Measuring device

Abstract

To provide a technique that allows an object at a desired distance to be scanned by the electromagnetic wave.SOLUTION: A measuring device (200) includes a measuring unit (202) and a control unit (204). The measuring unit (202) performs a scan of an object by emitting an electromagnetic wave and receiving the electromagnetic wave reflected by the object. The scan is performed while changing an emission direction of the electromagnetic wave in two dimensions, in a height direction and in a lateral direction. The control unit (204) determines a scan range in a subsequent scan by the measuring unit (202) based on a received signal by the measuring unit (202) in the scan of the measuring unit (202).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a measurement device, a control device, a control method, and a program. [Background technology]

[0002] Technologies have been developed that detect obstacles and the like by irradiating electromagnetic waves to scan objects. Patent Document 1 discloses a technology in which a device installed in an automobile or the like irradiates a laser beam to scan within a target area to detect obstacles and the like. Patent Document 1 also discloses a technology for changing the lateral central axis of the scan area according to the steering angle of the automobile. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-258604 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a measurement device that performs scanning using electromagnetic waves, it is sometimes desired to scan an object located at a desired distance from the measurement device. One method for enabling the measurement device to scan an object located at a desired distance from the measurement device is to calibrate the measurement device before operating the measurement device to appropriately set the scanning range. However, even if calibration is performed, it may not be possible to scan an object located at a desired distance from the measurement device due to inaccurate calibration or a change in the attitude of the measurement device after calibration.

[0005] Even if the central axis of the scan area is shifted laterally, as in the technology disclosed in Patent Document 1, it is not possible to achieve a desired distance between the scanned object and the measurement device.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has as its object to provide a technique that enables scanning of an object at a desired distance using electromagnetic waves. [Means for solving the problem]

[0007] A first invention related to the present disclosure is a measurement device having (1) a measurement unit that performs scanning by irradiating electromagnetic waves and receiving the electromagnetic waves reflected by a reflecting object, and (2) a control unit that controls the measurement unit. The control unit determines a scanning range in a second scan performed after the first scan, based on a signal received by the measurement unit in a first scan by the measurement unit.

[0008] The present disclosure includes a control device having a control unit of the above-described measuring device.

[0009] The present disclosure includes a control method for controlling a measurement device by a computer. The measurement device performs scanning by emitting electromagnetic waves and receiving the electromagnetic waves reflected by a reflecting object. The control method determines a scan range in a second scan performed after the first scan by the measurement device, based on a signal received by the measurement unit in the first scan.

[0010] The present disclosure includes a program for causing a computer to execute the above control method. [Brief description of the drawings]

[0011] The above objects, as well as other objects, features and advantages, will become more apparent from the following preferred embodiments and the accompanying drawings.

[0012] [Figure 1] 1 is a block diagram illustrating a measurement device according to a first embodiment. [Diagram 2] 1 is a diagram illustrating an example of a front view of a scanning range of a measurement unit; FIG. [Diagram 3] 1A to 1C are diagrams illustrating examples of electromagnetic waves whose irradiation directions vary in the height direction. [Figure 4] 11 is a diagram illustrating a scanning range determined by a control unit; FIG. [Diagram 5] 4 is a flowchart illustrating the flow of processing executed by the measurement device of the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control unit. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a measurement unit. [Figure 8] FIG. 2 is a diagram illustrating an example of a hardware configuration of a measurement unit that irradiates light. [Figure 9] FIG. 1 is a diagram illustrating a measuring device installed on a moving body. [Figure 10] 11 is a diagram illustrating an example of a front view of a trajectory of scanning by a measurement unit; FIG. [Figure 11] 1 is a diagram illustrating an example of a scanning range as viewed from the front, divided into units into which electromagnetic waves are irradiated by a measurement device; [Figure 12] 11 is a diagram illustrating an example of a scanning range of a measurement unit in the height direction. FIG. [Figure 13] 11A and 11B are diagrams illustrating examples of scanning results of a measuring unit. [Figure 14] 11A and 11B are diagrams illustrating examples of scanning results of a measuring unit. [Figure 15] 11 is a diagram illustrating an example of a measurement result when a large obstacle is present at a position a predetermined distance away from the measurement device. FIG. [Figure 16] 13 is a flowchart illustrating a flow of processing executed by a control unit of the fourth embodiment. [Figure 17] FIG. 11 is a diagram illustrating an example of reference information in a table format. [Figure 18] FIG. 13 is a flowchart illustrating the flow of processing executed by the measurement device of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are given the same reference numerals and the description will be omitted as appropriate.

[0014] Fig. 1 is a block diagram illustrating a measuring device 200 according to the first embodiment. In Fig. 1, each block represents a functional configuration, not a hardware configuration. The hardware configuration of the measuring device 200 will be described later with reference to Figs. 6 to 8.

[0015] The measuring device 200 includes a measuring unit 202 and a control unit 204. The measuring unit 202 scans an object by irradiating it with electromagnetic waves. Here, the measuring unit 202 scans the object while changing the irradiation direction of the electromagnetic waves in two dimensions, the vertical direction and the horizontal direction. Note that the height direction means the approximately vertical direction. Also, the horizontal direction means the approximately horizontal direction.

[0016] 2 is a diagram illustrating an example of a front view of the scanning range of the measurement unit 202. A scanning range 224 represents the scanning range of the measurement unit 202.

[0017] The control unit 204 controls the measurement unit 202. Specifically, the control unit 204 determines the scanning range of the scanning to be performed by the measurement unit 202 in the height direction based on the reception signal of the measurement unit 202 (a signal indicating the reception result of the electromagnetic wave reflected by an object).

[0018] For example, in a scan performed by the measuring unit 202, the control unit 204 identifies an irradiation direction that satisfies a predetermined criterion in the height direction of the irradiation direction of the measuring unit 202 based on the elapsed time from when the measuring unit 202 irradiates an electromagnetic wave until the reflected wave of the electromagnetic wave is received by the measuring unit 202. The predetermined criterion is a criterion that indicates that "an object located at a desired distance from the measuring device 200 has been scanned." Specific examples of the predetermined criterion will be described in the embodiments described later.

[0019] Here, the distance to an object scanned by the measurement device 200 depends on the height direction of the irradiated electromagnetic wave. Figure 3 is a diagram illustrating examples of electromagnetic waves irradiated in different directions in the height direction. In the case of Figure 3(a), an object closer to the measurement device 200 is scanned compared to the case of Figure 3(b).

[0020] Based on the height direction of the irradiation direction that satisfies the above-mentioned predetermined criterion, the control unit 204 determines the scanning range in the height direction in the subsequent scanning by the measurement unit 202. For example, the control unit 204 determines a new scanning range 224 such that the height direction of the irradiation direction that satisfies the above-mentioned predetermined criterion is the center in the height direction of the scanning range 224. The subsequent scanning by the measurement unit 202 is performed in the scanning range determined in this manner.

[0021] FIG. 4 is a diagram illustrating a scanning range 224 determined by the control unit 204. FIG. 4(a) shows a scanning range 224-1 before the control unit 204 determines it. Meanwhile, FIG. 4(b) shows a scanning range 224-2 newly determined by the control unit 204. The cross in FIG. 4 shows the direction in which the electromagnetic wave satisfying the above-mentioned predetermined criteria is irradiated. In the example of FIG. 4, the control unit 204 determines a new scanning range 224-2 so that the height direction of the irradiation direction of the cross is a predetermined position in the height direction of the scanning range. For example, in FIG. 4(b), the control unit 204 determines a new scanning range 224-2 so that the height direction of the irradiation direction of the cross is the center of the height direction of the scanning range.

