JP2725184B2 - Anti-spin control system for electric power steering - Google Patents

Description

The present invention relates to an anti-spin control system for electric power steering, and more particularly to an anti-spin control system for electric power steering that can prevent a vehicle from spinning.

[Conventional technology]

Some vehicles are equipped with a power steering in order to reduce the burden on the driver when steering the steering wheel. Some power steering systems include an auxiliary steering hydraulic pump, an auxiliary steering electric motor, and the like as auxiliary steering driving means for applying an auxiliary steering force. For example, JP-A-62-194973 discloses that an auxiliary steering electric motor is provided as an auxiliary steering driving means for applying an auxiliary steering force when the driver steers a steering wheel, and the driver uses the auxiliary steering electric motor to perform the operation. An electric power steering that gives an auxiliary steering force when steering a steering wheel is disclosed.

Some power steerings do not assist the steering with the assisting steering force given by the assisting steering driving means as described above, but steer the steered wheels only by the steering force given by the steering driving means. In this power steering, the steered wheels are steered to a required steering angle only by the steering force given by a steering driving means, for example, a steering electric means, according to the steering state of the steering wheel.

[Problems to be solved by the invention]

Incidentally, the steering direction and the steering angle of the steering wheel are determined by the driver's will. However, when the vehicle is traveling, when traveling on snowy roads with a low coefficient of friction on the road surface, when turning at a high vehicle speed, etc., the wheel grip is lost and the vehicle skids, resulting in an abnormal traveling state. Sometimes. In such a case, an inexperienced driver cannot take a countermeasure to calm down and operate the steering wheel in the direction opposite to the direction in which the vehicle skids, causing the vehicle to spin. .

[Object of the invention]

Therefore, an object of the present invention is to steer the steered wheels to an appropriate steering angle when the vehicle is in a spin state,
An object of the present invention is to realize an anti-spin control system for an electric power steering that can prevent a vehicle from spinning.

[Means for solving the problem]

In order to achieve this object, the present invention relates to a vehicle equipped with an electric power steering that steers a right front wheel and a left front wheel, which are steering wheels, by a steering force given by a steering electric means, and controls a steering state of a steering wheel of the vehicle. A steering angle sensor and a steering torque sensor are provided as steering state detecting means for detecting, a vehicle speed sensor is provided as vehicle speed detecting means for detecting a vehicle speed of the vehicle, and a right front wheel rotational speed is provided as spin state detecting means for detecting a spin state of the vehicle. A steering wheel motor as a steering electric means for providing a steering force for steering the right front wheel and the left front wheel, which are steering wheels of the vehicle, and a steering angle sensor, a steering torque sensor, and a vehicle speed sensor. And a detection signal from the right front wheel rotation speed sensor and the left front wheel rotation speed sensor, A control circuit is provided as control means for driving and controlling the motive, and a steering state of the steering wheel of the vehicle is set based on detection signals of the steering angle sensor, the steering torque sensor, the vehicle speed sensor, the right front wheel speed sensor, and the left front wheel speed sensor. Accordingly, the steering electric motor is driven and controlled to steer the right front wheel and the left front wheel, which are the steered wheels, to a required steering angle. If it is larger than the calculated allowable value, the steering motor is driven and controlled to steer the right front wheel and the left front wheel, which are the steered wheels, to an appropriate steering angle calculated from a steering angle and a rotation speed difference. And

[Action]

According to the configuration of the present invention, the right front wheel as the steered wheel according to the steering state of the steering wheel of the vehicle, based on the detection signals of the steering angle sensor, the steering torque sensor, the vehicle speed sensor, the right front wheel speed sensor, and the left front wheel speed sensor. And driving control of the steering motor to steer the left front wheel to the required steering angle, and the rotational speed difference at the required steering angle of the right front wheel and the left front wheel as the steered wheels is smaller than the allowable value calculated from the vehicle speed and the steering angle. When it is large, the steering wheel is controlled by driving the steering electric motor to steer the right front wheel and the left front wheel, which are the steered wheels, to an appropriate steering angle calculated from the steering angle and the rotation speed difference. The front right wheel, which is a steering wheel, can reduce the burden and can be steered even when the vehicle is skidding due to sideways skidding. A fine left front wheel can be steered to the correct steering angle of the direction in which the skidding of the vehicle.

