JP2009075638A - Vehicle type discrimination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle type discrimination device for discriminating types of other vehicles by using detection means mounted on a vehicle. <P>SOLUTION: A vehicle type discrimination device 1 for determining types of vehicles includes vehicle detection means 3a for detecting the vehicles; frame detection means 3b for detecting frames of vehicle bodies of the vehicles detected by the detection means 3a; and vehicle type discrimination means 3c discriminating the types according to the presence/absence and/or shapes of the frames on the basis of detection results of the detection means 3b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle type discrimination device that discriminates a vehicle type of a vehicle.

In order to reduce the driving load on the driver, various traveling control devices that provide driving assistance have been developed. Some travel control devices perform inter-vehicle distance control in order to follow the vehicle ahead. When inter-vehicle control is performed, the front vehicle is detected based on the image captured by the camera or radar information from the radar, and when the front vehicle is detected, the inter-vehicle distance from the front vehicle is calculated, and the inter-vehicle distance from the front vehicle is set as the target. Brake control and engine control are performed so that the distance between vehicles is the same. Further, some inter-vehicle distance control makes the target inter-vehicle distance variable according to the vehicle type of the preceding vehicle. For example, when the front vehicle is a large vehicle such as a truck, the target inter-vehicle distance is made longer than that of a passenger car. For that purpose, it is necessary to discriminate the vehicle type, and a vehicle type discriminating apparatus has been developed. For example, in the vehicle type discriminating device described in Patent Document 1, the horizontal distance to the side surface of the vehicle body is detected by a plurality of radar ranging sensors arranged in the vertical direction, and the vehicle type is discriminated based on the unevenness of the side surface of the vehicle body.
Japanese Patent Laid-Open No. 9-62983 JP 2003-44995 A JP 2003-30792 A

  When the vehicle type information is used during vehicle control such as inter-vehicle control, it is necessary to determine the vehicle type at an arbitrary place while the vehicle is running. Therefore, it is essential to use detection means mounted on the vehicle. However, since the above-described vehicle type identification device needs to arrange a radar distance sensor on the side surface of the vehicle to be identified, the vehicle type identification can be performed only at a predetermined place where the radar distance sensor is disposed. The on-board detection means cannot discriminate the vehicle type.

  Then, this invention makes it a subject to provide the vehicle type discrimination | determination apparatus which discriminate | determines the vehicle type of another vehicle using the detection means mounted in the vehicle.

  A vehicle type discriminating apparatus according to the present invention is a vehicle type discriminating apparatus that is mounted on a vehicle and discriminates the vehicle type of the vehicle. The vehicle type discriminating device detects a vehicle and a vehicle body frame detected by the vehicle detecting unit. It is characterized by comprising a frame detection means and a vehicle type discrimination means for discriminating the vehicle type based on the presence or absence and / or shape of the frame based on the detection result of the frame detection means.

  In this vehicle type discrimination device, the vehicle is detected by the vehicle detection means, and the frame in the vehicle body detected by the frame detection means is detected. Generally, in the case of a passenger car, the frame of the vehicle body cannot be detected from the outside of another vehicle, but in the case of a large vehicle such as a truck, the frame of the vehicle body can be detected from the outside. Therefore, the vehicle type determination device determines the vehicle type based on whether or not the vehicle type frame can be detected by the vehicle type determination unit and the shape of the detected body frame (for example, parallel to the rear surface of the vehicle body). Thus, in this vehicle type discrimination device, the vehicle type of another vehicle can be discriminated using detection means mounted on the vehicle.

  In the above-described vehicle type identification device of the present invention, it is preferable that the frame detection means detects a frame that supports the differential gear of the rear wheel and / or the drive shaft of the rear wheel. In the case of a large vehicle such as a truck, the frame that supports the differential gear of the rear wheel and the drive shaft is disposed at a position where it can be seen from the rear of the vehicle. Therefore, the vehicle type can be easily identified by using this frame.

  The vehicle type discrimination device according to the present invention includes a radar detection unit, and the frame detection unit uses a reflection point detected by the laser detection unit to support the differential gear of the rear wheel and / or the drive shaft of the rear wheel. It is good also as a structure which detects.