[0022] As shown in Fig. 3, the distance to an object scanned by the measuring device 200 depends on the height direction of the irradiated electromagnetic wave (see Fig. 3). According to the measuring device 200 of this embodiment, a scanning range 224 of a scan subsequently performed by the measuring unit 202 is determined based on the result of the scan performed by the measuring unit 202. More specifically, the scanning range 224 is determined in the height direction such that a direction toward an area distant from the measuring device 200 by a desired distance is a predetermined position (e.g., the center) in the height direction of the scanning range 224. Therefore, it is possible to make the measuring device 200 scan an object located at an area distant from the measuring device 200 by the measuring device 200.

[0023] The measurement device 200 is installed on a moving object such as an automobile or a train. The measurement device 200 is used, for example, to detect obstacles on the path of movement of such a moving object. In this case, it may be preferable to be able to detect obstacles located at a desired distance from the moving object.

[0024] As a method for enabling scanning of an object located at a desired distance from the measuring device 200, it is conceivable to calibrate the measuring device 200 before operating the measuring device 200. However, even if calibration is performed, it may not be possible to scan an object located at a desired distance due to inaccurate calibration or a shift in the attitude of the measuring device 200 caused by vibrations applied to the measuring device 200 during operation.

[0025] According to the measuring device 200 of this embodiment, the scanning range 224 is automatically adjusted in the height direction during operation of the measuring device 200. Therefore, even if the calibration of the measuring device 200 is inaccurate or the attitude of the measuring device 200 is shifted due to vibration or the like during operation, adjustment can be automatically made so that the measuring device 200 can scan an object located at a desired distance from the measuring device 200.

[0026] Furthermore, according to the measuring device 200 of this embodiment, even if the measuring device 200 has not been calibrated, the scanning range of the measuring device 200 can be automatically adjusted so that an object located at a desired distance away can be scanned. Therefore, it is possible to save the trouble of calibrating the measuring device 200.

[0027] The measurement device 200 of this embodiment will be described in further detail below.

[0028] <Processing flow> 5 is a flowchart illustrating a process flow executed by the measurement device 200 of the embodiment 1. The measurement unit 202 irradiates an electromagnetic wave to scan an object (S102). The control unit 204 determines a scanning range of the subsequent scan by the measurement unit 202 based on a signal received by the measurement unit 202 in the scan performed in S102 (S104).

[0029] <Example of Hardware Configuration of Measurement Device 200> Each functional component of the measurement device 200 may be realized by hardware that realizes each functional component (e.g., a hardwired electronic circuit, etc.), or may be realized by a combination of hardware and software (e.g., a combination of an electronic circuit and a program that controls it, etc.). Below, a further explanation will be given of the case where each functional component of the measurement device 200 is realized by a combination of hardware and software.

[0030] 6 is a diagram illustrating an example of a hardware configuration of the control unit 204. The integrated circuit 100 is an integrated circuit that realizes the control unit 204. For example, the integrated circuit 100 is a SoC (System On Chip).

[0031] The integrated circuit 100 has a bus 102, a processor 104, a memory 106, a storage device 108, an input / output interface 110, and a network interface 112. The bus 102 is a data transmission path for the processor 104, the memory 106, the storage device 108, the input / output interface 110, and the network interface 112 to transmit and receive data to and from each other. However, the method of connecting the processor 104 and the like to each other is not limited to bus connection. The processor 104 is an arithmetic processing device realized by using a microprocessor or the like. The memory 106 is a memory realized by using a RAM (Random Access Memory) or the like. The storage device 108 is a storage device realized by using a ROM (Read Only Memory), a flash memory, or the like.

[0032] The input / output interface 110 is an interface for connecting the integrated circuit 100 to peripheral devices. In Fig. 6, the input / output interface 110 is connected to a driving circuit 30 for the irradiator. The driving circuit 30 for the irradiator will be described later.

[0033] The network interface 112 is an interface for connecting the integrated circuit 100 to a communication network. This communication network is, for example, a CAN (Controller Area Network) communication network. The method for connecting the network interface 112 to the communication network may be a wireless connection or a wired connection.

[0034] The storage device 108 stores a program module for implementing the functions of the control unit 204. The processor 104 implements the functions of the control unit 204 by reading the program module into the memory 106 and executing it.

[0035] The hardware configuration of the integrated circuit 100 is not limited to the configuration shown in Fig. 6. For example, the program module may be stored in the memory 106. In this case, the integrated circuit 100 may not include the storage device 108.

[0036] <<Example of Hardware Configuration of Measurement Unit 202>> 7 is a diagram illustrating an example of the hardware configuration of the measurement unit 202. The measurement unit 202 has an irradiator 10, an irradiator driving circuit 30, and a receiver 50. The irradiator 10 irradiates electromagnetic waves used for scanning. Here, the irradiator 10 is configured to be variable in irradiation direction, and can irradiate electromagnetic waves in various directions. The irradiator driving circuit 30 is a circuit that drives the irradiator 10. The receiver 50 receives reflected waves of the electromagnetic waves irradiated to the outside of the measurement device 200.

[0037] The control unit 204 detects that the reflected wave has been received by the receiver 50. For example, the receiver 50 is configured to transmit a predetermined signal to the control unit 204 in response to receiving the reflected wave. The control unit 204 detects that the reflected wave has been received by the receiver 50 by receiving this predetermined signal. The reception signal of the measuring unit 202 described above is, for example, this predetermined signal.

[0038] The electromagnetic waves irradiated by the irradiator 10 may be light such as laser light, or may be radio waves such as millimeter waves. Below, an example of the hardware configuration of the measurement unit 202 when the irradiator 10 irradiates light is described. A similar configuration can also be adopted for the measurement unit 202 when the irradiator 10 irradiates electromagnetic waves.

[0039] Fig. 8 is a diagram illustrating a hardware configuration of a measurement unit 202 that irradiates light. The projector 12 and the projector drive circuit 32 in Fig. 8 are examples of the irradiator 10 and the irradiator drive circuit 30 in Fig. 7, respectively. The projector 12 has a light source 14 and a movable reflector 16. The projector drive circuit 32 has a light source drive circuit 34 and a movable reflector drive circuit 36.

[0040] The light source 14 is any light source that irradiates light. The light source drive circuit 34 is a circuit that drives the light source 14 by controlling the supply of power to the light source 14. The light irradiated by the light source 14 is, for example, laser light. In this case, the light source 14 is, for example, a semiconductor laser that irradiates laser light.

[0041] The movable reflector 16 reflects light emitted from the light source 14. The light reflected by the movable reflector 16 is emitted to the outside of the measuring device 200. The movable reflector drive circuit 36 ​​is a circuit that drives the movable reflector 16. For example, the movable reflector 16 has one mirror that is configured to be rotatable in at least two directions, the height direction and the lateral direction. This mirror is, for example, a MEMS (Micro Electro Mechanical System) mirror.

[0042] The configuration of the movable reflector 16 is not limited to the configuration shown in Fig. 8. For example, the movable reflector 16 may be composed of two mirrors whose rotation axes intersect with each other.

