Power steering device
First Claim
Patent Images
1. A power steering apparatus comprising:
- a steering mechanism formed of an iron-series metallic material and which steers steerable wheels in accordance with a steering operation of a steering wheel;
an electrically driven motor which provides a steering force for the steering mechanism;
a speed reduction mechanism formed of the iron-series metallic material, interposed between the steering mechanism and the electrically driven motor, and which transmits a revolution force of the electrically driven motor to the steering mechanism;
a torque sensor which detects a steering torque generated in the steering mechanism;
a control unit which calculates a motor command current drivingly controlling the electrically driven motor on a basis of the steering torque and outputs the motor command current to the electrically driven motor;
a steering load average value calculating circuit installed in the control unit and which calculates an average value of a steering load corresponding value, the steering load corresponding value corresponding to any one of the steering torque within a predetermined interval of time, the motor command current, and a motor actual current actually flowing through the electrically driven motor; and
an abnormality detection circuit installed in the control unit, which compares the average value of the steering load corresponding value with a specified value stored in the control unit, and detects an abnormality of the apparatus when the average value is larger than the specified value,wherein the steering load average value calculating circuit stores a newest value of the average value of the steering load corresponding value into a non-volatile memory, when an ignition switch of a vehicle is turned off,wherein the steering load average value calculating circuit calculates the average value of the steering load corresponding value on a basis of an information of the average value of the steering load corresponding value stored in the non-volatile memory and the steering load corresponding value after the ignition switch is turned on, when the ignition switch of the vehicle is turned on, andwherein the steering load average value calculating circuit calculates the average value of the steering load corresponding value by making a weight of the average value of the steering load corresponding value stored in the non-volatile memory larger than the steering load corresponding value after the ignition switch is turned on.
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Abstract
A power steering apparatus includes: a steering load average value calculating circuit 39 which calculates a steering torque average value Trav which is the average value of steering torque Tr within a predetermined interval of time; and an abnormality detection circuit 40 which compares steering torque average value Trav with a specified steering torque value Trrf and detects the abnormality of the apparatus when steering torque average value Trav is larger than the specified value.
6 Citations
15 Claims
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1. A power steering apparatus comprising:
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a steering mechanism formed of an iron-series metallic material and which steers steerable wheels in accordance with a steering operation of a steering wheel; an electrically driven motor which provides a steering force for the steering mechanism; a speed reduction mechanism formed of the iron-series metallic material, interposed between the steering mechanism and the electrically driven motor, and which transmits a revolution force of the electrically driven motor to the steering mechanism; a torque sensor which detects a steering torque generated in the steering mechanism; a control unit which calculates a motor command current drivingly controlling the electrically driven motor on a basis of the steering torque and outputs the motor command current to the electrically driven motor; a steering load average value calculating circuit installed in the control unit and which calculates an average value of a steering load corresponding value, the steering load corresponding value corresponding to any one of the steering torque within a predetermined interval of time, the motor command current, and a motor actual current actually flowing through the electrically driven motor; and an abnormality detection circuit installed in the control unit, which compares the average value of the steering load corresponding value with a specified value stored in the control unit, and detects an abnormality of the apparatus when the average value is larger than the specified value, wherein the steering load average value calculating circuit stores a newest value of the average value of the steering load corresponding value into a non-volatile memory, when an ignition switch of a vehicle is turned off, wherein the steering load average value calculating circuit calculates the average value of the steering load corresponding value on a basis of an information of the average value of the steering load corresponding value stored in the non-volatile memory and the steering load corresponding value after the ignition switch is turned on, when the ignition switch of the vehicle is turned on, and wherein the steering load average value calculating circuit calculates the average value of the steering load corresponding value by making a weight of the average value of the steering load corresponding value stored in the non-volatile memory larger than the steering load corresponding value after the ignition switch is turned on. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A power steering apparatus comprising:
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a steering mechanism formed of an iron-series metallic material and which steers steerable wheels in accordance with a steering operation of a steering wheel; an electrically driven motor which provides a steering force for the steering mechanism; a speed reduction mechanism formed of the iron-series metallic material, interposed between the steering mechanism and the electrically driven motor, and which transmits a revolution force of the electrically driven motor to the steering mechanism; a torque sensor which detects a steering torque generated in the steering mechanism; a control unit which calculates a motor command current drivingly controlling the electrically driven motor on a basis of the steering torque and outputs the motor command current to the electrically driven motor; and an abnormality detection circuit, installed in the control unit, which compares a steering load corresponding value, the steering load corresponding value corresponding to any one of the steering torque within a predetermined interval of time, the motor command current, and a motor actual current actually flowing through the electrically driven motor with a specified value stored in the control unit, and which detects an abnormality of the apparatus when a frequency that the steering load corresponding value exceeds the specified value is larger than a predetermined value, wherein the control unit outputs the motor command current which has a smaller value than the motor command current when the abnormality of the apparatus is not present, when the abnormality detection circuit detects the abnormality of the apparatus. - View Dependent Claims (13, 14, 15)
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Specification