Satellite CORS mode agricultural machine braking detector

Abstract

The application discloses a satellite CORS mode agricultural machine braking detector and belongs to the technical field of agricultural machine detection and satellite navigation application, and comprises a flow station, a braking sensor, a matched hand book and a host computer, wherein a link acquisition module acquires differential correction numbers, correction number time delay parameters and carrier noise ratios by using virtual reference station technology, a space-time alignment module acquires a braking time stamp and performs clock synchronization and subsampling reconstruction, generates a position data chain containing the time stamp, a consistency inspection module outputs a correction data chain, a geometric bias module solves a pitch angle and outputs a corrected horizontal coordinate, and a dynamics fusion module introduces a second derivative constraint to solve a first braking distance, and combines a second braking distance and a confidence factor to calculate a final braking distance. The application eliminates recognition lag caused by sampling discreteness, compensates for projection geometric bias error caused by mechanical inertia, and improves the detection stability and measurement precision of the agricultural machine braking detector in a link fluctuation environment.

Description

Technical Field

[0001] This invention belongs to the field of agricultural machinery inspection and satellite navigation application technology, specifically involving a satellite CORS-based agricultural machinery braking detection instrument. Background Technology

[0002] Agricultural machinery braking testers are specialized equipment for testing the performance of agricultural machinery. They can measure the initial velocity, time, distance, and average deceleration of tractors and combine harvesters during braking. Traditional testing relies on pedal force sensors, non-contact five-wheel instruments, and signal processors. Pedal force sensors capture pedal trigger signals and record the agricultural machinery's trajectory. With the application of satellite differential positioning technology, agricultural machinery braking testers integrate global satellite navigation systems and use carrier phase differential technology to obtain the spatial coordinates and motion vectors of the agricultural machinery. They analyze the displacement from the start of braking to the machine coming to a stop, achieving digital evaluation of braking performance. This makes them a tool for assessing the operational level of agricultural machinery.

[0003] To address the issue of the time-domain misalignment between the discrete 3D coordinate data captured by the rover and the braking timestamps captured by the braking sensors, existing technologies simply increase the sampling frequency to record the braking trajectory. However, this approach still encounters situations where agricultural machinery experiences pitch angles during braking, leading to horizontal projection geometric offset errors in the rover mounted on the cab. Furthermore, due to fluctuations in the correction delay parameters during transmission of the differential corrections from satellite CORS, the accuracy of coordinate calculation results is affected by the quality of the bidirectional data transmission link, resulting in attenuation. Additionally, interference from the operating environment can cause coordinate jumps in the 3D coordinate data, leading to distortion of the position data link including timestamps and insufficient accuracy in braking distance measurement to meet the requirements for agricultural machinery inspection. Summary of the Invention

[0004] The purpose of this invention is to provide a satellite CORS-based agricultural machinery braking detector that eliminates the recognition lag caused by sampling discreteness, compensates for the projection geometric offset error caused by mechanical inertia, and improves the detection stability and measurement accuracy of the agricultural machinery braking detector in a link fluctuation environment.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: The satellite CORS-based agricultural machinery braking detector includes a rover, braking sensors, a matching handheld device, and a main unit. The main unit integrates a central processing unit for operation. The link acquisition module uses virtual reference station technology to obtain differential correction, correction delay parameters and carrier noise ratio, calculates confidence factor, and captures and preprocesses the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test when the rover is in a fixed solution state and meets the preset accuracy threshold. The spatiotemporal alignment module issues a braking prompt signal based on the preprocessed instantaneous velocity data, obtains the braking timestamp, performs clock synchronization and subsampling reconstruction with the preprocessed three-dimensional coordinate data, and generates a position data chain containing the timestamp. The consistency check module removes coordinate jump points based on the acceleration change rate in the position data link, performs trajectory completion, and outputs the corrected data link. The geometric offset module extracts the instantaneous vertical displacement during braking from the correction data link, calculates the elevation angle by combining it with the antenna installation height, and obtains the corrected horizontal coordinates. The dynamics fusion module introduces second-order derivative constraints to fit and correct the horizontal coordinates, calculates the first braking distance, and combines the second braking distance obtained by integrating the preprocessed instantaneous velocity data with the confidence factor to calculate the final braking distance.

[0006] Preferably, the rover is a global satellite navigation system receiver, including a receiver board supporting carrier phase differential technology and a mobile communication module. It is kept horizontally fixed to the top of the cab of the agricultural machinery under test by a magnetic base, and ensures that there are no obstacles in the surrounding area that obstruct satellite signals. It is used to establish a two-way data transmission link with the cloud base station and continuously capture differential correction, correction delay parameters, carrier noise ratio, three-dimensional coordinate data and instantaneous speed data. The brake sensor is installed at the brake pedal of the agricultural machine under test to acquire the driver's braking action and transmit the generated brake trigger signal to the host in real time; The accompanying handheld device has a configuration program that is used to set access parameters and display the location calculation status and correction latency parameters in real time. Access parameters include Internet Protocol address, port number, mount point, username and password. The main unit is electrically connected to the rover and braking sensor. It integrates a central processing unit, storage unit, alarm and display screen. The storage unit stores location data links with timestamps, antenna installation height, preset speed, braking timestamps and preset standard limit value library. The display screen displays the speed of the tested agricultural machinery in real time and presents the final braking distance, performance judgment results and full trajectory dynamic graph with dynamic constraint correction after the test is completed. The alarm is used to issue a braking warning signal when the tested agricultural machinery reaches the preset speed.

[0007] Preferably, the link acquisition module uses virtual reference station technology to obtain differential correction, correction delay parameters, and carrier-to-noise ratio, and the process of calculating the confidence factor includes: The host uses a mobile communication module to access the cloud base station through a preset Internet Protocol address, port number, mount point, username and password, and establishes a two-way data transmission link between the mobile station and the cloud base station. The rover receives observation signals broadcast by the Global Navigation Satellite System in real time and feeds back the real-time spatial coordinates of the rover contained in the observation signals to the cloud base station through a two-way network data transmission link; The cloud base station uses virtual reference station technology to generate differential observations corresponding to the location of the rover based on the real-time spatial coordinates of the rover. The differential observations are sent to the rover as differential corrections, and the correction delay parameters and carrier noise ratio output by the rover are extracted in real time. The ratio of the preset standard reference delay constant to the sum of the correction delay parameters is defined as the first confidence component. The ratio of the carrier noise ratio to the preset upper limit of the carrier noise ratio is defined as the second confidence component. The first confidence component is multiplied by the preset first weighting coefficient to obtain the first weighted value. The second confidence component is multiplied by the preset second weighting coefficient to obtain the second weighted value. The first weighted value and the second weighted value are added together to obtain the confidence factor with a value range between 0 and 1. The sum of the first weighting coefficient and the second weighting coefficient is 1.

[0008] Preferably, the link acquisition module, when the rover is in a fixed solution state and meets the preset accuracy threshold, captures and preprocesses the three-dimensional coordinate data and instantaneous velocity data of the agricultural machinery under test, including: The link acquisition module determines whether the rover is in a fixed state by parsing the positioning status flags broadcast by the rover. Under the premise of satisfying the fixed solution state, the link acquisition module retrieves the real-time positioning accuracy value output by the rover and determines whether the real-time positioning accuracy value is less than the preset accuracy threshold. After determining that the rover is in a fixed solution state and that the real-time positioning accuracy is less than the preset accuracy threshold, the link acquisition module captures the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test at a preset sampling frequency of 10 Hz to 20 Hz. The link acquisition module establishes a sliding window buffer of a preset length and stores the captured three-dimensional coordinate data and instantaneous velocity data into the sliding window buffer; The link acquisition module uses a sliding window filtering algorithm to smooth the three-dimensional coordinate data and instantaneous velocity data in the sliding window buffer, and obtains preprocessed three-dimensional coordinate data and instantaneous velocity data.

[0009] Preferably, the spatiotemporal alignment module issues a braking warning signal based on the preprocessed instantaneous velocity data, and the process of obtaining the braking timestamp includes: The spatiotemporal alignment module monitors the preprocessed instantaneous velocity data in real time. When it is determined that the preprocessed instantaneous velocity data has reached the preset speed, the host drives the alarm to issue a braking warning signal. The spatiotemporal alignment module captures the braking trigger signal generated by the braking sensor and obtains the braking timestamp corresponding to the braking moment when the braking trigger signal was generated.

[0010] Preferably, the spatiotemporal alignment module performs clock synchronization and subsampling reconstruction with the preprocessed 3D coordinate data to generate a location data chain containing timestamps, including the following processes: The spatiotemporal alignment module performs clock synchronization, unifying the braking timestamp to the time scale of the global satellite navigation system; Retrieve at least two preprocessed 3D coordinate data points located before and after the braking timestamp from the sliding window buffer; The preprocessed 3D coordinate data retrieved is reconstructed by subsampling using the Lagrange interpolation algorithm to calculate the braking start coordinate point corresponding to the braking timestamp; The spatiotemporal alignment module continuously monitors the preprocessed instantaneous velocity data. When it determines that the preprocessed instantaneous velocity data has decreased to zero, it determines the moment when the vehicle comes to a standstill and obtains the corresponding standstill timestamp. The spatiotemporal alignment module retrieves the preprocessed three-dimensional coordinate data within the time interval of the braking timestamp and the stationary timestamp, identifies and extracts the preprocessed three-dimensional coordinate data from the braking moment to the vehicle stationary moment as the full trajectory coordinate data; The braking start coordinate point is used as the trajectory start point. The full trajectory coordinate data containing the braking start coordinate point is associated and encapsulated with the corresponding sampling timestamp in chronological order to generate a position data chain containing timestamps.

[0011] Preferably, the consistency verification module, based on the rate of change of acceleration in the position data link, removes coordinate jump points, performs trajectory completion, and outputs the corrected data link. The process includes: The consistency verification module retrieves the location data chain containing timestamps and extracts the preprocessed 3D coordinate data and the corresponding sampling timestamps from the location data chain containing timestamps. The motion acceleration at each sampling moment in the position data chain is calculated based on the difference in preprocessed three-dimensional coordinate data between adjacent sampling points and the difference in sampling timestamps. Calculate the difference between adjacent accelerations and take the absolute value to obtain the acceleration change. Then, perform a division operation between the acceleration change and the corresponding sampling timestamp difference to obtain the acceleration rate of change. When the consistency check module determines that the rate of change of acceleration is greater than the preset rate of change of acceleration threshold, it identifies the sampling point at the corresponding sampling time as a coordinate jump point caused by interference. The consistency check module removes coordinate jump points from the location data chain containing timestamps and locates the coordinate jump segments formed on the time axis after removing the coordinate jump points; The consistency check module retrieves the preprocessed instantaneous velocity data, uses the preprocessed instantaneous velocity data to perform trajectory completion on the coordinate jump segment, and generates the completed coordinate points; The trajectory completion process includes identifying the coordinates of the starting sampling point and the starting timestamp of the coordinate jump segment, performing an integral operation on time on the preprocessed instantaneous velocity data corresponding to the coordinate jump segment to obtain the coordinate increment vector, and performing an addition operation on the coordinates of the starting sampling point and the coordinate increment vector to obtain the completed coordinate point; The consistency check module inserts the completed coordinate points into the coordinate jump segment, and repackages the completed coordinate points and the sampling points that have not been removed from the position data chain in chronological order, and outputs the corrected data chain.

