Vehicle detector, method for adjusting vehicle detector, and program

Abstract

To provide a vehicle detector capable of automatically adjusting optical axes of a projector and a light receiver into optimal directions.SOLUTION: A vehicle detector comprises: a projector unit including a projector which projects inspection light; a light receiver unit including a light receiver which is opposed to the projector while interposing a lane therebetween and receives the inspection light; a measurement section for measuring a light-receiving state of the inspection light by the light receiver; a first drive section for tilting a first unit, which is one of the projector unit and the light receiver unit, in a lane width direction; and a determination section for determining a tilt angle closer to a center of a range of the tilt angle, in which a light-receiving amount of the inspection light of the light receiver, than a tilt angle in an end of the range as a tilt angle in a normal driving mode of the first unit based on the light-receiving state of the light receiver measured by the measurement section while the first drive section changes the tilt angle of the first unit from a first angle to a second angle.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a vehicle detector, a method for adjusting the vehicle detector, and a program.

Background Art

[0002] In some toll booths on toll roads, there may be a vehicle detector for detecting the presence of vehicles entering the toll booth. As the vehicle detector, for example, a transmissive vehicle detector including a light projecting tower and a light receiving tower that face each other across a lane is used. The light projecting tower includes a plurality of light projectors arranged side by side in the vertical direction, and the light receiving tower includes a plurality of light receivers arranged side by side in the vertical direction. Each light projector projects light toward each light receiver, and the light receiver detects the light coming from the light projector. When a vehicle exists between the light projector and the light receiver, the light projected by the light projector is blocked by the vehicle and is not detected by the light receiver. The vehicle detector can detect the presence or absence of a vehicle on the lane by such a mechanism.

[0003] For such a vehicle detector, it is necessary to substantially align the optical axes with each other so that the light projected from each light projector is correctly detected by each light receiver. For example, Patent Document 1 describes a method of adjusting the installation position and orientation of the light projecting tower and the light receiving tower while checking a notification display (light emitting device) capable of notifying whether the light projected from the light projector is received by the light receiver by an operator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If the vertical deviation of the optical axes of the projector and the light receiver is within the allowable range, the light receiver can receive the light from the projector. However, if the deviation of the optical axis is large (close to the upper or lower limit of the allowable range), the margin against external factors such as mud and dirt adhering during the operation of the vehicle detector becomes small, and there is a possibility that malfunction (false detection) is likely to occur. Therefore, it is necessary to align the directions of the optical axes of the projector and the light receiver so that the margin against external factors is maximized.

[0006] In the prior art, since the adjustment of the optical axis is performed only by confirming that the light receiver has received light, there is no way for the operator to know the magnitude of the margin against external factors. For this reason, depending on the skill of the operator performing the adjustment, it has been difficult to adjust the optical axis to the direction in which the margin is maximized.

[0007] The present disclosure has been made in view of such problems, and provides a vehicle detector, a method for adjusting a vehicle detector, and a program that can automatically adjust the optical axes of a projector and a light receiver to an optimal direction.

Means for Solving the Problems

[0008] According to one aspect of the present disclosure, a vehicle detector includes a projector unit fixed to the lane-facing side of a first support member extending in the vertical direction and having a projector that projects inspection light, and a light receiver facing the projector with the lane therebetween, the light receiver being fixed to the lane-facing side of a second support member extending in the vertical direction and having a light receiver that receives the inspection light, a measurement unit that measures the light reception state of the inspection light by the light receiver, a first drive unit that tilts a first unit, which is one of the projector unit and the light receiver unit, in the lane width direction, and a determination unit that determines, from the light reception state of the light receiver measured by the measurement unit while the first drive unit changes the tilt angle of the first unit from a first angle to a second angle, an inclination angle closer to the center of a range of inclination angles in which the light reception amount of the inspection light by the light receiver becomes equal to or greater than a predetermined value, among the range of inclination angles that are the end portions of the range, as the inclination angle in the normal operation mode of the first unit.

[0009] According to one aspect of the present disclosure, a method for adjusting a vehicle detector includes a light projector unit fixed to a lane-facing side of a first support member extending in the vertical direction and having a light projector that projects inspection light, and a light receiver facing the light projector with a lane therebetween, the light receiver being fixed to a lane-facing side of a second support member extending in the vertical direction and having a light receiver that receives the inspection light, and a first drive unit that tilts a first unit, which is one of the light projector unit and the light receiver unit, in the lane width direction. The method for adjusting the vehicle detector includes measuring a light reception state of the inspection light by the light receiver, and determining, from the light reception state of the light receiver measured while the first drive unit changes the tilt angle of the first unit from a first angle to a second angle, a tilt angle closer to the center of a range of tilt angles in which the light reception amount of the inspection light by the light receiver is equal to or greater than a predetermined value, among the range of tilt angles, as the tilt angle of the first unit in the normal operation mode.

[0010] According to one aspect of the present disclosure, a program causes a vehicle detector including a light projector unit fixed to a lane-facing side of a first support member extending in the vertical direction and having a light projector that projects inspection light, a light receiver facing the light projector with a lane therebetween, the light receiver being fixed to a lane-facing side of a second support member extending in the vertical direction and having a light receiver that receives the inspection light, and a first drive unit that tilts a first unit, which is one of the light projector unit and the light receiver unit, in the lane width direction, to execute a step of measuring a light reception state of the inspection light by the light receiver, and a step of determining, from the light reception state of the light receiver measured while the first drive unit changes the tilt angle of the first unit from a first angle to a second angle, a tilt angle closer to the center of a range of tilt angles in which the light reception amount of the inspection light by the light receiver is equal to or greater than a predetermined value, among the range of tilt angles, as the tilt angle of the first unit in the normal operation mode.

Advantages of the Invention

[0011] According to the vehicle detector, the adjustment method of the vehicle detector, and the program according to the present disclosure, the optical axes of the projector and the light receiver can be automatically adjusted so as to be in an optimal orientation.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0013] <First Embodiment> Hereinafter, a vehicle detector according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 7.

[0014] (Overall Configuration of Tollgate) FIG. 1 is a diagram showing the overall configuration of a tollgate according to the first embodiment of the present disclosure. As shown in FIG. 1, a toll collection facility 1 is provided at the tollgate of the toll road. This toll collection facility 1 is provided, for example, at the entrance tollgate, exit tollgate, etc. of the toll road. In this embodiment, an example where the toll collection facility 1 is provided at the exit tollgate will be described.

[0015] Vehicle A on which the user of the toll road rides travels on lane L that leads from the toll road side to the general road side. On both sides in the width direction of lane L, a right island IR and a left island IL are laid. Various devices constituting the toll collection facility 1 are installed on the right island IR and the left island IL. In this embodiment, the right island IR is provided on the right side (-Y direction side) in the width direction of lane L, and the left island IL is provided on the left side (+Y direction side) in the width direction of lane L.

[0016] In this embodiment, the right island IR and the left island IL are formed symmetrically with each other across lane L, and an example where they extend along lane L is illustrated.

[0017] The toll collection facility 1 performs toll collection processing based on wireless communication for the user boarding vehicle A. As shown in FIG. 1, the toll collection facility 1 includes an entrance-side vehicle detector 10, a communication stop vehicle detector 20, and a communication antenna 30.

[0018] The entrance-side vehicle detector 10 includes a light projection tower 11 and a light reception tower 12 that face each other across lane L in the lane width direction (±Y direction). Further, the communication stop vehicle detector 20 includes a light projection tower 21 and a light reception tower 22 that face each other across lane L in the lane width direction (±Y direction).

