parameters including wheelbase, load shift, road surface roughness and separated road friction coefficient on brake efficiency, stability and ride comfort are analyzed. In addition, the interaction of brake and full vehicle dynamics is studied. Results show that small wheelbase and load shift may improve the brake efficiency of vehicles, small road surface roughness is beneficial to brake stability and ride comfort, and great frictional coefficient difference of separation road will worsen the brake efficiency and stability.

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Tonguç, Güray, İsmail Hakkı Akçay, and Habib Gürbüz. "Improvement of the visual warning system for various driving and road conditions in road transportation." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 2 (October 16, 2017): 175–87. http://dx.doi.org/10.1177/0954407017690962.

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This study aims to identify the potential adverse driving conditions which result from driver behavior, road surfaces and weather conditions for vehicles during a cruise, and to inform the drivers of the other vehicles moving on the same route. Adverse driving condition scenarios were developed via acceleration data in lateral, longitudinal and vertical directions gathered by using an accelerometer sensor placed at the gravity center of the test vehicles. The drivers were warned through the symbols designed according to the developed scenarios in different shapes and colors, displayed on an information screen showing the position of the vehicle. Three different software programs were used for gathering and evaluating the accelerometer data, storing scenario-specific symbols on the internet and transferring these symbols to the other vehicle information displays. The road tests were performed in conditions present in Turkey. It was observed that the vehicle drivers were alerted with the warning symbols which were designed for dangerous road and driving conditions with a latency of approximately 6s on Google maps which appeared on the driver information screen.

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Petritoli, Enrico, and Fabio Leccese. "High Accuracy Attitude and Navigation System for an Autonomous Underwater Vehicle (AUV)." ACTA IMEKO 7, no. 2 (July 4, 2018): 3. http://dx.doi.org/10.21014/acta_imeko.v7i2.535.

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<span lang="EN-GB">This paper examines the development of an attitude and control system for a tailless AUV (Autonomous Underwater Vehicle) without movable control surfaces. As the AUV does not have movable surfaces, the buoyancy system and the center of gravity displacement manage the entire maneuvering system.</span>

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Tan, Vu Van, and Nguyen Duy Hung. "Using an LQR active anti-roll bar system to improve road safety of tractor semi-trailers." Science and Technology Development Journal 23, no. 3 (August 21, 2020): 593–601. http://dx.doi.org/10.32508/stdj.v23i3.2060.

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Introduction: Tractor semi-trailer vehicles are playing an increasingly important role in the global freight chain. However, due to the heavy total load and height of the center of gravity, this type of vehicle is often at a higher risk of instability than other vehicles. This paper focuses on improving the vehicle roll stability by using an active anti-roll bar system. Methods: The Linear Quadratic Regulator (LQR) approach is used for this purpose with the control signal being the torque generated by the active anti-roll bar system. In order to synthesize the controller, the roll angle of the vehicle body and the normalized load transfer at all axles of the tractor semi-trailer vehicle are considered as the optimal goals. Results: The simulation results in time and frequency domains clearly show the effectiveness of the proposed method for the active anti-roll bar system, because the reduction of the desired criterias is about 40% less when compared to a vehicle using the passive anti-roll bar system. Conclusions: The effectiveness of the active anti-roll bar system on improving the vehicle roll stability, has been verified in this theoretical study with the LQR optimal controller. This is an important basis for conducting more in-depth studies and future experiments.

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Kondakov, S. V., O. O. Pavlovskaya, and A. R. Ishbulatov. "DEVELOPMENT OF A BENCH FOR SEMI-FULL-SCALE MODELING OF A CONTROL SYSTEMFOR THE MOVEMENT OF A TRACKED VEHICLE WITH A HYDROSTATIC TRANSMISSION." Bulletin of the South Ural State University series "Mechanical Engineering Industry" 20, no. 1 (2020): 5–14. http://dx.doi.org/10.14529/engin200101.

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The article presents the results of the development of a bench for a semi-full-scale simulation of the motion control system of a tracked vehicle with a hydrostatic trans-mission, intended both for teaching programming of logical controllers and for testing control algorithms at the stage of their development. The analysis of technical solutions known on the market with the identification of their main shortcomings is performed. In the framework of the concept of semi-full-scale modeling, a structure has been drawn up and implemented. A mathematical model of the control system for the movement of a tracked vehicle with hydrostatic transmission is presented. It is made on the basis of an industrial tracked tractor of traction class 15 tons manufactured by JSC Ural Road Construction Equipment Plant and adapted to the needs of the stand. A set of control algorithms has been formed, which includes an algorithm for controlling the movement of a caterpillar vehicle, an algorithm for activating the running-side brake when there is a risk of skidding, and an algorithm for activating the brake of the lagging side when the hydrostatic mechanism is overloaded by pressure. To organize the input of initial data, as well as observations of the simulation results, the Altair Embed software package developed a visualization system that includes an operator panel mimic diagram demonstrating changes in the basic parameters of the tracked vehicle's motion (center of gravity speed; center of gravity trajectory; pump flow control pa-rameters; curvature of the trajectory (set and current); track rotation speed on the left and right sides; soil resistance coefficient under each track), a panel settings the algorithms for motion control of a tracked vehicle, a panel of adjustment of parameters of the soil and the selection panel motion path of the tracked vehicle.

