Journal articles: 'Rigid robotic manipulators'

1

Lee, S. B., and H. S. Cho. "Dynamic Characteristics of Balanced Robotic Manipulators with Joint Flexibility." Robotica 10, no. 6 (November 1992): 485–95. http://dx.doi.org/10.1017/s0263574700005816.

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SUMMARYThe mass balancing of robotic manipulators has been shown to have favorable effects on the dynamic characteristics. In actual practice, however, since conventional manipulators have flexibility at their joints, the improved dynamic properties obtainable for rigid manipulators may be influenced by those joint flexibilities. This paper investigates the effects of the joint flexibility on the dynamic properties and the controlled performance of a balanced robotic manipulator. The natural frequency distribution and damping characteristics were investigated through frequency response analyses. To evaluate the dynamic performance a series of simulation studies of the open loop dynamics were made for various trajectories, operating velocities, and joint stiffnesses. These simulations were also carried out for the balanced manipulator with a PD controller built-in inside motor control loop. The results show that, at low speed, the joint flexibility nearly does not influence the performance of the balanced manipulator, but at high speed it tends to render the balanced manipulator susceptible to vibratory motion and yields large joint deformation error.

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Lee, S. B., and H. S. Cho. "Dynamic characteristics of balanced robotic manipulators with joints flexibility." Robotica 10, no. 1 (January 1992): 25–34. http://dx.doi.org/10.1017/s0263574700007049.

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SummaryThe mass balancing of robotic manipulators has been shown to have favorable effects on their dynamic characteristics. In actual practice, however, since conventional manipulators have flexibility at their joints, the improved dynamic properties obtainable for rigid manipulators may be influenced by those joints flexibilities. This paper investigates the effects of the joints flexibility on the dynamic properties and the controlled performance of a balanced robotic manipulator. The natural frequency distribution and damping characteristics were investigated through frequency response analyses. To evaluate the dynamic performance a series of simulation studies of the open-loop dynamics were made for various trajectories, operating velocities, and joint stiffnesses. These simulations were also carried out for the balanced manipulator with a PD controller situated inside the motor control loop. The results show that, at low speed, the joints flexibility does but little influence the performance of the balanced manipulator, but at high speed it tends to render the balanced manipulator susceptible to vibratory motion and yields large joints deformation errors.

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Vemuri, Arun T., and Marios M. Polycarpou. "A methodology for fault diagnosis in robotic systems using neural networks." Robotica 22, no. 4 (August 2004): 419–38. http://dx.doi.org/10.1017/s0263574703005204.

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Fault diagnosis plays an important role in the operation of modern robotic systems. A number of researchers have proposed fault diagnosis architectures for robotic manipulators using the model-based analytical redundancy approach. One of the key issues in the design of such fault diagnosis schemes is the effect of modeling uncertainties on their performance. This paper investigates the problem of fault diagnosis in rigid-link robotic manipulators with modeling uncertainties. A learning architecture with sigmoidal neural networks is used to monitor the robotic system for off-nominal behavior due to faults. The robustness, sensitivity, missed detection and stability properties of the fault diagnosis scheme are rigorously established. Simulation examples are presented to illustrate the ability of the neural network based robust fault diagnosis scheme to detect and accommodate faults in a two-link robotic manipulator.

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Petroka, R. P., and Liang-Wey Chang. "Experimental Validation of a Dynamic Model (Equivalent Rigid Link System) on a Single-Link Flexible Manipulator." Journal of Dynamic Systems, Measurement, and Control 111, no. 4 (December 1, 1989): 667–72. http://dx.doi.org/10.1115/1.3153111.

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Flexibility effects on robot manipulator design and control are typically ignored which is justified when large, bulky robotic mechanisms are moved at slow speeds. However, when increased speed and improved accuracy are desired in robot system performance it is necessary to consider flexible manipulators. This paper simulates the motion of a single-link, flexible manipulator using the Equivalent Rigid Link System (ERLS) dynamic model and experimentally validates the computer simulation results. Validation of the flexible manipulator dynamic model is necessary to ensure confidence of the model for use in future design and control applications of flexible manipulators.

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Man Zhihong and M. Palaniswami. "Robust tracking control for rigid robotic manipulators." IEEE Transactions on Automatic Control 39, no. 1 (1994): 154–59. http://dx.doi.org/10.1109/9.273355.

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Nurullayev, N. M., D. A. Turgunboyev, and Ye N. Zholdassov. "EVALUATION OF POSSIBILITIES TO IMPROVE RIGID BODIES." BULLETIN Series of Physics & Mathematical Sciences 69, no. 1 (March 10, 2020): 392–95. http://dx.doi.org/10.51889/2020-1.1728-7901.71.

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Manipulators are used for various purposes in order to simplify tasks or reduce the risk of tasks that are considered impossible, dangerous or difficult for humans. The robotic arm can be equipped with various types of end effectors to perform a variety of tasks. Grips are one of the most commonly used tools for manipulators. This article discusses the analysis of modeling new robotic gripping fingers, based on models of gripping gross rigid bodies of manipulators. A literature review was conducted in the relevant branches of scientific research. The ability to minimize dimensions and masses, as well as the final cost of the product, using available materials and electromechanical devices, various sensors, is evaluated. The external characteristics that make the previously developed analogues ineffective are analyzed. Modeling was released using the SolidWorks software package.