〔Example〕

Next, an embodiment of the present invention will be described in detail with reference to the drawings. 1 to 4 show an embodiment of the present invention.

In FIG. 1, 2 is a vehicle, 4 is an internal combustion engine, 6 is a steering wheel, 8 is a steering shaft, 10 is a steering gear, 12 is a steering rack, 14r and 14l are steering wheels and right front which is a driving wheel. Wheels and left front wheels, 16r and 16l are driven rear right and left rear wheels. The driving force of the internal combustion engine 4 mounted on the vehicle 2 is transmitted from the transmission 18 via the drive axles 20r and 20l to the right front wheel 14r and the left front wheel 14l, which are the steered wheels and the drive wheels, and travels the vehicle 2. Let it.

The steering wheel 6 is mounted on a steering shaft 8. When the steering wheel 6 is steered, the rotational motion of the steering wheel 6 is transmitted to the steering gear unit 10 via the steering shaft 8. The steering gear unit 10 converts the rotational motion into a linear motion, transmits the linear motion to the steering rack unit 12, and reciprocates the tie rods 22r and 22l. By the reciprocating movement of the tie rods 22r and 22l, the right front wheel 14r and the left front wheel 14l are steered via the knuckle arms 24r and 24l.

This vehicle 2 includes an electric power steering. The electric power steering is the right front wheel that is the steering wheel.
A steering motor 40 is provided as steering electric means for applying a steering force for steering the 14r and the left front wheel 14l. The steering motor 40 includes a clutch reducer 42 including a clutch that transmits and disconnects an output and a reducer that increases the output, and is provided in the steering rack unit 12. The right front wheel 14r and the left front wheel 14l are steered by only the steering force provided by the steering motor 40.

This anti-spin control system for electric power steering includes a steering angle sensor 26 and a steering torque sensor as steering state detecting means for detecting the steering state of the steering 6.
28 are provided. The steering angle sensor 26 is provided in the steering rack unit 12, and detects a linear motion of the steering rack unit 12 as a steering angle of the right front wheel 14r and the left front wheel 14l. Further, the steering torque sensor 28 is provided in the steering gear section.
The steering wheel 6 is provided with a rotational force of the steering wheel 6 as steering torque.

The vehicle 2 is provided with a vehicle speed sensor 30 as vehicle speed detecting means for detecting a vehicle speed, and a right front wheel speed sensor as a speed sensor for detecting a driving wheel speed as a spin state detecting means for detecting a spin state of the vehicle 2. 32r and a left front wheel speed sensor 32l are provided. The vehicle speed sensor 30, for example, is provided in the transmission 18, and detects the output rotation speed of the transmission 18 as the vehicle speed. The right front wheel speed sensor 32r and the left front wheel speed sensor 32l are, as shown in FIGS.
A coil 34 is provided on each of the right front wheel 14r and the left front wheel 14l.
r (34l) and a magnet 36r (36l), and the right front wheel 14
The rotation speed of the rotor 38r (38l) that rotates together with r (the left front wheel 14l) is detected as the drive wheel rotation speed.

Detection signals from the steering angle sensor 26, the steering torque sensor 28, the vehicle speed sensor 30, and the right and left front wheel rotation speed sensors 22r and 32l are input to a control circuit 44 as control means. Control circuit
44 includes a signal control unit 46 and a drive control unit 48. The signal control unit 44 receives signals from the sensors 26 to 32 and outputs a control signal to the drive control unit 48. The drive control unit 48 outputs a drive signal to drive and control the steering motor 40.

That is, the control circuit 44 includes the steering angle sensor 26, the steering torque sensor 28, the vehicle speed sensor 30, and the right and left front wheel rotation speed sensors 32.
Based on the detection signal of r · 32l, the steering motor 40 is controlled to steer the right front wheel 14r and the left front wheel 14l, which are the steered wheels, to a required steering angle according to the steering state of the steering wheel 6. Further, the control circuit 44 includes a right front wheel which is a steering wheel.
If the rotational speed difference between the required steering angle of the front wheel 14r and the left front wheel 14l is larger than the permissible value calculated from the vehicle speed and the steering angle at this time, the right front wheel 14r and the left front wheel 14l as the steered wheels are provided.
Is controlled to drive the steering motor 40 to an appropriate steering angle calculated from the steering angle and the rotational speed difference at this time.

