# US 9,757,834 B2 · Track control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,757,834 B2 - Document ID: US9757834B2 - Status: Granted - Kind: B2 - Application number: 14/374,576 - Filed: 2012-12-11 - Published: 2014-12-18 - Granted: 2017-09-12 - Earliest claimed: 2012-03-21 - Assignees: Mitsubishi Electric Corporation - Applicants: Kotaro Nagaoka - Inventors: Kotaro Nagaoka - Web page: https://patentgrep.com/patent/US9757834B2 ## CPC - B23Q 3/18: for positioning only - G05B 15/02: electric - G05B 19/404: characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia (G05B19/19, G05B19/41 take precedence) - G05B 2219/41189: Several axis, compensation for load for several axis at the same time - G05B 2219/41194: Axis error, one axis is corrected on other axis - B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT - 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 track control apparatus includes an interpolation/acceleration and deceleration calculating unit that interpolates a commanded route and calculates a post-acceleration and deceleration interpolation route, an axis distributing unit that generates a position command for each movable axis from the post-acceleration and deceleration interpolation route, a servo-response calculating unit that calculates a servo response to the position command, a tangential-direction-servo-response calculating unit that obtains a tangential direction servo response from the post-acceleration and deceleration interpolation route, a reference-point generating unit that obtains a reference point from the tangential direction servo response, a position-vector correcting unit that corrects the position command for each movable axis to output a post-correction position command for each movable axis, and a servo control unit that outputs motor driving torque such that each movable axis follows the corresponding post-correction position command. ## Claims ### Claim 1 A track control apparatus that controls a track of a movable part by simultaneously controlling motors for a plurality of movable axes, the track control apparatus comprising: a hardware processor configured to function as an interpolation/acceleration and deceleration calculator configured to interpolate a given commanded route and executes an acceleration and deceleration calculation along the commanded route, thereby calculating a post-acceleration and deceleration interpolation route; an axis distributor configured to generate a position command for each movable axis from the post-acceleration and deceleration interpolation route; a servo-response calculator configured to calculate, for each movable axis, a servo response of each movable axis on the basis of the position command for each movable axis; a tangential-direction-servo-response calculator configured to calculate a tangential direction servo response of a tangential direction movement amount on the basis of the post-acceleration and deceleration interpolation route; a reference-point generator configured to calculate a correction reference point from the tangential direction servo response; a position-vector corrector configured to calculate, on the basis of the servo response of each movable axis and the correction reference point, a correction vector for suppressing a track error and corrects the position command for each movable axis with the correction vector, thereby outputting a post-correction position command for each movable axis; and a servo controller configured to output motor driving torques to the motor for each movable axis respectively such that a position of each movable axis follow the post-correction position command for each movable axis. ### Claim 2 (depends on 1) The track control apparatus according to claim 1, wherein the servo-response calculator for each movable axis is independent for each movable axis, and is a filter whose response between an input and an output is the same as a position response of the corresponding movable axis respectively. ### Claim 3 (depends on 1) The track control apparatus according to claim 1, wherein the tangential-direction-servo-response calculator is a filter whose response between an input and an output is the same as a position response of each movable axis, and receives, as an input, a scalar value of a length along the commanded route from a start point of the commanded route to a post-acceleration/deceleration commanded position. ### Claim 4 (depends on 2) The track control apparatus according to claim 2, wherein the servo controller is independent for each movable axis, and the position response of the movable axis is a response characteristic of an input of the servo controller of the movable axis to a position signal of the motor for the movable axis. ### Claim 5 (depends on 2) The track control apparatus according to claim 2, wherein all the position responses for the movable axes are the same. ### Claim 6 (depends on 1) The track control apparatus according to claim 1, wherein the reference-point generator is configured to calculate, as the correction reference point, a point ahead of a start point of the commanded route by a length obtained by the tangential direction servo response along the post-acceleration and deceleration interpolation route. ### Claim 7 (depends on 1) The track control apparatus according to claim 1, wherein the position-vector corrector is configured to set, as the correction vector, a vector from a point determined by the servo response for each movable axis to the correction reference point and obtains, as the post-correction position command, a result obtained by adding the correction vector to a point determined by the position command. ### Claim 8 (depends on 3) The track control apparatus according to claim 3, wherein the servo controller is independent for each movable axis, and the position response of the movable axis is a response characteristic of an input of the servo controller of the movable axis to a position signal of the motor for the movable axis. ### Claim 9 (depends on 3) The track control apparatus according to claim 3, wherein all the position responses for the movable axes are the same.