Test system and test method of laser radar

Abstract

The embodiment of the invention discloses a test system and a test method of a laser radar. The test system comprises an incubator, a test module and a processing module, the incubator comprises an incubator door, an incubator shell, a temperature control assembly and a heat preservation assembly. The temperature control assembly is used for generating temperature control wind; the heat preservation assembly comprises a heat preservation cavity wall and an air knife, the air knife is used for obtaining an air curtain according to temperature control air, and the air curtain and the heat preservation cavity wall define a heat preservation cavity; the test module comprises a moving device and a target object, and the moving device is used for adjusting the initial pose of the target object to obtain the pose of the adjusted target object; the processing module is used for obtaining the performance parameters of the laser radar according to the adjusted pose of the target object and the echo signal, the echo signal is obtained according to the scanning beam reflected by the target object, and the scanning beam is emitted by the laser radar. The test method based on the test system is not limited by the transmittance of the observation window of the incubator and the internal space, and can be used for testing the performance of the laser radar at different environment temperatures.

Description

Technical Field

[0001] The present application relates to the field of lidar, and particularly to a test system and a test method for a lidar. Background Art

[0002] A lidar is a precision instrument that uses laser pulses for ranging and sensing, and has been widely used in fields such as autonomous driving, industrial surveying and mapping, robotics, and intelligent transportation. The ambient temperature in different application scenarios directly affects the working performance of the lidar. Therefore, existing lidar test systems usually use an incubator to simulate different ambient temperatures to test the performance of the lidar in a laboratory environment.

[0003] However, during the process of simulating the ambient temperature, the incubator needs to keep the cavity closed, resulting in the design of the test system being limited by the size of the incubator. In addition, since the observation window on the incubator door usually has a multi-layer glass structure, when the incubator door is closed, the laser beam during the transceiver process undergoes multiple reflections between the multi-layers of glass, and the transmittance of the incubator observation window for the laser wavelength is poor, resulting in a high attenuation of the photon energy of the laser beam. Therefore, existing lidar test systems cannot accurately detect the performance of lidars at different ambient temperatures. Summary of the Invention

[0004] To test the performance of a lidar at different ambient temperatures, embodiments of the present application disclose a test system and a test method for a lidar.

[0005] In a first aspect, embodiments of the present application disclose a test system for a lidar, the test system including an incubator, a test module, and a processing module;

[0006] The incubator includes an incubator door, an incubator housing, a temperature control component, and a heat insulation component. The temperature control component and the heat insulation component are located inside the incubator housing. The temperature control component is used to generate temperature control air. The heat insulation component includes a heat insulation cavity wall and at least one air knife. The air knife is used to obtain an air curtain according to the temperature control air, and the air curtain and the heat insulation cavity wall enclose to form a heat insulation cavity;

[0007] The test module includes a moving device and a target. The moving device is used to adjust the initial pose of the target to obtain the pose of the adjusted target;

[0008] The processing module is used to obtain the performance parameters of the lidar according to the pose of the adjusted target and the echo signal, where the echo signal is obtained by the target reflecting the scanning beam, and the scanning beam is emitted by the lidar.

[0009] In some embodiments, the thermal insulation assembly includes a plurality of air knives; the plurality of air knives are abutted end to end; or the plurality of air knives are arranged in a stacked manner. When the plurality of air knives are abutted end to end, they can cover a thermal insulation cavity with a larger size to prevent heat exchange between the thermal insulation cavity and the external environment. The plurality of air knives arranged in a stacked manner can be used to form a multi-layer air curtain to achieve a multiple heat insulation effect.

[0010] In some embodiments, the air knife includes at least one air nozzle, and the shape of the air nozzle includes one or a combination of more of a rectangle, a triangle, or an ellipse.

[0011] In some embodiments, the temperature control assembly includes an air return port, a temperature control device, and an air outlet; the air return port is used to transmit the air in the incubator housing to the temperature control device, the temperature control device is used to heat or cool the air to form temperature-controlled air, and the air outlet is used to transmit the temperature-controlled air to the thermal insulation assembly.

[0012] In some embodiments, the thermal insulation assembly further includes a first air blowing device and a second air blowing device; the first air blowing device is used to transmit the temperature-controlled air to the thermal insulation cavity, and the second air blowing device is used to transmit the temperature-controlled air to the air knife. The temperature-controlled air is used to adjust the environmental temperature in the thermal insulation cavity, and the thermal insulation assembly is used to maintain the environmental temperature in the thermal insulation cavity so that the test system can still effectively control the environmental temperature in the thermal insulation cavity when the incubator door is in the open state.

[0013] In some embodiments, the thermal insulation cavity wall is a thermal insulation structure formed by one or a combination of more of rock wool board, ferroalloy, or aluminum alloy.

[0014] In some embodiments, there is at least one cavity between the thermal insulation structures, and the cavity is filled with one or a combination of more of silica gel foam, polyurethane foam, polystyrene foam, or phenolic foam. The thermal insulation structures and the foam are overlapped with each other to form a multiple thermal sealing structure, which, in cooperation with the heat insulation effect of the air curtain, can effectively prevent the environmental temperature in the thermal insulation cavity from changing.

