Robot motion control based on joint torque sensing

The author proposes a joint-torque feedback (JTF) control scheme with a conventional position compensator for robot motion control. The advantage of this control scheme is that real-time computation is not required for the dynamic compensation. Also, the control system is robust against unexpected external disturbances, such as the action of gravity on objects picked up and put down, and other interactions with the environment. The author discusses the modeling and analysis of the JTF control and proposes a joint-torque sensing technique using the elasticity of the harmonic drive. The JTF control system worked well and insulated the conventional PD control loop from dynamic interventions in experiments with a two-link robot arm