CN112697035A - Three-point calibration method of 3D Hall angle sensor - Google Patents
Three-point calibration method of 3D Hall angle sensor Download PDFInfo
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- CN112697035A CN112697035A CN202011267576.6A CN202011267576A CN112697035A CN 112697035 A CN112697035 A CN 112697035A CN 202011267576 A CN202011267576 A CN 202011267576A CN 112697035 A CN112697035 A CN 112697035A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
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Abstract
The invention relates to a three-point calibration method of a 3D Hall angle sensor, which comprises the following steps: the method comprises the following steps that an upper computer is respectively in communication connection with a motion module and sensor calibration equipment, and the sensor calibration equipment is electrically connected with a 3D Hall angle sensor to be calibrated; setting a calibration range, and reading the output values of the 3D Hall angle sensor at a stroke starting point, a stroke end point and any point in the middle; and determining the variation trend of the output value, calculating a calibration parameter according to the output value, and writing the calibration parameter into the sensor. The invention can improve the calibration accuracy of the sensor and the measurement precision of the sensor.
Description
Technical Field
The invention relates to the technical field of sensor calibration in an industrial automation production line, in particular to a three-point calibration method of a 3D Hall angle sensor.
Background
With the continuous development of industrial automation, various sensors are widely applied to various measurement occasions in order to adapt to high measurement precision. The sensor can convert various physical measurands into electric signals, so that the electric signals are acquired by data acquisition equipment, and corresponding physical quantities are obtained after operation. Magnetic field sensors, and in particular hall effect sensors, are capable of accurate angular or positional detection in automotive and industrial environments and are therefore widely used in industrial and automotive electronics, such as powertrain systems, body systems, and safety applications. In the design, manufacture and use processes of the sensor, sensor calibration is an indispensable link, and accurate measurement and accurate transmission of measured values are finally realized through a calibration test.
Calibration of a sensor actually relies on standard type sensing equipment to determine the translation between the input and output of the sensor itself being calibrated. In the prior art, sensor calibration mainly depends on manual calibration, and because the direction is difficult to determine when the sensor is installed, discontinuous points may exist in an output value in a sensor measurement range, so that a calibration result is inaccurate, and therefore, a new sensor calibration method is needed in order to improve the accuracy of sensor calibration and the measurement precision of the sensor and adapt to an industrial automation production line.
Disclosure of Invention
The invention aims to provide a three-point calibration method of a 3D Hall angle sensor, which can improve the calibration accuracy of the sensor and the measurement accuracy of the sensor.
The technical scheme adopted by the invention for solving the technical problems is as follows: the three-point calibration method of the 3D Hall angle sensor comprises the following steps:
(1) the method comprises the following steps that an upper computer is respectively in communication connection with a motion module and sensor calibration equipment, and the sensor calibration equipment is electrically connected with a 3D Hall angle sensor to be calibrated;
(2) setting a calibration range, and reading the output values of the 3D Hall angle sensor at a stroke starting point, a stroke end point and any point in the middle;
(3) and determining the variation trend of the output value, calculating a calibration parameter according to the output value, and writing the calibration parameter into the sensor.
The motion module in the step (1) is a motor.
The method for determining the starting point and the end point of the stroke in the step (2) comprises the following steps: and controlling the motion module through the upper computer, reading the output value of the 3D Hall angle sensor, taking the current point as a travel starting point until the output value of the 3D Hall angle sensor has obvious change, and determining a travel end point according to a set calibration range.
The step (3) specifically comprises the following substeps:
(31) calculating an angle range to eliminate a break point in an output value of the 3D Hall angle sensor;
(32) calculating a reference position, and moving the discontinuous point to the maximum distance outside the measurement range by using the reference position;
(33) calculating a target value to obtain theoretical output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point;
(34) calculating an intermediate gain, a gain index and an intermediate bias;
(35) calculating a final gain and a final bias;
(36) and writing the reference position, the gain index, the final gain and the final bias into the sensor to finish calibration.