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Cetinkunt, Sabri, and B. Ittop. "Computer Automated Symbolic Modeling of Dynamics of Robotic Manipulators with Flexible Links." Robotica 10, no. 1 (January 1992): 19–24. http://dx.doi.org/10.1017/s0263574700007037.

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SummaryDynamic equations of chain structured robotic manipulators with compliant links and joints are developed in a non-recursive symbolic form. A program is developed in REDUCE to automate the symbolic expansion of these equations for any given chain structured manipulator. The symbolic non-recursive form of dynamic model is particularly suitable for controller synthesis and real-time control implementations. The link flexibility is included in the formulation using assumed mode shapes. The mode shapes and the parameters that are functions of the mode shapes are kept in symbolic form so that once a symbolic model is generated, different types of mode shapes can be studied using the same model. Because of the structural similarity between the developed equations and the well known rigid manipulator equations, the computer automated symbolic expansion capability presented here are likely to be utilized widely by many other researchers in the area who are already familiar with rigid manipulator problems.

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Al-Khulaidi, Rami, Rini Akmeliawati, Steven Grainger, and Tien-Fu Lu. "Structural Optimisation and Design of a Cable-Driven Hyper-Redundant Manipulator for Confined Semi-Structured Environments." Sensors 22, no. 22 (November 9, 2022): 8632. http://dx.doi.org/10.3390/s22228632.

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Structural optimisation of robotic manipulators is critical for any manipulator used in confined semi-structured environments, such as in agriculture. Many robotic manipulators utilised in semi-structured environments retain the same characteristics and dimensions as those used in fully-structured industrial environments, which have been proven to experience low dexterity and singularity issues in challenging environments due to their structural limitations. When implemented in environments other than fully-structured industrial environments, conventional manipulators are liable to singularity, joint limits and workspace obstacles. This makes them inapplicable in confined semi-structured environments, as they lack the flexibility to operate dexterously in such challenging environments. In this paper, structural optimisation of a hyper-redundant cable-driven manipulator is proposed to improve its performance in semi-structured and challenging confined spaces, such as in agricultural settings. The optimisation of the manipulator design is performed in terms of its manipulability and kinematics. The lengths of the links and the joint angles are optimised to minimise any error between the actual and desired position/orientation of the end-effector in a confined semi-structured task space, as well as to provide optimal flexibility for the manipulators to generate different joint configurations for obstacle avoidance in confined environments. The results of the optimisation suggest that the use of a redundant manipulator with rigid short links can result in performance with higher dexterity in confined, semi-structured environments, such as agricultural greenhouses.

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Tosunoglu, Sabri, Shyng-Her Lin, and Delbert Tesar. "Accessibility and Controllability of Flexible Robotic Manipulators." Journal of Dynamic Systems, Measurement, and Control 114, no. 1 (March 1, 1992): 50–58. http://dx.doi.org/10.1115/1.2896507.

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Although serial manipulator arms modeled with rigid links show full system controllability in the joint space, this condition does not necessarily hold for flexible robotic systems. In particular, in certain robot configurations, called inaccessible robot positions, one or more of the flexibilities may not be accessed directly by the actuators. This condition may significantly deteriorate system performance as reported earlier by the authors (Tosunoglu et al., 1988, 1989). The present study addresses the relationship between the accessibility and controllability concepts and establishes accessibility as a distinct concept from controllability. Although the theoretical framework is developed for general n-link, spatial manipulators modeled with m oscillation components, example case studies demonstrate the concepts on one- and two-link arms for brevity. Specifically, it is shown that although inaccessibility and uncontrollability may coincide in certain instances (as shown on a one-link arm), counter examples may be found where an arm in an inaccessible position can simultaneously demonstrate full system controllability (as shown on a two-link arm).

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Rugthum, Thummaros, and Gang Tao. "An adaptive actuator failure compensation scheme for a cooperative manipulator system." Robotica 34, no. 7 (October 7, 2014): 1529–52. http://dx.doi.org/10.1017/s0263574714002434.

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SUMMARYThis paper develops a new adaptive actuator failure compensation algorithm for the control of a cooperative robotic system subject to uncertain actuator failures. The benchmark robotic system has two manipulators to balance a rigid platform, and the right-side manipulator contains one actuator and the left-side manipulator has two actuators (one of which may fail during system operation, but it is uncertain how much, when and which actuator may fail). The developed adaptive actuator failure compensation scheme, based on adaptive integration of three individual failure compensators and direct adaptation of controller parameters, is capable of ensuring desired closed-loop stability and asymptotic output tracking, despite the failure uncertainties. Such an adaptive actuator failure compensation method is extended to control of a general cooperative robotic system. Simulation results are shown to verify the desired adaptive failure compensation control performance.

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Lanzon, A., and R. J. Richards. "Compliant motion control for non-redundant rigid robotic manipulators." International Journal of Control 73, no. 3 (January 2000): 225–41. http://dx.doi.org/10.1080/002071700219777.

