Honda Motor Co., Ltd.

Leland Stanford Junior University

Atsuo Orita

Takahide Yoshiike

Mark R Cutkosky

Hiroyuki Kaneko

Masao Kanazawa

Hidefumi Nikawa

Tadaaki Hasegawa

Naoaki Sumida

Kenichiro Sugiyama

Yoshinari Takemura

A control device of a variable stiffness mechanism controls a total stiffness by variably outputting a voltage from a DC power sourceto an 'm' number of stiffness control elastomersamong a plurality of dielectric elastomersof a variable stiffness mechanism. Further, in a state in which a square-wave signal is being output from a square-wave power sourceto an 'n' number of electrostatic capacitance estimation elastomers, a detection value of energizing current is acquired and the acquired detection value is used to estimate an electrostatic capacitance.

Control device of variable stiffness mechanism

A device capable of measuring the capacitance of a dielectric elastomer by variably manipulating the voltage applied to the dielectric elastomer includes a capacitance estimating unit that acquires current detection values at a plurality of sampling times in a current reduction period in which, when an output voltage of a power source changes, an energizing current of a dielectric elastomer increases and then gradually decreases according to the change in the output voltage, and estimates the capacitance of the dielectric elastomer on the basis of a model representing a correlation between the time-dependent change of the energizing current and the capacitance of the dielectric elastomer in the current reduction period, and the current detection values.

Capacitance measuring device and capacitance measurement method for dielectric elastomer

An electrostrictive element that can prevent the breakage includes a current collector that is constituted by sheet-shaped carbon nanotube aggregates, and can expand in the fiber direction in a state in which carbon nanotubes overlap with each other, when a dielectric film expands.

Electrostrictive element

Provided are an electrostrictive element comprising film electrodes that have a good elasticity and conductivity, and a manufacturing method therefor. Film electrodesof an electrostrictive elementare sheet-shaped carbon nanotube aggregates, and can expand in the fiber direction while maintaining a state in which carbon nanotubesoverlap with each other, when the dielectric filmexpands.

Electrostrictive element and manufacturing method therefor

An actuator capable of preventing occurrence of insulation breakdown while achieving an appropriate operation performance of a dielectric elastomer is provided. Electrode films to be bonded to a dielectric elastomer are formed such that a characteristic of a change in thickness d of the elastomer with an increase in an applied voltage of the elastomer shows a first voltage range in which a decline rate of to the increase in is high and a second voltage range, including a voltage higher than the first voltage range, in which the decline rate of d to the increase in is low, and a voltage value at which the insulation breakdown of the elastomer occurs falls within the second voltage range.

Actuator including a dielectric elastomer and electrode films

The present invention provides an electrostrictive element capable of preventing breakdown of a dielectric film. An electrostrictive elementincludes a dielectric filmcomposed of an elastomer, a film electrodeformed inside a peripheral edge on at least one surface of the dielectric filmand capable of expanding and contracting so as to follow expansion and contraction of the dielectric film, and a frameto keep the dielectric filmin an expansion state. The film electrodeincludes portionshaving a lower conductivity or a portionhaving a higher rigidity than the other portion on a portion to be subjected to a greater total stress of a mechanical stress and an electrical stress than the other portion of the dielectric film

The present invention provides a spring mechanism which can elastically deform an elastic deformation part with a film shape of a transducer into a shape having high symmetry, and also can be structured in a small size. A spring mechanismincludes: a cylindrical memberthat is provided so as to extend toward a first element memberfrom an elastic deformation partof a transducerand also is arranged so as to slidably penetrate the first element memberin the direction of a central axis line C of the elastic deformation partand a rod memberthat is provided so as to extend toward the cylindrical memberfrom a second element memberside, and is slidably inserted in the cylindrical memberin the direction of the central axis line C of the elastic deformation part

Spring mechanism and linear motion displacement mechanism

Provided is a method of manufacturing an electrostrictive element by which an electrostrictive element including an expandable and contradictable film electrode having a thin and uniform thickness can be easily formed. In a method of manufacturing an electrostrictive element, screen printing is performed while a first jigcontacts with a face of a dielectric filmopposite to a face where screen printing is performed such that the first jigsurrounds an area where the screen printing is performed. Thus, a film electrodeis formed.