[0043] 8, the measurement unit 202 has a photoreceiver 52. The photoreceiver 52 is an example of the receiver 50 in Fig. 7. The photoreceiver 52 receives reflected light of light irradiated to the outside of the measurement device 200. For example, the photoreceiver 52 has an APD (Avalanche Photodiode).

[0044] The configuration of the measuring unit 202 is not limited to the configuration shown in FIG. 7 or FIG. 8. For example, in FIG. 8, the measuring unit 202 is configured to be able to irradiate light in various directions by reflecting light irradiated from the light source 14 by the movable reflecting unit 16. However, the configuration for irradiating light in various directions is not limited to the configuration shown in FIG. 8. For example, the light source 14 itself may have a mechanism for rotating in the height direction and the horizontal direction. In this case, the measuring unit 202 can irradiate light in various directions by controlling the attitude of the light source 14. In this case, the measuring unit 202 may not have the movable reflecting unit 16 and the driving circuit 36 ​​for the movable reflecting unit. Furthermore, in this case, the light source driving circuit 34 controls the attitude of the light source 14 in addition to irradiating light from the light source 14.

[0045] The hardware realizing the control unit 204 (see FIG. 6) and the hardware realizing the measurement unit 202 (see FIG. 7 and FIG. 8) may be packaged in the same housing, or may be packaged in separate housings.

[0046] <Installation example of the measuring device 200> The measuring device 200 is installed on a moving object such as an automobile or a train. Fig. 9 is a diagram illustrating the measuring device 200 installed on a moving object 240. In Fig. 9, the measuring device 200 is fixed to the upper part of the moving object 240. The measuring device 200 is also connected to a control device 244 via a CAN communication network 242. The control device 244 is a control device that controls the moving object 240. For example, the control device 244 is an ECU (Electronic Control Unit).

[0047] Here, the control unit 204 may be realized as a part of a control device 244 that controls the moving object 240. In this case, a program module that realizes the control unit 204 described above is stored in a storage device included in the control device 244.

[0048] The location where the measuring device 200 is installed is not limited to the top of the moving body 240. For example, the measuring device 200 may be installed inside (for example, inside a room) the moving body 240. The measuring device 200 may also be installed on a stationary object.

[0049] <Scanning by the measuring unit 202> The scanning by the measuring unit 202 may be scanning performed in the horizontal direction or scanning performed in the height direction. FIG. 10 is a diagram illustrating a front view of the trajectory of scanning by the measuring unit 202. FIG. 10(a) illustrates scanning performed in the horizontal direction. In FIG. 10(a), scanning in the horizontal direction is performed sequentially for n lines (n is a natural number) that are different from each other in the height direction of the irradiation direction of the electromagnetic wave. Specifically, scans 220-1 to 220-n are performed sequentially. Then, after scan 220-n is performed, scans 220-1 to 220-n are performed sequentially again.

[0050] Hereinafter, scanning for one line will be referred to as "line scanning." Also, scanning each of n lines once (for example, scanning 220-1 to scanning 220-n once each in FIG. 10(a)) will be collectively referred to as "performing one cycle of scanning."

[0051] Fig. 10(b) illustrates scanning in the height direction. In scanning in the height direction, n lines that are different from each other in the horizontal direction of the electromagnetic wave irradiation direction are scanned in the height direction in sequence. In scanning in the height direction, scanning each of the n lines once (for example, scanning 222-1 to scanning 222-n once in Fig. 10(b)) is expressed as "performing one cycle of scanning."

[0052] The scanning range of the measurement unit 202 refers to the range scanned by one cycle of scanning. In other words, the scanning range of the measurement unit 202 is an area determined by the amplitude in the height direction and the amplitude in the lateral direction of the electromagnetic wave irradiated by the measurement device 200.

[0053] The measurement unit 202 irradiates electromagnetic waves multiple times in one line scan, thereby irradiating electromagnetic waves in multiple directions in one line scan. FIG. 11 is a diagram illustrating an example of a scanning range 224 viewed from the front, divided into units in which the electromagnetic waves are irradiated by the measurement device 200. The measurement unit 202 irradiates each electromagnetic wave so that it passes through each lattice shown in FIG. 11. For each electromagnetic wave thus irradiated, the measurement device 200 measures the time from when the electromagnetic wave is irradiated to when the reflected wave is received by the measurement device 200. Hereinafter, the direction of the electromagnetic wave irradiated so as to pass through the i-th row and j-th column lattice (i and j are both positive integers) of the scanning range 224 divided into such a lattice shape is expressed as the "i-th row and j-th column direction."

[0054] <Measurement by the measuring device 200> The control unit 204 measures the elapsed time from when the electromagnetic wave is irradiated from the irradiator 10 until the reflected wave of the electromagnetic wave is received by the receiver 50, and stores the measured time in a storage device (e.g., the storage device 108) in association with the irradiation direction. This elapsed time is represented, for example, by a value obtained by multiplying the number of clock signals counted from when the electromagnetic wave is irradiated from the irradiator 10 until the reflected wave of the electromagnetic wave is received by the clock period. Alternatively, for example, this elapsed time may be represented by the number of counted clock signals.

[0055] [Embodiment 2] The measurement apparatus 200 of the second embodiment is represented, for example, in Fig. 1, similarly to the measurement apparatus 200 of the first embodiment. Except for the points described below, the functions of the measurement apparatus 200 of the second embodiment are the same as those of the measurement apparatus 200 of the first embodiment.

[0056] In this embodiment, the measurement unit 202 performs horizontal line scanning (see FIG. 10(a)). The control unit 204 determines the scanning range of the measurement unit 202 by determining the center in the height direction of the scanning range (the center direction of the amplitude in the height direction in the direction in which the measurement device 200 irradiates electromagnetic waves) for the measurement unit 202 performing such horizontal line scanning.

[0057] 12 is a diagram illustrating an example of the scanning range of the measurement unit 202 in the height direction. An upper limit direction 225 is a direction that passes through an upper limit position of the scanning range 224 in the height direction. A center direction 226 is a direction that passes through a center position of the scanning range 224 in the height direction. A lower limit direction 227 is a direction that passes through a lower limit position of the scanning range 224 in the height direction.

[0058] 12(a), the angle that the center direction 226 forms with the Y axis is θ1. The amplitude of the height direction of the direction in which the measurement device 200 irradiates electromagnetic waves is 2α. Therefore, the direction in which the measurement device 200 irradiates electromagnetic waves ranges from θ1-α to θ1+α in the height direction.

[0059] Here, in the example of Fig. 12, it is assumed that the control unit 204 of this embodiment determines that the center direction in the height direction of the scanning range 224 is θ2. Then, the scanning range in the height direction of the scan performed after that scan will be the range shown in Fig. 12(b). Specifically, the direction in which the measuring device 200 irradiates electromagnetic waves will be in the range from θ2-α to θ2+α in the height direction.

[0060] The control unit 204 determines the scanning range 224 based on the results of multiple line scans among multiple line scans performed in the horizontal direction (for example, scans 220-1 to 220-n in FIG. 10(b)). Hereinafter, the line scan used to determine the scanning range 224 is referred to as the target line scan.

[0061] The target line scans may be all the line scans in a cycle, or may be a part of the line scans in a cycle. Furthermore, all the target line scans may be included in the same cycle, or all or some of the target line scans may be included in different cycles. Information indicating which line scans are to be treated as target line scans may be preset in the control unit 204, or may be stored in a storage device accessible from the control unit 204.

