CN117909684A - Motor movement direction identification method based on double Hall sensors - Google Patents

Abstract

The invention discloses a motor movement direction identification method based on double Hall sensors, which comprises the following steps: continuously reading square wave values of two paths of input Hall pulse signals, arranging and combining the square wave values of the two paths of Hall pulse signals at the same moment according to a certain sequence, and converting the combined square wave values into binary values; the binary value obtained by conversion is recorded as HALLSTATE, and an array HALLDX [ a ] corresponding to a binary values is introduced, the length of the array is a, and a numerical values contained in the array correspond to the binary values; substituting the binary number value into the array as a subscript to obtain a numerical value; subtracting the historical value from the numerical value, and recording the difference value of the numerical value and the historical value as temp_hall; judging whether the motor is rotated forwards or backwards according to the value of temp_hall, and when the motor is operated normally and the operation direction is unchanged, presetting the value temp_hall obtained by the forward rotation and the backward rotation of the motor asA total of a numbers and the numbers are different in size. The invention has high precision and strong anti-interference capability, accuracy and adaptability.

Description

Motor movement direction identification method based on double Hall sensors

Technical Field

The invention belongs to the field of automobile electronics, and particularly relates to a motor movement direction identification method based on double Hall sensors.

Background

With the wide use of automobile sensors, hall sensors are also increasingly applied to automobiles, and the hall sensors are most commonly used together with motors to be matched into driving motors with the hall sensors. The double-Hall sensor motor is used as one of Hall motors, has good stability, and can not lose signals even if the motor rotates too fast, so that the double-Hall sensor motor is very common in use on automobiles, and most of the double-Hall sensor motor is used for driving window glass and skylight glass on automobiles. In the simulation stage, hall signals often need to be processed to obtain the rotating speed and the motion state of the motor.

At present, many traditional algorithms are used for judging the movement direction of a motor directly according to different rotation directions of the motor and different positions of the output double Hall signals, and the method has the advantages that the anti-interference capability of the algorithm is very weak, and once the interference occurs, the output Hall waveforms are incomplete, so that the situation of wrong judgment occurs.

Disclosure of Invention

The invention aims to provide a motor movement direction identification method based on double Hall sensors, which not only considers motor characteristics, but also fully plays the advantages of the double Hall sensors, has high precision and stronger anti-interference capability, accuracy and adaptability, and can be expanded to other fields.

In order to solve the technical problems, the technical scheme of the invention is as follows: a motor movement direction identification method based on double Hall sensors comprises the following steps:

S100, continuously reading square wave values of two paths of input Hall pulse signals, arranging and combining the square wave values of the two paths of Hall pulse signals at the same moment according to a certain sequence, and converting the combined square wave values into binary values; wherein binary values obtained by conversion in one period are a, and the binary values are arranged and circulated according to a certain rule, wherein a is a positive even number which is more than or equal to 4;

S200, marking the binary values obtained by conversion as HALLSTATE, and introducing an array HALLDX [ a ] corresponding to a binary values, wherein the length of the array is a, and a numerical values contained in the array correspond to the binary values; substituting the binary number value as a subscript into the array to obtain a numerical value which is HALLDX [ HALLSTATE ];

S300, subtracting the historical value HALLDX [ HALLSTATELAST ] from HALLDX [ HALLSTATE ], and marking the difference value of the historical value and the historical value as temp_hall; wherein, the historical value HALLDX [ HALLSTATELAST ] is HALLDX [ HALLSTATE ] calculated in the last period;

S400, judging whether the motor rotates positively or reversely according to the value of temp_hall, and when the motor rotates normally and the running direction is unchanged, presetting the value temp_hall obtained by the positive rotation and the reverse rotation of the motor as A total of a numbers and the numbers are different in size.

The method also comprises the following steps:

S500, when the value of temp_hall is 0, judging the count value of a preset timer, when the count value of the timer is smaller than a preset threshold value, adding 1 to the count value, and jumping to S700; when the value of the timer is larger than the preset threshold value, judging that the motor stops rotating, and jumping to S700;

s600, judging Hallerror values when the value of temp_hall is not a preset value a or 0 obtained by forward rotation and reverse rotation of the motor, adding 1 to Hallerror values when Hallerror values are smaller than a preset error threshold value, and jumping to S700; when Hallerror value is larger than the preset error threshold, sending error report signal, ending the method; hallerror is a Hall error flag, when the abnormal state of the motor is judged, the variable is called, and the value of the variable is compared with a preset error threshold value to obtain whether the motor is in the abnormal state or not;

And S700, giving the HALLSTATE value to HALLSTATELAST, and jumping to S100 to perform calculation of the next period.

