CN117741622A - Automatic adjusting method for Gm-APD laser radar range gate - Google Patents
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Abstract
An automatic adjustment method for a Gm-APD laser radar range gate belongs to the technical field of laser radar measurement. In order to realize accurate and automatic adjustment of a Gm-APD laser radar range gate, the invention uses the laser radar position as a reference coordinate system to define the linear direction decomposition speed of a target relative to the laser radar; defining a Gm-APD laser radar area array staring imaging frame frequency, wherein a straight line points to a real-time measurement distance of an nth frame frequency image, and then constructing a relative movement distance calculation formula between every two continuous frame frequency images and an accumulated relative movement distance calculation formula between every two continuous frame frequency images; the method comprises the steps of constructing a plurality of groups of automatic adjustment judging conditions of the Gm-APD laser radar range gates, and carrying out automatic adjustment of the Gm-APD laser radar range gates according to a double judging mode of real-time linear pointing and real-time linear pointing decomposition speed aiming at the relative movement distance between every two continuous frame frequency images.
Description
Technical Field
The invention belongs to the technical field of laser radar measurement, and particularly relates to an automatic adjustment method for a Gm-APD laser radar range gate.
Background
The Gm-APD laser radar is a photoelectric radar system which takes laser as an information carrier and takes a time flight method as a ranging principle. The laser radar consists of a laser emission system, a Gm-APD laser receiving system, an image data processing system, a measurement and control and display system and the like (shown in figure 2), can realize the three-dimensional active imaging detection of the staring-like area array laser in a single quick flashing and multi-frame statistical mode, and belongs to the solid-state laser radar. Compared with passive imaging detection of visible light, infrared and the like, the laser radar can acquire a high-precision three-dimensional image (range profile + two-dimensional intensity profile) of a target; compared with the traditional microwave radar, the laser radar has the characteristics of higher ranging precision, higher angular resolution and stronger anti-interference capability due to the characteristics of shorter wavelength, better coherence and the like of laser.
To achieve target detection, gm-APD lidars also exist like microwave radar "gates" (range gates) and "gate widths" (gate widths). The wave gate or range gate refers to a time window (T 0 Time of day) for controlling the lidar receiving system to receive the laser echo signal at regular time. The measurement and control system instructs the laser emission system to emit a pulse light wave, and waits for receiving a laser echo signal carrying target information and reflected by a target in a time delay mode (shown as delta T) to realize laser three-dimensional detection of the target, and then the distance between the laser radar detection position and the target is S= (c delta T)/2. The gate width or gate width refers to the time length or distance length (delta t in terms of time and delta d in terms of distance length) from the time when the gate is opened to the time when the gate is closed, and the gate width time can be a delta t bin_a Resolution 1ns (nanosecond) subdivision modulation, i.e. Δd bin_a At 0.15m resolution. ) Namely, the detection is started when the gate is opened, and the detection is stopped when the gate is closed. Due to the influence of background light, the size of the gate width of the Gm-APD detector directly influences the detection probability and the ranging accuracy.
Because of the active detection principle of the laser radar and the unique multi-frame statistical properties of the Gm-APD laser radar, the Gm-APD system laser radar needs a large number of elements to detect targets. First, the intensity image of the target (x, y) needs to be detected, and the number of laser pulse frequency frames (N) is counted ft ) The method comprises the steps of carrying out a first treatment on the surface of the The distance gate is pushed again to search the object distance image (z), so that a frame-like staring image contains the (x, y, z) three-dimensional image of the object and the relative position or absolute position of the object in the inertial spaceInformation, i.e. the three-dimensional image includes { (x, y, z), N ft }。
As described above, for a fixed detection position and a stationary target, FIG. 3 is a schematic diagram of a stationary Gm-APD laser radar for detecting a range gate and a gate width of a target at a fixed position.
As shown in fig. 2 and 3, in actual working, the pulse laser emits a laser pulse and simultaneously sends a synchronizing signal to the Gm-APD laser area array detector, and the detector synchronously generates a START timing START pulse signal; after a fixed delay delta T, the START signal generates a distance gating signal EN to an ROIC (detector readout circuit) to serve as a starting signal of a high-frequency clock counter TDC (time and digital circuit) in each pixel of the detector; when the laser pulse echo signal returns to reach the photosensitive target surface of the detector, the pixel photosensitive will generate a geiger avalanche signal, a CMOS compatible voltage pulse STOP is generated after the threshold value identification circuit in the ROIC detects the avalanche signal, the pulse STOP STOPs the high-frequency clock counter TDC of the pixel, and then the TDC count value of each pixel is serially output after the EN signal is finished, so that imaging detection is realized.
Wherein TDC is currently a 12bit counter, and k is in the range of 0-4095, namely the maximum gate width can be set to delta t max ＝k×Δt bin_a =4095 ns or Δd max = 614.25m; the time delay DeltaT corresponds to the target distance S ΔT = (c·Δt)/2. By way of example, this is illustrated as follows: according to the principle of the time-of-flight method, a gate width Δt=2μs (microseconds) expressed in time, i.e. a gate width Δd=300m expressed in distance, is provided, which gate width time can be expressed in Δt bin_a Resolution 1ns (nanosecond) subdivision adjusts, i.e. 0.15m resolution. Assuming that the target is located at a distance of 3000m from the lidar, the distance s= (c·Δt)/2=3000 m between the lidar detection position and the target is determined by the time-of-flight method, and the range gate time delay Δt=20μs. That is, when the target distance is 3000m, and the gate width Δt=2μs (the gate width Δd=300m) is set, the target is in the range of 2850m to 3150m, and the target can be found by adjusting the gate delay Δt to be 19 μs to 21 μs by the theoretical 20 μs, and the target cannot be found outside the time delay range.
The laser radar and the target to be detected are generally moving in the actual application, namely the laser radar is on a related carrier (such as a car, an airplane and the like), the target is a moving target (such as a car, an airplane and the like), and the Gm-APD laser radar can detect, identify and track the target only when the target is within the range width; once the target is not within the door width, the Gm-APD lidar will not be able to detect the target.
When the relative moving target is outside the door width, the target cannot be detected, and the target is generally found by manually adjusting the distance door position (time delay delta T) and adjusting the door width delta d. The door width is smaller, background noise light can be greatly filtered, but the door width cannot be too small, for example, the door width is smaller than 1 mu s (150 m), and for building targets, the laser radar is easy to detect insufficiency when in relative motion; the gate width is set larger, for example, the gate width is larger than 3 mu s (450 m), the detection and the identification of small targets are seriously affected by background noise light, and a great pressure is added to a subsequent image processing algorithm. Together with the target being located at a position within the width of the door (e.g., near the proximal or distal end of the width of the door) will also affect the signal-to-noise ratio.
When the relative movement between the laser radar and the target is small (such as not more than 34 m/s), the manual adjustment of the position of the range gate is better realized; when the relative movement speed is greater than 34m/s and even greater than 340m/s, the rapid detection and tracking of the target can be hardly realized by manually adjusting the position of the range gate; and the distance door width are manually adjusted, so that the automatic detection of the laser radar on the target is not facilitated, and the autonomous and independent work of the laser radar cannot be realized.
Disclosure of Invention
The invention aims to solve the problem of realizing accurate and automatic adjustment of a Gm-APD laser radar range gate and provides an automatic adjustment method of the Gm-APD laser radar range gate.
In order to achieve the above purpose, the present invention is realized by the following technical scheme:
an automatic adjustment method for a Gm-APD laser radar range gate comprises the following steps:
s1, defining a linear direction decomposition speed v of a target relative to a laser radar by taking the position of a Gm-APD laser radar as a reference coordinate system 2 ；
S2, defining Gm-APD laser radar area array type staring imaging frame frequency as f, and determining real-time measurement distance of straight line-oriented nth frame frequency image as S n Then, a relative movement distance calculation formula of straight line pointing between every two continuous frame frequency images and an accumulated relative movement distance calculation formula of straight line pointing between the continuous frame frequency images are constructed, and a straight line pointing decomposition speed calculation formula of every two continuous frame frequency images is constructed;
s3, setting parameters of the Gm-APD laser radar, setting a range gate width delta d, a laser radar area array staring imaging frame frequency f, adjusting a laser radar time delay delta T to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through the Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar;
s4, constructing a plurality of groups of automatic adjustment judging conditions of the Gm-APD laser radar range gate, wherein the automatic adjustment judging conditions comprise a double judging mode for real-time linear direction relative movement distance between every two continuous frame frequency images and real-time linear direction decomposition speed measurement, the double judgment is carried out by utilizing the real-time measurement distance of each frame frequency image between the target and the laser radar measured in real time in the step S3, and the automatic adjustment of the Gm-APD laser radar range gate is carried out based on the judging result.
Further, in step S1, the actual velocity v of the actual moving direction of the target and the linear direction decomposition velocity v of the target relative to the laser radar are 2 The calculation formula of (2) is as follows:
v＝v 2 /cosα (1)
and alpha is an included angle between the actual motion direction of the target and the linear direction of the target relative to the laser radar.
