JP2006335223A - Preceding vehicle detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an error between a lane presumed after the operation of lane deviation prevention control and an actual lane. <P>SOLUTION: A preceding vehicle detection device presumes a lane on which its own vehicle travels based on a yaw rate after filter processing for smoothing the change of a yaw rate, and detects a preceding vehicle within the presumed lane. When lane deviation prevention control for controlling a vehicle is operated so that its own vehicle can be prevented from deviating from its own lane during the traveling of the vehicle, the characteristics of the filter processing is increased so that the change of the yaw rate can be further smooth. Thus, it is possible to reduce an error between a presumed lane 12 after the change of filter characteristics and an actual lane compared with a presumed lane 11 before the change of the filter characteristics. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus for estimating a host lane based on a yaw rate of a vehicle and detecting a preceding vehicle in the estimated host lane.

  Conventionally, a control for detecting a preceding vehicle and maintaining a distance between the preceding vehicle and a lane departure prevention control for controlling the vehicle so as not to deviate from the lane when the host vehicle is likely to deviate from the driving lane. A device that is used in combination is known (see Patent Document 1). There is also known a technique in which the preceding vehicle is detected in the own lane estimated based on the yaw rate and vehicle speed detected by the yaw rate sensor. In this own lane estimation technology, in order to prevent the estimated lane from fluctuating due to slight fluctuations in the yaw rate, the yaw rate detected by the yaw rate sensor is filtered, and the change of the yaw rate is detected. A technique for reducing the responsiveness of change is also known.

JP 2003-306135 A

  However, when the vehicle is about to deviate from its own lane, if the lane departure prevention control is activated and the direction of the vehicle changes, an error occurs between the estimated own lane and the actual lane, which is detected. The problem of losing sight of the preceding car arises.

  The preceding vehicle detection device according to the present invention estimates a lane in which the host vehicle travels based on a yaw rate that has been subjected to filter processing so that a change in the yaw rate becomes gradual, and detects a preceding vehicle in the estimated lane. When the lane departure prevention control for controlling the vehicle so that the own vehicle does not depart from the own lane is performed, the characteristic of the filter processing is changed so that the change of the yaw rate becomes more gradual. Features.

  According to the preceding vehicle detection device of the present invention, when the lane departure prevention control is performed, the characteristics of the filter processing are changed so that the change of the yaw rate becomes more gradual, so the error of the estimated lane with respect to the actual lane Can be prevented from losing sight of the preceding vehicle in the estimated lane.

  FIG. 1 is a diagram illustrating a configuration of a preceding vehicle detection device according to an embodiment. The preceding vehicle detection device in one embodiment is used by being mounted on a vehicle, and includes an inter-vehicle distance sensor 1, a vehicle speed sensor 2, a yaw rate sensor 3, a throttle actuator 4, a brake actuator 5, A camera 6 and a control device 7 are provided.

  The inter-vehicle distance sensor 1 includes a radar device, sends a laser beam to a predetermined range in front of the vehicle at predetermined intervals, and receives reflected light that is reflected back to the preceding vehicle, thereby allowing the inter-vehicle distance to the preceding vehicle. Is detected. The vehicle speed sensor 2 detects the speed of the host vehicle. The yaw rate sensor 3 detects the yaw rate of the vehicle, that is, the speed at which the vehicle rotates.

  Based on the yaw rate detected by the yaw rate sensor 3 and the vehicle speed detected by the vehicle speed sensor 2, the control device 7 estimates a road (own lane) on which the host vehicle will travel from now. A known method can be used for estimating the own lane. At this time, when estimating the own lane, the yaw rate detected by the yaw rate sensor 3 is filtered so that the estimated lane does not fluctuate due to slight fluctuations in the yaw rate. This filter can be realized by, for example, a low-pass filter.

  FIG. 2 is a diagram showing a flow of processing for estimating the own lane by the control device 7. The control device 7 includes a filter processing unit 7a and a lane estimation unit 7b for processing functions performed internally. The filter processing unit 7a performs a filtering process so that the yaw rate changes gradually with respect to the yaw rate detected by the yaw rate sensor 3. The lane estimation unit 7b estimates the own lane based on the yaw rate subjected to the filtering process and the vehicle speed detected by the vehicle speed sensor 2. Specifically, the curvature of the own lane is calculated, and information on the width of the own lane is added to estimate the own lane. Thus, by estimating the own lane using the yaw rate after the filter processing, it is possible to prevent the estimated lane from fluctuating with respect to a slight fluctuation in the yaw rate. That is, the estimated own lane changes slowly with respect to the actual change in the yaw rate.

