Multi-branch laser radar distance simulation control system and control method thereof

Abstract

The present invention discloses a multi-branch laser radar distance simulation control system and a control method thereof, including a photoelectric coupling system, a single-channel simulation system, a 10×1 optical switch, a 1×10 optical switch, a photoelectric control system, and a self-test system; the photoelectric control system is used to control the optical switch of the single-channel simulation system to connect to the corresponding channel according to the simulated distance and energy value selected by the host computer, and perform on-off control, distance simulation control, and attenuation gear selection control; the single-channel simulation system is used to control the optical switch to select the corresponding delay optical fiber and optical fiber attenuator according to the simulated distance and energy value to be tested by the photoelectric control system. During the simulation control, the self-test system is first used to detect each optical path in the single-channel simulation system, and then the corresponding detection branch is selected according to the host computer instruction, and the simulated optical path delay and energy attenuation gear are selected according to the simulated distance and energy value to be tested, so as to form the required simulation optical path.

Description

Technical Field

[0001] The present invention relates to the field of laser radar testing technology, and in particular to a multi-branch laser radar distance simulation control system and an implementation method thereof. Background Art

[0002] As the main measuring equipment in various fields, laser radar must be tested and traced in situ for distance information to ensure the authority of the measurement data. However, there is still a lack of unified equipment for in-situ testing of different types of radar equipment. Usually, the test is carried out based on the self-test and simple calibration of the radar system, mainly functional testing, so it is difficult to find changes in technical indicators. As the user of the radar, it is generally sent to the corresponding scientific research unit for corresponding testing to solve this problem, but there are great difficulties in actual implementation. In terms of time, in addition to the long transportation time required for external testing, scientific research institutes are usually full of work and require a long queue, which will seriously affect the use time of the laser radar. In addition, external delivery not only consumes manpower and material resources, but also has safety hazards, such as uncertain factors such as traffic accidents and changes in technical indicators of equipment during long-distance transportation, which will affect the reference of external test indicators. A laser radar system and control method as disclosed include an optical module, a detection device, a plurality of laser generators and a processor, wherein the detection device is arranged between the optical module and the laser generator and is a linear array structure, each of the laser generators is coupled to the detector and is arranged in one direction respectively, and all the laser generators together constitute a laser scanning plane; each pixel point of the detection device simultaneously points to at least one of the corresponding laser generators; the steps of the control method are as follows: (a) acquiring image data of the detection device and extracting information such as the azimuth angle, pitch angle and target depth of the target; (b) converting the azimuth angle and target depth of the target into position information in the angular coordinate system of the laser beam and calculating the direction of the laser beam; (c) matching the position information of the laser beam with the azimuth angle of the angular coordinate system to obtain the azimuth angle and azimuth radius of the laser beam; (d) calculating the normal vector and reflection coefficient of the target surface irradiated by the laser beam based on the azimuth angle and azimuth radius of the laser beam obtained in step (c), thereby solving the loss amount on the laser transmission path. Although it can accurately measure the distance of the laser radar, it can only measure individually. If multiple types of laser radars are to be tested in situ, it is very troublesome and cannot meet the current actual needs. In addition, the existing laser radar is generally installed on cars or aircraft. Due to the influence of the moving carrier, when the carrier moves, it will vibrate or even bump, resulting in misjudgment caused by the external influence and increased error; secondly, the temperature of the external environment will also directly affect the actual performance of the laser radar, so it is necessary to design a laser radar that can reduce the interference of the moving carrier on it while maintaining a stable working state. Summary of the invention

[0003] In order to solve the above technical problems existing in the background technology, the present invention discloses a multi-branch laser radar distance simulation control system and a control method thereof, which can meet the test requirements of existing high-precision laser radar products. The laser radar distance simulation control system proposed in this scheme is the first one proposed in China, and the system has a simple and compact structure and can be well compatible with the test requirements of many existing typical high-precision and high-power laser radar products.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a multi-branch laser radar distance simulation control system, which realizes the control of laser distance simulation, including a photoelectric coupling system, a single-channel simulation system, a 10×1 optical switch, a 1×10 optical switch, a photoelectric control system, and a self-test system;

[0005] The 10×1 optical switch and the 1×10 optical switch each include 10 channels, which are channels corresponding to 8 detection branches of the laser radar, a 9th alternative channel, and a 10th self-test channel;

[0006] The photoelectric coupling system is used to receive the laser emitted by the laser radar and control the simulated distance and energy value of the laser before returning it to the laser radar; it includes a transmitting coupling module and a receiving coupling module, the input end of the transmitting coupling module is connected to the transmitting port of the laser radar, and the output end of the transmitting coupling module is connected to the 10×1 optical switch; the input end of the receiving coupling module is connected to the 1×10 optical switch, and its output end is connected to the receiving port of the laser radar;

