An automatic leveling type geographic surveying instrument

Abstract

This invention discloses an automatic leveling geographic surveying instrument, belonging to the field of geographic surveying technology. The invention first acquires the tilt angle and tilt angle change rate of the total station base in real time, dividing station settlement into three stages: micro-settlement, significant settlement, and sudden settlement. For the micro-settlement stage, real-time error compensation is achieved through elevation correction of the line-of-sight height-time fitting curve and vertical axis tilt horizontal angle correction. For the significant settlement stage, high-precision automatic leveling based on a kinematic model, physical compensation for the three-dimensional displacement of the instrument center, and orientation reset are executed sequentially. For the sudden settlement stage, shutdown alarm and abnormal data marking are implemented. This invention also includes surveying instrument hardware with electrically telescopic outriggers and a multi-sensor system, adaptable to surveying operations in complex geological conditions, balancing measurement accuracy, operational continuity, equipment safety, and data utilization.

Description

Technical Field

[0001] This invention relates to the field of geographic surveying, and more specifically, to an automatic leveling geographic surveying instrument. Background Technology

[0002] As a core basic equipment for geographic topographic mapping, engineering deformation monitoring, and construction layout, the total station's measurement accuracy and reliability are highly dependent on the levelness of the station base and the stability of the station benchmark. In complex operating scenarios such as soft soil foundations, mining areas, slope monitoring areas, and the vicinity of deep foundation pits, the ground at the station is prone to uneven and continuous settlement and instantaneous collapse deformation, which directly leads to the tilting of the total station base, the deviation of the instrument's vertical axis from the plumb line, three-dimensional displacement of the station center, and continuous drift of the line of sight height. This, in turn, causes errors in horizontal angle measurement and elevation measurement, and in severe cases, even causes the equipment to tip over and the entire surveying results to become completely inaccurate. Therefore, real-time control and error compensation of station settlement have always been a core technical pain point and research focus in the engineering surveying industry.

[0003] In existing technologies, the settlement stages are not divided based on the base tilt angle and tilt change rate, making it impossible to match differentiated control strategies for different settlement conditions. The compensation accuracy and robustness are insufficient, and errors are prone to exceed limits when settlement intensifies. Alternatively, mechanical leveling operations are frequently interrupted, and there is a lack of emergency shutdown, risk warning, and abnormal data marking mechanisms for sudden settlement. It is impossible to balance measurement accuracy, operational continuity, and equipment safety. Furthermore, existing automatic leveling algorithms do not take into account the outrigger hinge angle and spatial attitude, resulting in insufficient leveling accuracy and stability. They ignore the three-dimensional spatial displacement of the instrument center caused by the leveling action, making it impossible to achieve physical displacement compensation for horizontal eccentricity and elevation. After leveling, the original station benchmark becomes completely invalid, requiring reorientation and station setting. Moreover, the measurement data before and after leveling are not segmented and the displacement parameters are not retained. Historical data cannot be reused through internal adjustment to compensate for errors, resulting in low operational efficiency and data utilization. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides an automatic leveling geographic mapping instrument to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic leveling geographic mapping instrument, wherein the automatic leveling geographic mapping instrument is controlled by the following control method:

[0006] S100. Real-time acquisition of the tilt angle and tilt angle change rate of the total station base, and determination of the current settlement stage of the station based on the tilt angle and tilt angle change rate. The settlement stage includes the micro settlement stage, the significant settlement stage, and the sudden settlement stage.

[0007] S200. When it is determined that the micro-settlement stage is in progress, real-time error compensation is activated: by periodically observing the backsight point to establish a fitting curve of line of sight height versus time, the elevation of subsequent measurement points is corrected by real-time interpolation; and based on the current base tilt angle and the telescope pointing azimuth and vertical angle, the horizontal angle is corrected for vertical axis tilt error.

[0008] S300. When it is determined that the area is in a significant settlement stage, automatic leveling, eccentricity and elevation physical displacement compensation and orientation reset are executed in sequence.

[0009] S400 When it is determined that a sudden settlement phase has occurred, stop the measurement operation, trigger an audible and visual alarm, and mark the current station data as suspicious.