  The control device 7 also detects a preceding vehicle existing in the own lane estimated by the above-described method based on the laser light transmitted and received by the inter-vehicle distance sensor 1, and the own vehicle follows the detected preceding vehicle. Then, the preceding vehicle follow-up control for automatic traveling is performed. That is, based on the inter-vehicle distance detected by the inter-vehicle distance sensor 1 and the speed of the own vehicle detected by the vehicle speed sensor 2, the throttle is set so that the inter-vehicle distance between the own vehicle and the preceding vehicle is maintained at a constant distance. The actuator 4 and the brake actuator 5 are controlled.

  The camera 6 images the front of the host vehicle. The control device 7 performs known image processing (for example, white line detection processing) on the image captured by the camera 6, thereby defining a lane (travel lane) in which the host vehicle is traveling (for example, (White line) is detected, and if it is determined that the vehicle is likely to deviate from the detected line, a braking force is applied to the wheels so that a yaw moment in a direction that prevents lane departure acts on the vehicle. That is, by applying braking force to the wheels on the opposite side of the lane departure direction from the left and right wheels, departure from the lane is prevented. This lane departure prevention control is a known control. The yaw moment with respect to the vehicle is calculated based on the vehicle speed, the lateral position of the vehicle in the lane, the yaw angle with respect to the lane, and the like. Since a well-known technique can be adopted for this in Japanese Patent Application Laid-Open No. 2003-112540 and the like, detailed description is omitted here.

  In the preceding vehicle detection device according to the embodiment, when the lane departure prevention control for preventing the vehicle from deviating from the own lane is activated, the filter processing unit 7a performs the filter processing so that the change in the yaw rate becomes more gradual. Change the characteristics (filter characteristics).

  FIG. 3 is a diagram showing lanes estimated by the lane estimation unit 7b when the lane departure prevention control is activated, and shows two lanes according to the characteristics of the filter processing performed by the filter processing unit 7a. The vehicle 20 represents the direction of the vehicle before the lane departure prevention control is activated, and the vehicle 21 represents the direction of the vehicle after the lane departure prevention control is activated.

  Lane 11 shows the estimated lane before changing the characteristics of the filtering process, and lane 12 shows the estimated lane after changing the characteristics of the filtering so that the change in yaw rate becomes more gradual. . By changing the characteristics of the filter processing so that the change in the yaw rate becomes more gradual, as shown in FIG. 3, the estimated own lane changes more gradually with respect to the change in the yaw rate.

  The filter processing unit 7a enhances the filter characteristics in order to further moderate the change in the yaw rate. That is, increasing the filter characteristics means lowering the responsiveness of the estimated lane that changes according to the change in the yaw rate. Conversely, reducing the characteristics of the filter processing means increasing the responsiveness of the estimated lane that changes according to the change in the yaw rate.

  As shown in FIG. 3, when the lane departure prevention control is activated and the direction of the vehicle is changed, by changing the characteristics of the filter processing so that the responsiveness of the estimated lane change to the change in the yaw rate becomes low, An increase in error between the estimated lane and the actual traveling lane can be suppressed. Thereby, when the preceding vehicle is detected in the estimated lane and the preceding vehicle follow-up control is performed, it is possible to prevent the preceding vehicle from being lost.

  In the preceding vehicle detection device according to the embodiment, the yaw given to the vehicle by the lane departure prevention control is the filter processing characteristic (responsiveness of the estimated lane change to the yaw rate change) when the lane departure prevention control is activated. It changes according to the moment and the relative speed of the preceding vehicle with respect to the host vehicle.

  FIG. 4A is a diagram showing the relationship between the yaw moment generated in the vehicle when the lane departure prevention control is activated (the yaw moment in the direction to prevent lane departure) and the characteristics of the filter processing. (B) is a figure which shows the relationship between the yaw moment generated in a vehicle when operating lane departure prevention control, and the responsiveness of the change of the estimated lane with respect to the change of a yaw rate. When the yaw moment generated in the vehicle increases, the estimated own lane is deviated from the actual lane, and the preceding vehicle existing in the estimated lane deviates from the estimated lane. Therefore, as shown in FIG. 4A, the filter characteristics are improved as the yaw moment generated in the vehicle increases. As a result, as shown in FIG. 4 (b), the greater the yaw moment generated in the vehicle, the lower the responsiveness of the estimated lane change to the yaw rate change, so the error between the actual lane and the estimated lane Is suppressed so that the preceding vehicle being detected is not lost.

