JP2021021691A - Distance measuring device - Google Patents

Abstract

To provide a distance measuring device with which it is possible to accurately and quickly measure a distance even when a change occurs to a direction in which a moving body such as a traveling device moves.SOLUTION: The distance measuring device comprises: a scan unit 2 for causing a laser beam which is an electromagnetic wave to be scanned with respect to a prescribed scan range SR and mounted in a moving body MO; an acceleration sensor 20 as a detection unit DT for detecting a change of movement mode of the moving body MO; and a distance measurement point control unit 11 for changing a density with respect to the distribution of distance measurement points RP in the scan range SR on the basis of the result of detection by the acceleration sensor 20. Thus, the distance measurement point control unit 11 causes, on the basis of the result of detection by the acceleration sensor 20, a density with respect to the distribution of distance measurement points RP in the scan range SR to change and detects the presence of an obstacle in the surrounding of the moving body MO.SELECTED DRAWING: Figure 1

Description

The present invention relates to a distance measuring device that emits an electromagnetic wave such as pulsed light toward a measurement target and measures the distance from the reflected component of the emitted electromagnetic wave to the measurement target.

As a device for measuring the distance to an object by the above method, for example, in an optical distance measuring device that measures a distance by Lissajous (or Lissajous) scanning, the emission timing of pulsed light and the amplitude of a movable part can be changed. (See Patent Document 1). Further, when determining an obstacle using distance measurement, it is known to distinguish between an obstacle and the ground based on the detection of an acceleration sensor so that the ground is not erroneously detected as an obstacle (see Patent Document 2). .. Further, as an in-vehicle radar device, a device that changes the scanning range according to the speed of the own vehicle is also known (see Patent Document 3).

However, in the measurement in Patent Documents 1 to 3 and the like, for example, when the moving direction of a traveling device equipped with a distance measuring device changes, it is accurate so as to enable obstacle detection at the changed moving destination. It is not always possible to perform quick distance measurement.

Japanese Unexamined Patent Publication No. 2011-53137 Japanese Unexamined Patent Publication No. 2016-65842 Japanese Unexamined Patent Publication No. 9-292461

The present invention has been made in view of the above points, and provides a distance measuring device capable of accurately and quickly measuring a distance even when a moving body such as a traveling device changes in a moving direction. The purpose is.

The ranging device for achieving the above object is mounted on a moving body and has a scanning unit that scans electromagnetic waves for a predetermined scanning range, a detecting unit that detects a change in the moving mode of the moving body, and detection by the detecting unit. Based on the result, it is provided with a AF point control unit that changes the density of the distribution of AF points in the scanning range.

In the above-mentioned distance measuring device, by changing the distribution of the distance measuring points according to the change of the moving mode of the moving body, for example, the detection of the presence or absence of an obstacle around the moving body can be accurately and quickly performed by the distance measuring. Can be done.

In a specific aspect of the present invention, the detection unit is an acceleration sensor. In this case, by detecting the change in acceleration, it is possible to capture a change in the movement mode such as a change in direction, a turn, or a change in the traveling trajectory due to the steering of the moving body.

In another aspect of the present invention, the detection unit is an information reception unit that receives information regarding a change in the movement mode from the moving body. In this case, for example, by receiving information from an external device such as a device provided on the moving body at the information receiving unit, it is possible to capture a change in the moving mode.

In yet another aspect of the present invention, the AF point control unit increases the distribution density of the AF points in the direction in which the movement mode of the moving body changes. In this case, for example, it is possible to quickly catch an obstacle at a destination where the movement mode changes.

In yet another aspect of the present invention, changes in the movement mode of the moving body include any of turning of the moving body, changes accompanying the steering operation of the moving body, and changes in the traveling trajectory of the moving body. In this case, distance measurement can be performed according to the above change.

In yet another aspect of the present invention, the AF point control unit keeps the number of AF points in one scan for the scanning range constant, and the number of AF points that is a distance equal to or less than the threshold value in the scanning range. Further, a determination unit for determining the presence or absence of an obstacle at the movement destination of the moving body is provided depending on whether or not there are a predetermined number or more. In this case, it is possible to quickly determine the presence or absence of an obstacle at a position that may cause a problem when moving.

In yet another aspect of the present invention, the scanning unit performs raster scan type scanning, and the AF point control unit changes the emission timing of electromagnetic waves according to the movement mode of the moving body. In this case, it is possible to easily and quickly change the density of the target AF point.

It is a block diagram for conceptually explaining the operation of distance measurement by the moving body equipped with the distance measurement device which concerns on 1st Embodiment. It is a block diagram about one configuration example of the distance measuring apparatus which concerns on 1st Embodiment. (A) is a conceptual diagram showing an example of a state of scanning by a distance measuring device, and (B) is a chart diagram showing an injection timing. (A) is a conceptual diagram showing another example of the state of scanning by the distance measuring device, and (B) is a chart diagram showing the injection timing. (A) to (D) are conceptual plan views and perspective views showing the movement of a moving body equipped with a distance measuring device. It is a conceptual diagram which illustrates the change of the density with respect to the distribution of the distance measurement points in the distance measurement by the distance measurement device. It is a conceptual diagram which shows another example of the change of density with respect to the distribution of AF points. It is a conceptual diagram which shows yet another example of the change of density with respect to the distribution of AF points. It is a flowchart for demonstrating an example about a series of operations of a distance measuring device. (A) is a block diagram of one configuration example of the distance measuring device according to the second embodiment, and (B) is a block diagram for conceptually explaining a moving body equipped with the distance measuring device. .. It is a conceptual diagram for demonstrating another example about scanning by a distance measuring device. (A) and (B) are conceptual diagrams for explaining another example of scanning by a distance measuring device.

[First Embodiment]
Hereinafter, an example of the distance measuring device according to the first embodiment and the moving body equipped with the distance measuring device will be described with reference to FIG. 1 and the like. The distance measuring device can be mounted on various moving bodies, and for example, a train traveling on a railroad track, an automobile or a motorcycle traveling on a road, a construction machine (heavy machine), or the like can be considered.

As illustrated in FIG. 1, the distance measuring device 1 of the present embodiment is mounted on the moving body MO, emits light in the moving direction of the moving body MO shown by the arrow A1, and receives the returned component. Then, measure the distance. Therefore, the ranging device 1 has, for example, a scanning unit 2 that scans a laser beam that is an electromagnetic wave for a predetermined scanning range. In particular, in the present embodiment, the distance measuring device 1 is set in the scanning range based on the detection result of the detection unit DT in addition to the detection unit DT (accelerometer 20 or the like) that detects the change in the movement mode of the moving body MO. The AF point control unit 11 for changing the density of the distribution of AF points is provided. As a result, in the present embodiment, for example, detection of the presence or absence of an obstacle in the vicinity of the moving body MO can be accurately and quickly performed by distance measurement. That is, the distance measuring device 1 functions as an obstacle detection device.

Here, as shown in the drawing, a predetermined scanning range in which scanning is performed by the scanning unit 2 is defined as a scanning range SR. That is, the distance measuring device 1 sets a predetermined number of distance measuring points RP in the scanning range SR that occupies a predetermined range in the traveling direction of the moving body MO. That is, by emitting laser light (pulse light) at the scanning timing, projecting the light, and capturing the reflected light component, the distance to the object in the direction at that timing is measured. In the illustrated example, the component of the laser light projected from the ranging device 1 is defined as the light projecting component PL. Further, among the components of the light projecting component PL that are reflected or scattered by the object (obstacle) existing in the scanning range SR, the component that follows the path in the direction opposite to the light projecting component PL is referred to as the reflection component RL. In the illustration, the scanning range SR is shown as a two-dimensional rectangular region for the sake of simplicity, but the scanning range SR is not limited to this, and various shapes are assumed.

Hereinafter, a more specific configuration example of the distance measuring device 1 will be described with reference to FIG.

As illustrated in FIG. 2, the distance measuring device 1 of the present embodiment constitutes the optical distance measuring device 50, and in addition to the scanning unit 2 described above, the light emitting unit 3 and the light receiving unit 4 are included. It has a control unit 10 that controls various operations of each part of the optical system. In particular, the control unit 10 includes a distance measurement point control unit 11 that controls the position of the distance measurement point. The distance measuring device 1 includes an optical distance measuring device 50, an acceleration sensor 20 as a detection unit DT, and an obstacle determination unit 30.

Among the optical ranging devices 50, the scanning unit 2 is a device for scanning a laser beam, which is an electromagnetic wave, with respect to a scanning range SR (see FIG. 1 or FIG. 3, FIG. 4, etc.) as described above. For example, it can be configured by a two-dimensional scanning mirror (scanner) or the like. Although details will be described later with reference to FIG. 3 and the like, in the present embodiment, raster scan type scanning is performed as an example.