[0007] The photoelectric control system is used to control the optical switch of the single-channel analog system to connect the corresponding channel according to the analog distance and energy value selected by the host computer, and perform on-off control, distance simulation control and attenuation gear selection control; the analog distance contains the length information of the two analog channels, and the length of each analog channel is different. When the signal of a certain analog channel needs to be changed, the corresponding optical switch can be modified according to the instruction to adjust the actual working analog path; the energy value is controlled by the optical attenuation subsystem;

[0008] The single-channel simulation system is used to control the optical switch to select the corresponding delay optical fiber and optical fiber attenuator according to the simulated distance and energy value to be tested by the photoelectric control system, so as to simulate the optical path delay and energy attenuation; the single-channel simulation system is composed of multiple delay optical fibers, multiple optical switches and optical attenuation subsystems, and the optical switch connects the corresponding delay optical fiber and optical fiber attenuator according to the instruction of the photoelectric control system to form a corresponding optical path; and the input end of the single-channel simulation system is connected to the 10×1 optical switch, and the output end is connected to the 1×10 optical switch;

[0009] The optical attenuation subsystem includes multiple optical fiber attenuators for simulating optical attenuation; and the delay optical fiber lengths are different, and the attenuation values ​​of at least two of the fixed optical fiber attenuators are different, which are used to set the laser energy attenuation to two levels of attenuation to ensure that the laser energy input to the laser radar reaches either saturated or unsaturated states.

[0010] The optical switch (SPDT Switch) includes a high-speed distance switching switch and an attenuation switching optical switch; the high-speed distance switching switch also serves as the input and output ends of the single-channel analog system; the attenuation switching optical switch is used to switch the optical fiber attenuator;

[0011] Among them, the attenuation switching optical switch and optical fiber attenuator are used to attenuate and adjust the power of the working light entering the instrument, so as to facilitate the provision of suitable data set samples for different scenarios; and the attenuation switching optical switch and optical fiber attenuator mainly play the role of attenuating light intensity rather than simply weakening the light intensity. Due to the limitations of the emission power of the laser itself and the simulation environment and other factors, the system must be able to flexibly control the range of light intensity and thus generate a suitable target curve data map.

[0012] The self-test system is used to detect each optical path formed by the single-path simulation system before simulation, and includes a self-test light source and a self-test detector. In the self-test stage, the self-test light source is connected to the 10th self-test channel of the 10×1 optical switch, and the self-test detector is connected to the 10th self-test channel of the 1×10 optical switch.

[0013] Furthermore, the multi-branch laser radar distance simulation control system also includes a communication module, which is connected to the host computer and the photoelectric control system and adopts a ttl level control communication mode.

[0014] Furthermore, the multi-branch laser radar distance simulation control system also includes a laser clamping device, which is used to accommodate the photoelectric coupling system, and the laser clamping device has a sealing mechanism that cooperates with the end face of the laser radar. The laser clamping device is used to install the simulation control system on the laser radar under test, and can be installed at the same position of the device under test; more preferably, the internal structure and shape of the laser clamping device are the same as the form of the product under test so that the two can be clamped tightly to avoid interference from external stray light.

[0015] Furthermore, the single-channel analog system includes a first 1×3 MEMS optical switch, a second 3×1 MEMS optical switch, a first delay optical fiber, a second delay optical fiber, a first 1×2 optical switch, a second 1×2 optical switch, a first 2×1 optical switch, a second 2×1 optical switch and an optical attenuation subsystem; the optical attenuation subsystem includes a first fixed optical fiber attenuator, a second fixed optical fiber attenuator, a third fixed optical fiber attenuator, a fourth fixed optical fiber attenuator, and necessary optical fiber jumpers. The optical attenuation subsystem is a laser attenuation system based on a fixed optical attenuator, and its function is to quantitatively attenuate the incoming laser energy.

[0016] Furthermore, the distance simulation control of the single-channel simulation system is to switch the delay optical fiber according to the on-off switching of the optical switch so that the multi-channel laser signals are switched and transmitted in different optical fiber branches to complete the delay simulation of different distances; the energy value control is to control the 1×2 optical switch and the 2×1 optical switch to select a fixed attenuation value.

[0017] The distance simulation system is mainly composed of optical path on-off switches and includes two main components: the first part is to set optical path on-off switches of different lengths but sufficient in number outside the distance simulation system; the second part is to use optical fibers of different lengths to form a distance simulation system to simulate a fixed distance.

[0018] Furthermore, the first delay optical fiber and the second delay optical fiber are multimode optical fibers, and the lengths thereof are determined according to the required detection distance and the lengths of the delay optical fibers used.

