JPH10211886A - Steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering device for a vehicle such that by performing steering suppression in accordance with a hazardous degree, a driver is made to recognize a condition in a periphery of the vehicle, thus to be assisted in safety driving operation. SOLUTION: In the periphery of a vehicle, a plurality of obstacle detection means 17A to 17F formed by a radar or the like are arranged, an obstacle in the periphery of a self vehicle is detected. In an obstacle recognition means 23, relating to one or a plurality of the obstacles, relative motion condition information comprising respectively an azimuth angle α(i), relative speed Vrel(i), distance d(i) is output. Based on the relative motion condition information, a potential hazardous degree (risk potential) R in this point of time is obtained. Based on the risk potential R, a target correction value IRL is generated, through a subtracter 29, a target value IT is corrected. Based on a corrected target value ITH, an electric motor is driven, by adjusting supply of auxiliary torque, steering is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering system, and more particularly to a vehicle steering system that detects an obstacle around the vehicle and suppresses the steering operation according to the degree of danger to the obstacle. Things.

[0002]

2. Description of the Related Art There is known an electric or hydraulic power steering apparatus which can turn a vehicle with a small steering force (manual steering force). FIG. 1 is a schematic structural view of an electric power steering device. The electric power steering device 1 includes an electric motor 10 in a steering system, and controls the power supplied from the electric motor 10 by using the control device 20 to reduce the steering force of the driver.

[0003] A steering shaft 3 integrally provided on a steering wheel (handle) 2 includes a universal joint 4.
The rack & pinion mechanism 5 is connected to a pinion 6 via a connection shaft 4 having a and b. The rack shaft 7 includes rack teeth 7a that mesh with the pinion 6. The rack and pinion mechanism 5 converts the rotation of the pinion 6 into a reciprocating motion of the rack 7 in the axial direction. Left and right front wheels 9 as rolling wheels are connected to both ends of the rack shaft 7 via tie rods 8. When the steering wheel 2 is steered, the front wheel 9 is swung via the rack and pinion mechanism 5 and the tie rod 8. Thereby, the direction of the vehicle can be changed.

In order to reduce the steering force, an electric motor 10 for supplying an assist torque (a steering assist torque) is connected to a rack shaft 7.
The rotation output of the electric motor 10 is converted into a thrust via the ball screw mechanism 11 and acts on the rack shaft 7. The ball screw mechanism 11 includes a nut 12 connected to a rotor of the electric motor 10 and a screw shaft 7b formed on the rack shaft 7. The turning power of the nut 12 is converted into an axial thrust of the rack shaft 7 by the screw shaft 7b. The manual steering force is reduced by converting the assist torque generated by the electric motor 10 into a thrust to the rack shaft 7 and transmitting the thrust.

[0005] Steering torque detecting means (steering torque sensor)
18, the manual steering torque TP acting on the pinion 6
And a steering torque signal Tp related to the detected steering torque TP is supplied to the control device 20. Control device 20
Is a motor drive signal VM based on the steering torque signal Tp.
And output power of the motor 10 (steering assist torque)
Control.

FIG. 2 is a block diagram showing a specific example of a conventional control device. The conventional control device 20 includes a target assist torque determination unit 21 and a motor drive unit 22. The target assist torque determining unit 21 determines a target assist torque based on the steering torque signal Tp, and outputs a target assist torque signal IT
Is output. If the absolute value of the steering torque is smaller than a preset dead threshold, the target assist torque determination unit 21 sets the target assist torque to zero. If the steering torque exceeds the dead threshold, the target assist torque determination unit 21 outputs a target assist torque proportional to the steering torque. The target assist torque determination unit 21 limits the output target assist torque so as not to exceed a preset upper limit value even when the steering torque increases.

The motor drive unit 22 includes a target auxiliary torque signal IT supplied from the target auxiliary torque determination unit 21 and a motor current signal supplied from a current detection unit (not shown) for detecting a current actually flowing through the motor 10. IM and a motor drive signal V so that the obtained deviation becomes zero.
M is generated and output, and the electric motor 10 is driven so that a target auxiliary torque is supplied from the electric motor 10.

