Patent ID: 9627996
Date: 2017-04-18
CPC Classifications: H01L

Claim:
1. A controller of a variable stiffness mechanism that includes a dielectric elastomer, the dielectric elastomer being interposed between a first member and a second member, which is relatively displaceable with respect to the first member, such that an elastic force is generated according to a relative displacement between the first member and the second member, and the dielectric elastomer also being configured such that a degree of stiffness thereof can be changed according to an applied voltage, the controller comprising: a power source which outputs a voltage applied to the dielectric elastomer such that the voltage can be variably controlled; a power source control unit which controls an output of the power source; and a capacitance estimating unit which sequentially estimates a capacitance of the dielectric elastomer, wherein the power source control unit is configured to carry out processing for setting a desired reference value of the applied voltage to meet a requirement related to the degree of stiffness of the dielectric elastomer in response to the requirement, processing for setting a desired value of the capacitance of the dielectric elastomer from the desired reference value and an observation value of an amount of the relative displacement between the first member and the second member based on a pre-established correlation among the voltage applied to the dielectric elastomer, the amount of relative displacement, and the capacitance of the dielectric elastomer, and processing for setting a desired value for control of an output voltage of the power source by correcting the desired reference value by a feedback manipulated variable determined based on a difference between the desired value of the capacitance and an estimated value of the capacitance obtained by the capacitance estimating unit such that the difference is approximated to zero, thereby controlling the output of the power source according to the desired value for control.