[0019] The entrance-side vehicle detector 10 and the communication-stop vehicle detector 20 are each capable of detecting the presence of vehicle A at their respective installation positions. In the toll collection facility 1 according to the present embodiment, for example, when the entrance-side vehicle detector 10 detects the entry of vehicle A, radio waves are transmitted from the communication antenna 30, and toll collection processing (wireless communication) is started with the in-vehicle device mounted on vehicle A. Further, when the communication-stop vehicle detector 20 detects that vehicle A has "passed through the rear end" (the rear end of vehicle A has passed by the installation position of the communication-stop vehicle detector 20), the radio waves transmitted from the communication antenna 30 are controlled to stop.

[0020] In this way, the toll collection facility 1 appropriately controls the operations of various devices according to the detection results of the vehicles by the entrance-side vehicle detector 10 and the communication-stop vehicle detector 20.

[0021] (Structure of the vehicle detector) Next, the structures of the respective vehicle detectors (entrance-side vehicle detector 10, communication-stop vehicle detector 20) included in the toll collection facility 1 will be described in detail. In the following description, the entrance-side vehicle detector 10 will be described as an example, but the same applies to the communication-stop vehicle detector 20 and other vehicle detectors (not shown). In the following description, the entrance-side vehicle detector 10 will also be simply referred to as the "vehicle detector".

[0022] FIG. 2 is a diagram showing the structure of the vehicle detector according to the first embodiment. FIG. 2 schematically shows the structure of the vehicle detector 10. Hereinafter, the structure of the vehicle detector 10 will be described in detail with reference to FIG. 2.

[0023] First, the structure of the light projection tower 11 will be described in detail.

[0024] The light projection tower 11 includes a light projector unit 110, a housing 111, a drive unit 112, and a control unit 113.

[0025] The projector unit 110 consists of a projector 110a and a support member 110b. The projector 110a includes a light-emitting element such as an infrared LED (Light Emitting Diode), and a lens or the like that suppresses the diffusion of light (inspection light) from the light-emitting element. With this configuration, the projector 110a has a directivity such that it emits the largest amount of light in the direction of its optical axis E. The support member 110b is a plate-shaped or columnar member that extends in the vertical direction (±Z direction). The projector 110a is fixed to the surface of the support member 110b facing the lane L (-Y direction side surface).

[0026] The projector unit 110 according to this embodiment has a plurality of projectors 110a as shown in FIG. 2. The plurality of projectors 110a are arranged in a row in the vertical direction (±Z direction). The plurality of projectors 110a are all fixed to the support member 110b such that the optical axis E faces the direction in which the light receiving tower 12 is installed (-Y direction), that is, such that the largest amount of light is emitted in the direction in which the light receiver 120a is installed. Each projector 110a is attached such that their respective optical axes E are parallel to each other.

[0027] The housing 111 is formed to cover the projector unit 110, the drive unit 112, and the control unit 113. An opening 111a is provided on the surface of the housing 111 facing the lane L so that the inspection light projected by each projector 110a can travel from the inside of the housing 111 to the outside along the optical axis E. In addition, in order to suppress the intrusion of rainwater or the like from the outside into the inside of the housing 111, each opening 111a is shielded by a transparent plate.

[0028] The drive unit 112 tilts the projector unit 110 in the lane width direction (±Y direction).

[0029] FIG. 3 is a schematic diagram of the projector unit and the light receiver unit according to the first embodiment. As shown in FIG. 3, the drive unit 112 according to this embodiment is a motor provided substantially at the vertical center of the projector unit 110. The drive unit 112 rotates the projector unit 110 around the rotation axis 112a to tilt the projector unit 110 so that the optical axis E of the projector 110a faces upward (+Z direction) or downward (-Z direction).

[0030] As shown in FIG. 3, the projector unit 110 has the position P5 where each projector 110a is arranged vertically as the default position. Also, the tilt angle of the projector unit 110 at the default position P5 is set to 0 degrees. The projector unit 110 can be tilted to the first position P1 tilted by an angle θ1 (for example, -10 degrees) to the left side in the width direction (+Y direction side) of the lane L and to the second position P2 tilted by an angle θ2 (for example, +10 degrees) to the right side in the width direction (-Y direction side). The first position P1 is the upper limit position when the optical axis E of the projector 110a faces upward. The second position P2 is the lower limit position when the optical axis E of the projector 110a faces downward.

[0031] The values of the angle θ1 and the angle θ2 are set according to the dimensions and device arrangement in the housing 111 so that the projector unit 110 does not interfere with other devices in the housing 111 or the optical axis E of the projector 110a is not blocked by the housing 111.

[0032] The control unit 113 is a computer that controls the operation of the projection tower 11. Details of the functional configuration of the control unit 113 will be described later.

[0033] Next, the structure of the light receiving tower 12 will be described in detail.

[0034] As shown in FIG. 2, the light receiving tower 12 includes a light receiver unit 120, a housing 121, a drive unit 122, and a control unit 123.

[0035] The light receiver unit 120 is composed of a light receiver 120a and a support member 120b. The light receiver 120a includes a light receiving element such as an infrared light receiving PD (Photo Diode), and a lens or the like that condenses light (inspection light) onto the light receiving element. With this configuration, the light receiver 120a has a directivity such that the largest amount of light is incident from the direction of its optical axis R. The support member 120b is a plate-like or columnar member extending in the vertical direction (±Z direction). The light receiver 120a is fixed to the surface of the support member 120b facing the lane L (the surface on the +Y direction side).

[0036] The light receiver unit 120 according to the present embodiment has a plurality of light receivers 120a as shown in FIG. 2. The plurality of light receivers 120a are arranged in a line in the vertical direction (±Z direction). The plurality of light receivers 120a are all fixed to the support member 120b so that light can be incident from the direction where the light projection tower 11 is installed (+Y direction). Each light receiver 120a is attached such that its respective optical axis R is parallel to each other. Each light receiver 120a is arranged to face each light projector 110a of the light projection tower 11 and receives the light (inspection light) projected by each light projector 110a.

[0037] The housing 121 is formed to cover the light receiver unit 120, the drive unit 122, and the control unit 123. The housing 121 is provided with an opening 121a so that the inspection light projected by each light projector 110a can travel from the outside to the inside of the housing 121. In order to suppress the intrusion of rainwater or the like from the outside into the inside of the housing 121, each opening 121a is shielded by a transparent plate.

[0038] The drive unit 122 tilts the light receiver unit 120 in the lane width direction (±Y direction).

[0039] As shown in FIG. 3, the drive unit 122 is a motor provided substantially at the center in the vertical direction of the light receiver unit 120. The drive unit 122 tilts the light receiver unit 120 by rotating the light receiver unit 120 around the rotation shaft 122a so that the optical axis R of the light receiver 120a faces upward (+Z direction) or downward (-Z direction).

[0040] As shown in FIG. 3, the light receiver unit 120 has the position P6 where the light receivers 120a are arranged vertically as the default position. Also, the inclination angle of the light receiver unit 120 at the default position P6 is set to 0 degrees. The light receiver unit 120 can be inclined up to the third position P3 inclined by an angle θ3 (for example, -10 degrees) to the right side (-Y direction side) in the width direction of the lane L and up to the fourth position P4 inclined by an angle θ4 (for example, +10 degrees) to the left side (+Y direction side) in the width direction. The third position P3 is the upper limit position when the optical axis R of the light receiver 120a faces upward. The fourth position P4 is the lower limit position when the optical axis R of the light receiver 120a faces downward.

[0041] The values of the angle θ3 and the angle θ4 are set according to the dimensions and device arrangement in the housing 121 so that the light receiver unit 120 does not interfere with other devices in the housing 121 or the optical axis R of the light receiver 120a is not blocked by the housing 121.

