Dynamic Modeling of Quadrupedal Running Gaits Using a Simple Template With Asymmetrical Body Mass Distribution

Most quadruped robots capable of running have employed bounding gaits at speeds far below those at which an animal of equal mass would gallop, which is a similar gait. This paper extends the spring-loaded inverted pendulum (SLIP) model to capture the key characteristics of trotting and galloping in biological systems. The objective is to establish a tool that will aid in determining the speed at which bounding or galloping is efficient for robotic systems. The SLIP model includes a linear damper in the legs to model all energy losses in a stride, and in the case of bounding, the body is taken to have an asymmetrical mass distribution. Results indicate that the model exhibits biological characteristics for both trotting and galloping, although duty factors are unrealistically low. Including leg mass in the models to account for additional energy loss does not offer improvement over the use of a linear damper alone.© 2004 ASME