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Neila, Mezghani Ben Romdhane, and Damak Tarak. "Adaptive terminal sliding mode control for rigid robotic manipulators." International Journal of Automation and Computing 8, no. 2 (May 2011): 215–20. http://dx.doi.org/10.1007/s11633-011-0576-2.

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13

Dawei Cai. "Comments on "Robust tracking control for rigid robotic manipulators"." IEEE Transactions on Automatic Control 43, no. 7 (July 1998): 1008. http://dx.doi.org/10.1109/9.701113.

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Zhu, W. H. "Comments on "Robust tracking control for rigid robotic manipulators"." IEEE Transactions on Automatic Control 45, no. 8 (August 2000): 1577–80. http://dx.doi.org/10.1109/9.871778.

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15

Feng, Yong, Minghao Zhou, Xinghuo Yu, and Fengling Han. "Full‐Order Sliding‐Mode Control of Rigid Robotic Manipulators." Asian Journal of Control 21, no. 3 (May 31, 2018): 1228–36. http://dx.doi.org/10.1002/asjc.1813.

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Chang, Liang-Wey, and J. F. Hamilton. "Dynamics of Robotic Manipulators With Flexible Links." Journal of Dynamic Systems, Measurement, and Control 113, no. 1 (March 1, 1991): 54–59. http://dx.doi.org/10.1115/1.2896359.

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This paper presents a dynamic model for the robotic manipulators with flexible links by means of the Finite Element Method and Lagrange’s formulation. By the concept of the Equivalent Rigid Link System (ERLS), the generalized coordinates are selected to represent the total motion as a large motion and a small motion. Two sets of coupled nonlinear equations are obtained where the equations representing small motions are linear with respect to the small motion variables. An example is presented to illustrate the importance of the flexibility effects.

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Fasse, E. D. "On the Spatial Compliance of Robotic Manipulators." Journal of Dynamic Systems, Measurement, and Control 119, no. 4 (December 1, 1997): 839–44. http://dx.doi.org/10.1115/1.2802402.

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Interactive control schemes, such as stiffness control and impedance control, are widely accepted as a means to actively accommodate environmental forces, but have not been widely applied. This is in part because well-known controllers are parametrized in a mathematically convenient, but nonintuitive way. “Spatial compliance control” is a Euclidean-geometrical version of compliance control that is parametrized in an intuitive way. A family of compliances is introduced with spatial transformation properties that simplify spatial reasoning aspects of compliance parameter selection. A control law is derived assuming that the robot consists of a serial linkage of rigid links actuated by variable-effort actuators.

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Chalhoub, Nabil G., and Xiaoying Zhang. "Reduction of the End Effector Sensitivity to the Structural Deflections of a Single Flexible Link: Theoretical and Experimental Results." Journal of Dynamic Systems, Measurement, and Control 115, no. 4 (December 1, 1993): 658–66. http://dx.doi.org/10.1115/1.2899193.

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The fine positioning problem of the gripper of flexible robotic manipulators is addressed in this study. A two-axis cartesian micro-manipulator is implemented to reduce the sensitivity of the gripper to the structural deformations of a single flexible link. A laser head with a dual axis photodetector are used to provide direct measurements of the transverse deflections at the free-end of the beam and to detect mechanical inaccuracies caused by manufacturing imperfections and assembly misalignment. The advantages of the integrated system of the micro-manipulator with a single compliant beam are demonstrated and compared to the one without the micro-manipulator for two different control schemes, “rigid body controller (RBC)” and “rigid and flexible motion controller (RFMC).” Both theoretical and experimental results have proven the capability of the micro-manipulator in significantly improving the gripper positional accuracy. Furthermore, it was demonstrated that the micro-manipulator tends to complement rather than overlap the efforts exerted by the host beam controller.

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Pinto, Vítor H., José Gonçalves, and Paulo Costa. "Towards a More Robust Non-Rigid Robotic Joint." Applied System Innovation 3, no. 4 (October 20, 2020): 45. http://dx.doi.org/10.3390/asi3040045.

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The following paper presents an improved, low cost, non-rigid joint that can be used in both robotic manipulators and leg-based traction robotic systems. This joint is an improvement over the previous one presented by the same authors because it is more robust. The design iterations are presented and the final system has been modeled including some nonlinear blocks. A control architecture is proposed that allows compliant control to be used under adverse conditions or in uncontrolled environments. The presented joint is a cost-effective solution that can be used when normal rigid joints are not suitable.

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Etxebarria, Victor, Arantza Sanz, and Ibone Lizarraga. "Control of a Lightweight Flexible Robotic Arm Using Sliding Modes." International Journal of Advanced Robotic Systems 2, no. 2 (June 1, 2005): 11. http://dx.doi.org/10.5772/5798.

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This paper presents a robust control scheme for flexible link robotic manipulators, which is based on considering the flexible mechanical structure as a system with slow (rigid) and fast (flexible) modes that can be controlled separately. The rigid dynamics is controlled by means of a robust sliding-mode approach with well-established stability properties while an LQR optimal design is adopted for the flexible dynamics. Experimental results show that this composite approach achieves good closed loop tracking properties both for the rigid and the flexible dynamics.

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Pai, Dinesh K., and M. C. Leu. "Uncertainty and Compliance of Robot Manipulators with Applications to Task Feasibility." International Journal of Robotics Research 10, no. 3 (June 1991): 200–213. http://dx.doi.org/10.1177/027836499101000302.