The step (31) is specifically as follows: judging the magnitude relation of the three output values, and setting the three output values as OUT1、OUT2And OUT3In which OUT1、OUT2Output values, OUT, of the 3D Hall angle sensor at the starting point and the end point of the stroke, respectively3The output value of the 3D Hall angle sensor at the middle point is obtained; when OUT1<OUT3<OUT2Angle range OUT2－OUT1(ii) a When OUT2<OUT3<OUT1Angle range OUT1－OUT2(ii) a When OUT3<OUT1<OUT2Or OUT1<OUT2<OUT3Angle range X-OUT2+OUT1(ii) a When OUT3<OUT2<OUT1Or OUT2<OUT1<OUT3Angle range X-OUT1+OUT2(ii) a And X is the maximum value of the output value of the 3D Hall angle sensor.
In the step (32) by
Where DAC _ zero represents the reference position, OUT1The output value of the 3D Hall angle sensor at the stroke starting point is shown, angle _ range is an angle range, and X is the maximum value of the output value of the 3D Hall angle sensor; if the reference position DAC _ zero is greater than 2, 2 is subtracted from DAC _ zero as the reference position.
In the step (33)By passing
Wherein, target1And target2Respectively are theoretical output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point; voltage1And voltage2The voltage values of the 3D Hall angle sensor at the stroke starting point and the stroke end point are respectively; x is the maximum value of the output value of the 3D Hall angle sensor; the voltage is a voltage value corresponding to the maximum output value of the 3D Hall angle sensor.
In the step (34) by
Calculating an intermediate gain by DAC _ Offset to target1-OUT1The intermediate offset is calculated by multiplying DAC _ Gain, where DAC _ Gain is the intermediate Gain, target1And target2Respectively the theoretical output values, OUT, of the 3D Hall angle sensor at the starting point and the end point of the stroke1、OUT2Respectively are output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point, and DAC _ Offset is middle Offset; the initial value of the Gain exponent multi is 1, if DAC _ Gain is less than 0, the absolute value of DAC _ Gain is taken, and multi takes the value-1.
In the step (35) by
Calculating a final gain by
And calculating a final Offset, wherein Gain is a final Gain, multi is a Gain index, DAC _ Gain is an intermediate Gain, X is the maximum value of the output value of the 3D Hall angle sensor, Offset is the final Offset, and DAC _ Offset is the intermediate Offset.
Advantageous effects
Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects: according to the invention, the break points existing in the output value of the sensor are eliminated, the installation direction of the sensor does not need to be judged manually, the calibration parameters can be obtained by one-time calculation, the labor and time cost is saved, and the calibration efficiency of the sensor is improved; the calibrated sensor has improved measurement precision, and the measurement result of the sensor is more accurate.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention.
Fig. 2 is a sensor mounting pattern in an embodiment of the present invention.
Fig. 3 is a theoretical relationship diagram of sensor output and actual value in the embodiment of the present invention.
FIG. 4 is a graphical representation of sensor output values over a range of travel prior to calibration.
FIG. 5 is a graphical representation of sensor output values over the range of travel after calibration, with the solid line representing the sensor output values prior to linear optimization and the dashed line representing the sensor output values after linear optimization.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
The embodiment of the invention relates to a three-point calibration method of a 3D Hall angle sensor, which comprises the following steps as shown in figure 1:
the method comprises the following steps: the method comprises the following steps of respectively connecting an upper computer with a motion module and sensor calibration equipment in a communication mode, electrically connecting the sensor calibration equipment with a sensor to be calibrated, wherein the motion module is a motor, and the sensor to be calibrated is a 3D Hall angle sensor. And after the modules are connected, parameters such as the induction magnetic field of the sensor are set.