[0019] Furthermore, the 10×1 optical switch and the 1×10 optical switch work in two groups at the same time, and the switching time is 15ms; the first 1×3 optical switch and the second 3×1 optical switch work in two groups at the same time, and the switching time is 15ms, and the switching jitter time is 0.5ms; the first 1×2 optical switch, the second 1×2 optical switch, the first 2×1 optical switch and the second 2×1 optical switch work in two groups at the same time, and the switching time is 15ms.

[0020] The optical transmission channel involved in the present invention mainly includes the optical path channel of the laser clamping device, the optical path channel in the distance simulation control system and the multi-channel optical cable connecting the radar clamping equipment and the distance simulation system, which is mainly used for optical path transmission; the optical path channel refers to a complete low-loss optical path channel from the laser channel at the output end of the radar clamping device to the laser channel of the transceiver in the distance simulation control system.

[0021] Furthermore, the photoelectric coupling system is used to receive various types of laser sources, including 865nm~950nm lasers from the radar's eight detection branches, and can receive lasers at radial angles of 45°~50° and axial angles of 1.5°~2°. The coupling system can ensure that the laser is actually received within the 18° field of view.

[0022] The present invention also discloses a multi-branch laser radar distance simulation control method, which utilizes the multi-branch laser radar distance simulation control system, wherein the multi-branch laser radar distance simulation control system realizes the simulation distance and energy value control of the laser through an optical switch according to a control command, and specifically includes:

[0023] Step 1: Control system initialization and self-test

[0024] First, a self-test light source is connected to the self-test channel of the 10×1 optical switch, and a self-test detector is connected to the self-test channel of the 1×10 optical switch; a photoelectric control system controls the self-test light source to emit light, and a test light from the self-test light source enters the single-channel analog system through the self-test channel of the 10×1 optical switch, and is sequentially connected to the input end of the single-channel analog system, and a multi-channel optical path formed by the optical switch connection is detected, so that the self-test light source reaches the self-test detector after passing through the optical switch and the optical attenuation subsystem;

[0025] When the self-test detector outputs a high level, it is considered that the current detection optical path is normal and the next step is carried out; otherwise, the self-test is abnormal and the program ends;

[0026] Step 2: The 1×10 optical switch selects the corresponding detection branch according to the host computer instruction, selects the simulated optical path delay and energy attenuation gear according to the simulated distance and energy value to be tested, thereby controlling the opening / closing of the corresponding high-speed distance switching switch and attenuation switching optical switch, and connecting the corresponding delay optical fiber and optical fiber attenuator to form the required simulated optical path;

[0027] Then, it enters the 1×10 optical switch through the optical fiber jumper and is output to the receiving coupling module on the laser clamping device. The optical signal is then transmitted back to the laser radar receiving port to complete the in-situ test of the laser radar's distance information.

[0028] Furthermore, during the self-check process of the control system, it is also used to detect the switching time of different detection branches of the single-channel analog system; when the system is powered on, it will pass through the 10 channels of the 10×1 optical switch in turn, and detect the time for the light source to change from unstable to stable when the optical switch is switched. When the 10×1 optical switch and the 1×10 optical switch switch from channel 1 to the target channel, the corresponding time interval is calculated by monitoring the / READY pin of the optical switch, and the switching time of the simulated distance is reported to the photoelectric control system to complete the calculation of the switching time of the detection branch.

[0029] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0030] 1. The multi-branch laser radar distance simulation control system described in the present invention is constructed based on the characteristic that a single-beam laser is widely used as a detection means during the radar product testing process. It uses the light energy change output to the receiving window after the space laser passes through a specific optical path delay to perform in-situ measurement of the laser radar. Through the precise control of the spatial laser optical path delay time, the working state of the laser radar is tested based on the light energy change output to the receiving window after the laser passes through the specific optical path delay of the simulated optical path switching switch and the distance delay device. The present invention can not only meet the testing requirements of most types of existing high-precision laser radar products, but also has good scalability and compatibility. In the future, only certain components need to be added to adapt to the testing conditions of more types of radar model products.

[0031] 2. The present invention adopts multi-branch testing technology, which can collect, store and analyze 8-branch laser channel signals at the same time. After the optical signal emitted by the laser radar is switched by the MEMS optical switch, it is output to multiple branches, and each branch is collected and analyzed independently. And the acquisition results of each branch signal are automatically stored and analyzed.

[0032] 3. The present invention adopts a high-speed MEMS optical switch, and the switching time of each channel is less than 50ms, which ensures the real-time data collection and transmission between channels and ensures the high reliability of data collection and transmission.

[0033] 4. The laser light of the present invention, which has been delayed by an optical path, can be subjected to constant energy attenuation, and the simulation requirement of attenuation of the optical power amplitude of the echo signal can be achieved through an optical attenuator.

[0034] 5. The present invention can ensure the stability and reliability of the system and reduce the failure rate and maintenance cost of the system through a complete self-test function. When the system self-tests, the photoelectric control system controls the self-test light source to emit light, and the test light enters the optical path control system through the self-test light source interface, and judges the presence and size of the signal received by the self-test detector, and analyzes the status of different channels and the switching time between different channels. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flow chart of a multi-branch distance simulation control method of the system in the embodiment;

[0036] Figure 2 is a connection diagram of the first 1×10 optical switch in the embodiment;

[0037] Figure 3 is a flow chart of the principle of the self-test optical path;

[0038] Figure 4 is the schematic diagram of the single-channel simulation system;

[0039] Figure 5 It is a software control flow chart of the photoelectric control system described in the present invention.

[0040] in:

[0041] 101: transmission coupling module; 102: 10×1 optical switch; 103: 1×10 optical switch;

[0042] 104: receiving coupling module; 105: self-testing light source; 106: self-testing detector;

[0043] 1: first 1×3 optical switch; 2: first delay optical fiber; 3: second delay optical fiber; 4: first 1×2 optical switch;

[0044] 5: second 1×2 optical switch; 6: first fixed optical fiber attenuator; 7: second fixed optical fiber attenuator;

[0045] 8: third fixed optical fiber attenuator; 9: fourth fixed optical fiber attenuator; 10: first 2×1 optical switch;

[0046] 11: second 2×1 optical switch; 12: second 3×1 optical switch. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The described specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0048] Reference will now be made in detail to specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Although the present invention will be described in conjunction with specific embodiments, it will be understood that it is not intended to limit the present invention to the embodiments described. On the contrary, it is intended to cover changes, modifications and equivalents included in the spirit and scope of the present invention as defined by the appended claims. It should be noted that the method steps described herein can all be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of the two.

[0049] In the description of the following embodiments, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this patent.

[0050] In the description of the following embodiments, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0051] like Figure 1 As shown, a multi-branch laser radar distance simulation control system includes a photoelectric coupling system, a 10×1 optical switch 102, a 1×10 optical switch 103, a single-channel simulation system, a photoelectric control system, a self-test system and a laser clamping device (the self-test system is in Figure 1 not shown).

[0052] The optoelectronic coupling system includes a transmitting coupling module 101 and a receiving coupling module 104: the transmitting coupling module 101 is used to receive lasers emitted from different channels of the laser radar, and its input end is connected to the optical signal through an optical fiber, and its output end is connected to a 10×1 optical switch 102, and the other end of the 10×1 optical switch 102 is connected to a single-channel analog system; the receiving coupling module 104 is used to recouple the lasers emitted from different channels to the receiving windows of the laser radars corresponding to the different channels after delay and attenuation, and the input end of the receiving coupling module 104 is connected to a 1×10 optical switch 103, and the other end of the 1×10 optical switch 103 is connected to a single-channel analog system. Figure 2 As shown, the 10×1 optical switch 102 and the 1×10 optical switch 103 each include 10 channels, which are channels corresponding to 8 detection branches of the radar, a 9th alternative channel, and a 10th self-test channel; the photoelectric coupling system installs the optical fiber jumper of the FCPC interface in the mechanical structure by screws to realize the laser coupling function.

[0053] The photoelectric coupling system is located in the laser clamping device, which includes an upper shell and a lower shell, which can be closed; the laser clamping device is made of aluminum alloy as a whole, and the aluminum alloy is used because of its advantages of light weight, high strength and easy processing; and the incident end and the output end of the analog control system are the transmitting coupling module 101 and the receiving coupling module 104, the laser radar transmitting port passes through the laser clamping device to connect with the transmitting coupling module 101, and the laser radar receiving port passes through the laser clamping device to connect with the receiving coupling module 104. The transmitting coupling module 101 couples the laser output by the laser into the optical fiber, and delays it differently through the first delay optical fiber 2 and the second delay optical fiber 3, and then enters the product under test through the receiving coupling module 104 after attenuation. In addition, the sealing of the two end faces of the laser radar is carried out through the left sealing cover and the right sealing cover. There are sealing ring mechanisms on the two sealing covers that cooperate with the end faces of the laser radar, and cooperate with the inner cavity of the end face of the laser radar, and a part of sponge is pre-placed in the cable hole to protect and seal the cable. The emission coupling module 101 can receive laser light at an angle ranging from 45° to 50° at a radial angle and 1.5° to 2° at an axial angle.

[0054] The single-channel simulation system includes multiple optical switches and optical attenuation subsystems; the single-channel simulation system includes an input end and an output end, wherein the input end is connected to a 10×1 optical switch 102, and the output end is connected to a 1×10 optical switch 103. The single-channel simulation system can test eight different detection branches of the laser radar through the 1×10 optical switch.

[0055] The photoelectric control system uses Ethernet communication for communication between the host computer and the entire photoelectric system, and controls all optical switches of the communication control system through TTL level. The photoelectric control system is used to perform on-off control, distance simulation control and attenuation control on the optical switches and optical fiber attenuators of the single-channel analog system.

[0056] The photoelectric control system controls the on-off control, distance simulation control and attenuation gear selection of the optical switch of the single-channel analog system through ttl level control communication; the distance simulation control is to switch the delay optical fiber according to the on-off switching of the optical switch so that the multi-channel laser signals are switched and transmitted in different optical fiber branches to complete the delay simulation of different distances; the attenuation control is to control the 1×2 optical switch and the 2×1 optical switch to select the fixed attenuation value. In this embodiment, the spatial 865nm~950nm laser signal of the 8 branches of the laser radar is connected to the transmitting coupling module 101 through the optical fiber jumper, coupled to the inside of the photoelectric coupling system, and recoupled to the receiving coupling module 104 of the 8 corresponding branches of the analog control system after delay and attenuation in the single-channel analog system. The control signal parsed by the photoelectric control system performs the on-off control of each of the eight signals. The photoelectric control system can control the workflow and distance switching according to the instructions of the test equipment.

[0057] The self-test system includes a self-test light source 105 and a self-test detector 106. In the self-test stage, the self-test light source 105 is connected to the input end of the distance simulation control system (the 10th channel of the first 1×10 optical switch), and the self-test detector 106 is connected to the output end of the distance simulation control system (i.e., the 10th channel of the second 1×10 optical switch).

[0058] Specifically, Figure 4 As shown, the single-channel simulation system includes a first 1×3 MEMS optical switch 1, a second 3×1 MEMS optical switch 12, two delay optical fibers (a first delay optical fiber 2 and a second delay optical fiber 3), a first 1×2 optical switch 4, a second 1×2 optical switch 5, a first 2×1 optical switch 10, a second 2×1 optical switch 11 and an optical attenuation subsystem; the optical attenuation subsystem includes a first fixed optical fiber attenuator 6, a second fixed optical fiber attenuator 7, a third fixed optical fiber attenuator 8, and a fourth fixed optical fiber attenuator 9. The fixed optical fiber attenuator is used to simulate optical attenuation and includes necessary optical fiber jumpers.

[0059] The input end of the first 1×3 optical switch 1 is connected to the 10×1 optical switch 102, the output end of the first 1×3 optical switch 1 is respectively connected to the first delay optical fiber 2 and the second delay optical fiber 3, the output end of the first delay optical fiber 2 is connected to the first 1×2 optical switch 4, the output end of the first 1×2 optical switch 4 is respectively connected to the first fixed optical fiber attenuator 6 and the second fixed optical fiber attenuator 7, the output ends of the first fixed optical fiber attenuator 6 and the second fixed optical fiber attenuator 7 are connected to the third 1×2 optical switch 10; the output end of the second delay optical fiber 3 is connected to the second 1×2 optical switch 5, the output end of the second 1×2 optical switch 5 is respectively connected to the third fixed optical fiber attenuator 8 and the fourth fixed optical fiber attenuator 9, the output ends of the third fixed optical fiber attenuator 8 and the fourth fixed optical fiber attenuator 9 are connected to the second 2×1 optical switch 11; the output ends of the first 2×1 optical switch 10 and the second 2×1 optical switch 11 are connected to the second 3×1 optical switch 12 to restore to one output, and then connected to the photoelectric control system.

[0060] The single-channel simulation system forms four optical paths according to the host computer instruction, wherein the first optical path passes through: the first delay optical fiber 2, the first 1×2 optical switch 4, the second fixed optical fiber attenuator 7, the first 2×1 optical switch 10, and is output to the second 3×1 optical switch 12; the second optical path passes through: the first delay optical fiber 2, the first 1×2 optical switch 4, the first fixed optical fiber attenuator 6, the first 2×1 optical switch 10, and then is output to the second 3×1 optical switch 12; the third optical path passes through: the second delay optical fiber 3, the second 1×2 optical switch 5, the fourth fixed optical fiber attenuator 9, the second 2×1 optical switch 11, and then is output to the second 3×1 optical switch 12; the fourth optical path passes through: the second delay optical fiber 3, the second 1×2 optical switch 5, the third fixed optical fiber attenuator 8, the second 2×1 optical switch 11, and then is output to the second 3×1 optical switch 12.

[0061] The lengths of the first delay optical fiber 2 and the second delay optical fiber 3 are determined according to the detection distance requirements and the length of the delay optical fiber used, and the lengths of the two delay optical fibers are different; and the first delay optical fiber 2 and the second delay optical fiber 3 are multimode optical fibers, and the optoelectronic coupling system can ensure that the laser is actually received within the 18° field of view.

[0062] The calculation method for the simulated distance of 52m and 72m is as follows:

[0063] The transmission speed of light waves and electromagnetic waves in a vacuum is c=3×10 5 km / s. Light propagates in a straight line in a homogeneous medium, and its speed is inversely proportional to the refractive index of the medium, that is:

[0064] Vn=c / n………………(1)

[0065] Where n represents the refractive index of the medium, 1.458; c represents the speed of light in a vacuum.

[0066] The refractive index of light in a vacuum is 1, and the refractive index of other media is greater than 1, so the transmission speed is lower than that in a vacuum. The refractive index of air is approximately 1, and the refractive index of quartz optical fiber is 1.458, so the speed of light waves is v=2×10 5 km / s.

[0067] Dn=D / n……………………(2)

[0068] Then the simulated optical fiber length of 52m is: Dn(52m)=52 / 1.458=35.6653m.

[0069] Simulate the optical fiber length of 72m: Dn(72m)=72 / 1.458=49.3827m.

[0070] Where D is the actual distance in the simulation space, and n is the medium light refractive index n=1.458.

[0071] like Figure 2-4 As shown, the optical switches are divided into three types: one is a transmitting coupling and receiving coupling optical switch, namely, a 10×1 optical switch 102 and a 1×10 optical switch 103, two groups work simultaneously, and the switching time is 15ms; one is a high-speed distance switching switch, including a first 1×3 optical switch 1 and a second 3×1 optical switch 12, two groups work simultaneously, the switching time is 15ms, and the switching jitter time is 0.5ms; one is an attenuation switching optical switch, including a first 1×2 optical switch 4, a second 1×2 optical switch 5, a first 2×1 optical switch 10 and a second 2×1 optical switch 11, two groups work simultaneously, and the switching time is 15ms.

[0072] The laser that has been delayed by the simulated optical path needs to be attenuated with a fixed value of energy. It is used to automatically simulate the change in the optical energy of the space laser input to the corresponding receiving window of the distance simulator after the target detection light is attenuated. The laser energy attenuation is set to two levels of attenuation to ensure that the laser energy input to the corresponding receiving window of the distance simulation system reaches saturation or unsaturation. The first, second, third, and fourth fixed optical fiber attenuators in this system have powers of 2dB, 5dB, 2dB, and 7dB, respectively.

[0073] like Figure 5 As shown, the control method of the multi-branch laser radar distance simulation photoelectric control system includes:

[0074] Step 1: Control system initialization and self-test

[0075] S11: Determine whether the working mode is real-time dynamic or preset working state. If it is set to real-time dynamic, enter the subsequent automatic simulation stage.

[0076] S12: Figure 2-3 As shown, to perform self-test, first connect the self-test light source 105 to the 10th channel of the 10×1 optical switch 102, and connect the self-test detector 106 to the 10th channel of the 1×10 optical switch 103; the photoelectric control system controls the self-test light source 105 to emit light, and the test light from the self-test light source 105 enters the 10th channel of the 10×1 optical switch through the self-test light source interface. Figure 4 In the single-channel analog system shown, the optical path passes through the optical switch and the optical attenuation subsystem in sequence before reaching the self-test detector 106. Under normal circumstances, the self-test detector 106 outputs a high level, which can be recognized by the circuit board of the photoelectric control system;

[0077] S13: Then the self-test light source 105 is connected to the input end of the single-channel analog system in turn for detection. If all are normal, the photoelectric control system reports a "self-test normal" signal and proceeds to the next step; otherwise, when the signal received by the self-test detector does not match the response signal of the light source, the self-test is abnormal, and a "self-test abnormal" signal is reported to the communication module to end the program;

[0078] S14: The self-test system is also used to detect the switching time of different optical paths of the single-channel analog system. When the system is powered on, it will pass through the 10 channels of the 10×1 optical switch 102 in sequence, and detect the time it takes for the light source to change from unstable to stable when the optical switch is switched. When the 10×1 optical switch 102 and the 1×10 optical switch 103 switch from channel 1 to the target channel, the corresponding time interval is calculated by monitoring the / READY pin of the optical switch, and the switching time of the simulated distance is reported to the photoelectric control system.

[0079] Step 2: The host computer transmits instructions through the communication module, and the 1×10 optical switch 103 selects the corresponding detection branch according to the host computer instructions; Figure 2 As shown, the 10×1 optical switch 102 and the 1×10 optical switch 103 each include 10 channels, which are channels corresponding to 8 detection branches of the radar, a 9th alternative channel, and a 10th self-test channel;

[0080] Subsequently, the first 1×3 optical switch 1 selects the first delay optical fiber 2 according to the host computer simulation distance gear instruction, and then controls the first 1×2 optical switch 4 to select the attenuation gear according to the host computer instruction, and selects the second fixed optical fiber attenuator 7 connected thereto, whose power is 5dB; the first 2×1 optical switch 10 selects the attenuation gear according to the host computer instruction, and the optical path passes through the first delay optical fiber 2, the first 1×2 optical switch 4, the second fixed optical fiber attenuator 7, the first 2×1 optical switch 10 in sequence, and then outputs to the second 3×1 optical switch 12; wherein, the first 1×3 optical switch 1 and the second 3×1 optical switch 12 select the same simulation distance gear;

[0081] Then, the optical signal enters the 1×10 optical switch 103 through the optical fiber jumper and is output to the receiving coupling module 104 on the laser clamping device. The optical signal is then transmitted back to the laser radar receiving port to complete the in-situ test of the laser radar's distance information.

[0082] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A multi-branch laser radar distance simulation control system, characterized in that: It realizes the selection and control of laser through mechanical devices, including a photoelectric coupling system, a single-channel analog system, a 10×1 optical switch (102), a 1×10 optical switch (103), a photoelectric control system, and a self-test system; The photoelectric coupling system is used to receive the laser emitted by the laser radar and control the simulated distance and energy value of the laser before returning it to the laser radar; It comprises a transmitting coupling module (101) and a receiving coupling module (104), wherein the input end of the transmitting coupling module (101) is connected to the transmitting port of the laser radar, and the output end of the transmitting coupling module (101) is connected to a 10×1 optical switch (102); the input end of the receiving coupling module (104) is connected to a 1×10 optical switch (103), and the output end thereof is connected to the receiving port of the laser radar; The 10×1 optical switch (102) and the 1×10 optical switch (103) each include 10 channels, which are channels corresponding to 8 detection branches of the laser radar, as well as an alternative channel and a self-test channel; The photoelectric control system is used to control the optical switch of the single-channel analog system to connect the corresponding channel according to the analog distance and energy value selected by the host computer, and perform on-off control, distance simulation control and attenuation gear selection control; the analog distance contains the length information of two analog paths, and the length of each analog path is different. When the signal of a certain analog path needs to be changed, the corresponding optical switch can be modified according to the instruction to adjust the actual working analog path; the energy value is controlled by the optical attenuation subsystem; The single-channel simulation system is used to control the optical switch to select the corresponding delay optical fiber and optical fiber attenuator according to the simulated distance and energy value to be tested by the optoelectronic control system, so as to simulate the optical path delay and energy attenuation; the single-channel simulation system is composed of a plurality of delay optical fibers, a plurality of optical switches and an optical attenuation subsystem, and the optical switch is connected to the corresponding delay optical fiber and optical attenuation subsystem according to the instruction of the optoelectronic control system to form a corresponding optical path; and the input end of the single-channel simulation system is connected to a 10×1 optical switch (102), and the output end is connected to a 1×10 optical switch (103); the optical attenuation subsystem includes a plurality of optical fiber attenuators for simulating optical attenuation; and the lengths of the delay optical fibers are different, and the attenuation values ​​of at least two of the optical fiber attenuators are different, so as to set the laser energy attenuation to two levels of attenuation, so as to ensure that the laser energy input to the laser radar reaches two states of saturation or unsaturation; The optical switch includes a high-speed distance switching switch and an attenuation switching optical switch; the high-speed distance switching switch also serves as the input and output ends of the single-channel analog system; the attenuation switching optical switch is used to switch the optical fiber attenuator; The self-test system comprises a self-test light source (105) and a self-test detector (106). In the self-test stage, the self-test light source (105) is connected to the 10th self-test channel of the 10×1 optical switch (102), and the self-test detector (106) is connected to the 10th self-test channel of the 1×10 optical switch (103). The self-test system is used to detect each optical path formed by the single-channel simulation system before simulation. The photoelectric control system controls the self-test light source to emit light. The test light from the self-test light source (105) enters the single-channel simulation system through the self-test channel of the 10×1 optical switch (102), and is sequentially connected to the input end of the single-channel simulation system. The multiple optical paths formed by the optical switch connection are detected, so that the self-test light source reaches the self-test detector (106) after passing through the optical switch and the optical attenuation subsystem. When the self-test detector (106) outputs a high level, it is considered that the optical path currently being detected is normal, otherwise it is considered that the self-test is abnormal and the program ends; During the self-check process, it is also used to detect the switching time of different detection branches of the single-channel analog system; when the system is powered on, it will pass through the 10 channels of the 10×1 optical switch (102) in sequence, and detect the time when the light source changes from unstable to stable when the optical switch is switched; when the 10×1 optical switch (102) and the 1×10 optical switch (103) switch from channel 1 to the target channel, the corresponding time interval is calculated by monitoring the / READY pin of the optical switch, and the switching time of the simulation distance is reported to the photoelectric control system, thereby completing the calculation of the detection branch switching time.

2. The multi-branch laser radar distance simulation control system according to claim 1, characterized in that: The multi-branch laser radar distance simulation control system also includes a communication module, which is connected to the host computer and the photoelectric control system and adopts a ttl level control communication mode.

3. The multi-branch laser radar distance simulation control system according to claim 1, characterized in that: The multi-branch laser radar distance simulation control system also includes a laser clamping device, which is used to accommodate the photoelectric coupling system, and the laser clamping device has a sealing mechanism that cooperates with the end face of the laser radar.

4. The multi-branch laser radar distance simulation control system according to claim 1, characterized in that: The single-channel analog system comprises a first 1×3 optical switch (1), a second 3×1 optical switch (12), a first delay optical fiber (2), a second delay optical fiber (3), a first 1×2 optical switch (4), a second 1×2 optical switch (5), a first 2×1 optical switch (10), a second 2×1 optical switch (11) and an optical attenuation subsystem; the optical attenuation subsystem comprises a first fixed optical fiber attenuator (6), a second fixed optical fiber attenuator (7), a third fixed optical fiber attenuator (8), a fourth fixed optical fiber attenuator (9), and necessary optical fiber jumpers.

5. The multi-branch laser radar distance simulation control system according to claim 4, characterized in that: The distance simulation control of the single-channel simulation system is to switch the delay optical fiber according to the on-off switching of the optical switch so that the multi-channel laser signals are switched and transmitted in different optical fiber branches to complete the delay simulation of different distances; the energy value control is to control the 1×2 optical switch and the 2×1 optical switch to select the fixed attenuation value.

6. The multi-branch laser radar distance simulation control system according to claim 4, characterized in that: The first delay optical fiber (2) and the second delay optical fiber (3) are multimode optical fibers, and the lengths thereof are determined according to the required detection distance and the lengths of the delay optical fibers used.

7. The multi-branch laser radar distance simulation control system according to claim 5, characterized in that: The 10×1 optical switch (102) and the 1×10 optical switch (103) are operated in two groups at the same time, and the switching time is 15 ms; the first 1×3 optical switch (1) and the second 3×1 optical switch (12) are operated in two groups at the same time, and the switching time is 15 ms, and the switching jitter time is 0.5 ms; the first 1×2 optical switch (4), the second 1×2 optical switch (5), the first 2×1 optical switch (10) and the second 2×1 optical switch (11) are operated in two groups at the same time, and the switching time is 15 ms.

8. The multi-branch laser radar distance simulation control system according to claim 1, characterized in that: The photoelectric coupling system receives 865nm-950nm lasers from 8 detection channels of the radar, and the receiving laser angle range is 45°-50° at a radial angle and 1.5°-2° at an axial angle.

9. A multi-branch laser radar distance simulation control method, which uses the multi-branch laser radar distance simulation control system as claimed in claim 1, wherein the simulation control system realizes the simulation distance and energy value control of the laser through an optical switch according to the command of the host computer, comprising: Step 1: Control system initialization and self-test First, a self-test light source (105) is connected to the self-test channel of a 10×1 optical switch (102), and a self-test detector (106) is connected to the self-test channel of a 1×10 optical switch (103); a photoelectric control system controls the self-test light source to emit light, and the test light from the self-test light source (105) enters the single-channel analog system through the self-test channel of the 10×1 optical switch (102), and is sequentially connected to the input end of the single-channel analog system, and the multi-channel optical paths formed by the optical switch connection are tested, so that the self-test light source reaches the self-test detector (106) after passing through the optical switch and the optical attenuation subsystem; When the self-test detector (106) outputs a high level, it is considered that the optical path currently being detected is normal, and the next step is performed; otherwise, the self-test is abnormal, and the program ends; Step 2: The 1×10 optical switch (103) selects the corresponding detection branch according to the host computer instruction, thereby controlling the opening / closing of the corresponding high-speed distance switching switch and the attenuation switching optical switch, connecting the corresponding delay optical fiber and the optical fiber attenuator, and selecting the simulated optical path delay and energy attenuation gear according to the simulated distance and energy value to be tested, so as to form the required simulated optical path; Then, the optical signal enters the 1×10 optical switch (103) through the optical fiber jumper and is output to the receiving coupling module (104) on the laser clamping device, and then the optical signal is transmitted back to the laser radar receiving port, thereby completing the in-situ test of the distance information of the laser radar.

10. The control method according to claim 9, characterized in that: During the self-checking process of the control system, it is also used to detect the switching time of different detection branches of the single-channel analog system; when the system is powered on, it will pass through the 10 channels of the 10×1 optical switch (102) in sequence, and detect the time when the light source changes from unstable to stable when the optical switch is switched; when the 10×1 optical switch (102) and the 1×10 optical switch (103) switch from channel 1 to the target channel, the corresponding time interval is calculated by monitoring the / READY pin of the optical switch, and the switching time of the simulation distance is reported to the photoelectric control system, thereby completing the calculation of the detection branch switching time.

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