A method for automatically adjusting the range of LVDT displacement sensor in oil motor servo system

Abstract

The present invention discloses a method for automatically adjusting the range of an LVDT displacement sensor in a hydraulic motor servo system, including a zeroing adjustment process, an amplitude modulation adjustment process, and a completion adjustment process. The zeroing adjustment process involves dynamically acquiring voltage signal data of the displacement sensor's secondary primary and secondary coils at their current positions when the hydraulic motor is nearing a fully closed state, performing a fluctuation determination on the voltage signal data of the multiple dynamically acquired secondary primary and secondary coils, and entering an amplitude modulation adjustment process if the fluctuation determination is satisfied. The amplitude modulation adjustment process involves dynamically acquiring voltage signal data of the displacement sensor's secondary primary and secondary coils at their current positions when the hydraulic motor is nearing a fully open state, performing a fluctuation determination on the voltage signal data of the multiple dynamically acquired secondary primary and secondary coils, and entering a completion adjustment process if the fluctuation determination is satisfied. The present invention reliably matches the hydraulic motor's opening and closing range to the optimal effective range of the LVDT displacement sensor as much as possible, achieving high accuracy and facilitating improved reliability of the hydraulic motor's semi-open-loop control.

Description

Technical Field

[0001] The invention relates to a control parameter setting method for an industrial servo control system, in particular to an automatic setting method for an effective range of an LVDT displacement sensor in an oil motor servo system. Background Art

[0002] Hydraulic motor servo systems are common automatic control systems used in steam turbines, hydroelectric generators, and industrial manufacturing equipment. They use pulsed oil pressure to drive the hydraulic motor to generate corresponding opening and closing movements to execute control commands. In the hydraulic motor servo control system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. The servo controller performs semi-open-loop control of the hydraulic motor based on the displacement signal detected by the LVDT displacement sensor. Therefore, in the hydraulic motor servo system, the matching of the LVDT displacement sensor with the effective range of the hydraulic motor opening directly affects the reliability of the hydraulic motor's semi-open-loop control.

[0003] Before the LVDT displacement sensor is matched to the hydraulic motor, there is no necessary correspondence between the total range of the LVDT displacement sensor and the opening of the hydraulic motor. This requires that the hydraulic motor and LVDT displacement sensor, which are connected together, be adjusted according to the changes in the opening state of the hydraulic motor to find the corresponding range on the LVDT displacement sensor - that is, the effective range corresponding to the opening of the hydraulic motor. Usually, the effective range found on the LVDT displacement sensor is not based on the start and end points of the total range. Instead, the middle section with better linearity in the total range is selected to match the opening of the hydraulic motor. This involves the adjustment process of the matching relationship between the range of the LVDT displacement sensor and the opening of the hydraulic motor. The effective range of the LVDT displacement sensor corresponding to the opening of the hydraulic motor is obtained by adjusting the zero value and the amplitude.

[0004] Currently, the common method for calibrating the range of LVDT displacement sensors in hydraulic motor servo systems is to obtain the corresponding displacement signal data of the LVDT displacement sensor as the zero value when the hydraulic motor is fully closed, and the corresponding displacement signal data of the LVDT displacement sensor as the amplitude when the hydraulic motor is fully open. This calibration method ignores the impact of the instability of oil pressure pulses on the fluctuation of the current displacement signal data of the LVDT displacement sensor, the impact of possible jamming failures of the hydraulic motor during the calibration process on the acquired range, and the impact of possible disconnection failures of the LVDT displacement sensor during the calibration process on the current displacement signal data. As a result, the acquired calibration zero value and calibration amplitude are difficult to accurately reflect the corresponding opening of the hydraulic motor, and the hydraulic motor opening and closing range cannot be reliably matched to the optimal effective range of the LVDT displacement sensor, which directly affects the reliability of the hydraulic motor's semi-open-loop control. Summary of the Invention

[0005] The technical purpose of the present invention is to provide an automatic tuning method that can reliably match the opening and closing range of the hydraulic motor with the optimal effective range of the LVDT displacement sensor in view of the particularity of the above-mentioned hydraulic motor servo system and the shortcomings of the existing technology.

[0006] The technical purpose of the present invention is achieved through the following technical solution: a method for automatically adjusting the range of an LVDT displacement sensor in an oil motor servo system, wherein the method comprises a zero adjustment process, an amplitude modulation process, and a completion adjustment process;

[0007] The zero adjustment process is:

[0008] The servo controller outputs a zeroing control signal to the servo valve. When the control oil motor is close to the fully closed state, the voltage signal data of the secondary coil and secondary coil of the LVDT displacement sensor at the current position is dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to fluctuation judgment processing.

[0009] If the fluctuation judgment condition is met, the latest voltage signal data of the sub-primary coil and the sub-secondary coil will be recorded, and the amplitude modulation setting process will begin;

[0010] If the fluctuation judgment conditions are not met, the tuning will fail and exit;

[0011] The amplitude modulation setting process is:

[0012] The servo controller outputs an amplitude modulation control signal to the servo valve. When the control oil motor is close to the fully open state, the voltage signal data of the secondary coil and secondary coil of the LVDT displacement sensor at the current position is dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to fluctuation judgment processing.

[0013] If the fluctuation judgment condition is met, the latest voltage signal data of the sub-primary coil and the sub-secondary coil will be recorded, and the setting process will be completed;

[0014] If the fluctuation judgment conditions are not met, the tuning will fail and exit;

[0015] The completion setting process is:

[0016] The memory stores the voltage signal data of the secondary coil and the secondary coil recorded by zero adjustment, the zero adjustment value obtained based on the voltage signal data of the secondary coil and the secondary coil recorded by zero adjustment, the voltage signal data of the secondary coil and the secondary coil recorded by amplitude modulation, and the amplitude modulation value obtained based on the voltage signal data of the secondary coil and the secondary coil recorded by amplitude modulation.

[0017] The setting is successfully exited.

[0018] The above technical measures are aimed at the particularity of the above-mentioned oil motor servo system. Based on the one-button automatic operation function of the servo controller, the oil motor is controlled to be in a state close to fully closed / close to fully open. Under the corresponding state, the voltage signal data of the secondary coil and the secondary coil of the LVDT displacement sensor at the current position are dynamically obtained multiple times. These voltage signal data obtained dynamically multiple times are processed through fluctuation judgment to obtain a set value that can basically and truly reflect the current opening state of the oil motor, thereby basically eliminating the possible error between the set value and the actual opening of the oil motor, so that the obtained set zero value and set amplitude can basically and truly reflect the corresponding opening of the oil motor, and make the opening and closing range of the oil motor reliably match the optimal effective range of the LVDT displacement sensor as much as possible, with high accuracy, which is conducive to improving the reliability of the semi-open loop control of the oil motor.

[0019] As one of the preferred solutions, the LVDT displacement sensor range automatic adjustment method further includes a process of judging whether the adjustment range is too small;

[0020] The process of judging whether the setting range is too small is as follows:

[0021] Obtain the voltage signal data of the secondary coil and the secondary coil recorded in the zeroing process, and calculate the difference to obtain the process zeroing value;

[0022] Obtain the voltage signal data of the secondary coil and the secondary coil recorded by the amplitude modulation, and calculate the difference to obtain the process amplitude modulation value;

[0023] Calculate the difference between the process amplitude adjustment value and the process zero adjustment value, and compare the difference with the set value. If the difference is greater than the set value, it is determined that the setting range is normal and the automatic tuning is completed. Otherwise, it is determined that the setting range is too small and the tuning fails and exits.

