Laser radar calibration system and method and vehicle
By introducing a time measurement circuit into the lidar, the self-calibration of the lidar is achieved, and the problem of calibration data failure caused by mechanical vibration is solved, the calibration cost is reduced and the efficiency is improved, and the accuracy of distance measurement is ensured.
Patent Information
- Application Number
- CN202311560792.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-21
- Publication Date
- 2025-05-23
AI Technical Summary
In the field of autonomous driving, the calibration data failure of the lidar ranging device in vehicles due to mechanical vibration, resulting in inaccurate distance measurement. The prior art requires large calibration space and expensive equipment, which is low in efficiency and high cost.
A calibration system for lidar is proposed, which realizes self-calibration through the time measurement circuit inside the lidar, including a signal generation unit, a delay unit, a pulse width modulation unit, a selection unit, a time measurement unit and a processing unit, which can be calibrated without the need for special equipment and calibration sites.
The self-calibration of lidar is realized, which reduces calibration costs, improves calibration efficiency, and ensures the accuracy of distance measurement.
Smart Images
Figure CN120028775A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of autonomous driving technology, and in particular to a laser radar calibration system, method and vehicle. Background Art
[0002] In the field of autonomous driving, as the mileage of the vehicle on the road increases, the mechanical vibration of the laser radar ranging device in the vehicle will cause the calibration data corresponding to the laser radar ranging device to become invalid, resulting in inaccurate laser radar ranging. In the related art, calibration of the laser radar ranging device requires a large calibration space and expensive calibration equipment, which is inefficient and costly. Summary of the invention
[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.
[0004] To this end, the present application proposes a laser radar calibration system, which realizes self-calibration of the laser radar through a timing circuit inside the laser radar, thereby reducing the calibration cost and improving the calibration efficiency.
[0005] In one aspect, an embodiment of the present application provides a laser radar calibration system, the calibration system comprising a timing circuit, the timing circuit comprising a signal generating unit, a delay unit, a pulse width modulation unit, a selection unit, a time measurement unit and a processing unit electrically connected in sequence;
[0006] The signal generating unit is used to generate a first laser signal to be emitted, and send the first laser signal carrying the emission time to the delay unit and the time measuring unit;
[0007] The delay unit is used to receive the first laser signal and send the first laser signal to the pulse width modulation unit after delay according to a set delay time;
[0008] The pulse width modulation unit is used for sending the received first laser signal to the time measurement unit through the first path in response to detecting that the first path of the selection unit is turned on;
[0009] The time measurement unit is used to receive the first laser signal and determine a first receiving time when the first laser signal is received, and determine a circuit transmission delay time of the first laser signal in the calibration system of the laser radar according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time;
[0010] The processing unit is used to calibrate the timing circuit of the laser radar according to the transmission delay length of the circuit.
[0011] Another aspect of the present application provides a laser radar calibration method, which is applied to the laser radar calibration system described in the above aspect, including:
[0012] Generate a first laser signal to be emitted through the signal generating unit, and send the first laser signal carrying the emission time to the delay unit and the time measuring unit;
[0013] receiving the first laser signal through a delay unit, and sending the first laser signal to the pulse width modulation unit after delay according to a set delay time;
[0014] In response to detecting that the first path of the selection unit is turned on, the pulse width modulation unit sends the received first laser signal to the time measurement unit through the first path;
[0015] The first laser signal is received by a time measurement unit, and a first receiving time when the first laser signal is received is determined; according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time, a circuit transmission delay time of the first laser signal in the calibration system of the laser radar is determined;
[0016] The processing unit calibrates the timing circuit of the laser radar according to the transmission delay length of the circuit.
[0017] Another aspect of the present application provides a vehicle, comprising the laser radar calibration system described in the aforementioned aspect.
[0018] Another aspect of the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor in a vehicle, the method described in the aforementioned aspect is implemented.
[0019] The laser radar calibration system, method and vehicle proposed in the present application, wherein a signal generating unit is used to generate a first laser signal to be emitted, and send the first laser signal carrying the emission time to a delay unit and a time measurement unit; the delay unit is used to receive the first laser signal, and send the first laser signal to the pulse width modulation unit with a delay according to a set delay time; the pulse width modulation unit is used to send the received first laser signal to the time measurement unit through the first path in response to detecting that the first path of the selection unit is turned on; the time measurement unit is used to receive the first laser signal and determine a first receiving time of receiving the first laser signal; according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time, determine the circuit transmission delay time of the first laser signal in the laser radar calibration system; the processing unit is used to perform timing circuit calibration on the laser radar according to the circuit transmission delay time, so that the laser radar can be self-calibrated without the need for special calibration equipment and calibration site, thereby reducing the calibration cost and improving the calibration efficiency.