[0015] In some embodiments, the incubator further includes one or a combination of more of an electromagnetic interference device, a strong light illumination device, a water spraying device, a spraying device, or a dust spraying device. By means of environmental simulation devices such as an electromagnetic interference device, a strong light illumination device, a water spraying device, a spraying device, or a dust spraying device, the working environment of the lidar under different working conditions can be simulated, and then the performance level of the lidar under complex working conditions can be tested. The incubator integrated with various environmental simulation devices can also reduce the test cost and improve the test efficiency.

[0016] In some embodiments, the target includes one or more combinations of a reflector with a diffuse reflection surface or a target with a characteristic pattern; the characteristic pattern includes one or more combinations of a checkerboard, a QR code, or grayscale stripes. The surface reflectivity of the reflector can be changed according to actual test requirements, and is used to test performance parameters such as the detection probability and maximum detection distance of the lidar. The target with a characteristic pattern can also provide scale information for testing the ranging accuracy of the lidar.

[0017] In a second aspect, the present application discloses a method for testing a lidar. The lidar is located inside an incubator, and the incubator includes an incubator door, an incubator housing, a temperature control component, and a heat insulation component. The temperature control component and the heat insulation component are located inside the incubator housing. The heat insulation component includes a heat insulation cavity wall and at least one air knife. The testing method includes:

[0018] Generating temperature control air by the temperature control component and transmitting the temperature control air to the heat insulation component through the temperature control component;

[0019] The air knife forms an air curtain according to the temperature control air, and the air curtain and the heat insulation cavity wall enclose a heat insulation cavity, and the lidar is located inside the heat insulation cavity;

[0020] The lidar emits a scanning beam towards the target, wherein the incubator door is in an open state;

[0021] Adjusting the initial pose of the target based on a mobile device to obtain the adjusted pose of the target, and the target reflects the scanning beam to form an echo beam;

[0022] The lidar obtains an echo signal according to the echo beam;

[0023] The processing module obtains the performance parameters of the lidar according to the adjusted pose of the target and the echo signal.

[0024] The present application discloses a testing system and a testing method for a lidar. The testing system simulates the environmental temperature of the lidar based on the temperature control component of the incubator. And during the process of the lidar transmitting and receiving laser, the incubator door is in an open state, reducing the photon energy attenuation during the transmitting and receiving process of the laser. The incubator also includes a heat insulation component for maintaining the environmental temperature when the incubator door is in an open state. Compared with the prior art solutions, the testing method based on this testing system is not limited by the transmittance of the incubator observation window and the internal space of the incubator, and can be used to test the performance of the lidar at different environmental temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present application.

[0026] Figure 1It is a system block diagram of a test system for a lidar provided by an embodiment of the present application;

[0027] Figure 2 It is a schematic diagram of an incubator provided by an embodiment of the present application;

[0028] Figure 3 It is a sectional view of an incubator provided by an embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of a test module provided by an embodiment of the present application;

[0030] Figure 5 It is a schematic diagram of a test system for a lidar provided by an embodiment of the present application;

[0031] Figure 6 It is a flowchart of an automated test method provided by an embodiment of the present application.

[0032] Among them, the reference numerals in the figure: 10, incubator; 11, incubator housing; 111, side through hole; 12, incubator door; 13, heat preservation component; 131, first air blowing device; 1311, first air collection hood; 1312, first blower; 1313, first air duct; 132, second air blowing device; 1321, second air collection hood; 1322, second blower; 1323, second air duct; 133, air knife; 134, heat preservation cavity wall; 135, heat preservation cavity; 20, processing module; 30, test module; 31, moving device; 311, controller; 312, slide rail; 313, rotating platform; 314, moving platform; 32, target; 321, double-sided reflector; 322, target support. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are only examples of structures consistent with some aspects of the present application as detailed in the appended claims.

[0034] LiDAR is one of the core sensors for high-level autonomous driving technology and an important direction for the intelligent development of automobiles. The performance of LiDAR at different ambient temperatures is an important evaluation index to measure its performance. At present, the ambient temperature during the actual operation of in-vehicle LiDAR is in the range of -40 to 85 °C, and an incubator is usually used to simulate this ambient temperature range. However, during the process of simulating the ambient temperature, the incubator door needs to be kept closed, and the laser emitted by the LiDAR passes through the observation window on the incubator door to complete the transceiver process. However, the transmittance of the observation window to the laser wavelength is low, and the laser beam will be reflected multiple times between the multi-layer glasses of the observation window, resulting in a high attenuation of the photon energy when the laser passes through the incubator observation window, and the performance of the LiDAR at different ambient temperatures cannot be accurately detected. When the temperature inside the incubator is low, external water vapor is likely to cause condensation problems on the surface of the observation window, resulting in refraction or reflection of the laser beam emitted by the LiDAR during propagation, changing the propagation direction of the laser beam, and thus affecting the detection of the target during testing.

[0035] This application discloses a test system for LiDAR. The test system simulates different ambient temperatures based on the temperature control component of the incubator. The incubator also includes a heat preservation component for maintaining the ambient temperature when the incubator door is open. The test system is not restricted by the transmittance of the incubator observation window and the internal space of the incubator, and can be used to test the performance of LiDAR at different ambient temperatures.