[0012] Preferably, the geometric offset module extracts the instantaneous vertical displacement during braking from the correction data link, calculates the elevation angle in conjunction with the antenna installation height, and obtains the corrected horizontal coordinates through the following process: The vertical displacement is obtained by subtracting the elevation component of the preprocessed 3D coordinate data corresponding to the braking start time from the elevation component of the preprocessed 3D coordinate data corresponding to each sampling time in the corrected data chain. The vertical displacement is divided by the antenna installation height stored in the storage unit to obtain the height change ratio. The elevation cosine value is obtained by subtracting the height change ratio from the value 1. The elevation cosine value is then subjected to an inverse cosine operation to obtain the elevation angle. The horizontal coordinate components in the corrected data link are offset compensated using the elevation angle and antenna installation height. The elevation angle is sine-operated and multiplied with the antenna installation height to obtain the horizontal offset vector. The horizontal offset vector is then summed with the horizontal coordinate components in the corrected data link to obtain the corrected horizontal coordinates. The horizontal coordinate components at each sampling time in the corrected data chain are replaced with the corresponding corrected horizontal coordinates to complete the trajectory coordinate correction including dynamic constraints.

[0013] Preferably, the dynamics fusion module, by introducing second-order derivative constraints to fit and correct the horizontal coordinates, calculates the first braking distance through the following process: The second derivative constraint is introduced to perform nonlinear fitting operation to reconstruct the continuous deceleration trajectory of the tested agricultural machinery. The nonlinear fitting operation process includes using the corrected horizontal coordinate as the observation value, constructing an objective function containing the fitting residual term and the second derivative penalty term, and constraining the second derivative magnitude of the fitting curve by minimizing the objective function. The function defining the continuous deceleration trajectory as a function of time along the horizontal axis of the horizontal coordinate system is: The function defining the continuous deceleration trajectory as a function of time along the vertical axis of the horizontal coordinate system is... ,right Perform first-order differentiation and squaring to obtain the squared term of the velocity on the horizontal axis. Perform first-order differentiation and squaring to obtain the vertical axis velocity squared term. Add the horizontal axis velocity squared term and the vertical axis velocity squared term together and perform square root operation to obtain the resultant velocity function. Perform time integration on the resultant velocity function within the time interval from braking timestamp to rest timestamp to obtain the first braking distance.

[0014] Preferably, the dynamics fusion module, combining the second braking distance obtained by integrating the preprocessed instantaneous velocity data and the confidence factor, calculates the final braking distance by including: The second braking distance is obtained by performing time integration on the preprocessed instantaneous velocity data within the time interval from the braking timestamp to the stationary timestamp. The confidence factor is multiplied with the first braking distance to obtain the first weight value. The confidence factor is subtracted from the value 1 to obtain the weight difference. The weight difference is multiplied with the second braking distance to obtain the second weight value. The first weight value and the second weight value are added together to obtain the final braking distance. The final braking distance is compared with the standard limit library stored in the storage unit; If the final braking distance is less than or equal to the preset standard limit, the performance judgment result is qualified; if the final braking distance is greater than the preset standard limit, the performance judgment result is unqualified. Based on the performance assessment results, the host computer drives the alarm to issue a braking warning signal and drives the display screen to simultaneously display the final braking distance and performance assessment results.

[0015] The technological advancements achieved by this invention compared to existing technologies are as follows: This invention captures braking actions and records braking timestamps using a braking sensor, and uses a Lagrange interpolation algorithm to perform subsampling reconstruction on the preprocessed three-dimensional coordinate data to determine the braking start coordinate point. This eliminates the recognition lag caused by the time-domain mismatch between the discrete sampling mechanism of the global satellite navigation system and the instantaneous nature of the braking action, and improves the accuracy of braking start point capture.

[0016] This invention utilizes a consistency verification module to eliminate coordinate jump points caused by interference from the operating environment and to complete the trajectory. Simultaneously, it uses a geometric offset module to calculate the pitch angle and obtain the corrected horizontal coordinates in conjunction with the antenna installation height. This eliminates the antenna horizontal projection displacement error caused by dynamic pitch attitude changes due to braking inertia of agricultural machinery, ensuring the authenticity of the location data link containing timestamps.

[0017] This invention utilizes the correction delay parameter and carrier noise ratio to calculate the confidence factor, and uses a dynamic fusion module to perform weighted fusion of the first braking distance and the second braking distance. This overcomes the negative impact of differential correction transmission delay and network bidirectional data transmission link quality fluctuations on measurement accuracy, and improves the detection stability of agricultural machinery braking detectors in complex field environments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall architecture and equipment deployment of the detector of the present invention; Figure 2 This is a block diagram of the detector of the present invention; Figure 3 This is a physical model diagram of the geometric offset correction caused by the dynamic pitch attitude of the detector of the present invention. Figure 4 A comparison diagram of trajectory completion and coordinate jump elimination of the consistency verification module of the present invention; Figure 5 This is a diagram showing the adaptive logic results of the confidence factor of the link acquisition module of the present invention. Figure 6 This is a diagram showing the results of multi-source ranging fusion and performance evaluation of the dynamics fusion module of this invention.

[0019] In the diagram: 1. Rover station; 2. Braking sensor; 3. Supporting handheld device; 4. Main unit; 5. Cloud base station; 6. Two-way network data transmission link. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0021] Example 1: As Figure 1 As shown, the satellite CORS-based agricultural machinery braking detection instrument includes a rover 1, a braking sensor 2, a matching handheld device 3, and a main unit 4. Rover 1 is a global satellite navigation system receiver, including a receiver board supporting carrier phase differential technology and a mobile communication module. It is kept horizontally fixed to the top of the cab of the agricultural machinery under test by a magnetic base, ensuring that there are no obstacles in the surrounding area that would obstruct the satellite signal. It is used to establish a two-way data transmission link 6 with the cloud base station 5 and continuously capture differential correction, correction delay parameters, carrier noise ratio, three-dimensional coordinate data and instantaneous velocity data.

[0022] The brake sensor 2 is installed at the brake pedal of the agricultural machine under test, and is used to acquire the driver's braking action and transmit the generated brake trigger signal to the host 4 in real time.

[0023] The accompanying handbook 3 has a configuration program that is used to set access parameters and display the location calculation status and correction delay parameters in real time. Access parameters include Internet Protocol address, port number, mount point, username and password.

