JP7031137B2 - Laser scanning device - Google Patents

Description

The present invention relates to a laser scanning device mounted on a vehicle, and relates to, for example, a laser scanning device using an infrared laser.

Equipment for automatic driving of vehicles or driving support for vehicles is being actively developed. Further, LIDAR (Light Detection and Ranging) mounted on a vehicle or the like is known. LIDAR uses a laser beam (for example, wavelength λ = 905 nm) to scan a certain area in front of the vehicle, and detects the reflected light from the detected object in this scanning range to detect the object and from the vehicle. Measure the distance to the object.

As LIDAR, several methods have been proposed. A method of arranging a plurality of transmitters that emit laser light in the vertical direction and rotating the whole in a horizontal plane to scan (Patent Document 1), scanning in the vertical direction (vertical direction) by changing the laser incident angle, and polygons. There are a method of scanning in the horizontal direction (horizontal direction) by rotating the mirror (Patent Document 2), and a method of using a MEMS mirror whose angle can be changed independently on two axes (Patent Document 3). In addition to these mechanical methods, there are methods for changing the emission angle of light by electrically changing the phase (Patent Documents 4 and 5).

However, with the mechanical method, it is difficult to change the scanning range quickly or scan finely. Further, in Patent Documents 4 and 5, an optical power splitter, an optical phase shifter, an optical coupler, and the like are required, and there are many components, which makes the structure complicated.

U.S. Patent Application Publication No. 2010/0020306 Japanese Unexamined Patent Publication No. 2010-38859 Japanese Unexamined Patent Publication No. 2009-216789 International Publication No. 2014/110017 International Release 2016/022220

The present invention provides a laser scanning apparatus capable of dynamically changing the density of scanning points and improving reliability.

The laser scanning device according to one aspect of the present invention is a laser scanning device that scans a region to be scanned by a laser beam, and is a laser source that emits the laser beam at a constant cycle and the laser source that emits the laser beam. It includes a scanning element that transmits laser light and changes the emission angle of the laser light, and a control unit that controls the scanning element. The control unit controls the scanning element so as to change the size of the scanned region scanned by the laser beam and the density of the points at which the laser beam is transmitted with respect to the scanned region.

According to the present invention, it is possible to provide a laser scanning apparatus capable of dynamically changing the density of scanning points and improving reliability.

The block diagram which shows the structure of the in-vehicle system which concerns on embodiment. The block diagram which shows the structure of the operation support ECU. The block diagram which shows the structure of LIDAR. Top view of the liquid crystal element. FIG. 4 is a cross-sectional view of the liquid crystal element along the AA'line shown in FIG. The figure explaining the operation of a liquid crystal element. The figure explaining the operation which the laser beam is refracted by a liquid crystal element. The figure explaining the effective voltage applied to a cell electrode. The figure explaining the operation which the laser beam is refracted by a liquid crystal element. The figure explaining the operation which the laser beam is refracted by a liquid crystal element. The graph which shows an example of the relationship between the inclination angle of a liquid crystal molecule and an effective voltage. The graph which shows an example of the relationship between a scanning angle and an effective voltage. A flowchart illustrating an operation of detecting an object by the driving support ECU. A flowchart illustrating an operation of estimating the position of the own vehicle by the driving support ECU. The schematic diagram explaining the basic operation of LIDAR. The figure explaining the waveform of the laser beam by LIDAR. The schematic diagram explaining the scanning area control operation by LIDAR. The schematic diagram explaining the scanning area control operation by LIDAR. The schematic diagram explaining the scanning area control operation by LIDAR. The schematic diagram explaining the scanning area control operation by LIDAR. The schematic diagram explaining the scanning area control operation by LIDAR. The flowchart explaining the scanning operation which concerns on 1st Embodiment. The figure explaining the state of scanning the lower area of a scanning object. The figure explaining the state of scanning the upper area of the scanning object. The figure explaining the state of scanning the area where there is a person close to a vehicle. The flowchart explaining the scanning operation which concerns on 2nd Embodiment. The schematic diagram explaining the scanning range in a normal time. The figure explaining an example of scanning by LIDAR. The figure explaining an example of scanning by LIDAR. The figure explaining an example of scanning by LIDAR. The flowchart explaining the scanning operation which concerns on 3rd Embodiment. The figure explaining the scanning area which concerns on 3rd Example.

Hereinafter, embodiments will be described with reference to the drawings. However, it should be noted that the drawings are schematic or conceptual, and the dimensions and ratios of each drawing are not necessarily the same as the actual ones. Further, even when the same part is represented between the drawings, the relationship and ratio of the dimensions of each other may be represented differently. In particular, some embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and depending on the shape, structure, arrangement, etc. of the components, the technical idea of the present invention. Is not specified. In the following description, elements having the same function and configuration are designated by the same reference numerals, and duplicate explanations will be given only when necessary.

[1] Configuration of the in-vehicle system 1 First, the overall configuration of the in-vehicle system 1 mounted on the vehicle will be described. FIG. 1 is a block diagram showing a configuration of an in-vehicle system 1 according to an embodiment of the present invention.

The in-vehicle system 1 includes a driving support ECU (Electronic Control Unit) 10, a LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging) 20 as a laser scanning device, a camera 30, an ultrasonic radar 31, a millimeter wave radar 32, and a GNSS. (Global Navigation Satellite System) A receiving unit 33, a communication unit 34, a vehicle ECU 35, a steering device 36, a driving device 37, a braking device 38, and the like are provided. The LIDAR 20, the camera 30, the ultrasonic radar 31, the millimeter wave radar 32, and the GNSS receiver 33 may be referred to as sensors, respectively.

The vehicle ECU 35 is a device that comprehensively controls the traveling of the vehicle. The vehicle ECU 35 is well known including one or more processors (including a CPU (Central Processing Unit) and / or an MPU (Micro Processing Unit)), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. It is a microcomputer. The vehicle ECU 35 executes traveling control based on the program stored in the ROM. The vehicle ECU 35 controls the steering device 36, the drive device 37, the braking device 38, and the like.

The steering device 36 switches the traveling direction of the vehicle based on the command of the vehicle ECU 35.

The drive device 37 generates the driving force of the vehicle based on the command of the vehicle ECU 35. For example, if the vehicle is an engine vehicle, the drive unit 37 has an engine, a transmission (not shown), and the like. When the vehicle is an electric vehicle, the drive device 37 includes a traveling motor, a transmission (not shown), and the like.

The braking device 38 generates the braking force of the vehicle based on the command of the vehicle ECU 35.

The driving support ECU 10 is a device that comprehensively controls driving support or automatic driving. The driving support ECU 10 is a well-known microcomputer including one or more processors (including a CPU and / or an MPU), a ROM, a RAM, and the like. The driving support ECU 10 executes the driving support control based on the program stored in the ROM.

