# US 10,246,126 B2 · Feedback control apparatus, electrically driven 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 10,246,126 B2 - Document ID: US10246126B2 - Status: Granted - Kind: B2 - Application number: 15/506,022 - Filed: 2015-06-29 - Published: 2017-09-07 - Granted: 2019-04-02 - Earliest claimed: 2014-08-27 - Assignees: Hitachi Automotive Systems, Ltd. - Applicants: Hitachi Automotive Systems, Ltd. - Inventors: Nobuyasu Kanekawa; Ryoichi Kobayashi; Tomonobu Koseki; Tomishige Yatsugi - Web page: https://patentgrep.com/patent/US10246126B2 ## CPC - B62D 5/0481: {monitoring the steering system, e.g. failures} - B62D 5/0484: {for reaction to failures, e.g. limp home} - B62D 6/00: Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits (means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00) - G05B 9/02: electric - G05B 11/36: with provision for obtaining particular characteristics, e.g. proportional, integral, differential - G05B 11/42: for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D. - G05B 15/02: electric - 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) - 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 An object of the present invention is to realize a feedback control apparatus and an electrically driven power steering apparatus capable of safely continuing control operation even in the event of the occurrence of a soft error. A controller 202 of the present invention determines a d-axis target voltage Vd and a q-axis target voltage Vq, which are control values for controlling an output value of the electrically driven power steering apparatus on the basis of a d-axis error signal δId and a q-axis error signal δIq, which are input values. In this processing, in a period before the occurrence of the soft error, the controller 202 determines the d-axis target voltage Vd and the q-axis target voltage Vq by means of PID control that uses a current input value and a past input value. In a period after the occurrence of the soft error, the d-axis target voltage Vd and the q-axis target voltage Vq are determined by means of P control that uses a current input value but does not use a past input value. In a period after a lapse of the above period, the PID control is resumed. ## Claims ### Claim 1 A feedback control apparatus for determining a control value for controlling an output value on the basis of an input value depending on a difference between a target value and the output value, wherein in a first period before occurrence of a soft error, the control value is determined by means of first feedback control using a current input value and a past input value, in a predetermined second period after the occurrence of the soft error, the control value is determined by means of second feedback control using a current input value but not using a past input value, after a lapse of the second period, the first feedback control is resumed, and in the first feedback control, the control value is determined by adding up a calculation value obtained by multiplying the current input value by a predetermined first factor and a calculation value obtained by multiplying a value based on the past input value by a predetermined second factor, and in the second feedback control, the second factor is reduced to zero, and a value based on the past input value is not used. ### Claim 2 (depends on 1) The feedback control apparatus according to claim 1, wherein in a predetermined fourth, the second factor is gradually increased from zero to an initial value. ### Claim 3 (depends on 1) The feedback control apparatus according to claim 1, wherein in a predetermined fifth period in the second period, a cycle of the second feedback control is made longer than a cycle of the first feedback control. ### Claim 4 (depends on 1) The feedback control apparatus according to claim 1, wherein in the first period, PID control is performed as the first feedback control, and in the second period, P control is performed as the second feedback control. ### Claim 5 (depends on 1) The feedback control apparatus according to claim 1, wherein in the first period, feedback control based on an equation of state according to modern control theory is performed as the first feedback control and the second feedback control. ### Claim 6 (depends on 1) The feedback control apparatus according to claim 1, wherein after the soft error occurs, a value based on the past input value used in the first feedback control is reset. ### Claim 7 (depends on 1) An electrically driven power steering apparatus comprising: the feedback control apparatus according to claim 1; a motor for generating an assist torque to a steering mechanism; and an inverter for driving the motor on the basis of a control value determined by the feedback control apparatus. ### Claim 8 (depends on 7) The electrically driven power steering apparatus according to claim 7, further comprising a storage device for redundantly storing a magnetic pole position of the motor.