[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:
[0022] Figure 1 A schematic diagram of the structure of a laser radar calibration system provided in an embodiment of the present application;
[0023] Figure 2 A schematic diagram of the structure of another laser radar calibration system provided in an embodiment of the present application;
[0024] Figure 3 A schematic diagram of a flow chart of a laser radar calibration method provided in an embodiment of the present application;
[0025] Figure 4 A schematic diagram of a flow chart of another laser radar calibration method provided in an embodiment of the present application;
[0026] Figure 5 A schematic diagram of the structure of another laser radar calibration system provided in an embodiment of the present application. DETAILED DESCRIPTION
[0027] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.
[0028] The following describes the laser radar calibration system, method and vehicle of the embodiments of the present application with reference to the accompanying drawings.
[0029] Figure 1 A schematic diagram of the structure of a laser radar calibration system provided in an embodiment of the present application.
[0030] like Figure 1 As shown, the calibration system includes a timing circuit 10, which includes a signal generating unit 101, a delay unit 102, a pulse width modulation unit 103, a selection unit 104, a time measurement unit 105 and a processing unit 106 which are electrically connected in sequence.
[0031] The signal generating unit 101 is used to generate a first laser signal to be emitted, and send the first laser signal carrying the emission time to the delay unit and the time measuring unit 105 .
[0032] The delay unit 102 is used to receive the first laser signal and send the first laser signal to the pulse width modulation unit 103 after a delay according to a set delay time.
[0033] The pulse width modulation unit 103 is used to send the received first laser signal to the time measurement unit 105 through the first channel in response to detecting that the first channel of the selection unit 104 is turned on.
[0034] The time measurement unit 105 is used to receive the first laser signal and determine the first receiving moment of the first laser signal. According to the first receiving moment of the first laser signal, the transmitting moment of the first laser signal and the set delay time, the circuit transmission delay time of the first laser signal in the laser radar calibration system is determined. The circuit transmission delay time is the total transmission delay time of the first laser signal in the timing circuit.
[0035] The processing unit 106 is used to calibrate the timing circuit of the laser radar according to the circuit transmission delay length, specifically, to calibrate the timing error of the timing circuit of the laser radar.
[0036] In one scenario of an embodiment of the present application, a laser radar is installed in a vehicle. As the mileage of the vehicle increases, the mechanical vibration during the vehicle's driving will cause micro-displacement of components in the internal circuit of the laser radar, resulting in deviations in the calibration data stored at the factory, thereby causing inaccurate measurement results. In an embodiment of the present application, based on the timing circuit 10, the circuit transmission delay duration in the laser radar is measured to determine the circuit transmission delay duration of the laser signal.
[0037] In the embodiment of the present application, the first laser signal may be a pulsed laser signal, and the first laser signal may be one or more. The first laser signal is received by the delay unit 102, and the first laser signal is delayed and sent to the pulse width modulation unit 103 according to the set delay time. As an example, the delay time is set to set picoseconds, which can be set specifically according to the needs and is not limited in this embodiment. In the embodiment of the present application, the first laser signal is delayed by the delay unit 102, and the delay time is equivalent to the transmission time of the first laser signal at a fixed distance in the actual air, that is, the time of the first laser signal flying between the laser radar and the target plate when the flight time is measured by the slide rail and the target plate in the simulation related technology. Then, the delayed laser signal is sent to the time measurement unit 105 by the pulse width modulation unit 103 to realize the laser signal forming a loop in the timing circuit inside the laser radar. The pulse width modulation unit 103 is used to respond to the detection that the first path of the selection unit is turned on, that is, the detection that the selection unit 104 is in the first signal state, and the received first laser signal is sent to the time measurement unit through the first path. The time measurement unit 105 receives the first laser signal and determines the first receiving moment of the first laser signal. According to the first receiving moment of the first laser signal, the transmitting moment of the first laser signal and the set delay time, the circuit transmission delay time of the first laser signal in the laser radar calibration system is determined, so as to measure the carry chain delay change caused by the temperature rise of the timing circuit of the main chip inside the laser radar, compensate for the deviation of the calibration data caused by the temperature drift of the laser radar, and do not need to install the special equipment and space occupation requirements for calibrating the micro-displacement rail, so the measurement cost is low and the efficiency is high.
[0038] The delay unit, as an implementation, may be composed of a carry chain or gate circuit generated by a main controller in the vehicle, such as a Field-Programmable Gate Array (FPGA). As another implementation, it may be a delay chip outside the main controller.
[0039] It should be noted that the signal generating unit 101 can generate a signal for a repetitive pulse, that is, it can generate multiple laser pulse signals per second, so that repeated measurements and statistical calculations can be performed based on the multiple laser pulse signals. The final transmission delay duration is stored in the FPGA internal ROM as online calibration compensation data for the laser radar.
[0040] Based on the above embodiments, Figure 2 A schematic diagram of the structure of another laser radar calibration system provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the system further includes an optical component 20 , and the optical component 20 includes an optical transmitting unit 201 and an optical receiving unit 202 .
[0041] The pulse width modulation unit 103 is used to send the first laser signal to the optical emission unit 201 through the second path of the selection switch in response to detecting that the second path of the selection unit 104 is turned on, that is, detecting that the selection unit 104 is in the second signal state. Which path of the selection switch is turned on is determined based on the trigger signal. If the trigger signal is 1, that is, in the second signal state, the second path is turned on. If the trigger signal is 0, that is, in the first signal state, the first path is turned on. If the trigger signal is 1, it indicates that the user has selected to measure the delay time of the circuit transmission; if the trigger signal is 0, it indicates that the user has selected to measure the delay time of the system transmission.
[0042] The optical transmitting unit 201 irradiates the received first laser signal onto a reflective element arranged in front of the window of the laser radar.
[0043] The optical receiving unit 202 is used to receive the first laser signal reflected by the reflector and send the first laser signal to the time measurement unit 105 .
[0044] The time measurement unit 105 is used to receive the first laser signal, determine the second receiving time of the first laser signal, and determine the system transmission delay time of the first laser signal in the laser radar calibration system according to the second receiving time of the first laser signal, the emission time of the first laser signal and the set delay time. The system transmission delay time includes the sum of the transmission delay time of the first laser signal in the timing circuit 10 and the delay time of the transmission in the optical component 20, which is the total transmission delay time of the system.
[0045] The processing unit 106 is used to calibrate the laser radar according to the system transmission delay time, and specifically, to calibrate the timing error of the entire laser radar system.
[0046] In the embodiment of the present application, the reflector is used to reflect the first laser signal to simulate targets with different reflectivity. The reflector can be of different roughness, such as a dedicated shielding material, a decontamination shield, a cloth strip, a piece of paper, etc., to simulate targets with different reflectivity. Since the flight time of the first laser signal in the air in a real measurement scenario can be simulated inside the timing circuit, the distance between the reflector and the window of the laser radar can be a set distance, such as 5 cm.
[0047] Among them, the selection unit 104 includes a selection switch, for example, a 2-to-1 selection switch. When the switch signal of the selection unit is the first switch signal, the channel between the selection unit 104 and the time measurement unit 105 is opened, so that the first laser signal can be sent from the pulse width modulation unit 103 to the time measurement unit 105. When the second channel of the selection unit is opened, the channel between the selection unit 104 and the optical emission unit 201 is opened, so that the first laser signal can be sent from the pulse width modulation unit to the optical emission unit 201, thereby realizing the selection of the signal transmission channel, so as to realize the multiplexing of the timing circuit and save the timing cost.
[0048] In the embodiment of the present application, mechanical vibration may cause micro-displacement of the optical devices and electronic components inside the laser radar, causing the calibration data stored at the factory to become invalid. Therefore, the entire positioning system of the laser radar can also be delayed. Therefore, the first laser signal is controlled to be transmitted in the optical component to measure the delay of the entire system, so as to achieve calibration compensation of the timing circuit and optical component (optical-mechanical part) of the system. Among them, the system transmission delay time, including the transmission delay time in the timing circuit and the transmission delay time in the optical component, is the total delay time of the calibration system of the entire laser radar. The laser radar is calibrated by the system transmission delay time, thereby achieving system calibration.
[0049] It should be understood that the introduction of the delay time can also avoid the problem of being unable to measure when the transmission delay in the timing circuit is small (smaller than the set value) or the system delay is small.
[0050] In the embodiment of the present application, not only the internal system delay caused by temperature change, etc. can be calibrated, but also the influence of targets with different reflectivity on the distance can be calibrated. Among them, a reflector is arranged in front of the window of the laser radar to replace the common target plate, wherein the reflector can be arranged at a set distance in front of the transparent window of the laser radar, such as 5 cm or 10 cm, and the reflector can be made of materials with different reflectivity, such as paper, clothing, etc. The reflector can also be blocked on the window in the form of a shield, so that after the first laser signal is irradiated on the reflector, it will be reflected back by the reflector to be received by the optical receiving unit, and then the optical receiving unit sends the received first laser signal to the time measurement unit to achieve the measurement of the delay time, wherein the flight time of the first laser signal is simulated by the internal delay unit 102 through delayed transmission, so as to achieve calibration compensation of the optical machine part and the circuit, and at the same time consider the influence of reflectors with different reflectivity on the delay, thereby improving the accuracy. It should be noted that by setting reflectors with different reflectivity, it is possible to measure under the conditions of reflectors with different reflectivity to determine the influence of objects with different reflectivity on the calibration.
[0051] In one implementation of the embodiment of the present application, when a reflector is provided in front of the window of the laser radar, if the laser energy is too large, it will cause overexposure, making the optical receiving unit 202 inaccurate in measurement. Therefore, it is necessary to take measures to reduce the instantaneous transmission power of the laser radar to avoid the problem of overexposure caused by the excessive energy of the first laser signal. As an implementation, the pulse width modulation unit 103 is used to adjust the pulse width of the first laser signal to a set range pulse width in response to detecting that the second path of the selection unit 104 is turned on, and send the first laser signal of the set range pulse width to the optical transmitting unit 201, so as to reduce the instantaneous transmission power of the laser radar by adjusting the pulse width of the first laser signal to control the intensity of the first laser signal and avoid overexposure. As another implementation, the number of first laser signals generated by the signal generating unit 101 can also be adjusted, wherein the number is proportional to the transmission power, so as to reduce the number of the transmitted first laser signals, and the instantaneous transmission power of the laser radar can be reduced to avoid overexposure.
[0052] Based on the above embodiments, the present application provides a laser radar calibration method. Figure 3 A schematic diagram of a laser radar calibration method provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the method comprises the following steps:
[0053] Step 301: Generate a first laser signal to be emitted through a signal generating unit, and send the first laser signal carrying the emission time to a delay unit and a time measuring unit.
[0054] Step 302: Receive the first laser signal through the delay unit, and send the first laser signal to the pulse width modulation unit after delay according to the set delay time.
[0055] Step 303: In response to detecting that the first path of the selection unit is turned on, the pulse width modulation unit sends the received first laser signal to the time measurement unit through the first path.
[0056] Step 304, receiving the first laser signal through the time measurement unit, and determining the first receiving time of the first laser signal, and determining the circuit transmission delay time of the first laser signal in the laser radar calibration system according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time.
[0057] As an implementation method, the first delay duration is determined based on the time difference between the first reception time of the first laser signal and the emission time of the first laser signal, and the circuit transmission delay duration of the first laser signal in the laser radar calibration system is determined based on the difference between the first delay duration and the set delay duration.
[0058] Step 305, calibrate the timing circuit of the laser radar according to the circuit transmission delay length through the processing unit.
[0059] The explanations and beneficial effects in the aforementioned embodiments are also applicable to this embodiment, and the principles are the same, so they will not be repeated here.
[0060] In the calibration method of the laser radar of the embodiment of the present application, there is no need for special calibration equipment and calibration site. The laser radar can be self-calibrated in any environment, and the laser radar calibration data can be updated. The cost is low and the efficiency is high. For example, if the user's vehicle is equipped with a laser radar for ranging, after one year of use, the laser radar can be self-calibrated according to the method of the embodiment of the present application to improve the measurement accuracy of the laser radar. It is simple and convenient. At the same time, the calibration accuracy is high, the compensation coverage range is wide, and the delay unit can achieve precise delay, good accuracy, and stable performance.
[0061] Based on the above embodiments, the present application provides a laser radar calibration method. Figure 4 A schematic diagram of a flow chart of another laser radar calibration method provided in an embodiment of the present application, such as Figure 4 As shown, the method comprises the following steps:
[0062] Step 401: Generate a first laser signal to be emitted through a signal generating unit, and send the first laser signal carrying the emission time to a delay unit and a time measuring unit.
[0063] Step 402: Receive the first laser signal through the delay unit, and send the first laser signal to the pulse width modulation unit after delay according to the set delay time.