A steering angle detecting means 19 for detecting the steering angle θS is provided, and a steering rotation speed is calculated based on a steering angle signal θs corresponding to the steering angle θS output from the steering angle detecting means 19, and The target auxiliary torque I according to the rotation speed
There has also been proposed a control device that corrects T to control not only the steering force but also the assist torque including the steering speed. This makes it possible to improve the response of the generation of the steering assist torque to the manual steering. Also, a control device that corrects the magnitude of the assist torque according to the vehicle speed has been proposed. This makes it possible to prevent the steering force from becoming too light during high-speed running.

Japanese Patent Application Laid-Open No. HEI 4-19274 discloses that an obstacle such as another vehicle traveling behind a vehicle is detected, and when a driver tries to steer in the direction of the obstacle, power assist ( There is described a vehicle steering apparatus in which a steering assist force of a power steering apparatus is reduced and a steering operation force is increased to suppress a steering operation.

Japanese Patent Application Laid-Open No. Hei 8-2434 discloses that when a driver performs a steering operation, a steering assist force is applied when the front of the vehicle is not in a dangerous state and the rear side of the vehicle is in a dangerous state. There is described a steering apparatus for a vehicle in which the steering wheel is not provided.

JP-A-8-207811 discloses that when an obstacle sensor detects that an obstacle exists around the vehicle and a steering operation is performed in the detection direction, the vehicle is steered toward the obstacle. An electric power steering device that changes an assist current value supplied to an electric motor so as not to be performed is described.

Japanese Patent Laid-Open Publication No. Hei 8-175413 discloses that when danger is predicted by danger prediction means for predicting danger due to approach of an obstacle, a target control value for driving an electric motor is periodically changed so that steering can be performed. There is described an electric power steering device that vibrates a wheel to warn a driver.

[0013]

However, the steering devices and the like described in the above-mentioned publications determine the presence or absence of an obstacle and whether the approach state is dangerous or not, and based on the result of the determination, assist the steering. Since the force is controlled, there is a problem that it is difficult for the driver to understand the degree of danger.
Further, in some cases, the steering assist force may be suddenly suppressed during steering, which causes a problem of giving the driver an uneasy feeling.

The present invention has been made to solve such a problem, and performs steering suppression according to the degree of danger so that the driver can recognize the situation around the vehicle, thereby supporting safe driving operation. It is an object of the present invention to provide a steering device for a vehicle.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a vehicle steering system according to the present invention comprises: an obstacle detecting means for detecting an obstacle present around a host vehicle; and a signal from the obstacle detecting means. Obstacle detection means for detecting the position, distance, and relative speed of the obstacle with respect to the own vehicle based on the vehicle, danger determination means for determining the degree of danger based on a signal from the obstacle recognition means, and danger determination means And a steering suppression unit that suppresses the steering operation based on the signal of.

It is to be noted that a steering state detecting means for detecting a steering state may be provided, and the steering suppressing means may suppress the steering operation based on signals from the danger determining means and the steering state detecting means.

The vehicle further includes a steering state detecting means for detecting a steering state, and a movement state estimating means for estimating the movement state of the vehicle based on a signal from the steering state detecting means. The steering operation may be suppressed based on signals from the means, the steering state detecting means, and the motion state estimating means.

The obstacle detecting means detects an obstacle around the own vehicle. The obstacle recognition means obtains the position, distance, and relative speed of the obstacle. The risk determining means obtains the risk based on the position, distance, and relative speed of the obstacle. The steering suppression means adjusts the degree to which the steering operation is suppressed according to the degree of danger. This makes it possible to continuously vary the degree of suppressing steering according to the degree of danger.

It is to be noted that the steering state detecting means is provided, and the steering suppressing means is configured to suppress the steering operation based on the degree of danger and the steering state, so that the degree of suppressing the steering according to the intensity of the steering is determined. Can be variable.

Further, the vehicle includes a motion state estimating means for estimating the motion state of the vehicle, and the steering suppressing means suppresses the steering operation based on the degree of danger, the steering state, and the motion state of the vehicle. The degree of suppression of steering can be changed according to the degree of danger including the behavior of.

