JP2004274855A - Method and device for detection and adjustment of rotor position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically correct and adjust the dislocation of a rotor detected by a position sensor which is attached to the rotating shaft of a motor being the control target, by a simple and inexpensive constitution with light processing load. <P>SOLUTION: This device rotates the motor which is the control target in the clockwise and counterclockwise directions severally and converts the detected AC of drive currents obtained severally in both rotations into on two-axis components of a rotating orthogonal coordinate systems; detects the error (deviation) from the specified rotor' position of the detected rotor position, from the voltage difference of the axial components in the direction of field magnetic flux from among these two-axis components; and corrects and adjusts the rotor's position detected by the position sensor attached to the rotating shaft of the motor which is the control target, based on this error. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotor position detection adjustment method and a rotor position detection adjustment device that corrects a deviation of a rotor position (detected rotor position) detected by a position sensor attached to a rotation shaft of a servomotor from a predetermined rotor position.
[0002]
[Prior art]
Conventionally, brushless DC servomotors (three-phase permanent magnet synchronous motors), servomotors such as AC servomotors including three-phase induction motors, and brushless DC motors do not require so-called brush maintenance and are required to have control accuracy. It is used for various appliances for consumer and consumer use.
[0003]
The motors on the stator side are controlled by controlling one of a feedback loop of torque control (current control), position control, and speed control, or a multiplex feedback loop of any two or all of the controls. The drive current (three-phase alternating current) of the child winding (stator winding) is controlled and driven.
[0004]
Incidentally, the AC servomotor is widely used for applications requiring high speed and high accuracy, and its feedback loop is called a servo loop. In the loop control, the position of the rotating rotor (rotor position) is used. In order to detect this, a position sensor attached to the rotating shaft of a motor, such as a resolver, is used, and high-speed and high-precision control is performed using an MPU or the like having a high processing speed.
[0005]
The brushless DC motor is generally used for hydraulic control or the like that does not require much speed and accuracy. In the loop control, a Hall sensor is frequently used for detecting a rotor position. In applications where high speed and high precision are required, in the loop control, a position sensor attached to the rotating shaft of a motor, such as the resolver, is used, and a computer with a high processing speed is used. Is used to control a high-speed and high-precision feedback loop (hereinafter, referred to as a quasi-servo loop) according to the servo loop control.
[0006]
By the way, the servo loop, the position sensor used for the control of the quasi-servo loop, in addition to the resolver, which is an electromagnetic sensor, there is an optical incremental encoder, an absolute encoder, a magnetic incremental encoder, and the like. Each of them is attached to a rotating shaft of a motor to be controlled, which is a servo motor or a brushless DC motor.
[0007]
Then, this type of position sensor generates a signal of one phase or a plurality of phases whose phase changes following an electrical angle change (phase change) during each rotation of the rotor as a signal of the detected rotor position.
[0008]
For example, in the case of the resolver described above, a two-phase signal whose amplitude changes according to a change in the electrical angle in each rotation of the rotor is generated as a signal of the detected rotor position, and the phase difference between the two-phase signals is: This is the detection phase of the electrical angle in each rotation of the rotor, and is the detected rotor position every moment.
[0009]
Next, motor control based on the detected rotor position will be described.
[0010]
First, it is assumed that the motor to be controlled is a brushless DC servomotor, which is one of the AC servomotors, and the torque is controlled by a servo loop.
[0011]
In this case, the three-phase armature current, which is the driving current, is controlled by a servo loop having a torque command value given from a host device as a target value.
[0012]
An armature current is detected by a current detector, and a signal of the detected AC is used as a feedback input of the servo loop.
[0013]
At this time, in order to simplify control and the like, the signal of the detected AC of the current detector expressed in the three-phase coordinate system is two signals in the orthogonal coordinate system that rotates in synchronization with the rotation of the motor, specifically, , D-q coordinate system, are converted into signals of the d-axis component and the q-axis component, and are used for feedback input of the servo loop.
[0014]
The q-axis component is a component for torque control, and the torque command value is a current command value for the q-axis component.
[0015]
Then, the control output of the dq coordinate system of the servo loop based on the deviation between the torque command value and the signal value of the q-axis component of the coordinate-converted detection current is returned to the output of the three-phase coordinate system by reverse coordinate conversion. The output of the three-phase coordinate system controls the armature current through the control of the armature voltage.
[0016]
In the case of a three-phase induction motor, since the current and voltage of the rotor and the stator are both handled as DC, the servo loop employs a γ-δ coordinate system instead of the dq coordinate system. Is done.
