JP2011123535A - Obstacle detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately obtain a position of a target even in close range. <P>SOLUTION: An obstacle detection device 1 where a sensor 2 detects a target includes an estimation means 83 that detects the position of the target when the sensor 2 can not detect the target from position and speed information on the target while the sensor 2 can detect the target, and a time elapsing after the sensor 2 can not detect the target when a state where the sensor 2 can detect the target changes into a state where the sensor 2 can not detect the target. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an obstacle detection apparatus.

  A technique for changing the timing of starting braking based on the size of an obstacle in the estimated course of the host vehicle and the relative speed with the obstacle is known (see, for example, Patent Document 1).

  Here, when the relative speed between the host vehicle and the obstacle is low, in order to accurately determine whether the host vehicle collides with the obstacle, it is closer than when the relative speed is high. It is necessary to accurately detect the position of an obstacle up to a distance. Further, if the position of the obstacle can be accurately obtained until immediately before the collision, the host vehicle can be stopped while maintaining an appropriate distance from the obstacle.

  However, when the obstacle is at a close distance, a sensor such as a radar shortens the time from the transmission of the radar wave to the reception of the reflected wave, so that the detection accuracy of the position of the obstacle may be lowered.

JP 2008-132867 A JP 2008-302850 A JP 2007-274037 A

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technique capable of accurately obtaining the position of a target even at a short distance.

In order to achieve the above object, the obstacle detecting apparatus according to the present invention employs the following means. That is, the obstacle detection device according to the present invention is
In an obstacle detection device that detects a target with a sensor,
When the target is not detected from the state in which the target has been detected by the sensor, the position and speed information of the target when the target has been detected by the sensor; and An estimation means is provided for estimating the position of the target when the target cannot be detected by the sensor from the elapsed time from when the target can no longer be detected by the sensor.

  That is, when the target cannot be detected by the sensor, the position of the target is complemented by estimating the position of the target. The estimation means estimates the position of the target based on how the target has moved relative to the sensor. For example, it is assumed that the state in which the target is relatively moving immediately before the target cannot be detected by the sensor continues as it is. And a position can be estimated according to the elapsed time after that. The speed information can include the speed of the sensor (may be the speed of the host vehicle on which the sensor is mounted) and the speed of the target. The speed of the target may be zero. The velocity information can also include acceleration or velocity direction and radius of curvature.

  In the present invention, the time when the target cannot be detected may be the time when the distance of the target is closer than the latest distance where the performance of the sensor is guaranteed.

  If the distance of the target is closer than this recent distance, even if the target can be detected by the sensor, the information is not guaranteed and the reliability is low. Therefore, in such a state, the information detected by the sensor is not used, but estimation by the estimation unit is performed instead. Thereby, the position of the target can be obtained with high accuracy.

  In the present invention, the time when the target cannot be detected may be when the target is lost.

  This is a state in which the target is not detected by the sensor. This is because the target may not be detected because the target does not actually exist, or the target may not be detected even though the target actually exists. If the position of the target is estimated in such a case, the position of the target can be obtained with high accuracy.

  In the present invention, the estimation means can estimate the position of the target based on the relative speed with the target.

  This is a relative speed with respect to the target actually detected by the sensor. Since this relative speed shows how the distance between the sensor and the target changes, the position of the target can be estimated.

  In the present invention, the estimating means can estimate the position of the target in consideration of the turning radius.

  This turning radius is the turning radius of the sensor. The turning radius of the obstacle detection device may be used, or the turning radius of the host vehicle on which the obstacle detection device is mounted. If the sensor is turning, the relative position of the target with respect to the sensor changes. Therefore, if the position of the target is estimated in consideration of the turning radius, the accuracy can be improved. For example, it is assumed that the turning radius of the sensor immediately before the target cannot be detected by the sensor continues after that.

  In the present invention, the estimation means can end the estimation of the position of the target when a target that moves away is detected by the sensor after the target cannot be detected.

  In this case, the target that has become undetectable and the target that is separated by the sensor are considered to be the same target. In addition, the fact that a target that is separated is detected means that there is no other target between the sensor and the target that is separated. If the target can be detected by the sensor, the target may be detected by the sensor, and thus the estimation of the target position can be terminated.

  In the present invention, the estimation means terminates the estimation of the position of the target when a target whose distance is greater than a threshold is detected by the sensor after the target cannot be detected. Can do.