The LIDAR 20, the camera 30, the ultrasonic radar 31, the millimeter wave radar 32, the GNSS receiving unit 33, and the communication unit 34 are connected to the operation support ECU 10 via a communication bus, respectively. In FIG. 1, for simplification, only one LIDAR 20, a camera 30, an ultrasonic radar 31, and a millimeter wave radar 32 are shown. However, a plurality of LIDAR 20, a camera 30, an ultrasonic radar 31, and a millimeter wave radar 32 may be provided. For example, four lidars are attached to the front, rear, left and right of the vehicle, and the four lidars can scan the front, back, left and right of the vehicle. The camera 30, the ultrasonic radar 31, and the millimeter wave radar 32 are the same as the arrangement example of the LIDAR 20.

The LIDAR 20 is located on the front side of the vehicle (eg, front bumper or front grille), on the rear side of the vehicle (eg, rear bumper or rear grille) and / or on the side of the vehicle (eg, side of the front bumper). .. Further, the LIDAR 20 may be arranged on the upper part of the vehicle such as a roof or a bonnet.

The LIDAR 20 transmits a laser beam (infrared laser) to a predetermined range around the vehicle and receives the reflected light. Then, the LIDAR 20 detects the existence of the reflection point (object) and the distance to the object. As an example, the LIDAR 20 uses a laser beam to scan a predetermined area in front of the vehicle.

The camera (image processing device) 30 takes an image of the surroundings of the vehicle at a predetermined cycle. Further, the camera 30 detects an object such as a surrounding vehicle or a person, and an object (a lane marking, a curb, a median strip, etc.) used for specifying a traveling lane. The camera 30 includes an image pickup device such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor).

The ultrasonic radar 31 uses ultrasonic waves to detect an object around the vehicle. The millimeter wave radar 32 uses millimeter waves to detect an object around the vehicle.

The GNSS receiving unit 33 receives signals from a plurality of GNSS (Global Positioning System) satellites and acquires position information indicating the position of the own vehicle. The location information includes, for example, latitude and longitude. In this embodiment, the configuration using GNSS is shown, but a configuration using a receiver of a positioning system other than GNSS, such as GPS, may be used.

The communication unit 34 performs wireless communication with the driving support server and the management center via the network. Then, the communication unit 34 acquires various information from the driving support server and the management center.

[1-1] Configuration of the driving support ECU 10 Next, the configuration of the driving support ECU 10 will be described. FIG. 2 is a block diagram showing the configuration of the driving support ECU 10.

The driving support ECU 10 includes a storage unit 11, a vehicle position estimation unit 12, an object detection unit 13, a sensor control unit 14, a scanning control unit 15, a voltage control unit 16, and an action plan generation unit 17.

The storage unit 11 includes a storage area for storing the reference three-dimensional map data (3D map data) 11A. Further, the storage unit 11 stores an action plan (travel plan) and the like.

The reference three-dimensional map data 11A includes road position information, road shape information (including the type of curve and straight line, curve curvature, lane width, road shoulder width, etc.), position information of intersections and branch points, and so on. Includes facility information, traffic light information, and traffic sign information. The reference three-dimensional map data 11A is created in advance by LIDAR, which is different from the system for creating a three-dimensional map, for the range in which the vehicle can travel. The reference three-dimensional map data 11A may include vehicle position information at the time of creating the three-dimensional map. The reference three-dimensional map data 11A is stored in the non-volatile memory included in the storage unit 11. The reference three-dimensional map data 11A can be updated with the latest information by using the communication unit 34.

The sensor control unit 14 controls the operation of the sensor group including the camera 30, the ultrasonic radar 31, the millimeter wave radar 32, and the GNSS receiving unit 33. The sensor control unit 14 recognizes and identifies an object by using the information detected by the sensor group.

The scanning control unit 15 controls the scanning operation of the LIDAR 20. The scanning control unit 15 executes control by the LIDAR 20 to change the size of the scanning region (frame), control to change the density of scanning points (points to which the laser beam is transmitted) for scanning the scanning region, and the like.

The voltage control unit 16 drives the LIDAR 20. Specifically, the voltage control unit 16 supplies various voltages to the liquid crystal element 22 so that the liquid crystal element 22 included in the LIDAR 20 can realize a desired operation.

The own vehicle position estimation unit 12 estimates the position of the own vehicle based on the information from various sensors. The object detection unit 13 detects an object around the vehicle based on information from various sensors. The action plan generation unit 17 generates an action plan, which is a route on which the vehicle travels, based on the estimation result of the position of the own vehicle and the detection result of the object.

[1-2] Configuration of LIDAR 20 Next, the configuration of LIDAR 20 will be described. FIG. 3 is a block diagram showing the configuration of LIDAR 20.

The LIDAR 20 includes a laser source 21, a liquid crystal element 22 as a scanning element, and a detection circuit 23. The basic operation of the LIDAR 20 is to measure the round-trip time (TOF: Time of Flight) of the transmitted laser light until it is reflected by the object and returned to the detection circuit 23.

The laser source 21 generates and emits laser light. As the laser beam, an infrared laser (for example, wavelength λ = 905 nm) is used.

The liquid crystal element 22 transmits the infrared laser from the laser source 21 and scans the infrared laser, that is, the emission angle of the infrared laser is changed in time division. This makes it possible to irradiate a plurality of points of the object with an infrared laser. The specific configuration of the liquid crystal element 22 will be described later.

The detection circuit 23 detects the infrared laser reflected by the object. The detection circuit 23 is composed of, for example, an infrared sensor. In addition, an infrared camera may be used as the detection circuit 23.

[1-3] Configuration of Liquid Crystal Element 22 Next, the configuration of the liquid crystal element 22 included in the LIDAR 20 will be described. FIG. 4 is a plan view of the liquid crystal element 22. FIG. 5 is a cross-sectional view of the liquid crystal element 22 along the AA'line shown in FIG.

The liquid crystal element 22 is a transmissive liquid crystal panel. The liquid crystal element 22 includes substrates 40 and 41 arranged to face each other and a liquid crystal layer 42 sandwiched between the substrates 40 and 41. Each of the substrates 40 and 41 is composed of a transparent substrate (for example, a glass substrate or a plastic substrate). The substrate 40 is arranged to face the laser source 21, and the laser light from the laser source 21 is incident on the liquid crystal layer 42 from the substrate 40 side.

The liquid crystal layer 42 is filled between the substrates 40 and 41. Specifically, the liquid crystal layer 42 is enclosed in a region surrounded by the substrates 40 and 41 and the sealing material 43. The sealing material 43 is made of, for example, an ultraviolet curable resin, a thermosetting resin, an ultraviolet / heat combined type curable resin, or the like, and is applied to the substrate 40 or the substrate 41 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. Be done.

The liquid crystal material constituting the liquid crystal layer 42 changes its optical characteristics by manipulating the orientation of the liquid crystal molecules according to the voltage (electric field) applied between the substrates 40 and 41. The liquid crystal element 22 of the present embodiment has a homogeneous mode. That is, a positive (P-type) nematic liquid crystal having a positive dielectric anisotropy is used as the liquid crystal layer 42, and the liquid crystal molecules are oriented substantially horizontally with respect to the substrate surface when no voltage (electric field) is applied. do. In the homogenous mode, the long axis (director) of the liquid crystal molecule is substantially oriented in the horizontal direction when no voltage is applied, and the long axis of the liquid crystal molecule is tilted in the vertical direction when the voltage is applied. The magnitude of the tilt angle changes depending on the effective voltage applied. The initial orientation of the liquid crystal layer is controlled by two alignment films (not shown) provided on the substrates 40 and 41 so as to sandwich the liquid crystal layer 42.

As the liquid crystal mode, a vertical alignment (VA: Vertical Alignment) mode using a negative type (N type) nematic liquid crystal may be used. In the VA mode, the major axis of the liquid crystal molecule is oriented substantially vertically when no electric field is applied, and the major axis of the liquid crystal molecule is tilted in the horizontal direction when a voltage is applied.

A plurality of cell electrodes 44, each extending in the Y direction, are provided on the liquid crystal layer 42 side of the substrate 40. An arbitrary number of cell electrode groups constitutes the unit electrode 45. Although FIG. 4 illustrates three unit electrodes 45-1 to 45-3, in reality, more unit electrodes 45 are provided. Further, in FIG. 4, one unit electrode 45 includes 10 cell electrodes, but the number of cell electrodes can be arbitrarily set. The length of the unit electrode 45 in the X direction can be changed by changing the number of cell electrodes 44 constituting the unit electrode 45. The cell electrode 44 is composed of a transparent electrode, and for example, ITO (indium tin oxide) is used.

The plurality of unit electrodes 45 are electrically separated from each other, and the plurality of cell electrodes 44 are electrically separated from each other. That is, the voltage can be individually controlled for the cell electrode 44, and the voltage can be individually controlled for the unit electrode 45.

A plurality of cell electrodes 46, each extending in the X direction, are provided on the liquid crystal layer 42 side of the substrate 41. An arbitrary number of cell electrode groups constitutes a unit electrode 47. Although FIG. 4 illustrates three unit electrodes 47-1 to 47-3, in reality, more unit electrodes 45 are provided. The length of the unit electrode 47 in the Y direction can be changed by changing the number of cell electrodes 46 constituting the unit electrode 47. The cell electrode 46 is composed of a transparent electrode, and for example, ITO is used.

The plurality of unit electrodes 47 are electrically separated from each other, and the plurality of cell electrodes 46 are electrically separated from each other. That is, the voltage can be individually controlled for the cell electrode 46, and the voltage can be individually controlled for the unit electrode 47.

As can be understood from FIG. 4, the liquid crystal element 22 is a passive matrix system (simple matrix system) and is also a dot matrix system. That is, the liquid crystal element 22 has a dot matrix pattern. The liquid crystal element 22 can control the liquid crystal orientation for each dot where one cell electrode 44 and one cell electrode 46 intersect.

One intersection region between the unit electrode 45 and the unit electrode 47 is a substantially square in the example of FIG. 4, and this intersection region is a unit for controlling the phase of light. The voltage control of the unit electrode 45 and the unit electrode 47 is performed by the voltage control unit 16 included in the operation support ECU 10.

As the liquid crystal element 22, a transmissive liquid crystal panel (transmissive LCOS) using an LCOS (Liquid Crystal on Silicon) method may be used. By using the transmissive LCOS, the electrodes can be finely processed, and a smaller liquid crystal element 22 can be realized. In the transmissive LCOS, a silicon substrate (or a silicon layer formed on the transparent substrate) is used. Since the silicon substrate transmits light (including infrared rays) having a wavelength equal to or higher than a specific wavelength in relation to the band gap, LCOS can be used as a transmissive liquid crystal panel. By using LCOS, the cell electrode can be made into a smaller liquid crystal panel, so that the size can be further reduced. Further, since the mobility of the liquid crystal molecules is high, it is possible to scan the laser beam at high speed.

(Operation of liquid crystal element 22)
Next, the operation of the liquid crystal element 22 included in the LIDAR 20 will be described. FIG. 6 is a diagram illustrating the operation of the liquid crystal element 22. The laser light from the laser source 21 is incident on the liquid crystal layer 42 from the substrate 40 side. The voltage control of the liquid crystal element 22 is executed by the voltage control unit 16 included in the operation support ECU 10. In the following description, an example of scanning in the X direction of FIG. 6 will be described.

The voltage control unit 16 applies 0V to all the cell electrodes 44 included in the unit electrode 45 provided on the substrate 40 and all the cell electrodes 46 included in the unit electrode 47 provided on the substrate 41. In this case, as shown in FIG. 6, the liquid crystal molecules are oriented substantially horizontally over the entire region of the liquid crystal layer 42. At this time, the liquid crystal layer 42 does not have a gradient of refractive index. Therefore, the laser light incident from the laser source 21 passes through the liquid crystal element 22 without being refracted.

FIG. 7 is a diagram illustrating an operation in which the laser beam is refracted by the liquid crystal element 22. The voltage control unit 16 applies an effective voltage that increases in order from the left to the right in FIG. 7 to the plurality of cell electrodes 44 included in one unit electrode 45.

FIG. 8 is a diagram illustrating an effective voltage applied to the cell electrode 44. The horizontal axis of FIG. 8 corresponds to the numbers of the plurality of cell electrodes 44 included in one unit electrode 45, and represents, for example, 10 cell electrodes arranged in order from left to right in FIG. 7. The vertical axis of FIG. 8 is the effective voltage (V), and an AC voltage is applied to the cell electrode 44.

When a plurality of effective voltages having a gradient are applied to the plurality of cell electrodes 44, a gradient of the refractive index is formed in the liquid crystal layer 42. That is, as the applied voltage increases, the inclination of the liquid crystal molecules with respect to the horizontal direction increases. Due to the gradient of the refractive index of the liquid crystal layer 42, the laser light transmitted through the liquid crystal element 22 is refracted at an angle θ.

9 and 10 are diagrams illustrating the operation of refracting the laser beam when the effective voltage is increased in order. As the maximum effective voltage applied to the unit electrode 45 increases, the inclination of the liquid crystal molecules with respect to the horizontal direction increases. As a result, the gradient of the refractive index of the liquid crystal layer 42 becomes larger. That is, the angle θ of the laser beam can be arbitrarily changed by changing the effective voltage.

Next, the scanning angle θ of the laser beam emitted by the LIDAR 20 will be described. Thickness _{d LC} of liquid crystal layer 42, length L in scanning direction in each of unit electrode 45 and unit electrode 47, refractive index ne of abnormal light, refractive index no _o of normal light, tilt angle of liquid crystal molecule with respect to horizontal direction Let α _max and the coefficients A and B. “Δn” is the refractive index anisotropy (birefringence) of the liquid crystal, and is the difference between the refractive index of abnormal light and the refractive index of normal light. “Δn ^* ” is the apparent birefringence. The scanning angle θ is represented by the following equations (1) to (3).

α _max = 90 / (1 + A ・ exp (−B ・ V)) ・ ・ ・ (3)

FIG. 11 is a graph showing an example of the relationship between the tilt angle of the liquid crystal molecule and the effective voltage. The vertical axis of FIG. 11 is the maximum tilt angle α _max (degrees) of the liquid crystal molecule with respect to the horizontal direction, that is, exists in the region where the maximum effective voltage is applied in one unit electrode 45 (or unit electrode 47). The tilt angle of the liquid crystal molecule. The horizontal axis of FIG. 11 is the effective voltage (V).

FIG. 12 is a graph showing an example of the relationship between the scanning angle θ and the effective voltage. The vertical axis of FIG. 12 is the scanning angle θ (degrees), and the horizontal axis of FIG. 12 is the effective voltage (V). The effective voltage in FIG. 12 is the maximum effective voltage applied to the unit electrode 45 (or the unit electrode 47), that is, the maximum effective voltage among a plurality of effective voltages having a gradient.

In FIGS. 11 and 12, for example, the thickness of the liquid crystal layer 42 _{d LC} = 30 μm, the length of the unit electrode 45 L = 30 μm, the refractive index of abnormal light ne = _1.592 , and the refractive index of normal light no =. It is 1.415, the coefficient A = 863, and the coefficient B = 0.24. For example, assuming that one unit electrode is composed of 10 cell electrodes, the width of one cell electrode is approximately 2.5 μm, and the distance between the two cell electrodes is approximately 0.5 μm. In the case of this example, if the effective voltage is changed from 15V to 40, the scanning angle can be changed from 0 degrees to 10 degrees.

11 and 12 show scanning angles for scanning to one side in a direction perpendicular to the substrate 41 (that is, a traveling direction of light that has traveled without refraction in the liquid crystal element 22). Actually, it is possible to scan on both sides in the direction perpendicular to the substrate 41, and the scanning angle in this case is 2θ. When scanning to the other side in the direction perpendicular to the substrate 41, the laser beam can be emitted by increasing the slope of the effective voltage in the reverse direction of FIG. 8, that is, increasing the effective voltage in order from the left to the right in FIG. It can be scanned on the opposite side (right side) of FIG.

Further, when scanning in one dimension along the Y direction, a gradient of the refractive index may be formed along the Y direction. That is, a plurality of effective voltages having a gradient are applied to the plurality of cell electrodes 46 included in one unit electrode 47. Further, when scanning in two dimensions, a gradient of the refractive index may be formed in each of the X direction and the Y direction.

[2] Operation of the in-vehicle system 1 The operation of the in-vehicle system 1 configured as described above will be described.

First, the operation of detecting an object will be described. FIG. 13 is a flowchart illustrating an operation of detecting an object by the driving support ECU 10.

The camera 30 takes an image of a predetermined area around the vehicle at predetermined intervals (step S100). The image data captured by the camera 30 is sent to the driving support ECU 10.

Subsequently, the ultrasonic radar 31 uses ultrasonic waves to scan a predetermined scanning range around the vehicle at predetermined intervals (step S101). Further, the millimeter wave radar 32 uses millimeter waves to scan a predetermined scanning range around the vehicle at predetermined cycles (step S101). The measurement data by the ultrasonic radar 31 and the millimeter wave radar 32 are sent to the driving support ECU 10.

Subsequently, the LIDAR 20 uses a laser beam to scan a predetermined scanning range around the vehicle at predetermined intervals (step S102). The measurement data by LIDAR 20 is sent to the driving support ECU 10.

The order of steps S100 to S102 is arbitrary, and for example, the LIDAR 20, the ultrasonic radar 31, the millimeter wave radar 32, and the camera 30 may perform measurement operations in parallel. Further, as described above, a plurality of LIDAR 20s are attached to the vehicle, and the plurality of LIDAR 20s perform measurement operations. The same applies to the ultrasonic radar 31, the millimeter wave radar 32, and the camera 30.

Subsequently, the object detection unit 13 uses the image pickup data by the camera 30, the measurement data by the ultrasonic radar 31 and the millimeter wave radar 32, and the measurement data by the LIDAR 20, for example, an object (person or obstacle) in front of the vehicle. It is determined whether or not (including an object) is detected (step S103). Specifically, the object detection unit 13 detects an object by comparing two or more data captured by the camera 30 with a time difference and determining the difference information as the comparison result. Further, the object may be detected from the data captured by the camera 30 by using a known pattern recognition technique, shape matching technique, or the like. By using the measurement data by the ultrasonic radar 31 and the millimeter wave radar 32, the distance and direction from the vehicle to the object can be detected. By using the measurement data by LIDAR20, it is possible to detect the three-dimensional shape of the object around the vehicle.

If the object is not detected in step S103, the process proceeds to step S106.

When an object is detected in step S103, the object detection unit 13 limits the scanning range by the LIDAR 20 and determines whether or not it is necessary to scan a part of the scannable range in detail (step S104). ). When a person is detected in front of the vehicle in S103, for example, it is necessary to recognize the number of people, the walking direction, and the like, so it is determined that detailed scanning is necessary. On the other hand, when no person or other vehicle is detected around the vehicle in S103, it is determined that detailed scanning is not necessary because it is not necessary to pay attention to a specific object.

If it is determined in step S104 that detailed scanning is not necessary, the process proceeds to step S106.

When it is determined in step S104 that detailed scanning is necessary, the object detection unit 13 identifies to which region the scanning range is limited, and transmits an instruction to change the scanning range to LIDAR 20 (. Step S105). When the transmission of the instruction to the LIDAR 20 is completed, the process proceeds to step S106.

Subsequently, the action plan generation unit 17 determines the route of the vehicle and makes an action plan (step S106). From the information about the object detected in the object detection operation, the optimum route for traveling in the traveling direction while avoiding the object is calculated. The optimum route is a route that normally has a small load on the mechanism of the automobile and a small physical burden on the driver. However, if a danger such as an accident is expected as a result of detecting an object, a route that requires an action such as sudden acceleration, sudden deceleration, or sudden turn may be selected. The established action plan is sent to the vehicle ECU 35. Since the vehicle ECU 35 travels according to the action plan established in step S106, it controls the mechanisms necessary for traveling such as the steering device 36, the drive device 37, and the braking device 38.

After that, the process returns to step S100, and the driving support ECU 10 repeats the detection operation of the object.

Next, the operation of estimating the position of the own vehicle will be described. FIG. 14 is a flowchart illustrating an operation of estimating the position of the own vehicle by the driving support ECU 10.

The GNSS receiving unit 33 receives position information from the GNSS satellite at predetermined intervals (step S110). The position information received by the GNSS receiving unit 33 is sent to the driving support ECU 10. The driving support ECU 10 estimates a rough position of the own vehicle by using the position information. The position information received at this time may include an error of about several meters to a dozen meters. If you are traveling in a place where you cannot receive location information from the GNSS satellite, such as in a tunnel or between buildings, you may proceed to the next step without receiving the location information. Further, by using a gyro sensor or an acceleration sensor, it is possible to acquire information about the orientation of the own vehicle, and it is possible to improve the accuracy of estimating the position of the own vehicle.

Subsequently, the LIDAR 20 uses a laser beam to scan a predetermined scanning range around the vehicle (step S111). The measurement data by LIDAR 20 is sent to the driving support ECU 10.

Subsequently, the own vehicle position estimation unit 12 creates three-dimensional map data using the measurement data in step S111 (step S112). Subsequently, the own vehicle position estimation unit 12 reads out the reference three-dimensional map data 11A from the storage unit 11 (step S113).

Subsequently, the own vehicle position estimation unit 12 compares the three-dimensional map data created in step S112 with the reference three-dimensional map data 11A read out in step S113 (step S114). Subsequently, the own vehicle position estimation unit 12 estimates the own vehicle position based on the comparison result (for example, matching result) of step S114 (step S115). As the matching method of the two three-dimensional maps, a general matching method can be applied. Further, the position of the own vehicle may be estimated by using a known SLAM (Simultaneous Localization And Mapping). Further, by using the position information of the vehicle at the time of creating the map included in the reference 3D map data 11A, it is possible to estimate the position of the own vehicle in the 3D map in more detail.

Subsequently, the object detection unit 13 determines whether or not the object has been detected based on the comparison result in step S114 (step S116). That is, the object detection unit 13 determines that the non-matching region of the two three-dimensional map data is the object. It should be noted that the determination in step S116 may be performed and the process may proceed to the next step S117.

If the object is not detected in step S116, the process proceeds to step S119.

When an object is detected in step S116, the object detection unit 13 limits the scanning range by the LIDAR 20 and determines whether or not it is necessary to scan a part of the scannable range in detail (step S117). ).

If it is determined in step S117 that detailed scanning is not necessary, the process proceeds to step S119.

When it is determined in step S117 that detailed scanning is necessary, the object detection unit 13 identifies to which region the scanning range is limited, and transmits an instruction to change the scanning range to LIDAR 20 (. Step S118). When the transmission of the instruction to the LIDAR 20 is completed, the process proceeds to step S119.

Subsequently, the action plan generation unit 17 determines the route of the vehicle and makes an action plan (step S119). From the information about the object detected in the object detection operation, the optimum route for traveling in the traveling direction while avoiding the object is calculated. The established action plan is sent to the vehicle ECU 35. Since the vehicle ECU 35 travels according to the action plan established in step S119, the vehicle ECU 35 controls the mechanisms necessary for traveling such as the steering device 36, the drive device 37, and the braking device 38.

After that, the process returns to step S110, and the driving support ECU 10 repeats the own vehicle position estimation operation.

Step S106 in the above-mentioned object detection operation and step S119 in the own vehicle position estimation operation are performed in parallel by simultaneously processing the determination result in the detection operation and the determination result in the own vehicle position estimation operation. May be good. In this case, only one action plan can be made, not two.

[2-1] Basic operation of LIDAR 20 Next, the basic operation of LIDAR 20 will be described. FIG. 15 is a schematic diagram illustrating the basic operation of LIDAR 20. Note that FIG. 15 shows, as an example, a mode in which the LIDAR 20 scans the front of the vehicle 2.

The laser source 21 and the liquid crystal element 22 included in the LIDAR 20 transmit laser light within a range of an angle θ. The detection circuit 23 detects the laser beam reflected by the object. Let the distance L to the assumed object and the scanning range R at the distance L. For example, when the angle θ = 10 degrees and the distance L = 10 m, the scanning range R = 1.7 m, and when the angle θ = 10 degrees and the distance L = 50 m, the scanning range R = 8.7 m. be. The angle θ, the distance L, and the scanning range R can be arbitrarily designed according to the specifications required for the LIDAR 20.

FIG. 16 is a diagram illustrating a waveform of a laser beam generated by LIDAR 20. The upper side of FIG. 16 is the transmission waveform, and the lower side is the reception waveform. The horizontal axis of FIG. 16 is time, and the vertical axis of FIG. 16 is intensity (light intensity).

The laser source 21 emits a laser beam composed of a pulse signal. That is, the laser source 21 emits laser light in a time-division manner. The LIDAR 20 transmits laser light as a pulse signal. Let the period P of the pulse signal and the pulse width W. Let the delay amount Δ, which is the time from the transmission of one pulse to the reception of the pulse reflected by the object, and the speed of light C. The delay amount Δ is calculated by “Δ = 2L / C”.

For example, it is assumed that the pulse width W = 10 nsec and the period P = 10 μsec (that is, the frequency f = 100 kHz). When the delay amount Δ = 67 nsec, the distance L = 10 m is calculated.

By such an operation, the object can be detected and the distance to the object can be calculated.

[2-2] Scan area control operation of LIDAR 20 Next, a scan area control operation of LIDAR 20 will be described. In the present embodiment, the LIDAR 20 can change the size of the scanning area and the position of the scanning area depending on the situation. 17 to 21 are schematic views illustrating a scanning area control operation by LIDAR 20. The scanning area of the LIDAR 20 is controlled by the scanning control unit 15 included in the driving support ECU 10.

FIG. 17 is a diagram illustrating an operation of scanning the scanning region AR1 at a distance L from the LIDAR 20. It is assumed that the size of the scanning area AR1 is the maximum scanning area. The circle in FIG. 17 represents the scanning point SP (corresponding to one pulse in FIG. 16) of the laser beam transmitted by the LIDAR 20. As shown in FIG. 16, the cycle in which the LIDAR 20 transmits the laser beam is predetermined. One frame corresponding to one scan area AR1 is scanned by a predetermined number of scan points SP.

