An automotive pulsed lidar ranging system

Abstract

The present invention discloses an automotive pulsed lidar ranging system. In this system, the main controller issues a detection start signal to start the pulse gate control circuit. The pulse gate control circuit triggers the counter / timer circuit to start counting. The pulse drive power supply outputs a pulse signal, and the pulsed laser part emits pulsed laser light. After the pulsed laser detects a moving vehicle, a reflected light signal is generated. The APD detection part detects the reflected light signal and converts it into an analog alternating voltage signal. The pulse voltage signal is amplified by the amplifier circuit to form a digital pulse signal, which is input into the counter / timer circuit to trigger the counter / timer circuit to stop working. The main controller ARM reads the data information of the counter / timer circuit through the data buffer circuit. The structure of the present invention is simple and the manufacturing cost is low, which is suitable for application in the high beam of automotive headlights.

Description

Technical Field

[0001] The invention belongs to the technical field of automobiles, and in particular relates to an automobile pulse laser radar ranging system. Background Art

[0002] LiDAR is widely used in the field of navigation, such as: automatic driving of cars. The application scenarios are constantly expanding, breaking the situation that it was originally limited to the military field, and it has developed rapidly in the civil and commercial fields. Taking the Chinese market as an example, in the civil and commercial fields, there has been a long-term shortage of LiDAR. It is still in its infancy, with few market participants and a small market size. The biggest advantage of LiDAR positioning is low cost and relatively simple technical solutions. It is indirectly positioned by identifying the moving vehicle as a reference. The problem is that the phased array LiDAR for accurate ranging and positioning is expensive, because the external environment transmits digital information by measuring, specifically the time difference, and the digital information is positioned by identifying objects. LiDAR is the mainstream sensor currently selected for positioning. Commercial products of indoor sweepers with autonomous navigation are generally equipped with LiDAR. In the field of autonomous driving, high-precision ranging acquisition and positioning applications, simple LiDAR solutions have cost advantages. LiDAR is divided into single-line and multi-line. Single-line radar can only scan obstacles on one plane through a combination of multiple scanning surfaces. The points scanned by the laser have highly accurate depth information, so when doing back-end loop optimization, there is no need to optimize the observation values ​​in a certain position.

[0003] LiDAR technology still needs to be improved and enhanced, such as reducing the overall cost and opening up the market in other new fields. The LiDAR market needs to be expanded in the future, especially as the development of driverless cars is gaining more and more attention, and there is no lack of support for technology development and application. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a vehicle-mounted pulsed laser radar ranging method and system, which can solve technical problems such as judging the distance to the vehicle in front of an automatic driving car.

[0005] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0006] An automobile pulse laser radar ranging system, including a main controller ARM, a pulse driving power supply, a pulse laser part, a pulse gate control circuit, an APD detection part, a second optical lens, an amplifier circuit, a counter / timer circuit and a data buffer circuit;

[0007] The master controller ARM sends out a detection start signal, which starts the pulse gate control circuit. The pulse gate control circuit triggers the counter / timer circuit to start counting. The pulse drive power supply outputs a pulse signal, and the pulsed laser part emits pulsed laser. After the pulsed laser detects a moving vehicle, a reflected light signal is generated. The APD detection part detects the reflected light signal and converts it into an analog alternating voltage signal. The pulse voltage signal is amplified by the amplifier circuit to form a digital pulse signal APD-enable, which is input into the counter / timer circuit to trigger the counter / timer circuit to stop working;

[0008] The master controller ARM reads the data information of the counter / timer circuit through the data buffer circuit.

[0009] Further, the counter / timer circuit includes a crystal oscillator CZ10, a first capacitor C1, a second capacitor C2, a first R-S flip-flop U-10, a second R-S flip-flop U-13, a first NOT gate U-11, a second NOT gate U-14, a level conversion circuit U-12, and n + 1 counters U0 to Un;

[0010] The n + 1 counters U0 to Un are all JK flip-flops;

[0011] The crystal oscillator CZ10, the first capacitor C1, and the second capacitor C2 form a pulse generator circuit. The two ends of the crystal oscillator CZ10 are respectively connected to the first capacitor C1 and the second capacitor C2. The other ends of the first capacitor C1 and the second capacitor C2 are both grounded. The two ends of the crystal oscillator CZ10 are respectively connected to the first input terminal AS1 and the second input terminal AS2 of the level conversion circuit U-12. The output terminal CP of the level conversion circuit U-12 is output to the clock input terminal of the first counter U0;