[0017]
When performing a coordinate transformation from the three-phase coordinate system to the dq coordinate system and vice versa, a sine wave and a cosine wave based on phase information of a momentarily detected rotor position detected by a position sensor such as the resolver. Is substituted into the transformation matrix to perform coordinate transformation.
[0018]
Therefore, the accuracy of the detected rotor position of the position sensor greatly affects the control accuracy of the motor.
[0019]
The accuracy of the detected rotor position depends on the deviation of the position of the position sensor from the predetermined rotor position in the control system, which is determined by the relative positional relationship between the magnetic pole position of the rotor and the origin of the detected rotor position of the position sensor. The deviation includes the influence of the mechanical processing accuracy and the like.
[0020]
Therefore, there is a limit in the manual adjustment of this deviation, and in actuality, the manual adjustment can cause errors of several degrees. Therefore, the mounting position of the position sensor of this kind is shifted from the predetermined rotor position of the detected rotor position. In other words, it is desired that the automatic adjustment be performed according to the phase difference between the detected rotor position and the predetermined rotor position.
[0021]
As the automatic adjustment (rotor position detection adjustment), conventionally, in the case of torque control of a synchronous motor (brushless DC servomotor) which receives a torque command value as input, a d-axis current command value and a d-axis current detection are performed during motor operation. A d-axis voltage compensation value is calculated from a deviation from the value, and on the condition that the torque command value is equal to or less than a predetermined value, the d-axis voltage compensation value is integrated and a magnetic pole position correction value as a correction value of the deviation is calculated. It has been proposed to obtain the rotor rotation position detection value and add the magnetic pole position correction value to the rotor rotation position detection value to correct and adjust the rotor rotation position detection value (for example, see Patent Document 1).
[0022]
[Patent Document 1]
JP-A-2000-166278 (pages 1 to 5, FIG. 1)
[0023]
[Problems to be solved by the invention]
In the case of the conventional rotor position detection adjustment, the d-axis voltage compensation value is calculated from the calculation of the deviation of the d-axis current, and the d-axis voltage compensation is performed on condition that the torque command value is equal to or less than a predetermined value. A magnetic pole position correction value as a correction value for the deviation must be calculated from the integration of the values, which requires extremely complicated calculations, complicates the processing of a computer or the like for performing the calculations, and increases the processing load. However, there is a problem that a device incorporating the computer or the like becomes complicated and expensive.
[0024]
In addition, despite the fact that the displacement of the detected rotor position depends on the mounting position and does not change depending on the load of the motor or the like, the above-described complicated calculation is always repeated while the load is mounted, and the d-axis Since the voltage compensation value and the magnetic pole position correction value are obtained, in the no-load state before mounting the load with only the position sensor attached to the rotating shaft of the motor, that is, in the state of the motor unit alone, the deviation of the detected rotor position may be reduced. There are also problems that cannot be adjusted.
[0025]
The present invention automatically corrects the displacement of the detection rotor position of the position sensor attached to the rotating shaft of the motor to be controlled by a simple, low processing load and an inexpensive configuration without performing complicated calculations such as integration. The purpose is to automatically correct and complete the adjustment even in the no-load state (only the motor unit) before mounting the load with only the position sensor attached to the motor rotation shaft. I do.
[0026]
[Means for Solving the Problems]
In order to solve the above-described problem, a rotor position detection adjustment method according to the present invention is based on a detection rotor position of a position sensor attached to a rotation shaft of a control target motor including a servo motor or a brushless DC motor, and the motor has The detected alternating current of the drive current is converted into a two-axis component of a rotating rectangular coordinate system, and the rotor position of the motor drive control for controlling the drive current is controlled by a feedback loop of the rectangular coordinate system to which the two-axis component is input as feedback. A detection adjustment method, wherein the motor is rotated clockwise and counterclockwise based on the control of the drive current by the feedback loop, and the field of the two-axis component obtained by the rotation in each of the two directions is changed. From the voltage difference of the axial component in the magnetic flux direction, an error from the predetermined rotor position of the detected rotor position is detected, The difference is characterized by adjusting to correct the detected rotor position of the sensor (claim 1).
[0027]
In addition, the rotor position detection adjustment device according to the present invention includes a current detector that detects a drive current of a motor to be controlled including a servomotor or a brushless DC motor, and a detection rotor position of a position sensor attached to a rotation shaft of the motor. A converter that converts an AC detection output of the current detector into a biaxial component of a rotating rectangular coordinate system, and a converter of the rectangular coordinate system that controls the driving current by feedback-inputting the biaxial component. A rotor position detection adjustment device of a motor drive control device comprising a feedback loop, wherein the control drive of the feedback loop based on an adjustment command causes the motor to rotate clockwise and counterclockwise, respectively. Control means, and an axial component of the field magnetic flux direction among the two axial components obtained by the rotation in each of the two directions. An error detecting means for detecting an error of the detected rotor position from a predetermined rotor position from a pressure difference, and a position adjusting means for correcting and adjusting the detected rotor position of the sensor based on the error. (Claim 6).
