A high-load, high-precision, reset-type automatic calibration system for balances

Abstract

This invention discloses a high-load, high-precision, reset-type automatic calibration system for a balance. Each automatic loading subsystem uses a screw jack to lift and lower weights, transferring different weight forces through a boom to a steel belt and then to a loading head. The loading head then transfers the load to the balance being calibrated, achieving multi-component load application. Displacement sensors measure distance changes at various locations and calculate the deformation. The reset subsystem adjusts and resets the balance's attitude. Each subsystem has a compact structure and clearly defined functions. The reset subsystem maximizes the use of the advanced performance of servo motors, making the reset accuracy of linear displacement equivalent to the motion accuracy of the servo motor, and the reset accuracy of angular displacement is also improved accordingly. The control logic of each subsystem, including the reset subsystem, automatic loading system, and displacement measurement system, is simple and easy to integrate, achieving automated calibration and significantly improving calibration efficiency while freeing up manpower.

Description

Technical Field

[0001] This application relates to the technical field of aerospace wind tunnel balance calibration, and in particular to a high-load, high-precision, reset-type automatic balance calibration system. Background Technology

[0002] The main purpose of wind tunnel balance calibration is to determine the relationship between balance readings and loads, i.e., to obtain the balance calibration formula. In wind tunnel force measurement tests, aerodynamic loads can be calculated based on balance readings collected from the aircraft at different attitudes, using the calibration formula. Therefore, the accuracy of the balance calibration directly determines the accuracy of the aerodynamic data from the wind tunnel test, and a high-precision balance calibration system is a prerequisite for obtaining a high-precision balance formula.

[0003] In the process of balance calibration, the current mainstream approach is to load the balance according to the balance coordinate system, thereby obtaining a body-axis balance calibration formula based on the balance coordinate system. However, due to the stiffness issues of the balance and its support system, the balance inevitably deforms under load, causing the loading coordinate system and the balance coordinate system to no longer coincide. At this point, it is necessary to restore the balance attitude to its state before loading, i.e., to achieve balance reset. The reset mechanism of the balance calibration is the core device for achieving balance reset. It is required that the mechanism can simultaneously have the motion capability of linear displacement in three directions and angular displacement in three directions to ensure that the balance attitude can be completely reset. The motion accuracy of the reset mechanism directly determines the accuracy of the balance attitude; therefore, a high-precision motion mechanism is the core content of the development of the reset mechanism.

[0004] In addition to the above, the reset process of balance calibration involves measuring the balance's position and attitude, controlling the sequence of motion of each degree of freedom of the reset mechanism, and, under heavy load conditions, controlling the loading and unloading of each loading subsystem. The calibration process involves numerous steps, and manual control of each step inevitably leads to operational errors, potentially causing damage to the balance due to impact. Therefore, to avoid potential errors during manual control and improve the efficiency of balance calibration, fully automated loading is an inevitable trend for heavy load reset calibration systems, which places higher demands on the control of the balance calibration system. Summary of the Invention

[0005] This application provides a high-precision reset-type balance automatic calibration system with large load capacity. It proposes a high-precision reset-type balance calibration system with an advanced reset mechanism and a flexible control system, which solves the problems of high-precision reset and full automation in balance calibration systems, and realizes high-precision automatic calibration of large load balances with reset capability.

[0006] In the first aspect, a high-load, high-precision reset-type automatic calibration system for a balance is provided, including a reset subsystem, six automatic loading subsystems, five load reversal subsystems, a balance mounting subsystem, a displacement measurement subsystem, a test bench, and a control system;

[0007] The reset subsystem is located at the center of the calibration system and is connected to the balance mounting subsystem. It is used to adjust the attitude of the balance mounting subsystem.

[0008] The balance mounting subsystem is used to set up the balance being calibrated.

[0009] Six automatic loading subsystems are distributed around the balance mounting subsystem along the top, bottom, left, right, front, and rear directions, respectively. Five load reversing subsystems include a 180° load reversing subsystem, a first 90° load reversing subsystem, a second 90° load reversing subsystem, a third 90° load reversing subsystem, and a fourth 90° load reversing subsystem. The downward-distributed automatic loading subsystems are directly connected to the balance mounting subsystem to apply downward loads, while the upward-distributed automatic loading subsystems are connected to the balance mounting subsystem via the 180° load reversing subsystems to apply upward loads. The automatic loading subsystems distributed on the left side are connected to the balance mounting subsystem via the first 90° load reversing subsystem to apply a horizontal load to the left; the automatic loading subsystems distributed on the right side are connected to the balance mounting subsystem via the second 90° load reversing subsystem to apply a horizontal load to the right; the automatic loading subsystems distributed on the front side are connected to the balance mounting subsystem via the third 90° load reversing subsystem to apply a horizontal load to the front; and the automatic loading subsystems distributed on the rear side are connected to the balance mounting subsystem via the fourth 90° load reversing subsystem to apply a horizontal load to the rear.