Step two: setting a calibration range and a sensor voltage output range, wherein FIG. 2 shows a sensor mounting manner, a sensor output value increases along an arrow direction, and the set calibration range is assumed to be angle1、angle2Voltage range is voltage1、voltage2The sensor output voltage ranges from 0 to voltage (see fig. 3). The upper computer software controls the motor to move until the output value of the sensor is obviously changed, the position is used as a stroke starting point, a stroke end point is determined according to the measuring range of the sensor, and the distance from the stroke starting point to the stroke end point is the measuring range of the sensor. And respectively reading output values of the sensor at a stroke starting point and a stroke end point, and then taking a point in the middle of the stroke, and reading the output value of the sensor in order to avoid the fluctuation of the output value of the sensor, wherein the middle point can not be too close to the starting point or the end point. As shown in fig. 2, 1 is a starting point and 2 is an end point. And respectively reading output values of the sensor at a stroke starting point and a stroke end point, and taking a point 3 in the middle of the stroke, wherein the middle point cannot be too close to the starting point or the end point in order to avoid the influence of the fluctuation of the output value of the sensor on a calculation result.
Step three: calculating a calibration parameter according to the output value, and writing the parameter into the sensor, wherein the specific method comprises the following steps:
(1) calculating the angle range, wherein the purpose of the step is to eliminate the break point in the output value of the sensor, judge the magnitude relation of the three output values, because the installation direction of the sensor is uncertain, the output values may not be in a linear relation, namely, the break point exists, and the three output values are set as OUT1、OUT2、OUT3In which OUT1、OUT2Output values, OUT, for start and end points, respectively3For the intermediate point output value, the following four cases can be classified according to the magnitude relationship:
①OUT1<OUT3<OUT2since the output value tends to increase, the angle range is OUT2－OUT1；
②OUT2<OUT3<OUT1Since the output value trend is decreased, the angle range is OUT1－OUT2；
③OUT3<OUT1<OUT2Or OUT1<OUT2<OUT3Since the output value tends to decrease first and then increase when there is a break point, the angle range is 32768－OUT2+OUT1；
④OUT3<OUT2<OUT1Or OUT2<OUT1<OUT3Since the output value trend increases first and then decreases when there is a break point, the angle range 32768-OUT is an angular range1+OUT2；
It is apparent that FIG. 2 shows OUT2<OUT1<OUT3In line with the fourth case, the angular range is therefore 32768-OUT1+OUT2。
(2) Calculating a reference position, wherein the discontinuous point can be moved to the maximum distance outside the measurement range by using the reference position, and the calculation formula is as follows:
if the reference position DAC _ zero is greater than 65536, subtracting 65536 from DAC _ zero as the reference position;
(3) calculating a target value, which is used for calculating theoretical output values of the sensor at the stroke starting point and the stroke end point:
(4) calculating the intermediate gain and gain index:
the initial value of the Gain exponent multi is 1, if DAC _ Gain is smaller than 0, the absolute value of DAC _ Gain is taken, and the value of multi is-1;
(5) calculating a middle bias: DAC _ Offset ═ target1-OUT1×DAC_Gain；
(6) Calculating final gain, and further performing linear optimization by a least square method to improve the measurement accuracy of the sensor:
(7) calculating the final bias:
(8) the reference position, gain index, final gain and final bias are written to the sensor.
FIG. 4 is a graphical representation of sensor output values over a range of travel prior to calibration. Fig. 5 is a diagram showing the output values of the sensor in the stroke range after calibration, in fig. 5, the solid line shows the output values of the sensor before linear optimization, and the dotted line shows the output values of the sensor after linear optimization. Comparing fig. 4 and fig. 5, it can be seen that the calibration method provided by the present invention eliminates the break point in the output value of the sensor and reduces the measurement error of the sensor.
Claims (9)
1. A three-point calibration method of a 3D Hall angle sensor is characterized by comprising the following steps:
(1) the method comprises the following steps that an upper computer is respectively in communication connection with a motion module and sensor calibration equipment, and the sensor calibration equipment is electrically connected with a 3D Hall angle sensor to be calibrated;
(2) setting a calibration range, and reading the output values of the 3D Hall angle sensor at a stroke starting point, a stroke end point and any point in the middle;
(3) and determining the variation trend of the output value, calculating a calibration parameter according to the output value, and writing the calibration parameter into the sensor.
2. The three-point calibration method for the 3D Hall angle sensor according to claim 1, wherein the motion module in step (1) is a motor.
3. The three-point calibration method for the 3D Hall angle sensor according to claim 1, wherein the determination method for the stroke starting point and the stroke ending point in the step (2) is as follows: and controlling the motion module through the upper computer, reading the output value of the 3D Hall angle sensor, taking the current point as a travel starting point until the output value of the 3D Hall angle sensor has obvious change, and determining a travel end point according to a set calibration range.
4. The three-point calibration method for the 3D Hall angle sensor according to claim 1, wherein the step (3) specifically comprises the following sub-steps:
(31) calculating an angle range to eliminate a break point in an output value of the 3D Hall angle sensor;
(32) calculating a reference position, and moving the discontinuous point to the maximum distance outside the measurement range by using the reference position;
(33) calculating a target value to obtain theoretical output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point;
(34) calculating an intermediate gain, a gain index and an intermediate bias;
(35) calculating a final gain and a final bias;
(36) and writing the reference position, the gain index, the final gain and the final bias into the sensor to finish calibration.
5. The three-point calibration method of the 3D Hall angle sensor according to claim 4, wherein the step (31) is specifically: judging the magnitude relation of the three output values, and setting the three output values as OUT1、OUT2And OUT3In which OUT1、OUT2Output values, OUT, of the 3D Hall angle sensor at the starting point and the end point of the stroke, respectively3The output value of the 3D Hall angle sensor at the middle point is obtained; when OUT1<OUT3<OUT2Angle range OUT2－OUT1(ii) a When OUT2<OUT3<OUT1Angle range OUT1－OUT2(ii) a When OUT3<OUT1<OUT2Or OUT1<OUT2<OUT3Angle range X-OUT2+OUT1(ii) a When OUT3<OUT2<OUT1Or OUT2<OUT1<OUT3Angle range X-OUT1+OUT2(ii) a And X is the maximum value of the output value of the 3D Hall angle sensor.
6. Three-point calibration method of a 3D Hall angle sensor according to claim 4, characterized in that, in step (32), the calibration is performed by
Where DAC _ zero represents the reference position, OUT1The output value of the 3D Hall angle sensor at the stroke starting point is shown, angle _ range is an angle range, and X is the maximum value of the output value of the 3D Hall angle sensor; if the reference position DAC _ zero is greater than 2, 2 is subtracted from DAC _ zero as the reference position.
7. Three-point calibration method of a 3D Hall angle sensor according to claim 4, characterized in that, in step (33), the calibration is performed by
Wherein, target1And target2Respectively are theoretical output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point; voltage1And voltage2The voltage values of the 3D Hall angle sensor at the stroke starting point and the stroke end point are respectively; x is the maximum value of the output value of the 3D Hall angle sensor; the voltage is a voltage value corresponding to the maximum output value of the 3D Hall angle sensor.
8. Three-point calibration method of a 3D Hall angle sensor according to claim 4, characterized in that, in step (34), the calibration is performed by
Calculating an intermediate gain by DAC _ Offset to target1-OUT1The intermediate offset is calculated by multiplying DAC _ Gain, where DAC _ Gain is the intermediate Gain, target1And target2Respectively the theoretical output values, OUT, of the 3D Hall angle sensor at the starting point and the end point of the stroke1、OUT2Respectively are output values of the 3D Hall angle sensor at a stroke starting point and a stroke ending point, and DAC _ Offset is middle Offset; initiation of gain index MultiThe value is 1, if DAC _ Gain is less than 0, the absolute value of DAC _ Gain is taken, and the multi value is-1.