[0028]
According to these configurations, the control target motor driven by the control of the servo loop and the quasi-servo loop is rotated clockwise and counterclockwise respectively, and the detected alternating current of the drive current obtained in each of the rotations is rotated. An error (deviation) of the detected rotor position from a predetermined rotor position is detected from the voltage difference between the two axial components in the field magnetic flux direction of the orthogonal coordinate system. , The detected rotor position of the position sensor attached to the rotating shaft of the motor to be controlled is corrected and adjusted.
[0029]
Therefore, a very simple calculation for obtaining the voltage difference (deviation) of the axial component in the field magnetic flux direction obtained in each of the two rotations is simple, the processing load is low, and the cost is low without performing complicated calculations such as integration. With the configuration, the displacement of the detection rotor position of the position sensor is automatically corrected and adjusted. Moreover, this adjustment ends in a no-load state (a single motor unit) before mounting a load, in which only the position sensor is attached to the rotating shaft of the motor to be controlled.
[0030]
Then, it is suitable when the drive current of the motor to be controlled is torque-controlled by control by a feedback loop based on a torque command value (servo loop, quasi-servo loop control).
[0031]
Next, the rotor position detecting and adjusting method according to the present invention detects the error of the detected rotor position from the predetermined rotor position until the voltage difference of the axial component in the field magnetic flux direction becomes 0 or less than a set value. The correction phase of the detected rotor position is repeatedly increased and decreased by an electrical angle corresponding to 1/2 of the voltage difference, and is repeated (claim 3).
[0032]
Further, in the rotor position detection adjusting device according to the present invention, the error detecting means has a storage means for rewritably holding a correction phase of the detected rotor position of the position sensor, and an error of the detected rotor position from a predetermined rotor position. Until the voltage difference of the axial component in the field magnetic flux direction becomes 0 or less than a set value, the correction phase of the storage means is increased and decreased by an electrical angle corresponding to の of the voltage difference. (Claim 8).
[0033]
According to these configurations, the correction phase of the detected rotor position is detected so that the voltage difference of the axial component in the field magnetic flux direction obtained by rotating in the clockwise direction and the counterclockwise direction becomes 0 or less than the set value. The adjustment is performed in an extremely practical configuration in which the control target motor is repeatedly rotated clockwise and counterclockwise while increasing and decreasing the deviation by 1/2.
[0034]
Next, in the rotor position detection adjustment method and apparatus according to the present invention, the servomotor as the motor to be controlled is a brushless DC servomotor, and the rotating rectangular coordinate system has a d-axis and a phase that is 90 degrees ahead of the axis. It is a dq coordinate system with the q axis, and the axial component in the field magnetic flux direction is the d axis component of the dq coordinate system (claims 4 and 9).
[0035]
According to these configurations, a specific configuration is provided in which, when the motor to be controlled is a brushless DC servomotor, the deviation of the detected rotor position of the position sensor is corrected and adjusted.
[0036]
Next, the rotor position detection adjustment method and apparatus according to the present invention are arranged so that the rotation of the motor to be controlled in the clockwise and counterclockwise directions is performed in a no-load state in which only a position sensor is attached to the rotation shaft of the motor. The present invention is characterized in that the current command value of the axial component in the magnetic flux direction is set to 0, and this is performed.
[0037]
According to these configurations, a specific configuration is provided in which the deviation of the detection of the rotor position of the position sensor is adjusted in a no-load state (a single motor unit) before mounting the load.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention applied to a case where the motor to be controlled is a three-phase brushless DC servomotor, which is one of AC servomotors, and its torque is controlled by a servo loop, with reference to FIGS. Will be explained.
[0039]
FIG. 1 is a block diagram of the rotor position detecting and adjusting device, and FIG. 2 is a flowchart for explaining the operation thereof.
[0040]
The brushless DC servomotor 1 as a motor to be controlled shown in FIG. 1 is composed of three-phase U, V, and W armature windings and a permanent magnet (magnet) rotor that generates rotating magnetic poles. From the output terminals 3u, 3v, 3w of each phase of the three-phase PWM inverter (output unit) 3 of the control unit 2, terminals 1u, 1v, 1w of each phase of the armature winding so that the resultant vector with the magnetic flux is orthogonal. Are supplied with three-phase alternating currents iua, iva, and iwa of voltages Vua, Vva, and Vwa. Based on this supply, a torque is generated and the motor 1 rotates.