[0042] Note that the position where the drive unit 112 of the light projection tower 11 is provided is not limited to the position illustrated in FIG. 3. For example, the drive unit 112 may be provided at a part such as the lower end (-Z side end) or the upper end (+Z side end) of the light projector unit 110. The same applies to the drive unit 122 of the light receiver tower 12.

[0043] Further, the drive unit 112 of the light projection tower 11 may further have a handle mechanism that allows an operator to manually change the inclination angle of the light projector unit 110 in case of a motor failure or the like. The same applies to the drive unit 122 of the light receiver tower 12.

[0044] The control unit 123 is a computer that controls the operation of the light receiver tower 12. Details of the functional configuration of the control unit 123 will be described later.

[0045] (Functional Configuration of Vehicle Detector) FIG. 4 is a block diagram showing the functional configuration of the vehicle detector according to the first embodiment. First, with reference to FIG. 4, the functional configuration of the control unit 113 of the light projection tower 11 will be described. As shown in FIG. 4, the control unit 113 includes a processor 113A, a memory 113B, a storage 113C, and an interface 113D.

[0046] By operating according to a predetermined program, the processor 113A functions as an operation mode reception unit 1130, an angle control unit 1131, and a light emission control unit 1132.

[0047] The operation mode reception unit 1130 receives a selection of one of "normal operation mode" and "adjustment mode".

[0048] In the adjustment mode, the angle control unit 1131 controls the drive unit 112 so as to continuously change the tilt angle of the projector unit 110 from the angle θ1 to the angle θ2 at a constant speed.

[0049] The light emission control unit 1132 controls the start and stop of light projection by each projector 110a. In the adjustment mode, the light emission control unit 1132 controls the projector 110a to project inspection light while the drive unit 112 is changing the tilt angle of the projector unit 110.

[0050] The predetermined program executed by the processor 113A is stored in a computer-readable recording medium. The computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. Also, this computer program may be distributed to a computer via a communication line, and the computer that has received this distribution may execute the program. Furthermore, this program may be for realizing a part of the above-described functions. Moreover, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

[0051] Memory 113B has a memory area necessary for the operation of processor 113A.

[0052] Storage 113C is a so-called auxiliary storage device, such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc.

[0053] Interface 113D is an interface for transmitting and receiving information with the control unit 123 of the light receiving tower 12 and the maintenance computer 50.

[0054] Next, with reference to FIG. 4, the functional configuration of the control unit 123 of the light receiving tower 12 will be described. As shown in FIG. 4, the control unit 123 includes a processor 123A, a memory 123B, a storage 123C, and an interface 123D.

[0055] By operating according to a predetermined program, processor 123A functions as an operation mode reception unit 1230, an angle control unit 1231, a determination unit 1232, and a measurement unit 1233.

[0056] The operation mode reception unit 1230 receives a selection of one of "normal operation mode" and "adjustment mode" from the operator. For example, when the operator adjusts the optical axis of the vehicle detector 10, the maintenance computer 50 is connected to the control unit 123 of the light receiving tower 12, and an operation to select the "adjustment mode" is performed via the maintenance computer 50. Also, when the optical axis adjustment is completed, the operator performs an operation to select the "normal operation mode" via the maintenance computer 50. The maintenance computer 50 transmits a signal specifying either mode to the control unit 123 according to the operator's operation. The operation mode reception unit 1230 of the control unit 123 switches the mode of the light receiving tower 12 based on the signal received from the maintenance computer 50.

[0057] In addition, when the operation mode reception unit 1230 of the light receiving tower 12 receives the selection of the operation mode, it notifies the selected operation mode to the light projecting tower 11 so that the operation mode of the light projecting tower 11 is interlocked and switched. Then, based on the notification from the light receiving tower 12, the operation mode reception unit 1130 of the light projecting tower 11 switches the operation mode of the light projecting tower 11 to the same mode as that of the light receiving tower 12.

[0058] The angle control unit 1231 controls the drive unit 122 so as to continuously change the tilt angle of the light receiver unit 120 from the angle θ3 to the angle θ4 at a constant speed.

[0059] The determination unit 1232 determines the tilt angles of the light projector unit 110 and the light receiver unit 120 in their respective normal operation modes.

[0060] Specifically, the determination unit 1232 determines, from the light reception state of the light receiver 120a measured by the measurement unit 1233 (described later) while changing the tilt angle of the light projector unit 110, among the range of tilt angles at which the light reception amount of the inspection light of the light receiver 120a becomes equal to or greater than a predetermined value, the tilt angle closer to the center of the range than the tilt angle at the end of the range as the tilt angle of the light projector unit 110 in the normal operation mode.

[0061] In addition, the determination unit 1232 determines, from the light reception state of the light receiver 120a measured by the measurement unit 1233 while changing the tilt angle of the light receiver unit 120, among the range of tilt angles at which the light reception amount of the inspection light of the light receiver 120a becomes equal to or greater than a predetermined value, the tilt angle closer to the center of the range than the tilt angle at the end of the range as the tilt angle of the light receiver unit 120 in the normal operation mode.

[0062] More specifically, the determination unit 1232 adopts the inclination angle at which the light reception amount is maximized within the range of inclination angles at which the light reception amount is equal to or greater than a predetermined value for the light projector unit 110 and the light receiver unit 120. The ends of the range of inclination angles at which the light reception amount is equal to or greater than a predetermined value are close to the upper limit or the lower limit of the allowable range of the deviation of the optical axes of the light projector 110a and the light receiver 120a, and are the positions with the lowest margin against external factors. Therefore, the determination unit 1232 improves the margin against external factors by bringing the inclination angles of the light projector unit 110 and the light receiver unit 120 as close as possible to the center of this range.

[0063] The measurement unit 1233 measures the light reception state of the inspection light by the light receiver 120a. Further, the measurement unit 1233 transmits the measurement result in which the inclination angles of the light projector unit 110 and the light receiver unit 120 are associated with the light reception state to the maintenance computer 50.

[0064] The memory 123B has a memory area necessary for the operation of the processor 123A.

[0065] The storage 123C is a so-called auxiliary storage device, such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like.

[0066] The interface 123D is an interface for transmitting and receiving information to and from the control unit 113 of the light projection tower 11 and the maintenance computer 50.

[0067] At a tollgate where the vehicle detector 10 is installed, there may be a water gradient in which the road surface of the lane L is inclined in the width direction (±Y direction) of the lane L, causing a shift in the heights (positions in the vertical direction) of the light projection tower 11 and the light reception tower 12. At this time, if the directions of the optical axes of the light projector 110a and the light receiver 120a are simply aligned horizontally, their optical axes may not fully coincide, reducing the margin against external factors and increasing the likelihood of malfunction. Therefore, the vehicle detector 10 according to the present embodiment can automatically adjust the inclination angles of the light projector unit 110 and the light receiver unit 120 with respect to the width direction of the lane L so that the optical axes of the light projector 110a and the light receiver 120a substantially coincide. Next, this adjustment method will be described in detail.

[0068] (Processing Flow of Vehicle Detector) FIG. 5 is a first flowchart showing an example of the processing of the vehicle detector according to the first embodiment. FIG. 6 is a second flowchart showing an example of the processing of the vehicle detector according to the first embodiment. Hereinafter, with reference to FIGS. 5 to 6, the flow of processing in the adjustment mode of the vehicle detector 10 will be described.

[0069] When an operator adjusts the optical axis of the vehicle detector 10, for example, as shown in FIG. 2, an operation of selecting the "adjustment mode" is performed via the maintenance computer 50 connected to the control unit 123 of the light reception tower 12. Then, based on the signal received from the maintenance computer 50, the operation mode reception unit 1230 of the light reception tower 12 switches the light reception tower 12 to the "adjustment mode" and notifies the control unit 113 of the light projection tower 11 of the switch to the "adjustment mode". Further, based on the notification from the light reception tower 12, the operation mode reception unit 1130 of the light projection tower 11 switches the light projection tower 11 to the "adjustment mode" (step S10).

