Information Processing Apparatus, Information Processing Method, and Program

Abstract

The present invention provides an information processing apparatus, an information processing method, and a program. The information processing apparatus includes a plurality of optical transmission / reception units and an information processing unit. Each optical transmission / reception unit includes: a transmission unit that emits light; a scanning unit that scans the light emitted by the transmission unit; and a light reception unit that receives the light reflected by a target object. The information processing unit obtains the angle and / or distance of the target object based on the light reception result of the light reception unit. Each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and the scanning units scan the entire direction in the horizontal direction in a shared manner.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201580083058.X, titled "Information Processing Apparatus, Information Processing Method, and Program", filed on October 6, 2015. Technical Field

[0002] The present invention relates to a technique for measuring distance. Background Art

[0003] A known lidar (LIDAR) scans in a horizontal direction and intermittently emits laser light while detecting a point cloud on the surface of an object by receiving the reflected light. Patent Document 1 discloses a technique for performing one-dimensional or two-dimensional scanning of the surrounding environment by a LIDAR mounted on a vehicle to detect information on the surrounding environment of the vehicle. Patent Document 2 discloses incorporating a lidar into a headlight unit of a vehicle.

[0004] Prior Art References

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-89691

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2015-76352 Summary of the Invention

[0008] Problems to be Solved by the Present Invention

[0009] As disclosed in Patent Document 1 (refer to FIG. 2), a lidar is usually mounted at a relatively high position on a vehicle. However, in this case, information on the lower position of the vehicle cannot be obtained. At the same time, Patent Document 2 discloses an example in which a lidar is mounted in each of two headlight units of a vehicle. However, in this case, due to the presence of the vehicle body, information in all directions (especially the rear direction) cannot be obtained.

[0010] The above are examples of the problems to be solved by the present invention. An object of the present invention is to provide an information processing apparatus capable of obtaining information on an object existing at a lower position in all directions.

[0011] Means for Solving the Problems

[0012] One aspect of the present invention is an information processing apparatus, comprising: a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit configured to emit light, a scanning unit configured to scan the light emitted by the transmission unit, and a light reception unit configured to receive the light reflected by an object; and an information processing unit configured to obtain at least one of a distance to the object and an angle of the object based on a light reception result of the light reception unit, wherein each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and the scanning units scan the light omnidirectionally in the horizontal direction in a shared manner.

[0013] Another aspect of the present invention is an information processing method executed by an information processing apparatus, the information processing apparatus including a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit, the method comprising: a transmission / reception process executed by each of the optical transmission / reception units, the transmission / reception process including a transmission process of emitting light rays from the transmission unit, a scanning process of scanning the light emitted by the transmission unit by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit; and an information processing process of obtaining at least one of a distance to the object and an angle of the object based on a light reception result of the light reception process, wherein each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and wherein the scanning process scans the light omnidirectionally in the horizontal direction in a shared manner by the scanning units.

[0014] Another aspect of the present invention is a storage medium storing a program executed by an information processing apparatus, the information processing apparatus including: a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit; and a computer, the program causing the computer to execute: a transmission / reception process executed by each of the optical transmission / reception units, the transmission / reception process including a transmission process of emitting light rays from the transmission unit, a scanning process of scanning the light emitted by the transmission unit by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit; and an information processing process of obtaining at least one of a distance to the object and an angle of the object based on a light reception result of the light reception process, wherein each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and wherein the scanning process scans the light omnidirectionally in the horizontal direction in a shared manner by the scanning units.

[0015] Another aspect of the present invention is an information processing apparatus, comprising: a plurality of optical transmission / reception units provided at a first position on a vehicle and at a second position different from the first position on the vehicle, each of the optical transmission / reception units including: (i) a transmission unit configured to transmit light, (ii) a scanning unit configured to scan the light transmitted by the transmission unit, and (iii) a light reception unit configured to receive light reflected by an object; and an information processing unit configured to perform a synthesis process of synthesizing light reception results of the light reception units of the plurality of optical transmission / reception units to obtain at least one of a distance to the object and an angle of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a block diagram showing the configuration of a lidar unit according to an embodiment.

[0017] Figure 2A and Figure 2B shows the positions of scanning units provided on a vehicle.

