Laser radar ranging method, device, electronic equipment and storage medium

Abstract

The present application is applicable to the field of distance measurement technology, and provides a laser radar distance measurement method, device, electronic device and storage medium, including: transmitting M laser pulses to a target object, M being a natural number greater than 0; receiving M echoes formed by the target object reflecting the M laser pulses; generating M electrical signals according to the M echoes; generating M×N amplified signals according to the M electrical signals; the M×N amplified signals are generated by each of the N amplifying subcircuits amplifying the M electrical signals respectively; the amplification coefficients of the N amplifying subcircuits are different, N being a natural number greater than 1; determining the distance of the target object according to the M×N amplified signals. The present application can increase the system's distance measurement range and the ability to measure objects with different reflectivity.

Description

Technical Field

[0001] The present application belongs to the field of distance measurement technology, and in particular, relates to a laser radar distance measurement method, device, electronic equipment and storage medium. Background Art

[0002] At present, LiDAR mainly uses triangulation and TOF (Time Of Flight) to measure distance. Among them, TOF has a wider range of applications. TOF has two solutions: phase and pulse. The pulse solution is widely used in the radar market. The current pulse solution is suitable for close-range objects and high-emissivity objects, and the ranging range and measurement capabilities are limited. Summary of the invention

[0003] The embodiments of the present application provide a laser radar ranging method, device, electronic device and storage medium, which can increase the system's ranging range and the ability to measure objects with different reflectivity.

[0004] In a first aspect, an embodiment of the present application provides a laser radar ranging method, comprising: transmitting M laser pulses to a target object, where M is a natural number greater than 0;

[0005] Receiving M echoes formed by the target object reflecting the M laser pulses;

[0006] generating M electrical signals according to the M echoes;

[0007] Generate M×N amplified signals according to the M electrical signals; the M×N amplified signals are generated by each of the N amplifying sub-circuits amplifying the M electrical signals respectively; the amplification coefficients of the N amplifying sub-circuits are different, and N is a natural number greater than 1;

[0008] The distance of the target object is determined according to the M×N amplified signals.

[0009] In a possible implementation manner of the first aspect, determining the distance of the target object according to the M×N amplified signals includes:

[0010] Generate at least one comparison signal according to the M×N amplified signals; the at least one comparison signal is generated by a comparator;

[0011] The distance of the target object is determined based on one of the at least one comparison signal.

[0012] In a possible implementation of the first aspect, transmitting M laser pulses to the target object includes: transmitting M laser pulses with different powers to the target object;

[0013] Determining the distance of the target object according to a comparison signal of the at least one comparison signal comprises:

[0014] Selecting a comparison signal whose signal strength is closest to the set signal strength from the at least one comparison signal as a ranging echo pulse;

[0015] The distance of the target object is determined according to the ranging echo pulse.

[0016] In a possible implementation manner of the first aspect, the method further includes:

[0017] According to the power of the laser pulse corresponding to the ranging echo pulse, searching from the preset first data for the reflectivity corresponding to the power of the laser pulse as the measured reflectivity of the target object;

[0018] The first data is data of power and distance from the material when the laser pulse irradiates materials with different reflectivities when the signal strength of the echo is the set signal strength.

[0019] In a second aspect, an embodiment of the present application provides a laser radar ranging device, comprising:

[0020] A transmitting unit, used for transmitting M laser pulses to a target object, where M is a natural number greater than 0;

[0021] A receiving unit, configured to receive M echoes formed by the target object reflecting the M laser pulses;

[0022] A signal processing device, used to: generate M electrical signals according to the M echoes, and generate M×N amplified signals according to the M electrical signals; the M×N amplified signals are generated after each of the N amplifying sub-circuits amplifies the M electrical signals; the amplification coefficients of the N amplifying sub-circuits are different, and N is a natural number greater than 1; the signal processing device includes the N amplifying sub-circuits;

[0023] The distance determining device is used to determine the distance of the target object according to the M×N amplified signals.

[0024] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the methods described in the first aspect when executing the computer program.

[0025] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any one of the above-mentioned first aspects is implemented.

[0026] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the terminal device to execute any of the methods described in the first aspect above.

