JP2006038698A - Another vehicle detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an another vehicle detection apparatus which can discriminate whether the origin of a reflected wave is another vehicle or other objects such as a road structure. <P>SOLUTION: The another vehicle detection apparatus for detecting another vehicle using a reflected wave of an irradiation wave irradiated by an own vehicle comprises an another vehicle decision means (Step S3 to Step S5) for deciding the presence or absence of another vehicle from an intensity pattern of the reflected wave. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an other vehicle detection device that receives a reflected wave of an irradiation wave emitted from an own vehicle and detects another vehicle near the own vehicle.

This type of technology includes changes in the inter-vehicle distance and reflected signal intensity obtained from this reflected signal by emitting micro light or laser light to the front of the vehicle, and whether or not the vehicle is traveling in a curve. By using the determination result and recognizing the change of the detected preceding vehicle, it is determined that the detection target has shifted from the preceding lane preceding vehicle to another vehicle traveling in the adjacent lane. Therefore, the mode of the following traveling or constant speed traveling is changed to another new mode so that smooth traveling can be continued. (For example, refer to Patent Document 1).
Japanese Patent No. 3125496

  However, in the prior art described in Patent Document 1, the road structure having the same reflection intensity is detected because the preceding vehicle is detected and the tracking control mode transition is performed by relying only on the temporal change in the reflection intensity. It is impossible to distinguish a stationary object such as other vehicles from other vehicles, which causes a road structure to be misrecognized as another vehicle, and the vehicle's brake is applied to approach a stationary road structure. As a result, the driver may feel uncomfortable.

  The present invention has been made paying attention to the above problems, and the object of the present invention is that the reflected wave causes the reflected wave to be another vehicle or other object such as a road structure. It is providing the other vehicle detection apparatus which can distinguish whether there exists.

  In order to achieve the above problem, in the present invention, in another vehicle detection device that detects another vehicle using the reflected wave of the irradiation wave emitted from the own vehicle, the presence or absence of the other vehicle is determined from the intensity pattern of the reflected wave. Other vehicle determination means is provided.

  In the present invention, the other vehicle detection device can distinguish other vehicles from other objects such as road structures, so that a more precise detection result can be obtained and an unnecessary brake is activated. Can be suppressed.

  The best mode for carrying out another vehicle detection apparatus of the present invention will be described below with reference to the drawings.

  First, the configuration will be described.

  FIG. 1 is a system block diagram showing the configuration of an inter-vehicle distance control device provided with another vehicle detection device of the present invention.

  The inter-vehicle distance control device 100 for a vehicle has a setting unit 1 for inputting a set vehicle speed desired by the driver (upper limit vehicle speed during follow-up traveling) and a desired set inter-vehicle distance, and the inter-vehicle distance and relative speed between the host vehicle and the preceding vehicle. A preceding vehicle inter-vehicle detection unit 8 that detects the vehicle speed, a vehicle speed detection unit 9 that detects the vehicle speed of the host vehicle, and an inter-vehicle control unit that calculates and determines the target vehicle speed from the inter-vehicle distance between the host vehicle and the preceding vehicle according to the vehicle speed of the host vehicle. 2, a vehicle speed command value selection unit 3 that selects a lower vehicle speed from the set vehicle speed of the driver and the target vehicle speed determined by the inter-vehicle distance control unit 2, and uses the speed command value to drive an engine or the like And a vehicle speed control unit 4 that controls force and braking force of the brake.

  In the setting unit 1, the driver can set the set vehicle speed and the set inter-vehicle distance by operating a button switch or the like. The set vehicle speed can be input and set every 5 km / h with a button switch between 50 km / h and 100 km / h, for example. The set inter-vehicle distance can be set, for example, every three times by pressing a button switch, such as “long”, “medium”, and “short”. The setting unit 1 outputs the set vehicle speed information and the set inter-vehicle distance information set here to the inter-vehicle control unit 2, the vehicle speed command value selection unit 3, and the vehicle speed control unit 4.

