Measuring device

Abstract

This invention provides a technology that enables scanning of objects at a desired distance using electromagnetic waves. [Solution] The measuring device (200) has a measuring unit (202) and a control unit (204). The measuring unit (202) scans an object by irradiating it with electromagnetic waves and receiving the electromagnetic waves reflected by the object. This scanning is performed while changing the direction of irradiation of electromagnetic waves in two dimensions, the vertical and horizontal directions. The control unit (204) determines the scanning range for subsequent scanning by the measuring unit (202) based on the signal received by the measuring unit (202) during scanning by the measuring unit (202).

Description

Technical Field

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

Background Art

[0002] Techniques for detecting obstacles and the like by irradiating electromagnetic waves to scan an object have been developed. Patent Document 1 discloses a technique for detecting obstacles and the like by irradiating laser light to perform scanning within a target area in a device installed in an automobile or the like. Further, Patent Document 1 discloses a technique for changing the central axis in the lateral direction of the scanning area according to the steering angle of the automobile.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a measuring device that performs scanning using electromagnetic waves, there are cases where it is desired to scan an object existing around a desired distance from the measuring device. To enable scanning of an object around a desired distance from the measuring device, there is a method of appropriately setting the scanning range by performing calibration of the measuring device before operation of the measuring device. However, even if calibration is performed, due to inaccurate calibration or a change in the posture of the measuring device after calibration, it may become impossible to scan an object around a desired distance from the measuring device.

[0005] Even if the central axis of the scanning area is changed in the lateral direction as in the technique disclosed in Patent Document 1, it is not possible to make the distance between the scanned object and the measuring device a desired distance.

[0006] This invention has been made in view of the above-mentioned problems, and one of its objectives is to provide a technology that enables scanning of an object at a desired distance using electromagnetic waves. [Means for solving the problem]

[0007] The first invention relating to this disclosure is a measuring device having (1) a measuring unit that performs scanning by irradiating electromagnetic waves and receiving the electromagnetic waves reflected by a reflector, and (2) a control unit that controls the measuring unit. The control unit determines the scanning range for the second scan, which is performed after the first scan, based on the signal received by the measurement unit during the first scan performed by the measurement unit.

[0008] This disclosure includes a control device having a control unit for the above-mentioned measuring device.

[0009] This disclosure includes a control method for controlling a measuring device using a computer. The measuring device performs scanning by irradiating electromagnetic waves and receiving the electromagnetic waves reflected by a reflector. The control method determines the scanning range for a second scan, which is performed after the first scan, based on the signal received by the measuring unit during the first scan by the measuring device.

[0010] This disclosure includes a program that causes a computer to execute the control method described above. [Brief explanation of the drawing]

[0011] The aforementioned objectives, as well as other objectives, features, and advantages, will become even clearer from the preferred embodiments described below and the accompanying drawings.

[0012] [Figure 1] This is a block diagram illustrating a measuring device according to Embodiment 1. [Figure 2] This diagram illustrates a front view of the scanning range of the measurement unit. [Figure 3] A diagram illustrating electromagnetic waves with different irradiation directions in the height direction. [Figure 4] A diagram illustrating the scanning range determined by the control unit. [Figure 5] A flowchart illustrating the processing flow executed by the measuring device of Embodiment 1. [Figure 6] A diagram illustrating the hardware configuration of the control unit. [Figure 7] A diagram illustrating the hardware configuration of the measuring unit. [Figure 8] A diagram illustrating the hardware configuration of the measuring unit that irradiates light. [Figure 9] A diagram illustrating the measuring device installed on the moving body. [Figure 10] A diagram illustrating the front view of the scanning trajectory by the measuring unit. [Figure 11] A diagram illustrating the scanning range in the front view divided by the unit irradiated with electromagnetic waves by the measuring device. [Figure 12] A diagram illustrating the scanning range of the measuring unit in the height direction. [Figure 13] A diagram illustrating the scanning result of the measuring unit. [Figure 14] A diagram illustrating the scanning result of the measuring unit. [Figure 15] A diagram illustrating the measurement result when there is a large obstacle at a position a predetermined distance away from the measuring device. [Figure 16] A flowchart illustrating the processing flow executed by the control unit of Embodiment 4. [Figure 17] A diagram illustrating the reference information in a table format. [Figure 18] A diagram illustrating a flowchart illustrating the processing flow executed by the measuring device of Embodiment 5.

Embodiments of the Invention

[0013] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0014] Figure 1 is a block diagram illustrating a measuring device 200 according to Embodiment 1. In Figure 1, each block represents a functional unit configuration, not a hardware unit configuration. The hardware configuration of the measuring device 200 will be described later using Figures 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 direction of irradiation of the electromagnetic waves in two dimensions, the vertical and horizontal directions. The height direction refers to the approximately vertical direction, and the horizontal direction refers to the approximately horizontal direction.

[0016] Figure 2 illustrates a front view of the scanning range of the measurement unit 202. The 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 in the height direction for the subsequent scan performed by the measurement unit 202, based on the received signal from the measurement unit 202 (a signal representing the result of receiving electromagnetic waves reflected by an object).

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

[0019] Here, the distance to the object scanned by the measuring device 200 depends on the height direction of the irradiated electromagnetic wave. Figure 3 illustrates electromagnetic waves with different irradiation directions in the height direction. In the case of Figure 3(a), objects that are closer to the measuring device 200 are scanned compared to the case of Figure 3(b).

[0020] The control unit 204 determines the scanning range in the subsequent scan by the measurement unit 202 in the height direction based on the height direction of the irradiation direction that satisfies the predetermined criteria. For example, the control unit 204 determines a new scanning range 224 such that the height direction of the irradiation direction that satisfies the predetermined criteria becomes the center of the scanning range 224 in the height direction. The subsequent scan by the measurement unit 202 is performed within the scanning range determined in this way.

[0021] Figure 4 illustrates the scanning range 224 determined by the control unit 204. Figure 4(a) shows the scanning range 224-1 before the control unit 204 makes a determination. On the other hand, Figure 4(b) shows the scanning range 224-2 newly determined by the control unit 204. The cross marks in Figure 4 represent the direction in which electromagnetic waves satisfying the predetermined criteria are irradiated. In the example in Figure 4, the control unit 204 determines the new scanning range 224-2 such that the height direction of the irradiation direction of the cross marks is at a predetermined position in the height direction of the scanning range. For example, in Figure 4(b), the control unit 204 determines the new scanning range 224-2 such that the height direction of the irradiation direction of the cross marks is at the center of the height direction of the scanning range.

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

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

[0024] One possible method for enabling the scanning of objects located at a desired distance from the measuring device 200 is to calibrate the measuring device 200 before operation. However, even if calibration is performed, inaccurate calibration or vibrations applied to the measuring device 200 during operation may cause the device's orientation to shift, making it impossible to scan objects at the desired distance.

[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 if the orientation of the measuring device 200 is shifted due to vibration or other reasons during operation, it is possible to automatically adjust the device so that it 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 it can scan an object located at a desired distance. Therefore, it is possible to eliminate the need to calibrate the measuring device 200.

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

[0028] <Processing flow> Figure 5 is a flowchart illustrating the processing flow performed by the measuring device 200 of Embodiment 1. The measuring unit 202 scans an object by irradiating it with electromagnetic waves (S102). The control unit 204 determines the scanning range for subsequent scans by the measuring unit 202 based on the signal received by the measuring unit 202 during the scan performed in S102 (S104).

[0029] <Example of hardware configuration of measuring device 200> Each functional component of the measuring device 200 may be implemented by hardware (e.g., hardwired electronic circuits) or by a combination of hardware and software (e.g., a combination of an electronic circuit and a program to control it). The case in which each functional component of the measuring device 200 is implemented by a combination of hardware and software will be further explained below.

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

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

[0032] The input / output interface 110 is an interface for connecting the integrated circuit 100 to peripheral devices. In Figure 6, the irradiator drive circuit 30 is connected to the input / output interface 110. The irradiator drive circuit 30 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 by which the network interface 112 connects to the communication network may be wireless or wired.

[0034] The storage device 108 stores program modules for realizing the functions of the control unit 204. The processor 104 reads these program modules into memory 106 and executes them to realize the functions of the control unit 204.

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

[0036] <<Example Hardware Configuration of Measurement Unit 202>> Figure 7 illustrates the hardware configuration of the measurement unit 202. The measurement unit 202 includes an irradiator 10, an irradiator drive circuit 30, and a receiver 50. The irradiator 10 emits electromagnetic waves used for scanning. The irradiator 10 has a variable irradiation direction, allowing it to emit electromagnetic waves in various directions. The irradiator drive circuit 30 is a circuit that drives the irradiator 10. The receiver 50 receives the reflected electromagnetic waves emitted to the outside of the measurement device 200.

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

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

[0039] Figure 8 illustrates the hardware configuration of the measurement unit 202 that emits light. The light emitter 12 and the drive circuit 32 of the light emitter in Figure 8 are examples of the irradiator 10 and the drive circuit 30 of the irradiator in Figure 7, respectively. The light emitter 12 has a light source 14 and a movable reflector 16. The drive circuit 32 of the light emitter has a drive circuit 34 for the light source and a drive circuit 36 ​​for the movable reflector.

[0040] The light source 14 is any light source that emits 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 emitted by the light source 14 is, for example, laser light. In this case, for example, the light source 14 is a semiconductor laser that emits 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 drive circuit 36 ​​for the movable reflector is a circuit that drives the movable reflector 16. For example, the movable reflector 16 has a single 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 reflective section 16 is not limited to the configuration shown in Figure 8. For example, the movable reflective section 16 may be composed of two mirrors whose rotation axes intersect with each other.

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

[0044] The configuration of the measurement unit 202 is not limited to the configurations shown in Figures 7 and 8. For example, in Figure 8, the measurement unit 202 is configured to irradiate light in various directions by reflecting the light emitted from the light source 14 with the movable reflector 16. However, the configuration for irradiating light in various directions is not limited to the configuration shown in Figure 8. For example, the light source 14 itself may have a mechanism that rotates in the height direction and the horizontal direction. In this case, the measurement unit 202 can irradiate light in various directions by controlling the orientation of the light source 14. In this case, the measurement unit 202 does not need to have the movable reflector 16 and the drive circuit 36 ​​for the movable reflector. Furthermore, in this case, the drive circuit 34 for the light source controls the orientation of the light source 14 in addition to irradiating light from the light source 14.

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

[0046] <Example of installation of measuring device 200> The measuring device 200 is installed on a moving object, such as an automobile or a train. Figure 9 illustrates the measuring device 200 installed on a moving object 240. In Figure 9, the measuring device 200 is fixed to the top of the moving object 240. The measuring device 200 is also connected to the 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 implemented as part of a control device 244 that controls the mobile body 240. In this case, a program module that implements the aforementioned control unit 204 is stored in the storage device of the control device 244.

[0048] Furthermore, the location where the measuring device 200 is installed is not limited to the top of the mobile body 240. For example, the measuring device 200 may be installed inside the mobile body 240 (e.g., indoors). Alternatively, the measuring device 200 may be installed on a stationary object.

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

[0050] Hereafter, a scan performed on a single line will be referred to as a "line scan." Furthermore, performing one scan on each of the n lines (for example, performing scans 220-1 through 220-n once each in Figure 10(a)) will be collectively referred to as "performing one scan cycle."

[0051] Figure 10(b) illustrates scanning in the height direction. In height scanning, the scan is performed sequentially on n lines, each with a different lateral direction of electromagnetic wave irradiation. In height scanning, performing one scan on each of the n lines (for example, performing scans 222-1 to 222-n once in Figure 10(b)) is referred to as "performing one scan cycle."

[0052] The scanning range of the measurement unit 202 represents the range scanned by one scanning cycle. In other words, the scanning range of the measurement unit 202 is the region determined by the amplitude of the vertical and horizontal fluctuations of the electromagnetic wave irradiated by the measurement device 200.

[0053] The measurement unit 202 irradiates electromagnetic waves in multiple directions within a single line scan by irradiating them multiple times within a single line scan. Figure 11 is a diagram illustrating the division of the scanning range 224, viewed from the front, into units to which electromagnetic waves are irradiated by the measurement device 200. The measurement unit 202 irradiates each electromagnetic wave so as to pass through each grid shown in Figure 11. For each electromagnetic wave irradiated in this manner, the measurement device 200 measures the time from when the electromagnetic wave is irradiated until its 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 grid (i and j are both positive integers) of the scanning range 224 divided into such grids will be referred to as the "i-th row j-th column direction".

[0054] <Regarding measurements using measuring device 200> The control unit 204 measures the elapsed time from when electromagnetic waves are emitted from the irradiator 10 until the reflected waves are received by the receiver 50, and stores this measured time in a memory device (e.g., storage device 108) in association with the irradiation direction. This elapsed time is expressed, for example, by multiplying the number of clock signals counted between the time electromagnetic waves are emitted from the irradiator 10 and the time reflected waves are received by the clock period. Alternatively, this elapsed time may be expressed by the number of clock signals counted.

[0055] [Embodiment 2] The measuring device 200 of Embodiment 2 is represented, for example, by Figure 1, similar to the measuring device 200 of Embodiment 1. Except for the points described below, the functions of the measuring device 200 of Embodiment 2 are the same as those of the measuring device 200 of Embodiment 1.

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

[0057] Figure 12 illustrates the scanning range of the measurement unit 202 in the height direction. The upper limit direction 225 is the direction that passes through the upper limit position of the scanning range 224 in the height direction. The center direction 226 is the direction that passes through the center position of the scanning range 224 in the height direction. The lower limit direction 227 is the direction that passes through the lower limit position of the scanning range 224 in the height direction.

[0058] In Figure 12(a), the angle that the central direction 226 makes with respect to the Y-axis is θ1. Also, the amplitude of the vertical deflection in the direction in which the measuring device 200 irradiates electromagnetic waves is 2α. Therefore, the direction in which the measuring device 200 irradiates electromagnetic waves is in the range from θ1-α to θ1+α in the vertical direction.

[0059] Here, let's assume that in the example shown in Figure 12, the control unit 204 of this embodiment decides to set the center direction in the height direction of the scanning range 224 to θ2. Then, the scanning range in the height direction of the subsequent scan will be the range shown in Figure 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 performed in the lateral direction (for example, scans 220-1 to 220-n in Figure 10(b)). Hereinafter, the line scans used to determine the scanning range 224 will be referred to as target line scans.

[0061] The target line scan may be all line scans in a given cycle, or it may be some line scans in a given cycle. Furthermore, all 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 should be treated as target line scans may be pre-set in the control unit 204, or it may be stored in a memory 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 scanning multiple target lines. As mentioned above, the predetermined criterion is that "an object located at a desired distance from the measuring device 200 was scanned." Based on the identified measurement results, the control unit 204 then determines the scanning range for scans in cycles later than those cycles.

[0063] For example, the predetermined criteria mentioned above are criteria relating to the distance between the object scanned by the measuring device 200 and the measuring device 200, or criteria relating to the elapsed time measured by the measuring device 200. Below, several examples of methods for determining the scanning range 224 using the respective criteria are given.

[0064] <Decision method 1> The control unit 204 determines the scanning range 224 based on measurement results in which the distance between each object scanned and the measuring device 200 in the scanning of multiple target lines meets a predetermined standard. To do this, the control unit 204 calculates the distance between each scanned object and the measuring device 200 based on the measurement results in the scanning of multiple target lines. Then, the control unit 204 determines the scanning range 224 based on the measurement results in which that distance meets a predetermined standard.

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

number

[0066] The control unit 204 uses the predetermined distance, or a predetermined range of distance, as the predetermined standard described above. Each of these will be explained in detail below.

[0067] <<When a predetermined distance is used as the standard>> The control unit 204 identifies the distance closest to a predetermined distance from among the distances D[m][i][j] calculated for scanning multiple target lines. This predetermined distance may be pre-set in the control unit 204 or stored in a storage device accessible from the control unit 204.

[0068] The control unit 204 then sets the height direction of the irradiation direction in the scan where the specified distance was obtained as the center of the height direction of the scanning range 224 in the subsequent scan. For example, suppose 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 scan 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, assume that the distance closest to a predetermined distance has been calculated for each of the two or more target line scans. In this case, the control unit 204 may (1) determine the scanning range 224 for the subsequent scan using the height direction of the irradiation direction in one of the two or more target line scans, or (2) determine the scanning range 224 for the subsequent scan using the statistical values ​​of the height direction of the irradiation direction in the two or more target line scans.

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

[0071] Figure 13 illustrates the scanning results of the measurement unit 202. In Figure 13, as in Figure 11, the scanning range 224 is divided into a grid. In the example in Figure 13, the predetermined distance is 100m. An "X" mark is shown in the irradiation direction corresponding to the electromagnetic wave calculated to be 100m from the measurement device 200 to the object.

[0072] In Figure 13, among the distances calculated for the target line scan in the fourth row, there are three values ​​of 100m, which is the same as the predetermined distance. On the other hand, among the distances calculated for the target line scan in the fifth row, there are six values ​​of 100m, 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 of the fifth row as the center of the height direction of the scanning range 224 in the subsequent scan.

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

[0074] When using the results of scanning in multiple cycles, the control unit 204 may operate as follows, for example. First, for each cycle, the control unit 204 identifies the target line scan with the highest number of values ​​for which the distance closest to a predetermined distance was calculated. Then, the control unit 204 uses the height-direction statistical value of the irradiation direction in each identified target line scan as the height-direction center of the scanning range 224 in subsequent scans.

[0075] For example, suppose the scanning range for subsequent scans is determined using the results of scans from the first to the fifth cycle. In this case, suppose the target line scan with the most instances where the distance closest to a predetermined distance was calculated was the target line scan of the fifth row in the first cycle, the target line scan of the fourth row in the second cycle, the target line scan of the fifth row in the third cycle, the target line scan of the sixth row in the fourth cycle, and the target line scan 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 mode, as the center of the height direction of the scanning range 224 in subsequent scans. Alternatively, 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 scanning range 224 in subsequent scans.

[0076] <<When a predetermined range of distance is used as the standard>> The control unit 204 determines the scanning range such that the distance to the object scanned by the measurement unit 202 falls within a predetermined range. The control unit 204 then calculates the distance D[m][i][j] for each of the two or more target line scans using the method described above. Furthermore, the control unit 204 identifies the distance that falls within the predetermined range from among the calculated distances D[m][i][j]. The control unit 204 then sets the height direction of the irradiation direction in the target line scan where the identified distance was obtained as the center of the height direction of the scanning range 224 in subsequent scans. The predetermined range may be pre-set in the control unit 204 or stored in a storage device accessible from the control unit 204.

[0077] Here, suppose that the distance included in a predetermined range is calculated from the measurement results for each of two or more target line scans. In this case, the control unit 204 determines the center in 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 used when a predetermined distance is used as a predetermined reference, in which the center in the height direction of the scanning range 224 in the subsequent scan is determined based on the results of two or more target line scans for which the distance closest to the predetermined distance was calculated. For example, the control unit 204 sets the height direction of the irradiation direction of the target line scan for which the measurement results for the distance included in the predetermined range are most numerous as the center in 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 measurement results where the elapsed time measured in scanning multiple target lines meets 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 explained below.

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

number

[0080] The control unit 204 determines the scanning range 224 using the predetermined time tp. For example, the control unit 204 identifies the elapsed time t[m][i][j] closest to the predetermined time tp from among the elapsed times t[m][i][j] measured for multiple target line scans. The control unit 204 then sets the height direction of the electromagnetic wave irradiation direction in the target line scan where the identified elapsed time was obtained as the center of the height direction of the scanning range 224 in subsequent scans. Furthermore, the method for determining the scanning range when the elapsed time closest to the predetermined time tp is measured for multiple target line scans is the same as the method for 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 predetermined range of elapsed time is used as the predetermined standard>> The control unit 204 determines the scanning range 224 using a predetermined range of elapsed time as a predetermined criterion, in the same manner as when a predetermined range of distance is used as a predetermined criterion in the determination method 1 described above. 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 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 formula (2). The above predetermined range may be set in advance in the control unit 204, or it may be stored in a storage device accessible from the control unit 204.

[0082] For example, the control unit 204 identifies the elapsed time t[m][i][j] that falls within a predetermined range of elapsed time. The control unit 204 then sets the height direction of the irradiation direction in the target line scan where the identified elapsed time was obtained as the center of the height direction of the scanning range 224 in subsequent scans. Furthermore, the method for determining the scanning range when the elapsed time within the predetermined range is measured for multiple target line scans is the same as the method for determining the scanning range when the distance within the predetermined range is calculated for multiple target line scans in determination method 1.

[0083] <Timing for determining the scanning range 224> The timing at which the control unit 204 determines the scanning range 224 is arbitrary. For example, the control unit 204 determines the scanning range 224 periodically. This ensures that the center of the scanning range 224 in the height direction is in the desired direction at regular intervals.

