JP2006098220A - Obstacle detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an obstacle detector precluding a road face reflecting plate and a structure in an upper side of a road face from being judged as an obstacle. <P>SOLUTION: An irradiation wave is emitted to make an upper irradiation wave 30 and a lower irradiation wave 31 superposed partially, in a preceding vehicle detector 13, and a kind of an object from which the irradiation wave is reflected is determined using respective reflected wave intensities of the upper irradiation wave 30 and the lower irradiation wave 31. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an obstacle detection device that detects an obstacle near a host vehicle from a reflected wave of an irradiation wave emitted from the host vehicle.

As this type of technology, a radar device that radiates microwaves or laser light and detects a preceding vehicle ahead of the traveling direction of the host vehicle is disclosed (for example, see Patent Document 1).
Japanese Patent No. 3125496

  However, in the prior art described in Patent Document 1, since the preceding vehicle on the traveling road ahead of the host vehicle is detected from the reflected wave, a road surface reflector such as a cat's eye or a guide sign above the road When a reflected wave from a road surface upper structure such as the above is received, there is a problem that a road surface reflector or a road surface upper structure that should not be determined as an obstacle may be determined as an obstacle.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide an obstacle detection device that does not determine a road surface reflector or a road surface upper structure as an obstacle.

  In order to achieve the above object, in the present invention, in the obstacle detection apparatus for detecting an obstacle using a reflected wave of an irradiation wave irradiated in the traveling direction from the own vehicle, irradiation of an upward irradiation wave irradiated upward in the traveling direction The irradiation means for irradiating the irradiation wave so that the region and the irradiation range of the lower irradiation wave that irradiates downward in the traveling direction partially overlap, and the traveling direction from the reflected wave intensity of the upper irradiation wave and the lower irradiation wave Determining means for determining the type of the object existing in.

  In the present invention, in the obstacle detection device, it can be reduced that the road surface reflector and the road surface upper structure are judged as obstacles.

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

  First, the configuration will be described.

  FIG. 1 is an overall system diagram of a vehicle equipped with a travel control device including a preceding vehicle detection device 13 and an inter-vehicle distance control device 100 according to the first embodiment, and FIG. 2 is a system block diagram showing a configuration of the travel control device. FIG. 3 is a system diagram showing the configuration of the preceding vehicle detection device 13.

  The vehicle equipped with the travel control device is driven using the engine 1, the automatic transmission 2 that changes the engine output according to the travel state, the fuel injection control by the fuel injection control device 5, and the shift control by the transmission control device 6. Force control (according to engine brake control in some cases), braking force control using the braking fluid pressure control device 8, a control device 12 for controlling the following inter-vehicle distance, and an obstacle ahead of the host vehicle for performing the inter-vehicle distance control A preceding vehicle detection device 13 for detecting an object and detecting a distance and relative speed with respect to the preceding vehicle.

  The engine 1 is composed of a gasoline engine, a diesel engine, or the like, and the output from the engine 1 is input to the automatic transmission 2. The engine 1 is not particularly limited as long as it generates a driving force such as an electric motor regardless of the internal combustion engine.

  The automatic transmission 2 shifts between the input and output by switching the electromagnetic solenoid valve in the transmission control device 6 in accordance with the shift signal from the control device 12 to engage and release the clutch and brake, thereby automatically changing the speed. The driving force output from the machine 2 is transmitted to the drive wheels 4a and 4b via the speed reducer 3.

  The brake fluid pressure control device 8 adjusts the brake fluid pressure from the master cylinder 11 operated by the brake pedal 10 by the control signal from the control device 12, and supplies the pressure to the wheel cylinders 7a to 7d of the respective wheels.

  The control device 12 receives detection signals from various detection devices such as the brake fluid pressure sensor 9, the preceding vehicle detection device 13, the wheel speed sensor 14, the accelerator opening sensor 15, and the manual switch 16, and based on these detection signals. The calculation is performed and a control signal is output to the fuel injection control device 5, the transmission control device 6, the brake fluid pressure control device 8, and the like.

  As shown in FIG. 2, the inter-vehicle distance control device 100 includes an inter-vehicle control unit 101 that calculates and determines a 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, and a set vehicle speed and inter-vehicle control unit 101. A vehicle speed command value selection unit 102 that selects one of the determined target travel speeds as a speed command value, a vehicle speed control unit 103 that controls a driving force of an engine or the like and a braking force of a brake or the like based on the speed command value; It has.