  The preceding vehicle inter-vehicle distance detection unit 8 is provided on the front body of the vehicle, and transmits a transmitter that irradiates an irradiation wave or the like toward the traveling direction of the host vehicle, and a reflected wave reflected by an object in front of the host vehicle. A receiver for receiving. As the irradiation wave, laser radar, millimeter wave radar, infrared radar, sonar, or the like is used. The preceding vehicle distance detection unit 8 determines whether or not there is another vehicle ahead of the host vehicle from the reflected wave, calculates the inter-vehicle distance and relative speed between the host vehicle and the preceding vehicle, and generates the vehicle generated here. Presence / absence determination information, inter-vehicle distance information Dps, and relative speed information are output to the inter-vehicle control unit 2 and the vehicle speed control unit 4. Further, it is determined whether or not an object in front of the host vehicle is a vehicle by the processing described later, and permission or prohibition of inter-vehicle distance control in the inter-vehicle distance control unit 2 or the vehicle speed control unit 4 is commanded according to the determination result.

  The vehicle speed detector 9 calculates the vehicle speed based on a signal from a vehicle speed sensor (not shown), and outputs the vehicle speed information VSP to the setting unit 1, the inter-vehicle distance controller 2, and the vehicle speed controller 4.

  The inter-vehicle distance control unit 2 receives inter-vehicle distance information Dps, relative speed information, vehicle speed information VSP, set inter-vehicle distance information, etc., sets the inter-vehicle distance according to the vehicle speed from these information, and calculates the target vehicle speed. .

  The vehicle speed command value selection unit 3 compares the set vehicle speed information with the target vehicle speed information, and outputs the vehicle speed command value to the vehicle speed control unit 4 as the vehicle speed command value.

  The vehicle speed control unit 4 receives the set vehicle speed information, the set inter-vehicle distance information, the preceding inter-vehicle distance information, the relative speed information, the vehicle speed information, and the like, and uses the engine torque command value Teng determined according to the inter-vehicle distance control as a driving force. The brake torque command value Tbk determined in accordance with the inter-vehicle distance control is output to the control unit 5 and to the hydraulic brake control unit 6.

  The driving force control unit 5 controls the accelerator opening AP using, for example, an electronically controlled throttle actuator in accordance with the engine torque command value Teng input from the vehicle speed control unit 4.

  In response to the brake torque command value Tbk input from the vehicle speed control unit 4, the hydraulic brake control unit 6 generates a brake hydraulic pressure Pbk0 that applies braking force to the wheels using, for example, an ABS actuator.

  The engine 7a and the brake 7b move the vehicle at a constant speed, accelerate or decelerate according to the accelerator opening AP by the driving force control unit 5 and the brake hydraulic pressure Pbk0 by the hydraulic brake control unit 6. Is controlled to be the set inter-vehicle distance and the set vehicle speed.

Next, the operation will be described.
[Other vehicle determination process]

  FIG. 2 is a flowchart showing a flow of control for determining whether or not an object in the traveling direction of the host vehicle is a vehicle in the other vehicle detection apparatus of the first embodiment.

  In step S1, the preceding vehicle distance detection unit 8 performs a forward object presence / absence determination process for determining whether or not there is an object in the traveling direction of the host vehicle, and proceeds to step S2. That is, in the object presence / absence determination processing, in order to determine whether or not there is an object in the traveling direction of the host vehicle, the reflected light is received by irradiating the laser beam in the traveling direction of the host vehicle. If the strength is greater than or equal to a predetermined value, it is determined that there is an obstacle or an object estimated to be a following vehicle in the traveling direction.

  In step S2, if it is determined in step S1 that there is an object in front, the preceding vehicle distance detector 8 further has the same height as the reflectors 10 attached to both rear sides of the vehicle 11 as shown in FIG. Scanning with a laser beam is performed in the lateral direction as indicated by an arrow in the figure, and the detection angle and reflection intensity of the reflected wave of the object ahead are detected.

