# US 5,140,238 A · Robot control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,140,238 A - Document ID: US5140238A - Status: Granted - Kind: A - Application number: 07/671,926 - Filed: 1991-03-20 - Granted: 1992-08-18 - Earliest claimed: 1990-03-20 - Assignees: Matsushita Electric Industrial Co., Ltd. - Inventors: Kenji Sogawa; Yoichi Sugitomo - Web page: https://patentgrep.com/patent/US5140238A ## CPC - B25J 9/1633: {compliant, force, torque control, e.g. combined with position control} - G05B 19/237: {with a combination of feedback covered by G05B19/232 - G05B19/235} - G05B 2219/37323: Derive acceleration from position or speed - G05B 2219/41166: Adaptive filter frequency as function of oscillation, rigidity, inertia load - G05B 2219/42066: Position and speed and acceleration and current feedback - G05B 2219/43152: Feed in, transfer line, rapid traverse to work, grip speed - 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 robot control apparatus includes a sine wave signal-outputting device, an operating device, a command device for outputting a current value, a substracting device, an electric power amplifying device, and a programmable filter. The outputting device outputs sine wave signals of first and second phases having a phase difference of approximate 90.degree. generated by a position shift of a movable portion of a motor for driving an arm of a robot. The operating device determines the difference between a product of a value corresponding to the first phase signal and a value obtained by first-order differentiating a value corresponding to the second phase signal and a product of a value corresponding to the second phase signal and a value obtained by first-order differentiating the value corresponding to the first phase signal. The subtracting device subtracts the current value from the value outputted from the operating device based on the current value, and outputs a signal corresponding to a result the subtraction. The amplifying device outputs a signal to supply electric power to the motor in response to the signal outputted from the subtracting device. A filter operates as one of a high-pass and a band-pass filters according to the difference outputted from the command device, and is provided between the outputting device and the operating device and operates as a high-pass filter when the arm starts moving and the band-pass filter operates when the arm stops in contact with an object, and outputs a signal to the operating device. ## Claims ### Claim 1 A robot control apparatus comprising: a sine wave signal-outputting means for respectively outputting two sine wave signals of a first phase and a second phase, of a predetermined frequency and having a phase difference of approximately 90.degree., said sine wave signals being generated by a position shift of a movable portion of a motor used for driving an arm of a robot; an operating means for determining a difference value between a first product of a just value corresponding to the sine wave signal having the first phase and a second value obtained by first-order differentiating a signal corresponding to the sine wave signal having the second phase, and a second product of a third value corresponding to the sine wave signal having the second phase and a fourth value obtained by first-order differentiating the signal corresponding tot he sine wave signal having the first phase; a command means for outputting a current value; a subtracting means for subtracting the current value outputted form the command means from the difference value outputted from the operating means based on the current value outputted by the command means, and for outputting a signal corresponding to a result of subtraction; an electric power amplifying means for outputting a signal to the motor in response tothe signal outputted from the subtracting means to supply electric power to the motor for driving the motor; and a programmable filter for operating as one of a high-pass filter and a band-pass filter according to the current value outputted for the command means, the programmable filter being provided between the outputting means and the operating means so that the programmable filter operates as a high-pass filter when the arm of the robot starts moving and the programmable filter operates as a band-pass filter when the arm of the robot stops in contact with an object, and for outputting a signal to the operating means, the signal having been inputted into the programmable filter and passed therethrough. ### Claim 2 (depends on 1) The robot control apparatus as claimed in claim 1, further comprising a current detecting means for detecting a value of current flowing to the motor and for inputting the detected current value into the subtracting means, wherein the subtracting means subtracts the current value outputted from the command means from the difference value outputted from the operating means while considering the detected current value detected by the current detecting means. ### Claim 3 (depends on 1) The robot control apparatus as claimed in claim 1, wherein the operating means performs second-order differentiation in which the first-order differentiated value is further differentiated by a first-order differentiation. ### Claim 4 (depends on 2) The robot control apparatus as claimed in claim 2, wherein the operating means performs second-order differentiation in which the first-order differentiated value is further differentiated by first-order differentiation.