[0010] The displacement measurement subsystem is used to monitor the attitude changes of the balance mounting subsystem;

[0011] The platform is used to support the automatic loading subsystem and also provides an aerial work platform for the operator;

[0012] The control system is used to realize the parameter measurement and control of various subsystems.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the reset subsystem includes a roll mechanism, an axial motion mechanism, a pitch and normal motion mechanism, and a yaw and lateral motion mechanism; the roll mechanism, axial motion mechanism, pitch and normal motion mechanism, and yaw and lateral motion mechanism are connected together in series; from top to bottom, the roll mechanism is mounted on the axial motion mechanism, the bottom of the axial motion mechanism is connected to the pitch and normal motion mechanism, and the pitch and normal motion mechanism is connected to the yaw and lateral motion mechanism through its base;

[0014] The roll angle of the balance to be calibrated is adjusted and reset through the roll mechanism, the axial displacement of the balance to be calibrated is adjusted and reset through the axial motion mechanism, the normal displacement and pitch angle of the balance to be calibrated are adjusted and reset through the pitch and normal motion mechanism, and the lateral displacement and yaw angle of the balance to be calibrated are adjusted and reset through the yaw and lateral motion mechanism.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the automatic loading subsystem includes a weight string and a weight lifting mechanism. The weight string serves as the source of load applied during balance calibration. The entire weight string is placed on the weight lifting mechanism, which drives the weight string to rise and fall. The weight string includes a steel belt, a lifting rod, weights, and a counterweight pan. The weight lifting mechanism includes a bracket, a tray, a slide rail, and a screw jack. The counterweight pan hangs freely at the bottom, connected to the lifting rod above, and the lifting rod is connected to one end of the steel belt. If the automatic loading subsystem is downwardly distributed... The automatic loading subsystem connects the other end of the steel belt to the balance mounting subsystem. If the automatic loading subsystem is an upward, left-side, right-side, front-side, or rear-side distributed automatic loading subsystem, the other end of the steel belt connects to the corresponding load reversing subsystem. The weights consist of multiple weight blocks stacked vertically and distributed along the lifting rod. The tray is below the weights and supports all the weight blocks. The tray is connected to the lower part of the support via a slide rail. The tray is connected to the screw of the screw jack, which is fixed to the bottom of the support.

[0016] When the automatic loading subsystem is working, the counterweight plate, boom, and steel belt do not move actively. The screw jack drives the pallet to move up and down, which in turn drives the weights on the pallet to move up and down, causing relative movement between the weight blocks and the boom. When the pallet lowers the weights, each weight block detaches from the other weight blocks from top to bottom and is suspended on the boom. The weight of the weights is then transferred to the balance installation subsystem through the boom and steel belt to achieve loading. When the pallet raises the weights, each weight block detaches from the boom from bottom to top and is stacked back together, finally resting on the pallet to achieve unloading. The counterweight plate is manually suspended by the weights, which straighten the steel belt by their weight.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the load reversing subsystem includes a platform, a base, a pulley support, a pulley, and a screw; the platform is a steel frame structure, with its lower surface mounted on the ground and its uppermost surface being a reference platform with a slide rail; the base is mounted on the reference platform and moves along the slide rail of the reference platform to achieve position adjustment; the pulley support is mounted on one side of the base; the pulley is mounted on the pulley support via bearings and achieves low-friction rotation around the pulley axis; the pulley height is adjusted by the screw, and after adjustment, the pulley support is locked to the base by screws to limit the position of the pulley on the horizontal plane.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, the balance mounting subsystem includes a calibration support rod and a loading head; the calibration support rod is mounted on the reset subsystem, the first end of the balance being calibrated is mounted on the end of the calibration support rod away from the reset subsystem, and the second end of the balance being calibrated is disposed on the loading head;

[0019] The loading head has a sandwich structure, consisting of a split structure of an inner cylinder and a loading head body. The inner cylinder is used to connect to the balance being calibrated according to the specified interface of the balance and is fitted around the outer periphery of the rolling mechanism of the reset subsystem. The outer contour of the loading head body is provided with multiple corresponding interfaces for connecting the steel belt of the automatic loading subsystem, which is used to achieve connection with the steel belt. Under the traction of the steel belt, the loading head is subjected to loading forces in the up, down, left, right, forward and backward directions. The loading head body slides freely back and forth on the inner cylinder. After sliding to the designated position, it is pressed and locked by the screws on the clamp, fixing the relative position of the loading head body and the inner cylinder, so as to realize the adjustment of the loading center position relative to the balance.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the displacement measurement subsystem includes a cross-shaped target plate, a circular target plate, and laser displacement sensors; wherein the cross-shaped target plate is mounted on the upper surface of the loading head, the circular target plate is mounted on the front end face of the loading head, and the four ends of the cross-shaped target plate and the circular target plate are respectively used to receive laser displacement sensor signals from different directions; the laser displacement sensors include displacement sensor No. 1, displacement sensor No. 2, displacement sensor No. 3, displacement sensor No. 4, displacement sensor No. 5, displacement sensor No. 6, and displacement sensor No. 7; the seven laser displacement sensors are mounted on separate displacement sensor brackets and do not contact the loading head body or the target plate;

[0021] Displacement sensors 1 and 2 are arranged along the x-axis to detect the laser reflected from the first plane of the cross-shaped target plate; displacement sensors 3 and 4 are arranged along the x-axis to detect the laser reflected from the second plane of the cross-shaped target plate, which is perpendicular to the first plane; displacement sensors 5 and 6 are arranged along the y-axis to detect the laser reflected from the third plane of the cross-shaped target plate, which is parallel to the first plane; laser displacement sensor 7 is located at the foremost point of the cross-shaped target plate in the x-axis direction to detect the laser reflected from the circular target plate.