[0070] When switching to the adjustment mode, the angle control unit 1131 of the light projection tower 11 controls the drive unit 112 to return the light projector unit 110 to the default position P5. Similarly, the angle control unit 1231 of the light reception tower 12 controls the drive unit 122 to return the light receiver unit 120 to the default position P6 (step S11).

[0071] Also, in the adjustment mode, first, a process of determining the tilt angle of the first unit, which is one of the light projector unit 110 and the light receiver unit 120, is performed (step S12). Then, the first unit is fixed at the determined tilt angle (step S13), and a process of determining the tilt angle of the second unit, which is the other of the light projector unit 110 and the light receiver unit 120, is performed (step S14). Here, an example will be described in which the light projector unit 110 is adjusted first and then the light receiver unit 120 is adjusted in order. That is, in the present embodiment, the light projector unit 110 and the drive unit 112 of the light projection tower 11 correspond to the "first unit" and the "first drive unit", and the light receiver unit 120 and the drive unit 122 of the light reception tower 12 correspond to the "second unit" and the "second drive unit".

[0072] First, the flow of the process S12 for determining the tilt angle of the light projector unit 110 (the first unit) will be described with reference to FIG. 6.

[0073] The angle control unit 1131 of the light projection tower 11 controls the drive unit 112 to move the light projector unit 110 to the upward limit position P1 (FIG. 3) (step S101). That is, the tilt angle of the light projector unit 110 is set to the angle θ1 (the first angle), which is the maximum angle on the left side (+Y direction side) in the width direction of the lane L.

[0074] Next, the angle control unit 1131 of the light projection tower 11 controls the drive unit 112 to move the light projector unit 110 at a constant speed until it reaches the downward limit position P2 (Fig. 3). That is, the inclination angle of the light projector unit 110 is changed at a constant speed until it becomes the angle θ2 (second angle), which is the maximum angle on the right side (-Y direction side) in the width direction of the lane L. During this period, the light projector 110a projects inspection light under the control of the light emission control unit 1132. Also, the measurement unit 1233 of the light reception tower 12 measures the light reception state of the light receiver 120a while the light projector unit 110 moves from the upward limit position P1 to the downward limit position P2, and records it in the storage 123C in association with the inclination angle of the light projector unit 110 (step S101).

[0075] Fig. 7 is a diagram showing an example of the measurement result of the measurement unit according to the first embodiment. In step S101, the measurement unit 1233 records the measurement result in which the inclination angle of the light projector unit 110 and the light reception state of the light receiver 120a are associated as shown in Fig. 7. In this embodiment, the light reception state is represented by two states: "light reception on" where the light reception amount of the inspection light by the light receiver 120a is equal to or greater than a predetermined value, and "light reception off" where the light reception amount of the inspection light by the light receiver 120a is less than the predetermined value. Note that the measurement unit 1233 may transmit this measurement result to the maintenance computer 50 via the interface 123D. The maintenance computer 50 displays a graph of the measurement result shown in Fig. 7 so that the operator can confirm the light reception state (light reception on or light reception off) at each inclination angle.

[0076] Next, the determination unit 1232 specifies the range of the inclination angle of the light projector unit 110 at which the light receiver 120a is in the light reception on state based on the measurement result of the measurement unit 1233 (step S103).

[0077] The determination unit 1232 refers to the measurement results illustrated in FIG. 7 and specifies the range of the tilt angle at which the light receiver 120a becomes "light reception on", that is, the light reception on range. In the example of FIG. 7, the light reception is on when the tilt angle of the projector unit 110 is from θ10 to θ12. Therefore, the determination unit 1232 specifies the range from θ10 to θ12 as the light reception on range (step S103).

[0078] Next, the determination unit 1232 determines, as the tilt angle in the normal operation mode of the projector unit 110, the tilt angle closest to the center within the light reception on range (step S103). The light reception on range represents the allowable range of the deviation of the optical axes of the projector 110a and the light receiver 120a. The closer to the end of the light reception on range (θ10 or θ12 in FIG. 7), the smaller the margin against external factors and the more likely an operation failure occurs. For example, if the optical axes are aligned at the end of the light reception on range, there is a possibility of operation failures such as the light receiver 120a not being able to receive the inspection light with sufficient light quantity even though there is no vehicle present, and false detection when a vehicle is present. On the other hand, at the center of the light reception on range (angle θ11 in FIG. 7), the margin against external factors is the largest and the possibility of an operation failure is the smallest. Therefore, the determination unit 1232 according to the present embodiment determines the angle θ11, which is the median value of the light reception on range, as the optimal tilt angle of the projector unit 110 (step S103). Note that, for example, when the drive unit 112 can change the tilt angle at every fixed angle such as a stepping motor, the determination unit 1232 may adopt the tilt angle closest to the median value among the tilt angles that can be changed by the drive unit 112. When the process S12 (a series of processes in FIG. 6) in which the determination unit 1232 determines the tilt angle of the projector unit 110 (the first unit) ends, the process proceeds to step S13 in FIG. 5.

[0079] The angle control unit 1131 of the projection tower 11 controls the drive unit 112 to fix the posture of the projector unit 110 at the tilt angle determined in step S103 of FIG. 6 (step S13). In this state, a process of determining the tilt angle of the light receiver unit 120 (the second unit) is executed (step S14).

[0080] The process of determining the tilt angle of the light receiver unit 120 (second unit) will be described with reference to FIG. 6.

[0081] The angle control unit 1231 of the light receiving tower 12 controls the drive unit 122 to move the light receiver unit 120 to the upper limit position P3 (FIG. 3) (step S101). That is, the tilt angle of the light receiver unit 120 is set to the angle θ3 (third angle), which is the maximum angle on the right side (-Y direction side) in the width direction of the lane L.

[0082] Next, the angle control unit 1231 of the light receiving tower 12 controls the drive unit 122 to move the light receiver unit 120 at a constant speed until it reaches the lower limit position P4 (FIG. 3). That is, the tilt angle of the light receiver unit 120 is changed at a constant speed until it becomes the angle θ4 (fourth angle), which is the maximum angle on the left side (+Y direction side) in the width direction of the lane L. During this period, the projector 110a projects inspection light under the control of the light emission control unit 1132. Also, the measurement unit 1233 of the light receiving tower 12 measures the light reception state of the light receiver 120a while the light receiver unit 120 moves from the upper limit position P3 to the lower limit position P4, and records it in the storage 123C in association with the tilt angle of the light receiver unit 120 (step S101).

[0083] Next, based on the measurement result of the measurement unit 1233, the determination unit 1232 specifies the range of the tilt angle of the light receiver unit 120 (light reception on range) in which the light receiver 120a becomes light reception on (step S103). This process is the same as the process of specifying the light reception on range of the projector unit 110 described above. That is, the determination unit 1232 determines the tilt angle closest to the center among the light reception on ranges as the tilt angle of the light receiver unit 120 in the normal operation mode (step S103). Then, the process S14 of determining the tilt angle of the light receiver unit 120 (second unit) ends, and the process proceeds to step S15 in FIG. 5.

[0084] The angle control unit 1231 of the light receiving tower 12 controls the drive unit 122 to fix the posture of the light receiver unit 120 at the inclination angle determined in step S103 of FIG. 6 (step S15).

[0085] Next, the determination unit 1232 determines whether there is a problem with the adjustment results of the inclination angles of the light projector unit 110 and the light receiver unit 120 (step S16).

