JP2002286500A - Positioning device, brushless dc motor, and their manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity of a positioning device while maintaining the measurement accuracy of the positioning device. SOLUTION: A zero offset Δθ can be defined as the amount of displacement (one-dimensional vector) of the amount of positioning θ between the location of a temporary origin (S=4u+2v+w=1, θ=0 deg.) assumed on the basis of the phase of a divided phase S constituted of three phases of a u-phase, a v-phase, and a w-phase and a true origin θ0 located on an origin signal (origin mark) in Fig. The value of the zero offset Δθ is expressed with the true origin θ0 as a reference (starting point) and with the positive direction of an electrical angle θ as it is. The zero offset Δθ is measured at the start of the positioning device and, for example, used as the amount of correction to the electrical angle θ when controlling the passage of electricity through a motor. By eliminating the need for executing conventional physical alignment in this way, it is possible to shorten manufacturing time of an encoder, a linear scale, a brushless DC motor, etc., reduce production cost, and improve productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-dimensional displacement measuring device for measuring a rotation angle or a position of a moving body by detecting phase information periodically set on a measured object. Such a one-dimensional displacement amount positioning device can be used, for example, as an encoder or a linear scale. In addition, if an encoder composed of such a positioning device is used, a brushless DC motor or a motor control device having the operation and effect of the present invention, and further provided with these devices, for example, the operation and effect of the present invention It is possible to configure an electric power steering device and the like having the above.

[0002]

2. Description of the Related Art As a conventional encoder whose positioning at the time of assembly is relatively easy, for example, an encoder described in Japanese Patent Laid-Open Publication No. Hei 6-311718: Magnetic encoder for brushless motor is generally known. Have been. These prior arts form a pair of “goal marks” that can be relatively moved or rotated in the positioning direction, and match the “goal marks” by physical alignment to obtain a positioning amount ( It is intended to suppress the occurrence of a detection error relating to the movement amount or the rotation angle). Further, unless such a detection error relating to a positioning amount is suppressed, a positioning device (encoder, linear scale, or the like) satisfying a desired measurement accuracy cannot be manufactured, or desired angle control or position control cannot be performed. Needless to say.

[0003]

However, in order to carry out the above-mentioned "physical alignment", a certain or more work time or adjustment time is always required. Therefore, even if such a physical alignment process could be performed mechanically or automatically, the intervention of this alignment process would cause the manufacture of a positioning device such as an encoder, a brushless DC motor, and the like. In this case, the manufacturing time is increased, and further improvement in productivity is hindered. In addition, in order to perform “physical alignment” such as origin adjustment, an adjustment mechanism for the adjustment is required, which increases the number of parts of the apparatus and causes a cost increase.

[0004] Further, if a desired measurement accuracy is not obtained in the encoder, for example, in the case of a brushless DC motor configured using such an encoder, a sufficient torque cannot be obtained because the motor control cannot be performed accurately. Unable to output, variation in output torque of each product,
This is not desirable because the output torque varies depending on the rotation direction of the motor. Also, in the case of a linear motor using a linear scale, if the desired measurement accuracy is not obtained, sufficient acceleration may not be obtained, or the acceleration may differ depending on the traveling direction. Inconvenience may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to eliminate the necessity of performing the above-mentioned "physical alignment", thereby providing an encoder and a linear scale. Another object of the present invention is to improve the productivity of a positioning device while maintaining the measurement accuracy of the positioning device high. A further object of the present invention is to suppress defects, quality variations, or prices of various products to which the positioning device is applied, such as a brushless DC motor and an electric power steering device.

[0006]

Means for Solving the Problems, Functions and Effects of the Invention In order to solve the above-mentioned problems, the following means are effective. That is, the first means is a positioning device that measures the rotation angle or the position of the moving body by detecting the phase information of the “measuring phase I” periodically set on the measured object. This is to provide a recording medium in which “origin information” indicating the position of the reference point θ0 of the positioning amount θ of the positioning device fixed in the process is recorded after the above-described assembling process.

However, any means for expressing the phase information such as the "phase measurement I" and the "origin information" may be used. That is, the means for expressing these phase information may be based on the magnetism of a magnetized recording medium, may be based on irregularities on a storage medium such as a compact disk, or may be based on a mirror surface or the like. A device for controlling reflection may be used. That is, in general, any recording medium can be used as long as it can hold information expressed by physical quantities that can be converted into electric signals.