As described above, the steering apparatus for a vehicle according to the present invention can adjust the degree of suppression of steering according to the degree of danger, so that the driver can recognize the surrounding situation and support safe driving operation. be able to.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 3 is an overall configuration diagram of a vehicle steering system according to the present invention. Obstacle detecting means 17A to 17F are provided at appropriate positions on the outer peripheral portion of the vehicle 13. In FIG. 3, an obstacle detecting unit 17A having a detection area on the right front of the vehicle, an obstacle detecting unit 17B having a detection area on the left front of the vehicle, and an obstacle detecting means 17C having a detection area on the right side of the vehicle. And obstacle detection means 17D having a detection area on the left side of the vehicle, obstacle detection means 17E having a detection area on the right rear side of the vehicle, and obstacle detection means 17F having a detection area on the left rear side of the vehicle. Six obstacle detecting means 17
A to 17F show the configuration for detecting an obstacle existing around the vehicle 13, but the position and number of the obstacle detection means are arbitrary.

The obstacle detecting means 17A to 17F are constructed using radar. Obstacle detection means 17A to 17F
May be configured using a sonar using an ultrasonic wave, a television camera, or the like. Each of the obstacle detecting means 17A to 17F includes:
An obstacle existing in each detection area is detected. Obstacle detection signals S (i) (S
a to Sf) are supplied to the control device 30.

The steering torque detecting means 18 and the steering angle detecting means 1 provided in the steering gear box 14 are provided.
The steering torque signal Tp and the steering angle signal θs which are the respective detection outputs of No. 9 are supplied to the control device 30. The steering torque detecting means 18 and the steering angle detecting means 19 constitute a steering state detecting means for detecting a steering state. Instead of the steering angle detecting means 19, a steering rotational speed detecting means for outputting a detection signal corresponding to the angular velocity may be used.

The steering torque detecting means 18 and the steering angle detecting means 19 may be provided at a connecting portion 2a between the steering wheel 2 and the steering shaft. The vehicle speed signal from the vehicle speed sensor 15 and the yaw rate signal from the yaw rate sensor 16 may be supplied to the control device 30 as needed. 9F is a front wheel, 9R is a rear wheel, and 10 is an electric motor.

FIG. 4 is a block diagram of a control device for a vehicle steering system according to the present invention. The control device 30 includes a target assist torque determining unit 21, an electric motor driving unit 22, an obstacle recognizing unit 23, a risk determining unit 40, and a gain unit 2.
7, output limiting means 28, and a subtractor 29. The gain means 27, the output limiting means 28, and the subtractor 29 constitute a steering suppression means described in the claims.
The obstacle recognition unit 23 includes an azimuth angle detection unit 24, a relative speed detection unit 25, and a distance detection unit 26.

Each obstacle detection signal S (i) of each of the obstacle detection means 17A to 17F is supplied to the obstacle recognition means 23. The obstacle recognizing means 23 outputs each of the obstacle detection signals S (i)
The relative motion state between each obstacle and the own vehicle is calculated based on. Specifically, each of the obstacle detection signals S (i) is transmitted to the azimuth angle detection means 24, the relative speed detection means 25, and the distance detection means 2
6 respectively. The azimuth detecting means 24 calculates an azimuth indicating the azimuth where the obstacle exists based on each obstacle detection signal S (i), and outputs an azimuth signal α (i) related to the obtained azimuth. The relative speed detection means 25 calculates the relative speed between the obstacle and the own vehicle based on each obstacle detection signal S (i), and calculates the relative speed signal Vrel based on the obtained relative speed.
(I) is output. The distance detecting means 26 calculates the distance between the obstacle and the own vehicle based on each obstacle detection signal S (i),
A distance signal d (i) related to the obtained distance is output. The relative motion state information (azimuth angle signal α (i), relative speed signal Vrel (i), distance signal d (i)) between the own vehicle and each obstacle obtained in this way is supplied to the risk degree determination means 40. You.

Based on the relative motion state information (azimuth angle signal α (i), relative speed signal Vrel (i), distance signal d (i)), the risk degree determining means 40 determines the potential risk degree ( (Risk potential) R is output.

