Measurement apparatus for braking distance of mine fall arrester, and measurement method therefor

Abstract

A measurement apparatus for the braking distance of a mine fall arrester, the measurement apparatus comprising a housing (1), wherein a display screen (2) is provided on the housing (1); an optical observation window (3), indicator lights (5), functional operation buttons (6), a mode switch (7), a memory card slot (8), and a data transmission interface (9) are provided on the front face of the housing (1); a cubic neodymium magnet (10) is provided on the back face of the housing (1); an optical glass column (11), a laser ranging module (13), a measurement LED fill light module (14), an imaging module (15), and an outwardly-flared metal shielding cover (16) are provided at the lower portion of the housing (1); and a central control module (17), a GPS module (18), an active ceramic GPS antenna (19), a wireless receiver module (20), a wireless transmitter module (21), a 315MHz control module (22), a 433MHz communication output module (23), a nine-axis accelerometer and gyroscope module (24), a power supply module, and a loudspeaker module (26) are provided in the housing (1). Further provided is a measurement method for the braking distance of a mine fall arrester.

Description

Mine fall arrester braking distance measuring device and measuring method Technical Field

[0001] The invention relates to a device for measuring the braking distance of a mine fall arrester and a method thereof, and belongs to the field of detection and testing. Background Art

[0002] Energy industry standards such as NB / T 10050-2018, "Specifications for Inspection and Testing of Fall Arresters in Use in Shaft Hoisting Systems in Coal Mines," require regular testing of all types of mine fall arresters as a crucial measure for ensuring safe production. Inspection and testing of shaft hoisting fall arresters include: unhooked, no-load, and loaded unhooked tests. While the unhooked test has a relatively comprehensive solution, the unhooked test still has various drawbacks.

[0003] The unhooking test mainly measures the descent distance of the fall arrester. In order to more intuitively reflect its actual braking performance, it is necessary to detect the distance traveled in each stage after the cage is unhooked, including the distance before braking, the distance during braking, etc. In order to meet the requirements of the standard, the braking distance is sometimes combined with time to analyze other parameters such as braking deceleration and idle travel time.

[0004] Under current technical conditions, braking an arrester during both no-load and loaded unhooking tests generates significant impact. Traditional arrester measuring instruments require connection to a cage or arrester for testing. The impact force at the moment of braking is extremely strong, and the significant impact and vibration affect the linearity and physical structure of traditional arrester measuring instruments, easily causing accuracy drift and instrument structural damage. For example, the CCZ series arrester measuring instruments use a linear resistance scale with a rigid connection for measurement. This significant impact can easily damage the scale's concentricity and sliding contact points, affecting accuracy and causing uncontrollable data drift. Currently, conventional conventional technologies and methods are unable to effectively and thoroughly address these issues. Other single measurement methods also have various drawbacks, and there are currently no targeted designs or solutions on the market to address these drawbacks. Summary of the Invention

[0005] The present invention provides a device and method for measuring the braking distance of a mine fall arrester, which solve the problems of accuracy drift and easy damage of the instrument structure in the existing measurement of the braking distance of a mine fall arrester.

[0006] To achieve the above-mentioned object, the present invention provides a device for measuring the braking distance of a mine fall arrester and a method thereof. The device for measuring the braking distance of a mine fall arrester of the present invention comprises a housing, characterized in that an optical observation window is provided on the front of the housing, the optical observation window runs through the entire housing, and an inclined reflector is provided at the rear hole position of the optical observation window of the housing;

[0007] The front of the shell is also equipped with a display screen, multiple indicator lights, function operation buttons, a mode switch, a memory card slot and a data transmission interface;

[0008] A cubic neodymium magnet is provided on the back of the housing and below the reflector. The surface of the neodymium magnet is gold-plated and five sides of the neodymium magnet are wrapped with mm polytetrafluoroethylene. The outside of the polytetrafluoroethylene is wrapped with a metal shielding layer. The neodymium magnet is connected to the core of the feeder line, and the metal shielding layer is connected to the shielding layer of the feeder line. The neodymium magnet protrudes from the back of the housing.

[0009] The lower part of the shell is provided with a concave area and is sealed with a transparent optical sapphire cover. The cover contains an optical glass column, a laser ranging module, a measuring LED fill light module, a camera module, and an outward-flared trapezoidal metal shield. The sides of the optical glass column are frosted, and both ends are smooth. One end is adhered to the transparent optical sapphire cover, and the other end is adhered to the laser transmitter head of the laser ranging module.

[0010] A central control module, a GPS module, an active ceramic GPS antenna, a wireless receiving module, a wireless transmitting module, an M control module, an M communication output module, a nine-axis accelerometer gyroscope module, and a speaker module are set in the shell. The central control module includes an input signal bus and an output signal bus, among which the GPS module, laser ranging module, wireless receiving module, camera module, nine-axis accelerometer gyroscope module, M control module and function operation buttons are respectively connected to the input signal bus, among which the display screen, wireless transmitting module, indicator light, M communication output module, speaker module, measurement LED fill light module, and observation LED fill light module are respectively connected to the output signal bus.

[0011] According to the described braking distance measuring device for a mine fall arrester, anti-fall rubber edges made of PU material protruding from the surface of the body are provided on the left and right sides of the shell, and a removal groove is provided at the upper and lower positions of each anti-fall rubber edge. A strap fixing area is provided in the middle of the anti-fall rubber edge, which is recessed toward the center side of the body for embedding the fixing strap.

[0012] According to the described braking distance measuring device for a mine fall arrester, the indicator lights are located above the optical observation window, and from left to right are: a yellow indicator light, a green indicator light, a blue indicator light, and a red indicator light. The yellow indicator light indicates preheating, the green indicator light indicates working, the blue indicator light indicates the end, and the red indicator light indicates a fault. When the red indicator light is on, all programs and detection actions are terminated until the instrument is manually restarted.

[0013] According to the described mining fall arrester braking distance measuring device, a trapezoidal prism is provided in the middle of the back of the shell, and the neodymium magnet is provided in the concave part of the trapezoidal prism, and the neodymium magnet protrudes .mm from the back of the shell. It also includes an observation LED fill light module, which is provided in the lower strip-shaped protrusion area of ​​the neodymium magnet and irradiates toward the upper neodymium magnet. The observation LED fill light module is connected to the output signal bus.

[0014] According to the described mine fall arrester braking distance measuring device, an inward recess is provided on the upper part of the shell, and a power switch, a charging interface, and an SMA interface are provided in the inner recess from left to right. The mode switching switch is connected to the power amplifier, and the power amplifier is connected to the wireless transmitting module.

[0015] According to the braking distance measuring device for a mine fall arrester, the metal shielding covers are three nested ones, which are parallel to each other, insulated from each other, and spaced mm apart. The innermost metal shielding cover is connected to the feeder shielding layer of the wireless receiving module. The innermost metal shielding cover contains a sheet-shaped directional antenna. The innermost metal shielding cover is insulated from the directional antenna. The sheet-shaped directional antenna is connected to the wireless receiving module through the core of the feeder. The wireless receiving module has a built-in wireless radio frequency power detection module.

[0016] According to the described mine fall arrester braking distance measuring device, the nine-axis accelerometer gyroscope module integrates a 3-axis accelerometer, a 3-axis magnetometer and a 3-axis gyroscope. The static attitude measurement accuracy does not exceed 0.05 degrees, and the dynamic attitude measurement accuracy does not exceed 0.1 degrees. It has a built-in Kalman attitude solution algorithm with a magnetometer ellipsoid correction function. △ acceleration is the acceleration fluctuation variable, △ three-axis gyroscope data is the X, Y, and Z axis fluctuation variable, and △ ellipsoid magnetic data is the magnetometer data fluctuation variable after the ellipsoid fitting algorithm.

[0017] According to the measuring method of the braking distance measuring device of the mine fall arrester,

[0018] The steps include:

[0019] 1) Install the device to the measurement position as required, check the adsorption status through the optical observation window, and select the corresponding measurement mode;

[0020] 2) Power on the instrument. The yellow indicator light will light up and a tone will sound. The tone includes the distance limit between the operator and the instrument. The GPS module will be preheated and search for satellites at the same time. After the tone ends, the nine-axis accelerometer and gyroscope module will be powered on and enter the working state. It will collect acceleration data, three-axis gyroscope data, and magnetometer data after the ellipsoid fitting algorithm in real time. At the same time, the GPS data collected by the GPS module will be recorded and the device time will be calibrated according to the time collected by the GPS module.

[0021] 3) Calculate the △ acceleration, △ three-axis gyroscope data, and △ ellipsoid magnetic data. If the fluctuation of the △ acceleration and △ three-axis gyroscope data is less than 0.1% and the fluctuation of the △ ellipsoid magnetic data is less than 1% within 5 seconds, directly proceed to the next step. If the △ acceleration and △ three-axis gyroscope data are greater than 0.1% and less than or equal to 0.3%, delay 5 seconds and repeat the detection calculation. This jump cycle is performed up to 5 times. If it exceeds 5 times or the fluctuation of a single △ acceleration or △ three-axis gyroscope data is greater than 0.3% and less than 0.6%, it prompts to check the environmental vibration factor and lights up the red indicator light.

[0022] 4) Execute this single-threaded monitoring task and directly proceed to the next step. This single-threaded monitoring task will terminate after the cage starts to move. This single-threaded monitoring task has a delayed error reporting function. If the cage starts to move, the error reporting in the delay will be terminated, and the subsequent error reporting action will not be executed. At the same time, the single-threaded monitoring task will be terminated;

[0023] 5) Power on the wireless transmitter module, power amplifier, and wireless receiver module, detect and set the optimal channel, count the signal strength of the valid coded signal, and count and calculate the average, standard deviation, and range of the received signal strength dBm value within 5 seconds. If the ratio of the standard deviation of the strength dBm value to the average value does not exceed 0.5%, that is, the standard deviation / average value ≤ 0.5% and the ratio of the range to the average value does not exceed 5%, that is, the range / average value ≤ 5%, then proceed directly to the next step. Otherwise, the display will prompt an error. There are two types of errors here. If the (range / average value) is detected to be ≥ 10%, the error prompt indicates that the signal receiving and sending modules are suspected to be faulty. In addition to the above situations, a unified error prompt indicates that there is radio interference on site that needs to be eliminated, and the red indicator light is on.

[0024] 6) Set the camera sampling rate to the rated working frame rate, load the data captured by the camera into the RAM of the central controller, denoise the cage top information captured by the camera, use a Gaussian filter to smooth the image, use the Sobel operator to calculate the gradient strength and direction of each pixel in the image, perform maximum value detection in the gradient direction, retain only the points with the largest pixel gradient, and classify the pixels into three categories: strong edge, weak edge, and non-edge. Strong edges are directly output, non-edges are directly discarded, and weak edges are output only when they are connected to strong edges. Use the connectivity analysis algorithm to connect weak edges To the strong edge, forming a complete edge, and dividing the continuous edge into a single line segment along the intersection point, the tester uses the 315M wireless controller to select the cage edge line segment that meets the requirements. After the tester confirms the selection, the length and coordinate position information of the current cage edge line segment in the image data are recorded. At this time, the laser ranging module measures the distance from the instrument to the top of the cage and records it as D1. At the same time, the green indicator light is turned on, completing the preparation of this device. The display (2) prompts that the uncoupling test can be carried out. At this time, the camera rated frame rate sampling is continuously maintained, and a low resource consumption strategy is adopted to write the sampled video data into the RAM in real time. Only the first 1000 milliseconds of high-speed video data is retained in the RAM, and the high-speed video data is cyclically overwritten. The video information in the RAM exists in the form of raw data without additional analysis and encoding by the CPU;

[0025] 7) Execute the default mode program, or select the strict mode program according to the user's settings. If no settings are made, execute the default mode program. Both modes will be executed after the program ends normally and then go directly to the next step. The default mode program features are: when it is detected that the current coded signal strength changes by more than ±20% of the average value and cannot be restored to the average signal strength, the time of the transient change is taken as T1. Regardless of whether the coded signal strength is restored, the laser ranging module is linked to perform ranging at the T1 time when the intensity dBm value changes instantaneously, which is recorded as DC. If the signal strength does not recover after 500 milliseconds, the execution of this program ends normally. If the signal strength dBm value changes by more than ±20% of the average value but can be restored to within 5% of the intensity average value within 500 milliseconds, the user is prompted that there may be a fault in the signal receiving and sending modules. At the same time, an error is reported, the T1 and DC variables are cleared, and the red indicator light is on.

[0026] 8) Terminate the camera's low resource consumption strategy, stop the RAM video data overwriting strategy, prevent the real-time recorded sampled video data from being overwritten in RAM, increase the CPU main frequency to the highest frequency, stop the display output and release the memory resources it occupies, and simultaneously perform real-time analysis and processing of the video data. Mark the video frame at time T1, use the optical flow algorithm to detect the motion state of the "cage edge", and when it detects that the "cage edge" stops changing, record the current time as T2, mark the video frame at time T2, and simultaneously use the laser ranging module to measure the distance as D2. Terminate camera capture and video RAM writing, compress the sampled video in H.265 format and store it in ROM, and embed the GPS metadata collected by the GPS module into the video file;

[0027] 9) Calculate D2-D1=D3, analyze the video stream frame by frame, find the cage edge based on the length and coordinate position information of the marked cage edge segment, use the mean shift algorithm to track and identify the cage edge in each frame, track and record the changes in the pixel position of the cage edge in each frame, and calculate the actual displacement:

[0028] (a) Calculate the cage edge pixel position difference ΔPi between the i-th frame and the i+1-th frame,

[0029] (b) Sum all ΔPi to get the total pixel displacement ΔPt,

[0030] (c) Divide D3 by the total pixel displacement ΔPt to obtain the conversion ratio K, K = D3 / ΔPt,

[0031] (d) Calculate ΔD = K*ΔPi, ΔT = 1 / camera operating frame rate;

[0032] 10) Draw a curve: The horizontal axis is time T, the vertical axis is displacement distance D, and the starting point of the curve is set as the origin of the coordinate axis, which is (T1, D1). Point T1 is the time point when the cage has not yet moved at the moment of uncoupling, and point D1 is the measurement value completed by the laser ranging module when the cage has not moved. According to the calculated actual displacement ΔD distance value of each cage edge and the time interval ΔT between two frames, each point in the coordinate system is determined, and these points are connected in sequence to draw a curve A of distance changing with time. D2 is the curve The end point of the line, D3 is the difference between D2 and D1, that is, the actual displacement of the cage before and after the fall arrester is activated, T2 is the stopping point of the cage movement, and the expected curve is drawn according to the law of v=gt, that is, D=0.5gt^2. The separation point of the two curves is (Tx, Dx). The D value of the overlapping part of the two curves is the idle travel distance, that is, D1 to Dx is the idle travel distance; the T value of the overlapping part of the two curves is the idle time, that is, T1 to Tx is the idle travel time; Dx to D2 is the deceleration distance, and Tx to T2 is the deceleration time;

[0033] 11) Restore the display screen output, output the display curve, output the curve as an image format, and store it in the same folder as the current video. The folder is named after the location and time recorded by GPS. Output the difference between DC and D1 or DC2 and D1, prompting personnel to check the difference, and light up the blue indicator light.