Among the optical ranging devices 50, the light projecting unit 3 includes, for example, a laser driver, a laser element (semiconductor laser), a lens, and the like, and emits laser light (pulse light) to emit laser light. It is a department. The laser beam emitted from the light projecting unit 3 is directed to the scanning unit 2 via various optical systems (not shown) provided as needed, and is reflected by the scanning unit 2. As a result, the ranging device 1 scans the light projecting component PL with respect to the scanning range SR (see FIG. 1 and the like). The light projecting unit 3 emits the light projecting component PL at a predetermined timing in accordance with a command from the AF point control unit 11 constituting the control unit 10.

Among the optical ranging devices 50, the light receiving section 4 is a laser receiving section that receives the reflection component RL of the laser light emitted from the ranging device 1. In addition to the light receiving element (photodiode), the light receiving unit 4 is provided with, for example, a light receiving optical system, a preamplifier, an A / D converter, etc., and sets the reflected component RL into, for example, a detectable pulse wave state. , Output to the control unit 10.

As described above, the laser light emitted from the light projecting unit 3 is scanned in a predetermined range as scanning light by the scanning unit 2, and at this time, the obstacle OB exists at a position where the distance can be measured in the scanning range SR. Then, the light projecting component PL is reflected or scattered on the surface of the obstacle OB, and the reflected component RL is captured by the light receiving unit 4.

Although detailed description and illustration are omitted, in the optical ranging device 50, in addition to the above, for example, the light projecting component PL and the reflecting component RL travel in the same optical path in opposite directions, but they are appropriately separated. Various optical devices such as a light flood / light receiving separator are provided.

Among the optical ranging devices 50, the control unit 10 is composed of, for example, various circuit mechanisms and the like, and controls various operations of the optical system as described above. In particular, in the present embodiment, the control unit 10 is provided with the AF point control unit 11, or the control unit 10 functions as the AF point control unit 11 to perform distance measurement. It is possible to adjust the light. In other words, the position of the AF point RP in the scanning range SR shown in FIG. 1 can be changed, and in particular, the distribution of the AF point RP in the scanning range SR can be changed in density, that is, the degree of scattering can be biased. Is possible.

The control unit 10 performs various arithmetic processing and the like in addition to controlling the operation of the optical system constituting the optical ranging device 50. For example, the control unit 10 determines the operation timing of the light projecting unit 3 and the measurement result (detection result) of the light receiving unit 4 in order to calculate the distance to the obstacle OB when the obstacle OB is present. Performs operations based on analysis. Specifically, the control unit 10 measures the time difference from the light projection to the light reception from the injection timing of the light projection component PL, the measured value of the reflection component RL, and the measurement timing as the time difference measurement unit. Further, the control unit 10 calculates the distance to the obstacle OB from the measured time difference as the distance calculation unit. Although detailed description will be omitted, the control unit 10 as the distance calculation unit can also acquire information on the posture of the scanning unit 2 at each timing, that is, the emission direction (angle) of the projection component PL, for example. It may be possible to create a distance image in a range to be scanned two-dimensionally. The control unit 10 outputs the measurement results of the time difference and the amount of light measured as described above to the obstacle determination unit 30.

Hereinafter, among the distance measuring devices 1, the acceleration sensor 20 as the detection unit DT and the obstacle determination unit 30 which are constituent requirements other than the optical distance measuring device 50 will be described.

The acceleration sensor 20 as the detection unit DT functions as a detection unit DT that detects a change in the acceleration of the distance measuring device 1 that moves together with the moving body MO, and the detection result is controlled by the distance measuring point that constitutes the control unit 10. Output to unit 11.

The AF point control unit 11 changes the distribution of AF points RP in the scanning range SR (see FIG. 1 and the like) based on the detection result of the acceleration sensor 20 as the detection unit DT, that is, the scanning unit. The operation timing of 2 and the emission timing of pulsed light (laser light) at the light projecting unit 3 are changed. In other words, the AF point control unit 11 changes the scanning mode based on the result of the detection by the acceleration sensor 20 as a trigger. In order to perform the above operation, for example, threshold values are set in advance for various numerical values detected by the detection unit DT, and the AF point control unit 11 determines the distribution of the AF points RP based on the threshold values. Determine the degree of sparse and dense change.

The obstacle determination unit 30 determines the obstacle OB based on the calculation result of the optical ranging device 50 which is composed of, for example, an arithmetic circuit or the like and operates based on the detection result of the acceleration sensor 20 as described above. It is a judgment unit to perform. Typically, with respect to something like an obstacle OB, whether or not it hinders the movement (running) of the moving body MO, and by extension, whether or not there is a danger in the movement of the moving body MO, etc. Make a judgment.

As a method of determination in the obstacle determination unit 30, typically, in the scanning range SR (see FIG. 1 and the like), the distance measurement point RP whose distance is equal to or less than the threshold value for the predetermined distance is set. It is conceivable to determine the presence or absence of an obstacle at the destination of the moving body MO depending on whether or not the number is equal to or greater than a predetermined number. In this case, the higher the density of the AF point RP, the higher the detection sensitivity (resolution).

Hereinafter, with reference to FIGS. 3 and 4, an example will be described of scanning the pulsed light (laser light) in the distance measuring by the distance measuring device 1 and changing the operation mode in the scanning. FIG. 3A is a conceptual diagram showing an example of the state of scanning by the ranging device 1, and FIG. 3B is a chart diagram showing the emission timing of pulsed light (laser light) in the light projecting unit 3. is there. Further, FIGS. 4 (A) and 4 (B) are views corresponding to FIGS. 3 (A) and 3 (B), respectively, and show another example of the state of scanning by the distance measuring device 1. ..

In the present embodiment, as described above, and as shown in FIG. 3A, the scanning unit 2 performs raster scan type scanning. That is, in FIG. 3A, the timing at which the pulsed light (laser light) is irradiated is shown as the AF point RP on the scanning range SR conceptually shown in the two-dimensional region, and is shown on the scanning range SR. Since the method of scanning the AF point RP in the above is a raster scan type, the raster scan type is used here. Specifically, for example, in the illustrated example, a line-shaped (one-dimensional) scanning is performed at high speed in the horizontal direction (from left to right in the figure) in order from the upper left of the scanning range SR, which is a rectangular area. Then, such a scan is repeated a plurality of times, proceeds downward in the vertical direction, and reaches the lower right of the scanning range SR, whereby the entire scanning range SR is scanned. In this case, the emission timing of the pulsed light (laser light) at the light projecting unit 3 is as shown in FIG. 3 (B). That is, during the scanning of the first line indicated by the arrow L1 in FIG. 3A, pulsed light (laser light) is emitted at equal intervals, and after the interval, the second line indicated by the arrow L2 is emitted. During the scan, pulsed light (laser light) is also emitted at regular intervals. By repeating this, AF point RPs at equal intervals in the horizontal direction as shown in FIG. 3A are formed in the entire scanning range SR.

On the other hand, the AF point control unit 11 distributes the AF points RP as shown in FIGS. 4 (A) and 4 (B) as another example, depending on the information output from the detection unit DT. That is, the position of the AF point RP in the scanning range SR is changed to change the bias. For example, if the density on the left and right is changed as in the example shown in FIG. 4 (A), as shown in FIG. 4 (B), in the scanning of each line by the command from the AF point control unit 11. , The injection timing in the light projecting unit 3 may be shifted. In this case, for example, the degree of deviation of the injection timing may be adjusted in an analog manner according to the result of the detection unit DT. Although detailed illustrations and the like are omitted, for example, by adjusting the operation of the scanning unit 2 in addition to adjusting the injection timing in the light projecting unit 3, the density change is not limited to the density change on the left and right, and is further various. It can be in the mode of.

Here, regarding the movement in the above-mentioned moving body MO, it is highly possible that obstacle detection at the changed moving destination is important, particularly in the change of the moving direction and the change of the posture. For example, in the case of trains and vehicles, if there is an obstacle at the end of the turn defined by the rail or at the end of the turn when turning the road, this is detected as soon as possible. It is important to inform the danger. In addition, it is very important to quickly confirm the presence of people and objects in the turning direction even when turning with heavy machinery. In addition, these things are important both in the case of manned operation and the case of unmanned operation of the mobile MO.

However, for example, when trying to ensure detection by increasing the number of AF points, there is a trade-off relationship between the increase in the AF points and the detection speed, and when the performance of the conventional AF device is taken into consideration. However, sufficient detection cannot always be performed quickly. Therefore, in the present embodiment, the AF point control unit 11 moves by changing the distribution of the AF points RP based on the detection by the detection unit DT, for example, without increasing the AF points. It makes it possible to catch obstacles more quickly and accurately according to the direction of movement of the body. That is, when the moving direction of the moving body MO such as the mounted traveling device changes, the distance measuring device 1 focuses on detecting obstacles at the changed moving destination, thereby performing accurate and quick distance measuring. Is possible.

