A precision correction device for aircraft rudder control surface control and a correction method thereof

Abstract

The application discloses a precision correction device for aircraft rudder control surface control and a correction method thereof, comprising a base; a rudder mounting platform arranged on the base; an encoder mounting seat arranged on the base; a high-precision encoder arranged on the encoder mounting seat; a connecting shaft connected with an output shaft of an aircraft rudder and an input shaft of the high-precision encoder; and an angle calibration assembly electrically connected with the aircraft rudder and the high-precision encoder, used for driving the aircraft rudder to rotate, collecting a feedback angle signal of an internal potentiometer of the aircraft rudder and an actual angle signal of the high-precision encoder, generating a correction parameter and writing the correction parameter into a memory. The precision correction device realizes automatic collection of a deviation between a feedback value of the internal potentiometer of the rudder and a real angle and writing of a correction parameter through the rudder mounting platform arranged on the base, the high-precision encoder and the connecting shaft, and cooperation of the angle calibration assembly, so that the control precision of the rudder on the control surface of the aircraft is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of aircraft control surface technology, and in particular to a precision correction device and method for aircraft servo control surface control. Background Technology

[0002] In aircraft control systems, servos, as key actuators driving control surfaces (such as ailerons, elevators, and rudders), directly affect the aircraft's attitude response and flight stability with their angle control accuracy. To meet the demands of low-cost, mass production, aircraft servos commonly employ miniature conductive plastic potentiometers or magnetic encoders as internal angle feedback elements. These components are compact, inexpensive, and suitable for integration into small servos. The servo achieves closed-loop angle control by reading the voltage signal output from the potentiometer or magnetic encoder.

[0003] In existing technologies, aircraft servos, limited by manufacturing costs and physical dimensions, suffer from low absolute accuracy and poor linearity due to the potentiometers or magnetic encoders they employ. Within the servo's large-angle operating range (e.g., ±60°), a significant nonlinear relationship exists between the output signal and the actual output shaft angle, and this error accumulates nonlinearly as the angle increases. This nonlinear error cannot be eliminated by simple proportional correction, resulting in significant deviations in the servo's output position under large-angle commands. This, in turn, affects the accuracy of the aircraft's control surface deflection, limiting the accuracy and stability of flight attitude control. Improving servo angle control accuracy typically requires replacing internal sensors with higher-precision ones or redesigning the servo structure, but this significantly increases costs and development time, hindering its adoption in low-cost servo products.

[0004] The present invention aims to provide a precision correction device and method for aircraft servo control surfaces, thereby effectively eliminating angular errors caused by poor linearity of internal sensors, improving the control precision of the servo on the aircraft control surfaces, and maintaining the advantage of low cost. Summary of the Invention

[0005] In view of the problems existing in the control of aircraft servo control surfaces, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to provide a precision correction device and method for aircraft servo control surface control, which aims to solve the problem of insufficient control surface deflection precision caused by poor linearity of internal potentiometers or low-precision encoders in existing UAV servos.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including a base.

[0008] A servo mounting platform, which is set on the base, is used to fix the aircraft servo.

[0009] An encoder mounting base is disposed on the base.

[0010] A high-precision encoder is mounted on the encoder mounting base.

[0011] A connecting shaft is provided, one end of which is connected to the output shaft of the aircraft servo, and the other end of which is connected to the input shaft of the high-precision encoder; the connecting shaft, the aircraft servo, and the high-precision encoder are coaxially arranged.

[0012] An angle calibration component is electrically connected to the aircraft servo and the high-precision encoder, respectively, and is used to drive the aircraft servo to rotate. The angle calibration component collects the feedback angle signal from the potentiometer inside the aircraft servo and the actual angle signal from the high-precision encoder. It generates a correction parameter based on the difference between the feedback angle signal and the actual angle signal and writes the correction parameter into the memory inside the aircraft servo.

[0013] In a preferred embodiment of the precision correction device of the present invention, the encoder mounting base is provided with a bearing mounting hole, a mounting bracket, and a mounting bearing; the bearing mounting hole and the mounting bracket are formed by the same clamping process, and the high-precision encoder is mounted on the mounting bracket by at least one locating pin; the mounting bearing is fixed in the bearing mounting hole.