  FIG. 5A is a diagram showing the relationship between the relative speed of the preceding vehicle with respect to the host vehicle and the characteristics of the filter processing, and FIG. 5B is a diagram showing the change in the relative speed of the preceding vehicle with respect to the host vehicle and the yaw rate. It is a figure which shows the relationship with the responsiveness of the estimated lane with respect to. 5 (a) and 5 (b), the relative speed when the preceding vehicle approaches the host vehicle is set in the left direction on the page with respect to the origin, and the relative speed when the preceding vehicle moves away from the host vehicle is set on the page. It is set to the right. If the relative speed of the preceding vehicle with respect to the host vehicle exceeds a predetermined speed V1 due to acceleration of the preceding vehicle, the preceding vehicle is likely to be excluded from the subject of the preceding vehicle follow-up control. The change responsiveness, i.e., the characteristics of the filtering process is not changed. When the relative speed is equal to or less than the predetermined speed V1, the characteristics of the filter processing are increased as the relative speed decreases, so that the response of the estimated lane change to the yaw rate change is lowered.

  As described above, the preceding vehicle is detected in the lane estimated based on the vehicle speed and the yaw rate. Here, a lane for detecting the preceding vehicle and a lane for determining that the detected preceding vehicle is lost are set separately. FIG. 6 is a diagram showing a lane 61 for detecting a preceding vehicle and a lane 62 for determining that the detected preceding vehicle has been lost. As shown in FIG. 6, the lane 62 for determining that the preceding vehicle has been lost is set outside the lane 61 for detecting the preceding vehicle. Thereby, it is possible to prevent the detection of the preceding vehicle and the loss (missing) from being frequently switched.

  In the preceding vehicle detection device in one embodiment, when the lane departure prevention control that prevents the departure from the lane in which the host vehicle is traveling is activated, the yaw moment generated in the vehicle and the relative speed of the preceding vehicle with respect to the host vehicle are determined. Thus, the lane width for detecting the preceding vehicle and the lane width of the lane 62 for determining that the preceding vehicle has been lost are respectively changed.

  FIG. 7 is a diagram showing the relationship between the yaw moment generated in the vehicle during the lane departure prevention control and the lane width of the lane 61 for detecting the preceding vehicle. As shown in FIG. 7, the lane width of the lane 61 for detecting the preceding vehicle is reduced as the yaw moment generated in the vehicle increases. As a result, the lane departure prevention control is activated and the direction of the vehicle is changed, so that even if the direction of the estimated lane deviates from the direction of the actual lane, the vehicle traveling in the adjacent lane is mistakenly preceded. It can prevent detecting as a car.

  FIG. 8 is a diagram showing the relationship between the yaw moment generated in the vehicle during the lane departure prevention control and the lane width of the lane 62 for determining that the preceding vehicle has been lost. As shown in FIG. 8, the lane width of the lane 62 for determining that the preceding vehicle has been lost is increased as the yaw moment generated in the vehicle increases. As a result, when the lane departure prevention control is activated and the direction of the vehicle is changed, even if the direction of the estimated lane deviates from the direction of the actual lane, the detected preceding vehicle is lost. Can be prevented.

  FIG. 9 is a diagram illustrating the relationship between the relative speed of the preceding vehicle with respect to the host vehicle and the lane width of the lane 61 for detecting the preceding vehicle. As described above, if the relative speed of the preceding vehicle with respect to the host vehicle exceeds a predetermined speed V1 due to acceleration of the preceding vehicle, there is a high possibility that the preceding vehicle will be excluded from the subject of the preceding vehicle follow-up control. It does not change. On the other hand, when the relative speed becomes smaller than V1, the lane width of the lane 61 for detecting the preceding vehicle is reduced in order to prevent the vehicle traveling in the adjacent lane from being erroneously detected as the preceding vehicle.