[0036] In one embodiment, as Figure 1 shown, the test system for LiDAR includes an incubator 10, a processing module 20, and a test module 30. In one example, the LiDAR is inside the incubator 10. The incubator 10 is used to adjust the ambient temperature of the LiDAR. The test module 30 includes a moving device and a target. The moving device is used to adjust the initial pose of the target to obtain the adjusted pose of the target. The processing module 20 is used to obtain the performance parameters of the LiDAR at different ambient temperatures according to the echo signal and the adjusted pose of the target, where the echo signal is obtained by the target reflecting the scanning beam, and the scanning beam is emitted by the LiDAR. In some embodiments, the LiDAR includes one or a combination of a mechanical LiDAR, a semi-solid-state LiDAR, or a fully solid-state LiDAR. The test system for LiDAR in the above embodiments can be used for the performance test of different types of LiDAR.

[0037] In some embodiments, Figure 1The processing module 20 shown may be a Field-Programmable Gate Array (FPGA), System on Chip (SoC), Central Processor Unit (CPU), Network Processor (NP), digital signal processing circuit, Micro Controller Unit (MCU), Programmable Logic Device (PLD), Application-Specific Integrated Circuit (ASIC), or any combination thereof for implementing related functions. The above PLD may be a Complex Programmable Logic Device (CPLD), Field-Programmable Gate Array (FPGA), Generic Array Logic (GAL), or other integrated chips.

[0038] In some embodiments, Figure 1 The processing module 20 shown is electrically connected to the incubator 10, the processing module 20 is electrically connected to the test module 30, and the processing module 10 is electrically connected to the lidar. The electrical connection includes one or more combinations of Bluetooth connection, wireless local area network connection, serial interface connection, or Ethernet interface connection. In one example, as Figure 2 shown, the incubator 10 includes an incubator housing 11 and an incubator door 12. The incubator housing 11 includes side through-holes 111. The side through-holes 111 are located on both sides of the incubator housing 11 and are used to accommodate control lines. The lidar is located inside the incubator housing 11. The lidar and the processing module 20 are connected through a serial interface or an Ethernet interface based on the control lines. The control lines are coated with a thermal insulation material, which includes one or more combinations of foaming glue materials such as silica gel, polyurethane, polystyrene, or phenolic aldehyde. The thermal insulation material is used to fully fill the side through-holes 111 to prevent heat exchange between the internal cavity of the incubator housing 11 and the external environment.

[0039] In one embodiment, Figure 2 the incubator 10 shown further includes a thermal insulation component and a temperature control component, and the thermal insulation component and the temperature control component are located inside the incubator housing 11. In one example, as Figure 3The figure shows a cross-section of an incubator 10 disclosed in an embodiment of the present application. The temperature control component includes an air outlet, a temperature control device, and an air return port. The temperature control device is not shown in the figure. The air return port is used to transfer the air in the incubator housing to the temperature control device, and the temperature control device is used to heat or cool the air to generate temperature-controlled air. The air outlet is used to transfer the temperature-controlled air to the heat preservation component 13, and the heat preservation component 13 is used to adjust the ambient temperature of the lidar according to the temperature-controlled air. In some embodiments, the air outlet is a porous grid, and the grid is made of one or a combination of materials such as steel, aluminum alloy, or plastic. A part of the air outlet is communicated with the heat preservation component 13. The air return port is a porous grid, and the grid is made of one or a combination of materials such as steel, aluminum alloy, or plastic, and is used to collect the air in the incubator housing 11, so that the temperature-controlled air is circulated and transferred in the incubator housing 11, accelerating the flow of the temperature-controlled air and quickly adjusting the ambient temperature of the lidar.

[0040] In one embodiment, Figure 3 The shown heat preservation component 13 includes a first air blowing device 131, a second air blowing device 132, an air knife 133, and a heat preservation cavity wall 134. The air knife 133 is used to obtain an air curtain according to the temperature-controlled air. The air curtain and the heat preservation cavity wall 134 enclose a heat preservation cavity 135, and the lidar is located in the heat preservation cavity 135 during the test. In one example, the heat preservation cavity wall 134 is fixedly connected to the inner wall of the incubator housing 11. The air knife 133 is horizontally placed in the incubator housing 11, and both ends of the air knife 133 are fixedly connected to the inner wall of the incubator housing 11. The fixed connection includes bolt and nut connection, welding connection, strong glue bonding, or lap joint connection. The first air blowing device 131 is used to transfer the temperature-controlled air to the heat preservation cavity 135, so as to adjust the ambient temperature of the lidar. The second air blowing device 132 is used to transfer the temperature-controlled air to the air knife 133. In one example, the temperature-controlled air is transferred through the air knife 133 to form an air curtain with a vertically downward wind direction. The air curtain is used to cooperate with the heat preservation cavity wall 134 when the incubator door 12 is opened to isolate the heat preservation cavity 135 from the external environment and prevent the ambient temperature of the lidar from changing. In another example, the air knife 133 is vertically placed to form an air curtain with a horizontal wind direction to prevent heat exchange between the heat preservation cavity 135 and the external environment. In some embodiments, the heat preservation component 13 includes a plurality of air knives 133 that are abutted end to end. The plurality of air knives 133 are used to form an air curtain in the same plane with the same wind direction to cover a heat preservation cavity 135 with a larger size. In some embodiments, the heat preservation component 13 includes a plurality of air knives 133 that are stacked. The plurality of air knives 133 are used to form multiple air curtains with the same direction and in different planes to achieve a multiple heat insulation effect. In some embodiments, the heat preservation component 13 includes a plurality of air knives 133 that are placed opposite to each other. The plurality of air knives 133 are used to form multiple air curtains with different wind directions to achieve a multiple heat insulation effect.

[0041] In one embodiment,Figure 3 The first air blowing device 131 shown includes a first air collection hood 1311, a first blower 1312, and a first air duct 1313. The second air blowing device 132 includes a second air collection hood 1321, a second blower 1322, and a second air duct 1323. In one example, the air outlet is in communication with the first air collection hood 1311, and the air outlet is in communication with the second air collection hood 1312. The first air collection hood 1311 is used to collect the temperature-controlled air transmitted by the air outlet, and the first blower 1312 is used to transmit the temperature-controlled air collected by the first air collection hood 1311 to the first air duct 1313. The first air duct 1313 is in communication with the heat preservation cavity wall 134 and is used to transmit the temperature-controlled air into the cavity of the heat preservation cavity 135. The second air collection hood 1321 is used to collect the temperature-controlled air from the air outlet, and the second blower 1322 is used to transmit the temperature-controlled air collected by the second air collection hood 1321 to the second air duct 1323. The second air duct 1323 is in communication with the air knife 133 and is used to transmit the temperature-controlled air to the air knife 133. In one example, the air knife 133 has a rectangular air nozzle, and the temperature-controlled air transmitted by the second air duct 1323 is blown downward through the rectangular air nozzle to form an air curtain. The width of the rectangular air nozzle is adjustable and can be 0.1 mm, 0.5 mm, 1 mm, or 2 mm. The length of the rectangular air nozzle can be designed according to the size of the heat preservation cavity wall 134 to ensure that the air curtain can effectively isolate the heat preservation cavity 135 from the external environment. In some embodiments, the air knife includes a plurality of air nozzles, and the plurality of air nozzles can be used to form multiple layers of air curtains. The plurality of air nozzles can be distributed in parallel or staggered on the air knife. In some embodiments, the shape of the air nozzle also includes one or a combination of a rectangle, a triangle, or an ellipse, and the size and shape of the air nozzle can be designed according to the outer contour of the heat preservation cavity wall 134. In this embodiment, the heat insulation effect of the air curtain cooperates with the heat preservation effect of the heat preservation cavity wall 134 to jointly prevent the heat preservation cavity 135 from exchanging heat with the external environment, so as to maintain the environmental temperature of the lidar when the incubator door 12 is in the open state.

[0042] In one embodiment, Figure 3 The heat preservation cavity 135 shown further includes a temperature sensor, and the temperature sensor is used to monitor the environmental temperature inside the heat preservation cavity 135. In one example, the temperature control device is used to control the temperature of the temperature-controlled air according to the environmental temperature monitored by the temperature sensor. The first blower 1312 and the second blower 1322 are used to adjust the wind speed of the temperature-controlled air according to the environmental temperature monitored by the temperature sensor, so that the environmental temperature inside the heat preservation cavity 135 meets the test requirements. In another example, when the environmental temperature inside the heat preservation cavity 135 monitored by the temperature sensor is too high or too low, the second blower 1322 is in the off state. At this time, the incubator door 12 is in the open state, and the heat preservation cavity 135 exchanges heat with the external environment, so as to realize the rapid adjustment of the environmental temperature inside the heat preservation cavity 135.

[0043] In some embodiments, Figure 3The heat preservation cavity wall 134 shown is a heat preservation structure formed by a combination of one or more of materials such as rock wool board, aluminum alloy, ferroalloy, and glass wool. In one example, the heat preservation cavity wall 134 is a double-layer structure with a cavity made of two layers of 304 stainless steel plates, and the cavity is filled with polyurethane foam material. In another example, the heat preservation cavity wall 134 is a multi-layer heat preservation structure with at least one cavity formed by alternating layers of 304 steel plates and asbestos boards, and the cavity is filled with a combination of one or more of foaming materials such as silica gel, polyurethane, polystyrene, or phenolic aldehyde. The multi-layer heat preservation structure and the foaming material overlap with each other to achieve a multi-layer thermal sealing structure, which can effectively prevent the ambient temperature in the heat preservation cavity 135 from changing.

[0044] In some embodiments, Figure 2 and Figure 3 the incubator 10 shown can adjust the ambient temperature within a temperature range of -60 to 200 °C, -50 to 120 °C, or -40 to 85 °C, etc., and is used to test the performance of lidar under different simulated ambient temperature conditions. In some embodiments, the incubator 10 further includes a combination of one or more of an electromagnetic interference device, a strong light illumination device, a water spraying device, a spraying device, a dust spraying device, or a vibration device, which is used to simulate the real working conditions under different application scenarios such as electromagnetic interference, strong light irradiation, high temperature and high humidity, frost and snow weather, rain and fog weather, sand and dust weather, or bumpy road sections, so as to realize the performance test of lidar under different simulated environments.

[0045] In one embodiment, as Figure 4As shown, the test module 30 includes a mobile device 31 and a target 32. In one example, the mobile device 31 includes a controller 311, a slide rail 312, a rotating platform 313, and a moving platform 314. The controller 311 is used to control the rotation of the rotating platform 313. The controller 311 is also used to control the movement of the moving platform 314 on the slide rail 312, and the placement position and orientation of the slide rail 312 can be changed. The moving platform 314 is used to carry the rotating platform 313 and the target 32 to move on the slide rail 312, thereby changing the detection distance. The rotating platform 313 is used to drive the target 32 to rotate counterclockwise or clockwise, thereby changing the deflection angle of the target 32. In one example, the target 32 includes a double-sided reflector 321 and a target bracket 322. The double-sided reflector 321 includes two diffuse reflection surfaces, a first surface and a second surface, for reflecting the scanning beam emitted by the lidar. In one example, the surface reflectivity of the first surface is 1.2%, and the surface reflectivity of the second surface is 80%. Among them, the surface reflectivity refers to the reflection ability of the reflection surface for incident light, that is, the ratio of the intensity of the reflected light to the intensity of the incident light on the reflection surface. The target bracket 322 is used to carry the double-sided reflector 321. The rotating platform 313 is used to drive the target bracket 322 to rotate counterclockwise or clockwise, and further drive the double-sided reflector 321 to rotate counterclockwise or clockwise. In another example, the target bracket 322 is also used to adjust the relative height between the double-sided reflector 321 and the lidar, so that the scanning beam emitted by the lidar can smoothly reach the surface of the double-sided reflector 321.

[0046] In some embodiments, Figure 4 The double-sided reflector 321 shown can be replaced with a target with a characteristic pattern, and the characteristic pattern includes one or more combinations of a checkerboard, a QR code, a grayscale stripe, or an AprilTag. In one example, the characteristic pattern has scale information, and the processing module 20 can be used to obtain the point cloud information corresponding to the double-sided reflector 321 according to the echo signal. The processing module 20 is also used to obtain the detection accuracy of the lidar according to the point cloud information and the known scale information.

[0047] In one embodiment, the present application discloses a Figure 5 test system for a lidar as shown. The test system can also be used to test other performance parameters of the lidar at different ambient temperatures, and the performance parameters include one or more combinations of the minimum detection distance, the maximum detection distance, the field of view angle, or the point frequency. In some embodiments, the test system can also be used to test the performance of other sensing devices at different ambient temperatures, such as cameras, infrared detectors, millimeter-wave radars, or ultrasonic radars.

[0048] The above embodiments are a test system for a lidar disclosed in the present application. The test system simulates the ambient temperature of the lidar based on an incubator. And during the process of the lidar transmitting and receiving laser light, the incubator door is in an open state, and the laser beam does not exit through the observation window of the incubator door, thereby reducing the photon energy attenuation during the transmission and reception of the laser. This test system can be used to implement the performance test of the lidar under different ambient temperatures and different detection distances.

[0049] Based on Figures 1-5 the test system shown above, an embodiment of the present application discloses a test method for a lidar, as Figure 6 shown in the schematic flowchart of the test method.

[0050] S101. Adjust the ambient temperature of the lidar based on the incubator.

[0051] In one example, as shown in Figure 2 and Figure 3 when the preset ambient temperature is -20°C, the temperature control device cools the air transmitted through the return air outlet to form a temperature control air flow with a temperature not higher than -20°C. The temperature control air flow enters the heat preservation component 13 and the incubator housing 11 from the air outlet. The first blower 1312 transmits the temperature control air flow collected by the first air collection cover 1311 to the heat preservation cavity 135 through the first air duct 1313, so that the ambient temperature in the heat preservation cavity 135 gradually decreases. The temperature sensor located in the heat preservation cavity 135 monitors the ambient temperature. When the ambient temperature monitored by the temperature sensor reaches -20°C, the temperature control device adjusts the temperature of the temperature control air flow to -20°C. The second blower 1322 transmits the temperature control air flow collected by the second air collection cover 1321 to the air knife 133 through the second air duct 1323. The air knife 133 transmits the temperature control air flow to form an air curtain with a vertically downward wind direction, so that the ambient temperature in the heat preservation cavity 135 is maintained at -20°C. In another example, the preset ambient temperature is 80°C, and the temperature control device heats the air transmitted through the return air outlet to form a temperature control air flow with a temperature not lower than 80°C. When the ambient temperature monitored by the temperature sensor reaches 80°C, the temperature control device adjusts the temperature of the temperature control air flow to 80°C. The second blower 1322 transmits the temperature control air flow to the air knife 133 through the second air duct 1323 to form an air curtain, so that the ambient temperature in the heat preservation cavity 135 is maintained at 80°C.

