Computed torque scheme based adaptive tracking for robot manipulators
21 May 1995-Vol. 1, pp 587-590
TL;DR: A computed torque scheme based adaptive tracking control approach for robot manipulators, which can be regarded as a modified version of Craig's adaptive control law (1987), is presented in this paper.
Abstract: A computed torque scheme based adaptive tracking control approach for robot manipulators, which can be regarded as a modified version of Craig's adaptive control law (1987), is presented in this paper. Utilising a two component structure, this controller consists of a linear PD control component and an adaptive component. The PD control, using some reasonable estimates of system parameters, is used to stabilise the robot system in the sense that all internal signals remain bounded. The adaptive control component is to reduce the tracking errors for the resultant error dynamics. In this scheme, even though the acceleration signals are still needed in parameter estimation, there is no need to compute the inverse of the estimated inertial matrix, which is required in Craig's scheme. The adaptive controller design is based on the standard Lyapunov method and the linear-in-parameter property of robot motion equations. The scheme ensures the global convergence of the tracking errors and will approach the computed torque scheme provided that the parameter estimates converge to their true values.
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01 Dec 2015
TL;DR: In this paper, a comparative performance analysis of the control strategies for a two-link planar robotic manipulator is presented, which demonstrates that neural network controller gives the most effective results and confirms that the dynamical system can track the desired trajectory.
Abstract: This paper presents a comparative performance analysis of the control strategies for a two link planar robotic manipulator. In this work PD/PID computed torque control, filtered error approximation based adaptive control, and neural network (NN) control methods are considered for comparative performance analysis. The comparative analysis of the results demonstrates that the neural network controller gives the most effective results and confirms that the dynamical system can track the desired trajectory. The computer simulation is carried out using MATLAB and satisfactory results are presented which demonstrate the tracking capability and the effectiveness of the proposed control scheme.
14 citations
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...The steady state error is removed by adding an integral term to the PD controller [7]....
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01 Sep 1999
TL;DR: In this paper, an adaptive controller for rigid manipulators is presented, which takes full advantage of the known parameters of the manipulator while estimating the unknown parameters, and the overall control system maintains the structure of the computed torque system with an adaptive element.
Abstract: An adaptive controller for rigid manipulators is discussed in this paper. The scheme presented is applied to a two-link rigid manipulator. It takes full advantage of the known parameters of the manipulator while estimating the unknown parameters. In deriving the dynamic equations of motion, all the physical parameters of the manipulator, including the distributed masses of the links, are taken into account. The overall control system maintains the structure of the computed torque system with an adaptive element. The convergence of the control is considered in detail. A method of selecting the best combination of the various gains is presented. Some simulation results of the manipulator with unknown payload masses following a desired trajectory are presented.
8 citations
Proceedings Article•
25 Jul 2012TL;DR: In this article, a switched adaptive control scheme for robot manipulators to solve the problem caused by the load variation is proposed, where the parameter jump caused by load changing is treated as the mode switching of the robot manipulator system.
Abstract: A switched adaptive control scheme is proposed for robot manipulators to solve the problem caused by the load variation. The parameter jump caused by load changing is treated as the mode switching of the robot manipulator system. A switched controller, that switches synchronously with the system is designed. The update laws are designed in a way that the estimation value unchanged when its corresponding subsystem is inactive. Asymptotic state tracking under arbitrary switching is gained. An example of a two DOF robot arm is presented to validate the proposed method.
5 citations
01 Sep 2018
TL;DR: In this work, the trajectory tracking control using Computed Torque Control (CTC) and Sliding Mode Control (SMC) strategies for a nonlinear three-link robot manipulator have been presented.
Abstract: In this work, the trajectory tracking control using Computed Torque Control (CTC) and Sliding Mode Control (SMC) strategies for a nonlinear three-link robot manipulator have been presented. Both the control strategies are implemented and the performance analysis has been carried out through simulations in MATLAB/SIMULINK. A comparative performance analysis of CTC and SMC has been presented.
5 citations
Cites background from "Computed torque scheme based adapti..."
...CTC gives very good stability to the robotic manipulator in case any external disturbances applied to the system are absent [4]....
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TL;DR: It is shown that all the error signals in the learning system are bounded and the repetitive robot motion converges to the desired one exponentially fast with guaranteed convergence rate.
Abstract: An intelligent control method is proposed for control of rigid robot manipulators which achieves exponential tracking of repetitive robot trajectory under uncertain operating conditions such as parameter uncertainty and unknown deterministic disturbance. In the learning controller, exponentially stable learning algorithms are combined with stabilizing computed error feedforward and feedback inputs. It is shown that all the error signals in the learning system are bounded and the repetitive robot motion converges to the desired one exponentially fast with guaranteed convergence rate. An engineering workstation based control system is built to verify the effectiveness of the proposed control scheme.
Cites background from "Computed torque scheme based adapti..."
...1 Introduction In recent years adaptive control schemes which accommodate the complete nonlinear dynamics of manipulator have been developed [4], [8], [10], [13], [14], [15], [17]–[19]....
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References
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TL;DR: In this paper, an adaptive robot control algorithm is derived, which consists of a PD feedback part and a full dynamics feed for the compensation part, with the unknown manipulator and payload parameters being estimated online.
Abstract: A new adaptive robot control algorithm is derived, which consists of a PD feedback part and a full dynamics feedfor ward compensation part, with the unknown manipulator and payload parameters being estimated online. The algorithm is computationally simple, because of an effective exploitation of the structure of manipulator dynamics. In particular, it requires neither feedback of joint accelerations nor inversion of the estimated inertia matrix. The algorithm can also be applied directly in Cartesian space.
2,117 citations
TL;DR: In this paper, an accurate dynamic model of a mechanical manipulator is used in a nonlinear, model-based scheme to control the manipulator, which yields a controllable manipulator.
Abstract: When an accurate dynamic model of a mechanical manipu lator is available, it may be used in a nonlinear, model-based scheme to control the manipulator. Such a control formula tion yields a controll...
889 citations
TL;DR: In this paper, the adaptive control of rigid link manipulator systems is examined and linear estimation techniques together with a computed torque control law are shown to give a globally convergent adaptive system which does not require measurements of accelerations.
387 citations
TL;DR: In this article, the stability properties of various time-varying linear differential equations arising in model reference adaptive identification schemes are examined and necessary and sufficient conditions for exponential stability are presented.
Abstract: The stability, properties are examined of various time-varying linear differential equations which arise in model reference adaptive identification schemes. Necessary and sufficient conditions for exponential stability are presented.
371 citations