  FIG. 10 is a diagram showing the relationship between the relative speed of the preceding vehicle with respect to the host vehicle and the lane width of the lane 62 for determining that the preceding vehicle has been lost. Also in this case, if the relative speed of the preceding vehicle with respect to the host vehicle exceeds the predetermined speed V1, the lane width is not changed. On the other hand, when the relative speed decreases below V1, the lane width of the lane 62 for determining that the preceding vehicle has been lost is increased in order to prevent the detected preceding vehicle from being lost.

  FIG. 11 is a flowchart showing the processing contents performed by the preceding vehicle detection device in one embodiment. The control device 7 starts the control in step S10 when starting the preceding vehicle following control based on the command from the driver. In step S10, it is determined whether or not the lane departure prevention control is activated. Here, it is determined that the lane departure prevention control is activated when it is determined that the host vehicle is about to depart from the traveling lane. If it is determined that the lane departure prevention control is activated, the process proceeds to step S20. If it is determined that the lane departure prevention control is not activated, the process waits in step S10.

  In step S20, it is determined whether the relative speed of the preceding vehicle with respect to the host vehicle is higher than a predetermined speed V1. The relative speed of the preceding vehicle with respect to the host vehicle is calculated based on the inter-vehicle distance detected by the inter-vehicle distance sensor 1. If it is determined that the relative speed of the preceding vehicle with respect to the host vehicle is higher than the predetermined speed V1, it is determined that there is a high possibility that the preceding vehicle is not subject to the preceding vehicle following control, and the characteristics of the filtering process and the detection / The process returns to step S10 without changing the lane width of the lane for determining the lost.

  If it is determined in step S20 that the relative speed of the preceding vehicle with respect to the host vehicle is equal to or lower than the predetermined speed V1, the process proceeds to step S30. In step S30, the filter characteristic is obtained based on the yaw moment generated in the vehicle during the lane departure prevention control and the correlation between the yaw moment and the filter characteristic shown in FIG. The yaw moment generated in the vehicle during the lane departure prevention control is calculated by the control device 7 according to the state of the vehicle. It should be noted that the relationship between the yaw moment generated in the vehicle and the filter characteristics shown in FIG. 4A may be obtained in advance by experiments or the like and stored in a memory (not shown) of the control device 7. When the filter characteristic corresponding to the yaw moment generated in the vehicle during the lane departure prevention control is obtained, the process proceeds to step S40.

  In step S40, the filter characteristic is obtained based on the relative speed of the preceding vehicle with respect to the host vehicle and the correlation between the relative speed and the filter characteristic shown in FIG. The relationship between the relative speed and the filter characteristics shown in FIG. 5A may be obtained in advance through experiments or the like and stored in a memory (not shown) of the control device 7. When the filter characteristic corresponding to the relative speed of the preceding vehicle is obtained, the process proceeds to step S50.

  In step S50, the characteristic of the filter processing performed by the filter processing unit 7a is changed to the filter characteristic having the higher value among the filter characteristics obtained in steps S30 and S40. As described above, by increasing the filter characteristics, the change in the yaw rate after the filter processing becomes more gradual. When the characteristics of the filter process are changed, the process proceeds to step S60.

  In step S60, the lane width of the lane 61 for detecting the preceding vehicle and the preceding vehicle are determined based on the yaw moment generated in the vehicle during the lane departure prevention control and the correlation shown in FIGS. The lane width of the lane 62 for determining that the sight has been lost is obtained. The relationship between the yaw moment generated in the vehicle and the lane width shown in FIGS. 7 and 8 may be obtained in advance through experiments or the like and stored in a memory (not shown) of the control device 7. When the lane width of the lane 61 for detecting the preceding vehicle and the lane width of the lane 62 for determining that the preceding vehicle has been lost are obtained based on the yaw moment generated in the vehicle during the lane departure prevention control, Proceed to S70.

  In step S70, it is determined that the lane width of the lane 61 for detecting the preceding vehicle and the preceding vehicle are lost based on the relative speed of the preceding vehicle with respect to the host vehicle and the correlation shown in FIG. 9 and FIG. The lane widths of the lanes 62 to be obtained are respectively determined. The relationship between the relative speed and the lane width shown in FIGS. 9 and 10 may be obtained in advance by experiments or the like and stored in a memory (not shown) of the control device 7. When the lane width of the lane 61 for detecting the preceding vehicle and the lane width of the lane 62 for determining that the preceding vehicle has been lost are obtained based on the relative speed of the preceding vehicle with respect to the own vehicle, the process proceeds to step S80. .