[0012] The output Q10 of the first R-S flip-flop U-10 is respectively connected to the J terminals of the n + 1 counters U0 to Un, and the output Q13 of the second R-S flip-flop U-13 is respectively connected to the K terminals of the n + 1 counters U0 to Un;

[0013] Among the n + 1 counters U1 to Un, the Q-terminal output Q0 of the first counter U0 is input into the data buffer circuit and the clock input terminal of the second counter U1. The Q-terminal output Q1 of the second counter U1 is input into the data buffer circuit and the clock input terminal of the third counter U2, and so on. The Q-terminal output Qn of the last counter Un is input into the data buffer circuit;

[0014] The pulse gate control circuit sends the L-enable signal directly to the R terminal of the first R-S flip-flop U-10, and after passing through the first NOT gate U-11, it is input to the S terminal of the first R-S flip-flop U-10. At this time, the output Q10 of the first R-S flip-flop U-10 is at the "1" level, the output Q of the second R-S flip-flop U-13 is at the "0" level, and the n + 1 counters U0 to Un start counting. There is a corresponding relationship between the pulse frequency of the pulse generator circuit and the counting time, that is, the duty cycle of each pulse of the pulse generator circuit corresponds to the time;

[0015] When the digital pulse signal APD-enable pulse is input, the digital pulse signal APD-enable is directly input to the R terminal of the second R-S flip-flop U-13, and after passing through the second NOT gate U-14, it is input to the S terminal of the second R-S flip-flop U-13. At this time, the output Q13 of the second R-S flip-flop U-13 is at the "1" level;

[0016] When the output Q10 of the first R-S flip-flop U-10 is at the "1" level and the output Q13 of the second R-S flip-flop U-13 is at the "1" level, the n + 1 counters U0 to Un stop counting.

[0017] Further, the main controller ARM sends a read control signal CS1 to the data buffer circuit to read the pulse numbers D0 to Dn output by the data buffer circuit.

[0018] Further, the pulsed laser part includes a VCSEL laser diode and a first optical lens;

[0019] The VCSEL laser diode emits a laser signal that is detected by the first optical lens for a moving vehicle, generating a reflected light signal.

[0020] Further, the APD detection part receives the reflected light signal. The APD detection part includes an APD photosensitive element and a second optical lens. The reflected light signal passes through the second optical lens and is converted into an analog voltage signal by the APD photosensitive element.

[0021] Further, the amplifier circuit amplifies the analog voltage signal until it reaches saturation and outputs it, forming a pulsed digital signal APD-enable.

[0022] Further, in the counter / timer circuit, the corresponding relationship between counting and timing adopts a single count and timing of one microsecond (μS) or millisecond (mS), and it can also be designed according to needs. The specific implementation steps are:

[0023] A microsecond (μS) or millisecond (mS) level counter / timer is designed using a chip. The oscillation frequency of the crystal oscillator CZ-10 is selected to design a multi-digit counter. One count in the multi-digit counter represents one microsecond (μS) or millisecond (mS). The corresponding time can be obtained through the counted data. There is a corresponding relationship between the pulse frequency of the pulse generator circuit and the counting time, that is, the duty cycle of each pulse in the pulse generator circuit corresponds to the time.

[0024] Furthermore, the time when the vehicle returns to the detector is detected by cycling and detecting the pulse signal M times, and the average value of the M detection results is taken as the final detection result, that is, a filtering effect in the form of an average value is adopted to avoid the generation of interference signals and ensure the accuracy of the detection data.

[0025] Furthermore, the chip uses the Artix series FPGA chip of XILINX, and a multi-digit counter is designed through FPGA programming software.

[0026] Furthermore, the multi-digit counter is an 8-bit, 16-bit, 32-bit or 64-bit counter of binary numbers, corresponding to decimal 2 8 = 256, 2 16 = 65536, 2 32 = 4294967296, and 2 64 = 18446744073709551616.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The automotive lidar ranging system provided by the present invention has a simple structure and low manufacturing cost, and is suitable for application in the high beam of automotive headlights. The simple circuit counting / timer circuit structure of the present invention can measure the relative position of a moving vehicle. By using a laser for ranging, it has characteristics such as a small emission angle and concentrated emission energy. It can achieve a longer emission and detection distance. By using multiple groups of lasers for emission and detection, the distance and position of a moving vehicle can be accurately detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of an automotive pulsed lidar ranging system in an embodiment of the present invention;

[0030] Figure 2 It is a schematic structural diagram of the counter / timer circuit and data buffer circuit in an embodiment of the present invention;

[0031] Figure 3 It is a schematic structural diagram and schematic principle diagram of the APD detection part and pulsed laser part in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the following examples are provided in conjunction with the accompanying drawings to elaborate on the specific implementation of the present invention in detail.

[0033] In the following description, the technical solutions are elaborated in conjunction with specific illustrations to fully understand the present invention application. However, the present application can be implemented in many other ways different from those described herein. Similar extended embodiments made by those of ordinary skill in the art without creative efforts all fall within the scope of protection of the present invention.

[0034] Embodiment:

[0035] An automotive pulsed lidar ranging system, as Figure 1 shown, includes a main controller ARM, a pulsed drive power supply, a pulsed laser part, a pulsed gate control circuit, an APD detection part, a second optical lens, an amplifier circuit, a counter / timer circuit 106, and a data buffer circuit 107;

[0036] The main controller ARM issues a detection start signal. The detection start signal starts the pulsed gate control circuit. The pulsed gate control circuit triggers the counter / timer circuit 106 to start counting. The pulsed drive power supply outputs a pulsed signal. The pulsed laser part emits pulsed laser light. After the pulsed laser light detects a moving vehicle, a reflected light signal is generated. The APD detection part detects the reflected light signal and converts it into an analog alternating voltage signal. The pulsed voltage signal is amplified by the amplifier circuit to form a digital pulsed signal APD-enable, which is input into the counter / timer circuit 106 to trigger the counter / timer circuit 106 to stop working;

[0037] The main controller ARM reads the data information of the counter / timer circuit 106 through the data buffer circuit 107.

[0038] As Figure 2 shown, the counter / timer circuit includes a crystal oscillator CZ10, a first capacitor C1, a second capacitor C2, a first R-S flip-flop U-10, a second R-S flip-flop U-13, a first NOT gate U-11, a second NOT gate U-14, a level conversion circuit U-12, and n + 1 counters U0 to Un;

[0039] The n + 1 counters U0 to Un are all JK flip-flops;

[0040] The crystal oscillator CZ10, the first capacitor C1, and the second capacitor C2 form a pulse generator circuit. The two ends of the crystal oscillator CZ10 are respectively connected to the first capacitor C1 and the second capacitor C2, and the other ends of the first capacitor C1 and the second capacitor C2 are both grounded. The two ends of the crystal oscillator CZ10 are respectively connected to the first input terminal AS1 and the second input terminal AS2 of the level conversion circuit U-12, and the output terminal CP of the level conversion circuit U-12 outputs to the clock input terminal of the first counter U0;

[0041] The output Q10 of the first R-S flip-flop U-10 is respectively connected to the J terminals of n+1 counters U0~Un, and the output Q13 of the second R-S flip-flop U-13 is respectively connected to the K terminals of n+1 counters U0~Un;

[0042] Among the n+1 counters U1~Un, the Q-terminal output Q0 of the first counter U0 is input to the data buffer circuit and the clock input terminal of the second counter U1. The Q-terminal output Q1 of the second counter U1 is input to the data buffer circuit and the clock input terminal of the third counter U2, and so on. The Q-terminal output Qn of the last counter Un is input to the data buffer circuit;

[0043] The pulse gate control circuit issues an L-enable signal and directly inputs it to the R terminal of the first R-S flip-flop U-10, and after passing through the first NOT gate U-11, it is input to the S terminal of the first R-S flip-flop U-10. At this time, the output Q10 of the first R-S flip-flop U-10 is at the "1" level, the output Q of the second R-S flip-flop U-13 is at the "0" level, and the n+1 counters U0~Un start to count. The pulse frequency of the pulse generator circuit has a corresponding relationship with the counting time, that is, the duty cycle of each pulse of the pulse generator circuit corresponds to the time;

[0044] When the digital pulse signal APD-enable pulse is input, the digital pulse signal APD-enable is directly input to the R terminal of the second R-S flip-flop U-13, and after passing through the second NOT gate U-14, it is input to the S terminal of the second R-S flip-flop U-13. At this time, the output Q13 of the second R-S flip-flop U-13 is at the "1" level;

[0045] When the output Q10 of the first R-S flip-flop U-10 is at the "1" level and the output Q13 of the second R-S flip-flop U-13 is at the "1" level, the n+1 counters U0~Un stop counting.

[0046] The main controller ARM issues a read control signal CS1 to the data buffer circuit 107 to read the pulse numbers D0~Dn output by the data buffer circuit 107.