[0024] The value range of the setting value 1 is 800 to 1200.

[0025] The above technical measures determine that the obtained process setting zero value (i.e., process zero adjustment value) and process setting amplitude (i.e., process amplitude adjustment value) have too small a setting range, thereby eliminating possible jamming faults of the oil motor during the setting process, and preventing the oil motor from having an adverse effect on the setting results due to jamming faults during the setting process, and further enabling the obtained setting zero value and setting amplitude to basically and truly reflect the corresponding opening of the oil motor, and further enabling the opening and closing range of the oil motor to reliably match the optimal effective range of the LVDT displacement sensor as much as possible.

[0026] As one of the preferred solutions, the LVDT displacement sensor range automatic adjustment method further includes a disconnection judgment process;

[0027] The disconnection judgment process is:

[0028] Obtaining the voltage signal data of the secondary coil and the secondary coil recorded in the zeroing process, and summing the data to obtain the zeroing secondary coil voltage signal data and value;

[0029] Acquire the voltage signal data of the secondary coil and the secondary coil recorded by the amplitude modulation, and sum them to obtain the sum value of the voltage signal data of the amplitude modulation secondary coil;

[0030] Calculate the difference between the sum of the voltage signal data of the amplitude modulation secondary coil and the sum of the voltage signal data of the zero adjustment secondary coil, and compare the difference with the set value 2. If the difference is less than the set value 2, it is determined that the wiring is normal and the automatic tuning is completed. Otherwise, it is determined that the wiring is broken and the tuning fails and exits.

[0031] The value of the second set value is less than 20% of the difference between the sum of the amplitude modulation secondary coil voltage signal data and the sum of the zero adjustment secondary coil voltage signal data.

[0032] The above technical measures eliminate the possible wire breakage faults that may exist in the LVDT displacement sensor during the tuning process, so as to prevent the LVDT displacement sensor from having an adverse effect on the tuning results due to the wire breakage fault during the tuning process, and further enable the obtained tuning zero value and tuning amplitude to basically and truly reflect the corresponding opening of the oil motor, and further enable the opening and closing range of the oil motor to reliably match the optimal effective range of the LVDT displacement sensor as much as possible.

[0033] As one of the preferred solutions, the fluctuation determination process is:

[0034] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and the secondary secondary coil, where m is ≥ 8;

[0035] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero adjustment value / process amplitude modulation value;

[0036] Obtain m groups of initial process zero adjustment values / process amplitude adjustment values;

[0037] Step 2. Bubble sort the m groups of initial process zero adjustment values / process amplitude adjustment values ​​in ascending order;

[0038] Form a queue sorting;

[0039] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0040] Compare the difference with the set corresponding fluctuation threshold. If the difference is less than the corresponding fluctuation threshold, the fluctuation is determined to be normal and the fluctuation judgment is completed. Otherwise, it is determined that the fluctuation is too large and proceed to step 4.

[0041] The corresponding fluctuation threshold value range is 300 to 500;

[0042] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0043] The voltage signal data of the secondary coil and the secondary coil currently collected and accumulated are processed by difference processing to obtain the current accumulated process zero adjustment value / process amplitude modulation value;

[0044] Step 5. Combine the current accumulated process zero adjustment value / process amplitude adjustment value in step 4 into the bubble sort in step 2;

[0045] Form a new queue sorting;

[0046] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0047] Compare the difference with the corresponding fluctuation threshold. If the difference is less than the corresponding fluctuation threshold, the fluctuation is determined to be normal and the fluctuation judgment is completed. Otherwise, the fluctuation is determined to be too large and steps 4 to 6 are repeated.

[0048] The number of repetitions of steps 4 to 6 is ≤ 80. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits.

[0049] The above-mentioned fluctuation judgment technical measures are aimed at the particularity of the oil pressure pulse of the hydraulic motor. Under the corresponding opening state of the hydraulic motor, multiple sets of process zero adjustment values / process amplitude modulation values ​​are dynamically obtained. These process zero adjustment values / process amplitude modulation values ​​are judged through fluctuation analysis, so as to screen out the set value that can basically and truly reflect the current opening state of the hydraulic motor, basically eliminate the possible error between the set value and the actual opening of the hydraulic motor, and improve the setting accuracy.

[0050] As one of the preferred solutions, the oil motor is close to a fully closed state, which means that the current opening is 0.5 to 3% of the effective opening.

[0051] The oil motor being close to a fully open state means that the current opening is 97 to 99.5% of the effective opening.

[0052] The above technical measures obtain the zero value when the oil motor is close to the fully closed state, and obtain the amplitude modulation value when the oil motor is close to the fully open state, so that the effective range of the LVDT displacement sensor obtained is reasonably slightly smaller than the effective opening of the oil motor, and a reasonable surplus control amount is reserved to prevent the oil motor from being fully closed while the throttle valve controlled by the oil motor (such as the turbine throttle valve) is not closed, and to prevent the oil motor from being fully opened while the throttle valve controlled by the oil motor is not fully opened, thereby improving the reliability of the oil motor servo control.

[0053] As one of the preferred solutions, the voltage signal data of each secondary coil and secondary coil of the LVDT displacement sensor is obtained as the preferred voltage signal data, which is collected and obtained as follows:

[0054] During the acquisition period, multiple sets of voltage signal data corresponding to the secondary coil are acquired;

[0055] Bubble sort the collected multiple groups of voltage signal data corresponding to the secondary coils in ascending order;

[0056] The voltage signal data that are too small or too large in the corresponding secondary coil queue are filtered out, multiple groups of voltage signal data in the middle section are extracted, and the average value of these extracted middle section voltage signal data is calculated to obtain the optimal voltage signal data of the corresponding secondary coil.

[0057] The above technical measures are targeted at the particularity of the oil motor servo system, so that the voltage signal data of the secondary coil and secondary coil of the LVDT displacement sensor collected each time are the preferred data, effectively eliminating the interference of the execution jitter of the pulse oil pressure on the signal data collected by the LVDT displacement sensor at the current execution moment of the oil motor, basically eliminating the possible error between the collected value and the actual value, improving the accuracy of voltage signal data collection, and thus helping to improve the range adjustment accuracy.

[0058] Furthermore, the preferred acquisition period for the voltage signal data is ≤20ms, and the acquisition period follows the program execution cycle of the servo controller;

[0059] The interval between the previous and next voltage signal data acquisition within the same acquisition time period is 15 to 25 μs;

[0060] During the acquisition period, 8 to 14 groups of voltage signal data corresponding to the secondary coil are collected;

[0061] In the corresponding secondary coil queue sorting, 4 to 8 groups of intermediate segment voltage signal data are extracted.

[0062] The above technical measures are based on the acquisition speed and data processing capabilities of the common analog acquisition chip (ADS8320E chip) of the servo controller. Under permitted conditions, the acquisition is as fast as possible, which is conducive to accurately obtaining the real displacement signal of the hydraulic motor. The obtained preferred voltage signal data is as accurate as possible and is less affected by the interference of execution jitter.

[0063] As one of the preferred solutions, the LVDT displacement sensors connected to the oil motor are relatively independent and form two redundant configurations;

[0064] The LVDT displacement sensor has a six-wire structure.