  An operation signal from the manual switch 16 is input to the vehicle speed command value selection unit 102. The manual switch 16 is composed of, for example, a plurality of button switches, and the driver can set a desired vehicle speed (upper limit vehicle speed in follow-up traveling) and an inter-vehicle time by operating the button switches. The set vehicle speed can be input and set every 5 km / h by operating a button switch between 50 km / h and 100 km / h, for example. In addition, the set inter-vehicle time can be set by switching the three-step inter-vehicle time such as “long”, “medium”, and “short” every time the button switch is pressed.

  As shown in FIG. 3, the preceding vehicle detection device 13 is provided on the front body of the vehicle, determines whether there is an obstacle or a preceding vehicle in front of the own vehicle from the reflected wave, The inter-vehicle distance and relative speed of the vehicle are obtained by calculation processing, and the vehicle presence / absence determination information, inter-vehicle distance information and relative speed information generated here are output to the inter-vehicle control unit 101 and the vehicle speed control unit 103. As shown in FIG. 4, the preceding vehicle detection device 13 includes a laser light emitting element 203 that emits a laser as an irradiation wave in response to a command from the CPU 201, a laser light emitting circuit 202 that controls the laser light emitting element 203, and a laser for detecting the preceding vehicle. A projection window 205 for irradiating the outside of the apparatus 13, a reflection mirror 204 for scanning the irradiation wave, a stepping motor 207 for rotating the reflection mirror 204 up and down, left and right, and a motor for driving the stepping motor 207 It has a drive circuit 206, a light receiving window 208 for receiving the reflected wave, a laser light receiving element 209 for detecting the reflected wave, and a received light signal amplifying circuit 210 for amplifying a signal from the laser light receiving element 209. The preceding vehicle detection device 13 corresponds to the obstacle detection device of the present invention.

  The wheel speed sensor 14 detects the wheel speed Vwj. The vehicle speed of the host vehicle is calculated from the wheel speed Vwj, and this vehicle speed information is output to the inter-vehicle distance controller 101 and the vehicle speed controller 103.

  The inter-vehicle distance control unit 101 receives inter-vehicle distance information, relative speed information, set vehicle speed information, set inter-vehicle time information, and the like, sets an inter-vehicle distance according to the vehicle speed from these information, and calculates a target vehicle speed.

  The vehicle speed command value selection unit 102 compares the set vehicle speed with the target vehicle speed, and outputs the smaller vehicle speed to the vehicle speed control unit 103 as a vehicle speed command value.

  The vehicle speed control unit 103 receives the set vehicle speed information, the set inter-vehicle time information, the preceding vehicle inter-vehicle distance information, the relative speed information, the vehicle speed information, and the like, and fuel-injects the engine torque command value Teng determined according to the inter-vehicle distance control. The brake torque command value Tbk determined in accordance with the inter-vehicle distance control is output to the control device 5 and to the brake fluid pressure control device 8, respectively.

  The fuel injection control device 5 controls the fuel injection amount FI according to the engine torque command value Teng input from the vehicle speed control unit 103.

  The brake fluid pressure control device 8 generates a brake fluid pressure Pbk that applies a braking force to the wheels using, for example, an ABS actuator in accordance with the brake torque command value Tbk input from the vehicle speed control unit 103.

  The engine 1 and the wheel cylinders 7a to 7d make the vehicle run at a constant speed, accelerate or decelerate according to the fuel injection amount FI by the fuel injection control device 5 and the brake fluid pressure Pbk by the brake fluid pressure control device 8. Thus, the vehicle is controlled to have the set inter-vehicle time and the set vehicle speed.

  Next, the operation will be described.

[Leading vehicle detection process]
In the preceding vehicle detection process, whether the object detected when the irradiation wave is scanned horizontally is, for example, a preceding vehicle, a road surface reflector such as a cat's eye, or a road surface upper structure such as a guide sign. to decide. FIG. 5 is a flowchart showing the flow of the preceding vehicle detection process executed by the CPU 201, and each step will be described below.

  In step S1, it is determined whether or not an object is detected within the detection range (for example, 100 m) of the preceding vehicle detection device 13. If YES, the process proceeds to step S2, and if NO, the process proceeds to step S8.