[0062] The control unit 204 identifies measurement results that satisfy a predetermined criterion from among the measurement results of the multiple target line scans. As described above, the predetermined criterion is a criterion that indicates that "an object located approximately a desired distance away from the measurement device 200 has been scanned." Then, the control unit 204 determines the scanning range of the scan in the subsequent cycles based on the identified measurement results.

[0063] For example, the above-mentioned predetermined criterion is a criterion related to the distance between the object scanned by the measurement device 200 and the measurement device 200, or a criterion related to the elapsed time measured by the measurement device 200. Below, several examples of methods for determining the scanning range 224 using the respective criterion will be described.

[0064] <Decision method 1> The control unit 204 determines the scanning range 224 based on the measurement results in which the distance between each object scanned in the multiple target line scans and the measurement device 200 satisfies a predetermined criterion. To this end, the control unit 204 calculates the distance between each scanned object and the measurement device 200 based on the measurement results in the multiple target line scans. Then, the control unit 204 determines the scanning range 224 based on the measurement results in which the distance satisfies the predetermined criterion.

[0065] To this end, first, the control unit 204 calculates the distance between each object scanned by the measurement unit 202 and the measurement device 200. The calculation is performed using, for example, the following equation (1).

number

[0066] The control unit 204 sets a predetermined distance or a predetermined range of distance as the above-mentioned predetermined criterion. Each of these will be specifically described below.

[0067] <<When a specified distance is used as a specified standard>> The control unit 204 identifies the distance D[m][i][j] calculated for the multiple target line scans that is closest to a predetermined distance. This predetermined distance may be preset in the control unit 204 or may be stored in a storage device accessible from the control unit 204.

[0068] Then, the control unit 204 sets the height direction of the irradiation direction in the scan in which the above specified distance was obtained as the center of the height direction of the scanning range 224 in the subsequent scan. For example, assume that the distance closest to the predetermined distance is D[2][3][4]. In this case, the control unit 204 sets the height direction of the irradiation direction in the scanning of the target line of the third row in the second cycle as the center of the height direction of the scanning range 224 in the subsequent scan.

[0069] Here, it is assumed that the distance closest to the predetermined distance is calculated for each of two or more target line scans. In this case, the control unit 204 may (1) use the height direction of the irradiation direction in one of the two or more target line scans to determine the scanning range 224 in the subsequent scan, or (2) use a statistical value of the height direction of the irradiation direction in the two or more target line scans to determine the scanning range 224 in the subsequent scan.

[0070] In the former case, for example, the control unit 204 counts the number of measurement results for which the distance closest to the predetermined distance is calculated for each target line scan. Then, the control unit 204 determines the height direction of the irradiation direction in the target line scan with the largest number of such results as the center in the height direction of the scanning range 224 in the subsequent scan. Note that the two or more target line scans may include only line scans in the same cycle, or may include line scans in different cycles. This method will be specifically described below with reference to the drawings.

[0071] Fig. 13 is a diagram illustrating a scanning result of the measuring unit 202. In Fig. 13, the scanning range 224 is divided into a lattice shape, similar to Fig. 11. In the example of Fig. 13, the predetermined distance is 100 m. A cross is indicated in the irradiation direction corresponding to the electromagnetic wave for which the distance from the measuring device 200 to the object is calculated to be 100 m.

[0072] 13, there are three distances calculated for the target line scan in the fourth row that are 100 m, which is the same as the predetermined distance. Meanwhile, there are six distances calculated for the target line scan in the fifth row that are 100 m, which is the same as the predetermined distance. Therefore, the control unit 204 sets the height direction of the irradiation direction in the target line scan in the fifth row as the height direction center of the scanning range 224 in the subsequent scan.

[0073] When using statistical values ​​of the height direction of the irradiation direction in two or more target line scans, the control unit 204 sets the statistical values ​​of the height direction of the irradiation direction in these target line scans as the center of the height direction of the scanning range 224 in the subsequent scan. For example, in the case of FIG. 13, the control unit 204 sets the average of the height direction of the irradiation direction in the target line scan in the fourth row and the height direction of the irradiation direction in the target line scan in the fifth row as the center of the height direction of the scanning range 224 in the subsequent scan. Note that at this time, the control unit 204 may specify the number of measurement results in which the distance closest to the predetermined distance is calculated for each target line scan, and calculate a weighted average based on the number. For example, in the case of FIG. 13, the control unit 204 assigns a weight of 3 to the height direction of the irradiation direction in the target line scan in the fourth row, and a weight of 6 to the height direction of the irradiation direction in the target line scan in the fifth row to calculate the weighted average.

[0074] When using the results of scanning in multiple cycles, the control unit 204 may operate, for example, as follows: First, the control unit 204 identifies the target line scan for each cycle that has the largest number of lines for which the closest distance to the predetermined distance has been calculated. Then, the control unit 204 sets the statistical value of the height direction of the irradiation direction in each identified target line scan as the center of the height direction of the scanning range 224 in the subsequent scan.

[0075] For example, the results of the scans from the first to fifth cycles are used to determine the scan range in the scans of the following cycles. In this case, the target line scans with the largest number of calculated distances closest to the predetermined distance are the target line scans of the fifth row in the first cycle, the target line scans of the fourth row in the second cycle, the target line scans of the fifth row in the third cycle, the target line scans of the sixth row in the fourth cycle, and the target line scans of the fifth row in the fifth cycle. In this case, for example, the control unit 204 determines the height direction of the irradiation direction in the target line scan of the fifth row, which is the most frequent value, as the center of the height direction of the scan range 224 in the following scan. Also, for example, the control unit 204 determines the average of the height direction of the irradiation direction in each identified target line scan as the center of the height direction of the scan range 224 in the following scan.

[0076] <<When a specific distance range is used as a specific standard>> The control unit 204 determines the scanning range so that the distance to the object scanned by the measurement unit 202 is within a predetermined range. Then, the control unit 204 calculates the distance D[m][i][j] for each of two or more target line scans by the above-mentioned method. Furthermore, the control unit 204 specifies a distance within the predetermined range from the calculated distances D[m][i][j]. Then, the control unit 204 sets the height direction of the irradiation direction in the target line scan in which the specified distance is obtained as the center of the height direction of the scanning range 224 in the subsequent scan. The above-mentioned predetermined range may be preset in the control unit 204, or may be stored in a storage device accessible from the control unit 204.

[0077] Here, it is assumed that the distance included in the predetermined range is calculated from the measurement results of each of two or more target line scans. In this case, the control unit 204 determines the center of the height direction of the scanning range 224 in the subsequent scan based on the results of these two or more target line scans. The method is the same as the method of determining the center of the height direction of the scanning range 224 in the subsequent scan based on the results of two or more target line scans in which the distance closest to the predetermined distance is calculated when the predetermined distance is used as the predetermined reference. For example, the control unit 204 determines the height direction of the irradiation direction in the target line scan in which the most measurement results are calculated to have a distance included in the predetermined range as the center of the height direction of the scanning range 224 in the subsequent scan.

[0078] <Decision method 2> The control unit 204 determines the scanning range 224 based on the measurement result that the elapsed time measured in the scanning of multiple target lines satisfies a predetermined criterion. In this case, a predetermined time or a predetermined range of elapsed time is used as the predetermined criterion. Each of these will be described below.