If the target moves outside the detection range of the sensor by changing the course or turning right and left, the target cannot be detected by the sensor. Here, when there are a plurality of targets, the other target may not be detected due to the other target entering the shadow of one target. In this case, if one target moves out of the detection range of the sensor, the other target is detected. The other target to be detected exists at a certain distance. That is, if the lower limit value of the distance at which the other target is detected is set in advance as a threshold value, it can be determined whether the other target has been detected based on the distance detected by the sensor. Then, when the other target is detected, since the one target does not already exist, the estimation of the position of the target can be terminated.

  In the present invention, there can be provided fusion means for fusing the position of the target estimated by the estimation means and the position of the target detected by the sensor at a predetermined ratio.

  Here, even when the distance of the target is closer than the recent distance where the performance of the sensor is guaranteed, the position of the target may be detected by the sensor. However, although the position of the target detected at this time is not guaranteed, an approximate position of the target can be obtained. On the other hand, if the speed or the direction of travel of the target changes after the sensor is in a state where it cannot be detected, the accuracy of estimation of the position of the target decreases. Therefore, the position of the target can be obtained based on a plurality of detection results by fusing the position of the target estimated by the estimating means and the position of the target detected by the sensor. The detection accuracy of the mark can be improved. For example, the position of a point obtained by dividing the line connecting the position of the target estimated by the estimating means and the position of the target detected by the sensor at a predetermined ratio is set as the position of the target obtained by the fusion means. .

  The predetermined ratio may be a constant value or may be changed. For example, the influence degree of the position of the target detected by the sensor may be lowered as the elapsed time from when the target cannot be detected by the sensor is longer. Immediately after the target cannot be detected by the sensor, the accuracy of the detection value by the sensor is high. Therefore, the accuracy can be increased by increasing the ratio of the position of the target detected by the sensor for fusion. Moreover, you may change according to speed or distance.

  According to the present invention, the position of a target can be obtained with high precision even at a short distance.

It is a block diagram which shows the obstruction detection apparatus which concerns on an Example. It is the figure which showed the conditions when a complement flag is set to ON. It is the figure which showed the conditions when a complement flag is set to ON. It is the figure which showed the conditions when it is set to OFF after a complement flag is set to ON. It is the figure which showed the conditions when it is set to OFF after a complement flag is set to ON. It is the figure which showed the outline | summary when estimating the position of a target. It is the figure which showed the outline | summary when estimating the position of a target. It is the figure which showed the outline | summary when estimating the position of a target. It is the figure which showed the outline | summary when calculating | requiring a fusion position. It is the figure which showed an example of the relationship between the elapsed time from the estimation start of the position of a target, and the mixing ratio. It is the flowchart which showed the flow when the obstruction detection apparatus which concerns on an Example operate | moves.

Hereinafter, specific embodiments of the obstacle detection apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an obstacle detection apparatus 1 according to the present embodiment. The obstacle detection apparatus 1 according to the present embodiment is an apparatus that is mounted on a host vehicle traveling on a road and detects a target (obstacle) such as another vehicle in front of the host vehicle. In the present embodiment, another vehicle in front of the host vehicle will be described as an example.

  The obstacle detection device 1 includes a millimeter wave radar 2, a radar ECU 3, a steering angle sensor 4, a yaw rate sensor 5, a wheel speed sensor 6, and a system ECU 8.

  The millimeter wave radar 2 is provided in the front part of the host vehicle and detects the direction and distance from the host vehicle of a target existing in front of the host vehicle. The millimeter wave radar 2 scans the millimeter wave in a predetermined range in front of the host vehicle and receives the reflected wave, thereby detecting the distance to the target in each direction in which the reflected wave is detected. Detection by the millimeter wave radar 2 is performed every predetermined time. The millimeter wave radar 2 sequentially outputs a signal corresponding to the detected direction and distance to the radar ECU 3.

  Here, a minimum guaranteed distance is set for the millimeter wave radar 2. At a distance shorter than the minimum guaranteed distance, the detection accuracy of the millimeter wave radar 2 is lowered, and the performance of the millimeter wave radar 2 is not guaranteed. For this reason, in this embodiment, it is assumed that the detection accuracy of the millimeter wave radar 2 decreases at a distance closer than the minimum guaranteed distance.

  In this embodiment, the millimeter wave radar 2 corresponds to the sensor in the present invention. In the present embodiment, the target is detected by the millimeter wave radar 2, but other sensors capable of detecting the distance and speed of the target may be used.