As shown in FIG. 17, for the sake of brevity, one frame is assumed to be scanned at 12 scan points SP, but in reality, more scans are made to obtain one frame. Points are used. The scanning direction is, for example, the vertical direction as shown by the broken line in FIG. That is, a plurality of columns are scanned in order in the vertical direction from left to right. Then, a plurality of frames are sequentially acquired by time division.

FIG. 18 is a diagram illustrating an operation of scanning a scanning area AR2 narrower than the scanning area AR1. FIG. 18 assumes, for example, that when it is detected that a person is present in a narrow area of the scanning area AR1, scanning is performed by focusing on the narrow area centered on the person. The number of scanning points SP in the scanning area AR2 is the same as the number of scanning points SP in the scanning area AR1. Since the cycle in which the LIDAR 20 transmits the laser beam does not change, the time required to scan the scanning region AR1 and the time required to scan the scanning region AR2 are the same. In this way, it is possible to change the size of the scanning area. Further, the density of the scanning points SP can be increased. As a result, it is possible to acquire more accurate information for the scanning region AR2 in the same time as scanning the scanning region AR1, and to acquire the shape of the detected scanning object in more detail. Can be done.

FIG. 19 is a diagram illustrating an operation of scanning the scanning region AR1 by changing the density of the scanning points SP. The LIDAR 20 scans the scanning region AR1 at fewer scanning points than in the example of FIG. 17, for example, 6 scanning points. By scanning at a lower density of the scanning points SP, the same range can be scanned at a higher speed, and it becomes easier to find a scanning object coming in from outside the scanning range such as a person.

FIG. 20 is a diagram illustrating an operation of scanning the scanning region AR3 by changing the density of the scanning points SP. The scanning area AR3 is narrower than the scanning area AR1. Further, the number of scanning points SP in the scanning area AR3 is smaller than the number of scanning points SP in the scanning area AR1. In FIG. 20, the time for acquiring the frame in the scanning area AR3 is shorter than the time for acquiring the frame in the scanning area AR1. In the example of FIG. 20, assuming that the scanning area AR3 has two scanning points, the time for acquiring the scanning area AR1 for one frame is equal to the time for acquiring the scanning area AR3 for six frames. As described above, the scanning region AR3 narrower than the scanning region AR1 can be scanned coarsely and at a higher speed, which is effective for detecting the movement of a moving scanning object, for example.

FIG. 21 is a diagram illustrating an operation of scanning the scanning regions AR4 and AR5 which are separated from each other. The scanning area AR4 is narrower than the scanning area AR1. Further, the number of scanning points SP for scanning the scanning area AR4 is smaller than the number of scanning points SP for scanning the scanning area AR1. Similarly, the scan area AR5 is narrower than the scan area AR1. Further, the number of scanning points SP for scanning the scanning area AR5 is smaller than the number of scanning points SP for scanning the scanning area AR1. The scanning area AR4 and the scanning area AR5 are spatially separated from each other.

In the example of FIG. 21, the number of scanning points SP in the scanning area AR4 is the same as the number of scanning points SP in the scanning area AR5. The total number of scanning points SP in the scanning areas AR4 and AR5 is the same as the number of scanning points SP in the scanning area AR1 in FIG. That is, the time for scanning the scanning area AR1 is the same as the time for scanning the scanning areas AR4 and AR5. In this way, since it is possible to scan the scanning regions AR4 and AR5 which are separated from each other in one frame (scanning region AR1), it is possible to scan two or more scanning objects in detail at the same time. It is also possible to scan by dividing into three or more areas.

[2-3] Scanning operation according to the first embodiment Next, the scanning operation according to the first embodiment will be described. In the first embodiment, the scanning area of the LIDAR 20 is changed according to the surrounding conditions in which the vehicle is traveling. For example, when driving on a highway, the road surface is scanned in detail, and in the city, the scanning area is changed so as to scan the front of the vehicle in detail. FIG. 22 is a flowchart illustrating a scanning operation according to the first embodiment.

The scanning control unit 15 uses the LIDAR 20 to scan the entire region to be scanned (step S200). The entire area to be scanned corresponds to the scanning area AR1 in FIG.

Subsequently, the scanning control unit 15 acquires GNSS information (position information) using the GNSS receiving unit 33 (step S201).

Subsequently, the scanning control unit 15 determines whether or not the vehicle is traveling on the highway by using the position information in step S201 (step S202). When it is determined in step S202 that the vehicle is traveling on the highway, the scanning control unit 15 uses the LIDAR 20 to scan the lower region of the scanning target (step S203). As a result, the scanning area can be narrowed, so that the density of scanning points can be increased and only the lower area can be scanned in detail. Then, for example, after a predetermined time has elapsed, the operation from step S200 is repeated.

FIG. 23 is a diagram illustrating a state of scanning the lower region AL of the scanning target. In FIG. 23, when traveling on a highway, the upper region to be scanned is often empty. In this case, even if the laser beam is transmitted to the upper region of the scanning target, it is not reflected, resulting in waste in scanning. Therefore, by scanning the lower region AL of the scanning target at a high density, the detection accuracy of the target object is improved.

On the other hand, when it is determined in step S202 that the vehicle is not traveling on the expressway (traveling in the city), the scanning control unit 15 uses the LIDAR 20 to scan the upper region to be scanned (step S204). .. This makes it possible to scan the upper region with a higher density of scanning points.

FIG. 24 is a diagram illustrating a state of scanning the upper region AU to be scanned. In FIG. 24, it is assumed that an object farther from the vehicle is detected earlier in the city.

Subsequently, the scanning control unit 15 uses the camera 30 to acquire, for example, image pickup data in front of the vehicle (step S205). Subsequently, the scanning control unit 15 determines whether or not there is a person in the imaging region using the imaging data obtained in step S205 (step S206).

When it is determined in step S206 that a person is present, the scanning control unit 15 uses the LIDAR 20 to scan the area where the person is present (step S207). Then, for example, after a predetermined time has elapsed, the operation from step S200 is repeated.

FIG. 25 is a diagram illustrating how the areas (personal areas) AH1 and AH2 in which a person close to the vehicle is present are scanned. In FIG. 25, even when a person is near the vehicle, the person near the vehicle can be detected by using the image pickup data of the camera 30.

On the other hand, when it is determined in step S206 that there is no person, the scanning control unit 15 repeats the operation from step S200, for example, after a predetermined time has elapsed.

[2-4] Scanning operation according to the second embodiment Next, the scanning operation according to the second embodiment will be described. In the second embodiment, when the LIDAR 20 detects an uphill as a result of scanning, the scanning area is changed. FIG. 26 is a flowchart illustrating the scanning operation according to the second embodiment.

