JP2021025840A - General-purpose type rotary encoder - Google Patents

Abstract

To provide a rotary encoder that uses a general-purpose sensor, achieves high precision comparable to a conventional encoder equipped with a high-precision sensor, is excellent in environment resistance and inexpensive.SOLUTION: A general-purpose rotary encoder comprises: a function of driving an initial setting-purpose motor; a function of acquiring initial setting data unique to a genera-purpose sensor; a function of acquiring and generating normal operation-purpose data to be used when a motor of a control object having the general-purpose type rotary encoder loaded undergoes the normal operation; an encoder memory that holds calibration data for calibrating the initial setting data; and an encoder output method selection part. The calibration data is the data obtained by a standard sensor in which high precision with absolute precision higher in two digits or three digits than the general-purpose sensor is warranted, and the encoder output method selection unit has a function of selecting any output method of absolute data and incremental data as an output method of the encoder.SELECTED DRAWING: Figure 2A

Description

The present invention relates to a general-purpose rotary encoder that employs a general-purpose sensor.

The rotary encoder is used as an encoder for electrical equipment to measure the absolute angular position of a rotating shaft driven by a motor. For example, as a control method for a brushless DC motor, a rotary encoder that detects the phases of Z-phase, U-phase, V-phase, and W-phase is synchronized with the magnetic pole position of the rotor to control the motor as a completely closed-loop servomotor. Is being done.

Patent Document 1 includes a set of MR sensor units for detecting the rotation phase of the rotation axis of the motor, and drives signals of A phase, B phase, Z phase signal, U phase, V phase, and W phase, and an absolute origin position. A motor control device configured to assign an EEPROM address to the information of the above and record it in the EEPROM as multi-rotation / absolute signal data is disclosed. The MR sensor unit also includes an axis misalignment correction processing unit.

In Patent Document 2, among the light passing through the pattern provided on the circular substrate, the light that becomes stray light incident on the light receiving element arranged at a position deviated from the predetermined light receiving element in the first direction is described. An optical rotary encoder is disclosed that includes a suppressor that suppresses ejection from a diaphragm.

Patent Document 3 describes a magnetic sensor that detects a magnetic field on a magnetic scale, a photosensor that detects reflected light from a position detection scale, and a relative position of the magnetic sensor with respect to a magnetic scale based on the detection result of the magnetic sensor. An absolute encoder equipped with a data control unit that obtains the absolute position of the position detection target based on the detection result of the photo sensor, and the position detection target in the data control unit based on the detection results of the photo sensor and the magnetic sensor. An invention is disclosed that automatically calibrates data representing the relationship between and absolute position.

Japanese Patent No. 6339307 JP-A-2015-225007 Japanese Unexamined Patent Publication No. 2005-172696

In order to control the motor that drives each driven member as a rotary encoder in a closed loop, accurate information such as the rotation speed, rotation speed, and rotation direction of the motor is required. Therefore, in the detection of the rotation angle using the rotary encoder, various techniques have been proposed in order to further improve the detection accuracy.

In the invention described in Patent Document 1, information on the magnet origin position of the MR sensor with respect to the rotation axis is acquired, a Z-phase signal is set based on the absolute origin position, an EEPROM address is assigned, and a multi-rotation / absolute signal is used. It generates data and has a function as a rotary encoder. Since the MR sensor is adopted in the present invention, it is possible to provide an inexpensive and relatively high-precision rotary encoder. As an example, an encoder using a general-purpose GMR that is mass-produced has a low price of several hundred yen to several thousand yen per unit.
In the present invention, this kind of general-purpose sensor that is inexpensive and has a predetermined accuracy is defined as a general-purpose sensor.

However, this type of general-purpose sensor is originally manufactured on the premise that it is supplied in large quantities and at low cost as parts for automobiles and the like. Therefore, there are variations and distortions in the output characteristics of individual general-purpose sensors. That is, due to the magnetization deviation of the magnet itself, the variation in the sensitivity of the magnetoresistive element sensor, the phase angle deviation due to the error when the magnetoresistive element sensor is fixed to the motor, etc., each general-purpose sensor has its output characteristics. There is a problem that there are variations and distortions peculiar to the sensor. Therefore, when a general-purpose sensor is used as a sensor for a rotary encoder, a function such as axis misalignment correction processing is provided in order to correct variations and distortions peculiar to the sensor and secure a predetermined accuracy. However, it is difficult to correct variations and strains at intermediate angles other than the absolute origin position of the rotating shaft with high accuracy. Therefore, the rotation angle (mechanical angle) can only be obtained with a scale accuracy of ± 1 degree to several degrees. Such a rotary encoder cannot be used in equipment that requires accuracy on the order of μm, for example, a chip mounter.
In addition, the resolver used as a sensor for rotary encoders is also relatively inexpensive, but each sensor has its own variation and distortion, so the output characteristics vary widely, and the scale accuracy is about ± 10 degrees. Only obtained.
As described above, it is difficult to realize an inexpensive and consistently high-precision rotary encoder having sufficient absolute accuracy to discriminate the rotation speed and the rotation direction with high accuracy by using a general-purpose sensor.

On the other hand, many optical rotary encoders as described in Patent Document 2 employ a glass substrate as a substrate fixed to a rotating shaft in order to ensure high accuracy. Therefore, for example, in some high-resolution models having a resolution exceeding 10,000 pulses, the scale accuracy is guaranteed to be ± 2 seconds. Further, even in a high-resolution model having a resolution (signal period / rotation) of 4096, the scale accuracy is guaranteed to be ± 10 seconds. However, such high-precision optical rotary encoders are quite expensive, on the order of hundreds of thousands of yen or millions of yen, and the equipment that can be installed is limited to expensive equipment. ..
In the present invention, a sensor having an absolute accuracy of 2 to 3 orders of magnitude higher than that of a general-purpose sensor of this type, inferior in environmental resistance, and at a high price is defined as a high-precision sensor.
Further, in an optical rotary encoder as described in Patent Document 2, a specific optical pattern is generally formed on a substrate, and the output method of the encoder is uniformly determined by this optical pattern. Therefore, when different output methods are required, it is necessary to prepare an optical rotary encoder equipped with a substrate having an optical pattern corresponding to each output method.

The absolute encoder described in Patent Document 3 determines whether or not to calibrate the output from the photosensor at startup (S101 in FIG. 6), and when calibrating, the magnetic sensor (corresponding to the general-purpose sensor in the present invention). A table for calibration is created using the output from, and the output from the photosensor is calibrated (S102-109 in FIG. 6). However, the output from the general-purpose sensor has the above-mentioned problems. Therefore, it is difficult to realize an absolute encoder that can correct the output from the photo sensor with high accuracy by the output of the magnetic sensor.

One object of the present invention is to provide a rotary encoder using a general-purpose sensor, which has high accuracy comparable to that provided with a high-precision sensor, has excellent environmental resistance, and is inexpensive.

Another object of the present invention is to use a general-purpose sensor with high precision comparable to that provided with a high precision sensor, excellent environmental resistance, and any output format with one high precision rotary encoder. The purpose is to provide an inexpensive rotary encoder that can handle the above.

According to one aspect of the invention, the general purpose rotary encoder
A general-purpose sensor mounted on the motor to detect the rotation angle of the rotation axis of the motor,
A rotation angle detection unit that outputs information on the rotation angle of the rotation axis of the motor based on an output signal from the general-purpose sensor, and a rotation angle detection unit.
A general-purpose rotary encoder including an encoder control unit that generates and outputs a signal for driving the motor based on the rotation angle information.
The encoder control unit has a function of driving a motor for initial setting and
An initial setting data acquisition unit that acquires initial setting data unique to the general-purpose sensor,
A normal operation data acquisition unit that acquires and generates data for normal operation used when the motor to be controlled equipped with the general-purpose rotary encoder is normally operated.
Encoder output method selection section and
It is equipped with an encoder memory that holds calibration data for calibrating the initial setting data unique to the general-purpose sensor.
For the calibration data, a sensor whose absolute accuracy is guaranteed to be two or three orders of magnitude higher than that of the general-purpose sensor is used as a standard sensor, and the general-purpose sensor and the standard sensor are simultaneously connected to the motor for initial setting. It is the calibration data regarding the rotation angle of the rotation axis obtained by driving at least one forward and reverse rotation.
The output method selection unit of the encoder has a function of selecting an output method of either absolute data or incremental data as the output method of the general-purpose rotary encoder.
The normal operation data acquisition unit acquires and generates data for normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. It is a feature.

