A separate DC motor, identical to the motors of the IRp-6 robot, and a digital servocontroller are the core of the testbed. The motor is coupled to a harmonic gearbox. This actuator rotates a variable length rigid beam. The arm may be loaded with a mass at its end.

The hardware of the servocontroller was produced by the Industrial Research Institute for Automation and Measurements. Its sampling rate may be reduced even to 1ms. In our laboratory a self-made, fast interface links the servo hardware to a PC computer. The testbed was designed to provide control of the servomotor and easy access to motor control parameters.

A DOS based program, written in the C language, enables the modification of the servo parameters and controlling motor on line. The following servodrive parameters are monitored simultaneously: motor velocity, position and motor current.

The motor and the beam are housed in a protective, partially transparent casing.

Thus the control and measuring apparatus compose a versatile tool for teaching students the basics of servodrive behaviour. It is also a good reasearch platform for experimental verification of theoretical results.