FIG. 5 is a block diagram of the risk determining means. The risk determination means 40 includes a risk function function 41
, Divider 42, weighting function means 43, and multiplier 4
4 and an adder 45. The azimuth signal α (i) is supplied to the weighting function means 43. Relative speed signal Vrel
(I) is supplied to the risk degree function means 41. The distance signal d (i) is supplied to the divider 42.

The risk degree function means 41 outputs a risk degree value 41a associated in advance according to the relative speed between the vehicle and the obstacle. The relative speed is represented by a positive sign when the own vehicle and the obstacle are approaching each other, and a negative sign when the own vehicle is away from the obstacle. The risk degree function means 41 is configured to output a larger risk degree value 41a when the relative speed has a positive sign and the value increases. The risk degree value 41a is supplied to the divider 42. The divider 42 divides the risk degree value 41a by the distance d (i) between the vehicle and the obstacle for which the risk degree value 41a was obtained, and outputs a normalized risk degree value 42a. Normalized risk degree value 4
2a is supplied to a multiplier 44.

The weighting function means 43 stores a weighting coefficient W set in advance corresponding to the azimuth. The weighting function means 43 may calculate and output the weighting coefficient W based on an arithmetic expression registered in advance. Based on the azimuth angle signal α (i), the weighting function unit 43 calculates a weighting coefficient corresponding to the azimuth angle α (i) at which the obstacle for which the risk degree value 41a and the normalized risk degree value 42a are found exists. Outputs W. The weighting coefficient W is supplied to the multiplier 44.

The multiplier 44 multiplies the normalized risk value 42a of a certain obstacle by a weighting coefficient W corresponding to the direction in which the obstacle exists, and normalizes the multiplication result. The weighted risk degree value 44a is output. The normalized and weighted risk degree value 44a is supplied to the adder 45. The adder 45 adds the normalized and weighted risk degree values 44a to all the obstacles i recognized by the obstacle recognition means 23, and obtains the sum of the risk degree values 44a for the individual obstacles. , And outputs the calculated sum as a risk potential R.

To summarize the above, the risk potential R is the relative motion state information (the azimuth signal α) of the obstacle.
(I), relative speed signal Vrel (i), distance signal d
For (i)), it is defined as Equation 1.

[0034]

(Equation 1)

Here, considering that the impact when colliding with an obstacle greatly depends on the relative speed, the relative speed Vre is taken into consideration.
It is desirable that the function f of l (i) is an odd function including third-order and higher-order terms. The constant k is a correction term relating to the distance d (i).

The thus obtained risk potential R
Represents the potential degree of danger to the result when the driver performs a steering operation input at the position where the own vehicle is present at that time. For example, when a driver performs a steering operation on a risk potential field in a direction in which an approaching obstacle exists, that is, in a direction in which the risk potential increases, a steering assist force according to the magnitude of the risk potential. Or
A steering reaction force can be applied.

FIG. 6 is an explanatory diagram showing a procedure from the detection of an obstacle to the calculation of a risk potential field. In step 2, the obstacle detection signal S (i) obtained by the obstacle detection means 17A to 17F is used in step 2 by the obstacle recognition means 23 to obtain the relative motion state information of the obstacle (the azimuth angle signal α (i), Speed signal Vrel (i), distance signal d
Converted to (i)), a risk potential field representing a potential danger degree according to the relative state is calculated in step 3. In FIG. 6A, the traveling direction of each vehicle is indicated by an arrow, and the speed is represented by the length.
In FIG. 6B, the direction of each obstacle (other vehicle) with respect to the own vehicle is indicated by an arrow, and the direction of the arrow indicates whether the obstacle is approaching or away, and the length of the arrow indicates the relative speed. I have. FIG. 6C shows the risk potential in contour display. FIG. 6 (c) shows that the thinner the hatching, the higher the risk potential.

As shown in FIG. 4, the risk potential R obtained by the risk determining means 40 is supplied to the gain means 27. The gain means 27 multiplies (or divides) the risk potential R by a preset coefficient, and outputs a target value correction signal IR. Gain means 27
May be constituted by a conversion table between the risk potential R and the target value correction signal IR. Target value correction signal IR
Is supplied to the output limiting means 28.