  In step S2, when the upper scanning is performed by irradiating the upper irradiation wave 30 and the object is detected, the upper reflected wave intensity Bu of the reflected wave of the upper irradiation wave 30 and the distance and direction to the object are stored. In step S3, when the lower scanning is performed by irradiating the lower irradiation wave 31 and the object is detected, the upper reflected wave intensity Bu of the reflected wave of the upper irradiation wave 30, the distance to the object, and the direction are stored. As shown in FIG. 6A, the upper irradiation wave 30 and the lower irradiation wave 31 are irradiated so that the vertical position overlaps at the position of the reflector 33 mounted behind the preceding vehicle 32. Specifically, as shown in FIG. 7, the reflector mounted on the rear of the vehicle is usually mounted so that the height of the upper edge from the ground is 1500 mm or less and the height of the lower edge from the ground is 250 mm or more. Therefore, the irradiation region of the upper irradiation wave 30 and the irradiation region of the lower irradiation wave 31 are irradiated so as to overlap in a range of 250 mm or more and 1500 mm or less from the ground at a position where object detection starts (for example, 100 m ahead). Steps S2 and S3 correspond to the vertical irradiation means of the present invention.

  In step S4, the difference (Bu−Bd) between the upper reflected wave intensity Bu of the reflected wave from the upper irradiated wave 30 and the lower reflected wave intensity Bd of the reflected wave from the lower irradiated wave 31 is within a predetermined range, that is, −d1. If it is larger and smaller than d2, the process proceeds to step S5 and is determined to be a preceding vehicle. When (Bu-Bd) is equal to or greater than the predetermined value d2, the process proceeds to step S7 and is determined to be a road surface upper structure. Note that d1 and d2 are errors due to noise or the like between the upward reflected wave intensity Bu and the downward reflected wave intensity Bd from the preceding vehicle 32, and are values obtained in advance through experiments and calculations. D2 corresponds to the first predetermined value of the present invention, and d1 corresponds to the second predetermined value of the present invention. The determination in step S4 will be described with reference to FIG. As shown in FIG. 6A, the reflector 33 of the preceding vehicle 32 is irradiated with the upper irradiation wave 30 and the lower irradiation wave 31, so that the difference between the upper reflected wave intensity Bu and the lower reflected wave intensity Bd is noise. It is a range of errors such as. Further, as shown in FIG. 6B, the road surface reflecting plate 34 is irradiated only with the lower irradiation wave 31, so that the lower reflection wave intensity Bd is increased. Further, as shown in FIG. 6 (c), the road surface upper structure 35 is irradiated with only the upper irradiation wave 30, so that the upper reflected wave intensity Bu is increased. Steps S4 to S7 correspond to the reflecting object type determining means of the present invention.

  In step S <b> 8, the preceding vehicle, road surface reflector, road surface upper structure, or road object not detected which is the processing result is output to the control device 12.

[Measurement of preceding vehicle information]
The CPU 201 measures the distance and relative distance between the host vehicle and the preceding vehicle 32 from the time change of the light reception signal from the laser light receiving element 209 and outputs the measured distance to the inter-vehicle distance control device 100.

[Constant speed running]
When the preceding vehicle detection device 13 does not detect the preceding vehicle 32, the inter-vehicle distance control device 100 determines the driving force of the engine 1 and the wheel cylinder 7a so as to maintain the set vehicle speed set by the driver with the manual switch 16. Control braking force by ~ 7d. For example, if the driver sets the set vehicle speed to 100 km / h using the manual switch 16, the inter-vehicle distance control unit 101 does not output the target vehicle speed because the preceding vehicle 32 has not been detected. As a result, the vehicle speed command value selection The unit 102 selects 100 km / h of the set vehicle speed information input from the manual switch 16, and outputs 100 km / h to the vehicle speed control unit 103 as a vehicle speed command value. Thereafter, the vehicle speed control unit 103 controls the engine 1 via the fuel injection control device 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 32 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 time. Therefore, when a preceding vehicle 32 (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 101 determines the inter-vehicle distance according to the speed based on the driver's set inter-vehicle time information. Then, the target vehicle speed calculated from the relative speed between the host vehicle and the preceding vehicle 32 is output to the vehicle speed command value selection unit 102. In the vehicle speed command value selection unit 102, set vehicle speed information (here, 100 km / h) from the manual switch 16 and target vehicle speed information (here, 80 km / h) from the inter-vehicle distance control unit 101 are input. The smaller target vehicle speed is output to the vehicle speed control unit 103 as a vehicle speed command value (80 km / h in this case). The vehicle speed control unit 103 controls the fuel injection control device 5 and the brake fluid pressure control device 8 so as to achieve the set inter-vehicle time based on the input vehicle speed command value, thereby driving the engine 1 and the wheel cylinders 7a to 7d. The braking force by is controlled.

