Patent ID: 8092402

Claim:
A power assist control method for controlling a power assist apparatus by a controller in such a way that a driver for applying force to an object outputs an assist force F or a speed F based on an assist target force X applied from outside and measured by force a detector for measuring force applied to the object, the power assist control method comprising: the controller commanding the driver to output the assist force F or the speed F by power assist control on the basis of a function f(X) having the assist target force X as a variable, wherein the function f(X) is a function which is an increasing function and whose derivative f′(X) is a decreasing function, and wherein the function f(X) is expressed by a formula 8 ( Formula ⁢ ⁢ 8 ) f ⁡ ( X ) = A · ( B · X + C ) 1 n + D where A and B are positive constants, C and D are constants, and n is a natural number not less than 2.