The present paper proposes analog integrated circuit (IC) implementation of a biologically inspired controller in quadruped robot locomotion. Our controller is based on the central pattern generator (CPG), which is known as the biological neural network that generates fundamental rhythmic movements in locomotion of animals. Many CPG-based controllers for robot locomotion have been proposed, but have mostly been implemented in software on digital microprocessors. Such a digital processor operates accurately, but it can only process sequentially. Thus, increasing the degree of freedom of physical parts of a robot deteriorates the performance of a CPG-based controller. We therefore implemented a CPG-based controller in an analog complementary metal-oxide-semiconductor (CMOS) circuit that processes in parallel essentially, making it suitable for real-time locomotion control in a multi-legged robot. Using the simulation program with integrated circuit emphasis (SPICE), we show that our controller generates stable rhythmic patterns for locomotion control in a quadruped walking robot, and change its rhythmic patterns promptly.
Getting grip in changing environments: the effect of friction anisotropy inversion on robot locomotion