  In this vehicle type discriminating apparatus, an electromagnetic wave is transmitted from a vehicle by a radar detection means, a reflected wave of the electromagnetic wave is received, and a reflection point is detected based on the transmission / reception data. In the vehicle type identification device, the frame detecting means detects the frame that supports the differential gear and the drive shaft of the rear wheel based on the reflection point. In the case of radar detection means, the distance to the reflection point can be detected with high accuracy based on the electromagnetic wave transmission / reception data. Can be determined. Further, since the frame is made of metal, it easily reflects electromagnetic waves and is easily detected by the radar detection means.

  In the vehicle type discriminating apparatus of the present invention, it is preferable that the vehicle type discriminating means discriminates a truck when a frame supporting the differential gear of the rear wheel and / or the drive shaft of the rear wheel is detected. In the case of a truck, since the space portion below the vehicle body is higher than other vehicle types, there are many portions where the frame supporting the differential gear of the rear wheel and the drive shaft is exposed to the outside, and it is easy to detect from other vehicles.

  In the vehicle type identification device of the present invention, the vehicle type identification unit may be configured to discriminate a track when the number of reflection points detected by the laser detection unit is equal to or greater than a threshold value.

  The frame that supports the differential gear and drive shaft on the rear wheel of the truck is a frame that is arranged between the tires on the left and right rear wheels, so it has a certain length in the left-right direction (vehicle width direction) according to the vehicle width of the truck. Have. Therefore, when the electromagnetic waves from the radar detection means are reflected with respect to the frame of the truck, the number of reflection points is smaller than when the electromagnetic waves are reflected with respect to other parts of the truck (excluding the rear surface of the vehicle body). Become more. Therefore, the vehicle type discriminating apparatus discriminates a truck when a reflection point equal to or greater than the threshold value can be detected. The threshold is set in consideration of the resolution of the laser detection means.

  In the vehicle type discriminating apparatus of the present invention, the vehicle type discriminating means includes a plurality of lines reflected from the line of the plurality of reflection points reflected by the frame detected by the laser detecting means and the back of the vehicle body detected by the laser detecting means. A configuration may be adopted in which a track is determined when a straight line obtained from the arrangement of reflection points is substantially parallel.

  In the case of a truck, the frame that supports the differential gears and the drive shaft on the rear surface of the vehicle body and the rear wheels has a certain length in the left-right direction according to the vehicle width of the truck. Therefore, when the electromagnetic wave from the radar detection means is reflected on the frame of the truck or the back of the vehicle body, the number of reflection points increases, and a straight line can be obtained from the arrangement of the reflection points. Further, the rear surface of the vehicle body and the frame are parallel to each other in plan view. Therefore, the vehicle type discriminating apparatus can discriminate a truck when the obtained two straight lines are substantially parallel.

  According to the present invention, by using the detection result of the frame of the vehicle body by the detection means mounted on the vehicle, the vehicle type of the other vehicle can be determined using the detection means mounted on the vehicle.

  Hereinafter, an embodiment of a vehicle type identification device according to the present invention will be described with reference to the drawings.

  In the present embodiment, the vehicle type identification device according to the present invention is mounted on a vehicle type identification device mounted on a vehicle. The vehicle type discriminating apparatus according to the present embodiment discriminates the vehicle type of a vehicle existing ahead of the host vehicle and provides the vehicle type information to a vehicle control device (such as an inter-vehicle control device).

  With reference to FIGS. 1-5, the vehicle type discrimination | determination apparatus 1 which concerns on this Embodiment is demonstrated. FIG. 1 is a configuration diagram of a vehicle type identification device according to the present embodiment. FIG. 2 is an example of a track viewed from the back. FIG. 3 is a schematic diagram showing a detection state of the laser radar when a track is present ahead. FIG. 4 is an explanatory diagram of processing in the vehicle detection unit of FIG. FIG. 5 is an explanatory diagram of processing in the vehicle body lower frame detection unit of FIG.

  The vehicle type discriminating apparatus 1 discriminates a passenger car and a truck as the vehicle type of the preceding vehicle. For this purpose, the vehicle type determination device 1 performs determination based on the presence / absence of the lower frame of the vehicle body and the shape of the frame (arrangement relationship with the rear surface of the vehicle body). For this purpose, the vehicle type identification device 1 includes a laser radar 2 and an ECU [Electronic Control Unit] 3.