[0034] 9. The method for measuring the braking distance of a mine fall arrester according to claim 8, wherein in step 4), when the fluctuation data of the delta acceleration and delta three-axis gyroscope is greater than 0.1% and less than or equal to 0.3%, a count is performed. When the count reaches 5 times or the fluctuation of a single delta acceleration and delta three-axis gyroscope data is greater than 0.3%, an error delay is started. After a delay of 1500 milliseconds, an error is reported and a prompt is given, indicating that the vibration is too large and needs to be eliminated and requiring manual confirmation to confirm whether the instrument is fixed at the rigid connection, and a red indicator light is turned on.

[0035] 10. The method for measuring the braking distance of a mine fall arrester according to claim 8, wherein step 7) further comprises the following steps:

[0036] 1) Preprocess the signal and select the strongest signal in the selected working channel as the valid candidate signal;

[0037] 2) For valid candidate signals, the check bit is verified. If the verification is successful, it is recorded as a valid signal, and the ratio of invalid signals to the total signals is calculated in real time;

[0038] 3) If the invalid signal ratio is greater than 0.1%, an error will be reported, prompting the user that the on-site radio environment is poor and instructing the user to troubleshoot or use the default mode. After the error occurs, this step will be terminated and the red indicator light will be on.

[0039] 4) If there is no error, the valid signal is further verified to check whether the file header code number is continuous with the previous signal code. If it is continuous, a valid count is performed. When the valid count reaches 10,000, the next step is jumped to calculate and count the time information of the coded signal. If it is not satisfied, an interrupt count is performed for each discontinuity. If the interrupt count accumulates to 10, an error is reported, indicating that there is interference in the channel or poor magnet adsorption needs to be eliminated. At the same time, an error is reported and the red indicator light is on.

[0040] 5) In the valid signal, calculate the difference between the time information carried by each received valid coded signal and the current system time, referred to as "difference" in the subsequent description. Calculate the average of 10,000 differences, referred to as "mean" in the subsequent description. Compare each received difference with the mean. When the difference changes by more than ±10% of the mean for three times, take the time when the first time a transient change in the time information is detected as T1. Regardless of whether the difference continues to change, the laser ranging module is linked to perform ranging at time T1 when the time information carried by the valid coded signal is first detected to change. The ranging result is recorded as DC2. If the subsequent difference change still exceeds ±10% of the mean, the execution of this program ends normally. If the difference change returns to within ±10% of the mean, continue with this time mean comparison strategy, clear the T1 and DC2 variables, and the green light flashes at this time, indicating that the magnet may have poor contact and adsorption.

[0041] The advantages of the present invention are: measuring the distance change trend of the entire braking process of the fall arrester by a composite method that can support each other, using a scientific analysis method to measure and analyze the detection data, thereby overcoming the defects and shortcomings of traditional measurement solutions;

[0042] This measuring instrument has scientific measurement and solves the drawbacks of the single measurement method of existing measuring instruments. All aspects support each other and comprehensively improve the overall function of the measuring instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a front perspective view of the present invention,

[0044] FIG2 is a rear perspective view of the present invention,

[0045] FIG3 is a top perspective view of the present invention,

[0046] FIG4 is a bottom perspective view of the present invention,

[0047] FIG5 is a circuit connection diagram of the present invention,

[0048] FIG6 is a schematic diagram of a braking distance curve drawn by the test braking method of the present invention.

[0049] Figure 1: 1. Housing, 2. Display, 3. Optical observation window, 4. Reflector, 5. Indicator light, 6. Function operation button, 7. Mode switch, 8. Memory card slot, 9. Data transmission interface, 10. Neodymium magnet, 11. Optical glass column, 12. Transparent optical sapphire cover, 13. Laser ranging module, 14. Measuring LED fill light module, 15. Camera module, 16. Metal shield, 17. Central control module, 18. GPS module, 19. Active ceramic GPS antenna, 20. Wireless receiving module, 201. Wireless power detection module Block, 21. Wireless transmission module, 22. 315M control module, 23. 433M communication output module, 24. Nine-axis accelerometer gyroscope module, 25. Power amplifier, 26. Speaker module, 27. Trapezoidal prism, 28. Observation LED fill light module, 29. Power switch, 30. Charging port, 31. SMA port, 32. Anti-drop rubber edge, 33. Removal groove, 34. Strap fixing area, 35. Directional antenna, 36. Output control bus, 37. Input control bus, 38. Function A area, 39. Function B area, 40. Function C area. DETAILED DESCRIPTION

[0050] The content of the present invention will be further described below:

[0051] The measuring instrument has a flat cubic shell as a whole, and a control circuit is arranged inside.

[0052] Specifically, a display screen is provided in the middle of the front of the shell, and an optical observation window is provided on the upper part of the display screen. The optical observation window runs through the front and back surfaces of the shell. A speaker opening is provided in the optical observation window channel. The speaker opening cannot be directly seen from the outside, which is more beautiful.

[0053] Above the optical observation window on the front of the housing are operating status indicators. From left to right, they are: yellow, green, blue, and red. Yellow indicates preheating, green indicates operation, blue indicates completion, and red indicates a fault. These indicators provide a clear and direct indication of the instrument's operating status.

[0054] The lower portion of the display features a recessed rectangular Function Area A. Function buttons are located on the left side of this area, and a mode switch is located on the upper right side. The SMA connector and the feed line for the neodymium magnet are connected to the mode switch. Below the mode switch, on the left, is a TF card slot, and on the right, is a Type-C data transfer port.

[0055] A downward-inclined reflector is provided at the rear of the optical observation window, that is, the rear of the shell. The reflector can be seen at the front of the optical observation window for observing the adsorption and fixing conditions of the rear of the shell.

[0056] A cubic neodymium magnet is located at the trapezoidal prism in the center of the back of the housing. A reflector is used to observe the magnet's attachment to the device under test. The cubic neodymium magnet is gold-plated with a thickness greater than 50 microns and wrapped on five sides with 1 mm of polytetrafluoroethylene. The polytetrafluoroethylene is then covered with a trapezoidal metal shield. The neodymium magnet connects to the feeder's core, and the metal shield connects to the feeder's shield. The neodymium magnet protrudes 0.5 mm from the housing. The outer flat surface of the neodymium magnet can be embossed with surface plating, and any unused markings can be removed to prevent damage to the instrument if lost. The feeder is connected to the power amplifier module of the internal control circuit.

[0057] A strip-shaped protrusion is located below the neodymium magnet, which is used to mount a strip-shaped observation LED fill light module, which is used to observe the magnet's attraction through an observation window. The observation LED fill light module shines light on the neodymium magnet, and a reflector monitors the magnet's attraction through the optical observation window.

[0058] The left and right sides of the housing feature PU rubber edges that protrude from the surface. Each edge has a removal notch at the top and bottom. To retrieve the housing after testing, simply grip and remove the entire magnetically attached housing. A strap attachment area recessed toward the center of the housing is located in the center of the rubber edge. This area allows for secure strapping around the housing to secure it to various devices under test.

[0059] An inward-concave rectangular functional area B is provided on the upper part of the shell, and specifically, from left to right, a power switch, a charging port, and an SMA port are provided.

[0060] The lower portion of the housing features a recessed Functional Area C. A square, artificially transparent optical sapphire cover seals the opening of Functional Area C. The cover is 2mm thick and adheres one end of a frosted, polished optical glass column to the interior. The other end of the optical glass column is bonded to the laser emitter of the laser ranging module. The adhesive is preferably 705 optical silicone rubber; UV-curing adhesive is prohibited. Functional Area C is also covered entirely with a black, light-absorbing coating. A measurement LED fill light module is located at one end of Functional Area C, while a camera module is located at the other end. The barrel distortion of the camera module should be less than 0.1%. The camera module uses a fixed-focus lens with a viewing angle of at least 69.9 degrees but not more than 90 degrees. The optimal focal length of the lens is 4mm (behind the lens), and the sampling rate is at least 1000 fps. Coated optical glass is preferred as the lens material.

[0061] Three nested, outward-flaring trapezoidal metal shields are located in the center of Functional Zone C. These shields are parallel, insulated, and spaced 1mm apart. The innermost metal shield is connected to the wireless receiver module's feeder shield. This innermost metal shield houses a sheet-shaped directional antenna, which is insulated from the antenna. The sheet-shaped directional antenna is connected to the wireless receiver module via the feeder core. The module also includes a built-in radio frequency power detection module.

[0062] The shell houses a central control module, GPS module, active ceramic GPS antenna, wireless receiving module, wireless transmitting module, 315M control module, 433M communication output module, nine-axis accelerometer and gyroscope module, power module, speaker module, etc.

[0063] The central control module contains input signal buses and output signal buses. The core adopts a high-performance 64-bit quad-core processor, LPDDR4 memory, and has a standard 40-pin GPIO interface, including power and programmable GPIO. Some GPIO can be reused as IIC, SPI, UART, PWM, etc.

[0064] The GPS module 18, laser ranging module 13, wireless receiving module 20, camera module 15, nine-axis accelerometer and gyroscope module 24, 315M control module 22, and function operation buttons 6 are connected to the input signal bus. The display screen 2, wireless transmission module, indicator light 5, 433M communication output module 23, speaker module 26, and measurement LED fill light module 28 are connected to the output signal bus. The SMA interface 31 and the feed line of the neodymium magnet 10 are connected to the mode switch 7, which is connected to the power amplifier, which is connected to the wireless transmission module 21.

[0065] Specific specifications of each component, among which the GPS module is a multi-mode satellite navigation and positioning module, which supports single-system positioning and multi-system joint positioning of BDS / GPS / GLONASS satellite navigation systems, and supports QZSS and SBAS systems. The active ceramic GPS antenna is connected to the GPS module.

[0066] The transmitting and receiving frequency bands of the wireless receiving module and the wireless transmitting module match each other, with the transmitting and receiving frequency being no less than 2GHz and no more than 6GHz. They support six-channel data reception, support modulation methods such as GFSK / FSK, and have no less than 126 frequency points to meet the needs of multi-point communication and frequency hopping communication. The sensitivity must be at least -96dbm (at an air rate of 250kbps), and an LDO with high PSRR is integrated internally.

[0067] The nine-axis accelerometer and gyroscope module integrates a three-axis accelerometer, a three-axis magnetometer, and a three-axis gyroscope. The static attitude measurement accuracy does not exceed 0.05 degrees, and the dynamic attitude measurement accuracy does not exceed 0.1 degrees. It has a built-in Kalman attitude solution algorithm and a magnetometer ellipsoid correction function. It supports two transmission modes: serial port output and IIC output data.

[0068] The 315M control module is used by staff to wirelessly operate the control instrument to select the edge of the cage. Most 315M control modules on the market can meet the needs; the 433M communication output module is used to output data such as print data, with a transmission rate of not less than 19.2kbps.

[0069] The power module of the present invention is powered by a lithium-ion battery and is provided with a charge-discharge integrated protection board. The power module provides electrical energy for internal electrical components.

[0070] Description of the wireless transmitter module's coded signal: The coded signal consists of three components: a header, time information, and a CRC checksum. The header contains the coded sequence number. The coded interval transmission time slot is adjustable, but the maximum time slot must not exceed one-tenth of the camera's single-frame time. For example, if the camera operates at a frame rate of 10,000 frames per second, the coded interval transmission time slot must not exceed 10 microseconds.

[0071] The following is a detailed description of the measurement method using this device:

[0072] S1. Preparation: Attach the gold-plated neodymium magnet on the back to the unhooker or the rigid metal connecting frame of the fixed unhooker. Do not attach it to movable parts. At the same time, use the fixing strap on the side of the shell to embed it into the strap fixing area to fix it. The fixing strap is fixed to the unhooker or the rigid metal connecting frame of the fixed unhooker. Make sure that there is no displacement or shaking when the measuring instrument is working. If the on-site conditions cannot meet this requirement, a special bracket for fixing the measuring instrument can be set up. After the fixation is completed, the adsorption and fit of the magnet should also be checked through the optical observation port. If there is light leakage at the suction point, it means that the suction is incomplete and the measuring instrument needs to be adjusted to a flat surface that meets the requirements for installation.

[0073] Adjust the angle of the measuring instrument so that the camera faces the top of the cage. The four sides of the cage top need to be visible on the screen. If the installation angle does not meet the requirements, please remove and adjust it. Do not rotate it directly when the measuring instrument is adsorbed.

[0074] Step 2: Turn on the power. The yellow indicator light illuminates, and a voice message begins: "The instrument is preparing to begin calibration. Please wait. Do not move or touch the instrument. Do not approach the cage within 1 meter." Simultaneously, the GPS module powers on, warms up, and begins searching for satellites. The camera starts, and the screen displays real-time video captured by the camera. The camera sampling rate is the screen refresh rate.

[0075] After the voice broadcast ends, the nine-axis accelerometer and gyroscope module is powered on and enters the working state, collecting acceleration, three-axis gyroscope data, and magnetometer data after the ellipsoid fitting algorithm in real time. At the same time, it records the GPS data collected by the GPS module and calibrates the instrument time based on the time collected by the GPS module.

[0076] S3. In this article, execute S3.1 first, and then jump to S3.2 from S3.1.

[0077] S3.1. Calculate △ acceleration (acceleration fluctuation variable), △ three-axis gyroscope data (X, Y, Z axis fluctuation variable), and △ ellipsoid magnetic data (magnetometer data variable after ellipsoid fitting algorithm). When the △ acceleration and △ three-axis gyroscope data are less than 0.1% within 5 seconds, and the △ ellipsoid magnetic data is less than 1%, directly proceed to 3.2. When the △ acceleration and △ three-axis gyroscope data are greater than 0.1% and less than or equal to 0.3%, delay 5 seconds and continue to repeat the detection calculation in this step. The maximum number of repeated detection calculations is 5 times. If the number exceeds 5 or the fluctuation of a single △ acceleration and △ three-axis gyroscope data is greater than 0.3% and less than 0.6%, a prompt will be given: "The environmental vibration factor is too large. Please suspend nearby traction machines, water pumps and other equipment until the uncoupling test is completed. This instrument takes about 2 minutes, including calibration and testing." The program will be terminated while the prompt tone is broadcast, the red indicator light will be turned on, and the start button signal will be waited for to guide the inspection personnel to reinstall and start from step S1.

[0078] S3.2. Use a separate thread to execute this program task and directly enter S4. This program works as a separate thread and monitors until the execution of S6 program is terminated. In this separate thread task, if it is detected that the S6 step program is executed and an error is reported during the delay, it will be terminated and no subsequent actions will be executed. At the same time, this separate thread task will be terminated. The following are the execution actions of this program: "When the △ acceleration and △ three-axis gyroscope are greater than 0.1% and less than or equal to 0.3%, count once. When the count reaches 5 times or the single △ acceleration and △ three-axis gyroscope data fluctuates by more than 0.3%, start the error delay. After a delay of 1500 milliseconds, perform the following actions: Prompt: "The vibration is too large, please eliminate it and please confirm again whether the shell is fixed to the rigid connection." The program will be terminated while the prompt tone is broadcast, the red indicator light will be turned on, and the start button signal will be waited for to guide the inspection personnel to reinstall and start from step S1."

[0079] S4. Power on the wireless transmitter module, power amplifier, and wireless receiver module, detect the status of each channel and set the optimal channel. Start counting the signal strength of the valid coded signal, and count and calculate the average, standard deviation, and range of the received signal strength dBm value within 5 seconds. When the ratio of the standard deviation to the average value does not exceed 0.5%, that is, (standard deviation / average value) ≤ 0.5% and the ratio of the range to the average value does not exceed 5%, that is, (range / average value) ≤ 5%, directly proceed to step 5. Otherwise, an error is reported.

[0080] There are two types of errors. If the (range / average) is ≥ 10%, an error message is displayed: "The signal receiving and transmitting modules are suspected to be faulty." If this occurs repeatedly, please return the device to the factory for repair. In addition to the above situations, the error message will be: "Radio interference is present on site. Please eliminate it." The program will terminate upon the error message, and the red indicator light will illuminate. Wait for the start button signal, which will guide the inspector to reinstall and restart the device from step S1.

[0081] S5. Set the camera sampling rate to the rated operating frame rate. Load the captured data into RAM. De-noise the cage top information. Smooth the image using a Gaussian filter. Calculate the gradient strength and direction of each pixel in the image using the Sobel operator. Detect the maximum value in the gradient direction, retaining only the points with the largest gradient. Pixels are then classified into three categories: strong edges, weak edges, and non-edges. Strong edges are output directly, while non-edges are discarded. Weak edges are only output when they are connected to strong edges. Connectivity analysis algorithms are used to connect weak edges to strong edges to form complete edges. Continuous edges are then segmented into individual segments along their intersections. The inspector uses the 315M wireless controller to select and mark the cage edge segments that meet the requirements. After confirming the selection, the inspector records the length and coordinate position of the current cage edge segment. The laser rangefinder module measures the instrument once, recording the distance from the instrument to the cage top as D1. The green indicator light illuminates, indicating that the instrument is ready for the unhooking test. The operator is instructed to release the cage to complete the arrester test.

[0082] At this time, the camera continues to maintain rated frame rate sampling and adopts a low resource consumption strategy to write the sampled video data into RAM in real time. However, only the first 1000 milliseconds of high-speed video data is retained in RAM, and the high-speed video data is overwritten cyclically. The video information in RAM exists in the form of raw data without additional CPU analysis and encoding.

[0083] S6. Select S6.1 or S6.2 according to user settings. S6.1 is executed by default.

[0084] S6.1, Default Intensity Mode: When it is detected that the current coded signal strength changes by more than ±20% of the average value and cannot be restored to the signal strength average value calculated in step S4, the time of the transient change is taken as T1. Regardless of whether the coded signal strength is restored, the laser ranging module is linked to perform ranging at the T1 time when the intensity dBm value changes instantaneously, which is recorded as DC. If it does not recover after 500 milliseconds, the execution of this program ends normally and step S7 is executed. If the signal strength dBm value changes by more than ±20% of the average value but can be restored to within 5% of the intensity average value recorded in step S4 within 500 milliseconds, it is prompted that there is a suspected fault in the signal receiving and sending module. If it occurs multiple times, please return to the factory for inspection. At the same time, terminate the program, clear the T1 and DC variables, light the red indicator light, and wait for the start button signal to guide the inspection personnel to reinstall and start from step S1.

[0085] S6.2, Strict Mode:

[0086] Preprocessing: The strongest signal in the selected working channel is selected as the valid candidate signal. The valid candidate signal verifies the check bit and becomes a valid signal after successful verification.

[0087] Each valid signal is added to the variable Valid, and each invalid signal is added to the variable Invalid. The ratio of invalid signals to the total signals is calculated in real time. If the invalid signal ratio exceeds 0.1%, an error message will be displayed, with the screen prompting: "Poor on-site radio environment. Please correct it or use the default mode." The program will also terminate, the red indicator light will illuminate, and the system will wait for the start button signal, directing the inspector to restart from step S1.

[0088] The valid signal is further verified to see if the file header code sequence number is continuous with the previous signal code. If so, a valid count is performed. When the valid count reaches 10,000, the next step in this section is continued, calculating and counting the time information of the coded signal. If it does not meet the requirements, an interrupt count is performed for each discontinuity. If the interrupt count accumulates to 10, an error is reported. The display screen will display the error message: "Channel interference or poor adsorption of the neodymium magnet. Please correct it." The program is terminated, the red indicator light is illuminated, and the tester will be guided to restart from step S1. If the interrupt count does not reach 10, the valid count is restarted.

[0089] In the valid signal, the difference between the time information carried by each received valid coded signal and the current system time is calculated, which is referred to as "difference" in the subsequent description. The average of 10,000 differences is calculated, which is referred to as "mean" in the subsequent description. Each received difference is compared with the mean. When the difference changes more than ±10% of the mean for three times, the time when the time information transient is first detected is taken as T1. Regardless of whether the difference continues to change, the laser ranging module is linked to perform ranging at T1 when the time information carried by the valid coded signal is first detected to change. The ranging result is recorded as DC2. If the subsequent difference change still exceeds ±10% of the mean, the execution of this program ends normally and step S7 is executed. If the difference change returns to within ±10% of the mean, the time mean comparison strategy of this clause is continued, and the T1 and DC2 variables are cleared. At this time, the green light flashes, indicating that the magnet may have poor contact and adsorption.

[0090] S7. Terminate the camera's low resource consumption strategy, stop the RAM video data overwriting strategy, prevent the real-time recorded sampled video data from being overwritten in RAM, increase the CPU main frequency to the highest frequency, stop the display output and release the memory resources it occupies, and perform real-time analysis and processing on the video data. Mark the video frame at time T1, use the optical flow algorithm to detect the motion state of the "cage edge", compress the sampled video in H.265 format and store it in ROM, and embed the GPS metadata collected by the GPS module into the video file.

[0091] When it is detected that the "cage edge" stops changing, the current time is recorded as T2, a mark is added to the video frame at time T2, and the laser ranging module is linked to measure the distance and record it as D2, and the camera capture and RAM writing are terminated.

[0092] S8. Calculate D2-D1=D3. Analyze the video stream frame by frame. Find the edge based on the initial length and coordinate position information of the marked cage edge segment. The coordinate position information is obtained in step S5. Use the mean shift algorithm to track and identify the edge in each frame. Track and record the change in pixel position of the edge in each frame and calculate the actual displacement:

[0093] (a) Calculate the edge pixel position difference ΔPi for each adjacent frame pair (i.e., the i-th frame and the i+1-th frame),

[0094] (b) Sum all ΔPi to get the total pixel displacement ΔPtotal, which is referred to as ΔPt for simplicity.

[0095] (c) Divide D3 by the total pixel displacement ΔPt to obtain the conversion ratio K: K = D3 / ΔPt. If the supplier's lens distortion control is not ideal, you can also add compensation calibration coefficients to each quadrant to adjust the K value. However, this method is not recommended. In principle, the supplier's hardware should be strictly controlled.

[0096] (d) Calculate ΔD = K * ΔPi (ΔPi is the pixel position difference between adjacent frame pairs), ΔT = 1 / camera operating frame rate.

[0097] Draw a curve: The horizontal axis represents time T, and the vertical axis represents displacement distance D. Set the curve's starting point to the coordinate axis origin (T1, D1). T1 represents the moment the cage is unhooked and has not yet moved. D1 represents the value measured by the laser ranging module in step 5. Based on the calculated actual displacement ΔD of each edge and the time interval ΔT between two frames, determine each point in the coordinate system. Connect these points sequentially to draw a distance-versus-time curve A. Finally, display this connected curve on the display. D2 represents the curve's end point. D3 represents the difference between D2 and D1, indicating the actual cage displacement before and after the arrester is activated. T2 represents the point at which the cage stops moving.

[0098] The expected curve is drawn according to the rule that v=gt, that is, D=0.5gt^2, as shown in Figure 6. The separation point of the two curves is (Tx, Dx). The D value of the overlapping part of the two curves is the idle travel distance, that is, D1 to Dx is the idle travel distance; the T value of the overlapping part of the two curves is the idle time, that is, T1 to Tx is the idle travel time; Dx to D2 is the deceleration distance, and Tx to T2 is the deceleration time.

[0099] S9. Restore the display screen output, output the display, and output the curve in image format. The curve is stored in the same folder as the current video. The folder is named after the location and time recorded by GPS. The difference between the factory test value of DC minus D1 or DC2 minus D1 and the actual measurement value is output next to the curve to provide a basis for judging whether the measurement is valid.

[0100] The distance data of each time point is stored as a text file. Each line of the text file is the horizontal and vertical coordinates of a point, followed by the time information. The text file is stored in the same folder as the curve image and uses ASCII encoding.

[0101] After completing the above measurements, the blue indicator light will light up to indicate that the test is complete. At the same time, memory resources will be released and the CPU frequency will be reduced to the standby frequency.

[0102] In the above method, each time an indicator light is turned on, only one indicator light is illuminated. When that indicator light is on, all other indicators are off, and the indicator light remains on permanently. Unless otherwise specified, the indicator light remains on permanently. The parameters mentioned in the method represent optimal values. Technicians have invested extensive testing and labor in selecting these specific data. These parameters are fixed in this solution and should be followed in production. Any changes will have uncontrollable effects on the overall measurement results.

[0103] Detailed description of the use and operation of this device:

[0104] 1. Press the power button on the top to turn on the instrument. The instrument screen displays "Starting Up". After about 8 seconds, the instrument startup is completed, the light is on, the camera starts, and the screen displays the real-time video information captured by the camera (the camera sampling rate at this time is the screen refresh rate).

[0105] 2. Attach the gold-plated neodymium magnet on the back of the instrument to the decoupler or the rigid metal connecting frame that secures the decoupler. Do not attach it to any movable parts. Ensure that the instrument does not move or shake during operation. If the on-site conditions cannot meet this requirement, a dedicated bracket can be installed to secure the instrument. Press the mode switch and enable forced vertical mode in the system settings. If forced vertical mode is not selected, pressing the mode switch will cause the instrument to operate in landscape mode. The mode switch is a physical switch connected to the wireless transmitter amplifier inside the instrument. It switches the signal between the SMA interface and the gold-plated neodymium magnet. After switching to the SMA interface, the extension feeder can be directly connected to the decoupler via the SMA interface.

[0106] 3. Adjust the instrument's angle so the camera faces the top of the cage. You should be able to see all four sides of the cage's top on the display. If the mounting angle doesn't meet the requirements, remove and adjust it. Do not rotate the instrument while it is being attached. To ensure proper attachment, you can also use a strap to secure it along the grooves in the strap fixing area. However, ensure that the neodymium magnet on the back is attached as required in step 2. After attachment is complete, inspect the magnet's attachment and fit through the optical observation port. If light leakage occurs at the attached point, this indicates incomplete attachment and the instrument needs to be adjusted to a flat surface that meets the requirements.

[0107] 4. After the instrument is installed, click the Start button. A voice prompt will sound: "The instrument is preparing to begin calibration. Please wait." The yellow indicator light will illuminate. Do not move the instrument at this time. If there is excessive vibration on site, appropriate coordination will be required. The use of heavy equipment or blasting operations that may cause strong vibrations is prohibited during instrument operation. The instrument calibration and testing time takes approximately 2 minutes, but the instrument can be completed in 1 minute. The time for the operator to select the intelligent edge recognition is less than 1 minute.

[0108] 5. When the green light on the instrument is on, it means that the preheating is complete and ready. Under the premise of ensuring safety, you can immediately unhook and release the cage to complete the fall arrester test.

[0109] 6. After the uncoupling test is completed, the inspector can print the results. The braking distance measurement results and other test information are transmitted to an external portable printer via the 433M communication output module using the universal serial port transmission protocol. The report and certificate can be printed directly on site. The portable printer is not included in the instrument package and must be purchased separately.

[0110] 7. Indicator Lights: Red light indicates a fault, and the specific fault condition can be viewed on the screen; Yellow light indicates warm-up and calibration, and the instrument must not be moved at this time; Green light indicates preparation is complete and the instrument is working; Blue light indicates the test is complete.

[0111] 8. The instrument comes with a charger and memory card by default. The TF memory card has been initialized and installed on the instrument. Please do not remove it unless necessary.

[0112] The instrument can also be used horizontally to the cage, subject to site conditions. However, it can only be operated semi-automatically, resulting in reduced accuracy. The mode switch must be manually switched, and the signal feeder must be connected to the decoupler via the SMA connector on the top of the instrument. D1 and D2 are no longer measured, and DC and DC2 are no longer calibrated. At least three sides of the cage, both before and after decoupling, must be within the camera's field of view. The D3 value must be manually measured on-site and entered into the instrument. The output result is also labeled "Horizontal Mode." Horizontal mode is provided only as an auxiliary function and is indicated as not recommended in the instrument manual.

[0113] This device must be used in conjunction with a metal rigid decoupling device. During use, ensure that the instrument is stationary and stable.

[0114] The default mode has high decoupling detection sensitivity and is suitable for most scenarios. It has strong anti-interference ability and should not be switched unless necessary. The strict mode can be used in strict and important places due to the addition of verification, but the on-site radio environment must be clean. It is suitable for important remote mining areas with relatively clean radio environments.

[0115] This measuring instrument has a reasonable design and scientific measurement, which solves the drawbacks of the single measurement method of existing measuring instruments. All aspects support each other and comprehensively improve the overall function of the measuring instrument.

Claims

1. A device for measuring the braking distance of a mine fall arrester, comprising a housing (1), characterized in that: An optical observation window (3) is provided on the front of the housing (1), the optical observation window (3) runs through the entire housing (1), and an inclined reflector (4) is provided on the housing (1) at a hole position at the rear of the optical observation window (3); The front of the housing (1) is also provided with a display screen (2), a plurality of indicator lights (5), function operation buttons (6), a mode switching switch (7), a memory card insertion hole (8) and a data transmission interface (9); A cubic neodymium magnet (10) is arranged on the back side of the housing (1) and below the reflector (4); the surface of the neodymium magnet (10) is gold-plated; five sides of the neodymium magnet (10) are wrapped with 1 mm thick polytetrafluoroethylene; a metal shielding layer is arranged outside the polytetrafluoroethylene; the neodymium magnet (10) is connected to the core of the feeder line; the metal shielding layer is connected to the shielding layer of the feeder line; and the neodymium magnet (10) protrudes from the back side of the housing (1); The lower part of the housing (1) is provided with a concave area and is sealed with a transparent optical sapphire cover plate (12); an optical glass column (11), a laser distance measurement module (13), a measuring LED fill light module (14), a camera module (15) and a trapezoidal metal shielding cover (16) with an outward expansion are arranged inside the cover plate; the optical glass column (11) has frosted side surfaces and two ends are smooth surfaces, one end of the smooth surface is adhered to the transparent optical sapphire cover plate (12), and the other end is adhered to the laser emission head of the laser distance measurement module (13); A central control module (17), a GPS module (18), an active ceramic GPS antenna (19), a wireless receiving module (20), a wireless transmitting module (21), a 315M control module (22), a 433M communication output module (23), a nine-axis accelerometer gyroscope module (24), and a speaker module (26) are arranged in the housing (1). The central control module (17) comprises an input signal bus and an output signal bus, wherein the GPS module (18), the laser ranging module (13), the wireless receiving module (20), the camera module (15), the nine-axis accelerometer gyroscope module (24), the 315M control module (22), and the function operation button (6) are respectively connected to the input signal bus (37), wherein the display screen (2), the wireless transmitting module (21), the indicator light (5), the 433M communication output module (23), the speaker module (26), the measurement LED fill light module (14), and the observation LED fill light module (28) are respectively connected to the output signal bus (36).

2. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: The left and right sides of the shell (1) are provided with PU anti-drop rubber edges (32) protruding from the surface of the body, and each anti-drop rubber edge is provided with a removal groove (33) at the upper and lower positions, and a strap fixing area (34) recessed towards the center of the body is provided in the middle of the anti-drop rubber edge (32) for embedding and fixing the strap.

3. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: The indicator lights (5) are located above the optical observation window (3). From left to right, they are: yellow indicator light, green indicator light, blue indicator light, and red indicator light. The yellow indicator light indicates preheating, the green indicator light indicates operation, the blue indicator light indicates completion, and the red indicator light indicates a fault. When the red indicator light is on, all programs and detection actions are terminated until the instrument is manually restarted.

4. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: A trapezoidal prism (27) is arranged in the middle of the back of the shell body, and the neodymium magnet (10) is arranged in a recessed manner in the trapezoidal prism (27). The neodymium magnet (10) protrudes 0.5 mm from the back of the shell body. The shell body also includes an observation LED fill light module (28) which is arranged in the lower strip-shaped protrusion area of ​​the neodymium magnet (10) and irradiates the upper neodymium magnet (10). The observation LED fill light module (28) is connected to the output signal bus (36).

5. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: An inward recess is provided at the upper portion of the housing, and a power switch (29), a charging interface (30), and an SMA interface (31) are provided inside the recess from left to right. The mode switching switch (7) is connected to the power amplifier (25), and the power amplifier is connected to the wireless transmission module (21).

6. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: The metal shielding covers (16) are three nested ones, which are parallel to each other, insulated from each other, and spaced 1 mm apart. The innermost metal shielding cover is connected to the feeder shielding layer of the wireless receiving module (20). The innermost metal shielding cover contains a sheet-shaped directional antenna (35). The innermost metal shielding cover and the directional antenna (35) are insulated from each other. The sheet-shaped directional antenna is connected to the wireless receiving module (20) via a wire core of a feeder. The wireless receiving module (20) has a built-in wireless radio frequency power detection module (201).

7. The device for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: The nine-axis accelerometer gyroscope module (24) integrates a three-axis accelerometer, a three-axis magnetometer and a three-axis gyroscope, with a static attitude measurement accuracy of no more than 0.05 degrees and a dynamic attitude measurement accuracy of no more than 0.1 degrees. It has a built-in Kalman attitude solution algorithm and a magnetometer ellipsoid correction function. △ acceleration is the acceleration fluctuation variable, △ three-axis gyroscope data is the X, Y, Z axis fluctuation variable, and △ ellipsoid magnetic data is the magnetometer data fluctuation variable after the ellipsoid fitting algorithm.

8. A method for measuring the braking distance of a mine fall arrester according to claim 1, characterized in that: The steps include: 1) Install the device to the measuring position as required, check the adsorption status through the optical observation window, and select the corresponding measurement mode; 2) Start the power supply, the instrument lights up a yellow warning light, and broadcasts a warning tone, which includes the distance limit requirements between the personnel and the instrument. While the warning tone is broadcast, the GPS module (18) is preheated and searches for satellites. After the warning tone is broadcast, the nine-axis accelerometer gyroscope module (24) is powered on and enters the working state, and collects acceleration data, three-axis gyroscope data, and magnetometer data after the ellipsoid fitting algorithm in real time. At the same time, the GPS data collected by the GPS module (18) is recorded, and the time of the device is calibrated according to the time collected by the GPS module (18); 3) Calculate △ acceleration, △ three-axis gyroscope data, and △ ellipsoid magnetic data. When the fluctuation of △ acceleration and △ three-axis gyroscope data is less than 0.1% and the fluctuation of △ ellipsoid magnetic data is less than 1% within 5 seconds, directly enter the next step. When △ acceleration and △ three-axis gyroscope data are greater than 0.1% and less than or equal to 0.3%, delay 5 seconds to repeat the detection calculation. This jump cycle is performed up to 5 times. If it exceeds 5 times or the fluctuation of a single △ acceleration and △ three-axis gyroscope data is greater than 0.3% and less than 0.6%, it will prompt to check the environmental vibration factor and light up the red indicator light; 4) Execute this single-thread monitoring task and directly enter the next step. This single-thread monitoring task will be terminated after the cage starts to move. This single-thread monitoring task has a delayed error reporting function. If the cage starts to move, the error reporting in the delay will be terminated, and the subsequent error reporting action will not be executed, and the single-thread monitoring task will be terminated at the same time; 5) The wireless transmitting module (21), the power amplifier (25), and the wireless receiving module (20) are powered on, and the optimal channel is detected and set. The signal strength of the effective coded signal is counted, and the average, standard deviation, and range of the signal strength dBm value received within 5 seconds are counted and calculated. When the ratio of the standard deviation of the strength dBm value to the average value does not exceed 0.5%, that is, the standard deviation / average value ≤ 0.5% and the ratio of the range to the average value does not exceed 5%, that is, the range / average value ≤ 5%, directly proceed to the next step. Otherwise, the display screen (2) prompts an error. There are two types of errors here. If it is detected that (range / average value) ≥ 10%, the error prompt indicates that the signal receiving and sending modules are suspected to be faulty. In addition to the above situation, a unified error prompt indicates that there is radio interference on site that needs to be eliminated, and the red indicator light is lit; 6) Set the camera sampling rate to the rated working frame rate, load the data captured by the camera into the RAM of the central controller, denoise the cage top information captured by the camera, use a Gaussian filter to smooth the image, use the Sobel operator to calculate the gradient strength and direction of each pixel in the image, perform maximum value detection in the gradient direction, only retain the points with the largest pixel gradient, divide the pixels into three categories: strong edge, weak edge and non-edge, output the strong edge directly, discard the non-edge directly, output the weak edge only when they are connected to the strong edge, and use the connectivity analysis algorithm to connect the weak edges To the strong edge, a complete edge is formed, and the continuous edge is divided into a single line segment along the intersection point. The tester uses the 315M wireless controller to select and mark the cage edge line segment that meets the requirements. After the tester confirms the selection, the length and coordinate position information of the current cage edge line segment in the image data are recorded. At this time, the distance from the laser ranging module to the top of the cage is recorded as D1, and the green indicator light is lit at the same time. The preparation of this device is completed. The display screen (2) prompts that the uncoupling test can be carried out. At this time, the camera rated frame rate sampling is continuously maintained, and a low resource consumption strategy is adopted to write the sampled video data into the RAM in real time. Only the first 1000 milliseconds of high-speed video data is retained in the RAM, and the high-speed video data is cyclically overwritten. The video information in the RAM exists in the form of raw data without additional analysis and encoding by the CPU; 7) Execute the default mode program, or choose to execute the strict mode program according to the user's settings. If no settings are made, execute the default mode program. Both modes will be executed after the program ends normally and then go directly to the next step. The default mode program features are: when it is detected that the current coded signal strength changes by more than ±20% of the average value and cannot be restored to the signal strength average value, the transient time is taken as T1, but regardless of whether the coded signal strength is restored, the laser ranging module is linked to perform ranging at the T1 time when the intensity dbm value changes instantly and is recorded as DC. If the signal strength does not recover after 500 milliseconds, the execution of this program ends normally. If the signal strength dbm value changes by more than ±20% of the average value but can be restored to within 5% of the intensity average value within 500 milliseconds, the user is prompted that the signal receiving and sending modules may have faults, and an error is reported at the same time, the T1 and DC variables are cleared, and the red indicator light is turned on; 8) Terminate the low resource consumption strategy of the camera, stop the RAM video data overwriting strategy, and prevent the real-time recorded sampled video data from being overwritten in the RAM. Increase the CPU main frequency to the highest frequency, stop the display screen output and release the memory resources it occupies. Meanwhile, perform real-time analysis and processing on the video data, add a mark to the video frame at time T1, use the optical flow algorithm to detect the motion state of the "cage edge", and when it is detected that the "cage edge" stops changing, record the current time as T2, add a mark to the video frame at time T2, and simultaneously link the laser ranging module (13) to measure the distance and record it as D2, and stop the camera capture and video RAM writing, compress the sampled video in H.265 format and store it in ROM, and embed the GPS metadata collected by the GPS module into the video file; 9) Calculate D2-D1=D3, analyze the video stream frame by frame, find the cage edge according to the length of the marked cage edge line segment and the coordinate position information, use the mean shift algorithm to track and identify the cage edge in each frame, track and record the changes in the pixel position of the cage edge in each frame, and calculate the actual displacement: (a) Calculate the cage edge pixel position difference ΔPi between the i-th frame and the i+1-th frame, (b) Sum all ΔPi to get the total pixel displacement ΔPt, (c) Divide D3 by the total pixel displacement ΔPt to obtain the conversion ratio K, K = D3 / ΔPt, (d) Calculate ΔD = K*ΔPi, ΔT = 1 / camera frame rate; 10) Draw a curve: The horizontal axis is time T, the vertical axis is displacement distance D, and the starting point of the curve is set as the origin of the coordinate axis, the origin is (T1, D1), T1 is the time point when the cage has not yet moved at the moment of unhooking, D1 is the measurement value completed by the laser ranging module when the cage has not moved, and each point in the coordinate system is determined according to the calculated actual displacement ΔD distance value of each cage edge and the time interval ΔT between two frames. These points are connected in sequence to draw a curve A of distance changing with time, D2 is the end point of the curve, D3 is the difference between D2 and D1, that is, the actual displacement of the cage before and after the fall arrester is activated, T2 is the stop point of the cage movement, and the expected curve is drawn according to the law of v=gt, that is, D=0.5gt^2. The separation point of the two curves is (Tx, Dx), and the D value of the overlapping part of the two curves is the empty travel distance, that is, D1 to Dx is the empty travel distance; the T value of the overlapping part of the two curves is the empty movement time, that is, T1 to Tx is the empty travel time; Dx to D2 is the deceleration distance, and Tx to T2 is the deceleration time; 11) Restore the display screen output, output the display curve, output the curve as a picture format, and store it in the same folder as the current video. The folder is named after the location and time recorded by GPS. Output the difference between DC and D1 or the difference between DC2 and D1, prompt the personnel to check the difference, and light up the blue indicator light.

9. The measuring method according to claim 8, characterized in that: In step 4), when the △ acceleration and △ three-axis gyroscope fluctuation data are greater than 0.1% and less than or equal to 0.3%, a count is performed. When the count reaches 5 times or the single △ acceleration and △ three-axis gyroscope data fluctuation is greater than 0.3%, the error delay is started. After a delay of 1500 milliseconds, an error and prompt are given again, indicating that the vibration is too large and needs to be eliminated, and requiring manual confirmation whether the instrument is fixed at the rigid connection, and the red indicator light is on.

10. The measuring method according to claim 8, characterized in that: Step 7) also includes the following steps: 1) Preprocess the signal and take the strongest signal in the selected working channel as the valid candidate signal; 2) For valid candidate signals, the check bit is verified. After successful verification, it is recorded as a valid signal, and the proportion of invalid signals to the total signals is calculated in real time; 3) If the invalid signal ratio is greater than 0.1%, an error will be reported directly, prompting the user that the on-site radio environment is poor, and informing the user to eliminate it or use the default mode. After the error occurs, this step will be terminated and the red indicator light will be turned on; 4) If there is no error, further check the valid signal to check whether the file header coding sequence is continuous with the previous signal coding. If it is continuous, perform effective counting. When the effective count reaches 10,000, jump to the next step to calculate and count the time information of the coded signal. If it is not satisfied, do an interrupt count for each discontinuity. If the interrupt count accumulates to 10, an error is reported, indicating that there is interference in the channel or poor magnet adsorption needs to be eliminated. At the same time, an error is reported and the red indicator light is on; 5) In the valid signal, the difference between the time information carried by each received valid coded signal and the current system time is calculated, which is referred to as "difference" in the subsequent description. The average value of 10,000 differences is calculated, which is referred to as "mean" in the subsequent description. Each received difference is compared with the mean. When the difference changes more than ±10% of the mean for three times, the time when the time information transient is first detected is taken as T1. Regardless of whether the difference continues to change, the laser ranging module is linked to perform ranging at T1 when the time information carried by the valid coded signal is first detected. The ranging result is recorded as DC2. If the subsequent difference changes still exceed ±10% of the mean, the execution of this program ends normally. If the difference changes back to within ±10% of the mean, continue with this time mean comparison strategy, clear the T1 and DC2 variables, and the green light flashes at this time, indicating that the magnet may have poor contact and adsorption.

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