  The radar ECU 3 calculates the position of a target existing ahead of the host vehicle with respect to the host vehicle, and is configured mainly by a computer including a CPU, a ROM, and a RAM, for example. The radar ECU 3 includes a target relative position calculation unit 31 and a target relative speed calculation unit 32.

  The target relative position calculation unit 31 sequentially acquires signals output from the millimeter wave radar 2, and detects the target when the target is present in front of the host vehicle based on this signal. Further, the target relative position calculation unit 31 calculates the position (relative position) of the detected target with respect to the host vehicle. The relative position is indicated by distance and lateral position. When the target is located obliquely forward of the host vehicle, the actual distance is considered by dividing it into a traveling direction component of the host vehicle and a true lateral component of the host vehicle (a direction component orthogonal to the traveling direction). Then, the component in the traveling direction of the host vehicle is determined as “distance”, and the component in the right lateral direction of the host vehicle is determined as “lateral position”. The target relative position calculation unit 31 outputs a signal corresponding to the calculation result to the system ECU 8.

  The target relative speed calculation unit 32 calculates the speed of the detected target with respect to the host vehicle. The target relative speed calculation unit 32 outputs a signal corresponding to the calculation result to the system ECU 8. Note that the speed of the target may be simply calculated.

  The millimeter wave radar 2 and the radar ECU 3 function as means for acquiring target information.

The steering angle sensor 4 is a sensor that is provided on the steering shaft of the host vehicle and detects the steering angle of the steering of the host vehicle. The steering angle sensor 4 includes a rotary encoder and the like, and detects the direction and magnitude of the steering angle input by the driver of the host vehicle. The steering angle sensor 4 outputs a steering angle signal corresponding to the detected direction and magnitude of the steering angle to the system ECU 8.

  The yaw rate sensor 5 is a sensor that is provided in a part of the host vehicle and detects the yaw rate of the host vehicle. The yaw rate sensor 5 detects the yaw rate of the host vehicle and outputs a signal corresponding to the detected yaw rate to the system ECU 8.

  The wheel speed sensor 6 is a sensor that is provided on each wheel of the host vehicle and detects wheel speed pulses. The wheel speed sensor 6 detects a wheel speed pulse at each wheel, and outputs a wheel speed pulse signal corresponding to the detected wheel speed pulse to the system ECU 8.

  The steering angle sensor 4, the yaw rate sensor 5, and the wheel speed sensor 6 function as means for acquiring information on the host vehicle.

  The system ECU 8 determines whether or not to issue an alarm or the like according to the detected or estimated position of the target, and is configured mainly by a computer including a CPU, a ROM, and a RAM, for example. The system ECU 8 acquires signals output from the radar ECU 3, the steering angle sensor 4, the yaw rate sensor 5, and the wheel speed sensor 6, and performs a predetermined process based on the acquired signals, thereby giving an alarm or the like. It is determined whether or not to perform. The system ECU 8 includes a complement flag calculation unit 81, a complement flag cancellation calculation unit 82, an estimated position calculation unit 83, a fusion position calculation unit 84, and a collision determination calculation unit 85.

  The complement flag calculation unit 81 sets a complement flag. The complement flag is a flag indicating whether the position of the target is estimated by calculation instead of being detected by the millimeter wave radar 2. When the complement flag is ON, the target position is estimated. When the complement flag is OFF, the target position is detected by the millimeter wave radar 2.

  2 and 3 are diagrams showing conditions when the complement flag is turned on. The reference point of the distance and the lateral position is a place where the millimeter wave radar 2 is attached. FIG. 2 shows a case where the distance between the target and the host vehicle is shorter than the minimum guaranteed distance (the same applies hereinafter). Here, a minimum guaranteed distance is set for the millimeter wave radar 2, and this minimum guaranteed distance is determined in consideration of variations due to individual differences of the millimeter wave radar 2. Therefore, there are some devices that can accurately detect the position even if the distance is shorter than the minimum guaranteed distance. However, since the accuracy is not guaranteed, the estimated position is used instead of the position detected by the millimeter wave radar 2 at a distance shorter than the minimum guaranteed distance. In FIG. 2, since the own vehicle is approaching the target, the relative speed of the target is a negative value. Then, the complement flag is set to ON when the target approaches less than the minimum guaranteed distance.

  FIG. 3 shows a case where the target detected by the millimeter wave radar 2 is lost. When the target detected by the millimeter wave radar 2 is lost, there is no possibility of collision if the target is far away, but there is a possibility of collision if the target is close. For this reason, when the target is lost at a short distance, the position is estimated. In FIG. 3, since the own vehicle is approaching the target, the relative speed of the target is a negative value. Then, the lost flag is turned ON when the target is lost on the way. The lost flag will be described later.

