Journal articles: 'Linear suspension'

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East, William, Jérôme Turcotte, Jean-Sébastien Plante, and Guifré Julio. "Experimental assessment of a linear actuator driven by magnetorheological clutches for automotive active suspensions." Journal of Intelligent Material Systems and Structures 32, no. 9 (February 11, 2021): 955–70. http://dx.doi.org/10.1177/1045389x21991237.

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The main functions of automotive suspensions are to improve passenger comfort as well as vehicle dynamic performance. Simultaneously satisfying these functions is not possible because they require opposing suspension adjustments. This fundamental design trade-off can be solved with an active suspension system providing real-time modifications of the suspension behavior and vehicle attitude corrections. However, current active suspension actuator technologies have yet to reach a wide-spread commercial adoption due to excessive costs and performance limitations. This paper presents a design study assessing the potential of magnetorheological clutch actuators for automotive active suspension applications. An experimentally validated dynamic model is used to derive meaningful design requirements. An actuator design is proposed and built using a motor to feed counter-rotating MR clutches to provide upward and downward forces. Experimental characterization shows that all intended design requirements are met, and that the actuator can output a peak force of ±5300 N, a peak linear speed of ±1.9 m/s and a blocked-output force bandwidth of 92 Hz. When compared to other relevant technologies, the MR approach simultaneously shows both better force density and speeds (bandwidth) while adding minimal costs and weight. Results from this experimental assessment suggest that MR slippage actuation is promising for automotive active suspensions.

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Buckner, Gregory D., Karl T. Schuetze, and Joe H. Beno. "Intelligent Feedback Linearization for Active Vehicle Suspension Control." Journal of Dynamic Systems, Measurement, and Control 123, no. 4 (July 3, 2000): 727–33. http://dx.doi.org/10.1115/1.1408945.

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Effective control of ride quality and handling performance are challenges for active vehicle suspension systems, particularly for off-road applications. Off-road vehicles experience large suspension displacements, where the nonlinear kinematics and damping characteristics of suspension elements are significant. These nonlinearities tend to degrade the performance of active suspension systems, introducing harshness to the ride quality and reducing off-road mobility. Typical control strategies rely on linear, time-invariant models of the suspension dynamics. While these models are convenient, nominally accurate, and tractable due to the abundance of linear control techniques, they neglect the nonlinearities and time-varying dynamics present in real suspension systems. One approach to improving the effectiveness of active vehicle suspension systems, while preserving the benefits of linear control techniques, is to identify and cancel these nonlinearities using Feedback Linearization. In this paper the authors demonstrate an intelligent parameter estimation approach using structured artificial neural networks that continually “learns” the nonlinear parameter variations of a quarter-car suspension model. This estimation algorithm becomes the foundation for an Intelligent Feedback Linearization (IFL) controller for active vehicle suspensions. Results are presented for computer simulations, real-time experimental tests, and field evaluations using an off-road vehicle (a military HMMWV). Experimental results for a quarter-car test rig demonstrate 60% improvements in ride quality relative to baseline (non-adapting) control algorithms. Field trial results reveal 95% reductions in absorbed power and 65% reductions in peak sprung mass acceleration using this IFL approach versus conventional passive suspensions.

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Wan, Yi, and Joseph M. Schimmels. "Improved Vibration Isolating Seat Suspension Designs Based on Position-Dependent Nonlinear Stiffness and Damping Characteristics." Journal of Dynamic Systems, Measurement, and Control 125, no. 3 (September 1, 2003): 330–38. http://dx.doi.org/10.1115/1.1592189.

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The design of seat suspensions having linear stiffness and damping characteristics involves a tradeoff between three performance measures. These measures are: (1) suspension range of motion, (2) improved average vibration isolation (weighted average across a wide exposure spectrum), and (3) improved isolation at the frequency of peak transmissibility. To overcome the limitations associated with this tradeoff, nonlinear mechanical properties are used here in the design of a seat suspension. From the infinite number of possible nonlinear mechanical characteristics, several possibilities that showed promise in previous studies were selected. The selected nonlinear force-deflection relationship (stiffness) of the seat is described by a combination of cubic and linear terms. The selected damping behavior of the seat is described by a combination of a linear term and a position-dependent term. A lumped parameter model (linear-human/nonlinear-seat) of the human/seat-suspension coupled system and a robust direct search routine are used to obtain pseudo-optimal values of the seat design parameters (mass, stiffness, and damping) via simulation in the time domain. Results indicate that the optimal nonlinear seat suspension is significantly better than the optimal linear seat suspension in overall vibration isolation characteristics.

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Liu, De Jun, Hui Da Duan, and Zhen Xiong Zhou. "Control of Magnetic Suspension Linear Feed System." Advanced Materials Research 616-618 (December 2012): 1918–21. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.1918.

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A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control has better dynamic, static and robust characters by using the auto-disturbance rejection controller.

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Hirata, Tohru, Takasi Hikihara, and Yoshihisa Hirane. "Suspension characteristics of magnetic suspension system by linear induction motor." IEEJ Transactions on Industry Applications 110, no. 10 (1990): 1091–99. http://dx.doi.org/10.1541/ieejias.110.1091.

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Hirata, Tohru, Takashi Hikihara, and Yoshihisa Hirane. "Suspension characteristics of magnetic suspension system by linear induction motor." Electrical Engineering in Japan 111, no. 3 (1991): 136–44. http://dx.doi.org/10.1002/eej.4391110315.

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Xia, Jun Zhong, Zong Po Ma, Shu Min Li, and Xiang Bi An. "Influence of Vehicle Suspension System on Ride Comfort." Applied Mechanics and Materials 141 (November 2011): 319–22. http://dx.doi.org/10.4028/www.scientific.net/amm.141.319.