  In step S3, the peak portion is detected from the reflected wave waveform pattern obtained in step S2. If two peaks are detected, the process proceeds to step S4. If two peaks are not detected, the process proceeds to step S7.

  FIG. 4 is a diagram showing a detection example when there is another vehicle in front of the host vehicle as a result of the scanning, the detection angle when the direction of the reflected wave is detected on the horizontal axis, and the reflection intensity of the reflected wave on the vertical axis. Indicates. If the detected object is a vehicle, the reflected wave is detected as a waveform pattern having two large peak values separated in the horizontal axis direction as shown by a solid line in FIG. In this way, the two large peaks appear at the detection angle positions obtained by scanning the two reflectors behind the vehicle.

In step S4, it is determined whether or not the central reflection intensity divided by the peak intensity is equal to or greater than the first threshold value PD. If YES, the process proceeds to step S5, and if NO, the process proceeds to step S7. Here, in FIG. 4, the peak intensity is the intensity A ₀ at the peak detection positions θ _P1 and θ _P2 of the reflected wave, and the center intensity is the intensity A at the center position θ _A between the peak detection positions θ _P1 and θ _P2 or A '. When a vehicle ahead is detected, a waveform as shown by a solid line in FIG. 4 is detected. For example, when a radio wave is applied to two reflectors on a guardrail, a waveform as shown by a dashed line in FIG. 4 is detected. There are things to do.

Between the two peak detection positions θ _P1 and θ _{P2, as} a result of interference of reflected waves from the left and right reflectors, the reflection intensity is higher than that outside the peak detection positions θ _P1 and θ _P2 . In addition, when a reflected wave from the vehicle ahead is detected, there is a metal body between the left and right reflectors, so the reflected wave from the body also interferes, so compared to other obstacles where there is no detected object between the reflectors. As a result, the reflection intensity increases. Using this characteristic, in step S4, it is determined whether the object detected by the reflected wave is another vehicle or a road structure.

  Since each reflection intensity changes according to the distance between the host vehicle and the obstacle, the first threshold value PD is set according to the distance between the host vehicle and the obstacle as shown in FIG. The first threshold value PD is set to increase as the distance from the obstacle increases. The magnitude of the first threshold value PD is obtained by calculation or experiment so that it can be determined whether or not it is a reflected wave from the vehicle. Further, FIG. 5 does not show what is actually used as the first threshold value PD, but schematically shows the tendency thereof.

In step S5 shown in FIG. 4, the center intensity at the detection position theta _A reflection intensity B of the peak detection position theta _P1 central intensity detected position theta _A fraction, at the detection position theta _B folded back in the opposite direction to this It is determined whether or not what is divided by A or A ′ is smaller than the second threshold BD. If YES, the process proceeds to step S6, and if NO, the process proceeds to step S7.

Note that the reflection intensity _B at the detection position θ _B has substantially the same value for both the reflection intensity from the reflector of the vehicle and the reflection intensity from other reflectors. In addition, as described above, the central reflection intensity A ′ from the vehicle is compared with the central reflection intensity A ′ of the two reflection plates other than the vehicle. Is big. In step S5 using this characteristic, in addition to the determination in step S4, it is further determined whether the object detected by the reflected wave is another vehicle or a road structure. Here, since each reflection intensity changes according to the distance between the own vehicle and the obstacle, the second threshold BD is similar to the first threshold PD as shown in FIG. 6 between the own vehicle and the obstacle. A value is set according to the distance, and the second threshold value BD is set to increase as the distance from the obstacle increases. The magnitude of the second threshold value is obtained by calculation or experiment so that it can be determined whether or not the reflected wave is from the vehicle. Further, FIG. 6 does not show what is actually used as the second threshold value BD, but schematically shows the tendency thereof.

  In step S6, 1 is input to the inter-vehicle distance control permission flag to permit inter-vehicle distance control to the inter-vehicle distance controller 2 and the vehicle speed controller 4.

