Electric power steering control apparatus
First Claim
1. An electric power steering control apparatus comprising:
- a steering torque detection section that detects steering torque generated by a driver of a vehicle;
a motor that generates assist torque to assist the steering torque;
a rotational speed detection section that detects the rotational speed of the motor;
a torque control section that calculates an assist torque current corresponding to the assist torque based on the steering torque; and
a damping control section that calculates a damping current to be added to the assist torque current for suppressing vibrations generated in a steering system of the vehicle;
wherein the damping control section reduces a damping control gain for calculation of the damping current when a steering wheel is in a steering holding state or in a slight steering state that occurs when the rotational speed of the motor is equal to or less than a predetermined speed and there is less movement of the steering wheel,wherein the rotational speed detection section comprises;
at least one of a current detection section and an addition section;
a voltage calculation section;
a rotational speed estimation section;
a current detection section;
a voltage detection section; and
wherein the current detection section detects a motor drive current to be supplied to the motor;
the addition section calculates a target motor current to be supplied to the motor by adding the assist torque current and the damping current to each other;
the voltage calculation section calculates a target motor voltage to he impressed to the Motor;
the rotation speed estimation section estimates the rotational speed of the motor based on the target motor current or the motor target voltage, and based on the motor drive current;
the voltage detection section detects a motor drive voltage to be impressed to the motor; and
the rotation speed estimation section estimates the rotational speed of the motor based on the motor drive current and the motor drive voltage.
1 Assignment
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Accused Products
Abstract
An electric power steering control apparatus can reduce steering torque even in a steering holding state or a slight steering state without providing an unpleasant feeling to a driver. The apparatus includes a torque sensor for detecting steering torque generated by the driver for a vehicle, a motor for generating assist torque to assist the steering torque, a rotational speed detector for detecting the rotational speed of the motor, a torque controller for calculating an assist torque current corresponding to the assist torque based on the steering torque, and a damping control section for calculating a damping current to be added to the assist torque current to suppress vibrations generated in a steering system of the vehicle. The damping controller reduces a damping control gain to calculate the damping current when the rotational speed of the motor is equal to or less than a predetermined speed.
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Citations
8 Claims
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1. An electric power steering control apparatus comprising:
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a steering torque detection section that detects steering torque generated by a driver of a vehicle; a motor that generates assist torque to assist the steering torque; a rotational speed detection section that detects the rotational speed of the motor; a torque control section that calculates an assist torque current corresponding to the assist torque based on the steering torque; and a damping control section that calculates a damping current to be added to the assist torque current for suppressing vibrations generated in a steering system of the vehicle; wherein the damping control section reduces a damping control gain for calculation of the damping current when a steering wheel is in a steering holding state or in a slight steering state that occurs when the rotational speed of the motor is equal to or less than a predetermined speed and there is less movement of the steering wheel, wherein the rotational speed detection section comprises; at least one of a current detection section and an addition section; a voltage calculation section; a rotational speed estimation section; a current detection section; a voltage detection section; and wherein the current detection section detects a motor drive current to be supplied to the motor; the addition section calculates a target motor current to be supplied to the motor by adding the assist torque current and the damping current to each other; the voltage calculation section calculates a target motor voltage to he impressed to the Motor; the rotation speed estimation section estimates the rotational speed of the motor based on the target motor current or the motor target voltage, and based on the motor drive current; the voltage detection section detects a motor drive voltage to be impressed to the motor; and the rotation speed estimation section estimates the rotational speed of the motor based on the motor drive current and the motor drive voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification