In the control of the actual plant, there exits a difference between output of compensator and control input momentarily. This is caused by mechanical constraint on the actuator like saturation and rate limit, and constraint on the control input to protect the plant in the aircraft engine controls etc. Difference between output of compensator with integral element and control input causes windup phenomenon and gives adverse effects to the control performance. One of the techniques to prevent the above phenomenon is anti-windup and bumpless transfer technique.
In this paper, we derive sufficient condition of robust stability for the system consisting of the plant with linear time invariant multiplicative uncertainty, compensator, constraint on the control input, and anti-windup and bumpless transfer block. Then, we propose a new algorism of anti-windup and bumpless transfer block synthesis which directly uses this stability condition. In numerical example, we design the anti-windup and bumpless transfer block to a given system, and evaluate its performance by computer simulation.