摘要:
When it is determined that the torque output from the electric motor abnormally fluctuates or the torque output from the electric motor varies between clockwise and counterclockwise turning operations of the driver's steering wheel, the steering assist control is continued if the vehicle speed v is equal to or lower than the reference speed v0. In this case, the width of the dead band of the steering torque in the assist map used to calculate the target assist torque is increased. Thus, only in a case where the vehicle is moving at a low speed and the driver's steering wheel is operated with a great force, the steering assist torque is produced to alleviate the burden on the driver. In the other cases, the electric motor is stopped to minimize a sense of discomfort in the steering operation.
摘要:
When it is determined that the torque output from the electric motor abnormally fluctuates or the torque output from the electric motor varies between clockwise and counterclockwise turning operations of the driver's steering wheel, the steering assist control is continued if the vehicle speed v is equal to or lower than the reference speed v0. In this case, the width of the dead band of the steering torque in the assist map used to calculate the target assist torque is increased. Thus, only in a case where the vehicle is moving at a low speed and the driver's steering wheel is operated with a great force, the steering assist torque is produced to alleviate the burden on the driver. In the other cases, the electric motor is stopped to minimize a sense of discomfort in the steering operation.
摘要:
When it is determined that a malfunction has occurred in a rotational angle sensor, an electronic control unit changes the control manner from the normal assist control to the sensorless assist control. In the sensorless assist control, an assist stop command unit receives the information concerning the motor rotational angular speed ωm from an angular speed conversion unit. Then, the motor rotational angular speed ωm is compared with the threshold value ωm1. If the motor rotational angular speed ωm is equal to or higher than the threshold value ωm1, an assist enabling signal is transmitted to a PWM voltage production unit to continue the power assist. On the other hand, if the motor rotational angular speed ωm is lower than the threshold value ωm1, a stop command signal is transmitted to the PWM voltage production unit to stop the power assist.
摘要:
In a power supply apparatus, a power supply circuit includes a primary power supply circuit including a high-voltage battery and a step-down circuit for stepping down the voltage of the high-voltage battery, and a secondary power supply circuit including a low-voltage battery and a step-up circuit for stepping up the voltage of the low-voltage battery. The primary power supply circuit and the secondary power supply circuit are connected in parallel. An output voltage of the secondary power supply circuit is set to be lower than an output voltage of the primary power supply circuit. When the output voltage of the primary power supply circuit becomes lower than a target voltage of the secondary power supply circuit, the voltage stepped-up by the step-up circuit is supplied to a motor drive circuit. Accordingly, power supply backup of an electric power steering apparatus can be performed at low cost.
摘要:
The CPU calculates axial force matching external force that acts on a rack bar by combining steering torque MT that acts on a steering shaft with assist torque AT generated by an electric motor. The CPU then determines whether a vehicle is running straight based on a steering angle θ, a vehicle speed V, and the axial force F. Thus, even in a state where a control steering angle midpoint is deviated and a driver applies torque so as to return a turning position of a steering wheel to a neutral position, whether the vehicle is running straight can be accurately determined by making a determination by using the axial force F that acts on the rack bar. The CPU can set a considerably accurate control steering angle midpoint by calculating a smoothed steering angle midpoint by using an instantaneous steering angle midpoint in an accurately determined straight-running state.
摘要:
An electric power steering device, including an electric motor supplied with power from a power supply device to generate a predetermined steering assistance force for a steered wheel, and an assistance control device the controls the amount of electrical power supplied to the electric motor, according to the steering state of a steering wheel. The assistance control device detects the power supply voltage of the power supply device. The assistance control device controls the electrical current supplied to the electric motor, so as to maintain the power supply voltage greater than or equal to a set voltage which is set in advance.
摘要:
When it is determined that a malfunction has occurred in a rotational angle sensor, an electronic control unit changes the control manner from the normal assist control to the sensorless assist control. In the sensorless assist control, an assist stop command unit receives the information concerning the motor rotational angular speed ωm from an angular speed conversion unit. Then, the motor rotational angular speed ωm is compared with the threshold value ωm1. If the motor rotational angular speed ωm is equal to or higher than the threshold value ωm1, an assist enabling signal is transmitted to a PWM voltage production unit to continue the power assist. On the other hand, if the motor rotational angular speed ωm is lower than the threshold value ωm1, a stop command signal is transmitted to the PWM voltage production unit to stop the power assist.
摘要:
In a power supply apparatus 40, a power supply circuit is formed by a primary power supply circuit 50 which includes a high-voltage battery 51 and a step-down circuit 55 for stepping down the voltage of the high-voltage battery 51, and a secondary power supply circuit 60 which includes a low-voltage battery 61 and a step-up circuit 70 for stepping up the voltage of the low-voltage battery 61. The primary power supply circuit 50 and the secondary power supply circuit 60 are connected in parallel. An output voltage of the secondary power supply circuit 60 is set to be lower than an output voltage of the primary power supply circuit 50. When the output voltage of the primary power supply circuit 50 becomes lower than a target voltage of the secondary power supply circuit 60, the voltage stepped-up by the step-up circuit 70 is supplied to a motor drive circuit 32. Accordingly, power supply backup of an electric power steering apparatus can be performed as low cost.
摘要:
The CPU calculates axial force matching external force that acts on a rack bar by combining steering torque MT that acts on a steering shaft with assist torque AT generated by an electric motor. The CUP then determines whether a vehicle is running straight based on a steering angle θ, a vehicle speed V, and the axial force F. Thus, even in a state where a control steering angle midpoint is deviated and a driver applies torque so as to return a turning position of a steering wheel to a neutral position, whether the vehicle is running straight can be accurately determined by making a determination by using the axial force F that acts on the rack bar. The CPU can set a considerably accurate control steering angle midpoint by calculating a smoothed steering angle midpoint by using an instantaneous steering angle midpoint in an accurately determined straight-running state.
摘要:
An electric power steering device, including an electric motor supplied with power from a power supply device to generate a predetermined steering assistance force for a steered wheel, and an assistance control device the controls the amount of electrical power supplied to the electric motor, according to the steering state of a steering wheel. The assistance control device detects the power supply voltage of the power supply device. The assistance control device controls the electrical current supplied to the electric motor, so as to maintain the power supply voltage greater than or equal to a set voltage which is set in advance.