[0052] In one embodiment, when the ambient temperature in the heat preservation cavity 135 needs to be rapidly increased or decreased, the second blower 1322 stops working, and the incubator door 12 is in an open state. So that the heat preservation cavity 135 exchanges heat with the external environment of the heat preservation cavity 135. When the ambient temperature monitored by the temperature sensor reaches the preset ambient temperature. The second blower 1322 resumes working, transmits the temperature control air flow to the air knife 133 through the second air duct 1323 to re-form an air curtain, and maintains the ambient temperature in the heat preservation cavity 135.

[0053] S102. Adjust the pose of the target object based on the mobile device. The lidar emits a scanning beam towards the target object and receives the echo signal.

[0054] In one embodiment, as Figure 4 shown, the test module 30 includes a mobile device 31 and a target object 32. The mobile device 31 includes a controller 311, a slide rail 312, a rotating platform 313, and a mobile platform 314. The target object 32 includes a double-sided reflector 321 and a target object bracket 322. The surface reflectivity of the first surface of the double-sided reflector 321 is 1.2%, and the surface reflectivity of the second surface of the double-sided reflector 321 is 80%. Based on the step S101, the controller 31 controls the rotating platform 313 to rotate, thereby changing the deflection angle of the double-sided reflector 321. In one example, the initial deflection angle of the double-sided reflector 321 is 0°, and the first surface of the double-sided reflector 321 faces the lidar. When the environmental temperature in the insulation chamber 135 is consistent with the preset environmental temperature, the incubator door 12 opens, and the lidar emits laser light towards the first surface of the double-sided reflector 321. The first surface reflects the laser to form an echo beam, and the lidar obtains the echo signal corresponding to the low-reflectivity surface based on the echo beam. The controller 31 keeps the mobile platform stationary and controls the rotating platform 313 to rotate counterclockwise by 180°, so that the side of the double-sided reflector 321 facing the lidar is the second surface with high reflectivity. The second surface reflects the laser to form an echo beam, and the lidar obtains the echo signal corresponding to the high-reflectivity surface based on the echo beam. In another example, the controller 311 controls the rotating platform 313 to rotate successively at a step angle of 10°, thereby successively changing the initial deflection angle of the double-sided reflector 321. The controller 31 keeps the mobile platform stationary during the interval time of each adjustment of the step angle, and controls the rotating platform 313 to rotate counterclockwise by 180°. So that the lidar obtains the echo signal corresponding to the low-reflectivity surface and the echo signal corresponding to the high-reflectivity surface at different initial deflection angles.

[0055] In one embodiment, based on the step S101, as Figure 4The controller 311 shown controls the mobile platform 314 to move on the slide rail 312, thereby changing the detection distance between the lidar and the double-sided reflector 321, and obtaining echo signals corresponding to different detection distances. In one example, the controller 311 controls the mobile platform 314 to move on the slide rail 312 such that the detection distance between the double-sided reflector 321 and the lidar is 10 m, and the reflectivity of the surface of the double-sided reflector 321 facing the lidar is 1.2%. The lidar 10 emits a scanning beam and receives the echo beam reflected by the double-sided reflector 321, obtaining the echo signal corresponding to an object with a surface reflectivity of 1.2% at a detection distance of 10 m. In another example, the reflectivity of the surface of the double-sided reflector 321 facing the lidar is 10%. The controller 311 controls the mobile platform 314 to move on the slide rail 312 with a step distance of 5 m, successively changing the detection distance of the lidar. The lidar obtains the echo signals corresponding to an object with a surface reflectivity of 10% at different detection distances according to the echo beam reflected by the double-sided reflector 321.

[0056] In one embodiment, based on the step S101, the controller 311 can control the rotary platform 313 to rotate clockwise and control the mobile platform 314 to move on the slide rail 312, thereby changing the initial deflection angle of the double-sided reflector 321 and the detection distance of the lidar. The lidar obtains the echo signals corresponding to different initial deflection angles and different detection distances according to the echo beam.

[0057] S103. The processing module obtains the performance parameters of the lidar according to the echo signal and the pose of the target object.

[0058] In one embodiment, based on the step S102, the processing module 20 obtains the detection probability of the lidar at a preset ambient temperature according to the echo signal and the detection distance. In one example, the detection distance between the lidar and the double-sided reflector 321 is 10 m, and the preset ambient temperature is 80°C. As Figure 4The surface reflectivity of the first side of the double-sided reflector 321 shown is 1.2%, and the surface reflectivity of the second side of the double-sided reflector 321 is 80%. The processing module 20 obtains the number of echo points M according to the echo signal actually received by the lidar when the side of the double-sided reflector 321 facing the lidar is the low-reflectivity side. The processing module 20 obtains the number of echo points N according to the echo signal actually received by the lidar when the side of the double-sided reflector 321 facing the lidar is the high-reflectivity side. The processing module 20 also obtains the detection probability of the lidar at a detection distance of 10 m and a preset ambient temperature of 80°C according to the ratio of the number of echo points M to the number of echo points N. In some embodiments, by changing the detection distance and the preset ambient temperature, the detection probability of the lidar at different detection distances and / or different preset ambient temperatures can be obtained. In some embodiments, by changing the initial deflection angle of the double-sided reflector 321, the detection probability of the lidar for the double-sided reflector 321 with different initial deflection angles can be obtained.