[0041]
In a motor production line or the like, a position sensor 4 made of, for example, a resolver is attached to a rotating shaft 1 r of the motor 1, and the motor 1 to which the sensor 4 is attached and the control unit 2 form a so-called motor unit (motor assembly). ).
[0042]
The motor unit is incorporated in various industrial and consumer devices that require control accuracy, and is operated in a loaded state in which a load is connected to the rotating shaft 1r.
[0043]
Next, when the motor 1 is controlled by so-called software processing, a microcomputer (MPU) capable of performing arithmetic processing at high speed and having high processing capability is used, except for the inverter 3 and the position signal processor 5 of FIG. The circuit part of the control unit 2 is formed.
[0044]
Then, the position sensor 4 detects the position of each magnetic pole from the change of the intersecting magnetic flux of each rotation of the rotor of the motor 1, and based on this detection, a two-phase signal (a triangular function waveform) whose amplitude changes according to the change in the electrical angle. Signal) is generated as a signal of the detected rotor position, and the phase difference between the two signals is the detected phase of the electrical angle in each rotation of the rotor, and is the signal of the phase information of the detected rotor position every moment. .
[0045]
A signal of the detected rotor position of the position sensor 4 is input to a position signal processor 5, which converts the signal into digital data of the electrical angle (phase).
[0046]
Further, this data is input to the position data adjuster 6, and the adjuster 6 stores the detected position of the position sensor 4 in a nonvolatile rewritable correction value memory 7 as storage means by an initial setting process described later. The data of the correction phase α for compensating the error (shift) is written, and thereafter, the phase of the data output from the processor 5 is corrected by adding the phase of the memory 7, and the corrected data is added to the detection rotor position of the position sensor 4. The digital data of the electric angle θre (rotational phase of the rotor) adjusted for the deviation is supplied to the trigonometric function generator 8.
[0047]
The generator 8 calculates function values sin (θre) and cos (θre) of a sine wave and a cosine wave of the electrical angle θre, and converts these function values sin (θre) and cos (θre) into three-phase AC / d. It is supplied to a -q coordinate converter 9 and a dq / 3-phase AC coordinate converter 10.
[0048]
On the other hand, two-phase currents iua, iva of the three-phase drive currents ua, iva, iwa supplied from the inverter 3 to the motor 1 are detected by the current detectors 11u, 11v. The signal is input to the coordinate converter 9.
[0049]
Then, the coordinate converter 9 substitutes the function values sin (θre) and cos (θre) into the coordinate transformation matrix of the trigonometric function, and performs a matrix operation of the coordinate transformation using the transformation matrix after the substitution to obtain the drive currents ua, The signal of the detected AC of iva and the signal of the drive current iwa obtained by calculation using these signals are converted to a d-axis of a dq coordinate system which is a rotating rectangular coordinate system, and a phase advanced by 90 degrees from this axis. The current components are converted into q-axis current components ida and iqa.
[0050]
In the dq coordinate system, the d axis is the axis in the direction of the field magnetic flux generated by each magnetic pole of the rotor.
[0051]
The current components ida and iqa are calculated by a dq coordinate system servo loop formed by the subtracters 12d and 12q, the current controllers 13d and 13q, the coordinate converters 9 and 10, the inverter 3, and the current detectors 11u and 11v. The feedback is input to the 14 subtracters 12d and 12q.
[0052]
Then, the subtracters 12d and 12q subtract the current components ida and iqa from the d-axis and q-axis current command values i * da and i * qa of the command value input terminals 15d and 15q, and control the d-axis and q-axis. The deviation is supplied to the current controllers 13d and 13q.
[0053]
Note that the current command value i * da that determines the efficiency of the motor 1 is set to 0 or negative by the host device 16 of the control unit 2 which is a device outside the servo loop 14, and in the case of torque control, the torque of the motor 1 is reduced. The determined current command value i * qa is also given from the host device 16 and set.
[0054]
The host device 16 is a test device of a motor production line or a control device of a device in which the motor 1 is incorporated.
[0055]
The current controllers 13d and 13q adjust the gain of the current control and the response characteristics to the input by PI control to form the d-axis and q-axis armature voltage commands V * da and V * qa. The voltage commands V * da and V * qa are output to the coordinate converter 10.
