JP2015032154A - Collision prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision prevention device which enables a vehicle to perform more proper collision prevention.SOLUTION: A collision prevention device 1 comprises: detection means 2 which detects a pedestrian in front of a vehicle; calculation means 3a which calculates crossing speed V of the pedestrian on the basis of a detection result of the detection means 2; and determination means 3b which determines whether the pedestrian stops crossing or not. When the determination means 3b determines affirmative, the calculation means 3a reduces a time for calculating the crossing speed V.

Description

  The present invention relates to a collision prevention apparatus that is suitable for use in vehicles such as passenger cars, trucks, and buses.

  Recent vehicles may be equipped with a PCS (Pre Crash Safety System) as one form of driver assistance, and this PCS tends to control pedestrians that are crossing along with obstacles such as preceding vehicles. It's getting higher. For example, in the PCS described in Patent Document 1, a time-series change in the position of a pedestrian existing in front of the host vehicle and a time-series change in moving speed are acquired to determine whether or not the pedestrian jumps out toward the vehicle. ing.

JP 2010-102437 A

  However, there are many cases where a pedestrian who is crossing interrupts the crossing immediately before coming into contact with the host vehicle, and it is difficult to accurately determine whether or not the situation should originally prevent collision. That is, in the prior art, it has not been possible to perform collision prevention more appropriately.

  An object of this invention is to provide the collision prevention apparatus which can aim at collision prevention more appropriately in view of the said problem.

  In order to solve the above problems, a collision preventing apparatus according to the present invention includes a detection unit that detects a pedestrian in front of a vehicle, and a calculation unit that calculates a crossing speed of the pedestrian based on a detection result of the detection unit. And determining means for determining whether or not the pedestrian has stopped crossing, and when the determining means determines affirmative, the calculating means shortens the calculation time of the crossing speed. The calculation time may be shortened by reducing the number of time-series data used for the calculation, or by shortening the calculation cycle. Moreover, the said determination means may perform the said determination based on the said crossing speed, and may perform the said determination based on the said pedestrian's face direction (line of sight). In the latter case, a face orientation detecting means may be provided.

  According to the present invention, when a pedestrian stops crossing, the stop can be appropriately determined. That is, it is possible to prevent the collision prevention function from functioning as appropriate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an embodiment of a collision prevention apparatus 1 according to an embodiment of the present invention. It is a flowchart which shows the control content of the collision prevention apparatus 1 of an Example. It is a schematic diagram which shows the control result of the collision prevention apparatus 1 of an Example.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  The collision prevention apparatus 1 of an Example has the form shown in FIG. The collision prevention device 1 includes a millimeter wave radar 2, an ECU 3, and a camera 4. The millimeter wave radar 2 constitutes detection means for detecting an obstacle including a pedestrian in front of the vehicle on which the collision prevention apparatus 1 is mounted, and outputs a detection result to the ECU 3. The millimeter wave radar 2 may be replaced with other devices such as a laser radar and a camera.

  The ECU 3 includes, for example, a CPU, a ROM, a RAM, a data bus that connects them, and an input / output interface. The CPU performs predetermined processing according to a program stored in the ROM. The ECU 3 constitutes a calculation means 3a that performs processing described below and a determination means 3b.

  The camera 4 includes a CCD camera or a CMOS camera and a built-in microcomputer, images an area including a pedestrian located in front of the vehicle, digitizes the captured image, performs image processing, and performs image processing. A face orientation signal S indicating the face orientation is generated, and this face orientation signal S is output to the ECU 3 as an output signal. The face orientation may be replaced with a line of sight.

  The calculation means 3 a of the ECU 3 calculates a lateral position P and a crossing speed V in the vehicle width direction of the pedestrian's vehicle based on the detection result from the millimeter wave radar 2. The computing means 3a computes the lateral position P and the crossing speed V based on a history of N data, which is a sum of N-1 data of the current value and the previous value for each predetermined control period.

  The determination means 3b of the ECU 3 determines “whether or not the pedestrian has stopped crossing” based on the lateral position P, the crossing speed V, and the face direction signal S. More specifically, the determination unit 3b combines the current value of the crossing speed V, which is the fluctuation amount of the lateral position P, and M data (M <N), which is M−1 data smaller than the previous value N−1. The determination is affirmative in the OR condition whether the history of the data of) is equal to or less than a certain threshold value Vth or the pedestrian is looking at the vehicle based on the face direction signal S. The OR condition may be an AND condition. Further, in the determination described above, the determination unit 3b may make a negative determination when the pedestrian stops crossing after the lateral position P of the pedestrian has already reached the vehicle width of the vehicle.

  When the determination unit 3b determines that the determination is affirmative, the calculation unit 3a calculates the M data including the current value and the previous value of M-1 data for each predetermined control period for the crossing speed V. The crossing speed V is calculated based on the history.

  Hereinafter, the control content of the collision preventing apparatus 1 according to the embodiment will be described with reference to the flowchart of FIG. As shown in step S1, the determination means 3b performs the determination of “whether or not the crossing person's stop action has been detected”, that is, “whether or not the pedestrian has stopped crossing” based on the above-described method. If the determination is affirmative, the process proceeds to step S2, and if the determination is negative, the process proceeds to step S3.

  In step S2, the calculation means 3a calculates M data including the current value and M-1 data of the previous value for each predetermined control period for the lateral position P and the crossing speed V that is a change amount thereof. Calculate based on the history and reduce the calculation time. That is, the vector calculation result of the lateral position P and the crossing speed V is subtracted (calculated) by the shortened time. Note that the calculation time may be shortened by resetting the previous value (forcing the crossing speed V to zero based on detection of stop of crossing).

  In step S3, the calculation means 3a does not shorten the calculation time, but based on a history of N data that combines the current value and the previous value of N-1 data for each predetermined control period for the crossing speed V. To calculate the crossing speed V.

  As described above, the collision preventing apparatus 1 according to the embodiment is provided for preventing collision when “when the pedestrian stops crossing” or “when the pedestrian stops crossing and is not located within the vehicle width”. Does not brake. In addition, N mentioned above shall be 5-10, for example, M can be set to the integer value of 2-3 with a value smaller than N, for example.

  As shown in FIG. 3, the collision prevention apparatus 1 according to the embodiment described above improves the responsiveness of the calculation result of the crossing speed V and approaches the behavior of the actual crossing speed Vr as compared with the crossing speed Vc obtained by the conventional calculation method. be able to. That is, for example, as shown in FIG. 3, when the pedestrian crosses at a certain speed and stops crossing and the crossing speed V becomes zero, the behavior of the crossing speed V that is the calculation result is the behavior of the actual crossing speed Vr. The delay can be made smaller than the conventional calculation method.

  For this reason, the embodiment can quickly determine whether or not the pedestrian has stopped crossing, and can immediately stop the brake operation for preventing the collision when the pedestrian stops the crossing. That is, in the embodiment, the collision prevention function can function more appropriately, and the brake operation in an unnecessary scene can be eliminated. In addition, except for the case where the pedestrian stops crossing, the embodiment can increase the calculation accuracy by calculating the crossing speed V by a normal calculation method.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

  In the collision prevention apparatus for assisting the driver of the vehicle according to the present invention, it is possible to more appropriately determine the case where the collision prevention is unnecessary, and to prevent the collision prevention from functioning when the collision prevention is unnecessary. For this reason, this invention can function a collision prevention function more appropriately. Therefore, the present invention is useful when applied to various vehicles such as passenger cars, trucks, and buses.

1 Collision prevention device 2 Millimeter wave radar (detection means)
3 ECU
3a calculation means 3b determination means 4 camera (face orientation detection means)

Claims (1)

  Detection means for detecting a pedestrian in front of the vehicle, calculation means for calculating the pedestrian's crossing speed based on the detection result of the detection means, and determining whether or not the pedestrian has stopped crossing. An anti-collision apparatus comprising: a determination unit, wherein when the determination unit determines affirmative, the calculation unit reduces the calculation time of the crossing speed.

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