[0059] In one embodiment, based on the step S102, the processing module 20 obtains the maximum detection distance of the lidar at the preset ambient temperature according to the echo signal and the detection distance. In one example, the preset ambient temperature is -20°C, the reflectivity of the first side of the double-sided reflector 321 is 1.2%, the scanning beam emitted by the lidar is normally incident on the first side, and the initial detection distance between the lidar and the double-sided reflector 321 is 5 m. The controller 311 controls the mobile platform 314 to move on the slide rail 312 so that the detection distance gradually increases from 5 m until the power of the echo signal received by the lidar is exactly equal to the minimum detectable power, and the detection distance at this time is denoted as R 1.2％ . During the detection process of the lidar, when the detection target is a diffuse reflection target with a Lambertian surface, the maximum detection distance R of the lidar max is proportional to the square root of the surface reflectivity ρ of the target. Therefore, the maximum detection distances corresponding to targets with different surface reflectivities satisfy R 2 max1 / R 2 max2 = ρ1 / ρ2. According to the above proportional relationship and the value of R 1.2％ , the maximum detection distance R of the lidar for a target with a surface reflectivity of 10% can be obtained 10％ . In some embodiments, by changing the preset ambient temperature, the maximum detection distance of the lidar for a target with a surface reflectivity of 10% at different preset ambient temperatures can also be obtained. The lidar test system in the above embodiments can obtain the actual maximum detection distance of the lidar for targets with different surface reflectivities when the site is limited, which is beneficial to simplifying the test system, reducing the test cost, and improving the test efficiency.

[0060] In one embodiment, based on Figure 6 the test method shown, an embodiment of the present application discloses an automated test algorithm. The processing module 20 is used to store the automated test algorithm and send control instructions to perform automated testing. In one example, the processing module 20 sends a temperature control instruction to the incubator 10, and the temperature control instruction includes one or a combination of parameters such as a preset ambient temperature range, a step temperature, a heating rate, a cooling rate, or a heat preservation time. The processing module 20 sends a test instruction to the test module 30, and the test instruction includes one or a combination of test parameters such as a detection distance range, a step distance, a moving rate, an initial deflection angle of the target object, and a step angle. The processing module 20 sends a scanning instruction to the lidar, and the scanning instruction includes one or a combination of lidar operating parameters such as a scanning period, a working power, and a scanning beam orientation angle.

[0061] In one example, the automated test algorithm is used to test the detection probability of the lidar at different preset ambient temperatures and different detection distances. Based on Figures 1 to 5 the lidar test system shown, the double-sided reflector 321 is used as the detection target. The first side of the double-sided reflector 321 faces the lidar directly. In one example, the reflectivity of the first side is 1.2%, and the reflectivity of the second side is 80%. The echo signal obtained by the lidar within one scanning period is recorded as a frame of point cloud. The temperature control instruction sent by the processing module 20 to the incubator 10 includes a test temperature range T1 to T2, a step temperature S, and a heat preservation time t. The test instruction sent by the processing module 20 to the test module 30 includes a detection distance range L1 to L n , a step distance P, and a rotation signal. The controller 311 controls the rotation platform to rotate 180° according to the rotation signal, changing the surface reflectivity of the double-sided reflector 321 facing the lidar. During the test, the processing module 20 sends a temperature control instruction to the incubator, and the incubator 10 receives the temperature control instruction and maintains the temperature at T1 for t time. During the heat preservation time t, the controller 311 receives the test instruction and controls the moving platform 314 to move on the slide rail 312 so that the detection distance is equal to L1. The lidar emits a scanning beam according to the scanning instruction to obtain an echo signal corresponding to the first side. The lidar transmits the echo signal to the processing module 20. The processing module 20 respectively records the number of point clouds of 100 frames of point clouds as A1, A2, A3,..., A 100 . After collecting 100 frames of point clouds corresponding to the first side, the controller 311 controls the rotation platform 313 to rotate 180° according to the rotation signal. The lidar emits a scanning beam according to the scanning instruction to obtain an echo signal corresponding to the second side. The lidar transmits the echo signal to the processing module 20. The processing module 20 records the number of point clouds of 100 frames of point clouds as B1, B2, B3,..., B 100. The processing module 20 calculates the detection probability K1 of the lidar when the preset ambient temperature is T1 and the distance is L1 according to the obtained number of point clouds, where K1 = (A1 + A2 + A3 +... + A 100 ) / (B1 + B2 + B3 + … + B 100 ). Subsequently, the controller 311 changes the detection distance according to the test instruction by the step distance P. The lidar re-collects the echo signals corresponding to different reflectivity surfaces according to the scanning instruction. The processing module 20 obtains the detection probability K2 of the lidar at the detection distance L2, the detection probability K3 at the detection distance L3, …, and the detection probability K n at the detection distance L n according to the echo signals. After the above tests are completed, the incubator 10 ends the heat preservation according to the temperature control instruction, changes the ambient temperature successively by the step temperature S and maintains it for the time t respectively. During the heat preservation time t, the lidar obtains the echo signals corresponding to the first surface according to the scanning instruction. The test module 30 keeps the detection distance at L n unchanged and rotates the double-sided reflector 321 by 180°. The lidar obtains the echo signals corresponding to the second surface according to the scanning instruction. The processing module 20 obtains the number of point clouds of the frame point clouds corresponding to different reflectivity surfaces according to the echo signals corresponding to different reflectivity surfaces obtained by the lidar, and further obtains the detection probability of the lidar at different ambient temperatures when the detection distance is L n . This automated test algorithm can be used to implement the automated test of the detection probability of the lidar at different preset ambient temperatures and / or different detection distances, improving the test efficiency.

