Steering control unit
First Claim
1. A steering control unit comprising:
- a control unit that controls driving of a motor in response to a steering operation that a driver performs to operate a steering mechanism of a vehicle, the motor being a source of an assist force supplied to the steering mechanism, wherein the control unit is configured toobtain a vertical force that is information about a vertical load on a steered wheel of the vehicle, the vertical load being obtained by a bearing device that rotatably supports the steered wheel and that has a sensor for detecting a force applied to the steered wheel,calculate a torque command value that is a target for the assist force of the motor, the torque command including a multiplication of an assist component and a load compensation component,calculate the load compensation component in accordance with the vertical load, andcalculate the assist component, whereinthe assist force reduces the change in load on the driver that is caused when the vertical load on the steered wheel changes,the load compensation component is a compensation gain that has a linear relationship with change in the vertical force,the compensation gain is calculated in accordance with a percentage of change in the vertical force with respect to a predetermined reference value, andthe reference value is predetermined such that when the vertical force is equal to the reference value, it is not necessary to make compensation that reduces the change in load on the driver that is caused when the vertical load on the steered wheel changes.
1 Assignment
0 Petitions
Accused Products
Abstract
A steering control unit includes a microcomputer that controls the driving of a motor on the basis of a steering torque to cause the motor to produce an assist force that is supplied to a steering mechanism as power to steer front wheels. The microcomputer calculates, on the basis of the steering torque, an assist component indicative of the assist force that the motor needs to produce. The microcomputer obtains vertical forces related to the front wheels that are calculated by hub units that rotatably support the front wheels and have front wheel sensors for detecting forces applied to the front wheels. The microcomputer compensates the assist component by using the obtained vertical forces, to reduce a change in load on a driver that is caused when vertical loads on the front wheels change.
7 Citations
10 Claims
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1. A steering control unit comprising:
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a control unit that controls driving of a motor in response to a steering operation that a driver performs to operate a steering mechanism of a vehicle, the motor being a source of an assist force supplied to the steering mechanism, wherein the control unit is configured to obtain a vertical force that is information about a vertical load on a steered wheel of the vehicle, the vertical load being obtained by a bearing device that rotatably supports the steered wheel and that has a sensor for detecting a force applied to the steered wheel, calculate a torque command value that is a target for the assist force of the motor, the torque command including a multiplication of an assist component and a load compensation component, calculate the load compensation component in accordance with the vertical load, and calculate the assist component, wherein the assist force reduces the change in load on the driver that is caused when the vertical load on the steered wheel changes, the load compensation component is a compensation gain that has a linear relationship with change in the vertical force, the compensation gain is calculated in accordance with a percentage of change in the vertical force with respect to a predetermined reference value, and the reference value is predetermined such that when the vertical force is equal to the reference value, it is not necessary to make compensation that reduces the change in load on the driver that is caused when the vertical load on the steered wheel changes. - View Dependent Claims (2, 3, 4)
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5. A steering control unit comprising;
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a control unit that controls driving of a motor on a basis of an operation state quantity that changes in response to a steering operation that a driver performs to operate a steering mechanism of a vehicle, the motor being a source of an assist force supplied to the steering mechanism, wherein the control unit is configured to obtain a vertical force that is information about a vertical load on a steered wheel of the vehicle, the vertical load being obtained by a bearing device that rotatably supports the steered wheel and that has a sensor for detecting a force applied to the steered wheel, calculate a torque command value that is a target for the assist force of the motor, the torque command including a combination of a basic assist component, a basic compensation component, and a load compensation component, calculate the basic assist component, calculate the basic compensation component using values appropriate for conditions of the vehicle and the steering mechanism, and calculate the load compensation component to reduce a change in load on the driver that is caused when the vertical load on the steered wheel changes, wherein the load compensation component is a compensation gain that has a linear relationship with change in the vertical force, the compensation gain is calculated in accordance with a percentage of change in the vertical force with respect to a predetermined reference value, and the reference value is predetermined such that when the vertical force is equal to the reference value, it is not necessary to make compensation that reduces the change in load on the driver that is caused when the vertical load on the steered wheel changes. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification