Laser positioning method, processing chip unit and laser positioning system

Abstract

The invention provides a laser positioning method, a processing chip unit and a laser positioning system.The method is applied to the processing chip unit in the laser positioning system, the laser positioning system further comprises a transmitting device and a receiving device which are connected with the processing chip unit, and the method comprises the steps that the transmitting device is controlled to output a laser signal to a measured object; receiving a feedback signal sent by the receiving device, wherein the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object; determining the time difference between the time when the transmitting device outputs the laser signal to the measured object and the time when the transmitting device receives the feedback signal; correcting the time difference by using a carry delay chain method to obtain the flight duration of the laser signal; and positioning the measured object according to the flight duration. The carry delay chain method is introduced into the laser positioning method, so that the measurement precision of the flight duration of the laser signal is improved, and the laser positioning precision is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser ranging, and in particular to a laser positioning method, a processing chip unit and a laser positioning system. Background Art

[0002] As a high-precision distance measurement sensor, laser distance measurement equipment or laser positioning equipment (such as laser radar) is a key information collection device that is vigorously developed in the field of driverless cars and drones. The principle of laser positioning equipment is to calculate the distance between the equipment and the object under test based on the flight time of the laser signal when the speed of light is known. Therefore, the measurement accuracy of the laser signal flight time determines the positioning accuracy of the laser positioning equipment. Therefore, how to improve the measurement accuracy of the flight time is an issue that needs to be considered in the design process of laser positioning equipment or laser distance measurement equipment. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a laser positioning method, a processing chip unit and a laser positioning system, aiming to improve the measurement accuracy of flight time during laser ranging.

[0004] In a first aspect, an embodiment of the present application provides a laser positioning method, the method is applied to a processing chip unit in a laser positioning system, the laser positioning system also includes a transmitting device and a receiving device connected to the processing chip unit, the method includes:

[0005] Controlling the transmitting device to output a laser signal to the object to be measured;

[0006] receiving a feedback signal sent by the receiving device, wherein the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object;

[0007] Determine the time difference between controlling the transmitting device to output the laser signal to the measured object and receiving the feedback signal;

[0008] Correcting the time difference by using a carry delay chain method to obtain the flight time of the laser signal;

[0009] The measured object is positioned according to the flight duration.

[0010] In some embodiments, the receiving device includes a signal amplification module, a trigger module and a time identification module, the trigger module is connected to the amplification module, the time identification module is connected to the amplification module, and the feedback signal is obtained by the trigger module converting the voltage signal, and the voltage signal is obtained by the amplification module converting the echo signal.

[0011] Before positioning the measured object according to the flight duration, the method further includes:

[0012] Dynamically adjusting the reference voltage of the time identification module according to the strength of the echo signal;

[0013] Sending the dynamically adjusted reference voltage to the time identification module, so that the time identification module outputs an identification signal when the voltage signal is greater than the reference voltage;

[0014] Determining a dynamic delay duration according to the arrival time of the feedback signal and the arrival time of the identification signal;

[0015] Performing delay compensation on the flight duration according to the dynamic delay duration and the configured fixed delay duration;

[0016] The positioning of the measured object according to the flight duration includes:

[0017] The object to be measured is positioned according to the flight time after the delay compensation.

[0018] In some embodiments, controlling the transmitting device to output a laser signal to the object under test includes:

[0019] Controlling the transmitting device to output a laser signal to the object to be measured and generating a start signal at the same time;

[0020] The receiving the feedback signal sent by the receiving device includes:

[0021] receiving a feedback signal sent by the receiving device and generating a stop signal;

[0022] The determining and controlling the time difference between the transmitting device outputting the laser signal to the measured object and receiving the feedback signal comprises:

[0023] The time difference is determined according to a generation time of the start signal and a generation time of the stop signal.

[0024] In some embodiments, the time difference is corrected by using a carry delay chain method to obtain the flight time of the laser signal, including:

[0025] Inputting the stop signal into a carry delay chain, wherein the carry delay chain includes a plurality of logic units, and the plurality of logic units are sequentially connected;

[0026] Acquire signal arrival information of the multiple logic units, and correct the time difference according to the signal arrival information and the delay duration of each of the logic units to obtain the flight duration, wherein the signal arrival information is used to indicate whether each of the logic units has received the stop signal.

[0027] In some embodiments, the method further comprises:

[0028] Inputting a plurality of random signals into the carry delay chain;

[0029] The number of times each of the logic units receives the random signal is obtained, and the delay duration of each of the logic units is adjusted according to the number of times.

[0030] In some implementations, before positioning the measured object according to the flight duration, the method further includes:

[0031] Using a circular buffer to store the flight duration;

[0032] The positioning of the measured object according to the flight duration includes:

[0033] The flight duration is obtained from the ring buffer, and the object under test is positioned according to the flight duration.

[0034] In some implementations, positioning the detected object according to the flight duration includes:

[0035] Acquiring output information of the laser signal, wherein the output information includes an output frequency and an output angle of the laser signal;

[0036] The coordinates of the measured object are determined according to the flight duration and the output information.

[0037] In some embodiments, after determining the coordinates of the measured object according to the flight duration and the output information, the method further includes:

[0038] When there are multiple coordinates of the object to be measured, point cloud data of the object to be measured is generated.

[0039] In a second aspect, an embodiment of the present application provides a processing chip unit, which is applied to a laser positioning system. The laser positioning system also includes a transmitting device and a receiving device connected to the processing chip unit. The processing chip unit includes:

[0040] A control module, used to control the transmitting device to output a laser signal to the object to be measured;

[0041] A receiving module, used to receive a feedback signal sent by the receiving device, wherein the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object;

[0042] A determination module, used to determine the time difference between controlling the emitting device to output the laser signal to the measured object and receiving the feedback signal;

[0043] A correction module, which uses a carry delay chain method to correct the time difference to obtain the flight time of the laser signal;

[0044] A positioning module is used to locate the object under test according to the flight duration.

[0045] In a third aspect, an embodiment of the present application provides a laser positioning system, which includes a transmitting device, a receiving device and a processing chip unit, wherein the processing chip unit is connected to the transmitting device and the receiving device, and the processing chip unit is used to execute the laser positioning method provided in the first aspect of the embodiment of the present application.

[0046] In the embodiment of the present application, the laser positioning method is implemented in the processing chip unit in the laser positioning system. The processing chip unit outputs a laser signal to the object to be measured by controlling the transmitting device, and receives the echo signal fed back by the receiving device, and determines the time difference between the laser signal emission and the echo signal reception. In traditional measurements, due to limitations such as hardware delays and clock accuracy, the measurement of time differences is prone to errors. In the embodiment of the present application, the time difference is corrected using the carry delay chain method, that is, the coarse measurement is combined with the fine measurement to improve the accuracy of the flight time measurement result. That is, the embodiment of the present application introduces the carry delay chain method in the laser positioning method to improve the measurement accuracy of the laser signal flight time, thereby improving the accuracy of laser positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the process of the laser positioning method provided in the embodiment of the present application;

[0048] Figure 2 is a schematic diagram of the structure of a laser positioning system provided in an embodiment of the present application;

[0049] Figure 3 is another structural schematic diagram of the laser positioning system provided in an embodiment of the present application;

[0050] Figure 4 is a schematic diagram of signal delay provided in an embodiment of the present application;

[0051] Figure 5 It is a schematic diagram of a coordinate calculation method provided in an embodiment of the present application;

[0052] Figure 6 It is a schematic diagram of the structure of the processing chip unit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0054] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0055] As a high-precision distance measurement sensor, laser distance measurement equipment or laser positioning equipment (such as laser radar) is a key information collection device that is vigorously developed in the field of driverless cars and drones. The principle of laser positioning equipment is to calculate the distance between the equipment and the object under test based on the flight time of the laser signal when the speed of light is known. Therefore, the measurement accuracy of the laser signal flight time determines the positioning accuracy of the laser positioning equipment. Therefore, how to improve the measurement accuracy of the flight time is an issue that needs to be considered in the design process of laser positioning equipment or laser distance measurement equipment.

[0056] Based on this, the embodiments of the present application provide a laser positioning method, a laser positioning device and a laser positioning system, which aim to improve the measurement accuracy of flight time during laser ranging.

[0057] The laser positioning method, processing chip unit and laser positioning system provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0058] See also Figure 1 and Figure 2 , Figure 1 is a flow chart of the laser positioning method provided in the embodiment of the present application, Figure 2 Schematic diagram of the structure of the laser positioning system provided in the embodiment of the present application. Figure 1 and Figure 2As shown, the laser positioning method is applied to a processing chip unit 100 in a laser positioning system. The laser positioning system also includes a transmitting device 200 and a receiving device 300 connected to the processing chip unit 100. The method includes the following steps S100 to S500.

[0059] Step S100: controlling the transmitting device 200 to output a laser signal to the object to be measured.

[0060] When performing laser positioning on the object to be measured, the processing chip unit 100 first sends a control signal to the transmitting device 200. The control signal may include the output frequency and output angle of the laser signal indicated by it, triggering the transmitting device 200 to emit the corresponding laser signal. The laser signal propagates with a certain energy and directionality and irradiates the object to be measured.

[0061] For example, Figure 3 This is another structural diagram of the laser positioning system provided in the embodiment of the present application. Please refer to Figure 1-Figure 3 , the transmitting device 200 includes a laser emission driving circuit 210, a laser 220 and a collimating lens 230. The performance indicators of the laser emission driving circuit 210 can output high frequency, narrow pulse width and high instantaneous current. The laser 220 can be a laser diode or other light source, which can generate a narrow pulse width and high frequency laser signal. After receiving the control signal, the laser emission driving circuit 210 drives the laser 220 to emit light and then reaches the object to be measured through the collimating lens 230. In the unmanned driving scene, the processing chip unit 100 of the laser radar system sends a control signal to the laser emission driving circuit 210 to control the laser emission driving circuit 210 to drive the laser 220 to emit a laser signal at a frequency of 10kHz and an angle of 30°. A beam of laser signal is emitted from the front end of the laser positioning device equipped with the laser positioning system provided in the embodiment of the present application, and irradiates the target vehicle 10 meters away from the device.

[0062] Step S200: receiving a feedback signal sent by the receiving device 300, where the feedback signal is a signal generated by the receiving device 300 according to an echo signal after the laser signal is reflected by the measured object.

[0063] The processing chip unit 100 receives the signal fed back by the receiving device 300. The receiving device 300 is used to receive the echo signal reflected back by the measured object, and convert it into a feedback signal to feed back to the processing chip unit 100.

[0064] Exemplarily, the receiving device 300 may include a laser receiving driving circuit 310, a detector 320, and a collimating lens 330. The detector 320 may be an avalanche photodiode, which receives an echo signal reflected from the target vehicle through the collimating lens 330. The surface characteristics and distance of the target vehicle determine the strength of the echo signal. The laser receiving driving circuit 310 in the receiving device 300 converts the echo signal into a feedback signal and sends it to the processing chip unit 100 for analysis.

[0065] Step S300: determining the time difference between controlling the emitting device 200 to output a laser signal to the object under test and receiving a feedback signal.

[0066] The processing chip unit 100 calculates the time difference from laser emission to laser reception according to the trigger time of the emission signal and the arrival time of the received feedback signal.

[0067] For example, in a drone inspection scenario, the time when the laser signal is emitted from the transmitting device 200 is 1000 picoseconds, and the time when the echo signal reaches the receiving device 300 is 1300 picoseconds. The processing chip unit 100 calculates the time difference as 1300-1000=300 picoseconds.

[0068] Step S400: Correcting the time difference using a carry delay chain method to obtain the flight time of the laser signal.

[0069] After obtaining the time difference, the processing chip unit 100 uses the carry delay chain method to finely correct the time difference. The processing chip unit 100 can use the logic unit in the carry delay chain to measure the carry delay time of the signal in the processing chip unit 100, and use it to correct the time difference to obtain the accurate laser flight time.

[0070] The module for determining the time difference in the processing chip unit 100 and the module for correcting the time difference using the carry delay chain may be a TDC (Time-to-digital converter) module in the processing chip unit 100. The time difference is determined by a coarse measurement module in the TDC module, and the time difference can be corrected by a fine measurement module in the TDC module.

[0071] For example, in a distance measurement application, the processing chip unit 100 detects a time difference of 300 picoseconds, but then uses the carry delay chain method to detect an additional signal carry delay of 5 picoseconds, and the final corrected laser flight time is 300-5=295 picoseconds.

[0072] Step S500: Positioning the object to be measured according to the flight duration.

[0073] The processing chip unit 100 calculates the distance between the laser radar and the object to be measured according to the flight time of the laser signal using the formula d=c×t / 2 (where c is the speed of light and t is the flight time), thereby determining the position of the object to be measured. The processing chip unit 100 can also combine the ranging results of multiple echo signals to generate three-dimensional point cloud data of the object to be measured and send it to the host computer for imaging.

[0074] For example, during the positioning process, the flight time of the laser signal is 295 picoseconds, and the speed of light c≈3×10 8 m / s, the target distance is calculated as d = 3 × 10 8 ×295×10 -12 / 2=0.044 meters. By combining multiple echo signals, the processing chip unit 100 generates the precise position and point cloud profile of the object being measured.

[0075] Through the above steps S100 to S500, the laser positioning method is implemented in the processing chip unit in the laser positioning system. The processing chip unit outputs a laser signal to the object to be measured by controlling the transmitting device, and receives the echo signal fed back by the receiving device, and determines the time difference between the laser signal emission and the echo signal reception. In traditional measurements, due to limitations such as hardware delays and clock accuracy, the measurement of time differences is prone to errors. In the embodiment of the present application, the time difference is corrected using the carry delay chain method, that is, the coarse measurement is combined with the fine measurement to improve the accuracy of the flight time measurement result. That is, the embodiment of the present application introduces the carry delay chain method in the laser positioning method to improve the measurement accuracy of the laser signal flight time, thereby improving the accuracy of laser positioning.

[0076] In some embodiments, the receiving device 300 includes a signal amplification module 311, a trigger module 312, and a time identification module 313, wherein the trigger module 312 is connected to the amplification module 311, and the time identification module 313 is connected to the amplification module 311, and the feedback signal is obtained by converting the voltage signal by the trigger module 312, and the voltage signal is obtained by converting the echo signal by the amplification module 311.

[0077] Before locating the object to be measured according to the flight duration, the method further includes:

[0078] Dynamically adjusting the reference voltage of the time identification module 313 according to the strength of the echo signal;

[0079] Sending the dynamically adjusted reference voltage to the time identification module 313, so that the time identification module 313 outputs an identification signal when the voltage signal is greater than the reference voltage;

[0080] Determine the dynamic delay time according to the arrival time of the feedback signal and the arrival time of the identification signal;

[0081] Delay compensation for flight time based on dynamic delay time and configured fixed delay time;

[0082] Position the object under test according to the flight duration, including:

[0083] The object under test is positioned according to the flight time after delay compensation.

[0084] In this embodiment, the receiving device 300 includes a signal amplification module 311, a trigger module 312 and a moment identification module 313. Among them, the signal amplification module 311 can be a transimpedance amplifier circuit, the trigger module 312 can be a high-speed comparator, and the moment identification module 313 can be an analog-to-digital conversion circuit. The signal amplification module 311, the trigger module 312 and the moment identification module 313 can be integrated into the laser receiving drive circuit 310 in the receiving device 300. The echo signal acquired by the detector 320 is converted into a voltage signal by the amplification module 311, and is transmitted to the trigger module 312 and the moment identification module 313; the trigger module 312 further processes the voltage signal, generates a feedback signal and sends it to the processing chip unit 100 to trigger the TDC module in the processing chip unit 100 to determine the time difference. On this basis, in order to ensure the accuracy of the ranging, this embodiment introduces a mechanism for real-time dynamic adjustment of the reference voltage of the moment identification circuit and comparison of the two signals for delay compensation. Specifically, the processing chip unit 100 adjusts the reference voltage in real time according to the intensity of the echo signal (the specific parameter can be the time difference of adjacent photons in the echo signal obtained by the receiving device 300), and transmits the adjusted reference voltage to the moment identification module 313. The moment identification module 313 compares the input voltage signal with the reference voltage, and outputs an identification signal when the input voltage signal exceeds the reference voltage.

[0085] The processing chip unit 100 calculates the dynamic delay duration through the difference between the arrival time of the feedback signal and the arrival time of the identification signal. The dynamic delay duration represents the additional delay introduced by the signal strength during the circuit transmission process (weak signals are slower during the circuit transmission process). At the same time, combined with the fixed delay duration (the fixed delay duration represents the inherent delay of the hardware circuit, such as the sampling time of the analog-to-digital conversion circuit, the delay of the transimpedance amplifier circuit, the delay of the high-speed comparator, etc., which is constant and can be calibrated through testing and built into the processing chip unit 100), the flight duration of the laser signal is delayed to eliminate the delay error during the circuit transmission process. The flight duration after delay compensation is used to calculate the distance, thereby determining the position of the object being measured. In this way, through the delay analysis of the moment identification module 313, the positioning error introduced by the signal strength fluctuation and circuit delay is solved, and the adaptability and accuracy of the laser positioning system in complex scenes are improved.

[0086] For example, in the laser ranging system of the driverless car, the laser signal emitted by the system passes through the reflective object on the road and is returned by the receiving device 300. When the echo signal reaches the receiving device 300, it is first amplified by the amplification module 311, and the original weak current signal is converted into a voltage signal. The trigger module 312 further processes the voltage signal, generates a feedback signal and transmits it to the processing chip unit 100.

[0087] The processing chip unit 100 detects that the echo signal is weak and starts the dynamic adjustment mechanism to reduce the reference voltage of the time identification module 313 from 0.8V to 0.5V to adapt to the current signal condition. The adjusted reference voltage is transmitted to the time identification module 313 by the processing chip unit 100.

[0088] The moment identification module 313 receives the voltage signal (peak value 0.6V) and the adjusted reference voltage (0.5V) sent by the amplification module 311. At this time, the input voltage signal exceeds the reference voltage, and the moment identification module 313 outputs an identification signal to mark the moment when the echo signal arrives.

[0089] The arrival time of the identification signal recorded by the processing chip unit 100 is 10 picoseconds later than the arrival time of the feedback signal. The processing chip unit 100 determines that the dynamic delay caused by the signal strength is 10 picoseconds. The fixed delay time configured in the processing chip unit 100 is 100 picoseconds. The flight time of the laser signal measured by TDC is 1200 picoseconds. The processing chip unit 100 compensates for the flight time and calculates the compensated flight time: compensated flight time = 1200 picoseconds - (100 picoseconds + 10 picoseconds) = 1090 picoseconds. After the calculation is completed, the processing chip unit 100 uses the compensated flight time to locate the object under test.

[0090] In some embodiments, controlling the transmitting device 200 to output a laser signal to the object under test includes:

[0091] Controlling the emitting device 200 to output a laser signal to the object to be measured and generating a start signal at the same time;

[0092] Receiving a feedback signal sent by the receiving device 300 includes:

[0093] receiving a feedback signal sent by the receiving device 300 and generating a stop signal;

[0094] Determining the time difference between controlling the emitting device 200 to output a laser signal to the object under test and receiving a feedback signal includes:

[0095] The time difference is determined according to the generation time of the start signal and the generation time of the stop signal.

[0096] In this embodiment, when the processing chip unit 100 controls the transmitting device 200 to transmit a laser signal to the object to be measured, it also generates a start signal to mark the emission time of the laser signal. The start signal can be generated by the PL counter in the TDC module. The start signal can be synchronized with the rising edge of the system clock. The TDC module can use the system clock to start timing from the moment the start signal is generated. After the laser signal is reflected by the object to be measured, the echo signal is received by the receiving device 300 and a feedback signal is generated. The processing chip unit 100 generates a stop signal while obtaining the feedback signal sent by the receiving device 300 to mark the reception time of the feedback signal. The stop signal can also be generated by the PL counter in the TDC module. The processing chip unit 100 calculates the time difference from the emission to the reception of the laser signal based on the time difference between the generation time of the start signal and the generation time of the stop signal. This time difference can reflect the flight time of the laser signal and provide accurate time data for subsequent distance calculation and positioning.

[0097] Exemplarily, in the drone navigation system, the processing chip unit 100 controls the transmitting device 200 to transmit a laser signal to the target ground at a frequency of 10kHz, and generates a start signal at the moment of laser emission to mark the emission moment. After the laser signal is reflected by the ground, the echo signal reaches the receiving device 300, and the receiving device 300 generates a stop signal while generating a feedback signal to mark the receiving moment. The processing chip unit 100 determines that the flight time difference of the laser signal is 300 picoseconds by calculating the time difference between the generation moment of the start signal and the generation moment of the stop signal. Subsequently, the processing chip unit 100 uses the time difference to calculate the distance between the drone and the ground target, and adjusts the flight path in real time in combination with multiple measurement results to avoid interference from obstacles.

[0098] In some embodiments, the time difference is corrected using a carry delay chain method to obtain the flight time of the laser signal, including:

[0099] Inputting the stop signal into a carry delay chain, the carry delay chain includes a plurality of logic units, and the plurality of logic units are sequentially connected;

[0100] Signal arrival information of multiple logic units is obtained, and the time difference is corrected according to the signal arrival information and the delay duration of each logic unit to obtain the flight duration, wherein the signal arrival information is used to indicate whether each logic unit has received a stop signal.

[0101] Figure 4 is a schematic diagram of signal delay provided in an embodiment of the present application, such as Figure 4As shown in the figure, the time interval between the start signal (START) and the stop signal (STOP) is the flight time of the laser, and both the start signal and the stop signal have a certain delay time. Simply measuring the time difference between the two may lead to certain errors. Therefore, the TDC module needs to use a combination of a coarse measurement module (COARSE) and a fine measurement module (FINE) to determine the flight time. Figure 4 As shown, the start signal is synchronized with the rising edge of the system clock (SYS_CLK). After the start signal is generated, the coarse measurement module starts counting. After detecting the stop signal, it stops counting at the next rising edge of the system clock following the stop signal. The fine measurement module starts calculating the duration of the stop signal carry delay after detecting the stop signal. Like the coarse measurement module, it stops counting at the next rising edge of the system clock following the stop signal. It can be seen that the corrected time difference, i.e., the flight time, can be expressed as: t = t COARSE -t FINE , where t is the flight time, t COARSE is the time difference, i.e. the duration measured by the coarse measurement module, t FINe The fine measurement module measures the duration of the carry delay of the signal obtained.

[0102] The fine measurement module calculates the carry delay time by using a carry delay chain. The fine measurement module inputs the stop signal into the carry delay chain, which is composed of multiple logic units (such as CARRY4 units) cascaded, and each logic unit has a delay time. After the stop signal enters the carry delay chain, it will propagate to each logic unit in turn to generate signal arrival information. The signal arrival information records whether each logic unit has received the stop signal, usually expressed in the form of a binary bit string, such as "11110000". The processing chip counts the number of logic units through which the signal passes based on this information, and combines the delay time of each logic unit to calculate the total delay time of the stop signal propagating in the carry delay chain. The delay time is combined with the time difference recorded by the coarse measurement module to correct the time measurement error, and finally obtain the precise flight time of the laser signal. The correction achieved by the carry delay chain method can break through the limitation of the system clock cycle and improve the time measurement accuracy to the picosecond level.

[0103] Exemplarily, during the laser positioning process, the coarse measurement module records the time difference between transmission and reception as 305 nanoseconds (the system clock cycle is 10 nanoseconds) through a 100MHz system clock. In order to further correct the time measurement error, the stop signal is input into the carry delay chain, which consists of 10 logic units, and the delay time of each logic unit is 50 picoseconds. In the delay chain, when the stop signal propagates to the fourth logic unit, the signal cannot continue, and the recorded signal arrival information is "1111000000". According to information statistics, the signal passes through 4 logic units, and the total delay time is 4×50 picoseconds=200 picoseconds. Combined with the results of the coarse measurement module, the corrected flight time is: 305 nanoseconds-0.2 nanoseconds=304.8 nanoseconds.

[0104] In some embodiments, the method further comprises:

[0105] Inputting a plurality of random signals to the carry delay chain;

[0106] The number of times each logic unit receives the random signal is obtained, and the delay time of each logic unit is adjusted according to the number.

[0107] In this embodiment, the processing chip unit 100 also corrects the delay duration of the logic unit in the delay chain. Multiple random signals are sequentially input into the carry delay chain (code density test method), and the carry delay chain is composed of multiple cascaded logic units. The delay duration of each logic unit determines the time for signal propagation. The processing chip unit 100 records the number of times each logic unit receives the random signal, and adjusts the delay duration of each logic unit based on these times. Specifically, if a logic unit is triggered a large number of times, it means that the delay duration of the unit may be deviated and needs to be adjusted; conversely, if the number of triggers is small, it may indicate that the delay duration of the unit is short, and corresponding adjustments are also required.

[0108] Specifically, the processing chip unit 100 counts the number of times the random signal appears on each logic unit, and calculates the DNL (Differential Non-Linearity) of each logic unit. The calculation method of DNL is as follows:

[0109]

[0110] Where n(i) is the number of random pulses that occur in the i-th logic unit in the delay chain, T clk is the cycle length of the system clock, N is the total number of measurements, N c is the number of delay units in the delay chain.

[0111] After the DNL of each logic unit is calculated, the delay time of each logic unit is adjusted using the DNL of each logic unit, that is, the real delay time of each logic unit is restored, so as to calibrate the delay chain.

[0112] In this way, the system is able to dynamically optimize the delay time of each logic unit in the delay chain, thereby improving the overall measurement accuracy and ensuring the accuracy of time difference measurement in the laser positioning system.

[0113] In some embodiments, before locating the measured object according to the flight duration, the method further includes:

[0114] Use a circular buffer to store flight time;

[0115] Position the object under test according to the flight duration, including:

[0116] The flight duration is obtained from the ring buffer, and the object under test is positioned according to the flight duration.

[0117] In this embodiment, the processing chip unit 100 determines the position of the target object by calculating the flight time of the laser signal. In this process, the flight time is stored in a circular buffer to ensure that the data can be efficiently stored and accessed in a circular manner. A single DDR (Double Data Rate) chip can be used as a storage chip in the processing chip unit 100. The circular buffer is a special memory management method that allows the processing chip unit 100 to continuously update data through pointers when storing data, while avoiding frequent memory allocation and release, ensuring that the processing chip unit 100 efficiently uses memory resources during continuous scanning. The circular buffer connects the storage space end to end to form a "ring". The write pointer in the processing chip unit 100 is responsible for writing data, and the read pointer in the processing chip unit 100 is responsible for reading data. The two chase each other but do not overlap. For example, there is a circular buffer with a length of 10, which is used to store flight time data. The write pointer starts from the 0th position. After each point cloud data is stored, the pointer is increased by 1, and the positions 1, 2, 3... until 9 are written in sequence. When the write pointer reaches the end of the buffer (position 9), the next data will be written to position 0, forming a loop; the read pointer starts reading from position 0, and when it reads to position 9, it will return to position 0 to continue reading.

[0118] The positioning process of the processing chip unit 100 includes reading the latest flight time data from the ring buffer and using the data to calculate the position of the target object. Through this method, the processing chip unit 100 can quickly and in real time obtain the positioning information of the target object, while improving the efficiency of data storage and access, and ensuring accurate positioning in dynamic scenes.

[0119] For example, in the laser positioning system of an unmanned vehicle, the processing chip unit 100 emits and receives laser signals multiple times per second to measure the distance of the obstacle ahead. The flight duration of each measurement will be stored in a circular buffer. Assume that the processing chip unit 100 is set to a buffer size of 100 measurements, and each calculated flight duration is stored in a different position in the buffer. When the 101st measurement is completed, the data will overwrite the earliest data position, thereby keeping the latest 100 measurement data. The processing chip unit 100 reads the latest flight duration data from the circular buffer, for example, 520 nanoseconds, and calculates the distance of the obstacle based on the data. Assuming the speed of light is 3×10 8 m / s, the distance of the obstacle is calculated to be 78 m.

[0120] In some implementations, positioning the object under test according to the flight duration includes:

[0121] Obtaining output information of the laser signal, the output information including the output frequency and output angle of the laser signal;

[0122] The coordinates of the object being measured are determined based on the flight duration and output information.

[0123] In this embodiment, the processing chip unit 100 first obtains the output information of the laser signal, which includes the output frequency and output angle of the laser signal. The output frequency of the laser signal provides the time interval for transmitting the signal, while the output angle determines the direction of laser emission, thereby affecting the spatial position of the target object. Subsequently, combining the measured flight time and the above output information, the processing chip unit 100 can accurately calculate the coordinates of the target object in three-dimensional space. The flight time reflects the time from the emission of the laser to the receipt of the echo signal. Combined with the frequency and angle data, the relative position of the target object can be determined and real-time positioning can be performed. In this way, the laser positioning system effectively combines time and space information, and improves the ranging accuracy and real-time performance of the laser positioning system in complex environments.

[0124] Figure 5 is a schematic diagram of a coordinate calculation method provided in an embodiment of the present application, such as Figure 5 As shown, for example, the three-dimensional coordinates of a certain point (x0, y0, z0) of the object under test can be obtained by the following calculation:

[0125]

[0126] x0=d×sinθ×cosλ

[0127] y0=d×sinθ×sinλ

[0128] z0=d×cosθ

[0129] Wherein, d is the distance, v is the speed of light, t is the flight time, θ is the azimuth angle of the coordinate origin, and λ is the elevation angle (θ and λ can both be obtained according to the output angle in the output information).

[0130] In some embodiments, after determining the coordinates of the measured object according to the flight duration and the output information, the method further includes:

[0131] When the number of coordinates of the object to be measured is plural, point cloud data of the object to be measured is generated.

[0132] In this embodiment, after obtaining the flight duration and output information (such as output frequency and angle) of the laser signal, the processing chip unit 100 determines the coordinates of the object to be measured in three-dimensional space by calculation. If the number of measured coordinates of the object to be measured exceeds one (that is, multiple measurements are performed or multiple flight times are obtained in the same time and multiple coordinates are calculated), the processing chip unit 100 will generate point cloud data based on these coordinate data. Point cloud data is a set of multiple three-dimensional coordinate points, each point corresponds to a position in space, and is usually used to describe the shape, position and distribution of the object to be measured. The generated point cloud data can be sent to the host computer by the processing chip unit 100 for further applications such as spatial modeling, obstacle detection, environmental perception, and path planning, and is widely used in fields such as unmanned driving, robot navigation, and three-dimensional reconstruction.

[0133] Figure 6 is a schematic diagram of the structure of the processing chip unit provided in the embodiment of the present application, such as Figure 6 As shown, the second aspect of the embodiment of the present application provides a processing chip unit 100, the processing chip unit 100 is applied to a laser positioning system 1000, the laser positioning system 1000 also includes a transmitting device 200 and a receiving device 300 connected to the processing chip unit 100, and the processing chip unit 100 includes:

[0134] The control module 110 is used to control the transmitting device to output a laser signal to the object to be measured;

[0135] The receiving module 120 is used to receive a feedback signal sent by the receiving device, where the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object;

[0136] A determination module 130, for determining a time difference between controlling the emission device to output a laser signal to the object under test and receiving a feedback signal;

[0137] The correction module 140 corrects the time difference by using a carry delay chain method to obtain the flight time of the laser signal;

[0138] The positioning module 150 is used to locate the object under test according to the flight duration.

[0139] The processing chip unit provided in the second aspect of the embodiment of the present application can implement each process implemented in the above-mentioned method embodiment and achieve the same beneficial effects. To avoid repetition, it will not be described here.

[0140] In some embodiments, the processing chip unit 100 can be a ZYNQ chip, the control module 110, the receiving module 120, the determination module 130 and the correction module 140 are integrated in the programmable logic (PL) unit part of the ZYNQ chip, and the positioning module 150 is integrated in the processing system (PS) part of the ZYNQ chip.

[0141] In some embodiments, in order to realize multi-line laser scanning (the laser positioning system simultaneously emits multiple laser signals for measurement and positioning), a multi-channel determination module and a correction module (i.e., a multi-channel TDC module) can be set in the processing chip unit to cooperate with the corresponding multi-channel receiving device and multi-channel transmitting device (the number of TDC modules, the number of receiving devices, and the number of transmitting devices are the same) to determine the flight time of the multi-line laser signal.

[0142] like Figure 2 As shown, the third aspect of the embodiment of the present application provides a laser positioning system 1000, the laser positioning system 1000 includes a transmitting device 200, a receiving device 300 and a processing chip unit 100, the processing chip unit 100 is connected to the transmitting device 200 and the receiving device 300, and the processing chip unit 100 is used to execute the laser positioning method provided in the first aspect of the embodiment of the present application.

[0143] The laser positioning system 1000 provided in the third aspect of the embodiment of the present application can implement each process implemented in the above method embodiment and achieve the same beneficial effects. To avoid repetition, it will not be described here.