[0027] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0028] M laser pulses are emitted to the target object, and M electrical signals are generated based on the M received echoes. N amplifying subcircuits with different amplification factors generate M×N amplified signals based on the M electrical signals, and the distance of the target object is determined based on the M×N amplified signals. When measuring close objects and objects with high reflectivity, the pulse width of the amplified signal generated by the amplifying subcircuit with a smaller amplification factor is normal and can meet the measurement accuracy. When the laser measures objects with low reflectivity and objects at a distance, the amplifying subcircuit with a larger amplification factor will amplify the weak signal to a specified level, thereby completing the distance measurement. In this way, in the actual distance measurement process, the amplification with a larger amplification factor ensures that low reflectivity objects and objects at a distance can be measured, and the amplification with a smaller amplification factor is used to measure high reflectivity objects, which can effectively improve the dynamic range of the entire system, increase the system's distance measurement range and the ability to measure objects with different reflectivities.

[0029] Some possible implementations of the embodiments of the present application have the following beneficial effects:

[0030] M laser pulses with different powers are emitted to the target object, M electrical signals are generated according to the M received echoes, N amplification subcircuits with different amplification factors generate M×N amplified signals according to the M electrical signals, at least one comparison signal is generated through a comparator according to the M×N amplified signals, and a comparison signal with a signal strength closest to the set signal strength is selected from the comparison signals as the ranging echo pulse, so that the echo strength at different distances remains unchanged, and the function of dynamically adjusting power is realized. The dynamic power adjustment mode can ensure that the signal strength within the measurement range is maintained within a certain range, and can reduce the ranging offset caused by the change of signal strength, thereby improving the ranging accuracy.

[0031] According to the power of the laser pulse corresponding to the ranging echo pulse, the reflectivity corresponding to the power of the laser pulse is searched from the preset first data as the measured reflectivity of the target object. The relative strength of the reflectivity of the target object can be calculated, and the position of the target object can be determined from different objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 It is a flowchart of the laser radar ranging method provided in Example 1 of the present application;

[0034] Figure 2 This is a flow chart of a variant of the laser radar ranging method provided in Example 1 of the present application;

[0035] Figure 3 It is a flowchart of the laser radar ranging method provided in Example 2 of the present application;

[0036] Figure 4 It is a schematic diagram of the structure of the laser radar ranging device provided in Example 1 of the present application;

[0037] Figure 5 is a waveform diagram of a signal processed by the comparator provided in Embodiment 1 of the present application;

[0038] Figure 6 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0039] Figure 7 This is a power-distance curve diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the following Figures 1 to 7 It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0042] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0043] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0044] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0045] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0046] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0047] Embodiment 1

[0048] This embodiment provides a laser radar ranging method, specifically a ranging method with dynamically adjusted power, which is used to measure the distance of a target object 200; the target object 200 is an object that can reflect laser, such as a high-reflectivity positioning plate, wherein the reflection can be diffuse reflection or total reflection.

[0049] Figure 1A schematic flow chart of the laser radar ranging method provided in this embodiment is shown. As an example but not a limitation, the method can be applied to the laser radar ranging device 100. The laser radar ranging device 100 provided in this embodiment corresponds to the laser radar ranging method provided in this embodiment.

[0050] refer to Figure 4 The laser radar ranging device 100 provided in this embodiment includes a transmitting unit 11, a receiving unit 12, a signal processing device 13 and a distance determining device 14.

[0051] The laser radar ranging method provided in this embodiment includes steps S11 to S14, and the method is performed by the laser radar ranging device 100. The present embodiment is described below in combination with the laser radar ranging method and the laser radar ranging device 100 provided in this embodiment.

[0052] Step S11, transmitting M laser pulses to the target object, where M is a natural number greater than 0.

[0053] The laser radar ranging device 100 emits a laser pulse to the target object 200. Figure 4 The transmitting unit 11 includes a pulse laser 111 and a transmitting side optical device 112; wherein the pulse laser 111 is a pulsed LD (LaserDiode, laser semiconductor) laser. When it is necessary to measure the target object 200, the pulse laser 111 of the transmitting unit 11 emits a laser pulse; the laser pulse is irradiated to the target object 200 by the transmitting side optical device 112, specifically, to the surface of the target object 200; in this process, the transmitting side optical device 112 focuses and / or shapes the laser pulse, so the transmitting side optical device 112 can be a lens (such as a lens).

[0054] The transmitting unit 11 transmits three laser pulses to the target object 200 in sequence, that is, M is equal to three (in this case, M is a natural number greater than 1, or M≥2 in this case); the powers of the three laser pulses are different. In some other embodiments, the transmitting unit 11 transmits one laser pulse to the target object 200, that is, M is equal to one.

[0055] Step S12, receiving M echoes formed by the target object reflecting the M laser pulses.

[0056] The receiving unit 12 of the laser radar distance measuring device 100 receives the echo formed by the laser pulse reflected by the target object 200. The receiving unit 12 includes a receiving-side optical device 121.

[0057] refer to Figure 4, three laser pulses with different powers emitted successively by the transmitting unit 11 irradiate the surface of the target object 200, and the laser pulses are diffusely reflected on the surface of the target object 200, forming diffusely reflected light as echoes that irradiate the receiving-side optical device 121 of the receiving unit 12, and the receiving-side optical device 121 transmits the three echoes corresponding to the three laser pulses successively to the subsequent signal processing device 13; in this process, the receiving-side optical device 121 focuses and / or shapes the three echoes, and therefore, the receiving-side optical device 121 can be a lens (such as a lens).

[0058] It should be noted that all three echoes are optical signals.

[0059] Step S13: Generate M×N amplified signals according to the M echoes.

[0060] The signal processing device 13 of the laser radar ranging device 100 generates an amplified signal according to the echo transmitted from the receiving unit 12. The signal processing device 13 includes a signal converter 131 and an amplifier circuit 132. The amplifier circuit 132 includes N amplifier subcircuits, specifically a first amplifier subcircuit, a second amplifier subcircuit, ..., an Nth amplifier subcircuit, and the amplification coefficients of the N amplifier subcircuits are different, and N is a natural number greater than 1.

[0061] In this embodiment, the amplifier circuit 132 includes three amplifier sub-circuits, that is, N is equal to three. The three amplifier sub-circuits are respectively a first amplifier sub-circuit, a second amplifier sub-circuit and a third amplifier sub-circuit; wherein, the first amplifier sub-circuit is a first-stage amplifier, the second amplifier sub-circuit is a second-stage amplifier, and the third amplifier sub-circuit is a third-stage amplifier. The amplification factor (or magnification factor) of the second amplifier sub-circuit is greater than the amplification factor of the first amplifier sub-circuit, and the amplification factor of the third amplifier sub-circuit is greater than the amplification factor of the second amplifier sub-circuit; specifically, the amplification factor of the first amplifier sub-circuit is one times, the amplification factor of the second amplifier sub-circuit is ten times the amplification factor of the first amplifier sub-circuit, and the amplification factor of the third amplifier sub-circuit is twenty times the amplification factor of the first amplifier sub-circuit. The amplification factor of each amplifier sub-circuit can be changed and can be determined during actual testing. In some other embodiments, the amplifier circuit 132 includes two amplifier sub-circuits.

[0062] The M×N amplified signals are generated by each of the N amplifying subcircuits amplifying each of the M signals corresponding to the M echoes. In this embodiment, the M signals corresponding to the M echoes are three electrical signals; the M×N amplified signals are specifically 3×3 amplified signals, that is, 9 amplified signals. As mentioned above, the three echoes are all optical signals, and the signal converter 131 of the signal processing device 13 converts the three echoes into three electrical signals. Therefore, the signal converter 131 is a photoelectric converter, specifically an avalanche photodiode (APD), and the avalanche photodiode receives the signal emitted by the pulse laser 111. Based on the above content, step S13 (generating M×N amplified signals according to the M echoes) includes step S131 and step S132.

[0063] Step S131, generating M electrical signals according to the M echoes.

[0064] The receiving unit 12 transmits the three echoes to the signal converter 131 (i.e., an avalanche photodiode) of the signal processing device 13. The signal converter 131 receives the three echoes in sequence, generates three electrical signals (or echo electrical signals) corresponding to the three echoes, and inputs the three electrical signals into the amplifier circuit 132. Of course, after the signal converter 131 generates the signal, the signal can be processed (such as filtered) before being input into the amplifier circuit 132, that is, the content of step S131 includes the aforementioned related processing. In some other embodiments, the number of signal converters 131 is M, and the M signal converters 131 respectively receive M echoes, generate M electrical signals, and input them into the amplifier circuit 132.

[0065] Step S132, generating M×N amplified signals according to the M electrical signals.

[0066] The amplifier circuit 132 receives three electrical signals transmitted by the signal converter 131 (i.e., the avalanche photodiode) and generates nine amplified signals. The nine amplified signals are generated by each of the three amplifying sub-circuits amplifying the three electrical signals respectively. Specifically, each of the three amplifying sub-circuits of the amplifier circuit 132 amplifies each of the three electrical signals to generate nine amplified signals, that is, each electrical signal is amplified by the first amplifying sub-circuit, the second amplifying sub-circuit, and the third amplifying sub-circuit respectively, and each electrical signal corresponds to three amplified signals. It should be noted that the amplifying sub-circuit can be the amplitude of the amplified electrical signal or the power of the amplified electrical signal, and the present embodiment is not limited thereto. If it is the amplitude of the amplified electrical signal, then each amplifying sub-circuit amplifies the amplitude of the electrical signal; if it is the power of the amplified electrical signal, then each amplifying sub-circuit amplifies the power of the electrical signal; that is, the indicators (or electrical parameters) of the amplified electrical signals of each amplifying sub-circuit are the same.

[0067] refer to Figure 4 After the signal processing device 13 of the laser radar ranging device 100 generates M×N amplified signals (nine amplified signals), the M×N amplified signals are transmitted to the distance determination device 14 of the laser radar ranging device 100.

[0068] Step S14: determining the distance of the target object according to the M×N amplified signals.

[0069] The distance determination device 14 receives the M×N amplified signals (nine amplified signals) transmitted by the signal processing device 13 , and calculates the distance of the target object 200 , specifically, the distance between the target object 200 and the laser radar ranging device 100 .

[0070] The nine amplified signals are analog signals, and in order to calculate the distance of the target object 200, the analog signals need to be converted into digital signals. To this end, in this embodiment, the distance determination device 14 includes a comparator 141 and a calculation and processing device 142. Accordingly, step S14 (determining the distance of the target object according to the M×N amplified signals) includes step S141 and step S142.

[0071] Step S141 , generating at least one comparison signal according to the M×N amplified signals.

[0072] The number of comparators 141 of the distance determination device 14 is nine (M×N). One amplified signal is input into one comparator 141. After receiving the input amplified signal, each comparator 141 operates on the amplified signal, generates and outputs a comparison result, and obtains nine comparison results; these nine comparison results are nine comparison signals, all of which are digital signals (such as rectangular wave signals) with high and low levels. In some other embodiments, some of the nine amplified signals fail to trigger the comparator, such as the amplitude of the amplified signal is less than the set amplitude of the comparator, then the number of comparison signals generated by the comparator is less than nine.

[0073] Step S142: determining the distance of the target object according to a comparison signal of the at least one comparison signal.

[0074] The three laser pulses with different powers emitted by the emitting unit 11 correspond to nine comparison signals, and the nine comparison signals can be used to determine the distance of the target object 200, but only one distance is finally determined. In this regard, in this embodiment, one of the comparison signals is selected to determine the distance of the target object 200. Figure 4The calculation and processing device 142 includes a signal screening unit 1421, a timing unit 1422 (also referred to as a timing module) and a processing control unit 1423 (also referred to as a processing control module). Then, step S142 includes step S1421 and step S1422.

[0075] Step S1421: Select a comparison signal whose signal strength is closest to a set signal strength from at least one comparison signal as a ranging echo pulse.

[0076] The signal screening unit 1421 of the calculation and processing device 142 receives nine comparison signals, and determines which comparison signal among the nine comparison signals has a signal strength closest to the preset signal strength according to the preset signal strength, and uses the comparison signal as the ranging echo pulse.