[0086] For example, the operator checks the measurement results of the light projector unit 110 and the light receiver unit 120 displayed on the maintenance computer 50 to confirm whether there is a problem with the adjustment results of these inclination angles. When the drive unit 112 of the light projection tower 11 or the drive unit 122 of the light receiving tower 12 is not operating normally, or when dirt or the like adheres to the light projection tower 11 or the light receiving tower 12 and an error is suspected in the measurement results, the operator performs an operation of instructing readjustment via the maintenance computer 50. When the determination unit 1232 receives a signal instructing readjustment from the maintenance computer 50, it determines that there is a problem with the adjustment results (step S16; NO), and returns to step S12. At this time, the inclination angles of the light projector unit 110 and the light receiver unit 120 are not returned to the default positions, but remain at the positions determined in the first adjustment process.

[0087] In the second adjustment process, the movement ranges of the light projector unit 110 and the light receiver unit 120 may be narrowed with reference to the measurement results by the first measurement unit 1233. In the example of the measurement results shown in FIG. 7, the inclination angle of the light projector unit 110 was changed over the entire range from θ1 to θ2 in the first adjustment process, but in the second adjustment process, it may be changed within the range of the light reception on range ±α. That is, an inclination angle inclined α degrees to the left in the lane width direction from θ10 is set as the first angle of the second time, and an inclination angle inclined α degrees to the right in the lane width direction from θ12 is set as the second angle of the second time. The same applies to the light receiver unit 120. By narrowing the movement range in this way, the execution time of the adjustment process after the second time can be shortened.

[0088] On the one hand, when the operator determines that there is no problem with the adjustment result, the operator performs an operation of selecting the "normal operation mode" via the maintenance computer 50. When the determination unit 1232 receives a signal specifying the "normal operation mode" from the maintenance computer 50, it determines that there is no problem with the adjustment result (step S16; YES). Further, the operation mode reception unit 1130 of the light projection tower 11 and the operation mode reception unit 1230 of the light reception tower 12 each switch their own operation mode to the "normal operation mode" (step S17). Thereafter, the vehicle detector 10 operates the light projector unit 110 and the light receiver unit 120 in a state where they are tilted at the determined tilt angle.

[0089] In addition, in other embodiments, the order of adjusting the light projector unit 110 and the light receiver unit 120 may be interchanged. In this case, the light projector unit 110 and the drive unit 112 of the light projection tower 11 correspond to the "second unit" and the "second drive unit", and the light receiver unit 120 and the drive unit 122 of the light reception tower 12 correspond to the "first unit" and the "first drive unit".

[0090] Also, in other embodiments, in step S100 of FIG. 6, the light projector unit 110 and the light receiver unit 120 may be moved to the downward limit position, and the light reception state may be measured while moving the light projector unit 110 and the light receiver unit 120 to the upward limit position in step S101.

[0091] (Function, effect) As described above, for the vehicle detector 10 according to the present embodiment, for example, when the light projector unit 110 is the first unit, from the light reception state of the light receiver 120a measured while changing the light projector unit 110 (first unit) from the first angle to the second angle, among the range of tilt angles at which the light reception amount of the inspection light of the light receiver 120a becomes a predetermined value or more (light reception is turned on), the tilt angle closer to the center of the range than the tilt angle at the end of the range is determined as the tilt angle in the normal operation mode of the light projector unit 110.

[0092] By doing so, the vehicle detector 10 can automatically adjust the direction of the optical axis E of the projector 110a so that the margin against external factors is maximized. Thereby, it is possible to suppress variations in the adjustment results depending on the skill level of the operator.

[0093] Further, when the light receiver unit 120 is used as the second unit, for example, the vehicle detector 10 fixes the projector unit 110 (first unit) at the inclination angle in the normal operation mode in which it is determined, and while changing the light receiver unit 120 (second unit) from the third angle to the fourth angle, from the light reception state of the light receiver 120a measured during this change, among the range of inclination angles at which the received light amount of the inspection light of the light receiver 120a becomes equal to or greater than a predetermined value (light reception is turned on), an inclination angle closer to the center of the range than the inclination angle at the end of the range is determined as the inclination angle of the light receiver unit 120 in the normal operation mode.

[0094] By doing so, the vehicle detector 10 can automatically adjust the direction of the optical axis R of the light receiver 120a in accordance with the direction of the optical axis E of the projector 110a after adjustment.

[0095] Further, the vehicle detector 10 determines, as the inclination angle in the normal operation mode, the inclination angle at which the received light amount is maximized among the range of inclination angles (light reception on range) at which the light receiver 120a turns on light reception.

[0096] As described above, when the projector 110a and the light receiver 120a direct their optical axes toward the center of the light reception on range, the margin against external factors is maximized. Therefore, the vehicle detector 10 can automatically adjust the directions of the optical axis E of the projector 110a and the optical axis R of the light receiver 120a so that the margin against external factors is maximized by adopting the inclination angle at which the received light amount is maximized among the light reception on range in this way.

[0097] <Second Embodiment> Next, the vehicle detector 10 according to the second embodiment of the present disclosure will be described with reference to FIG. 8. The same reference numerals are given to the components common to the first embodiment, and the detailed description thereof will be omitted.

[0098] FIG. 8 is a diagram showing an example of the measurement result of the measurement unit according to the second embodiment. FIG. 8 shows an example of the measurement result of the measurement unit 1233 according to the present embodiment. The light reception state according to the first embodiment was represented by two values, "light reception on" and "light reception off", but the light reception state according to the present embodiment is represented by the actual measured value (sensor value) of the light reception amount, as illustrated in FIG. 8.

[0099] Hereinafter, the processing flow of the vehicle detector 10 according to the present embodiment will be described with reference to the flowchart of FIG. 6 and the example of the measurement result of FIG. 8.

[0100] In step S101 of FIG. 6, the measurement unit 1233 according to the present embodiment records the measured values of the light reception amounts of the inspection light of the light receiver 120a for each tilt angle of the projector unit 110.

[0101] Also, in step S102 of FIG. 6, the determination unit 1232 refers to the measurement result by the measurement unit 1233 and specifies the range of the tilt angle at which the light reception amount of the light receiver 120a is equal to or greater than the light reception on lower limit value, that is, the light reception on range. In the example of FIG. 8, light reception is on when the tilt angle of the projector unit 110 is from θ20 to θ22. Therefore, the determination unit 1232 specifies the range from θ20 to θ21 as the light reception on range.

[0102] Next, in step S103 of FIG. 6, the determination unit 1232 determines the tilt angle at which the light reception amount becomes the maximum value as the tilt angle in the normal operation mode of the projector unit 110. In the example of FIG. 8, the determination unit 1232 adopts the tilt angle θ21 at which the light reception amount becomes the maximum value.

[0103] Further, the measurement unit 1233 and the determination unit 1232 perform the same processing for the light receiver unit 120, and set the tilt angle at which the light reception amount becomes the maximum value as the tilt angle during the normal operation mode of the light receiver unit 120. Other processes are the same as those in the first embodiment.

[0104] As described above, the vehicle detector 10 according to the present embodiment determines the tilt angle at which the light reception amount of the light receiver 120a becomes the maximum value as the tilt angle during the normal operation mode of the projector unit 110 and the light receiver unit 120.

[0105] By doing so, the vehicle detector 10 can automatically adjust to the direction in which the light reception amount of the light receiver 120a becomes the maximum value, that is, the direction in which the optical axis E of the projector 110a and the optical axis R of the light receiver 120a substantially coincide.

[0106] <Third Embodiment> Next, the vehicle detector 10 according to the third embodiment of the present disclosure will be described with reference to FIGS. 9 to 10. The same reference numerals are given to the components common to the first and second embodiments, and the detailed description thereof is omitted.