Further, the specific implementation method of the step S2 includes the following steps:
s2.1, based on the Gm-APD laser radar imaging mechanism, an area array is adopted, the staring-like imaging whole image statistics frame frequency is adopted, and the staring-like imaging frame frequency of the Gm-APD laser radar area array is defined as f;
s2.2, when the Gm-APD laser radar detects a target, simultaneously giving a two-dimensional intensity image, a range image and a three-dimensional point cloud image of the target in real time, and obtaining a real-time image with a straight line pointing to an nth frame frequency image through the range imageMeasuring distance S n ；
S2.3, constructing a calculation formula of a relative movement distance between every two continuous frame frequency images of straight line directions, wherein the calculation formula is as follows:
wherein,s is the relative movement distance between the continuous n-1 frame frequency image and the n frame frequency image n-1 Real-time measurement distance for straight line pointing to frame frequency image of n-1 frame, n=2, 3..i, i is total number of frame frequency images;
s2.4, constructing accumulated relative movement distance between straight line pointing continuous frame frequency imagesThe calculation formula of (2) is as follows:
s2.5, calculating the linear direction decomposition speed of each two continuous frame frequencies by adopting an image-frame frequency method, and calculating the time for obtaining a three-dimensional point cloud image according to the gaze imaging frame frequency f of the Gm-APD laser radar area array type to be t' =1/f, wherein the calculation formula for obtaining the linear direction decomposition speed of each two continuous frame frequencies is as follows:
further, the specific implementation method of the step S3 includes the following steps:
s3.1, setting the width delta d of the range gate to be 150m or 300m or 450m, and setting the maximum value delta d of the width of the range gate max When searching for a target in a range gate, = 614.25m, the range gate width resolution Δd is set bin_a Traverse range gate width Δd =0.15m;
s3.2, setting a staring imaging frame frequency f of a laser radar area array type, adjusting time delay delta T of the laser radar to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through the Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar.
Further, the specific implementation method of the step S4 includes the following steps:
s4.1, calculating the relative movement distance between each two continuous frame frequency images of the linear direction by using a formula (2) based on the real-time measurement distance between each frame frequency image between the obtained target and the laser radar obtained in the step S3
S4.2, the calculation of the step S4.1Make a judgment, set a first judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.3, calculating the step S4.1Make a judgment, set a second judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.4. the calculation of the step S4.1Making a judgment, setting a third judgment condition asIf yes, storing record in real time>Then move the distance gate by Δd distance in real time single and double frame frequency interval,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.5, calculating the step S4.1Make the judgment, set the fourth judgment condition asIf yes, storing record in real time>Then moving the distance gate every 4-10 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.6, the calculation of the step S4.1Make the judgment, set the fifth judgment condition asIf yes, storing record in real time>Then moving the distance gate every 10-20 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.7. the calculation of the step S4.1Making a judgment, setting a sixth judgment condition asIf yes, continuing to judge whether the formula is satisfied>If yes, storing record in real time>Then move the range gate in real time with Δd distance, < > and>push the range gate far when positive, increase time delay DeltaT,/>When the value is negative, the distance gate is pushed to the near direction and the time delay DeltaT is reduced, and the value is judged as +.>Non-moving range gateThen calculate +.>Storing records in real time; the sixth judgment condition judges as otherwise, the next step is carried out;
s4.8. the calculation result of the step S4.1Making a judgment, setting a seventh judgment condition to +.>If yes, continuing to judge whether the formula is satisfied>And if yes, traversing the steps S4.2-S4.7, and if not, judging that the system overflows, the range gate is kept still, the target frame frequency is lost instantaneously, and the conclusion is that the Gm-APD laser radar is not suitable for target detection.
The invention has the beneficial effects that:
the invention relates to an automatic adjustment method for a distance gate of a Gm-APD laser radar, which uses different whole three-dimensional image staring frame rates of the Gm-APD laser radar and the difference delta S between front and back frames n-1 Instantaneous pointing speed between front and rear framesMatching is carried out, and difference between the front frame and the rear frame is built>Model, instantaneous pointing speed between front and rear frames +.>Model, accumulated frame frequency and accumulated relative movement distance +.>The relative motion condition of the target can be judged in real time, and the Gm-AP can be realized by matching with a related software algorithmThe D laser radar automatically pushes and sweeps from the position of the door, and the real-time detection, detection and tracking of the relative moving target can be realized through the matching of other subsequent upper computer systems.