[0079] <<When a specified time is used as a specified standard>> The control unit 204 determines the scanning range 224 using a predetermined time as a predetermined criterion in the same manner as in the above-mentioned determination method 1 in which a predetermined distance is used as a predetermined criterion. This predetermined time corresponds to the time from when an electromagnetic wave is irradiated onto an object at a predetermined distance from the measurement device 200 until the reflected wave of the electromagnetic wave is received by the measurement device 200. For example, the predetermined time tp can be calculated using the following formula (2) using a predetermined distance dp and a speed C of the electromagnetic wave. Note that the predetermined time tp may be preset in the control unit 204, or may be stored in a storage device accessible from the control unit 204.

number

[0080] The control unit 204 determines the scanning range 224 using the above-mentioned predetermined time tp. For example, the control unit 204 identifies the elapsed time closest to the predetermined time tp from among the elapsed times t[m][i][j] measured for multiple target line scans. Then, the control unit 204 sets the height direction of the electromagnetic wave irradiation direction in the target line scan in which the above-mentioned identified elapsed time was obtained as the center of the height direction of the scanning range 224 in the subsequent scan. In addition, the method of determining the scanning range when the elapsed time closest to the predetermined time tp is measured in multiple target line scans is the same as the method of determining the scanning range 224 when the distance closest to the predetermined distance is calculated for multiple target line scans in determination method 1.

[0081] <<When a specific range of elapsed time is used as the specific criterion>> The control unit 204 determines the scanning range 224 using the predetermined range of elapsed time as the predetermined criterion in the same manner as in the above-mentioned determination method 1, in which the predetermined range of distance is used as the predetermined criterion. The lower limit of the predetermined range of elapsed time can be calculated based on the lower limit of the predetermined range of distance and the above-mentioned formula (2). The upper limit of the predetermined range of elapsed time can be calculated based on the upper limit of the predetermined range of distance and the above-mentioned formula (2). The above-mentioned predetermined range may be preset in the control unit 204, or may be stored in a storage device accessible from the control unit 204.

[0082] For example, the control unit 204 identifies an elapsed time included in a predetermined range of elapsed times from among the elapsed times t[m][i][j]. Then, the control unit 204 sets the height direction of the irradiation direction in the target line scan in which the identified elapsed time was obtained as the center in the height direction of the scanning range 224 in the subsequent scan. In addition, the method of determining the scanning range when the elapsed time included in the predetermined range is measured in multiple target line scans is the same as the method of determining the scanning range when the distance included in the predetermined range is calculated for multiple target line scans in determination method 1.

[0083] <Timing for determining the scanning range 224> The control unit 204 may arbitrarily determine the scanning range 224. For example, the control unit 204 may periodically determine the scanning range 224. In this manner, it is possible to periodically ensure that the center of the scanning range 224 in the height direction is in the desired direction.

[0084] Also, for example, the control unit 204 may determine the scanning range 224 in response to the detection of vibration. For example, the detection of vibration is performed using a vibration sensor. Note that the vibration sensor may be provided inside the measuring device 200 or outside the measuring device 200. In the latter case, for example, the vibration sensor is provided on the moving body 240. In this case, when the measuring device 200 detects vibration of a magnitude equal to or greater than a predetermined magnitude by the moving body 240, the measuring device 200 receives a notification of the detection from the moving body. Then, the measuring device 200 determines the scanning range 224 in response to receiving the notification. In this way, the scanning range 224 is determined at a timing when the measuring device 200 or the moving body 240 on which the measuring device 200 is installed may have shifted in posture due to the application of vibration, and the scanning range 224 is adjusted. Therefore, even if the posture of the measuring device 200 shifts due to vibration, the center of the height direction of the scanning range 224 can be maintained in a desired direction.

[0085] <Example of hardware configuration> The hardware configuration of the measuring device 200 of the second embodiment is shown in, for example, Figures 6 to 8, similar to the hardware configuration of the measuring device 200 of the first embodiment. In this embodiment, the program modules stored in the storage device 108 described above further include programs for realizing the functions described in this embodiment.

[0086] According to the measuring device 200 of this embodiment, the center in the height direction of the scanning range 224 is determined based on the measurement results in the lateral scan and a predetermined criterion. This makes it possible to ensure that an object located at a desired distance away from the measuring device 200 is included in the scanning range 224 even if the calibration of the measuring device 200 is inaccurate or the attitude of the measuring device 200 is shifted due to vibration or the like during operation. It is also possible to save the effort of calibrating the measuring device 200.

[0087] [Embodiment 3] The measurement apparatus 200 of the third embodiment is represented, for example, in Fig. 1, similarly to the measurement apparatus 200 of the first and second embodiments. Except for the points described below, the functions of the measurement apparatus 200 of the third embodiment are the same as the functions of the measurement apparatus 200 of the first embodiment.

[0088] In this embodiment, the measurement unit 202 performs line scanning in the height direction (see FIG. 10(b)). The control unit 204 determines the scanning range of the measurement unit 202 by determining the center in the height direction of the scanning range 224 (the center of the swing width in the height direction in the irradiation direction of the irradiator 10) for the measurement unit 202 performing such line scanning in the height direction.

[0089] Here, as described above, the measurement unit 202 of the second embodiment determines the scanning range using the results of multiple line scans. In contrast, the measurement unit 202 of the present embodiment may determine the scanning range based on the results of one line scan, or may determine the scanning range based on the results of multiple line scans. The reason for this is as follows.

[0090] First, the distance between the object scanned by the measuring device 200 and the measuring device 200 depends on the height direction of the irradiated electromagnetic wave, but depends little on the lateral direction of the electromagnetic wave. Therefore, in a lateral line scan, there is a high probability that the distance between each object scanned in the line scan and the measuring device 200 will be approximately the same. Therefore, with only one line scan, there is a low probability that a measurement result in which an object located at a desired distance away from the measuring device 200 is scanned can be obtained. Therefore, the measuring device 200 of the second embodiment uses the measurement results of multiple line scans.

[0091] On the other hand, in line scanning in the height direction, the irradiation directions of the electromagnetic waves irradiated in one line scan are different in the height direction. Therefore, in line scanning in the height direction, there is a high probability that the distances between the objects scanned in the line scan and the measuring device 200 are different from each other. Therefore, even with just one line scan, it is highly likely that a measurement result in which an object located at a desired distance away from the measuring device 200 is scanned can be obtained. Therefore, the measuring device 200 of this embodiment can determine the scanning range 224 based on the result of one line scan.

[0092] The control unit 204 determines the scanning range based on the results of one or more of the multiple line scans (e.g., scans 222-1 to 222-n in FIG. 10(b)) performed in the height direction. As described above, the line scan used to determine the scanning range is referred to as the target line scan. When multiple line scans are treated as the target line scans, all the target line scans may be included in the same cycle, or all or some of the target line scans may be included in different cycles. Information indicating which line scans are to be treated as the target line scans may be preset in the control unit 204, or may be stored in a storage device accessible from the control unit 204.

[0093] In this embodiment, the control unit 204 also determines the scanning range 224 based on various predetermined criteria (predetermined distance, predetermined range of distance, predetermined time, and predetermined range of elapsed time, etc.) described in embodiment 2. This will be described in detail below.

[0094] <Decision method 1> The control unit 204 calculates the distance from each object scanned in the target line scan to the measurement device 200. Then, the control unit 204 determines the scan range 224 based on a predetermined distance or a predetermined range of distances as a predetermined criterion.