[0056]
The coordinate converter 10 performs a reverse coordinate conversion on the voltage commands V * da and V * qa with respect to the coordinate converter 9 based on the function values sin (θre) and cos (θre) of the trigonometric function generator 8, The commands V * da and V * qa are converted into three-phase AC armature voltage commands V * ua, V * va and V * wa, and these armature voltage commands V * ua, V * va and V * wa are converted. To the three-phase control terminals 3 * u, 3 * v, 3 * w of the inverter 3.
[0057]
The inverter 3 drives the torque control from the output terminals 3u, 3v, 3w to the terminals 1u, 1v, 1w of each phase of the motor 1 based on the armature voltage commands V * ua, V * va, V * wa. Supply currents ua, iva, iwa.
[0058]
Next, adjustment of the detection rotor position of the position sensor 4, that is, writing of the correction phase α in the memory 7 will be described.
[0059]
In this embodiment, when the motor unit is shipped from a factory or the like, the detection rotor position is adjusted in the state of the motor unit (no load state).
[0060]
Therefore, the higher-level device 16 controls the drive currents ua, iva, and iwa of the servo loop (feedback loop) 14 based on the adjustment command of the adjuster 6 to perform the adjustment drive control for rotating the motor 1 clockwise and counterclockwise. Form means.
[0061]
The adjuster 6 includes the following error detecting means and position adjusting means.
[0062]
(1) Error detection means
This means uses a voltage difference between the d-axis (axis in the direction of the field magnetic flux) component of the two-axis components of the d-axis and the q-axis obtained by the respective rotations in both directions to determine a predetermined rotor position of the detected rotor position of the position sensor 4. Detect errors from the position.
[0063]
(2) Position adjustment means
This means corrects and adjusts the detected rotor position of the position sensor 4 based on the error.
[0064]
Then, for example, when the software or hardware initial set switch 17 of the adjuster 6 is pressed, the adjuster 6 executes the adjustment program of the detected rotor position in FIG. An adjustment command for driving at 100% PWM in the clockwise direction (CW direction) is notified.
[0065]
Based on this notification, the host device 16 sets the current command value i * da to 0 and sets the current command value i * qa to a value sufficiently larger than the specified value for the no-load operation. Note that the current command value i * da may be set to a predetermined constant value instead of 0.
[0066]
Then, under the control of the servo loop 14 based on these sets, the motor 1 rotates clockwise at the power supply voltage (rated voltage).
[0067]
When a predetermined time τ (τ is an appropriate time of, for example, 1 second or less) set in consideration of the rise time of the motor 1 or the like has elapsed, the process proceeds from step S1 to step S2 in FIG. The error detection means 6 takes in and temporarily stores the voltage Vdcw of the voltage command V * da of the d-axis component input to the coordinate converter 10.
[0068]
Next, the process proceeds from step S2 in FIG. 2 to step S3, in which the adjuster 6 notifies the host device 16 of an adjustment command for driving the power supply voltage (100% output of PWM) in the counterclockwise direction (CCW direction).
[0069]
Prior to this notification, the controller 6 may instruct the host device 16 to stop, and the motor 1 may be temporarily stopped.
[0070]
Then, since the motor 1 is rotated in the counterclockwise direction, the host device 16 sets the current command value i * da to 0, and performs no-load operation with the polarity opposite to that of rotating the current command value i * qa clockwise. Are set to values sufficiently larger than the specified values.
[0071]
Under the control of the servo loop 14 based on these sets, the motor 1 rotates counterclockwise at the power supply voltage.
[0072]
Then, when the predetermined time τ has elapsed, the process proceeds from step S3 to step S4 in FIG. 2, and the error detecting means of the controller 6 sets the voltage command V * of the d-axis component input to the coordinate converter 10. The voltage Vdccw of da is taken in and temporarily stored.
[0073]
Next, the process proceeds from step S4 in FIG. 2 to step S5, in which the error detecting means of the controller 6 determines that the absolute value of the difference between the voltage Vdcw and the voltage Vdccw, in other words, d obtained by the rotation in each of the two directions. The voltage difference ΔV of the axial component (axial component in the field magnetic flux direction) is calculated.
[0074]
At this time, the attachment of the position sensor 4 is appropriate, and the relative positional relationship between the magnetic pole position of the rotor and the origin of the encoder detection position of the position sensor 4 accurately matches the predetermined positional relationship set in advance in the control unit 2. , The detected rotor position of the position sensor 4 substantially coincides with the predetermined rotor position, and the voltage difference ΔV is 0 ≦ ΔV <ε (ε is an allowable limit error, and is, for example, 0.3 degree in terms of phase angle. )become.
[0075]
If 0 ≦ ΔV <ε, it is detected that the error of the detected rotor position of the position sensor 4 from the predetermined rotor position is 0, and the step S5 is affirmed (YES), and the writing to the memory 7 is performed. Instead, the correction phase α is set to the initial value (= 0), and the adjustment of the detected rotor position is completed.
[0076]
On the other hand, if ε ≦ ΔV, it is detected that the error of the detected rotor position of the position sensor 4 from the predetermined rotor position is not 0, and the process proceeds from step S5 to step S6.
[0077]
Then, in step S6, a voltage ΔV / 2, which is の of the voltage difference ΔV, is calculated, and a phase angle (unit electric angle) per d-axis unit voltage set in advance based on an experiment or the like is calculated. ) Multiply by Δθ to obtain the corresponding electrical angle Δθ · (ΔV / 2).
[0078]
Further, the process proceeds from step S6 to step S7 to determine the magnitude relationship between the voltage Vdcw and the voltage Vdcw. The correction phase α of the memory 7 is rewritten by, for example, adding Δθ · (ΔV / 2) so as to be shifted by (ΔV / 2), and the electrical angle corresponding to の of the voltage difference ΔV is increased and corrected. I do.
[0079]
If Vdcw> Vdccw, the process proceeds from step S7 to step S9, and the correction phase α of the memory 7 is set to, for example, Δθ · so that the detected rotor position is shifted clockwise by an electrical angle Δθ · (ΔV / 2). (ΔV / 2) is subtracted and rewritten, and the electrical angle corresponding to の of the voltage difference ΔV is reduced and corrected.
[0080]
After the corrections in steps S8 and S9, the process returns to step S1, and repeats the processing in steps S1 to S9 until the voltage difference ΔV becomes 0 ≦ ΔV <ε, and determines the correction phase α of the memory 7 as the detected voltage difference ΔV Is increased or decreased by an electric angle Δθ · (ΔV / 2) corresponding to の of the above.
[0081]
The correction phase α of the memory 7 is automatically adjusted so that the detection rotor position of the position sensor 4 is accurately corrected and adjusted to a predetermined reference detection position with an accuracy of 0 ≦ ΔV <ε by this variable increase / decrease. Is set to
[0082]
When the voltage difference ΔV becomes 0 ≦ ΔV <ε, step S5 is affirmatively passed, and the adjustment of the detected rotor position ends.
[0083]
In this case, highly accurate automatic adjustment of the detection rotor position can be performed without being affected by the load.
[0084]
Also, no matter how the mounting position of the position sensor 4 is shifted, the detection rotor position can be adjusted with the accuracy that the voltage difference ΔV becomes 0 ≦ ΔV <ε, so that it is not necessary to increase the mounting accuracy of the position sensor 4. In addition, production efficiency can be improved.
[0085]
The more accurately the position sensor 4 is mounted on the rotating shaft 1r of the motor 1, the shorter the adjustment of the detected rotor position is completed. Therefore, the mounting accuracy of the position sensor 4 is determined in consideration of the adjustment time. Is preferred.
[0086]
Then, after the adjustment of the detected rotor position is completed, the operation switch 18 of the software or hardware of the adjuster 6 is pressed, and the adjuster 6 is set to the operating state.
[0087]
When set in this state, the controller 6 is inhibited from executing the detection rotor position adjustment program until the switch 17 is pressed again, and enters a state in which the motor servo normal program is executed.
[0088]
When this motor unit is mounted on a device and operated with a load attached to the rotating shaft 1 r of the motor 1, the controller 6 executes the normal program to execute the correction phase α stored in the memory 7. Is read by the adder 19, and the adder 19 adds the correction phase α to the data phase of the processor 5, and adjusts the electrical angle θre (rotational phase of the rotor) ) Is supplied to the trigonometric function generator 8.
[0089]
Therefore, the influence of the displacement of the detection rotor position of the position sensor 4 is eliminated and the torque of the motor 1 is controlled with high accuracy.
[0090]
By the way, in a brushless DC servomotor, generally, a speed electromotive force that interferes between the d-axis and the q-axis is generated.
[0091]
Even in the case of the motor 1, the speed electromotive force affects the d-axis and q-axis current components ida and iqa output from the coordinate converter 6, so that this effect is eliminated. It is conceivable that a decoupling controller is provided and the current components ida, iqa are supplied to the subtractors 12d, 12q via the decoupling controller. However, in this embodiment, the decoupling controller is omitted. However, since the deviation of the detected rotor position of the position sensor 4 in a state including the influence of the speed electromotive force is corrected by the correction phase α held in the memory 7, the decoupling controller is omitted. A servo loop 14 is formed.