The output limiting means 28 limits the magnitude of the target value correction signal IR so as not to hinder the driver's steering operation in an emergency avoidance operation or the like. The output limiting unit 28 may stop outputting the target value correction signal IR when a steering input exceeding a preset steering torque value continues for a preset time or more.

The target correction signal I whose upper limit value (the maximum value on the positive side and the maximum value on the negative side) is limited by the output limiting means 28.
The RL is supplied to the subtractor 29. The subtractor 29 subtracts the target correction signal IRL from the target auxiliary torque signal IT when the target auxiliary torque signal IT is output from the target auxiliary torque determination unit 21 (adds the target correction signal IRL if the target correction signal IRL is negative), The result of the subtraction (addition) is output as a corrected target auxiliary torque signal ITH. The corrected target assist torque signal ITH is supplied to the motor drive unit 22.

The motor drive unit 22 calculates a deviation between the corrected target auxiliary torque signal ITH and a motor current signal IM supplied from a motor current detecting means (not shown), and calculates the motor drive signal VM so that the deviation approaches zero. Is generated and output, and the electric motor 10 is operated.

The risk potential R or the target correction signal IR is varied in accordance with the vehicle speed in consideration of the difference in safety margin (safety zone) such as the vehicle interval between low-speed running and high-speed running. It is desirable that

FIG. 7 is a block diagram of another control device of the vehicle steering system according to the present invention. The control device 50 shown in FIG. 7 is obtained by adding a correction coefficient generation gain means 51 and a multiplier 52 to the control device 30 shown in FIG. In the control device 30, the correction coefficient generating gain means 51, the multiplier 52, the gain means 27, the output limiting means 28, and the subtractor 2
9 constitutes the steering suppression means described in the claims. The steering torque detecting means 18 constitutes a steering state detecting means described in claims.

The steering torque signal Tp output from the steering torque detecting means 18 is supplied to a target assist torque determining unit 21 and a correction coefficient generating gain means 51. The correction coefficient generation gain means 51 outputs a correction coefficient KR corresponding to the steering torque. The correction coefficient generating gain means 51 multiplies (or divides) the steering torque Tp by a preset coefficient.
As a result, the correction coefficient KR is output. The correction coefficient generation gain means 51 may be configured by a conversion table of the steering torque Tp and the correction coefficient KR. The correction coefficient KR is calculated by the multiplier 52
Supplied to The multiplier 52 calculates the risk potential R
Is multiplied by a correction coefficient KR, and the multiplication result RH (R · K
R) is supplied to the gain means 27.

The correction coefficient generating gain means 51 and the multiplier 5
2, the value of the risk potential R is corrected in accordance with the steering torque Tp, so that the steering reaction force is adjusted in accordance with the magnitude of the driver's steering input, in other words, in accordance with the time allowed before contact with an obstacle. Can be varied. The driving operation amount input to the correction coefficient generation gain means 51 includes a differential value of steering torque (a change amount of the steering torque per unit time) and a steering rotation speed (a change amount of the steering angle per unit time). May be used.

FIG. 8 is a block diagram of still another control device of the vehicle steering system according to the present invention. The control device 60 shown in FIG. 8 adds a lateral displacement and a lateral displacement speed calculating / estimating means 61 to the control device 50 shown in FIG. ,
A risk determining means 70 for calculating a risk potential R based on the relative speed signal Vrel (i), the distance signal d (i)), the lateral displacement speed Δyd, and the lateral displacement Δy is provided. The steering torque detecting means 18 and the steering angle detecting means 19 constitute a steering state detecting means described in the claims. The lateral displacement and lateral displacement speed calculating / estimating means 61 constitutes a motion state estimating means for estimating the motion state of the vehicle based on a signal from the steering state detecting means described in the claims.

