阅读说明：本技术 一种动磁式绝对位置检测装置和方法 (Moving magnet type absolute position detection device and method ) 是由 王雷 张桢 徐永向 于 2021-04-17 设计创作，主要内容包括：本发明涉及一种动磁式绝对位置检测装置和方法,该检测装置包括动磁头、传感器采集板和信号计算模块；动磁头安装于待检测位置的运动构件上,随运动构件进行线性移动,使用多个永磁体根据特定编码和排布方式组合的三排永磁阵列构成；传感器采集板平行固定于动磁头下方,提供位置基准,由多组等间隔排布的三排线性磁性传感器阵列组成；信号计算模块由数据处理单元、存储模块和数据通信模块组成,实时采集磁传感器的信号并解算出绝对位移信息。本发明可实现在无线缆约束的条件下对被测运动构件进行绝对位置检测和唯一编码,提高位置检测装置的灵活性和运动行程,采用三轴线性磁传感器阵列进行位移测量和细分,提高了装置的测量精度,节约了成本。(The invention relates to a moving magnetic absolute position detection device and a method, wherein the detection device comprises a moving magnetic head, a sensor acquisition board and a signal calculation module; the moving magnetic head is arranged on a moving component at a position to be detected, linearly moves along with the moving component, and is formed by three rows of permanent magnet arrays combined by a plurality of permanent magnets according to a specific coding and arrangement mode; the sensor acquisition board is fixed below the moving magnetic head in parallel, provides position reference and consists of a plurality of groups of three-row linear magnetic sensor arrays which are arranged at equal intervals; the signal calculation module consists of a data processing unit, a storage module and a data communication module, and is used for collecting the signals of the magnetic sensor in real time and calculating absolute displacement information. The invention can realize absolute position detection and unique coding of the detected motion component under the condition of no cable constraint, improves the flexibility and the motion stroke of the position detection device, adopts the three-axis linear magnetic sensor array to carry out displacement measurement and subdivision, improves the measurement precision of the device and saves the cost.)

1. A moving-magnet type absolute position detecting apparatus characterized by comprising: the device comprises a moving magnetic head, a sensor acquisition board and a signal calculation module; the moving magnetic head is fixedly arranged on a moving component to be detected for linear displacement and can linearly move along with the moving component; the sensor acquisition board is fixedly arranged below the moving magnetic head in parallel, and is distributed with a plurality of groups of three rows of magnetic sensor arrays, so that magnetic field signals provided by the moving magnetic head are detected in real time, and a position positioning reference is provided for displacement measurement; the signal calculation module comprises a data processing unit, a storage module and a data communication module and is used for acquiring the magnetic field information of the moving magnetic head in real time to calculate the absolute displacement.

2. The moving-magnet absolute position detecting device according to claim 1, characterized in that: the moving magnetic head comprises a first permanent magnet array, a second permanent magnet array and a third permanent magnet array, wherein the three rows of permanent magnet arrays are arranged in parallel at certain intervals, the first permanent magnet array and the second permanent magnet array are used for measuring the serial number and the relative displacement of the moving magnetic head, and the third permanent magnet array is used for encoding the relative displacement interval.

3. The moving-magnet absolute position detecting device according to claim 2, characterized in that: the first permanent magnet array and the second permanent magnet array are formed by closely arranging a plurality of permanent magnets with the same size according to an N-S or S-N mode, and the third permanent magnet array is formed by closely arranging a plurality of permanent magnets with different sizes according to a binary coding rule in an N-S or S-N mode.

4. The moving-magnet absolute position detecting device according to claim 1, characterized in that: the sensor acquisition board is formed by arranging a plurality of groups of three rows of magnetic sensor arrays according to a specific interval.

5. The moving-magnet absolute position detecting device according to claim 4, characterized in that: the three-row linear magnetic sensor array comprises a first sensor array, a second sensor array and a third sensor array, the first sensor array and the second sensor array are respectively used for acquiring magnetic signals of the first permanent magnet array and the second permanent magnet array, and the third sensor array is used for detecting magnetic signals of the third permanent magnet array.