[Following running]
The vehicle is controlled to travel following the preceding vehicle 32 while maintaining the inter-vehicle time calculated according to the speed based on the set inter-vehicle time set by the driver. The inter-vehicle control unit 101 sets an inter-vehicle distance according to the vehicle speed based on the input vehicle speed information, inter-vehicle distance information, relative vehicle speed information, and set inter-vehicle time information, and calculates a target vehicle speed. The vehicle speed command value selection unit 102 selects a vehicle with a low vehicle speed from the driver's set vehicle speed information and the target vehicle speed from the inter-vehicle control unit 101 and outputs the selected vehicle speed value to the vehicle speed control unit 103 as a command vehicle speed value. The vehicle speed control unit 103 performs acceleration / deceleration control of the host vehicle via the fuel injection control device 5 and the brake fluid pressure control device 8 according to a vehicle speed command value or 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 32 in the traveling direction of the host vehicle disappears from the previous travel lane, for example, by changing the travel lane, the vehicle is accelerated to the upper limit set by the driver. At this time, the vehicle speed command value selection unit 102 inputs the driver's set vehicle speed to the vehicle speed control unit 103 as the vehicle speed command value because the inter-vehicle distance control unit 101 does not set the target vehicle speed. The vehicle speed control unit 103 increases the fuel injection amount by the fuel injection control device 5 and accelerates the host vehicle to the vehicle speed command value.

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

  (1) The upper irradiation wave 30 and the lower irradiation wave 31 are irradiated so that the vertical position partially overlaps at the position of the reflector 33 mounted behind the preceding vehicle, and the upper reflected wave intensity Bu and the lower reflected wave Since the type of the detected object can be specified by the reflection intensity with the intensity Bd, even if the road surface reflecting plate 34 or the road surface upper structure 35 is detected, a brake or the like is not activated, and a more accurate inter-vehicle distance Control can be performed.

  (2) When the difference between the upper reflected wave intensity Bu and the lower reflected wave intensity Bd is within a predetermined range (-d1 or more and d2 or less), the object reflecting the upper irradiation wave 30 and the lower irradiation wave 31 is the preceding vehicle. 32. Since the upper irradiation wave 30 and the lower irradiation wave 31 overlap in an area where the reflector of the preceding vehicle can be detected, the difference in the intensity of the reflected waves is small, and there is no reflection from the reflector due to dirt or damage of the reflector 33 In addition, since the reflected wave having substantially the same intensity is obtained by the reflection from the vehicle body, it can be determined that the obstacle is the preceding vehicle.

  (3) If the difference (Bu-Bd) between the upward reflected wave intensity Bu and the downward reflected wave intensity Bd is equal to or greater than d2, the detected object is determined to be a road surface upper structure. Thus, more accurate inter-vehicle distance control can be performed without operating a brake or the like.

  (4) If the difference (Bd-Bu) between the downward reflected wave intensity Bd and the upper reflected wave intensity Bu is equal to or less than d1, the detected obstacle is determined to be a road reflector, More accurate inter-vehicle distance control can be performed without operating a brake or the like.

  As described above, the obstacle detection device of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to these embodiments, and the invention according to each claim of the claims is described. Design changes and additions are allowed without departing from the gist.

For example, in the obstacle detection apparatus according to the first embodiment, an example in which laser light is used as an irradiation wave is shown, but a millimeter wave radar, an infrared laser, or the like may be used. In this embodiment, the preceding vehicle is detected. However, an obstacle on the road may be detected and used for a collision prevention device or the like.
In this embodiment, the upper irradiation wave 30 and the lower irradiation wave 31 are temporally separated and alternately irradiated. However, the present invention is not limited to this, for example, the upper irradiation wave 30 and the lower irradiation wave 31. And may be irradiated simultaneously. In this case, in order to distinguish the reflected wave from the upper irradiation wave 30 and the reflected wave from the lower irradiation wave 31, for example, the frequency of each irradiation wave is set to a different frequency band, and the detectors sensitive to the respective frequency bands are separately provided. It should be provided in.