[0024] The host 4 is electrically connected to the rover 1 and the brake sensor 2. It integrates a central processing unit, a storage unit, an alarm and a display screen. The storage unit is used to store the location data link with timestamps, antenna installation height, preset speed, braking timestamp and preset standard limit library. The display screen is used to display the speed of the tested agricultural machinery in real time, and after the test is completed, it presents the final braking distance, performance judgment result and full trajectory dynamic graph with dynamic constraint correction. The alarm is used to issue a braking warning signal when the tested agricultural machinery reaches the preset speed.

[0025] Example 2: As Figure 2 As shown, based on Embodiment 1, the host 4 integrates a central processing unit for running: The link acquisition module uses virtual reference station technology to obtain differential correction, correction delay parameters and carrier noise ratio, calculates confidence factor, and captures and preprocesses the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test when rover 1 is in a fixed solution state and meets the preset accuracy threshold.

[0026] The host 4 uses a mobile communication module to access the cloud base station 5 through a preset Internet Protocol address, port number, mount point, username and password, and establishes a two-way data transmission link 6 between the mobile station 1 and the cloud base station 5.

[0027] Rover 1 receives observation signals broadcast by the Global Navigation Satellite System in real time and feeds back the real-time spatial coordinates of Rover 1 contained in the observation signals to cloud base station 5 through network two-way data transmission link 6.

[0028] The cloud base station 5 uses virtual reference station technology to generate differential observation values ​​corresponding to the location of the rover 1 based on the real-time spatial coordinates of the rover 1. The differential observation values ​​are sent to the rover 1 as differential correction values, and the correction delay parameters and carrier noise ratio output by the rover 1 are extracted in real time.

[0029] The preset standard reference delay constant With correction delay parameter The ratio of the sums is defined as the first confidence component, which is the carrier-to-noise ratio. The upper limit of the carrier-to-noise ratio is compared with the preset upper limit value. The ratio is defined as the second confidence component, and the first confidence component is compared with a preset first weighting coefficient. Multiply to obtain the first weighted value, then combine the second confidence component with the preset second weighting coefficient. Multiply the first and second weighted values ​​to obtain the second weighted value. Add the first and second weighted values ​​together to obtain the confidence factor, which ranges from 0 to 1. Among them, the first weighting coefficient With the second weighting coefficient The sum is 1.

[0030] The link acquisition module determines whether rover 1 is in a fixed solution state by parsing the positioning status flag broadcast by rover 1.

[0031] Under the premise of satisfying the fixed solution state, the link acquisition module retrieves the real-time positioning accuracy value output by rover 1 and determines whether the real-time positioning accuracy value is less than the preset accuracy threshold.

[0032] After determining that rover 1 is in a fixed solution state and that the real-time positioning accuracy is less than the preset accuracy threshold, the link acquisition module captures the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test at a preset sampling frequency of 10 Hz to 20 Hz.

[0033] The link acquisition module establishes a sliding window buffer of a preset length and stores the captured 3D coordinate data and instantaneous velocity data into the sliding window buffer.

[0034] The link acquisition module uses a sliding window filtering algorithm to smooth the three-dimensional coordinate data and instantaneous velocity data in the sliding window buffer, eliminating observation noise caused by multipath effects and electromagnetic interference, and obtaining preprocessed three-dimensional coordinate data and instantaneous velocity data.

[0035] The spatiotemporal alignment module issues a braking warning signal based on the preprocessed instantaneous velocity data, obtains the braking timestamp, performs clock synchronization and subsampling reconstruction with the preprocessed 3D coordinate data, and generates a position data chain containing the timestamp.

[0036] The spatiotemporal alignment module monitors the pre-processed instantaneous velocity data in real time. When it is determined that the pre-processed instantaneous velocity data has reached the preset speed, the host 4 drives the alarm to issue a braking warning signal.

[0037] The spatiotemporal alignment module captures the braking trigger signal generated by the braking sensor 2 and obtains the braking timestamp corresponding to the braking moment when the braking trigger signal is generated.

[0038] The time-space alignment module performs clock synchronization and sets the braking timestamp. Unify the time scale with the global satellite navigation system.

[0039] Retrieve the braking timestamp from the sliding window buffer. At least two preprocessed 3D coordinate data points before and after the specified time point.

[0040] The preprocessed 3D coordinate data retrieved is reconstructed using the Lagrange interpolation algorithm through subsampling to calculate the corresponding braking timestamp. Braking start coordinates ,in, For the first Preprocessed three-dimensional coordinate data of discrete sampling points For the first The time value corresponding to each discrete sampling point For the first The time value corresponding to each discrete sampling point.

[0041] The spatiotemporal alignment module continuously monitors the preprocessed instantaneous velocity data. When it determines that the preprocessed instantaneous velocity data has decreased to zero, it determines the moment when the vehicle comes to a standstill and obtains the corresponding standstill timestamp.

[0042] The spatiotemporal alignment module retrieves preprocessed 3D coordinate data within the time interval of braking timestamp and stationary timestamp, identifies and extracts the preprocessed 3D coordinate data from the braking moment to the vehicle's stationary moment as the full trajectory coordinate data.

[0043] The braking start coordinate point is used as the trajectory start point. The full trajectory coordinate data containing the braking start coordinate point is associated and encapsulated with the corresponding sampling timestamp in chronological order to generate a position data chain containing timestamps.

[0044] The consistency check module removes coordinate jump points based on the acceleration change rate in the position data link, performs trajectory completion, and outputs the corrected data link.

[0045] The consistency verification module retrieves the location data chain containing timestamps and extracts the preprocessed 3D coordinate data and the corresponding sampling timestamps from the location data chain containing timestamps.

[0046] Based on the difference in preprocessed 3D coordinate data between adjacent sampling points and the difference in sampling timestamps, the motion acceleration at each sampling moment in the position data chain is calculated.

[0047] Calculate the difference between adjacent accelerations and take the absolute value to obtain the change in acceleration. The difference between the change in acceleration and the corresponding sampling timestamp Perform a division operation to obtain the rate of change of acceleration. ,in, For the first Motion acceleration at the sampling time, For the first The acceleration of motion at the sampling moment.

[0048] When the consistency check module determines that the rate of change of acceleration is greater than the preset rate of change of acceleration threshold, it identifies the sampling point at the corresponding sampling time as a coordinate jump point caused by interference.

[0049] The consistency check module removes coordinate jump points from the location data chain containing timestamps and locates the coordinate jump segments formed on the time axis after removing the coordinate jump points.

[0050] The consistency check module retrieves the preprocessed instantaneous velocity data, uses the preprocessed instantaneous velocity data to perform trajectory completion on the coordinate jump segment, and generates the completed coordinate points.

[0051] The trajectory completion process includes identifying the coordinates of the starting sampling point of the coordinate transition segment. and start timestamp The preprocessed instantaneous velocity data corresponding to the coordinate jump segment Integrating over time yields the coordinate increment vector. Adding the coordinates of the initial sampling point to the coordinate increment vector results in the completed coordinate points. ,in, To complete the target timestamp corresponding to the coordinate point.

[0052] The consistency check module inserts the completed coordinate points into the coordinate jump segment, and repackages the completed coordinate points and the sampling points that have not been removed from the position data chain in chronological order, and outputs the corrected data chain.

[0053] The geometric offset module extracts the instantaneous vertical displacement during braking from the correction data link, calculates the elevation angle by combining it with the antenna installation height, and obtains the corrected horizontal coordinates.

[0054] Correct the elevation components of the preprocessed 3D coordinate data corresponding to the braking initiation time in the data chain. Elevation components of the preprocessed 3D coordinate data corresponding to each sampling time. Perform a subtraction operation to obtain the vertical displacement. .

[0055] vertical displacement Antenna mounting height stored in the storage unit The altitude change ratio is obtained by performing a division operation. The pitch cosine value is obtained by subtracting the altitude change ratio from the value 1. The pitch angle is obtained by performing an inverse cosine operation on the pitch cosine value. .

[0056] Using pitch angle and antenna installation height Perform offset compensation on the horizontal coordinate components in the correction data link, and on the pitch angle. Perform sine calculations and determine the antenna installation height. Perform a multiplication operation to obtain the horizontal bias vector, and then combine the horizontal bias vector with the first element in the corrected data link. Horizontal coordinate components at each sampling time Perform an addition operation to obtain the corrected horizontal coordinates. .

[0057] The horizontal coordinate components at each sampling time in the data link will be corrected. Replace with the corresponding corrected horizontal coordinates Complete the trajectory coordinate correction including dynamic constraints.

[0058] The dynamics fusion module introduces second-order derivative constraints to fit and correct the horizontal coordinates, calculates the first braking distance, and combines the second braking distance obtained by integrating the preprocessed instantaneous velocity data with the confidence factor to calculate the final braking distance.

[0059] By introducing second-order derivative constraints to perform nonlinear fitting operations, the continuous deceleration trajectory of the tested agricultural machinery is reconstructed. The nonlinear fitting operation process includes using the corrected horizontal coordinates as the observation value, constructing an objective function that includes fitting residual terms and second-order derivative penalty terms, and minimizing the second-order derivative amplitude of the fitting curve by the objective function constraint to ensure that the acceleration change of the reconstructed continuous deceleration trajectory conforms to the dynamic characteristics of agricultural machinery.

[0060] The function defining the continuous deceleration trajectory as a function of time along the horizontal axis of the horizontal coordinate system is: The function defining the continuous deceleration trajectory as a function of time along the vertical axis of the horizontal coordinate system is... ,right Perform first-order differentiation and squaring to obtain the squared term of the velocity on the horizontal axis. Perform first-order differentiation and squaring to obtain the squared velocity term on the vertical axis. Add the squared velocity terms on the horizontal axis and vertical axis and then perform a square root operation to obtain the resultant velocity function. (This is done at the braking timestamp.) to static timestamp Perform time integration on the resultant velocity function within the time interval to obtain the first braking distance. .

[0061] Braking timestamp to static timestamp Preprocessed instantaneous velocity data within the time interval Perform time integration to obtain the second braking distance. .

[0062] Confidence factor With first braking distance Perform a multiplication operation to obtain the first weight, and then subtract the confidence factor from the value 1. Obtain the weight difference value and then compare the weight difference value with the second braking distance. Perform a multiplication operation to obtain the second weight, then perform an addition operation between the first and second weights to obtain the final braking distance. .

[0063] Final braking distance Compare with the standard limit library stored in the storage unit.

[0064] If the final braking distance meets the preset standard limit, the performance is deemed acceptable; if the final braking distance exceeds the preset standard limit, the performance is deemed unacceptable.

[0065] Based on the performance assessment results, the host 4 drives the alarm to issue a braking warning signal and drives the display screen to simultaneously display the final braking distance and performance assessment results.

[0066] In summary, the complete detection process of the satellite CORS-based agricultural machinery braking detector in this embodiment is as follows: When using it, first install and deploy the hardware equipment. Horizontally fix the rover 1 to the center of the top of the cab of the agricultural machine under test using its own strong magnetic base, and ensure that there are no obstacles around it that would obstruct the satellite signal, so that the rover 1 can continuously capture and observe the signal. Install the brake sensor 2 at the brake pedal of the agricultural machine under test to obtain the driver's braking action in real time. Install the main unit 4 in an easily observable position in the cab, and ensure that it is electrically connected to the rover 1 and the brake sensor 2.

[0067] Subsequently, system configuration and link establishment are carried out. The operator runs the configuration program through the accompanying handbook 3 and inputs the corresponding access parameters, including Internet Protocol address, port number, mount point, username and password. The host 4 uses the mobile communication module to access the cloud base station 5 according to the above access parameters, and establishes a two-way data transmission link 6 between the rover 1 and the cloud base station 5. The rover 1 feeds back its real-time spatial coordinates to the cloud base station 5 and receives the differential correction data generated by the cloud base station 5 using virtual reference station technology.

[0068] During the preparation phase before testing, the operator needs to monitor the positioning and calculation status of the rover 1 in real time through the accompanying handbook 3. When the link acquisition module determines that the rover 1 is in a fixed solution state and the real-time positioning accuracy value is less than the preset accuracy threshold, the data capture sequence is automatically started. At this time, the host 4 captures the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test at a preset sampling frequency of 10 Hz to 20 Hz, and stores them in the sliding window buffer for smoothing preprocessing.

[0069] During the testing phase, the driver starts the agricultural machine under test and accelerates it. The host 4 displays the pre-processed instantaneous speed data of the agricultural machine under test in real time. When the pre-processed instantaneous speed data reaches the preset speed, the host 4 drives the alarm to issue a braking warning signal. After hearing the signal, the driver immediately performs an emergency braking operation. The brake sensor 2 captures this action and sends a braking trigger signal to the host 4.

[0070] During and after braking, the central processing unit integrated inside the host 4 uses a runtime alignment module to obtain the braking timestamp based on the braking trigger signal and performs subsampling reconstruction using a Lagrange interpolation algorithm to determine the braking start coordinate point. The consistency check module eliminates coordinate jump points based on the rate of change of acceleration and performs trajectory completion. The geometric offset module calculates the elevation angle and corrects the horizontal coordinates based on the antenna installation height. The dynamic fusion module performs weighted fusion of the first braking distance and the second braking distance based on the confidence factor to calculate the final braking distance.

[0071] Finally, the host 4 automatically compares the final braking distance with the standard limit library stored in the storage unit to determine whether the performance judgment result is qualified. After the test is completed, the host 4 drives the display screen to simultaneously display the final braking distance, performance judgment result, and full trajectory dynamic graph including dynamic constraint correction. Users can record or export the test data as needed.

[0072] Example 3: As Figures 3 to 6 As shown in Example 2, through simulation experiments, the satellite CORS mode agricultural machinery braking detection instrument of the present invention is verified to have the ability to capture braking trajectory with high precision and achieve centimeter-level braking distance measurement in complex dynamic attitude and non-stationary data link environments.

[0073] This verification example uses a sampling frequency of 10Hz, an initial speed of 30km / h, and an antenna installation height of 2.5m as experimental parameters. The simulation results are shown in the figure below. Figures 3-6 As shown.

[0074] Figures 3-6 The image shows a braking warning signal (brake timestamp) emitted from the host 4 drive alarm. =3.25s) Dynamic correction and integration of the entire process from when the agricultural machinery comes to a complete stop.

[0075] Figure 3The diagram illustrates the dynamic pitch correction process of the geometric offset module. The thick gray line in the figure simulates the dynamic pitch attitude of the tested agricultural machine during braking, and the blue pole represents the antenna pole. Experimental results show that when the agricultural machine's dynamic pitch attitude causes a change in the elevation component, the geometric offset module extracts the vertical displacement at the moment of braking, calculates the pitch angle by combining it with the antenna installation height, and obtains the horizontal offset vector by performing a sine operation on the pitch angle and multiplying it with the antenna installation height. This yields the corrected horizontal coordinates (red diamond points in the figure), successfully eliminating the projection geometric offset error caused by mechanical inertia and completing the trajectory coordinate correction including dynamic constraints.

[0076] Figure 4 The diagram illustrates the consistency verification stage of the method of this invention. The blue dashed line in the figure represents the original position data of coordinate jump points caused by environmental interference within the position data chain. Experimental results show that the consistency verification module obtains the acceleration change rate by calculating the difference between adjacent motion accelerations. When the acceleration change rate is determined to be greater than a preset acceleration change rate threshold, it accurately identifies and removes coordinate jump points. Furthermore, it uses preprocessed instantaneous velocity data to perform integral operations on the coordinate jump segments to complete the trajectory. The generated red solid line (corrected data chain) maintains excellent physical consistency, eliminating distortion in the position data chain.

[0077] Figure 5 The diagram illustrates the confidence evaluation process during the link acquisition phase. The purple curve represents the dynamic fluctuation trend of the correction delay parameter, while the green curve represents the confidence factor calculated using parameters such as the standard reference delay constant and carrier-to-noise ratio. Experimental results show a significant negative correlation between the confidence factor and the correction delay parameter. When fluctuations in network link quality lead to an increase in the correction delay parameter, the link acquisition module automatically lowers the confidence factor, thereby quantifying the reliability of the preprocessed 3D coordinate data.

[0078] Figure 6 The figure shows the final distance measurement and judgment output of the dynamics fusion module. The figure shows the first braking distance (blue dotted line) calculated by fitting and reconstructing the corrected data link after second-order derivative constraint, the second braking distance (magenta dashed line) obtained by integrating the preprocessed instantaneous velocity data, and the final braking distance (red solid line) after weighted fusion using confidence factor. The experiment shows that during the entire braking process, the dynamics fusion module can adaptively adjust the weights according to the link quality, effectively overcoming the negative impact of differential correction transmission delay on measurement accuracy. At the end of the simulation, the host 4 compares the final braking distance (7.42m) with the preset standard limit library, and the performance judgment result is "qualified". The final result is also displayed synchronously on the screen.

[0079] This simulation embodiment verifies that the present invention effectively solves the problems of recognition lag caused by satellite sampling discreteness and projection geometric bias error caused by mechanical inertia by combining subsampling reconstruction and geometric bias modules. By introducing multi-source dynamic fusion of confidence factors, the detection stability of agricultural machinery automatic detection instrument is guaranteed in complex field environments.

[0080] In summary, the satellite CORS-based agricultural machinery braking detection instrument proposed in this invention demonstrates excellent spatial dimension correction and temporal dimension alignment capabilities in dynamic operating environments. Furthermore, by constructing a consistency verification mechanism that includes dynamic constraints, a highly reliable braking evaluation system is built, demonstrating significant technological advancements and practical application value.