[0018] Figure 3 is a block diagram showing the configuration of an optical transmission / reception unit.

[0019] Figure 4 shows waveforms of a trigger signal and a segmented extraction signal.

[0020] Figure 5 shows a scanning method of a scanning unit according to a first embodiment.

[0021] Figure 6 shows a positional relationship between an r1θ1 coordinate system and an rθ coordinate system.

[0022] Figure 7 shows a set of reception waveforms of a scanning unit obtained in the r1θ1 coordinate system.

[0023] Figure 8A and Figure 8B shows ranges of an L1 frame in the r1θ1 coordinate system and the rθ coordinate system.

[0024] Figure 9A and Figure 9B shows a conversion from an r1θ1 coordinate frame to an rθ coordinate frame.

[0025] Figures 10A to 10D shows a conversion from an x1y1 coordinate frame to an xy coordinate frame.

[0026] Figure 11 shows scanning areas of a plurality of scanning units in a first embodiment.

[0027] Figure 12Shows the scanning areas of the multiple scanning units in the first embodiment.

[0028] Figure 13 Shows the composite signal of the L1 - L4 frames obtained by the composite process.

[0029] Figure 14 Shows the scanning method of the scanning unit according to the second embodiment.

[0030] Figure 15 Shows the scanning areas of the multiple scanning units in the second embodiment.

[0031] Figure 16 Shows the scanning areas of the multiple scanning units described in the second embodiment.

[0032] Figure 17A and Figure 17B Shows the method of detecting an object in the prior art.

[0033] Figure 18A and Figure 18B Shows the method of detecting an object in the embodiment.

[0034] Figure 19A and Figure 19B Shows the method of detecting an object in the improved example.

[0035] List of reference numerals

[0036] L1 - L4 scanning unit

[0037] TR1 - TR4 optical transmission / reception unit

[0038] SP signal processing unit

[0039] 13 laser diodes

[0040] 16 optical receiving elements Detailed description of the invention

[0041] According to one aspect of the present invention, there is provided an information processing apparatus, comprising: a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit configured to emit light, a scanning unit configured to scan the light emitted by the transmission unit, and an optical receiving unit configured to receive the light reflected by an object; and an information processing unit configured to obtain at least one of a distance to the object and an angle of the object based on a light reception result of the optical receiving unit, wherein each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and the scanning units scan the light omnidirectionally in the horizontal direction in a shared manner.

[0042] The information processing device includes a plurality of optical transmission / reception units and an information processing unit. Each of the optical transmission / reception units includes: a transmission unit configured to transmit light rays; a scanning unit configured to scan the light transmitted by the transmission unit; and a light reception unit configured to receive the light reflected by an object. The information processing unit is configured to obtain at least one of the distance to the object and the angle of the object based on the light reception result of the light reception unit. Each scanning unit is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and the scanning units share the scanning of light in all directions in the horizontal direction. Note that "omnidirection" means that in addition to a 360° dead angle-free situation, it also includes a situation where there is a certain degree of dead angle. According to this information processing device, objects existing in all directions and in the horizontal direction can be detected by the plurality of scanning units, and thus surrounding environment information can be obtained.

[0043] In one mode of the information processing device, the information processing unit respectively converts the light reception results of the light reception units of the plurality of optical transmission / reception units into conversion information based on a predetermined position of the vehicle, and performs a synthesis process of synthesizing each piece of the conversion information. In this mode, by synthesizing the light reception results of the plurality of optical transmission / reception units, surrounding environment information in all directions can be obtained.

[0044] In another mode of the information processing device, if the scanning ranges of the plurality of optical transmission / reception units overlap, the information processing unit performs an averaging process on the light reception results of the light reception units of the plurality of optical transmission / reception units for the overlapping range. In this mode, the noise component in the light reception result can be reduced by the averaging process.

[0045] In a preferred embodiment, the number of the plurality of optical transmission / reception units is four, and the plurality of optical transmission / reception units are provided in the lighting unit of the vehicle.

[0046] According to another aspect of the present invention, there is provided an information processing method executed by an information processing apparatus, the information processing apparatus including a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit. The method includes: a transmission / reception process executed by each of the optical transmission / reception units, which includes a transmission process of emitting light rays from the transmission unit, a scanning process of scanning the light emitted by the transmission unit by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit; and an information processing process of obtaining at least one of the distance to the object and the angle of the object based on the light reception result of the light reception process. Wherein, each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and wherein the scanning process scans the light omnidirectionally in the horizontal direction in a manner shared by the scanning units. According to this information processing method, objects existing in all directions and in the horizontal direction can be detected by a plurality of scanning units, and thus surrounding environment information can be obtained.

[0047] According to still another aspect of the present invention, there is provided a program executed by an information processing apparatus, the information processing apparatus including: a plurality of optical transmission / reception units, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit; and a computer. The program causes the computer to execute: a transmission / reception process executed by each of the optical transmission / reception units, which includes a transmission process of emitting light rays from the transmission unit, a scanning process of scanning the light emitted by the transmission unit by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit; and an information processing process of obtaining at least one of the distance to the object and the angle of the object based on the light reception result of the light reception process. Wherein, each of the scanning units is provided at a position where there is a direction in which the light scanned by the scanning unit is blocked by the vehicle itself, and wherein the scanning process scans the light omnidirectionally in the horizontal direction in a manner shared by the scanning units. By executing this program by a computer, objects existing in all directions and in the horizontal direction can be detected by a plurality of scanning units, and thus surrounding environment information can be obtained. The program may be stored in a storage medium.

[0048] According to another aspect of the present invention, there is provided an information processing apparatus, comprising: a plurality of optical transmission / reception units provided at a first position on a vehicle and a second position different from the first position on the vehicle, each of the optical transmission / reception units comprising: (i) a transmission unit configured to transmit light, (ii) a scanning unit configured to scan the light transmitted by the transmission unit, and (iii) a light reception unit configured to receive the light reflected by an object; and an information processing unit configured to perform a synthesis process of synthesizing the light reception results of the light reception units of the plurality of optical transmission / reception units to obtain at least one of the distance to the object and the angle of the object.

[0049] The information processing apparatus includes a plurality of optical transmission / reception units and an information processing unit. The optical transmission / reception units are provided at a first position on a vehicle and a second position different from the first position on the vehicle. Each of the optical transmission / reception units includes: (i) a transmission unit configured to transmit light; (ii) a scanning unit configured to scan the light transmitted by the transmission unit; and (iii) a light reception unit configured to receive the light reflected by an object. The information processing unit performs a synthesis process of synthesizing the light reception results of the light reception units of the plurality of optical transmission / reception units to obtain at least one of the distance to the object and the angle of the object. With this information processing apparatus, objects existing in all directions and in the horizontal direction can be detected by a plurality of scanning units, and thus surrounding environment information can be obtained.

[0050] Examples

[0051] Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings.

[0052] [Configuration]

[0053] Figure 1 It is a block diagram of a lidar unit to which the information processing apparatus according to the present invention is applied. Figure 1The lidar unit 100 shown is a lidar (light detection and ranging, or laser imaging detection and ranging) of a TOF (time of flight) system, and measures the distance to an object in all directions and the horizontal direction. The lidar unit 100 is used for the purpose of assisting in recognizing the surrounding environment of the vehicle as part of an advanced driver assistance system. The lidar unit 100 mainly includes scanning units L1 to L4, optical transmission / reception units TR1 to TR4, and an information processing unit SP. Hereinafter, if each of the scanning units L1 to L4 is not distinguished from each other, each of the scanning units L1 to L4 is simply referred to as "scanning unit L", and if each of the optical transmission / reception units TR1 to TR4 is not distinguished from each other, each of the optical transmission / reception units TR1 to TR4 is simply referred to as "optical transmission / reception unit TR".

[0054] The scanning units L1 to L4 are arranged at four positions, namely, the front, rear, left, and right positions of the vehicle, respectively. Figure 2A and Figure 2B shows the vehicle on which the scanning units L1 to L4 are arranged. As Figure 2A and Figure 2B shown, the scanning units L1 to L4 are arranged at the four corners of the front, rear, left, and right of the vehicle. As Figure 2A shown, the scanning units L1 to L4 emit laser pulses (hereinafter also referred to as "transmitted light pulses") in all directions (360°) respectively. Preferably, the scanning units L1 and L2 arranged on the front side of the vehicle are arranged in the headlight unit of the vehicle, and the scanning units L1 and L2 arranged on the rear side of the vehicle are arranged in the taillight unit of the vehicle. Alternatively, the scanning units L1 to L4 may be arranged in other light units on the front and rear sides of the vehicle.

[0055] Since the scanning units L1 to L4 are respectively arranged at the four positions of the front, rear, left, and right of the vehicle, the transmitted light pulses emitted by each scanning unit L are partially blocked by the vehicle itself (the body of the vehicle). For example, in the transmitted light pulse L1 emitted omnidirectionally by the scanning unit L1 on the front side of the vehicle, a part of the transmitted light pulse L1 on the rear side of the vehicle is blocked by the body of the vehicle. That is to say, the transmitted light pulses emitted by the scanning units L1 to L4 omnidirectionally actually have a dead angle of a certain angle formed by the vehicle body respectively.

[0056] The optical transmission / reception unit TR emits transmission optical pulses in all directions of 360° in the horizontal direction with a gradually changing emission direction. At the same time, the optical transmission / reception unit TR emits transmission optical pulses at each segment (there are 900 segments in this embodiment) obtained by equally angularly dividing the full direction of 360° in the horizontal direction. Then, the optical transmission / reception unit TR generates a signal (hereinafter referred to as "segment signal Sseg") associated with the optical reception intensity at each segment by receiving the reflected light of the transmission optical pulse (hereinafter referred to as "received optical pulse") within a predetermined time period after emitting the transmission optical pulse, and outputs the segment signal Sseg to the signal processing unit SP.

[0057] Based on the segment signals Sseg at each segment received from the optical transmission / reception unit TR, the signal processing unit SP outputs surrounding environment information including at least one of the distance to the object and the angle of the object. The surrounding environment information indicates the surrounding environment of the vehicle on which the lidar unit 100 is installed, and specifically indicates the distance and angle of the objects existing in all directions around the vehicle.

[0058] Figure 3 Shows a schematic configuration of the optical transmission / reception unit TR. As Figure 3 shown, the optical transmission / reception unit TR mainly includes a crystal oscillator 10, a synchronization control unit 11, an LD driver 12, a laser diode 13, a motor control unit 15, a light receiving element 16, a current-voltage conversion circuit (transimpedance amplifier) 17, an A / D converter 18, and a segmenter 19.

[0059] The crystal oscillator 10 outputs a pulse-type clock signal S1 to the synchronization control unit 11 and the A / D converter 18. In this embodiment, as an example, the clock frequency is 1.8 GHz. Hereinafter, the clock represented by the clock signal S1 is also referred to as "sample clock".

[0060] The synchronization control unit 11 outputs a pulse-type signal (hereinafter referred to as "trigger signal S2") to the LD driver 12. In this embodiment, the trigger signal S2 periodically operates with a period of 131072 (= 2 17 ) sample clocks. Hereinafter, the time period between the time when the trigger signal S2 operates and the time when the trigger signal S2 operates next is referred to as "segment period". Similarly, the synchronization control unit 11 outputs a signal (hereinafter referred to as "segment extraction signal S3") to the segmenter 19 to determine the timing for the segmenter 19 to extract the output of the A / D converter 18 described below. The trigger signal S2 and the segment extraction signal S3 are logic signals, and as described below Figure 4Synchronize with each other as shown. In this embodiment, the synchronization control unit 11 causes the segmented extraction signal S3 to act for a time width of 2048 sample clocks (referred to as "gate width Wg").

[0061] The LD driver 12 applies a pulsed current to the laser diode 13 in synchronization with the trigger signal S2 input from the synchronization control unit 11. The laser diode 13 can be, for example, an infrared (905 nm) pulsed laser, and emits light pulses based on the pulsed current supplied by the LD driver 12. In this embodiment, the laser diode 13 emits light pulses close to 5 nsec.

[0062] For example, the scanning unit L configured to include a scanner with a transmission and reception optical system scans the transmitted light pulses emitted by the laser diode 13 360° in the horizontal plane, and guides the received light pulses, that is, the return light rays reflected by an object (also referred to as "target") irradiated by the transmitted light pulses emitted, to the light receiving element 16. In this embodiment, the scanning unit L includes a motor for rotation, and the motor is controlled by the motor control unit 15 to rotate once every 900 segments. In this case, the angular resolution of each segment is 0.4° (= 360° / 900).

[0063] The light receiving element 16 is, for example, an avalanche diode, and generates a weak current corresponding to the reflected light from the object (i.e., the light amount of the received light pulses) guided by the scanning unit L. The light receiving element 16 supplies the generated weak current to the current-voltage conversion circuit 17. The current-voltage conversion circuit 17 amplifies the weak current supplied by the light receiving element 16, converts it into a voltage signal, and inputs the converted voltage signal to the A / D converter 18.

[0064] The A / D converter 18 converts the voltage signal supplied by the current-voltage conversion circuit 17 into a digital signal based on the clock signal L1 supplied by the crystal oscillator 10, and supplies the converted digital signal to the segmenter 19. Hereinafter, the digital signal generated by the A / D converter 18 at each clock will be referred to as a "sample". One sample corresponds to the data of one pixel in one frame in the polar coordinate space.

[0065] The segmenter 19 generates the digital signal output by the A / D converter 18 during 2048 sample clocks in the period of the gate width Wg during which the segmented extraction signal S3 is acting as the segmented signal Sseg. The segmenter 19 supplies the generated segmented signal Sseg to the signal processing unit SP.

[0066] Figure 4 Shows the waveforms of the trigger signal S2 and the segmented extraction signal S3 in the time sequence. As Figure 4As shown, in this embodiment, the segmentation period, which is one cycle period during which the trigger signal S2 takes effect, is set to a length of 131,072 sample clocks (as Figure 3 indicated by "smpclk" in

[0067] ). The pulse width of the trigger signal S2 is set to a length of 64 sample clocks, and the gate width Wg is set to a length of 2,048 sample clocks.

[0068] In this case, since the segmented extraction signal S3 takes effect during the time period of the gate width Wg after the trigger signal S2 takes effect, the segmenter 19 extracts 2,048 samples output by the A / D converter 18 while the trigger signal S2 takes effect. As the gate width Wg becomes longer, the maximum measurement distance (limit measurement distance) from the lidar unit 100 becomes longer.

[0069] In the above configuration, the laser diode 13 is an example of the "emission unit" according to the present invention, and the light receiving element 16, the current-voltage conversion circuit 17, and the A / D converter 18 are examples of the "light receiving unit" according to the present invention. Similarly, the signal processing unit SP is an example of the "information processing unit" according to the present invention.

[0070] [Operation]

[0071] The operation of the lidar unit 100 will be described below.

[0072] (First Embodiment)

[0073] Figure 5 is a plan view showing the operation of the scanning unit L1 according to the first embodiment. Assuming that the traveling direction of the vehicle is θ1 = 0, the scanning unit L1 has a horizontal viewing angle from θ a = -60° to θ b = 150°, that is, 210°. At the same time, the scanning unit L1 has 150° < θ 1 < 180° and -180° < θ 1Dead angles within the range of <-60°. The scanning unit L1 scans the transmitted light pulses within this horizontal viewing angle range, receives the light reflected by the object as received light pulses, and supplies the received light pulses to the optical transmission / reception unit TR1.

[0074] Figure 6 Shows the positional relationship between the polar coordinate system with the position of the scanning unit L1 as the pole and another polar coordinate system with the position of the vehicle center as the pole. The polar coordinate system with the position of the scanning unit L1 (hereinafter referred to as "center L1") as the pole is defined by the scanning angle "θ1" and the distance "r1", and it is called the "r1θ1 coordinate system". Based on the segmented signal Sseg supplied by the optical transmission / reception unit TR1, the signal processing unit SP generates a set of digital waveforms (hereinafter referred to as "full-frame signal") in the r1θ1 coordinate frame with the position of the scanning unit L1 as the pole. The range of the scanning angle θ1 of the full-frame signal is -60° < θ 1 <150°. It should be noted that the frame generated in the r1θ1 coordinate system is called the "r1θ1 coordinate frame". In contrast, the polar coordinate system with the vehicle center V as the pole is defined by the scanning angle "θ" and the distance "r", and it is called the "rθ coordinate system". Similarly, the frame generated in the rθ coordinate system is called the "rθ coordinate frame".

