Compliant Proprioceptive Touch without a Force Sensor: A Kinesthetic Feedback Control Approach

The focus of this paper is on an approach to use a reference tracking feedback control for sensing a touch between a compliant soft robotic finger and an object in its environment. The approach uses the reference tracking error as an indicator of contact with the object and removes the necessity for a distal force sensor. The study is performed in virtual reality on a device that mimics essential properties of a previously fabricated soft finger. To achieve the reference tracking control, we identify the finger model and use it for the control design. We demonstrate the work of the controller and the approach in experiments with a robot-mounted finger in which the finger interacts with objects in its environment. In these experiments, we are able to detect objects, obtain data about their geometry and control the finger to get in a compliant touch with an object.