Study on sensorless force control based on disturbance observer with friction force compensation

This paper explained the disturbance observer, the system which is different from the force sensor control, because the disturbance observer force control can observe the external torque without force sensors. If the system has the rigid mass or soft mass, concerning the environment, the disturbance observer can control and work well however when using disturbance observer in the system, it will also use the low-pass filter because the feedback following the amplitude rang was setting. when the system has friction force has to be improved by friction force compensation, this estimated method is called a reaction torque observer. Thus, the disturbance observer is a solution of the problem which happen by force sensor. For example, disturbance torque, can be applied as quickly as possible for the another systems.