[0107] In the present embodiment, the operation mode reception unit 1130 of the projection tower 11 and the operation mode reception unit 1230 of the light reception tower 12 are different from the first and second embodiments in that they further receive the selection of the first adjustment mode or the second adjustment mode by the operator.

[0108] The first adjustment mode is an adjustment mode for determining the optimum tilt angle among a plurality of tilt angles as the tilt angle during the normal operation mode based on the light reception state. The second adjustment mode is a mode for determining the tilt angle offset by a predetermined amount from the optimum tilt angle as the tilt angle during the normal operation mode. Further, depending on the functional configuration of the vehicle detector 10, the first adjustment mode and the second adjustment mode are divided into the following two cases.

[0109] (Case 1) Case 1 is an aspect in which the functions of the operation mode reception units 1130 and 1230 are added to the vehicle detector 10 according to the first embodiment. At this time, the first adjustment mode indicates an adjustment mode in which an inclination angle closer to the center of the light reception on range is determined as the inclination angle in the normal operation mode. The second adjustment mode indicates an adjustment mode in which an inclination angle offset by a predetermined amount from the inclination angle closer to the center of the light reception on range is determined as the inclination angle in the normal operation mode.

[0110] (Case 2) Case 2 is an aspect in which the functions of the operation mode reception units 1130 and 1230 are added to the vehicle detector 10 according to the second embodiment. At this time, the first adjustment mode indicates an adjustment mode in which an inclination angle at which the light reception amount becomes the maximum value is determined as the inclination angle in the normal operation mode. The second adjustment mode indicates an adjustment mode in which an inclination angle offset by a predetermined amount from the inclination angle at which the light reception amount becomes the maximum value is determined as the inclination angle in the normal operation mode.

[0111] The second adjustment mode further has first to fourth sub - modes.

[0112] The first sub - mode is a mode in which, based on an inclination angle closer to the center of the light reception on range (Case 1) or an inclination angle at which the light reception amount becomes the maximum value (Case 2) as a reference angle, the inclination angle is offset so as to face the upward direction (+Z direction) rather than the direction of the optical axis E of the projector 110a at this reference angle.

[0113] The second sub - mode is a mode in which the inclination angle is offset so as to face the downward direction (-Z direction) rather than the direction of the optical axis E of the projector 110a at the reference angle.

[0114] The third sub - mode is a mode in which the inclination angle is offset so as to face the upward direction (+Z direction) rather than the direction of the optical axis R of the light receiver 120a at the reference angle.

[0115] The fourth sub-mode is a mode in which the tilt angle is offset so as to face downward (-Z direction) rather than the direction of the optical axis R of the light receiver 120a at the reference angle.

[0116] The offset amount in the second adjustment mode is set based on a preset fixed value or a fixed value input by the operator via the maintenance computer 50. Note that the operator may specify any fixed value or select any one of a plurality of fixed values.

[0117] For example, in Case 1, a fixed value X1 is set so as to offset by X1 degrees (e.g., 5 degrees) from the reference angle. Also, a fixed value X2 is set so as to offset by an angle of X2% (e.g., 5%, 10%, etc.) of the light reception on range from the reference angle.

[0118] Also, in Case 2, a fixed value X3 is set so as to offset to the tilt angle corresponding to the light reception amount of X3% (e.g., 90%, 80%, 70%, etc.) of the maximum value.

[0119] Depending on environmental conditions such as the installation location, time, and time zone of the vehicle detector 10, the light receiver 120a of the vehicle detector 10 may be affected by sunlight or other lighting devices (receive the light of sunlight or lighting devices). For example, at a tollgate in a mountainous area, there is a case where the light of the rising or setting sun enters from the lateral direction of the vehicle detector 10. In such a case, since the light receiver 120a receives sunlight, there is a possibility of false detection that a vehicle does not exist. Therefore, the vehicle detector 10 according to the present embodiment has a second adjustment mode so that the optical axis E of the projector 110a and the optical axis R of the light receiver 120a can be shifted (offset) to directions less susceptible to the influence of the light source in an environment with a light source that interferes with the vehicle detector 10 in this way.

[0120] FIG. 9 is a flowchart showing an example of the processing of the vehicle detector according to the third embodiment. FIG. 10 is a diagram showing an example of the measurement result of the measurement unit according to the third embodiment. Next, the processing flow of the vehicle detector 10 according to the present embodiment will be described with reference to the flowchart of FIG. 9 and an example of the measurement results of FIG. 10. Here, for the sake of simplicity of explanation, the mode of Case 2 will be described as an example.

[0121] As shown in FIG. 9, in the present embodiment, it is different from each of the above-described embodiments in that step S10 of FIG. 5 is divided into steps S10A and S10B.

[0122] The operation mode reception unit 1230 of the light receiving tower 12 receives, via the maintenance computer 50, the selection of the "first adjustment mode" or the "second adjustment mode" by the operator (step S10A). When the operator selects the "second adjustment mode", the operation mode reception unit 1230 further receives the selection of any one of the first to fourth sub-modes. Further, when the operator selects the "second adjustment mode", the operation mode reception unit 1230 may further receive the selection of the offset amount by the operator.

[0123] Then, based on the signal received from the maintenance computer 50, the operation mode reception unit 1230 of the light receiving tower 12 switches the light receiving tower 12 to the "first adjustment mode" or the "second adjustment mode (any one of the first to fourth sub-modes)", and notifies the control unit 113 of the light projecting tower 11 of the switching to the adjustment mode. Further, based on the notification from the light receiving tower 12, the operation mode reception unit 1130 of the light projecting tower 11 switches the light projecting tower 11 to the same adjustment mode as the light receiving tower 12 (step S10B).

[0124] Also, in steps S12 and S14 of FIG. 10, the vehicle detector 10 performs a process of determining the tilt angles of the light projector unit 110 and the light receiver unit 120 according to the flowchart shown in FIG. 6. Here, the determination unit 1232 determines the tilt angles of the light projector unit 110 and the light receiver unit 120 based on the conditions set in step S10A of FIG. 10 in step S103 of FIG. 6. Here, the details of the process of the determination unit 1232 (step S103 of FIG. 6) in each adjustment mode will be described.

[0125] When the first adjustment mode is selected, the determination unit 1232 determines the tilt angle at which the light reception amount becomes the maximum value as the tilt angle in the normal operation mode of each of the projector unit 110 and the light receiver unit 120. In the example of FIG. 10, for the projector unit 110, when the tilt angle is θ32, the light reception amount is at the maximum value. Therefore, the determination unit 1232 determines θ32 as the tilt angle in the normal operation mode of the projector unit 110. The determination unit 1232 performs the same process for the light receiver unit 120.

[0126] Among the second adjustment modes, when the first sub-mode is set, the determination unit 1232 uses the tilt angle at which the light reception amount becomes the maximum value as a reference angle, and offsets the tilt angle so as to face upward (+Z direction) rather than the direction of the optical axis E of the projector 110a at this reference angle. For example, in the example of FIG. 10, it is assumed that the tilt angle is set to be offset to the tilt angle at which the light reception amount becomes 90% of the maximum value. Also, the tilt angles at which the light reception amount becomes 90% of the maximum value are θ31 or θ33. Among these, the tilt angle at which the optical axis E of the projector 110a faces upward is θ31. Therefore, in the example of FIG. 10, the determination unit 1232 determines θ31 as the tilt angle in the normal operation mode of the projector unit 110.

