JP2007045356A - Vehicle control device - Google Patents

Abstract

To support a driver's avoidance operation.
A vehicle that detects the behavior of a preceding vehicle, determines the possibility of a driver performing an avoidance operation based on the behavior of the preceding vehicle, and determines that the driver may perform the avoidance operation. Improve the ability to turn.
[Selection] Figure 9

Description

  The present invention relates to a control device for a vehicle.

  There is known a vehicle control device that determines that the possibility of stepping on the brake is high when the distance between the preceding vehicle and the preceding vehicle is short, and controls the damping force of the suspension to suppress the dive generation during braking (for example, , See Patent Document 1).

Prior art documents related to the invention of this application include the following.
JP 2001-341511 A

  However, in the above-described conventional vehicle control device, when the preceding vehicle performs sudden steering in order to avoid an obstacle, the host vehicle is likely to perform sudden steering in the same manner. High turnability cannot be kept high.

  In addition to detecting the behavior of the preceding vehicle, the possibility of the driver performing an avoidance operation based on the behavior of the preceding vehicle is determined, and if it is determined that the driver may perform the avoidance operation, the turning performance of the vehicle is determined. Improve.

  According to the present invention, the turning ability of the vehicle can be increased prior to the driver's avoidance operation.

  FIG. 1 is a diagram showing a configuration of an embodiment. The imaging device 1 images the front of the vehicle, detects a preceding vehicle, a lane, and the like by image processing, and detects an inter-vehicle distance to the preceding vehicle. The inter-vehicle distance detection device 2 includes a scanning type or multi-beam type laser radar or a millimeter wave radar, and detects an inter-vehicle distance to a preceding vehicle. Based on the detection results of the imaging device 1 and the inter-vehicle distance detection device 2, the behavior of the preceding vehicle in the lateral direction and the front-rear direction and the loss of the preceding vehicle can be detected.

  The vehicle speed sensor 3 detects the vehicle speed of the host vehicle. The throttle sensor 4 detects the throttle valve opening of an engine (not shown), and the brake sensor 5 detects the brake fluid pressure. Further, the steering angle sensor 6 detects the steering angle of the steering. Based on the detection results of the vehicle speed sensor 3, the throttle sensor 4, the brake sensor 5, and the steering angle sensor 6, the state of the host vehicle can be detected.

  The vehicle controller 10 includes a CPU 10a, a ROM 10b, a RAM 10c, and the like. The vehicle controller 10 detects the behavior of the preceding vehicle by the imaging device 1 and the inter-vehicle distance detection device 2, and automatically detects the vehicle speed sensor 3, the throttle sensor 4, the brake sensor 5, and the steering angle sensor 6. In order to detect the state of the vehicle and avoid the behavior of the preceding vehicle, the driver estimates the possibility of sudden steering and sudden braking. When there is a possibility of sudden steering and sudden braking, the suspension control device 11, The stabilizer control device 12, the steering control device 13, and the four-wheel steering (4WS) control device 14 are controlled to switch to control for increasing the turning ability.

  The suspension control device 11 controls the damping force of the shock absorber, and the stabilizer control device 12 controls the torsional rigidity of the stabilizer (not shown). Further, the steering control device 13 controls the transmission ratio of the steering (steering angle / front wheel steering angle), and the four-wheel steering control device 14 steers the rear wheels in phase or in phase with the front wheels.

  Here, a lateral behavior of the preceding vehicle, a behavior in the front-rear direction, and a method for detecting loss of the preceding vehicle will be described. First, the behavior of the preceding vehicle in the lateral direction is detected by determining whether the preceding vehicle tends to leave the lane and avoids an obstacle by lateral movement.