[0010] Preferably, the micro-settling stage is characterized by an inclination angle less than a second threshold and an inclination angle change rate less than a first rate threshold.

[0011] The significant settlement stage is defined as follows: the tilt angle is between the second threshold and the third threshold, or the tilt angle change rate is greater than or equal to the first rate threshold and the tilt angle is less than the third threshold.

[0012] The sudden settlement stage is defined as: the tilt angle is greater than or equal to the third threshold.

[0013] Wherein, the third threshold > the second threshold > the first threshold.

[0014] Preferably, in step S200, establishing the line-of-sight height versus time fitting curve specifically includes: using the line-of-sight height calculated from the backsight point at the initial station setup as the reference point, recording the time of each subsequent observation of the backsight point and the corresponding instantaneous line-of-sight height; using a sliding time window, performing curve fitting on the data points within the window to obtain the elevation attenuation fitting function; calculating the root mean square error of the residual of the fitting function in real time, and when the root mean square error of the residual exceeds a fourth threshold, automatically resetting the line-of-sight height at the current moment as the new reference point and clearing the current sliding window.

[0015] Preferably, the vertical axis tilt error correction specifically includes:

[0016] The tilt components of the base in the longitudinal and lateral directions are obtained by a dual-axis tilt sensor. Combined with the azimuth and vertical angles of the telescope, the horizontal angle correction is calculated, and the corrected horizontal angle is output for coordinate calculation.

[0017] Preferably, in step S300, the automatic leveling step specifically involves: obtaining the relative angle between each electric telescopic outrigger and the hinge point of the base; combining the current tilt angle of the base, calculating the absolute angle between each electric telescopic outrigger and the vertical line through coordinate transformation; establishing a first Jacobian matrix based on the absolute angle; calculating the first length adjustment amount of each electric telescopic outrigger required to restore the base to a horizontal state through inverse kinematics; driving each outrigger to perform telescopic actions until the tilt angle of the base is less than a first threshold.

[0018] Preferably, the eccentricity and elevation physical displacement compensation step specifically involves: obtaining the actual length change of each electric telescopic outrigger relative to before leveling after the automatic leveling action is completed; based on the forward kinematic model of the parallel mechanism, calculating the displacement vector generated by the instrument center in three-dimensional space according to the actual length change and the absolute angle of the outriggers before leveling, wherein the displacement vector includes a horizontal displacement component and a vertical displacement component; using the horizontal displacement component as the station eccentricity parameter to correct the horizontal coordinate of the measurement point, and using the vertical displacement component as the line-of-sight height correction parameter to correct the absolute elevation of the measurement point.

[0019] Preferably, the orientation reset step includes: after leveling is completed, resetting the line-of-sight height benchmark of the elevation compensation in the system, guiding the user to re-aim at the backsight point to update the station azimuth, marking the measurement data collected before and after leveling as different benchmark segment identifiers, and recording the displacement vector parameters caused by leveling so as to introduce segmented system error compensation during the internal adjustment.

[0020] An automatic leveling geographic mapping instrument includes:

[0021] Total station: including telescope and base;

[0022] Tripod: Includes three sets of electrically operated telescopic legs;

[0023] Sensing system: including a dual-axis tilt sensor installed at the bottom of the base, a displacement sensor installed inside the outrigger, and an angle sensor installed at the hinge point between the outrigger and the base;

[0024] Control module: Connected to the sensing system and stepper motor, used to receive real-time attitude data and execute the control method.

[0025] Preferably, each set of electric telescopic outriggers includes a first outrigger and a second outrigger slidably connected within the first outrigger. The top end of the first outrigger is hinged to the base. The first outrigger is equipped with a stepper motor and a lead screw. The lead screw is connected to the stepper motor via a coupling and is threadedly connected to the second outrigger.

[0026] Preferably, the displacement sensor is disposed on the top of the first leg, and the top of the second leg is provided with a receiving plate corresponding to the displacement sensor.

[0027] The technical effects and advantages of this invention are as follows:

[0028] This invention scientifically divides and classifies station settlement into multiple stages, and implements differentiated management, taking into account the surveying accuracy, operational continuity, and equipment safety under different settlement conditions. For micro-settlement scenarios, it simultaneously achieves dual-dimensional error compensation through elevation fitting interpolation and vertical axis tilt correction, effectively improving the measurement accuracy and robustness of continuous operations. By combining a high-precision kinematic leveling algorithm for outrigger spatial attitude with physical compensation for three-dimensional displacement after leveling, it solves the industry pain points of inaccurate station benchmarks and inefficient operation interruptions caused by leveling. Furthermore, through segmented identification management of measurement data and marking of abnormal data, it significantly improves the utilization rate and reliability of surveying data. The accompanying multi-sensor collaborative hardware structure achieves closed-loop adaptation between the algorithm and hardware, fully adapting to the high-precision geographic surveying needs under complex geological conditions. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the total station of the present invention.

[0030] Figure 2 This is a schematic diagram of the main operating logic of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure of the electric telescopic leg in this invention.

[0032] Figure 4 This is a schematic diagram of the base and dual-axis tilt sensor in this invention.

[0033] In the picture:

[0034] 1. Total station; 11. Telescope; 12. Base;

[0035] 2. Tripod; 21. First leg; 22. Second leg; 23. Stepper motor; 24. Lead screw; 25. Coupling; 26. Receiving plate;

[0036] 3. Dual-axis tilt sensor;

[0037] 4. Displacement sensor;

[0038] 5. Angle sensor;

[0039] 6. Control module. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] Please read Figures 1 to 4 As shown, this embodiment provides an automatic leveling geographic mapping instrument, including:

[0043] Total station 1: Includes telescope 11 and base 12. Total station 1 includes measuring telescope 11 and rigid base 12 supporting telescope 11. Telescope 11 has built-in high-precision azimuth and vertical angle encoders, which can output the azimuth and vertical angle data pointed by telescope 11 in real time. Total station 1 has built-in laser rangefinder module, which can simultaneously complete the distance and angle measurement and three-dimensional coordinate calculation of target point. Base 12 is the core bearing reference of total station 1, and its horizontal state directly determines the measurement accuracy. Total station 1 has built-in servo motor drive system and automatic target recognition module to control total station 1 to automatically aim at backsight point for observation.

[0044] Tripod 2: Includes three sets of electrically operated telescopic legs, which are evenly distributed along the circumference of the base 12 to form a stable parallel support mechanism. Each set of electrically operated telescopic legs includes a first leg 21 and a second leg 22 slidably connected in the inner cavity of the first leg 21. The top end of the first leg 21 is hinged to the bottom surface of the base 12. A stepper motor 23 and a lead screw 24 are fixedly installed in the inner cavity of the first leg 21. One end of the lead screw 24 is coaxially fixed to the output shaft of the stepper motor 23 through a coupling 25. The nut seat of the lead screw 24 is fixedly connected to the top end of the second leg 22. When the stepper motor 23 receives a pulse signal and rotates, the rotational motion is converted into linear telescopic motion of the second leg 22 along the axial direction of the first leg 21 through the lead screw 24, so as to achieve precise adjustment of the total length of the legs.

[0045] The hinge points of the three sets of electrically telescopic outriggers of tripod 2 and the bottom surface of base 12 are evenly distributed in an equilateral triangle. Specifically, a local coordinate system is established with the geometric center of the bottom surface of base 12 (i.e., the projection point of the vertical axis rotation center of total station 1 on the bottom surface of base 12) as the origin. The tops of the three sets of first outriggers 21 and the three hinge points of the bottom surface of base 12 are in the same reference plane, and the horizontal distance (i.e., eccentricity) from the center of each hinge point to the center of the bottom surface of base 12 is a fixed constant R. The angle between the line connecting any two adjacent hinge points and the center of the bottom surface of base 12 is 120 degrees. When performing kinematic model calculation and establishing the first Jacobian matrix, the system uses this fixed eccentricity R and the 120-degree phase angle as the basic geometric topological constraint parameters of the parallel support mechanism, thereby ensuring that the length adjustment of each outrigger and the displacement vector generated by the instrument center in three-dimensional space can be accurately calculated.

[0046] The sensing system includes a dual-axis tilt sensor 3, a displacement sensor 4, and an angle sensor 5. Specifically, the dual-axis tilt sensor 3 is fixedly installed at the center of the bottom surface of the base 12. It can collect the longitudinal tilt component and the lateral tilt component of the base 12 relative to the horizontal plane in real time, and output the overall tilt angle of the base 12 (the sum of the longitudinal and lateral tilt components) and the real-time rate of change of the tilt angle.

[0047] The displacement sensor 4 is a high-precision laser displacement sensor 4, which is fixedly installed on the top of the inner cavity of the first leg 21. The top of the second leg 22 is fixedly installed with a receiving plate 26 facing the displacement sensor 4. The displacement sensor 4 can collect the straight distance between itself and the receiving plate 26 in real time. The amount of extension and retraction of the second leg 22 relative to the first leg 21 is calculated by the change in distance, that is, the actual change in the length of the leg.

[0048] The angle sensor 5 is an absolute rotary encoder, which is set at the end of the hinge shaft between the outrigger and the base 12. It can collect the relative angle between each electric telescopic outrigger and the hinge of the base 12 in real time, that is, the swing angle of the outrigger relative to the reference plane of the base 12.

[0049] The signal input terminals of the control module 6 are electrically connected to the encoder disks of the dual-axis tilt sensor 3, displacement sensor 4, angle sensor 5, and total station 1, respectively. The signal output terminals of the control module 6 are electrically connected to the drivers of each outrigger stepper motor 23. The control module 6 can receive real-time attitude data collected by each sensor system and measurement data from the total station 1, execute the following control method, output control signals to drive the stepper motors 23 to perform outrigger extension and retraction actions, and simultaneously complete real-time error compensation and data marking of the measurement data.

[0050] Example 2

[0051] Existing geographic surveying instrument settlement and tilt control technologies have a single, fixed control strategy, poor adaptability to different settlement conditions, insufficient compensation accuracy and robustness, and are prone to exceeding measurement error limits. Mechanical leveling is prone to interrupting operations, and the ability to prevent risks and ensure data reliability in sudden settlement scenarios is insufficient. At the same time, the automatic leveling algorithm has insufficient accuracy and poor leveling stability. The leveling action will destroy the original measurement benchmark, causing benchmark inaccuracy. Repeated station setting and orientation are required, resulting in low operation efficiency. Historical measurement data before and after leveling cannot be effectively reused, resulting in low data utilization.

[0052] To resolve the above technical issues, please refer to Figures 1 to 4 As shown, the second embodiment of the present invention provides an automatic leveling geographic mapping instrument, which is controlled by the following control method:

[0053] S100. The tilt angle and tilt angle change rate of the total station 1 base 12 are acquired in real time. The settlement stage of the current station is determined based on the tilt angle and tilt angle change rate. The settlement stage includes the micro settlement stage, the significant settlement stage and the sudden settlement stage. The control module 6 acquires the tilt angle of the total station 1 base 12 and the tilt angle change rate over time in real time through the dual-axis tilt sensor 3.

[0054] Micro-settlement stage: The tilt angle is less than the second threshold and the rate of change of tilt angle is less than the first rate threshold. During this stage, the station settles slowly and the tilt amount is small, which does not exceed the compensation range of the vertical axis tilt error of the total station 1, and there is no need to perform mechanical leveling.

[0055] Significant settlement stage: The tilt angle is between the second and third thresholds, or the rate of change of the tilt angle is greater than or equal to the first rate threshold. During this stage, the station settlement is obvious, and compensation alone cannot guarantee the measurement accuracy. Mechanical leveling and physical displacement compensation are required.

[0056] Sudden Settlement Stage: When the tilt angle is greater than or equal to the third threshold, the station tilts significantly during this stage, posing a risk of equipment tipping over. Measurement data becomes completely inaccurate, and operations must be stopped immediately and an alarm must be triggered.