[0077] In some other embodiments, step S1421 is to select a comparison signal with a pulse width closest to the set pulse width from at least one comparison signal as the ranging echo pulse. Specifically, the signal screening unit 1421 of the calculation and processing device 142 receives nine comparison signals, and according to the preset pulse width, determines which comparison signal among the nine comparison signals has a pulse width close to the set pulse width, and uses the comparison signal as the ranging echo pulse, thereby selecting the signal with a pulse width closest to the ideal value as the ranging signal, which can ensure the ranging accuracy.

[0078] Step S1422, determining the distance of the target object according to the ranging echo pulse.

[0079] After the signal screening unit 1421 selects the ranging echo pulse, it transmits the ranging echo pulse to the timing unit 1422. The timing unit 1422 has started timing when the transmitting unit 11 transmits the laser pulse. The timing unit 1422 receives the ranging echo pulse, stops timing and outputs the timing result to the processing control unit 1423, and the processing control unit 1423 calculates the distance of the target object 200 according to the timing result.

[0080] In this embodiment, the timing unit 1422 is a time-to-digital converter (TDC for short); the processing control unit 1423 is a single chip microcomputer, such as a MCU (Microcontroller Unit).

[0081] Based on the above content, the specific process of the laser radar ranging method provided by this embodiment is described. Execute the timing while transmitting M laser pulses to the target object: the processing control unit 1423 controls the pulse laser 111 of the transmitting unit 11 to transmit laser pulses, and sends a start signal START as a start timing signal of the timing unit 1422; the timing unit 1422 starts timing after receiving the start signal START. In response to detecting the rising edge of the ranging echo pulse, the timing is ended and the timing data is generated: the laser pulse emitted by the pulse laser 111 is diffusely reflected by the surface of the target object 200, and the signal converter 131 (avalanche photodiode) receives the signal emitted by the pulse laser 111, which is amplified by the amplifier circuit 132 to generate an amplified signal that is input to the comparator 141; the comparator 141 generates a comparison signal as a ranging echo pulse based on the amplified signal and outputs it to the timing unit 1422; the timing unit 1422 detects the rising edge of the ranging echo pulse as the end timing signal STOP, and stops the timing; by calculating the time difference from the signal STOP to the signal START, the time difference from the signal (laser pulse) being emitted to the completion of the reception is obtained, and this time difference is the time t1 used as the timing data. The distance of the target object 200 is determined based on the timing data: the timing unit 1422 records the time t1 from laser emission to reception and sends it to the processing control unit 1423; according to the formula distance = speed * time (L = V * T), where the default speed of light is C = 3 * 10^8 m / s, then the distance between the two points L = C * t1 / 2; the processing control unit 1423 reads the timing data (including the time t1) of the timing unit 1422, calculates the distance between the two points, that is, the distance of the target object 200, and then outputs it to the display unit (such as a display screen) or other external devices.

[0082] According to the above, when measuring close objects and objects with high reflectivity, the amplifying subcircuit with a larger amplification factor (such as the second and third stage amplifying subcircuit) will cause the pulse width of the amplified signal to be widened, thereby affecting the ranging accuracy; at this time, the pulse width of the amplified signal generated by the amplifying subcircuit with a smaller amplification factor (such as the first stage amplifying subcircuit) is normal and can meet the measurement requirements. When the laser measures objects with low reflectivity and objects at a distance, the amplified signal generated by the amplifying subcircuit with a smaller amplification factor (such as the first stage amplified signal) may be too weak to be used to determine the distance, such as failing to trigger the comparator, resulting in the echo signal being zero. The amplifying subcircuit with a larger amplification factor (such as the second and third stage amplifying subcircuit) will amplify the weak signal to a specified level, such as a level sufficient to trigger the comparator, thereby completing the ranging. In this way, in the actual ranging process, the amplification with a larger amplification factor (such as the second and third stage amplification) ensures that low reflectivity objects and objects at a distance can be measured, and the amplification with a smaller amplification factor (such as the first stage amplification) is used to measure objects with high reflectivity. The use of multi-stage amplification can effectively improve the dynamic range of the entire system, increase the system's ranging range and measurement capabilities for different reflectivities.

