Control of a robot leg with an adaptive aVLSI CPG chip

The rhythmic locomotion of animals, such as walking, swimming, and flying, is controlled by group of neurons called central pattern generators (CPGs). CPGs can autonomously produce rhythmic output, but under normal biological conditions make extensive use of peripheral sensory feedback. Models of CPGs have been used to control robot locomotion, but none of these models have incorporated sensory feedback adaptation. We have constructed an adaptive CPG in an analog VLSI chip, and have used the chip to control a running robot leg. We show that adaptation based on sensory feedback permits a stable gait even in an underactuated condition: the leg can be driven using a hip actuator alone while the knee is purely passive.