[0075] As Figure 6 shown, assuming that the scanning units L1 to L4 are respectively arranged at the four corners of the vehicle, the length of the vehicle is "Lv", and the width of the vehicle is "Wv", then Figure 6 the poles of the rθ coordinate frame and the r1θ1 coordinate frame in

[0076] In this embodiment, the signal processing unit SP converts the signal obtained by the scanning unit L1, that is, the signal sampled in the r1θ1 coordinate frame, into a signal sampled in the rθ coordinate frame through appropriate resampling processing. In other words, coordinate conversion from the r1θ1 coordinate frame to the rθ coordinate frame is performed. In this case, as the distance "r" becomes shorter, the deformation of the distance "r" and the scanning angle "θ" caused by the conversion becomes larger.

[0077] Figure 7 Shows an example of the received waveform group (full-frame signal) of the scanning unit L1 obtained in the r1θ1 coordinate system. The horizontal axis indicates the distance to the pole, that is, the center L1. In this example, the distance ranges from 0 to 50 m. The vertical axis indicates the scanning angle θ1, which generally ranges from -180° to 180°. Since the scanning unit L1 as Figure 5The scanning shown has a horizontal viewing angle range from -60° to 150°, i.e., 210°, as Figure 7 shown. Based on the scanning of the scanning unit L1, a full-frame signal with a horizontal viewing angle range from -60° to 150°, i.e., 210°, can be obtained from the signal processing unit SP.

[0078] Figure 8A shows the range of the r1θ1 coordinate frame in the r1θ1 coordinate system. Since the scanning unit L1 scans a horizontal viewing angle range from -60° to 150°, i.e., 210°, the r1θ1 coordinate frame becomes a full-frame signal within the range from -60° to 150°. In contrast, Figure 8B in the rθ coordinate system indicates the r1θ1 coordinate frame as Figure 8A shown, and it is a full-frame signal within the range approximately from -60° to 150°.

[0079] Figure 9A and Figure 9B show the conversion from the r1θ1 coordinate frame to the rθ coordinate frame. When the grid of the r1θ1 coordinate frame is mapped to the rθ coordinate frame, the grid as Figure 9B shown can be obtained. Hereinafter, the r1θ1 coordinate frame obtained by scanning with the scanning unit L1 is simply referred to as the "L1 frame". Similarly, the r2θ2 coordinate frame obtained by scanning with the scanning unit L2 is called the "L2 frame", the r3θ3 coordinate frame obtained by scanning with the scanning unit L3 is called the "L3 frame", and the r4θ4 coordinate frame obtained by scanning with the scanning unit L4 is simply referred to as the "L4 frame".

[0080] Figures 10A to 10D indicates the conversion from the x1y1 coordinate frame to the xy coordinate frame. It should be noted that the "x1y1 coordinate frame" is a frame generated in the xy coordinate system with the position of the scanning unit L1 as the origin, while the "xy coordinate frame" is a frame generated in the xy coordinate system with the vehicle center V as the origin. When the grid in the x1y1 coordinate frame as Figure 10A shown is mapped to the xy coordinate frame, the grid as Figure 10B shown can be obtained. Figure 10C is Figure 10A an enlarged view of the part around the position of the scanning unit L1 in Figure 10D is Figure 10B an enlarged view of the part around the vehicle center V in

[0081] The signal processing unit SP converts the full-frame signals of the L2 - L4 frames generated by the scanning units L2 - L4 into full-frame signals of the rθ coordinate frame in the same way. Specifically, the full-frame signal of the L2 frame is in the range -150° < θ 2 < 60°, the full-frame signal of the L3 frame is in the range 120° < θ 3 < 180° and -180° < θ3 <-30°, and the full-frame signal of the L4 frame is within the range of 30° < θ 4 <180° and -180° < θ 4 <-120°. Then, the signal processing unit SP performs a synthesis process to synthesize the full-frame signals of the L1 - L4 frames. It should be noted that the "synthesis process" is a process of adding the full-frame signals of each frame to generate omnidirectional data. Through the synthesis process, an omnidirectional full-frame signal (hereinafter also referred to as "synthesis signal") can be generated based on the full-frame signals respectively obtained by the scanning of the scanning units L1 - L4.