[0092]
Therefore, there is an advantage that the control unit 2 is extremely simple and inexpensive.
[0093]
In order to perform general motor servo, a decoupling controller may be provided between the coordinate converter 9 and the subtracters 12d and 12q.
[0094]
The present invention is not limited to the above-described embodiment, and various changes other than those described above can be made without departing from the gist of the present invention.
[0095]
For example, in the above-described embodiment, the present invention is applied to the adjustment of the deviation of the detected rotor position of the position sensor 4 when performing the torque control. However, when the position control and the speed control are performed by the servo loop, the detected rotor position of the position sensor 4 is not changed. The same can be applied to the adjustment of the displacement.
[0096]
When performing position control and speed control, the position signal processor 5 differentiates the signal of the detected rotor position of the position sensor 4 to create a speed feedback value, and the speed command generated based on the position deviation and the speed command Control is performed by obtaining a deviation (speed deviation) from the speed feedback value.
[0097]
The present invention is also applicable to the adjustment of the displacement of the detected rotor position of the position sensor 4 when performing any two or all of the multiplex control of the torque control, the position control, and the speed control based on the detected rotor position of the position sensor 4. Can be similarly applied.
[0098]
Furthermore, in the present embodiment, the motor to be controlled is the brushless DC servo motor 1, and the present invention is applied to the adjustment of the deviation of the detection rotor position of the position sensor 4 when the motor 1 is controlled by the servo loop. When the motor to be controlled is a servomotor such as an AC servomotor other than the brushless DC servomotor (for example, a three-phase squirrel-cage induction motor) and the motor is controlled by a servo loop, the deviation of the detected rotor position of the position sensor is adjusted. The present invention can be similarly applied to the adjustment of the displacement of the detected rotor position of the position sensor when the motor to be controlled is a brushless DC motor and this motor is controlled by a quasi-servo loop.
[0099]
Next, in the above embodiment, the correction phase α of the memory 7 is increased or decreased by an electric angle Δθ · (ΔV / 2) corresponding to の of the voltage difference ΔV, and the detected rotor position of the position sensor 4 is changed. For example, the unit phase angle set in step S6 of FIG. 2 is added or subtracted as a unit correction amount, and the correction phase α of the memory 7 is changed by increasing or decreasing the unit electrical angle by a unit electric angle. The deviation of the detection rotor position of the sensor 4 may be corrected and adjusted.
[0100]
Next, each part of the control unit 2 in FIG. 1 may be formed by a so-called hardware circuit, and, of course, the program for adjusting the detected rotor position may be different from that in FIG.
[0101]
Further, the orthogonal coordinate system that rotates according to the motor to be controlled or the like may be a coordinate system other than the dq coordinate system.
[0102]
【The invention's effect】
As described above, according to the first and sixth aspects of the present invention, the detected alternating current of the drive current obtained by each of the clockwise and counterclockwise rotations of the motor to be controlled is converted into two axes of a rotating rectangular coordinate system. The error (deviation) of the detected rotor position from the predetermined rotor position is detected from the voltage difference between the axial components in the field magnetic flux direction of the two axial components. It is possible to correct and adjust the detection rotor position of the position sensor attached to the rotation axis of the axis, and to calculate the voltage difference (deviation) of the axis component in the direction of the field magnetic flux obtained in each of both rotations by an extremely simple calculation , A simple operation with a small processing load and an inexpensive configuration without performing complicated calculations such as integration, etc., can automatically correct and adjust the displacement of the detection rotor position of the position sensor.
[0103]
This adjustment can be performed even in a no-load state (a single motor unit) before mounting a load in which only the position sensor is attached to the rotation axis of the motor to be controlled.
[0104]
Further, according to the second and seventh aspects of the invention, the same effects as those of the first and sixth aspects can be obtained when the torque of the control target motor is controlled.
[0105]
According to the third and eighth aspects of the present invention, the control target is controlled while increasing or decreasing the correction phase of the detected rotor position so that the voltage difference of the axial component in the field magnetic flux direction becomes 0 or less than a set value. It is possible to automatically correct and adjust the displacement of the detection rotor position of the position sensor with an extremely practical configuration that repeatedly rotates the motor clockwise and counterclockwise.
[0106]
According to the fourth and ninth aspects of the present invention, when the motor to be controlled is a brushless DC servo motor, the deviation of the detected rotor position of the position sensor can be automatically corrected and adjusted. A configuration can be provided.
[0107]
Further, according to the fifth and tenth aspects of the present invention, a specific configuration in a case where the deviation of the rotor position detection of the position sensor is adjusted in a no-load state (motor unit alone) before mounting the load. Can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram of one embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of FIG. 1;
[Explanation of symbols]
1 Brushless DC servo motor
2 control unit
4 Position sensor
6 Position data controller
7 Correction value memory
8 Trigonometric function generator
9, 10 coordinate converter
11u, 11v current detector
14 Servo loop

Claims (10)

Based on the detected rotor position of a position sensor attached to the rotation axis of a control target motor consisting of a servo motor or a brushless DC motor, the detected AC of the drive current of the motor is converted into a two-axis component of a rotating rectangular coordinate system,
A rotor position detection adjustment method of motor drive control for controlling the drive current by a feedback loop of the rectangular coordinate system to which the two-axis components are input as feedback.
Based on the control of the drive current by the feedback loop, the motor rotates clockwise, counterclockwise,
From the voltage difference between the axial components in the field magnetic flux direction of the two axial components obtained by the rotation in each of the two directions, an error from the predetermined rotor position of the detected rotor position is detected.
A rotor position detection adjustment method, wherein the detected rotor position of the sensor is corrected and adjusted based on the error. In the rotor position detection adjustment method according to claim 1,
A rotor position detection adjustment method, wherein the control of the drive current by the feedback loop is control based on a torque command value. In the rotor position detection adjustment method according to claim 1 or 2,
Detection of the error of the detected rotor position from the predetermined rotor position,
Until the voltage difference of the axial component in the direction of the field magnetic flux becomes 0 or less than a set value, the correction phase of the detected rotor position of the position sensor is repeatedly increased and decreased by an electrical angle corresponding to 1/2 of the voltage difference, and is repeatedly performed. A rotor position detection adjusting method. In the rotor position detection adjustment method according to any one of claims 1 to 3,
The servo motor as the motor to be controlled is a brushless DC servo motor,
The rotating rectangular coordinate system is a dq coordinate system including a d axis and a q axis having a phase advanced by 90 degrees from the axis,
A rotor position detection adjustment method, wherein an axis component in a field magnetic flux direction is a d-axis component of the dq coordinate system. In the rotor position detection adjustment method according to any one of claims 1 to 4,
Clockwise and counterclockwise rotation of the motor to be controlled is performed in a no-load state where only a position sensor is attached to the rotation axis of the motor, and the current command value of the axis component in the field magnetic flux direction is set to 0. A rotor position detection adjusting method. A current detector for detecting a drive current of a control target motor including a servo motor or a brushless DC motor;
A converter that converts an AC detection output of the current detector into a two-axis component of a rotating rectangular coordinate system based on a detection rotor position of a position sensor attached to a rotation axis of the motor;
A rotor position detection adjustment device of a motor drive control device, comprising: a feedback loop of the rectangular coordinate system in which the two-axis components are feedback-input to control the drive current.
Adjustment drive control means for rotating the motor clockwise and counterclockwise by controlling the drive current of the feedback loop based on an adjustment command,
Error detecting means for detecting an error of the detected rotor position from a predetermined rotor position from a voltage difference between axial components in the field magnetic flux direction among the two axial components obtained by the rotation in each of the two directions,
And a position adjusting means for correcting and adjusting the detected rotor position of the sensor based on the error. The rotor position detection adjustment device according to claim 6,
A rotor position detection adjusting device, wherein the control of the drive current by the feedback loop is a control based on a torque command value. In the rotor position detection adjusting device according to claim 6 or 7,
The error detection means has a storage means for rewritably holding a correction phase of the detected rotor position of the position sensor,
The detection of the error of the detected rotor position from the predetermined rotor position is performed by setting the correction phase of the storage means to の of the voltage difference until the voltage difference of the axial component in the field magnetic flux direction becomes 0 or less than a set value. A rotor position detecting and adjusting device characterized in that the electric angle is increased or decreased by a corresponding electric angle, and is repeatedly performed. The rotor position detection adjustment device according to any one of claims 6 to 8,
The servo motor as the motor to be controlled is a brushless DC servo motor,
The rotating rectangular coordinate system is a dq coordinate system including a d axis and a q axis having a phase advanced by 90 degrees from the axis,
A rotor position detection adjustment device, wherein an axis component in a field magnetic flux direction is a d-axis component of the dq coordinate system. The rotor position detection adjustment device according to any one of claims 6 to 9,
Clockwise and counterclockwise rotation of the motor to be controlled is performed in a no-load state in which only a position sensor is attached to the rotating shaft of the motor, and the current command value of the axial component in the field magnetic flux direction is set to 0. A rotor position detecting and adjusting device characterized in that:

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