抄録
A power-assisted chair helps the user to stand up. The force directly acts on the user and soft actuation is thus important. In this paper, a virtual spring is proposed to realize the soft actuation. The seat is pushed up with a pneumatic cylinder, whose head pressure is controlled to be proportional to the seat angle. This leads to spring characteristics. Combination of a proportional pressure-reducing valve and a single rod cylinder is the key to realize the virtual spring. With its control, the seat behaves like a spring, and the spring constant and the pre-compression can be adjusted by the control. The virtual spring is examined experimentally to reveal its performance.