[0047] Such as Figure 3As shown, the pulsed laser section 103 includes a VCSEL laser diode and a first optical lens;

[0048] The VCSEL laser diode emits a laser signal 102 that is detected by the first optical lens for the moving vehicle 101, generating a reflected light signal 105.

[0049] As Figure 3 shown, the APD detection section 104 receives the reflected light signal 105. The APD detection section includes an APD photosensitive element and a second optical lens. The reflected light signal 105 passes through the second optical lens and is converted into an analog voltage signal by the APD photosensitive element.

[0050] The amplifier circuit amplifies the analog voltage signal until it reaches saturation and outputs it, forming a pulsed digital signal APD-enable.

[0051] In the counter / timer circuit 106, the corresponding relationship between counting and timing uses a single count and timing of one microsecond (μS). It can also be designed as needed. The specific implementation steps are as follows:

[0052] Use a chip to design a counter / timer at the microsecond (μS) level. Select the oscillation frequency of the crystal oscillator CZ-10 and design a multi-digit counter. One count in the multi-digit counter is one microsecond (μS). The corresponding time can be obtained through the counting data. The pulse frequency of the pulse generator circuit has a corresponding relationship with the counting time, that is, the duty cycle of each pulse of the pulse generator circuit corresponds to the time.

[0053] Detect M times in a loop, and take the average of the M detection results as the final detection result. That is, use the filtering effect in the form of an average to avoid the generation of interference signals and ensure the accuracy of the detection data.

[0054] The chip uses an Artix series FPGA chip from XILINX, and designs a multi-digit counter through FPGA programming software.

[0055] The multi-digit counter is an 8-bit counter of binary numbers, corresponding to decimal 2 8 = 256.

[0056] Embodiment 2:

[0057] In this embodiment, in the counter / timer circuit 106, the corresponding relationship between counting and timing uses a single count and timing of one millisecond (mS). It can also be designed as needed. The specific implementation steps are as follows:

[0058] A chip is used to design a counter / timer at the millisecond (mS) level. The oscillation frequency of the crystal oscillator CZ-10 is selected to design a multi-digit counter. One count in the multi-digit counter represents one millisecond (mS). The corresponding time can be obtained through the counting data. There is a corresponding relationship between the pulse frequency of the pulse generator circuit and the counting time, that is, the duty cycle of each pulse in the pulse generator circuit corresponds to the time.

[0059] In this embodiment, the multi-digit counter is a 16-bit counter of binary numbers, corresponding to decimal 2 16 = 65536.

[0060] Embodiment 3:

[0061] In this embodiment, the multi-digit counter is a 32-bit counter of binary numbers, corresponding to decimal 2 32 = 4294967296.