[0064] Step 403: In response to detecting that the second path of the selection unit is turned on, the pulse width modulation unit sends the first laser signal to the optical emission unit through the second path.
[0065] Step 404: irradiate the received first laser signal onto a reflective element disposed in front of the window of the laser radar through an optical transmitting unit.
[0066] Step 405: receiving the first laser signal reflected by the reflector through the optical receiving unit, and sending the first laser signal to the time measurement unit.
[0067] Step 406, receiving the first laser signal through the time measurement unit, and determining the second receiving time of the first laser signal, and determining the system transmission delay time of the first laser signal in the laser radar calibration system according to the second receiving time of the first laser signal, the emission time of the first laser signal and the set delay time.
[0068] Step 407, the processing unit calibrates the laser radar system according to the system transmission delay time.
[0069] The explanations and beneficial effects in the aforementioned embodiments are also applicable to this embodiment, and the principles are the same, so they will not be repeated here.
[0070] As an implementation manner, sending the first laser signal to the optical transmitting unit through the second path includes:
[0071] The pulse width of the first laser signal is adjusted to a pulse width within a set range, and the first laser signal with a pulse width within the set range is sent to the optical emission unit through the second path.
[0072] The explanations and beneficial effects in the aforementioned embodiments are also applicable to this embodiment, and the principles are the same, so they will not be repeated here.
[0073] Based on the above embodiments, Figure 5 A schematic diagram of the structure of another laser radar calibration system provided in an embodiment of the present application. In actual application scenarios, the laser radar calibration system and the laser radar ranging system can realize multiplexing of multiple units to save circuits and reduce costs.
[0074] like Figure 5As shown, two selection units are provided, wherein one selection unit is connected to the signal generation unit. As an implementation method, a selection button may be provided on the laser radar to determine whether the user needs to measure the distance or calibrate. If the user needs to measure the distance, the first path of the selection unit connected to the signal generation unit is opened, and the generation unit sends the first laser signal to the pulse width modulation unit through the first path of the selection unit, but not to the delay unit and the measurement unit. At the same time, the pulse width modulation unit sends the first laser signal to the optical transmitting unit in the optical component through a path to another selection unit to achieve laser ranging. If the user needs to calibrate the laser radar, the second path of the selection unit connected to the signal generation unit is opened, and the first laser signal is sent to the delay unit through the second path of the selection unit for delay processing, and then the calibration of the laser radar is achieved according to the relevant explanations in the aforementioned embodiments, which will not be repeated here.
[0075] It should be noted that, when the laser driver of the optical transmitting unit receives the first laser signal, it will drive the laser lens to transmit the first laser signal; the optical receiving unit includes an optical-mechanical structure for receiving the first laser signal, and after being processed by the signal processing unit, it is transmitted to the time measurement unit. The time measurement unit includes a moment identification unit for receiving the first laser signal, determining the second receiving moment of receiving the first laser signal, and sending the first laser signal carrying the second receiving moment to the delay calculation unit of the time measurement unit for calculating the corresponding delay duration, such as the circuit transmission delay duration of the timing circuit, or the system transmission delay duration. For details, please refer to the explanation in the aforementioned embodiment, the principle is the same, and it will not be repeated here.
[0076] In order to implement the above-mentioned embodiment, the present application also proposes a vehicle, including a laser radar calibration system as described in the above-mentioned method embodiment.
[0077] In order to implement the above embodiments, the present application also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor in a vehicle, the method described in the above method embodiments is implemented.
[0078] In order to implement the above embodiments, the present application also proposes a computer program product on which a computer program is stored. When the computer program is executed by a processor, the method described in the above method embodiments is implemented.
[0079] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0080] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0081] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.
[0082] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution device, apparatus or device (such as a computer-based device, a device including a processor, or other device that can fetch instructions from an instruction execution device, apparatus or device and execute the instructions), or in combination with these instruction execution devices, apparatuses or devices. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution device, apparatus or device or in combination with these instruction execution devices, apparatuses or devices. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.
[0083] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
[0084] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.
[0085] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.
