What is Pulse Width Modulation (PWM)

There is still no artificial life with the same adaptability and flexibility as animals. Although artificial life will advance by acquiring nervous systems similar to those of animals, its role and mechanisms remain unknown. The authors have developed a quadruped robot with a bio-inspired gait generation method to realize robots that can behave like animals. The method could generate gaits using pulse-type hardware neuron models (P-HNMs). However, characteristics of the P-HNMs had large scatterings, and the robot could maintain gaits only a few cycles. This chapter explains the method and P-HNM integrated circuits (ICs) developed to improve P-HNMs' characteristics. In addition, dynamic simulations with a simplified method and discussions of the methods and ICs are provided. Although the proposed methods are simple, they could actively generate gaits using interactions between the body and the environment. Therefore, the methods will lead to the realization of a quadruped robot with flexible adaptability.