Actuator gripping force estimation apparatus and method for estimating actuator gripping force

An actuator gripping force estimation apparatus that estimates, as a gripping force of a fluid pressure actuator, a force acting in a direction orthogonal to a tube axis of the fluid pressure actuator when the tube axis is not curved due to curvature, in which the fluid pressure actuator includes a tubular main body portion having a tube wall of which one side is shortened in a tube axis direction and curved due to an increase in internal pressure in a tube, a proximal end side along the tube axis which is fixed to a base body, and a distal end which moves relative to the base body, the actuator gripping force estimation apparatus comprising:

• a pressure sensor that acquires a tube internal pressure of the main body portion;
• a length acquisition unit that acquires a length from one end portion to another end portion of a side surface of the main body portion which has a largest shortened amount;
• and
• a gripping force estimation unit that estimates the gripping force using Equation F=ω1P(L−Lmin)+ω2, wherein L represents the length obtained by the length acquisition unit, P represents the internal pressure in the tube obtained by the pressure sensor, F represents the gripping force, ω1 and ω2 represent parameters set based on basic characteristics of the fluid pressure actuator, and Lmin represents a constant based on geometric properties of the fluid pressure actuator.