Practical PID controller tuning for motion control

Abstract

The most popular control method in the industry is PID control due to its simple structure and effective performance. Although huge numbers of PID controller tuning methods have been proposed so far, existing ones still do not have the desired performances and the simplicity. Complex system dynamics make it challenging for engineers and students to apply these methods on their applications especially in the motion control and robotics areas. Such systems generally include nonlinearity, friction, varying inertia and unknown disturbances which make the conventional tuning methods ineffective and too complex to be used. There is need for simple and effective PID tuning methods in these areas. In order to solve this problem, this paper proposes two novel practical PID tuning methods for motion control systems. These methods bring the superiority of the 2 degree of freedom control approach to simple PID controller structures analytically. They are very effective in motion control and robust both to parameter uncertainty and unknown disturbances, yet very simple. They can be easily used by the engineers in the industry and the students with very basic control knowledge, so little effort and time. The tuning methods of robust PID and PI controllers with velocity feedbacks are proposed, for position and force control problems of servo systems, respectively. The validities of the proposals are verified by the experimental results.