CN111076761A - Magnetic encoder calibration method and system - Google Patents
Magnetic encoder calibration method and system Download PDFInfo
- Publication number
- CN111076761A CN111076761A CN201911392579.XA CN201911392579A CN111076761A CN 111076761 A CN111076761 A CN 111076761A CN 201911392579 A CN201911392579 A CN 201911392579A CN 111076761 A CN111076761 A CN 111076761A
- Authority
- CN
- China
- Prior art keywords
- angle
- magnetic encoder
- joint angle
- motor joint
- rotating shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- G01D18/00—Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
Abstract
The invention discloses a magnetic encoder calibration method and a magnetic encoder calibration system. The method comprises the following steps: acquiring a motor joint angle obtained by measurement of a magnetic encoder; correcting the angle of the motor joint obtained by measurement by combining an angle corresponding relation table and a linear interpolation algorithm; the angle corresponding relation table is established by the following steps: selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of sampling points and the calibration angle range; and controlling a rotating shaft provided with a magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table. The magnetic encoder is arranged on the rotating shaft of the rotating equipment to be directly calibrated, the angle of the motor joint angle obtained by measuring the magnetic encoder is mapped into a real angle, and the operation is simple and rapid.
Description
Technical Field
The invention relates to the technical field of machine/instrument calibration, in particular to a magnetic encoder calibration method and system.
Background
Along with the rapid development and popularization of artificial intelligence in recent years, more and more intelligent devices begin to appear, the life of people is greatly facilitated, and the motion of the intelligent devices is often realized by a motor. The brushless DC motor does not use a mechanical structure of a commutating brush, but uses an electronic commutator, so that the brushless DC motor has better torque and rotating speed characteristics, high efficiency, low noise and long service life, and is widely applied to various intelligent devices. The brushless direct current motor has various control methods, wherein a motor vector control principle is simple, a control effect is excellent, the brushless direct current motor is widely applied, a position sensor is required to be used for detecting the position of a rotor in vector control, and a magnetic encoder is small in size and high in measurement angle precision in small intelligent equipment, so that the brushless direct current motor is widely used.
However, the angle measured by the magnetic encoder has an error problem, which is specifically shown in that the process of outputting the measured value of the magnetic encoder from 0 to 360 degrees is nonlinear, and the angle change of some positions is faster than the actual angle change, and the angle change of some positions is slower than the actual angle change, so that the angle measurement of some positions has an error, which causes the problems of torque pulse, speed fluctuation and the like in the motor vector control, and influences the motor control effect.
In order to ensure the accuracy of angle measurement, the current mainstream method is to calibrate an encoder, the key of the method lies in the acquisition of an accurate angle, for example, the method and the system for calibrating a magnetic encoder disclosed in patent application publication with publication number CN106679710A published by the national intellectual property office in 5/17/2017 disclose that an electric adjustment plate is used to drive a motor to rotate to a fixed electric angle to realize calibration, but the method is essentially open-loop control, the disadvantage of the open-loop control is that no feedback exists, the accuracy of a result cannot be ensured, and the obtained electric angle needs to be converted into a mechanical angle, but the corresponding relation between the electric angle and the mechanical angle is not unique, the process of converting the electric angle into the accurate mechanical angle is complex, meanwhile, an upper computer and the electric adjustment plate interact, the reliability of data acquisition is low, the hardware requirement is high, and the operation cost is high, the experimental scheme is complex. Also, as disclosed in the patent application publication No. CN104767467A published by the national intellectual property office at 7/8/2015, the method discloses that injecting a direct-axis component current into a motor can ensure that a rotor rotates to a position with an electrical angle of 0, and is simple to operate, but the method is also very inconvenient for operating a multi-pair-stage motor because n positions with an electrical angle of 0 will appear in n pairs of stage motors within a mechanical angle of 0-360 °, and the positions where the motor rotates have randomness, so as to ensure that all collected mechanical zero points need to be sampled for many times, and the result is checked, thereby increasing the operation amount and the operation difficulty, in addition, the number of sampling points in the method is limited by the number of pole pairs of the motor in principle, and at most, n data of the number of pole pairs of the motor can be collected as an accurate value within a range of 0-360 °, the calibration effect is limited.
Disclosure of Invention
The embodiment of the invention provides a method and a system for calibrating a magnetic encoder, aiming at directly calibrating the magnetic encoder without special jigs and calibration equipment, having low operation cost, simple and rapid operation and strong reliability, and without complicated conversion of electrical angle and mechanical angle.
In a first aspect, an embodiment of the present invention provides a magnetic encoder calibration method, which includes: acquiring a motor joint angle obtained by measurement of a magnetic encoder; correcting the motor joint angle obtained by measurement by combining an angle corresponding relation table and a linear interpolation algorithm to obtain a corrected motor joint angle; the angle corresponding relation table is established by the following steps: selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of sampling points and the calibration angle range; and controlling a rotating shaft provided with a magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table.
In a second aspect, an embodiment of the present invention further provides a magnetic encoder calibration system, configured to calibrate a magnetic encoder of a rotating device having a rotating shaft, where the rotating shaft is provided with a motor for controlling the rotating shaft to rotate, and the magnetic encoder is installed on the rotating shaft of the rotating device and is used to measure and acquire a joint angle of the motor corresponding to the motor, and the magnetic encoder calibration system includes: the acquisition module is used for acquiring the motor joint angle measured by the magnetic encoder; the correction module is used for correcting the motor joint angle obtained by measurement by combining the angle corresponding relation table and the linear interpolation algorithm to obtain a corrected motor joint angle; the setting module is used for selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of the sampling points and the calibration angle range; and the angle corresponding processing module is used for controlling the rotating shaft provided with the magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table.