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This paper focuses on the influence of various vehicle suspension systems on ride comfort. A vehicle model with eight degrees of freedom is introduced. With this model, various types of non-linear suspensions such as active and semi-active suspensions are investigated. From this investigation, we draw the conclusion that the active and semi-active suspensions models are beneficial for ride comfort.

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Mohite, Ajit G., and Anirban C. Mitra. "Development of Linear and Non-linear Vehicle Suspension Model." Materials Today: Proceedings 5, no. 2 (2018): 4317–26. http://dx.doi.org/10.1016/j.matpr.2017.11.697.

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9

Zhang, Yu Lin. "Sliding Mode Control for Magneto-Rheological Vehicle Suspension Accounting for its Nonlinearity." Applied Mechanics and Materials 433-435 (October 2013): 1072–77. http://dx.doi.org/10.4028/www.scientific.net/amm.433-435.1072.

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The non-linear characteristics of magneto-rheological (MR) suspension systems have limited control performance of modern control theory based on linear feedback control. In this paper, a four DOF half car suspension model with two nonlinear MR dampers is adopted. In order to account for the nonlinearity, a sliding mode controller, which has inherent robustness against system nonlinearity, is formulated to improve comfort and road holding of the car under industrial specifications and it is fit to semi-active suspensions. The numerical result shows that the semi-active suspension using the sliding mode controller can achieve better ride comfort than the passive and also improve stability.

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Pisarski, Dominik, and Czeslaw I. Bajer. "Smart Suspension System for Linear Guideways." Journal of Intelligent & Robotic Systems 62, no. 3-4 (August 7, 2010): 451–66. http://dx.doi.org/10.1007/s10846-010-9450-7.

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Tang, Ai Hua, Jian Ping Tian, and Xiao Xu Liu. "Kinematics Characteristic Analysis and Structural Parameter Optimization of Twist Beam Rear Suspension." Advanced Materials Research 201-203 (February 2011): 1710–13. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.1710.

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The multi-body dynamics analysis is an important method to analyze the movement and dynamics characteristics of a car in modern vehicle design process . The twist beam rear suspension which is for rear wheel steering was widely equipped on front engine rear wheel drive vehicles . The modeling of twist beam rear suspensions is always difficult to describe accurately for its unique structural behaviour . First of all , a non-linear method based on multi-body dynamics was used to establish the dynamics model of the twist beam rear suspension system by using the ADAMS/Car . Secondly, the kinematics analysis of the rear suspension was realized and the main suspension parameters (toe angle, camber angle and wheel base) were calculated by changing wheel travel by means of ADAMS/Car . Finally , the suspension was optimized . The result shows that integrative use of ADAMS/Car and ADAMS/Insight in the kinematics analysis and optimized design of the suspensions is rapidly and effectively to design vehicle suspensions .

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Tang, Ai Hua, Ou Jian, and Guo Hong Deng. "Modeling and Kinematics Characteristic Analysis of Twist Beam Rear Suspension Using ADAMS/Car." Advanced Materials Research 139-141 (October 2010): 1056–59. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.1056.

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The multi-body system analysis has become one of the main simulation techniques to calculate the kinematics characteristics of a car suspension under wheel travel or to build a virtual prototype model of a vehicle in order to predict the vehicle dynamics performance. The modeling of twist beam rear suspensions is always difficult for the unique structural behavior of this component. A non-linear method based on multi-body dynamics software (ADAMS/Car) was used to represent the twist beam within the suspension system. The kinematics characteristic analysis of the rear suspension was realized by means of ADAMS/Car. The main suspension parameters (toe angle, camber angle and wheel track variation) were calculated by changing wheel travel. The result shows that the method of suspension kinematics analysis by using ADAMS/Car can be used in the design of suspensions conveniently.

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13

Ulsoy, A. G., D. Hrovat, and T. Tseng. "Stability Robustness of LQ and LQG Active Suspensions." Journal of Dynamic Systems, Measurement, and Control 116, no. 1 (March 1, 1994): 123–31. http://dx.doi.org/10.1115/1.2900666.

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A two-degree-of-freedom quarter-car model is used as the basis for linear quadratic (LQ) and linear quadratic Gaussian (LQG) controller design for an active suspension. The LQ controller results in the best rms performance trade-offs (as defined by the performance index) between ride, handling and packaging requirements. In practice, however, all suspension states are not directly measured, and a Kalman filter can be introduced for state estimation to yield an LQG controller. This paper (i) quantifies the rms performance losses for LQG control as compared to LQ control, and (ii) compares the LQ and LQG active suspension designs from the point of view of stability robustness. The robustness of the LQ active suspensions is not necessarily good, and depends strongly on the design of a backup passive suspension in parallel with the active one. The robustness properties of the LQG active suspension controller are also investigated for several distinct measurement sets.

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14

Likaj, Rame, and Ahmet Shala. "Optimisation and Control of Vehicle Suspension Using Linear Quadratic Gaussian Control." Strojnícky casopis – Journal of Mechanical Engineering 68, no. 1 (April 1, 2018): 61–68. http://dx.doi.org/10.2478/scjme-2018-0006.

