Steering mechanism control apparatus

Patent metadata

Field	Value
Publication number	US-10315689-B2
Application number	US-201715641546-A
Country	US
Kind code	B2
Filing date	Jul 5, 2017
Priority date	Jul 12, 2016
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A correction circuit receives a steering torque and an electric signal indicative of an operating state of a clutch. The correction circuit selectively uses a first correction value and a second correction value in accordance with the operating state of the clutch. The first correction value is set to correct deviation of the steering torque relative to its zero point when an exciting coil of the clutch is not energized. The second correction value is set to correct deviation of the steering torque relative to its zero point, caused by magnetic flux generated by energization of the exciting coil of the clutch. Adding the first correction value or the second correction value to the steering torque in accordance with the operating state of the clutch suitably corrects deviation of the steering torque relative to its zero point in accordance with the operating state of the clutch.

First claim

What is claimed is:

1. A control apparatus for controlling a steering mechanism, the steering mechanism including
an electromagnetic clutch to connect and disconnect a power transmission path between a steering wheel and a steered wheel in response to whether power is supplied to the electromagnetic clutch,
a reaction motor to generate a steering reaction, the steering reaction being a torque to be applied to a portion of the power transmission path between the steering wheel and the electromagnetic clutch in a direction opposite to a steering direction, and
a steering motor to generate a steering force, the steering force being power to be applied to a portion of the power transmission path between the electromagnetic clutch and the steered wheel so as to steer the steered wheel,
the control apparatus comprising:
a plurality of control circuits to control supply of power to each of the electromagnetic clutch, the reaction motor, and the steering motor, the plurality of control circuits being configured to calculate a current command value for at least one of the reaction motor and the steering motor in accordance with a quantity of state indicative of a steering state of the steering wheel magnetically detected by a sensor provided for the steering mechanism; and
a memory storing a first correction value set so as to reduce deviation of the quantity of state relative to a zero point of the quantity of state when the electromagnetic clutch is in an engaged state, and a second correction value set so as to reduce deviation of the quantity of state relative to the zero point of the quantity of state when the electromagnetic clutch is in a disengaged state, wherein
the plurality of control circuits include a correction circuit to correct the quantity of state using the first correction value when the electromagnetic clutch is in the engaged state, and correct the quantity of state using the second correction value when the electromagnetic clutch is in the disengaged state.

2. The control apparatus according to claim 1 , wherein
the electromagnetic clutch enters the disengaged state when power is supplied to the electromagnetic clutch, and enters the engaged state when supply of power to the electromagnetic clutch is stopped.

3. The control apparatus according to claim 2 , wherein
the second correction value is set in accordance with an amount of deviation of the quantity of state relative to the zero point of the quantity of state, the deviation being caused by influence of magnetic flux on the sensor, the magnetic flux being generated by supply of power to the electromagnetic clutch.

4. The control apparatus according to claim 1 , wherein
the quantity of state is a steering torque applied to a steering shaft through the steering wheel, the steering shaft being an element of the power transmission path.

5. The control apparatus according to claim 1 , wherein
the quantity of state is a steering angle applied to a steering shaft through the steering wheel, the steering shaft being an element of the power transmission path.

6. The control apparatus according to claim 4 , wherein
the sensor is a torque sensor to generate an electric signal responsive to the steering torque, and
the plurality of control circuits include a conversion circuit to calculate the steering torque in accordance with the electric signal generated by the torque sensor.

7. The control apparatus according to claim 4 , wherein
the sensor is a steering angle sensor to detect a steering angle, the steering angle being a rotation angle of the steering shaft, and
the plurality of control circuits include a conversion circuit to calculate the steering torque in accordance with the steering angle detected by the steering angle sensor.

8. The control apparatus according to claim 1 , wherein
an amount of energization to the electromagnetic clutch is constant, and
the correction circuit is configured to correct the quantity of state by adding the first or second correction value to the quantity of state.

Assignees

• Jtekt Corp

Inventors

• Kodera Takashi

Classifications

• B62D5/043

  characterised by clutch means between driving element, e.g. motor, and driven element, e.g. steering column or steering gear · CPC title

• B62D5/001 Primary

  Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup · CPC title

• B62D15/0245

  Means or methods for determination of the central position of the steering system, e.g. straight ahead position · CPC title

• B62D6/002

  computing target steering angles for front or rear wheels (B62D7/159 takes precedence) · CPC title

• B62D5/0478 Primary

  Clutches · CPC title