Abstract: An actuator subsystem preferably for a robot or bionic linkage. A joint between two robotic or bionic members includes at least first and second actuators such as piston-cylinder assemblies connected between the members. A hydraulic circuit includes a sensor subsystem for sensing the magnitude of the load on the piston-cylinder assemblies and/or members. A fluid supply system includes an actuatable control valve operable to supply fluid to one or both piston-cylinder assemblies. A control circuit is responsive to the sensor and is configured to electronically control the fluid subsystem to supply fluid to the first piston-cylinder assembly when the sensor subsystem senses a load below a predetermined magnitude and to supply fluid to both piston-cylinder assemblies when the sensor subsystem senses a load above the predetermined magnitude.

Abstract: An actuator subsystem preferably for a robot or bionic linkage. A joint between two robotic or bionic members includes at least first and second actuators such as piston-cylinder assemblies connected between the members. A hydraulic circuit includes a sensor subsystem for sensing the magnitude of the load on the piston-cylinder assemblies and/or members. A fluid supply system includes an actuatable control valve operable to supply fluid to one or both piston-cylinder assemblies. A control circuit is responsive to the sensor and is configured to electronically control the fluid subsystem to supply fluid to the first piston-cylinder assembly when the sensor subsystem senses a load below a predetermined magnitude and to supply fluid to both piston-cylinder assemblies when the sensor subsystem senses a load above the predetermined magnitude.

Abstract: A robot apparatus that is able to perform jumping. In a leg structure 110 of the robot apparatus, connecting bars 113, 114 and pivots 112a to 112d constitute a four-point link mechanism. A rod 117 is inserted into an opening formed in the distal end of a leg part 116. A coil spring 118 as an elastic member is provided between one end of the rod 117 and the distal end of the leg part 116. A bar member 120 is connected and secured to a preset point of a connecting member 115 as a knee joint. The coil spring 118 is extended/contracted by the stretching/contraction of the connecting member 115. By the operation of the four-point link mechanism, the trajectory of the distal end of the leg part is linear. The coil spring 118 is mounted at a position such that the distance between a driving shaft 101 and the distal end of the bar member 120 has a substantially linear relationship with respect to the force virtually operating between a driving shaft 101 and the distal end of the bar member 120.