Vibration Suppression for a Speed Control System with Gear

Drive units for robots and other automatic machines are generally composed of a motor and a reducing gear. Such units with inertia load show vibrational response to the reference change as well as to the load variation. In order to improve response speed and accuracy of the machines, these vibrations have to be suppressed. Many control methods successfully deal with the problem, but most of them are difficult to be practically realised or have a disadvantage of a needed high degree of knowledge for the controller design. An aim of the present research is a design of a simple but effective method for a vibration suppression. In this purpose a disturbance rejection control is used for motor and thus a dynamically decoupled motor and load system is obtained. The decoupling enables a simple design of a feedback loop for the vibration suppression. This paper discusses about the design of the feedback loop and its effect on the system's transient response.