The automatic adjustment method of the distance gate of the Gm-APD laser radar can be used for not only the Gm-APD laser radar, but also the automatic distance gate of the distance gating type laser radar and a laser range finder of other systems; the realization method of the invention is balanced with other related upper computers, and can also realize track prediction of laser radar detection targets, track restoration of laser detection targets, target type identification and the like.
Drawings
FIG. 1 is a flow chart of a Gm-APD laser radar range gate automatic adjustment method according to the invention;
FIG. 2 is a schematic block diagram of a prior art Gm-APD lidar system;
FIG. 3 is a schematic diagram of a range gate and gate width detection of a stationary Gm-APD lidar of the prior art for a fixed position target;
FIG. 4 is a schematic diagram of the velocity exploded view of the laser radar of the present invention in relative motion with a target.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and detailed description. It should be understood that the embodiments described herein are for purposes of illustration only and are not intended to limit the invention, i.e., the embodiments described are merely some, but not all, of the embodiments of the invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein can be arranged and designed in a wide variety of different configurations, and the present invention can have other embodiments as well.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.
For further understanding of the invention, the following detailed description is to be taken in conjunction with fig. 1-4, in which the following detailed description is given, of the invention:
the first embodiment is as follows:
an automatic adjustment method for a Gm-APD laser radar range gate comprises the following steps:
s1, defining a linear direction decomposition speed v of a target relative to a laser radar by taking the position of a Gm-APD laser radar as a reference coordinate system 2 ；
Further, in step S1, the actual velocity v of the actual moving direction of the target and the linear direction decomposition velocity v of the target relative to the laser radar are 2 The calculation formula of (2) is as follows:
v＝v 2 /cosα (1)
wherein alpha is an included angle between the actual motion direction of the target and the linear direction of the target relative to the laser radar;
further, the relative motion between the lidar and the target is divided into a plurality of types, and the relative motion between the lidar and the target can be decomposed by taking the position of the lidar as a reference coordinate system for simplifying the model, as shown in fig. 4. v is the actual relative movement speed of the target in the actual movement direction (the coming direction is positive and the going direction is negative); v 2 The relative speed (the moment speed) of the laser radar and the target relative motion pointing direction is the decomposed instantaneous speed, namely the measured relative speed of the invention; v 1 、v 2 The two decomposition speeds are perpendicular, and the sum of the angle alpha and the angle beta is 90 DEG right angle.
S2, defining Gm-APD laser radar area array type staring imaging frame frequency as f, and determining real-time measurement distance of straight line-oriented nth frame frequency image as S n Then, a relative movement distance calculation formula of straight line pointing between every two continuous frame frequency images and an accumulated relative movement distance calculation formula of straight line pointing between the continuous frame frequency images are constructed, and a straight line pointing decomposition speed calculation formula of every two continuous frame frequency images is constructed;
further, the specific implementation method of the step S2 includes the following steps:
s2.1, based on the Gm-APD laser radar imaging mechanism, an area array is adopted, the staring-like imaging whole image statistics frame frequency is adopted, and the staring-like imaging frame frequency of the Gm-APD laser radar area array is defined as f;
furthermore, the Gm-APD laser radar imaging mechanism is an area array, pulse frame frequency statistics and gaze-like imaging, the formed three-dimensional image adopts the whole image frame frequency (Hz) of gaze-like imaging as evaluation, when the frame frequency is counted according to the whole image, the frame frequency can be counted between 1Hz and 100Hz, and when the frame frequency of the whole image is required to be high, the frame frequency can even be counted to be more than 100Hz, but the frame frequency is generally used between 5Hz and 100 Hz. The frame frequency after statistics is set to be fHz;
s2.2, when the Gm-APD laser radar detects a target, simultaneously giving a two-dimensional intensity image, a range image and a three-dimensional point cloud image of the target in real time, and obtaining a real-time measurement distance S of a frame frequency image with a straight line pointing to an nth frame frequency image through the range image n ；
Further, in the first frame of image, the target is at a linear distance S from the laser radar 1 In the second frame of image, the linear distance between the target and the laser radar is S 2 In the third frame of image, the linear distance between the target and the laser radar is S 3 ,. the detection is performed in such a way that the linear distance between the target and the laser radar is S until the last frame of image is detected n ；
S2.3, constructing a calculation formula of a relative movement distance between every two continuous frame frequency images of straight line directions, wherein the calculation formula is as follows:
