# US 8,739,618 B2 · Apparatus and method for determining deformation speed of elastic member, and actuator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,618 B2 - Document ID: US8739618B2 - Status: Granted - Kind: B2 - Application number: 13/549,733 - Filed: 2012-07-16 - Published: 2013-01-24 - Granted: 2014-06-03 - Earliest claimed: 2011-07-20 - Assignees: Honda Motor Co., Ltd. - Applicants: Atsuo Orita; Masao Kanazawa - Inventors: Atsuo Orita; Masao Kanazawa - Web page: https://patentgrep.com/patent/US8739618B2 ## CPC - B25J 9/1635: {flexible-arm control} - G05B 2219/41251: Servo with spring, resilient, elastic element, twist - B25J: MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES ({manipulators specially adapted for use in surgery A61B34/70; manipulators used in cleaning hollow articles B08B9/04}; manipulators associated with rolling mills B21B39/20; manipulators associated with forging machines B21J13/10; {manipulators associated with picking-up and placing mechanisms B23P19/007}; means for holding wheels or parts thereof B60B30/00; {vehicles with ground-engaging propulsion means, e.g. walking members B62D57/02, B62D57/032; devices for picking-up and depositing articles or materials between conveyors B65G47/90, B65G47/91; manipulators with gripping or holding means for transferring packages B65H67/065}; cranes B66C; {manipulators used in the protection or supervision of pipe-line installations F17D5/00; walking equipment adapted for nuclear steam-generators F22B37/006}; manipulators specially adapted for, or associated with, nuclear reactors G21C; {apparatus used for handling wafers during manufacture or treatment of semiconductor H10P72/50}) - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A driving speed Vd that is a speed of a driving force input point at which a driving force from a driving element is transmitted to an elastic member is acquired. An approximate rate Ve of change of an amount of elastic deformation Pe is computed based upon a plurality of values of the amount of elastic deformation Pe acquired as a quantized value at different points in time, by smoothing out an abrupt change in the values of the amount of elastic deformation Pe caused to appear by quantization. A deformation speed V is computed based upon the driving speed Vd and the approximate Ve by: V=A·(−Vd)+B·Ve where A is a coefficient increasing with increase in frequency of fluctuations in a position of the driving force input point, and B is a coefficient increasing with decrease in the frequency of fluctuations in the position of the driving force input point. ## Claims ### Claim 1 An apparatus for determining a deformation speed V that is a rate of change of an amount of elastic deformation of an elastic member that connects a driving element and a driven element to be actuated, the deformation speed V being determined based upon quantized values of the amount of elastic deformation, the apparatus comprising: a driving speed acquisition unit configured to acquire a driving speed Vd that is a speed at a driving force input point at which a driving force from the driving element is transmitted to the elastic member; a deformation amount acquisition unit configured to acquire an amount of elastic deformation Pe of the elastic member as a quantized value; an approximate rate computation unit configured to compute an approximate rate Ve based upon a plurality of values of the amount of elastic deformation Pe acquired at different points in time by the deformation amount acquisition unit, the approximate rate Ve being a rate of change of the amount of elastic deformation Pe obtained by smoothing out an abrupt change in the values of the amount of elastic deformation Pe caused to appear by quantization; and a deformation speed computation unit configured to compute the deformation speed V of the elastic member based upon the driving speed Vd acquired by the driving speed acquisition unit and the approximate rate Ve computed by the approximate rate computation unit, by the following formula: V=A·(−Vd)+B·Ve where A is a coefficient increasing with increase in frequency of fluctuations in a position of the driving force input point, and B is a coefficient increasing with decrease in the frequency of fluctuations in the position of the driving force input point. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein A+B=1. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein A=Ts/(Ts+1), and B=1/(Ts+1) where T is a time constant, and s is an independent variable. ### Claim 4 A method for determining a deformation speed V that is a rate of change of an amount of elastic deformation of an elastic member that connects a driving element and a driven element to be actuated, the deformation speed V being determined based upon quantized values of the amount of elastic deformation, the method comprising: acquiring a driving speed Vd that is a speed of a driving force input point at which a driving force from the driving element is transmitted to the elastic member; acquiring an amount of elastic deformation Pe of the elastic member as a quantized value; computing an approximate rate Ve based upon a plurality of values of the amount of elastic deformation Pe acquired at different points in time, the approximate rate Ve being a rate of change of the amount of elastic deformation Pe obtained by smoothing out an abrupt change in the values of the amount of elastic deformation Pe caused to appear by quantization; and computing the deformation speed V of the elastic member based upon the driving speed Vd and the approximate rate Ve, by the following formula: V=A·(−Vd)+B·Ve where A is a coefficient increasing with increase in frequency of fluctuations in a position of the driving force input point, and B is a coefficient increasing with decrease in the frequency of fluctuations in the position of the driving force input point. ### Claim 5 An actuator comprising: a driving element; a driven element to be actuated by a driving force transmitted from the driving element; an elastic member that is an elastically deformable member having a first end configured to receive the driving force from the driving element and a second end connected to the driven element, to transmit a motion of the driving element to the driven element; a driving element speed sensor configured to detect a speed of the driving element; a displacement sensor configured to detect an amount of elastic deformation Pe of the elastic member to output quantized values of the amount of elastic deformation Pe of the elastic member; and a deformation speed determination apparatus configured to determine a deformation speed V that is a rate of change of an amount of elastic deformation of the elastic member, based upon the speed of the driving element detected by the driving element speed sensor and the quantized values of the amount of elastic deformation Pe detected by the displacement sensor, wherein the deformation speed determination apparatus includes: a driving speed acquisition unit configured to acquire a driving speed Vd that is a speed of a driving force input point at which the driving force from the driving element is transmitted to the elastic member, based upon the speed of the driving element detected by the driving element speed sensor; a deformation amount acquisition unit configured to acquire the quantized values of the amount of elastic deformation Pe detected from the displacement sensor; an approximate rate computation unit configured to compute an approximate rate Ve based upon the quantized values of the amount of elastic deformation Pe acquired at different points in time by the deformation amount acquisition unit, the approximate rate Ve being a rate of change of the amount of elastic deformation Pe obtained by smoothing out an abrupt change in the values of the amount of elastic deformation Pe caused to appear by quantization; and a deformation speed computation unit configured to compute the deformation speed V of the elastic member based upon the driving speed Vd acquired by the driving speed acquisition unit and the approximate rate Ve computed by the approximate rate computation unit, by the following formula: V=A·(−Vd)+B·Ve where A is a coefficient increasing with increase in frequency of fluctuations in a position of the driving force input point, and B is a coefficient increasing with decrease in the frequency of fluctuations in the position of the driving force input point. ### Claim 6 (depends on 5) The actuator according to claim 5, further comprising a speed reducer disposed between the driving element and the elastic member to reduce an amount of motion of the driven element relative to an amount of the motion of the driving element. ### Claim 7 (depends on 5) The actuator according to claim 5, wherein A+B=1. ### Claim 8 (depends on 7) The actuator according to claim 7, wherein A=Ts/(Ts+1), and B=1/(Ts+1) where T is a time constant, and s is an independent variable. ### Claim 9 (depends on 6) The actuator according to claim 6, wherein the speed reducer includes strain wave gearing. ### Claim 10 (depends on 6) The actuator according to claim 6, wherein the driving speed acquisition unit includes a driving force input point speed computation unit configured to determine the speed of the driving force input point based upon an output of the driving element speed sensor and a reduction ratio of the speed reducer. ### Claim 11 (depends on 5) The actuator according to claim 5, wherein the displacement sensor includes an optical encoder which comprises an encoder plate and a photosensor.