  In step S80, the lane width to be changed is determined based on the lane width obtained in step S60 and step S70, and the lane width is changed. That is, for the lane width of the lane 61 for detecting the preceding vehicle, the narrower lane width (the smaller one) of the lane widths obtained in step S60 and step S70 is selected as the lane width to be changed. Then, the lane width of the lane 61 for detecting the preceding vehicle is changed to the selected lane width. Further, regarding the lane width of the lane 62 for determining that the preceding vehicle has been lost, the lane width of the wider lane width (the one with the larger value) of the lane widths obtained in step S60 and step S70 is changed. And the lane width of the lane 62 for determining that the preceding vehicle has been lost is changed to the selected lane width.

  In step S90 following step S80, it is determined whether or not the preceding vehicle has been lost. If it is determined that the preceding vehicle has not been lost, the process returns to step S10. If it is determined that the preceding vehicle has been lost, the process proceeds to step S100. In step S100, a command is issued to the brake actuator 5 so that the vehicle decelerates for a predetermined time.

  In general, if the preceding vehicle is lost while the preceding vehicle tracking control is operating, control is performed to accelerate the vehicle in order to make the vehicle speed coincide with a predetermined vehicle speed. However, when the lane departure prevention control is operating, the braking force is applied to the wheels so that the yaw moment in the direction to prevent lane departure acts on the vehicle, so while the braking force is applied to the vehicle, You may lose sight of the preceding car temporarily. Therefore, if the preceding vehicle can be detected again during the predetermined time by performing the control that the vehicle decelerates only for the predetermined time, the vehicle behavior does not change significantly without unnecessary acceleration. Following control can be resumed.

  In the present embodiment, the timing at which the yaw moment is applied to the vehicle by the lane departure prevention control is step S10, and the filter characteristics are changed during the application of the yaw moment. For example, it may be added as a new step between step S80 and step S90.

  The preceding vehicle detection device in one embodiment estimates the own lane based on the filtered yaw rate, detects the preceding vehicle in the estimated own lane, and is likely to deviate from the own lane If it is determined, the vehicle is controlled so that the own vehicle does not deviate from the own lane. In such a device, when the lane departure prevention control is performed, the characteristics of the filter processing are enhanced so that the change in the yaw rate becomes more gradual. Even if it changes, it can suppress that the error between an actual lane and an estimated lane expands. According to the conventional method that does not change the characteristics of the filter processing, the direction of the estimated lane also changes according to the direction of the vehicle, so there is a possibility that the preceding vehicle detected in the estimated lane may be missed. According to the preceding vehicle detection device in this form, it is possible to prevent losing sight of the detected preceding vehicle.

  According to the preceding vehicle detection device in one embodiment, the characteristics of the filter processing are enhanced so that the greater the yaw moment generated in the vehicle during the lane departure prevention control, the greater the degree to which the yaw rate changes more slowly. Even when the lane departure prevention control is activated and the direction of the vehicle is greatly changed, it is possible to prevent the detected preceding vehicle from being lost. Also, as the relative speed of the preceding vehicle with respect to the host vehicle decreases, the characteristics of the filter processing are changed so that the degree of the change in the yaw rate becomes more gradual, so the preceding vehicle decelerates and approaches the host vehicle In addition, even in a scene where it is desired to reliably capture the preceding vehicle, it is possible to continue to detect without losing sight of the preceding vehicle.

  Further, according to the preceding vehicle detection device in the embodiment, when the lane departure prevention control is performed, the estimated lane width of the own lane is narrowed, so that the lane departure prevention control is activated and the direction of the vehicle is changed. Even if the direction of the estimated lane is different from the direction of the actual lane, it is possible to prevent the vehicle traveling in the adjacent lane from being erroneously recognized as the preceding vehicle. At this time, the larger the yaw moment generated in the vehicle during the lane departure prevention control, the larger the ratio of narrowing the lane width, so even if the lane departure prevention control is activated and the direction of the vehicle changes greatly, the adjacent lane It is possible to prevent a traveling vehicle from being erroneously detected as a preceding vehicle. Also, as the relative speed of the preceding vehicle with respect to the host vehicle decreases, the rate of narrowing the lane width increases, so that the preceding vehicle decelerates and approaches the host vehicle so that the preceding vehicle can be reliably captured. In addition, it is possible to prevent a vehicle traveling in the adjacent lane from being erroneously detected as a preceding vehicle.

