JPH0314768A - Motor-driven power steering device for car working also as automatic steering device - Google Patents

Abstract

PURPOSE:To have easy and safe garaging as well as parking in a row by continuing the automatic steering until the values from sensing become identical to the corresponding stored values in memory about the moving distance and steering angle, and actuating applicable motions only at braking with the car speed zero. CONSTITUTION:A motor 4 is controlled by a controller 3 on the basis of signals from a steering torque sensor 1 and a car speed sensor 2, and thereby power assist is given to a steering device 5. When a switch 9 is put on to set in the memory mode, the signals from a wheel rotational angle sensor 7 and a steering angle sensor 8 are stored in the memory device 3a of the controller 3 at certain time intervals. When another switch 10 is put on to set in the automatic steering mode, the control is performed so that the values from the sensors 7, 8 become identical to their corresponding stored values in memory. When the switches 9, 10 are put on, these motions shall be started only when a brake switch 11 to sense the braking condition is on.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric buff steering device/automatic steering device. Conventional technology In automobiles, in order to reduce the need for steering wheel operations during steering, a torque sensor is installed to detect the steering torque during steering operation, and this converts the steering torque into an electrical quantity. An electric power steering device has already been developed that variably controls the output of the electric device in response to changes in the steering torque and provides power assist in accordance with the steering torque (see, for example, Japanese Patent Laid-Open No. 195470/1983). Problems to be Solved by the Invention The present invention was made with the focus on the fact that the control of the electric device used in the electric puff steering device as described above is simpler than that of a hydraulic device. By using this electric device as a power source for steering in situations where it is necessary to take a nearly constant traveling trajectory and requires considerable skill to operate, such as when parking in a garage or parallel parking, The objective is to provide an automatic steering system that can easily park the vehicle in a garage or parallel park. Means for Solving the Problems The present invention provides a power assist control means for controlling voltage or current to an electric motor in connection with a steering operation and providing power assist to a steering mechanism by rotation of the electric motor; A signal processing and storage means that momentarily detects and stores the distance traveled by the vehicle from the reference stop position and the steering angle corresponding to the distance traveled by turning on the storage mode switch; an automatic steering control means that controls the electric motor according to the memorized content stored in the signal processing and storage means, and performs automatic steering according to a certain steering pattern by rotating the electric motor; The means is provided with operation start logic that starts operation when the memory mode switch is on, the vehicle speed is zero, and the brakes are applied, and the automatic steering control means is provided with operation start logic that starts the operation when the automatic steering mode switch is on, the vehicle speed is zero, and the brakes are applied. This feature is characterized by the provision of operation start logic that starts operation when the machine is in use. Operation When the steering method is constant, such as parking at the parking position specified above, once the distance traveled from the reference parking position and the steering angle corresponding to the distance traveled are memorized, After that, you can stop at the standard stop position, turn on the automatic steering mode switch, and press the accelerator pedal to start automatic steering, which frees you from the troublesome steering wheel operation. Not only can it prevent the automatic steering from being dangerous due to turning on the switch and rewriting the memory contents due to accidentally turning on the memory mode switch while driving, but also prevents the automatic steering from being overwritten by turning the automatic steering mode switch off. It is possible to perform the following functions. Examples Examples of the present invention will be explained below with reference to the accompanying drawings. The figure is a block diagram showing an embodiment of the present invention, in which 1 is a steering torque sensor that detects steering torque, 2 is a vehicle speed sensor that detects vehicle speed and emits a pulse according to the vehicle speed, and 3
is the controller of the electric puff steering device,
In normal bow assist operation, the controller 3 issues a motor current command value that gradually increases as the steering torque detected by the steering torque sensor 1 increases, and also adjusts the motor current command value according to the vehicle speed detected by the vehicle speed sensor 2. It is configured for variable control. 4 is an electric motor that rotates based on the motor current command value of the controller 3 and provides power assist to the steering device 5; 6 is a current detection section that detects the motor current flowing through the electric motor 4; The controller 3 performs feedback control through the controller. 7 is a wheel rotation angle sensor that detects the distance traveled by the vehicle, 8 is a steering angle sensor that detects the turning angle, 9 is a memory mode switch, 10 is an automatic steering mode switch, and 11 is a sensor that detects that the vehicle is in a braking state. This is a brake switch that The controller 3 is provided with operation start logic that starts operation by turning on the memory mode switch 9 when the vehicle speed sensor 2 detects that the vehicle has stopped and the brake switch l1 detects that the vehicle is in a braking state. and when the conditions of the operation start logic are satisfied, the vehicle's moving distance detected by the wheel rotation angle sensor 7 and the moving distance when parking in a garage or parallel parking is activated by steering by the driver. The steering angle detected by the steering angle sensor 8 is stored in the storage device 3a of the controller 3 every moment. The controller 3 includes an operation start logic that starts operation by turning on the automatic steering mode switch 10 when the vehicle speed sensor 2 detects that the vehicle has stopped and the brake switch l1 detects that the vehicle is in a braking state. When the condition of the operation start logic is satisfied, the vehicle travel distance detected by the wheel rotation angle sensor 7 and the steering angle obtained from the steering angle sensor 8 according to the travel distance are transmitted to the controller. 3 is configured to perform control such that the moving distance of the vehicle supplied from the storage device 3a of No. 3 is equal to the steering angle corresponding to the moving distance. The operations of the automatic steering system configured as described above in memory mode and automatic steering mode are as follows. First, a reference stop position is set at which to start garage parking or parallel parking operation, the vehicle is stopped at the reference stop position, and after a braking operation such as by depressing the brake pedal, the memory mode switch 9 is turned on to start the memory mode. Next, when the driver starts parking the garage or parallel parking by steering, the distance traveled by the vehicle from the reference stopping position and the steering angle corresponding to the distance are determined by the vehicle width rotation angle sensor 7 and the steering angle sensor. 8 and controller 3 is detected by interrupt processing.
The power assist operation is performed as usual based on the steering torque and vehicle speed detected by the steering torque sensor 1 and vehicle speed sensor 2. Next, if you want to use automatic steering to park your vehicle in a garage or parallel park, stop the vehicle at a preset standard stopping position, apply braking by depressing the brake pedal, etc., and then turn on the automatic steering mode switch lO, and the automatic steering will start. The mode starts. In this state, when the gear shift lever (not shown) is switched to the reverse side and the accelerator pedal (also not shown) is depressed, the vehicle starts parking in the garage or parallel parking. At this time, the controller 3 stores the moving distance of the vehicle detected by the wheel rotation angle sensor 7 and the steering angle obtained from the steering angle sensor 8 according to the moving distance in the storage device 3 of the controller 3.
Since the electric motor 4 is controlled so that the moving distance of the vehicle supplied from a is equal to the steering angle corresponding to the moving distance, the vehicle is in the storage mode in the storage device 3 of the controller 3.
The vehicle is automatically steered according to the travel distance stored in a and the steering angle corresponding to the travel distance. In the above, the return from the automatic steering mode to the normal power assist operation may be performed by the driver turning off the automatic steering mode switch 10 when the driver enters the garage or finishes the parallel parking operation, or by turning off the automatic steering mode switch 10 in the memory mode. 3
The automatic steering mode switch 10 may be automatically turned off when the memory contents stored by a are completed. In the above embodiment, the wheel rotation angle sensor 7 is used to determine the travel distance of the vehicle, but it can also be determined from the number of pulses of the vehicle speed sensor 2, which detects the vehicle speed and generates pulses corresponding to the vehicle speed. good. Further, in the above embodiment, an example was described in which the application is applied to an electric power steering device that performs power assist based on signals from a steering torque sensor and a vehicle speed sensor. Needless to say, this method can also be applied to an electric puff steering device that performs restoration control according to the detected steering angle, and in this case, there is no need to install a new steering angle sensor. Effects of the Invention As described above, according to the present invention, the power assist control means controls the voltage or current to the electric motor in connection with a steering operation, and provides power assist to the steering mechanism by the rotation of the electric motor. a signal processing and storage means that momentarily detects and stores the distance traveled by the vehicle from the reference stop position and the steering angle corresponding to the distance traveled by turning on the storage mode switch; and turning on the automatic steering mode switch. an automatic steering control means that controls the electric motor according to the stored contents stored in the signal processing and storage means and performs automatic steering according to a certain steering pattern by rotating the electric motor; The means is provided with operation start logic that starts operation when the memory mode switch is on, the vehicle speed is zero, and the brakes are applied, and the automatic steering control means is provided with operation start logic that starts the operation when the automatic steering mode switch is on, the vehicle speed is zero, and the brakes are applied. By providing an operation start logic that starts operation when the vehicle is stopped, when the steering method is constant, such as when parking in a garage or parallel parking, the vehicle can be moved once from the standard stopping position by turning on the memory mode switch. Once the distance and steering angle corresponding to the travel distance are memorized, automatic steering can be performed by simply stopping the vehicle at the standard stopping position, turning on the automatic steering mode switch, and depressing the accelerator pedal. In addition to freeing you from the troublesome steering wheel operation, it also prevents the risk of automatic steering due to the accidental turning on of the automatic steering mode switch while driving and the rewriting of the memory contents due to the accidental turning on of the memory mode switch while driving. In addition to ensuring that the automatic steering mode switch is turned off, the function of a normal electric power steering device can be fulfilled, and parts can be shared between the electric power steering device and the automatic steering device. This, combined with the fact that it is possible to achieve this goal and simplify the structure, can bring about great practical effects.

