# US 8,786,228 B2 · Controller for electrical power steering apparatus

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- Number: US 8,786,228 B2
- Document ID: US8786228B2
- Status: Granted
- Kind: B2
- Application number: 13/398,140
- Filed: 2012-02-16
- Published: 2012-08-23
- Granted: 2014-07-22
- Earliest claimed: 2011-02-23
- Assignees: Jtekt Corporation
- Applicants: Hiroshi Kitamoto
- Inventors: Hiroshi Kitamoto
- Web page: https://patentgrep.com/patent/US8786228B2

## CPC

- B62D 5/0487: {detecting motor faults (B62D5/0496 takes precedence)}
- B62D 5/0481: {monitoring the steering system, e.g. failures}
- H02P 29/0241: {the fault being an overvoltage}
- H03K 17/18: Modifications for indicating state of switch
- H03K 17/6874: {in a symmetrical configuration}
- 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
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)

## Abstract

The electrical power steering apparatus 10 includes the 1st MOS-FET 13 and the 2nd MOS-FET 14 accommodating the 1st parasitic diode 15 and the 2nd parasitic diode 16 in the conducting path between the battery 100 and the motor driving circuit 11 and being connected in series at the opposite direction respectively, and the condenser 18 in an output side of the latter 2nd MOS-FET 14. The ECU 6 of the controller of the electrical power steering apparatus controls to turn on or off the 1st MOS-FET 13 and the 2nd MOS-FET 14 in accordance with the predetermined sequence after the ignition switch 17 is turned on, detecting the fault of the 1st MOS-FET 13, the 2nd MOS-FET 14 and the 1st parasitic diode 15 and the 2nd parasitic diode 16 on the basis of the output voltage from each of the 1st MOS-FET 13 and the 2nd MOS-FET 14.

## Claims

### Claim 1

A controller for a power steering apparatus comprising:
a motor supplying a steering assist force to said power steering apparatus for a vehicle;
a motor driving member outputting a driving power to said motor;
a battery supplying power voltage to said motor driving member;
an ignition switch turning on or off said battery;
a switching member mounted in a conducting path from said battery to said motor driving member; and
a condenser mounted at an input side of said motor driving member;
said switching member has two switching elements to turn on or off said conducting path by turning on or off according to a driving signal being input into a gate, and parasitic diodes mounted in parallel between a drain and a source of said switching elements, said switching elements are connected in series at the opposite direction respectively on said conducting path and are connected to said ignition switch;
a voltage detecting member detecting output voltage from each of said switching elements; and
a fault judging member judging faults of each of said switching elements and said parasitic diodes in accordance with each of said output voltages detected by said voltage detecting member.

### Claim 2 (depends on 1)

The controller for a power steering apparatus according to claim 1, wherein said switching member turns on or off said switching elements in a predetermined sequence after said ignition switch is turned on.