Hereinafter, an example of the mobile MO on which the distance measuring device 1 is mounted will be described with reference to FIG. 5 and the like, and the operation of the mounted distance measuring device 1 will be described.

5 (A) to 5 (D) show a conceptual example of the moving body MO on which the distance measuring device 1 is mounted. As shown in the figure, the moving body MO here is composed of a first main body MOa constituting the front side, a second main body MOb forming the rear side, and a connecting portion CN connecting them. .. In the illustration, the traveling direction of the moving body MO is the + X direction, and the X direction is the front-rear direction. Further, the directions orthogonal to each other in the plane (vertical plane) perpendicular to the X direction are defined as the Y direction and the Z direction. That is, the plane perpendicular to the X direction is defined as the YZ plane. Of these, the horizontal direction (horizontal direction) is the Y direction, and the vertical direction (vertical direction) is the Z direction.

Among the moving body MOs, the first main body MOa constituting the front side (+ X side) is provided with a front portion FP and a pair of front wheel FWs. These are attached to the housing SCa. Further, a pair of rear wheel RWs are attached to the housing SCb on the second main body MOb forming the rear side (−X side). The front wheel FW and the rear wheel RW are rotationally driven.

Further, the connecting portion CN that connects the first main body portion MOa and the second main body portion MOb is made of a bellows-shaped member, that is, is deformable. As a result, the positional relationship between the first main body MOa and the second main body MOb can be changed in various ways, for example, a turning operation in the left-right direction is performed.

Here, for example, as shown by arrows R1 and R2 in FIG. 5A, the front wheel FW can change the direction, that is, the steering operation of the moving body MO is possible. As described above, the moving body MO is run and turned. Therefore, the change in the movement mode of the moving body MO detected by the detection unit DT (accelerometer 20 or the like) shown in FIG. 1 or the like includes a change accompanying the turning of the moving body MO and the steering operation of the moving body MO. Further, for example, as shown by arrows TL and TR in FIGS. 5 (B) and 5 (C), the orientation of the moving body MO in the left-right direction (Y direction) can be changed, or the moving body MO can be changed in the left-right direction (Y). It is possible to turn in the direction).

Further, among the first main body MOa, the front FP is equipped with, for example, a camera or the like, and it is possible to capture the situation regarding the traveling direction of the moving body MO, for example. In the illustrated example, the ranging device 1 is attached to the front FP. That is, the distance measuring device 1 changes various postures together with the front FP in moving with the moving body MO. Further, as shown by the solid line and the broken line in FIG. 5D, here, the front portion FP is attached to the tip end side of the movable portion PP composed of the axial member, while the base of the movable portion PP. The side is rotatably attached around the Y-axis in the housing SCa. As a result, the front portion FP can turn in the vertical direction (Z direction) as shown by the arrow UD. The front FP is not limited to the case where a camera as described above is mounted to capture the front. For example, a movable arm-shaped portion of a construction machine (heavy machine) or its tip, that is, an arm of a hydraulic excavator. Various parts such as a bucket part, an elevating loading platform part of a dump truck, a movable part of a forklift, and the like are considered to correspond to this.

In addition, various modes can be considered for the traveling of the moving body MO. By changing the rotational drive of the front wheel FW and the rear wheel RW, for example, high-speed movement or low-speed movement (including stop) can be performed. Alternatively, the mode may be such that the vehicle travels on a rail that defines a track. As for the mode of traveling on the rail, typically, there may be a configuration in which there is no steering operation, as in the case where the train is regarded as a moving body MO. When traveling on a specified track, the change in the traveling mode of the moving body MO is affected by the change in the traveling track of the moving body MO. For example, when the curve or inclination of the rail is detected by the detection unit DT (accelerometer 20 or the like), a sparse and dense change in the distribution of the AF point RP based on the detection is caused. It should be noted that the track status of the traveling position (current position) of the moving body MO may be grasped by collating the map data regarding the defined trajectory with the position detection of the moving body MO.

Hereinafter, with reference to FIG. 6 and the like, some methods of changing the density of the distribution of the AF point RP in the distance measurement by the distance measuring device will be illustrated. Regarding the moving body MO (see FIG. 4 and the like) capable of various movements as described above, in the example shown in FIG. 6 and below, particularly when the moving body MO is turned left and right and the traveling speed (moving speed) changes. Consider.