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The uncertainty and compliance of a robot manipulator used to perform a task are considered. A formula is derived for the efficient computation of a tight bound on the uncertainty of the end effector, given the uncertainty in the kinematic pa rameters of the robot. It is shown that the total uncertainty is the Minkowski difference of the manipulator uncertainty and the task position uncertainty. Simulations are performed in which the results are used to determine configurations of a robot for which the total uncertainty is within a specified tolerance. The suitability of the compliance of a manipulator for performing a planar peg-in-hole type assembly task is also studied. Manipulators are modeled as having rigid links and compliant joints, following experimental results. It is shown that given any symmetric positive semidefinite compliance, a robot manipulator of the above type can be constructed that will realize this compliance at some point in its work space. A new condition on the stiffness is proposed for preventing jamming. If the peg is supported by the end effector of a robot, we can determine configurations of the robot at which jam ming can be avoided. Simulations are performed to compute the no-jam configurations of a manipulator. The results developed here have direct application to sev eral areas of robotics: determining whether a robotic task is feasible in the presence of uncertainty and joint compliance, choosing work space locations for a robotic task, and the design and selection of robot manipulators. 1. This is called two- point contact in Whitney (1982). 2. That is, errors resulting from both the end-effector and task position uncertainties. 3. The symbol ( ) T denotes the transpose. 4. The half-size of a box is half the length of the box in a specified coordinate direction. 5. Also called the set-sum. 6. The effective compliance refers to the compliance at the peg tip resulting from the compliance of the robot or some other support.

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Vinogradov, Oleg. "CUSTOMIZED SCALAR DYNAMIC EQUATIONS FOR ROBOTIC MANIPULATORS." Transactions of the Canadian Society for Mechanical Engineering 20, no. 4 (December 1996): 401–20. http://dx.doi.org/10.1139/tcsme-1996-0023.

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A robotic manipulator is considered as a reduction of a topologically uniform 3D-chain which is defined as a system of one-dimensional links connected by spherical joints. It has been shown in (4) that for the introduced chain the dynamic equations can be derived in an explicit scalar form. Such a chain can be viewed as a generic manipulator so that any specific type of the latter can be obtained from this chain by imposing additional kinematic constraints. It is shown in the paper that for practically all joints the governing equations for the chain and the constraints equations can be solved together resulting in an explicit scalar form of equations for a given manipulator. This form of equations has a potential for more efficient computer simulations. An application of the results to a 3-DOF rigid-body manipulator is given.

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Yu, Zhongwei, Huitang Chen, and Peng-Yung Woo. "Advanced gain scheduledH∞controller for robotic manipulators." Robotica 20, no. 5 (September 2002): 537–44. http://dx.doi.org/10.1017/s0263574701004015.

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SummaryA conservatism-reduced design of a gain scheduled output feedbackH∞controller for ann-joint rigid robotic manipulator, which integrates the varying-parameter rate without their feedback, is proposed. The robotic system is reduced to a 1inear parameter varying (LPV) form, which depends on the varying-parameter. By using a parameter-dependent Lyapunov function, the design of a controller, which satisfies the closed-loopH∞performance, is reduced to a solution of the parameterized linear matrix inequalities (LMIs) of parameter matrices. With a use of the concept of “multi-convexity”, the solution of the infinite LMIs in the varying-parameter and its rate space is reduced to a solution of the finite LMIs for the vertex set. The proposed controller eliminates the feedback of the varying-parameter rate and fixes its upper boundary so that the conservatism of the controller design is reduced. Experimental results verify the effectiveness of the proposed design.

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Antonelli, Dario, and Khurshid Aliev. "Intelligent energy management for mobile manipulators using machine learning." FME Transactions 50, no. 4 (2022): 752–61. http://dx.doi.org/10.5937/fme2204752a.

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Integrated robotic systems combining manipulators with mobile robots provide outstanding improvement opportunities for semi-automatic assembly processes leveraged by Industry 4.0. Factory operations are released from the rigid layout constraints imposed by conventional fixed robots. Thus, they introduce new challenges in managing the recharge cycles as the energy consumption of mobile manipulators is not simply related to the travelled distance but to the overall tasks executed. Its estimation requires a systemic approach. In the proposed solution, an intelligent monitoring system is implemented on board. Data gathered online, and Key Performance Indicators (KPIs) calculated during the working tasks are exploited by Machine Learning (ML) to optimize energy recharging cycles. Although the development of an intelligent monitoring framework for a mobile manipulator was the original objective of the research, the monitoring system is exploited here for energy management only, leaving space for other future applications.

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Chang, Liang-Wey, and J. F. Hamilton. "The Kinematics of Robotic Manipulators With Flexible Links Using an Equivalent Rigid Link System (ERLS) Model." Journal of Dynamic Systems, Measurement, and Control 113, no. 1 (March 1, 1991): 48–53. http://dx.doi.org/10.1115/1.2896358.

