Robotic soft servo for industrial high precision assembly

Industrial robots can be made compliant to the environment when the control loop gains are reduced, creating a so-called ¿soft servo¿ capability. This allows industrial robots to be used for assemblies with limited contact requirements. In this paper, we propose an assembly method using soft servo to perform certain assembly tasks where part location errors typically require the use of force control or Remote Center of Compliance (RCC) methods. A typical industrial application, valve body assembly, was used to validate the developed method. This assembly was chosen because it is simple, yet requires compliance in all directions. Lab experiments were performed and the assembly operations were consistently successful enough to show that the developed soft servo strategy can perform certain assembly tasks with small part location errors. Therefore, the soft servo strategy may open a new door for low cost industrial assembly.