[0081] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A satellite CORS-based agricultural machinery automatic detection instrument, characterized in that, The detector includes a rover, a brake sensor, a matching handheld device, and a main unit. The main unit integrates a central processing unit for operation. The link acquisition module uses virtual reference station technology to obtain differential correction, correction delay parameters and carrier noise ratio, calculates confidence factor, and captures and preprocesses the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test when the rover is in a fixed solution state and meets the preset accuracy threshold. The spatiotemporal alignment module issues a braking prompt signal based on the preprocessed instantaneous velocity data, obtains the braking timestamp, performs clock synchronization and subsampling reconstruction with the preprocessed three-dimensional coordinate data, and generates a position data chain containing the timestamp. The consistency check module removes coordinate jump points based on the acceleration change rate in the position data link, performs trajectory completion, and outputs the corrected data link. The geometric offset module extracts the instantaneous vertical displacement during braking from the correction data link, calculates the elevation angle by combining it with the antenna installation height, and obtains the corrected horizontal coordinates. The dynamics fusion module introduces second-order derivative constraints to fit and correct the horizontal coordinates, calculates the first braking distance, and combines the second braking distance obtained by integrating the preprocessed instantaneous velocity data with the confidence factor to calculate the final braking distance.

2. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that: The rover is a receiver for the Global Navigation Satellite System, including a receiver board that supports carrier phase differential technology and a mobile communication module. It is kept horizontally fixed to the top of the cab of the agricultural machinery under test by a magnetic base, ensuring that there are no obstacles around it that obstruct satellite signals. It is used to establish a two-way data transmission link with the cloud base station and continuously capture differential correction, correction delay parameters, carrier noise ratio, three-dimensional coordinate data and instantaneous velocity data. The brake sensor is installed at the brake pedal of the agricultural machine under test to acquire the driver's braking action and transmit the generated brake trigger signal to the host in real time; The accompanying handheld device has a configuration program that is used to set access parameters and display the location calculation status and correction latency parameters in real time. Access parameters include Internet Protocol address, port number, mount point, username and password. The main unit is electrically connected to the rover and braking sensor. It integrates a central processing unit, storage unit, alarm and display screen. The storage unit stores location data links with timestamps, antenna installation height, preset speed, braking timestamps and preset standard limit value library. The display screen displays the speed of the tested agricultural machinery in real time and presents the final braking distance, performance judgment results and full trajectory dynamic graph with dynamic constraint correction after the test is completed. The alarm is used to issue a braking warning signal when the tested agricultural machinery reaches the preset speed.

3. The satellite CORS-based agricultural machinery braking detection instrument according to claim 2, characterized in that, The link acquisition module uses virtual reference station technology to obtain differential corrections, correction delay parameters, and carrier-to-noise ratio. The process of calculating the confidence factor includes: The host uses a mobile communication module to access the cloud base station through a preset Internet Protocol address, port number, mount point, username and password, and establishes a two-way data transmission link between the mobile station and the cloud base station. The rover receives observation signals broadcast by the Global Navigation Satellite System in real time and feeds back the real-time spatial coordinates of the rover contained in the observation signals to the cloud base station through a two-way network data transmission link; The cloud base station uses virtual reference station technology to generate differential observations corresponding to the location of the rover based on the real-time spatial coordinates of the rover. The differential observations are sent to the rover as differential corrections, and the correction delay parameters and carrier noise ratio output by the rover are extracted in real time. The ratio of the preset standard reference delay constant to the sum of the correction delay parameters is defined as the first confidence component. The ratio of the carrier noise ratio to the preset upper limit of the carrier noise ratio is defined as the second confidence component. The first confidence component is multiplied by the preset first weighting coefficient to obtain the first weighted value. The second confidence component is multiplied by the preset second weighting coefficient to obtain the second weighted value. The first weighted value and the second weighted value are added together to obtain the confidence factor with a value range between 0 and 1. The sum of the first weighting coefficient and the second weighting coefficient is 1.

4. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that, The link acquisition module, when the rover is in a fixed solution state and meets the preset accuracy threshold, captures and preprocesses the three-dimensional coordinate data and instantaneous velocity data of the agricultural machinery under test, including: The link acquisition module determines whether the rover is in a fixed state by parsing the positioning status flags broadcast by the rover. Under the premise of satisfying the fixed solution state, the link acquisition module retrieves the real-time positioning accuracy value output by the rover and determines whether the real-time positioning accuracy value is less than the preset accuracy threshold. After determining that the rover is in a fixed solution state and that the real-time positioning accuracy is less than the preset accuracy threshold, the link acquisition module captures the three-dimensional coordinate data and instantaneous speed data of the agricultural machine under test at a preset sampling frequency of 10 Hz to 20 Hz. The link acquisition module establishes a sliding window buffer of a preset length and stores the captured three-dimensional coordinate data and instantaneous velocity data into the sliding window buffer; The link acquisition module uses a sliding window filtering algorithm to smooth the three-dimensional coordinate data and instantaneous velocity data in the sliding window buffer, and obtains preprocessed three-dimensional coordinate data and instantaneous velocity data.

5. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that, The spatiotemporal alignment module issues a braking warning signal based on the preprocessed instantaneous velocity data. The process of obtaining the braking timestamp includes: The spatiotemporal alignment module monitors the preprocessed instantaneous velocity data in real time. When it is determined that the preprocessed instantaneous velocity data has reached the preset speed, the host drives the alarm to issue a braking warning signal. The spatiotemporal alignment module captures the braking trigger signal generated by the braking sensor and obtains the braking timestamp corresponding to the braking moment when the braking trigger signal was generated.

6. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that, The spatiotemporal alignment module performs clock synchronization and subsampling reconstruction with the preprocessed 3D coordinate data to generate a location data chain containing timestamps. This process includes: The spatiotemporal alignment module performs clock synchronization, unifying the braking timestamp to the time scale of the global satellite navigation system; Retrieve at least two preprocessed 3D coordinate data points located before and after the braking timestamp from the sliding window buffer; The preprocessed 3D coordinate data retrieved is reconstructed by subsampling using the Lagrange interpolation algorithm to calculate the braking start coordinate point corresponding to the braking timestamp; The spatiotemporal alignment module continuously monitors the preprocessed instantaneous velocity data. When it determines that the preprocessed instantaneous velocity data has decreased to zero, it determines the moment when the vehicle comes to a standstill and obtains the corresponding standstill timestamp. The spatiotemporal alignment module retrieves the preprocessed three-dimensional coordinate data within the time interval of the braking timestamp and the stationary timestamp, identifies and extracts the preprocessed three-dimensional coordinate data from the braking moment to the vehicle stationary moment as the full trajectory coordinate data; The braking start coordinate point is used as the trajectory start point. The full trajectory coordinate data containing the braking start coordinate point is associated and encapsulated with the corresponding sampling timestamp in chronological order to generate a position data chain containing timestamps.

7. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that, The consistency check module, based on the rate of change of acceleration in the position data link, removes coordinate jump points, performs trajectory completion, and outputs the corrected data link. The process includes: The consistency verification module retrieves the location data chain containing timestamps and extracts the preprocessed 3D coordinate data and the corresponding sampling timestamps from the location data chain containing timestamps. The motion acceleration at each sampling moment in the position data chain is calculated based on the difference in preprocessed three-dimensional coordinate data between adjacent sampling points and the difference in sampling timestamps. Calculate the difference between adjacent accelerations and take the absolute value to obtain the acceleration change. Then, perform a division operation between the acceleration change and the corresponding sampling timestamp difference to obtain the acceleration rate of change. When the consistency check module determines that the rate of change of acceleration is greater than the preset rate of change of acceleration threshold, it identifies the sampling point at the corresponding sampling time as a coordinate jump point caused by interference. The consistency check module removes coordinate jump points from the location data chain containing timestamps and locates the coordinate jump segments formed on the time axis after removing the coordinate jump points; The consistency check module retrieves the preprocessed instantaneous velocity data, uses the preprocessed instantaneous velocity data to perform trajectory completion on the coordinate jump segment, and generates the completed coordinate points; The trajectory completion process includes identifying the coordinates of the starting sampling point and the starting timestamp of the coordinate jump segment, performing an integral operation on time on the preprocessed instantaneous velocity data corresponding to the coordinate jump segment to obtain the coordinate increment vector, and performing an addition operation on the coordinates of the starting sampling point and the coordinate increment vector to obtain the completed coordinate point; The consistency check module inserts the completed coordinate points into the coordinate jump segment, and repackages the completed coordinate points and the sampling points that have not been removed from the position data chain in chronological order, and outputs the corrected data chain.

8. The satellite CORS-based agricultural machinery braking detection instrument according to claim 2, characterized in that, The geometric offset module extracts the instantaneous vertical displacement during braking from the correction data link, calculates the elevation angle based on the antenna installation height, and obtains the corrected horizontal coordinates through the following process: The vertical displacement is obtained by subtracting the elevation component of the preprocessed 3D coordinate data corresponding to the braking start time from the elevation component of the preprocessed 3D coordinate data corresponding to each sampling time in the corrected data chain. The vertical displacement is divided by the antenna installation height stored in the storage unit to obtain the height change ratio. The elevation cosine value is obtained by subtracting the height change ratio from the value 1. The elevation cosine value is then subjected to an inverse cosine operation to obtain the elevation angle. The horizontal coordinate components in the corrected data link are offset compensated using the elevation angle and antenna installation height. The elevation angle is sine-operated and multiplied with the antenna installation height to obtain the horizontal offset vector. The horizontal offset vector is then summed with the horizontal coordinate components in the corrected data link to obtain the corrected horizontal coordinates. The horizontal coordinate components at each sampling time in the corrected data chain are replaced with the corresponding corrected horizontal coordinates to complete the trajectory coordinate correction including dynamic constraints.

9. The satellite CORS-based agricultural machinery braking detection instrument according to claim 1, characterized in that, The dynamics fusion module, by introducing second-order derivative constraints to fit and correct the horizontal coordinates, calculates the first braking distance through the following process: The second derivative constraint is introduced to perform nonlinear fitting operation to reconstruct the continuous deceleration trajectory of the tested agricultural machinery. The nonlinear fitting operation process includes using the corrected horizontal coordinate as the observation value, constructing an objective function containing the fitting residual term and the second derivative penalty term, and constraining the second derivative magnitude of the fitting curve by minimizing the objective function. The function defining the continuous deceleration trajectory as a function of time along the horizontal axis of the horizontal coordinate system is: The function defining the continuous deceleration trajectory as a function of time along the vertical axis of the horizontal coordinate system is... ,right Perform first-order differentiation and squaring to obtain the squared term of the velocity on the horizontal axis. Perform first-order differentiation and squaring to obtain the vertical axis velocity squared term. Add the horizontal axis velocity squared term and the vertical axis velocity squared term together and perform square root operation to obtain the resultant velocity function. Perform time integration on the resultant velocity function within the time interval from braking timestamp to rest timestamp to obtain the first braking distance.

10. The satellite CORS-based agricultural machinery braking detection instrument according to claim 2, characterized in that, The dynamics fusion module, combining the second braking distance obtained by integrating the preprocessed instantaneous velocity data with the confidence factor, calculates the final braking distance through the following process: The second braking distance is obtained by performing time integration on the preprocessed instantaneous velocity data within the time interval from the braking timestamp to the stationary timestamp. The confidence factor is multiplied with the first braking distance to obtain the first weight value. The confidence factor is subtracted from the value 1 to obtain the weight difference. The weight difference is multiplied with the second braking distance to obtain the second weight value. The first weight value and the second weight value are added together to obtain the final braking distance. The final braking distance is compared with the standard limit library stored in the storage unit; If the final braking distance is less than or equal to the preset standard limit, the performance judgment result is qualified; if the final braking distance is greater than the preset standard limit, the performance judgment result is unqualified. Based on the performance assessment results, the host computer drives the alarm to issue a braking warning signal and drives the display screen to simultaneously display the final braking distance and performance assessment results.

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