[Brief explanation of drawings]

The attached figure is a block diagram showing one embodiment of the present invention. 1... Steering torque sensor, 2... Vehicle speed sensor, 3...
... Controller, 3a... Storage device, 4... Electric motor, 5... Steering device, 6... Current detection section, 7.
...Wheel rotation angle sensor, 8...Steering angle sensor, 9...
・Memory mode switch, 10... Automatic steering mode switch, 11... Brake switch. that's all

Claims (1)

[Claims] A power assist control means that controls the voltage or current to the electric motor in connection with the steering operation and provides power assist to the steering mechanism by the rotation of the electric motor, and a power assist control means that controls the voltage or current to the electric motor in connection with the steering operation, and provides power assist to the steering mechanism by the rotation of the electric motor; a signal processing and storage means for momentarily detecting and storing the moving distance of the vehicle and the turning angle corresponding to the moving distance; and according to the memory contents stored by the signal processing and storage means by turning on the automatic steering mode switch. an automatic steering control means that controls the electric motor and performs automatic steering according to a certain steering pattern by rotating the electric motor;
The signal processing and storage means is provided with operation start logic that starts operation when the memory mode switch is on, the vehicle speed is zero, and the brakes are applied, and the automatic steering control means is provided with operation start logic that starts operation when the automatic steering mode switch is on and the vehicle speed is zero. An electric power steering device and automatic steering device for an automobile, characterized in that an operation start logic is provided to start operation when the brake is applied.