Speed control and sensorless force control with magnetic gear

This paper describes a study of the speed control and sensorless force control with non-contact magnetic transmission system (the magnetic gear). The magnetic gear has various features. For example, this device is characterized by negligibly small friction because of transmitting torque without contact. However, the magnetic gear introduces a cogging torque and a spring characteristic because it transmits torque via magnetism. Therefore, we applied various control method to reject the disturbances such as cogging torque in speed control. Additionally, using the magnetic gear for force control is primary candidate. If the magnetic gear is applied to a robot manipulator, force control can be performed without using a force sensor because of non-contact. We conducted experiments to examine the sensorless force control using an experimental magnetic geared device, and we verified the promising possibility for the sensorless feedback.