According to the first means, the "origin information" indicating the position of the reference point .theta.0 of the positioning quantity .theta. Of the positioning device fixed by assembling the positioning device is stored. , It is possible to dynamically or in real time correct the positioning amount θ at the time of positioning. Further, such correction processing based on the “origin information” does not necessarily have to be performed dynamically or in real time. For example, a “phase adjustment or zero point adjustment” relating to phase information or the like is performed in advance.
For example, it is also possible to carry out the measurement before the measurement.

By performing the above logical correction processing as an alternative, it is not necessary to perform the "physical position adjustment" such as the origin adjustment based on the "match mark" or the like, which has been conventionally performed. Because of these, the manufacturing time is shortened, the productivity of the device is improved, and an adjusting mechanism is not required. Therefore, the device can be manufactured at low cost or in a shorter time than before.

A second means is the first means, wherein the recording medium is capable of holding at least information represented by a physical quantity convertible into an electric signal without power. It consists of a medium.

[0011] As such a so-called nonvolatile recording medium, for example, an EEPROM or the like can be used.
More generally, any of these recording media may be used as long as it is a "recording medium capable of holding information expressed by a physical quantity that can be converted into an electric signal without power". Therefore,
For example, the deviation amount (correction amount) of the reference point θ0 (origin) may be stored using a variable resistor or the like as a resistance value or the like in proportion to the deviation amount.

According to the second means of the present invention, "origin information" (the correction amount and the like) is obtained once after the positioning device is assembled, and the content is stored in the recording medium. After that, it is possible to perform the above correction continuously unless some kind of failure occurs in the positioning device itself, replace the above recording medium, or reassemble the positioning device. Become. In this case, the positioning of the reference point θ0 at which the moving body should be located at the time of starting the positioning device or the like is performed again by mechanical or electrical means,
"Pre-processing" for re-calculating "Origin information" (above correction amount, etc.)
Is not necessary, so that the initial control immediately after the positioning device is started can be easily and quickly performed.

[0013] A third means is that, in the first means, the recording medium comprises a volatile storage medium. According to this means, the above-described recording medium can be configured by using only the primary storage device (volatile storage medium) provided in the control device (computer) of various positioning devices such as the motor control device. it can. Therefore, using the third means, the above-mentioned “origin information” (the above-mentioned correction amount) is rotated every time the positioning device is started (at the time of initial movement).
If, for example, it is necessary to replace the parts, etc. in accordance with the repair of the positioning device itself, or when re-assembling the positioning device, no new special measures are required, The positioning control based on the above correction can be continuously performed as before the repair.

[0014] The fourth means may be the first or second means.
In the means, the recording medium is constituted by at least the object to be measured. That is, since the phase information of the “measurement phase I” is set on the measured object of the positioning device of the present invention as described above, the phase information is simultaneously or simultaneously with the phase information. In an additional form, the above-mentioned “origin information” can be stored on the above-mentioned measured object in the same manner as these phase information.

For example, when the object to be measured is a rotating body such as a rotor of a motor, the phase information of the "measuring phase I" is obtained from a magnetic recording medium or the like provided on the surface of the rotating body. Can be recorded on the magnetic recording medium or the like at the same time as the above-mentioned “origin information” as well as the phase information.
Can be stored. According to such a configuration, an additional external storage device is not required, and the once stored “origin information” (the above correction amount) does not evaporate.
There is no need to rotationally obtain the “origin information” every time the positioning device is activated (initial movement).

The fifth means includes the first to fourth means.
In any one of the means, the object to be measured is provided with a “divided phase S” that indicates the positioning amount θ stepwise in a predetermined width unit larger than the measurement accuracy of the positioning amount θ.

Such a "split phase S" is useful for detecting the approximate position of the above-mentioned moving body (rotating body or translation body), and in particular, it is difficult to detect the current clear position. "Initial control at the time of device startup", or alternative control such as at the time of abnormality when the phase information of "phase measurement I" cannot be detected,
Alternatively, it can be used for an abnormality detection process or the like based on a process of verifying consistency between the “phase measurement I” and the “split phase S”.

In a sixth aspect, in the fifth aspect, the recording medium comprises at least an object to be measured, and the origin information is recorded with the phase adjusted or zero adjusted. Is uniquely expressed by the phase information of the divided phase S.

According to such a means, the phase information of the divided phase S is newly recorded as a phase state in which the correction amount is 0, so that it is the same as the conventional "physical alignment". Can be obtained without performing the conventional “physical alignment”. Therefore, according to the sixth means, it is not necessary to dynamically execute the correction processing, and therefore, it is possible to control the positioning apparatus of the present invention with the same control algorithm as that of the related art. The operation and effect of this means will be described in more detail in the "third embodiment" of the present invention.

[0020] The seventh means may be the fourth or fifth means.
In the means, the recording medium is composed of at least the object to be measured, and the origin information is uniquely represented by an “origin mark” written at a position corresponding to or coincident with the reference point θ0.

For example, in the above-mentioned fourth means, when the "origin mark" is written at a position corresponding to the above-mentioned reference point .theta.0, the positioning amount .theta. The value may be set to 0 at the position where the “origin mark” is detected. However, this constant "0"
May be another predetermined constant. Even by such means, a desired positioning amount θ can be accurately measured without performing “physical alignment”.

The eighth means is the seventh means, wherein the above-mentioned recording medium is divided into a predetermined width unit, which is sufficiently larger than the measurement accuracy of the positioning amount θ, to represent the positioning amount θ stepwise. S ”, and the above-mentioned origin mark is expressed by an exception signal of the divided phase S. Such an exception signal may be set, for example, such that the value of the detected phase signal becomes a non-standard value, or such that the state transition of the detected phase signal becomes a non-standard state transition. It can be configured by making settings.

According to such a means, the origin mark can be defined without further adding another phase in the positioning device having the above-mentioned "split phase S". Therefore, for the purpose of simply detecting the origin mark,
There is no need to extend or improve means such as a sensor for detecting a phase signal. Therefore, according to this means, manufacturing of a device (hardware) in a positioning device having a "split phase S" Cost can be sufficiently suppressed.

In a ninth aspect, in accordance with the eighth aspect, the divided phase S is defined as a total of three of a u phase, a v phase, and a w phase.
And the above-mentioned origin mark is represented by “(u, v, w) =
(0, 0, 0) or (u, v, w) = (1, 1,
1)). There are many other methods for configuring the above-described exception signal of the divided phase S.
For example, the exception signal of the divided phase S can be simply configured by such means.

A tenth means is that, in the seventh means, the origin mark is represented by an exception signal of the phase measurement I. Such an exception signal may be set, for example, such that the value of the detected phase signal becomes a non-standard value, or such that the state transition of the detected phase signal becomes a non-standard state transition. It can be configured by making settings.

According to such a means, even in a positioning device having no "divided phase S", an origin mark can be defined without adding another separate phase, as described above. Therefore, there is no need to extend or improve means such as a sensor for detecting a phase signal for the purpose of simply detecting the origin mark.
According to this means, the manufacturing cost of the device (hardware) in the positioning device having the “split phase S” can be sufficiently suppressed.

An eleventh means according to the tenth means, wherein the measured phase I comprises a total of three phases of a u phase, a v phase and a w phase, and the origin mark is set to "(u , V,
w) = (0,0,0) or (u, v, w) = (1,
1, 1)). There are many other methods for configuring the above-described exception signal of the phase measurement I. For example, such a means can easily configure the exception signal of the measurement phase I.

The twelfth means is the device according to any one of the seventh to eleventh means, wherein the width of the origin mark in the positioning direction of the positioning amount θ is determined by the positioning direction of the phase information of the phase I. , The setting accuracy, or the measurable minimum unit α of the positioning amount θ.

As a method of expressing the position of the reference point θ0 (origin), for example, a method of expressing more strictly using a rising point or a falling point of the phase information of the origin mark, or a middle point of the two, or the like. However, according to the above-described means, for example, the position of the reference point θ0 (origin) can be expressed by a relatively simple method and with relatively high accuracy.

