# US 11,121,658 B2 · Motor control apparatus, image forming apparatus, and control method of motor control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,121,658 B2 - Document ID: US11121658B2 - Status: Granted - Kind: B2 - Application number: 16/199,621 - Filed: 2018-11-26 - Published: 2019-05-30 - Granted: 2021-09-14 - Earliest claimed: 2017-11-27 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Jumpei Ashida - Web page: https://patentgrep.com/patent/US11121658B2 ## CPC - H02P 21/14: Estimation or adaptation of machine parameters, e.g. flux, current or voltage - H02P 6/28: Arrangements for controlling current (H02P6/10 takes precedence) - H02P 21/26: Rotor flux based control - H02P 6/12: Monitoring commutation; Providing indication of commutation failure - H02P 25/089: Sensorless control (direct torque control H02P23/30) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract A parameter concerning rotation of a motor is estimated (first estimation). A parameter concerning rotation of the motor is estimated, based on a model representing a prescribed change in a rotation speed of the motor (second estimation). It is determined whether an anomaly has occurred in the rotation of the motor, based on the parameter estimated in the first estimation and the parameter estimated in the second estimation. ## Claims ### Claim 1 A motor control apparatus comprising: a first estimation unit configured to estimate a parameter concerning rotation of a motor; a second estimation unit configured to estimate a parameter concerning rotation of the motor, based on a model representing a prescribed change in a rotation speed of the motor; and a determination unit configured to determine that an anomaly has occurred in the rotation of the motor if an observation error of the parameter estimated by the first estimation unit is greater than an observation error of the parameter estimated by the second estimation unit; wherein the determination unit (i) calculates, as the observation error of the parameter estimated by the first estimation unit, difference between a voltage based on a circuit equation of a motor model and an induced voltage being the parameter estimated by the first estimation unit, and (ii) calculates, as the observation error of the parameter estimated by the second estimation unit, difference between the voltage based on the circuit equation of the motor model and an induced voltage being the parameter estimated by the second estimation unit. ### Claim 2 (depends on 1) The motor control apparatus according to claim 1, wherein the second estimation unit estimates the parameter concerning the rotation of the motor, based on a model representing a change of the rotation speed corresponding to loss of synchronism of the motor. ### Claim 3 (depends on 1) The motor control apparatus according to claim 1, wherein the model is a relative speed to a command speed of the rotation speed of the motor, and the second estimation unit performs estimation of the parameter concerning the rotation of the motor, based on the parameter estimated by the first estimation unit and the relative speed. ### Claim 4 (depends on 1) The motor control apparatus according to claim 1, further comprising: a second determination unit configured to determine whether an anomaly has occurred in the rotation of the motor with a simpler determination than the determination by the determination unit, wherein the second estimation unit, in a case where it is determined by the second determination unit that an anomaly has occurred in the rotation of the motor, estimates the parameter concerning the rotation of the motor, based on the model. ### Claim 5 (depends on 1) The motor control apparatus according to claim 1, further comprising: a second determination unit configured to determine whether an anomaly has occurred in the rotation of the motor, with a simpler determination than the determination of the anomaly by the determination unit, wherein the second estimation unit estimates the parameter concerning the rotation of the motor, based on a model that depends on a result of the determination by the second determination unit. ### Claim 6 (depends on 1) The motor control apparatus according to claim 1, further comprising: a calculation unit configured to calculate a phase and a speed concerning the rotation of the motor, based on the parameter estimated by the first estimation unit. ### Claim 7 (depends on 1) The motor control apparatus according to claim 1, further comprising: a calculation unit configured to calculate a phase and a speed concerning the rotation of the motor, based on a sum obtained by weighting the parameter estimated by the first estimation unit and the parameter estimated by the second estimation unit with likelihoods respectively corresponding to the parameters. ### Claim 8 (depends on 1) The motor control apparatus according to claim 1, wherein the first estimation unit and the second estimation unit estimate an induced voltage that occurs in the motor, as the parameter concerning the rotation of the motor. ### Claim 9 (depends on 1) The motor control apparatus according to claim 1, wherein the motor is a motor for driving a photoconductive drum and a transfer belt in an image forming apparatus. ### Claim 10 An image forming apparatus comprising: a motor; and a motor control apparatus including: a first estimation unit configured to estimate a parameter concerning rotation of the motor; a second estimation unit configured to estimate a parameter concerning rotation of the motor, based on a model representing a prescribed change in a rotation speed of the motor; and a determination unit configured to determine that an anomaly has occurred in the rotation of the motor if an observation error of the parameter estimated by the first estimation is greater than with an observation error of the parameter estimated by the second estimation unit; wherein the determination unit (i) calculates, as the observation error of the parameter estimated by the first estimation unit, difference between a voltage based on a circuit equation of a motor model and an induced voltage being the parameter estimated by the first estimation unit, and (ii) calculates, as the observation error of the parameter estimated by the second estimation unit, difference between the voltage based on the circuit equation of the motor model and an induced voltage being the parameter estimated by the second estimation unit. ### Claim 11 A control method of a motor control apparatus, comprising: performing a first estimation for estimating a parameter concerning rotation of a motor; performing a second estimation for estimating a parameter concerning rotation of the motor, based on a model representing a prescribed change in a rotation speed of the motor; and determining that an anomaly has occurred in the rotation of the motor if an observation error of the parameter estimated in the first estimation is greater than with an observation error of the parameter estimated in the second estimation; wherein in the determining (i) difference between a voltage based on a circuit equation of a motor model and an induced voltage being the parameter estimated in the first estimation is calculated as the observation error of the parameter estimated in the first estimation, and (ii) difference between the voltage based on the circuit equation of the motor model and an induced voltage being the parameter estimated in the second estimation is calculated as the observation error of the parameter estimated in the second estimation. ### Claim 12 (depends on 11) The control method of a motor control apparatus according to claim 11, wherein, in the second estimation, the parameter concerning the rotation of the motor is estimated, based on a model representing a change of the rotation speed corresponding to loss of synchronism of the motor. ### Claim 13 (depends on 11) The control method of a motor control apparatus according to claim 11, wherein the model is a relative speed to a command speed of the rotation speed of the motor, and in the second estimation, estimation of the parameter concerning the rotation of the motor is performed based on the parameter estimated in the first estimation and the relative speed. ### Claim 14 (depends on 11) The control method of a motor control apparatus according to claim 11, further comprising: performing a second determination for determining whether an anomaly has occurred in the rotation of the motor with a simpler determination than the determination, wherein, in the second estimation, in a case where it is determined in the second determination that an anomaly has occurred in the rotation of the motor, the parameter concerning the rotation of the motor is estimated, based on the model. ### Claim 15 (depends on 11) The control method of a motor control apparatus according to claim 11, further comprising: performing a second determination for determining whether an anomaly has occurred in the rotation of the motor, with a simpler determination than the determination of the anomaly in the determination, wherein, in the second estimation, the parameter concerning the rotation of the motor is estimated, based on a model that depends on a result of the determination in the second determination. ### Claim 16 (depends on 11) The control method of a motor control apparatus according to claim 11, further comprising: performing calculation for calculating a phase and a speed concerning the rotation of the motor, based on the parameter estimated in the first estimation. ### Claim 17 (depends on 11) The control method of a motor control apparatus according to claim 11, further comprising: performing calculation for calculating a phase and a speed concerning the rotation of the motor, based on a sum obtained by weighting the parameter estimated in the first estimation and the parameter estimated in the second estimation with likelihoods respectively corresponding to the parameters. ### Claim 18 (depends on 11) The control method of a motor control apparatus according to claim 11, wherein, in the first estimation and the second estimation, an induced voltage that occurs in the motor is estimated, as the parameter concerning the rotation of the motor. ### Claim 19 (depends on 11) The control method of a motor control apparatus according to claim 11, wherein a photoconductive drum and a transfer belt in an image forming apparatus are driven by the motor. ### Claim 20 (depends on 19) The control method of a motor control apparatus according to claim 19, wherein image forming s performed by the image forming apparatus.