Automatic displacement calibration system and method for double-rotary-transformer servo mechanism

Abstract

The invention relates to an automatic displacement calibration system and method for a double-rotary-transformer servo mechanism, and belongs to the technical field of intelligent servo control. According to the invention, a complex and tedious manual calibration process is analyzed and refined, automatic switching of a displacement calibration process, automatic acquisition of calibration parameters, self-diagnosis of a mechanism motion state and self-correction of the displacement calibration parameters are realized, the accuracy and the calibration efficiency of displacement calibration are improved, and standardization and controllability of the whole calibration process are realized. According to the method, the safety and reliability of the displacement calibration process and the accurate calibration result can be ensured, the labor cost is reduced, the automation level of the calibration process is improved, and the displacement calibration efficiency is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of intelligent servo control technology, and relates to an automated displacement calibration system and method for a dual-rotor servo mechanism. Background Technology

[0002] In servo mechanism design, using a resolver to replace a displacement sensor is a feasible and common solution, especially in applications requiring high reliability, high integration, and strong anti-interference capabilities. However, due to the limitations of the resolver's construction mechanism, a single resolver can only provide the absolute position for a single turn, and cannot measure displacements exceeding the range of a single turn. To solve this problem, the dual resolver design has emerged. The dual resolver servo mechanism cleverly solves the problem of a single resolver being unable to measure displacements exceeding the range of a single turn by utilizing the one-to-one mapping relationship between the angle difference of two resolvers installed on the motor and the mechanism and the displacement, as illustrated in invention patent 202318011445.X, "Measurement Coefficient and Method for Linear Displacement of an Electric Servo Motor." However, the displacement calibration of the dual resolver servo mechanism is complex, and currently, it is done manually. The main steps include: pushing the actuator to a certain position, connecting the simulator to run the software, observing and recording relevant data, and slowly moving the actuator to mark the displacement jump point, etc. For integrated servo mechanisms, this involves disassembly and assembly, making the process even more labor-intensive and resource-intensive.

[0003] Invention patent CN114578788B describes a displacement calibration method and apparatus for a displacement mechanism. It completes displacement calibration by establishing a mapping relationship between multiple step vectors of the motor and multiple displacement calibration values. This method is for a single resolver and is not applicable to dual resolver servo mechanisms. Invention patent CN117706359A describes a coaxial dual resolver testing device and method. Both resolvers are located on the output shaft of the motor. The difference between the two resolvers when the motor is not running determines whether the current delay compensation of the soft decoding algorithm in the soft decoding control board is correct; this does not involve displacement calibration. Invention patent CN115842492A describes an inertial displacement calibration method, apparatus, medium, controller, and lifting assembly. This method calibrates the displacement inertia coefficient by detecting the ripple compensation number and its statistical value of the motor drive control signal; this method is not applicable to the displacement calibration of dual resolver servo mechanisms. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art. This invention provides an automated displacement calibration system and method for a dual-rotor servo mechanism.

[0005] The solution of this invention is: an automated displacement calibration system for a dual-rotor servo mechanism, comprising: a main control module, a displacement correction module, a data acquisition module, a displacement calibration module, a motion control module, and a self-diagnosis module; wherein, the displacement correction module and the main control module are located in a host computer and communicate with each other through an internal bus; the data acquisition module, the motion control module, the displacement calibration module, and the self-diagnosis module are located inside the servo mechanism to be calibrated and communicate with the main control module through an external bus;

[0006] The main control module is the control center of the automatic displacement calibration system. It is responsible for scheduling and calling the execution order of each module inside the servo mechanism to be calibrated during the entire displacement calibration process, receiving and processing abnormal information from each module inside the servo mechanism to be calibrated, and determining the execution path.

[0007] The displacement correction module corrects the displacement values ​​calculated by the displacement calibration module.

[0008] The data acquisition module collects calibration parameters when the servo mechanism to be calibrated moves to the mechanical limit, and monitors the motion status of the servo mechanism to be calibrated at the same time.

[0009] The displacement calibration module completes the displacement calibration of the servo mechanism to be calibrated throughout its entire stroke.

[0010] The motion control module is the motion control part of the servo mechanism to be calibrated, and it completes the mode switching control.

[0011] The self-diagnostic module is used to monitor the internal status of the servo mechanism to be calibrated, predict faults, and assist in maintenance.

[0012] Furthermore, the main control module interacts with the data acquisition module, motion control module, displacement calibration module, and self-diagnosis module via command transmission and reception.

[0013] When the command is sent, on the one hand, the main control module sends motion mode command, motion position command, motion speed command, motion current command and mechanism stop command to the motion control module; on the other hand, the main control module sends displacement calibration parameters and displacement compensation parameters to the displacement calibration module.

[0014] When receiving instructions, the main control module receives the mechanism resolver code value, motor resolver code value and mechanism telemetry information output by the data acquisition module; on the other hand, the main control module receives the self-diagnosis information output by the self-diagnosis module.

[0015] Furthermore, the calibration parameters are the mechanism resolver value, the motor resolver value, and the initial displacement value.

[0016] Furthermore, the monitoring of the motion state of the servo mechanism to be calibrated includes monitoring the voltage, current, and motor speed information of the servo mechanism to be calibrated throughout the entire calibration process.

[0017] Furthermore, the servo mechanism to be calibrated has the following operating modes: position closed-loop mode, speed closed-loop mode, and current closed-loop mode; and during the calibration process, the servo mechanism to be calibrated is in speed closed-loop mode or current closed-loop mode, and after the calibration is completed, the servo mechanism to be calibrated operates in position closed-loop mode.

[0018] Furthermore, the self-diagnostic module completes self-diagnosis of power supply voltage faults, motor faults, communication link faults, mechanical motion faults, and triggering safety mechanisms; when an abnormality occurs, the self-diagnostic information is updated and reported to the main control module. The main control module decides whether to terminate the displacement calibration process based on the fault level. The fault level setting is determined according to the user's usage requirements.

[0019] The aforementioned power supply voltage fault refers to an overvoltage or undervoltage input voltage.

[0020] The aforementioned motor fault refers to overcurrent in one phase of the motor.

[0021] The aforementioned communication link failure refers to a communication bus open circuit or response timeout;

[0022] The aforementioned mechanical motion failure refers to the mechanism operating at excessive speed;

[0023] The aforementioned security trigger mechanism refers to the watchdog timer being reset when the software malfunctions.

[0024] Furthermore, the displacement calibration module provides the core algorithm of the automated displacement calibration system. By using the displacement calibration parameters obtained by the data acquisition module and the displacement compensation parameters output by the displacement correction module, the displacement value is calculated, thereby completing the displacement calibration of the servo mechanism throughout its entire stroke.

[0025] Furthermore, the displacement calibration includes:

[0026] The servo mechanism to be calibrated is powered on and operates in any position.

[0027] First, load the displacement calibration parameters N1 and N2, as well as the displacement compensation parameters K1, K2, and K3;

[0028] The total code value and angle fthlt1 of the motor resolver are calculated by the difference between the current motor resolver value and the displacement calibration parameter N2.

[0029] The total code value rotated by the mechanism resolver is calculated by the difference between the current resolver value and the displacement calibration parameter N1, and then the angle difference between the two resolvers is calculated.

[0030] Next, calculate fN and uN; where fN = Deltathlt / M, the coefficient M represents the angular difference between the two resolvers in a single revolution, which is determined by the structure of the servo mechanism to be calibrated; uN is the integer part of fN.

[0031] Based on the judgment conditions, displacement correction is performed using displacement compensation parameters K1, K2, and K3 to obtain the final displacement calibration value, where 360>K1>K2>0 and 1>K3>0.

[0032] Furthermore, the correction of the displacement compensation parameters includes: first, the main control module sends a command to put the servo mechanism to be calibrated into a speed closed-loop mode, then sends a speed command to make the servo mechanism to be calibrated move the entire stroke, while recording the uncorrected displacement and motor rotation angle fthlt1 output by the displacement calibration module, plotting the displacement curve, filtering out displacement jump points, removing displacement jump points by setting parameters K1, K2 and K3, and finally returning K1, K2 and K3 to the displacement calibration module to complete the displacement correction.

[0033] An automated displacement calibration method for a dual-rotor servo mechanism includes:

[0034] (1) The main control module sets the servo mechanism to be calibrated to work in current closed-loop mode. If the setting is successful, (2) is executed; otherwise, a fault is reported.

[0035] (2) The main control module sends a current command to the servo mechanism to be calibrated, controls it to move slowly toward the mechanical limit direction, and monitors the current feedback value. If the mechanical limit is reached, (3) is executed; otherwise, wait.

[0036] (3) The main control module sends a stop command to the servo mechanism to be calibrated. At this time, the servo mechanism should stop moving. If the stop is successful, (4) is executed; otherwise, a fault is reported.

[0037] (4) The main control module reads the motor resolver code value and the mechanism resolver code value at this moment, and binds them together with the mechanical limit value as calibration parameters to the servo mechanism to be calibrated and stores them in non-volatile memory. If the binding is successful, (5) is executed; otherwise, a fault is reported.

[0038] (5) Perform displacement calibration according to the displacement calibration module workflow;

[0039] (6) Perform displacement correction according to the displacement correction module workflow. If successful, proceed to (7); otherwise, report a fault.

[0040] (7) The main control module loads parameters K1, K2 and K3 into the servo mechanism to be calibrated and stores them in non-volatile memory. If successful, the calibration process ends; otherwise, a fault is reported.

[0041] The beneficial effects of this invention compared to the prior art are:

[0042] (1) This invention proposes a displacement correction method for a dual resolver servo mechanism, which solves the problem of jump points in resolver displacement acquisition caused by mechanical backlash of the servo mechanism and realizes automated calibration of the displacement of the dual resolver servo mechanism.

[0043] (2) This invention automates the entire displacement calibration process, automatically acquiring and downloading calibration parameters and automatically binding them, thus achieving automatic switching of the displacement calibration process. This reduces the impact of factors such as operator skill level, fatigue, and attention deficit, improving the quality and efficiency of displacement calibration. Furthermore, it can automatically diagnose faults and report them when abnormalities occur, reducing the significant workload of manual monitoring and judgment, saving testing time, and improving safety. The entire calibration process is unified, with low human risk, strong data management and traceability, and is easily integrated into automated frameworks such as intelligent production lines. Attached Figure Description

[0044] Figure 1 System structure diagram of the displacement calibration platform;

[0045] Figure 2 The instruction block diagram of the main control module;

[0046] Figure 3 This is a structural diagram of the data acquisition module;

[0047] Figure 4 This is a structural diagram of the motion control module;

[0048] Figure 5 Here is a flowchart of the self-diagnosis module's workflow;

[0049] Figure 6 Here is a flowchart of the displacement calibration module's workflow;

[0050] Figure 7 Here is a flowchart of the displacement correction module's workflow;

[0051] Figure 8 A flowchart illustrating the workflow of the automated displacement calibration method. Detailed Implementation

[0052] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1As shown, a displacement calibration platform is established, consisting of a host computer and a servo mechanism to be calibrated. It comprises six parts: a main control module, a data acquisition module, a motion control module, a displacement calibration module, a displacement correction module, and a self-diagnostic module. The host computer includes the main control module and the displacement correction module. The data acquisition module, motion control module, displacement calibration module, and self-diagnostic module are located within the servo mechanism to be calibrated. The host computer and the servo mechanism to be calibrated are connected via an external bus, such as a CAN bus or a 422 bus. The main control module and the displacement correction module are connected via the host computer's internal bus.

[0054] like Figure 2 The diagram shows the instruction block diagram of the main control module. The main control module is the control center for automated displacement calibration, responsible for scheduling and calling the execution order of other functional modules, receiving and processing abnormal information from submodules, and determining the execution path throughout the entire displacement calibration process. Data interaction between the main control module and other submodules is conducted via instruction transmission and reception. Instructions sent to the motion control module include motion mode instructions, motion position instructions, motion speed instructions, motion current instructions, and stop instructions; instructions sent to the displacement calibration module are displacement calibration and compensation parameters; the instruction receiving section includes the mechanism resolver code value, motor resolver code value, and telemetry information such as current and motor speed output from the data acquisition module, as well as diagnostic information output from the self-diagnosis module.

[0055] like Figure 3 As shown, the data acquisition module, when the mechanism moves to the mechanical limit, transmits the acquired mechanism resolver value, motor resolver value and initial displacement value to the main control module in a timely manner as calibration parameters. During the entire calibration process, it also transmits information such as voltage, current and motor speed to the main control module in a timely manner as monitoring data of the mechanism's motion status.

[0056] like Figure 4 As shown, the motion control module is the motion control part of the servo mechanism. Its main function is to switch between the position closed-loop mode, speed closed-loop mode and current closed-loop mode of the mechanism during the motion process. The module receives instructions from the main control module in real time and executes the switching between the three modes according to different instructions. During the calibration process, the mechanism is in speed closed-loop mode or current closed-loop mode. After the calibration is completed, the mechanism can run in position closed-loop mode.

[0057] like Figure 5The diagram shows the workflow of the self-diagnostic module. Self-diagnosis is a key functional module for monitoring internal status, predicting faults, and assisting in maintenance; it is an important method for improving the reliability of the calibration process. It includes self-diagnosis of power supply voltage, motor status, communication link, mechanical motion status, and safety mechanisms. Power supply voltage faults refer to overvoltage or undervoltage of the input voltage; motor faults refer to overcurrent in the motor phases; communication link faults refer to open circuits in the communication bus or response timeouts; mechanical motion faults refer to overspeed operation of the mechanism; and triggering safety mechanisms refers to software malfunctions or triggering a watchdog reset. When an abnormality occurs, the self-diagnostic information is updated and reported to the main control module. The main control module decides whether to terminate the displacement calibration process based on the fault level; the fault level setting is determined according to user requirements.

[0058] like Figure 6 As shown in the diagram, the displacement calibration module provides the core algorithm for automated displacement calibration. It calculates the displacement value using the displacement calibration parameters obtained from the data acquisition module and the displacement compensation parameters output by the displacement correction module, thereby completing the displacement calibration of the servo mechanism throughout its entire stroke.

[0059] The specific process is as follows: When the servo mechanism is powered on at any position, the displacement calibration parameters N1 and N2 and the displacement compensation parameters K1, K2 and K3 are loaded first. The total code value and angle fthlt1 of the motor resolver are calculated by the difference between the current motor resolver value and the displacement calibration parameter N2. The total code value of the mechanism resolver is calculated by the difference between the mechanism resolver value and the displacement calibration parameter N1. Then, the angle difference Deltathlt between the two resolvers is calculated, and fN and uN are calculated. fN represents the ratio of Deltathlt to the coefficient M, and the coefficient M represents the angle difference of a single revolution of the two resolvers, which is determined by the structure of the servo mechanism to be calibrated. fthlt1, fN, and uN are corrected by the displacement compensation parameter to obtain the final displacement calibration value. The letter K represents the maximum value of the resolver decoding. If it is a 14-bit resolver, the value is 16383. K1, K2, and K3 are the compensation parameters output by the displacement correction module (360>K1>K2>0, 1>K3>0). uN is the integer part of fN, and u16 is the rounding operator. S1 is the initial displacement value.

[0060] like Figure 7The diagram shows the workflow of the displacement correction module. This module corrects the displacement values ​​calculated by the displacement calibration module. Due to the gaps in the structural components of the servo mechanism, displacement values ​​may jump at the points where the resolver code crosses a certain number of revolutions. The correction method of this module is as follows: First, a command is sent to put the servo mechanism into a speed closed-loop mode. Then, a speed command is sent to make the servo mechanism move its full stroke. At the same time, the uncorrected displacement and motor rotation angle fthlt1 output by the displacement calibration module are recorded. The displacement curve is plotted, and displacement jump points are filtered out. By setting parameters K1, K2, and K3, displacement jump points are removed. Finally, K1, K2, and K3 are returned to the displacement calibration module to complete the displacement correction.

[0061] like Figure 8 As shown, an automated displacement calibration method for a dual-rotor servo mechanism includes the following steps:

[0062] Step (1): The main control module sets the servo mechanism to be calibrated to work in current closed-loop mode. If the setting is successful, step (2) is executed; otherwise, a fault is reported.

[0063] Step (2): The main control module sends a current command to the servo mechanism to be calibrated, controlling it to move slowly towards the mechanical limit direction, while monitoring the current feedback value. If the mechanical limit is reached, step (3) is executed; otherwise, wait.

[0064] Step (3): The main control module sends a stop command to the servo mechanism to be calibrated. At this time, the servo mechanism should stop moving. If the stop is successful, step (4) is executed; otherwise, a fault is reported.

[0065] Step (4): The main control module reads the motor and mechanism resolver code values ​​at this moment, and binds them together with the mechanical limit values ​​as calibration parameters to the servo mechanism and stores them in non-volatile memory. If the binding is successful, step (5) is executed; otherwise, a fault is reported.

[0066] Step (5): Perform displacement calibration according to the displacement calibration module workflow. After calibration, proceed to step (6).

[0067] Step (6): Perform displacement correction according to the displacement correction module workflow. If successful, proceed to step (7); otherwise, report a fault.

[0068] Step (7): The main control module binds parameters K1, K2 and K3 to the servo mechanism and stores them in non-volatile memory. If successful, the calibration process ends; otherwise, a fault is reported.

[0069] 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 to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. An automated displacement calibration system for a dual-rotor servo mechanism, characterized in that, include: The system comprises a main control module, a displacement correction module, a data acquisition module, a displacement calibration module, a motion control module, and a self-diagnosis module. The main control module and the displacement correction module are located in the host computer and communicate with each other via an internal bus. The data acquisition module, the motion control module, the displacement calibration module, and the self-diagnosis module are located inside the servo mechanism to be calibrated and communicate with the main control module via an external bus. The main control module is the control center of the automatic displacement calibration system. It is responsible for scheduling and calling the execution order of each module inside the servo mechanism to be calibrated during the entire displacement calibration process, receiving and processing abnormal information from each module inside the servo mechanism to be calibrated, and determining the execution path. The displacement correction module corrects the displacement values ​​calculated by the displacement calibration module. The data acquisition module collects calibration parameters when the servo mechanism to be calibrated moves to the mechanical limit, and monitors the motion status of the servo mechanism to be calibrated at the same time. The displacement calibration module completes the displacement calibration of the servo mechanism to be calibrated throughout its entire stroke. The motion control module is the motion control part of the servo mechanism to be calibrated, and it completes the mode switching control. The self-diagnostic module is used to monitor the internal status of the servo mechanism to be calibrated, predict faults, and assist in maintenance.

2. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The main control module interacts with the data acquisition module, motion control module, displacement calibration module, and self-diagnosis module via command transmission and reception. When the command is sent, on the one hand, the main control module sends motion mode command, motion position command, motion speed command, motion current command and mechanism stop command to the motion control module; on the other hand, the main control module sends displacement calibration parameters and displacement compensation parameters to the displacement calibration module. When receiving instructions, the main control module receives the mechanism resolver code value, motor resolver code value and mechanism telemetry information output by the data acquisition module; on the other hand, the main control module receives the self-diagnosis information output by the self-diagnosis module.

3. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The calibration parameters are the mechanism resolver value, the motor resolver value, and the initial displacement value.

4. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The monitoring of the motion state of the servo mechanism to be calibrated includes monitoring the voltage, current, and motor speed information of the servo mechanism to be calibrated throughout the entire calibration process.

5. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The servo mechanism to be calibrated has the following operating modes: position closed-loop mode, speed closed-loop mode, and current closed-loop mode; during the calibration process, the servo mechanism to be calibrated is in speed closed-loop mode or current closed-loop mode, and after the calibration is completed, the servo mechanism to be calibrated operates in position closed-loop mode.

6. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The self-diagnostic module performs self-diagnosis of power supply voltage faults, motor faults, communication link faults, mechanical motion faults, and safety mechanism triggers. When an abnormality occurs, the self-diagnostic information is updated and reported to the main control module. The main control module decides whether to terminate the displacement calibration process based on the fault level. The fault level is set according to the user's usage requirements. The aforementioned power supply voltage fault refers to an overvoltage or undervoltage input voltage. The aforementioned motor fault refers to overcurrent in one phase of the motor. The aforementioned communication link failure refers to a communication bus open circuit or response timeout; The aforementioned mechanical motion failure refers to the mechanism operating at excessive speed; The aforementioned security trigger mechanism refers to the watchdog timer being reset when the software malfunctions.

7. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 1, characterized in that, The displacement calibration module provides the core algorithm of the automated displacement calibration system. It calculates the displacement value using the displacement calibration parameters obtained by the data acquisition module and the displacement compensation parameters output by the displacement correction module, thereby completing the displacement calibration of the servo mechanism throughout its entire stroke.

8. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 7, characterized in that, The displacement calibration includes: The servo mechanism to be calibrated is powered on and operates in any position. First, load the displacement calibration parameters N1 and N2, as well as the displacement compensation parameters K1, K2, and K3; The total code value and angle fthlt1 of the motor resolver are calculated by the difference between the current motor resolver value and the displacement calibration parameter N2. The total code value rotated by the mechanism resolver is calculated by the difference between the current resolver value and the displacement calibration parameter N1, and then the angle difference between the two resolvers is calculated. Next, calculate fN and uN; where fN = Deltathlt / M, the coefficient M represents the angular difference between the two resolvers in a single revolution, which is determined by the structure of the servo mechanism to be calibrated; uN is the integer part of fN. Based on the judgment conditions, displacement correction is performed using displacement compensation parameters K1, K2, and K3 to obtain the final displacement calibration value, where 360>K1>K2>0 and 1>K3>0.

9. The automated displacement calibration system for a dual-rotor servo mechanism according to claim 8, characterized in that, The correction of the displacement compensation parameters includes: first, the main control module sends a command to put the servo mechanism to be calibrated into a speed closed-loop mode, then sends a speed command to make the servo mechanism to be calibrated move the full stroke, and at the same time records the uncorrected displacement and motor rotation angle fthlt1 output by the displacement calibration module, plots the displacement curve, filters out displacement jump points, removes displacement jump points by setting parameters K1, K2 and K3, and finally returns K1, K2 and K3 to the displacement calibration module to complete the displacement correction.

10. A method for automated displacement calibration of a dual-rotor servo mechanism, characterized in that, include: (1) The main control module sets the servo mechanism to be calibrated to work in current closed-loop mode. If the setting is successful, (2) is executed; otherwise, a fault is reported. (2) The main control module sends a current command to the servo mechanism to be calibrated, controls it to move slowly toward the mechanical limit direction, and monitors the current feedback value. If the mechanical limit is reached, (3) is executed; otherwise, wait. (3) The main control module sends a stop command to the servo mechanism to be calibrated. At this time, the servo mechanism should stop moving. If the stop is successful, (4) is executed; otherwise, a fault is reported. (4) The main control module reads the motor resolver code value and the mechanism resolver code value at this moment, and binds them together with the mechanical limit value as calibration parameters to the servo mechanism to be calibrated and stores them in non-volatile memory. If the binding is successful, (5) is executed; otherwise, a fault is reported. (5) Perform displacement calibration according to the displacement calibration module workflow; (6) Perform displacement correction according to the displacement correction module workflow. If successful, proceed to (7); otherwise, report a fault. (7) The main control module loads parameters K1, K2 and K3 into the servo mechanism to be calibrated and stores them in non-volatile memory. If successful, the calibration process ends; otherwise, a fault is reported.

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