[0084] For example, the control unit 204 may determine the scanning range 224 in response to vibration detection. For example, vibration detection is performed using a vibration sensor. This vibration sensor may be located inside the measuring device 200 or outside the measuring device 200. In the latter case, for example, the vibration sensor is located on the mobile body 240. In this case, the measuring device 200 receives notification from the mobile body 240 when vibration of a predetermined magnitude or greater is detected by the mobile body 240. The measuring device 200 then determines the scanning range 224 in response to receiving this notification. In this way, the scanning range 224 is determined and adjusted at a time when there is a possibility that the orientation of the measuring device 200 has shifted due to vibration applied to the measuring device 200 or the mobile body 240 on which the measuring device 200 is installed. Therefore, even if the orientation of the measuring device 200 shifts due to vibration, the center of the scanning range 224 in the height direction can be maintained in the desired direction.

[0085] <Example of hardware configuration> The hardware configuration of the measuring device 200 in Embodiment 2 is similar to that of the measuring device 200 in Embodiment 1, as shown in Figures 6 to 8, for example. In this embodiment, the program module stored in the aforementioned storage device 108 further includes a program that implements the functions described in this embodiment.

[0086] According to the measuring device 200 of this embodiment, the height center of the scanning range 224 is determined based on the measurement results in the lateral scanning and a predetermined standard. This ensures that even if the calibration of the measuring device 200 is inaccurate or the orientation of the measuring device 200 shifts due to vibration or other factors during operation, an object located at a desired distance from the measuring device 200 can be included in the scanning range 224. Furthermore, it eliminates the need to perform calibration of the measuring device 200.

[0087] [Embodiment 3] The measuring device 200 of Embodiment 3 is represented, for example, by Figure 1, similar to the measuring devices 200 of Embodiments 1 and 2. Except for the points described below, the functions of the measuring device 200 of Embodiment 3 are the same as those of the measuring device 200 of Embodiment 1.

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

[0089] In this embodiment, the measurement unit 202 determines the scanning range using the results of multiple line scans, as described above. In contrast, the measurement unit 202 of this embodiment may determine the scanning range based on the result of a single line scan, or it 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, while having little dependence 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 within that line scan and the measuring device 200 will be approximately the same. Consequently, with only one line scan, the probability of obtaining a measurement result for an object located at a desired distance from the measuring device 200 is not high. Therefore, the measuring device 200 of Embodiment 2 utilizes the measurement results of multiple line scans.

[0091] On the other hand, in line scanning in the height direction, the irradiation direction of each electromagnetic wave irradiated in a single line scan differs from one another in the height direction. Therefore, in line scanning in the height direction, there is a high probability that the distance between each object scanned in that line scan and the measuring device 200 will be different from one another. Thus, even with just one line scan, it is possible to obtain measurement results that scan objects at a desired distance from the measuring device 200 with a high probability. Therefore, the measuring device 200 of this embodiment can determine the scanning range 224 based on the results of a single line scan.

[0092] The control unit 204 determines the scan range based on the results of one or more line scans performed in the height direction (for example, scans 222-1 to 222-n in Figure 10(b)). As mentioned above, the line scans used to determine the scan range are referred to as target line scans. When multiple line scans are treated as target line scans, all 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 pre-set in the control unit 204 or stored in a memory device accessible from the control unit 204.

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

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

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

[0096] For example, suppose that among the calculated distances, the one 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 4x5 direction (height direction of the 4th row) as the center of the height direction of the scanning range 224 in the subsequent scan. The method for calculating the distance from the scanned object to the measuring device 200 is as described in Embodiment 1.

[0097] Here, assume that the distance closest to a predetermined distance has been calculated for two or more measurement results. In this case, for example, the control unit 204 sets the height-direction statistical value of the electromagnetic wave irradiation direction at the time each measurement result was obtained as the height-direction center of the scanning range 224 in the subsequent scan.

[0098] Figure 14 is an example of the scanning results of the measurement unit 202. Figure 14 shows a scanning range 224 divided into a grid. In Figure 14, as in Figure 11, the scanning range 224 is divided into a grid. In the example of Figure 14, the predetermined distance is 100m. An "X" mark is shown on the grid corresponding to the direction of electromagnetic wave irradiation, calculated as the distance from the measurement device 200 to the object being 100m.

[0099] In Figure 14, the grids marked with an "X" are the 4x5 grid and the 5x6 grid. The control unit 204 then uses the statistical values ​​(e.g., the average) of the height direction of the 4th row and the 5th row as the center of the height direction of the scanning range 224 in the subsequent scan.

[0100] Here, the control unit 204 may exclude some target line scans from the calculation of the statistical values ​​when calculating the above statistical values. As mentioned above, the measuring device 200 is installed on, for example, a mobile body 240. In this case, for example, it is preferable that the center of the scanning range 224 in the height direction of the measuring device 200 is toward an object located at a predetermined distance (for example, 100 m) away from the measuring device 200.

[0101] At this time, if there is a large obstacle such as a building located at a predetermined distance from the measuring device 200, the measurement results of the line scan that scans the obstacle will include many measurement results that calculate a distance equal to or close to the predetermined distance. Figure 15 is an example of the measurement results when there is a large obstacle located at a predetermined distance from the measuring device 200. In Figure 15, the predetermined distance is 100m. An "X" is shown in the measurement results where 100m 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 measuring device 200 is different from each other. Therefore, the line scan 222-1 calculates only one measurement result which is the same as the predetermined distance of 100m. Thus, by using the measurement result of the line scan 222-1, the vertical center of the scanning range 224 can be appropriately determined.