wherein,s is the relative movement distance between the continuous n-1 frame frequency image and the n frame frequency image n-1 Real-time measurement distance for straight line pointing to frame frequency image of n-1 frame, n=2, 3..i, i is total number of frame frequency images;
further, in the second frame of imageThe movement distance of the target decomposition pointing laser radar isIn the third frame of image, the movement distance of the target decomposition pointing laser radar is +.>Doing so until the last frame of image is detected; s is S 1 、S 2 ....S n When forming a complete three-dimensional image for the laser radar in real time, measuring the real-time distance between the laser radar and a detected target in real time by each frame of image, wherein the real-time distance is +.>The method has no unknown quantity and can be calculated in real time;
s2.4, constructing accumulated relative movement distance between straight line pointing continuous frame frequency imagesThe calculation formula of (2) is as follows:
s2.5, calculating the linear direction decomposition speed of each two continuous frame frequencies by adopting an image-frame frequency method, and calculating the time for obtaining a three-dimensional point cloud image according to the gaze imaging frame frequency f of the Gm-APD laser radar area array type to be t' =1/f, wherein the calculation formula for obtaining the linear direction decomposition speed of each two continuous frame frequencies is as follows:
furthermore, because the optical wave band used by the laser radar is shorter, the inter-frame velocity measurement adopting the Doppler effect is not obvious and can cause larger error, and the linear pointing velocity measurement of the target and the laser radar is realized by adopting an image-frame frequency method. Since the frame rate "fHz" is known at the time of lidar-like gaze imaging,the time t' =1/f of forming a complete three-dimensional image can be calculated; and also (b)To be calculated, the resolved pointing line is therefore at about instantaneous speed>Can be calculated;
s3, setting parameters of the Gm-APD laser radar, setting a range gate width delta d, a laser radar area array staring imaging frame frequency f, adjusting a laser radar time delay delta T to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through the Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar;
further, the specific implementation method of the step S3 includes the following steps:
s3.1, setting the width delta d of the range gate to be 150m or 300m or 450m, and setting the maximum value delta d of the width of the range gate max When searching for a target in a range gate, = 614.25m, the range gate width resolution Δd is set bin_a Traverse range gate width Δd =0.15m;
further, for Gm-APD laser radar detection based on the principle of time flight method, the gate width expressed by time is deltat, deltat or deltad as a set known value, and the maximum gate width can be set deltat max =4095 ns or Δd max = 614.25m. In general, to balance the signal-to-noise ratio and the target gating range, the range gate width Δd is a fixed set parameter value, where the set value range is generally between 150m and 450m, and one of three common fixed values of 150m or 300m or 450m, and Δd=300m is a common value. When searching for a target in a range gate, the target is searched according to delta d bin_a ＝0.15m(Δt bin_a =1 ns) resolution traversal range gate width Δd;
s3.2, setting a staring imaging frame frequency f of a laser radar area array type, adjusting time delay delta T of the laser radar to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through a Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar;
s4, constructing a plurality of groups of automatic adjustment judging conditions of the Gm-APD laser radar range gates, wherein the automatic adjustment judging conditions comprise a double judging mode for real-time linear direction relative movement distance between every two continuous frame frequency images and real-time linear direction decomposition speed measurement, the double judgment is carried out by utilizing the real-time measurement distance of each frame frequency image between the target and the laser radar measured in real time in the step S3, and the automatic adjustment of the Gm-APD laser radar range gates is carried out based on the judging result;
further, the specific implementation method of the step S4 includes the following steps:
s4.1, calculating the relative movement distance between each two continuous frame frequency images of the linear direction by using a formula (2) based on the real-time measurement distance between each frame frequency image between the obtained target and the laser radar obtained in the step S3
S4.2, the calculation of the step S4.1Make a judgment, set a first judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
further, at this time, the lidar parameter is set to Δd max 614.25m, gaze-like imaging frame rate "f=25 Hz", then t' =1/f=40 ms, Such large relative instantaneous speeds, at 11Ma (mach) to 22Ma, are generally only possible in very specific cases;
s4.3, calculating the step S4.1Make a judgment, set a second judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
further, in this case, if the lidar parameter is Δd=300 m and the gaze-like imaging frame rate "f=25 Hz", t' =1/f=40 ms, Such large relative instantaneous speeds, at 2.2Ma (mach) to 11Ma, are generally only very specific;
s4.4. the calculation of the step S4.1Making a judgment, setting a third judgment condition asIf yes, storing record in real time>Then move the distance gate by Δd distance in real time single and double frame frequency interval,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
further, in this case, if the lidar parameter is Δd=300 m and the gaze-like imaging frame rate "f=25 Hz", t' =1/f=40 ms, The relative instantaneous speed is also very high between 1.1Ma and 2.2 Ma;