FIG. 9 is a block diagram showing a specific example of the lateral displacement and lateral displacement speed calculating / estimating means. The lateral displacement and lateral displacement speed calculating / estimating means 61 includes a filter means 6
2 and a pre-stage integrator 63 and a post-stage integrator 64. The filter means 62 is configured to output a lateral acceleration whose transfer function G (s) is expressed by Equation 2 with respect to the steering input θs of the vehicle.

[0048]

(Equation 2)

The steering angle signal θs output from the steering angle detecting means 19 is supplied to the filter means 62. The vehicle speed signal Sv output from the vehicle speed sensor 15 is supplied to the filter means 62. The filter means 62 determines the steering angle θs and the vehicle speed S
and calculates a lateral acceleration generated according to v and outputs a lateral acceleration signal ydd. The lateral acceleration signal ydd is supplied to the integrator 63 in the preceding stage. The pre-stage integrator 63 converts the lateral acceleration into a lateral displacement speed by integrating the lateral acceleration signal ydd, and outputs a lateral displacement speed signal Δyd. Post-stage integrator 6
4 converts the lateral displacement speed into a lateral displacement by integrating the lateral displacement speed signal Δyd, and outputs a lateral displacement signal Δy.

FIG. 10 is a block diagram of the risk determining means. The risk determining means 70 is obtained by adding a relative motion state information correcting means 71 to the risk determining means 40 shown in FIG. The relative motion state information correcting means 71 calculates the relative motion state information (azimuth angle signal α (i), relative speed signal Vre) of the obstacle based on the lateral displacement speed Δyd and the lateral displacement Δy.
1 (i), the distance signal d (i)), and outputs a corrected azimuth signal Hα (i), a corrected relative speed signal HVrel (i), and a corrected distance signal Hd (i). This risk determination means 7
0 is the corrected signals Hα (i), HVrel
(I), risk potential R based on Hd (i)
Is output.

The control device 60 shown in FIG. 8 multiplies the risk potential R output from the risk determining means 70 by a correction coefficient to obtain a multiplication result RH, and based on the multiplication result RH, a target correction signal IR. And the target correction signal IR
The target auxiliary torque signal IT is corrected by the signal IRL in which the output is limited, and the electric motor 10 is operated based on the corrected target auxiliary torque signal ITH.

By performing such control, it is possible to determine the degree of danger while predicting the behavior of the own vehicle due to the driver's steering input. Therefore, safe driving operation can be supported more effectively.

The relative movement state information correcting means 71 shown in FIG. 10 is controlled by a throttle opening detecting means and the like in addition to the lateral displacement speed Δyd and the lateral displacement Δy generated based on the steering angle signal θs. The acceleration signal generated based on the detected throttle opening and the braking operation signal generated based on the detection output of the brake operating pressure detecting means and the like are also input, and the corrected azimuth signal Hα (i ),
Corrected relative speed signal HVrel (i), corrected distance signal Hd
(I) may be output.

Each of the control devices 30 and 5 shown in FIGS.
Each of 0 and 60 controls steering in a direction with a high degree of danger. On the other hand, for example, when there is a large risk potential R in the traveling direction and the danger of contact is high when the vehicle continues to travel as it is, the driver is actively guided to avoid avoidance. Is also good.

FIG. 11 is a block diagram of a main part of a control device for performing steering guidance. The control device 80 for performing steering guidance shown in FIG.
The risk potential R obtained by the step 70 is converted into a steering torque correction value TR including a steering direction via a gain means 81 having an appropriate gain, and this steering torque correction value TR is converted to a steering torque correction value as necessary. Limiting means 82
Is supplied to the subtractor 83 and the steering torque value T detected by the steering torque detecting means 18 in the subtractor 83.
Subtract (or add) the steering torque correction value TR from p,
The output of the subtracter 83 is supplied to the target assist torque determination unit 21 to determine the target assist torque value IT, and the motor 10 is driven via the motor drive unit 22 (not shown).

By adopting such a configuration, the steering assist force is urged in a safer direction, and the avoidance operation can be guided to the driver. Further, as shown in FIG. 12, when the magnitude of the risk potential in the traveling direction or the rate of increase thereof exceeds a preset threshold value and it is determined that the collision cannot be avoided by steering alone. ,
In combination with other automatic braking devices installed in the vehicle, a series of avoidance operations by deceleration and steering are performed so that the vehicle is directed to the safest direction on the risk potential field (the direction indicated by the thick arrow). Guided, so-called risk management becomes possible.