According to another aspect of the present invention, the output method selection unit of the encoder has a function of selecting whether or not to include data for a motor drive signal as the output method of the general-purpose rotary encoder. ,
The normal operation data acquisition unit acquires and generates data for the normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. It is characterized by.

According to still another aspect of the present invention, the output method selection unit of the encoder has a function of selecting either a multi-rotation rotation angle or a one-rotation rotation angle of the rotation shaft.
The normal operation data acquisition unit acquires and generates data for the normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. It is characterized by.

According to still another aspect of the present invention, one piece of information that transmits information necessary for generating A, B, Z signals which are outputs of the general-purpose rotary encoder between the general-purpose sensor and the encoder memory. There is a transmission path and another information transmission path for transmitting information necessary for generating U, V, W signals which are outputs of the general-purpose rotary encoder. From the general-purpose rotary encoder, the A, B, It is characterized in that the Z signal and the U, V, W signals are output in parallel.

According to the present invention, a general-purpose sensor is used, and the accuracy is as high as that of a high-precision sensor, the environment resistance is excellent, and one high-precision rotary encoder can handle any output format. An inexpensive rotary encoder can be provided.

It is a figure which shows the system configuration example of the initialization apparatus for the general-purpose rotary encoder in the 1st Example of this invention. It is a functional block diagram which shows the structural example of the general-purpose rotary encoder based on 1st Example. It is a vertical sectional view which shows the structure of the general-purpose rotary encoder in 1st Example. It is a vertical cross-sectional view which shows the other structure of the general-purpose rotary encoder in 1st Example. FIG. 5 is a sectional view taken along line AA of FIG. 1 showing a configuration example of a brushless DC motor for an initial setting device. It is a figure which shows the example of the functional block of output type 1 of the general-purpose rotary encoder and the initialization controller in 1st Example. It is a figure which shows the example of the functional block of output type 2 of the general-purpose rotary encoder and the initialization controller in 1st Example. It is a figure which shows the example of the functional block of output type 3 of the general-purpose rotary encoder and the initialization controller in 1st Example. It is a time chart which shows one form of the initial setting processing in 1st Example. It is a figure which shows an example of the characteristic of the general-purpose rotary encoder in 1st Example. It is a figure which shows an example of the calibration method of the characteristic of the general-purpose rotary encoder in 1st Example. It is a figure which shows an example of the relationship of the table of a general-purpose rotary encoder, the table of an optical rotary encoder, and the calibration table in 1st Example. It is a figure which shows the other example of the relation of the table of the general-purpose rotary encoder, the table of the optical rotary encoder, and the calibration table in 1st Example. FIG. 5 is a flowchart showing a process during normal operation of a brushless DC motor using a calibrated general-purpose rotary encoder in the example of the functional block shown in FIG. 4A. It is a figure explaining the relationship between the Z phase, the A phase, the B phase signal, and the U phase, V phase, and W phase signals at the time of multiple rotations in the Example of FIG. It is a figure which shows an example of the calibrated characteristic of the general-purpose rotary encoder at the time of multi-rotation in the Example of FIG. It is a figure which shows the effect of the calibration process in the normal operation mode using the general-purpose rotary encoder based on the Example of FIG. FIG. 5 is a flowchart showing a process during normal operation of a DC motor using a calibrated general-purpose rotary encoder in the example of the functional block shown in FIG. 4B. FIG. 5 is a flowchart showing a process during normal operation of a brushless DC motor using a calibrated general-purpose rotary encoder in the example of the functional block shown in FIG. 4C. It is a figure which shows the example of the functional block of the general-purpose rotary encoder and the initialization controller in the 2nd Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a system configuration example of an initial setting device for a general-purpose rotary encoder according to the first embodiment of the present invention.
This initial setting device includes a brushless DC motor 200 dedicated to initial setting, an optical rotary encoder 300 dedicated to initial setting with high absolute accuracy (functioning as a standard sensor) fixed to one end of the rotating shaft thereof, and a user terminal. The system is composed of the (input / output terminal) 400 and the initial setting controller 800.
The initial setting controller 800 has an "initial setting function" 810 that switches the information transmission path of the general-purpose rotary encoder 100 and performs initial setting by a rotary encoder (standard sensor) 300 with high absolute accuracy, and a general-purpose rotary encoder that has been initialized. It is configured to realize a "normal operation switching function" 820 that enables the 100 to be used as a rotary encoder during normal operation.
A part or all of the functions of the initial setting controller 800 may be provided inside the general-purpose rotary encoder 100.
When performing the initial setting, the general-purpose rotary encoder 100 to be the target of the initial setting is installed in the initial setting device. The information necessary for performing the initial setting is set by the user in the initial setting controller 800 and the general-purpose rotary encoder 100 via the user terminal 400.
In the example of FIG. 1, a general-purpose rotary encoder 100 is installed between the other end of the rotating shaft 203 of the brushless DC motor 200 and the substrate 118 fixed to the housing cover 250. Then, using the data of the rotary encoder (standard sensor) 300 with high absolute accuracy, the calibration data accompanying the initial setting is generated, and the initial setting recording / holding is performed in the memory or the like of the general-purpose rotary encoder 100.
The general-purpose rotary encoder 100 that has been initialized is removed from the initial setting device after being switched to a state in which it can be used as a rotary encoder during normal operation by the "normal operation switching function" 820.
Similarly, a new general-purpose rotary encoder 100 is sequentially installed between the other end of the rotating shaft 203 of the brushless DC motor 200 of this initial setting device and the substrate 118 fixed to the housing cover 250, and its memory. In addition, the process of recording and retaining the calibration data associated with the initial setting is repeated. In this way, one initial setting device can be used to perform initial setting processing for a large number of general-purpose rotary encoders 100 to function as rotary encoders with high absolute accuracy.

Various information necessary for the initial setting of the general-purpose rotary encoder 100 is acquired from the user terminal 400 and the initial setting controller 800. The rotational state of the brushless DC motor 200 is simultaneously acquired by the general-purpose rotary encoder 100 and the optical rotary encoder 300, in other words, two sets of data relating to the rotation of the same rotating shaft 203 are sequentially acquired, and they are acquired. The data is recorded in the general-purpose rotary encoder 100 and also held in the initial setting controller 800.

The general-purpose rotary encoder 100 includes a general-purpose sensor, for example, a magnetic sensor, which has a predetermined absolute accuracy but does not have strict high accuracy, but has excellent environmental resistance and is inexpensive. As the magnetic sensor, for example, an MR sensor (magnetoresistive sensor) such as GMR, TMR, AMR, or a Hall element can be used. As the general-purpose sensor, a capacitive sensor or an optical sensor may be used. A sensor of any type that does not satisfy a predetermined absolute accuracy, for example, a sensor having an absolute accuracy of ± 3 degrees or more at 360 degrees per rotation is excluded. In addition, those with poor environmental resistance and those with high prices are not covered.
On the other hand, the optical rotary encoder 300 of the initial setting device has an absolute accuracy of 2 to 3 orders of magnitude higher than that of a general-purpose sensor as a standard sensor dedicated to the initial setting, but is slightly inferior in environmental resistance and expensive. Sensors such as optical sensors are provided. The high-precision optical sensor in the present invention has a high absolute accuracy, for example, an absolute accuracy of ± 10 seconds or less. A laser sensor satisfying such a condition is also included in the high-precision optical sensor in the present invention.

Hereinafter, a brushless DC motor will be described as an example of the motor 200 dedicated to the initial setting. The brushless DC motor 200 includes a field iron core 212 and a field coil 211 wound around the field iron core 212 via an insulating member 213 as a stator fixed inside the motor housing 210. The magnet formed integrally with the rotating shaft is an 8-pole rotor having a rotor yoke 221 and eight permanent magnets 222 fixed to the outer peripheral portion thereof. The rotating shaft 203 is held by bearings 218 provided on the motor housing 210 and the end cover 214. A motor controller 240, a motor driver 242 such as an inverter circuit, and the like are also mounted on the substrate 118, and a signal line 228 and a power supply line (not shown) are connected to these.

The motor dedicated to the initial setting is not limited to the brushless DC motor as long as it has a function of stably rotating at a constant speed in response to a command value. On the other hand, the control target of the general-purpose rotary encoder of the present invention is not limited to the brushless DC motor. That is, the motor dedicated to the initial setting may be a motor of a type different from the control target of the general-purpose rotary encoder 100, for example, a DC motor with a brush or an AC synchronous motor.
In this embodiment, it is assumed that the general-purpose rotary encoder 100 whose initial setting has been completed, that is, the motor to be controlled is a brushless DC motor, and the general-purpose rotary encoder is used for brushless DC motor control. An example having a function of generating rotary absolute data (Z, U, V, W) will be described.

