The Hydraulic Infinite Linear Actuator, HILA, has been presented in , , and . The novel actuator consists of one, two or more double acting cylinders with a common piston rod and hydraulically detachable pistons. In the basic gait , alternatingly, one cylinder engages and drives the load while the other retracts, the HILA thus works in a kind of rope climbing motion. But the concept allows also other gaits, pattern of motion.
This contribution focuses on the ballistic gait, a pattern of motion where one cylinder engages to give the load a push. Then the load carries on with its motion by inertia, cylinders disengaged. The actuator realizes thus hydro-mechanical pulse-frequency modulation (PFM). This gait is energy efficient and able to recuperate energy.
Keywords: Novel actuator, infinite linear motion, digital fluid power, digital hydromechanical motion, energy recuperation