The embodiment of the invention provides a magnetic encoder calibration method and a magnetic encoder calibration system. The embodiment of the invention obtains the angle of the motor joint angle obtained by the measurement of the magnetic encoder by controlling the rotating shaft to rotate around the shaft to a preset angle and correcting the angle of the motor joint angle by combining the angle corresponding relation table and a linear interpolation algorithm, thereby realizing that the angle of the motor joint angle obtained by the measurement of the magnetic encoder can be directly mapped into a real and accurate angle, improving the linearity of the magnetic encoder, directly realizing the calibration of the magnetic encoder without a special jig and a calibration device, having low operation cost and without complicated conversion of an electrical angle and a mechanical angle, wherein the angle corresponding relation table can obtain the corresponding relation between the target Euler angle and the angle of the motor joint obtained by the measurement of the magnetic encoder on the rotating shaft by controlling the rotating shaft to rotate around the shaft for a plurality of times, the operation is simple and quick, and the reliability is strong.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also provide other drawings without inventive labor.
FIG. 1 is a schematic block diagram of a magnetic encoder calibration system provided by an embodiment of the present invention;
FIG. 2 is a schematic block diagram of an angle correspondence processing module of a magnetic encoder calibration system according to an embodiment of the present invention;
FIG. 3 is a schematic block diagram of an acquisition module of a magnetic encoder calibration system provided by an embodiment of the present invention;
FIG. 4 is a schematic block diagram of a particular application of a magnetic encoder calibration system provided by an embodiment of the present invention;
FIG. 5 is a flow chart illustrating a method for calibrating a magnetic encoder according to an embodiment of the present invention;
FIG. 6 is a flowchart illustrating a calibration method for a magnetic encoder according to an embodiment of the present invention
FIG. 7 is a schematic flow chart illustrating a table for establishing an angle correspondence relationship according to a calibration method for a magnetic encoder according to an embodiment of the present invention; and
fig. 8 is a sub-flow diagram illustrating the establishment of an angle mapping table according to the calibration method of a magnetic encoder provided in the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.
Referring to fig. 1, fig. 1 is a schematic block diagram of a calibration system of a magnetic encoder according to an embodiment of the present invention. As shown in fig. 1, the present invention provides a magnetic encoder calibration system 10 for calibrating a magnetic encoder 210 of a rotating device 20 having a rotating shaft, the rotating shaft being provided with a motor for controlling the rotation of the rotating shaft, the magnetic encoder 210 being mounted on the rotating shaft of the rotating device 20, each of the magnetic encoders 210 being in communication with a corresponding motor for measuring and acquiring a motor joint angle of the corresponding motor.
The magnetic encoder calibration system 10 includes an acquisition module 110, a correction module 120, a setting module 130, and an angle correspondence processing module 140, where the acquisition module 110 is configured to acquire a motor joint angle obtained by measurement of the magnetic encoder 210. The correction module 120 is configured to correct the measured motor joint angle by combining the angle correspondence table and the linear interpolation algorithm, so as to obtain a corrected motor joint angle; the motor joint angle obtained by measurement is corrected through the angle corresponding relation table and the linear interpolation algorithm, so that the linearity of the measured value of the magnetic encoder 210 is improved, and the accuracy of the magnetic encoder 210 is improved.
The setting module 130 is configured to select a calibration angle range, set a sampling point number according to the calibration angle range, and set a target euler angle corresponding to each sampling point according to the sampling point number and the calibration angle range. The selection of the calibration angle range and the setting of the number of the sampling points can be input by a user, wherein the number of the sampling points can be set to be n, n is larger than or equal to 3, the sampling points are respectively 1-n according to the number of the sampling points n, the calibration angle range is averagely divided into n equal parts by combining the selected calibration angle range and the number of the sampling points, corresponding target Euler angles are respectively set corresponding to each sampling point, and the corresponding target Euler angles between two adjacent sampling points are in an equal difference increasing relationship. Suppose the sampling points have serial numbers i, i ═ 1,2, ·, n, and their corresponding target euler angles are denoted by biIndicates that the corresponding sampling point serial numbers are b1,b2,···,bnCorrespondingly, the motor joint angle is aiIndicates that the corresponding sampling point serial numbers are respectively a1,a2,···,an。
The angle correspondence processing module 140 is configured to control the rotating shaft of the rotating device 20, which is provided with the magnetic encoder 210, to sequentially rotate to all target euler angles according to the sampling points, obtain and record corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target euler angle, and establish an angle correspondence table.
In some embodiments, as shown in fig. 2, the angle correspondence processing module 140 includes a rotation control unit 141, a sampling recording unit 142, a rotation counter 143, and a table building unit 144, where the rotation control unit 141 is connected to the rotating device 20 having a rotating shaft, and is configured to control the rotating shaft of the rotating device 20, on which the magnetic encoder 210 is installed, to rotate around the corresponding axial direction to a corresponding target euler angle. The sampling recording unit 142 is connected to the magnetic encoder 210, and is configured to acquire a motor joint angle measured by the corresponding magnetic encoder 210 when the rotating shaft rotates to the target euler angle, and record the target euler angle and the motor joint angle corresponding to the target euler angle. The rotation counter 143 counts the number of rotations of a rotation axis representing a rotation axis on which the rotation control unit 141 controls the rotation of the rotary device 20, and the initial number of rotations is 0, and the number of rotations may correspond to the sampling point. The table building unit 144 is configured to build an angle correspondence table according to the number of sampling points, in combination with all target euler angles and motor joint angle angles corresponding to the target euler angles.
After the rotation control unit 141 controls the rotation shaft of the rotating device 20 to rotate around the corresponding axial direction to the corresponding target euler angle, the magnetic encoder 210 on the rotation shaft measures and obtains the corresponding motor joint angle, and the sampling and recording unit 142 obtains the motor joint angle and records the target euler angle and the corresponding motor joint angle. When the rotating shaft finishes one rotation, the rotation counter 143 updates the number of rotation times, the number of rotation times is the counted number of rotation times plus one, and whether the updated number of rotation times reaches the number of sampling points is judged according to the comparison between the updated number of rotation times and the number of sampling points set in the setting module 130; if not, it represents that the rotation control unit 141 does not control the rotation shaft to rotate to all target euler angles, and the rotation control unit 141 controls the rotation shaft to rotate according to the target euler angle corresponding to the next sampling point in the setting module 130; the acquisition and recording unit 142 acquires and records the target euler angle and the motor joint angle measured by the corresponding magnetic encoder 210; if yes, it means that the rotation control unit 141 has controlled the rotation shaft to rotate to all target euler angles, and has acquired and recorded all target euler angles and their corresponding points and joint angle angles through the sampling recording unit 142, the table building unit 144 works to build an angle correspondence table according to all sampling points, in combination with all target euler angles and their corresponding motor joint angle angles, and at the same time, the rotation control unit 141 stops working, and the number of rotations of the rotation counter 143 returns to zero.
In some embodiments, as shown in fig. 3, specifically, the acquisition module 110 includes a rotation unit 111 and a sampling unit 112, and the rotation unit 111 is configured to control a rotation shaft of the rotation device 20, on which the magnetic encoder 210 is installed, to rotate to a preset angle. The sampling unit 112 is used for acquiring the motor joint angle measured by the magnetic encoder 210 on the rotating shaft. Preferably, the correction module 120 includes a processing unit, and the processing unit is configured to obtain a joint angle interval where the motor joint angle is located according to the motor joint angle obtained by measurement of the magnetic encoder 210 on the rotating shaft in combination with the angle correspondence table, and obtain a modified motor joint angle through a linear interpolation algorithm according to an end point of the joint angle interval and a target euler angle corresponding to the end point by using the following calculation formula:
when a < a1When the temperature of the water is higher than the set temperature,
when a is1≤a＜anWhen the temperature of the water is higher than the set temperature,
when a is more than or equal to anWhen the temperature of the water is higher than the set temperature,
wherein a represents the motor joint angle measured by the magnetic encoder on the rotating shaft, a-represents the corrected motor joint angle, i represents the sampling point number, ai、ai+1Respectively representing the end points of the joint angle interval in which the motor joint angle a is positioned, a1、a2、an-1And anRespectively representing the angle of the motor joint corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point in the angle corresponding relation table, b1、b2、bn-1And bnRespectively representing target Euler angles corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point, biAnd bi+1Respectively representing target Euler angles corresponding to the joint angle interval end points where the motor joint angle a is located. The target Euler angle and the motor joint angle related in the calibration process are mechanical angles, and complex conversion of the electrical angle and the mechanical angle is not needed, so that the calibration process is simpler and faster.
Based on the design, when the device works, the rotating unit of the acquisition module controls the rotating shaft of the rotating equipment, which is provided with the magnetic encoder, to rotate to a preset angle, the sampling unit acquires the motor joint angle obtained by measuring the magnetic encoder on the rotating shaft, and the correction module corrects the motor joint angle obtained by measuring according to the motor joint angle obtained by measuring the magnetic encoder by combining an angle correspondence table and a linear interpolation algorithm to obtain a corrected motor joint angle; the system comprises an angle correspondence table, a setting module, an angle correspondence processing module, a sampling point number setting module and a target Euler angle setting module, wherein the angle correspondence table is obtained through the setting module and the angle correspondence processing module; the rotation control unit of the angle corresponding processing module controls a rotating shaft of the rotating equipment, which is provided with a magnetic encoder, to rotate to a corresponding target Euler angle around a corresponding axial direction according to the number of sampling points of the setting module and the corresponding target Euler angle; a sampling and recording unit acquires motor joint angle angles measured by corresponding magnetic encoders when the rotating shaft rotates to each target Euler angle, and records the target Euler angles and the motor joint angle angles corresponding to the target Euler angles; when the rotating shaft finishes one rotation, the rotating counter updates the rotating times, and whether the updated rotating times reach the sampling points is judged according to the comparison between the updated rotating times and the sampling points set in the setting module; if not, the rotation control unit does not control the rotation shaft to rotate to all target Euler angles, and the rotation control unit controls the rotation shaft to rotate according to the target Euler angle corresponding to the next sampling point in the setting module; the acquisition and recording unit acquires and records the target Euler angle and the motor joint angle measured by the corresponding magnetic encoder; if so, the table building unit works to build an angle corresponding relation table according to the number of all sampling points and by combining all target Euler angles and corresponding motor joint angle angles, and meanwhile, the rotation control unit stops working, and the rotation frequency of the rotation counter returns to zero.