The optical rotary encoder 300, which constitutes a part of the initial setting device, is directly connected to the rotation shaft 203 of the brushless DC motor 200, which also forms a part of the initial setting device. That is, the rotating shaft of the optical rotary encoder 300 is integrated with the rotating shaft 203 of the motor, is held by the casing 304 via the bearing 305, and the rotating substrate 306 is fixed to one end of the rotating shaft. If the condition for ensuring high accuracy can be satisfied, the rotating shaft of the optical rotary encoder 300 may be connected to the rotating shaft 203 of the brushless DC motor 200 via a clutch.

The rotating substrate 306 is made of a rigid material such as glass, metal, or ceramics that is not easily deformed by rotation, impact, vibration, or the like. A light emitting element 311, an aperture 310 of an aperture 308, a lens 309, a light receiving element 314, a controller 316, and the like are arranged in a casing at positions facing each other with the rotating substrate 306 sandwiched between them. A set of slit patterns (optical patterns) 312 for the A phase and the B phase are formed on the rotating substrate 306 in the circumferential direction. The rotating substrate 306 rotates, and the slit pattern 312 passes between the light emitting element 311 and the light receiving element 314, so that the state in which the light from the light emitting element is transmitted and the state in which the light is blocked are alternately repeated, and the output of the light receiving element 314 is output. Is counted by the controller 316 as an A-phase / B-phase signal. The diaphragm 308 is provided so as to limit the region of the incident light so that extra light does not enter the light receiving element 314. Further, on the rotating substrate 306, a slit pattern for Z phase and a light receiving element are provided at positions having a radius of gyration different from that of the slit pattern 312 (not shown), and this Z phase signal is also counted by the controller 316. To. The details of the configuration and operation of such an optical rotary encoder will be replaced by the reference described in Patent Document 2. Needless to say, the optical rotary encoder forming a part of the initial setting device may function as a high-precision optical sensor, and is not limited to the example of Patent Document 2.

Next, FIG. 2A is a functional block diagram showing a configuration example of a general-purpose rotary encoder based on the first embodiment.
The general-purpose rotary encoder 100 includes a magnet unit 110, a sensor output processing unit 120, an encoder control unit 130, an encoder memory 160, and a communication interface 170. The general-purpose rotary encoder of the present invention functions as a rotary encoder of the brushless DC motor 200 during the initial setting process using the initial setting processing device, and after the initial setting, it can be used as a motor or a rotating body of various devices to be controlled. It is a rotary encoder that can be installed. The magnet unit 110 of the general-purpose rotary encoder 100 is held by the rotating shaft of the motor, and other components other than the magnet unit 110, such as the sensor output processing unit 120 and the encoder control unit 130, are formed on the circuit board 150. It is fixed to the 200 fixed side of the motor, for example, the motor housing. Hereinafter, the magnet unit 110 and the sensor output processing unit 120 may be included as a general-purpose sensor.

The magnet unit 110, which forms a part of the general-purpose sensor, includes a cylindrical magnet holder 111 made of a non-magnetic material, for example, a resin, and a hollow portion 112 for inserting a rotating body such as a rotating shaft of a motor into the holder. It has a flat plate-shaped magnet 113 fixed to the end face of the magnet holder, and fixing means 114 for fixing the magnet holder to the rotating body. One of the boundaries between the north and SN poles of the magnet 113, in the example of FIG. 1, the upper end of the magnet is the origin position Z0 of the rotation axis. The signal at the origin position Z0 and the Z signal of the optical rotary encoder both give the same rotation angle of the rotation axis, and are hereinafter referred to as "Z signal" when it is not necessary to distinguish them. ..

The sensor output processing unit 120 constitutes the rest of the general purpose sensor. This sensor output processing unit is separated from the magnet 113 at a position facing the magnet 113 and is fixed to a fixed side of the motor, for example, a motor housing, a pair of MR sensors (magneto resistive sensor) 121, 122, a temperature sensor 123, and a temperature sensor 123. It is equipped with a sensor output processing circuit unit. When the magnet 113 rotates by the angle θ (mechanical angle) and the direction of the magnetic field acting on each MR sensor rotates, the electrical resistance value of the MR sensor, in other words, the voltage of the output signal of the general-purpose sensor fluctuates accordingly. For each rotation of the rotating shaft 13, a pulse signal for one cycle is output at 360 degrees (mechanical angle) for each of the SIN wave and the COS wave.
The magnet 113 is composed of a Si or glass substrate and a thin film of an alloy formed on the magnet 113 containing a ferromagnetic metal such as Ni or Fe as a main component.

The sensor output processing circuit unit of the sensor output processing unit 120 includes sensors such as an AD converter 124, a pulse counter 125, an inverse tangent calculation processing unit 126, an axis misalignment correction processing unit 127, an A-phase / B-phase signal generation unit 128, and a RAM. It has each function of the memory 129. This sensor output processing circuit unit is realized, for example, by executing a predetermined program on a microcomputer with a memory.

In the sensor output processing circuit section, the analog signals of the pair of MR sensors are quantized and divided into multiple parts by the insertion processing of the electric angle, and each rotation of the rotation axis, for example, 30,000 pulses, phase A, It is converted into a B-phase digital signal. The A-phase and B-phase signals obtained from the pair of MR sensors 121 and 122 may contain errors (mainly axis misalignment errors) due to production errors, installation errors, temperature effects, etc. of each sensor. Therefore, the axis deviation correction processing unit 127 and the like perform the correction processing.

The A-phase and B-phase digital signals are cumulatively added by the pulse counter 125, and the value is calculated by the inverse tangent calculation processing unit 126. The value of this inverse tangent calculation becomes a right-angled triangular shape in which the cumulative addition value repeats increasing and decreasing linearly in synchronization with the position of the angle 0 for each rotation of the rotation shaft 13.
Based on this cumulative addition value, the A-phase / B-phase signal generation unit 128 generates incremental pulse data of the A-phase signal and the B-phase signal (hereinafter, A-phase / B-phase signal) in the sensor memory 129. Be retained. Further, the A-phase / B-phase signal generation unit 128 generates and outputs the origin position Z0 or Z signal synchronized with the position of the angle 0 that appears for each rotation of the rotation shaft 13. This Z signal is used to generate information Zn (Z1, Z2, −, Zn) representing the rotation speed of the rotation shaft 13.

The encoder control unit 130 drives a brushless DC motor for initial setting for initial setting of the general-purpose rotary encoder 100, acquires necessary information, and records it in the encoder memory 160, whereby the general-purpose rotary encoder 100 Is given a function as a high-precision rotary encoder comparable to an optical rotary encoder.

The encoder control unit 130 includes an initial setting drive signal generation unit 131, a general-purpose sensor initial setting data acquisition unit 132, a standard sensor initial setting data acquisition unit 133, and a Z-phase signal generation (A, B, Z) recording unit. 134, origin position setting unit 135, slot / pulse number setting, recording unit 136, U, V, W signal generation / recording unit 137 during normal operation, calibration data generation / recording unit 138, encoder output method selection unit 139. , Incremental data generation / recording unit 1310, and absolute data generation / recording unit 1320.

The initial setting drive signal generation unit 131 generates and outputs drive signals (iu, iv, iw) for driving the brushless DC motor dedicated to the initial setting in the forward rotation and reverse rotation directions.
The initial setting data acquisition unit 132 of the general-purpose sensor drives the brushless DC motor by a drive signal (iu, iv, iw) at a predetermined low speed, for example, in the range of 5 to 20 rpm, preferably about 10 rpm. The data of the A-phase / B-phase signal at the time of initial setting, which is peculiar to the general-purpose sensor, is acquired.

Initial setting data acquisition unit 133 of the standard sensor is the initial setting of the standard sensor when the brushless DC motor is driven by the drive signal at a constant speed of, for example, 10 rpm with the general-purpose rotary encoder 100 attached. Acquires A-phase and B-phase signal data at the time.
The Z-phase signal generation (A, B, Z) recording unit 134 is based on the A-phase / B-phase signal and the Z signal, and has a Z-phase width signal and a Z-phase signal (Z1, Z2, −, −, Zn). Is generated and recorded. For example, a signal having a "Z width (1)" synchronized with the rising edge of the A signal and a signal having a "Z width (2)" having a different width are generated in synchronization with the rising edge of the A signal. Each of these signals is a signal that repeats at 306 degree intervals. Similarly, starting from the Z signal, the "Z width (3)" and the "Z width (4)" that are synchronized with the rising edge of the B signal are generated.