  According to the preceding vehicle detection device in the embodiment, the lane (lost determination lane) for determining that the detected preceding vehicle is lost is set outside the estimated own lane, and the lane departure prevention control is performed. When done, the lane width of the lost judgment lane is widened, so the lane departure prevention control is activated, the direction of the vehicle changes, and even if the direction of the estimated lane is different from the direction of the actual lane, it is detected. You can prevent you from losing sight of the preceding car. At this time, the larger the yaw moment generated in the vehicle during the lane departure prevention control, the larger the ratio of widening the lane width of the lost judgment lane, so even if the lane departure prevention control is activated and the direction of the vehicle changes greatly. It is possible to prevent losing sight of the preceding vehicle being detected. In addition, as the relative speed of the preceding vehicle with respect to the host vehicle decreases, the ratio of widening the lane width of the lost judgment lane increases, so that the preceding vehicle decelerates and approaches the host vehicle to reliably capture the preceding vehicle. Even in such a situation, it is possible to prevent the detected preceding vehicle from being lost.

  According to the preceding vehicle detection device in one embodiment, when the preceding vehicle is lost when the lane departure prevention control is activated, the vehicle decelerates for a predetermined time, so that the preceding vehicle is detected again during the predetermined time. If possible, the preceding vehicle follow-up control can be resumed without unnecessary acceleration.

  The present invention is not limited to the embodiment described above. For example, the preceding vehicle is detected by transmitting and receiving laser light from the inter-vehicle distance sensor 1, but it can also be performed based on transmission / reception of signals other than laser light, or other devices can be used. it can. For example, a camera that captures the front of the vehicle may be mounted on the vehicle, and a preceding vehicle existing in the estimated lane may be detected based on an image captured by the in-vehicle camera.

  In the above-described embodiment, the characteristics of the filter processing and the lane width are changed based on the yaw moment generated in the vehicle when the lane departure prevention control is operated. However, after the lane departure prevention control is operated, the yaw rate sensor is changed. Based on the yaw rate detected by No. 3, the characteristics of the filtering process and the lane width may be changed.

  In the lane departure prevention control, the braking force is applied to the wheels so that the yaw moment in the direction of preventing the lane departure acts on the vehicle, but the lane departure may be prevented by operating the steering. In other words, the lane departure can be prevented by turning the steering to the side opposite to the lane departure direction. In addition to the image processing, the lane (white line) may be detected using, for example, an infrared sensor. Furthermore, not only the deviation from the lane, but also a deviation from the road (asphalt road surface) may be detected.

  Although a low-pass filter has been described as an example of a filter for performing the filter processing, a filter other than the low-pass filter may be used.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the yaw rate sensor 3 is the yaw rate detection means, the control device 7 is the lane estimation means, the preceding vehicle detection means, the lane departure prevention control means, the filter characteristic change means, the relative speed detection means, the lane width change means, and the lost determination lane setting means. The controller 7 and the brake actuator 5 constitute vehicle control means. In addition, the above description is an example to the last, and when interpreting invention, it is not limited to the correspondence of the component of said embodiment and the component of this invention at all.

The figure which shows the structure of the preceding vehicle detection apparatus in one embodiment. Diagram showing the flow of processing to estimate the own lane The figure which shows the own lane estimated using the yaw rate after filter processing FIG. 4A is a diagram showing the relationship between the yaw moment generated in the vehicle when the lane departure prevention control is operated and the characteristics of the filter processing, and FIG. 4B is the case when the lane departure prevention control is operated. Figure showing the relationship between the yaw moment generated in the vehicle and the response of the estimated lane change to the yaw rate change The figure which shows the relationship between the relative speed of the preceding vehicle with respect to the own vehicle, and the responsiveness with respect to the yaw rate change A diagram showing a lane for detecting a preceding vehicle and a lane for determining that the preceding vehicle being detected is lost. The figure which shows the relationship between the yaw moment generated in a vehicle at the time of lane departure prevention control, and the lane width of the lane for detecting a preceding vehicle The figure which shows the relationship between the yaw moment generated in a vehicle at the time of lane departure prevention control, and the lane width of the lane for determining that the preceding vehicle was lost. The figure which shows the relationship between the relative speed of the preceding vehicle with respect to the own vehicle, and the lane width of the lane 51 for detecting a preceding vehicle. The figure which shows the relationship between the relative speed of the preceding vehicle with respect to the own vehicle, and the lane width of the lane for determining that the preceding vehicle has been lost. The flowchart which shows the processing content performed by the preceding vehicle detection apparatus in one embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle distance sensor, 2 ... Vehicle speed sensor, 3 ... Yaw rate sensor, 4 ... Throttle actuator, 5 ... Brake actuator, 6 ... Camera, 7 ... Control apparatus

