Development of a Surface Sensing Tool for Normal Measurement for Robotic Machining Tasks

The growing adoption of robot manipulators for complex machining operations, particularly polishing, highlights the need for advancements in maintaining consistent contact on diverse and unpredictable geometric surfaces. In response to this need, a compliant tool was designed to perform real-time depth and angle deviation measurements without relying on workpiece's pre-defined geometric model. The end-effector comes with the following three main parts: a three-axis force/torque sensor, a compliant contact pin, and a data acquisition (DAQ) board. To continuously evaluate depth and angles, an integrated pose correction algorithm uses estimated contact forces as feedback during robotic surface tracking. As a result, the optimal separation and perpendicular attachment between the end-effector and the surface under operation are established. The DAQ system, with its automatic weight compensation feature, facilitates real-time measurements, enhancing the end-effector precision. The proposed approach is of considerable promise in robotic machining operations to generate normal trajectories, as it ensures control adaptively and correctly in dynamic situations, which is essential for maintaining high-quality outcomes.