The origin position setting unit 135 has a function of extracting the origin position Z0 and determining the fixed position of the magnet when the origin position of the rotating shaft is unknown when the general-purpose sensor is mounted on the brushless DC motor to be controlled. If the origin position Z0 of the rotation axis is known in advance, it is not used.
The slot pulse number setting and recording unit 136 allows the user to input and record necessary information according to the type and configuration of the motor to be controlled to which the general-purpose sensor is mounted. For example, the user determines and records the number of magnetic poles or the number of iron core slots of the brushless DC motor to be controlled. This information is used to generate control signals for the motor based on the electrical angle.

The U, V, W signal generation / recording unit 137 during normal operation generates and records data for normal operation. The data for normal operation is data used when a brushless DC motor to be controlled, which is equipped with a general-purpose sensor, is controlled by a controller or a driver and is normally operated. For example, based on the data of the A-phase / B-phase signal, the origin position Z0 or Z signal, the number of poles, etc., the data for the drive signal such as the U, V, W signal for PWM control of the motor is generated and recorded. To do.
The calibration data generation / recording unit 138 has a function of generating calibration data for calibrating the data at the time of initial setting peculiar to the general-purpose sensor with the data at the time of initial setting of the standard sensor acquired under the same conditions. .. The generation of calibration data will be described later.
As an encoder output method, the encoder output method selection unit 139 allows the user to perform multi-rotation / absolute data, one rotation / absolute data, and the rotation angle (or rotation position) of the rotation axis via the user terminal. One of the methods of incremental data is selected. Further, as an output method, the user uses only the information on the rotation angles of these rotation axes, or when the motor, for example, a brushless DC motor is controlled by the controller and normally operated together with the information on the rotation angles. It is possible to select whether to include data for generating motor drive signals such as U, V, and W signals. An example of this output method will be described later as output types 1 to 3.

The incremental data generation / recording unit 1310 calibrates the A-phase / B-phase signals and Z signals acquired by the general-purpose sensor with the calibration data when the incremental data is selected by the output method selection unit 139 of the encoder. It has a function to generate incremental data, record it in the encoder memory, and output it.
The absolute data generation / recording unit 1320 calibrates the A-phase / B-phase signal and Z-signal data acquired by the general-purpose sensor with the calibration data when the absolute data is selected by the output method selection unit 139 of the encoder. It also has a function to generate absolute data, record it in the encoder memory, and output it. When multi-rotation / absolute data is selected, this multi-rotation / absolute data, which also includes multi-rotation data based on the origin position Z0 or Z signal information, is controlled as the output of the general-purpose rotary encoder 100. Used to control the target brushless DC motor.
When absolute data for each rotation of the motor is required as the absolute data, it is sufficient that there are A-phase / B-phase signals calibrated by the calibration data and data of the origin position Z0 or Z-phase signal.
When data for a drive signal is also selected as the output method of the encoder, it is generated / recorded by the U, V, W signal generation / recording unit 137 during normal operation based on the information of the slot / pulse number setting. It also generates data for the drive signal of the motor and outputs it together with absolute data and incremental data.

The encoder memory 160 includes a ROM 161 and a RAM 162, an EP ROM 163, and an EEPROM 164, and is connected to the encoder control unit via a bus or a memory controller. In the EPROM and EEPROM, multi-rotation / absolute signals and the like calibrated with calibration data related to the operation of the brushless DC motor are sequentially held.
There are a serial bus type and a parallel bus type in the external interface of the 164 chip of EEPROM. The operation method of EEPROM differs greatly depending on this interface. The bus standard signal lines used in the serial bus type EEPROM are 1 to 4 lines. On the other hand, the parallel EEPROM chip generally has eight (8-bit) data terminals and address terminals corresponding to the storage capacity. The general-purpose rotary encoder 100 of this embodiment is configured to be compatible with both the serial bus type and the parallel bus type.

FIG. 2B shows an example of a specific configuration of the general-purpose rotary encoder 100 of the first embodiment. The magnet holder 111 that holds the magnet unit 110 is rotatably held by the cylindrical box 115 via the bearing 116. A flat plate magnet 113 is fixed to the magnet holder 111. A pair of MR sensors 121 and 122, a temperature sensor 123, a sensor output processing unit 120, an encoder control unit 130, an encoder memory 160, and a communication interface 170 are mounted on a substrate 118 fixed to the space 117 in the box 115. Has been done. The encoder memory 160 holds a multi-rotation / absolute signal that has been calibrated with calibration data. In order to allow the pair of MR sensors 121 and 122 to secure a predetermined magnetic sensitivity, the surface of the magnet 113 and the pair of MR sensors 121 and 122 have a predetermined minute distance, for example, 20 mm to 30 mm. It is set in the gap.
The box body 115 has a spring-shaped holding portion 119 at its outer peripheral end, and in a state where a rotating body such as a rotating shaft 203 of the motor 200 is inserted into the hollow portion 112, the box body 115 is inserted into the motor housing or the like of the brushless DC motor 200. It is configured to be fixed.
According to this configuration example, the positional relationship between the magnet 113 and the pair of MR sensors 121 and 122 is set to an appropriate value in advance. Therefore, the general-purpose rotary encoder can be easily and accurately mounted on the motor of the initial setting device or the motor to be controlled by simply fixing the box 115 to the motor housing or the like.

FIG. 2C shows another configuration of the general-purpose rotary encoder 100 of the first embodiment, which has a specific configuration. In this example, unlike the example of FIG. 2B, the box is omitted. The magnet holder 111 that holds the magnet 113 is fixed to the rotating shaft 203 of the motor 200. The substrate 118 on which the pair of MR sensors 121 and 122, the temperature sensor 123, the sensor output processing unit 120, the encoder control unit 130, the encoder memory 160, and the communication interface 170 are mounted is, for example, a housing as shown in FIG. It is fixed to the cover 250. This completes the DC servo motor.
Compared to the example of FIG. 2B, this example requires the work of positioning the MR sensors 121 and 122 with respect to the magnet 113. On the other hand, the degree of freedom in designing the entire brushless DC motor 200 is increased, for example, the motor controller 240 and the motor driver 242 are collectively installed on the substrate 118.

Next, FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 showing a configuration example of a brushless DC motor for the initial setting device. Note that FIG. 3 is also a diagram showing a configuration example of the brushless DC motor when the motor to be controlled, that is, the motor on which the initialized general-purpose rotary encoder is mounted is a brushless DC motor.
The brushless DC motor 200 includes a rotor yoke 221 fixed to a rotating shaft 203, a rotor including eight permanent magnets 222 arranged at equal intervals in the circumferential direction on the outer periphery thereof, a field iron core 212, and each field. It is composed of a stator including nine sets of field coils 211 wound in a slot around the magnetic iron core via an insulating member. The field coil includes a U-phase field coil (211U1 to 211U3), a V-phase field coil (211V1 to 211V3), and a W-phase field coil (211V1 to 211V3) depending on the phase of the voltage applied from the motor driver 242. It is classified into 211W1 to 211W3).

The brushless DC motor 200 is controlled by the controller 240 of the motor based on a command from a higher-level controller and an output of the general-purpose rotary encoder 100.
The controller 240 of the motor is realized by, for example, a single-chip microcomputer in which a CPU, a memory, an oscillation circuit, a timer, an I / O interface, a serial I / F, and the like are integrated in one LSI. By executing the program stored in the memory on the CPU, each function of the BLCD controller 240 of the brushless DC motor is realized. Memory such as ROM and RAM is connected to the CPU via a bus. The ROM stores a program to be executed at power-on or reset, and constants that do not change during program execution. A flash memory may be adopted as the ROM. The RAM holds program variables, external command values, multi-rotation / absolute signal data, and the like. In addition, the target speed of the brushless DC motor (inverter sine wave drive signal, PWM control duty ratio) is also stored in the RAM.

Next, FIGS. 4A to 4C are diagrams showing examples of functional blocks of the general-purpose rotary encoder 100 and the initial setting controller 800 in the first embodiment. These figures show the functions of the general-purpose rotary encoder 100 shown in FIG. 2A corresponding to the output type selected by the user in the encoder output method selection unit 139 via the user terminal 400.