Claims (11)

Yaw rate detection means for detecting the yaw rate of the vehicle;
A lane estimation unit that estimates a lane in which the host vehicle travels by performing a filtering process such that a change in the yaw rate becomes gentle with respect to the yaw rate detected by the yaw rate detection unit;
Preceding vehicle detection means for detecting a preceding vehicle in the lane estimated by the lane estimation means;
A lane departure prevention control means for generating a yaw moment in the vehicle so that the vehicle does not deviate from the own lane when it is determined that the own vehicle is likely to deviate from the own lane;
When the control for preventing the own vehicle from deviating from the own lane (hereinafter, lane departure prevention control) is performed by the lane departure prevention control means, the filter processing is performed so that the change in the yaw rate becomes more gradual. A preceding vehicle detection device comprising: filter characteristic changing means for changing characteristics (hereinafter referred to as filter characteristics). In the preceding vehicle detection device according to claim 1,
The filter characteristic changing means changes the filter characteristic such that the greater the yaw moment generated in the vehicle during the operation of the lane departure prevention control, the greater the degree of gradual change in the yaw rate. A preceding vehicle detection device. In the preceding vehicle detection device according to claim 1 or 2,
A relative speed detecting means for detecting a relative speed of the preceding vehicle with respect to the host vehicle;
The filter characteristic changing means changes the filter characteristic so that the degree of a gentle change in yaw rate increases as the relative speed detected by the relative speed detecting means decreases during the operation of the lane departure prevention control. A preceding vehicle detection device characterized in that: In the preceding vehicle detection apparatus in any one of Claims 1-3,
A preceding vehicle detection further comprising lane width changing means for narrowing the lane width of the lane estimated by the lane estimation means when the lane departure prevention control is performed by the lane departure prevention control means. apparatus. In the preceding vehicle detection device according to claim 4,
The preceding lane width changing means increases the rate of narrowing the lane width as the yaw moment generated in the vehicle during the operation of the lane departure prevention control increases. In the preceding vehicle detection device according to claim 4 or 5,
The preceding lane width changing device increases the ratio of narrowing the lane width as the relative speed of the preceding vehicle with respect to the host vehicle decreases. In the preceding vehicle detection apparatus in any one of Claims 1-6,
Lost determination lane setting means for setting a lane (hereinafter referred to as a lost determination lane) for determining that the preceding vehicle being detected is lost outside the lane estimated by the lane estimation means;
The vehicle further comprises lost determination lane width changing means for widening the lane width of the lost determination lane set by the lost determination lane setting means when the lane departure prevention control is performed by the lane departure prevention control means. A preceding vehicle detection device. In the preceding vehicle detection device according to claim 7,
The preceding vehicle detection device, wherein the lost determination lane width changing means increases the rate of widening the lane width of the lost determination lane as the yaw moment generated in the vehicle during the operation of the lane departure prevention control increases. The preceding vehicle detection device according to claim 7 or 8,
The preceding vehicle detection device characterized in that the lost determination lane width changing means increases the ratio of increasing the lane width of the lost determination lane as the relative speed of the preceding vehicle with respect to the host vehicle decreases. In the preceding vehicle detection apparatus in any one of Claims 1-9,
Vehicle control means is further provided for controlling the vehicle to decelerate for a predetermined time when the preceding vehicle detected by the preceding vehicle detection means is lost when the lane departure prevention control is activated. Leading vehicle detection device. In the preceding vehicle detection device that estimates the lane in which the host vehicle travels based on the yaw rate that has been subjected to the filter processing so that the change in the yaw rate becomes gentle, and detects the preceding vehicle in the estimated lane,
The preceding characteristic is characterized in that the characteristic of the filtering process is changed so that the change in the yaw rate becomes more gradual when the lane departure prevention control for controlling the vehicle so that the own vehicle does not depart from the own lane Car detection device.

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