CN118129586B - Serial detection method for acquiring linear absolute position by adopting array reluctance Hall - Google Patents

Abstract

The invention relates to the technical field of magnetic suspension, and particularly discloses a serial detection method for acquiring a linear absolute position by adopting array reluctance Hall, wherein 12 magnetic Hall convert magnetic field signals into electric signals, gating is carried out through a high-speed switch, and after the high-speed switch is switched on to a corresponding sensor, a magnetic field- > voltage conversion signal of the sensor is acquired; converting the demodulated voltage signals into standard sine and cosine signals, performing arctangent operation on the sine and cosine signals of each magnetic Hall sensor to obtain corresponding angles, and performing square sum operation on the sine and cosine signals to evaluate the linearity of the sine and cosine signals; judging the rough region where the current magnetic pole is located through the linear region, judging the subdivided position region according to the current specific angle value of each magnetic Hall, and finally fusing the linear region data and the subdivided position data to obtain the specific position of the magnetic pole. The absolute position of the moving object loaded with the magnetic pole can be obtained at low cost, small volume and high speed.

Description

A serial detection method for obtaining absolute position of a straight line using array magnetoresistive Hall

Technical Field

The invention relates to the field of magnetic suspension technology, in particular to a serial detection method for obtaining the absolute position of a straight line by using array magnetoresistive Hall.

Background technique

With the improvement of industrial automation, the requirements for the responsiveness, accuracy, reliability and load capacity of linear transportation technology are getting higher and higher. For example, the linear motor modules used in high-precision machine tools and the magnetic suspension conveyor used in high-speed and high-flexibility transportation lines, these linear transportation technologies and equipment are inseparable from servo motors and position feedback sensors, especially position feedback sensors, which determine the accuracy and stability of linear transportation technology.

At present, the application of linear motor solutions in linear conveying technology has become relatively mature, especially permanent magnet synchronous linear motors have become mainstream due to their simple structure, small size, high efficiency, high power factor and other advantages. However, whether it is the traditional moving coil linear motor or the increasingly popular moving magnet flexible splicing linear motor, its basic principle is to accurately control the motor coil to generate a vector magnetic field through the feedback of the position sensor and the calculation of the digital processor, thereby interacting with the permanent magnet to control the movement of the object;

The existing technology uses a parallel acquisition solution of array AMR magnetoresistive sensors. Each AMR magnetoresistive sensor needs to be equipped with multiple high-precision analog-to-digital conversion sensors. This type of sensor is expensive, and a high-performance digital processor is also required to process data synchronously. Therefore, the cost is high, the number of components is large, and the volume is large. Another solution is to use two AMR magnetoresistive sensors. Although this solution is low-cost, this method cannot directly read the position as soon as the device is powered on. It must be calibrated manually by an external uninterruptible power supply or each time it is powered on.

In summary, the shortcomings of the prior art are as follows:

(1) Although the current linear Hall and proximity switches are low-cost, they are not very accurate and are very easy to lose their position, making it impossible to achieve absolute position reading;

(2) The two-point AMR magnetoresistive sensors currently used are not accurate and cannot read absolute positions;

(3) The array currently used, although low-cost, cannot directly read the current position of the mover after power-on. Each power-on requires manual special operations on all movers, which is complex and difficult to operate.

(4) The magnetic gratings or optical gratings currently used are expensive and must work in a clean environment, which places high demands on the environment.

Therefore, a low-cost, high-performance, and small-sized position sensor is the key to determining the performance of the linear motor.

Summary of the invention

The object of the present invention is to provide a serial detection method for obtaining the absolute position of a straight line by using array magnetoresistive Hall to solve the problems raised in the above background technology.

To achieve the above object, the present invention provides the following technical solution: a serial detection method for obtaining the absolute position of a straight line using an array magnetoresistive Hall, detecting the change of the magnetic field through 12 magnetic Hall sensors in the array, and obtaining the specific position of the magnetic pole by solving the magnetic field signal, thereby determining the absolute position of the object with the magnetic pole, which specifically includes the following steps:

Step 1: First, in the high-speed serial data acquisition module, 12 magnetic Hall sensors convert the magnetic field signal into an electrical signal and select it through a high-speed switch. After the high-speed switch selects the corresponding sensor, the magnetic field -> voltage conversion signal of the sensor is obtained, and the voltage signal is filtered and demodulated;

Step 2: In the original signal processing module, the demodulated voltage signal is converted into a standard sine and cosine signal, an arc tangent operation is performed on the sine and cosine signals of each magnetic Hall sensor to obtain the corresponding angle, and a square sum operation is performed on the sine and cosine signals to evaluate their linearity;

Step 3: In the position calculation module, on the one hand, the approximate area where the current magnetic pole is located is determined by the linear area, and on the other hand, the subdivided position area is determined according to the current specific angle value of each magnetic Hall. Finally, the linear area data and the subdivided position data are merged to obtain the specific position of the magnetic pole.