[0095] <<When a specified distance is used as a specified standard>> The control unit 204 identifies the distance closest to the predetermined distance from among the distances D[m][i][j] calculated for the target line scan, and determines the height direction of the electromagnetic wave irradiation direction corresponding to the measurement result from which the identified distance was calculated as the height center of the scanning range 224 in the subsequent scan.

[0096] For example, let us assume that the calculated distance that is closest to the predetermined distance is D[1][4][5]. In this case, the control unit 204 determines the height direction of the electromagnetic wave irradiated in the 4-row, 5-column direction (the height direction of the 4th row) as the center of the height direction of the scanning range 224 in the subsequent scan. The method of calculating the distance from the scanned object to the measuring device 200 is as described in the first embodiment.

[0097] Here, it is assumed that the distance closest to the predetermined distance is calculated for two or more measurement results. In this case, for example, the control unit 204 sets the statistical value of the height direction of the electromagnetic wave irradiation direction when each measurement result is obtained as the center of the height direction of the scanning range 224 in the subsequent scan.

[0098] Fig. 14 is a diagram illustrating an example of the scanning result of the measuring unit 202. Fig. 14 illustrates a scanning range 224 divided into a grid pattern. In Fig. 14, similar to Fig. 11, the scanning range 224 is divided into a grid pattern. In the example of Fig. 14, the predetermined distance is 100 m. A cross is indicated in the grid corresponding to the irradiation direction of the electromagnetic wave in which the distance from the measuring device 200 to the object is calculated to be 100 m.

[0099] 14, the grids indicated with crosses are a grid of 4 rows and 5 columns and a grid of 5 rows and 6 columns. Therefore, the control unit 204 sets the statistical value (for example, the average) of the height direction of the 4th row and the height direction of the 5th row as the center of the height direction of the scanning range 224 in the subsequent scan.

[0100] Here, when calculating the statistical value, the control unit 204 may exclude some target line scans from the calculation of the statistical value. As described above, the measurement device 200 is installed on, for example, the moving body 240. In this case, for example, the measurement device 200 is preferably arranged such that the center of the height direction of the scanning range 224 of the measurement device 200 is oriented toward an object located at a predetermined distance (for example, 100 m) from the measurement device 200.

[0101] At this time, if there is a large obstacle such as a building at a position a predetermined distance away from the measuring device 200, the measurement results of the line scan that scans the obstacle will include many measurement results in which a distance equal to or close to the above-mentioned predetermined distance is calculated. Figure 15 is a diagram illustrating measurement results when there is a large obstacle at a position a predetermined distance away from the measuring device 200. In Figure 15, the predetermined distance is 100 m. A cross is indicated by the measurement results in which 100 m is calculated as the distance from the measuring device 200.

[0102] The line scan 222-1 scans the road. In this case, the distance between each position on the road scanned by the line scan 222-1 and the measurement device 200 is different from one another. Therefore, the line scan 222-1 produces only one measurement result that calculates the same distance as the predetermined distance, 100 m. Therefore, by using the measurement result of the line scan 222-1, the center of the scanning range 224 in the height direction can be appropriately determined.

[0103] On the other hand, the line scan 222-2 scans a building 228. The building 228 is located 100 m away from the measurement device 200. Therefore, there are many measurement results in the line scan 222-2 that calculate the same distance as the specified distance, 100 m. Therefore, if the measurement results of the line scan 222-2 are used, there is a risk that the center of the height direction of the scan range 224 of the scan cannot be appropriately determined.

[0104] Therefore, the control unit 204 excludes line scans that have many measurement results in which the distance closest to the predetermined distance is calculated, such as the line scan 222-2 in FIG. 15, from the calculation of the above-mentioned statistics, among the target line scans in which the measurement results in which the distance closest to the predetermined distance is calculated are obtained. For example, the control unit 204 extracts only target line scans in which the number of measurement results in which the distance is calculated is equal to or less than a predetermined number, from the target line scans in which the distance closest to the predetermined distance is calculated. Then, the control unit 204 calculates a statistical value in the height direction of the irradiation direction of the electromagnetic wave corresponding to each measurement result in which the distance closest to the predetermined distance is calculated in the extracted target line scans. In this way, even if there is a large obstacle at a position at a predetermined distance away from the measurement device 200 or in the vicinity thereof, the scanning range 224 of the measurement device 200 can be appropriately determined.

[0105] Also, according to this method, it is possible to simply exclude line scans that may cause a decrease in the accuracy of the determination of the scanning range 224 by the control unit 204, such as the measurement results obtained by scanning a large obstacle. Therefore, it is possible to simply increase the accuracy of the determination of the scanning range 224 by the control unit 204.

[0106] <<When a specific distance range is used as a specific standard>> The control unit 204 determines the scanning range so that the distance to the object scanned by the measurement unit 202 is within a predetermined range. The control unit 204 calculates the distance D[m][i][j] for each of one or more target line scans by the above-mentioned method. Furthermore, the control unit 204 specifies a distance within the predetermined range from the calculated distances D[m][i][j]. Then, the control unit 204 sets the height direction of the electromagnetic wave irradiation direction corresponding to the measurement result from which the specified distance is obtained as the center of the height direction of the scanning range 224 in the subsequent scan. The above-mentioned predetermined range may be preset in the control unit 204 or may be stored in a storage device accessible from the control unit 204.

[0107] Here, it is assumed that the distance included in the predetermined range is calculated for each of two or more measurement results. In this case, the control unit 204 determines the center of the height direction of the scanning range 224 in the subsequent scan based on these two or more measurement results. For example, similar to the case where the predetermined distance is used as the predetermined reference, the control unit 204 determines the statistical value of the height direction of the electromagnetic wave irradiation direction from which each measurement result in which the distance included in the predetermined range is calculated is obtained as the center of the height direction of the scanning range 224 in the subsequent scan.

[0108] When calculating this statistical value, some target line scans may be excluded from the calculation of the statistical value, as in the case where the predetermined distance is used as the predetermined criterion. Specifically, among the target line scans from which measurement results are obtained that calculate a distance that falls within a predetermined range, line scans from which many measurement results (e.g., a predetermined number or more) are obtained that calculate a distance that falls within the predetermined range are excluded from the calculation of the above-mentioned statistical value.

[0109] <Decision method 2> The control unit 204 determines the scanning range 224 with the predetermined time or the predetermined range of the elapsed time as the predetermined range in the same manner as in the above-described determination method 1 in which the predetermined distance or the predetermined range of the distance is used as the predetermined criterion. As described in the description of the second embodiment, the predetermined time can be calculated from the predetermined distance based on the formula (2). Also, as described in the description of the second embodiment, the upper and lower limit values ​​of the predetermined range of the elapsed time can be calculated using the upper and lower limit values ​​of the predetermined range of the distance and the formula (2).

[0110] <Timing for determining the scanning range 224> The timing at which the control unit 204 of this embodiment determines the scanning range 224 is similar to the timing at which the control unit 204 of the second embodiment determines the scanning range 224.

[0111] <Example of hardware configuration> The hardware configuration of the measuring device 200 of the third embodiment is shown in, for example, Figures 6 to 8, similar to the hardware configuration of the measuring device 200 of the first embodiment. In this embodiment, the program modules stored in the storage device 108 described above further include programs for realizing the functions described in this embodiment.

[0112] According to the measuring device 200 of this embodiment, the center in the height direction of the scanning range 224 is determined based on the measurement result in scanning in the height direction and a predetermined criterion. As a result, similar to the case of using the measuring device 200 of the second embodiment, even if the calibration of the measuring device 200 is inaccurate or the attitude of the measuring device 200 is shifted due to vibration or the like during operation, it is possible to ensure that an object located at a desired distance away from the measuring device 200 is included in the scanning range 224. It is also possible to save the effort of calibrating the measuring device 200.

[0113] As described above, the measuring device 200 of this embodiment can determine the scanning range 224 based on the measurement results of one line scan. Therefore, compared to the measuring device 200 of the second embodiment, this has the advantage that the time required to determine the scanning range 224 can be shortened, and the amount of computer resources required to determine the scanning range 224 can be reduced.

[0114] Furthermore, as described above, according to the measurement device 200 of this embodiment, line scans that include many measurement results that satisfy a predetermined criterion, such as line scans that scan a large obstacle, can be easily excluded from the line scans used to determine the scan range 224. In this way, the accuracy with which the control unit 204 determines the scan range 224 can be easily improved.

[0115] [Embodiment 4] The measurement apparatus 200 of the fourth embodiment is represented, for example, in Fig. 1, similarly to the measurement apparatus 200 of the first to third embodiments. Except for the points described below, the functions of the measurement apparatus 200 of the fourth embodiment are the same as the functions of the measurement apparatus 200 of any of the first to third embodiments.

[0116] The measuring device 200 of the fourth embodiment is provided on a moving body 240 (see FIG. 9). The control unit 204 of the fourth embodiment acquires information indicating the speed of the moving body (hereinafter, speed information). Then, when the speed of the moving body indicated by the speed information is equal to or greater than a predetermined speed, the control unit 204 determines the scanning range 224. On the other hand, when the speed of the moving body indicated by the speed information is equal to or greater than the predetermined speed, the control unit 204 does not determine the scanning range 224.

[0117] The method by which the control unit 204 obtains the speed information is arbitrary. For example, the control unit 204 obtains the speed information generated by the control device 244 via the CAN communication network 242. Note that existing technologies can be used for the method by which the control device of the moving object grasps the speed of the moving object and the method by which the control device of the moving object transmits information to another device. Also, a device that measures the speed of the moving object 240 may be provided inside the measurement device 200. In this case, the measurement device 200 obtains the speed information from this device.

[0118] <Processing flow> 16 is a flowchart illustrating the flow of processing executed by the control unit 204 of embodiment 4. The processing performed in S102 and S104 in FIG. 16 is similar to the processing performed in S102 and S104 in FIG.

[0119] In S202, the control unit 204 acquires speed information. If the speed of the moving object indicated by the speed information is equal to or greater than a predetermined speed (S204: YES), the control unit 204 executes S104. On the other hand, if the speed of the moving object indicated by the speed information is less than the predetermined speed (S204: NO), the process of FIG. 16 ends.

[0120] The control unit 204 may or may not determine whether the speed indicated in the speed information is equal to or greater than a predetermined speed every time the above-mentioned scanning range 224 is performed (periodic timing or timing when vibration is detected). In the latter case, for example, the control unit 204 performs a process based on the result of the determination after determining once whether the speed indicated in the speed information is equal to or greater than a predetermined speed until the next determination. Specifically, when it is determined that the speed indicated in the speed information is equal to or greater than a predetermined speed, the control unit 204 determines the scanning range 224 one or more times until the next determination. Similarly, when it is determined that the speed indicated in the speed information is equal to or greater than a predetermined speed, the control unit 204 does not determine the scanning range 224 until the next determination.

[0121] When the speed of the moving body 240 is relatively slow, it is considered that large vibrations are unlikely to be applied to the moving body 240. Therefore, if the calibration of the measuring device 200 is performed accurately, it can be said that there is a high probability that an object located at a desired distance away from the measuring device 200 will be scanned by the measuring device 200 even if the scanning range 224 is not adjusted when the speed of the moving body 240 is slow.

[0122] Therefore, according to this embodiment, the scanning range 224 is determined when the speed of the moving object 240 is equal to or greater than a predetermined value. This reduces the frequency with which the scanning range 224 is determined, thereby reducing the consumption of computer resources of the control unit 204. On the other hand, when it is considered that there is a high need to adjust the scanning range 224 (when the speed of the moving object 240 is equal to or greater than a predetermined value), the scanning range 224 is determined, so that an object located at a desired distance away from the measuring device 200 can be scanned by the measuring device 200.

[0123] In addition, assuming a case where the measurement device 200 has not been calibrated or the calibration of the measurement device 200 is inaccurate, the scanning range 224 may be determined at least once after startup, regardless of the speed of the moving object 240. For example, the control unit 204 determines the scanning range 224 regardless of the speed of the moving object 240 for a predetermined number of times or for a predetermined period of time after startup. Thereafter, the control unit 204 determines the scanning range 224 when the speed of the moving object 240 is equal to or greater than a predetermined speed. In this way, even if the measurement device 200 has not been calibrated or the calibration of the measurement device 200 is inaccurate, an object located at a desired distance from the measurement device 200 can be scanned at an early stage after startup.

[0124] <Example of hardware configuration> The hardware configuration of the measuring device 200 of the fourth embodiment is shown in, for example, Figures 6 to 8, similar to the hardware configuration of the measuring device 200 of the first embodiment. In this embodiment, the program modules stored in the storage device 108 described above further include programs for realizing the functions described in this embodiment.

[0125] [Embodiment 5] The measurement device 200 of the fifth embodiment is represented, for example, in Fig. 1, similarly to the measurement device 200 of the first to fourth embodiments. Except for the points described below, the functions of the measurement device 200 of the fifth embodiment are the same as the functions of the measurement device 200 of any of the first to fourth embodiments.

[0126] The measuring device 200 of this embodiment is provided on a moving object 240, similar to the measuring device 200 of the fourth embodiment. The control unit 204 of the fifth embodiment acquires speed information, similar to the control unit 204 of the fourth embodiment. Then, the control unit 204 determines a predetermined criterion for determining the scanning range 224 based on the speed of the moving object 240. The predetermined criterion is, for example, a predetermined distance, a predetermined range of distance, a predetermined time, or a predetermined range of elapsed time, as described in the description of the second and third embodiments.

[0127] The predetermined criterion is determined in association with the speed of the moving body 240. More specifically, the predetermined criterion is determined such that the faster the speed of the moving body 240, the more distant an object located from the measuring device 200 is scanned. This is because the faster the speed of the moving body 240, the longer the distance the moving body 240 moves in a short time, and therefore it is preferable to set the measuring device 200 to scan a more distant object.

[0128] For example, if the predetermined criterion is a predetermined distance or a predetermined time, these values ​​will be larger as the speed of the moving object 240 increases. Also, for example, if the predetermined criterion is a predetermined range of distance or elapsed time, the lower and upper limits of these predetermined ranges will be larger as the speed of the moving object 240 increases.

[0129] Information indicating the correspondence between a predetermined criterion and the speed of a moving body is called reference information. FIG. 17 is a diagram illustrating an example of reference information in the form of a table. The table shown in FIG. 17 is called reference information 300. Reference information 300 has speed 302 and criterion 304. Speed ​​302 indicates a range of speed. Criterion 304 indicates a predetermined criterion associated with the range of speed indicated by speed 302. Note that in FIG. 17, criterion 304 indicates a predetermined distance. For example, the record in the second row of reference information 300 indicates that the speed of moving body 240, "greater than v1 and equal to or less than v2", is associated with a predetermined criterion of "predetermined distance=a2 [m]".

[0130] Note that the reference information is not limited to selectively determining a predetermined reference according to the speed of the moving body as exemplified in Fig. 17. For example, the reference information may be a calculation formula that calculates the predetermined reference from the speed of the moving body 240. In this case, for example, the reference information is determined as a function that uses the speed of the moving body 240 as an argument and returns the predetermined reference.

[0131] The reference information may be preset in the control unit 204 or may be stored in a storage device accessible from the control unit 204.

[0132] <Processing flow> Fig. 18 is a diagram illustrating a flowchart illustrating the flow of processing executed by the measuring device 200 of embodiment 5. The processing performed in S102, S104, and S202 in Fig. 18 is similar to the processing performed in S102, S104, and S202 in Fig. 17. In S302, the control unit 204 determines a predetermined criterion based on the speed of the moving object 240 indicated by the speed information.

[0133] The faster the moving object 240 is, the greater the distance the moving object 240 travels in a short period of time. Therefore, it may be preferable for the measuring device 200 to scan objects that are farther away when the moving object 240 is moving at a higher speed.

[0134] Therefore, in the measurement device 200 of this embodiment, a predetermined criterion for determining the scanning range 224 is set according to the speed of the moving body 240. In this way, it is possible to scan an object at an appropriate distance according to the speed of the moving body 240.

[0135] <Example of hardware configuration> The hardware configuration of the measuring device 200 of the fifth embodiment is shown in, for example, Figures 6 to 8, similar to the hardware configuration of the measuring device 200 of the first embodiment. In this embodiment, the program modules stored in the storage device 108 described above further include programs for realizing the functions described in this embodiment.

[0136] [Embodiment 6] The measurement device 200 of this embodiment is represented, for example, in Fig. 1, similarly to the measurement device 200 of embodiment 1. Except for the points described below, the functions of the measurement device 200 of embodiment 6 are the same as the functions of the measurement device 200 of any of embodiments 1 to 5.

[0137] In each of the above-described embodiments, the control unit 204 determines the scanning range in the height direction in the subsequent scanning by the measuring unit 202 based on the height direction of the irradiation direction that satisfies the predetermined criterion. The "predetermined criterion" is a criterion that indicates that "an object located at a desired distance from the measuring device 200 has been scanned." The predetermined criterion is, for example, that "the calculated distance to the target object is a predetermined distance (distance range)" or "the time from when an electromagnetic wave is irradiated to an object to when the reflected wave of the electromagnetic wave by the object is received by the measuring device 200 is a predetermined time."

[0138] However, the attitude of the measuring device 200 (i.e., the scanning range of the measuring device) may vary significantly (may deviate significantly from the initial attitude). Such variation may occur, for example, due to vibration of a vehicle such as an automobile in which the measuring device 200 is placed. When such variation occurs, the signal received by the measuring unit 202 may not satisfy the above-mentioned predetermined criterion at the timing when the height direction of the scanning range in the subsequent scanning by the measuring unit 202 is to be determined as described above. More specifically, there is a possibility that none of the grids shown in FIG. 11 may satisfy the predetermined criterion. For example, as shown in FIG. 13, when a cross is shown on a grid where the distance calculated for the target line operation is the same as the predetermined distance, a situation may occur in which there is no grid where a cross is shown.

[0139] More specifically, for example, if the attitude of the measuring device 200 (i.e., the range of electromagnetic wave irradiation by the measuring device 200) fluctuates significantly upward, all of the distances calculated for the target line scan may be greater than 100 m. Conversely, if the attitude of the measuring device 200 fluctuates significantly downward, all of the distances calculated for the target line scan may be less than 100 m.

[0140] If a deviation occurs in the attitude of the measurement device 200 in this way, it becomes difficult to appropriately scan and measure the periphery of the desired distance range (a position 100 m away from the measurement device 200 in the above example).

[0141] Therefore, in the measuring device 200 of this embodiment, if the signal received by the measuring unit 202 does not satisfy the above-mentioned criteria, the control unit 204 controls the measuring unit 202 so that the scanning range of the measuring unit 202 (i.e., the emission range of the electromagnetic wave irradiated by the measuring unit 202) is shifted upward or downward. In other words, if none of the irradiation directions of the electromagnetic wave in the scanning range of the measuring unit 202 satisfies the predetermined condition, the control unit 204 moves the scanning range of the measuring unit 202 upward or downward by a predetermined amount.

[0142] For example, assume that all of the distances calculated for the target line scan are below a predetermined standard (for example, when the predetermined distance is set to 100 m, all of them are below 100 m) at the timing when the height direction of the scanning range in the subsequent scanning by the measuring unit 202 is to be determined. In this case, the control unit 204 controls the measuring unit 202 so that the scanning range of the measuring unit 202 is moved upward by a predetermined angle. That is, the control unit 204 starts scanning based on a state in which the irradiator 10 (movable reflecting unit 16) is tilted upward by a predetermined angle.

[0143] Then, the control unit 204 repeats this control until the signal received by the measurement unit 202 satisfies the above-mentioned criteria (until any of the distances calculated for the target line scan satisfies the predetermined criteria). In other words, the scanning range of the measurement unit 202 is shifted upward by a predetermined angle at a time until the predetermined criteria is satisfied.

[0144] Similarly, at the timing when the height direction of the scanning range in the subsequent scanning by the measuring unit 202 is to be determined, all of the distances calculated for the target line scanning exceed a predetermined criterion (for example, when the predetermined distance is set to 100 m, all of them exceed 100 m). In this case, the control unit 204 controls the measuring unit 202 so that the scanning range of the measuring unit 202 is shifted downward by a predetermined angle. That is, the control unit 204 starts scanning based on a state in which the irradiator 10 (movable reflecting unit 16) is tilted downward by a predetermined angle. Then, the control unit 204 repeats this control until the signal received by the measuring unit 202 meets the above-mentioned criterion (until any of the distances calculated for the target line scanning meets the predetermined criterion). That is, the scanning range of the measuring unit 202 is shifted downward by a predetermined angle at a time until the predetermined criterion is met.

[0145] By performing such control, even if a situation occurs in which the attitude of the measurement device 100 changes significantly, it becomes possible to identify the height direction of the irradiation direction that satisfies a predetermined criterion, and based on the identified height direction, it becomes possible to determine the scanning range in the height direction in the subsequent scanning by the measurement unit 202. This enables the measurement device 200 to scan objects at a desired distance with electromagnetic waves in a wider variety of environments.

[0146] <Example of hardware configuration> The hardware configuration of the measuring device 200 of the sixth embodiment is shown, for example, in Figures 6 to 8, similar to the hardware configuration of the measuring device 200 of the first embodiment. In this embodiment, the program modules stored in the storage device 108 described above further include programs for realizing the functions described in this embodiment.

[0147] Although the embodiments of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and it is also possible to adopt combinations of the above-described embodiments or various configurations other than those described above.

[0148] This application claims priority based on Japanese Patent Application No. 2016-169960, filed on August 31, 2016, the disclosure of which is incorporated herein in its entirety.

Claims

[Claim 1] a measurement unit that performs scanning by irradiating an electromagnetic wave and receiving the electromagnetic wave reflected by a reflecting object; A control unit that controls the measurement unit, The control unit is The measurement device determines a scan range for a second scan performed after the first scan based on a signal received by the measurement unit during a first scan by the measurement unit.

Images