That is, there are two conditions (1) or (2) below for setting the complement flag to ON. Then, when any of the conditions is satisfied, the complement flag is turned ON. If neither condition is satisfied, the complement flag is turned off.
(1) When the distance to the target is less than the minimum guaranteed distance (see Fig. 2).
(2) When the lost flag is ON and the distance to the target when the lost flag is ON is less than the threshold A (see FIG. 3).
The lost flag is a flag indicating whether or not the target that has been captured so far has been lost. The lost flag is a flag that is turned ON when the target that has been captured by the millimeter wave radar 2 is lost, and is OFF otherwise. The threshold A is a distance for which the position needs to be estimated even after losing sight of the target. For example, the threshold A may be a minimum guaranteed distance, or an optimum value may be obtained through experiments or the like. For example, when the target that has been captured is lost at a distance where the target may collide, the position of the target is estimated.

  Even after the complement flag is turned on by the complement flag computation unit 81, the complement flag cancel computation unit 82 turns the complement flag off when there is no possibility that the target will collide with the host vehicle.

  Here, FIG. 4 and FIG. 5 are diagrams showing conditions when the complement flag is turned off after being turned on. FIG. 4 shows a case where a target that moves away from the host vehicle is detected after the complement flag is turned ON. For example, when the target position is estimated when the target is stopped at a close distance in front of the host vehicle in a traffic jam, if the target starts and moves away from the host vehicle, there is a risk of collision. Will disappear. Further, since the target is detected by the millimeter wave radar 2, it can be determined that no other target exists at a distance closer to the target. Therefore, if such a target is detected on the traveling lane of the own vehicle, there is no need to estimate the position of the target, and therefore there is another target that becomes a separation object on the traveling lane of the own vehicle. Sometimes the complement flag is turned off. The relative speed of the target at this time is a positive value and is a direction away from the host vehicle. It should be noted that the complement flag may be turned OFF even when a target that moves away from the minimum guaranteed distance is detected.

  FIG. 5 shows a case where a target whose distance from the vehicle is larger than the threshold B after the complement flag is turned ON is shown. Here, when the position of the target is estimated, if the target turns right or left and does not exist on the traveling lane of the host vehicle, the possibility of a collision is eliminated. If another target exists further ahead of the target that has turned left or right, the other target is detected. Therefore, when another target existing at a relatively far distance from the host vehicle (a distance larger than the threshold value B) is detected, the target existing between the other target and the host vehicle is detected. Determines that the vehicle has moved from the traveling lane of the host vehicle, and the complement flag is turned OFF.

That is, paying attention to another target detected by the millimeter wave radar 2 while estimating the position of the target, it is determined whether or not there is no possibility that the target whose position is being estimated collides with the host vehicle. ing. Then, when one of the following two conditions (3) or (4) is satisfied, the complement flag is set to OFF, and otherwise, the complement flag is maintained as it is.
(3) When a target that becomes a separation object exists on the traveling lane of the host vehicle.
(4) When a target whose distance is greater than the threshold B exists on the traveling lane of the host vehicle.
Note that an optimum value for the threshold value B is obtained by experiments or the like. Further, in both cases (3) and (4), the turning radius of the own vehicle is obtained from the steering angle sensor 4 and the yaw rate sensor 5, and the traveling lane of the own vehicle is obtained based on the turning radius. It can be determined whether or not a target exists on the traveling lane of the vehicle.

  The estimated position calculation unit 83 calculates the position of the target using the information detected by the millimeter wave radar 2 immediately before the complement flag is turned ON and the information on the host vehicle. When the complement flag is OFF, the target position is not calculated.

6, 7, and 8 are diagrams illustrating an outline when the position of the target is estimated. FIG. 6 shows a case where the host vehicle is traveling straight. FIG. 7 shows a case where the host vehicle is turning at a turning radius R. FIG. 8 shows a case where the relative speed is calculated from the past history.

In FIG. 6, the distance and lateral position of the target one cycle before in the calculation cycle are Y (K−1) [m] and X (K−1) [m], respectively, and the speed of the host vehicle is V [ m / s], the calculation cycle is ΔT [s], and the current estimated distance Y (K) [m] and lateral position X (K) [m] are obtained. This can be obtained by the following equation.
X (K) = X (K-1)
Y (K) = Y (K−1) −V · ΔT

  That is, since the host vehicle is traveling straight, the lateral position of the target is not changed. Further, the distance of the target is calculated based on how close it is during the calculation period ΔT. Thus, if the distance and the horizontal position of the target are calculated, the distance and the horizontal position of the target at the time of calculation can be estimated. It is also possible to reduce the target distance at the present time by subtracting the value obtained by multiplying the elapsed time since losing the target by the speed V from the target distance when the estimation of the target position is started. Can be estimated.

  In the above equation, it is assumed that the host vehicle is traveling straight, and only the distance is estimated from the speed information of the host vehicle. On the other hand, the distance and the lateral position can be obtained simultaneously by using the steering information (turning radius R) of the own vehicle (see FIG. 7). That is, the distance and the lateral position of the target can be calculated on the assumption that the turning radius R of the host vehicle when the estimation of the position of the target is started is maintained thereafter. It is also possible to estimate from the relative speed estimated from the history of past captured points (see FIG. 8). For example, taking into account the relative acceleration when the estimation of the position of the target is started, the relative speed of the target at the time of calculation can be obtained, and the distance and lateral position of the target can be calculated.

  Note that the position of the target estimated by the estimated position calculation unit 83 may be used as it is or after weighting. Since the position of the target estimated by the estimated position calculation unit 83 is less reliable than the position of the target obtained based on the detection value of the millimeter wave radar 2, the position of the target is actually detected by the millimeter wave radar 2. The weight of the estimated position of the target is made smaller than when it was detected (the degree of influence is lowered). In this embodiment, the estimated position calculation unit 83 corresponds to the estimation means in the present invention.

  Next, when the target is detected by the millimeter wave radar 2 when the position of the target is estimated, the fusion position calculation unit 84 estimates the position of the detected target. The position that is combined with the position is calculated (fused). The position obtained by combining is referred to as a fusion position.

  Here, even when the distance to the target is less than the minimum guaranteed distance, the millimeter wave radar 2 may be able to detect the target. However, since the position of the target detected at this time is not guaranteed, it is not used as it is. In the present embodiment, the estimated position of the target is improved by combining the estimated position of the target and the position of the target detected by the millimeter wave radar 2.

FIG. 9 is a diagram showing an outline when obtaining the fusion position. If the lateral position and distance detected by the millimeter wave radar 2 are XM (K) and YM (K), respectively, the fusion position (XF (K), YF (K)) can be obtained by the following equations. Note that the fusion position is not obtained when the target cannot be captured by the millimeter wave radar 2.
XF (K) = (1-C) .X (K) + C.XM (K)
YF (K) = (1-C) .Y (K) + C.YM (K)
However, C is a ratio (mixing ratio) in which position information detected by the millimeter wave radar 2 is used, and an optimum value is obtained by experiment. The higher the mixing ratio C, the greater the influence of the detection value by the millimeter wave radar 2.

  Note that the mixing ratio C may be a constant value, but may be changed according to time, distance, vehicle speed, and the like after the estimation is started.

  FIG. 10 is a diagram illustrating an example of the relationship between the elapsed time from the start of estimation of the target position and the mixing ratio C. In FIG. 10, the mixing ratio is reduced as the elapsed time from the start of estimation becomes longer. That is, the longer the elapsed time, the lower the influence of the position detected by the millimeter wave radar 2. In the present embodiment, the fusion position calculation unit 84 corresponds to the fusion means in the present invention.

  When the collision determination calculation unit 85 determines that the position and relative speed of the target are in a predetermined state, the system ECU 8 outputs a signal to the operation device 9. This predetermined state is a state where the host vehicle may collide with the target. The operating device 9 is, for example, an alarm device 91 using sound or light, or a device 92 (automatic brake device 92) for automatically applying a brake. Then, the activation device 9 is activated when the host vehicle and the target are in a predetermined state. In addition, the device for avoiding the target by steering can be included in the actuation device 9.

  FIG. 11 is a flowchart showing a flow when the obstacle detection apparatus 1 according to the present embodiment operates. This routine is repeatedly executed by the system ECU 8 every predetermined time.

  In step S101, it is determined whether the distance to the target detected by the millimeter wave radar 2 is less than the minimum guaranteed distance. That is, it is determined whether or not the detection result of the millimeter wave radar 2 cannot be used as it is. If an affirmative determination is made in step S101, the process proceeds to step S102, where the complement flag is turned ON. On the other hand, if a negative determination is made in step S101, the process proceeds to step S103.

