Control device of variable stiffness mechanism

A control device of a variable stiffness mechanism which includes a first member and a second member, which are relatively displaceable with each other, and a plurality of dielectric elastomers interposed in parallel between the first member and the second member such that an elastic force is generated according to the relative displacement of the first member and the second member, and which is configured to be capable of changing a stiffness of each of the dielectric elastomers by variably manipulating a voltage to be applied to each of the dielectric elastomers, the control device comprising:

• a first power source that variably outputs a voltage for controlling the stiffness of each of an “m” number (m:
• an integer of 1 or more) of dielectric elastomers among the plurality of dielectric elastomers to each of the “m” number of the dielectric elastomers;
• a second power source that outputs a voltage signal which has a predetermined cycle for estimating an electrostatic capacitance of an “n” number (n:
• an integer of 1 or more) of dielectric elastomers among the plurality of dielectric elastomers excluding the “m” number of the dielectric elastomers, and which is for supplying a current correlated to the electrostatic capacitance of the “n” number of the dielectric elastomers to each of the “n” number of the dielectric elastomers;
• and
• an electrostatic capacitance estimating unit which acquires a detection value of an energizing current flowing between the second power source and the “n” number of the dielectric elastomers in a state in which the voltage signal is being output from the second power source, and which estimates the electrostatic capacitance of the “n” number of the dielectric elastomers by using the detection value of the energizing current.