With reference to fig. 4, in some embodiments, the rotating apparatus with a rotating shaft may employ a cradle head 30, the magnetic encoder calibration system 10 is configured to calibrate a magnetic encoder 310 of the cradle head 30, each shaft of the cradle head 30 is respectively provided with a magnetic encoder 310, each shaft of the cradle head 30 is further provided with a motor for controlling each shaft to rotate, and each magnetic encoder 310 is in communication connection with a corresponding motor to measure and obtain a joint angle of the motor of each shaft. An Inertial Measurement Unit (IMU) 320 is disposed in the pan/tilt head 30, the IMU320 is disposed on the pan/tilt head 30, and includes a gyroscope and an accelerometer, the gyroscope is used for measuring an angular velocity of each axial direction according to the rotation of the pan/tilt head 30, and the accelerometer is used for measuring an acceleration of each axial direction according to the rotation of the pan/tilt head 30. The holder 30 is closed-loop control, so that the accuracy of the Euler angle can be ensured, the accuracy of the rotation of the rotating shaft to the target Euler angle can be improved, and the calibration reliability of the magnetic encoder can be improved. Wherein, cloud platform 30 adopts the triaxial cloud platform, and it includes three axle, is roll axle (roll axle), pitch axle (pitch axle) and course axle (yaw axle) respectively, corresponds to x axle, y axle and the z axle of space coordinate system respectively, and during cloud platform 20 rotated, roll axle (roll axle) is around x axle axial rotation, pitch axle (pitch axle) is around y axle axial rotation, course axle (yaw axle) is around z axle axial rotation. During calibration, the motor controls the rotating shaft to rotate to the required motor joint angle, the euler angle of the corresponding shaft is used for calculation, and after calibration is completed, the motor joint angle corrected by the magnetic encoder 310 is used for calculation. In calibration, the base of the pan/tilt head 30 can be placed vertically, i.e. the rotation axis corresponding to the motor of the yaw axis is perpendicular to the horizontal plane.
The rotation unit 111 of the acquisition module 110 of the magnetic encoder calibration system 10 controls a shaft of the pan/tilt head 30 to rotate to a preset angle, the sampling unit 112 obtains a motor joint angle measured by the magnetic encoder 310 on the rotation shaft, and the correction module 120 corrects the measured motor joint angle according to the motor joint angle measured by the magnetic encoder 310 and by combining an angle correspondence table and a linear interpolation algorithm, so as to obtain a corrected motor joint angle. The angle correspondence table is obtained through the setting module 130 and the angle correspondence processing module 140, the user selects a calibration angle range through the setting module 130, sets the number of sampling points according to the calibration angle range, and sets a target euler angle corresponding to each sampling point according to the number of sampling points and the calibration angle range; the rotation control unit 141 of the angle correspondence processing module 140 controls a shaft of the pan/tilt head 30 to rotate to a corresponding target euler angle around a corresponding axial direction according to the number of sampling points of the setting module 130 and the corresponding target euler angle; the sampling and recording unit 142 obtains a motor joint angle measured by the corresponding magnetic encoder 310 when the rotating shaft rotates to the target euler angle, and records the target euler angle and the motor joint angle corresponding to the target euler angle; when the rotating shaft finishes one rotation, the rotation counter 143 updates the number of rotation times, and judges whether the updated number of rotation times reaches the number of sampling points according to the comparison between the updated number of rotation times and the number of sampling points set in the setting module 130; if not, it represents that the rotation control unit 141 does not control the rotation shaft to rotate to all target euler angles, and the rotation control unit 141 controls the rotation shaft to rotate according to the target euler angle corresponding to the next sampling point in the setting module 130; the acquisition and recording unit 142 acquires and records the target euler angle and the corresponding motor joint angle measured by the magnetic encoder 310 on the rotating shaft; if yes, it means that the rotation control unit 141 has controlled the rotation shaft to rotate to all target euler angles, and has obtained and recorded all target euler angles and their corresponding points and joint angle angles through the sampling recording unit 142, the table building unit 144 works to build an angle correspondence table according to all sampling points, in combination with all target euler angles and their corresponding motor joint angle angles, and at the same time, the rotation control unit 141 stops working, and the number of rotations of the rotation counter 143 returns to zero. The calibration of the magnetic encoders 310 corresponding to the roll axis, the pitch axis and the yaw axis is completed in sequence, and the pitch axis and the yaw axis do not work when the magnetic encoder 310 of the roll axis is calibrated; while the pitch axis is calibrated, the roll axis and the yaw axis are not operated. When calibrating the yaw axis, the roll axis and the pitch axis are controlled to be at the position where the euler angle is zero, and because there is a certain integral drift in the euler angle of the yaw axis, in order to improve the calibration accuracy of the magnetic encoder of the yaw axis, the base of the pan/tilt head 30 can be horizontally placed, that is, the rotation axis corresponding to the motor of the yaw axis is parallel to the horizontal plane. When calibrating the yaw axis, the motors controlling the roll axis and the pitch axis are in a position where the joint angle is zero, and the motor controlling the yaw axis rotates to a position of a required Euler angle for calibration.
The present invention also provides another preferred embodiment of a magnetic encoder calibration system, in which the magnetic encoder calibration system includes a processor and a memory, the processor is configured to execute the following program modules stored in the memory:
the acquisition module is used for acquiring the motor joint angle measured by the magnetic encoder;
the correction module is used for correcting the motor joint angle obtained by measurement by combining the angle corresponding relation table and the linear interpolation algorithm to obtain a corrected motor joint angle;
the setting module is used for selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of the sampling points and the calibration angle range;
and the angle corresponding processing module is used for controlling the rotating shaft provided with the magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording all corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to all target Euler angles, and establishing an angle corresponding relation table.
Wherein the processor may be an MCU.
According to the embodiment of the invention, the magnetic encoder is directly arranged on the rotating shaft of the rotating equipment, the rotating shaft is controlled to rotate around the axial direction to a preset angle through the acquisition module, the motor joint angle obtained by the measurement of the magnetic encoder is obtained, the motor joint angle obtained by the measurement of the magnetic encoder is corrected by utilizing the correction module according to the motor joint angle in combination with the angle corresponding relation table and the linear interpolation algorithm, the corrected motor joint angle is obtained, the motor joint angle obtained by the measurement of the magnetic encoder can be directly mapped into a real and accurate angle, the linearity of the magnetic encoder is improved, the calibration of the magnetic encoder is directly realized without special jigs and calibration equipment, the operation cost is low, and the complex conversion of the electrical angle and the mechanical angle is not required, wherein the angle corresponding relation table can control the rotating shaft of the rotating equipment provided with the magnetic encoder according to the acquisition through the angle corresponding processing module according to the sampling point in the setting module and the corresponding target Euler angle The sampling points sequentially rotate to all target Euler angles, all corresponding motor joint angle angles obtained by measurement of a magnetic encoder on the rotating shaft when the rotating shaft rotates to all target Euler angles are obtained and recorded, and an angle corresponding relation table is established.
FIG. 5 is a flowchart illustrating a calibration method for a magnetic encoder according to an embodiment of the present invention. As shown, the method includes the following steps S101-S102.
And S101, acquiring a motor joint angle obtained by measurement of the magnetic encoder.
Specifically, as shown in fig. 6, the step S101 specifically includes:
and S1011, controlling the rotating shaft of the rotating device, which is provided with the magnetic encoder, to rotate to a preset angle.
And step S1012, acquiring a motor joint angle measured by the magnetic encoder on the rotating shaft.
And S102, correcting the measured motor joint angle by combining the angle corresponding relation table and the linear interpolation algorithm to obtain a corrected motor joint angle. According to the embodiment of the invention, the angle of the motor joint angle obtained by measurement is corrected through the angle corresponding relation table and the linear interpolation algorithm, so that the linearity of the measured value of the magnetic encoder is improved, and the accuracy of the magnetic encoder is improved.
Preferably, the step S102 specifically includes: combining the motor joint angle obtained by measuring the magnetic encoder on the rotating shaft with the angle corresponding relation table to obtain a joint angle section where the motor joint angle is located, and obtaining the corrected motor joint angle through a linear interpolation algorithm according to the end point of the joint angle section and the target Euler angle corresponding to the end point by using the following calculation formula:
when a < a1When the temperature of the water is higher than the set temperature,
when a is1≤a＜anWhen the temperature of the water is higher than the set temperature,
when a is more than or equal to anWhen the temperature of the water is higher than the set temperature,
in the formula, a represents the motor joint angle measured by a magnetic encoder on the rotating shaft,
represents the corrected angle of the motor joint, i represents the sampling point serial number, aiAnd ai+1Respectively representing the end points of the joint angle interval in which the motor joint angle a is positioned, a1、a2、an-1And anRespectively representing the angle of the motor joint corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point in the angle corresponding relation table, b1、b2、bn-1And bnRespectively representing target Euler angles corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point, biAnd bi+1Respectively representing target Euler angles corresponding to the joint angle interval end points where the motor joint angle a is located. The target Euler angle and the motor joint angle related in the calibration process are mechanical angles, and complex conversion of the electrical angle and the mechanical angle is not needed, so that the calibration process is simpler and faster.
Specifically, as shown in fig. 7, the angle correspondence table may be established by the following steps:
step S110, selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of sampling points and the calibration angle range.
The selection of the calibration angle range and the setting of the number of the sampling points can be input by a user, the number of the sampling points can be set to be n, n is larger than or equal to 3, the sampling points are respectively 1-n according to the number of the sampling points n, the calibration angle range is averagely divided into n equal parts by combining the selected calibration angle range and the number of the sampling points, corresponding target Euler angles are respectively set corresponding to each sampling point, and the corresponding target Euler angles between two adjacent sampling points are in an equal difference increasing relationship. Suppose the sampling points have serial numbers i, i ═ 1,2, ·, n, and their corresponding target euler angles are denoted by biIndicates that the corresponding sampling point serial numbers are b1,b2,···,bnCorrespondingly, the motor joint angle is aiIndicates that the corresponding sampling point serial numbers are respectively a1,a2,···,an。
And step S120, controlling a rotating shaft provided with a magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table.
Specifically, as shown in fig. 8, the step S120 specifically includes:
and S121, controlling a rotating shaft of the rotating equipment, which is provided with the magnetic encoder, to rotate around the corresponding axial direction to a corresponding target Euler angle, and updating the rotating times.
Preferably, the step S121 specifically includes: and according to the set number of sampling points and the target Euler angle corresponding to each sampling point, controlling a rotating shaft of the rotating equipment, which is provided with a magnetic encoder, to sequentially rotate to the corresponding target Euler angle around the corresponding axial direction, and updating the rotating times. The initial rotation frequency is 0, the updated rotation frequency is the counted rotation frequency plus one, and the updated rotation frequency can correspond to the sampling point.
