This paper presents a PID control of a prototype transmission-based robot servo-actuator system (TBA) and its implementation using real time application interface (RTAI) under Linux. The PID control presented can achieve stability and performance requirement in terms of attenuation of disturbance due to gear shift. The control software has a real time multithread design. Verification test shows the new control software has a deterministic control loop time, and significant performance improvement is achieved compared with the implementation using Labview Express under Windows XP

A novel actuator concept has been developed and prototyped. By integrating a multi-speed transmission with a high performance permanent magnet DC servomotor, it has been shown that an electrical drive can provide power/torque density and physical size that approaches the capabilities of electrohydraulics. Preliminary experimental tests of the prototype are encouraging and the first steps toward verifying the concept.

This paper addresses aspects of the feasibility of extending high performance brushless DC motor torque-speed capabilities by using multi-speed transmissions. Initial dynamic modeling and simulation results show that a transmission-based electrical servo actuator can have similar load capabilities with widely used hydraulic actuator in robot manipulators.