FIG. 27 is a schematic diagram illustrating a scanning range in a normal time (when the vehicle 2 is traveling on a substantially flat road). For simplicity, the LIDAR 20 shall scan vertically. It is assumed that the scanning range is from the angle −θ ₀ to the angle + θ ₀ around the traveling direction of the vehicle 2 (horizontal direction of the LIDAR 20). When scanning is performed in order from the angle −θ ₀ while reducing the angle, the angle at the time of performing the _Nth scan is the angle θN.

The scanning control unit 15 sets the variable N = 0 (step S300). Subsequently, the scanning control unit 15 determines whether or not the variable N = M (step S301). “M” is a predetermined maximum value and is an integer of 1 or more.

When the variable N has not reached the maximum value M in step S301, the scanning control unit 15 transmits the laser beam at an angle θ _N using the LIDAR 20 (step S302). FIG. 28 is a diagram illustrating an example of scanning by LIDAR 20. The maximum angle θ is θ ₀ , and the angle becomes smaller toward θ _M. Assuming that scanning is performed three times at angles θ ₀ , θ ₁ , and θ ₃ , “θ ₀ > θ ₁ > θ ₃ ”.

Subsequently, the scanning control unit 15 measures the distance l _N corresponding to the angle θ _N (step S303). The distance l _N is a distance along the angle θ _N. Specifically, the distance l _N to the object is measured by using the delay amount Δ from the transmission of the laser light in step S302 to the reception of the laser light reflected by the object. FIG. 28 shows a distance l ₀ at an angle θ ₀ , a distance l ₁ at an angle θ ₁ , and a distance l ₂ at an angle θ ₃ .

Subsequently, the scanning control unit 15 determines whether or not “l _N-1 sinθ _N-1 > l _N sinθ _N ” (step S304). When the condition of step S304 is not satisfied (S304 = No), the scanning control unit 15 executes scanning in the range of “−θ ₀ <θ <+ θ ₀ ” as usual. In FIG. 28, “l ₀ sin θ ₀ = l ₁ sin θ ₁ = l ₂ sin θ ₂ ”. That is, it can be recognized that the road on which the vehicle 2 is traveling is substantially flat. Actually, there is some error in the numerical value obtained by "l _N sinθ _N ", so if the error is within a predetermined value, "l ₀ sinθ ₀ = l ₁ sinθ ₁ = l ₂ sinθ ₂ ". It is determined that it is.

Subsequently, the scanning control unit 15 sets the variable N = N + 1 (step S306). Subsequently, the scanning control unit 15 returns to step S301 and repeats scanning by changing the angle θ until N = M.

On the other hand, when the condition of step S304 is satisfied (S304 = Yes), the scanning control unit 15 changes the scanning range to “−θ _N <θ <2θ ₀ −θ _N ” (step S307). The above-mentioned error is also taken into consideration in the calculation in step S307.

FIG. 29 is a diagram illustrating an example of scanning by LIDAR 20. In FIG. 29, “l ₀ sinθ ₀ = l ₁ sinθ ₁ > l ₂ sinθ ₂ ”. That is, it can be detected that there is an uphill in front of the vehicle 2. In this case, as shown in FIG. 30, the scanning range is changed to “−θ ₂ <θ <2θ ₀ −θ ₂ ”, and scanning by LIDAR 20 is executed.

As a modification of the second embodiment, if the vehicle 2 is scanned in the horizontal direction, the scanning region can be changed according to the curve of the tunnel when the vehicle 2 is traveling in the tunnel.

[2-5] Scanning operation according to the third embodiment Next, the scanning operation according to the third embodiment will be described. In the third embodiment, the determination scan is executed before the actual scan (main scan), and the main scan is executed according to the result of the determination scan. FIG. 31 is a flowchart illustrating the scanning operation according to the third embodiment. FIG. 32 is a diagram illustrating a scanning region according to the third embodiment.

The scan control unit 15 executes a determination scan prior to the main scan. Steps S400 to S403 in FIG. 31 correspond to the determination scan. The scanning control unit 15 uses the LIDAR 20 to transmit laser light to the entire region to be scanned (step S400).

Subsequently, the detection circuit 23 receives the laser beam reflected by the object (step S401). Subsequently, the scanning control unit 15 acquires scanning data from the LIDAR 20 (step S402). Subsequently, the scanning control unit 15 repeats the scanning operation until the predetermined number of times X is reached (step S403). As a result, X frames are acquired. X is an integer of 1 or more.

FIG. 32 shows, as an example, a state in which a vehicle performs a scanning operation while traveling on a highway. In the determination scan, the laser beam is transmitted to the entire region to be scanned. In FIG. 32, a region (transmission region) in which the laser beam is transmitted is shown by being surrounded by a broken line. The laser beam is not reflected from the sky, and the laser beam is received from a region other than the sky (reception region).

The scan control unit 15 executes the main scan after the determination scan. Steps S404 to S408 in FIG. 31 correspond to the main scan. That is, the scanning control unit 15 determines the scanning area using the scanning data (plurality of frames) acquired in step S402 (step S404). Specifically, the first region, which is a region without laser light (unreceived region) commonly received by the plurality of frames acquired in step S402, is determined. Then, the second area, which is the area excluding the unreceived area from the entire area to be scanned, is newly determined as the scanning area. It is desirable to set the scanning area in this scan to the same area as or slightly larger than the area where the laser beam is received.

Subsequently, the scanning control unit 15 uses the LIDAR 20 to transmit laser light to the scanning region (a part of the region to be scanned) determined in step S404 (step S405).

Subsequently, the detection circuit 23 receives the laser beam reflected by the object (step S406). Subsequently, the scanning control unit 15 acquires scanning data from the LIDAR 20 (step S407). Subsequently, the scanning control unit 15 repeats the scanning operation until the predetermined number of times Y is reached (step S408). As a result, Y frames are acquired. Y is an integer of 1 or more.

In the main scan shown in FIG. 32, the transmission area is narrowed down to a part of the entire area to be scanned.

[3] Effect of the Present Invention As described in detail above, in the present embodiment, the laser scanning device included in the in-vehicle system 1 transmits the laser light emitted from the laser source 21 and the laser light from the laser source 21. It includes a liquid crystal element (scanning element) 22 that changes the direction of the laser light, a detection circuit 23 that detects the laser light reflected by the object, and a scanning control unit 15 that controls the liquid crystal element 22. Then, the scanning control unit 15 changes the size of the region scanned by the laser beam.

Therefore, according to the present embodiment, it is possible to concentrate the scanning on a necessary area according to the situation of the place where the vehicle travels, so that the detection of the object and the distance measurement can be performed faster. Further, since the density of the scanning points (measurement points) for scanning the narrowed scanning area can be increased, highly accurate scanning data can be acquired. This makes it easier for the driver or driver assistance system to avoid a crisis.

