Development of shear sensing system for a three-finger robot hand

In this work, we design and implement a control and sensing system for a three-finger robot hand. The system effectively controls the joint angles and forces of the hand. Then, the grasping capability of the hand is demonstrated using the system. The MSP430 is employed as the microcontroller for the position and force feedback control circuit. For the position control, the adaptive PD controller is employed, while the traditional PID controller is used for the force control. In addition, using the force/position hybrid control method, the aforementioned two controllers are integrated. We adapt the commercially-available pressure sensor elements to build a multi-axis sensing system. The required platform for the demonstration of the control and sensing system are also developed. We use an x-y table to emulate the arm of a robot hand. The developed control/driving/sensing circuit boards are attached on the x-y table. Labview is employed as the software platform for the high-level control commands. Furthermore, the codes developed in Labview are connected with Matlab for computing with other control algorithms, such as the force closure. Moreover, with the measured force data collected by sensing system, it is demonstrated that the hand can be real-time controlled to steadily grasping an object.