FIG. 6 is a conceptual diagram illustrating changes in sparseness and density with respect to the distribution of distance measurement point RPs in distance measurement by the distance measurement device 1, and shows four changes in the scanning range SR in which a predetermined number of distance measurement point RPs are set in advance. The embodiment is illustrated. Here, it is assumed that the AF point control unit 11 keeps the number of AF points RP constant in one scan for the scanning range SR. That is, the number of AF points RP in the four scanning range SRs shown is the same (49 in the illustrated example). In other words, in this case, distance measurement can be performed without changing the frame rate in scanning, for example.

In the example of FIG. 6, first, the scanning range C1 shows the distribution of the AF point RP when the turning is not performed and the traveling speed (moving speed) is low (including stopping). .. In this case, the AF point RP is uniformly spread in the scanning range C1.

On the other hand, the scanning range C2 exemplifies the distribution of the AF point RP when the traveling speed (moving speed) is low (including stopping) and the right turning (turning to the −Y side) is performed. In this case, the AF point control unit 11 increases the density of the AF point RP on the right side (−Y side), that is, in the direction in which the movement mode of the moving body MO changes. It's changing.

The scanning range C3 exemplifies the distribution of the AF point RP when the traveling speed (moving speed) is low (including stopping) and a left turn (turning to the + Y side) is made. In this case, the AF point control unit 11 changes the density on the left side (+ Y side), that is, in the direction in which the movement mode of the moving body MO changes, so as to increase the distribution density of the AF point RP. I'm letting you.

The scanning range C4 shows the distribution of the AF points RP when the vehicle is not turned and the traveling speed (moving speed) is high. In this case, by setting the substantial scanning range to a limited range narrowed to the scanning range CC4 shown by the broken line, priority is given to the situation judgment for a farther range.

In the example with reference to FIG. 6, for the sake of simplicity, the traveling speed is divided into two stages of high and low, and the turning is divided into the presence and absence, but these can be further divided into multiple stages or combined. It may be made to do.

That is, as shown in FIG. 7, with respect to the right turn, in the scanning range SR, the turning speed gradually increases from the state where the turning is not performed (corresponding to the scanning range C1) shown at the left end, and is shown at the right end. The distribution of the AF point RP may be gradually biased to the right according to the change until the turning state (corresponding to the scanning range C2) is reached to some extent.

Further, as shown as another example in FIG. 8, when the traveling speed (moving speed) changes (gradually increases) in addition to the right turn, the state of not turning (scanning) shown at the left end is not performed. From (corresponding to range C1) to a state in which the traveling speed increases while gradually turning to a certain degree of turning (scanning range C5) shown at the right end, the distribution of AF points RP gradually increases according to the change. The overall scanning range may be narrowed while being biased to the right.

Hereinafter, an example of a series of operations of the distance measuring device 1 will be described with reference to the flowchart of FIG. In the example here, for the sake of simplification of the explanation, there are two stages of movement (running), low speed and high speed, and two stages of turning movement, with or without.

First, among the distance measuring devices 1, the distance measuring point control unit 11 constituting the control unit 10 reads various parameters (step S101). That is, various data and the like from the acceleration sensor 20 which is the detection unit DT are read out to grasp the moving state of the distance measuring device 1. Of these, first, the AF point control unit 11 determines whether or not the movement is low speed (step S102).

When it is determined in step S102 that the movement is not low speed (high speed movement) (step S102: No), the AF point control unit 11 further confirms the presence or absence of turning movement (step S103).

When it is determined in step S103 that there is a turning movement (step S103: Yes), the AF point control unit 11 concentrates (biass) the AF point RP in the turning direction and scans with the scanning range SR as a narrow region. The operations of the scanning unit 2 and the light projecting unit 3 are controlled so as to be performed (step S104).

On the other hand, when it is determined in step S103 that there is no turning movement (step S103: No), the AF point control unit 11 narrows the scanning range SR without concentrating (biasing) the AF point RP in the turning direction. The operation of the scanning unit 2 and the light projecting unit 3 is controlled so as to perform the scanning (step S105).

When it is determined in step S102 that the movement is low speed (including the case of stopping) (step S102: Yes), the AF point control unit 11 further confirms the presence or absence of turning movement (step S106).

When it is determined in step S106 that there is a turning movement (step S106: Yes), the AF point control unit 11 concentrates (biass) the AF point RP in the turning direction and performs scanning over a wide scanning range SR. The operation of the scanning unit 2 and the light projecting unit 3 is controlled so as to be performed (step S107).

On the other hand, when it is determined in step S106 that there is no turning movement (step S106: No), the AF point control unit 11 sets the scanning range SR to a wide area without concentrating (biasing) the AF point RP in the turning direction. The operation of the scanning unit 2 and the light projecting unit 3 is controlled so as to perform the scanning (step S108). The distance measuring device 1 repeats the above operation until it receives a stop command for the distance measuring operation.

