Trace evidence discovery and extraction unmanned aerial vehicle

Abstract

The invention relates to a trace material evidence discovery and extraction unmanned aerial vehicle which comprises video recording equipment, a carrying platform, an extraction control device, an extraction combination device, an unmanned aerial vehicle body and a remote controller. The video recording equipment is used for recording related environments on site and searching, discovering and fixing shooting of trace material evidences; the carrying platform is used for carrying a multi-band visible light source, various laser light sources and various spectral imaging devices; the extraction control device is used for controlling the action of the extraction combination device, and a laser ranging module is arranged on the extraction control device; the extraction combination device is used for extracting trace material evidences; the unmanned aerial vehicle is used for sending the high-definition video recording equipment, the carrying platform, the extraction control device and the extraction combination device to a specified position; the remote controller is used for remotely controlling takeoff, landing and hovering of the unmanned aerial vehicle and extracting actions of the control device. According to the invention, effective, rapid and accurate extraction of trace material evidences can be realized in hazardous environments such as high altitude, blast sites and the like, and dangerous operation is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of unmanned aerial vehicles, in particular to a trace evidence discovery and extraction unmanned aerial vehicle. Background Art

[0002] In the fields of criminal case scene investigation and forensic identification, the discovery and extraction of trace evidence is an important link. At present, it is mainly discovered by technical personnel using the naked eye, high-definition recording equipment combined with various light sources / spectra, and the use of professional consumables such as paint brushes, reagent sprayers or adhesive extractors, cotton swabs, etc. to extract trace evidence.

[0003] However, when the trace evidence that needs to be discovered and extracted is located in potentially hazardous environments such as high altitudes, explosion sites, etc., traditional practices mainly rely on manual climbing or wearing protective equipment to enter, which is affected by environmental factors. Not only is the speed of discovering and extracting trace evidence slow, but the potential dangerous factors also pose a certain threat to the life safety of operators. Summary of the invention

[0004] The purpose of the present invention is to provide a trace evidence discovery and extraction drone, which can realize the effective, rapid and accurate extraction of trace evidence in hazardous environments such as high altitudes and explosion sites, thereby avoiding dangerous operations.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a trace evidence discovery and extraction drone, comprising a video recording device, a carrying platform, an extraction control device, an extraction combination device, a drone and a remote controller;

[0006] The video recording device is used to record the relevant environment at the scene and search, discover, shoot and fix trace evidence. The video recording device is fixed at the front end of the drone;

[0007] The carrying platform is used to carry a multi-band visible light source, various laser light sources, and various spectral imaging devices, and the carrying platform is fixed below the UAV;

[0008] The extraction control device is used to control the action of the extraction combination device, and the extraction control device is provided with a laser ranging module;

[0009] The extraction assembly device is used to extract trace evidence;

[0010] The drone is used to deliver the high-definition video recording equipment, the carrying platform, the extraction control device, and the extraction combination device to the designated location;

[0011] The remote controller is used to remotely control the take-off, landing, hovering of the drone and to extract the actions of the control device.

[0012] Furthermore, the recording device is a high-definition camera combined with an infrared camera.

[0013] Furthermore, the extraction control device includes a support plate, a rotating motor and a steering gear, the support plate is fixed above the drone through a support plate, the steering gear is fixed on the support plate through a square block, a long strip is fixed at the upper end of the square block, a U-shaped block is provided at the upper end of the long strip, a telescopic control component for controlling the forward and backward movement of the U-shaped block is provided at the output end of the steering gear, a long board is provided above the U-shaped block, the rotating motor is fixed at the rear end of the long board, a long rod is fixed at the output end of the rotating motor, and the extraction combination device is fixed at the other end of the long rod.

