Steering control system
First Claim
1. A steering control system comprising:
- a steering operation processing circuit that controls a controlled variable for a motor so as to apply a steering force for steering steered wheels to a steering device in response to an operation of a steering wheel, whereinthe steering operation processing circuit comprises;
a basic controlled variable calculation circuit that calculates a first component that is a basic component of the controlled variable for the motor, based on a vehicle speed value that is a detected value of a traveling speed of a vehicle and a steering torque that is a detected value of a load applied to the steering wheel;
a rotation angle command value calculation circuit that calculates a rotation angle command value for a rotary shaft of the motor, based on at least the vehicle speed value and a torque command value, the torque command value being a summation of the steering torque and the first component, and the rotation angle command value being convertible into a steered angle of the steered wheels;
a feedback calculation processing circuit that calculates a second component of the controlled variable for the motor, the second component being a difference between the rotation angle command value and a rotation angle of the rotary shaft, the second component being used to adjust a rotation angle of the rotary shaft to the rotation angle command value through feedback control, and the rotation angle of the rotary shaft being a detected value;
a control processing circuit that controls an operation of the motor based on the controlled variable for the motor, the controlled variable being a summation of the first component and the second component; and
a limited-state setting circuit that sets a first limited state when the vehicle speed is determined to be normal and the vehicle speed value is equal to or lower than a reference vehicle speed value that is a reference value at or below which it is determined that the vehicle is not traveling, the first limited state being a state where a variation range of the second component is more limited than when the vehicle speed value is higher than the reference vehicle speed value, whereinthe steering operation processing circuit sets the vehicle speed value to a provisional vehicle speed value that is higher than the reference vehicle speed value, during an abnormality determination period during which the vehicle speed value is determined to be abnormal,the basic controlled variable calculation circuit calculates the first component based on the provisional vehicle speed value during the abnormality determination period,during the abnormality determination period, when the vehicle speed is determined to be abnormal and the vehicle is not traveling, the limited-state setting circuit sets a second limited state, the second limited state being a state where the variation range of the second component is more limited than when the vehicle speed value is normal,the vehicle speed value is abnormal when;
(i) the vehicle speed value is stuck at a particular value;
or (ii) when the vehicle speed value is not equal to zero although a yaw rate of the vehicle indicates that the vehicle is stationary, and the vehicle speed value is normal when the vehicle speed value is not abnormal.
1 Assignment
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Accused Products
Abstract
The microcomputer calculates a first assist component based on a vehicle speed value and a steering torque, calculates a rotation angle command value based on at least the vehicle speed value and a first assist component, and calculates a second assist component by adjusting a rotation angle to the rotation angle command value through feedback control. The microcomputer sets a limited state 1 where the second assist component is disabled when a vehicle is stationary. During an abnormality determination period during which the vehicle speed value is determined to be abnormal, the microcomputer sets the vehicle speed value to a provisional vehicle speed value. Further, in a limited state 2 that is set when the vehicle is stationary during the abnormality determination period, the microcomputer calculates the first assist component based on a provisional vehicle speed value, and disables the second assist component.