The method also comprises the following steps:

s800, calculating the motor rotating speed according to the Hall pulse signal, wherein the calculating method comprises the following steps:

wherein n is the motor rotation speed, t is the time interval, s is the number of Hall pulses read in the time interval t.

The method also comprises the following steps:

s900, calculating the commutation current in the running process of the motor, wherein the calculation method comprises the following steps:

Wherein i _a is the armature current when no commutation exists between the electric brush and the commutating strip, T ₀ is the time required for commutation, T _k is the commutation time period, e _r is the reactance potential of the commutating element, e _w is the induction potential outside the commutation, the commutating element comprises a first commutating strip and a second commutating strip, and r ₁、r₂ is the contact resistance of the first commutating strip, the second commutating strip and the electric brush respectively.

The method also comprises the following steps:

s1000, generating a high-frequency component when the current of the motor is commutated, namely current commutating pulsation frequency, wherein the current pulsation frequency has the following relation with the rotating speed of the motor:

wherein f is the current pulse frequency, k is the number of commutator segments, and n is the motor rotation speed obtained by a Hall sensor;

The current ripple is subjected to a conditioning circuit to obtain a square wave similar to Hall pulse, a current ripple period T is obtained through the square wave, and a motor rotating speed w obtained through current ripple calculation is obtained through calculation, wherein the calculation method comprises the following steps:

The method also comprises the following steps:

S1100, when the running direction of the motor is changed, the motor needs a certain time to complete the reverse rotation due to the inertia effect and the load inertia inside the motor.

The method also comprises the following steps:

S1200, acquiring rotation speed data of a motor, wherein the rotation speed w of the motor obtained through current ripple calculation and the rotation speed n of the motor obtained through a Hall sensor in S1000 are determined in the actual acquisition process, and abnormal data in the motor are removed according to the maximum rotation speed n _max of the motor; the acquisition period of the rotating speed data of the motor is consistent with the acquisition period of the Hall pulse signal.

The method also comprises the following steps:

and S1300, storing the acquired motor rotation speed data in a group of four, and respectively calculating the average motor rotation speed value of each group of data.

The method also comprises the following steps:

S1400, setting an error threshold value, and taking absolute values of differences among the motor rotating speed obtained through current ripple calculation and the data of each group corresponding to the motor rotating speed obtained through a Hall sensor in the same period, wherein the absolute values are expressed as follows:

n_p＝|n-w|

wherein n is the average motor speed value of a certain group of data obtained by a Hall sensor, w is the average motor speed value of the group of data obtained by current ripple calculation corresponding to n, and n _p is the absolute value of the difference result of the two;

And comparing the absolute value of the difference result of each group with an error threshold value, and judging the error of the two.

A computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method according to any of the preceding claims.

Compared with the prior art, the invention has the beneficial effects that:

the invention has stronger anti-interference capability under the conditions of ensuring higher accuracy and simple and stable algorithm structure, does not influence the accuracy of the algorithm when the Hall signal fluctuates, and improves the reliability and the robustness of the whole system.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of the present invention;

FIG. 2 is a schematic diagram of clockwise rotation of a motor and a corresponding two-way Hall signal square wave diagram in an embodiment of the invention;

FIG. 3 is a schematic diagram of a motor counter-clockwise rotation and a corresponding two-way Hall signal square wave diagram in an embodiment of the invention;

FIG. 4 is a graph of square wave values of two Hall signals at a specific moment and binary numbers converted from the square wave values;

FIG. 5 is a graph showing the calculation of the difference temp_hall at different time points according to the embodiment of the present invention;

fig. 6 is a schematic structural diagram of a motor connected to a commutator segment according to an embodiment of the present invention;

fig. 7 is a schematic diagram of the principle of motor commutation current generation in an embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

The technical scheme of the embodiment of the invention is as follows: a motor movement direction identification method based on double Hall sensors comprises the following steps:

Step 100, as shown in fig. 1, firstly, continuously reading square wave values of two input hall pulse signals, arranging the square wave values of two hall signals at the same moment in a certain sequence, for example, arranging the square wave value of a first hall signal at the front and arranging the square wave value of a second hall signal at the rear, for example: 01 and in this order the values are converted into binary values, the converted value being 1, noted as value b.