Further, the origin mark is made thin (short) in this manner.
By setting, the program of the abnormality detection processing based on the check processing of the output value of the “split phase S” or the verification processing of the consistency between the “phase measurement I” and the “split phase S” ( (Extension or modification) or execution, the influence of the above-mentioned origin mark on these programs can be limited to a minimum range, and furthermore, a phase signal representing the origin mark and an abnormal condition relating to a disconnection / short circuit, etc. It is possible to prevent or minimize the decrease in the detection accuracy or the detection speed of the abnormality detection due to the combined use with the detection signal at the time.

The length (width) of the origin mark in the positioning direction
Is too long, the position of the origin (reference point θ0) may be uncertain. In such a case, the origin may be clearly defined using the rising point and the falling point of the origin mark, or the middle point between the two, but the origin specification processing becomes slightly complicated, and the abnormality detection is performed. It is difficult to obtain the above-described functions and effects, such as suppressing a decrease in the detection accuracy. If the length (width) of the origin mark in the positioning direction is too short, the origin mark may not be detected.

The thirteenth means corresponds to any one of the seventh to twelfth means, wherein the thirteenth means corresponds to the reference point θ0 based on a predetermined positional relationship, and is substantially similar to the origin mark. Is provided with another “reference point mark” corresponding to the origin mark.

According to such a means, since the average time until the origin mark or the reference point mark is first detected at the time of the initial movement is shortened, the accurate positioning amount θ can be obtained from an earlier stage immediately after the positioning device is started. It becomes possible to output.

In a fourteenth aspect, in any one of the first to thirteenth aspects, the position of the moving body associated with a predetermined steady magnetic field formed around the moving body is determined based on the origin information. It is to indicate the position where the energy is minimum or minimum. Conversely, the origin information may be determined or defined based on the position information of the position where the potential energy is minimum or minimum.

For example, in the case of a brushless DC motor, such a position where the potential energy is minimum or minimum can be obtained by applying a DC current to the motor and fixing the rotation angle of the rotor at a certain fixed position. Can be. Also,
When the rotor is formed of a permanent magnet, for example, such positioning may be performed using a permanent magnet instead of a DC current. The same means can be used for a linear scale. That is, according to such means, the position of the reference point θ0 can be determined by a positioning operation with high objectivity and reproducibility.

There may be a plurality of positions where the potential energy becomes minimum or minimum depending on the configuration of the moving body and the like. Therefore, in such a case, an appropriate one may be selected from those positions, or the above thirteenth means and the fourteenth means may be combined, for example. A positioning device having another “reference point mark” may be configured.

A fifteenth means is the apparatus according to any one of the fourth to fourteenth means, wherein the recording medium is constituted by at least the object to be measured, and origin information is recorded on the object to be measured. And a device for reading the origin information from the object to be measured is to be constituted by the same or integrated device.

According to such a means, when the positioning device is disassembled and reassembled again at the time of repairing the positioning device, a "dedicated writing device" for recording the origin information on the measured object is unnecessary. Becomes Also, in any other case, the origin information can be easily recorded again on the measured object. Therefore, under such a configuration, the degree of freedom regarding the process or timing of recording the origin information on the measured object can be significantly increased.

According to such a means, even when the positioning device is manufactured, after the origin information is recorded on the object to be measured, the device for recording the origin information on the object to be measured and the origin information are transmitted from the object to be measured. Since there is no need to replace the readout device, the manufacturing time can be further reduced.
Such a configuration is particularly effective when the price difference between a “dedicated reading device (component)” for reading the origin information from the measured object and a device (component) that can perform both reading and writing is relatively small. .

The sixteenth means includes a linear scale for measuring the position of the moving body that translates as a positioning amount θ.
The present invention is configured by a positioning device using any one of the first to fifteenth means. By such means, a linear scale with high measurement accuracy can be manufactured at a lower cost than before or in a shorter time than before.

The seventeenth means uses an encoder for measuring the rotation angle of a rotating body (rotating body R) as a positioning amount θ by using any one of the first to fifteenth means. It consists of a positioning device. By such means, an encoder with high measurement accuracy can be manufactured at a lower cost than before or in a shorter time than before.

According to an eighteenth aspect, in a brushless DC motor, the encoder according to the seventeenth aspect is provided, and a rotor is constituted by the rotating body R, and the rotor is formed based on a rotation angle detected by the encoder. Brushless D
That is, the drive control of the C motor is performed. By such means, a brushless DC motor with high control accuracy and small variations in output torque of each product can be manufactured at a lower cost than in the past or in a shorter time than in the past.