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He, Miaolei, Changji Ren, Jilin He, Kang Wu, Yuming Zhao, Zhijie Wang, and Can Wu. "Design, analysis and experiment of an eight-wheel robotic vehicle with four-swing arms." Industrial Robot: the international journal of robotics research and application 46, no. 5 (August 19, 2019): 682–91. http://dx.doi.org/10.1108/ir-12-2018-0260.

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Purpose Excellent obstacle surmounting performance is essential for the robotic vehicles in uneven terrain. However, existing robotic vehicles depend on complex mechanisms or control algorithms to surmount an obstacle. Therefore, this paper aims to propose a new simple configuration of an all-terrain robotic vehicle with eight wheels including four-swing arms. Design/methodology/approach This vehicle is driven by distributed hydraulic motors which provide high mobility. It possesses the ability to change the posture by means of cooperation of the four-swing arms. This ensures that the vehicle can adapt to complex terrain. In this paper, the bionic mechanism, control design and steering method of the vehicle are introduced. Then, the kinematic model of the center of gravity is studied. Afterward, the obstacle surmounting performance based on a static model is analyzed. Finally, the simulation based on ADAMS and the prototype experiment is carried out. Findings The experiment results demonstrate that the robotic vehicle can surmount an obstacle 2.29 times the height of the wheel radius, which verifies the feasibility of this new configuration. Therefore, this vehicle has excellent uneven terrain adaptability. Originality/value This paper proposes a new configuration of an all-terrain robotic vehicle with four-swing arms. With simple mechanism and control algorithms, the vehicle has a high efficiency of surmounting an obstacle. It can surmount a vertical obstacle 2.29 times the height of the wheel radius.

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KAWATA, Hitoshi, and Makoto YOKOYAMA. "B07 Traction control of a vehicle robot by change of its center of gravity." Proceedings of the Symposium on the Motion and Vibration Control 2009.11 (2009): 91–96. http://dx.doi.org/10.1299/jsmemovic.2009.11.91.

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Nozawa, Taichi, Keita Nakamura, Ryosuke Katsuyama, Shunki Kuwajima, Ziyan Li, Akira Nomizu, Riku Okamoto, Toshitatsu Munakata, and Takanobu Watanabe. "The WiFly: Flapping-Wing Small Unmanned Aerial Vehicle with Center-of-Gravity Shift Mechanism." Journal of Robotics and Mechatronics 33, no. 2 (April 20, 2021): 205–15. http://dx.doi.org/10.20965/jrm.2021.p0205.

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This paper describes the development of a flapping-wing unmanned aerial vehicle (UAV) named WiFly, which is equipped with a center-of-gravity (COG) shift mechanism. This mechanism allows seamless changes in the flight attitude between hovering and level flight by controlling the pitch angle. We implemented two types of feedback control systems in WiFly: PID control and reinforcement learning (shallow Q-learning) to stabilize the flight attitude. The controllability of WiFly is drastically improved by employing a double-motor drive system to independently control the flipping frequencies of the left and right wings.

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Kozioł, Stanisław. "Truck Driving Parameters - A Comparative Study." Solid State Phenomena 237 (August 2015): 142–47. http://dx.doi.org/10.4028/www.scientific.net/ssp.237.142.

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Rescue and fire-fighting vehicles and other vehicles used by the fire department, such as tankers and aerial ladder trucks have typically a high centre of gravity. Driving such vehicles involves the danger of transverse stability loss and rolling over. This problem is augmented by inadequate driver experience due to the low mileage of emergency vehicles. The safety of a moving vehicle largely depends on its driving characteristics, which can be studied and compared, and these in turn can be the basis for the evaluation of the vehicle safety with a specific body design.The aim of the study was to develop a set of measuring devices for identifying driving properties for trucks. A dynamics study was conducted using constructed prototype solutions for selected trucks with a high centre of gravity, including emergency vehicles for fire departments. The study was performed during selected standard road tests for determining driveability properties. Three road tests were used to assess the road stability and manoeuvrability of the vehicles: driving in a circle in predetermined conditions, steering wheel jump while driving straight ahead, and braking while driving in a circle. The results of this study allow determining the characteristic values of parameters describing vehicle behaviour in each test and a comparative assessment of their safety in traffic. Moreover, the study constituted a verification of the developed system that can be used for dynamics tests and the evaluation of vehicle safety.