6. The moving-magnet absolute position detecting device according to claim 5, characterized in that: the first sensor array and the second sensor array are arranged according to a specific spacing distance, a plurality of three-axis linear magnetic sensor chips are used for measuring and subdividing magnetic signals, the third sensor array is arranged according to a specific distance, and a plurality of linear magnetic sensor chips are used for measuring magnetic signals.

7. The moving-magnet absolute position detecting device according to claim 1, characterized in that: the signal processing module is used for processing the magnetic sensor signals and resolving the displacement signals, and the signal processing module is provided with a communication module and can output the absolute displacement signals obtained through calculation.

8. A moving-magnet absolute position detection method is characterized in that: applied to the moving magnet type absolute position detecting device according to any one of claims 1 to 7; the moving magnet type absolute position detection method comprises the following steps:

s1, sending a data reading instruction to the N groups of three-row magnetic sensor arrays on the sensor acquisition board by the data processing unit in a bus mode, reading digital magnetic signals output by the N groups of three-row magnetic sensor arrays in real time, and filtering and storing the digital magnetic signals in groups;

s2, numbering and preprocessing the magnetic signals after the grouping storage, judging and recording the group number of effective data by the data processing unit according to the magnitude of the magnetic signals, and determining the initial position offset of the motion unit;

s3, extracting effective data according to the group number, comparing the data detected by the third sensor array in the data with a set threshold value T, and carrying out binary coding;

s4, selecting data of the first sensor array and the second sensor array in the effective data, and identifying the serial number of the read head according to the positive and negative of the data;

s5, the data processing unit reads the calibration data stored in the external storage module through the data bus, and selects the data collected by the first sensor array and the second sensor array to perform relative displacement calculation through a table look-up mode;

s6, adding the initial position offset and the relative displacement calculation results to determine the absolute displacement information of the movement;

and S7, outputting the measurement result data in real time by the data processing module through the data communication module.

9. The moving-magnet absolute position detecting method according to claim 8, characterized in that: in step S1, the first sensor array and the second sensor array need to detect and output magnetic signals in both the horizontal direction and the vertical direction, and the third sensor array needs to detect and output magnetic signals in the vertical direction.

Technical Field

The invention belongs to the field of position detection, and particularly relates to a moving magnet type absolute position detection device and method.

Background

In the field of intelligent manufacturing, automatic production, processing, assembly and manufacturing of products depend on accurate positioning and feedback of position detection sensors in a control system, and the structural form and performance of the sensors directly influence the production efficiency and the product quality of an automatic system. In linear displacement measurement, the position detection method using a grating scale and a magnetic grating scale is most commonly used. The grating ruler is a displacement measuring device manufactured by utilizing the principle of light interference and diffraction, and is widely applied to precision measurement and closed-loop servo control systems due to the advantages of high measurement precision, high response speed, long service life and the like. The magnetic grid ruler is a sensor manufactured by utilizing the characteristics of magnetic poles and through a magnetoelectric conversion principle. Compared with a grating ruler, the grating ruler has the advantages of simple structure, no influence of oil stain, dust and the like, good vibration resistance and impact resistance, and is widely applied to industrial fields.

The conventional grating ruler or magnetic grating ruler is used for linear displacement measurement in industrial production, the cost is relatively high, the sensor reading head is fixedly arranged on a moving component, power supply and communication cables connected with the reading head directly influence the moving stroke and the performance of a moving unit, and the layout of the cables can complicate the structure of a control system and increase the cost of the system. In an industrial production system with cooperation of multiple moving components, a plurality of sensors are required to be used for position location and measurement, and conventional sensors cannot be uniquely numbered on hardware and cannot be flexibly configured and used. Patent CN 101915590B proposes a position detection system based on magnetoresistive array, which obtains the position of the moving unit by processing the unequal distance magnetoresistive sensing components, and this way needs to cooperate with multiple analog signal processing circuits and ADC converter channels during displacement measurement, resulting in too complex and high cost of the circuit during long-stroke position measurement, which is difficult to be applied in practice, and it is impossible to number and distinguish multiple moving components during position measurement of multiple moving components. Patent CN 111750904 a proposes a position detection device using a single-row magnetic sensor array, which performs position detection by gating a plurality of magnetic sensors in advance, and in the practical application process, when influenced by an external stray magnetic field, the method is limited in detection precision, and the detection device cannot meet the requirement of numbering and distinguishing a plurality of moving components.

Disclosure of Invention

To solve the problems and defects of the prior art. The invention provides a moving magnet type absolute position detection device and a moving magnet type absolute position detection method which are flexible, free of cable constraint, low in cost and capable of carrying out numbering differentiation, and aims to meet the requirement of linear absolute position detection in industrial production.

In order to achieve the purpose, the invention provides the following scheme:

a moving magnet absolute position detecting device comprising: the device comprises a moving magnetic head, a sensor acquisition board and a signal calculation module;

the moving magnetic head is fixedly arranged on a moving component to be detected for absolute displacement and can linearly move along with the moving component;

the sensor acquisition board is fixedly arranged below the moving magnetic head, and is distributed with a plurality of groups of three rows of magnetic sensor arrays to provide a position positioning reference for displacement measurement and detect the magnetic signal of the moving magnetic head in real time;

the signal calculation module comprises a data processing unit, a storage module and a data communication module and is used for acquiring and calculating the absolute displacement information of the moving magnetic head permanent magnet array in real time;

the moving magnetic head comprises a first permanent magnet array, a second permanent magnet array and a third permanent magnet array, wherein the first permanent magnet array and the second permanent magnet array are closely arranged by a plurality of permanent magnets with the same size according to an N-S or S-N mode and are used for measuring the serial number and the relative displacement of the moving magnetic head, the third permanent magnet array is closely arranged by a plurality of permanent magnets with different sizes according to an N-S or S-N mode and is used for carrying out binary coding on a relative displacement measurement interval, and the three rows of permanent magnet arrays have certain spacing distances and are parallel to each other in the arrangement direction of magnetic poles.

The sensor acquisition board is distributed with a plurality of groups of three rows of magnetic sensor arrays, the groups are arranged according to a specific interval, each group of magnetic sensor array comprises a first sensor array, a second sensor array and a third sensor array, wherein the first sensor array and the second sensor array are respectively used for acquiring magnetic signals of the first permanent magnet array and the second sensor array, and the third sensor array is used for detecting magnetic signals of the third permanent magnet array;

the magnetic sensor chips in the first sensor array and the second sensor array are arranged according to a specific distance, a plurality of three-axis linear magnetic sensor chips are used for subdividing and measuring magnetic signals, the magnetic sensor chips in the third sensor array are arranged according to a specific distance, and a plurality of linear magnetic sensor chips are used for measuring magnetic signals.

The arrangement pitch of the sensor chips in the first sensor array in the horizontal direction is the same as the pitch of the sensor chips in the second sensor array.

The signal processing module comprises an external storage module, and the storage module is used for storing displacement calibration data.

The signal processing module is used for processing the magnetic sensor signals and resolving the displacement signals, and the signal processing module is provided with a communication module and can output the absolute displacement signals obtained through calculation.

A moving magnet type absolute position detection method is applied to the moving magnet type absolute displacement detection device, and comprises the following steps:

the data processing unit sends a data reading instruction to the N groups of three-row magnetic sensor arrays on the sensor acquisition board in a bus mode, reads the digital magnetic signals output by the N groups of three-row magnetic sensor arrays in real time, and filters and stores the digital magnetic signals in groups.

The magnetic signals after the grouping storage are numbered and preprocessed, the data processing unit judges and records the group number of the effective data according to the magnitude of the magnetic signals, and the initial position offset of the moving unit is determined.

And extracting effective data according to the group number, comparing the data detected by the third sensor array in the data with a set threshold value T, and carrying out binary coding.

And selecting data of the first sensor array and the second sensor array in the effective data, and identifying the serial number of the read head according to the positive and negative of the data.

The data processing unit reads calibration data stored in the external storage module through the data bus, and selects data acquired by the first sensor array and the second sensor array to perform relative displacement calculation in a table look-up mode.

And adding the calculation results according to the initial position offset and the relative displacement to determine the absolute displacement information of the motion.

And the data of the measurement result is output by the data processing module through the data communication module in real time.

The first sensor array and the second sensor array are required to detect and output magnetic signals in both the horizontal direction and the vertical direction, and the third sensor array is required to detect and output magnetic signals in the vertical direction.

Drawings

In order to more clearly illustrate the embodiments of the present invention and the technical solutions in the prior art, the drawings used in the embodiments will be briefly described below, wherein:

FIG. 1 is a schematic diagram of a moving magnet type absolute position detecting apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic block diagram of a signal calculation module of the moving magnet type absolute position detecting device according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating a method for measuring absolute displacement in a moving magnet system according to an embodiment of the present invention;

description of the symbols:

100-moving magnetic head, 101-sensor acquisition board, 102-signal calculation module, 103-three-row magnetic sensor array, 201-data processing unit, 202-data storage module, 203-communication module

Detailed Description

The technical solutions and embodiments of the present invention will be described in detail below with reference to the accompanying drawings of the embodiments of the present invention.

Fig. 1 is a structural layout diagram of an example of a moving magnet type absolute position detecting device provided by the present invention, and fig. 2 is a schematic block diagram of a signal calculating module in the moving magnet type absolute position detecting device provided by the present invention. Fig. 3 is a calculation flow chart of the moving magnet type absolute displacement measurement method provided by the invention.

The device in the embodiment comprises a moving magnetic head 100, a sensor acquisition board 101 and a signal calculation module 102.

The moving magnetic head 100 is fixedly arranged on a moving component to be detected for absolute displacement and can linearly move along with the moving component;

the moving magnetic head 100 comprises a first permanent magnet array, a second permanent magnet array and a third permanent magnet array, wherein the first permanent magnet array and the second permanent magnet array are arranged in an N-S or S-N mode by using permanent magnets with the same size, and the third permanent magnet array is formed by closely arranging a plurality of permanent magnets with different sizes in an N-S or S-N mode to form a binary coding permanent magnet array for coding a relative displacement interval.

The shape of the permanent magnet array is preferably a sheet permanent magnet, the thickness is preferably less than 1mm, the thickness direction is magnetized, and the permanent magnet is preferably made of neodymium iron boron.

The sensor acquisition board 101 is distributed with a plurality of groups of three-row magnetic sensor arrays 102, the groups are arranged according to a specific interval, and each group of magnetic sensor arrays has a unique number.

Each set of magnetic sensor arrays comprises a first sensor array, a second sensor array and a third sensor array, wherein the first sensor array is used for collecting magnetic signals of the first permanent magnet array, the second sensor array is used for detecting magnetic signals of the second permanent magnet array, and the third sensor array is used for detecting magnetic signals of the third permanent magnet array.

The center-to-center spacing of the sensor chips in the first sensor array and the second sensor array is equal to or smaller than the width of a single permanent magnet of the first permanent magnet array, the magnetic signal measurement and subdivision are realized by using a plurality of three-axis linear magnetic sensor chips, and the magnetic signal measurement is carried out by using a plurality of single-axis or three-axis linear magnetic sensor chips in the third sensor array.

The magnetic sensor chip preferably uses a 3-axis Hall magnetic sensor with model number TMAG5170-Q1 or ASL31300, an Analog-to-digital converter (ADC) and a digital controller are integrated in the sensor, Analog signals can be directly converted and processed digitally, and the sensor chip preferably uses a data interface as an SPI bus or an I2C interface, so that a plurality of chips can be mounted on a single bus.

In practical application, in order to ensure the continuity of displacement measurement data, the length of the coding permanent magnet array is ensured to completely cover two groups of three rows of magnetic sensor arrays.

As shown in fig. 2, the signal calculation module 102 includes a data processing unit 201, a storage module 202 and a data communication module 203, and is configured to collect and calculate absolute displacement information of the permanent magnet array on the read head in real time. The signal computation module 102 exchanges information among the modules by means of a data bus.

The data processing unit 201 is used as a control and operation core of the detection device and is responsible for collecting and processing digital signals output by a plurality of groups of magnetic sensor arrays, and calculating absolute displacement according to the magnitude of the signals and a specific calculation method. The data processing unit 201 is preferably implemented by a Field Programmable Gate Array (FPGA) and a Complex Programmable Logic Device (CPLD), and depends on its parallel computing capability to improve the performance and efficiency of the detection system.

The storage module 202 is used for storing table look-up data of displacement calculation, and preferably, an external EEPROM memory chip is used for data storage.

The invention also provides a moving magnetic absolute position detection method corresponding to the moving magnetic absolute position detection device. As shown in fig. 3, the method comprises the steps of:

step 20: the data processing module sends a data reading instruction to the N groups of three-row magnetic sensor arrays on the sensor acquisition board through the bus, reads the digital magnetic signals output by the N groups of three-row magnetic sensor arrays, and filters and stores the digital magnetic signals in groups.

Specifically, after power-on is completed, the data processing module firstly performs self-checking test, and sequentially performs read-write detection judgment on each access module. After the self-checking is successful, the data processing module circularly sends data reading requests to the three rows of magnetic sensor arrays of each group through the data bus, and digital quantity signals detected by each group of magnetic sensor arrays are read in real time. And the signals are filtered, and the processed data are stored in a data register in the data processing module in groups according to the serial number of the group.

Step 21: the magnetic signals after the grouping storage are numbered and preprocessed, and the data processing module judges and records the group number of the effective data according to the magnitude of the magnetic signals and determines the initial position offset of the motion unit.

Specifically, each group of three rows of magnetic sensor arrays are arranged according to a specific interval, and in order to ensure the continuity of displacement signal data, the magnetic signals of two adjacent groups of magnetic sensor arrays need to be processed in a combined manner, so that the measurement of the displacement section between the groups is realized. After the magnetic signals after being stored in groups are combined, the numerical value of each group of magnetic signals is sequentially judged, the group number capable of carrying out displacement calculation is determined, and the initial position offset of the motion unit is determined according to the group number.

Step 22: and extracting effective data according to the group number, comparing the data detected by the third sensor array in the data with a set threshold value T, and carrying out binary coding.

Specifically, valid data is extracted according to the group number for encoding judgment, all magnetic signals detected by the third sensor array in the data are compared with a set threshold value T, and binary '0' and '1' judgment is carried out.

The judgment condition is that if the magnetic signal is greater than the threshold value T, the code is "0", and if the magnetic signal is less than or equal to T, the code is "1".

Step 23: and selecting data of the first sensor array and the second sensor array in the effective data, and identifying the serial number of the read head according to the positive and negative of the data.

Step 24: and determining a relative displacement interval where the motion unit is located according to the codes, selecting effective data acquired by the first sensor array and the second sensor array to perform table look-up calculation on the relative displacement, and reading calibration data stored in the storage module by the data processing module to calculate the relative displacement.

Step 25: and adding the initial position offset and the relative displacement calculation result to determine the absolute displacement information of the motion unit.

Step 26: and the data of the measurement result is output by the data processing module through the data communication module in real time.