Sliding resistance type displacement sensor calibration method

Abstract

The invention belongs to the technical field of displacement sensors, and particularly relates to a sliding resistance type displacement sensor calibration method, which comprises the following steps of: (1) acquiring a calibration data set; a sliding block of the sliding resistance type displacement sensor to be calibrated is moved, the sliding block slides from an initial position S1 to a target position Sn according to the displacement interval d, and a calibration data set # imgabs0 # is constructed according to the voltage value ak of each position point; acquiring a current voltage value v by using the sliding resistance type displacement sensor to be calibrated, and calculating a real displacement D according to the current voltage value v and the calibration data set M; before the sensor is used, a precise measuring instrument is adopted to measure corresponding voltage and displacement as calibration data, calibration is carried out through the calibration data, the measurement accuracy of the sensor is improved, and errors are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of displacement sensors, and in particular relates to a calibration method for a sliding resistance type displacement sensor. Background Art

[0002] The sliding resistor displacement sensor is a device that converts mechanical displacement into electrical signal output and is widely used in various industrial automation systems. The core of the sliding resistor displacement sensor is a variable resistor whose resistance changes as the slider moves on the resistor track. When the sensor is connected to a steady-state DC power supply, the position of the slider can be accurately reflected by measuring the voltage change between the slider and the starting end, thereby realizing the monitoring of the displacement of the object.

[0003] Due to the materials and processes of the sliding resistor displacement sensor (manual multiple coating, natural drying, etc.), the sliding resistor displacement sensor cannot meet the stable accuracy requirements. For example, the sliding resistor displacement sensor with a nominal error range of 1% to 2% may even deviate by 30% due to the measured error caused by local uniformity, which cannot meet the requirements in a high-precision use environment; the displacement sensor has a range of 0 to 20cm, and the corresponding resistor feedback voltage value is 0 to 2V. The actual product requires an accuracy of 1mm. If the displacement sensor is linear and uniform, the voltage should change by 10mV for every 1mm movement of the slider. However, in actual applications, when the slider moves 1mm, the voltage measurement value may change between 7mV and 13mV, resulting in an error range of 30%, and the corresponding displacement cannot be fed back within the accuracy requirement range. Sensor calibration can effectively improve the measurement accuracy and reliability of the sensor and ensure its stable performance in various industrial applications; but there is no method to easily and quickly calibrate the sliding resistor displacement sensor. Summary of the invention

[0004] The purpose of the present invention is to provide a sliding resistor displacement sensor calibration method. Before the sensor is used, the method uses a precision measuring instrument to measure the corresponding voltage and displacement as calibration data. The calibration data is used for calibration to improve the measurement accuracy of the sensor and reduce errors.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A sliding resistance displacement sensor calibration method comprises the following steps:

[0007] (1) Obtain a calibration data set;

[0008] Move the slider of the sliding resistance displacement sensor to be calibrated so that it slides from the initial position S1 to the target position S according to the displacement interval d. n, and measure the voltage value a of the displacement point after each movement k , k = 1, 2, ..., n; build a calibration data set

[0009] (2) Calibration of sliding resistance displacement sensor;

[0010] Using the sliding resistance displacement sensor to be calibrated to obtain a current voltage value v, and calculating a true displacement D according to the current voltage value v and the calibration data set M;

[0011]

[0012] Where D is the actual displacement value currently measured, a k+1 >v,a k ≤v,a k+1 and a k The voltage value of the displacement point measured in step (1) is the actual displacement calculated by querying the corresponding displacement point in the calibration data set based on the current voltage value v and the voltage values ​​before and after the point.

[0013] Furthermore, the sliding resistance type displacement sensor to be calibrated is connected to a motor or a stepping motor with an encoder to control the movement of a slider of the sliding resistance type displacement sensor;

[0014] The movement of the slider with a displacement distance d is achieved by controlling the rotation of the motor.

[0015] Furthermore, the motor is connected to a controller, the controller is connected to a voltage measuring device, and the calibration data set is automatically acquired through the controller.

[0016] Furthermore, the controller is provided with a storage module for storing the calibration data set and a calculation module for calculating the real displacement, and the computer module calculates the real displacement by the following formula;

[0017]

[0018] Where D is the actual displacement value currently measured, a k+1 >v,a k ≤v,a k+1 and a k The voltage value of the displacement point measured in step (1) is the actual displacement calculated by querying the corresponding displacement point in the calibration data set based on the current voltage value v and the voltage values ​​before and after the point.

[0019] Furthermore, the smaller the displacement interval d is, the more accurate the measured true displacement value is.

[0020] The present invention solves the problem that when the linear uniformity of the sliding resistance displacement sensor is not ideal, the displacement measurement requirement of the product can be well realized; before use, the displacement voltage of the displacement sensor is marked according to the set accuracy, and when in use, the marked displacement is found, and then the calibration displacement is calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the process of the present invention.

[0022] Figure 2 It is a simple schematic diagram of the present invention.

[0023] Figure 3 A schematic diagram of the present invention for automatically implementing calibration and measurement. DETAILED DESCRIPTION

[0024] like Figure 1 to Figure 3 As shown, a sliding resistance displacement sensor calibration method provided in this embodiment includes the following steps:

[0025] Step 1: Fix the sliding resistor displacement sensor to facilitate the movement of the slider and enable accurate measurement.

[0026] In this embodiment, after the sliding resistance displacement sensor is fixed, a motor with an encoder is connected to the sensor, the motor drives the slider of the sensor to move, and the encoder is controlled to achieve precise movement of the slider.

[0027] Step 2: Set the initial position S1 and target position S n and displacement distance d. In this embodiment, the starting position of the displacement sensor is taken as the initial position S1, and the end position is taken as the target position S n , the displacement spacing d is 1mm.

[0028] The setting and stopping of the displacement interval d is achieved by controlling the speed and angle of the motor. A high-precision voltage measuring device is connected to the displacement sensor, and the voltage value a of each displacement point is measured by the voltage measuring device. k .

[0029] The voltage measurement value corresponding to the displacement point S1 is a1, S n The corresponding voltage measurement value is a n , the displacement of the displacement sensor is (n-1)d.

[0030] According to the physical characteristics of the sliding resistance displacement sensor, from the starting position to the end position, the measured voltage value increases as the slider moves, that is, a1 <a2<…<a n It should be known that if the reverse measurement is also possible, that is, as the slider moves, the voltage value becomes smaller and smaller.

[0031] The corresponding position points and measured voltage values ​​are mapped one by one to construct a calibration data set And store the corresponding calibration data set.

[0032] In order to automatically obtain the calibration data set, in this embodiment, a controller is connected to the motor, a control instruction is loaded into the controller, and the controller is connected to a voltage measuring device to intelligently obtain the calibration data set. The calibration data set is stored in a storage module connected to the controller.

[0033] Step 3: Apply the obtained calibration data set to the actual displacement measurement. During the measurement, the slider in the sliding resistance displacement sensor moves to a certain position, obtains the voltage value v at the current position, and calculates the actual displacement D based on the current voltage value v and the calibration data set M;

[0034]

[0035] Where D is the actual displacement value currently measured, a k+1 >v,a k ≤v,a k+1 and a k The voltage value of the displacement point measured in step (1) is the actual displacement calculated by querying the corresponding displacement point in the calibration data set based on the current voltage value v and the voltage values ​​before and after the point.

[0036] In this embodiment, the controller loads the calculation module based on the above formula principle, and after obtaining the voltage value v at the current position, the storage module queries the corresponding displacement point and the voltage values ​​a before and after the point. k+1 、a k ,like Figure 2 As shown,

[0037] The above description is only a preferred implementation manner of the present invention, but the protection scope of the present invention is not limited thereto, and any modification and replacement based on the technical solution and inventive concept provided by the present invention should be included in the protection scope of the present invention.

Claims

1. A sliding resistance displacement sensor calibration method, characterized in that: The steps include: (1) Obtain a calibration data set; Move the slider of the sliding resistance displacement sensor to be calibrated so that it slides from the initial position S1 to the target position S according to the displacement interval d. n , and the voltage value a at each location point k , k = 1, 2, ..., n; build a calibration data set (2) Calibration of sliding resistance displacement sensor; Using the sliding resistance displacement sensor to be calibrated to obtain a current voltage value v, and calculating a true displacement D according to the current voltage value v and the calibration data set M; Where D is the actual displacement value currently measured, a k+1 >v,a k ≤v,a k+1 and a k The voltage value of the displacement point measured in step (1) is the actual displacement calculated by querying the corresponding displacement point in the calibration data set based on the current voltage value v and the voltage values ​​before and after the point.

2. A sliding resistance displacement sensor calibration method according to claim 1, characterized in that: The sliding resistance type displacement sensor to be calibrated is connected to a motor or a stepping motor with an encoder to control the movement of a slider of the sliding resistance type displacement sensor; The movement of the slider with a displacement distance d is achieved by controlling the rotation of the motor.

3. A sliding resistance displacement sensor calibration method according to claim 2, characterized in that: The motor is connected to a controller, and the controller is connected to a voltage measuring device, so that the calibration data set is automatically acquired through the controller.

4. A sliding resistance displacement sensor calibration method according to claim 3, characterized in that: The controller is provided with a storage module for storing the calibration data set and a calculation module for calculating the real displacement, and the computer module calculates the real displacement by the following formula; Where D is the actual displacement value currently measured, a k+1 >v,a k ≤v,a k+1 and a k The voltage value of the displacement point measured in step (1) is the actual displacement calculated by querying the corresponding displacement point in the calibration data set based on the current voltage value v and the voltage values ​​before and after the point.

5. A sliding resistance displacement sensor calibration method according to claim 1, characterized in that: The smaller the displacement distance d is, the more accurate the measured true displacement value is.

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