  The laser radar 2 is a radar for detecting an object using laser light. The laser radar 2 is attached to the front center of the host vehicle. The laser radar 2 emits laser light forward from the host vehicle while scanning the laser light horizontally at predetermined intervals in the vertical direction H (vertical direction), and receives the reflected radar light. Then, the laser radar 2 calculates a reflection point from the emitted light and reflected light data of the laser beam, and calculates the position of the reflection point (relative position from the host vehicle), the distance to the reflection point, and the like. Then, the laser radar 2 transmits information regarding the reflection point to the ECU 3 as a radar signal. The ECU 3 may calculate the position of the reflection point and the distance to the reflection point. In the present embodiment, the laser radar 2 corresponds to the radar detection means described in the claims.

  Incidentally, in the case of the truck T, as shown in FIGS. 2 and 3, the vehicle height is high, the space portion of the lower part of the vehicle body is higher than the passenger car A, and the lower part of the vehicle body that supports the differential gear G and the drive shaft of the rear wheel. Frame F comes out below the vehicle. This frame F can be detected from the passenger car A behind the truck T, and since it is metallic, it reflects the laser light well. Therefore, when the truck T is present in front of the passenger car A on which the vehicle type identification device 1 is mounted, the detection K2 for the frame F can be performed in addition to the detection K1 for the rear surface B of the truck T by the detection by the laser radar 2. In addition, the frame F is disposed in parallel with the rear surface B of the vehicle body in plan view in terms of the vehicle body structure.

  The ECU 3 is an electronic control unit including a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like, and comprehensively controls the vehicle type identification device 1. The ECU 3 loads the application program stored in the ROM onto the RAM and executes it by the CPU, thereby configuring the vehicle detection unit 3a, the vehicle body lower frame detection unit 3b, and the vehicle type determination unit 3c. Then, the ECU 3 receives a radar signal from the laser radar 2 at regular intervals, performs processing in each unit 3a, 3b, 3c using the radar signal, and transmits the determined vehicle type information to the vehicle control device as a vehicle type signal. . In the present embodiment, the vehicle detection unit 3a corresponds to the vehicle detection unit described in the claims, and the lower body frame detection unit 3b corresponds to the frame detection unit described in the claims. The part 3c corresponds to a vehicle type discrimination means described in the claims.

  The vehicle detection unit 3a extracts a reflection point where the distance between the host vehicle and the reflection point is equal to or less than the inter-vehicle distance threshold value from the reflection point information of the radar signal in order to determine whether or not a vehicle ahead is present. The inter-vehicle distance threshold is a threshold for determining whether or not the vehicle exists within a distance that can be recognized as a front vehicle to be controlled in performing vehicle control such as inter-vehicle distance control, and includes a target inter-vehicle distance used for vehicle control, etc. Is set in advance. That is, since the vehicle ahead is far away from the control object, the vehicle type is not determined.

  In the vehicle detection unit 3a, in order to select only the reflection points reflected on the back of the vehicle body of the preceding vehicle, the point interval (vehicle front-rear direction D (depth direction)) of the extracted reflection point group is equal to or less than the interval threshold value. Group. The interval threshold is determined in advance by an experiment or the like in consideration of the distance detection accuracy by the laser radar 2 or the like. When the laser beam of the laser radar 2 is reflected on the back surface of the vehicle body, the distance between the own vehicle and the reflection point is substantially equal for all of the reflection points, so that the reflection point group can be grouped. However, if a plurality of groups can be grouped, the group with the shortest distance between the host vehicle and the reflection point is selected. In the case of a truck, since it is reflected by the back of the vehicle body and the frame, two groups may be formed, and the back surface of the vehicle body is closer to the host vehicle.

  The vehicle detection unit 3a determines whether or not the number of grouped reflection points is equal to or greater than a vehicle presence / absence determination threshold value. If there are many reflection points where the distance between the vehicle and the reflection point is less than the inter-vehicle distance threshold and the point interval is less than or equal to the interval threshold, it can be assumed that the reflection point is reflected from the back of the vehicle body having a large area, and there is a vehicle ahead. Can be judged. The vehicle presence / absence determination threshold is determined in advance by an experiment or the like in consideration of the resolution of the laser radar 2 or the like. The vehicle detection unit 3a determines that there is a vehicle ahead when it is determined that the number of grouped reflection points is equal to or greater than the vehicle presence / absence determination threshold.