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Abstract The paper deals with the optimal design and analysis of quarter car vehicle suspension system based on the theory of linear optimal control because Linear Quadratic Gaussian (LQG) offers the possibility to emphasize quantifiable issues like ride comfort or road holding very easily by altering the weighting factor of a quadratic criterion. The theory used assumes that the plant (vehicle model + road unevenness model) is excited by white noise with Gaussian distribution. The term quadratic is related to a quadratic goal function. The goal function is chosen to provide the possibility to emphasize three main objectives of vehicle suspensions; ride comfort, suspension travel and road holding. Minimization of this quadratic goal function results in a law of feedback control. For optimal designs are used the optimal parameters which have been derived by comparison of two optimisation algorithms: Sequential Quadratic Program (SQP) and Genetic Algorithms (GA's), for a five chosen design parameters. LQG control is considered to control active suspension for the optimal parameters derived by GA's, while the main focus is to minimise the vertical vehicle body acceleration

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15

Shannan, J. E., and M. J. Vanderploeg. "A Vehicle Handling Model With Active Suspensions." Journal of Mechanisms, Transmissions, and Automation in Design 111, no. 3 (September 1, 1989): 375–81. http://dx.doi.org/10.1115/1.3259009.

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This paper presents two vehicle models used to investigate the effects of active suspensions. One is a linear seven degree of freedom ride model. The second is a nonlinear ten degree of freedom ride and handling model. Full state feedback optimal control algorithms are developed for both models. The seven degree of freedom model is used to study ride effects. The active suspension substantially reduced the motion of the sprung mass. The ten degree of freedom model is used to study the effects of the active suspension on the directional response characteristics of the vehicle. The handling characteristics exhibited by the active suspension are very similar to those of the passive suspension. However, the active suspension did significantly reduce sprung mass motions during the handling maneuvers. It is then illustrated that by altering various feedback gains, active suspensions can be made to change the handling characteristics in the nonlinear range.

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16

Zanatta, Ana Paula, Ben Hur Bandeira Boff, Paulo Roberto Eckert, Aly Ferreira Flores Filho, and David George Dorrell. "Tubular linear permanent magnet synchronous machine applied to semi-active suspension systems." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 5 (September 3, 2018): 1781–94. http://dx.doi.org/10.1108/compel-01-2018-0022.

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Purpose Semi-active suspension systems with electromagnetic dampers allow energy regeneration and the required control strategies are easier to implement than the active suspensions are. This paper aims to address the application of a tubular linear permanent magnet synchronous machine for a semi-active suspension system. Design/methodology/approach Classical rules of mechanics and electromagnetics were applied to describe a dynamic model combining vibration and electrical machines theories. A multifaceted MATLAB®/Simulink model was implemented to incorporate equations and simulate global performance. Experimental tests on an actual prototype were carried out to investigate displacement transmissibility of the passive case. In addition, simulation results were shown for the dissipative semi-active case. Findings The application of the developed model suggests convergent results. For the passive case, numerical and experimental outcomes validate the parameters and confirm system function and proposed methodology. MATLAB®/Simulink results for the semi-active case are consistent, showing an improvement on the displacement transmissibility. These agree with the initial conceptual thoughts. Originality/value The use of linear electromagnetic devices in suspension systems is not a novel idea. However, most published papers on this subject outline active solutions, neglect semi-active ones and focus on experimental studies. However, here a dynamic mechanical-electromagnetic coupled model for a semi-active suspension system is reported. This is in conjunction with a linear electromagnetic damper.

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17

DENG, Zhaoxiang. "Electromagnetic Linear Actuator for Vehicle Active Suspension." Journal of Mechanical Engineering 47, no. 14 (2011): 121. http://dx.doi.org/10.3901/jme.2011.14.121.

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18

Bechtel, Toni M., and Aditya S. Khair. "Linear viscoelasticity of a dilute active suspension." Rheologica Acta 56, no. 2 (January 7, 2017): 149–60. http://dx.doi.org/10.1007/s00397-016-0991-y.

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DRATLER, D. I., W. R. SCHOWALTER, and R. L. HOFFMAN. "Dynamic simulation of shear thickening in concentrated colloidal suspensions." Journal of Fluid Mechanics 353 (December 25, 1997): 1–30. http://dx.doi.org/10.1017/s0022112097007167.

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Stokesian Dynamics has been used to investigate the origins of shear thickening in concentrated colloidal suspensions. For this study, we considered a monolayer suspension composed of charge-stabilized non-Brownian monosized rigid spheres dispersed at an areal fraction of ϕa=0.74 in a Newtonian liquid. The suspension was subjected to a linear shear field. In agreement with established experimental data, our results indicate that shear thickening in this system is associated with an order–disorder transition of the suspension microstructure. Below the critical shear rate at which this transition occurs, the suspension microstructure consists of two-dimensional analogues of experimentally observed sliding layer configurations. Above this critical shear rate, suspensions are disordered, contain particle clusters, and exhibit viscosities and microstructures characteristic of suspensions of non-Brownian hard spheres. In addition, suspensions possessing the sliding layer microstructure at the beginning of supercritical shearing tend to retain this microstructure for a period of time before disordering. The onset of this disorder is due to the formation of particle doublets within the suspension. Once formed, these doublets rotate, due to the bulk motion, and disrupt the long-range order of the suspension. The cross-stream component of the centre-to-centre separation vector associated with the two particles forming a doublet, which is zero when the doublet is perfectly aligned with the bulk velocity vector, grows exponentially with time. This strongly suggests that the evolution of these doublets is due to a change in the stability of the sliding layer configurations, with this type of ordered microstructure being linearly unstable above a critical shear rate. This contention is supported by results of a stability analysis. The analysis shows that a single string of particles is subject to a linear instability leading to the formation of particle doublets. Simulations were repeated with different numbers of particles in the computational domain, with the results found to be qualitatively independent of system size.

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Du, Haiping, James Lam, and Kam Yim Sze. "Design of Non-Fragile H∞ Controller for Active Vehicle Suspensions." Journal of Vibration and Control 11, no. 2 (February 2005): 225–43. http://dx.doi.org/10.1177/1077546305049392.