[0065] These technical measures address the operational stability requirements of the turbine unit's hydraulic motor servo system. By redundantly configuring two LVDT displacement sensors on the hydraulic motor, they effectively ensure stable and reliable semi-open-loop control of the motor. The LVDT displacement sensors employed offer advantages such as compact size, high precision, stable performance, excellent reliability, and long life.

[0066] The beneficial technical effect of the present invention is: the above technical measures are aimed at the particularity of the above-mentioned oil motor servo system, and the oil motor is controlled to be in a state close to fully closed / close to fully open based on the one-button automatic operation function of the servo controller. Under the corresponding state, the voltage signal data of the secondary coil and the secondary coil of the LVDT displacement sensor at the current position are dynamically obtained multiple times. These voltage signal data obtained dynamically multiple times are subjected to fluctuation judgment processing to obtain a setting value that can basically and truly reflect the current opening state of the oil motor. Assisted by eliminating possible blocking faults of the oil motor and possible disconnection faults of the LVDT displacement sensor during the setting process, the possible error between the setting value and the actual opening of the oil motor is basically eliminated, so that the obtained setting zero value and setting amplitude can basically and truly reflect the corresponding opening of the oil motor, and the opening and closing range of the oil motor is reliably matched to the optimal effective range of the LVDT displacement sensor as much as possible, with high accuracy, which is conducive to improving the reliability of the semi-open loop control of the oil motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a schematic diagram of an automatic tuning process of the present invention.

[0068] Figure 2 for Figure 1 Flow chart of the zero setting fluctuation judgment process.

[0069] Figure 3 for Figure 1 Flow chart of the fluctuation judgment of the amplitude modulation setting.

[0070] Figure 4 for Figure 1 Flowchart for judging whether the setting range is too small.

[0071] Figure 5 for Figure 1 Flowchart of interrupt line judgment. DETAILED DESCRIPTION

[0072] The present invention relates to a control parameter tuning method for an industrial servo control system, specifically a method for automatically tuning the effective range of an LVDT displacement sensor in an oil motor servo system. The main technical solution of the present invention is described in detail below with reference to a number of embodiments. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 The technical solution of the present invention is clearly and in detail explained; although other embodiments are drawn in separate drawings, their main structures can still refer to the drawings of Example 1.

[0073] It should be noted that the drawings of the present invention are schematic, and unnecessary details have been simplified to clarify the technical purpose of the present invention, so as to avoid blurring the technical solutions that the present invention contributes to the prior art.

[0074] Example 1

[0075] The hydraulic motor servo system of the present invention is connected to the hydraulic motor with two relatively independent, redundant LVDT displacement sensors (LVDT displacement sensor #1 and LVDT displacement sensor #2). Each LVDT displacement sensor has a six-wire structure, forming a redundant dual-channel, six-wire LVDT displacement sensor on the hydraulic motor.

[0076] The six-wire LVDT displacement sensor is mainly composed of an iron core, one set of primary coils, two sets of secondary coils (i.e., the secondary primary coil and the secondary secondary coil).

[0077] The iron core of the LVDT displacement sensor is connected to the piston rod of the hydraulic motor, and the iron core moves when the hydraulic motor opens and closes.

[0078] The LVDT displacement sensor's primary, secondary, and secondary coils are connected to a servo controller. The servo controller provides an excitation signal to the primary coil, which in turn generates voltage signals in the secondary and secondary coils. When the hydraulic motor moves the core, the voltage signals on the secondary and secondary coils change. By calculating the voltage difference between the primary and secondary coils, the opening and closing degree of the hydraulic motor can be determined.

[0079] Therefore, in a hydraulic motor servo system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. To ensure the reliability of this detection, it is necessary to calibrate the hydraulic motor's opening and closing range to match the LVDT displacement sensor's optimal effective range. The present invention achieves this automatic calibration process through a one-touch start on the servo controller.

[0080] See also Figure 1 As shown, the automatic tuning method for the effective range of the #1 LVDT displacement sensor of the present invention mainly includes the following zeroing tuning process, amplitude modulation tuning process, setting range too small judgment process, disconnection judgment process and completion tuning process.

[0081] See also Figure 1 and Figure 2 As shown, the zero adjustment process is:

[0082] The servo controller outputs a zeroing control signal (e.g., 4 mA) to the servo valve, driving the hydraulic motor to close. When the closing action of the hydraulic motor is approximately at 2% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the following zeroing adjustment process.

[0083] The fluctuation judgment and processing during the zero setting process are as follows:

[0084] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 10.

[0085] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero value D1′;

[0086] Obtain 10 sets of initial process zeroing values ​​D1′;

[0087] Step 2. Bubble sort the 10 sets of initial process zero values ​​D1′ in ascending order and cache them in a queue that can store 10 sets of data to form a queue sort.

[0088] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0089] Compare the difference with the set corresponding fluctuation threshold X, and the value of the corresponding fluctuation threshold X is 400;

[0090] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0091] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0092] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0093] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are subjected to difference processing to obtain the zero adjustment value D1′ of the current accumulation process;

[0094] Step 5. Combine the current accumulation process zero value D1′ in step 4 into the bubble sort in step 2;

[0095] Form a new queue sorting;

[0096] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0097] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0098] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0099] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0100] The number of repetitions of steps 4 to 6 is 50. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0101] During the above zero adjustment process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0102] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0103] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0104] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0105] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0106] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0107] See also Figure 1 and Figure 3 As shown in FIG, the amplitude modulation setting process is:

[0108] The servo controller outputs an amplitude modulation control signal (e.g., 20 mA) to the servo valve, driving the hydraulic motor to open. When the opening action of the hydraulic motor is approximately at 98% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the amplitude modulation setting process described below.

[0109] The fluctuation judgment and processing of the amplitude modulation setting process are as follows:

[0110] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 10.

[0111] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process amplitude modulation value F1′;

[0112] Obtain 10 sets of initial process amplitude modulation values ​​F1′;

[0113] Step 2. Bubble sort the 10 sets of initial process amplitude modulation values ​​F1′ in ascending order and cache them in a queue that can store 10 sets of data to form a queue sort.

[0114] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0115] Compare the difference with the set corresponding fluctuation threshold X, and the value of the corresponding fluctuation threshold X is 400;

[0116] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0117] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0118] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0119] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are processed by difference processing to obtain the current accumulation process amplitude modulation value F1′;

[0120] Step 5. Combine the current accumulated process amplitude modulation value F1′ in step 4 into the bubble sort in step 2;

[0121] Form a new queue sorting;

[0122] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0123] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0124] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0125] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0126] The number of repetitions of steps 4 to 6 is 50. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0127] During the above-mentioned amplitude modulation setting process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0128] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0129] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0130] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0131] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0132] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0133] See also Figure 1 and Figure 4 As shown in FIG, the process of judging that the setting range is too small is:

[0134] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zero adjustment, and calculate the difference to obtain the process zero adjustment value D1′;

[0135] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by the amplitude modulation, and calculate the difference to obtain the process amplitude modulation value F1′;

[0136] Calculate the difference between the process amplitude modulation value F1′ and the process zero adjustment value D1′, and compare the difference Dr1 with the set value -a. The set value -a is generally set to 1000 based on engineering experience. Usually, this engineering experience is calculated based on the total code value after removing the allowable vibration of the hydraulic motor, but it can also be customized by the user.

[0137] If the difference Dr1 is greater than the set value - a, it is determined that the setting range is normal and the disconnection judgment process begins;

[0138] Otherwise, it is determined that the setting range is too small, the setting fails and exits, and an alarm indicating that the setting range is too small is prompted on the servo control interface.

[0139] See also Figure 1 and Figure 5 As shown, the disconnection judgment process is:

[0140] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zeroing process, and sum them to obtain the zeroing secondary coil voltage signal data and value Sz1;

[0141] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by amplitude modulation, and sum them to obtain the amplitude modulation secondary coil voltage signal data and value Sf1;

[0142] The difference between the amplitude modulation secondary coil voltage signal data sum value Sf1 and the zero adjustment secondary coil voltage signal data sum value Sz1 is calculated, and the difference Dd1 is compared with the set value b. The value of the set value b is less than 15% of Dd1.

[0143] If the difference Dd1 is less than the set value b, it is determined that the wiring is normal and the setting process is completed;

[0144] Otherwise, it is judged as disconnection and the tuning fails to exit, and a disconnection alarm is prompted on the servo control interface.

[0145] The above disconnection judgment process is based on the characteristics of the LVDT displacement sensor. It analyzes that no matter what position the iron core moves to, the sum of the two sets of secondary coils remains basically unchanged. That is, during zero adjustment and amplitude modulation, the sum of the two sets of secondary coils remains basically unchanged. Excluding factors such as hydraulic motor vibration, if the difference Dd1 is less than b, the sensor wiring is determined to be normal; otherwise, the sensor is determined to be disconnected.

[0146] See also Figure 1 As shown, the completion setting process is:

[0147] After completing the above zero adjustment process, amplitude adjustment process, setting range too small judgment process and line break judgment process, the final setting parameters are determined;

[0148] In memory I 2 C stores the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment that meet the above-mentioned fluctuation judgment, too-small setting range judgment, and disconnection judgment conditions, the zero adjustment value D1 obtained based on the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment, the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation, and the amplitude modulation value F1 obtained based on the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation;

[0149] The setting is successfully exited.

[0150] The automatic adjustment method for the effective range of the #2 LVDT displacement sensor of the present invention is the same as the automatic adjustment method for the effective range of the #1 LVDT displacement sensor described above, and will not be described in detail.

[0151] Example 2

[0152] The oil motor servo system of the present invention is connected to an LVDT displacement sensor which has a six-wire structure.

[0153] The six-wire LVDT displacement sensor is mainly composed of an iron core, one set of primary coils, two sets of secondary coils (i.e., the secondary primary coil and the secondary secondary coil).

[0154] The iron core of the LVDT displacement sensor is connected to the piston rod of the hydraulic motor, and the iron core moves when the hydraulic motor opens and closes.

[0155] The LVDT displacement sensor's primary, secondary, and secondary coils are connected to a servo controller. The servo controller provides an excitation signal to the primary coil, which in turn generates voltage signals in the secondary and secondary coils. When the hydraulic motor moves the core, the voltage signals on the secondary and secondary coils change. By calculating the voltage difference between the primary and secondary coils, the opening and closing degree of the hydraulic motor can be determined.

[0156] Therefore, in a hydraulic motor servo system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. To ensure the reliability of this detection, it is necessary to calibrate the hydraulic motor's opening and closing range to match the LVDT displacement sensor's optimal effective range. The present invention achieves this automatic calibration process through a one-touch start on the servo controller.

[0157] The automatic adjustment method for the effective range of the LVDT displacement sensor of the present invention mainly includes the following zero adjustment adjustment process, amplitude modulation adjustment process, adjustment range too small judgment process, disconnection judgment process and completion adjustment process.

[0158] The zero adjustment process is:

[0159] The servo controller outputs a zeroing control signal (e.g., -40 mA) to the servo valve, driving the hydraulic motor to close. When the closing action of the hydraulic motor is approximately at 3% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the following zeroing adjustment process.

[0160] The fluctuation judgment and processing during the zero setting process are as follows:

[0161] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 8.

[0162] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero value D1′;

[0163] Obtain 8 sets of initial process zero adjustment values ​​D1′;

[0164] Step 2. Bubble sort the eight sets of initial process zero values ​​D1′ in ascending order and cache them in a queue that can store eight sets of data to form a queue sort.

[0165] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0166] Compare the difference with the set corresponding fluctuation threshold X, and the value of the corresponding fluctuation threshold X is 300;

[0167] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0168] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0169] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0170] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are subjected to difference processing to obtain the zero adjustment value D1′ of the current accumulation process;

[0171] Step 5. Combine the current accumulation process zero value D1′ in step 4 into the bubble sort in step 2;

[0172] Form a new queue sorting;

[0173] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0174] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0175] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0176] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0177] The number of repetitions of steps 4 to 6 is 40. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0178] During the above zero adjustment process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0179] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0180] - Within the set acquisition time period, 14 sets of voltage signal data of the secondary primary coil and secondary coil are collected at intervals of approximately 15μs;

[0181] - Sort the 14 sets of collected voltage signal data in ascending order by bubble sorting;

[0182] -Filter out the voltage signal data that is too small or too large, and extract the 8 sets of voltage signal data in the middle section;

[0183] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0184] The amplitude modulation setting process is:

[0185] The servo controller outputs an amplitude modulation control signal (for example, +40mA) to the servo valve, driving the hydraulic motor to open. When the opening action of the hydraulic motor is approximately at 97% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the amplitude modulation setting process described below.

[0186] The fluctuation judgment and processing of the amplitude modulation setting process are as follows:

[0187] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 8.

[0188] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process amplitude modulation value F1′;

[0189] Obtain 8 sets of initial process amplitude modulation values ​​F1′;

[0190] Step 2. Bubble sort the eight sets of initial process amplitude modulation values ​​F1′ in ascending order and cache them in a queue that can store eight sets of data to form a queue sort.

[0191] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0192] Compare the difference with the set corresponding fluctuation threshold X, and the value of the corresponding fluctuation threshold X is 300;

[0193] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0194] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0195] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0196] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are processed by difference processing to obtain the current accumulation process amplitude modulation value F1′;

[0197] Step 5. Combine the current accumulated process amplitude modulation value F1′ in step 4 into the bubble sort in step 2;

[0198] Form a new queue sorting;

[0199] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0200] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0201] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0202] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0203] The number of repetitions of steps 4 to 6 is 40. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0204] During the above-mentioned amplitude modulation setting process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0205] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0206] - Within the set acquisition time period, 14 sets of voltage signal data of the secondary primary coil and secondary coil are collected at intervals of approximately 15μs;

[0207] - Sort the 14 sets of collected voltage signal data in ascending order by bubble sorting;

[0208] -Filter out the voltage signal data that is too small or too large, and extract the 8 sets of voltage signal data in the middle section;

[0209] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0210] See also Figure 1 and Figure 4 As shown in FIG, the process of judging that the setting range is too small is:

[0211] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zero adjustment, and calculate the difference to obtain the process zero adjustment value D1′;

[0212] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by the amplitude modulation, and calculate the difference to obtain the process amplitude modulation value F1′;

[0213] Calculate the difference between the process amplitude modulation value F1′ and the process zero adjustment value D1′, and compare the difference Dr1 with the set value -a. The set value -a is generally set to 1100 based on engineering experience. Usually, this engineering experience is calculated based on the total code value after removing the allowable vibration of the hydraulic motor, but it can also be customized by the user.

[0214] If the difference Dr1 is greater than the set value - a, it is determined that the setting range is normal and the disconnection judgment process begins;

[0215] Otherwise, it is determined that the setting range is too small, the setting fails and exits, and an alarm indicating that the setting range is too small is prompted on the servo control interface.

[0216] See also Figure 1 and Figure 5 As shown, the disconnection judgment process is:

[0217] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zeroing process, and sum them to obtain the zeroing secondary coil voltage signal data and value Sz1;

[0218] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by amplitude modulation, and sum them to obtain the amplitude modulation secondary coil voltage signal data and value Sf1;

[0219] The difference between the amplitude modulation secondary coil voltage signal data sum value Sf1 and the zero adjustment secondary coil voltage signal data sum value Sz1 is calculated, and the difference value Dd1 is compared with the set value b. The value of the set value b is less than 18% of Dd1.

[0220] If the difference Dd1 is less than the set value b, it is determined that the wiring is normal and the setting process is completed;

[0221] Otherwise, it is judged as disconnection and the tuning fails to exit, and a disconnection alarm is prompted on the servo control interface.

[0222] The above disconnection judgment process is based on the characteristics of the LVDT displacement sensor. It analyzes that no matter what position the iron core moves to, the sum of the two sets of secondary coils remains basically unchanged. That is, during zero adjustment and amplitude modulation, the sum of the two sets of secondary coils remains basically unchanged. Excluding factors such as hydraulic motor vibration, if the difference Dd1 is less than b, the sensor wiring is determined to be normal; otherwise, the sensor is determined to be disconnected.

[0223] See also Figure 1 As shown, the completion setting process is:

[0224] After completing the above zero adjustment process, amplitude adjustment process, setting range too small judgment process and line break judgment process, the final setting parameters are determined;

[0225] In memory I 2 C stores the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment that meet the above-mentioned fluctuation judgment, too-small setting range judgment, and disconnection judgment conditions, the zero adjustment value D1 obtained based on the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment, the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation, and the amplitude modulation value F1 obtained based on the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation;

[0226] The setting is successfully exited.

[0227] Example 3

[0228] The hydraulic motor servo system of the present invention is connected to the hydraulic motor with two relatively independent, redundant LVDT displacement sensors (LVDT displacement sensor #1 and LVDT displacement sensor #2). Each LVDT displacement sensor has a six-wire structure, forming a redundant dual-channel, six-wire LVDT displacement sensor on the hydraulic motor.

[0229] The six-wire LVDT displacement sensor is mainly composed of an iron core, one set of primary coils, two sets of secondary coils (i.e., the secondary primary coil and the secondary secondary coil).

[0230] The iron core of the LVDT displacement sensor is connected to the piston rod of the hydraulic motor, and the iron core moves when the hydraulic motor opens and closes.

[0231] The LVDT displacement sensor's primary, secondary, and secondary coils are connected to a servo controller. The servo controller provides an excitation signal to the primary coil, which in turn generates voltage signals in the secondary and secondary coils. When the hydraulic motor moves the core, the voltage signals on the secondary and secondary coils change. By calculating the voltage difference between the primary and secondary coils, the opening and closing degree of the hydraulic motor can be determined.

[0232] Therefore, in a hydraulic motor servo system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. To ensure the reliability of this detection, it is necessary to calibrate the hydraulic motor's opening and closing range to match the LVDT displacement sensor's optimal effective range. The present invention achieves this automatic calibration process through a one-touch start on the servo controller.

[0233] The automatic adjustment method for the effective range of the #1LVDT displacement sensor of the present invention mainly includes the following zero adjustment adjustment process, amplitude modulation adjustment process, disconnection judgment process and completion adjustment process.

[0234] The zero adjustment process is:

[0235] The servo controller outputs a zeroing control signal (e.g., 1V) to the servo valve, driving the hydraulic motor to close. When the closing action of the hydraulic motor is approximately at 0.5% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the following zeroing adjustment process.

[0236] The fluctuation judgment and processing during the zero setting process are as follows:

[0237] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 12;

[0238] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero value D1′;

[0239] Obtain 12 sets of initial process zero adjustment values ​​D1′;

[0240] Step 2. Bubble sort the 12 sets of initial process zero values ​​D1′ in ascending order and cache them in a queue that can store 12 sets of data to form a queue sort.

[0241] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0242] Compare the difference with the set corresponding fluctuation threshold X; the value range of the corresponding fluctuation threshold X is 450;

[0243] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0244] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0245] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0246] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are subjected to difference processing to obtain the zero adjustment value D1′ of the current accumulation process;

[0247] Step 5. Combine the current accumulation process zero value D1′ in step 4 into the bubble sort in step 2;

[0248] Form a new queue sorting;

[0249] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0250] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0251] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0252] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0253] The number of repetitions of steps 4 to 6 is 70. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0254] During the above zero adjustment process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0255] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0256] - Within the set acquisition time period, eight sets of voltage signal data from the secondary coil and secondary coil are collected at intervals of approximately 25 μs;

[0257] - Sort the 8 sets of voltage signal data collected in ascending order by bubble sorting;

[0258] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0259] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0260] The amplitude modulation setting process is:

[0261] The servo controller outputs an amplitude modulation control signal (e.g., 5V) to the servo valve, driving the hydraulic motor to open. When the opening action of the hydraulic motor is approximately at 99.5% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil of the LVDT displacement sensor at the current position is dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the amplitude modulation setting process described below.

[0262] The fluctuation judgment and processing of the amplitude modulation setting process are as follows:

[0263] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 12;

[0264] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process amplitude modulation value F1′;

[0265] Obtain 12 sets of initial process amplitude modulation values ​​F1′;

[0266] Step 2. Bubble sort the 12 sets of initial process amplitude modulation values ​​F1′ in ascending order and cache them in a queue that can store 12 sets of data to form a queue sort.

[0267] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0268] Compare the difference with the set corresponding fluctuation threshold X, and the corresponding fluctuation threshold X is set to 450;

[0269] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the secondary primary and secondary coils (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the disconnection judgment process begins.

[0270] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0271] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0272] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are processed by difference processing to obtain the current accumulation process amplitude modulation value F1′;

[0273] Step 5. Combine the current accumulated process amplitude modulation value F1′ in step 4 into the bubble sort in step 2;

[0274] Form a new queue sorting;

[0275] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0276] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0277] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the secondary primary and secondary coils (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the disconnection judgment process begins.

[0278] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0279] The number of repetitions of steps 4 to 6 is 70. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0280] During the above-mentioned amplitude modulation setting process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0281] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0282] - Within the set acquisition time period, eight sets of voltage signal data from the secondary coil and secondary coil are collected at intervals of approximately 25 μs;

[0283] - Sort the 8 sets of voltage signal data collected in ascending order by bubble sorting;

[0284] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0285] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0286] The disconnection judgment process is:

[0287] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zeroing process, and sum them to obtain the zeroing secondary coil voltage signal data and value Sz1;

[0288] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by amplitude modulation, and sum them to obtain the amplitude modulation secondary coil voltage signal data and value Sf1;

[0289] The difference between the amplitude modulation secondary coil voltage signal data sum Sf1 and the zero adjustment secondary coil voltage signal data sum Sz1 is calculated, and the difference Dd1 is compared with the set value b. The set value b is less than 16% of Dd1.

