Mule like robot
We developed a pneumatically driven four legged mule-like robot. The robot is actuated with 12 pneumatic cylinders which are operated by compressed air that comes from a combustion engine driven air compressor. The robot weighs about 300 Kg and can carry about a 100 Kg of payload. The compliance property of the air makes the robot very stable. We developed a model based back-stepping based controller for the servo control of pneumatic cylinders. We also developed a potential function based free-gait motion planning algorithm that navigates the robot and select foothold locations along a desired path or from point to point.