  The present invention not only identifies the type of obstacle detected using the reflected wave of the irradiation wave emitted from the own vehicle and performs inter-vehicle distance control on the preceding vehicle, but also obstacles other than the preceding vehicle on the road, etc. It can also be used for other vehicle control such as a collision prevention device that detects the situation and gives a warning or the like to the driver.

1 is an overall system diagram of a vehicle equipped with a travel control device according to a first embodiment. 1 is a system block diagram illustrating a configuration of a travel control device according to a first embodiment. It is a figure which shows the attachment position of the preceding vehicle detection apparatus based on Example 1. FIG. 1 is a system block diagram illustrating a configuration of a preceding vehicle detection device according to a first embodiment. 3 is a flowchart illustrating a flow of a preceding vehicle detection process according to the first embodiment. It is a figure explaining the detection method of the preceding vehicle by the preceding vehicle detection apparatus based on Example 1, a road surface reflecting plate, and a road surface upper structure. It is a figure which shows the mode of the overlap of an upper irradiation wave and a lower irradiation wave based on Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Automatic transmission 3 Reducer 4a, 4b, 4c, 4d Drive wheel 5 Fuel injection control device 6 Transmission control device 7a, 7b, 7c, 7d Wheel cylinder 8 Braking fluid pressure control device 9 Braking fluid pressure sensor 10 Brake Pedal 11 Master cylinder 12 Control device 13 Leading vehicle detection device 14 Wheel speed sensor 15 Accelerator opening sensor 16 Manual switch 30 Upper irradiation wave 31 Lower irradiation wave 32 Leading vehicle 33 Reflector 34 Road surface reflector 35 Road surface upper structure 100 Inter-vehicle distance control Device 101 Distance control unit 102 Vehicle speed command value selection unit 102 Speed command value selection unit 103 Vehicle speed control unit 201 CPU
202 Laser Light Emitting Circuit 203 Laser Light Emitting Element 204 Reflecting Mirror 205 Light Projecting Window 206 Motor Driving Circuit 207 Stepping Motor 208 Light Receiving Window 209 Laser Light Receiving Element 210 Light Receiving Signal Amplifying Circuit

Claims (5)

In the obstacle detection device that detects an obstacle using the reflected wave of the irradiation wave irradiated in the traveling direction from the own vehicle,
Irradiation means for irradiating the irradiation wave such that an irradiation region of the upper irradiation wave irradiated upward in the traveling direction and an irradiation range of the lower irradiation wave irradiated downward in the traveling direction partially overlap;
Determining means for determining the type of an object existing in the traveling direction from the reflected wave intensity of each of the upper irradiation wave and the lower irradiation wave;
An obstacle detection device comprising: The obstacle detection device according to claim 1,
The determination means determines that the reflected object is a vehicle when the difference between the intensity of the reflected wave of the upper irradiation wave and the intensity of the reflected wave of the lower irradiation wave is within a predetermined range. Obstacle detection device. In the obstacle detection device according to claim 1 or 2,
The determination means has a structure in which the reflected object exists above the road when a value obtained by subtracting the intensity of the reflected wave of the lower irradiation wave from the intensity of the reflected wave of the upper irradiation wave in the previous period is equal to or greater than a first predetermined value. An obstacle detection apparatus characterized by determining that the object is an object. In the obstacle detection device according to any one of claims 1 to 3,
The determination means determines whether the reflected object is a structure on the road surface when a value obtained by subtracting the intensity of the reflected wave of the upper irradiation wave from the intensity of the reflected wave of the lower irradiation wave is equal to or greater than a second predetermined value. It is judged that it is. The obstacle detection apparatus characterized by the above-mentioned. In the obstacle detection device according to any one of claims 1 to 4,
The said irradiation means irradiates the same irradiation wave alternately as the said upper irradiation wave and the said lower irradiation wave to the advancing direction upward and downward, The obstacle detection apparatus characterized by the above-mentioned.

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