[0290] If the difference Dd1 is less than the set value b, it is determined that the wiring is normal and the setting process is completed;

[0291] Otherwise, it is judged as disconnection and the tuning fails to exit, and a disconnection alarm is prompted on the servo control interface.

[0292] The above disconnection judgment process is based on the characteristics of the LVDT displacement sensor. It analyzes that no matter what position the iron core moves to, the sum of the two sets of secondary coils remains basically unchanged. That is, during zero adjustment and amplitude modulation, the sum of the two sets of secondary coils remains basically unchanged. Excluding factors such as hydraulic motor vibration, if the difference Dd1 is less than b, the sensor wiring is determined to be normal; otherwise, the sensor is determined to be disconnected.

[0293] The completion setting process is:

[0294] After completing the above zero adjustment process, amplitude adjustment process and disconnection judgment process, the final adjustment parameters are determined;

[0295] In memory I 2 C stores the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment that meet the above-mentioned fluctuation judgment and disconnection judgment conditions, the zero adjustment value D1 obtained based on the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment, the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation, and the amplitude modulation value F1 obtained based on the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation;

[0296] The setting is successfully exited.

[0297] The automatic adjustment method for the effective range of the #2 LVDT displacement sensor of the present invention is the same as the automatic adjustment method for the effective range of the #1 LVDT displacement sensor described above, and will not be described in detail.

[0298] Example 4

[0299] The hydraulic motor servo system of the present invention is connected to the hydraulic motor with two relatively independent, redundant LVDT displacement sensors (LVDT displacement sensor #1 and LVDT displacement sensor #2). Each LVDT displacement sensor has a six-wire structure, forming a redundant dual-channel, six-wire LVDT displacement sensor on the hydraulic motor.

[0300] The six-wire LVDT displacement sensor is mainly composed of an iron core, one set of primary coils, two sets of secondary coils (i.e., the secondary primary coil and the secondary secondary coil).

[0301] The iron core of the LVDT displacement sensor is connected to the piston rod of the hydraulic motor, and the iron core moves when the hydraulic motor opens and closes.

[0302] The LVDT displacement sensor's primary, secondary, and secondary coils are connected to a servo controller. The servo controller provides an excitation signal to the primary coil, which in turn generates voltage signals in the secondary and secondary coils. When the hydraulic motor moves the core, the voltage signals on the secondary and secondary coils change. By calculating the voltage difference between the primary and secondary coils, the opening and closing degree of the hydraulic motor can be determined.

[0303] Therefore, in a hydraulic motor servo system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. To ensure the reliability of this detection, it is necessary to calibrate the hydraulic motor's opening and closing range to match the LVDT displacement sensor's optimal effective range. The present invention achieves this automatic calibration process through a one-touch start on the servo controller.

[0304] The automatic adjustment method for the effective range of the #1LVDT displacement sensor of the present invention mainly includes the following zero adjustment adjustment process, amplitude modulation adjustment process, adjustment range too small judgment process and completion adjustment process.

[0305] The zero adjustment process is:

[0306] The servo controller outputs a zeroing control signal (e.g., -10V) to the servo valve, driving the hydraulic motor to close. When the closing action of the hydraulic motor is approximately at 1.5% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the following zeroing adjustment process.

[0307] The fluctuation judgment and processing during the zero setting process are as follows:

[0308] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 15.

[0309] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero value D1′;

[0310] Obtain 15 sets of initial process zeroing values ​​D1′;

[0311] Step 2. Bubble sort the 15 sets of initial process zero values ​​D1′ in ascending order and cache them in a queue that can store 15 sets of data to form a queue sort.

[0312] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0313] Compare the difference with the set corresponding fluctuation threshold X, and the value range of the corresponding fluctuation threshold X is 500;

[0314] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0315] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0316] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0317] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are subjected to difference processing to obtain the zero adjustment value D1′ of the current accumulation process;

[0318] Step 5. Combine the current accumulation process zero value D1′ in step 4 into the bubble sort in step 2;

[0319] Form a new queue sorting;

[0320] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0321] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0322] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0323] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0324] The number of repetitions of steps 4 to 6 is 80. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0325] During the above zero adjustment process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0326] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0327] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0328] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0329] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0330] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0331] The amplitude modulation setting process is:

[0332] The servo controller outputs an amplitude modulation control signal (e.g., +10V) to the servo valve, driving the hydraulic motor to open. When the opening action of the hydraulic motor is approximately at 98.5% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the amplitude modulation setting process described below.

[0333] The fluctuation judgment and processing of the amplitude modulation setting process are as follows:

[0334] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 15.

[0335] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process amplitude modulation value F1′;

[0336] Obtain 15 sets of initial process amplitude modulation values ​​F1′;

[0337] Step 2. Bubble sort the 15 sets of initial process amplitude modulation values ​​F1′ in ascending order and cache them in a queue that can store 15 sets of data to form a queue sort.

[0338] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0339] Compare the difference with the set corresponding fluctuation threshold X, and the corresponding fluctuation threshold X is set to 500;

[0340] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0341] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0342] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0343] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are processed by difference processing to obtain the current accumulation process amplitude modulation value F1′;

[0344] Step 5. Combine the current accumulated process amplitude modulation value F1′ in step 4 into the bubble sort in step 2;

[0345] Form a new queue sorting;

[0346] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0347] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0348] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0349] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0350] The number of repetitions of steps 4 to 6 is 80. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0351] During the above-mentioned amplitude modulation setting process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0352] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0353] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0354] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0355] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0356] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0357] The process of judging whether the setting range is too small is as follows:

[0358] Obtain the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded in the zero adjustment, and calculate the difference to obtain the process zero adjustment value D1′;

[0359] Obtain the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by the amplitude modulation, and calculate the difference to obtain the process amplitude modulation value F1′;

[0360] Calculate the difference between the process amplitude modulation value F1′ and the process zero adjustment value D1′, and compare the difference Dr1 with the set value -a. The set value -a is generally set to 1200 based on engineering experience. Usually, this engineering experience is calculated based on the total code value after removing the allowable vibration of the hydraulic motor, but it can also be customized by the user.

[0361] If the difference Dr1 is greater than the set value - a, it is determined that the setting range is normal and the setting process is completed;

[0362] Otherwise, it is determined that the setting range is too small, the setting fails and exits, and an alarm indicating that the setting range is too small is prompted on the servo control interface.

[0363] The completion setting process is:

[0364] After completing the above zero adjustment process, amplitude adjustment process and the process of judging whether the adjustment range is too small, the final adjustment parameters are determined;

[0365] In memory I 2 C stores the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment that meet the above-mentioned fluctuation judgment and too-small setting range judgment conditions, the zero adjustment value D1 obtained based on the voltage signal data (Z1a, Z1b) of the secondary primary and secondary coils recorded by zero adjustment, the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation, and the amplitude modulation value F1 obtained based on the voltage signal data (F1a, F1b) of the secondary primary and secondary coils recorded by amplitude modulation;

[0366] The setting is successfully exited.

[0367] The automatic adjustment method for the effective range of the #2 LVDT displacement sensor of the present invention is the same as the automatic adjustment method for the effective range of the #1 LVDT displacement sensor described above, and will not be described in detail.

[0368] Example 5

[0369] The hydraulic motor servo system of the present invention is connected to the hydraulic motor with two relatively independent, redundant LVDT displacement sensors (LVDT displacement sensor #1 and LVDT displacement sensor #2). Each LVDT displacement sensor has a six-wire structure, forming a redundant dual-channel, six-wire LVDT displacement sensor on the hydraulic motor.

[0370] The six-wire LVDT displacement sensor is mainly composed of an iron core, one set of primary coils, two sets of secondary coils (i.e., the secondary primary coil and the secondary secondary coil).

[0371] The iron core of the LVDT displacement sensor is connected to the piston rod of the hydraulic motor, and the iron core moves when the hydraulic motor opens and closes.

[0372] The LVDT displacement sensor's primary, secondary, and secondary coils are connected to a servo controller. The servo controller provides an excitation signal to the primary coil, which in turn generates voltage signals in the secondary and secondary coils. When the hydraulic motor moves the core, the voltage signals on the secondary and secondary coils change. By calculating the voltage difference between the primary and secondary coils, the opening and closing degree of the hydraulic motor can be determined.

[0373] Therefore, in a hydraulic motor servo system, an LVDT displacement sensor is used to detect the hydraulic motor's opening displacement. To ensure the reliability of this detection, it is necessary to calibrate the hydraulic motor's opening and closing range to match the LVDT displacement sensor's optimal effective range. The present invention achieves this automatic calibration process through a one-touch start on the servo controller.

[0374] The automatic adjustment method for the effective range of the #1LVDT displacement sensor of the present invention mainly includes the following zero adjustment adjustment process, amplitude modulation adjustment process and completion adjustment process.

[0375] The zero adjustment process is:

[0376] The servo controller outputs a zeroing control signal (e.g., 4 mA) to the servo valve, driving the hydraulic motor to close. When the closing action of the hydraulic motor is approximately at 0.5-3% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the following zeroing adjustment process.

[0377] The fluctuation judgment and processing during the zero setting process are as follows:

[0378] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 10.

[0379] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process zero value D1′;

[0380] Obtain 10 sets of initial process zeroing values ​​D1′;

[0381] Step 2. Bubble sort the 10 sets of initial process zero values ​​D1′ in ascending order and cache them in a queue that can store 10 sets of data to form a queue sort.

[0382] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0383] Compare the difference with the set corresponding fluctuation threshold X; the value range of the corresponding fluctuation threshold X is 400;

[0384] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0385] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0386] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0387] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are subjected to difference processing to obtain the zero adjustment value D1′ of the current accumulation process;

[0388] Step 5. Combine the current accumulation process zero value D1′ in step 4 into the bubble sort in step 2;

[0389] Form a new queue sorting;

[0390] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0391] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0392] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (Z1a, Z1b) are recorded and stored in the zero adjustment buffer. The fluctuation judgment is completed and the amplitude modulation adjustment process begins.

[0393] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0394] The number of repetitions of steps 4 to 6 is 60. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0395] During the above zero adjustment process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0396] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0397] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0398] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0399] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0400] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0401] The amplitude modulation setting process is:

[0402] The servo controller outputs an amplitude modulation control signal (e.g., 20 mA) to the servo valve, driving the hydraulic motor to open. When the opening action of the hydraulic motor is approximately at 97% to 99.5% of the effective opening (the effective opening is set to 100%), the voltage signal data of the secondary coil and secondary coil at the current position of the LVDT displacement sensor are dynamically obtained. The voltage signal data of the secondary coil and secondary coil obtained multiple times are subjected to the fluctuation judgment processing of the amplitude modulation setting process described below.

[0403] The fluctuation judgment and processing of the amplitude modulation setting process are as follows:

[0404] Step 1. Initially dynamically collect m voltage signal data of the secondary primary coil and secondary secondary coil, where m is 10.

[0405] The voltage signal data of each secondary primary coil and secondary secondary coil are processed by difference processing to obtain the corresponding initial process amplitude modulation value F1′;

[0406] Obtain 10 sets of initial process amplitude modulation values ​​F1′;

[0407] Step 2. Bubble sort the 10 sets of initial process amplitude modulation values ​​F1′ in ascending order and cache them in a queue that can store 10 sets of data to form a queue sort.

[0408] Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting;

[0409] Compare the difference with the set corresponding fluctuation threshold X, and the value of the corresponding fluctuation threshold X is 400;

[0410] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the process of judging whether the setting range is too small is entered.

[0411] Otherwise, it is determined that the fluctuation is too large and proceed to step 4;

[0412] Step 4. If the fluctuation is determined to be too large, the voltage signal data of the secondary primary coil and the secondary secondary coil are accumulated and collected once;

[0413] The voltage signal data of the secondary coil and the secondary coil currently collected by accumulation are processed by difference processing to obtain the current accumulation process amplitude modulation value F1′;

[0414] Step 5. Combine the current accumulated process amplitude modulation value F1′ in step 4 into the bubble sort in step 2;

[0415] Form a new queue sorting;

[0416] Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting in step 5;

[0417] Compare the difference with the corresponding fluctuation threshold X set for judgment;

[0418] If the difference is less than the corresponding fluctuation threshold X, the fluctuation is determined to be normal. The latest voltage signal data of the sub-primary coil and the sub-secondary coil (F1a, F1b) are recorded and stored in the amplitude modulation buffer. The fluctuation judgment is completed and the tuning process is completed.

[0419] Otherwise, it is determined that the fluctuation is too large and steps 4 to 6 are repeated;

[0420] The number of repetitions of steps 4 to 6 is 60. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits. The servo control interface prompts that the actual displacement fluctuation of the #1 LVDT displacement sensor is large.

[0421] During the above-mentioned amplitude modulation setting process, the voltage signal data of the secondary coil and the secondary coil dynamically collected each time are all preferred voltage signal data. The preferred voltage signal data are collected and obtained in the following manner:

[0422] - The program execution cycle (approximately 60ms) of the servo controller is used as an acquisition cycle. Within the acquisition cycle, a collection time period (≤20ms) is set based on the acquisition speed of the analog acquisition chip - ADS8320E chip.

[0423] - Within the set acquisition time period, 10 sets of voltage signal data of the secondary primary coil / secondary coil are collected at intervals of approximately 20μs;

[0424] - Sort the 10 sets of collected voltage signal data in ascending order by bubble sorting;

[0425] -Filter out the voltage signal data that is too small or too large, and extract the 4 sets of voltage signal data in the middle section;

[0426] - Calculate the average value of these extracted intermediate segment voltage signal data to obtain the optimal voltage signal data of the primary coil / secondary coil.

[0427] The completion setting process is:

[0428] After completing the above zero adjustment and amplitude modulation adjustment processes, the final adjustment parameters are determined;

[0429] In memory I 2C stores the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded by zero adjustment that meet the above-mentioned fluctuation judgment conditions, the zero adjustment value D1 obtained based on the voltage signal data (Z1a, Z1b) of the secondary coil and the secondary coil recorded by zero adjustment, the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by amplitude modulation, and the amplitude modulation value F1 obtained based on the voltage signal data (F1a, F1b) of the secondary coil and the secondary coil recorded by amplitude modulation;

[0430] The setting is successfully exited.

[0431] The automatic adjustment method for the effective range of the #2 LVDT displacement sensor of the present invention is the same as the automatic adjustment method for the effective range of the #1 LVDT displacement sensor described above, and will not be described in detail.

[0432] The above embodiments are only used to illustrate the present invention, rather than to limit it.

[0433] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the above embodiments or make equivalent replacements for some of the technical features therein, such as zeroing when the oil motor is fully closed and amplitude modulation when it is fully open, etc.; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A method for automatically adjusting the range of an LVDT displacement sensor in an oil motor servo system, including a zero adjustment process, an amplitude modulation adjustment process, and a completion adjustment process; The zero adjustment process is: The servo controller outputs a zeroing control signal to the servo valve. When the control oil motor is close to the fully closed state, the voltage signal data of the secondary and secondary coils of the LVDT displacement sensor at the current position is dynamically obtained. The voltage signal data of the secondary and secondary coils obtained dynamically multiple times are used for fluctuation judgment. If the fluctuation judgment condition is met, the latest voltage signal data of the primary and secondary coils will be recorded and the amplitude modulation setting process will be started; otherwise, it will fail and exit; The AM setting process is: The servo controller outputs an amplitude modulation control signal to the servo valve. When the control oil motor is close to the fully open state, the voltage signal data of the secondary and secondary coils of the LVDT displacement sensor at the current position is dynamically obtained. The voltage signal data of the secondary and secondary coils obtained dynamically multiple times are used for fluctuation judgment. If the fluctuation judgment condition is met, the latest voltage signal data of the primary and secondary coils will be recorded and the tuning process will be completed; otherwise, it will fail and exit; The tuning process is completed by: The memory stores the voltage signal data of the secondary primary and secondary coils recorded in the zero adjustment that meet the judgment conditions, the zero adjustment value obtained based on the voltage signal data of the secondary primary and secondary coils recorded in the zero adjustment, the voltage signal data of the secondary primary and secondary coils recorded in the amplitude modulation, and the amplitude modulation value obtained based on the voltage signal data of the secondary primary and secondary coils recorded in the amplitude modulation; The setting is successfully exited; The fluctuation judgment process is: Step 1. Initially dynamically collect m times of voltage signal data of the sub-primary and sub-secondary coils, where m is ≥ 8; The voltage signal data of each sub-primary and sub-secondary coils are processed by difference to obtain the initial process zero adjustment value / process amplitude modulation value of the corresponding time; Obtain m groups of initial process zero adjustment values / process amplitude adjustment values; Step 2. Bubble sort the m groups of initial process zero adjustment values / process amplitude adjustment values ​​in ascending order; Form a queue sorting; Step 3. Calculate the difference between the maximum and minimum values ​​in the queue sorting; The difference is compared with the corresponding fluctuation threshold value set in the range of 300 to 500. If the difference is less than the corresponding fluctuation threshold value, the fluctuation is determined to be normal and the fluctuation judgment is completed. Otherwise, go to step 4; Step 4. If the fluctuation is determined to be too large, the voltage signal data of the sub-primary and sub-secondary coils are accumulated and collected once; The voltage signal data of the secondary coil and the secondary coil currently collected and accumulated are processed by difference processing to obtain the current accumulated process zero adjustment value / process amplitude modulation value; Step 5. Combine the current accumulated process zero adjustment value / process amplitude adjustment value of step 4 into the bubble sort of step 2; Form a new queue sorting; Step 6. Calculate the difference between the maximum and minimum values ​​in the queue sorting of step 5; Compare the difference with the corresponding fluctuation threshold. If the difference is less than the corresponding fluctuation threshold, the fluctuation is considered normal and the fluctuation judgment is completed. Otherwise, repeat steps 4 to 6. The number of repetitions of steps 4 to 6 is ≤ 80. If the fluctuation is still judged to be too large after the maximum number of repetitions, the tuning fails and exits.

2. The automatic range setting method of the LVDT displacement sensor in the oil motor servo system according to claim 1 is characterized in that: The LVDT displacement sensor range automatic adjustment method also includes a setting range too small judgment process; The process of judging whether the setting range is too small is as follows: Obtain the voltage signal data of the secondary coil and the secondary coil recorded in the zeroing process, and calculate the difference to obtain the process zeroing value; Obtain the voltage signal data of the secondary coil and the secondary coil recorded by the amplitude modulation, and calculate the difference to obtain the process amplitude modulation value; Calculate the difference between the process amplitude adjustment value and the process zero adjustment value, and compare the difference with the set value. If the difference is greater than the set value, it is determined that the setting range is normal and the automatic tuning is completed. Otherwise, it is determined that the setting range is too small and the tuning fails and exits. The value range of the setting value 1 is 800 to 1200.

3. The automatic range setting method for LVDT displacement sensor in the oil motor servo system according to claim 1 or 2, characterized in that: The LVDT displacement sensor range automatic adjustment method also includes a disconnection judgment process; The disconnection judgment process is: Obtaining the voltage signal data of the secondary coil and the secondary coil recorded in the zeroing process, and summing the data to obtain the zeroing secondary coil voltage signal data and value; Acquire the voltage signal data of the secondary coil and the secondary coil recorded by the amplitude modulation, and sum them to obtain the sum value of the voltage signal data of the amplitude modulation secondary coil; Calculate the difference between the sum of the voltage signal data of the amplitude modulation secondary coil and the sum of the voltage signal data of the zero adjustment secondary coil, and compare the difference with the set value 2. If the difference is less than the set value 2, it is determined that the wiring is normal and the automatic tuning is completed. Otherwise, it is determined that the wiring is broken and the tuning fails and exits. The value of the second set value is less than 20% of the difference between the sum of the amplitude modulation secondary coil voltage signal data and the sum of the zero adjustment secondary coil voltage signal data.

4. The automatic range setting method for LVDT displacement sensor in the hydraulic motor servo system according to claim 1 is characterized in that: The oil motor being close to the fully closed state means that the current opening is 0.5 to 3% of the effective opening.

5. The automatic range adjustment method for LVDT displacement sensor in the hydraulic motor servo system according to claim 1 is characterized in that: The oil motor being close to a fully open state means that the current opening is 97 to 99.5% of the effective opening.

6. The automatic range setting method for LVDT displacement sensor in the hydraulic motor servo system according to claim 1 is characterized in that: The voltage signal data of each secondary coil and secondary coil of the LVDT displacement sensor is preferably obtained as follows: During the acquisition period, multiple sets of voltage signal data corresponding to the secondary coil are acquired; Bubble sort the collected multiple groups of voltage signal data corresponding to the secondary coils in ascending order; The voltage signal data that are too small or too large in the corresponding secondary coil queue are filtered out, multiple groups of voltage signal data in the middle section are extracted, and the average value of these extracted middle section voltage signal data is calculated to obtain the optimal voltage signal data of the corresponding secondary coil.

7. The automatic range setting method for LVDT displacement sensor in the oil motor servo system according to claim 6 is characterized in that: The preferred acquisition period of the voltage signal data is ≤20ms, and the acquisition period follows the program execution cycle of the servo controller; The interval between the previous and next voltage signal data acquisition within the same acquisition time period is 15 to 25 μs; During the acquisition period, 8 to 14 groups of voltage signal data corresponding to the secondary coil are collected; In the corresponding secondary coil queue sorting, 4 to 8 groups of intermediate segment voltage signal data are extracted.

8. The automatic range setting method for LVDT displacement sensor in the hydraulic motor servo system according to claim 1 is characterized in that: The LVDT displacement sensors connected to the hydraulic motor are relatively independent and form two redundant configurations; The LVDT displacement sensor has a six-wire structure.

Images