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In this paper we present an approach to design the non-fragile H ∞ controller for active vehicle suspensions. A quarter-car model with active suspension system is considered in this paper. By suitably formulating the sprung mass acceleration, suspension deflection and tire deflection as the optimization object and considering a priori norm-bounded controller gain variations, the non-fragile state-feedback H ∞ controller can be obtained by solving a linear matrix inequality. The designed controller not only can achieve the optimal performance for active suspensions but also preserves the closed-loop stability in spite of the controller gain variations.

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PARTHASARATHY, M., K. H. AHN, B. M. BELONGIA, and D. J. KLINGENBERG. "THE ROLE OF SUSPENSION STRUCTURE IN THE DYNAMIC RESPONSE OF ELECTRORHEOLOGICAL SUSPENSIONS." International Journal of Modern Physics B 08, no. 20n21 (September 1994): 2789–809. http://dx.doi.org/10.1142/s0217979294001135.

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The dynamic response of electrorheological (ER) suspensions has received little attention relative to the effort devoted to the study of the steady shear response. We report on simulation and experimental investigations of the dynamic oscillatory response of ER suspensions, in particular focusing on the relationship between suspension structure and the rheological response. We consider the response of monodisperse and polydisperse suspensions under linear deformation, as well as the response in the nonlinear regime. Dimensional analysis of the equations of motion predict that the linear rheological response obeys a time-field strength superposition principle, which is confirmed by experiment. The response is found to exhibit a sharp dispersion that is only broadened slightly by polydispersity. Nonlinear deformation is found to significantly broaden the observed dispersion.

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Liu, Nan, Hui Pang, and Rui Yao. "Robust Mixed H2/H∞ State Feedback Controller Development for Uncertain Automobile Suspensions with Input Delay." Processes 8, no. 3 (March 20, 2020): 359. http://dx.doi.org/10.3390/pr8030359.

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In order to achieve better dynamics performances of a class of automobile active suspensions with the model uncertainties and input delays, this paper proposes a generalized robust linear H2/H∞ state feedback control approach. First, the mathematical model of a half-automobile active suspension is established. In this model, the H∞ norm of body acceleration is determined as the performance index of the designed controller, and the hard constraints of suspension dynamic deflection, tire dynamic load and actuator saturation are selected as the generalized H2 performance output index of the designed controller to satisfy the suspension safety requirements. Second, a generalized H2/H∞ guaranteed cost state-feedback controller is developed in terms of Lyapunov stability theory. In addition, the Cone Complementarity Linearization (CCL) algorithm is employed to convert the generalized H2/H∞ output-feedback control problem into a finite convex optimization problem (COP) in a linear matrix inequality framework. Finally, a numerical simulation case of this half-automobile active suspension is presented to illustrate the effectiveness of the proposed controller in frequency-domain and time-domain.

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Zhang, Hailong, Ning Zhang, Fuhong Min, Subhash Rakheja, Chunyi Su, and Enrong Wang. "Coupling Mechanism and Decoupled Suspension Control Model of a Half Car." Mathematical Problems in Engineering 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/1932107.

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A structure decoupling control strategy of half-car suspension is proposed to fully decouple the system into independent front and rear quarter-car suspensions in this paper. The coupling mechanism of half-car suspension is firstly revealed and formulated with coupled damping force (CDF) in a linear function. Moreover, a novel dual dampers-based controllable quarter-car suspension structure is proposed to realize the independent control of pitch and vertical motions of the half car, in which a newly added controllable damper is suggested to be installed between the lower control arm and connection rod in conventional quarter-car suspension structure. The suggested damper constantly regulates the half-car pitch motion posture in a smooth and steady operation condition meantime achieving the expected completely structure decoupled control of the half-car suspension, by compensating the evolved CDF.

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Pazooki, Alireza, Avesta Goodarzi, Amir Khajepour, Amir Soltani, and Claude Porlier. "A novel approach for the design and analysis of nonlinear dampers for automotive suspensions." Journal of Vibration and Control 24, no. 14 (March 28, 2017): 3132–47. http://dx.doi.org/10.1177/1077546317701011.

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This paper proposes an analytical technique for frequency analysis and the design of nonlinear dampers to further improve ride dynamics performance of vehicle suspensions over a wide range of excitation frequencies. Using the energy balance method (EBM), the proposed methodology estimates the equivalent linear damping coefficient of any nonlinear passive damper whose force is a general function of the damper’s relative displacement and relative velocity. Knowing the equivalent linear damping coefficient makes it possible to perform a frequency analysis of the suspension ride performance with any nonlinear damper. Some specific criteria are defined to design the desired form of equivalent linear damping coefficient which provides a high/small damping ratio at low-/high-frequency excitations, so the corresponding nonlinear damping force required to obtain improved ride performance of the suspension using a 1-degree-of-freedom quarter car model is also defined. A sensitivity analysis is then performed to provide a design guideline. The results show that the dependency of the equivalent damping coefficient either relative to the velocity of the suspension (velocity-dependent damper) or the relative displacement of the suspension (position-dependent damper) could provide a variable damping ratio leading to better vibration isolation over the excitation frequency. A noticeable ride dynamic performance can be reached over the entire range of the excitation frequency by designing a nonlinear damper such that its equivalent linear damping ratio becomes a desired function of both its relative displacement and relative velocity (position-velocity-dependent damper).

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Higuchi, Toshiro, and Koichi Oka. "Reluctance Control Magnetic Suspension System-Suspension System with Permanent Magnet and Linear Actuator." IEEJ Transactions on Industry Applications 113, no. 8 (1993): 988–94. http://dx.doi.org/10.1541/ieejias.113.988.

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Higuchi, Toshiro, and Koichi Oka. "Reluctance control magnetic suspension system—suspension system with permanent magnet and linear actuator." Electrical Engineering in Japan 114, no. 7 (1994): 115–23. http://dx.doi.org/10.1002/eej.4391140711.