Electrostrictive element manufacturing method

A present invention provides a device capable of controlling a variable stiffness mechanism, which has a dielectric elastomer interposed between two members, so as to suppress an increase in the strain of the dielectric elastomer caused by the creep phenomenon. A power source control unitcorrects a reference supply voltage Vbase of an output voltage of a power source, which is determined on the basis of a desired degree of stiffness of a dielectric elastomer, by a feedback manipulated variable determined on the basis of a difference between a desired value of the capacitance of the elastomerand an estimated value thereof, thereby setting a desired value for controlling the output voltage of the power sourcein order to control the power sourceaccording to the desired value for control.

Controller of variable stiffness mechanism

A control deviceof a power transmission devicesets an allowable range of a temporal change rate of an inter-element driving force transmitted between a driving element(elastic member) and a driven elementsuch that the allowable range changes in accordance with an observed value of the amount of elastic deformation of the elastic member (driving element), and controls the inter-element driving force, via an actuator, in such a way as to restrict the temporal change rate of the inter-element driving force to be within the allowable range thus set.

Power transmission device

Provided is an inexpensive conductive paste composition capable of forming an electrode having a sufficient expansion and contraction property and conductivity as an membrane electrode for use in an electrostrictive element. The conductive paste composition comprises an electrode-forming component, and a solvent in an amount of 10% to 70% by mass with respect to the electrode-forming component. The electrode-forming component comprises, with respect to the total amount of the solids content of the electrode-forming component, 2.5% to 4.7% by mass of a conductive carbon material, 54% to 68% by mass of silicone rubber, 0.05% to 0.2% by mass of a curing catalyst composed of a platinum-siloxane complex, and 16% to 30% by mass of silica.

Conductive paste composition

By a control processing of the sliding-mode control using a switching function configured from a first variable component, which is a deviation between an observed value and a desired value of a secondary power imparted to a secondary element () from a primary element () via an elastic deformation member (), and a second variable component which is a temporal change rate of the deviation, so as to sequentially determine a control input to control an actuator () to converge the first variable component to zero on a switching hyperplane. A gradient of the switching hyperplane is set such that a time constant corresponding to the gradient of the switching hyperplane is equal to or larger than a given specific time constant.

Control device of power transmission device

Provided is a control device for a link mechanism capable of preventing a damage of joint mechanisms even in the case of a collision of a movable part against an external object. The control deviceincludes: a characteristic determination unitwhich determines desired stiffness k_cmd_i of an elastic elementof each joint mechanism Ji so as to be within a range of first stiffness k_i wherein the joint maximum elastic energy is equal to or more than joint collision kinetic energy to second stiffness k_i wherein a first time is equal to or longer than a second time; and a characteristic control unitwhich controls stiffness k_i of the elastic elementof each joint mechanism Ji to be the desired stiffness k_cmd_i.

Control device for link mechanism

A power transmission device has two roller members which are rotatable on their own axes and the outer peripheral portions of which are pressed against a wire member tightly stretched between two pulley members, a rotary gear which is rotatable around a revolution axial center of the roller members integrally with a supporting member which supports the roller members, a spring worm meshed with the rotary gear, and an actuator which controls the rotation amount of the spring worm.

A power devicehas a speed reducerand a spring memberprovided in a power transmission system between an actuatorand a driven element, an operation target of the actuatoris determined according to a linear combination of values that are obtained by passing through low-pass filters, a deviation &#x394;&#x3c9;between an estimated value &#x3c9;of a velocity of an input unitof the spring memberand an estimated value &#x3c9;of a velocity of the driven element, and a deviation &#x394;&#x3b8;def between a value &#x3b8;defof a deviation between the input unitof the spring memberand the driven element, and a target value &#x3b8;def_cmd of the displacement difference corresponding to a target driving force &#x3c4;ref of the driven element

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Wako, Japan

Atsuo Orita