[0127] Among the second adjustment modes, when the second sub-mode is set, the determination unit 1232 uses the tilt angle at which the light reception amount becomes the maximum value as a reference angle, and offsets the tilt angle so as to face downward (-Z direction) rather than the direction of the optical axis E of the projector 110a at this reference angle. For example, in the example of FIG. 10, it is assumed that the tilt angle is set to be offset to the tilt angle at which the light reception amount becomes 90% of the maximum value. Also, the tilt angles at which the light reception amount becomes 90% of the maximum value are θ31 or θ33. Among these, the tilt angle at which the optical axis E of the projector 110a faces downward is θ32. Therefore, in the example of FIG. 10, the determination unit 1232 determines θ32 as the tilt angle in the normal operation mode of the projector unit 110.

[0128] When the third sub-mode is set in the second adjustment mode, the determination unit 1232 sets the inclination angle at which the received light amount becomes the maximum value as the reference angle, and offsets the inclination angle so as to face upward (+Z direction) rather than the direction of the optical axis E of the light receiver 120a at this reference angle. This process is the same as the process of offsetting the optical axis E of the projector 110a upward.

[0129] When the fourth sub-mode is set in the second adjustment mode, the determination unit 1232 sets the inclination angle at which the received light amount becomes the maximum value as the reference angle, and offsets the inclination angle so as to face downward (-Z direction) rather than the direction of the optical axis E of the light receiver 120a at this reference angle. This process is the same as the process of offsetting the optical axis E of the projector 110a downward.

[0130] As described above, the vehicle detector 10 according to the present embodiment sets the inclination angle close to the center of the light reception ON range or the inclination angle at which the received light amount becomes the maximum value as the reference angle, and determines the reference angle as the inclination angle in the normal operation mode when receiving the selection of the first adjustment mode. When receiving the selection of the second adjustment mode, the inclination angle offset by a predetermined amount from the reference angle is determined as the inclination angle in the normal operation mode.

[0131] By doing so, the vehicle detector 10 can adjust the projector unit 110 and the light receiver unit 120 to an appropriate inclination angle according to the selected adjustment mode. Further, in an installation environment where the vehicle detector 10 is affected by other light sources when adjusted in the first adjustment mode, the vehicle detector 10 can reduce the influence of other light sources by offsetting the inclination angle in the second adjustment mode.

[0132] Further, the second adjustment mode is further divided into a plurality of sub-modes (first to fourth sub-modes), and the offset direction and offset amount of the projector unit 110 or the light receiver unit 120 are set for each sub-mode.

[0133] By doing so, according to the selected sub-mode, the vehicle detector 10 can automatically adjust the direction of the optical axis E of the projector 110a or the optical axis R of the light receiver 120a to a direction less affected by the light source. Also, the operator can adjust the optical axis E of the projector 110a or the optical axis R of the light receiver 120a to an appropriate direction with a simple operation of only selecting any sub-mode according to the arrangement of the projection tower 11 and the light receiving tower 12, the position of other light sources, etc.

[0134] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

[0135] <Supplementary Note> The vehicle detector, the method for adjusting the vehicle detector, and the program described in the above embodiments are understood as follows, for example.

[0136] (1) According to a first aspect of the present disclosure, a vehicle detector (10) includes a light projector unit (110) fixed to a lane-facing side of a first support member (110b) extending in the vertical direction and having a light projector (110a) that projects inspection light, a light receiver unit (120) having a light receiver (120a) that faces the light projector (110a) with the lane therebetween, the light receiver (120a) being fixed to a lane-facing side of a second support member (120b) extending in the vertical direction, a measurement unit (1233) that measures a light reception state of the inspection light by the light receiver (120a), a first drive unit (112, 122) that tilts one of the light projector unit (110) and the light receiver unit (120) in the lane width direction, and a determination unit (1232) that determines, from the light reception state of the light receiver (120a) measured by the measurement unit (1233) while the first drive unit (112, 122) changes the tilt angle of the first unit from a first angle to a second angle, an inclination angle closer to the center of a range of inclination angles at which the light reception amount of the inspection light by the light receiver (120a) is equal to or greater than a predetermined value, than an inclination angle at an end of the range, as the inclination angle in the normal operation mode of the first unit.

[0137] By doing so, the vehicle detector can automatically adjust the direction of the optical axis of the first unit so that the margin against external factors is maximized. Thereby, it is possible to suppress variations in the adjustment results depending on the skill level of the operator.

[0138] (2) According to a second aspect of the present disclosure, the vehicle detector (10) according to the first aspect further includes a second drive unit that tilts the second unit, which is the other of the light projector unit (110) and the light receiver unit (120), in the lane width direction, and the determination unit determines, from the light reception state measured by the measurement unit while the second drive unit changes the tilt angle of the second unit from a third angle to a fourth angle, with the tilt angle in the normal operation mode of the first unit fixed by the determination unit, an inclination angle closer to the center of a range of inclination angles at which the light reception amount of the inspection light by the light receiver (120a) is equal to or greater than a predetermined value, than an inclination angle at an end of the range, as the inclination angle in the normal operation mode of the second unit.

[0139] By doing so, the vehicle detector can automatically adjust the orientation of the optical axis of the second unit according to the orientation of the adjusted optical axis of the first unit.

[0140] (3) According to the third aspect of the present disclosure, in the vehicle detector (10) according to the first or second aspect, the determination unit determines, as the inclination angle in the normal driving mode, the inclination angle at which the light reception amount is maximum among the ranges of inclination angles at which the light reception amount is equal to or greater than a predetermined value.

[0141] By doing so, the vehicle detector can automatically adjust the orientations of the optical axes of the projector and the light receiver so that the margin against external factors is maximized.

[0142] (4) According to the fourth aspect of the present disclosure, in the vehicle detector (10) according to the first or second aspect, the determination unit determines, as the inclination angle in the normal driving mode, the inclination angle at which the light reception amount is maximum.

[0143] By doing so, the vehicle detector can automatically adjust to the orientation at which the light reception amount of the light receiver is maximum, that is, the orientation in which the optical axes of the projector and the light receiver substantially coincide.

[0144] (5) According to the fifth aspect of the present disclosure, the vehicle detector (10) according to the first or second aspect further includes an operation mode reception unit that receives a selection of either a first adjustment mode or a second adjustment mode. When the determination unit receives the selection of the first adjustment mode, it determines, as the inclination angle in the normal driving mode, the inclination angle at which the light reception amount is maximum among the ranges of inclination angles at which the light reception amount is equal to or greater than a predetermined value. When the determination unit receives the selection of the second adjustment mode, it determines, as the inclination angle in the normal driving mode, the inclination angle offset by a predetermined amount from the inclination angle at which the light reception amount is maximum.

[0145] By doing so, the vehicle detector can adjust the projector unit and the light receiver unit to appropriate tilt angles according to the selected adjustment mode. Further, in an installation environment where the vehicle detector is affected by other light sources when adjusted in the first adjustment mode, the vehicle detector can reduce the influence of other light sources by offsetting the tilt angle in the second adjustment mode.

[0146] (6) According to a sixth aspect of the present disclosure, the vehicle detector (10) according to the first or second aspect further includes an operation mode reception unit that receives a selection of either the first adjustment mode or the second adjustment mode. When the determination unit receives a selection of the first adjustment mode, the determination unit determines the tilt angle at which the light reception amount becomes the maximum value as the tilt angle during the normal operation mode. When the determination unit receives a selection of the second adjustment mode, the determination unit determines the tilt angle offset by a predetermined amount from the tilt angle at which the light reception amount becomes the maximum value as the tilt angle during the normal operation mode.

[0147] By doing so, the vehicle detector can adjust the projector unit and the light receiver unit to appropriate tilt angles according to the selected adjustment mode. Further, in an installation environment where the vehicle detector is affected by other light sources when adjusted in the first adjustment mode, the vehicle detector can reduce the influence of other light sources by offsetting the tilt angle in the second adjustment mode.

[0148] (7) According to a seventh aspect of the present disclosure, a method for adjusting a vehicle detector includes a light projector unit (110) fixed to a lane-facing side of a first support member (110b) extending in the vertical direction and having a light projector (110a) that projects inspection light, a light receiver (120a) facing the light projector (110a) with the lane therebetween, the light receiver (120a) being fixed to a lane-facing side of a second support member (120b) extending in the vertical direction and having a light receiver (120a) that receives inspection light, and a first drive unit (112, 122) that tilts a first unit, which is one of the light projector unit (110) and the light receiver unit (120), in the lane width direction. The method for adjusting a vehicle detector includes a step of measuring a light reception state of the inspection light by the light receiver (120a), and a step of determining, from the light reception state of the light receiver (120a) measured while the first drive unit (112, 122) changes the tilt angle of the first unit from a first angle to a second angle, a tilt angle closer to the center than the tilt angle at an end of a range of tilt angles in which the light reception amount of the inspection light by the light receiver (120a) is equal to or greater than a predetermined value, as the tilt angle in the normal operation mode of the first unit.

[0149] (8) According to an eighth aspect of the present disclosure, the program is fixed to the lane-facing side of a first support member (110b) extending in the vertical direction, and includes a light projector unit (110) having a light projector (110a) that projects inspection light, and a light receiver (120a) facing the light projector (110a) with the lane therebetween. The light receiver unit (120) is fixed to the lane-facing side of a second support member (120b) extending in the vertical direction and has a light receiver (120a) that receives inspection light. The vehicle detector further includes a first drive unit (112, 122) that tilts one of the light projector unit (110) and the light receiver unit (120) in the lane width direction. The vehicle detector executes steps of measuring a light reception state of the inspection light by the light receiver (120a), and determining, from the light reception state of the light receiver (120a) measured while the first drive unit (112, 122) changes the tilt angle of the first unit from a first angle to a second angle, a tilt angle closer to the center than the tilt angle at the end of a range of tilt angles in which the light reception amount of the inspection light by the light receiver (120a) is equal to or greater than a predetermined value, as the tilt angle in the normal operation mode of the first unit.

Explanation of Reference Numerals

[0150] 10 Vehicle detector (incoming vehicle detector) 11 Light projection tower 110 Light projector unit 110a Light projector 110b Support member 111 Housing 112 Drive unit 113 Control unit 113A Processor 1130 Operation mode reception unit 1131 Angle control unit 1132 Light emission control unit 113B Memory 113C Storage 113D Interface 12 Light reception tower 120 Light receiver unit 120a Light receiver 120b Support member 121 Housing 122 Drive unit 123 Control Unit 123A Processor 1230 Operation Mode Reception Unit 1231 Angle Control Unit 1232 Decision Unit 1233 Measurement Unit 123B Memory 123C Storage 123D Interface 20 Vehicle Detector for Communication Stop 21 Light Projection Tower 22 Light Reception Tower 30 Communication Antenna 50 Maintenance Computer

Claims

1. A light projector unit fixed to the side of a first support member extending in the vertical direction facing the lane and having a light projector for projecting inspection light; A light receiver facing the light projector with the lane therebetween, the light receiver being fixed to the side of a second support member extending in the vertical direction facing the lane and having a light receiver for receiving the inspection light; A measuring unit for measuring the light reception state of the inspection light by the light receiver; A first driving unit for tilting a first unit, which is one of the light projector unit and the light receiver unit, in the lane width direction; A determination unit that determines, from the light reception state of the light receiver measured by the measuring unit while the first driving unit changes the tilt angle of the first unit from a first angle to a second angle, an inclination angle closer to the center of the range than the inclination angle at the end of the range of inclination angles at which the light reception amount of the inspection light by the light receiver becomes equal to or greater than a predetermined value, as the inclination angle in the normal operation mode of the first unit; A vehicle detector comprising the above.

2. Further comprising a second driving unit for tilting a second unit, which is the other of the light projector unit and the light receiver unit, in the width direction of the lane, The determination unit, in a state where the inclination angle in the normal operation mode of the first unit determined by the determination unit is fixed, determines, from the light reception state measured by the measuring unit while the second driving unit changes the inclination angle of the second unit from a third angle to a fourth angle, an inclination angle closer to the center of the range than the inclination angle at the end of the range of inclination angles at which the light reception amount of the inspection light by the light receiver becomes equal to or greater than a predetermined value, as the inclination angle in the normal operation mode of the second unit. The vehicle detector according to claim 1.

3. The determination unit determines the inclination angle closest to the center of the range of inclination angles at which the light reception amount becomes equal to or greater than a predetermined value as the inclination angle in the normal operation mode. The vehicle detector according to claim 1 or 2.

4. The determination unit determines the inclination angle at which the light reception amount becomes the maximum value as the inclination angle in the normal operation mode. The vehicle detector according to claim 1 or 2.

5. Further comprising an operation mode reception unit that receives a selection of either a first adjustment mode or a second adjustment mode, The determination unit, when receiving the selection of the first adjustment mode, determines the inclination angle closest to the center of the range of inclination angles at which the light reception amount becomes equal to or greater than a predetermined value as the inclination angle in the normal operation mode. When accepting the selection of the second adjustment mode, determine an inclination angle offset by a predetermined amount from the inclination angle at which the received light amount becomes maximum as the inclination angle in the normal operation mode. The vehicle detector according to claim 1 or 2.

6. Further comprising an operation mode reception unit that receives a selection of either a first adjustment mode or a second adjustment mode. The determination unit When accepting the selection of the first adjustment mode, determine the inclination angle at which the received light amount becomes the maximum value as the inclination angle in the normal operation mode. When accepting the selection of the second adjustment mode, determine an inclination angle offset by a predetermined amount from the inclination angle at which the received light amount becomes the maximum value as the inclination angle in the normal operation mode. The vehicle detector according to claim 1 or 2.

7. A light projector unit fixed to the side facing the lane of the first support member extending in the vertical direction and having a light projector that projects inspection light, A light receiver facing the light projector with the lane therebetween, fixed to the side facing the lane of the second support member extending in the vertical direction, and having a light receiver that receives the inspection light. A first drive unit that tilts a first unit, which is one of the light projector unit and the light receiver unit, in the lane width direction. A method for adjusting a vehicle detector, comprising: A step in which the vehicle detector measures a light reception state of the inspection light by the light receiver. A step in which the vehicle detector determines, from the light reception state of the light receiver measured while the first drive unit changes the tilt angle of the first unit from a first angle to a second angle, an inclination angle closer to the center of the range than the inclination angle at the end of the range among the ranges of inclination angles at which the received light amount of the inspection light by the light receiver is equal to or greater than a predetermined value, as the inclination angle in the normal operation mode of the first unit. A method for adjusting a vehicle detector having the above.

8. A light projector unit fixed to the side facing the lane of the first support member extending in the vertical direction and having a light projector that projects inspection light, A light receiver facing the light projector with the lane therebetween, fixed to the side facing the lane of the second support member extending in the vertical direction, and having a light receiver that receives the inspection light. A first drive unit that tilts a first unit, which is one of the light projector unit and the light receiver unit, in the lane width direction. In a vehicle detector provided with A step of measuring a light reception state of the inspection light by the light receiver. From the light reception state of the light receiver measured while the first drive unit changes the tilt angle of the first unit from the first angle to the second angle, among the range of tilt angles at which the amount of received inspection light of the light receiver is equal to or greater than a predetermined value, a tilt angle closer to the center of the range than the tilt angle at the end of the range is determined as the tilt angle in the normal operation mode of the first unit; A program for causing the execution.

Images