FIG. 4A shows a general-purpose rotary encoder when the user selects the absolute data and the data for the drive signal of the motor by the output method selection unit 139 of the encoder via the user terminal 400 (output type 1). The functional blocks of 100 and the initialization controller 800 are shown.
A first information transmission path exists between the standard sensor (optical rotary encoder) 300 and the data recording unit 181 of the standard sensor, and the general-purpose sensor (110, 120) and the absolute encoder output / recording unit 186 There is a second information transmission path including the SSC-BUS converter 172, the SPI-BUS converter 174, and the first calibration 176, between the general-purpose sensors (110, 120) and the absolute encoder output / recording unit 186. There is a second calibration 182 and a third information transmission path including the U, V, W signal generation / recording unit 184. Further, there is a fourth information transmission path between the data recording unit 181 of the standard sensor and the first calibration 76 and the second calibration 182.

First, the initial setting controller 800 causes the general-purpose rotary encoder 100 to be initialized to configure an information transmission path capable of executing the "initial setting function" 810 (see FIG. 1) for performing the initial setting. In this case, the standard sensor (optical rotary encoder) 300 and the data recording unit 181 of the standard sensor are connected via the first information transmission path, and the general-purpose sensor (110, 120) and the absolute encoder output / recording unit 186 are connected. Is connected via the second information transmission path, and the data recording unit 181 of the standard sensor and the second calibration 182 are connected via the fourth information transmission path. The third information transmission path is valid only between the second calibration 182 and the U, V, W signal generation / recording unit 184 and the absolute encoder output / recording unit 186.
The A, B, Z signals that are the outputs of the general-purpose sensors (110, 120) are input to the SSC-BUS converter 172 as serial bus signals, and these signals are serialized via the SPI-BUS converter 174. It becomes a signal (digital) and a parallel signal (digital), and is recorded in the first data recording unit 180 of the general-purpose rotary encoder.
The data of the first data recording unit 180 is calibrated based on the data of the data recording unit 181 of the standard sensor in the first calibration 176, and the calibrated A, B, and Z signals are the absolute encoder output / recording unit 186. Recorded in.
Further, in the second calibration 182, A, B, Z signals based on the data of the standard sensor are sent to the U, V, W signal generation / recording unit 184, the slot / pulse number setting, and the number of poles of the recording unit 136. U, V, W signals are generated and recorded based on the information such as. The U, V, and W signals are held in the absolute encoder output / recording unit 186.

When the initial setting of the general-purpose rotary encoder 100 is completed, the initial setting controller 800 uses the "normal operation switching function" 820 (see FIG. 1) to provide the general-purpose rotary encoder 100 with no first information transmission path. , The third information transmission path is switched to the normal operation mode in which the general-purpose sensors (110, 120) and the absolute encoder output / recording unit 186 are enabled. Therefore, during normal operation, the A, B, and Z signals, which are the outputs of the general-purpose sensors (110, 120), are recorded in the second data recording unit 178 of the general-purpose rotary encoder via the third information transmission path. To. This data is calibrated in the second calibration 182 based on the data of the data recording unit 181 of the standard sensor, and further, based on the calibrated data, the U, V, W signal generation / recording unit 184 uses the U, Absolute data (U, V, W) of V and W are generated and held in the absolute encoder output / recording unit 186.
The data of the absolute encoder output / recording unit 186 is recorded in a memory, for example, EEPROM 164, and the A, B, Z signals and the U, V, W are output to the motor controller 240 and the motor driver 242 in parallel. Will be done. By supplying the calibrated A, B, Z signals and U, V, W in parallel, the motor controller 240 quickly generates the signals necessary for controlling the brushless DC motor and outputs them to the driver. be able to.
The output type 1 general-purpose rotary encoder 100 is a rotary encoder suitable for a brushless DC motor. When multi-rotation is selected as the output method, multi-rotation absolute data (Z, U, V, W) is generated, and when single rotation is selected, only one rotation absolute data (Z, U, V, W) is generated. Z, U, V, W) is generated.

Next, FIG. 4B shows a functional block of the general-purpose rotary encoder 100 when the user selects incremental data (output type 2). This output type 2 does not use the third information transmission path.
When the "initial setting function" 810 is operating, the data of the standard sensor (optical rotary encoder) 300 is recorded in the data recording unit 181 of the standard sensor. The A, B, and Z signals, which are the outputs of the general-purpose sensors (110, 120), are recorded in the first data recording unit 180 of the general-purpose rotary encoder via the second information transmission path. The data of the first data recording unit 180 is calibrated based on the data of the data recording unit 181 of the standard sensor in the calibration 183, and the calibrated A, B, and Z signals are recorded in the incremental encoder output / recording unit 190. And further recorded in EEPROM 164.
When the initial setting of the general-purpose rotary encoder 100 is completed, the "normal operation switching function" 820 switches the general-purpose rotary encoder 100 to the normal operation mode in which the first information transmission path does not exist. In the calibration 183, the A, B, and Z signals, which are the outputs of the general-purpose sensor, are calibrated based on the data recorded in the data recording unit 181 of the standard sensor.
The output type 2 general-purpose rotary encoder 100 is a rotary encoder suitable for motors other than brushless DC motors, such as DC commutator motors.
When multi-rotation is selected as the output method, multi-rotation incremental data (A, B, Z) is generated, and when single rotation is selected, incremental data (A, B, Z) of only one rotation is generated. B, Z) is generated. These data are output to the controller 240 of the motor and the motor driver 242.

Further, FIG. 4C shows a general-purpose type in the case where the user selects the incremental data and the data for the drive signal of the motor by the output method selection unit 139 of the encoder via the user terminal 400 (output type 3). The functional block of the rotary encoder 100 is shown. In this output type 3, the third information transmission path is used in the same manner as in the example of FIG. 4A.
When the "initial setting function" 810 is operating, in the general-purpose rotary encoder 100 and the initial setting controller 800, the A, B, and Z signals, which are the outputs of the general-purpose sensors (110, 120), use the second information transmission path. It is recorded in the first data recording unit 180 of the general-purpose rotary encoder via. This data is calibrated based on the data of the data recording unit 181 of the standard sensor in the first calibration 176, and the calibrated A, B, and Z signals are recorded in the incremental encoder output / recording unit 192. In addition, U, V, W signals are generated based on information such as the A, B, Z signals calibrated based on the data of the standard sensor in the second calibration 182, the slot pulse number setting, and the number of poles of the recording unit 136. -The recording unit 184 generates U, V, W incremental data (Z, U, V, W), which is recorded in the incremental encoder output / recording unit 192.

When the initial setting of the general-purpose rotary encoder 100 is completed, the initial setting controller 800 operates the general-purpose rotary encoder 100 in a normal operation in which the first information transmission path does not exist and the entire third information transmission path becomes effective. Switch to the mode. In this case, the A, B, and Z signals output from the general-purpose sensor (110, 120) are directly recorded in the second data recording unit 178 of the general-purpose rotary encoder. In the second calibration 182, the A, B, and Z signals, which are the outputs of the general-purpose sensor, are calibrated based on the data recorded in the data recording unit 181 of the standard sensor.
The data of the incremental encoder output / recording unit 192 is output to the motor controller 240 and the motor driver 242 in parallel with the calibrated A, B, Z signals and the U, V, W signals.
The output type 3 general-purpose rotary encoder 100 is a rotary encoder suitable for a brushless DC motor. When multi-rotation is selected as the output method, multi-rotation incremental (Z, U, V, W) is generated, and when single rotation is selected, incremental data (Z) of only one rotation is generated. , U, V, W).

The initial setting process in the first embodiment will be further described with reference to the time chart of FIG.
For initial setting, start the program related to the initial setting of the general-purpose rotary encoder 100, the brushless DC motor 200 dedicated to the initial setting, and the optical rotary encoder (standard sensor) 300 from the initial setting controller 800, and set the necessary parameters. It is started by setting. At the time of initial setting, the environmental temperatures of the general-purpose rotary encoder 100, the brushless DC motor 200, and the optical rotary encoder 300 are always maintained at room temperature (for example, 20 ° C.). If necessary, calibration data in which the ambient temperature of the brushless DC motor 200 and the optical rotary encoder 300 may be changed may be generated.

In this example, it is assumed that the magnet origin position Z0 of the brushless DC motor 200 constituting the initial setting device is clear.
First, the general-purpose rotary encoder 100 is installed in the brushless DC motor 200, and both circuits are electrically connected (S501). The optical rotary encoder 300 is directly connected to the output shaft of the brushless DC motor 200 dedicated to the initial setting (S502). Then, the magnet 113 is fixed to the rotating shaft 203 of the brushless DC motor 200 (S504). Next, the brushless DC motor 200 is driven at a constant speed with a predetermined three-phase drive signal dedicated to the initial setting generated by the encoder control unit 130 (S505). That is, while the drive power is supplied to the three-phase stator coil of the brushless DC motor 200 and the data for the initial setting is acquired, the brushless DC motor 200 rotates forward and reverse at a constant low rotation speed, for example, 10 rpm. It is controlled to maintain rotation. Along with this, the brushless DC motor 200 rotor and the magnet 113 of the MR sensor rotate, and the MR sensor generates an output signal for at least one forward / reverse rotation (mechanical angle) peculiar to the general-purpose rotary encoder (S506). Normally, one rotation in the forward and reverse directions is sufficient, but if it is particularly necessary depending on the application, the number of rotations in the forward and reverse directions may be multiple rotations, for example, 2-3 rotations.