[0014] In a preferred embodiment of the precision correction device of the present invention, the connecting shaft is connected to the output shaft of the aircraft servo via a split connecting spline, and the connecting spline is fixed to one end of the connecting shaft by two connecting pins and a tight fit.

[0015] In a preferred embodiment of the precision correction device of the present invention, a slot and a screw are provided at the interface between the connecting spline and the output shaft of the connecting shaft, and zero-gap connection between the connecting spline and the output shaft of the aircraft servo is achieved by tightening the screw.

[0016] As a preferred embodiment of the precision correction device of the present invention, the servo mounting platform is a replaceable module for adapting to the aircraft servos with different mechanical shapes; the angle calibration component supports at least two communication interfaces, including a controller area network bus and a serial port.

[0017] A precision correction method for aircraft servo control surfaces, applied to the aforementioned precision correction device, characterized by comprising the following steps: The aircraft servo is mounted on the servo mounting platform, and the output shaft of the aircraft servo is rigidly connected to the high-precision encoder through a connecting shaft.

[0018] The aircraft's servo motor is driven by an angle calibrator to rotate from the negative limit angle to the positive limit angle, and multiple calibration points are generated at set angle intervals.

[0019] At each calibration point, the aircraft servo stays for a preset dwell time.

[0020] During the dwell time, the angle values ​​fed back by the potentiometer inside the aircraft's servo motor and the actual angle values ​​of the high-precision encoder are collected simultaneously.

[0021] The difference between the potentiometer feedback angle value and the actual angle value of the high-precision encoder at each calibration point is calculated as the correction error of the calibration point.

[0022] The correction error of each calibration point is written into the non-volatile memory inside the aircraft's servo motor.

[0023] During subsequent operation of the aircraft servo, based on the current potentiometer feedback angle value, and utilizing the correction error of each calibration point, the corresponding error compensation value is calculated based on the calibration point range where the current potentiometer feedback angle value is located, thereby correcting the potentiometer feedback angle value and improving the control accuracy of the aircraft servo on the control surfaces.

[0024] In a preferred embodiment of the precision correction device of the present invention, during the dwell time of each calibration point, multiple sampling points are collected, the average value of the potentiometer feedback angle value and the average value of the actual angle value of the high-precision encoder are calculated, and the correction error is calculated by the average value of the potentiometer feedback angle value and the average value of the actual angle value of the high-precision encoder to eliminate the influence of angle acquisition noise.

[0025] As a preferred embodiment of the precision correction device of the present invention, it further includes the static state identification step of the aircraft servo motor: Before calibration begins, a static angle data sample of the same duration as the dwell time is collected, the variance of the static angle data sample is calculated, and the variance is used as the static detection threshold.

[0026] During the calibration process, for the data sequence collected during the dwell time of each calibration point, the variance magnitude is calculated. If the variance magnitude is less than the static detection threshold, it is determined that the aircraft servo is in a stationary state, and the data sequence is used for error correction calculation; otherwise, the data sequence is discarded.

[0027] In a preferred embodiment of the accuracy correction device of the present invention, the variance amplitude is the square root of the sum of squares of each sampling point in the data sequence.

[0028] A precision correction system for aircraft servo control surfaces, applied to the aforementioned precision correction device, is characterized by comprising a computer, wherein angle calibration software is installed on the computer and connected to an angle calibrator via a serial communication interface; the angle calibration software is used to set calibration parameters, receive potentiometer feedback angle values ​​and encoder actual angle values ​​returned by the angle calibrator, automatically calculate correction errors, and write the correction parameters into the aircraft servo via the angle calibrator.

