Modelling And Simulation Of Robot Arm

摘要

The paper deals with the modelling and simulation of industrial robots. To find the best possible control system for robots which were made in our department, corresponding model hod to be developed. Because of complexity and nonlinearity of a real construction, our model is limited to a single kinematic stage. So we do not consider its multivariable character. The model gives information about arm position, speed and pressure in hydraulic cylinder. It includes linear servovalve, hidraulic cylinder, displacement sensor and controller. Saturation and delay of the servovalve, flow modulation by the pressure, compressibility and leakage of fluid are also considered. The characteristic feotures of the positioning system were determined by means of hybrid simulation. In the paper some possibilities for model simplifications neglecting information about speed and pressure are dicussed. Some local control lows are presented together with a comparison of analog and digital controllers. It was established that the main problem in analog robot control is to choose the right gain (no'llinearity). Satisfactory results were obtained with digital controllers, which change their control low or parameters depending on movement direction or error magnitude. 80th point-to-piont and continuous-path control are studied and illustrated by the simulation results.