According to a nineteenth means, in the motor control device for driving and controlling the brushless DC motor according to the eighteenth means, the brushless DC motor is driven and controlled based on the origin information. is there. By such means, a motor control device with high control accuracy can be manufactured at a lower cost than in the past or in a shorter time than in the past.

A twentieth means uses the phase information of the divided phase S in the initial operation control, alternative control, or abnormality detection processing of the brushless DC motor in the motor control device of the nineteenth means. is there.

Such a "split phase S" is useful for detecting the approximate position of the moving body (rotating body).
It is difficult to detect the current clear position, such as “initial operation control at the time of device startup”, or “alternative control in the event of an abnormality in which the phase information of“ phase measurement I ”cannot be detected”, or “phase measurement I” and “ This is very useful because it can be used for abnormality detection processing based on verification processing of consistency with the “divided phase S”.

A twenty-first means is the recording medium and the rotator R according to the nineteenth or twentieth means.
Is composed of the object to be measured having the above-mentioned "phase measurement I", "division phase S" and "origin mark", and when the brushless DC motor is initially operated, a predetermined position of the division phase S and the origin mark are set. This is to execute an initial process for obtaining the rotation angle difference Δθ.

If the rotation angle difference Δθ is obtained in this way, information (origin information) equivalent to the origin mark can be obtained for the edge of the divided phase S (the rising point or the falling point of the phase).
Can be provided. The operation and effect of this means will be described in more detail in the "first embodiment" of the present invention.

A twenty-second means according to the nineteenth or twentieth means, wherein the recording medium is formed of a volatile storage medium, and is provided around the rotating body R at the time of the initial operation of the brushless DC motor. A predetermined stationary magnetic field is formed, and by detecting the position where the potential energy of the rotating body R accompanying the stationary magnetic field is minimum or minimum, the initial processing for obtaining the origin information and storing the information in the volatile storage medium is performed. It is to be.

By using this means to obtain the above-mentioned "origin information" (the above-mentioned correction amount) every rotation when the positioning device is started (initial movement), for example, the positioning device itself can be repaired. Even if the parts etc. are replaced or the positioning device is reassembled in accordance with the above, the correct "origin information" is newly updated each time it is started, so the above correction must be performed continuously. Becomes possible. The operation and effect of this means will be described in more detail in the "second embodiment" of the present invention.

According to a twenty-third means, an electric power steering device mounted on a vehicle includes the motor control device according to any one of the nineteenth to twenty-second means. By such means, it is possible to manufacture an electric power steering device with high control accuracy and a small variation in output torque for each product and a small variation in steering feeling between left and right at a lower cost than in the past or in a shorter time than in the past. Can be done.

The twenty-fourth means has means for detecting phase information of "phase measurement I" periodically set on the object to be measured, and is applied to an encoder, a linear scale, a brushless DC motor, or the like. “Origin information” indicating the position of the reference point θ0 of the positioning amount θ of the positioning device fixed in the assembling process of the positioning device in the manufacturing process of the possible positioning device.
Is provided on a predetermined recording medium or an object to be measured after this assembling step.

However, since the “origin information recording step” can be performed from the stage where the position of the reference point θ0 of the positioning amount θ of the positioning device is fixed, the above “assembly step” is referred to as the “positioning device”. The step of fixing the position of the reference point θ0 of the positioning amount θ ”. Therefore, the process of assembling parts that do not directly affect such fixing of the position is performed after the above-mentioned “origin information recording process” or performed in parallel with the above “origin information recording process”. Is also good.

By such a method of manufacturing a positioning device, it is possible to actually manufacture a device constituted by any one of the above-described first to twenty-third means.
That is, for the first time by such a method of manufacturing a positioning device,
Any one of the first to twenty-third means can be specifically realized. The above means can effectively solve the above-mentioned problem.

[0054]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on specific embodiments. However, the present invention is not limited to the embodiments described below. (First Embodiment) FIG. 1 is a graph (a) showing a relationship between an electric angle θ (positioning amount θ) and a divided phase S (phase signal S) according to each embodiment of the present invention, and this phase signal. 5 is a definition table (b) of S.

