Abstract
A pneumatically actuated six legged robot is introduced and demonstrated in this paper. With the concept of actuator reduction and gravitationally decoupled actuation (GDA), four-actuator configuration is realized. Especially, only two of these should produce a force against gravity. A required force of these is less than half of whole weight. With this designing concept, a 73kg hexapod can walk with carrying a load of 76kg human onboard. A stroke of straight walk is up to 800mm, where the length of whole robot is 1428mm. An energy saving actuation technique, such as zero-air-consumption to keep its posture, brings a long working time of about two hours with a built-in compressor driven by a battery. The gait of this hexapod is a kind of tripod gait, but a state of all six leg contact to the terrain may not exist. Using a partial leg exchange sequence that we proposed, the robot can negotiate uneven terrain by only four actuators.