Further, the optical rotary encoder 300 directly connected to the brushless DC motor 200 also generates an output signal for at least one forward / reverse rotation based on the same operating conditions (SS505, 508). Next, in the general-purpose rotary encoder and the optical rotary encoder, the EEPROM address is set based on the incremental cumulative addition values of the output signals of A and B based on the absolute origin position Z0 for at least one rotation in the forward and reverse directions. By adding, incremental data of A-phase and B-phase signals for one rotation is generated (S507, S509). In addition, in order to improve the accuracy of the measurement, the output signals for at least one forward / reverse rotation may be acquired a plurality of times, and the average value thereof may be obtained.

The encoder control unit 130 of the general-purpose rotary encoder acquires the data of the output signals of A and B of the optical rotary encoder (S510). Then, based on the A and B phase signal data of both the general-purpose rotary encoder and the optical rotary encoder, the A and B phase signal data of the general-purpose rotary encoder based on the absolute origin position Z0 is obtained from the optical rotary encoder A. , Create a table to calibrate with B-phase signal and Z signal data, and record it in the memory (S511). Even if both the general-purpose rotary encoder and the optical rotary encoder acquire data for one forward and reverse rotation multiple times and calculate the average value at each rotation position to improve the accuracy of the calibration table. good. After this, the optical rotary encoder is separated from the motor (S512).

FIG. 6A is a diagram showing an example of characteristics obtained by a general-purpose rotary encoder. There are various factors of variation and distortion in the output characteristics of general-purpose sensors. Here, it is assumed that the magnet 113 of the MR sensor is biasedly fixed with respect to the rotation shaft 203 of the motor. In this example, the boundary between the S pole and the N pole of the magnet is deviated from the original position P1A by an angle Δθ to be the position P1S. Due to this installation error, as shown in the graph on the right side in FIG. 6A, there is a phase angle shift between the output angle θS of the MR sensor shown by the solid line and the rotation angle θA of the actual axis shown by the broken line. Occurs.

FIG. 6B is a diagram showing an example of calibrating the characteristics of a general-purpose rotary encoder with data of an optical rotary encoder. The optical rotary encoder in the present invention employs a sensor whose accuracy is guaranteed to be two or three orders of magnitude higher than that of a general-purpose sensor. The data at each position of the A-phase and B-phase digital signals of the general-purpose rotary encoder for one rotation forward and reverse of the rotation axis is calibrated based on the output data of the optical rotary encoder. As a calibration method, the calibration amount is determined for all pulses for one rotation based on the absolute origin position Z0, and the calibration data is tabulated.
For example, the resolution of the optical rotary encoder is RE1 and the resolution of the general-purpose rotary encoder is RE2, and the rotation angle data at a certain point on the rotation axis of the same motor is the rotation angle of 45.00 degrees in the optical rotary encoder. On the other hand, in the general-purpose rotary encoder, the number of pulses is QG1 (corresponding to 46.56 degrees). In this case, the output angle at the position of the QG1 pulse of the general-purpose rotary encoder is calibrated to 45.00 degrees indicated by the optical rotary encoder.

According to the experiments of the inventors, the deviation of the phase angle of the output of the MR sensor is often repeated in the same pattern every 360 degrees of the mechanical angle. Therefore, even when targeting a multi-rotation device, if highly accurate angle data for one rotation (machine angle of 360 degrees) can be obtained, practically highly reliable control becomes possible.
Further, the output characteristics of the MR sensor change according to the environmental temperature. However, according to the experiments of the inventors, the relationship between the output characteristics of the magnetoresistive sensor and the optical rotary encoder obtained at room temperature, for example, shown by the broken line and the solid line in FIG. 5B, is that even if the environmental temperature changes. A similar relationship is maintained. Therefore, by correcting the output characteristics of the MR sensor based on the output of the temperature sensor 123 of the general-purpose rotary encoder 100 and the calibration data, even if the environmental temperature changes, the accuracy calibrated from the general-purpose rotary encoder is achieved. High angle data can be obtained.

Returning to FIG. 5, next, the output method of the general-purpose rotary encoder is selected (S513). The encoder output method selection unit 139 selects one of multi-rotation / absolute data, one-rotation / absolute data, and incremental data as the encoder output method (output type). Further, it is possible to select whether to include only the information on the rotation angle of these rotation axes, or whether to include the data for the drive signal together with the information on the rotation angle.
When multi-rotation / absolute data is selected (output type 1 in FIG. 4A), the standard absolute data is obtained by calibrating the A-phase / B-phase signal data acquired by the general-purpose sensor based on the calibration data. Generate (S514).
Next, in the encoder control unit 130, the number of U-phase, V-phase, and W-phase pulses corresponding to the drive signal is acquired from the memory. Further, based on the Z-phase width signal, the Z signal, etc., the multi-rotation speed data is acquired, the EEPROM address is assigned, and the multi-rotation absolute data of the motor to be controlled to which the general-purpose rotary encoder is mounted. (Z, U, V, W) is generated (S515).

FIG. 7A shows a general-purpose encoder table 140 (corresponding to the data recording units 178 and 180 of FIGS. 4A to 4C), an optical rotary encoder table 142 (corresponding to the data recording unit 181 of FIGS. 4A to 4C), and calibration. It is a figure which shows an example of the relationship of the table 144 (corresponding to the 1st and 2nd calibrations 176, 182 of FIGS. 4A-4C).
A calibration table 144 for calibrating the data of the general purpose encoder is created so as to match the data of the optical rotary encoder. In this example, the calibration table 144 is a table of detection angle values in which the values of each detection angle of the general-purpose encoder are replaced with the data of the optical rotary encoder.
In the example of FIG. 7B, the calibration table 144 is a table that gives calibration / correction positions based on the data of the optical rotary encoder to the values of each detection angle of the general-purpose encoder.
In the calibration table 144 of FIGS. 7A and 7B, the incremental value based on the information Z0 and Zn representing the rotation speed may be replaced with the angle data of the optical rotary encoder instead of the detection angle. That is, instead of the angle value, each of the general-purpose encoders utilizes the relationship between the cumulative addition value of the general-purpose rotary encoder and the cumulative addition value of the optical rotary encoder, which are repeated in units of Z0, Z1, Z2, −, Zn. The value of the detection angle may be calibrated and interpolated.

As described above, the multi-rotation absolute data (Z, U, V, W) based on the general-purpose rotary encoder is converted into the multi-rotation absolute data (Z, U, V, W) based on the optical rotary encoder. , Recorded in memory (S516 in FIG. 5), and complete the general-purpose rotary encoder 100 as an absolute encoder (output type 1). Through the above processing, the initial setting of one general-purpose encoder is completed (S517).
Even when one rotation / absolute data is selected in the selection of the output method of the general-purpose rotary encoder (S513) (output type 4), the one rotation / absolute data is generated and the encoder memory is generated as in S513 to S517. Record at 160.

Next, when incremental data is selected in the selection of the output method of the general-purpose rotary encoder (S513) (output type 2 in FIG. 4A), incremental data (A, B, Z) is generated based on the calibration data. (S518), this incremental data is recorded in EEPROM 164 (S519), and completed as an incremental encoder (output type 2) (S520).
Further, when incremental U, V, W (A, B, Z, U, V, W) is selected in the selection of the output method of the general-purpose rotary encoder (S513) (output type 3 in FIG. 4A), calibration is performed. Based on the data for use, the data of the A-phase and B-phase signals acquired by the general-purpose sensor is calibrated to generate standard absolute data (S521).
Next, in the encoder control unit 130, the number of U-phase, V-phase, and W-phase pulses corresponding to the drive signal is acquired from the memory. Further, based on the Z-phase width signal, the Z signal, etc., the multi-rotation speed data is acquired, the EEPROM address is assigned, and the multi-rotation absolute data of the motor to be controlled to which the general-purpose rotary encoder is mounted. (Z, U, V, W) is generated (S522).
This incremental data is recorded in EEPROM 164 (S523) and completed as an incremental encoder (output type 3) (S524).
After that, the general-purpose rotary encoder 100 is separated from the brushless DC motor dedicated to the initial setting (S525).