Step S122, obtaining a motor joint angle measured by a corresponding magnetic encoder when the rotating shaft rotates to the target Euler angle, and recording the target Euler angle and the motor joint angle corresponding to the target Euler angle;
step S123, judging whether the updated rotation frequency reaches the sampling point number, if so, executing step S124; otherwise, returning to execute the step S121;
and step S124, establishing an angle corresponding relation table according to the sampling points and by combining all target Euler angles and corresponding motor joint angle angles.
The embodiment of the invention obtains the angle of the motor joint angle obtained by the measurement of the magnetic encoder by controlling the rotating shaft to rotate to a preset angle around the shaft, and corrects the angle of the motor joint angle by combining the angle corresponding relation table and the linear interpolation algorithm according to the angle of the motor joint angle to obtain the corrected angle of the motor joint angle, thereby realizing that the angle of the motor joint obtained by the measurement of the magnetic encoder can be directly mapped into a real and accurate angle, improving the linearity of the magnetic encoder, directly realizing the calibration of the magnetic encoder without a special jig and a calibration device, having low operation cost and without complicated conversion of the electrical angle and the mechanical angle, wherein the angle corresponding relation table can control the rotating shaft provided with the magnetic encoder of the rotating device to sequentially rotate to all target Euler angles according to the set sampling points and the corresponding target Euler angles, and the corresponding motor joint angle measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle is obtained and recorded, and an angle corresponding relation table is established, so that the operation is simple and rapid, and the reliability is high.
Specifically, the rotating equipment can adopt the cloud platform, be provided with IMU and magnetic encoder on the cloud platform, and respectively with cloud platform interconnect, IMU includes gyroscope and accelerometer, is used for acquireing each axial angular velocity and acceleration of cloud platform respectively, the magnetic encoder set up respectively in each epaxial of cloud platform. Each shaft of the holder is also provided with a motor for controlling each shaft to rotate, and each magnetic encoder is in communication connection with the corresponding motor so as to measure and acquire the angle of the motor joint angle of each shaft. The cloud platform can adopt the triaxial cloud platform, and it includes three axle, is roll axle (roll axle), pitch axle (pitch axle) and course axle (yaw axle) respectively, corresponds to x axle, y axle and the z axle of space coordinate system respectively, and during the cloud platform rotated, roll axle (roll axle) was around x axle axial rotation, pitch axle (pitch axle) was around y axle axial rotation, course axle (yaw axle) was around z axle axial rotation. The euler angles are obtained by data fusion of the angular velocity and the acceleration, namely the euler angles of the corresponding axes can be obtained by data fusion of the angular velocity of the corresponding axes obtained by the measurement of the gyroscope and the acceleration of the corresponding axes obtained by the measurement of the accelerometer. The cradle head is in closed-loop control, so that the accuracy of the Euler angle can be guaranteed, the accuracy of the rotation of the rotating shaft to the target Euler angle can be improved, and the calibration reliability of the magnetic encoder is improved. When the magnetic encoder of the pan-tilt is calibrated, the calibration of the magnetic encoders corresponding to the roll shaft, the pitch shaft and the yaw shaft can be completed in sequence, and the pitch shaft and the yaw shaft do not work when the magnetic encoder of the roll shaft is calibrated; when calibrating the pitch axis, the roll axis and the yaw axis do not work, and when calibrating the roll axis and the pitch axis, the base of the pan-tilt can be vertically placed, namely the rotating shaft corresponding to the motor of the yaw axis is perpendicular to the horizontal plane. When the raw axis is calibrated, the roll axis and the pitch axis are controlled to be positioned at the position where the Euler angle is zero, and because the Euler angle of the raw axis has certain integral drift, in order to improve the calibration accuracy of the magnetic encoder of the raw axis, the base of the holder can be horizontally placed, namely, the rotating shaft corresponding to the motor of the raw axis is parallel to the horizontal plane. When calibrating the yaw axis, the motors controlling the roll axis and the pitch axis are in a position where the joint angle is zero, and the motor controlling the yaw axis rotates to a position of a required Euler angle for calibration.
In the embodiments provided in the present invention, it should be understood that the disclosed system and method can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of each unit is only one logic function division, and there may be another division manner in actual implementation. For example, various elements or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented.
The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs. The units in the system of the embodiment of the invention can be merged, divided and deleted according to actual needs. In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. A method of calibrating a magnetic encoder, comprising:
acquiring a motor joint angle obtained by measurement of a magnetic encoder;
correcting the motor joint angle obtained by measurement by combining an angle corresponding relation table and a linear interpolation algorithm to obtain a corrected motor joint angle;
the angle corresponding relation table is established by the following steps:
selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of sampling points and the calibration angle range;
and controlling a rotating shaft provided with a magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table.
2. The calibration method of claim 1, wherein the step of controlling the rotation device to rotate the rotation shaft with the magnetic encoder to all target euler angles in sequence according to the sampling points, obtaining and recording the corresponding motor joint angle measured by the magnetic encoder on the rotation shaft when the rotation shaft rotates to each target euler angle, and establishing the angle correspondence table specifically comprises:
step S121, controlling a rotating shaft of the rotating equipment, which is provided with a magnetic encoder, to rotate around the corresponding axial direction to a corresponding target Euler angle, and updating the rotating times;
step S122, obtaining a motor joint angle measured by a corresponding magnetic encoder when the rotating shaft rotates to the target Euler angle, and recording the target Euler angle and the motor joint angle corresponding to the target Euler angle;
step S123, judging whether the updated rotation frequency reaches the sampling point number, if so, executing step S124; otherwise, returning to execute the step S121;
and step S124, establishing an angle corresponding relation table according to the sampling points and by combining all target Euler angles and corresponding motor joint angle angles.