[0057] S200. When it is determined that the micro-settlement stage is in progress, real-time error compensation is activated: by periodically observing the backsight point to establish a fitting curve of line of sight height versus time, the elevation of subsequent measurement points is corrected by real-time interpolation; and based on the current tilt angle of the base 12 and the pointing azimuth and vertical angle of the telescope 11, the vertical axis tilt error of the horizontal angle is corrected.

[0058] The specific steps for establishing the line-of-sight height versus time fitting curve include: using the line-of-sight height calculated from the backsight point at the initial station setup as the reference point, recording the time of each subsequent backsight point observation and the corresponding instantaneous line-of-sight height; and using a sliding time window to perform curve fitting on the data points within the window to obtain the elevation attenuation fitting function.

[0059] The root mean square error of the residuals of the fitted function is calculated in real time. When the root mean square error of the residuals exceeds the fourth threshold, the current line of sight height is automatically reset to the new reference point and the current sliding window is cleared.

[0060] After initial station setup, total station 1 is aimed at the backsight reference point. The initial line-of-sight height of total station 1 is calculated using the known elevation of the backsight point and stored in control module 6. During the surveying operation, control module 6 controls total station 1 to automatically aim at the backsight point for observation at preset time intervals, recording the time of each backsight point observation and the instantaneous line-of-sight height calculated from this observation. This forms multiple sets of data points for time and instantaneous line-of-sight height. Control module 6 uses a sliding time window to perform curve fitting on the data points within the window. The fitting method uses the least squares method to perform second-order polynomial fitting, obtaining the elevation attenuation fitting. When measuring the elevation of subsequent measurement points, the control module 6 calculates the corrected line-of-sight height in real time based on the observation time of the measurement points using the elevation attenuation fitting function. This corrects the elevation measurement value of the measurement points in real time, offsetting the elevation error caused by the slow settlement of the station. At the same time, the control module 6 calculates the root mean square error of the residual of the fitting function in real time. When the root mean square error of the residual exceeds the preset fourth threshold, it is determined that the current fitting curve can no longer match the settlement trend. The line-of-sight height obtained by the backsight point observation at the current time is automatically reset as the new benchmark point, and the current sliding time window is cleared. Data points are then collected again for fitting.

[0061] The vertical tilt error correction is as follows: The tilt components of the base 12 in the longitudinal and lateral directions are acquired using the dual-axis tilt sensor 3. Combined with the azimuth and vertical angles currently pointed by the telescope 11, the horizontal angle correction is calculated, and the corrected horizontal angle is output for coordinate calculation. Specifically, the control module 6 first acquires the tilt components of the base 12 in the longitudinal and lateral directions, and simultaneously acquires the azimuth and vertical angles currently pointed by the telescope 11. Based on the longitudinal tilt component, lateral tilt component, azimuth angle, and vertical angle, the horizontal angle correction is calculated. After the correction calculation is completed, the control module 6 superimposes the original horizontal angle value measured by the total station 1 with the calculated horizontal angle correction to obtain the final corrected horizontal angle. This corrected horizontal angle is then used to calculate the plane coordinates of the measurement point, thereby offsetting the horizontal angle measurement deviation caused by the tilt of the base 12.

[0062] S300. When it is determined that the significant settlement stage is underway, automatic leveling, eccentricity and elevation physical displacement compensation and orientation reset are executed sequentially. The automatic leveling steps are as follows: obtain the relative angle between each electric telescopic outrigger and the hinge point of the base 12, combine it with the current tilt angle of the base 12, and calculate the absolute angle between each electric telescopic outrigger and the vertical line through coordinate transformation; establish the first Jacobian matrix according to the absolute angle, calculate the first length adjustment amount of each electric telescopic outrigger required to restore the base 12 to a horizontal state through inverse kinematics, and drive each outrigger to perform telescopic action until the tilt angle of the base 12 is less than the first threshold.

[0063] The automatic leveling step is as follows: the control module 6 obtains the relative angle between each electric telescopic outrigger and the base 12 hinge in real time through the angle sensor 5 at each outrigger hinge. Combined with the current tilt angle of the base 12, the absolute angle between each electric telescopic outrigger and the vertical line is calculated through coordinate transformation.

[0064] The specific coordinate transformation process is as follows: A connected coordinate system for base 12 is established with the center of base 12 as the origin, where the Z-axis is perpendicular to the plane of base 12 and points upwards. A world coordinate system is established with the reference point of the measuring station as the origin, where the Zw-axis points upwards along the vertical direction. The rotation matrix of the connected coordinate system relative to the world coordinate system is calculated using the tilt angle of base 12. The outrigger axis vectors in the connected coordinate system are transformed to the world coordinate system using the rotation matrix, and the angle between the outrigger axis and the Zw-axis (vertical line) of the world coordinate system is calculated; this is the absolute angle of the outrigger. Based on the absolute angles of the three sets of outriggers and the current actual length of the outriggers, the first Jacobian matrix of the parallel support mechanism is established. The Jacobian matrix describes the mapping relationship between the change in outrigger length and the change in the attitude of base 12. Through inverse kinematics, the first length adjustment of each electrically operated telescopic outrigger required to restore base 12 to a horizontal state is calculated. Based on the calculated first length adjustment amount, the control module 6 outputs pulse control signals to the stepper motor 23 driver of each leg, driving each leg to perform synchronous extension and retraction actions. During the leveling process, the dual-axis tilt sensor 3 provides real-time feedback on the tilt angle of the base 12. The control module 6 uses a closed-loop PID control algorithm to correct the length adjustment amount of the legs in real time until the tilt angle of the base 12 is less than the first threshold and the automatic leveling action is completed.

[0065] The specific steps for eccentricity and elevation physical displacement compensation are as follows: After the automatic leveling action is completed, obtain the actual length change of each electric telescopic outrigger relative to before leveling. Based on the forward kinematic model of the parallel mechanism, calculate the displacement vector generated by the instrument center in three-dimensional space according to the actual length change and the absolute angle of the outriggers before leveling. The displacement vector includes a horizontal displacement component and a vertical displacement component. Use the horizontal displacement component as the station eccentricity parameter to correct the horizontal coordinate of the measurement point, and use the vertical displacement component as the line-of-sight height correction parameter to correct the absolute elevation of the measurement point.

[0066] Specifically, after the automatic leveling action is completed, the control module 6 acquires the actual length change fed back by the displacement sensors 4 in each outrigger before and after the leveling action. The actual length change is the difference between the actual length of the outrigger after leveling and the actual length of the outrigger before leveling. Based on the forward kinematics model of the parallel mechanism, according to the actual length change and the absolute angle of the outrigger before leveling, the displacement vector generated by the instrument center (i.e., the center of base 12, which coincides with the vertical axis center of total station 1) in three-dimensional space is calculated. The displacement vector includes horizontal displacement components and vertical displacement components. The specific calculation process is as follows: In the world coordinate system, the coordinate equations of three sets of outrigger contact points with the ground are established. Combining the length change and angle constraints of the outrigger before and after leveling, the coordinate change of the center of base 12 is solved through forward kinematics, which is the displacement vector. The control module 6 uses the horizontal displacement component as the station eccentricity parameter to correct the horizontal coordinate of the measurement point, and uses the vertical displacement component as the line-of-sight height correction parameter to correct the absolute elevation of the measurement point. Through the above correction, the measurement error caused by the spatial displacement of the instrument center caused by the automatic leveling action is offset, and the accuracy of the collected data can be guaranteed without resetting the station.

[0067] After leveling is completed, the line-of-sight height benchmark of the elevation compensation in the system is reset, and the user is guided to re-aim at the backsight point to update the station azimuth.

[0068] The measurement data collected before and after leveling are marked with different benchmark segment identifiers, and the displacement vector parameters caused by leveling are recorded so that segmented system error compensation can be introduced during the internal adjustment.

[0069] Specifically, after displacement compensation is completed, control module 6 resets the line-of-sight height benchmark for elevation compensation within the system, using the line-of-sight height calculated from the backsight point after leveling as the new benchmark value. It then clears the previous sliding time window and restarts elevation fitting compensation. Simultaneously, control module 6 guides the user to re-aim at the backsight benchmark point via the total station 1's display screen and voice prompts, completing the station azimuth update and orientation reset, eliminating azimuth deviations caused by the leveling action. Control module 6 marks the measurement data collected before and after leveling as different benchmark segment identifiers, records the displacement vector parameters caused by leveling, and the attitude data of base 12 before and after leveling, storing them along with the measurement data. During the internal adjustment process, segmented system error compensation can be introduced based on the segment identifiers and displacement vector parameters to further improve adjustment accuracy.

[0070] S400. When it is determined that the current station is in a sudden settlement phase, the measurement operation is stopped, an audible and visual alarm is triggered, and the current station data is marked as suspicious. Specifically, when the control module 6 determines that the current station is in a sudden settlement phase, it immediately sends a stop command to the total station 1 to terminate all ongoing measurement operations; at the same time, it triggers the built-in audible and visual alarm, emitting a high-frequency audible and visual alarm signal to alert on-site personnel that there is a safety risk at the station; and marks all measurement data collected at the current station and in the current time period as suspicious data, adds an anomaly mark when storing the data, and conducts key verification or rejection during internal processing to avoid inaccurate data affecting the quality of the surveying results.

[0071] It should be noted that the core principles and basic implementations of the various algorithms, mathematical models, and control logics involved in this application are all existing technologies in this field. Specifically, the least squares curve fitting and residual root mean square error verification methods used for elevation error compensation, which use discrete time-series data points to fit function models and calculate fitting deviations, are already known and widely used in the fields of numerical analysis and surveying data processing. The horizontal angle correction calculation model used for vertical axis tilt error correction is a classic basic model for total station angle system error correction in surveying engineering, and its core calculation logic has been widely disclosed in national surveying and mapping standards and related academic literature. The coordinate system transformation and rotation matrix construction methods involved in the spatial attitude calculation of the base and outriggers are conventional technical means in the fields of rigid body spatial kinematics and surveying reference coordinate system transformation. The Jacobian matrix construction and forward and inverse kinematics algorithms used in the automatic leveling and displacement calculation are mature and classic algorithms in the fields of robotics and parallel mechanism motion control. The PID control algorithm used for outrigger extension and retraction closed-loop leveling is a conventional control method widely used in the field of automatic control engineering.

[0072] The inventive point of this application lies in the creative combination and systematic application of these known algorithms, models, and control logics to solve the specific technical problem of inaccurate mapping instrument reference, excessive measurement error, and poor operational continuity caused by station settlement under complex geological conditions, rather than an improvement on the fundamental principles or mathematical models of the algorithms themselves. The specific calculation formulas and basic implementation logic of these known algorithms and models can be obtained by those skilled in the art from industry standards, publicly available academic literature, and mature engineering data; therefore, they will not be elaborated upon in this solution.

[0073] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will recognize that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic leveling geographic mapping instrument, characterized in that, The automatic leveling geographic mapping instrument is controlled using the following control method: S100. Real-time acquisition of the tilt angle and tilt angle change rate of the total station base, and determination of the current settlement stage of the station based on the tilt angle and tilt angle change rate. The settlement stage includes the micro settlement stage, the significant settlement stage, and the sudden settlement stage. S200. When it is determined that the micro-settlement stage is underway, real-time error compensation is activated. S300. When it is determined that the area is in a significant settlement stage, automatic leveling, eccentricity and elevation physical displacement compensation and orientation reset are executed in sequence. S400 When it is determined that a sudden settlement phase has occurred, stop the measurement operation, trigger an audible and visual alarm, and mark the current station data as suspicious.

2. The automatic leveling geographic mapping instrument according to claim 1, characterized in that: The micro-settling stage is characterized by an inclination angle less than the second threshold and an inclination angle change rate less than the first rate threshold. The significant settlement stage is defined as follows: the tilt angle is between the second threshold and the third threshold, or the tilt angle change rate is greater than or equal to the first rate threshold and the tilt angle is less than the third threshold. The sudden settlement stage is defined as: the tilt angle is greater than or equal to the third threshold. Wherein, the third threshold > the second threshold > the first threshold.

3. The automatic leveling geographic mapping instrument according to claim 2, characterized in that, In step S200, the real-time compensation is as follows: By periodically observing the backsight point, a fitting curve of line of sight height versus time is established, and the elevation of subsequent measurement points is corrected by real-time interpolation; and the vertical axis tilt error of the horizontal angle is corrected based on the current base tilt angle and the telescope pointing azimuth and vertical angle. The establishment of the line-of-sight height and time fitting curve specifically includes: taking the line-of-sight height calculated from the backsight point at the initial station setting as the reference point, recording the time of each subsequent observation of the backsight point and the corresponding instantaneous line-of-sight height; using a sliding time window, performing curve fitting on the data points within the window to obtain the elevation attenuation fitting function; The root mean square error of the residuals of the fitted function is calculated in real time. When the root mean square error of the residuals exceeds the fourth threshold, the current line of sight height is automatically reset to the new reference point and the current sliding window is cleared.

4. The automatic leveling geographic mapping instrument according to claim 3, characterized in that, The vertical axis tilt error correction specifically includes: The tilt components of the base in the longitudinal and lateral directions are obtained by a dual-axis tilt sensor. Combined with the azimuth and vertical angles of the telescope, the horizontal angle correction is calculated, and the corrected horizontal angle is output for coordinate calculation.

5. The automatic leveling geographic mapping instrument according to claim 4, characterized in that, In step S300, the automatic leveling step specifically includes: Obtain the relative angle between each electric telescopic outrigger and the hinge point of the base. Combined with the current tilt angle of the base, calculate the absolute angle between each electric telescopic outrigger and the vertical line through coordinate transformation. Establish a first Jacobian matrix based on the absolute angle. Calculate the first length adjustment amount of each electric telescopic outrigger required to restore the base to a horizontal state through inverse kinematics. Drive each outrigger to perform telescopic actions until the tilt angle of the base is less than a first threshold.

6. The automatic leveling geographic mapping instrument according to claim 5, characterized in that, The specific steps for compensating for eccentricity and elevation physical displacement are as follows: After the automatic leveling action is completed, obtain the actual length change of each electric telescopic outrigger relative to before leveling; Based on the forward kinematics model of the parallel mechanism, the displacement vector generated by the center of the instrument in three-dimensional space is calculated according to the actual length change and the absolute angle of the outriggers before leveling. The displacement vector includes a horizontal displacement component and a vertical displacement component. The horizontal displacement component is used as the station eccentricity parameter to correct the horizontal coordinate of the measurement point, and the vertical displacement component is used as the line-of-sight height correction parameter to correct the absolute elevation of the measurement point.

7. The automatic leveling geographic mapping instrument according to claim 6, characterized in that, The targeted reset step includes: After leveling is completed, the line-of-sight height benchmark of the elevation compensation in the system is reset, and the user is guided to re-aim at the backsight point to update the station azimuth. The measurement data collected before and after leveling are marked with different benchmark segment identifiers, and the displacement vector parameters caused by leveling are recorded so that segmented system error compensation can be introduced during the internal adjustment.

8. An automatic leveling geographic mapping instrument, wherein the automatic leveling geographic mapping instrument is controlled by the control method according to any one of claims 1-7, characterized in that, The automatic leveling geographic mapping instrument includes: Total station: including telescope and base; Tripod: Includes three sets of electrically operated telescopic legs; Sensing system: including a dual-axis tilt sensor installed at the bottom of the base, a displacement sensor installed inside the outrigger, and an angle sensor installed at the hinge point between the outrigger and the base; Control module: connected to the sensing system and stepper motor, used to receive real-time attitude data and execute the control method described in claims 1-7.

9. The automatic leveling geographic mapping instrument according to claim 8, characterized in that, Each set of electric telescopic outriggers includes a first outrigger and a second outrigger slidably connected within the first outrigger. The top end of the first outrigger is hinged to the base. The first outrigger contains a stepper motor and a lead screw. The lead screw is connected to the stepper motor via a coupling and is threadedly connected to the second outrigger.

10. The automatic leveling geographic mapping instrument according to claim 9, characterized in that, The displacement sensor is located on the top of the first leg, and the top of the second leg is provided with a receiving plate corresponding to the displacement sensor.

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