Design and Application of Chattering-Free Sliding Mode Controller to Cable-Driven Parallel Robot Manipulator: Theory and Experiment

Author(s):  
Meysar Zeinali ◽  
Amir Khajepour

High-performance robust controller design for nonlinear uncertain dynamical systems such as cable-driven parallel robot manipulators is a challenging work. In this paper, a new and systematic approach to combine sliding mode control, adaptive control design techniques and PID control for tracking control of cable-driven parallel robot manipulators, in the presence of model uncertainties is presented. In the proposed method, structured (parametric) and unstructured (un-modeled) uncertainties are lumped into one term and one uncertain parameter (term) is considered corresponding to each degrees of freedom of robot manipulator. Therefore, the problem of computation burden and large number of parameters, which are not addressed in the literature, is solved to a large extent. The global uniform ultimate boundedness stability is obtained in the presence of fast time-varying uncertainties. The simulation and experimental results revealed that the proposed method is robust against uncertainties and its simplicity makes the approach attractive for industrial applications.

2000 ◽  
Vol 122 (4) ◽  
pp. 611-615 ◽  
Author(s):  
Pe´ter Korondi ◽  
Pe´ter T. Szemes ◽  
Hideki Hasimoto

A high-performance human interface device needs accurate force feedback from the manipulated environment to the operator to improve the operation. The mechanism applied in the human interface device usually has a reasonable imminent friction. This friction must be compensated in a way that the operator cannot feel this friction force but only the force from the manipulated environment. The main contribution of this paper is a practical application of direct model based chattering free sliding mode friction estimator and compensator for a human interface device, which is used for virtual telemanipulation. Experimental results are presented for a sensor glove type haptic device with 20 degrees of freedom. [S0022-0434(00)01104-7]


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3653
Author(s):  
Lilia Sidhom ◽  
Ines Chihi ◽  
Ernest Nlandu Kamavuako

This paper proposes an online direct closed-loop identification method based on a new dynamic sliding mode technique for robotic applications. The estimated parameters are obtained by minimizing the prediction error with respect to the vector of unknown parameters. The estimation step requires knowledge of the actual input and output of the system, as well as the successive estimate of the output derivatives. Therefore, a special robust differentiator based on higher-order sliding modes with a dynamic gain is defined. A proof of convergence is given for the robust differentiator. The dynamic parameters are estimated using the recursive least squares algorithm by the solution of a system model that is obtained from sampled positions along the closed-loop trajectory. An experimental validation is given for a 2 Degrees Of Freedom (2-DOF) robot manipulator, where direct and cross-validations are carried out. A comparative analysis is detailed to evaluate the algorithm’s effectiveness and reliability. Its performance is demonstrated by a better-quality torque prediction compared to other differentiators recently proposed in the literature. The experimental results highlight that the differentiator design strongly influences the online parametric identification and, thus, the prediction of system input variables.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jeang-Lin Chang

For a class of linear MIMO uncertain systems, a dynamic sliding mode control algorithm that avoids the chattering problem is proposed in this paper. Without using any differentiator, we develop a modified asymptotically stable second-order sliding mode control law in which the proposed controller can guarantee the finite time convergence to the sliding mode and can show that the system states asymptotically approach to zero. Finally, a numerical example is explained for demonstrating the applicability of the proposed scheme.


Author(s):  
W. Kim ◽  
J. Rastegar

Abstract Trajectory synthesis for robot manipulators with redundant kinematic degrees-of-freedom has been studied by numerous investigators. Redundant manipulators are of interest since the redundant degrees-of-freedom can be used to improve the local and global kinematic and dynamic performance of a system. As a robot manipulator is forced to track a given trajectory, the required actuating torques (forces) may excite the natural modes of vibration of the system. Noting that manipulators with revolute joints have nonlinear dynamics, high harmonic excitation torques are generally generated even though such harmonics have been eliminated from the synthesized trajectories and filtered from the drive inputs. In this paper, a redundancy resolution method is developed based on the Trajectory Pattern Method (TPM) to synthesize trajectories such that the actuating torques required to realize them do not contain higher harmonic components with significant amplitudes. With such trajectories, a robot manipulator can operate at higher speeds and achieve higher tracking accuracy with suppressed residual vibration. As an example, optimal trajectories are synthesized for point to point motions of a plane 3R manipulator.


Author(s):  
Ronen Ben-Horin ◽  
Moshe Shoham

Abstract The construction of a new type of a six-degrees-of-freedom parallel robot is presented in this paper. Coordinated motion of three planar motors, connected to three fixed-length links, produces a six-degrees-of-freedom motion of an output link. Its extremely simple design along with much larger work volume make this high performance-to-simplicity ratio robot very attractive.


2019 ◽  
Vol 19 (08) ◽  
pp. 1940053
Author(s):  
SHUPENG ZHENG ◽  
XINJIAN NIU ◽  
CHENHUI PENG

In order to minimize the involuntary tremor of surgeon’s hands, the surgical robots are widely applied in the minimally invasive surgeries. However, unlike ordinary robots, the surgical robots require that the manipulator has high precision and strong anti-disturbance ability. Besides that, the manipulators of surgical robots must be able to move smoothly and respond quickly to the surgeon’s instructions during conducting tasks. To solve aforementioned problems, this paper describes a super-twisting sliding mode controller for the robot manipulator. The basic law is combined with the adaptive term to overcome the unknown disturbances and structural uncertainties, and with the prescribed performance allowing to influence the error dynamics. To ensure the robot system has good transient and steady-state performances, the transformation function of tracking errors is devised. Through using transformed errors, we attain the surface of sliding mode and propose a modified structure of traditional super-twisting algorithm. Considering the derivative of lumped disturbance has unknown boundary, a novel adaptive law is derived for the modified super-twisting sliding mode control which does not require the boundary of disturbance. Simulation experiments showed that the proposed control algorithm not only improves the tracking performance of surgical robot manipulators, but also facilitates the parameter tuning of controller. The devised robot manipulators are also potentially applicable to telesurgery where the steady-state response of surgical robots is required.


1996 ◽  
Vol 118 (4) ◽  
pp. 520-525 ◽  
Author(s):  
A. Karger

This paper is devoted to the description of the set of all singular configurations of serial robot-manipulators. For 6 degrees of freedom serial robot-manipulators we have developed a theory which allows to describe higher order singularities. By using Lie algebra properties of the screw space we give an algorithm, which determines the degree of a singularity from the knowledge of the actual configuration of axes of the robot-manipulator only. The local shape of the singular set in a neighbourhood of a singular configuration can be determined as well. We also solve the problem of escapement from a singular configuration. For serial robot-manipulators with the number of degrees of freedom different from six we show that up to certain exceptions singular configurations can be avoided by a small change of the motion of the end-effector. We also give an algorithm which allows to determine equations of the singular set for any serial robot-manipulator. We discuss some special cases and give examples of singular sets including PUMA 560.


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