[0022] In conjunction with the first aspect, in some implementations of the first aspect, displacement sensor No. 1 and displacement sensor No. 2 are combined to measure displacement in the z-axis direction and rotation angle around the y-axis; displacement sensor No. 3 and displacement sensor No. 4 are combined to measure displacement in the y-axis direction and rotation angle around the z-axis; displacement sensor No. 5 and displacement sensor No. 6 are combined to measure rotation angle around the x-axis; and displacement sensor No. 7 is used to measure displacement in the x-axis direction.

[0023] In combination with the first aspect, in certain implementations of the first aspect, the test stand is a three - layer platform - type steel frame structure. The first - layer platform is used to place the reset subsystem, the downward - distributed automatic loading subsystem, the front - side - distributed automatic loading subsystem, the rear - side - distributed automatic loading subsystem, the left - side - distributed automatic loading subsystem, the right - side - distributed automatic loading subsystem, the first 90° load commutation subsystem, the second 90° load commutation subsystem, the third 90° load commutation subsystem, the fourth 90° load commutation subsystem, the balance installation subsystem, the displacement measurement subsystem, the test stand and the control system. The second - layer platform is used to place the upward - distributed automatic loading subsystem. The third - layer platform is used to install and place the 180° load commutation subsystem supporting the upward - distributed automatic loading subsystem. The test stand also includes stairs leading from the first - layer platform to the second - layer platform and the third - layer platform to facilitate the up - and - down movement of operators.

[0024] In combination with the first aspect, in certain implementations of the first aspect, the working process of the control system includes: after the control system receives a loading instruction, it first reads the six - component load of the load point, then distributes the loading loads to each loading subsystem according to the positional relationship of each loading subsystem, and executes the loading of each loading subsystem. After the loading is completed, the displacement measurement subsystem measures the displacement of each laser displacement sensor, calculates the linear displacement and angular displacement changes of the balance installation subsystem, and the attitude difference from the zero position. According to the attitude difference, the reset program is started. The reset subsystem controls the movement of each motion mechanism to reset the roll angle, pitch angle, yaw angle, X - direction linear displacement, Y - direction linear displacement and Z - direction linear displacement in sequence. At this time, one round of the reset program is completed. After each round of the reset program is completed, the readings of each laser displacement sensor are read again and the attitude difference from the zero position is recalculated. If it is greater than the threshold requirement, the reset program is started again. If it is less than the threshold requirement, the balance reading acquisition function is started. When acquiring the balance readings, it is judged whether there is vibration in the system accessories causing the balance readings to oscillate, and the acquisition is performed only after the balance readings are stable. After the balance reading acquisition is completed, the loading of this load point is completed.

[0025] In the second aspect, a method for using a large - load high - precision reset - type balance automatic calibration system is provided. The system is the system described in any of the implementations in the first aspect above. The method includes:

[0026] By controlling 6 automatic loading subsystems, under the load conversion of 5 load commutation subsystems, the load is transmitted to the balance installation subsystem, and the balance installation subsystem further transmits the load to the calibrated balance.

[0027] The displacement sensor of the displacement measurement subsystem measures the attitude change generated by the balance installation subsystem.

[0028] The balance attitude is adjusted and reset through the reset subsystem.

[0029] Compared with the prior art, the solution provided in this application has at least the following beneficial technical effects:

[0030] The high-load, high-precision reset-type balance automatic calibration system of the present invention includes a novel high-precision reset mechanism for balance calibration. It maximizes the use of the advanced performance of the servo motor, simplifies the structure to the greatest extent, and directly drives the lead screw and other actuators. Its linear displacement reset accuracy is equivalent to the motion accuracy of the servo motor, reaching up to 0.1μm, and its angular displacement reset accuracy can reach 0.1″.

[0031] The high-load, high-precision reset-type balance automatic calibration system of the present invention includes a reset subsystem, an automatic loading system, and a displacement measurement system. The control logic of each subsystem is simple and easy to integrate and control. It has high reset efficiency, short loading time, and can achieve automated calibration. While freeing up manpower, it greatly improves calibration efficiency. Attached Figure Description

[0032] Figure 1 This is a perspective view of the high-load, high-precision, reset-type automatic calibration system for balances described in this invention.

[0033] Figure 2 This is a perspective view of the reset subsystem described in this invention.

[0034] Figure 3 This is the main view of the automatic loading subsystem described in this invention.

[0035] Figure 4 This is a front view of the load commutation subsystem described in this invention.

[0036] Figure 5 This is a perspective view of the balance mounting subsystem described in this invention.

[0037] Figure 6 This is a schematic diagram of the displacement measurement system described in this invention.

[0038] Figure 7 This is a flowchart of the control system described in this invention. Detailed Implementation

[0039] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0040] This invention addresses the high precision requirements of balance calibration systems for resetting and the low calibration efficiency under heavy load conditions. It proposes a high-precision resetting automatic balance calibration system for heavy load conditions to achieve high-precision resetting automatic calibration.

[0041] like Figure 1 As shown, the high-load, high-precision reset-type balance automatic calibration system includes a reset subsystem 1, six automatic loading subsystems 2, five load reversing subsystems 3, a balance mounting subsystem 4, a displacement measurement subsystem 5, a test bench 6, and a control system 7.

[0042] The reset subsystem 1, located at the center of the calibration system and connected to the balance mounting subsystem 4, is used to adjust the attitude of the balance mounting subsystem 4. The displacement measurement subsystem 5, located beside the balance mounting subsystem 4, monitors changes in its attitude. Six automatic loading subsystems 2 are distributed around the balance mounting subsystem 4 along the top, bottom, left, right, front, and back. The downward-distributed automatic loading subsystems 2 are directly connected to the balance mounting subsystem 4; the upward, left-right, and front-back distributed automatic loading subsystems 2 are connected to the balance mounting subsystem 4 through their corresponding load reversing subsystems 3. All automatic loading subsystems 2 work together to load the balance mounting subsystem 4. The platform 6 supports one automatic loading subsystem 2 and provides an elevated operating platform for the operator. The control system 7 is used to measure and control the parameters of each subsystem.

[0043] refer to Figure 2 The reset subsystem 1 of this invention includes a roll mechanism 11, an axial motion mechanism 12, a pitch and normal motion mechanism 13, and a yaw and lateral motion mechanism 14. The roll mechanism 11, axial motion mechanism 12, pitch and normal motion mechanism 13, and yaw and lateral motion mechanism 14 are connected in series. From top to bottom, the roll mechanism 11 is mounted on the axial motion mechanism 12, the bottom of the axial motion mechanism 12 is connected to the pitch and normal motion mechanism 13, and the pitch and normal motion mechanism 13 is connected to the yaw and lateral motion mechanism 14 through its base.

[0044] Preferably, the roll mechanism 11, axial motion mechanism 12, pitch and normal motion mechanism 13, and yaw and lateral motion mechanism 14 are mainly composed of various types of components such as servo motors, brakes, ball screws, bearings, linear guides, and grating rulers, and are precisely assembled to form a motion mechanism with various degrees of freedom.

[0045] refer to Figure 3The automatic loading subsystem 2 of this invention includes a weight string and a weight lifting mechanism. The weight string serves as the source of load applied during balance calibration. The entire weight string is placed on the weight lifting mechanism, which drives the weight string to rise and fall. The weight string includes a steel strip 21, a lifting rod 23, weights 24, and a counterweight pan 27. The weight lifting mechanism includes a bracket 22, a tray 25, a slide rail 26, and a screw jack 28. The counterweight pan 27 hangs freely at the bottom, connected above the lifting rod 23, which is connected to one end of the steel strip 21. If the automatic loading subsystem 2 is a downward-distributed automatic loading subsystem 2, the other end of the steel strip 21 is connected to the balance mounting subsystem 4. If the automatic loading subsystem 2 is an upward-distributed, left-side-distributed, right-side-distributed, front-side-distributed, or rear-side-distributed automatic loading subsystem 2, the other end of the steel strip 21 is connected to the corresponding load reversing subsystem 3. The weights 24 consist of multiple weight blocks stacked vertically and distributed along the lifting rod 23. A tray 25 lies below the weights 24 and supports all the weight blocks. The tray 25 is connected to the lower part of the support 22 via a slide rail 26. Furthermore, the tray 25 is connected to the lead screw of a screw jack 28, which is fixed to the bottom of the support 22.

[0046] Preferably, in the automatic loading subsystem 2, during operation, the counterweight plate 27, the boom 23, and the steel belt 21 do not move actively; only the screw jack 28 drives the tray 25 to move up and down, further driving the weights 24 on the tray 25 to move up and down, causing relative movement between the weight blocks and the boom 23. When the tray 25 lowers the weights 24, each weight block of the weights 24 detaches from the other weight blocks sequentially from top to bottom and is suspended above the boom 23, further transferring the weight force to the balance mounting subsystem 4 through the boom 23 and the steel belt 21 to achieve loading. When the tray 25 raises the weights 24, each weight block detaches from the boom 23 sequentially from bottom to top and is stacked back together, finally resting on the tray 25 to achieve unloading. In addition, the counterweight plate 27 can be manually suspended independently, relying on the weight of the weights to straighten the steel belt 21.

[0047] refer to Figure 4 The load reversing subsystem 3 of this invention includes a reversing platform 31, a base 32, a pulley support 33, a pulley 34, and a screw 35. The reversing platform 31 is a steel frame structure, with its lower surface mounted on the ground and its uppermost surface being a reference platform with a slide rail. The base 32 is mounted on the reference platform and can be moved along the slide rail to adjust its position. The pulley support 33 is mounted on one side of the base 32. The pulley 34 is mounted on the pulley support 33 via bearings and can rotate around its axis with low friction. The screw 35 allows for height adjustment of the pulley 34. After adjustment, the pulley support 33 is locked to the base 32 with screws to limit the position of the pulley 34 on the horizontal plane.

[0048] The load reversing subsystem 3 of this invention is used in conjunction with the automatic loading subsystem 2. The automatic loading subsystem 2, whether distributed upwards, horizontally, or forwards and backwards, is equipped with the load reversing subsystem 3. The steel belt 21 of the automatic loading subsystem 2 directly overlaps the pulley 34 to achieve reversal. Specifically, in the upward-distributed automatic loading subsystem 2, the steel belt 21 contacts the upper semicircle of the pulley 34, achieving a 180° reversal and converting the gravity of the weight 24 into an upward pulling force. In the horizontally and forwards and backwards-distributed automatic loading subsystems 2, the steel belt 21 contacts the quarter circle of the pulley 34, achieving a 90° reversal and converting the gravity of the weight 24 into horizontal pulling forces to the left, right, forward, and backwards, respectively.

[0049] refer to Figure 5 The balance mounting subsystem 4 of the present invention includes a calibration support rod 41 and a loading head 43. The calibration support rod 41 is mounted on the rolling mechanism 11 of the reset subsystem 1. The first end of the balance to be calibrated 42 is mounted on the end of the calibration support rod 41 that is away from the reset subsystem 1, and the second end of the balance to be calibrated 42 is disposed on the loading head 43.

[0050] Preferably, the loading head 43 has a sandwich structure, which can be designed as a split structure including an inner cylinder 431 and a loading head body 432. The inner cylinder 431 is used to connect to the balance being calibrated 42 according to the specified interface of the balance and is sleeved on the outer periphery of the rolling mechanism 11 of the reset subsystem 1. The outer contour of the loading head body 432 is provided with multiple corresponding interfaces for connecting to the steel belt 21 of the automatic loading subsystem 2, so as to realize the connection with the steel belt 21. Under the traction of the steel belt 21, the loading head 43 can be subjected to up, down, left, right, forward and backward loading forces. The loading head body 432 can slide freely back and forth on the inner cylinder 42. After sliding to the designated position, it is pressed and locked by the screws on the clamp 433 to fix the relative position of the loading head body 432 and the inner cylinder 42, so as to realize the adjustment of the loading center relative to the balance position.

[0051] refer to Figure 6 The displacement measurement subsystem 5 of this invention comprises a cross-shaped target plate 51, a circular target plate 52, and laser displacement sensors. The cross-shaped target plate 51 is mounted on the upper surface of the loading head 43, and the circular target plate 52 is mounted on the front end face of the loading head 43, sequentially used to receive laser displacement sensor signals from different directions. The laser displacement sensors include displacement sensor 501 (number 1), displacement sensor 502 (number 2), displacement sensor 503 (number 3), displacement sensor 504 (number 4), displacement sensor 505 (number 5), displacement sensor 506 (number 6), and displacement sensor 507 (number 7). The seven laser displacement sensors are mounted on separate displacement sensor supports and do not contact the loading head body 432 or the target plate.

[0052] In the displacement measurement subsystem 5 of this invention, the laser displacement sensor is installed after the balance mounting subsystem 4 is installed. Preferably, as follows... Figure 6 As shown, displacement sensors 501 and 502 are arranged along the x-axis and completely fix the laser displacement sensor, so that the laser is vertically downward and hits one plane of the cross-shaped target plate 51; displacement sensors 503 and 504 are arranged along the x-axis and completely fix the laser displacement sensor, so that the laser is horizontally hit on another plane of the cross-shaped target plate 51; displacement sensors 505 and 506 are arranged along the y-axis and completely fix the laser displacement sensor, so that the laser is vertically downward and hits the cross-shaped target plate 51; laser displacement sensor 507 is arranged at the front end of the x-axis, so that the laser is horizontally hit on the circular target plate 52.

[0053] refer to Figure 1 The platform 6 of this invention is a three-tiered platform-type steel frame structure. The second platform is used to house the upwardly distributed automatic loading subsystem 2, and the third platform is used to install and house the load reversing subsystem 3 (which enables the steel belt 21 to reverse 180°) that is compatible with the upwardly distributed automatic loading subsystem 2. The platform 6 also includes stairs from the ground (corresponding to the first platform) to the second and third platforms to facilitate the movement of operators.

[0054] The working process of the control system 7 of this invention is as follows: Figure 7 As shown. After receiving the loading command, the control system 7 first reads the six-component load of the load point, then distributes the loading load of each loading subsystem according to the positional relationship of each loading subsystem, and executes the loading of each loading subsystem. After loading is completed, the displacement of each laser displacement sensor is measured by the displacement measurement subsystem 5, and the linear and angular displacement changes of the loading head, as well as the attitude difference from the zero position, are calculated. Based on the attitude difference, the reset program is started. The reset subsystem 1 controls the movement of each motion mechanism to reset the roll angle, pitch angle, yaw angle, X-direction linear displacement, Y-direction linear displacement, and Z-direction linear displacement in sequence. At this time, one round of the reset program is completed. After each round of the reset program is completed, the readings of the seven laser displacement sensors are reread and the attitude difference from the zero position is recalculated. If it is greater than the threshold requirement, the reset program is started again. If it is less than the threshold requirement, the balance reading acquisition function is started. During balance reading acquisition, it is necessary to determine whether there is vibration of the loading head and other accessories that causes the balance reading to oscillate. Acquisition can only be performed after the balance reading is stable. After the balance reading acquisition is completed, the loading of the load point is completed.