  In the vehicle detection unit 3a, when a small number of reflection points whose distance between the host vehicle and the reflection point is equal to or less than the inter-vehicle distance threshold value are extracted or not extracted at all, or the number of grouped reflection points is determined to be less than the vehicle presence / absence determination threshold value. In this case, it is determined that there is no preceding vehicle, and the vehicle type is not determined.

  The vehicle body lower frame detection unit 3b calculates a straight line from the grouped reflection point group. Any method may be used as the method for obtaining the straight line, for example, Hough transform is used. This straight line is a straight line formed from an array of reflection points on the rear surface of the vehicle body of the preceding vehicle, and extends in the left-right direction W (vehicle width direction). Further, the vehicle body lower frame detection unit 3b extracts end points on both sides in the left-right direction W from the grouped reflection point group. Then, the vehicle body lower frame detection unit 3b draws a perpendicular line from each end point on both sides of the obtained straight line, and sets a line segment having the lowered points as both ends. This line segment is a line segment along the rear surface of the vehicle body.

  In the example shown in FIG. 4, the reflection points BP11,..., BP19 are grouped, and a straight line L1 is obtained from the reflection points BP11,. Further, a line segment S1 (thick line) is obtained from the straight line L1 based on the end points BP11, BP19 on both sides in the left-right direction W among the reflection points BP11,.

  The vehicle body lower frame detection unit 3b uses the obtained line segment S1 as one side, and extends a side having a predetermined length orthogonal to the one side in the front-rear direction D (depth direction) of the host vehicle to form a rectangle. This is a reflection point detection area. The predetermined length is set in advance to a length (for example, 5 m) sufficiently including the rear wheel frame from the rear surface of the vehicle in consideration of the distance between the rear surface and the rear wheel frame of various trucks.

  In the example shown in FIG. 5, sides N1 and N2 having a predetermined length M are extended from the vehicle segment to the front side from the line segment S1 corresponding to the rear surface of the vehicle body to form a rectangular detection region R.

  The vehicle body lower frame detection unit 3b counts the number of reflection points included in the detection area based on the reflection point information of the radar signal, and determines whether or not the count number is greater than or equal to a threshold value. In the case of a passenger car, there is almost no part that reflects the laser light other than the back of the vehicle body, so it can be estimated that the number of reflection points included in this detection region is 0 or a small number. On the other hand, in the case of a truck, there is a rear-wheel body lower frame as a part that reflects the laser beam in addition to the rear surface of the vehicle body. Since the lower frame of the vehicle body extends in the vehicle width direction W and is a long object disposed between the left and right rear wheels, the area where the laser beam can be reflected is large and the number of reflection points is also large. Therefore, when the vehicle ahead is a truck, it can be estimated that there are many reflection points included in the detection region. The number threshold is set in advance by experiments or the like in consideration of the resolution of the laser radar 2 or the like. When the number of reflection points included in the detection area is greater than or equal to a threshold value, the lower body frame detection unit 3b determines that there is a possibility that the lower body frame exists.

  In the vehicle type discrimination | determination part 3c, when the vehicle body lower frame detection part 3b determines with the number of the reflective points contained in a detection area being more than a several threshold value, a straight line is calculated from the arrangement | sequence of the reflective points contained in the detection area. In this case as well, as described above, it is also possible to group those whose point interval is equal to or smaller than the interval threshold value and obtain a straight line from the grouped reflection points. The method for obtaining the straight line is the same as described above. Further, the vehicle type discriminating unit 3c extracts end points on both sides in the left-right direction W from the reflection points for which the straight line has been obtained. In the vehicle type discriminating unit 3c, a perpendicular line is drawn to each end point on both sides of the obtained straight line, and a line segment having both ends of the lowered point is set. This line segment is highly likely to be a line segment along the lower body frame.