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CHOI, UNG-SU, and YOUNG-GUN KO. "ELECTRORHEOLOGICAL BEHAVIOR OF CHITOSAN DICARBOXYLATE SUSPENSIONS." International Journal of Modern Physics B 16, no. 17n18 (July 20, 2002): 2501–6. http://dx.doi.org/10.1142/s0217979202012578.

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The electrorheological (ER) behavior of chitosan dicarboxylate suspensions in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan dicarboxylate susepnsions showed a typical ER response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. Of these, chitosan malonicate suspension represented slightly higher rheological performance than any other suspensions due to dependent upon the carbon chain length. The shear stress for the suspension exhibited a linear dependence on an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan dicarboxylate suspensions were found to be an anhydrous ER fluid.

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Cupples, G., D. J. Smith, M. R. Hicks, and R. J. Dyson. "Oriented suspension mechanics with application to improving flow linear dichroism spectroscopy." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, no. 2232 (December 2019): 20190184. http://dx.doi.org/10.1098/rspa.2019.0184.

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Flow linear dichroism is a biophysical spectroscopic technique that exploits the shear-induced alignment of elongated particles in suspension. Motivated by the broad aim of optimizing the sensitivity of this technique, and more specifically by a hand-held synthetic biotechnology prototype for waterborne-pathogen detection, a model of steady and oscillating pressure-driven channel flow and orientation dynamics of a suspension of slender microscopic fibres is developed. The model couples the Fokker–Planck equation for Brownian suspensions with the narrow channel flow equations, the latter modified to incorporate mechanical anisotropy induced by the particles. The linear dichroism signal is estimated through integrating the perpendicular components of the distribution function via an appropriate formula which takes the biaxial nature of the orientation into account. For the specific application of pathogen detection via binding of M13 bacteriophage, it is found that increases in the channel depth are more significant in improving the linear dichroism signal than increases in the channel width. Increasing the channel depth to 2 mm and pressure gradient to 5 × 10 4 Pa m −1 essentially maximizes the alignment. Oscillating flow can produce nearly equal alignment to steady flow at appropriate frequencies, which has significant potential practical value in the analysis of small sample volumes.

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Tang, Ai Hua. "Modeling and Validation of MBS Using Joint Force Actuator in ADAMS Car." Advanced Materials Research 482-484 (February 2012): 2257–60. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.2257.

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With the advent of multibody dynamics software (ADAMS) , it has become one of the main simulation techniques to build a multibody system (MBS) in order to evaluate the dynamics performance. The modeling of some component parts such as anti-roll bars and torsion beam rear suspensions is always difficult for the unique structural and non-linear characteristics.A joint force actuator based on multibody dynamics was introduced to represent the component within suspension systems. The kinematics analysis of the torsion beam rear suspension was carried out to validate accuracy and rationality by means of joint force actuators in ADAMS/Car. The result shows that the joint force actuator can be used in the MBS modeling and simulation analysis of non-linear characteristics conveniently.

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Juozapaitis, Algirdas, Siim Idnurm, Gintaris Kaklauskas, Juhan Idnurm, and Viktor Gribniak. "NON-LINEAR ANALYSIS OF SUSPENSION BRIDGES WITH FLEXIBLE AND RIGID CABLES." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 16, no. 1 (March 31, 2010): 149–54. http://dx.doi.org/10.3846/jcem.2010.14.

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One of the main problems related to the design of suspension bridges is stabilisation of their initial form. The tendency of suspension bridges to deform is generally determined by the kinematical displacements of the suspension cable caused by asymmetrical loads rather than by the elastic deformations. There are some suspension bridges when the so‐called rigid (stiff in bending) cables instead of usual flexible cables are suggested for stabilisation of their initial form. The analysis methods of such suspension bridges with rigid cables are underdeveloped. For the analysis of classical suspension bridges analytical models can be applied. However, in case of concentrated forces, the numerical techniques are preferred. The article presents analytical expressions for the calculation of internal forces and displacements of suspension bridges with a rigid cable. The article also discusses the discrete calculation model for classical suspension bridges. Santrauka Viena iš pagrindiniu kabamuju tiltu projektavimo problemu yra pradinus ju formos stabilizavimas. Kabamuju tiltu deformatyvuma lemia iš esmes ne tiek tampriosios deformacijos, kiek asimetriniu apkrovu sukelti kinematiniai kabamojo lyno poslinkiai. Yra žinomi kabamieji tiltai, kuriu pradinei formai stabilizuoti siūloma vietoje iprastiniu lanksčiuju lynu taikyti vadinamuosius standžius lynus. Tokiu kabamuju tiltu su standžiaislynais skaičiavimo metodai nera iki galo parengti. Klasikiniams tiltams su lanksčiu lynu skaičiuoti taikomi daugiausia kontinualūs modeliai, kurie esant tam tikrai tilto sandarai ar veikiant sutelktoms apkrovoms nera pakankamai tikslūs. Straipsnyje pateikiamos analizines išraiškos kabamuju tiltu su standžiu lynu iražoms ir poslinkiams apskaičiuoti, aptariamas diskretusis klasikiniu kabamuju tiltu skaičiavimo modelis.

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Choi, Ung-su, Byeng-gil Ahn, and Oh-kwan Kwon. "ELECTRORHEOLOGICAL BEHAVIOR OF CHITOSAN DERIVATIVE SUSPENSIONS." International Journal of Modern Physics B 15, no. 06n07 (March 20, 2001): 1025–32. http://dx.doi.org/10.1142/s0217979201005556.