s4.5. Step of pairingS4.1 calculatedMake the judgment, set the fourth judgment condition asIf yes, storing record in real time>Then moving the distance gate every 4-10 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
further, in this case, if the lidar parameter is Δd=300 m and the gaze-like imaging frame rate "f=25 Hz", t' =1/f=40 ms, The relative instantaneous speed is also larger between 0.44Ma and 1.1 Ma;
s4.6, the calculation of the step S4.1Make the judgment, set the fifth judgment condition asIf yes, storing the record in real timeRecord->Then moving the distance gate every 10-20 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
further, in this case, if the lidar parameter is Δd=300 m and the gaze-like imaging frame rate "f=25 Hz", t' =1/f=40 ms, The instantaneous speed is also very high at 270 km/h-540 km/h;
s4.7. the calculation of the step S4.1Making a judgment, setting a sixth judgment condition asIf yes, continuing to judge whether the formula is satisfied>If yes, storing record in real time>Then move the distance in real time by Δd distanceLeave the door and add>Push the range gate far when positive, increase time delay DeltaT,/>When the value is negative, the distance gate is pushed to the near direction and the time delay DeltaT is reduced, and the value is judged as +.>The distance gate is not moved at all, and then +.>Storing records in real time; the sixth judgment condition judges as otherwise, the next step is carried out;
further, in this case, if the lidar parameter is Δd=300 m and the gaze-like imaging frame rate "f=25 Hz", t' =1/f=40 ms, Below 270km/h, the relative instantaneous speed is general, and the highest speed, low small and slow target movement speed of most automobiles can be covered at present;
s4.8. the calculation result of the step S4.1Making a judgment, setting a seventh judgment condition to +.>If yes, continuing to judge whether the formula is satisfied>If yes, step S4.2-step S4.7 are traversed, if no, the system overflows, the distance gate is kept still, the target frame frequency is lost instantaneously, and the conclusion is madeThe laser radar of Gm-APD is not suitable for target detection.
Furthermore, through the steps, the automatic distance gate push scanning of the Gm-APD laser radar is realized, and a basis is provided for tracking a dynamic (a special case of relatively static being dynamic) target by other follow-up upper computer systems of the laser radar.
Further, in the process of detecting the target by the Gm-APD laser radar real-time three-dimensional imaging, the real-time position of the target is realized through the stepsOr (I)>) Is to achieve a target real-time instantaneous pointing speed +.>The method provides the basis for real-time prediction and subsequent restoration of the target track for the software of other subsequent upper computer systems, and is convenient for the other subsequent upper computer systems to intercept targets in advance, analyze the targets afterwards and the like. The automatic distance gate implementation method can also be used for pre-judging and pre-estimating the position of the manipulator by matching with other upper computer systems.
It is noted that relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Although the present application has been described hereinabove with reference to specific embodiments, various modifications thereof may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, the features of the embodiments disclosed in this application may be combined with each other in any way as long as there is no structural conflict, and the exhaustive description of these combinations is not given in this specification merely for the sake of omitting the sake of brevity and saving resources. Therefore, it is intended that the present application not be limited to the particular embodiments disclosed, but that the present application include all embodiments falling within the scope of the appended claims.
Claims (5)
1. The automatic adjustment method for the distance gate of the Gm-APD laser radar is characterized by comprising the following steps of:
s1, defining a linear direction decomposition speed v of a target relative to a laser radar by taking the position of a Gm-APD laser radar as a reference coordinate system 2 ；
S2, defining Gm-APD laser radar area array type staring imaging frame frequency as f, and determining real-time measurement distance of straight line-oriented nth frame frequency image as S n Then, a relative movement distance calculation formula of straight line pointing between every two continuous frame frequency images and an accumulated relative movement distance calculation formula of straight line pointing between the continuous frame frequency images are constructed, and a straight line pointing decomposition speed calculation formula of every two continuous frame frequency images is constructed;
s3, setting parameters of the Gm-APD laser radar, setting a range gate width delta d, a laser radar area array staring imaging frame frequency f, adjusting a laser radar time delay delta T to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through the Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar;
s4, constructing a plurality of groups of automatic adjustment judging conditions of the Gm-APD laser radar range gate, wherein the automatic adjustment judging conditions comprise a double judging mode for real-time linear direction relative movement distance between every two continuous frame frequency images and real-time linear direction decomposition speed measurement, the double judgment is carried out by utilizing the real-time measurement distance of each frame frequency image between the target and the laser radar measured in real time in the step S3, and the automatic adjustment of the Gm-APD laser radar range gate is carried out based on the judging result.