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The Equivalent Rigid Link System (ERLS) is presented for the analysis of the kinematics of manipulators with flexible links. The concept of the ERLS is to separate the rigid-body dynamics and structural dynamics. The global motion of the flexible-link system is thereby separated into a large motion with a superimposed small motion. The large motion is represented by the ERLS and the small motion is due to the deviations with respect to the ERLS. The complete motion of manipulators is described by homogeneous transformations. The Jacobian and inverse kinematics are also presented in this paper.

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Xing, Bang Sheng, and Wen Hui Zhang. "Robust Adaptive Control for Robotic Manipulators Based on RBFNN." Applied Mechanics and Materials 397-400 (September 2013): 1477–81. http://dx.doi.org/10.4028/www.scientific.net/amm.397-400.1477.

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The rigid robotic manipulators is used in the mining industry more and more widely. An adaptive robust control algorithm of robotic manipulators based on radial basis function neural network (RBFNN) is proposed by the paper. Neural network controller is used to adaptive learn and compensate the unknown system, approach errors as disturbance are eliminated by robust controller. The weight adaptive laws on-line based on Lyapunov theory is designed. The robust controller was proposed based on H theory. Above these assured the stability of the whole system, and L2 gain also was less than the index. This control scheme possesses great control accuracy and dynamic function. The simulation results show that the presented neural network control algorithm is effective.

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Kotzev, A., D. B. Cherchas, P. D. Lawrence, and N. Sepehri. "Generalized predictive control of a robotic manipulator with hydraulic actuators." Robotica 10, no. 5 (September 1992): 447–59. http://dx.doi.org/10.1017/s0263574700010651.

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SUMMARYThis paper presents some aspects of the behavior of hydraulically actuated heavy duty manipulators. This category of manipulators is used extensively in large resource based industries and any improvement in efficiency may result in major financial benefits. In this paper an adaptive control algorithm is used for a two rigid link manipulator driven by hydraulic actuators. The dynamic model of the manipulator is derived as well as the models of the hydraulic actuators including compliance, dead time and full dynamics of the servo valves. An adaptive control algorithm is considered since changes occur on-line in the system's parameters. The adaptive algorithm used is Generalized Predictive Control (GPC). The GPC uses a controlled autoregressive integrated moving average (CARIMA) type model and a cost function that minimizes a predicted future output error and future weighted control inputs to the plant, resulting in a sequence of future control increments. The procedure, in this work, does not separate the hydraulic actuator and the link dynamics into separate sub-systems, but controls them as one system. The changes in the system's parameters due to the hydraulics or the link dynamics can be estimated and the coefficients of the model adjusted without the necessity of identifying the exact cause of the changes.It was found in this work that the variations of the GPC control horizon can lead to faster response during transients and significantly reduced overshoot in the nonlinear hydraulic actuation system. An on-line change of the maximum output horizon is also introduced.This work shows the analysis and results of a two link manipulator with hydraulic actuators. It can be implemented on any hydraulically actuated manipulator with any number of links and actuators.Numerical simulations are performed on a Vax 3200 computer and the results are presented.

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Wu, Yuqiang, Xinghuo Yu, and Zhihong Man. "A HYBRID FINITE TIME VARIABLE STRUCTURE CONTROLLER FOR RIGID ROBOTIC MANIPULATORS." IFAC Proceedings Volumes 35, no. 1 (2002): 389–94. http://dx.doi.org/10.3182/20020721-6-es-1901.00877.

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Misu, Kenji, Masahiro Ikeda, Keung Or, Mitsuhito Ando, Megu Gunji, Hiromi Mochiyama, and Ryuma Niiyama. "Robostrich Arm: Wire-Driven High-DOF Underactuated Manipulator." Journal of Robotics and Mechatronics 34, no. 2 (April 20, 2022): 328–38. http://dx.doi.org/10.20965/jrm.2022.p0328.

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We propose a wire-driven robotic arm inspired by the ostrich neck. It can pick up a small piece of feed from the ground while colliding with it. This arm is named robostrich arm (shortened form of robotic ostrich arm). It consists of a serial chain of 18 rigid bodies connected by free rotational joints that are designed to have angle limitations similar to the bones of a real ostrich. It moves in a vertical plane and is driven by two DC motors through antagonistic wires. The task considered in this study was to lift the arm tip (the “head” of the robostrich arm). The experimental results indicate that the tensioner balance and timing between the two wires are important for achieving the head-up task. This paper indicates the contribution of antagonist muscles to the performance of head-up tasks by high-degree-of-freedom underactuated manipulators in robotics and ostrich necks in biological studies.

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Zuo, Yi, Yaonan Wang, Lihong Huang, and Chunsheng Li. "Intelligent Hybrid Control Strategy for Trajectory Tracking of Robot Manipulators." Journal of Control Science and Engineering 2008 (2008): 1–13. http://dx.doi.org/10.1155/2008/520591.

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We address the problem of robust tracking control using a PD-plus-feedforward controller and an intelligent adaptive robust compensator for a rigid robotic manipulator with uncertain dynamics and external disturbances. A key feature of this scheme is that soft computer methods are used to learn the upper bound of system uncertainties and adjust the width of the boundary layer base. In this way, the prior knowledge of the upper bound of the system uncertainties does need not to be required. Moreover, chattering can be effectively eliminated, and asymptotic error convergence can be guaranteed. Numerical simulations and experiments of two-DOF rigid robots are presented to show effectiveness of the proposed scheme.