  The vehicle type discriminating unit 3c calculates a difference in inclination (angle formed) between the line segment corresponding to the rear surface of the vehicle body and the line segment obtained in the detection area. Then, the vehicle type determination unit 3c determines whether or not the difference in inclination is less than the angle threshold value. In the case of a truck, as described above, the rear surface of the vehicle body and the lower frame of the vehicle body are arranged in parallel. Therefore, when the line segment corresponding to the back of the vehicle body and the line segment obtained in the detection area are substantially parallel (including parallel), the line segment obtained in the detection area is the reflection point reflected by the lower frame of the vehicle body. It can be estimated as a line segment formed from the line. The angle threshold is a threshold for determining whether or not they are substantially parallel. If the vehicle type discriminating unit 3c determines that the difference in inclination is less than the angle threshold value, the vehicle type discriminating unit 3c determines that the lower body frame is present, and discriminates the vehicle type as a truck.

  In the case of the example shown in FIG. 5, a straight line L2 is obtained from the reflection points BP21,..., BP28 in the detection region R. Further, a line segment S2 (thick line) is obtained from the straight line L2 based on both end points BP21, BP28 in the vehicle width direction W among the reflection points BP21,. Since the line segment S1 corresponding to the rear surface of the vehicle body and the line segment S2 in the detection region R are substantially parallel, the line segment S2 in the detection region R is a line segment corresponding to the vehicle body lower frame.

  In the vehicle type discriminating unit 3c, when the lower body frame detecting unit 3b determines that the number of reflection points included in the detection area is less than the threshold value or when the difference in inclination is determined to be equal to or greater than the angular threshold value, there is no lower body frame. Therefore, it is determined that the lower frame of the vehicle body does not exist, and is determined to be a passenger car.

  With reference to FIGS. 1-5, the operation | movement in the vehicle classification device 1 is demonstrated. In particular, the operation of the ECU 3 will be described along the flowchart of FIG. FIG. 6 is a flowchart showing a flow of processing in the ECU of FIG.

  In the laser radar 2, the laser beam is emitted forward while scanning horizontally, the reflected radar beam is received, the reflection point is obtained from the emission light and reflected light data of the laser beam, and the position of the reflection point is determined. And the distance to the reflection point. Then, the laser radar 2 transmits radar information consisting of each information of the reflection point to the ECU 3 as a radar signal at regular time intervals.

  The ECU 3 receives a radar signal and acquires radar information (reflection point information) at regular time intervals (S1). Then, the ECU 3 detects the forward vehicle based on the reflection point of the radar information (S2). Here, the forward vehicle is detected by a group of reflection points that are closest to the host vehicle and whose point interval is equal to or smaller than the interval threshold (a group of reflection points on the back of the vehicle body of the forward vehicle). If the vehicle ahead cannot be detected, the current process is terminated without performing vehicle type discrimination.

  The ECU 3 calculates a line segment corresponding to the rear surface of the vehicle body from the arrangement of the reflection points of the group that detected the front vehicle (S3). Further, the ECU 3 forms a rectangle composed of a line segment corresponding to the rear surface of the vehicle body as one side and a side having a predetermined length orthogonal to the one side, and the vehicle body of the vehicle detected in the depth direction D of the host vehicle. It is set as a detection area for the reflection point of the lower frame (S4).

  The ECU 3 extracts reflection points included in the detection area from the radar information, and determines whether or not the number of extracted reflection points is equal to or greater than a threshold value (S5). If it is determined in S5 that the number of reflection points is less than the threshold value, the ECU 3 cannot detect the lower body frame from the detected vehicle, so the front vehicle is determined as a passenger car (S9), and the vehicle type information is used as the vehicle type signal. Send to control device.

  If it is determined in S5 that the number of reflection points is equal to or greater than a threshold value, the ECU 3 calculates a line segment from the arrangement of reflection points in the detection area (S6). Then, the ECU 3 calculates a difference (angle) in inclination between the line segment corresponding to the rear surface of the vehicle body and the line segment obtained in the detection area, and determines whether the angle is less than the angle threshold value (S7). If it is determined in S7 that the angle is equal to or greater than the angle threshold, the ECU 3 determines that the vehicle ahead is a passenger car (S9) because the line segment obtained in the detection area is not a line segment corresponding to the lower body frame (S9). Information is transmitted to the vehicle control device as a vehicle type signal.

  When it is determined in S7 that the angle is less than the angle threshold, the ECU 3 determines that the detected vehicle has a lower body frame positioned parallel to the rear surface of the vehicle body, determines that the vehicle ahead is a truck (S8), and information on the vehicle type Is transmitted as a vehicle type signal to the vehicle control device.