After that, the next new general-purpose encoder is attached to the brushless DC motor dedicated to the initial setting, and the initial setting process of the new general-purpose encoder is performed in the same manner as described above.
The optical rotary encoder and brushless DC motor constituting the initial setting device are used at a low speed and for a short time for the initial setting processing of one general-purpose encoder. Therefore, it is possible to repeatedly use the brushless DC motor and the optical rotary encoder that constitute the initial setting device, for example, 10,000 to 100,000 times. That is, the initial setting device in the present invention uses a high-precision, high-cost optical rotary encoder, but since it is possible to calibrate a large number of general-purpose encoders using this device, each general-purpose encoder can be calibrated. The manufacturing cost can be reduced.

Next, with reference to FIGS. 8 to 11, the brushless DC motor to be controlled by the general-purpose rotary encoder in which the output type 1 is initially set as shown in FIG. 4A is based on the first embodiment. The processing during normal operation will be described. A general-purpose rotary encoder having a configuration as shown in FIGS. 2B and 2C is fixed to the motor to be controlled. Here, the motor to be controlled is a brushless DC motor. Needless to say, when a motor of another type is targeted, the same processing is performed in the drive circuit required for the motor of that type.
The general-purpose rotary encoder 100 and BLCD controller 240 of the brushless DC motor to be controlled include an initial setting data acquisition unit for acquiring initial setting data, a normal operation mode DC servo control unit, and a normal operation mode motor control signal (iu, iv, iw) It has functions such as a generator and an inverter drive signal generator. The inverter drive signal generator receives the outputs of the normal operation mode motor control signal generator and the DC servo control unit, generates an inverter drive signal for controlling the rotation of the brushless DC motor, and drives the inverter of the motor driver. Control.

In the normal operation processing mode, the general-purpose rotary encoder 100 and the BLCD controller 240 make the brushless DC motor function as a servomotor based on an external command and information of the calibrated encoder memory 160 of the type rotary encoder 100. That is, the software in the general-purpose rotary encoder 100 (U, V, W signal generation / recording unit 137 during normal operation) generates U-phase, V-phase, and W-phase drive signals (S801), and the BLCD controller. It outputs to 240 and drives a brushless DC motor. The U-phase, V-phase, and W-phase pulses / rotation corresponding to the drive signal are acquired from the encoder memory 160 that has been calibrated based on the output of the standard sensor in the initial setting of the general-purpose encoder (S802), and further, the Z phase. A signal having a width of (S803) is acquired. As a result, the Z-phase signal (Z1, Z2, −, −, Zn) data as shown in FIG. 9, that is, the multi-rotation data is acquired (S804). Further, the rising edge of the U phase is synchronized with the absolute origin position (Z0) of the rotation axis (S805). Then, the calibrated A-phase / B-phase signal and Z signal from the general-purpose encoder are acquired via the RAM (S806), and the EEPROM address is assigned based on the incremental cumulative addition value. Record in RAM.

The general-purpose rotary encoder 100 and the BLCD controller 240 calibrate the incremental data of the general-purpose encoder using the calibration table 144 (S807).
Using this calibrated data, EEPROM addresses are assigned to A-phase / B-phase signals, Z-phase signals, U, V, and W-phase signals for each rotation to make them absolute and record them in RAM (S808). ).
Further, a multi-rotation absolute signal including information on the rotation speed and the rotation angle of the brushless DC motor is generated from the Z-phase signal and the A-phase / B-phase signal (S809), and the multi-rotation is performed in EEPROM via RAM. Record as absolute (S810).
That is, as shown in FIG. 10, the output obtained from the general-purpose encoder of the general-purpose rotary encoder is converted into high-precision multi-rotation / absolute data using the calibration table 144. This multi-rotation / absolute data is data that is repeated in the forward and reverse directions in units of Z0, Z1, Z2, −, and Zn.
The calibrated multi-rotation / absolute data of the EPROM is output to the motor controller 240 and the motor driver 242 in parallel with the A, B, Z signals and the U, V, W signals (S811). In FIG. 8, for convenience of explanation, the calibrated A-phase / B-phase signal and Z signal and the calibrated U, V, and W signals are described as a series of continuous processes, but they are actually The A-phase / B-phase signal and the Z signal, and the U, V, and W signals are calibrated in parallel and output to the motor controller 240 and the motor driver 242.

According to this embodiment, the information on the rotation angle of the rotation axis of the motor is calibrated based on the sequential calibration table 144 according to the forward rotation and the reverse rotation of the rotation axis of the brushless DC motor, and based on the calibrated angle data. , A, B, Z, U, V, W signals are incremented and decremented, and are sequentially recorded and updated in the EEPROM via RAM as information representing the current position of the rotation axis of the brushless DC motor with high accuracy. Will be done. Based on these updated information, the brushless DC motor is continuously servo-controlled (S806) to (S811).
This process is repeated to end the operation (S812).
As described above, the brushless DC motor that employs the general-purpose encoder of this embodiment operates as a servomotor having a high-precision rotary encoder function during normal operation.

FIG. 11 is a diagram showing the effect of the calibration process in the normal operation mode using the general-purpose rotary encoder.
During normal operation, the brushless DC motor changes its rotation direction and speed according to the command value. In the case of a general-purpose rotary encoder that has not been calibrated, in other words, it does not have strict absolute accuracy, it corresponds to the absolute origin position (Z0) of the axis and the Z-phase signal (Z1, Z2,-,-, Zn). The absolute accuracy of positions other than the position (hereinafter, positions other than the origin) is not high. Therefore, the absolute accuracy of movement from the first position other than the origin to the second position other than the origin is not high. For example, in FIG. 11, it is assumed that the general-purpose encoder is in the first position (the original rotation angle is θA1, and the shaft rotation angle is θS1 in the general-purpose rotary encoder that does not have strict absolute accuracy). When a command is issued to rotate from this state to the second position (the original rotation angle is θA2), the axis changes from the rotation angle θS1 to θS2 when a general-purpose rotary encoder that does not have strict absolute accuracy is used. Rotate. According to the brushless DC motor that employs the general-purpose encoder of this embodiment, positioning from θA1 to θA2 with high absolute accuracy is performed without accumulating such errors.
As described above, when the general-purpose rotary encoder 100 of the present embodiment is applied to a motor or a rotating body of various devices as a product after undergoing initial setting processing, the general-purpose sensor has a height comparable to that of a standard sensor. Used as an accuracy sensor.

Next, with reference to FIG. 12, the DC motor to be controlled by the general-purpose rotary encoder in which the initial setting of the output type 2 shown in FIG. 4B is set based on the first embodiment during normal operation. The process will be described. Incremental A, B, and Z signals are acquired by a general-purpose rotary encoder (S1201), and this data is calibrated with calibration data (S1202). The proofread data is recorded and updated in EEPROM as incremental data (S1203). Then, the incremental A, B, and Z signals are output to the motor (S1204), and the process ends with the end of the operation (S1205).
In this example as well, when the general-purpose rotary encoder 100 of this embodiment is applied to a motor or a rotating body of various devices, the general-purpose sensor is used as a high-precision sensor comparable to a standard sensor.

Next, with reference to FIG. 13, during normal operation of the brushless DC motor to be controlled by the general-purpose rotary encoder in which the initial setting of the output type 3 shown in FIG. 4C is made based on the first embodiment. The processing of is explained.
That is, the general-purpose rotary encoder 100 acquires the calibrated A-phase / B-phase signal and Z signal from the general-purpose encoder via the RAM (S1301), and uses a calibration table based on the output of the standard sensor. Then, the incremental data of the general-purpose rotary encoder is calibrated (S1302). The software in the general-purpose encoder 100 (U, V, W signal generation / recording unit 137 during normal operation) generates U-phase, V-phase, and W-phase drive signals (S1303) and outputs them to the BLCD controller 240. , Drives a brushless DC motor. The U-phase, V-phase, and W-phase pulses / rotation corresponding to the drive signal are acquired from the encoder memory 160 that has been calibrated by the initial setting of the general-purpose encoder (S1304), and the Z-phase width signal is further acquired. (S1305), thereby acquiring the Z-phase signal (Z1, Z2, −, −, Zn) data shown in FIG. 9, that is, the multi-rotation data (S1306). Further, the rising edge of the U phase is synchronized with the absolute origin position (Z0) of the rotation axis (S1307). Then, based on the incremental cumulative addition value, the address of the EEPROM is assigned (S1308), and the EEPROM is recorded / updated as incremental data via the RAM (S1309). The calibrated incremental data of this EPROM is output to the motor controller 240 and the motor driver 242 in parallel with the A, B, Z signals and the U, V, W signals (S1310).
This process is repeated to end the operation (S1311).