In step 200, the value of the value b is assigned to HALLSTATE, and in this embodiment, an array of length 4 is used as an example, and an array of length 4 is introduced HALLDX [4 ]. When the motor movement direction is unchanged, in a period, the binary numbers obtained in the step 100 are only 4 and are ordered and circulated according to a certain rule, so that 4 proper numbers are set in the array according to the requirement, and the binary numbers are taken into the array as subscripts to obtain one number HALLDX [ HALLSTATE ].

Step 300, subtracting the value HALLDX [ HALLSTATELAST ] of the last method to obtain a value HALLDX [ HALLSTATE ] obtained in step 300, and assigning the value to temp_hall.

Step 400, when the motor is running normally and the direction is unchanged, and the values selected in the array HALLDX [4] are appropriate, the value temp_hall obtained by applying the method for making difference is only 2 cases, i.e. when the motor is rotating forward, the obtained difference is p or q (corresponding to the preset 2 values obtained by rotating forward of the motor respectively), and when the motor is rotating backward, the obtained difference is m or n (corresponding to the preset 2 values obtained by rotating backward of the motor respectively).

In step 500, when the difference is 0, the judgment needs to be continued, when the difference is 0, the stop count is increased by 1, and when the stop exceeds the threshold, the motor is judged to be stopped. The method comprises the steps of running once every 64us, setting a threshold value when two paths of Hall signal values acquired within a period of time are the same, adding 1 to the stop when the number of stop times when the difference value temp_hall is 0 does not exceed the threshold value, and carrying out the next step; and when the stop is larger than the threshold value, judging that the motor is in a stop state, and continuing the next step.

Step 600, when the obtained difference temp_hall is not equal to p, q, m, n or 0, it may be that a hall square wave error occurs or a square wave fluctuates due to signal interference, when this occurs, it is determined whether Hallerror is greater than a set threshold, and when it is less than the threshold, hallerror is increased by 1, and the next step is continued; when the threshold value is exceeded, an error signal is sent, and the method is jumped out.

In step 700, when the motor does not report errors, the value HALLSTATE is assigned to HALLSTATELAST, and the operation is performed again in step 100.

When the motor normally operates, as shown in fig. 2 and 3, fig. 2 is a schematic diagram of the motor rotating clockwise, and fig. 2 is a schematic diagram of a double-hall signal square wave with two periods on the right side; fig. 3 is a schematic diagram of the counterclockwise rotation of the motor and two periodic hall pulse signal square waves, and fig. 2 and 3 respectively intercept 8 different hall signal square wave values at different moments of the two periods, from t ₁ to t ₈,t₁ 'to t ₈'.

According to the obtained values, the binary numbers are converted into binary numbers, as shown in fig. 4, the obtained binary numbers are ordered according to a certain rule, and when the motor rotates clockwise, the binary numbers a:0,1,3,2,0,1,3,2; when the motor rotates anticlockwise, binary number a':2,3,1,0,2,3,1,0. The ordering is performed in two orders respectively.

At this time, the value of the array HALLDX [4] is set, each binary number corresponds to one value in the array, and the required temp_hold value is obtained after the difference is made, for example, the array is set to HALLDX [4] = [0,1,3,2]. When the motor rotates clockwise, the binary number a is brought into an array, the obtained value is 0,1,2,3,0,1,2,3, the adjacent two numbers are differenced, the former number is subtracted from the latter number, and the obtained difference temp_hold is respectively: 1.1, -3, 1, the values obtained are only 1 and-3, and then cycle all the time according to this law. Likewise, when the motor rotates counterclockwise, a' is brought into the array HALLDX [4], which can result in a set of numbers: 3,2,1,0,3,2,1,0. The difference can be made in the same way to obtain the difference temp_hall of-1, 3, -1, and the values obtained are only-1 and 3.

Step 800, reading the hall pulse signal, and calculating the motor rotation speed, wherein the calculation formula is as follows: Where n is the motor speed, s is the number of Hall pulses read in t time, t is the time interval (in seconds), and multiplying 60 converts the speed from pulses per second to minutes.

Step 900, calculating a commutation current in the motor operation process according to the motor characteristics, wherein when the motor rotor rotates, the electric brush contacts with the commutating segments of the commutator, so that the circuit is changed, and the current is caused to flow, as shown in fig. 6 and 7. The commutation current can be used as an important parameter for reference to the motor operating state. The commutation current calculation formula is as follows: Wherein i _a is armature current when no commutation exists between the brush and the commutator segment; t is the time required for reversing from off; t _k is the commutation time period; e _w is the induced potential outside the commutation; and r ₁、r₂ is the contact resistance of the first reversing sheet, the second reversing sheet and the electric brush respectively.

In step 1000, the motor current commutates to generate a high frequency component called current commutating pulsation frequency, and the current pulsation frequency and the motor revolution are in the following relation: Wherein f is the current pulse frequency, k is the number of commutator segments, and n is the number of motor revolutions. The current ripple can obtain a square wave similar to Hall pulse through the conditioning circuit, the current ripple period T can be obtained through the square wave, and the rotating speed w of the motor is calculated according to the following formula:

In step 1100, when the motor direction is changed, the motor takes a certain time to complete the reverse rotation due to the inertia effect inside the motor and the load inertia. During this process, both the output torque and the rotational speed of the motor change. Specifically: when the motor direction changes, the motor rotor needs to stop and restart rotating. During this transition of the steering, the rotational speed of the motor will drop and gradually resume as the rotor re-accelerates.

Step 1200, collecting motor rotation speed data, calculating through current ripple to obtain motor rotation speed w and motor rotation speed n through a Hall sensor, wherein the maximum motor rotation speed is determined in the actual collection process, and eliminating abnormal data of the calculated two motor rotation speed data is needed.

In step 1300, the motor rotation speed acquisition data is consistent with the hall pulse signal acquisition period, one round of data sampling is completed for every 64us, the data processing is completed by setting a motor rotation speed threshold n _max in the method, and when the data larger than the threshold is generated, the data is discarded. Simultaneously, the calculated motor rotation speed values are stored in an array in groups of four, and the average motor rotation speed of the array is calculatedThe average motor speed obtained by the current ripple is also obtained in the same manner.

In step 1400, a certain deviation exists between the motor rotation speed acquired based on the hall signal and the motor rotation speed acquired based on the current ripple in the actual process, an error between the motor rotation speed and the motor rotation speed needs to be defined, and a threshold value n_dv is set. Taking a certain corresponding array as an example, carrying out difference between the average rotating speeds of the motors obtained by the two methods, and taking the absolute value of the result to obtain the difference n _p = |n-w| of the absolute values of the two.

Therefore, when the average rotating speed of the motor at the current moment is smaller than the average rotating speed at the previous moment and the difference value of the rotating speeds of the motor is smaller than the threshold value, the motor moving direction can be judged to be changed, and when the difference value temp_hall is equal to 1 or-3, the motor can be judged to be in a clockwise rotating state; when the difference temp _ hall is equal to-1 or 3, it can be judged that the motor is in a counterclockwise rotation state. When the motor stops, the values of the two paths of Hall signals are 0, the number stop of the time when the temp_hall signal is 0 exceeds a threshold value, and the average rotating speed difference value of the motor is 0, so that the motor is judged to be in a stop state.

It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (10)

1. The motor movement direction identification method based on the double Hall sensors is characterized by comprising the following steps of:

S100, continuously reading square wave values of two paths of input Hall pulse signals, arranging and combining the square wave values of the two paths of Hall pulse signals at the same moment according to a certain sequence, and converting the combined square wave values into binary values; wherein binary values obtained by conversion in one period are a, and the binary values are arranged and circulated according to a certain rule, wherein a is a positive even number which is more than or equal to 4;

S200, marking the binary values obtained by conversion as HALLSTATE, and introducing an array HALLDX [ a ] corresponding to a binary values, wherein the length of the array is a, and a numerical values contained in the array correspond to the binary values; substituting the binary number value as a subscript into the array to obtain a numerical value which is HALLDX [ HALLSTATE ];

S300, subtracting the historical value HALLDX [ HALLSTATELAST ] from HALLDX [ HALLSTATE ], and marking the difference value of the historical value and the historical value as temp_hall; wherein, the historical value HALLDX [ HALLSTATELAST ] is HALLDX [ HALLSTATE ] calculated in the last period;

S400, judging whether the motor rotates positively or reversely according to the value of temp_hall, and when the motor rotates normally and the running direction is unchanged, presetting the value temp_hall obtained by the positive rotation and the reverse rotation of the motor as A total of a numbers and the numbers are different in size.

2. The motor movement direction recognition method based on the double hall sensor according to claim 1, further comprising the steps of:

S500, when the value of temp_hall is 0, judging the count value of a preset timer, when the count value of the timer is smaller than a preset threshold value, adding 1 to the count value, and jumping to S700; when the value of the timer is larger than the preset threshold value, judging that the motor stops rotating, and jumping to S700;

s600, judging Hallerror values when the value of temp_hall is not a preset value a or 0 obtained by forward rotation and reverse rotation of the motor, adding 1 to Hallerror values when Hallerror values are smaller than a preset error threshold value, and jumping to S700; when Hallerror value is larger than the preset error threshold, sending error report signal, ending the method; hallerror is a Hall error flag, when the abnormal state of the motor is judged, the variable is called, and the value of the variable is compared with a preset error threshold value to obtain whether the motor is in the abnormal state or not;

And S700, giving the HALLSTATE value to HALLSTATELAST, and jumping to S100 to perform calculation of the next period.

3. The motor movement direction recognition method based on the double hall sensor according to claim 1, further comprising the steps of:

s800, calculating the motor rotating speed according to the Hall pulse signal, wherein the calculating method comprises the following steps:

wherein n is the motor rotation speed, t is the time interval, s is the number of Hall pulses read in the time interval t.

4. The motor movement direction recognition method based on the double hall sensor according to claim 1, further comprising the steps of:

s900, calculating the commutation current in the running process of the motor, wherein the calculation method comprises the following steps:

Wherein i _a is the armature current when no commutation exists between the electric brush and the commutating strip, T ₀ is the time required for commutation, T _k is the commutation time period, e _r is the reactance potential of the commutating element, e _w is the induction potential outside the commutation, the commutating element comprises a first commutating strip and a second commutating strip, and r ₁、r₂ is the contact resistance of the first commutating strip, the second commutating strip and the electric brush respectively.

5. The method for identifying the direction of motion of a motor based on double hall sensors according to claim 4, further comprising the steps of:

s1000, generating a high-frequency component when the current of the motor is commutated, namely current commutating pulsation frequency, wherein the current pulsation frequency has the following relation with the rotating speed of the motor:

wherein f is the current pulse frequency, k is the number of commutator segments, and n is the motor rotation speed obtained by a Hall sensor;

The current ripple is subjected to a conditioning circuit to obtain a square wave similar to Hall pulse, a current ripple period T is obtained through the square wave, and a motor rotating speed w obtained through current ripple calculation is obtained through calculation, wherein the calculation method comprises the following steps:

6. The method for identifying the movement direction of a motor based on double hall sensors according to claim 5, further comprising the steps of:

S1100, when the running direction of the motor is changed, the motor needs a certain time to complete the reverse rotation due to the inertia effect and the load inertia inside the motor.

7. The method for identifying the movement direction of a motor based on double hall sensors according to claim 5, further comprising the steps of:

S1200, acquiring rotation speed data of a motor, wherein the rotation speed w of the motor obtained through current ripple calculation and the rotation speed n of the motor obtained through a Hall sensor in S1000 are determined in the actual acquisition process, and abnormal data in the motor are removed according to the maximum rotation speed n _max of the motor; the acquisition period of the rotating speed data of the motor is consistent with the acquisition period of the Hall pulse signal.

8. The method for identifying the movement direction of a motor based on double hall sensors according to claim 7, further comprising the steps of:

and S1300, storing the acquired motor rotation speed data in a group of four, and respectively calculating the average motor rotation speed value of each group of data.

9. The method for identifying the movement direction of a motor based on double hall sensors according to claim 8, further comprising the steps of:

S1400, setting an error threshold value, and taking absolute values of differences among the motor rotating speed obtained through current ripple calculation and the data of each group corresponding to the motor rotating speed obtained through a Hall sensor in the same period, wherein the absolute values are expressed as follows:

n₀＝|n-w|

wherein n is the average motor speed value of a certain group of data obtained by a Hall sensor, w is the average motor speed value of the group of data obtained by current ripple calculation corresponding to n, and n _p is the absolute value of the difference result of the two;

And comparing the absolute value of the difference result of each group with an error threshold value, and judging the error of the two.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method according to any of claims 1-9.