  FIG. 2 shows a departure determination map for the preceding vehicle. In the figure, the horizontal axis of the map represents the lateral displacement amount E of the preceding vehicle, and the vertical axis represents the lateral speed v of the preceding vehicle. Coordinates (± W / 10, ± v1) on the map when the lateral displacement amount E is ± 1/10 of the lane width W and the lateral speed v is a relatively large predetermined value ± v1, and the lateral displacement amount A straight line connecting the coordinates (± W / 2, 0) on the map when E is ± 1/2 of the width W of the lane and the lateral speed v is 0 is the boundary line L1 of the preceding vehicle departure determination When the absolute value of the lateral displacement amount E or the lateral speed v increases beyond the boundary line L1, it is determined that the preceding vehicle tends to leave the lane. When the lateral displacement amount E is less than 1/10 of the lane width W, it is determined that the preceding vehicle does not tend to leave regardless of the lateral speed v.

  The boundary line L1 for determination of departure is desirably set to an appropriate boundary line for the driver to recognize the departure of the preceding vehicle through various experiments, and the shape thereof is not limited to a linear shape. In addition, as shown in FIG. 3, the boundary line L1 is changed according to the inter-vehicle distance D with the preceding vehicle, that is, the longer the inter-vehicle distance D, the smaller the absolute value of the lateral speed v1 and the preceding vehicle tends to leave. On the contrary, as the inter-vehicle distance D becomes shorter, the absolute value of the lateral speed v1 is increased to make it difficult to determine that the preceding vehicle has a tendency to leave. Note that the lateral behavior of the preceding vehicle (including the oncoming vehicle) traveling in the adjacent lane is similarly detected.

  A method for determining whether or not the preceding vehicle is avoiding an obstacle by lateral movement will be described. The first determination method determines that the preceding vehicle is avoiding an obstacle when the lateral acceleration absolute value | α | is equal to or greater than a predetermined acceleration αA. Here, the predetermined acceleration αA is determined in advance by experiments or the like. The predetermined acceleration αA may be decreased as the inter-vehicle distance D is shorter or the host vehicle speed V is higher.

  As shown in FIG. 4, in the second determination method, the lateral displacement absolute value | E | is a predetermined amount on a two-dimensional map of the lateral displacement absolute value | E | and the lateral acceleration absolute value | α |. If it is equal to or greater than EA and the lateral acceleration absolute value | α | is equal to or greater than the predetermined value αA, it is determined that the preceding vehicle is avoiding the obstacle. According to the second determination method, compared with the first determination method described above, for example, even if the wheel travels on the ridge and the behavior of the preceding vehicle is somewhat disturbed, the influence of such a lateral deviation of the preceding vehicle is affected. It is possible to accurately determine whether or not obstacle avoidance is being performed without receiving. Here, the predetermined acceleration αA and the predetermined displacement EA are determined in advance by experiments or the like. In the determination map of FIG. 4, the predetermined acceleration αA may be decreased as the inter-vehicle distance D is shorter or the host vehicle speed V is higher.

  Next, the behavior of the preceding vehicle in the front-rear direction is detected when the imaging device 1 and the inter-vehicle distance detection device 2 detect the deceleration of the preceding vehicle, and the deceleration of the preceding vehicle exceeds the longitudinal behavior determination threshold value. It is determined that the preceding vehicle had a large behavior in the front-rear direction. The front-rear direction behavior determination threshold value is set to a value that can be determined that the preceding vehicle has suddenly braked, for example, 0.5 G. Further, the behavior in the front-rear direction is similarly detected for preceding vehicles (including oncoming vehicles) traveling in the adjacent lane.

  In addition, the loss of a preceding vehicle on a blind curve or the like is detected by the following method. If the preceding vehicle passes through an intersection or curved road, it may be blocked by structures and may not be visible, or if the preceding vehicle exceeds the top of the hill, it may not be visible. FIG. 5A shows a situation in which the preceding vehicle cannot be seen from the host vehicle because the preceding vehicle has passed through a curved road with a wall. FIG.5 (b) shows the image ahead of the own vehicle imaged with the imaging device 1 in the condition shown to (a). The imaging device 1 processes the image ahead of the host vehicle and detects the presence or absence of a preceding vehicle in the image. If the preceding vehicle that has been detected so far disappears from the image, it is determined that the preceding vehicle has been lost.

  In this embodiment, when any of the behavior in the lateral direction of the preceding vehicle, the behavior in the front-rear direction and the loss of the preceding vehicle is detected by the above-described detection method, the turning ability is increased. Here, the turning ability means the speed at which the vehicle changes the direction of the vehicle body and its controllability. If the turning ability is good, the movement will be sporty with a “crisp” movement, but on the other hand, it tends to be unstable and increase instability.

  A method for increasing the turnability of an embodiment will be described. FIG. 6 shows the suspension control device 11 and the stabilizer control as shown in FIG. 6 when the behavior of the preceding vehicle in the lateral direction or the front-rear direction or the loss of the preceding vehicle is detected and there is a possibility that the driver performs an avoidance operation. The device 12, the steering control device 13 and the four-wheel steering (4WS) control device 14 are controlled to increase the turning ability.

  By increasing the damping force of the shock absorber of the suspension as shown in FIG. 6B and increasing the torsional rigidity of the stabilizer as shown in FIG. Can be improved.

  FIG. 7 shows a method for controlling the damping force of the shock absorber. Basically, the damping force increases as the piston speed of the shock absorber increases. It should be noted that the damping force may be further increased in the direction of the arrow in the figure as the degree of sudden steering and sudden braking of the preceding vehicle increases.

  In addition, as shown in FIG. 6 (d), by reducing the steering transmission ratio (steering steering angle / front wheel steering angle), the steering steering angle required to cut the same steering angle can be reduced. A more agile steering operation is possible, and the turning ability can be improved. Furthermore, as shown in FIG. 6 (e), the turning ability can be improved by reducing the rear wheel steering amount at the same time in the four-wheel steering.

  The imaging device 1 and the inter-vehicle distance detection device 2 detect the lateral acceleration and the longitudinal deceleration of the preceding vehicle, and the behavior speed of the preceding vehicle, that is, the lateral acceleration or the longitudinal deceleration is high. The steering transmission ratio may be reduced, the shock absorber damping force and the torsional rigidity of the stabilizer may be increased, and the 4WS rear wheel steering amount may be reduced. As a result, the faster the behavior of the preceding vehicle, the higher the turning performance of the vehicle, and the optimum turning performance corresponding to the speed of the behavior of the preceding vehicle can be obtained.

  Even if the behavior of the preceding vehicle in the lateral direction or the front-rear direction or the loss of the preceding vehicle is detected and the driver may perform an avoidance operation, the turning ability is not increased in the following cases. For example, when the distance between the vehicles approaches the preceding vehicle to a predetermined value or less, the driver's operation is likely to be a quick, condition-reflective emergency operation, so normal stability is emphasized without raising the turning ability. Keep control.

  Table 1 shows control methods of the suspension control device 11, the stabilizer control device 12, the steering control device 13, and the four-wheel steering (4WS) control device 14 when the turning performance is increased and when the stability is increased.

ショックアブゾーバーの減衰力とスタビライザーのねじり剛性については、回頭性向上時と安定性向上時とも前後輪の減衰力とねじり剛性を大きくする方法１と、回頭性向上時は前輪よりも後輪の減衰力とねじり剛性を大きくし、安定性向上時は後輪よりも前輪の減衰力とねじり剛性を大きくする方法２とがある。

For shock absorber damping force and stabilizer torsional rigidity, Method 1 is to increase the damping force and torsional rigidity of the front and rear wheels both when turning performance is improved and when stability is improved. There is a method 2 in which the force and the torsional rigidity are increased, and when the stability is improved, the damping force and the torsional rigidity of the front wheel are increased more than the rear wheel.

  The steering transmission ratio, the shock absorber damping force, the torsional rigidity of the stabilizer, and the 4WS rear wheel steering amount may be continuously changed according to the inter-vehicle distance from the preceding vehicle. That is, as the inter-vehicle distance is smaller, the transmission ratio of the steering is increased, the damping force of the shock absorber and the torsional rigidity of the stabilizer are decreased, and the rear wheel steering amount of 4WS is increased.

  When the inter-vehicle distance from the preceding vehicle is small and approaching the preceding vehicle, control is made with emphasis on normal stability without increasing the turning ability, but sufficient to avoid the preceding vehicle ahead of the host vehicle. When the area is secured and the driver's intention to avoid the vehicle toward the area is detected, the turning ability is improved to assist the driver's avoidance operation.

  FIG. 8 shows an example in which the preceding vehicle suddenly decelerates while suddenly steering to the left. An area for avoiding the preceding vehicle when the imaging device 1 and the inter-vehicle distance 2 always recognize the situation ahead of the host vehicle, for example, when the preceding vehicle suddenly decelerates while suddenly steering to the left to avoid an obstacle, In this case, it is possible to secure a distance L1 (m) that can proceed to the right side of the preceding vehicle and decelerate to the slow speed by slow deceleration (for example, 0.5 G), and the direction in which the driver avoids the preceding vehicle by the rudder angle sensor In this case, when it is detected that the vehicle is steered in the right direction, the turning ability is improved even if the vehicle approaches the preceding vehicle.

  Next, the conditions for returning to the normal stability-oriented state after controlling the steering transmission ratio, shock absorber damping force, stabilizer torsional rigidity, and 4WS rear wheel steering amount to increase the turning performance of the vehicle body will be explained. To do.

  The steering angle sensor 6 and the braking sensor perform steering and braking performed by the driver after any of the lateral behavior of the preceding vehicle, the behavior in the front-rear direction, and the loss of the preceding vehicle is detected and the turning performance is increased. 7 and recognize them as avoidance operations. Then, when the avoidance operation is released, for example, when steering and braking by the avoidance operation are returned to the state before the avoidance operation, it is determined that the avoidance operation has ended, and the transmission ratio of the steering with emphasis on normal stability is determined. Return to the shock absorber damping force, stabilizer torsional rigidity, and 4WS rear wheel steering amount.

  In addition, when any of the behavior in the lateral direction of the preceding vehicle, the behavior in the front-rear direction, or the loss of the preceding vehicle is detected and the turning performance is increased, the vehicle passes the point where the behavior or loss of the preceding vehicle is detected. The steering transmission ratio, the shock absorber damping force, the torsional rigidity of the stabilizer, and the 4WS rear wheel steering amount may be returned to the normal stability-oriented steering transmission ratio.

  Or you may make it return to the control amount of a normal stability emphasis at the time of detecting that the obstruction ahead of the own vehicle was lose | eliminated by the imaging device 1 and the distance 2 between vehicles. Of course, after increasing the turning ability, the control amount may be returned to the normal stability-oriented control amount when the vehicle has traveled for a predetermined distance or when the vehicle has traveled for a predetermined time.

  FIG. 9 is a flowchart showing a vehicle control program according to an embodiment. With reference to this flowchart, the operation of the embodiment will be described in an organized manner. The vehicle controller 10 of one embodiment repeatedly executes this vehicle control program when the ignition is on.

  In step 1, the lateral and front-rear behavior and loss of the preceding vehicle are detected by the method described above. In the following step 2, the behavior of the preceding vehicle and the possibility of the avoidance operation of the own vehicle with respect to losing are determined by the method described above. If it is determined in step 3 that there is no possibility of an avoidance operation, the process proceeds to step 7 and depends on the steering ratio, the shock absorber damping force, the torsional rigidity of the stabilizer, and the 4WS rear wheel steering amount. Continue vehicle control.

  On the other hand, if it is determined that there is a possibility of an avoidance operation with respect to the behavior and loss of the preceding vehicle, the process proceeds to step 4 to determine whether or not the situation improves the turnability. For example, as described above, when the vehicle is approaching the preceding vehicle and there is no area to avoid the preceding vehicle ahead of the host vehicle, in order to cope with the driver's quick, condition-reflective emergency operation, the turning ability is improved. Do not raise. In such a case, the process proceeds to step 7 and normal vehicle control with emphasis on stability is continued.

  If the turning performance is improved, the process proceeds to Step 5 to control the steering transmission ratio, the damping force of the shock absorber, the torsional rigidity of the stabilizer, and the 4WS rear wheel steering amount to increase the turning performance of the vehicle body.

  It is confirmed whether or not the avoidance operation is completed in step 6, that is, whether or not the condition for returning from the turning improvement control as described above to normal stability-oriented vehicle control is satisfied. If the condition is satisfied, the process proceeds to step 6. The vehicle returns to the vehicle control based on the steering ratio, the damping force of the shock absorber, the torsional rigidity of the stabilizer, and the 4WS rear wheel steering amount.

  Thus, according to one embodiment, the behavior of the preceding vehicle is detected, the possibility of the driver performing the avoidance operation based on the behavior of the preceding vehicle is determined, and the driver may perform the avoidance operation. The vehicle's turning ability is improved when it is determined that there is a vehicle, so when the driver performs a sudden avoidance operation such as sudden steering or sudden braking, the vehicle's turning ability is already high and sudden avoidance occurs. The body reacts quickly and stably according to the operation, and the direction and speed of the body can be changed quickly.

  According to one embodiment, an imaging device that images the front of the host vehicle is provided, the image captured by the imaging device is processed to detect the lateral behavior of the preceding vehicle, and the lateral behavior of the preceding vehicle is detected. Since the driver determines that there is a possibility of performing an avoidance operation, the behavior of the preceding vehicle in the lateral direction can be reliably detected, and the reliability of the determination of the possibility of the avoidance operation by the driver is improved. Can be made.

  According to one embodiment, when it is determined that there is a region for avoiding a preceding vehicle ahead of the host vehicle when the inter-vehicle distance decreases to a predetermined value or less, the turning ability of the vehicle is not increased. Therefore, the stability of the vehicle body can be ensured against the driver's quick and condition-reflective emergency operation.

  According to one embodiment, the front-rear direction behavior of the preceding vehicle is detected based on the inter-vehicle distance detection result with the preceding vehicle, and the driver can perform an avoidance operation when the front-rear direction behavior of the preceding vehicle is detected Since it is determined that there is a possibility, it is possible to reliably detect the behavior of the preceding vehicle in the front-rear direction, and it is possible to improve the reliability of the possibility determination of the avoidance operation by the driver.

  According to one embodiment, an imaging device for imaging the front of the host vehicle is provided, the image captured by the imaging device is processed to detect a loss of the preceding vehicle, and the driver performs an avoidance operation when the loss of the preceding vehicle is detected. Even if the preceding vehicle suddenly appears again after losing sight of the preceding vehicle on a curved road with poor visibility, etc., when the driver performs a sudden avoidance operation, the vehicle turns The vehicle body reacts quickly and stably in response to a sudden avoidance operation, and the direction and speed of the vehicle body can be quickly changed.

  According to one embodiment, the speed of the behavior of the preceding vehicle in the lateral direction and the front-rear direction is detected, and the speed of the vehicle is improved as the speed of the preceding vehicle in the lateral direction or the longitudinal behavior increases. As a result, it is possible to obtain the optimum turning ability according to the speed of the behavior of the preceding vehicle.

  According to one embodiment, when the driver's avoidance operation is finished, the vehicle turning performance improvement operation is finished. Therefore, usually, vehicle control with an emphasis on stability is performed, and the turning ability is performed only when necessary. Can be raised.

  According to one embodiment, when the host vehicle reaches the point where the behavior of the preceding vehicle is detected, the vehicle turning performance improvement operation is terminated. , You can increase the turning ability only when necessary.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the imaging device 1 and the inter-vehicle distance detection device 2 serve as behavior detection means, the vehicle controller 10 serves as avoidance operation determination means and control means, the suspension control device 11, the stabilizer control device 12, the steering control device 13, and the four-wheel steering control device. Reference numeral 14 is a turning ability improving means, and the steering angle sensor 6 and the brake sensor 5 are avoidance operation detecting means. The above description is merely an example, and when interpreting the invention, the correspondence between the items described in the above embodiment and the items described in the claims is not limited or restricted.

It is a figure which shows the structure of one embodiment. It is a figure which shows the lane departure determination map of a preceding vehicle. It is a figure which shows the lane departure determination map of the preceding vehicle in consideration of the inter-vehicle distance. It is a figure which shows the map which determines whether the preceding vehicle is avoiding the obstruction. It is a figure which shows the loss of the preceding vehicle in a blind curve. It is a figure which shows the damping force of the shock absorber at the time of rotation improvement, the torsional rigidity of a stabilizer, the transmission ratio of a steering, and 4WS rear-wheel steering amount. It is a figure which shows the control method of the damping force of a shock absorber. It is a figure which shows the area | region for avoiding a preceding vehicle. It is a flowchart which shows the vehicle control program of one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 2 Inter-vehicle distance detection device 3 Vehicle speed sensor 4 Throttle sensor 5 Brake sensor 6 Steering angle sensor 10 Vehicle controller 11 Suspension control device 12 Stabilizer control device 13 Steering control device 14 Four-wheel steering control device

Claims (9)

Behavior detecting means for detecting the behavior of the preceding vehicle;
Avoidance operation determination means for determining the possibility of the driver performing an avoidance operation based on the behavior of the preceding vehicle;
Means for improving the turning ability of the vehicle,
A vehicle control device comprising: control means for improving the turning ability of the vehicle by the turning ability improving means when it is determined that the driver may perform an avoidance operation. The vehicle control device according to claim 1,
The behavior detection means includes an imaging means for imaging the front of the host vehicle, processes a captured image by the imaging means to detect a lateral behavior of the preceding vehicle,
The avoidance operation determination means determines that there is a possibility that the driver performs an avoidance operation when a lateral behavior of a preceding vehicle is detected. The vehicle control device according to claim 2,
An inter-vehicle distance detecting means for detecting an inter-vehicle distance from a preceding vehicle;
An avoidance region determination unit that determines whether or not there is a region for processing a captured image by the imaging unit and avoiding a preceding vehicle ahead of the host vehicle,
When the control means determines that there is a region for avoiding the preceding vehicle ahead of the host vehicle when the inter-vehicle distance decreases to a predetermined value or less, the turning ability of the vehicle is improved by the turning ability improvement means. The vehicle control apparatus characterized by not performing. The vehicle control device according to claim 1,
The behavior detection means includes an inter-vehicle distance detection means for detecting an inter-vehicle distance to a preceding vehicle, and detects a behavior in the front-rear direction of the preceding vehicle based on an inter-vehicle distance detection result by the inter-vehicle distance detection means,
The vehicle control device according to claim 1, wherein the avoidance operation determination unit determines that there is a possibility that the driver performs an avoidance operation when the behavior in the front-rear direction of the preceding vehicle is detected. The vehicle control device according to claim 1,
The behavior detection means includes an imaging means for imaging the front of the host vehicle, processes a captured image by the imaging means to detect loss of a preceding vehicle,
The avoidance operation determination means determines that the driver may perform an avoidance operation when a loss of a preceding vehicle is detected. The vehicle control device according to claim 1,
The vehicle behavior detection means detects the speed of the behavior of the preceding vehicle in the lateral direction and the longitudinal direction,
The control device for a vehicle is characterized in that the turning performance of the vehicle is improved by the turning performance improvement means as the speed of the behavior of the preceding vehicle in the lateral direction or the front-rear direction increases. In the vehicle control device according to any one of claims 1 to 6,
An avoidance operation detecting means for detecting an avoidance operation of the driver corresponding to the behavior of the preceding vehicle,
The vehicle control apparatus according to claim 1, wherein when the driver's avoidance operation is finished, the control means finishes the turning performance improving operation of the vehicle by the turning ability improving means. In the vehicle control device according to any one of claims 1 to 6,
The control device for a vehicle, wherein when the host vehicle reaches a point where the behavior of the preceding vehicle is detected, the turning performance improving operation of the vehicle by the turning performance improving means is terminated. In addition to detecting the behavior of the preceding vehicle, the possibility of the driver performing an avoidance operation based on the behavior of the preceding vehicle is determined, and if it is determined that the driver may perform the avoidance operation, the turning performance of the vehicle is determined. A vehicle control device characterized by being improved.

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