Patent ID: 7378811

Claim:
A landing shock absorbing device of legged mobile robot moving by lifting and landing motions of a plurality of legs that can make contact with the ground though a ground-contacting face portion of a foot mechanism, respectively, the landing shock absorbing device comprising: a variable capacity element provided in the foot mechanism of each leg, each variable capacity element being compressed by undergoing a floor reaction force during the landing motion of an associated leg and being inflatable when no longer undergoing the floor reaction force at least by the lifting motion of the associated leg, thereby allowing fluid to flow into the variable capacity element with the inflation thereof and to flow out of an interior portion of the variable capacity element with the compression thereof, and an inflow/outflow means for communicating the fluid into the variable capacity element while inflating the variable capacity element in a lifting state of the associated leg and for communicating the fluid out of the variable capacity element with the compression of the variable capacity element caused by the floor reaction force, wherein outflow resistance is generated during the outflow of the compressible fluid in the variable capacity element by the inflow/outflow means, the landing shock absorbing device comprising inflation control means for controlling an inflow amount of the fluid into the variable capacity element by the inflow/outflow means depending on the gait type to change a size of the variable capacity element in a compression direction to become a predetermined size depending on a gait type of the legged mobile robot, when the variable capacity element is inflated in the lifting state of the associated leg, wherein the variable capacity element is constructed of a deformable bag-like member provided on a bottom face side of the foot mechanism of the associated leg to make contact with the ground ahead of the ground-contacting face portion of the foot mechanism of the associated leg during the landing motion of said associated leg.