On the Development of a Piezoelectric-Actuated Compliant Brake Mechanism for Modular Robots

A bistable brake mechanism can be beneficial to the development of an energy efficient module for a modular reconfigurable robot. These robots are comprised of many repeated units. To date, research efforts have focused on increasing specific torque to expand the capabilities of modular robots. In this work, we present the continued development of energy efficient joint-locking mechanisms, specifically a piezoelectric actuator and a compliant transmission. The design and manufacturing of the mechanism is presented along with a model for predicting the static and dynamic behavior of the device. We also present experimental results that indicate better performance in terms of power consumption, specific torque, and bandwidth than is possible with comparable devices that utilize magnetic particles and electromagnetically-actuated disc and drum brakes. When fully implemented, this joint-locking mechanism will lead to three critical improvements in the area of modular robotics: decreased energy expenditure per non-active module, increased ability to utilize dynamic motion due to less reliance on highly-geared servo motors, and improved ability to maintain configurations with high mechanical advantage.