[0103] On the other hand, line scan 222-2 scans building 228, which is located 100m away from measuring device 200. Therefore, line scan 222-2 produces many measurement results that are the same as the predetermined distance of 100m. Consequently, using the measurement results of line scan 222-2 may not allow for the proper determination of the vertical center of the scanning range 224.

[0104] Therefore, the control unit 204 excludes from the calculation of the above-mentioned statistical values ​​line scans that yield many measurement results showing the closest distance to the predetermined distance, such as line scan 222-2 in Figure 15, from the target line scans for which measurement results showing the closest distance to the predetermined distance were obtained. For example, the control unit 204 extracts only the target line scans for which the number of measurement results showing the closest distance to the predetermined distance is less than or equal to a predetermined number. Then, the control unit 204 calculates statistical values ​​in the height direction of the electromagnetic wave irradiation direction corresponding to each measurement result showing the closest distance to the predetermined distance in these extracted target line scans. In this way, even if there is a large obstacle at or near a predetermined distance from the measuring device 200, the scanning range 224 of the measuring device 200 can be appropriately determined.

[0105] Furthermore, this method makes it possible to easily exclude line scanning, which can reduce the accuracy of the control unit 204's determination of the scanning range 224, such as measurement results when scanning large obstacles. Therefore, the accuracy of the control unit 204's determination of the scanning range 224 can be increased in a simple manner.

[0106] <<When a predetermined range of distance is used as the standard>> The control unit 204 determines the scanning range such that the distance to the object scanned by the measurement unit 202 falls within a predetermined range. The control unit 204 then calculates a distance D[m][i][j] for each of the one or more target line scans using the method described above. Furthermore, the control unit 204 identifies the distance that falls within the predetermined range from among the calculated distances D[m][i][j]. The control unit 204 then sets the height direction of the electromagnetic wave irradiation direction corresponding to the measurement result from which the identified distance was obtained as the center of the height direction of the scanning range 224 in subsequent scans. The predetermined range may be pre-set in the control unit 204 or stored in a storage device accessible from the control unit 204.

[0107] Here, assume that the distance included within a predetermined range has been calculated for each of two or more measurement results. In this case, the control unit 204 determines the center in 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 a predetermined distance is used as a predetermined reference, the control unit 204 uses the statistical value in the height direction of the electromagnetic wave irradiation direction from which each measurement result for which the distance included within the predetermined range has been calculated as the center in the height direction of the scanning range 224 in the subsequent scan.

[0108] Furthermore, when calculating these statistical values, it is possible to exclude some target line scans from the calculation of the statistical values, similar to when a predetermined distance is used as a predetermined standard. Specifically, among the target line scans for which measurement results in which distances within a predetermined range are obtained, line scans for which a large number (e.g., a predetermined number or more) measurement results in which distances within a predetermined range are obtained are excluded from the calculation of the statistical values ​​described above.

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

[0110] <Timing for determining the scanning range 224> The timing at which the control unit 204 in this embodiment determines the scanning range 224 is the same as the timing at which the control unit 204 in Embodiment 2 makes its decision.

[0111] <Example of hardware configuration> The hardware configuration of the measuring device 200 in Embodiment 3 is similar to that of the measuring device 200 in Embodiment 1, as shown in Figures 6 to 8, for example. In this embodiment, the program module stored in the aforementioned storage device 108 further includes a program that implements the functions described in this embodiment.

[0112] According to the measuring device 200 of this embodiment, the center of the scanning range 224 in the height direction is determined based on the measurement results in the height direction scanning and a predetermined standard. This makes it possible to include objects located at a desired distance from the measuring device 200 within the scanning range 224, even if the calibration of the measuring device 200 is inaccurate or if the orientation of the measuring device 200 is shifted due to vibration or other factors during operation, similar to when using the measuring device 200 of Embodiment 2. Furthermore, it is possible to eliminate the effort required to calibrate the measuring device 200.

[0113] As mentioned above, the measuring device 200 of this embodiment allows the determination of the scanning range 224 based on the measurement results for a single line scan. Therefore, compared to the measuring device 200 of Embodiment 2, it has the advantage of reducing the time required to determine the scanning range 224 and reducing the amount of computing resources required to determine the scanning range 224.

[0114] Furthermore, as described above, the measuring device 200 of this embodiment makes it easy to exclude line scans that contain many measurement results that meet predetermined criteria, such as line scans that scan large obstacles, from the line scans used to determine the scanning range 224. In this way, the accuracy of the control unit 204's determination of the scanning range 224 can be easily improved.

[0115] [Embodiment 4] The measuring device 200 of Embodiment 4 is represented, for example, by Figure 1, similar to the measuring devices 200 of Embodiments 1 to 3. Except for the points described below, the functions of the measuring device 200 of Embodiment 4 are the same as those of any of the measuring devices 200 of Embodiments 1 to 3.

[0116] The measuring device 200 in Embodiment 4 is installed on the moving body 240 (see Figure 9). The control unit 204 in Embodiment 4 acquires information indicating the speed of the moving body (hereinafter referred to as speed information). If the speed of the moving body indicated by the speed information is greater than or equal to a predetermined speed, the control unit 204 determines the scanning range 224. On the other hand, if the speed of the moving body indicated by the speed information is greater than or equal to a predetermined speed, the control unit 204 does not determine the scanning range 224.