[0014] Furthermore, the telescopic control assembly includes a guide plate, a clamping plate and a fixing column, the guide plate is fixed to the output end of the servo, the guide plate is provided with a first long strip opening, the long strip block is provided with a second long strip opening, the clamping plates are fixed on both sides of the bottom of the U-shaped block, the clamping plates are located on both sides of the second long strip opening, and a fixing column is fixed on the inner side of the clamping plate, the fixing column is located in the second long strip opening, one end of the fixing column passes through the through hole on one side of the clamping plate and the first long strip opening and is fixedly connected to the limit block located on the outer side of the guide plate, an axis block is arranged between the clamping plate and the guide plate, and the axis block is sleeved on the fixing column.

[0015] Furthermore, a first guide sleeve is fixed on both the front and rear sides of the lower surface of the long board, a guide column is fixed on both the front and rear sides of the U-shaped block, the first guide sleeve is sleeved on the guide column, a first buffer spring is sleeved on the guide column, and the first buffer spring is located on the side of the guide sleeve.

[0016] Furthermore, a Japanese-shaped hollow block is fixed above the long board, a second through hole is opened on the hollow block, and the long rod is arranged in the second through hole through a bearing sleeve.

[0017] Furthermore, a connecting key is fixed to the front end of the long strip, a second guide sleeve is fixed on the connecting key, and the second guide sleeve is sleeved on the long rod.

[0018] Furthermore, the extraction assembly device includes a first connector, a second connector and a second buffer spring, the first connector is fixedly connected to the extraction control device, and the first connector is fixedly connected to the second connector via the second buffer spring.

[0019] Furthermore, the laser ranging module uses a cascade controller with a multi-stage filtering algorithm to filter the distance data, and the method for filtering the distance data includes the following steps:

[0020] Step S1: When initFlag is true, loop and perform the following operations: call lidarDriver() to obtain lidar data, check whether sampleTimer() returns true, whether sta is true, and whether index i is less than FILTER_N; if the conditions are met, store the obtained lidar data dis into the array values ​​and increment index i;

[0021] Step S2: traverse arrays values1 and values2, and initialize each element to the current lidar data dis;

[0022] Step S3: Store the latest lidar data dis into the current index position of the array values1, update the index indexFilter1 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in the array values1, and return the result of the sum divided by FILTER_N1*10 as the filtered output value;

[0023] Step S4: Use avg=filter() to store the average value obtained from the first filter() function, store the latest average value avg into the current index position of array values2, update index indexFilter2 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in array values2, and return the result of the sum divided by FILTER_N2 as the filtered output value.

[0024] Furthermore, storing the latest average value avg into the current index position of the array values2 is achieved by values2[indexFilter2]=avg.

[0025] Beneficial effects of the present invention: The device of the present invention combines various light source / spectrum platforms, searches for trace evidence by installing various color filters in front of the lens of the high-definition recording device, and the extraction assembly simulates the movement mode of manual extraction by the expansion and rotation movement formed during the operation of the extraction control device, thereby realizing the effective, rapid and accurate extraction of trace evidence. It has the following advantages:

[0026] ① High safety: The drone can be remotely controlled, and the drone can perform trace evidence discovery and extraction operations without the need for personnel to climb or enter potentially hazardous environments, which greatly reduces safety risks and improves operational safety.

[0027] ② High efficiency: The trace evidence discovery and extraction drone can quickly reach the specified height position or search for suspicious paths, and extract trace evidence, avoiding the drawbacks of traditional large-scale manpower search and greatly improving work efficiency.

[0028] ③Good accuracy: The extraction control device and extraction combination device of the trace evidence discovery and extraction drone can accurately control the extraction action simulated by rotation and extension, basically achieving the simulation of the manual extraction action mode, thereby improving the extraction accuracy and success rate.

[0029] ④ Strong adaptability: The high-altitude exfoliated cell extraction drone can adapt to various complex environments, including but not limited to high-rise buildings, bridge cables, combustion and explosion, toxic and harmful sites, etc., and can effectively adapt to various trace evidence discovery and extraction scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the present invention in the rear direction;

[0031] Figure 2 It is a schematic diagram of the structure of the present invention in the front direction;

[0032] Figure 3 is a side view of the present invention;

[0033] Figure 4 A top view of the present invention;

[0034] Figure 5 for Figure 1 A is an enlarged view of the structure of the extraction control device;

[0035] Figure 6 This is a schematic diagram of the structure of the extraction assembly.

[0036] Among them: 1. Video recording equipment, 2. Carrying platform, 3. Extraction control device, 31. Support plate, 32. Rotating motor, 33. Servo, 34. Support plate, 35. Square block, 36. Long strip block, 37. U-shaped block, 38. Telescopic control assembly, 381. Guide plate, 382. Clamp, 383. Shaft block, 384. First long strip opening, 385. Second long strip opening, 386. Limit block, 39. Long plate, 30. Long rod, 4. Extraction combination device, 41. First connector, 42. Second connector, 43. Second buffer spring, 5. UAV, 6. Laser ranging module, 7. First guide sleeve, 8. Guide column, 9. First buffer spring, 10. Hollow square, 11. Connecting key, 12. Second guide sleeve. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] See also Figures 1 to 6 , the present invention provides an embodiment: a trace evidence discovery and extraction drone, comprising a video recording device 1, a carrying platform 2, an extraction control device 3, an extraction combination device 4, a drone 5 and a remote controller;

[0039] The recording device 1 is used for recording the relevant environment at the scene and searching, discovering, photographing and fixing trace evidence. The recording device 1 is fixed at the front end of the drone 5; the recording device 1 is a recording device 1 such as a high-definition camera combined with an infrared camera, and also supports a combination device with various color filters installed in front of the lens. Its functions include but are not limited to recording the relevant environment at the scene and searching, discovering, photographing and fixing trace evidence.

[0040] The carrying platform 2 is used to carry multi-band visible light sources, various laser light sources, and various spectral imaging devices, and the carrying platform 2 is fixed below the drone 5; the carrying platform 2 is responsible for carrying, including but not limited to, multi-band visible light sources, various laser light sources, and various spectral imaging devices (which can be understood as flashlights that can be replaced with different light sources as needed). It is used to cooperate with the high-definition video recording device 1 to provide support for related light source imaging or spectral imaging.

[0041] The extraction control device 3 is used to control the action of the extraction assembly device 4, and a laser ranging module 6 is provided on the extraction control device 3; the extraction control device 3 is one of the core components of the drone 5, and is responsible for controlling the action of the extraction assembly device 4. The device drives the rotation of the extraction assembly device 4 through a rotating motor 32. The front and rear extension and retraction of the extraction assembly device 4 are controlled by a steering gear 33, so as to simulate the action mode during manual extraction (including but not limited to line brushing, line spraying, adhesive extraction, cotton swab wiping extraction, etc.). At the same time, the device has a laser ranging module 6. After the distance data obtained by the sensor is filtered by a cascade filtering algorithm, the distance information between the drone 5 and the target position can be displayed on the LED screen, providing a reference for the operator and improving the accuracy of the extraction action. In addition, the device also communicates with the remote control to receive control action instructions.

[0042] The extraction assembly 4 is used to extract trace evidence; the extraction assembly 4 is the part for extracting trace evidence. The extraction assembly 4 is mainly composed of two connectors and a second buffer spring 43. The external dimensions and inner diameter dimensions of the connector can be customized according to actual needs to meet different extraction needs (including but not limited to combined powder brushes for line brushing, combined reagents for line spraying, combined adhesive extractors for adhesive extraction, combined cotton swabs for wiping extraction, etc.). During use, the extraction device used by the assembly can be quickly installed and used, and can be replaced multiple times.

[0043] The drone 5 is used to deliver the high-definition video recording equipment 1, the carrying platform 2, the extraction control device 3, and the extraction combination device 4 to the designated location; the drone 5 body is the carrier of the entire system, responsible for delivering the high-definition video recording equipment 1, various light source / spectrum carrying platforms 2, the extraction control device 3, and the extraction combination device 4 to the designated location. The drone 5 is a four-rotor structure, which can be positioned and hovered at high altitude, has the ability to move accurately, and can be controlled to fly by a remote control. At the same time, the drone 5 is also equipped with a high-definition video recording equipment 1 and sensors for real-time transmission of on-site images and monitoring of environmental conditions to ensure the safety and accuracy of the operation.

[0044] The remote controller is used to remotely control the take-off, landing, hovering of the drone 5 and the action of the extraction control device 3. The remote controller is a tool for the operator to interact with the drone 5 system. Through the remote controller, the operator can remotely control the take-off, landing, hovering of the drone 5 and the action of the extraction control device 3. The remote controller is equipped with an intuitive operation interface and display screen, which can display the status, position and recorded image information of the drone 5 in real time.

[0045] Please continue reading Figure 1 Only Figure 6 As shown, in one embodiment of the present invention, the recording device 1 is a high-definition camera combined with an infrared camera.

[0046] Please continue reading Figures 2 to 5 As shown, in one embodiment of the present invention, the extraction control device 3 includes a support plate 31, a rotating motor 32 and a steering gear 33. The support plate 31 is fixed above the drone 5 through a support plate 34. The steering gear 33 is fixed to the support plate 31 through a square block 35. A long block 36 is fixed to the upper end of the square block 35. A U-shaped block 37 is provided at the upper end of the long block 36. A telescopic control component 38 for controlling the forward and backward movement of the U-shaped block 37 is provided at the output end of the steering gear 33. A long plate 39 is provided above the U-shaped block 37. The rotating motor 32 is fixed to the rear end of the long plate 39. A long rod 30 is fixed to the output end of the rotating motor 32. The extraction combination device 4 is fixed to the other end of the long rod 30. The U-shaped block 37 can move forward and backward driven by the servo 33 and the telescopic control assembly 38, thereby driving the long board 39 and the long rod 30 to move forward and backward. The rotating motor 32 can control the long rod 30 to rotate to simulate the action mode during manual extraction, thereby realizing the effective, fast and accurate extraction of trace evidence.

[0047] Please continue reading Figure 1 and Figure 5As shown, in one embodiment of the present invention, the telescopic control assembly 38 includes a guide plate 381, a clamping plate 382 and a fixing column, the guide plate 381 is fixed to the output end of the servo 33, a first long strip opening 384 is opened on the guide plate 381, a second long strip opening 385 is opened on the long strip block 36, the clamping plates 382 are fixed on both sides of the bottom of the U-shaped block 37, the clamping plates 382 are located on both sides of the second long strip opening 385, and a fixing column is fixed on the inner side of the clamping plate 382, ​​the fixing column is located in the second long strip opening 385, one end of the fixing column passes through the through hole on one side of the clamping plate 382 and the first long strip opening 384 and is fixedly connected to the limit block 386 located on the outer side of the guide plate 381, and an axle block 383 is arranged between the clamping plate 382 and the guide plate 381, and the axle block 383 is sleeved on the fixing column. The steering gear 33 drives the guide plate 381 to rotate so that the fixed column can move in the first long strip opening 384, thereby driving the fixed column to move forward and backward along the second long strip opening 385 synchronously, thereby driving the long plate 39 to move forward and backward above the long strip block 36.

[0048] Please continue reading Figure 3 As shown, in one embodiment of the present invention, the first guide sleeve 7 is fixed on both the front and rear sides of the lower surface of the long plate 39, and the guide column 8 is fixed on both the front and rear sides of the U-shaped block 37. The first guide sleeve 7 is sleeved on the guide column 8, and the guide column 8 is sleeved with a first buffer spring 9, which is located on the side of the guide sleeve. The guide column 8 and the first buffer spring 9 cooperate to buffer the movement of the long bar 30 driven by the long strip block 36 when the steering gear 33 controls the U-shaped block 37 to move forward and backward, thereby avoiding the destruction of the trace evidence by the extraction assembly device 4 due to the power of the steering gear 33.

