Edeh O.D.F.¹, Ossia C.V.^1,

Rapid technological advances to meet increasing demand for optimal, economical and environmentally friendly solutions has lead to the challenge of increased discontinuities of some service parts by manufacturers. These discontinuities had resulted in increased abandonment of some machines after a few years. Electronic and control modules often receive great share of this abandonment. Hence, the Selective Compliant Assembly Robot Arm (SR-600 SCARA Robot) had been cut-up by these discontinuities. Retrofitting enables existing machines access to new technologies and opportunities. In this study, SR-600 SCARA Robot was reviewed for this purpose. The forward and inverse kinematics equations were solved. An insulated-gate bipolar transistor (IGBT)-based power amplifier design was developed. Results of the amplifier Simulation, closed-loop control implementation and the PID (proportional integral derivative) tuning of the axes servos were presented. The results does not only offer cheap, compact and power efficient control solution, but also an improved multimode motion control using PID controls with velocity and acceleration feed-forward and high speed Ethernet communication between the Robot and the host computer. In this retrofit, results indicate an excellent angular resolution of 0.001^o for the three revolute joints, a translational resolution of 2.223µm and an overall motion accuracy of 0.038^o for the PID tune configuration of K_i = 1, K_p =50, and K_d =100.

retrofit, SCARA, IGBT, proportional integral derivative (PID)