# US 10,864,937 B2 · Electric power steering apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,864,937 B2 - Document ID: US10864937B2 - Status: Granted - Kind: B2 - Application number: 16/345,775 - Filed: 2017-03-30 - Published: 2020-02-20 - Granted: 2020-12-15 - Earliest claimed: 2017-03-30 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Munenori Yamamoto; Akihiko Mori; Jun Suzumura - Web page: https://patentgrep.com/patent/US10864937B2 ## CPC - B62D 5/0463: {calculating assisting torque from the motor based on driver input} - H02P 29/028: the motor continuing operation despite the fault condition, e.g. eliminating, compensating for or remedying the fault - B62D 5/0481: {monitoring the steering system, e.g. failures} - B62D 5/0484: {for reaction to failures, e.g. limp home} - B62D 5/0493: {detecting processor errors, e.g. plausibility of steering direction} - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - H02P 27/08: with pulse width modulation - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract When detecting an abnormality in a portion related to control of an electric motor, a CPU that calculates a control amount for controlling the electric motor calculates a control amount different from a control amount at a normal time so as to continue the control of the electric motor and changes a threshold value for detecting the abnormality to a value different from a value at a normal time. ## Claims ### Claim 1 An electric power steering apparatus comprising: an electric motor that produces assist torque, based on a steering torque produced by a driver of a vehicle; and a controller that controls the electric motor, wherein the controller includes an input circuit to which information to be utilized to control the electric motor is inputted, an inverter circuit that supplies an electric current to the electric motor, a CPU that calculates a control amount for controlling the electric motor, based on the information inputted to the input circuit, and outputs a command signal based on the control amount, and a driving circuit that drives the inverter circuit, based on the command signal outputted from the CPU, and wherein the CPU has an abnormality control mode in which, when detecting an abnormality in a portion related to control of the electric motor, the CPU calculates a control amount that is different at least from a control amount at a normal time, in accordance with the portion in which the abnormality has occurred and the contents of the abnormality, and then continues control of the electric motor; and when control of the electric motor is continued in the abnormality control mode, a threshold value for detecting the abnormality is changed to a value different from a value at a normal time, in accordance with the contents of the control in the abnormality control mode. ### Claim 2 (depends on 1) The electric power steering apparatus according to claim 1, wherein the threshold value has a hysteresis. ### Claim 3 (depends on 2) The electric power steering apparatus according to claim 2, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 4 (depends on 3) The electric power steering apparatus according to claim 3, wherein the abnormality determination time has a hysteresis. ### Claim 5 (depends on 1) The electric power steering apparatus according to claim 1, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 6 (depends on 5) The electric power steering apparatus according to claim 5, wherein the abnormality determination time has a hysteresis. ### Claim 7 An electric power steering apparatus comprising: an electric motor that produces assist torque, based on steering torque produced by a driver of a vehicle; and a controller that controls the electric motor, wherein the electric motor is provided with two sets of armature windings including a first armature winding and a second armature winding that are formed in substantially the same manner, wherein the controller is formed of two sets of controllers that are formed in substantially the same manner and that include a first controller formed in such a way as to be capable of independently controlling the first armature winding and a second controller formed in such a way as to be capable of independently controlling the second armature winding, wherein each of the first controller and the second controller has an input circuit to which information from a plurality of sensors is inputted, a driving circuit that generates a driving signal for driving the electric motor, an inverter circuit that is controlled by the driving signal, and a control circuit provided with a CPU that outputs a command signal for controlling the electric motor to the driving circuit, based on the information inputted to the input circuit, and wherein the CPU has an abnormality control mode in which when detecting an abnormality in part of the plurality of sensors, the CPU calculates a control amount that is different at least from a control amount at a normal time, in accordance with the sensor in which the abnormality has occurred and the contents of the abnormality, and then continues control of the electric motor; and when control of the electric motor is continued in the abnormality control mode, a threshold value for detecting the abnormality is changed to a value different from a value at a normal time, in accordance with the contents of the control in the abnormality control mode. ### Claim 8 (depends on 7) The electric power steering apparatus according to claim 7, wherein the CPU calculates the threshold value to which the value at a normal time is changed, based on a mutual inductance between the first armature winding and the second armature winding. ### Claim 9 (depends on 8) The electric power steering apparatus according to claim 8, wherein the threshold value has a hysteresis. ### Claim 10 (depends on 9) The electric power steering apparatus according to claim 9, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 11 (depends on 10) The electric power steering apparatus according to claim 10, wherein the abnormality determination time has a hysteresis. ### Claim 12 (depends on 8) The electric power steering apparatus according to claim 8, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 13 (depends on 12) The electric power steering apparatus according to claim 12, wherein the abnormality determination time has a hysteresis. ### Claim 14 (depends on 7) The electric power steering apparatus according to claim 7, wherein the threshold value has a hysteresis. ### Claim 15 (depends on 14) The electric power steering apparatus according to claim 14, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 16 (depends on 15) The electric power steering apparatus according to claim 15, wherein the abnormality determination time has a hysteresis. ### Claim 17 (depends on 7) The electric power steering apparatus according to claim 7, wherein the CPU is configured in such a way as to be capable of changing an abnormality determination time for detecting the abnormality. ### Claim 18 (depends on 17) The electric power steering apparatus according to claim 17, wherein the abnormality determination time has a hysteresis.