As described above, in the present embodiment, the scanning unit 2 mounted on the moving body MO and scanning the laser beam which is an electromagnetic wave for a predetermined scanning range SR and the detecting unit DT for detecting the change in the moving mode of the moving body MO. The accelerometer 20 is provided, and the AF point control unit 11 that changes the density of the distribution of the AF points RP in the scanning range SR based on the detection result of the acceleration sensor 20. That is, the AF point control unit 11 changes the density of the distribution of the AF points RP in the scanning range SR based on the detection result of the acceleration sensor 20, and detects the presence or absence of an obstacle in the vicinity of the moving body MO. I do. As a result, distance measurement can be performed accurately and quickly.

In the above description, the acceleration sensor 20 is illustrated as the sensor as the detection unit DT, but the present invention is not limited to this, and various sensors can be used. For example, a gyro sensor (angular velocity sensor) or the like may be used, or these sensors may be combined to form the detection unit DT. In this case, it is conceivable that the gyro sensor detects the turning and the acceleration sensor detects the change in speed or the like.

[Second Embodiment]
Hereinafter, an example of the distance measuring device of the second embodiment will be described with reference to FIG. This embodiment is a modification of the first embodiment and is the same as the case of the first embodiment except for the structure related to the detection unit DT. Therefore, the same reference numerals are given to the common components for the overall configuration. The details of the parts other than the detection unit DT will be omitted.

FIG. 10A is a block diagram of a configuration example of the distance measuring device 201 according to the present embodiment, and is a diagram corresponding to FIG. Further, FIG. 10B is a block diagram for conceptually explaining the moving body MO equipped with the distance measuring device 201, and is a diagram corresponding to FIG. 1.

As shown in FIG. 10A, the distance measuring device 201 of the present embodiment is the first in that the detection unit DT is composed of an information receiving unit 220 that receives information on a change in the moving mode from the moving body MO. It is different from the case of one embodiment. That is, in the first embodiment, as shown in FIG. 2 and the like, the distance measuring device 1 itself captures the change in the movement mode by various sensors such as the acceleration sensor 20. On the other hand, in the present embodiment, the information receiving unit 220 receives the information from the external device to capture the change in the moving mode. Therefore, in this example, as shown in FIG. 10B, the information receiving unit 220 is connected to the information providing unit PD provided in the moving body MO, and the AF point control unit 11 receives information. Various processes and judgments are performed based on the information obtained from the information providing unit PD via the unit 220.

In this case, various types of information providing unit PD as an information source can be considered. For example, when the moving body MO has an acceleration sensor, the acceleration sensor itself or information from the acceleration sensor is input. It is conceivable that the device or the like that can be acquired is the information providing unit PD. In addition, various measuring instruments or the like provided in the moving body MO for measuring the speed or the like may be used as the information providing unit PD to acquire necessary information.

Also in the present embodiment, the AF point control unit 11 determines the AF point RP in the scanning range SR based on the detection result of the information reception unit 220 as the detection unit DT that detects the change in the movement mode of the moving body MO. The presence or absence of obstacles around the mobile MO is detected by changing the density of the distribution. As a result, distance measurement can be performed accurately and quickly.

[Other]
The present invention is not limited to the above-described embodiment, and can be implemented in various embodiments without departing from the gist thereof.

First, in the above, the raster scan type scanning is performed, but the distribution of the AF points RP in the scanning range SR is not limited to this as long as it can change the desired density. Can be done.

For example, it is conceivable to apply a mode of performing a Lissajous type scanning that forms the Lissajous (or Lissajous) pattern illustrated in FIG. In this case, for example, a plurality of Lissajous patterns are prepared in order to change the distribution of the AF point RP, that is, a Lissajous pattern having a shape different from that illustrated in FIG. 11 (a pattern having a different period from that shown in the figure). ), And it is conceivable to take a method of associating each Lissajous pattern with the detection result by the detection unit DT.

Further, in the above embodiment, it is conceivable that the scanning unit 2 uses, for example, an electromagnetically driven two-dimensional galvanometer mirror as the optical scanning unit, but the present invention is not limited thereto, and the scanning unit 2 is electromagnetically driven or static. It can also be applied to an optical scanning unit having a configuration in which a movable unit having a light reflecting surface is oscillatedly driven by various driving methods such as an electric method, a piezoelectric method, and a thermal method.