[0144] A fourth aspect of an embodiment of the present application provides a machine-readable storage medium, on which instructions are stored. When the instructions are executed by a processor, the processor implements the above-mentioned laser positioning method.

[0145] In some implementations, the embodiments of the present application further provide a computer program product, including a computer program, which implements the laser positioning method according to the above implementation when executed by a processor.

[0146] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0147] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including the instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0149] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0150] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transcript media), such as modulated data signals and carrier waves.

[0151] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0152] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

[0153] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A laser positioning method, characterized in that: The method is applied to a processing chip unit in a laser positioning system, the laser positioning system further comprising a transmitting device and a receiving device connected to the processing chip unit, and the method comprises: Controlling the transmitting device to output a laser signal to the object to be measured; receiving a feedback signal sent by the receiving device, wherein the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object; Determine the time difference between controlling the transmitting device to output the laser signal to the measured object and receiving the feedback signal; Correcting the time difference by using a carry delay chain method to obtain the flight time of the laser signal; The measured object is positioned according to the flight duration.

2. The method according to claim 1, characterized in that The receiving device includes a signal amplifying module, a triggering module and a time identification module, wherein the triggering module is connected to the amplifying module, the time identification module is connected to the amplifying module, and the feedback signal is obtained by the triggering module converting a voltage signal, and the voltage signal is obtained by the amplifying module converting the echo signal. Before positioning the measured object according to the flight duration, the method further includes: Dynamically adjusting the reference voltage of the time identification module according to the strength of the echo signal; Sending the dynamically adjusted reference voltage to the time identification module, so that the time identification module outputs an identification signal when the voltage signal is greater than the reference voltage; Determining a dynamic delay duration according to the arrival time of the feedback signal and the arrival time of the identification signal; Performing delay compensation on the flight duration according to the dynamic delay duration and the configured fixed delay duration; The positioning of the measured object according to the flight duration includes: The object to be measured is positioned according to the flight time after the delay compensation.

3. The method according to claim 1, characterized in that: The step of controlling the transmitting device to output a laser signal to the object to be measured comprises: Controlling the transmitting device to output a laser signal to the object to be measured and generating a start signal at the same time; The receiving the feedback signal sent by the receiving device includes: receiving a feedback signal sent by the receiving device and generating a stop signal; The determining and controlling the time difference between the transmitting device outputting the laser signal to the measured object and receiving the feedback signal comprises: The time difference is determined according to a generation time of the start signal and a generation time of the stop signal.

4. The method according to claim 3, characterized in that The method of correcting the time difference by using a carry delay chain method to obtain the flight time of the laser signal includes: Inputting the stop signal into a carry delay chain, wherein the carry delay chain includes a plurality of logic units, and the plurality of logic units are sequentially connected; Acquire signal arrival information of the multiple logic units, and correct the time difference according to the signal arrival information and the delay duration of each of the logic units to obtain the flight duration, wherein the signal arrival information is used to indicate whether each of the logic units has received the stop signal.

5. The method according to claim 4, characterized in that The method further comprises: Inputting a plurality of random signals into the carry delay chain; The number of times each of the logic units receives the random signal is obtained, and the delay duration of each of the logic units is adjusted according to the number of times.

6. The method according to claim 1, characterized in that Before positioning the measured object according to the flight duration, the method further includes: Using a circular buffer to store the flight duration; The positioning of the measured object according to the flight duration includes: The flight duration is obtained from the ring buffer, and the object under test is positioned according to the flight duration.

7. The method according to claim 1, characterized in that The positioning of the measured object according to the flight duration includes: Acquiring output information of the laser signal, wherein the output information includes an output frequency and an output angle of the laser signal; The coordinates of the measured object are determined according to the flight duration and the output information.

8. The method according to claim 7, characterized in that After determining the coordinates of the measured object according to the flight duration and the output information, the method further includes: When there are multiple coordinates of the object to be measured, point cloud data of the object to be measured is generated.

9. A processing chip unit, characterized in that: The processing chip unit is applied to a laser positioning system, and the laser positioning system further comprises a transmitting device and a receiving device connected to the processing chip unit. The processing chip unit comprises: A control module, used to control the transmitting device to output a laser signal to the object to be measured; A receiving module, used to receive a feedback signal sent by the receiving device, wherein the feedback signal is a signal generated by the receiving device according to an echo signal after the laser signal is reflected by the measured object; A determination module, used to determine the time difference between controlling the emitting device to output the laser signal to the measured object and receiving the feedback signal; A correction module, which uses a carry delay chain method to correct the time difference to obtain the flight time of the laser signal; A positioning module is used to locate the object under test according to the flight duration.

10. A laser positioning system, characterized in that: The system includes a transmitting device, a receiving device and a processing chip unit. The processing chip unit is connected to the transmitting device and the receiving device, and the processing chip unit is used to execute the laser positioning method according to any one of claims 1 to 8.

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