[0086] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A laser radar calibration system, It is characterized in that The calibration system includes a timing circuit, which includes a signal generating unit, a delay unit, a pulse width modulation unit, a selection unit, a time measuring unit and a processing unit which are electrically connected in sequence; The signal generating unit is used to generate a first laser signal to be emitted, and send the first laser signal carrying the emission time to the delay unit and the time measuring unit; The delay unit is used to receive the first laser signal and send the first laser signal to the pulse width modulation unit after delay according to a set delay time; The pulse width modulation unit is used for sending the received first laser signal to the time measurement unit through the first path in response to detecting that the first path of the selection unit is turned on; The time measurement unit is used to receive the first laser signal and determine a first receiving time when the first laser signal is received, and determine a circuit transmission delay time of the first laser signal in the calibration system of the laser radar according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time; The processing unit is used to calibrate the timing circuit of the laser radar according to the transmission delay length of the circuit.
2. The system according to claim 1, It is characterized in that The system further comprises an optical assembly, wherein the optical assembly comprises an optical transmitting unit and an optical receiving unit; The pulse width modulation unit is used to send the first laser signal to the optical emission unit through the second path in response to detecting that the second path of the selection unit is turned on; The optical transmitting unit irradiates the received first laser signal onto a reflector disposed in front of a window of the laser radar; The optical receiving unit is used to receive the first laser signal reflected by the reflector and send the first laser signal to the time measurement unit; The time measurement unit is used to receive the first laser signal, determine a second receiving time when the first laser signal is received, and determine a system transmission delay time of the first laser signal in the calibration system of the laser radar according to the second receiving time of the first laser signal, the emission time of the first laser signal and the set delay time; The processing unit is used to calibrate the laser radar system according to the system transmission delay duration.
3. The system according to claim 1, It is characterized in that The time measurement unit is used to determine a first delay duration based on a time difference between a first reception time of the first laser signal and a transmission time of the first laser signal, and to determine a circuit transmission delay duration of the first laser signal in the calibration system of the laser radar based on a difference between the first delay duration and the set delay duration.
4. The system according to claim 2, It is characterized in that The pulse width modulation unit is used to adjust the pulse width of the first laser signal to a set range pulse width in response to detecting that the switch signal of the selection unit is the second switch signal, and send the first laser signal with the set range pulse width to the optical emission unit.
5. A laser radar calibration method, It is characterized in that The method for the laser radar calibration system applied to any one of claims 1 to 4 comprises: Generate a first laser signal to be emitted through a signal generating unit, and send the first laser signal carrying the emission time to the delay unit and the time measuring unit; receiving the first laser signal through a delay unit, and sending the first laser signal to the pulse width modulation unit after delay according to a set delay time; In response to detecting that the first path of the selection unit is turned on, the pulse width modulation unit sends the received first laser signal to the time measurement unit through the first path; The first laser signal is received by a time measurement unit, and a first receiving time when the first laser signal is received is determined; according to the first receiving time of the first laser signal, the emission time of the first laser signal and the set delay time, a circuit transmission delay time of the first laser signal in the calibration system of the laser radar is determined; The processing unit calibrates the timing circuit of the laser radar according to the transmission delay length of the circuit.
6. The method according to claim 5, It is characterized in that The determining, according to the first receiving moment of the first laser signal, the transmitting moment of the first laser signal and the set delay time, the circuit transmission delay time of the first laser signal in the calibration system of the laser radar comprises: Determining a first delay duration according to a time difference between a first receiving moment of the first laser signal and a transmitting moment of the first laser signal; According to the difference between the first delay time and the set delay time, the circuit transmission delay time of the first laser signal in the calibration system of the laser radar is determined.
7. The method according to claim 5, It is characterized in that The method further comprises: In response to detecting that the second path of the selection unit is turned on, the pulse width modulation unit sends the first laser signal to the optical emission unit through the second path; irradiating the first laser signal to a reflector disposed in front of a window of the laser radar through the optical emitting unit; receiving the first laser signal reflected by the reflector through an optical receiving unit, and sending the first laser signal to the time measurement unit; The first laser signal is received by the time measurement unit, and a second receiving time when the first laser signal is received is determined, and a system transmission delay time of the first laser signal in the calibration system of the laser radar is determined according to the second receiving time of the first laser signal, the emission time of the first laser signal and the set delay time; The processing unit performs system calibration on the laser radar according to the system transmission delay duration.
8. The method according to claim 7, It is characterized in that The step of sending the first laser signal to the optical transmitting unit through the second path includes: Adjusting the pulse width of the first laser signal to a pulse width within a set range; The first laser signal with a pulse width in the set range is sent to the optical transmitting unit through the second path.
9. A vehicle, It is characterized in that include: A laser radar calibration system as described in any one of claims 1 to 4.
10. A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by a processor in a vehicle, the steps of the method according to any one of claims 5 to 8 can be performed.