Further, as shown as another example in FIG. 12A, a scanning method different from the Lissajous type or the raster scan type may be adopted. In the example of FIG. 12A, instead of waving light (beam) from end to end with respect to the scanning range SR as in the Lissajous type and raster scan type, light is applied to any part of the scanning range SR. Therefore, more AF points RP are provided at necessary locations. For example, a liquid crystal polarizing diffraction element can be used to control scanning as described above. The liquid crystal polarizing diffraction element for this purpose is a multilayer laminate of a film having two refractive indexes and a liquid crystal element that changes the polarization state of light, and the direction of light rays passing through the film is discretely changed in an arbitrary direction. Can be made to. Further, an optical phased array (OPA) may be used instead of the liquid crystal polarization diffraction element as described above. The optical phased array can change the direction of the output light beam in any direction by controlling the phase of the light passing through the plurality of channels by branching.

For comparison, FIG. 12B shows a typical example of the raster scan type in which the scanning range SR is scanned from end to end. FIG. 12A exemplifies the case of driving a vehicle, in which the distance measuring device 1 (see FIG. 1 and the like) is arranged on the front side of the vehicle and the traveling direction is set as the scanning range SR. In this case, among the scanning range SRs, the information about the lower region SR1 is more important than the information about the upper region SR2. Therefore, in the scanning range SR, many AF points RP may be provided in advance for the region SR1. On this basis, the density of the AF point RP is further changed according to the detection status of the detection unit DT.

Further, even in the upper region SR2, if there is a distance measured as a distance close to some extent, the distribution may be biased in order to capture these. That is, when there is a possibility that there is an object within a certain distance in the upper region SR2 (for example, when even one such AF point RP is detected), the surrounding region (for example, a traffic light or a traffic light) It is conceivable to increase the AF point RP for the areas SR2a, SR2b) where the signboards and the like are installed. In addition, when applied to driving a car in this way, for example, a vehicle or a traffic light is simply detected and is not regarded as an obstacle, but is in a safe situation in consideration of changes in its existence position and relative distance. It is conceivable that the mode is such as determining whether the vehicle is an obstacle or not.

1 ... Distance measuring device, 2 ... Scanning unit, 3 ... Light emitting unit, 4 ... Light receiving unit, 10 ... Control unit, 11 ... Distance measuring point control unit, 20 ... Acceleration sensor, 30 ... Obstacle determination unit, 50 ... Optics Type ranging device, 201 ... ranging device, 220 ... information receiving unit, A1 ... arrow, C1-C5 ... scanning range, CC4 ... scanning range, CN ... connection part, DT ... detection unit, FP ... front part, FW ... Front wheel, L1 ... arrow, MO ... moving body, OB ... obstacle, PD ... information providing part, PL ... light projecting component, PP ... moving part, R1, R2 ... arrow, RL ... reflective component, RL ... rail, RP ... Distance measurement point, RW ... rear wheel, SCa, SCb ... housing, SR ... scanning range, SR1, SR2, SR2a, SR2b ... area, TL, TR ... arrow, UD ... arrow

Claims (7)

A scanning unit mounted on a moving body that scans electromagnetic waves over a predetermined scanning range.
A detection unit that detects changes in the movement mode of the moving body, and
A distance measuring device including a distance measuring point control unit that changes the density of the distribution of distance measuring points in the scanning range based on the detection result of the detection unit. The distance measuring device according to claim 1, wherein the detection unit is an acceleration sensor. The distance measuring device according to claim 1, wherein the detection unit is an information receiving unit that receives information on a change in the movement mode from the moving body. The distance measuring device according to any one of claims 1 to 3, wherein the distance measuring point control unit increases the distribution density of the distance measuring points in a direction in which the movement mode of the moving body changes. Any one of claims 1 to 4, wherein the change in the movement mode of the moving body includes any one of a turning of the moving body, a change accompanying the steering operation of the moving body, and a change in the traveling trajectory of the moving body. The distance measuring device described in the section. The AF point control unit keeps the number of AF points constant in one scan for the scanning range.
Claim 1 further includes a determination unit for determining the presence or absence of an obstacle at the destination of the moving body according to whether or not the number of AF points having a distance equal to or less than a threshold value in the scanning range is a predetermined number or more. The distance measuring device according to any one of 5 to 5. The scanning unit performs raster scan type scanning and performs scanning.
The distance measuring device according to any one of claims 1 to 6, wherein the distance measuring point control unit changes the injection timing of the electromagnetic wave according to the moving mode of the moving body.

Images