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Wan, Wenkang, Jingan Feng, Bao Song, and Xinxin Li. "Huber-Based Robust Unscented Kalman Filter Distributed Drive Electric Vehicle State Observation." Energies 14, no. 3 (February 1, 2021): 750. http://dx.doi.org/10.3390/en14030750.

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Accurate and real-time acquisition of vehicle state parameters is key to improving the performance of vehicle control systems. To improve the accuracy of state parameter estimation for distributed drive electric vehicles, an unscented Kalman filter (UKF) algorithm combined with the Huber method is proposed. In this paper, we introduce the nonlinear modified Dugoff tire model, build a nonlinear three-degrees-of-freedom time-varying parametric vehicle dynamics model, and extend the vehicle mass, the height of the center of gravity, and the yaw moment of inertia, which are significantly influenced by the driving state, into the vehicle state vector. The vehicle state parameter observer was designed using an unscented Kalman filter framework. The Huber cost function was introduced to correct the measured noise and state covariance in real-time to improve the robustness of the observer. The simulation verification of a double-lane change and straight-line driving conditions at constant speed was carried out using the Simulink/Carsim platform. The results show that observation using the Huber-based robust unscented Kalman filter (HRUKF) more realistically reflects the vehicle state in real-time, effectively suppresses the influence of abnormal error and noise, and obtains high observation accuracy.

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Haqq, Hakiki. "Analysis Ballistic Flight and Design of Control System RKX200TJ/Booster at Rocket Booster and Climb Phases." Jurnal Teknologi Dirgantara 18, no. 2 (December 27, 2020): 169. http://dx.doi.org/10.30536/j.jtd.2020.v18.a3438.

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The problem encountered while developing the RKX-200TJ/booster is the measurement of mass vehicle (center of gravity). The thrust line of the rocket booster does not coincide with the center of gravity can induce a pitch disturbance. By controlling the pitch parameter, the pitch disturbance phenomenon can be minimized. In this paper is presented the flight performance and dynamics analysis and the design of pitch and roll control system for RKX200TJ/booster during rocket booster and climb phase. The result indicates that the pitch disturbance can be reduced until decrease about 27% whereas roll angle ( ) can be damped at zero level ( ). Pitch angle ( ) can be maintained at angle 5° for climb phase. Although the one of moment arm case shows the static instability and uncontrollability during rocket booster phase, the control system can control vehicle the further phase. This simulation presented in X-Plane and Simulink. The PID controller is selected in control system design.

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Inoue, Tomoya, Tokihiro Katsui, Hisataka Murakami, and Ken Takagi. "Crawler System for Deep Sea ROVs." Marine Technology Society Journal 43, no. 5 (December 1, 2009): 97–104. http://dx.doi.org/10.4031/mtsj.43.5.29.

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AbstractIn order to reduce tension on a cable and process movability, a deep sea remotely operated vehicle (ROV) is designed to reduce its weight. However, a lightweight ROV is apt to wheelie when running by means of a crawler system. To run stably in counterpoise, the combination of the center of gravity and the center of buoyancy should be in an adequate area called the “stable area,” which by theory can be obtained as corresponding to the weight and the buoyancy. The stable area becomes small as the weight is light. The combination of the center of gravity and the center of buoyancy is designed to be in the stable area. However, it is important for the ROV to run forward and backward, which results in changing the discrimination of the stable area. This sometimes causes the center of gravity and the center of buoyancy to be outside the stable area. Thus, it is advantageous to increase the weight only when running by crawler system and to change the center of gravity meaningfully. Furthermore, the flipper-type crawler system is advantageous when running on the sea floor with inclination or undulation. This paper proposes a method to virtually increase the weight and to change the center of gravity by using thrusters. This paper also describes the flipper-type crawler system that improves movability when running on the sea floor with inclination or undulation. Furthermore, we conducted preliminary experiments in a water tank using a small-size ROV having four thrusters and a crawler system, a normal-type crawler, and a flipper-type crawler system, to confirm the advantages.

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Jiao, Ran, Wusheng Chou, Rui Ding, and Mingjie Dong. "Adaptive robust control of quadrotor with a 2-degree-of-freedom robotic arm." Advances in Mechanical Engineering 10, no. 8 (August 2018): 168781401877863. http://dx.doi.org/10.1177/1687814018778639.

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The control of quadrotor equipped with a robotic arm has received growing challenges. This article proposes a new adaptive control strategy of quadrotor equipped with a 2-degree-of-freedom robotic arm. To consider the positional variety of the center of gravity caused by the motion of the robotic arm, the kinematic and dynamic models are built. Based on the presented models, a backstepping and sliding mode controller with a terminal sliding mode manifold is first applied to cope with the condition in which the robotic arm is motionless relative to the quadrotor. As the evolvement of the backstepping and sliding mode controller, a novel adaptive backstepping and sliding mode controller is then designed for the vehicle with the robotic arm wavering. The robustness and effectiveness of the proposed control law are investigated through both simulations and flight tests. With the proposed control laws, several simulations are conducted in conditions of both a variable and a constant center of gravity, and the performance of hovering is tested with a variable center of gravity in an experiment. Overall results show that the proposed adaptive backstepping control could estimate and compensate the variable center of gravity which may seriously influence the stabilization of quadrotor flying in the air.

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Karmiadji, Djoko Wahyu, Muchamad Gozali, Muji Setiyo, Thirunavukkarasu Raja, and Tuessi Ari Purnomo. "Comprehensive Analysis of Minibuses Gravity Center: A Post-Production Review for Car Body Industry." Mechanical Engineering for Society and Industry 1, no. 1 (July 19, 2021): 31–40. http://dx.doi.org/10.31603/mesi.5250.

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The center of gravity (CoG) on the minibus is one of the fundamental parameters that affect the operation of the vehicle to maintain traffic safety. CoG greatly affects vehicle maneuverability due to load transfer between the front and rear wheels, such as when turning, braking, and accelerating. Therefore, this research was conducted to evaluate the operational safety of minibusses produced by the domestic car body industry. The case study was conducted on a minibus with a capacity of 30 passengers to be used in a mining area. Investigations on CoG were carried out based on the minibus specification data, especially the dimensions and forces acting on the wheels. Minibusses as test objects were categorized in two conditions, namely without passengers and with 30 passengers. The test results are expressed in a coordinate system (x, y, z) which represents the longitudinal, lateral, and vertical distances to the center of the front wheel axle. CoG coordinate values without passengers are (2194.92; 7.11; 1327.97) mm and CoG coordinates with full passengers (30 people) are (2388.52; 13.04; 1251.72) mm. The test results show that the change in CoG at full load is not significant which indicates the minibus is safe when maneuvering under normal conditions.

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Li, Xiaogao, Ning Zhang, and Nan Chen. "Research on the influence of electric vehicle driven system on vehicle shimmy based on numerical calculation." MATEC Web of Conferences 272 (2019): 01041. http://dx.doi.org/10.1051/matecconf/201927201041.

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A 6 degrees of freedom shimmy model for four in-wheel motors independent drive electric vehicle with independent front suspension is established, and numerical analysis and simulation are used to study the dynamic response of vehicle shimmy. The influence of electric vehicle driving system on shimmy is studied by comparing with fuelengined vehicle, and the influence of vehicle structural parameters such as the caster angle, the inclination angle of front suspensions and the centre of gravity of vehicle on shimmy are studied too. It shows that as the in-wheel motor in drive system increases the weight of wheel, the amplitude of each degree of freedom in electric vehicle are larger than in fuel-engined vehicle when vehicle shimmies. The influence of the caster angle and the centre of gravity of vehicle on vehicle shimmy is obvious, but the inclination angle of front suspension have little influence.

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Li, Bo, and Shaoyi Bei. "Research method of vehicle rollover mechanism under critical instability condition." Advances in Mechanical Engineering 11, no. 1 (January 2019): 168781401882121. http://dx.doi.org/10.1177/1687814018821218.

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In this article, a novel rollover prediction algorithm is developed for application on vehicles with large lateral velocity and high center of gravity. Lateral energy is the direct cause of rollover. Rollover prediction model is proposed by taking full account of the impact of the pavement, tire, and suspension and realizes the estimation of the vehicle lateral energy. By calculating the ratio of real-time lateral energy reserve and rollover threshold, the degree of rollover risk is obtained. The double-shift experiment and the Fishhook experiment are performed to verify the accuracy and suitability of the proposed model, and the proposed prediction is 0.2 s ahead of the actual liftoff situation and 0.45 s ahead of the actual rollover situation; therefore, the proposed rollover model can be regarded as an effective method.

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SAGO, Yukinori, Yoshiyuki NODA, Kiyoaki KAKIHARA, and Kazuhiko TERASHIMA. "2P1-R12 The conditions for stabilizing the parallel two-wheel vehicle with lower gravity center of vehicle body structurally(Wheeled Robot/Tracked Vehicle (3))." Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2013 (2013): _2P1—R12_1—_2P1—R12_4. http://dx.doi.org/10.1299/jsmermd.2013._2p1-r12_1.

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AJISAKA, Shimon, Sosuke NAKAMURA, Takashi KUBOTA, and Hideki HASHIMOTO. "Verification of Sensibility Estimation of Personal Vehicle Driver using Driver’s Center of Gravity Path Characteristics." Transactions of Japan Society of Kansei Engineering 13, no. 5 (2014): 621–27. http://dx.doi.org/10.5057/jjske.13.621.

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Journal articles on the topic 'Vehicle center of Gravity'

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