In FIG. 1, reference numeral 50 denotes an alternator,
52 is a battery.

 Next, the operation of the embodiment will be described with reference to FIG.

The control circuit 44 includes a steering angle sensor 26 and a steering torque sensor.
28, vehicle speed sensor 30, right and left front wheel speed sensors 32r and 32l
Based on the detection signal, the steering motor 40 is driven and controlled to steer the right front wheel 14r and the left front wheel 14l, which are the steered wheels, to a required steering angle according to the steering state of the steering wheel 6. Thereby, in response to the operation of the steering wheel 6 by the driver, the right front wheel 14r and the left front wheel 14l can be steered to the required steering angle only by the steering force given by the steering electric motor 40. Since the steering force of Step 6 can be reduced, the burden on the driver when operating the steering wheel can be reduced.

When the vehicle 2 skids and enters an abnormal running state,
Steering wheel, right front wheel 14r, regardless of driver's will
And automatically steers the left front wheel 14l to an appropriate steering angle.

As shown in FIG. 4, when the control starts (step 100), the control circuit 44 starts the right / left front wheel rotation speed sensor 32r.
・ Rear right front wheel 14r, which is always driven by 32l detection signal
Then, the rotation speed of the left front wheel 14l is detected and monitored (step 101), and it is determined whether or not the difference between the rotation speeds of the right front wheel 14r and the left front wheel 14l is large (step 102).

If the determination in step 102 is NO, the process jumps to step 111 and ends. If the determination in step 102 is YES, that is, if the rotational speed difference between the right front wheel 14r and the left front wheel 14l sharply changes greatly, the rotational speed difference is determined by the detection signals of the steering angle sensor 26 and the steering torque sensor 28 so that the steering wheel 6 (Step 10)
3) Yes. In other words, if the steering wheel 6 is in a straight-ahead operation even though the rotational speed difference is large, the vehicle 2 is skidding and spinning, so the process jumps to step 107 and executes steps 108 to 110 described later. I do.

On the other hand, when the steering wheel 6 is turned, YES
In the case of, the vehicle speed is detected based on the detection signal of the vehicle speed sensor 30 (step 104), and an allowable value of the rotational speed difference is calculated from a map of the vehicle speed and the steering angle set for each vehicle speed (step 105).
Then, it is determined whether or not the detected rotational speed difference is larger than an allowable value calculated from the vehicle speed and the steering angle at this time (step
106) Yes.

If the determination in step 106 is NO, the process jumps to step 111 and ends. If the determination in step 106 is YES, that is, if the detected rotational speed difference is larger than the allowable value calculated from the map of the vehicle speed and the steering angle at this time and the determination is YES, the vehicle 2 is skidding and spinning. Therefore, an optimum steering angle optimal for suppressing the slip is calculated from the steering angle and the rotational speed difference at this time (step 107), and the right front wheel 14r and the left front wheel 14l as the steered wheels are steered to the optimum steering angle. The drive of the steering motor 40 is controlled to achieve this.

The driving control of the steering motor 40 is performed until the steering angle and the steering torque are detected by the steering angle sensor 26 and the steering torque sensor 28 (step 109), and the detected values become larger than the set values (step 110, YES). . Thus, the current value and the driving direction of the steering motor 40 are controlled so that the steering angle becomes an appropriate steering angle regardless of the driver's intention.

In this way, when the vehicle 2 skids and enters the spin state, which is an abnormal running state, the right front wheel 14r and the left front wheel 14l, which are the steered wheels in the direction in which the vehicle 2 skids, are automatically set to the appropriate steering angle. Can be steered. For this reason, the spin of the vehicle 2 can be prevented, and the running stability can be improved.

Further, in a vehicle equipped with an electric power steering system that steers the steered wheels only by the steering force given by the steering motor 40 and an anti-skid control system, a program for the anti-spin control system is stored in the control means. Since it can be implemented only by adding, it is practically advantageous without causing a significant increase in cost.

In addition, despite the drive control of the steering motor 40 to steer the right front wheel 14r and the left front wheel 14l, which are the steered wheels at the proper steering angle, the driver steered in a direction opposite to the proper steering angle with a strong force. In such a case, the automatic steering to the appropriate steering angle is released, and the steering is performed according to the driver's will (steps 109 and 110).

〔The invention's effect〕

As described above, according to the present invention, the steering wheel is steered according to the steering state of the steering wheel of the vehicle based on the detection signals of the steering angle sensor and the steering torque sensor, the vehicle speed sensor, the right front wheel speed sensor, and the left front wheel speed sensor. The steering motor is driven and controlled to steer the right front wheel and the left front wheel to the required steering angle, and the rotational speed difference at the required steering angle of the right front wheel and the left front wheel as the steered wheels is an allowable value calculated from the vehicle speed and the steering angle. If it is larger than the steering wheel, the steering force of the driver's steering wheel is controlled by driving the steering motor to steer the right front wheel and the left front wheel, which are the steered wheels, to an appropriate steering angle calculated from the steering angle and the rotation speed difference. The right front wheel, which is the steering wheel, can be reduced even when the vehicle is skidding due to a side slip and an abnormal running state. It is possible to steer the left front wheel to the correct steering angle of the direction in which the skidding of the vehicle.

For this reason, the burden on the driver when operating the steering wheel can be reduced, and the spin of the vehicle can be prevented to improve running stability.

Also, in the case of a vehicle equipped with an electric power steering that steers the right front wheel and the left front wheel, which are the steered wheels only by the steering force given by the steering motor, a program for an anti-spin control system and a rotation speed sensor are added. This is practically advantageous without causing a significant increase in cost.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a plan view of a vehicle provided with an anti-spin control system for electric power steering, and FIG. 2 is a schematic perspective view of a front wheel portion provided with a vehicle speed sensor. FIG. 3 is an enlarged explanatory view of the vehicle speed sensor, and FIG. 4 is a flowchart of the control. In the figure, 2 is a vehicle, 4 is an internal combustion engine, 6 is a steering wheel, 14r is a right front wheel, 14l is a left front wheel, 16r is a right rear wheel, 16l is a left rear wheel, 26 is a steering angle sensor, and 28 is a steering torque sensor. , 30 is a vehicle speed sensor, 32r is a right front wheel rotation speed sensor, 32l is a left front wheel rotation speed sensor, 40 is a steering motor, 44 is a control circuit, 46 is a signal control unit, and 48 is a drive control unit.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B62D 137: 00 (56) References JP-A-62-210170 (JP, A) JP-A-63-28765 (JP) , A) JP-A-62-173372 (JP, A)

Claims (1)

(57) [Claims] 1. A vehicle equipped with an electric power steering system for steering a front right wheel and a front left wheel, which are steering wheels, by a steering force provided by an electric steering device, as steering state detecting means for detecting a steering state of a steering wheel of the vehicle. A right-front wheel speed sensor and a left-front wheel speed sensor as spin state detecting means for providing a steering angle sensor and a steering torque sensor, providing a vehicle speed sensor as vehicle speed detecting means for detecting the vehicle speed of the vehicle, and detecting a spin state of the vehicle; Provide a steering motor as a steering electric means for providing a steering force to steer the right front wheel and the left front wheel which are the steering wheels of the vehicle, the steering angle sensor and the steering torque sensor, the vehicle speed sensor, the right front wheel speed sensor and A control means for inputting a detection signal from a left front wheel speed sensor and controlling the driving of the steering motor; A control circuit is provided as the steering wheel sensor, a steering torque sensor, a vehicle speed sensor, a right front wheel rotation speed sensor, and a left front wheel rotation speed sensor, based on detection signals of the steering wheel of the vehicle according to a steering state of the steering wheel. And driving control of the steering motor to steer the left front wheel to a required steering angle, and a difference in rotation speed at the required steering angle between the right front wheel and the left front wheel as the steered wheels is determined from an allowable value calculated from the vehicle speed and the steering angle. The driving power of the steering motor is controlled to steer the right front wheel and the left front wheel, which are the steered wheels, to an appropriate steering angle calculated from a steering angle and a rotation speed difference. Spin control system.