[0062] The preferred embodiments of the present application disclosed above are only used to help understand the present invention and its core idea. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in specific application scenarios and implementation operations. This specification should not be construed as a limitation to the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. An automotive pulsed lidar ranging system, characterized in that, It includes a main controller ARM, a pulse drive power supply, a pulsed laser section, a pulse gate control circuit, an APD detection section, a second optical lens, an amplifier circuit, a counter / timer circuit, and a data buffer circuit; The main controller ARM sends out a detection start signal. The detection start signal starts the pulse gate control circuit. The pulse gate control circuit triggers the counter / timer circuit to start counting. The pulse drive power supply outputs a pulse signal. The pulsed laser section emits pulsed laser light. After the pulsed laser light detects a moving vehicle, a reflected light signal is generated. The APD detection section detects the reflected light signal and converts it into an analog alternating voltage signal. The amplifier circuit amplifies the pulsed voltage signal to form a digital pulse signal APD-enable, which is input into the counter / timer circuit to trigger the counter / timer circuit to stop working; The main controller ARM reads the data information of the counter / timer circuit through the data buffer circuit; The counter / timer circuit includes a crystal oscillator CZ10, a first capacitor C1, a second capacitor C2, a first R-S flip-flop U-10, a second R-S flip-flop U-13, a first NOT gate U-11, a second NOT gate U-14, a level conversion circuit U-12, and n + 1 counters U0 to Un; The n + 1 counters U0 to Un are all JK flip-flops; The crystal oscillator CZ10, the first capacitor C1, and the second capacitor C2 form a pulse generator circuit. The two ends of the crystal oscillator CZ10 are respectively connected to the first capacitor C1 and the second capacitor C2. The other ends of the first capacitor C1 and the second capacitor C2 are both grounded. The two ends of the crystal oscillator CZ10 are respectively connected to the first input terminal AS1 and the second input terminal AS2 of the level conversion circuit U-12. The output terminal CP of the level conversion circuit U-12 outputs to the clock input terminal of the first counter U0; The output Q10 of the first R-S flip-flop U-10 is respectively connected to the J terminals of the n + 1 counters U0 to Un. The output Q13 of the second R-S flip-flop U-13 is respectively connected to the K terminals of the n + 1 counters U0 to Un; Among the n + 1 counters U0 to Un, the Q output Q0 of the first counter U0 is input into the data buffer circuit and the clock input terminal of the second counter U1. The Q output Q1 of the second counter U1 is input into the data buffer circuit and the clock input terminal of the third counter U2, and so on. The Q output Qn of the last counter Un is input into the data buffer circuit; The pulse gate control circuit sends out an L-enable signal and directly inputs it to the R terminal of the first R-S flip-flop U-10, and after passing through the first NOT gate U-11, it is input into the S terminal of the first R-S flip-flop U-10. At this time, the output Q10 of the first R-S flip-flop U-10 is at the "1" level, the output Q of the second R-S flip-flop U-13 is at the "0" level, and the n + 1 counters U0 to Un start counting. The pulse frequency of the pulse generator circuit has a corresponding relationship with the counting time, that is, the duty cycle of each pulse of the pulse generator circuit corresponds to the time; When a digital pulse signal APD - enable is pulsed in, the digital pulse signal APD - enable is directly input to the R terminal of the second R - S flip - flop U - 13, and after passing through the second NOT gate U - 14, it is input to the S terminal of the second R - S flip - flop U - 13. At this time, the output Q13 of the second R - S flip - flop U - 13 is at the "1" level; When the output Q10 of the first R - S flip - flop U - 10 is at the "1" level and the output Q13 of the second R - S flip - flop U - 13 is at the "1" level, the n + 1 counters U0 to Un stop counting.

2. The pulsed lidar ranging system for vehicle according to claim 1, wherein The main controller ARM sends a read control signal CS1 to the data buffer circuit to read the pulse numbers D0 to Dn output by the data buffer circuit.

3. A pulsed lidar ranging system for an automobile according to claim 1, characterized in that, The pulsed laser part includes a VCSEL laser diode and a first optical lens; The VCSEL laser diode emits a laser signal that is detected by the first optical lens to the moving vehicle, generating a reflected light signal.

4. A pulsed lidar ranging system for an automobile according to claim 1, characterized in that, The APD detection part receives the reflected light signal. The APD detection part includes an APD photosensitive element and a second optical lens. The reflected light signal passes through the second optical lens and is converted into an analog voltage signal by the APD photosensitive element.

5. The pulsed lidar ranging system for vehicle according to claim 4, wherein The amplifier circuit amplifies the analog voltage signal until it reaches saturation and outputs it, forming a pulsed digital signal APD - enable.

6. The pulsed lidar ranging system for vehicle according to claim 1, wherein In the counter / timer circuit, the corresponding relationship between counting and timing uses a single count and timing as one microsecond (μS) or millisecond (mS). The specific implementation steps are as follows: Use a chip to design a counter / timer at the microsecond (μS) or millisecond (mS) level. Select the oscillation frequency of the crystal oscillator CZ - 10 and design a multi - digit counter. One count in the multi - digit counter is one microsecond (μS) or millisecond (mS). The corresponding time can be obtained through the counting data. The pulse frequency of the pulse generator circuit has a corresponding relationship with the counting time, that is, the duty cycle of each pulse of the pulse generator circuit corresponds to the time.

7. A pulsed lidar ranging system for an automobile according to claim 6, characterized in that, Circularly detect the time when the pulsed signal detects the vehicle returning to the detector M times, and obtain the average of the M detection results as the final detection result, that is, adopt the filtering effect in the form of an average to avoid the generation of interference signals and ensure the accuracy of the detection data.

8. A pulsed lidar ranging system for an automobile according to claim 6, characterized in that, The chip uses the Artix series FPGA chip of XILINX, and designs a multi - digit counter through the FPGA programming software.

9. The pulsed lidar ranging system for vehicle according to claim 6, wherein, The multi - digit counter is an 8 - bit, 16 - bit, 32 - bit or 64 - bit counter for binary numbers, corresponding to decimal 2 8 = 256, 2 16 = 65536, 2 32 = 4294967296, and 2 64 = 18446744073709551616.

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