Further, the LIDAR 20 of the present embodiment can observe a wide range roughly at one time and intensively observe a narrow range at another time by dynamically changing the density of scanning points. When the LIDAR 20 is composed of mechanical parts, it is difficult to dynamically change the density of scanning points. However, in the present embodiment, since the LIDAR 20 is configured by using the liquid crystal element 22 having no mechanical components, for example, on a highway, the city travels at a low speed while observing a distant place while lowering the resolution. Then, it is possible to use it properly, such as observing nearby areas with high resolution.

Further, the LIDAR 20 of the present embodiment has no mechanical components and no mechanical moving parts, so that the reliability can be improved. Further, the LIDAR 20 can be miniaturized.

In each of the above embodiments, an infrared laser is used as the laser light handled by the laser scanning device. However, the present invention is not limited to this, and the laser scanning apparatus according to the present embodiment can be applied to light other than infrared rays.

Further, in the above embodiment, the simple matrix method is applied to the liquid crystal element 22, but other electrode structures may be used. For example, a plurality of first electrodes corresponding to a plurality of dots and electrically separated from each other are formed on the first substrate, and one planar common electrode is formed on the second substrate facing the first substrate. Then, a plurality of first electrodes may be driven by using a plurality of switching elements composed of a TFT (Thin Film Transistor) or the like.

The present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate, in which case the combined effect can be obtained. Further, the above-described embodiment includes various inventions, and various inventions can be extracted by a combination selected from a plurality of disclosed constituent requirements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, if the problem can be solved and the effect is obtained, the configuration in which the constituent elements are deleted can be extracted as an invention.

1 ... In-vehicle system, 10 ... Driving support ECU, 20 ... LIDAR, 21 ... Laser source, 22 ... Liquid crystal element, 23 ... Detection circuit, 30 ... Camera, 31 ... Ultrasonic radar, 32 ... Millimeter wave radar, 33 ... GNSS reception Unit, 34 ... Communication unit, 35 ... Vehicle ECU, 36 ... Steering device, 37 ... Drive device, 38 ... Braking device, 40, 41 ... Board, 42 ... Liquid crystal layer, 43 ... Sealing material, 44, 46 ... Cell electrode, 45, 47 ... Unit electrode

Claims (10)

A laser scanning device that scans using laser light.
One laser source that emits the laser light at a constant cycle,
A scanning element that transmits the laser light emitted from the laser source and changes the emission angle of the laser light.
It is provided with a control unit that controls the scanning element.
The control unit controls the scanning element so as to change the size of the scanning region scanned by the laser beam and the density of the points at which the laser beam is transmitted with respect to the scanning region.
The scanning element is a liquid crystal element and is a liquid crystal element.
The liquid crystal element is
The first board and the second board arranged to face each other,
A liquid crystal layer sandwiched between the first substrate and the second substrate,
A plurality of first electrodes provided on the liquid crystal layer side of the first substrate and each extending in the first direction,
A plurality of second electrodes provided on the liquid crystal layer side of the second substrate and each extending in a second direction orthogonal to the first direction are included.
The control unit scans in two dimensions by controlling the voltages of the plurality of first electrodes and the plurality of second electrodes.
Laser scanning device. The control unit controls the scanning element so as to scan a first region and a second region separated from each other in the largest scanning range that can be scanned, and for two or more objects during one cycle of scanning operation . The laser scanning apparatus according to claim 1. It is equipped with a sensor that acquires information around the vehicle.
The laser scanning apparatus according to claim 1 or 2, wherein the control unit determines the size of the scanning region and the density of points at which the laser beam is transmitted to the scanning region based on the information from the sensor. Further equipped with a detection circuit for receiving the laser beam reflected by the object,
The control unit
The first scanning operation and the second scanning operation are executed in order by a predetermined time,
In the first scanning operation, the third region is set as the scanning target.
The laser scanning apparatus according to any one of claims 1 to 3, wherein in the second scanning operation, a fourth region excluding a region in which laser light is not received from the third region is a scanning target. It is further equipped with a detection circuit that receives the laser beam reflected by the object and detects the distance to the object.
The control unit
Using a plurality of detection results by the detection circuit, the slope of the road included in the scanning range is calculated.
The laser scanning apparatus according to any one of claims 1 to 3, wherein the scanning range is changed according to the slope of the road. A laser scanning device that scans using laser light.
One laser source that emits the laser light at a constant cycle,
A scanning element that transmits the laser light emitted from the laser source and changes the emission angle of the laser light.
It is provided with a control unit that controls the scanning element.
The control unit controls the scanning element so as to change the size of the scanning region scanned by the laser beam and the density of the points at which the laser beam is transmitted with respect to the scanning region.
The scanning element is a liquid crystal element and is a liquid crystal element.
The control unit
The first operation of scanning the first region using a plurality of scanning points, and
A second operation in which the density of scanning points is made higher than that of the first operation and the second region of the first region, which is smaller in size than the first region, is scanned.
A third operation of scanning the first region with a lower density of scanning points than the first operation,
A fourth operation in which the density of scanning points is made lower than that of the first operation and a third region of the first region, which is smaller in size than the first region, is scanned.
Among the first regions, the fifth operation of scanning the fourth region and the fifth region, each of which is smaller in size than the first region and is separated from each other , can be selected and executed.
The liquid crystal element is
The first board and the second board arranged to face each other,
A liquid crystal layer sandwiched between the first substrate and the second substrate,
A plurality of first electrodes provided on the liquid crystal layer side of the first substrate and each extending in the first direction,
A plurality of second electrodes provided on the liquid crystal layer side of the second substrate and each extending in a second direction orthogonal to the first direction are included.
The control unit scans in two dimensions by controlling the voltages of the plurality of first electrodes and the plurality of second electrodes.
Laser scanning device. It is equipped with a sensor that acquires information around the vehicle.
The laser scanning apparatus according to claim 6, wherein the control unit determines the size of the scanning region and the density of scanning points in the scanning region based on the information from the sensor. It is further equipped with a detection unit that detects an object using the scanning data acquired by scanning.
According to claim 6 or 7, the control unit executes at least one of the fifth operations from the second operation when an object is detected using the scanning data acquired in the first operation. The laser scanning device according to the description. Further equipped with a detection circuit for receiving the laser beam reflected by the object,
The control unit
The sixth operation and the seventh operation are executed in order by a predetermined time,
In the sixth operation, the sixth region is set as the scanning target.
The laser scanning apparatus according to any one of claims 6 to 8, wherein in the seventh operation, a seventh region excluding a region in which laser light is not received from the sixth region is targeted for scanning. It is further equipped with a detection circuit that receives the laser beam reflected by the object and detects the distance to the object.
The control unit
Using a plurality of detection results by the detection circuit, the slope of the road included in the scanning range is calculated.
The laser scanning apparatus according to any one of claims 6 to 8, wherein the scanning range is changed according to the slope of the road.

Images