On the other hand, in step S7, 0 is input to the inter-vehicle distance control permission flag to prohibit inter-vehicle distance control for the inter-vehicle distance controller 2 and the vehicle speed controller 4.
[Constant speed running]

When a preceding vehicle is not detected by the preceding vehicle distance detection unit 8, the inter-vehicle distance control device for the vehicle controls the host vehicle 11 that is a control target so as to maintain the set vehicle speed set by the driver in the setting unit 1. . For example, if the driver sets the set vehicle speed to 100 km / h, the inter-vehicle control unit 2 does not output the target vehicle speed because no preceding vehicle is detected, and the vehicle speed command value selection unit 3 100 km / h of the input set vehicle speed information is selected, and 100 km / h is output to the vehicle speed control unit 4 as a vehicle speed command value. Thereafter, the vehicle speed control unit 4 controls the host vehicle via the driving force control unit 5 while monitoring vehicle speed information and the like so as to maintain the driver's set vehicle speed of 100 km / h.
[Deceleration]

When there is a preceding vehicle that is slower than the current vehicle speed of the host vehicle in the traveling direction of the host vehicle, the vehicle is decelerated so as to maintain the inter-vehicle distance. At this time, when a preceding vehicle (for example, 80 km / h) slower than the driver's set vehicle speed (for example, 100 km / h) is detected, the inter-vehicle control unit 2 determines the inter-vehicle distance according to the speed based on the driver's set inter-vehicle information, and the own vehicle And the target vehicle speed calculated from the relative speed with the preceding vehicle is output to the vehicle speed command value selection unit 3. The vehicle speed command value selection unit 3 inputs the set vehicle speed information (here, 100 km / h) from the setting unit 1 and the target vehicle speed information (here, 80 km / h) from the inter-vehicle distance control unit 2, and the smaller vehicle speed Is output to the vehicle speed control unit 4 as a vehicle speed command value (80 km / h in this case). The vehicle speed control unit 4 controls the engine 7a and the brake 7b via the driving force control unit 5 and the hydraulic brake control unit 6 so as to achieve the vehicle speed command value and the set inter-vehicle distance.
[Following running]

  The vehicle is controlled such that the vehicle travels following the preceding vehicle while maintaining the inter-vehicle distance calculated according to the speed based on the set inter-vehicle distance set by the driver. In the inter-vehicle control unit 2, the vehicle speed information, the inter-vehicle distance information, the relative vehicle speed information, and the set inter-vehicle distance information are input, the inter-vehicle distance according to the vehicle speed is set, and the target vehicle speed is calculated. The vehicle speed command value selection unit 3 selects a vehicle with a low vehicle speed from the set vehicle speed information of the driver and the target vehicle speed from the inter-vehicle distance control unit 2 and outputs it to the vehicle speed control unit 4 as a command vehicle speed value. The vehicle speed control unit 4 performs acceleration / deceleration control of the control target (vehicle) 7 via the driving force control unit 5 and the hydraulic brake control unit 6 according to the vehicle speed command value and the like.

Note that the vehicle speed at this time is set to the upper limit of the set vehicle speed set by the driver, and when the vehicle speed exceeds the set vehicle speed, the follow-up running is stopped and constant speed running is performed.
[Acceleration running]

  When the preceding vehicle in the traveling direction of the host vehicle is no longer moving in the travel lane, the vehicle is accelerated if the vehicle speed is lower than the driver's set vehicle speed. At this time, since the target vehicle speed is not set in the inter-vehicle distance control unit 2 in the vehicle speed command value selection unit 3, the set vehicle speed of the driver is input to the vehicle speed control unit 4 as the vehicle speed command value. The vehicle speed control unit 4 accelerates the control target (vehicle) 7 to the vehicle speed command value via the driving force control unit 5.

  Next, the effect of the object detection apparatus of the first embodiment will be described.

