A new technique for robust control of servo systems

The robust controller has very simple structures and can be divided into two separate parts: a servo controller and an auxiliary controller. The two controllers are designed independently. The function of the auxiliary controller is to cancel out the plant uncertainties directly without the use of the high loop gain principle. Interpretation of robot controller as a signal-synthesis adaptive controller is given. Practical implementation issues of the auxiliary controller are discussed. Simulations of a design example with large parameter uncertainty, nonlinearity, and external disturbance are presented to demonstrate the effectiveness of the design technique. This technique is further tested with success in an experimental study of joint position control of a PUMA 560 robot arm