# US 10,370,026 B2 · Method and apparatus for controlling motor driven power steering system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,370,026 B2 - Document ID: US10370026B2 - Status: Granted - Kind: B2 - Application number: 15/291,430 - Filed: 2016-10-12 - Published: 2017-04-13 - Granted: 2019-08-06 - Earliest claimed: 2015-10-12 - Assignees: Hyundai Mobis Co., Ltd. - Applicants: Hyundai Mobis Co., Ltd. - Inventors: Do Young Kim - Web page: https://patentgrep.com/patent/US10370026B2 ## CPC - B62D 5/0463: {calculating assisting torque from the motor based on driver input} - B62D 5/0469: {End-of-stroke control} - B62D 5/049: {detecting sensor failures} - B62D 5/0493: {detecting processor errors, e.g. plausibility of steering direction} - B62D 6/02: responsive only to vehicle speed - B62D 6/10: characterised by means for sensing {or determining} torque - B62D 15/0245: {Means or methods for determination of the central position of the steering system, e.g. straight ahead position} - 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) ## Abstract A method for controlling a motor driven steering system includes setting a reference point of a motor angle by a control unit, estimating a steering angular speed and a steering angle using the reference point by the control unit, determining whether the steering angle is included within a predetermined setting range by the control unit, and controlling an output torque of the motor driven steering system by the control unit using the steering angular speed and the steering angle, when the steering angle is included within the setting range. ## Claims ### Claim 1 A method for controlling a motor driven power steering system, comprising: setting, by a control unit, a reference point of a motor angle; estimating, by the control unit, a steering angular speed and a steering angle using the reference point; determining, by the control unit, whether the steering angle is included within a predetermined setting range, the predetermined setting range being set to a range of the steering angle before a collision occurs between a stopper of a rack-bar and an inner ball joint socket of a gear box set; and controlling, by the control unit, an output torque of the motor driven steering system using the steering angular speed and the steering angle, upon a determination that the steering angle is included within the setting range. ### Claim 2 (depends on 1) The method of claim 1, wherein setting the reference point of a motor angle comprises: determining whether a steering angle sensor is failed or not after an ignition of a vehicle is on, and setting the reference point of the motor angle using one of a steering angle inputted from the steering angle sensor and a steering angle stored when the ignition of the vehicle is off, according to a result of determining whether the steering angle sensor is failed or not. ### Claim 3 (depends on 2) The method of claim 2, wherein in setting a reference point of a motor angle, as a result of determining whether the steering angle sensor is failed or not, if the steering angle sensor is in a normal state, the reference point of the motor angle is set to an angle corresponding to the steering angle inputted from the steering angle sensor. ### Claim 4 (depends on 2) The method of claim 2, wherein in setting a reference point of a motor angle, as a result of determining whether the steering angle sensor is failed or not, if the steering angle sensor is in a fail state, the reference point of the motor angle is set using the steering angle stored when the ignition of the vehicle is off. ### Claim 5 (depends on 4) The method of claim 4, wherein setting a reference point of a motor angle comprises: determining whether the vehicle is in a straight-running state; setting the current steering angle to 0 if the vehicle is determined to be in the straight-running state; determining whether an error between the current steering angle and the steering angle stored when the ignition of the vehicle is off is equal to or greater than a setting error, setting the reference point of the motor angle on the basis of the current steering angle if the error of the steering angle is determined to be equal to or greater than the setting error; and setting the reference point of the motor angle on the basis of the steering angle stored when the ignition of the vehicle is off if the error of the steering angle is determined to be less than the setting error. ### Claim 6 (depends on 5) The method of claim 5, wherein controlling an output torque of the motor driven steering system such that the output torque decreases as the steering angle increases. ### Claim 7 (depends on 1) The method of claim 1, wherein controlling an output torque of the motor driven steering system comprises: detecting a predetermined current decouple gain corresponding to the steering angular speed and the steering angle; and compensating the output torque of the motor driven steering system by reflecting the current decouple gain to the output torque of the motor driven steering system. ### Claim 8 (depends on 1) The method of claim 1, wherein controlling an output torque of the motor driven steering system further comprises: detecting a predetermined vehicle speed gain corresponding to a speed of a vehicle; and compensating the output torque of the motor driven steering system by reflecting the vehicle speed gain to the output torque of the motor driven steering system. ### Claim 9 An apparatus for controlling a motor driven power steering system, comprising: a steering angle sensor configured to detect a steering angle of a steering wheel; and a control unit configured to set a reference point of a motor angle on the basis of the steering angle, estimate a steering angular speed and a steering angle using the reference point, and control an output torque of the motor driven steering system using the estimated steering angular speed and steering angle if the estimated steering angle is included within a predetermined setting range, the predetermined setting range being set to a range of the steering angle before a collision occurs between a stopper of a rack-bar and an inner ball joint socket of a gear box set. ### Claim 10 (depends on 9) The apparatus for controlling a motor driven steering system of claim 9, wherein in setting the reference point of the motor angle, the control unit determines whether the steering angle sensor is failed or not after an ignition of a vehicle is on, and sets the reference point of the motor angle using one of a steering angle inputted from the steering angle sensor and a steering angle stored when the ignition of the vehicle is off, according to a result of determining whether the steering angle sensor is failed or not. ### Claim 11 (depends on 10) The apparatus for controlling a motor driven steering system of claim 10, wherein in setting the reference point of the motor angle, the control unit sets the reference point of the motor angle in response to the steering angle inputted from the steering angle sensor if the steering angle sensor is in a normal state, and the control unit sets the reference point of the motor angle using the steering angle stored when the ignition of the vehicle is off if the steering angle sensor is in a fail state. ### Claim 12 (depends on 11) The apparatus for controlling a motor driven steering system of claim 11, wherein in setting the reference point of the motor angle, the control unit sets the current steering angle to 0 if the vehicle is in the straight-running state, and the control unit determines whether an error between the current steering angle and the steering angle stored when the ignition of the vehicle is off is equal to or greater than a setting error, sets the reference point of the motor angle on the basis of the current steering angle if the error of the steering angle is determined to be equal to or greater than a setting error, and sets the reference point of the motor angle on the basis of the steering angle stored when the ignition of the vehicle is off if the error of the steering angle is determined to be less than the setting error. ### Claim 13 (depends on 9) The apparatus for controlling a motor driven steering system of claim 9, wherein in controlling the output torque of the motor driven steering system, the control unit detects a predetermined current decouple gain corresponding to the steering angular speed and the steering angle, and compensates the output torque of the motor driven steering system by reflecting the current decouple gain to the output torque of the motor driven steering system. ### Claim 14 (depends on 9) The apparatus for controlling a motor driven steering system of claim 9, wherein in controlling the output torque of the motor driven steering system, the control unit detects a predetermined vehicle speed gain corresponding to the speed of a vehicle, and compensates the output torque of the motor driven steering system by reflecting the vehicle speed gain to the output torque of the motor driven steering system.