2. The automatic adjustment method of a range gate of a Gm-APD laser radar according to claim 1, wherein in step S1, an actual speed v of an actual moving direction of a target and a linear direction decomposition speed of the target with respect to the laser radar are v 2 The calculation formula of (2) is as follows:
v＝v 2 /cosα (1)
and alpha is an included angle between the actual motion direction of the target and the linear direction of the target relative to the laser radar.
3. The automatic adjustment method for the range gate of the Gm-APD laser radar according to claim 2, wherein the specific implementation method of step S2 includes the following steps:
s2.1, based on the Gm-APD laser radar imaging mechanism, an area array is adopted, the staring-like imaging whole image statistics frame frequency is adopted, and the staring-like imaging frame frequency of the Gm-APD laser radar area array is defined as f;
s2.2, when the Gm-APD laser radar detects a target, simultaneously giving a two-dimensional intensity image, a range image and a three-dimensional point cloud image of the target in real time, and obtaining a real-time measurement distance S of a frame frequency image with a straight line pointing to an nth frame frequency image through the range image n ；
S2.3, constructing a calculation formula of a relative movement distance between every two continuous frame frequency images of straight line directions, wherein the calculation formula is as follows:
wherein,s is the relative movement distance between the continuous n-1 frame frequency image and the n frame frequency image n-1 Real-time distance measurement for straight line pointing to n-1 frame frequency imageN=2, 3,., i, i is the total number of frame rate images;
s2.4, constructing accumulated relative movement distance between straight line pointing continuous frame frequency imagesThe calculation formula of (2) is as follows:
s2.5, calculating the linear direction decomposition speed of each two continuous frame frequencies by adopting an image-frame frequency method, and calculating the time for obtaining a three-dimensional point cloud image according to the gaze imaging frame frequency f of the Gm-APD laser radar area array type to be t' =1/f, wherein the calculation formula for obtaining the linear direction decomposition speed of each two continuous frame frequencies is as follows:
4. the automatic adjustment method for a range gate of a Gm-APD lidar according to claim 3, wherein the specific implementation method in step S3 includes the steps of:
s3.1, setting the width delta d of the range gate to be 150m or 300m or 450m, and setting the maximum value delta d of the width of the range gate max When searching for a target in a range gate, = 614.25m, the range gate width resolution Δd is set bin_a Traverse range gate width Δd =0.15m;
s3.2, setting a staring imaging frame frequency f of a laser radar area array type, adjusting time delay delta T of the laser radar to find a target, locking the target, and then carrying out real-time three-dimensional imaging detection on the target through the Gm-APD laser radar to obtain a real-time measurement distance of each frame frequency image between the target and the laser radar.
5. The automatic adjustment method for a range gate of a Gm-APD lidar according to claim 4, wherein the specific implementation method of step S4 includes the steps of:
s4.1, calculating the relative movement distance between each two continuous frame frequency images of the linear direction by using a formula (2) based on the real-time measurement distance between each frame frequency image between the obtained target and the laser radar obtained in the step S3
S4.2, the calculation of the step S4.1Make a judgment, set a first judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.3, calculating the step S4.1Make a judgment, set a second judgment condition asIf yes, storing record in real time>Then moving the distance gate in real time every frame interval frequency with Δd distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.4. the calculation of the step S4.1Making a judgment, setting a third judgment condition asIf yes, storing record in real time>Then move the distance gate by Δd distance in real time single and double frame frequency interval,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.5, calculating the step S4.1Make the judgment, set the fourth judgment condition asIf yes, storing record in real time>Then moving the distance gate every 4-10 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.6, the calculation of the step S4.1Make the judgment, set the fifth judgment condition asIf yes, storing record in real time>Then moving the distance gate every 10-20 frame frequency intervals in real time with the delta d distance,/>Push the range gate far when positive, increase time delay DeltaT,/>When negative, the distance gate is pushed closer, the time delay DeltaT is reduced, and then +.>Storing the record in real time, and judging that the record is not processed in the next step;