  In step S103, it is determined whether the lost flag is ON. That is, it is determined whether the millimeter wave radar 2 has lost sight of the target. If an affirmative determination is made in step S103, the process proceeds to step S104, and if a negative determination is made, the process proceeds to step S108.

  In step S104, it is determined whether or not the distance (pre-lost detection distance) to the target detected when the millimeter wave radar 2 loses sight of the target is less than the threshold A. That is, it is determined whether it is better to estimate the position of the target. If an affirmative determination is made in step S104, the process proceeds to step S102, and the complement flag is turned ON. On the other hand, if a negative determination is made in step S104, the process proceeds to step S108.

  In step S105, it is determined whether or not a separation object exists. That is, it is determined whether or not the target (another vehicle) that has existed at a close distance has started and separated. If an affirmative determination is made in step S105, the process proceeds to step S107, and the complement flag is turned off. On the other hand, if a negative determination is made in step S105, the process proceeds to step S106.

In step S106, it is determined whether or not there is a target whose distance from the host vehicle is greater than the threshold value B. That is, it is determined whether or not another target that could not be captured so far can be captured. In this step, it is determined whether or not the target (another vehicle) that was present at a close distance has made a right turn, a left turn, or a course change. If an affirmative determination is made in step S106, the process proceeds to step S107, and the complement flag is turned OFF. On the other hand, step S106
If a negative determination is made in step S108, the process proceeds to step S108.

  In step S108, it is determined whether or not the complement flag is ON. That is, it is determined whether it is necessary to estimate the position of the target. If an affirmative determination is made in step S108, the process proceeds to step S109, and if a negative determination is made, this routine is terminated. When the complement flag is OFF, the millimeter wave radar 2 detects the position of the target.

  In step S109, the position of the target is estimated. In step S110, it is determined whether there is a capture point. That is, it is determined whether or not the target is captured by the millimeter wave radar 2 below the minimum guaranteed distance. That is, it is determined whether or not the fusion position can be obtained. If an affirmative determination is made in step S110, the process proceeds to step S111. If a negative determination is made, the routine is terminated to use the target position estimated in step S109 as it is.

  In step S111, fusion is performed between the position obtained by the millimeter wave radar 2 and the estimated position. That is, the fusion position is determined according to the mixing ratio C.

  In this way, the position of the target is obtained. Then, when the position of the target is a predetermined position, the system ECU 8 operates the operation device 9.

  As described above, according to the present embodiment, the target position can be obtained by estimating the target position even if it is less than the minimum guaranteed distance of the millimeter wave radar 2. Thereby, since it is not necessary to use the detection result of the millimeter wave radar 2 with low accuracy as it is, unnecessary alarms and driving assistance can be suppressed.

1 Obstacle detection device 2 Millimeter wave radar 3 Radar ECU
4 Steering angle sensor 5 Yaw rate sensor 6 Wheel speed sensor 8 System ECU
DESCRIPTION OF SYMBOLS 9 Actuation device 31 Target relative position calculating part 32 Target relative speed calculating part 81 Complement flag calculating part 82 Complement flag cancel calculating part 83 Estimated position calculating part 84 Fusion position calculating part 85 Collision judgment calculating part 91 Warning device 92 Automatic brake device

Claims (8)

In an obstacle detection device that detects a target with a sensor,
When the target is not detected from the state in which the target has been detected by the sensor, the position and speed information of the target when the target has been detected by the sensor; and An obstacle characterized by comprising estimation means for estimating the position of the target when the target cannot be detected by the sensor from the elapsed time from when the target can no longer be detected by the sensor. Detection device.   The time when the target becomes undetectable is when the distance of the target is closer than a recent distance in which the performance of the sensor is guaranteed. Obstacle detection device.   The obstacle detection apparatus according to claim 1, wherein the time when the target cannot be detected is when the target is lost.   4. The obstacle detection apparatus according to claim 1, wherein the estimation unit estimates the position of the target based on a relative speed with respect to the target. 5.   5. The obstacle detection apparatus according to claim 1, wherein the estimation unit estimates a position of a target in consideration of a turning radius.   The estimation means terminates the estimation of the position of a target when a target that moves away is detected by the sensor after the target cannot be detected. The obstacle detection device according to any one of the above.   The estimation means terminates the estimation of the position of the target when a target whose distance is larger than a threshold is detected by the sensor after the target cannot be detected. Item 7. The obstacle detection device according to any one of Items 1 to 6.   The obstacle according to claim 2, further comprising fusion means for fusing the position of the target estimated by the estimation means and the position of the target detected by the sensor at a predetermined ratio. Detection device.

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