[0055] The working principle of this invention is as follows:

[0056] During the balance calibration process, after all subsystems are installed, each automatic loading subsystem 2 uses a screw jack 28 to lift and lower the weights 24, transferring the weights of different weights to the steel belt 21 via the boom 23, and further to the loading head 43. The loading head 43 then transfers the load to the balance being calibrated 42, achieving multi-component loading of the balance 42. The loading head 43 is directly connected to the downward-distributed automatic loading subsystems 2 via the steel belt 21, allowing the weights to be directly transferred to it. The loading head 43 is connected to the upward-distributed automatic loading subsystems 2 on the second-level platform of the frame 6, and through a 180° reversal of the load reversal subsystem 3 on the third-level platform, the upward pulling force corresponding to the weights is transferred to the loading head 43. The loading head 43 is connected to the automatic loading subsystems 2 located at different positions around it, and through the surrounding load reversal subsystems 3, a 90° load reversal is achieved, converting the weights into a horizontal force that is transferred to the loading head 43. This allows the load to be applied to the calibrated balance 42 set on the loading head 43.

[0057] After the calibrated balance 42 is subjected to a load, it will undergo elastic deformation, including linear displacement in three directions and angular displacement in three directions. This elastic deformation of the calibrated balance 42 will cause the loading head 43 and the target plate mounted on it to change their attitude. Seven displacement sensors measure the distance changes at seven locations and calculate the deformation. Specifically, displacement sensors 501 and 502 combined can measure displacement in the z-axis direction and rotation angle around the y-axis; displacement sensors 503 and 504 combined can measure displacement in the y-axis direction and rotation angle around the z-axis; displacement sensors 505 and 506 combined can measure rotation angle around the x-axis; and displacement sensor 507 can measure displacement in the x-axis direction.

[0058] During the balance calibration process, the balance attitude can be adjusted and reset through the reset subsystem 1. Specifically, the roll angle of the balance to be calibrated can be adjusted and reset through the roll mechanism 11, the axial displacement of the balance to be calibrated can be adjusted and reset through the axial motion mechanism 12, the normal displacement and pitch angle of the balance to be calibrated can be adjusted and reset through the pitch and normal motion mechanism 13, and the lateral displacement and yaw angle of the balance to be calibrated can be adjusted and reset through the yaw and lateral motion mechanism 14.

[0059] In summary, the high-load, high-precision reset-type balance automatic calibration system provided by this invention features a compact structure and clearly defined functions for each subsystem. The reset subsystem maximizes the use of the advanced performance of the servo motor, enabling the reset accuracy of linear displacement to be equivalent to the motion accuracy of the servo motor, and the reset accuracy of angular displacement is also improved accordingly. Furthermore, the control logic of each subsystem, including the reset subsystem, automatic loading system, and displacement measurement system, is simple and easy to integrate, achieving automated calibration and significantly improving calibration efficiency while freeing up manpower.

[0060] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A large load high precision reset type balance automatic calibration system, characterized in that, The calibration system comprises a reset subsystem (1), six automatic loading subsystems (2), five load reversing subsystems (3), a balance mounting subsystem (4), a displacement measuring subsystem (5), a rack (6) and a control system (7); The reset subsystem (1) is located at the center of the calibration system and is connected with the balance mounting subsystem (4) to adjust the posture of the balance mounting subsystem (4); The balance mounting subsystem (4) is used for setting a balance (42) to be calibrated; The six automatic loading subsystems (2) are distributed around the balance mounting subsystem (4) along the up, down, left, right, front and back directions respectively; the five load reversing subsystems (3) comprise a 180° load reversing subsystem, a first 90° load reversing subsystem, a second 90° load reversing subsystem, a third 90° load reversing subsystem and a fourth 90° load reversing subsystem; wherein the downward automatic loading subsystem is directly connected with the balance mounting subsystem (4) to apply a downward load, the upward automatic loading subsystem is connected with the balance mounting subsystem (4) through the 180° load reversing subsystem to apply an upward load, the left automatic loading subsystem is connected with the balance mounting subsystem (4) through the first 90° load reversing subsystem to apply a horizontal left load, the right automatic loading subsystem is connected with the balance mounting subsystem (4) through the second 90° load reversing subsystem to apply a horizontal right load, the front automatic loading subsystem is connected with the balance mounting subsystem (4) through the third 90° load reversing subsystem to apply a horizontal front load, and the rear automatic loading subsystem is connected with the balance mounting subsystem (4) through the fourth 90° load reversing subsystem to apply a horizontal rear load; The displacement measuring subsystem (5) is used for monitoring the posture change of the balance mounting subsystem (4); The rack (6) is used for supporting the automatic loading subsystems (2) and providing a high-altitude operation platform for an operator; The control system (7) is used for measuring and controlling the parameters of the subsystems; The reset subsystem (1) comprises a roll mechanism (11), an axial movement mechanism (12), a pitch and normal movement mechanism (13) and a yaw and lateral movement mechanism (14); the roll mechanism (11), the axial movement mechanism (12), the pitch and normal movement mechanism (13) and the yaw and lateral movement mechanism (14) are connected in series; from top to bottom, the roll mechanism (11) is installed on the axial movement mechanism (12), the bottom of the axial movement mechanism (12) is connected with the pitch and normal movement mechanism (13), and the pitch and normal movement mechanism (13) is connected with the yaw and lateral movement mechanism (14) through a base thereof; The roll mechanism (11) is used for adjusting and resetting the roll angle of the balance to be calibrated, the axial movement mechanism (12) is used for adjusting and resetting the axial displacement of the balance to be calibrated, the pitch and normal movement mechanism (13) is used for adjusting and resetting the normal displacement and the pitch angle of the balance to be calibrated, and the yaw and lateral movement mechanism (14) is used for adjusting and resetting the lateral displacement and the yaw angle of the balance to be calibrated; The working flow of the control system (7) comprises the following steps: after the control system (7) receives a loading instruction, first, the six-component load of the load point is read, then the loading load of each loading subsystem is distributed according to the positional relationship of each loading subsystem, and the loading of each loading subsystem is performed; after the loading is completed, the displacement of each laser displacement sensor is measured by the displacement measurement subsystem (5), the linear displacement and angular displacement changes of the balance mounting subsystem (4) and the attitude difference from the zero position are calculated; the reset program is started according to the attitude difference, the reset subsystem (1) resets the roll angle, the pitch angle, the yaw angle, the X-direction linear displacement, the Y-direction linear displacement and the Z-direction linear displacement by controlling the movement of each movement mechanism, and one round of reset program is completed; after each round of reset program is completed, the readings of the laser displacement sensors are read again and the attitude difference from the zero position is recalculated, if the attitude difference is greater than the threshold requirement, the reset program is started again, if the attitude difference is less than the threshold requirement, the balance reading acquisition function is started; during the balance reading acquisition, it is judged whether there is vibration of the system accessories leading to balance reading oscillation, and the acquisition is performed after the balance reading is stable; after the balance reading acquisition is completed, the loading of the load point is completed.

2. The system of claim 1, wherein, The automatic loading subsystem (2) comprises a weight string and a weight lifting mechanism, the weight string is the source of the applied load during the balance calibration, the weight string is placed on the weight lifting mechanism as a whole, and the weight lifting mechanism drives the weight string to ascend and descend; the weight string comprises a steel belt (21), a boom (23), a weight (24) and a counterweight disc (27), the weight lifting mechanism comprises a support (22), a tray (25), a slide rail (26) and a screw lifting machine (28); the counterweight disc (27) is freely hung at the lowermost position, the boom (23) is connected to the upper part, and one end of the boom (23) is connected to the steel belt (21); if the automatic loading subsystem (2) is a downward distributed automatic loading subsystem, the other end of the steel belt (21) is connected to the balance mounting subsystem (4); if the automatic loading subsystem (2) is an upward distributed, left side distributed, right side distributed, front side distributed or rear side distributed automatic loading subsystem, the other end of the steel belt (21) is connected to the corresponding load reversing subsystem (3); the weight (24) comprises a plurality of weights (24) stacked vertically, and is distributed vertically along the boom (23), the tray (25) is below the weight (24) and supports all the weights (24), and the tray (25) is connected to the lower part of the support (22) through the slide rail (26); the lower part of the tray (25) is connected to the screw rod of the screw lifting machine (28), and the screw lifting machine (28) is fixed to the bottom of the support (22); When the automatic loading subsystem (2) is working, the counterweight disc (27), the boom (23) and the steel belt (21) do not move actively, the spiral elevator (28) drives the tray (25) to move up and down, and further drives the weights (24) on the tray (25) to move up and down, so that the weights (24) move relative to the boom (23); when the tray (25) drives the weights (24) to descend, each weight (24) of the weights (24) is sequentially separated from other weights (24) from top to bottom and hung on the boom (23), and further transmits the gravity of the weights (24) to the balance installation subsystem (4) through the boom (23) and the steel belt (21) to realize loading; when the tray (25) drives the weights (24) to ascend, each weight (24) is sequentially separated from the boom (23) from bottom to top and stacked together again, and finally stacked on the tray (25) to realize unloading; the counterweight disc (27) manually suspends the weights (24) alone, and relies on the gravity of the weights (24) to straighten the steel belt (21).

3. The system of claim 1, wherein, The load reversing subsystem (3) comprises a reversing rack (31), a base (32), a pulley support seat (33), a pulley (34) and a screw rod (35); the reversing rack (31) is a steel frame structure, the lower surface is installed on the ground, and the uppermost surface is a reference platform with a slide rail (26); the base (32) is installed on the reference platform and moves along the slide rail (26) of the reference platform to realize position adjustment; the pulley support seat (33) is installed on one side of the base (32); the pulley (34) is installed on the pulley support seat (33) through a bearing and realizes low-friction rotation around the pulley (34) shaft; the height of the pulley (34) is adjusted through the screw rod (35), and after adjustment, the pulley support seat (33) is locked on the base (32) through a screw to limit the position of the pulley (34) in the horizontal plane.

4. The system of claim 1, wherein, The balance installation subsystem (4) comprises a calibration support rod (41) and a loading head (43); the calibration support rod (41) is installed on the reset subsystem (1), a first end of the calibrated balance (42) is installed at an end of the calibration support rod (41) away from the reset subsystem (1), and a second end of the calibrated balance (42) is arranged on the loading head (43); The loading head (43) is a sandwich structure, including an inner cylinder (431) and a loading head body (432) in a split structure, wherein the inner cylinder (431) is used for connecting the calibrated balance (42) according to the balance specified interface, and is sleeved on the outer periphery of the rolling mechanism (11) of the reset subsystem (1); a plurality of corresponding interfaces of the steel belt (21) of the automatic loading subsystem (2) are arranged on the outer contour of the loading head body (432), and are used for realizing the connection with the steel belt (21); under the pulling of the steel belt (21), the up, down, left, right, front and back loading forces are applied to the loading head (43); the loading head body (432) is freely slidable forward and backward on the inner cylinder (431), and after sliding to a specified position, the relative position of the loading head body (432) and the inner cylinder (431) is fixed by the screw on the clamp (433) to realize the adjustment of the loading center relative to the balance position.

5. The system of claim 1, wherein, The displacement measurement subsystem (5) includes a cross-shaped target plate (51), a circular target plate (52) and a laser displacement sensor; wherein the cross-shaped target plate (51) is installed on the upper surface of the loading head (43), the circular target plate (52) is installed on the front end surface of the loading head (43), and the four ends of the cross-shaped target plate (51) and the circular target plate (52) are respectively used for receiving laser displacement sensor signals in different directions; the laser displacement sensor includes a No. 1 displacement sensor (501), a No. 2 displacement sensor (502), a No. 3 displacement sensor (503), a No. 4 displacement sensor (504), a No. 5 displacement sensor (505), a No. 6 displacement sensor (506) and a No. 7 displacement sensor (507); the seven laser displacement sensors are installed on a separate displacement sensor support (22) and do not contact the loading head body (432) and the target plate; The No. 1 displacement sensor (501) and the No. 2 displacement sensor (502) are arranged along the x-axis and are used for detecting the first plane reflected laser of the cross-shaped target plate (51); the No. 3 displacement sensor (503) and the No. 4 displacement sensor (504) are arranged along the x-axis and are used for detecting the second plane reflected laser of the cross-shaped target plate (51), the second plane is arranged perpendicularly to the first plane; the No. 5 displacement sensor (505) and the No. 6 displacement sensor (506) are arranged along the y-axis and are used for detecting the third plane reflected laser of the cross-shaped target plate (51), the third plane is arranged parallel to the first plane; the No. 7 laser displacement sensor is arranged at the forefront of the cross-shaped target plate (51) in the x-axis direction and is used for detecting the reflected laser of the circular target plate (52).

6. The system of claim 5, wherein, The No. 1 displacement sensor (501) and the No. 2 displacement sensor (502) are combined to realize the measurement of the z-axis direction displacement and the rotation angle around the y-axis; the No. 3 displacement sensor (503) and the No. 4 displacement sensor (504) are combined to realize the measurement of the y-axis direction displacement and the rotation angle around the z-axis; the No. 5 displacement sensor (505) and the No. 6 displacement sensor (506) are combined to realize the measurement of the rotation angle around the x-axis; and the No. 7 displacement sensor (507) realizes the measurement of the x-axis direction displacement.

7. The system of claim 1, wherein, The gantry (6) is a three-layer platform type steel frame structure, the first layer platform is used for placing the resetting subsystem (1), the downward distributed automatic loading subsystem, the front side distributed automatic loading subsystem, the rear side distributed automatic loading subsystem, the left side distributed automatic loading subsystem, the right side distributed automatic loading subsystem, the first 90° load reversing subsystem, the second 90° load reversing subsystem, the third 90° load reversing subsystem, the fourth 90° load reversing subsystem, the balance installation subsystem (4), the displacement measurement subsystem (5), the gantry (6) and the control system (7), the second layer platform is used for placing the upward distributed automatic loading subsystem, and the third layer platform is used for installing and placing the 180° load reversing subsystem matched with the upward distributed automatic loading subsystem; the gantry (6) further comprises stairs from the first layer platform to the second layer platform and the third layer platform, so as to facilitate the up and down movement of the operator.

8. A method of using a large load high precision repositionable balance automatic calibration system, characterized in that, The system is the system according to any one of claims 1 to 7; the method comprises: By controlling the 6 automatic loading subsystems (2), the load is transmitted to the balance installation subsystem (4) under the load conversion of the 5 load reversing subsystems (3), and the balance installation subsystem (4) further transmits the load to the calibrated balance (42); The attitude change of the balance installation subsystem (4) is measured by the displacement sensor of the displacement measurement subsystem (5); The adjustment and resetting of the balance attitude are realized by the resetting subsystem (1).

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