[0117] The method by which the control unit 204 acquires speed information is arbitrary. For example, the control unit 204 acquires speed information generated by the control device 244 via the CAN communication network 242. Existing technologies can be used for the method by which the control device of the mobile object determines the speed of the mobile object, and for the method by which the control device of the mobile object transmits information to other devices. In addition, a device for measuring the speed of the mobile object 240 may be provided inside the measuring device 200. In this case, the measuring device 200 acquires speed information from this device.

[0118] <Processing flow> Figure 16 is a flowchart illustrating the flow of processing performed by the control unit 204 of Embodiment 4. The processing performed in S102 and S104 in Figure 16 is the same as the processing performed in S102 and S104 in Figure 5.

[0119] In S202, the control unit 204 acquires speed information. If the speed of the moving object indicated by the speed information is greater than or equal to 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 in Figure 16 ends.

[0120] The control unit 204 may, or may not, determine each time the aforementioned scanning range 224 is performed (at regular intervals or when vibration is detected) whether the speed indicated in the speed information is above a predetermined speed. In the latter case, for example, the control unit 204 will, after determining once whether the speed indicated in the speed information is above a predetermined speed, perform processing based on the result of that determination until the next time the determination is made. Specifically, if it is determined that the speed indicated in the speed information is above a predetermined speed, the control unit 204 will determine the scanning range 224 one or more times until the next time the determination is made. Similarly, if it is determined that the speed indicated in the speed information is above a predetermined speed, the control unit 204 will not determine the scanning range 224 until the next time the determination is made.

[0121] When the speed of the moving object 240 is relatively slow, it is unlikely that the moving object 240 will be subjected to large vibrations. Therefore, if the measuring device 200 is accurately calibrated, when the speed of the moving object 240 is slow, there is a high probability that an object located at a desired distance from the measuring device 200 will be scanned by the measuring device 200 without having to adjust the scanning range 224.

[0122] Therefore, according to this embodiment, the scanning range 224 is determined when the speed of the moving body 240 is greater than or equal to a predetermined value. This reduces the frequency of determining the scanning range 224, thereby reducing the consumption of computing resources by 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 body 240 is greater than or equal to a predetermined value), the scanning range 224 is determined, so that an object located at a desired distance from the measuring device 200 is scanned by the measuring device 200.

[0123] Furthermore, considering cases where the measuring device 200 has not been calibrated or its calibration 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. Subsequently, the control unit 204 determines the scanning range 224 when the speed of the moving object 240 is above a predetermined speed. In this way, even if the measuring device 200 has not been calibrated or its calibration is inaccurate, an object located at a desired distance from the measuring device 200 can be scanned at an early stage after startup.

[0124] <Example of hardware configuration> The hardware configuration of the measuring device 200 in Embodiment 4 is similar to that of the measuring device 200 in Embodiment 1, as shown in Figures 6 to 8, for example. In this embodiment, the program module stored in the aforementioned storage device 108 further includes a program that implements the functions described in this embodiment.

[0125] [Embodiment 5] The measuring device 200 of Embodiment 5 is represented, for example, by Figure 1, similar to the measuring devices 200 of Embodiments 1 to 4. Except for the points described below, the functions of the measuring device 200 of Embodiment 5 are the same as those of any of the measuring devices 200 of Embodiments 1 to 4.

[0126] The measuring device 200 in this embodiment is installed on the moving body 240, similar to the measuring device 200 in Embodiment 4. The control unit 204 in Embodiment 5 acquires speed information, similar to the control unit 204 in Embodiment 4. The control unit 204 then determines a predetermined criterion for determining the scanning range 224 based on the speed of the moving body 240. This 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 descriptions of Embodiments 2 and 3.

[0127] The predetermined criteria are determined in relation to the speed of the moving object 240. More specifically, the predetermined criteria are set so that the faster the speed of the moving object 240, the further away the object from the measuring device 200 is scanned. This is because, as the speed of the moving object 240 increases, the moving object 240 travels a longer distance in a shorter time, so it is preferable to set the measuring device 200 to scan objects at a greater distance.

[0128] For example, if the predetermined standard is a predetermined distance or predetermined time, these values ​​will be larger as the speed of the moving object 240 increases. Also, for example, if the predetermined standard 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 that shows the correspondence between a predetermined standard and the speed of a moving object is called standard information. Figure 17 is a diagram illustrating standard information in table format. The table shown in Figure 17 is called standard information 300. Standard information 300 has speed 302 and standard 304. Speed ​​302 indicates the range of speed. Standard 304 indicates the predetermined standard that corresponds to the range of speed shown in speed 302. In Figure 17, standard 304 indicates a predetermined distance. For example, the second record of standard information 300 shows that the speed of the moving object 240, which is "greater than v1 and less than or equal to v2", is associated with the predetermined standard "predetermined distance = a2 [m]".

[0130] The reference information is not limited to those that selectively determine a predetermined standard according to the speed of the moving object, as illustrated in Figure 17. For example, the reference information may be a calculation formula that calculates a predetermined standard from the speed of the moving object 240. In this case, for example, the reference information is defined as a function that takes the speed of the moving object 240 as an argument and returns a predetermined standard as its return value.

[0131] The reference information may be pre-configured in the control unit 204, or it may be stored in a storage device accessible from the control unit 204.

[0132] <Processing flow> Figure 18 is a flowchart illustrating the flow of processing performed by the measuring device 200 of Embodiment 5. The processing performed in S102, S104, and S202 in Figure 18 is the same as the processing performed in S102, S104, and S202 in Figure 17. In S302, the control unit 204 determines a predetermined standard based on the speed of the moving body 240 indicated by the speed information.