10 Citations
6 Claims
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1. A steering control system comprising:
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a steering operation processing circuit that controls a controlled variable for a motor so as to apply a steering force for steering steered wheels to a steering device in response to an operation of a steering wheel, wherein the steering operation processing circuit comprises; a basic controlled variable calculation circuit that calculates a first component that is a basic component of the controlled variable for the motor, based on a vehicle speed value that is a detected value of a traveling speed of a vehicle and a steering torque that is a detected value of a load applied to the steering wheel; a rotation angle command value calculation circuit that calculates a rotation angle command value for a rotary shaft of the motor, based on at least the vehicle speed value and a torque command value, the torque command value being a summation of the steering torque and the first component, and the rotation angle command value being convertible into a steered angle of the steered wheels; a feedback calculation processing circuit that calculates a second component of the controlled variable for the motor, the second component being a difference between the rotation angle command value and a rotation angle of the rotary shaft, the second component being used to adjust a rotation angle of the rotary shaft to the rotation angle command value through feedback control, and the rotation angle of the rotary shaft being a detected value; a control processing circuit that controls an operation of the motor based on the controlled variable for the motor, the controlled variable being a summation of the first component and the second component; and a limited-state setting circuit that sets a first limited state when the vehicle speed is determined to be normal and the vehicle speed value is equal to or lower than a reference vehicle speed value that is a reference value at or below which it is determined that the vehicle is not traveling, the first limited state being a state where a variation range of the second component is more limited than when the vehicle speed value is higher than the reference vehicle speed value, wherein the steering operation processing circuit sets the vehicle speed value to a provisional vehicle speed value that is higher than the reference vehicle speed value, during an abnormality determination period during which the vehicle speed value is determined to be abnormal, the basic controlled variable calculation circuit calculates the first component based on the provisional vehicle speed value during the abnormality determination period, during the abnormality determination period, when the vehicle speed is determined to be abnormal and the vehicle is not traveling, the limited-state setting circuit sets a second limited state, the second limited state being a state where the variation range of the second component is more limited than when the vehicle speed value is normal, the vehicle speed value is abnormal when;
(i) the vehicle speed value is stuck at a particular value;
or (ii) when the vehicle speed value is not equal to zero although a yaw rate of the vehicle indicates that the vehicle is stationary, and the vehicle speed value is normal when the vehicle speed value is not abnormal. - View Dependent Claims (2, 3, 4, 5)
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6. A steering control system for controlling a controlled variable for a motor so as to apply a steering force for steering steered wheels to a steering device in response to an operation of a steering wheel comprising:
a computer programmed to; calculate a first component that is a basic component of the controlled variable for the motor, based on a vehicle speed value that is a detected value of a traveling speed of a vehicle and a steering torque that is a detected value of a load applied to the steering wheel; calculate a rotation angle command value for a rotary shaft of the motor, based on at least the vehicle speed value and a torque command value, the torque command value being a summation of the steering torque and the first component, and the rotation angle command value being convertible into a steered angle of the steered wheels; calculate a second component of the controlled variable for the motor, the second component being a difference between the rotation angle command value and a rotation angle of the rotary shaft, the second component being used to adjust a rotation angle of the rotary shaft to the rotation angle command value through feedback control, and the rotation angle of the rotary shaft being a detected value; control an operation of the motor based on the controlled variable for the motor, the controlled variable being a summation of the first component and the second component; and make a first determination of whether the vehicle speed value is normal or abnormal, the vehicle speed value being abnormal when;
(i) the vehicle speed value is stuck at a particular value;
or (ii) when the vehicle speed value is not equal to zero although a yaw rate of the vehicle indicates that the vehicle is stationary, and the vehicle speed value being normal when the vehicle speed value is not abnormal;make a second determination of whether or not the vehicle is traveling, by determining whether the vehicle speed value is equal to or lower than a reference vehicle speed value that is a reference value at or below which it is determined that the vehicle is not traveling; set a first limited state, a second limited state and a normal state based on the first determination and the second determination; when the first determination indicates that the vehicle speed value is normal and the second determination indicates that the vehicle is not traveling, set the first limited state, the first limited state being a state where the first component is calculated based on the vehicle speed value and the second component is calculated to be zero and disabled; when the first determination indicates that the vehicle speed value is abnormal and the second determination indicates that the vehicle is traveling, set the normal state, the normal state being a state where the first component is calculated based on a provisional vehicle speed value that is higher than the reference vehicle speed value, and the second component is calculated and enabled based on the first component; and when the first determination indicates that the vehicle speed value is abnormal and the second determination indicates that the vehicle is not traveling, set the second limited state, the second limited state being a state where the first component is calculated based on the provisional vehicle speed value and the second assist component is calculated to be zero and disabled.
Specification