Preferably, the specific functions of the high-speed serial data acquisition module are as follows:

The magnetic Hall uses magnetoresistive sensor AMR3001 or linear Hall sensor TMR2151. The data output channels of the 12 arrays of magnetic Hall are switched through 2 high-speed selection switches TMR2415, so that data can be collected serially at a frequency of up to 12MHZ.

After being selected by a high-speed selection switch, the magnetic Hall can be connected to an analog-to-digital converter to periodically convert the magnetic field signal into a processable digital signal;

After the digital signal is acquired, it is necessary to filter and modulate the digital signal on the one hand, and calibrate the digital signal according to the calibration data in the storage device on the other hand.

Preferably, the filtering and debugging process adopts a first-order filtering algorithm to reduce the algorithm complexity: Where: ω _c represents the filter cutoff angular frequency, T _s represents the sampling time, Y _(n) represents the current filtering value, Y _(n-1) represents the last filtering value, and X _(n) represents the current sampling value;

The calibration of the digital signal is to read the calibration value pre-stored in the storage device and collect the current real-time power supply voltage, and then add these two data to the digital signal of the sensor to correct the deviation of the digital signal.

Preferably, the number of magnetic Halls in the array and the number of induction poles are both 12, and the spacing is equal to 12 mm. One end of the high-speed selection switch is connected to the magnetic Hall, and the other end is connected to the ADC analog-to-digital sensor, which is used to convert the magnetic field signal into a digital signal in series. The ADC mode sensor transmits the digital signal to a digital processor with a storage function to complete the subsequent processing of the digital signal.

Preferably, the specific functions of the original signal processing module are as follows:

After passing through the high-speed serial data acquisition module, a digital signal that can be processed by a digital processor is obtained. The directly converted digital signal presents a sine and cosine distribution.

By performing an inverse tangent operation on the digital signal of the sine and cosine distribution, the angle value of each magnetic pole corresponding to the Hall can be obtained. This angle value can reflect the position of each magnetic pole relative to the Hall: Wherein: Sinθ represents the digital signal of sine distribution obtained from the high-speed serial data acquisition module, Cosθ represents the digital signal of cosine distribution obtained from the high-speed serial data acquisition module, and θ represents the specific angle value finally obtained by the inverse tangent.

Preferably, the linearity of the magnetic pole position is detected by a square sum operation: Where: R represents linearity, Sin(θ) represents the digital signal of sinusoidal distribution obtained from the high-speed serial data acquisition module, and Cos(θ) represents the digital signal of cosine distribution obtained from the high-speed serial data acquisition module;

When the R value is close to 1, it means that the magnetic Hall sensor detects a valid magnetic pole, and the digital signal is valid for further processing.

Preferably, the specific functions of the position solution module are as follows:

Compare the linearity values of the 12 arrays of magnetic Hall with the standard linearity values. If the absolute value is within the threshold range, the surface has a magnetic pole that enters the linear detection range of the magnetic Hall, and record the linear area mark of each magnetic Hall: Where: SH(n) represents the linear region mark data of the magnetic Hall; 1: in the linear region, 0: not in the linear region, R(n) represents the currently calculated linearity data, and Rstd represents the standard linearity data;

After obtaining the linear region mark of each Hall, the linear regions of the 12 Halls are combined in a weighted manner to obtain a comprehensive linear region judgment data: Wherein: SHA represents the data after the combination of 12 magnetic Hall linear signs, SH(0)...SH(n)-represents the linear signs of 12 magnetic Halls.

Preferably, in order to obtain a more accurate position, the subdivision angle is obtained by arc tangent calculation, and the final position is fitted; Among them: FinalPos represents the absolute position after the final fitting, FineAngle represents the subdivision angle obtained by inverse tangent, and Ln represents the preliminary position obtained by judging the linear region.