3. The method for calibrating a magnetic encoder according to claim 1, wherein the step of obtaining the motor joint angle measured by the magnetic encoder comprises:
controlling a rotating shaft of the rotating equipment, which is provided with a magnetic encoder, to rotate to a preset angle;
and acquiring the motor joint angle measured by the magnetic encoder on the rotating shaft.
4. The calibration method of claim 1, wherein the step of correcting the measured motor joint angle by combining the angle correspondence table and the linear interpolation algorithm to obtain the corrected motor joint angle specifically comprises:
combining the motor joint angle obtained by measuring the magnetic encoder on the rotating shaft with the angle corresponding relation table to obtain a joint angle section where the motor joint angle is located, and obtaining the corrected motor joint angle through a linear interpolation algorithm according to the end point of the joint angle section and the target Euler angle corresponding to the end point by using the following calculation formula:
when a < a1When the temperature of the water is higher than the set temperature,
when a is1≤a＜anWhen the temperature of the water is higher than the set temperature,
when a is more than or equal to anWhen the temperature of the water is higher than the set temperature,
in the formula, a represents the motor joint angle measured by a magnetic encoder on the rotating shaft,
presentation correctionThe angle of the joint of the motor, i represents the serial number of the sampling point, aiAnd ai+1Respectively representing the end points of the joint angle interval in which the motor joint angle a is positioned, a1、a2、an-1And anRespectively representing the angle of the motor joint corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point in the angle corresponding relation table, b1、b2、bn-1And bnRespectively representing target Euler angles corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point, biAnd bi+1Respectively representing target Euler angles corresponding to the end points between the joint angle areas.
5. The utility model provides a magnetic encoder calbiration system for the magnetic encoder of the rotary equipment that has the rotation axis is calibrated, be provided with on the rotation axis and be used for controlling the pivoted motor of rotation axis, magnetic encoder install in on the rotation axis of rotary equipment for measure and acquire the motor joint angle of the motor that corresponds, its characterized in that, magnetic encoder calbiration system includes:
the acquisition module is used for acquiring the motor joint angle measured by the magnetic encoder;
the correction module is used for correcting the motor joint angle obtained by measurement by combining the angle corresponding relation table and the linear interpolation algorithm to obtain a corrected motor joint angle;
the setting module is used for selecting a calibration angle range, setting the number of sampling points according to the calibration angle range, and setting a target Euler angle corresponding to each sampling point according to the number of the sampling points and the calibration angle range;
and the angle corresponding processing module is used for controlling the rotating shaft provided with the magnetic encoder of the rotating equipment to sequentially rotate to all target Euler angles according to the sampling points, acquiring and recording corresponding motor joint angle angles measured by the magnetic encoder on the rotating shaft when the rotating shaft rotates to each target Euler angle, and establishing an angle corresponding relation table.
6. The magnetic encoder calibration system of claim 5, wherein the angle correspondence processing module comprises:
the rotation control unit is used for controlling a rotating shaft provided with a magnetic encoder of the rotating equipment to rotate around the corresponding axial direction to a corresponding target Euler angle;
the sampling and recording unit is connected with the magnetic encoder and is used for acquiring a motor joint angle measured by the corresponding magnetic encoder when the rotating shaft rotates to the target Euler angle and recording the target Euler angle and the motor joint angle corresponding to the target Euler angle;
the rotating counter is used for counting the rotating times of the rotating shaft;
and the table building unit is used for building an angle corresponding relation table by combining all target Euler angles and corresponding motor joint angle angles according to the number of the sampling points.
7. The magnetic encoder calibration system of claim 5, wherein the correction module comprises:
the processing unit is used for combining the motor joint angle obtained by measurement of the magnetic encoder on the rotating shaft with the angle corresponding relation table to obtain a joint angle section where the motor joint angle is located, and obtaining the corrected motor joint angle through a linear interpolation algorithm according to the end point of the joint angle section and the target Euler angle corresponding to the end point by using the following calculation formula:
when a < a1When the temperature of the water is higher than the set temperature,
when a is1≤a＜anWhen the temperature of the water is higher than the set temperature,
when a is more than or equal to anWhen the temperature of the water is higher than the set temperature,
in the formula, a represents the motor joint angle measured by a magnetic encoder on the rotating shaft,
represents the corrected angle of the motor joint, i represents the sampling point serial number, aiAnd ai+1Respectively representing the end points of the joint angle interval in which the motor joint angle a is positioned, a1、a2、an-1And anRespectively representing the angle of the motor joint corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point in the angle corresponding relation table, b1、b2、bn-1And bnRespectively representing target Euler angles corresponding to the 1 st sampling point, the 2 nd sampling point, the n-1 st sampling point and the n th sampling point, biAnd bi+1Respectively representing target Euler angles corresponding to the end points between the joint angle areas.