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Hwang, Yunn Lin. "Nonlinear Recursive Formulation for Kinematic and Dynamic Analysis of Robotic Manufacturing Systems." Materials Science Forum 505-507 (January 2006): 553–58. http://dx.doi.org/10.4028/www.scientific.net/msf.505-507.553.

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The objective of this paper is to develop a nonlinear recursive formulation for the dynamic analysis of robotic manufacturing systems. The nonlinear recursive equations are used for open-loop flexible manipulators that undergo large translational and rotational displacements. These equations are formulated in terms of a set of time invariant scalars, vectors and matrices that depend on the spatial coordinates as well as the assumed displacement fields, and these time invariant quantities represent the dynamic manufacturing couplings between the rigid body motion and elastic deformation. This formulation applies recursive procedures with the nonlinear equations for flexible manipulators to obtain a large, loosely coupled system equation of motion in robotic manufacturing systems. The numerical techniques used to solve for the system equations of motion can be more efficiently implemented in any computer systems. The algorithms presented in this investigation are illustrated by using standard mechanical joints for robotic manufacturing systems that can be easily extended to other special joints. The nonlinear recursive formulation developed in this paper is illustrated by a robotic manufacturing system using standard revolute mechanical joints.

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Man Zhihong, A. P. Paplinski, and H. R. Wu. "A robust MIMO terminal sliding mode control scheme for rigid robotic manipulators." IEEE Transactions on Automatic Control 39, no. 12 (1994): 2464–69. http://dx.doi.org/10.1109/9.362847.

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Liang, Xinwu, Hesheng Wang, Weidong Chen, and Yun-Hui Liu. "Uncalibrated Image-Based Visual Servoing of Rigid-Link Electrically Driven Robotic Manipulators." Asian Journal of Control 16, no. 3 (November 13, 2013): 714–28. http://dx.doi.org/10.1002/asjc.796.

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Zhihong, Man, and M. Palaniswami. "A robust tracking control scheme for rigid robotic manipulators with uncertain dynamics." Computers & Electrical Engineering 21, no. 3 (May 1995): 211–20. http://dx.doi.org/10.1016/0045-7906(94)00021-8.

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Hughes, J. A. E., P. Maiolino, and F. Iida. "An anthropomorphic soft skeleton hand exploiting conditional models for piano playing." Science Robotics 3, no. 25 (December 19, 2018): eaau3098. http://dx.doi.org/10.1126/scirobotics.aau3098.

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The development of robotic manipulators and hands that show dexterity, adaptability, and subtle behavior comparable to human hands is an unsolved research challenge. In this article, we considered the passive dynamics of mechanically complex systems, such as a skeleton hand, as an approach to improving adaptability, dexterity, and richness of behavioral diversity of such robotic manipulators. With the use of state-of-the-art multimaterial three-dimensional printing technologies, it is possible to design and construct complex passive structures, namely, a complex anthropomorphic skeleton hand that shows anisotropic mechanical stiffness. We introduce a concept, termed the “conditional model,” that exploits the anisotropic stiffness of complex soft-rigid hybrid systems. In this approach, the physical configuration, environment conditions, and conditional actuation (applied actuation) resulted in an observable conditional model, allowing joint actuation through passivity-based dynamic interactions. The conditional model approach allowed the physical configuration and actuation to be altered, enabling a single skeleton hand to perform three different phrases of piano music with varying styles and forms and facilitating improved dynamic behaviors and interactions with the piano over those achievable with a rigid end effector.

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Abdellatif, Houssem, Martin Grotjahn, and Bodo Heimann. "Independent Identification of Friction Characteristics for Parallel Manipulators." Journal of Dynamic Systems, Measurement, and Control 129, no. 3 (August 28, 2006): 294–302. http://dx.doi.org/10.1115/1.2718242.

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The compensation for friction or joint losses in robotic manipulators contributes to an important improvement of the control quality. Besides appropriate friction modeling, experimental identification of the model parameters is fundamental toward better control performance. Conventionally steady-state friction characteristics are investigated for mechanical systems in the first step. However, and due to the high kinematic coupling, such procedure is already complicated for complex multiple closed-loop mechanisms, like parallel manipulators. Actuation friction of such mechanisms becomes configuration dependent. This paper presents a methodology that deals with such challenge. The kinematic coupling is regarded in the friction model and therefore in the design of the experimental identification. With the proposed strategy, it is possible to identify the steady-state friction parameters independently from any knowledge about inertial or rigid-body dynamics. Friction models for sensorless passive joints can also be provided. Besides, the method is kept very practical, since there is no need for any additional hardware devices or interfaces than a standard industrial control. The suitability for the industrial field is proven by experimental application to PaLiDA that is a six degrees of freedom parallel manipulator equipped with linear directly driven actuators.

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Galicki, Mirosław. "Robust Task Space Finite-Time Chattering-Free Control of Robotic Manipulators." Journal of Intelligent & Robotic Systems 85, no. 3-4 (July 12, 2016): 471–89. http://dx.doi.org/10.1007/s10846-016-0387-3.

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AbstractThis work deals with the problem of the accurate task space control subject to finite-time convergence. Kinematic and dynamic equations of a rigid robotic manipulator are assumed to be uncertain. Moreover, unbounded disturbances, i.e., such structures of the modelling functions that are generally not bounded by construction, are allowed to act on the manipulator when tracking the trajectory by the end-effector. Based on suitably defined task space non-singular terminal sliding vector variable and the Lyapunov stability theory, we derive a class of absolutely continuous (chattering-free) robust controllers based on the estimation of a Jacobian transpose matrix, which seem to be effective in counteracting uncertain both kinematics and dynamics, unbounded disturbances and (possible) kinematic and/or algorithmic singularities met on the robot trajectory. The numerical simulations carried out for a 2DOF robotic manipulator with two revolute kinematic pairs and operating in a two-dimensional task space, illustrate performance of the proposed controllers.

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Yin, Xiaolei, and Alan P. Bowling. "Dynamic Performance Limitations Due to Yielding in Cable-Driven Robotic Manipulators." Journal of Mechanical Design 128, no. 1 (June 20, 2005): 311–18. http://dx.doi.org/10.1115/1.2121748.

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This paper presents a method for characterizing the performance limitations imposed by the yielding of the cables in systems with cable-driven transmissions. The method involves developing a rigid-body model of the system, where the cable tensions are considered as reaction forces. The kinematic coupling between links in the mechanism due to the use of cables is also considered. Here, the limitations on dynamic performance caused by cable yielding are added to the limitations caused by the bounds on actuator torque capacity, in order to give a more comprehensive description of the system’s capabilities. A two degrees-of-freedom planar mechanism is analyzed in order to illustrate the methodology.

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ZHIHONG, Man, and Xinghuo YU. "Adaptive Terminal Sliding Mode Tracking Control for Rigid Robotic Manipulators with Uncertain Dynamics." JSME International Journal Series C 40, no. 3 (1997): 493–502. http://dx.doi.org/10.1299/jsmec.40.493.

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Zhihong, Man, and M. Palaniswami. "A robust decentralized three-segment nonlinear sliding mode control for rigid robotic manipulators." International Journal of Adaptive Control and Signal Processing 9, no. 5 (September 1995): 443–57. http://dx.doi.org/10.1002/acs.4480090506.

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Vukobratovic, Miomir, and Atanasko Tuneski. "Adaptive control of single rigid robotic manipulators interacting with dynamic environment ? An overview." Journal of Intelligent and Robotic Systems 17, no. 1 (September 1996): 1–30. http://dx.doi.org/10.1007/bf00435714.

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Zong, Guangdeng, Yuqiang Wu, and Lihua Zhang. "Finite time tracking control for rigid robotic manipulators with friction and external disturbances." Journal of Systems Science and Systems Engineering 14, no. 1 (March 2005): 115–25. http://dx.doi.org/10.1007/s11518-006-0185-8.

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Kim, Seon-Jae, and Youn-Sik Park. "Self-motion utilization for reducing vibration of a structurally flexible redundant robot manipulator system." Robotica 16, no. 6 (November 1998): 669–77. http://dx.doi.org/10.1017/s0263574798000770.

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This paper focuses on overcoming the problem of tracking control in structurally flexible redundant manipulators by utilizing their self-motion capabilities. In the proposed algorithm, the self-motion is evaluated in order to nullify the dominant modal force of flexural motion that is induced by a rigid body motion.The flexure motions of manipulators, which are induced by joint motion, cause undesired inaccuracy in end-effector tracking. In-plath planning states, joint trajectories are so designed as not to excite but to damp out the flexure motions. The self-motion, inherent in redundant manipulators, can alter joint motion, influencing the flexure motion (by exciting and damping the flexure modes), while not affecting end-effector motion at all. Therefore, the self-motion can be utilized to regulate flexibility and effectively reduce the end-effector tracking error.The effectiveness and applicability of the proposed algorithm have been demonstrated through numerical simulation with three-link planar robotic manipulators possessing flexible links.

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Chalhoub, N. G., and B. A. Bazzi. "Fuzzy Logic Control for an Integrated System of a Micro-Manipulator with a Single Flexible Beam." Journal of Vibration and Control 10, no. 5 (May 2004): 755–76. http://dx.doi.org/10.1177/1077546304040946.

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The use of lightweight robotic manipulators in advanced assembly and manufacturing applications is hindered by the end-effector positional inaccuracies induced by the structural deformations of the arm. To address this problem, a macro- and micro-manipulator system is considered herein. Three rigid and flexible motion controllers, consisting of an integral plus state feedback controller (ISFC), linear quadratic regulator with an integral action (LQI) and a fuzzy logic controller (FLC), have been implemented in this study. The performances of these controllers are compared based on achieving zero steady-state error in the rigid body angular displacement of the beam, damping out the unwanted vibrations, rendering the end-effector insensitive to the vibrations of the arm, and avoiding excessive control torque requirements. The digital simulation results demonstrate the superiority of the FLC over the ISFC and LQI in damping out the vibrations of the beam and reducing the gripper positional inaccuracies while requiring relatively smaller control torques. Furthermore, the results clearly demonstrate the robustness of the FLC to significant variations in the payload mass.

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Chen, Liming, and Nabil G. Chalhoub. "Modeling and Control of Transverse and Torsional Vibrations in a Spherical Robotic Manipulator: Theoretical and Experimental Results." Journal of Dynamic Systems, Measurement, and Control 119, no. 3 (September 1, 1997): 421–30. http://dx.doi.org/10.1115/1.2801274.

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The present work addresses modeling and control issues pertaining to the positioning and orientating of rigid body payloads as they are being manipulated by flexible spherical robotic manipulators. A general approach, to systematically derive the equations of motion of the robotic manipulator, is used herein. The objective of the controller is to yield a desired rigid body response of the arm while damping out the transverse and torsional vibrations of the compliant link. Note that the control objective has to be achieved by solely relying on the existing joint actuators whose band-widths are far below the natural frequencies of the torsional modes. The current work demonstrates that, in spite of the physical limitations of the system, the controller can actively damp out the torsional vibrations by relying on the coupling terms between the torsional vibrations and the remaining degrees of freedom of the arm. Moreover, a gain scheduling procedure is introduced to continuously tune the controller to the natural frequencies of the flexible link whose length is varied by the prismatic joint. The digital simulation results demonstrate the capability of the “rigid and flexible motion controller (RFMC)” in drastically attenuating the transverse and torsional vibrations during point-to-point (PTP) maneuvers of the arm. Furthermore, the gain scheduling procedure is shown to significantly reduce the degradations in the RFMC performance that are brought about by having the flexible link connected to a prismatic joint. A limited experimental work has also been conducted to demonstrate the viability of the proposed approach.

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Lipkin, H., and J. Duffy. "Hybrid Twist and Wrench Control for a Robotic Manipulator." Journal of Mechanisms, Transmissions, and Automation in Design 110, no. 2 (June 1, 1988): 138–44. http://dx.doi.org/10.1115/1.3258918.

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Three necessary conditions derived from classical geometry are proposed to evaluate formulations for the simultaneous twist and wrench control of rigid bodies, and for any theory to be meaningful it must be invariant with respect to (1) Euclidean collineations, (2) change of (Euclidean) unit length, and (3) change of basis. It is demonstrated in this paper that a previously established theory of hybrid control for robot manipulators is in fact based on the metric of elliptic geometry and is thus noninvariant with respect to (1) and (2). A new alternative invariant formulation based on the metric of Euclidean geometry and an induced metric of projective geometry is presented in terms of screw theory. An example of insertion illustrates both the invariant and noninvariant methods.

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Hoang, Nguyen Quang, Benjamin Boudon, Hyun-Jun BAE, Thu Thuy DANG, and Chedli Bouzgarrou. "Modeling of parallel manipulators with flexible links and joints driven by electric actuators." Vietnam Journal of Mechanics 44, no. 4 (December 30, 2022): 474–89. http://dx.doi.org/10.15625/0866-7136/17944.

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This paper presents the approach of building a mathematical model for a parallel robotic manipulator with flexible links and elastic joints. The links to the base are assumed to be rigid bodies, and the thin connecting rods are assumed to be flexible links. The elasticity of the transmission from the actuators to the transmission is modeled by a torsional spring and viscous damper. This is a mixed system of rigid bodies, spring, and flexible links. The deformation motion of the elastic link is approximated by shape functions similar to the finite element method. The differential equations of motion are established by combining the substructure method and the Lagrange equation of the 2nd kind for the serial multibody system. Based on the differential equation established for the parallel robot manipulator of five bars, numerical simulations were carried out to investigate the response of the system.

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Lu, Yu-Sheng, and Yi-Yi Lin. "Smooth motion control of rigid robotic manipulators with constraints on high-order kinematic variables." Mechatronics 49 (February 2018): 11–25. http://dx.doi.org/10.1016/j.mechatronics.2017.11.003.

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Kang-Bark Park and Ju-Jang Lee. "Comments on "A robust MIMO terminal sliding mode control scheme for rigid robotic manipulators"." IEEE Transactions on Automatic Control 41, no. 5 (May 1996): 761–62. http://dx.doi.org/10.1109/9.489220.

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Gutiérrez–Giles, Alejandro, and Marco Arteaga–Pérez. "Output Feedback Hybrid Force/Motion Control for Robotic Manipulators Interacting with Unknown Rigid Surfaces." Robotica 38, no. 1 (April 22, 2019): 136–58. http://dx.doi.org/10.1017/s0263574719000523.

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SummaryThe problem of hybrid force and motion control over unknown rigid surfaces when only joint position measurements are available is considered. To overcome this problem, an extended state high-gain observer is designed to simultaneously estimate the contact force and joint velocities. These estimated signals are in turn employed to design a local estimator of the unknown surface gradient. This gradient is utilized to decompose the task space into two orthogonal subspaces: one for force tracking and the other one for motion control. A simple position Proportional Integral Derivative (PID) and force Proportional Integral (PI) controllers are proposed to track the desired signals. Finally, a mathematical analysis of the closed-loop dynamics is carried out, guaranteeing uniform ultimate boundedness of the position and force tracking errors and of the surface gradient estimation error. A numerical simulation is employed to validate the approach in an ideal scenario, while experiments are carried out to test the proposed strategy when uncertainties and unmodeled dynamics are present.

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Journal articles on the topic 'Rigid robotic manipulators'

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