[0082] Figure 11 Shows the situation where the full-frame signals of the L1 - L4 frames are synthesized. When the distance to the vehicle is very close, there is an undetectable area not covered by the L1 - L4 frames. Figure 12 Schematically shows for Figure 11 A farther area (i.e., a larger distance "r") the situation where the full-frame signals of the L1 - L4 frames are synthesized. As shown in the figure, there are two-frame synthesis areas and three-frame synthesis areas.

[0083] Figure 13 Shows the synthesis signal obtained through the synthesis process in the rθ coordinate system. The synthesis signal includes two-frame synthesis areas and three-frame synthesis areas. For the synthesis areas of multiple frames, the signal processing unit SP performs an averaging process to average the multiple full-frame signals. That is, the signal processing unit SP adds and averages the segmented signals Sseg supplied by each optical transmission / reception unit TR. This can reduce the noise respectively generated by the light receiving elements 16 of the optical transmission / reception unit TR.

[0084] (Second Embodiment)

[0085] Figure 14 Is a plan view showing the operation of the scanning unit L1 according to the second embodiment. Assuming that the traveling direction of the vehicle is θ = 0, the scanning unit L1 has a horizontal viewing angle range from θ a =-90° to θ b =180°, that is, 270°. On the other hand, due to the vehicle body, the range of -180° < θ 1 <-90° becomes a blind spot. The signal processing unit SP obtains the full-frame signal of the L1 frame with this horizontal viewing angle.

[0086] The signal processing unit SP converts the full-frame signals of the L2 - L4 frames generated by the scanning units L2 - L4 into full-frame signals in the rθ coordinate frame in the same way. In the second embodiment, the full-frame signal of the L2 frame is within the range of -180° < θ 2 <90°, the full-frame signal of the L3 frame is within the range of 90° < θ 3 <180° and -180° < θ3 <in the range of 0°, and the full-frame signal of the L4 frame is at 0° < θ 4 <in the range of 270°. Then, the signal processing unit SP performs synthesis processing to synthesize the full-frame signals of the L1-L4 frames.

[0087] Figure 15 Schematically shows the state where the full-frame signals of the L1-L4 frames are synthesized. Compared with Figure 11 it can be seen that in the second embodiment, there is no non-detectable area near the vehicle. Figure 16 Schematically shows the state where the full-frame signals of the L1-L4 frames are synthesized in a farther range (larger distance "r").

[0088] [Comparison with the prior art]

[0089] Figure 17A and Figure 17B shows the way of detecting an object by the lidar installed on the vehicle roof. If the multi-layer lidar 40 is installed on the roof, as Figure 17A shown, an object 42 that is very close to the vehicle and at a lower position cannot be detected. Similarly, if the single-layer lidar 41 is installed on the roof, as Figure 17B shown, an object 43 that is farther from the vehicle and at a lower position cannot be detected.

[0090] Figure 18A and Figure 18B shows the way of detecting an object by the scanning unit L incorporated in the lighting unit of the vehicle as in the embodiment described above. According to the embodiment, with a single-layer lidar, an object 42 that is very close to the vehicle and at a lower position can be detected, as Figure 18A shown, and an object 43 that is farther from the vehicle and at a lower position can be detected, as Figure 18B shown.

[0091] Patent documents 1 and 2 will be described below. As disclosed in Patent Document 1, lidars are usually installed at a higher position on the vehicle to obtain omnidirectional information. However, in this case, information on lower positions as shown in Figure 17A and Figure 17B cannot be obtained. In addition, although Patent Document 2 discloses an example in which lidars are installed in two headlight units of the vehicle, due to the influence of the vehicle body, omnidirectional (mainly rear direction) information cannot be obtained.

[0092] Furthermore, since the objective of the lidar in Patent Document 2 is to detect obstacles in front to avoid collisions, it may not be necessary to obtain omnidirectional information. In other words, it is sufficient if information about the driving direction can be obtained. In contrast, the lidar of the present invention can obtain more information than the lidar used in Patent Document 2. For example, the lidar of the present invention can identify the detailed shapes of surrounding ground objects. Therefore, since the lidar of the present invention can be used, for example, to update map information, rather than just avoiding collisions, omnidirectional information needs to be obtained.

[0093] It can be presumed that the lidar in Patent Document 2 emits laser light with a wide angle in one direction and detects the intensity of the returned light to detect the presence / absence of an object (which returns the light), and there is no component corresponding to the scanning unit. Therefore, it can be presumed that the lidar in Patent Document 2 can measure the distance to an object, but cannot obtain information about the angle and / or point cloud information of a specific object. It can be presumed that each lidar in Patent Document 2 can only detect obstacles independently.

[0094] [Examples of improvements]

[0095] Although in the above embodiment, the single-layer lidar including the scanning unit L and the light transmission / reception unit TR is provided at the four corners of the vehicle, a multi-layer lidar can also be provided. Figure 19A and Figure 19B shows the way of detecting an object in this case. It is possible to detect an object 42 at a short distance and at a lower position, as Figure 19A shown, and it is also possible to detect an object 43 at a long distance and at a lower position, as Figure 19B shown.

[0096] Industrial Applicability

[0097] The present invention can be applied to a technique for obtaining information about the surrounding environment by emitting laser light.

Claims

1. An information processing device, comprising: a plurality of optical transmission / reception units, each of the optical transmission / reception units being mounted on a vehicle, each of the optical transmission / reception units including a transmission unit configured to emit light, a scanning unit configured to scan the light emitted by the transmission unit within a scanning range, and a light reception unit configured to receive the light reflected by an object and generate a light reception result for the entire scanning range; and an information processing unit configured to convert each of the light reception results of the light reception units into conversion information based on a predetermined position of the vehicle, and perform a synthesis process of synthesizing each piece of the conversion information into an omnidirectional signal, the synthesis process being a process of adding and averaging the conversion information of each frame to generate the omnidirectional signal.

2. The information processing device according to claim 1, wherein the information processing unit obtains at least one of a distance to the object and an angle relative to the object from the result of the synthesis process.

3. The information processing device according to claim 2, wherein if the scanning ranges of the plurality of optical transmission / reception units overlap, the information processing unit performs an averaging process on the light reception results of the light reception units of the plurality of optical transmission / reception units for the overlapping range.

4. The information processing device according to claim 1, wherein the number of the plurality of optical transmission / reception units is four, and wherein the plurality of optical transmission / reception units are provided in a lighting unit of the vehicle.

5. An information processing method executed by an information processing device, the information processing device including a plurality of optical transmission / reception units, each of the optical transmission / reception units being mounted on a vehicle, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit, the method comprising: a transmission / reception process executed by each of the optical transmission / reception units, the transmission / reception process including a transmission process of emitting light rays from the transmission unit, a scanning process of scanning the light emitted by the transmission unit within a scanning range by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit and generating a light reception result for the entire scanning range; and an information processing process of converting each of the light reception results of the light reception process into conversion information based on a predetermined position of the vehicle, and performing a synthesis process of synthesizing each piece of the conversion information into an omnidirectional signal, the synthesis process being a process of adding and averaging the conversion information of each frame to generate the omnidirectional signal.

6. A storage medium storing a program executed by an information processing device, the information processing device comprising: a plurality of optical transmission / reception units, each of the optical transmission / reception units being mounted on a vehicle, each of the optical transmission / reception units including a transmission unit, a scanning unit, and a light reception unit; and a computer, the program causing the computer to execute: The transmission / reception process performed by each of the optical transmission / reception units, which includes a transmission process of emitting light rays from the emission unit, a scanning process of scanning the light emitted by the emission unit within a scanning range by the scanning unit, and a light reception process of receiving the light reflected by an object by the light reception unit and generating a light reception result for the entire scanning range; and An information processing process that converts each of the light reception results in the light reception process into conversion information based on a predetermined position of the vehicle, and performs a synthesis process of synthesizing each piece of the conversion information into an omnidirectional signal. The synthesis process is a process of adding and averaging the conversion information of each frame to generate the omnidirectional signal.

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