Computation of Robot Dynamics by a Multiprocessor Scheme
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The computation of applied torques in real time in the dynamic control of robot systems is complicated and time consuming. The Newton-Euler state space formulation is used for computing the dynamics. By using this formulation, the backward recursion for calculating angular velocities and angular accelerations is eliminated. The calculation of linear acceleration is simplified. It involves only two steps. This reduces the height of the evaluation tree in calculating the applied torques which makes the parallel processing more effective. A multiprocessor system composed of a central CPU and a group of satellite CPU’s is suggested for implementing the computations. The task of each satellite CPU is to take care of one link of the system by calculating all its related data. The task of the CPU is to compute the applied torques. Because of this arrangement, the required software system is the same for all satellite CPU’s. The proposed multiprocessing scheme results in a flexible and modular system which is adaptive for a variety of dynamic configurations. Computer simulation results of this strategy are presented to show that the suggested multiprocessing scheme achieves a good speedup factor over the uniprocessing system.
KeywordsSpeedup Factor Task Allocation Global Memory Angular Acceleration Linear Acceleration
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- J.Y.S. Luh, ”An Anatomy of Industrial Robots and Their Controls,” IEEE Trans. Automat. Contr. Vol. AC-28,no. 2, pp. 133–153.Google Scholar
- Y.F. Zheng and F. R. Sias, ”Design and Motion Control of Pratical Biped Robots,” International Journal of Robotics and Automation, Vol.3,no.2, pp. 70–78, 1988.Google Scholar
- C.S.G. Lee ”Robot Arm Kinematics, Dynamics and Control,” IEEE COMPUTER, PP.62–80, December, 1982.Google Scholar
- M. Vukobratovic, and D. Stokic, ”Is Dynamic Control Needed in Robotic Systems, and, if so, to What Extent?”, The International Journal of Robotics Research, Vol.2,no. 2, Summer 1983.Google Scholar
- R.P. Paul, Robot Manipulators: Mathematics, Programming, and Control, Cambridge, Ma., M.I.T. Press, 1981.Google Scholar
- W.M. Silver, “On the Equivalence of Lagrangian and Newton-Euler Dynamics for Manipulators,” The International Journal of Robotics Research, Vol.1,no.2, Summer 1982.Google Scholar
- R.H. Lathrop, ”Parallelism in Arms and Legs”, M.S. Thesis, The Massachusetts Institute of Technology, December, 1983.Google Scholar
- B.H. Liebowitz, ”Multiple Processor Minicomputer System Part 1: Design Concepts.” Computer Design, pp. 87–95, Oct. 1978.Google Scholar