Force Control of a Robot Gripper Featuring Shape Memory Alloy Actuators

In this paper, we present design of a gripper for a robot arm. Our research brings out a new driven mechanism with shape memory alloy instead of servo motor as our actuator, and also the gripper is equipped with a force sensor inside. The fuzzy sliding-mode method is our control rule, and furthermore there is an anti-slipping control rule to avoid grabbing unknown object with insufficient force. The whole control strategies are integrated into a Microchip dsPIC MCU with DSP core inside which is good at dealing with complicated float-point calculation. Gripper can change grabbing force in real-time based on fuzzy sliding-mode control due to different weight objects. Finally, we grab five different objects with our gripper to verify our control strategy in the experiment.