Soft robots utilize compliant materials to perform motions and behaviors not typically achievable by rigid bodied systems. These materials and soft actuator fabrication methods have been leveraged to create multigait walking soft robots. However, soft materials are prone to failure, restricting the ability of soft robots to accomplish tasks. In this work we address the problem of generating reactive controllers for multigait walking soft robots that are resilient to actuator failure by applying methods of formal synthesis. We present a sensing-based abstraction for actuator performance, provide a framework for encoding multigait behavior and actuator failure in Linear Temporal Logic (LTL), and demonstrate synthesized controllers on a physical soft robot.

A soft orthotic with position control enabled via embedded optical fiber is presented. The design, manufacture, and integration of both the pneumatically powered actuators and optical sensors are described. This orthotic actuator-sensor pair is self-contained and worn on a human finger. When un-powered, the elastomeric actuator allows facile movement and, when pneumatically actuated, the orthotic causes bending of the wearer's finger. Position control is achieved by measurement of signal intensity from a light-emitting diode (LED) input traveling through an embedded optical fiber—greater curvature results in increased light intensity. Both the static and dynamic states are monitored via the optical sensor and the prescribed curvatures are achieved accurately and with stability by a gain-scheduled proportional-integral-derivative (PID) controller implemented by applying pulse-width-modulation (PWM) signals to a solenoid valve to adjust the internal pressure of the actuator.

Locomoting soft robots typically walk or crawl slowly relative to their rigid counterparts. In order to execute agile behaviors such as jumping, rapid actuation modes are required. Here we present an untethered soft-bodied robot that uses a combination of pneumatic and explosive actuators to execute directional jumping maneuvers. This robot can autonomously jump up to 0.6 meters laterally with an apex of up to 0.6 meters (7.5 times it's body height) and can achieve targeted jumping onto an object. The robot is able to execute these directed jumps while carrying the required fuel, pneumatics, control electronics, and battery. We also present a thermodynamic model for the combustion of butane used to power jumping, and calculate the theoretical maximum work output for the design. From experimental results, we find the mechanical efficiency of this prototype to be 0.8%.