[0029] The beneficial effects of this invention are as follows: This technical solution integrates a coaxially mounted servo mounting platform, a high-precision encoder, and a connecting shaft on a base. Combined with an angle calibration component, it automatically acquires and corrects the deviation between the servo's internal potentiometer feedback value and the actual angle. This significantly improves the servo's control accuracy over the aircraft's control surfaces without requiring any replacement of internal hardware, effectively overcoming the large-angle nonlinear error problem caused by poor linearity of internal potentiometers in existing low-cost servos. This technical solution eliminates mechanical transmission backlash and installation eccentricity through a split-type spline connection, a slotted locking structure, and dual coaxiality of bearings and locating pins, ensuring the authenticity of the calibration data. Furthermore, the servo mounting platform adopts a replaceable modular design, and the angle calibration component supports multiple communication interfaces such as Controller Area Network (CAN) bus and serial port, allowing the same device to adapt to servos with different mechanical shapes and electrical protocols, greatly reducing equipment investment costs for production lines. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the overall structure of the accuracy correction device in this embodiment is shown; Figure 2 A side view of the accuracy correction device of this embodiment is shown. Figure 3 A cross-sectional schematic diagram of the overall structure of the accuracy correction device in this embodiment is shown; Figure 4 A schematic diagram of the connecting shaft structure of this embodiment is shown; Figure 5 A flowchart illustrating the accuracy correction method of this embodiment is shown.

[0032] Reference numerals: 1. Base; 2. Handle; 3. Servo mounting platform; 4. Connecting shaft; 5. Encoder mounting base; 6. High-precision encoder; 7. Angle calibration assembly; 8. Positioning pin; 9. Bearing cover; 10. Mounting bearing; 11. Connecting spline; 12. Connecting pin; 13. Aircraft servo. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0034] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0035] Example 1, referring to Figures 1-4 A precision correction device for aircraft servo control surfaces is provided, the device including a base.

[0036] Servo mounting platform, which is set on the base, is used to fix the aircraft servos.

[0037] Encoder mounting bracket, which is mounted on the base.

[0038] A high-precision encoder, which is mounted on an encoder mount.

[0039] The connecting shaft has one end connected to the output shaft of the aircraft servo and the other end connected to the input shaft of the high-precision encoder; the connecting shaft, the aircraft servo, and the high-precision encoder are coaxially arranged.

[0040] An angle calibration component is electrically connected to the aircraft servo and the high-precision encoder respectively, and is used to drive the aircraft servo to rotate. The angle calibration component collects the feedback angle signal from the potentiometer inside the aircraft servo and the actual angle signal from the high-precision encoder. Based on the difference between the feedback angle signal and the actual angle signal, a correction parameter is generated and written into the memory inside the aircraft servo.

[0041] The device includes a base that serves as a support for the entire assembly. A servo mounting platform is fixed to the base, used to mount the aircraft servo to be calibrated. The servo is secured to the platform with bolts or quick-clamp mechanisms. An encoder mounting bracket is also fixed to the base, on which a high-precision encoder (e.g., a 17-bit photoelectric encoder or a high-resolution magnetic encoder) is mounted. One end of a connecting shaft is connected to the output shaft of the aircraft servo via a spline or coupling, and the other end is connected to the input shaft of the high-precision encoder via a set screw or clamping sleeve. Throughout the assembly process, the relative positions of the encoder mounting bracket and the servo mounting platform are adjusted to ensure that the connecting shaft, the servo output shaft, and the high-precision encoder input shaft are on the same axis, i.e., coaxially aligned. The angle calibration component consists of an angle calibrator and a host computer. The angle calibrator is connected via cables to the servo's signal interface (e.g., pulse width modulation (PWM) signal, CAN, or serial port) and the high-precision encoder's output interface. The angle calibration component first drives the servo to rotate according to a preset angle sequence. During rotation, it simultaneously acquires the angle signal fed back by the servo's internal potentiometer (or low-precision magnetic encoder) and the actual angle signal output by the high-precision encoder. Then, it calculates the difference between the two at the same commanded angle, using it as the correction parameter for that angle point. Finally, the correction parameter is written to the servo's internal non-volatile memory (such as EEPROM or Flash) via a communication interface. After completing the above operations, the servo can be used independently without the calibration device. In subsequent operation, it uses the stored correction parameters to correct the feedback value in real time, thereby improving the control accuracy of the aircraft's control surfaces.

[0042] Furthermore, the encoder mounting base is provided with bearing mounting holes, mounting brackets, and mounting bearings; the bearing mounting holes and mounting brackets are formed by the same clamping process, and the high-precision encoder is mounted on the mounting bracket by at least one locating pin; the mounting bearing is fixed in the bearing mounting holes.

[0043] The encoder mounting base features an integrally formed bearing mounting hole and mounting bracket. The bearing mounting hole is a precision round hole for mounting rolling bearings (such as deep groove ball bearings), with the bearing outer ring interfering with the hole wall. The mounting bracket is a plane or boss perpendicular to the axis of the bearing mounting hole, used to fix the high-precision encoder. To ensure the coaxiality of the high-precision encoder and the servo motor output shaft, the encoder positioning surfaces on the bearing mounting hole and mounting bracket are machined in the same clamping operation. For example, on a CNC machining center, without changing the workpiece clamping position, the bearing mounting hole is machined first, and then the positioning surface of the mounting bracket is machined, thus ensuring that the perpendicularity and positional error of the axes of both are less than 0.01mm. The high-precision encoder is mounted on the mounting bracket by at least one high-precision locating pin. The locating pin is inserted into the locating hole on the encoder housing and the locating pin hole on the mounting bracket to achieve angular positioning. Simultaneously, the mounting bearing is fixed in the bearing mounting hole, and the connecting shaft passes through the inner ring of the bearing, with the bearing providing radial support and rotational guidance. By employing dual control—bearing positioning (limiting the radial runout of the connecting shaft) and high-precision positioning pin positioning (limiting the encoder's installation position offset)—the coaxiality between the high-precision encoder and the servo motor output shaft is reliably guaranteed, avoiding angle measurement errors caused by eccentricity.

[0044] Furthermore, the connecting shaft is connected to the output shaft of the aircraft servo via a split-type connecting spline, which is fixed to one end of the connecting shaft by two connecting pins and a tight fit.

[0045] Since the spline specifications of different servo output shafts vary, and the machining cost of integral splines is high, this implementation adopts a split design: the main body of the connecting shaft is a smooth shaft or stepped shaft, with a cylindrical connector machined at one end; a separate connecting spline is provided, the inner hole of which matches the outer spline of the servo output shaft, and its outer circle matches the cylindrical connector at the end of the connecting shaft. The connecting spline is fixed to one end of the connecting shaft by two connecting pins and a tight fit. Specifically, two radial pin holes are drilled on the cylindrical connector at the end of the connecting shaft, and corresponding pin holes are also drilled on the connecting spline. After the connecting spline is fitted into the cylindrical connector, two cylindrical pins or elastic pins are hammered in to achieve anti-rotation and axial fixation. At the same time, an H7 / k6 grade interference fit is used between the inner hole of the cylindrical connector and the connecting spline to further ensure the rigidity of the connection. This split structure allows for the replacement of only the connecting spline for servos with different spline specifications, without the need to re-machine the entire connecting shaft. This reduces the machining difficulty and manufacturing cost of the spline, while improving the machining accuracy of the spline.

[0046] Furthermore, the output shaft interface connecting the spline and the connecting shaft is provided with a slot and a screw, and zero-gap connection between the connecting spline and the output shaft of the aircraft servo is achieved by tightening the screw.

[0047] The servo interface connecting the spline (i.e., the internal spline hole that mates with the servo output shaft) features a 1mm wide axial slot. This slot extends axially from the spline end face, providing a certain elastic shrinkage capability for this section of the inner hole. Similarly, the interface connecting the connecting shaft and the servo output shaft (i.e., the blind or through hole at the end of the connecting shaft used to accommodate the servo output shaft) also features a 1mm wide axial slot. When installing the servo, the servo output shaft is first inserted into the internal spline hole of the connecting spline. Then, a radial screw is tightened on the side of the connecting spline. The tightening of the screw brings the two sides of the slot closer together, slightly reducing the inner diameter of the hole, thus eliminating the radial clearance between the servo output shaft and the servo output shaft, achieving a zero-clearance connection. The same structure can also be used at the connection between the connecting shaft and the high-precision encoder input shaft. This slotted and screw-locking method completely eliminates mechanical backlash errors in the transmission chain, ensuring that every minute rotation of the servo output shaft is transmitted to the high-precision encoder without loss, improving the accuracy of the calibration data.

[0048] Furthermore, the servo mounting platform is a replaceable module to adapt to servos of aircraft with different mechanical shapes; the angle calibration component supports at least two communication interfaces, including the controller area network bus and serial port.

[0049] The servo mounting platform is designed as a replaceable modular component: the base has pre-drilled standardized mounting interfaces (e.g., a set of rectangularly distributed threaded holes or T-slots), and different servo shapes correspond to different servo mounting platforms with varying shapes and mounting hole positions. When calibrating a different servo model, simply remove the original servo mounting platform and replace it with one that matches the new servo model; core components such as the base, encoder mount, and connecting shaft do not need to be replaced. Simultaneously, the angle calibration component supports at least two communication interfaces, including CAN bus and RS422 serial port. The angle calibrator integrates a CAN transceiver and a serial transceiver, allowing software selection of the communication protocol used by the current servo. For servos supporting CAN communication, the angle calibrator uses the CAN interface to send angle commands and receive feedback; for servos supporting only serial communication, it switches to the serial channel. This modular electrical design allows a single calibration device to cover the vast majority of aircraft servos on the market, eliminating the need to purchase separate calibration equipment for each servo and significantly reducing equipment investment costs for the production line.

[0050] Example 2, refer to Figure 5 A precision correction method for aircraft servo control surfaces, applied to the aforementioned precision correction device, includes the following steps: The aircraft servo is mounted on the servo mounting platform, and the output shaft of the aircraft servo is rigidly connected to the high-precision encoder through a connecting shaft. The aircraft servo motor is driven to rotate from the negative limit angle to the positive limit angle by an angle calibrator, and multiple calibration points are generated at set angle intervals. At each calibration point, the aircraft's servos remain at a preset dwell time; During the dwell time, the angle values ​​fed back by the potentiometer inside the aircraft's servo motor and the actual angle values ​​of the high-precision encoder are collected simultaneously. Calculate the difference between the potentiometer feedback angle value and the actual angle value of the high-precision encoder at each calibration point, and use it as the correction error of the calibration point; The correction errors at each calibration point are written into the non-volatile memory inside the aircraft's servo motor; During subsequent operation of the aircraft servo, based on the current potentiometer feedback angle value, and utilizing the correction error of each calibration point, the corresponding error compensation value is calculated based on the calibration point range where the current potentiometer feedback angle value is located, thereby correcting the potentiometer feedback angle value and improving the control accuracy of the aircraft servo on the control surfaces.

[0051] First, the servo motor to be calibrated is mounted on a servo motor mounting platform. The output shaft of the servo motor is rigidly connected to the input shaft of a high-precision encoder via a connecting shaft, ensuring no relative slippage between the two. Then, an angle calibrator drives the servo motor to rotate uniformly or in steps from the negative limit angle (e.g., -60°) to the positive limit angle (e.g., +60°). Within this travel range, a series of calibration points are generated at set angle intervals (e.g., 5°), namely -60°, -55°, -50°...+60°, for a total of 25 points. At each calibration point, the angle calibrator controls the servo motor to stop moving and pause for a preset dwell time (e.g., 2 seconds) to stabilize the internal mechanical structure of the servo motor and eliminate the effects of motion inertia. During the dwell time, the angle calibrator simultaneously acquires two signals at a high sampling frequency (e.g., 1000Hz): one is the angle value fed back from the potentiometer inside the servo motor (denoted as angle_fb), and the other is the angle value measured by the high-precision encoder (denoted as angle_encoder). For each calibration point, the average of multiple sets of collected angle_fb and angle_encoder values ​​is calculated, and then the difference, error_X = average(angle_fb) - average(angle_encoder), is calculated. This difference represents the correction error of the servo's internal sensor relative to the true angle at that calibration point. The correction errors of all calibration points (a total of 25 values) are compiled into an error table and written to the servo's internal non-volatile memory via the angle calibrator's communication interface. During subsequent normal operation, after each reading of the potentiometer's original feedback angle value, the servo first determines which two adjacent calibration points in the error table the original value falls between. Then, a linear interpolation method is used to calculate the error compensation value corresponding to the current angle. Finally, the original feedback angle is subtracted from the compensation value to obtain the corrected angle for closed-loop control. In this way, the servo's control accuracy over the aircraft's control surfaces is significantly improved, and nonlinear errors are effectively suppressed.

[0052] Furthermore, during the dwell time at each calibration point, multiple sampling points are collected, and the average value of the potentiometer feedback angle and the average value of the actual angle of the high-precision encoder are calculated. The correction error is calculated using the average value of the potentiometer feedback angle and the average value of the actual angle of the high-precision encoder to eliminate the influence of angle acquisition noise.

[0053] During the dwell time T_X at each calibration point, the angle calibrator does not collect just one pair of data, but continuously collects N sampling points (e.g., N=200, corresponding to one sampling every 10 milliseconds within 2 seconds). For each of these N sampling points, the potentiometer feedback angle value angle_fb_i and the actual angle value angle_encoder_i of the high-precision encoder are recorded, where i=1~N. Then, the arithmetic mean of these two sets of data is calculated: mean_fb = (1 / N)*Σangle_fb_i, mean_encoder = (1 / N)*Σangle_encoder_i. These two means are used as the representative values ​​of the calibration point, and the correction error error_X = mean_fb - mean_encoder is calculated. Since random noise (such as electrical interference, quantization error, etc.) exhibits a zero-mean distribution in multiple samplings, the noise cancels out after averaging, making the correction error closer to the true value. Experiments show that by using the mean method, the standard deviation of the error table obtained by repeated calibration of the same servo motor can be reduced to less than 30% of that obtained by the original single-point sampling method, which significantly improves the consistency and reliability of the calibration results.

[0054] Furthermore, it also includes a static state identification step for the aircraft servo: before calibration begins, a static angle data sample of the same duration as the dwell time is collected, the variance of the static angle data sample is calculated, and the variance is used as the static detection threshold; during calibration, for the data sequence collected during the dwell time of each calibration point, the variance is calculated, if the variance is less than the static detection threshold, the aircraft servo is determined to be in a stationary state, and the data sequence is used for error correction calculation; otherwise, the data sequence is discarded.

[0055] This method introduces a variance-based static state identification step for the servo motor to avoid incorrectly using dynamic data from when the servo motor is not completely stationary for error correction calculations. The specific steps are as follows: Before formal calibration begins, static threshold learning is performed first. At this time, the servo motor is installed on the device but not yet powered on or rotating. The angle calibrator collects a segment of static angle data of the same length as the dwell time at the calibration point (e.g., 2 seconds). This data comes from the servo motor's internal potentiometer (or may also come from a high-precision encoder), denoted as angle_fb_static_i, i=1~n (n=200). The variance amplitude ξ of this static data is calculated using the formula:

[0056] The ξ value reflects the natural fluctuation amplitude of the servo signal when it is completely stationary (mainly caused by electrical noise). Then, during the dwell time at each calibration point in the formal calibration, the angle calibrator also collects a continuous data sequence (length n) and calculates the variance amplitude ξ_data of this data sequence. ξ_data is compared with a pre-measured threshold ξ: if ξ_data < ξ, the servo is determined to be truly stationary during that dwell time period, and all sampling points in this data sequence are used for subsequent mean calculation and error correction calculation; if ξ_data ≥ ξ, the servo is determined to still be in motion or exhibit abnormal jitter, and this data sequence is automatically discarded and not used for error calculation. The angle calibration software can then control the servo to return to the calibration point and remain stationary again until valid stationary data is collected. This method is fully automated, requiring no manual observation or intervention, effectively preventing calibration errors introduced by the servo's incomplete stabilization during the calibration process.

[0057] Furthermore, the variance magnitude is the square root of the sum of squares of each sampling point in the data sequence.

[0058] In this embodiment, the specific formula for calculating the variance amplitude is defined. Let a continuous data sequence have n sampling points, denoted as x1, x2, …, x… n The variance magnitude ξ of the data sequence is defined as the square root of the sum of squares of each sampling point. This definition is equivalent to calculating the L2 norm (Euclidean norm) of the sequence, which comprehensively reflects the energy magnitude of all sampling points in the sequence. For static data sequences, since each sampling point only fluctuates slightly near the noise floor, its sum of squares is small, and therefore ξ is small. For dynamic data sequences (such as a servo motor that is rotating or has just stopped but is still vibrating), the sampling point values ​​change drastically, the sum of squares increases significantly, and ξ also increases accordingly. By setting a reasonable threshold (e.g., multiplying the statically learned ξ_static by a coefficient slightly greater than 1), static and dynamic data can be clearly distinguished. This calculation method is simple and efficient, suitable for real-time execution in embedded angle calibrators, without the need for complex Fourier transforms or filtering algorithms.

[0059] Example 3: An aircraft servo control surface control accuracy correction system, applied to the above-mentioned accuracy correction device, includes a computer, on which angle calibration software is installed and connected to an angle calibrator via a serial communication interface; the angle calibration software is used to set calibration parameters, receive potentiometer feedback angle values ​​and encoder actual angle values ​​returned by the angle calibrator, automatically calculate correction errors, and write the correction parameters into the aircraft servo via the angle calibrator.

[0060] The system includes a personal computer or industrial control computer with specially developed angle calibration software installed. The computer connects to the angle calibrator via an RS422 serial communication interface, and the angle calibrator is connected to the servo motor to be calibrated and a high-precision encoder via cables. The angle calibration software has a graphical user interface, allowing users to set calibration parameters, including: negative and positive limits of the calibration stroke (e.g., -60° and +60°), calibration angle interval (e.g., 5°), dwell time at each calibration point (e.g., 2 seconds), servo command transmission cycle (e.g., 10ms), and servo motor communication protocol type (CAN or serial port). After setting, the software automatically generates a calibration angle sequence. When the user clicks the "Start Calibration" button, the software sends the calibration start command and parameters to the angle calibrator via the serial port. The angle calibrator then controls the servo motor power relay to turn on and sends angle commands according to the sequence. During calibration, the angle calibrator returns real-time angle values ​​from the servo motor potentiometer and the actual angle values ​​from the encoder. The software dynamically displays these data in curve and table format on the interface and automatically saves them to the hard drive. After calibration, the software automatically calculates the correction error for each calibration point based on the received complete dataset and generates an error table. After the user clicks the "Download Calibration Parameters" button, the software writes the error table into the servo's Flash memory using an angle calibrator. Once written, the software can also perform a verification test, i.e., re-drive the servo to rotate and compare the angle errors before and after calibration to confirm the calibration effect. The entire system achieves full automation of the calibration process, eliminating the need for manual data recording or parameter calculation, greatly improving production efficiency.

[0061] The bearing mounting holes and mounting bracket on the encoder mounting base of this invention are machined in a single clamping process. Combined with the dual positioning of high-precision positioning pins and mounting bearings, the coaxiality error between the high-precision encoder and the servo motor output shaft is controlled within 0.01mm, fundamentally ensuring the reference accuracy of angle acquisition. The connecting shaft and the servo motor output shaft are fixed using a split-type spline connection and two connecting pins with an interference fit, reducing the difficulty and cost of spline machining and facilitating quick replacement according to different servo motor types. Furthermore, a 1mm groove is pre-reserved at the interface between the connecting spline and the connecting shaft, and screws are used for locking, achieving a zero-clearance connection with the servo motor output shaft and completely eliminating transmission backlash error. In terms of calibration methods, the average of multiple sampling points is used to calculate the time spent at each calibration point, effectively suppressing electrical noise and quantization errors, reducing the standard deviation of repeatability in multiple calibrations to less than 30% of that of the single-point sampling method. Furthermore, by employing a static state identification method based on variance amplitude, the system automatically learns static thresholds and determines the stationary state of the servo motor in real time, eliminating dynamic jitter data, preventing calibration parameter distortion, and reducing calibration repeatability error by more than 70%. Finally, the automated system, consisting of a computer integrating angle calibration software and an angle calibrator, achieves unmanned operation throughout the entire process of calibration parameter setting, data acquisition, error calculation, parameter programming, and verification testing, significantly improving production efficiency. Experiments show that, after adopting the specific implementation method of this invention, the servo motor's angle error within the ±60° operating range is reduced from ±2.5° before correction to within ±0.3°, resulting in a qualitative improvement in the aircraft control surface deflection accuracy.

[0062] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0063] Furthermore, to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features not relevant to the currently considered best mode for carrying out the invention, or those features not relevant to implementing the invention) may be omitted. It should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention and not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A precision correction device for aircraft servo control surfaces, characterized in that: include, Base; and, A servo mounting platform, which is set on the base, is used to fix the aircraft servo; An encoder mounting base is disposed on the base; A high-precision encoder is mounted on the encoder mounting base; A connecting shaft, one end of which is connected to the output shaft of the aircraft servo, and the other end of which is connected to the input shaft of the high-precision encoder; the connecting shaft, the aircraft servo, and the high-precision encoder are coaxially arranged. An angle calibration component is electrically connected to the aircraft servo and the high-precision encoder, respectively, and is used to drive the aircraft servo to rotate. The angle calibration component collects the feedback angle signal from the potentiometer inside the aircraft servo and the actual angle signal from the high-precision encoder. It generates a correction parameter based on the difference between the feedback angle signal and the actual angle signal and writes the correction parameter into the memory inside the aircraft servo.

2. The accuracy correction device according to claim 1, characterized in that: The encoder mounting base is provided with a bearing mounting hole, a mounting bracket, and a mounting bearing; the bearing mounting hole and the mounting bracket are formed by the same clamping process, and the high-precision encoder is mounted on the mounting bracket by at least one locating pin; the mounting bearing is fixed in the bearing mounting hole.

3. The accuracy correction device according to claim 1, characterized in that: The connecting shaft is connected to the output shaft of the aircraft servo via a split-type connecting spline, and the connecting spline is fixed to one end of the connecting shaft by two connecting pins and a tight fit.

4. The accuracy correction device according to claim 3, characterized in that: The interface between the connecting spline and the output shaft of the connecting shaft is provided with a slot and a screw. By tightening the screw, a zero-gap connection is achieved between the connecting spline and the output shaft of the aircraft servo.

5. The accuracy correction device according to claim 1, characterized in that: The servo mounting platform is a replaceable module used to adapt to the aircraft servos with different mechanical shapes; the angle calibration component supports at least two communication interfaces, including a controller area network bus and a serial port.

6. A method for precision correction of aircraft servo control surfaces, applied to the precision correction device as described in claims 1 to 5, characterized in that, Includes the following steps: The aircraft servo motor is mounted on the servo motor mounting platform, and the output shaft of the aircraft servo motor is rigidly connected to a high-precision encoder via a connecting shaft. The aircraft servo motor is driven to rotate from the negative limit angle to the positive limit angle by an angle calibrator, and multiple calibration points are generated at set angle intervals. At each calibration point, the aircraft servo motors remain for a preset dwell time; During the dwell time, the angle values ​​fed back by the potentiometer inside the aircraft's servo motor and the actual angle values ​​of the high-precision encoder are collected simultaneously. Calculate the difference between the potentiometer feedback angle value and the actual angle value of the high-precision encoder at each calibration point, and use it as the correction error of the calibration point; The correction error of each calibration point is written into the non-volatile memory inside the aircraft's servo motor; During subsequent operation of the aircraft servo, based on the current potentiometer feedback angle value, and utilizing the correction error of each calibration point, the corresponding error compensation value is calculated based on the calibration point range where the current potentiometer feedback angle value is located, thereby correcting the potentiometer feedback angle value and improving the control accuracy of the aircraft servo on the control surfaces.

7. The accuracy correction method according to claim 6, characterized in that: During the dwell time of each calibration point, multiple sampling points are collected, and the average value of the potentiometer feedback angle and the average value of the actual angle of the high-precision encoder are calculated. The correction error is calculated using the average value of the potentiometer feedback angle and the average value of the actual angle of the high-precision encoder to eliminate the influence of angle acquisition noise.

8. The accuracy correction method according to claim 7, characterized in that: It also includes the aircraft servo static state identification step: Before calibration begins, a static angle data sample of the same duration as the dwell time is collected, the variance of the static angle data sample is calculated, and the variance is used as the static detection threshold. During the calibration process, for the data sequence collected during the dwell time of each calibration point, the variance magnitude is calculated. If the variance magnitude is less than the static detection threshold, it is determined that the aircraft servo is in a stationary state, and the data sequence is used for error correction calculation; otherwise, the data sequence is discarded.

9. The accuracy correction method according to claim 8, characterized in that: The variance magnitude is the square root of the sum of squares of each of the sampling points in the data sequence.

10. A precision correction system for aircraft servo control surfaces, applied to the precision correction device described in claims 1 to 5, characterized in that, The system includes a computer with angle calibration software installed on it, which is connected to an angle calibrator via a serial communication interface. The angle calibration software is used to set calibration parameters, receive potentiometer feedback angle values ​​and encoder actual angle values ​​returned by the angle calibrator, automatically calculate and correct errors, and write the correction parameters into the aircraft servo motors via the angle calibrator.

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