As an embodiment, steering suppression and steering guidance are performed by using a motor 10 provided in the electric power steering apparatus 1 and a ball screw mechanism 11 for converting the rotation output of the motor 10 into a steering assist force. Although an example of performing the operation is described, the vehicle steering apparatus according to the present invention can be applied to a vehicle that does not include a power steering apparatus. In a vehicle not equipped with a power steering device, for example, a member such as rubber having a large friction coefficient may be pressed against the steering shaft to suppress the driver's steering operation.

[0058]

As described above, the vehicle steering apparatus according to the present invention can adjust the degree of suppression of steering according to the degree of danger, so that the driver can recognize the surrounding conditions and perform safe driving. Operation can be supported.

Accordingly, it is possible to prevent a contact accident or the like due to a carelessness of the driver or the like. Further, the driver can detect the degree of danger due to an obstacle or the like based on the magnitude of the steering reaction force. Furthermore, even when steering is unavoidable in a situation where a plurality of obstacles are present in the surroundings, it is possible to minimize the risk associated with steering.

[Brief description of the drawings]

FIG. 1 is a schematic structural diagram of an electric power steering device.

FIG. 2 is a block diagram showing a specific example of a conventional control device.

FIG. 3 is an overall configuration diagram of a vehicle steering system according to the present invention.

FIG. 4 is a block diagram of a control device for a vehicle steering system according to the present invention.

FIG. 5 is a block diagram of a risk determination unit.

FIG. 6 is an explanatory diagram showing a procedure from detection of an obstacle to calculation of a risk potential field.

FIG. 7 is a block diagram of another control device of the vehicle steering device according to the present invention.

FIG. 8 is a block diagram of still another control device of the vehicle steering system according to the present invention.

FIG. 9 is a block diagram showing a specific example of a lateral displacement and lateral displacement speed calculating / estimating means.

FIG. 10 is a block diagram of a risk determination unit.

FIG. 11 is a block diagram of a main part of a control device that performs steering guidance.

FIG. 12 is an explanatory diagram showing an example of a risk potential field when the risk potential in the traveling direction is high.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric power steering device, 10 ... Electric motor, 18
... Steering torque detecting means constituting steering state detecting means, 1
9 ... steering angle detecting means constituting steering state detecting means, 3
0, 50, 60, 80: control device, 21: target assist torque determination unit, 22: electric motor drive unit, 23: obstacle recognition unit, 24: azimuth angle detection unit, 25: relative speed detection unit, 2
6 distance detecting means 27 gain means constituting steering suppression means 28 output limiting means constituting steering suppression means
29: subtractor constituting steering suppression means, 51: gain means for correction coefficient generation constituting steering suppression means, 52: multiplier constituting steering suppression means, 40, 70 ... risk determining means, 61 ... motion state Lateral displacement and lateral displacement speed calculating / estimating means constituting the estimating means.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B62D 137: 00

Claims (3)

[Claims] An obstacle detecting means for detecting an obstacle present around the own vehicle, and an obstacle for detecting a position, a distance, and a relative speed of the obstacle with respect to the own vehicle based on a signal from the obstacle detecting means. An object recognition unit, a danger determination unit that determines a danger degree based on a signal from the obstacle recognition unit, and a steering suppression unit that suppresses a steering operation based on a signal from the danger determination unit. A steering device for a vehicle, comprising: 2. A steering state detecting means for detecting a steering state, wherein the steering suppressing means suppresses a steering operation based on signals from the danger determining means and the steering state detecting means. The vehicle steering apparatus according to claim 1, wherein 3. The vehicle according to claim 1, further comprising: a steering state detecting means for detecting a steering state; and a movement state estimating means for estimating a movement state of the vehicle based on a signal from the steering state detecting means. 2. The vehicle steering apparatus according to claim 1, wherein a steering operation is suppressed based on signals from a risk determination unit, the steering state detection unit, and the motion state estimation unit.