s4.7. the calculation of the step S4.1Making a judgment, setting a sixth judgment condition to +.>If yes, continuing to judge whether the formula is satisfied>If yes, storing record in real time>Then move the range gate in real time with Δd distance, < > and>push the range gate far when positive, increase time delay DeltaT,/>When the value is negative, the distance gate is pushed to the near direction and the time delay DeltaT is reduced, and the value is judged as +.>The distance gate is not moved at all, and then +.>Storing records in real time; the sixth judgment condition judges as otherwise, the next step is carried out;
s4.8. the calculation result of the step S4.1Making a judgment, setting a seventh judgment condition to +.>If yes, continuing to judge whether the formula is satisfied>And if yes, traversing the steps S4.2-S4.7, and if not, judging that the system overflows, the range gate is kept still, the target frame frequency is lost instantaneously, and the conclusion is that the Gm-APD laser radar is not suitable for target detection.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120133550A1 (en) * | 2009-06-25 | 2012-05-31 | Eads Deutschland Gmbh | Method for Determining the Geographic Coordinates of Pixels in SAR Images |
| CN106814356A (en) * | 2017-01-24 | 2017-06-09 | 成都泰格微电子研究所有限责任公司 | It is a kind of based on Radar Signal Processing System apart from tracing subsystem |
| CN108304781A (en) * | 2017-12-29 | 2018-07-20 | 华中科技大学 | A kind of face battle array Geiger APD laser imaging radar image pre-processing methods |
| CN110554404A (en) * | 2019-08-08 | 2019-12-10 | 华中科技大学 | Gm-APD array laser radar imaging method and system under strong background noise |
| CN110609298A (en) * | 2019-09-26 | 2019-12-24 | 湖南国天电子科技有限公司 | Distance gate control method and device suitable for detecting complex scene |
| CN210005696U (en) * | 2018-12-25 | 2020-01-31 | 西南技术物理研究所 | Dual-wavelength adaptive distance laser radar |
| CN110988905A (en) * | 2019-11-29 | 2020-04-10 | 中国华能集团清洁能源技术研究院有限公司 | Automatic adjusting method for laser radar wind measurement distance door |
| CN113376648A (en) * | 2021-04-26 | 2021-09-10 | 上海航天控制技术研究所 | High-speed non-cooperative target track extraction method based on laser radar detection |
| CN116626599A (en) * | 2022-02-11 | 2023-08-22 | 北京华航无线电测量研究所 | Time sequence adjustment method for double-platform airborne radar |
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120133550A1 (en) * | 2009-06-25 | 2012-05-31 | Eads Deutschland Gmbh | Method for Determining the Geographic Coordinates of Pixels in SAR Images |
| CN106814356A (en) * | 2017-01-24 | 2017-06-09 | 成都泰格微电子研究所有限责任公司 | It is a kind of based on Radar Signal Processing System apart from tracing subsystem |
| CN108304781A (en) * | 2017-12-29 | 2018-07-20 | 华中科技大学 | A kind of face battle array Geiger APD laser imaging radar image pre-processing methods |
| CN210005696U (en) * | 2018-12-25 | 2020-01-31 | 西南技术物理研究所 | Dual-wavelength adaptive distance laser radar |
| CN110554404A (en) * | 2019-08-08 | 2019-12-10 | 华中科技大学 | Gm-APD array laser radar imaging method and system under strong background noise |
| US20210041568A1 (en) * | 2019-08-08 | 2021-02-11 | Huazhong University Of Science And Technology | Gm-apd array lidar imaging method and system under strong background noise |
| CN110609298A (en) * | 2019-09-26 | 2019-12-24 | 湖南国天电子科技有限公司 | Distance gate control method and device suitable for detecting complex scene |
| CN110988905A (en) * | 2019-11-29 | 2020-04-10 | 中国华能集团清洁能源技术研究院有限公司 | Automatic adjusting method for laser radar wind measurement distance door |
| CN113376648A (en) * | 2021-04-26 | 2021-09-10 | 上海航天控制技术研究所 | High-speed non-cooperative target track extraction method based on laser radar detection |
| CN116626599A (en) * | 2022-02-11 | 2023-08-22 | 北京华航无线电测量研究所 | Time sequence adjustment method for double-platform airborne radar |
Non-Patent Citations (2)
| Title |
|---|
| SANG-DONG KIM ET.AL.: "UWB radar receiver architecture based on range gates", 2011 3RD INTERNATIONAL ASIA-PACIFIC CONFERENCE ON SYNTHETIC APERTURE RADAR (APSAR), 30 September 2011 (2011-09-30) * |
| 杜达宽等: "基于GM-APD激光雷达数据融合的小目标检测", 光学精密工程, vol. 31, no. 3, 31 March 2023 (2023-03-31) * |
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