[0062] In the description of the present application, it should be understood that unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms “and / or” and “and / or” used herein describe the association relationship of associated objects and indicate that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character “ / ” generally represents an “or” relationship between the associated objects before and after. The singular forms “a” and “an” are also intended to include the plural forms unless the context clearly indicates otherwise. When the terms “comprise” and / or “include” are used in this specification, they indicate the presence of the described features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or their combinations, that is, they include any and all combinations of one or more of the related listed items. The ordinal numbers such as “first” and “second” cited in the embodiments of this application are only identifiers and do not refer to other meanings such as a specific order or imply relative importance.

[0063] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and diagonally above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and diagonally below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances. The "one or more embodiments" used herein do not refer to the same embodiments, but rather to any suitable combination of specific features, structures or characteristics. The above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A test system for a lidar, characterized in that, The test system includes an incubator, a test module, and a processing module; The incubator includes an incubator door, an incubator housing, a temperature control component, and a heat preservation component. The temperature control component and the heat preservation component are located inside the incubator housing; The temperature control component is used to generate temperature control air; The heat preservation component includes a heat preservation cavity wall and at least one air knife. The air knife is used to obtain an air curtain according to the temperature control air, and the air curtain and the heat preservation cavity wall enclose a heat preservation cavity; The test module includes a moving device and a target. The moving device is used to adjust the initial pose of the target to obtain the adjusted pose of the target; The processing module is used to obtain the performance parameters of the lidar according to the adjusted pose of the target and the echo signal. Wherein, the echo signal is obtained according to the target reflecting the scanning beam, and the scanning beam is emitted by the lidar.

2. The test system according to claim 1, wherein The heat preservation component includes a plurality of the air knives; Wherein, the plurality of air knives are abutted end to end; or the plurality of air knives are arranged in a stacked manner.

3. The test system according to claim 1, wherein The air knife includes at least one air nozzle, and the shape of the air nozzle includes one or more combinations of a rectangle, a triangle, or an ellipse.

4. The test system according to claim 1, characterized in that The temperature control component includes an air return port, a temperature control device, and an air outlet; The air return port is used to transfer the air inside the incubator housing to the temperature control device. The temperature control device is used to heat or cool the air to form the temperature control air, and the air outlet is used to transfer the temperature control air to the heat preservation component.

5. The test system according to claim 4, wherein The heat preservation component further includes a first air blowing device and a second air blowing device; The first air blowing device is used to transfer the temperature control air to the heat preservation cavity, and the second air blowing device is used to transfer the temperature control air to the air knife.

6. The test system according to claim 1, characterized in that, The heat preservation cavity wall is a heat preservation structure formed by one or more combinations of a rock wool board, a ferroalloy board, or an aluminum alloy board; 7. The test system according to claim 6, wherein There is at least one cavity between the heat preservation structures; The cavity is filled with one or more combinations of silica gel foam, polyurethane foam, polystyrene foam, or phenolic foam; 8. The test system according to claim 1, wherein, The incubator further includes one or more combinations of an electromagnetic interference device, a strong light illumination device, a water spraying device, a spraying device, or a dust spraying device; 9. The test system according to claim 1, characterized in that, The target includes one or more combinations of a reflector with a diffuse reflection surface or a target with a characteristic pattern; The characteristic pattern includes one or more combinations of a checkerboard, a two-dimensional code, or a grayscale stripe; 10. A testing method for a lidar, the lidar being located inside an incubator, the incubator including an incubator door, an incubator housing, a temperature control component, and a heat insulation component, the temperature control component and the heat insulation component being located inside the incubator housing, the heat insulation component including a heat insulation cavity wall and at least one air knife, characterized in that, The test method includes: Generating temperature control air based on the temperature control component, and transferring the temperature control air to the heat preservation component through the temperature control component; The air knife forms an air curtain according to the temperature control air, and the air curtain and the heat preservation cavity wall enclose a heat preservation cavity. The lidar is located inside the heat preservation cavity; The lidar emits a scanning beam towards the target. Wherein, the incubator door is in an open state; Adjusting the initial pose of the target based on the moving device to obtain the adjusted pose of the target, and the target reflects the scanning beam to form an echo beam; The lidar obtains an echo signal according to the echo beam; The processing module obtains the performance parameters of the lidar according to the adjusted pose of the target and the echo signal.

Images