[0083] In the laser constant power mode, when measuring objects of the same reflectivity material from near to far, the intensity of the echo signal will change with the distance, so that the ranging accuracy of each distance will change. Specifically, for targets with different reflectivities (target object 200) at the same distance, the intensity of the received signal will change: the signal will be strong for targets with high reflectivity and weak for targets with low reflectivity. When different signal intensities appear at the same position, the threshold of the comparator (such as the comparison threshold) y1 is fixed, such as Figure 5 , the leading edge position of the signal determined by the comparator is different, and the leading edge position of the generated comparison signal is also different. The timing unit 1422 calculates the time based on the detected rising edge of the comparison signal (ranging echo pulse) as t1 and t2, respectively, which leads to a larger accuracy deviation and cannot meet the high-precision ranging. In this embodiment, M laser pulses with different powers are emitted to the target object, and M×N amplified signals are generated through N amplification subcircuits with different amplification factors according to the received M echoes. At least one comparison signal is generated through the comparator according to the M×N amplified signals, and the comparison signal with the signal strength closest to the set signal strength is selected from the comparison signal as the ranging echo pulse, so that the echo strength at different distances remains unchanged, and the function of dynamically adjusting power is realized. The mode of dynamically adjusting power can ensure that the signal strength is kept within a certain range within the measurement range, and can reduce the ranging offset caused by the change of signal strength, thereby improving the ranging accuracy.

[0084] Through multi-stage amplification and dynamic power adjustment, the echo signal strength within the full range of radar ranging and the full reflectivity range can be kept within a relatively stable range, thereby reducing the ranging error caused by changes in signal strength. Among them, three-stage amplification can effectively improve the dynamic range of the circuit while ensuring the lowest cost.

[0085] The laser radar ranging device 100 stores first data, such as first data stored in a storage component (such as a flash memory). The first data is: when the signal strength of the echo is the set signal strength I0, the data of the power and the distance of the material when the laser pulse irradiates the material with different reflectivity. During the calibration process of the laser radar ranging device (or laser radar), when the signal strength of the echo is maintained at I0, the power variation curve of the laser radar acting on three materials with different reflectivity with distance is recorded, wherein the relative reflectivities of the three materials are 5%, 90% and 1000% respectively. For example: for a material with a reflectivity of n1 and a distance of L1, adjust the power of the emitted laser pulse so that the signal strength of the received echo (such as the signal strength of the aforementioned electrical signal) is the set signal strength I0, and record the corresponding power and distance; change the distance of the material to L2, adjust the power of the emitted laser pulse so that the signal strength of the received echo (such as the signal strength of the aforementioned electrical signal) is the set signal strength I0, and record the corresponding power and distance; repeat this process until multiple sets of power and distance are obtained, refer to Figure 7 , forming a power-distance curve; the same is true for materials with a reflectivity of n2 and materials with a reflectivity of n3; then, three power-distance curves can be obtained. The three curves are saved in a flash memory (Flash) as the first data. The number of power-distance curves contained in the first data corresponds to the number of laser pulses emitted by the transmitting unit 11, that is, it contains M power-distance curves; then, in the first data, one distance corresponds to M powers, or one power corresponds to M distances. The specific content of the first data includes the set signal intensity I0, the reflectivity of the material, the power of the laser pulse, and the distance of the material.

[0086] refer to Figure 2 , the laser radar ranging method provided in this embodiment also includes step S21.

[0087] Step S21 , searching the preset first data for M powers corresponding to the currently determined distance of the target object 200 as the power of the laser pulse to be emitted next time.

[0088] According to the aforementioned steps S11 to S14, a current distance of the target object 200 can be determined. Initially (such as when used for the first time), the power of the M laser pulses emitted by the transmitting unit 11 of the laser radar ranging device 100 is randomly determined, and the current distance of the target object 200 obtained may have errors. In order to improve the accuracy of the measured distance, after obtaining the current distance of the target object 200, the M powers corresponding to the currently determined distance of the target object 200 are searched from the aforementioned first data as the power of the laser pulse emitted next time. The transmitting unit 11 of the laser radar ranging device 100 uses the M powers found as the power of the next M laser pulses emitted. Then, a comparison signal with a signal strength closer to the set signal strength can be selected from the comparison signals corresponding to the M laser pulses as the ranging echo pulse, especially when one of the reflectivities corresponding to the M powers found is close to the reflectivity of the target object 200 (for example, the target object 200 with a known reflectivity is used as the material corresponding to the reflectivity in the first data, that is, the target object 200 with a known reflectivity is used as one of the materials with different reflectivities). In this way, the accuracy of ranging can be further improved.