[0133] The faster the moving object 240 moves, the longer the distance it travels in a shorter amount of time. Therefore, the faster the moving object 240 moves, the more desirable it may be for the measuring device 200 to scan for objects at a greater distance.

[0134] Therefore, in the measuring device 200 of this embodiment, a predetermined criterion for determining the scanning range 224 is set according to the speed of the moving object 240. This ensures that objects at an appropriate distance according to the speed of the moving object 240 are scanned.

[0135] <Example of hardware configuration> The hardware configuration of the measuring device 200 in Embodiment 5 is similar to that of the measuring device 200 in Embodiment 1, as shown in Figures 6 to 8, for example. In this embodiment, the program module stored in the aforementioned storage device 108 further includes a program that implements the functions described in this embodiment.

[0136] [Embodiment 6] The measuring device 200 of this embodiment is represented, for example, by Figure 1, similar to the measuring device 200 of Embodiment 1. Except for the points described below, the functions of the measuring device 200 of Embodiment 6 are the same as those of the measuring device 200 of any of Embodiments 1 to 5.

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

[0138] However, the orientation of the measuring device 200 (i.e., the scanning range of the measuring device) may fluctuate significantly (deviation from the initial orientation). Such fluctuations can be caused, for example, by vibrations of a vehicle such as an automobile on which the measuring device 200 is placed. When such fluctuations occur, the signal received by the measuring unit 202 may not meet the predetermined criteria at the time when the measuring unit 202 attempts to determine the height direction of the scanning range in subsequent scanning, as described above. More specifically, it is possible that none of the grids shown in Figure 11 will meet the predetermined criteria. For example, as shown in Figure 13, if an "X" mark is shown on the grid where the calculated distance for the target line operation is the same as a predetermined distance, a situation may occur where there are no grids on which an "X" mark is shown.

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

[0140] When the orientation of the measuring device 200 is misaligned in this way, it becomes difficult to properly scan and measure the area around the desired distance range (100m away from the measuring device 200 in the example above).

[0141] Therefore, in the measuring device 200 of this embodiment, if the signal received by the measuring unit 202 does not meet the above criteria, the control unit 204 controls the measuring unit 202 so that its scanning range (i.e., the emission range of electromagnetic waves irradiated by the measuring unit 202) is upward or downward. In other words, if the irradiation direction of electromagnetic waves within the scanning range of the measuring unit 202 does not meet the predetermined conditions, the control unit 204 moves the scanning range of the measuring unit 202 upward or downward by a predetermined amount.

[0142] For example, suppose that at the time when the measurement unit 202 attempts to determine the height direction of the scanning range in a subsequent scan, all of the distances calculated for scanning the target line fall below a predetermined standard (for example, if the predetermined distance is set to 100m, all of them fall below 100m). In this case, the control unit 204 controls the measurement unit 202 so that its scanning range is tilted upward by a predetermined angle. That is, the control unit 204 starts scanning based on a state in which the illuminator 10 (movable reflector 16) is tilted upward by a predetermined angle.

[0143] The control unit 204 then repeats this control until the signal received by the measurement unit 202 meets the above-mentioned criteria (until any of the distances calculated for scanning the target line meets a predetermined criterion). That is, the scanning range of the measurement unit 202 is shifted upward by a predetermined angle until the predetermined criterion is met.

[0144] Similarly, at the timing when the measurement unit 202 attempts to determine the height direction of the scanning range in a subsequent scan, if any of the distances calculated for the target line scan exceed a predetermined standard (for example, if the predetermined distance is set to 100m, all exceed 100m), the control unit 204 controls the measurement unit 202 so that its scanning range is lowered by a predetermined angle. That is, the control unit 204 starts scanning based on a state where the illuminator 10 (movable reflector 16) is tilted downward by a predetermined angle. The control unit 204 then repeats this control until the signal received by the measurement unit 202 satisfies the above standard (until any of the distances calculated for the target line scan satisfies the predetermined standard). In other words, the scanning range of the measurement unit 202 is shifted downward by a predetermined angle until the predetermined standard is met.

[0145] By performing this type of control, even if the orientation of the measuring device 100 changes significantly, it becomes possible to identify the height direction of the irradiation direction that satisfies a predetermined standard, and based on the identified height direction, the scanning range in the subsequent scan by the measuring unit 202 can be determined in the height direction. As a result, the measuring device 200 can scan objects at a desired distance using electromagnetic waves in a wider range of environments.

[0146] <Example of hardware configuration> The hardware configuration of the measuring device 200 in Embodiment 6 is similar to that of the measuring device 200 in Embodiment 1, as shown in Figures 6 to 8, for example. In this embodiment, the program module stored in the aforementioned storage device 108 further includes a program that implements the functions described in this embodiment.

[0147] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and combinations of the above embodiments or various other configurations can also be adopted.

[0148] This application claims priority based on Japanese Patent Application No. 2016-169960, filed on 31 August 2016, and incorporates all of its disclosures herein.

Claims

[Claim 1] A measuring unit that performs scanning by irradiating electromagnetic waves and receiving the electromagnetic waves reflected by a reflector, A control unit that controls the measurement unit, and has The control unit, A measuring device that determines the scanning range in a second scan performed after the first scan, based on the signal received by the measuring unit during the first scan performed by the measuring unit.

Images