The present invention proposes a serial detection method using array magnetoresistive Hall to obtain the absolute position of a straight line, which has the following beneficial effects:

1. The magnetic Hall array realizes serial sampling through high-speed selection switches, thus saving the cost of sampling devices while ensuring sufficient sampling speed;

2. Through the digital processor and storage device, the calibration value can be stored in advance, and the digital signal can be read out and calibrated during digital signal processing;

3. Position fitting is performed through the magnetic Hall of the array, and the absolute position can be directly obtained without any special operation after power-on;

4. The magnetic Hall type selected by this method has the advantages of strong anti-interference ability and wide detection range, so it has strong adaptability to the environment.

In summary, the present invention adopts an array of magnetic Hall sensors, each of which can detect the position of a magnetic pole. The magnetic pole position detected by each magnetic Hall sensor is serially acquired through a high-speed switching switch, and all data is then integrated through a digital processor. The absolute position of a moving object equipped with a magnetic pole can be obtained under low cost, small size, and high speed conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flowchart of the array magnetic Hall absolute position serial detection of the present invention;

FIG2 is a diagram showing the structure of the position detection device of the present invention and its relationship with the position of the induction magnetic pole;

FIG3 is a schematic diagram of a converted digital signal showing a sine-cosine distribution according to the present invention;

FIG4 is a schematic diagram of an inverse tangent processing module of the present invention;

Fig. 5 is an inverse tangent data diagram of the present invention;

FIG. 6 is a module operation diagram of original signal processing of the present invention.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Embodiment, please refer to Figures 1-6, the present invention provides a technical solution: a serial detection method for obtaining the absolute position of a straight line using an array magnetoresistive Hall, detecting the change of the magnetic field through 12 magnetic Halls of the array, and obtaining the specific position of the magnetic pole by solving the magnetic field signal, thereby determining the absolute position of the object with the magnetic pole, specifically comprising the following steps:

Step 1: First, in the high-speed serial data acquisition module, 12 magnetic Hall sensors convert the magnetic field signal into an electrical signal and select it through a high-speed switch. After the high-speed switch selects the corresponding sensor, the magnetic field -> voltage conversion signal of the sensor is obtained, and the voltage signal is filtered and demodulated;

Step 2: In the original signal processing module, the demodulated voltage signal is converted into a standard sine and cosine signal, an arc tangent operation is performed on the sine and cosine signals of each magnetic Hall sensor to obtain the corresponding angle, and a square sum operation is performed on the sine and cosine signals to evaluate their linearity;

Step 3: In the position calculation module, on the one hand, the approximate area where the current magnetic pole is located is determined by the linear area, and on the other hand, the subdivided position area is determined according to the current specific angle value of each magnetic Hall. Finally, the linear area data and the subdivided position data are merged to obtain the specific position of the magnetic pole.

The specific functions of the high-speed serial data acquisition module are as follows:

The magnetic Hall uses magnetoresistive sensor AMR3001 or linear Hall sensor TMR2151. The data output channels of the 12 arrays of magnetic Hall are switched through 2 high-speed selection switches TMR2415, so that data can be collected serially at a frequency of up to 12MHZ.

After being selected by a high-speed selection switch, the magnetic Hall can be connected to the analog-to-digital converter, thereby periodically converting the magnetic field signal into a processable digital signal. Due to the periodic serial processing, only an 8-channel analog-to-digital converter is required, maintaining the low-cost solution advantage;

After the digital signal is acquired, it is necessary to filter and modulate the digital signal on the one hand, and calibrate the digital signal according to the calibration data in the storage device on the other hand.

The filtering and debugging process uses a first-order filtering algorithm to reduce the algorithm complexity: Where: ω _c represents the filter cutoff angular frequency, T _s represents the sampling time, Y _(n) represents the current filtering value, Y _(n-1) represents the last filtering value, and X _(n) represents the current sampling value;

The calibration of the digital signal is to read the calibration value pre-stored in the storage device and collect the current real-time power supply voltage, and then add these two data to the digital signal of the sensor to correct the deviation of the digital signal.

As shown in Figure 2, the structure diagram of the position detection device integrating the array magnetic Hall, high-speed selection switch, ADC analog-to-digital sensor, and digital processor, as well as the position relationship diagram with the induction magnetic pole; the number of the array magnetic Hall and the number of the induction magnetic poles are both 12, and the spacing is equal to 12mm. One end of the high-speed selection switch is connected to the magnetic Hall, and the other end is connected to the ADC analog-to-digital sensor, which is used to convert the magnetic field signal into a digital signal in series. The ADC mode sensor transmits the digital signal to the digital processor with storage function to complete the subsequent processing of the digital signal.

The specific functions of the original signal processing module are as follows:

As shown in Figure 3: After passing through the high-speed serial data acquisition module, a digital signal that can be processed by a digital processor is obtained. The directly converted digital signal presents a sine and cosine distribution;

By performing an inverse tangent operation on the digital signal of the sine and cosine distribution, the angle value of each magnetic pole corresponding to the Hall can be obtained. This angle value can reflect the position of each magnetic pole relative to the Hall: Wherein: Sinθ represents the digital signal of sine distribution obtained from the high-speed serial data acquisition module, Cosθ represents the digital signal of cosine distribution obtained from the high-speed serial data acquisition module, and θ represents the specific angle value finally obtained by the inverse tangent.

In order to accurately determine whether the magnetic pole is in the linear range of the magnetic Hall, it is necessary to detect the sine and cosine of the acquired digital signal. Only when the linearity of the magnetic pole meets certain requirements, the magnetic pole angle and magnetic pole position information obtained by the inverse tangent operation are valid; the linearity of the magnetic pole position is detected by the square sum operation: Where: R represents linearity, Sin(θ) represents the digital signal with sinusoidal distribution obtained from the high-speed serial data acquisition module, and Cos(θ) represents the digital signal with cosine distribution obtained from the high-speed serial data acquisition module;

When the R value is close to 1, it means that the magnetic Hall sensor detects a valid magnetic pole, and the digital signal is valid for further processing.

The specific functions of the position solution module are as follows:

Compare the linearity values of the 12 arrays of magnetic Hall with the standard linearity values. If the absolute value is within the threshold range, the surface has a magnetic pole that enters the linear detection range of the magnetic Hall, and record the linear area mark of each magnetic Hall: Where: SH(n) represents the linear region mark data of the magnetic Hall; 1: in the linear region, 0: not in the linear region, R(n) represents the currently calculated linearity data, and Rstd represents the standard linearity data;

After obtaining the linear region mark of each Hall, the linear regions of the 12 Halls are combined in a weighted manner to obtain a comprehensive linear region judgment data: Where: SHA represents the data after the combination of 12 magnetic Hall linear signs, SH(0)...SH(n)- represents the linear signs of 12 magnetic Halls;

By looking up the integrated linear region data, the preliminary range of the current magnetic pole can be obtained. The following table shows the preliminary magnetic pole position corresponding to the linear region judgment data:

Magnetic pole positioning reference table:

Linear area data (SHA) Initial position (Ln) Number of poles entering (n) 1 360 1 3 720 2 7 1080 3 15 1440 4 31 1800 5 63 2160 6 127 2520 7 255 2880 8 511 3240 9 1023 3600 10 2047 3960 11 4095 4320 12 4094 4680 13 4092 5040 14 4088 5400 15 4080 5760 16 4064 6120 17 4032 6480 18 3968 6840 19 3840 7200 20 3072 7560 twenty one 2048 7920 twenty two

The preliminary position of the magnetic pole obtained through linear processing can roughly determine which part of the 12 magnetic Halls the magnetic pole is in, but it cannot get a more accurate position. In order to get a more accurate position, the arc tangent calculation is used to get the subdivision angle and fit the final position. Among them: FinalPos represents the absolute position after the final fitting, FineAngle represents the subdivision angle obtained by inverse tangent, and Ln represents the preliminary position obtained by judging the linear region.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. A serial detection method for acquiring a linear absolute position by adopting an array reluctance Hall is characterized in that: the change of the magnetic field is detected through 12 magnetic Hall of the array, and the specific position of the magnetic pole is obtained through the calculation of the magnetic field signal, so that the absolute position of the object with the magnetic pole is judged, and the method specifically comprises the following steps:

Firstly, converting magnetic field signals into electric signals in a high-speed serial data acquisition module by 12 magnetic Hall sensors, gating the electric signals through a high-speed switch, acquiring magnetic field- > voltage conversion signals of the sensor after the high-speed switch is switched on to the corresponding sensor, and filtering and demodulating the voltage signals;

Converting the demodulated voltage signal into a standard sine and cosine signal in an original signal processing module, performing arctangent operation on the sine and cosine signal of each magnetic Hall sensor to obtain a corresponding angle, and performing square sum operation on the sine and cosine signal to evaluate the linearity of the sine and cosine signal;

Judging the approximate area where the current magnetic pole is located through the linear area in the position resolving module, judging the subdivided position area according to the current specific angle value of each magnetic Hall on the other hand, and finally fusing the linear area data and the subdivided position data to obtain the specific position of the magnetic pole;

the position calculation module has the following specific functions:

Comparing the linearity values of the magnetic hall of the 12 arrays with standard linearity values, if the absolute value is within a threshold value range, indicating that magnetic poles enter the linear detection range of the magnetic hall, and recording the linear region mark of each magnetic hall:

Wherein: SH (n) represents linear region flag data of the magnetic Hall; 1 is in a linear region, 0 is not in the linear region, R (n) represents currently calculated linearity data, and Rstd represents standard linearity data;

After the linear region mark of each Hall is obtained, the linear regions of 12 Hall are combined in a weighting mode to obtain comprehensive linear region judgment data:

Wherein: SHA represents data from a combination of 12 magnetic hall linear signatures, SH (0)..sh (n) -represents a linear signature of 12 magnetic hall.

2. The serial detection method for acquiring the linear absolute position by adopting the array reluctance hall according to claim 1, wherein the serial detection method is characterized in that: the high-speed serial data acquisition module has the following specific functions:

The magnetic Hall adopts a magnetic resistance sensor AMR3001 or a linear Hall sensor TMR2151, and the data output channels of the magnetic Hall of 12 arrays are switched by 2 high-speed selection switches TMR2415, so that data acquisition can be carried out in series at the frequency of up to 12 MHZ;

after the high-speed selection switch is used for gating, the magnetic Hall can be connected with the analog-to-digital converter, so that a magnetic field signal is periodically converted into a digital signal which can be processed;

after the digital signal is collected, on one hand, filtering and modulating processing are required to be performed on the digital signal, and on the other hand, calibration is required to be performed on the digital signal according to calibration data in the storage device.

3. The serial detection method for acquiring the linear absolute position by adopting the array reluctance hall according to claim 2, wherein the serial detection method is characterized in that: the filtering and debugging process adopts a first-order filtering algorithm, so that the complexity of the algorithm is reduced: Wherein: omega _c represents the filter cut-off angular frequency, T _s represents the sampling time, Y _(n) represents the current filtering value, Y _(n-1) represents the last filtering value, and X _(n) represents the current sampling value;

The calibration of the digital signal is to read and collect the current real-time power supply voltage by the calibration value stored in the storage device in advance, and then add the two data into the digital signal of the sensor, so as to correct the deviation of the digital signal.

4. A serial detection method for acquiring an absolute position of a straight line by using an array reluctance hall according to claim 3, wherein: the number of the array magnetic Hall is 12, the distance is equal to 12mm, one end of the high-speed selection switch is connected with the magnetic Hall, and the other end of the high-speed selection switch is connected with the ADC analog-digital sensor for serially converting magnetic field signals into digital signals, and the ADC mode sensor transmits the digital signals to the digital processor with a storage function to finish the subsequent processing of the digital signals.

5. The serial detection method for acquiring the linear absolute position by using the array reluctance hall according to claim 4, wherein the serial detection method comprises the following steps: the specific function of the original signal processing module is as follows:

After the digital signals are processed by the digital processor, the digital signals are directly converted into sine and cosine distribution;

the digital signals distributed by sine and cosine are subjected to arctangent operation, so that the angle value of the corresponding magnetic pole of each magnetic Hall can be obtained, and the angle value can reflect the position of each magnetic pole relative to the Hall:

wherein: sin theta represents a sine-distributed digital signal obtained from the high-speed serial data acquisition module, cos theta represents a cosine-distributed digital signal obtained from the high-speed serial data acquisition module, and theta represents a specific angle value finally obtained by arctangent.

6. The serial detection method for acquiring the linear absolute position by using the array reluctance hall according to claim 5, wherein the serial detection method comprises the following steps: the linearity of the position of the magnetic pole is detected by a square sum operation mode:

wherein: r represents linearity, sin (theta) represents a sine-distributed digital signal acquired from the high-speed serial data acquisition module, and Cos (theta) represents a cosine-distributed digital signal acquired from the high-speed serial data acquisition module;

when the R value is near 1, indicating that the magnetic hall detects an active pole, the digital signal is now available for further processing.

7. The serial detection method for acquiring the linear absolute position by using the array reluctance hall according to claim 6, wherein the serial detection method comprises the following steps: in order to obtain a more accurate position, obtaining a subdivision angle through arctangent calculation, and fitting a final position;

Wherein: finalPos denotes the absolute position after final fitting, FINEANGLE denotes the subdivision angle by arctangent, and Ln denotes the preliminary position by linear region judgment.