9. Three-point calibration method for a 3D Hall angle sensor according to claim 4, characterized in that, in step (35), the calibration is performed by
Calculating a final gain by
And calculating a final Offset, wherein Gain is a final Gain, multi is a Gain index, DAC _ Gain is an intermediate Gain, X is the maximum value of the output value of the 3D Hall angle sensor, Offset is the final Offset, and DAC _ Offset is the intermediate Offset.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62165111A (en) * | 1986-01-17 | 1987-07-21 | Komatsu Ltd | Correcting method for detected angle of working machine sensor |
| US5644225A (en) * | 1996-04-16 | 1997-07-01 | Honeywell Inc. | Method for calibrating an angular position sensor |
| US20010003421A1 (en) * | 1999-12-08 | 2001-06-14 | Takamitsu Kubota | Rotational angle output regulating method |
| US20060155497A1 (en) * | 2005-01-08 | 2006-07-13 | Leopold Kostal Gmbh & Co. Kg | Method for correcting a characteristic curve derived from a magnetoresistive sensor signal |
| CN102419191A (en) * | 2011-09-09 | 2012-04-18 | 陆科 | Tool for calibrating and programming sensor |
| CN103900463A (en) * | 2014-04-25 | 2014-07-02 | 江西省智成测控技术研究所有限责任公司 | Method for improving absolute measurement accuracy of analog output angle in self-adaptive mode |
| US20170115362A1 (en) * | 2015-10-21 | 2017-04-27 | Allegro Microsystems, Llc | Methods and Apparatus for Sensor Having Fault Trip Level Setting |
| CN109828164A (en) * | 2019-01-28 | 2019-05-31 | 北京理工大学 | Method for detecting phases and device, computer equipment, computer readable storage medium |
| CN111649766A (en) * | 2020-06-01 | 2020-09-11 | 哈尔滨理工大学 | Method and device for actively suppressing noise of angle value of magnetoelectric encoder |
| US20200292362A1 (en) * | 2019-03-15 | 2020-09-17 | Pegatron Corporation | Method and device for correcting angle sensor |
-
2020
- 2020-11-13 CN CN202011267576.6A patent/CN112697035B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62165111A (en) * | 1986-01-17 | 1987-07-21 | Komatsu Ltd | Correcting method for detected angle of working machine sensor |
| US5644225A (en) * | 1996-04-16 | 1997-07-01 | Honeywell Inc. | Method for calibrating an angular position sensor |
| US20010003421A1 (en) * | 1999-12-08 | 2001-06-14 | Takamitsu Kubota | Rotational angle output regulating method |
| US20060155497A1 (en) * | 2005-01-08 | 2006-07-13 | Leopold Kostal Gmbh & Co. Kg | Method for correcting a characteristic curve derived from a magnetoresistive sensor signal |
| CN102419191A (en) * | 2011-09-09 | 2012-04-18 | 陆科 | Tool for calibrating and programming sensor |
| CN103900463A (en) * | 2014-04-25 | 2014-07-02 | 江西省智成测控技术研究所有限责任公司 | Method for improving absolute measurement accuracy of analog output angle in self-adaptive mode |
| US20170115362A1 (en) * | 2015-10-21 | 2017-04-27 | Allegro Microsystems, Llc | Methods and Apparatus for Sensor Having Fault Trip Level Setting |
| CN109828164A (en) * | 2019-01-28 | 2019-05-31 | 北京理工大学 | Method for detecting phases and device, computer equipment, computer readable storage medium |
| US20200292362A1 (en) * | 2019-03-15 | 2020-09-17 | Pegatron Corporation | Method and device for correcting angle sensor |
| CN111649766A (en) * | 2020-06-01 | 2020-09-11 | 哈尔滨理工大学 | Method and device for actively suppressing noise of angle value of magnetoelectric encoder |
Non-Patent Citations (1)
| Title |
|---|
| 王华茂: "《航天器综合测试技术》", 31 March 2018 * |
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