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The electrorheological (ER) behavior of chitosan and chitosan phosphate suspensions in silicone oil was investigated. Chitosan and chitosan phosphate suspensions showed a typical ER response (Bingham flow behavior) upon application of an electric field. However, chitosan phosphate suspension exhibited excellent shear yield stress compared with chitosan suspension. The difference in behavior results from the difference in the conductivity of the chitosan and chitosan phosphate particles due to their degree of the polarizability. The shear stress for chitosan and chitosan phosphate suspensions showed a linear dependence on the volume fraction of particles. The values of structure factor, A s obtained 1 and 3~4 for chitosan and chitosan phosphate suspensions and it may be due to the formation of single-row chains and multiple chains upon application of the electric field. Throughtout the experimental results, chitosan and chitosan phosphate suspensions were shown to be an ER fluid.

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32

Liu, Xiaofu, Jason Z. Jiang, Andrew Harrison, and Xiaoxiang Na. "Truck suspension incorporating inerters to minimise road damage." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 10-11 (April 6, 2020): 2693–705. http://dx.doi.org/10.1177/0954407020905149.

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Road damage caused by heavy vehicles is a serious problem experienced worldwide. This paper investigates the potential for reduction in road damage by incorporating the inerter element into truck suspension systems. Initially, quarter-car, pitch-plane and roll-plane models with two low-complexity inerter-based linear suspension layouts are investigated in the frequency domain. Reductions of the J95 road damage index for each model are identified against conventional parallel spring–damper truck suspension layouts. It is also shown that the proposed suspensions are capable of enhancing the roll stability while keeping the road damage at a given level. Subsequently, the nonlinear relationship between force and displacement as manifested by leaf springs is incorporated into the pitch-plane and roll-plane time-domain models. These confirm the potential advantage of inerter-based suspension layouts for road damage reduction.

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33

HAĆ, Aleksander. "Optimal Linear Preview Control of Active Vehicle Suspension." Vehicle System Dynamics 21, no. 1 (January 1992): 167–95. http://dx.doi.org/10.1080/00423119208969008.

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34

Keivan, Ashkan, and Brian M. Phillips. "Rate-independent linear damping in vehicle suspension systems." Journal of Sound and Vibration 431 (September 2018): 405–21. http://dx.doi.org/10.1016/j.jsv.2018.05.037.

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35

Mohite, A. G. "Development and Validation of Non-linear Suspension System." IOSR Journal of Mechanical and Civil Engineering 17, no. 01 (March 2017): 06–11. http://dx.doi.org/10.9790/1684-17010010611.

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36

Matsumura, Fumio, Shinji Maeda, Masayuki Fujita, and Hideki Fukuzono. "Completely contactless linear DC motor using magnetic suspension." Electrical Engineering in Japan 107, no. 1 (January 1987): 95–103. http://dx.doi.org/10.1002/eej.4391070111.

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37

Gaspar, P., I. Szaszi, and J. Bokor. "Active suspension design using linear parameter varying control." International Journal of Vehicle Autonomous Systems 1, no. 2 (2003): 206. http://dx.doi.org/10.1504/ijvas.2003.003539.

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38

D’Angola, A., G. Carbone, L. Mangialardi, and C. Serio. "Non-linear oscillations in a passive magnetic suspension." International Journal of Non-Linear Mechanics 41, no. 9 (November 2006): 1039–49. http://dx.doi.org/10.1016/j.ijnonlinmec.2006.10.013.

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39

Chan, T. C., C. K. Sung, and Paul C. P. Chao. "Non-linear suspension of an automatic ball balancer." International Journal of Non-Linear Mechanics 46, no. 2 (March 2011): 415–24. http://dx.doi.org/10.1016/j.ijnonlinmec.2010.11.001.

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40

Wang, Xiao Guang, Bin Mei, Feng Sha, and Xin Zhou. "Influence of Suspension Mass Variation on Dynamic Characteristic of Magnetic Suspension System." Applied Mechanics and Materials 150 (January 2012): 63–68. http://dx.doi.org/10.4028/www.scientific.net/amm.150.63.

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Magnetic suspension system is nonlinear and unstable essentially. It is according to the principle of nonlinear system having same topological structure near the operation point with the linear system that linear control arithmetic for a nonlinear system is adopted. The system is easy to lose stabilize and diverge when subjected to interference or system parameters variation. Suspension mass is a key parameter of a magnetic suspension system and suspension mass variation has great influence on the dynamic characteristic of a magnetic suspension system. The influence of suspension mass variation on the dynamic characteristic of a magnetic suspension system under the PID control condition is discussed. The relationship between dynamic characteristic and structure as well as control parameters of the magnetic suspension system is reached by means of experimental method.

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41

Kiisa, Martti, Juhan Idnurm, and Siim Idnurm. "DISCRETE ANALYSIS FOR SINGLE-PYLON SUSPENSION BRIDGES." Engineering Structures and Technologies 1, no. 4 (December 31, 2009): 166–71. http://dx.doi.org/10.3846/skt.2009.20.

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This paper presents calculation methods, developed at Tallinn University of Technology (Idnurm 2004; Kulbach 2007), for the single-pylon suspension bridges stiffened by a girder. Classical suspension bridge consists of a geometrically non-linear cable, connected by hangers with an elastic linear stiffening girder, pylons in both ends of the bridge and anchor cables. Alternate form of a suspension bridge is a bridge, with only one pylon on the middle of the span and suspension cable is connected to the abutments or the ends of the stiffening girder. In the calculation of suspension bridges, the geometrically non-linear behaviour of the parabolic cable is the main problem. The linear methods of analysis suit only for small spans. A geometrically non-linear continual model is especially useful for classical loading cases – a uniformly distributed load on the whole or half span. But the modern traffic models consist of concentrated and uniformly distributed loads. The discrete model of a suspension bridge allows us to apply all kinds of loads, such as distributed or concentrated ones. The assumptions of the discrete method described here are: linear elastic strain-stress dependence of the material and absence of horizontal displacements of hangers. Hanger elongation is taken into account.

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42

Soong, M. F., Rahizar Ramli, and Wan Nor Liza Wan Mahadi. "Ride Evaluation of Vehicle Suspension Employing Non-Linear Inerter." Applied Mechanics and Materials 471 (December 2013): 9–13. http://dx.doi.org/10.4028/www.scientific.net/amm.471.9.

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Inerter is a recent element in suspension systems with the property that the generated force is proportional to the relative acceleration between its two terminals, which is similar to the way a spring reacts to relative displacement and a damper to relative velocity. This paper presents the analysis of a non-linear inerter working in parallel to passive spring and damper of a vehicle suspension to evaluate its effect on vehicles ride. The non-linear inerter was theoretically capable of switching between on and off states depending on whether or not the suspension deflection was beyond a specified free play. In the study, this behavior was represented mathematically as control law which depended on the relative displacement between the sprung and unsprung masses. A mathematical quarter vehicle model incorporating the non-linear inerter was simulated in MATLAB/Simulink to determine the vehicle responses due to road input in the form of step profile for different combinations of free play and inerters on-state proportionality constant called the inertance. Results showed improvements in vehicle ride comfort, as demonstrated by the lower root-mean-squared sprung mass accelerations compared to the ordinary passive suspension with only spring and damper. Additionally, implementation of non-linear inerter gave lower percentage overshoot to step input, indicating better transient response than ordinary passive suspension.

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43

Jiang, Hui, Guoyan Xu, Wen Zeng, Feng Gao, and Kun Chong. "Lateral Stability of a Mobile Robot Utilizing an Active Adjustable Suspension." Applied Sciences 9, no. 20 (October 18, 2019): 4410. http://dx.doi.org/10.3390/app9204410.

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Mobile robots are expected to traverse on unstructured terrain, especially uneven terrain, or to climb obstacles or slopes. This paper analyzes one such passively–actively transformable mobile robot that is principally aimed at the above issue. A passive locomotion traverses on a rough and flat terrain; an active reconfiguration with an active suspension. This paper investigates the lateral stability of this mobile robot when it reconfigures itself to adjust its roll angle with the active suspension. The principles and configurations of the robot and its active suspension are presented. To analyze the effects of the suspensions’ inputs on robot stability, a mathematic model of the robot on side slopes is presented. Based on the evaluation method of the stability pyramid theory, an analytical expression representing the relationship between the input of the active suspension (linear actuator length) and stability evaluation index on transverse slopes is obtained. The results show that there is an increase in both the lateral stability and minimum lateral tip-over angle under different ground clearances when adjusting the active inputs. Furthermore, the models presented here provide theoretical references and optimization directions for the design and control of mobile robots with adjustable suspensions.

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44

Yu, Bin, Zhice Wang, Guoye Wang, Jianzhu Zhao, Liyang Zhou, and Jie Zhao. "Investigation of the suspension design and ride comfort of an electric mini off-road vehicle." Advances in Mechanical Engineering 11, no. 1 (January 2019): 168781401882335. http://dx.doi.org/10.1177/1687814018823351.

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In view of the little research that has been conducted on the ride comfort of mini vehicles, an electric mini off-road vehicle was designed in this study and a 2 degree-of-freedom quarter car model was established to investigate the ride comfortability. The amplitude-frequency and vibration response characteristics of the suspension were analyzed with the natural frequencies of the front and rear suspensions selected in accordance with the required driving performance. A comprehensive objective function with respect to the safety and comfortability was established, and the damping ratio of the suspension was determined. The damping characteristics of the shock absorber were analyzed to derive an adjustment rule of the suspension damping ratio. The piecewise linear speed characteristics of the shock absorber were subsequently obtained, and suspension-parameter identification and ride comfort tests were conducted. The test results showed that the natural frequencies and damping ratios of the front and rear suspensions were 1.676 and 1.922 Hz, and 0.225 and 0.242, respectively. The results of a pulse input test and D-level road random running test also demonstrated the safety and good ride comfortability of the vehicle.

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45

Fei, Jun Tao, and Jing Xu. "Dynamical Modeling and Neural Network Adaptive Control of Vehicle Suspension." Applied Mechanics and Materials 148-149 (December 2011): 516–19. http://dx.doi.org/10.4028/www.scientific.net/amm.148-149.516.

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This paper attempts to establish the vibration control technology based on neural network control. First, the dynamic model of vehicle suspension system is discussed, and the linear passive suspension model and nonlinear spring suspension model of the vertical acceleration are compared. It is shown that the performance of nonlinear spring suspension is better than that of the linear passive suspension model. Because of the great advantages of the neural network in dealing with the nonlinear property, secondly, model reference neural control module is introduced in the suspension system to realize the optimization of the body vertical acceleration. Simulation results demonstrate the effectiveness of the neural network adaptive controller with application to vehicle suspension.

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46

Zhou, Chenyu, Qiang Yu, Xuan Zhao, and Guohua Zhu. "T-S Fuzzy Model Based H-Infinity Control for 7-DoF Automobile Electrohydraulic Active Suspension System." Journal of Control Science and Engineering 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/6728364.

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This paper presents a double loop controller for a 7-DoF automobile electrohydraulic active suspension via T-S fuzzy modelling technique. The outer loop controller employs a modified H-infinity feedback control based on a T-S fuzzy model to provide the actuation force needed to ensure better riding comfort and handling stability. The resulting optimizing problem is transformed into a linear matrix inequalities solution issue associated with stability analysis, suspension stroke limit, and force constraints. Integrating these via parallel distributed compensation method, the feedback gains are derived to render the suspension performance dependent on the perturbation size and improve the efficiency of active suspensions. Adaptive Robust Control (ARC) is then adopted in the inner loop design to deal with uncertain nonlinearities and improve tracking accuracy. The validity of improvements attained from this controller is demonstrated by comparing with conventional Backstepping control and a passive suspension on a 7-DoF simulation example. It is shown that the T-S fuzzy model based controller can achieve favourable suspension performance and energy conservation under both mild and malevolent road inputs.

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47

Ray, L. R. "Robust Linear-Optimal Control Laws for Active Suspension Systems." Journal of Dynamic Systems, Measurement, and Control 114, no. 4 (December 1, 1992): 592–98. http://dx.doi.org/10.1115/1.2897729.

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The stability robustness of linear-optimal control laws for quarter-car active suspension systems is evaluated using stochastic robustness analysis. Simultaneous parameters variations and neglected actuator and sensor dynamics are considered for LQ active suspension systems and for a single-measurement LQG system to determine the effects of uncertainty on system stability. The results indicate that neglected actuator and sensor dynamics have a small effect on stability robustness, while parameter uncertainty, particularly that of the “sprung mass” is of great concern. The effectiveness of Loop Transfer Recovery on active suspension systems with both parameter uncertainty and higher-order uncertainty is discerned. The analysis shows that when Loop Transfer Recovery is applied arbitrarily to uncertain systems, both estimator performance and system robustness can decrease. Nevertheless, it is concluded that the impact of the robustness recovery method is determined by stochastic stability robustness analysis, and the recovery design parameter that provides sufficient robustness with minimal performance degradation is readily identified. The effect of LQ design parameters on robustness also is considered. The paper presents robustness analysis and synthesis methods for a quarter-car model that can be applied to higher-order active suspension systems.

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48

Li, Yinong, Ling Zheng, Yixiao Liang, and Yinghong Yu. "Adaptive compensation control of an electromagnetic active suspension system based on nonlinear characteristics of the linear motor." Journal of Vibration and Control 26, no. 21-22 (February 20, 2020): 1873–85. http://dx.doi.org/10.1177/1077546320909985.

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With the electrification and intellectualization of vehicle systems, electromagnetic active suspension has been paid more and more attention. Linear motor is one of the effective actuators of the electromagnetic active suspension system. The nonlinear factors of linear motor, such as nonlinear friction force and ripple force, as well as power limit and magnetic saturation, will reduce the performance of electromagnetic active suspension. However, the current research rarely considers the effect of these nonlinear factors on active suspension control. In this article, the effect of nonlinearities of linear motors on electromagnetic active suspension performance and the ways to improve their performance are studied. An adaptive filtering compensation method is proposed to reduce the influence of nonlinear factors on the electromagnetic active suspension control. According to the simulated calculations, performance degradation of the active suspension is observed in both the primary control objective and high-frequency range due to inherent disturbance from the nonlinear factors. Also, the electromagnetic nonlinearities will reduce the active suspension effective force output. By proposing an adaptive compensator based on the filtered-x recursive least squares algorithm, the first-order resonance of the suspension system could be controlled and the electromagnetic active suspension effective force could be magnified. Also, convergence of the adaptive compensator is found to be rapid and reasonable.

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49

Mao, Jing Feng, Guo Qing Wu, Ai Hua Wu, and Yang Cao. "Adaptive Integral-Type Sliding Mode Control for Magnetic Levitation Linear Guide Suspension Altitude." Advanced Materials Research 139-141 (October 2010): 867–71. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.867.

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This paper investigates the constant position suspension altitude control problem for a novel magnetic levitation linear guide. The magnetic levitation linear guide is comprised of a magnetic suspension processing platform and a linear motor direct-drive system. The magnetic suspension system has several characteristics of complicated nonlinearity, parameter perturbation and strong disturbance. In view of these characteristics, an adaptive integral-type sliding mode control (AISMC) technique is used to design magnetic suspension system constant position suspension altitude controller. The AISMC can alleviate chattering and reduce steady error by estimating the boundary of uncertain perturbation. The adaptive tuning algorithm is derived in the sense of the Lyapunov stability theorem, thus the stability of the system can be guaranteed. Simulation results indicate that the proposed AISMC has a better stability, transient and robustness compared with PID control.

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50

Hanafi, Dirman, Mohamad Fauzi Zakaria, Rosli Omar, M. Nor M. Than, M. Fua'ad Rahmat, and Rozaimi Ghazali. "Neuro Model Approach for a Quarter Car Passive Suspension Systems." Applied Mechanics and Materials 775 (July 2015): 103–9. http://dx.doi.org/10.4028/www.scientific.net/amm.775.103.

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The road handling, load carrying and passenger comfort are three intension factors on car suspension’s system. They should be compromised to achieve the good the car suspension dynamics. To fulfill the requirement, the car suspension system must be controlled and analyzed. To design and analyze the suspension controller, the realistic dynamics model of car suspension is needed. In this paper, the car suspension is assumed as a quarter car and has a model structure as a neural network structure. The model is assumed consist of nonlinear properties that are contributed by spring stiffness and damping elements of suspension system. The tire is assumed has linear properties and represented by spring stiffness element and damping element. The model responses are generated in simulation term. The random type of artificial road surface signal as an input variable is used in this simulation. The results show that the trend of neuro model have the same with the response of a quarter car nonlinear model from dynamic derivation. It means that the developed neuro model structure capable to represent the nonlinear model of a quarter car passive suspension system dynamics.

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Journal articles on the topic 'Linear suspension'

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