  (1) In addition to confirming the presence of an object, it can be determined whether or not the object is another vehicle from the peak of the reflected wave, and more accurate object detection can be performed.

  (2) Since it is possible to determine whether or not the obstacle in the traveling direction of the vehicle is a vehicle, when performing inter-vehicle distance control with the vehicle, unnecessary braking is performed by performing inter-vehicle distance control on obstacles other than the vehicle. And the inter-vehicle distance control can be performed without causing the driver to feel uncomfortable.

  (3) When two peaks are detected in the waveform of the reflected wave, the center intensity A or A ′ between the peaks can be compared with the peak intensity A0 to determine whether the obstacle is a vehicle. Therefore, more accurate vehicle determination can be performed. Therefore, the possibility of erroneous recognition of the vehicle determination is reduced, and the inter-vehicle distance control can be performed without causing the driver to feel uncomfortable when performing the inter-vehicle distance control.

(4) When two peaks were detected in the waveform of the reflected wave, the reflection intensity of the center intensity A or A 'and the center with respect to the peak position theta _P intensity detection position theta _A at symmetrical positions θB between the peak B Can be determined whether or not the obstacle is a vehicle, so that more accurate vehicle determination can be performed. Therefore, the possibility of erroneous recognition of the vehicle determination is reduced, and the inter-vehicle distance control can be performed without causing the driver to feel uncomfortable when performing the inter-vehicle distance control.

  As mentioned above, although the other vehicle detection apparatus of the vehicle of this invention has been demonstrated based on Example 1, it is not restricted to these Examples about a concrete structure, It concerns on each claim of a claim Design changes and additions are allowed without departing from the spirit of the invention.

  For example, in the first embodiment, vehicle determination is performed in step S4 and step S5, respectively, but any one of them may be used. Further, it may be possible to detect only a running vehicle by combining the determination of whether the vehicle is moving or the obstacle is moving. Further, the laser beam may be scanned during the object presence / absence determination process in step S1.

  The present application can detect other vehicles and can be used for other vehicle detection devices and the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole system figure which shows the inter-vehicle distance control apparatus of the vehicle provided with the other vehicle detection apparatus of this invention based on Example 1. FIG. 3 is a flowchart illustrating a flow of processing executed by the other vehicle detection device according to the first embodiment. It is a figure which shows the mode of the scanning by an electromagnetic wave based on Example 1. FIG. It is a figure which shows the reflected wave waveform obtained by the scanning by an electromagnetic wave based on Example 1. FIG. It is a figure which shows the relationship of the distance of threshold value PD, the own vehicle, and an obstruction based on Example 1. FIG. It is a figure which shows the relationship of the distance of threshold value BD, the own vehicle, and an obstruction based on Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Setting part 2 Vehicle distance control part 3 Vehicle speed command value selection part 4 Vehicle speed control part 5 Driving force control part 6 Hydraulic brake control part 7a Engine 7b Brake 8 Leading vehicle distance detection part 9 Vehicle speed detection part 10 Reflector 11 Vehicle

Claims (4)

In the other vehicle detection device that detects the other vehicle using the reflected wave of the irradiation wave emitted from the own vehicle,
Another vehicle detection device comprising: another vehicle determination means for determining the presence or absence of another vehicle from the intensity pattern of the reflected wave. The other vehicle detection device according to claim 1,
The other vehicle detection device detects the presence of another vehicle when the intensity pattern of the reflected wave has the two peaks. The other vehicle detection device according to claim 2,
The other vehicle determining means determines the presence or absence of the other vehicle by comparing the center intensity at the center position of the two peaks of the waveform pattern of the reflected wave with the peak intensity of the peak. Other vehicle detection device characterized. In the other vehicle detection device according to claim 2 or 3,
The other vehicle determination means compares the center intensity at the center position of the two peaks of the reflected wave with the intensity at the symmetrical position obtained by symmetrically folding the position of the center intensity with respect to the peak position. The other vehicle detection device, wherein the presence / absence of the other vehicle is determined.

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