  According to this vehicle type discriminating apparatus 1, the vehicle type of the preceding vehicle can be discriminated using the laser radar 2 mounted on the vehicle. In particular, in the vehicle type discriminating device 1, the vehicle type is discriminated based on the presence / absence of the lower body frame that supports the differential gear and the drive shaft of the rear wheel of the truck and the arrangement relationship between the rear surface of the car body, so the discrimination accuracy is high, The vehicle type can be easily identified.

  In this vehicle type discriminating apparatus 1, since the laser radar 2 is used as the detecting means, it is easy to detect a metallic frame or the back of the vehicle body, and the distance accuracy to the reflection point is high. Further, in the vehicle type identification device 1, each line segment is calculated from the arrangement of the reflection points, and by using the angle formed by the two line segments, the presence / absence of the lower frame of the vehicle body and the positional relationship between the frame and the rear surface of the vehicle body can be easily obtained. And it can judge with high precision.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in this embodiment, the present invention is applied to a vehicle type discriminating device that discriminates between a passenger car and a truck, but it can also be applied to discriminating other vehicle types (for example, buses, RV vehicles) in which a frame can be seen outside the vehicle body. It is good also as a structure incorporated in the other apparatus (for example, vehicle distance control apparatus) which needs vehicle type information.

  In this embodiment, the laser radar is applied as the radar detection means. However, other detection means such as a millimeter wave radar may be used, or any means other than the radar detection means may be used as long as it can detect the frame and the back of the vehicle body. Detection means may be used.

  Further, in the present embodiment, the lower body frame that supports the differential gear and the drive shaft of the rear wheel is set as the detection target, but another frame that is visible outside the vehicle body may be set as the detection target.

  In this embodiment, the straight line due to the reflection point reflected from the rear surface of the vehicle body and the straight line due to the reflection point reflected from the lower frame of the vehicle body are substantially parallel, but the lower frame of the vehicle body can be detected in addition to the rear surface of the vehicle body. Only the condition may be used.

It is a block diagram of the vehicle type discrimination | determination apparatus which concerns on this Embodiment. It is an example of the track seen from the back. It is a schematic diagram which shows the detection condition of the laser radar when a track exists ahead. It is explanatory drawing of the process in the vehicle detection part of FIG. It is explanatory drawing of the process in the vehicle body lower frame detection part of FIG. It is a flowchart which shows the flow of the process in ECU of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle type discrimination | determination apparatus, 2 ... Laser radar, 3 ... ECU, 3a ... Vehicle detection part, 3b ... Vehicle body lower frame detection part, 3c ... Vehicle type discrimination | determination part

Claims (6)

A vehicle type identification device that is mounted on a vehicle and determines the vehicle type of the vehicle,
Vehicle detection means for detecting a vehicle;
Frame detecting means for detecting a frame of a vehicle body detected by the vehicle detecting means;
A vehicle type discriminating device comprising: a vehicle type discriminating unit that discriminates a vehicle type based on the presence or absence and / or shape of a frame based on a detection result of the frame detection unit.   2. The vehicle type identification device according to claim 1, wherein the frame detection means detects a frame that supports a differential gear for a rear wheel and / or a drive shaft for a rear wheel. Equipped with radar detection means,
3. The frame detection unit detects a frame that supports a differential gear of a rear wheel and / or a drive shaft of a rear wheel using a reflection point detected by the laser detection unit. Car type discriminating device.   4. The vehicle type discriminating apparatus according to claim 2, wherein the vehicle type discriminating unit discriminates the vehicle from a truck when detecting a frame that supports a differential gear of a rear wheel and / or a drive shaft of a rear wheel. .   5. The vehicle type determination device according to claim 4, wherein the vehicle type determination unit determines that the vehicle is a truck when the number of reflection points detected by the laser detection unit is equal to or greater than a threshold value.   The vehicle type discriminating means is obtained from a straight line obtained from an arrangement of a plurality of reflection points reflected by a frame detected by the laser detection means and an arrangement of a plurality of reflection points reflected from the back of the vehicle body detected by the laser detection means. 6. The vehicle type discriminating apparatus according to claim 5, wherein the vehicle type discriminating device is discriminated as a truck when the straight line is substantially parallel.

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