[0089] Embodiment 2

[0090] The difference between this embodiment and the first embodiment is that: Figure 3 , the laser radar ranging method provided in this embodiment also includes step S31.

[0091] Step S31, according to the power of the laser pulse corresponding to the ranging echo pulse, searching the preset first data for the reflectivity corresponding to the power of the laser pulse as the measured reflectivity of the target object.

[0092] It should be noted that the first data in this embodiment is the data in the first embodiment.

[0093] Each time the distance is measured, the transmitting unit 11 of the laser radar ranging device 100 emits three laser pulses with different powers, thereby forming three echoes. The intensities of the three echoes (such as the signal intensity of the aforementioned electrical signal) are I1, I2 and I3 respectively. The echo with the signal intensity closest to the set signal intensity I0 among the three echoes is selected as the ranging echo pulse. At the same time, according to the power of the laser pulse corresponding to the selected ranging echo pulse (for example, the laser pulse corresponding to the ranging echo pulse is determined to be the first laser pulse based on the emission time) and the currently determined distance of the target object 200, the corresponding reflectivity is selected from the aforementioned first data (power-distance curve) as the measured reflectivity of the current target object 200; the measured reflectivity is a relative reflectivity.

[0094] When using a positioning plate with high reflectivity (referred to as a high-reflectivity positioning plate) for positioning, it is necessary to determine the position of the high-reflectivity positioning plate from ordinary materials, so it is necessary to know the reflectivity of the high-reflectivity positioning plate in order to distinguish the high-reflectivity positioning plate from ordinary materials. When this embodiment measures the distance of the target object 200, the relative strength of the reflectivity of the target object 200 can be calculated. Since the reflectivity of the high-reflectivity positioning plate is much higher than that of ordinary materials, as long as the high-reflectivity positioning plate can be distinguished, this can meet the requirements of actual use, so that the position of the high-reflectivity positioning plate can be determined.

[0095] Figure 6 This is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. Figure 6 As shown, the electronic device 6 of this embodiment includes: at least one processor 60 ( Figure 6 (only one is shown in the figure) a processor, a memory 61, and a computer program 62 stored in the memory 61 and executable on at least one processor 60; when the processor 60 executes the computer program 62, the steps in any of the above-mentioned laser radar ranging method embodiments are implemented.

[0096] The electronic device may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will appreciate that Figure 6 These are merely examples of electronic devices and do not constitute a limitation on the electronic devices. The electronic devices may include more or fewer components than those shown in the figures, or a combination of certain components, or different components. For example, the electronic devices may also include input and output devices, network access devices, buses, etc.

[0097] The processor 60 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0098] In some embodiments, the memory 61 may be an internal storage unit of the electronic device 6, such as a hard disk or memory of the electronic device. In other embodiments, the memory 61 may also be an external storage device of the electronic device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device. Further, the memory 61 may also include both an internal storage unit of the electronic device and an external storage device. The memory 61 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as program codes of a computer program, etc. The memory 61 may also be used to temporarily store data that has been output or is to be output.

[0099] Exemplarily, the computer program 62 may be divided into one or more modules / units, one or more modules / units are stored in the memory 61, and are executed by the processor 60 to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 62 in the electronic device 6.

[0100] The laser radar ranging method provided in the above embodiment is a ranging method with dynamically adjusted power. It uses multi-stage amplification to improve the dynamic range of the circuit, can increase the ranging capability of the system, can reduce the ranging error caused by changes in signal strength, can improve the ranging accuracy, and can calibrate the reflectivity of the object according to the current power value and distance.

[0101] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0102] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0103] If the aforementioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium; when the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media include: any entity or device that can carry computer program code to a device / terminal device, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0104] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0105] An embodiment of the present application provides a computer program product. When the computer program product is executed on a computing device, the computing device can implement the steps in the above-mentioned various method embodiments.

