Robust design of reaction torque measurement system based on disturbance observer

A novel robust control method based on disturbance observer (DOB) is presented, in order to achieve high performance control specifications for the torque measurement servo system. First, a position closed loop control system is established according to working principle of the torque measurement system. In order to estimate the measured torque, the DOB is added to the position closed loop control system. Next, a mathematical model of the DOB system is built. And an approximate design method for DOB is put forward. Simulation and experimental results show that, through the DOB added to the system, position interference rejection and torque dynamic performance of the system are increased. And the DOB can be easily designed through the approximate method; also it can improve the performance of the control system.