As described above, the brushless DC motor that employs the general-purpose rotary encoder of this embodiment operates as a servomotor having a high-precision rotary encoder function during normal operation.
By supplying the calibrated A, B, Z signals and the U, V, W signals in parallel to the motor controller 240, etc., the motor controller 240 can quickly transmit the signals necessary for controlling the brushless DC motor. It can be generated and output to the driver.
Further, it is possible to provide a high-precision and inexpensive general-purpose rotary encoder capable of supporting an arbitrary output format by using one high-precision rotary encoder.

As another embodiment of the present invention, a rotary encoder (standard sensor) having high absolute accuracy is used to output signals corresponding to not only A, B, and Z phases but also U, V, and W phases. You can also do it. An example of this will be described with reference to FIG.
FIG. 14 shows an example of a functional block of a general-purpose rotary encoder and an initial setting controller when not only A, B, Z phase data but also U, V, W phase data can be obtained as the output of the standard sensor 300. It is a figure which shows.
In this example, a case where the user selects the output method selection unit 139 of the encoder corresponding to the output type 1 of FIG. 4A will be described.
The initial setting controller 800 forms a fifth information transmission path between the data recording unit 181 of the standard sensor and the U, V, W signal generation / recording unit 184 in the initial setting. Therefore, the U, V, W signals at the time of initial setting are generated by the U, V, W signal generation / recording unit 184 using the output of the standard sensor 300 as it is (without calibration), and the data is generated. It is recorded in the absolute encoder output / recording unit 186.
The data of the first data recording unit 180 is calibrated based on the data of the data recording unit 181 of the standard sensor in the first calibration 176, and the calibrated A, B, Z signals are sent to the absolute encoder output / recording unit 186. Recorded.
When the initial setting of the general-purpose rotary encoder 100 is completed, the initial setting controller 800 opens the information transmission path between the standard sensor 300 and the data recording unit 181 of the standard sensor. In this case, the U, V, W signal generation / recording unit 184 generated U, V, W signal data based on the U, V, W signals recorded in the data recording unit 181 of the standard sensor is the first. Synchronized with the A, B, Z phase data based on the output of the general-purpose sensor (110, 120) calibrated by calibration 176, U, V, W signals for normal operation are generated, and the absolute encoder output. It is recorded in the recording unit 186.
In addition, the configuration of FIG. 14 is partially changed, and the A, B, Z signals which are the outputs of the general-purpose sensors (110, 120) are converted into the second data recording unit 178 of the general-purpose rotary encoder as shown in FIG. 4A. Based on the A, B, Z signals and the U, V, W signals recorded in the data recording unit 181 of the standard sensor, the U, V, W signal generation / recording unit 184 operates normally. The calibrated U, V, and W signals for use may be generated and recorded in the absolute encoder output / recording unit 186.
The data of the absolute encoder output / recording unit 186 is recorded in the encoder memory, and the A, B, Z signals and the U, V, W signals are output in parallel to the motor controller 240 and the motor driver 242. To.

When the user selects another output type, a predetermined information transmission path is formed as in the examples described in FIGS. 4B and 4C, and a predetermined output from the general-purpose rotary encoder 100 is a motor controller 240. Is output to the motor driver 242.
According to this embodiment, it is possible to provide a rotary encoder having high accuracy comparable to that provided with a high accuracy sensor, excellent in environmental resistance, and inexpensive.
Further, it is possible to provide a high-precision and inexpensive general-purpose rotary encoder capable of supporting an arbitrary output format by using one high-precision rotary encoder.

In each of the above embodiments, the case where the absolute origin position (Z0) of the rotating shaft is known in advance has been described, but there is also a case where the absolute origin position (Z0) of the rotating shaft of the brushless DC motor dedicated to the initial setting is unknown. is there. In this case, after determining the temporary origin position of the rotating shaft in advance and generating various data, the absolute origin position of the rotating shaft of the brushless DC motor is separately obtained, and the angle between the temporary origin position and the absolute origin position is obtained. The phase difference of is obtained, and the above-mentioned various data are corrected. The process of obtaining the absolute origin position (Z0) of the shaft of the brushless DC motor and the processing of the phase difference of angles will be replaced with detailed explanations by quoting the description of Patent Document 1. Needless to say, other known means may be used.

100 General-purpose rotary encoder 110 Magnet unit 111 Magnet holder 112 Hollow part 113 Magnet 114 Fixing means 120 Sensor output processing unit 121, 122 Pair of MR sensors (magneto resistive sensor)
130 Encoder control unit 139 Encoder output method selection unit 160 Encoder memory 170 Communication interface 172 SSC-BUS converter 174 SPI-BUS converter 176 First calibration 178 Second data recording unit of general-purpose encoder 180 Second general-purpose encoder Data recording unit 181 Standard sensor data recording unit 182 Second calibration 184 U, V, W signal generation / recording unit 186 Absolute encoder output / recording unit 200 Brushless DC motor 203 rotary shaft 210 motor housing 222 dedicated to initial setting Permanent magnet 228 Signal line 240 Motor controller 242 Motor driver 250 Housing cover 300 Optical rotary encoder 304 Casing 305 Bearing 306 Rotating board 311 Light emitting element 308 Aperture 309 Lens 312 Slit pattern 314 Light receiving element 316 Controller 400 User terminal ( Input / output terminal)
800 initialization controller

Claims (6)

A general-purpose sensor mounted on the motor to detect the rotation angle of the rotation axis of the motor,
A rotation angle detection unit that outputs information on the rotation angle of the rotation axis of the motor based on an output signal from the general-purpose sensor, and a rotation angle detection unit.
A general-purpose rotary encoder including an encoder control unit that generates and outputs a signal for driving the motor based on the rotation angle information.
The encoder control unit has a function of driving a motor for initial setting and
An initial setting data acquisition unit that acquires initial setting data unique to the general-purpose sensor,
A normal operation data acquisition unit that acquires and generates data for normal operation used when the motor to be controlled equipped with the general-purpose rotary encoder is normally operated.
Encoder output method selection section and
It is equipped with an encoder memory that holds calibration data for calibrating the initial setting data unique to the general-purpose sensor.
For the calibration data, a sensor whose absolute accuracy is guaranteed to be two or three orders of magnitude higher than that of the general-purpose sensor is used as a standard sensor, and the general-purpose sensor and the standard sensor are simultaneously connected to the motor for initial setting. It is the calibration data regarding the rotation angle of the rotation axis obtained by driving at least one forward and reverse rotation.
The output method selection unit of the encoder has a function of selecting an output method of either absolute data or incremental data as the output method of the general-purpose rotary encoder.
The normal operation data acquisition unit acquires and generates data for normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. A featured general-purpose rotary encoder. In the general-purpose rotary encoder according to claim 1,
The output method selection unit of the encoder has a function of selecting whether or not to include data for a motor drive signal as the output method of the general-purpose rotary encoder.
The normal operation data acquisition unit acquires and generates data for the normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. A general-purpose rotary encoder featuring. In the general-purpose rotary encoder according to claim 2.
The output method selection unit of the encoder has a function of selecting either a multi-rotation rotation angle or a one-rotation rotation angle of the rotation shaft.
The normal operation data acquisition unit acquires and generates data for the normal operation obtained by calibrating the output of the general-purpose sensor with the calibration data in accordance with the selected output method, and holds the data in the encoder memory. A general-purpose rotary encoder featuring. In any one of claims 1 to 3,
One information transmission path for transmitting information necessary for generating A, B, Z signals which are outputs of the general-purpose rotary encoder between the general-purpose sensor and the encoder memory, and an output of the general-purpose rotary encoder. There are other information transmission paths for transmitting information necessary for generating U, V, W signals, and the A, B, Z signals and the U, V, W signals are transmitted from the general-purpose rotary encoder. A general-purpose rotary encoder characterized in that is configured to output in parallel. In any one of claims 1 to 4,
The calibration data is
A first calibration provided in the one information transmission path for transmitting the A, B, Z signals and calibrating the A, B, Z signals with the output data of the standard sensor.
A second calibration provided in the other information transmission path for transmitting information necessary for generating the U, V, W signal and calibrating the U, V, W signal with the output data of the standard sensor. A general-purpose rotary encoder characterized by having. In any one of claims 1 to 5,
A general-purpose rotary encoder characterized in that the one information transmission path for transmitting information necessary for generating the A, B, and Z signals includes an SSC-BUS converter and an SPI-BUS converter.

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