8. The magnetic encoder calibration system of claim 5, wherein the acquisition module comprises:
the rotating unit is used for controlling a rotating shaft of the rotating equipment, which is provided with a magnetic encoder, to rotate to a preset angle;
and the sampling unit is used for acquiring the motor joint angle measured by the magnetic encoder on the rotating shaft.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911392579.XA CN111076761B (en) | 2019-12-30 | 2019-12-30 | Magnetic encoder calibration method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911392579.XA CN111076761B (en) | 2019-12-30 | 2019-12-30 | Magnetic encoder calibration method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111076761A true CN111076761A (en) | 2020-04-28 |
| CN111076761B CN111076761B (en) | 2023-02-03 |
Family
ID=70319349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911392579.XA Active CN111076761B (en) | 2019-12-30 | 2019-12-30 | Magnetic encoder calibration method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111076761B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112304210A (en) * | 2020-11-10 | 2021-02-02 | 陕西宏星电器有限责任公司 | Hall angle sensor angle calibration method |
| CN115562369A (en) * | 2022-09-22 | 2023-01-03 | 北京富吉瑞光电科技股份有限公司 | Control method and device of holder, storage medium and processor |
| CN117782187A (en) * | 2024-02-23 | 2024-03-29 | 泉州昆泰芯微电子科技有限公司 | Nonlinear error correction method of encoder and encoder |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102325262A (en) * | 2011-09-26 | 2012-01-18 | 比比威株式会社 | Control system for stereo video camera |
| CN105116926A (en) * | 2015-08-20 | 2015-12-02 | 深圳一电科技有限公司 | Holder control method and device |
| CN106325287A (en) * | 2015-06-14 | 2017-01-11 | 复旦大学 | Intelligent mower straight line walking control system based on inertial/magnetic sensor MARG attitude detection |
| CN106679710A (en) * | 2017-02-08 | 2017-05-17 | 亿航智能设备（广州）有限公司 | Magnetic encoder calibrating method and system |
| CN109655083A (en) * | 2019-02-15 | 2019-04-19 | 广州极飞科技有限公司 | Magnetic coder and its calibration method and calibrating installation, motor and unmanned vehicle |
-
2019
- 2019-12-30 CN CN201911392579.XA patent/CN111076761B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102325262A (en) * | 2011-09-26 | 2012-01-18 | 比比威株式会社 | Control system for stereo video camera |
| CN106325287A (en) * | 2015-06-14 | 2017-01-11 | 复旦大学 | Intelligent mower straight line walking control system based on inertial/magnetic sensor MARG attitude detection |
| CN105116926A (en) * | 2015-08-20 | 2015-12-02 | 深圳一电科技有限公司 | Holder control method and device |
| CN106679710A (en) * | 2017-02-08 | 2017-05-17 | 亿航智能设备（广州）有限公司 | Magnetic encoder calibrating method and system |
| CN109655083A (en) * | 2019-02-15 | 2019-04-19 | 广州极飞科技有限公司 | Magnetic coder and its calibration method and calibrating installation, motor and unmanned vehicle |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112304210A (en) * | 2020-11-10 | 2021-02-02 | 陕西宏星电器有限责任公司 | Hall angle sensor angle calibration method |
| CN115562369A (en) * | 2022-09-22 | 2023-01-03 | 北京富吉瑞光电科技股份有限公司 | Control method and device of holder, storage medium and processor |
| CN117782187A (en) * | 2024-02-23 | 2024-03-29 | 泉州昆泰芯微电子科技有限公司 | Nonlinear error correction method of encoder and encoder |
| CN117782187B (en) * | 2024-02-23 | 2024-05-07 | 泉州昆泰芯微电子科技有限公司 | Nonlinear error correction method of encoder and encoder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111076761B (en) | 2023-02-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111076761B (en) | Magnetic encoder calibration method and system | |
| CN106569512A (en) | Holder calibration method | |
| CN110645891B (en) | Motor calibration system, method and device, controller and storage medium | |
| CN107843227B (en) | Method for improving precision of encoder based on calibration technology | |
| CN108474671B (en) | Mechanical angle detection method, holder and machine-readable storage medium | |
| CN111366908B (en) | Laser radar rotary table and measuring device and measuring method thereof | |
| CN107121151B (en) | Stable platform testing device and testing method for experimental teaching | |
| CN108759657B (en) | Device and method for automatically detecting angle of induction synchronizer | |
| CN110705002A (en) | Compensation system and method for simulation test | |
| CN111106764B (en) | Sine and cosine encoder correction method and system | |
| CN109211278B (en) | System and method for automatic calibration of non-linearity of MIMU accelerometer | |
| CN111156893B (en) | Motor operation angle measuring method and system and joint angle measuring system | |
| RU111634U1 (en) | TWO-AXLE DYNAMIC STAND | |
| CN110133316B (en) | Precise speed measurement system and method for photoelectric encoder | |
| CN109724581B (en) | Strapdown north-seeking method based on automatic theodolite auxiliary rotation modulation | |
| CN110954080A (en) | Magnetic compass calibration method for eliminating carrier magnetic interference | |
| CN110954081A (en) | Quick calibration device and method for magnetic compass | |
| CN214951273U (en) | Position indicating system | |
| CN109308006A (en) | A kind of position marker Split rotary transformer precision compensation system and method | |
| CN106921333B (en) | Dynamic compensation method for motor torque ripple | |
| CN112665531B (en) | Multi-pair-level rotation-transformation coordinate transformation angle solving method | |
| CN111307176B (en) | Online calibration method for visual inertial odometer in VR head-mounted display equipment | |
| CN111146986B (en) | Position locating method and device of magnetic encoder, electronic equipment and computer readable storage medium | |
| CN114157186A (en) | Electrical angle calibration method, evaluation method and system of permanent magnet synchronous motor | |
| CN104682796A (en) | Control system with single shaft rotary platform |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |