Experimental Performance of Robust PID Controller on a Planar Cable Robot
In this paper dynamic analysis and experimental performance of robust PID control for fully-constrained cable driven robots are studied in detail. Since in this class of manipulators cables should remain in tension for all maneuvers through their whole wo
- PDF / 1,419,313 Bytes
- 16 Pages / 439.37 x 666.142 pts Page_size
- 53 Downloads / 207 Views
Abstract In this paper dynamic analysis and experimental performance of robust PID control for fully-constrained cable driven robots are studied in detail. Since in this class of manipulators cables should remain in tension for all maneuvers through their whole workspace, feedback control of such robots becomes more challenging than conventional parallel robots. To ensure that all the cables remain in tension, a corrective term is used in the proposed PID control scheme. In design of PID control it is assumed that there exist bounded norm uncertainties in Jacobian matrix and in all dynamics matrices. Then a robust PID controller is proposed to overcome partial knowledge of robot, and to guarantee boundedness of tracking errors. Finally, the effectiveness of the proposed PID algorithm is examined through experiments and it is shown that the proposed control structure is able to provide suitable performance in practice.
1 Introduction Cable driven parallel manipulators (CDPMs) are a special class of parallel robots in which the rigid extensible links are replaced by actuated cables. In a CDPM the end-effector is connected to the base by a number of active cables. While the cables length is changing, the end-effector is manipulated toward the desired position and orientation. Cable driven robots have some advantages compared to that of conventional robots. Using cables as an alternative to rigid links enables cable robots M. A. Khosravi(B) · H. D. Taghirad Advanced Robotics and Automated Systems, Industrial Control Center of Excellence, Faculty of Electrical and Computer Engineering, K. N. Toosi University of Technology, P.O. Box 6315-1355, Tehran, Iran e-mail: [email protected] H. D. Taghirad e-mail: [email protected] T. Bruckmann and A. Pott (eds.), Cable-Driven Parallel Robots, Mechanisms and Machine Science 12, DOI: 10.1007/978-3-642-31988-4_21, © Springer-Verlag Berlin Heidelberg 2013
337
338
M. A. Khosravi and H. D. Taghirad
to be used for very large workspace applications such as large adaptive reflector and SkyCam [1, 2]. Because of negligible mass and inertia of cables, they are suitable for high speed applications. Moreover, they can achieve some useful properties such as transportability and ease of assembly/disassembly, reconfigurability and economical structure and maintenance [3]. Consequently, CDPMs are exceptionally suitable to be used in many applications such as, handling of heavy materials [4], high speed manipulation [5, 6], cleanup of disaster areas [7], rapidly deployable rescue robots, and access to remote location and working in hazardous environment [8]. Using cables in the structure of the robot, however, introduces new challenges in the study of CDPMs. Cables can only apply tensile forces, therefore, the cables must be kept in tension in the whole workspace of the robot [9]. In order to fulfill this requirement, usually fully constrained structures are considered for a cable robot [7]. This kind of robots is being analyzed in this paper. In comparison to the large amount o
Data Loading...