[0049] Please continue reading Figure 5 As shown, in one embodiment of the present invention, a Japanese-shaped hollow block 10 is fixed above the long plate 39, a second through hole is formed on the hollow block 10, and the long rod 30 is arranged in the second through hole through a bearing sleeve. The hollow block 10 is used to limit the movement of the long rod 30 when the steering gear 33 controls the long rod 30 to move forward and backward.

[0050] Please continue reading Figure 5 As shown, in one embodiment of the present invention, a connecting key 11 is fixed to the front end of the long strip 36, and a second guide sleeve 12 is fixed to the connecting key 11, and the second guide sleeve 12 is sleeved on the long rod 30. The second guide sleeve 12 is used to limit the movement of the long rod 30 when the steering gear 33 controls the long rod 30 to move forward and backward.

[0051] Please continue reading Figure 5As shown, in one embodiment of the present invention, the extraction assembly device 4 includes a first connector 41, a second connector 42 and a second buffer spring 43. The first connector 41 is fixedly connected to the extraction control device 3, and the first connector 41 is fixedly connected to the second connector 42 via the second buffer spring 43. The first connector 41 is used to connect to the long rod 30, and the second connector 42 is used to fix extraction tools such as cotton swabs, adhesive extractors, and brushes.

[0052] Please continue reading Figures 1 to 5 As shown, in one embodiment of the present invention, the laser ranging module 6 uses a cascade controller with a multi-stage filtering algorithm to filter the distance data. The original distance data obtained by the laser ranging sensor is often full of noise, and direct output will cause the display end data to jump too frequently. Therefore, a cascade controller using a multi-stage filtering algorithm is designed. After being filtered by the algorithm, it is output to the LED screen, which can make the distance data display more stable and readable.

[0053] The code implements multi-stage data filtering with two filters, the first filter processes the lidar data directly, and the second filter processes the output of the first filter (or some form of average). Each filter uses a circular buffer to store the most recent N data points and calculates the average of these data points. This structure can be seen as a cascaded filtering, where the second filter uses the output of the first filter as input.

[0054] The method for filtering distance data comprises the following steps:

[0055] Step S1: When initFlag is true, loop and perform the following operations: Call lidarDriver() to obtain lidar data, and check whether sampleTimer() returns true, whether sta is true, and whether index i is less than FILTER_N; if the conditions are met, store the obtained lidar data dis into the array values, and increment index i; in the code, initFlag is used to control the loop in the initFIlter_1 function. When initFlag is true, the loop will continue to execute; when initFlag is set to false, the loop will terminate. initFlag is used to initialize the filter array values to ensure that the array is filled with initial data before the filter starts working. By controlling the execution of the loop, initFlag ensures that the initialization process is performed only once or under specific conditions; sampleTimer() is a function call that returns a boolean value indicating whether the sampling time interval has been reached. Only when sampleTimer() returns true (meeting the sampling condition), sta is true (system status is normal), and i is less than FILTER_N (not exceeding the array range), will values[i++] = dis be executed to store the lidar data into the array and increment index i; sta is a boolean variable indicating whether the system is in a normal working state. i < FILTER_N is a conditional judgment indicating whether the current index i is less than the length FILTER_N of the filter array, and is used to determine whether the condition for storing the lidar data into the array values is met.

[0056] Step S2: Traverse the arrays values1 and values2, and initialize each element to the current lidar data dis;

[0057] Step S3: Store the latest lidar data dis into the current index position of the array values1, update the index indexFilter1 so that it loops back to the starting point when it reaches the array length, calculate the sum of all elements in the array values1, and return the result of dividing the sum by FILTER_N1 * 10 as the filtered output value;

[0058] Step S4: Use avg = filter() to store the average value obtained from the first filter0 function, store the obtained latest average value avg into the current index position of the array values2, update the index indexFilter2 so that it loops back to the starting point when it reaches the array length, calculate the sum of all elements in the array values2, and return the result of dividing the sum by FILTER_N2 as the filtered output value.

[0059] The storing of the latest average value avg into the current index position of the array values2 is achieved by values2[indexFilter2]=avg. This line of code stores the calculated average value avg into the current index position of the values2 array. In this way, avg ensures that the data in the second filter array is always the latest average value, thereby achieving a higher level of filtering effect.