[0106] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0107] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0108] In the embodiments provided in the present application, it should be understood that the disclosed devices / equipment and methods can be implemented in other ways. For example, the device / equipment embodiments described above are merely schematic, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0109] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0110] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A laser radar ranging method, characterized in that: include: Emitting M laser pulses to the target object, where M is a natural number greater than 0; The transmitting M laser pulses to the target object comprises: transmitting M laser pulses with different powers to the target object; Receiving M echoes formed by the target object reflecting the M laser pulses; generating M electrical signals according to the M echoes; Generate M×N amplified signals according to the M electrical signals; the M×N amplified signals are generated after each of the N amplifying sub-circuits amplifies the M electrical signals respectively; the amplification coefficients of the N amplifying sub-circuits are different, and N is a natural number greater than 1; Determining the distance of the target object according to the M×N amplified signals; the determining the distance of the target object according to the M×N amplified signals comprises: generating at least one comparison signal according to the M×N amplified signals; the at least one comparison signal is generated by a comparator; if the amplitude of the amplified signal is less than the set amplitude of the comparator, the amplified signal fails to trigger the comparator; determining a distance of the target object based on a comparison signal of the at least one comparison signal; Determining the distance of the target object according to one of the at least one comparison signals includes: selecting a comparison signal whose signal strength is closest to a set signal strength from the at least one comparison signal as a ranging echo pulse; determining the distance of the target object according to the ranging echo pulse; or, selecting a comparison signal whose pulse width is closest to a set pulse width from the at least one comparison signal as a ranging echo pulse; and determining the distance of the target object according to the ranging echo pulse.

2. The method according to claim 1, characterized in that Also includes: According to the power of the laser pulse corresponding to the ranging echo pulse, searching from the preset first data for the reflectivity corresponding to the power of the laser pulse as the measured reflectivity of the target object; The first data is data of power and distance from the material when the laser pulse irradiates materials with different reflectivities when the signal strength of the echo is the set signal strength.

3. The method according to claim 1, characterized in that Also includes: Searching for M powers corresponding to the currently determined distance to the target object from the preset first data as the power of the laser pulse emitted next time; The first data is data of power and distance from the material when the laser pulse irradiates materials with different reflectivities when the signal strength of the echo is the set signal strength.

4. The method according to claim 1, 2 or 3, characterized in that: Determining the distance of the target object according to the ranging echo pulse includes: The timing is started while executing the step of emitting M laser pulses toward the target object; In response to detecting the rising edge of the ranging echo pulse, ending timing and generating timing data; A distance to the target object is determined based on the timing data.

5. A laser radar ranging device, characterized in that: include: A transmitting unit, used for transmitting M laser pulses to a target object, where M is a natural number greater than 0; The transmitting M laser pulses to the target object comprises: transmitting M laser pulses with different powers to the target object; A receiving unit, configured to receive M echoes formed by the target object reflecting the M laser pulses; A signal processing device, used to: generate M electrical signals according to the M echoes, and generate M×N amplified signals according to the M electrical signals; the M×N amplified signals are generated after each of the N amplifying sub-circuits amplifies the M electrical signals; the amplification coefficients of the N amplifying sub-circuits are different, and N is a natural number greater than 1; the signal processing device includes the N amplifying sub-circuits; A distance determining device is used to determine the distance of the target object according to the M×N amplified signals; the determining the distance of the target object according to the M×N amplified signals includes: generating at least one comparison signal according to the M×N amplified signals; the at least one comparison signal is generated by a comparator; if the amplitude of the amplified signal is less than the set amplitude of the comparator, the amplified signal fails to trigger the comparator; determining a distance of the target object based on a comparison signal of the at least one comparison signal; Determining the distance of the target object according to one of the at least one comparison signals includes: selecting a comparison signal whose signal strength is closest to a set signal strength from the at least one comparison signal as a ranging echo pulse; determining the distance of the target object according to the ranging echo pulse; or, selecting a comparison signal whose pulse width is closest to a set pulse width from the at least one comparison signal as a ranging echo pulse; and determining the distance of the target object according to the ranging echo pulse.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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