[0060] The method for filtering distance data in the present invention is further described below in conjunction with a specific embodiment:

[0061] Step S1: When initFlag is true, loop and perform the following operations: call lidarDriver() to obtain lidar data, check whether sampleTimer() returns true, whether sta is true, and whether index i is less than FILTER_N; if the conditions are met, store the obtained lidar data dis into the array values ​​and increment index i;

[0062] For example: Initialize the first filter:

[0063]

[0064] Step S2: Traverse the array values1 and initialize each element to the current lidar data dis; initialize the values ​​array:

[0065] Function initFIlter()

[0066] void initFIlter(){

[0067] for(int i=0; i <FILTER_N;i++){

[0068] values[i] = dis; / / Initialize the lidar data into the values ​​array

[0069] }

[0070] }

[0071] Step S3: Store the latest lidar data dis into the current index position of the array values1, update the index indexFilter1 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in the array values1, and return the result of the sum divided by FILTER_N1*10 as the filtered output value; for example: implement the filtering operation of the first filter

[0072] Function filter()

[0073] uint32_t filter(){

[0074] values[indexFilter] = dis; / / Update the latest value of the filter array

[0075] indexFilter=(indexFilter+1)%FILTER_N; / / Update index to realize circular buffer

[0076] uint32_t sum = 0;

[0077] for(int i=0; i <FILTER_N;i++){

[0078] sum += values[i]; / / Calculate the sum of all values ​​in the array

[0079] }

[0080] return sum / (FILTER_N*10); / / Return the average value, divided by FILTER_N*10 for scaling

[0081] }

[0082] Step S4: Store the latest average value avg into the current index position of the array values2, update the index indexFilter2 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in the array values2, and return the result of the sum divided by FILTER_N2 as the filtered output value.

[0083] For example: implement the filtering operation of the second filter.

[0084] Function filter2()

[0085] uint32_t filter2(){

[0086] avg = filter(); / / Get the average value obtained by the first filter (filter() function) values2[indexFilter2] = avg; / / Update the latest value of the second filter array indexFilter2 = (indexFilter2+1)%FILTER_N2; / / Update the index to implement circular buffering

[0087] uint32_t sum = 0;

[0088] for(int ii=0;ii <FILTER_N2;ii++){

[0089] sum = sum + values2[ii]; / / Calculate the sum of all values ​​in the array

[0090] }

[0091] return sum / FILTER_N2; / / Return the average value

[0092] }

[0093] The invention has the following working principle: the invention uses a drone to send high-definition video recording equipment, various light source / spectrum carrying platforms, extraction control devices, and extraction combination devices to a designated location; a high-definition camera, an infrared camera, and other video recording equipment cooperate with a multi-band visible light source, various laser light sources, and various spectral imaging devices on the carrying platform to record the relevant environment on the scene and search, discover, and shoot and fix trace evidence; a laser ranging module and a cascade controller of a multi-stage filtering algorithm are used to filter the distance data collected by the laser ranging module, so that the distance data display can be more stable and readable, and the drone can reach the designated location more accurately; when the drone flies to the designated location, the steering gear in the extraction control device drives the long strip block to rotate, thereby driving the U-shaped block to move forward and backward on the long strip block, so that the rotating motor and the long rod can move forward and backward, and the rotating motor can drive the rod to rotate, so as to realize the action mode of simulating manual extraction, thereby realizing effective, fast, and accurate extraction of trace evidence.

[0094] The above description is only a preferred embodiment of the present invention and should not be construed as limiting the present application. All equivalent changes and modifications made within the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A drone for discovering and extracting trace evidence, characterized by: Including video recording equipment, carrying platform, extraction control device, extraction combination device, drone and remote control; The video recording device is used to record the relevant environment at the scene and search, discover, shoot and fix trace evidence. The video recording device is fixed at the front end of the drone; The carrying platform is used to carry a multi-band visible light source, various laser light sources, and various spectral imaging devices, and the carrying platform is fixed below the UAV; The extraction control device is used to control the action of the extraction combination device, and the extraction control device is provided with a laser ranging module; The extraction assembly device is used to extract trace evidence; The drone is used to deliver the high-definition video recording equipment, the carrying platform, the extraction control device, and the extraction combination device to the designated location; The remote controller is used to remotely control the take-off, landing, hovering of the drone and to extract the actions of the control device.

2. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The recording device is a high-definition camera combined with an infrared camera.

3. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The extraction control device includes a support plate, a rotating motor and a steering gear. The support plate is fixed on the top of the drone through a support plate. The steering gear is fixed on the support plate through a square block. A long block is fixed on the upper end of the square block. A U-shaped block is arranged on the upper end of the long block. A telescopic control component for controlling the forward and backward movement of the U-shaped block is arranged on the output end of the steering gear. A long board is arranged above the U-shaped block. The rotating motor is fixed on the rear end of the long board. A long rod is fixed on the output end of the rotating motor. The extraction combination device is fixed on the other end of the long rod.

4. The trace evidence discovery and extraction drone according to claim 3 is characterized by: The telescopic control assembly includes a guide plate, a clamping plate and a fixing column, the guide plate being fixed to the output end of the servo, the guide plate being provided with a first long strip opening, the long strip block being provided with a second long strip opening, the clamping plates being fixed on both sides of the bottom of the U-shaped block, the clamping plates being located on both sides of the second long strip opening, and a fixing column being fixed on the inner side of the clamping plate, the fixing column being located in the second long strip opening, one end of the fixing column passing through a through hole on one side of the clamping plate and the first long strip opening and being fixedly connected to a limit block located on the outer side of the guide plate, an axis block being arranged between the clamping plate and the guide plate, and the axis block being sleeved on the fixing column.

5. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The first guide sleeves are fixed on both the front and rear sides of the lower surface of the long board, the guide posts are fixed on both the front and rear sides of the U-shaped block, the first guide sleeves are sleeved on the guide posts, the guide posts are sleeved with a first buffer spring, and the first buffer spring is located on the side of the guide sleeves.

6. The trace evidence discovery and extraction drone according to claim 1, characterized in that: A Japanese-shaped hollow block is fixed above the long board, a second through hole is opened on the hollow block, and the long rod is arranged in the second through hole through a bearing sleeve.

7. The trace evidence discovery and extraction drone according to claim 1, characterized in that: A connecting key is fixed to the front end of the long strip, a second guide shaft sleeve is fixed on the connecting key, and the second guide shaft sleeve is sleeved on the long rod.

8. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The extraction assembly device comprises a first connector, a second connector and a second buffer spring. The first connector is fixedly connected to the extraction control device, and the first connector is fixedly connected to the second connector via the second buffer spring.

9. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The laser distance measurement module uses a cascade controller with a multi-stage filtering algorithm to filter distance data. The method for filtering distance data includes the following steps: Step S1: When initFlag is true, loop and perform the following operations: call lidarDriver() to obtain lidar data, check whether sampleTimer() returns true, whether sta is true, and whether index i is less than FILTER_N; if the conditions are met, store the obtained lidar data dis into the array values ​​and increment index i; Step S2: traverse arrays values1 and values2, and initialize each element to the current lidar data dis; Step S3: Store the latest lidar data dis into the current index position of the array values1, update the index indexFilter1 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in the array values1, and return the result of the sum divided by FILTER_N1*10 as the filtered output value; Step S4: Use avg=filter() to store the average value obtained from the first filter() function, store the latest average value avg into the current index position of array values2, update index indexFilter2 so that it loops back to the starting point when the array length is reached, calculate the sum of all elements in array values2, and return the result of the sum divided by FILTER_N2 as the filtered output value.

10. The trace evidence discovery and extraction drone according to claim 1, characterized in that: The storing of the latest average value avg into the current index position of the array values2 is achieved by values2[indexFilter2]=avg.

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