As can be seen from the above-mentioned prior art, there is known an encoder having phase information (division phase S) representing the electric angle θ in steps of a predetermined width sufficiently larger than the measuring accuracy of the electric angle θ. Also, in the brushless DC motor 100 according to the first embodiment, such a “split phase S” includes the sensor rotor R made of a plastic magnet (magnetic material).
(FIG. 2) It is composed of a total of three phases of u-phase, v-phase, and w-phase.

FIG. 2 is a cross-sectional view of the brushless DC motor 100 according to the first embodiment in an origin signal writing step. The sensor rotor R (measurement object) on which the “split phase S” described above and the “measurement phase I” periodically set to obtain the positioning amount θ are recorded around the circumference of the motor shaft 3. Glued across. Window part 2 of motor housing 4
The origin signal (origin mark) can be written to the sensor rotor R by using the origin signal writing device 5 which is positioned by fitting into the sensor rotor R.

FIG. 3 is a developed plan view of the outer side surface of the sensor rotor R of the brushless DC motor 100. In this figure, the magnetized portion is represented by shading, but actually, even in a blank portion where the magnetized symbol of each phase is not drawn, the output difference (on / off difference) is increased. , A magnetic signal in the opposite direction is written. Origin offset Δ
θ is a divided phase S composed of three phases of a u phase, a v phase, and a w phase.
Of the hypothetical origin (S in FIG. 1A)
= 1, θ = 0 °) and the displacement (one-dimensional vector) of the positioning amount θ between the true origin θ0 located on the origin signal (origin mark) in FIG. . In addition, the value of the origin offset Δθ is such that the positive direction of the electrical angle θ is directly expressed as a positive direction with the true origin θ0 as a reference (start point).

The origin offset Δθ can be used as a correction amount for the electric angle θ when performing the motor energization control. Instead of directly correcting the electrical angle θ itself, other boundary values or the like directly related to the electrical angle θ may be corrected. Since these relations are relative, which correction means is adopted is arbitrary. Usually these means are:
The selection may be made in consideration of the amount of program correction, the maintenance and expandability of the program, and the like.

The above-described measurement phase I is composed of the two-phase incremental phase shown in FIG. 3, and the graph of FIG. 4A shows the positioning amount θ defined by the incremental phase (phase measurement I). Shows the relationship between the minimum measurable unit α and the phase signal (region signal C). The table in FIG. 4B is a definition table of the phase signal C. For example, by forming the incremental phase (measuring phase I) by the A phase and the B phase in this way, the positioning amount (electric angle) θ is expressed by the following equation (1).

## EQU1 ## θ = θ0 + dα (d is an integer) (1) Generally, the value of θ0 is arbitrary, but in the present specification, θ0 = 0 ° for simplicity. For example, as described above, if the above natural number d is measured based on the phase of the detected incremental phase, the electrical angle θ of the sensor rotor R can be obtained with an accuracy of α.
Can be measured.

FIG. 5 is a flowchart illustrating an outline of an assembling procedure of the brushless DC motor 100 according to the first embodiment. In this procedure, first, a bearing (not shown) and the motor shaft 3 are inserted into the motor housing 4 of FIG. 2, and the rotation axis direction of the sensor rotor R is fixed in a freely rotating state (the manufacturing process S10). ).

Next, in the manufacturing step S20, the brushless D
A predetermined DC current is supplied to the C motor 100 to fix the angle of the sensor rotor R at a predetermined position. That is, a predetermined stationary magnetic field is formed around the sensor rotor R (moving body), and the sensor rotor R is fixed at a position where the potential energy of the sensor rotor R associated with the stationary magnetic field is minimum or minimum. Hereinafter, such a manner of fixing the moving body (sensor rotor R) may be referred to as “electric lock”.

Next, in the manufacturing step S30, as shown in FIG. 2, the sensor rotor R is attached to the sensor rotor R by using the origin signal writing device 5 which is fitted and positioned in the window portion 2 of the motor housing 4. An origin signal (origin mark) is written as illustrated in FIG. At this time, if the value of “u + v + w” at the position of the determined reference point θ0 is 2 due to the above electric lock, a signal (u, v, w) = (1, 1, 1) (exception signal ) Is the phase signal of the origin mark. The value of “u + v + w” at the position of the reference point θ0 is 1
In this case, a signal (exception signal) of (u, v, w) = (0, 0, 0) is used as the phase signal of the origin mark.

With such a setting, as shown in FIG. 3, it is possible to form the "origin mark" by inverting only the phase information of only one of the u-phase, v-phase and w-phase. It becomes possible. Therefore, if such a configuration is adopted, it is not necessary to use a device capable of simultaneously writing three or two phases as the origin signal writing device 5 used in the above-described manufacturing process S30. Further, with such a configuration of the origin mark, it is possible to minimize changes to the three-phase information of the u-phase, v-phase, and w-phase, so that changes to the conventional control program are also minimized. It can be suppressed.

Next, in a manufacturing step S40 (FIG. 5), the origin signal writing device 5 used in the above-described manufacturing step S30 is detached, and thereafter, as shown in a sectional view of FIG. Assemble. According to the manufacturing process as described above, it is not necessary to perform the “adjustment process for physical alignment” which has been conventionally performed.

Hereinafter, a brushless D having such a configuration will be described.
A motor control method applicable to the motor control device that controls the C motor 100 will be described. FIG.
3 is a control block diagram illustrating a logical configuration of a motor control device that drives and controls the brushless DC motor 100 according to the first embodiment. This motor control device performs brushless DC control by known PI control (proportional / integral control) or the like.
The drive control of the motor 100 is performed by the three-phase drive current.

In this figure, the brushless D which is composed of the motor housing 4 shown in FIG.
The main part of the C motor 100 is represented by M. Also, i
df indicates a feedback value of the magnetizing current id, and iqf indicates a feedback value of the torque current iq, respectively.
The torque adjustment coefficient R is 1 when it is normal, but is a control parameter that is gradually or instantaneously changed from 1 to 0 when an abnormality occurs.

FIG. 8 is a time chart exemplifying the timing of switching of the energization method when driving the brushless DC motor 100. (Symbol) Δθ: Origin offset (see FIG. 3) ev0: First input event after power-on for pulse (phase signals of phase measurement I and divided phase S) evI ... Edge of divided phase S (rising point or rising edge) First detection event after power-on for falling point) evII ... First detection event after power-on for reference point θ0 (origin position) sw1 ... Energization method control flag sw1 = 0: rectangular wave energization is performed based on S Mode mode in which sine wave energization is executed based on mode sw1 = 1: θ

When the brushless DC motor 100 is energized, the above events ev0 and ev that occur immediately after the power is turned on.
The chronological order of I and evII is as shown in FIG. 8 (a) and (b).
It can be roughly divided into streets. When edge detection (determination) is performed by software, the determination is performed based on the results (state transition status) of two consecutive pulse inputs (each phase signal input of the phase measurement I and the divided phase S). Therefore, the event ev0 and the event evI are not detected at the same time. However, since the determination of the origin mark is performed based on the result of one pulse input, the event ev0 and the event evII may be detected at the same time. Therefore, in such a case, the rectangular wave energization (sw) shown in FIG.
The control period of (1 = 0) can be omitted from the beginning.

It should be noted that the above-described rectangular wave energizing method is known, and when such rectangular wave energizing is performed, for example, “0, ± 0.8”
A rectangular wave that approximates a sine wave very roughly with only three values such as “6” is used. Usually, when such a rectangular wave is used, for example, when controlling a three-phase motor, in controlling the motor drive current, the phases of each of the U, V, and W phases are mutually shifted. A method is used in which power is supplied to each phase at intervals of 1/3 cycle (120 ° in terms of electrical angle θ). Such an energization method can be adopted as a so-called "initial motion control" until a predetermined reference point θ0 (origin) or another predetermined reference point such as a predetermined edge is first detected.

The above-mentioned "sine wave energization" is an energization method in which an energization waveform is formed and power is supplied by approximation with high precision of the measurable minimum unit α of the positioning amount θ. Also,
The sine wave energization 1 in FIG. 8A temporarily assumes “Δθ = 0” until the value of Δθ is measured or the reference point θ0 is first detected. The above-described sine wave energization is performed, and the sine wave energization 2 performs more accurate sine wave energization by a correction process based on the measured value of Δθ.

FIGS. 9 and 10 show a brushless DC motor 1.
6 is a flowchart illustrating a main process of an angle calculation processing unit of a motor control device that drives and controls 00. That is, this algorithm is based on a periodic pulse input (input of each phase signal of the measured phase I and the divided phase S), and the electrical angle θ (= θ
0 + dα) or the phase signal S (= 4u + 2v +
w) is output together with the above-described energization method control flag sw1.

In the main processing of the angle calculation processing section, first, in step 802, a pulse test is executed. This pulse test tests whether the detection circuit (detector and wiring) of the phase measurement I (AB phase) and the divided phase S (uvw phase) has no physical defect such as a failure. This processing is performed independently of the phase information on the sensor rotor R. After that, the exception signal detected first in step 820 or step 860, which will be described later, is not caused by the above-described abnormality. , "Origin mark" itself.

In step 804, the result of the above-described pulse test is determined. If the result is normal, the process proceeds to step 810; otherwise, the process proceeds to step 806. Step 80
At 6, the abnormal process is executed. For example, this brushless D
When the C motor 100 is used in an in-vehicle electric power steering apparatus, the abnormality processing includes a manual control mode in which a user (driver) is warned of the details of the abnormality or an assist torque by the motor is not supplied to the steering mechanism. It is sufficient to execute an abnormal action such as shifting to.

At step 810, the origin signal saving area G
Substitute (set) the value “1” into M. This value “1” is used in a system in which the origin mark is expressed by “(u, v, w) = (0, 0, 0) or (u, v, w) = (1, 1, 1)”. This represents a state in which the origin signal to be expressed by either one has not been detected yet.

In step 814, pulse input (input of each phase signal of the measured phase I (AB phase) and the divided phase S (uvw phase)) is executed. That is, for example, phase information on the sensor rotor R as illustrated in FIG. 3 is input. Therefore, the execution time of this processing (step 814) is determined by the input event e.
This corresponds to the event occurrence time of v0. In step 816,
Initialization of the four variables D, S, δ0, ε is expressed by the following equation (2),
Perform according to (3) and (4).

## EQU2 ## D = 0 (2)

S = 4u + 2v + w (3)

Δ0 = φ1, ε = φ2 (4)

Here, the variable D is the origin offset Δ
is a counter used to measure θ, and the variable δ0
Is an error width used when checking consistency between the measured phase I (AB phase) and the divided phase S (uvw phase),
The value of the constant φ1 (> 0) is determined from the magnetic hysteresis error, the width of the origin mark, the value of the origin offset Δθ, and the like. However, since the value of the origin offset Δθ is unknown at this stage, the maximum value empirically assumed is assumed as the value of Δθ.

The variable ε is an origin mark (origin signal)
Is a parameter that defines an “allowable range” for determining whether or not the exception signal is the origin mark when the same exception signal is detected. 17). In this step, the maximum value of Δθ assumed empirically is assumed as the value of the constant φ2 (> 0).

In step 818, the motor energization method is set to "sw1 = 0", that is, "mode for executing rectangular wave energization based on S". In step 820, it is determined whether or not the current position of the sensor rotor R is on the origin (reference point θ0) based on the phase signal S most recently detected. This determination is made by the pulse test in steps 802 and 804 described above, and it is assured that the determination can be made correctly only by determining “origin” when S = 0 or S = 7, otherwise “other than the origin”. You. Here, if S = 0 or 7, the value is stored in the origin signal save area GM in step 825, and the process proceeds to step 870.

On the other hand, in step 820, S ≠ 0,
In the case of 7, the processing of step 830 to step 840 is executed. That is, in step 830, the above-mentioned energization method control flag sw1 and the value of the phase signal S are output to the means for performing the energization control (control of the drive current of the brushless DC motor 100). A known means may be used as a means for performing the energization control. Such an energization control means is usually often embodied by software such as a motor control device as illustrated in FIG. 7, but can be more generally realized by hardware.

In step 832, the value of the phase signal S is stored in the save area S0. In step 834, a process for waiting for the next pulse input time is performed so that the pulse input process in step 836 is periodically executed at a predetermined period ΔT. In step 836, the same pulse input processing as in step 814 is executed. In step 838, the latest value of the phase signal S is obtained according to the equation (3).

In step 840, for example, an edge detection process of the divided phase S (uvw phase) is performed by using a subroutine for performing a determination process as exemplified in FIG. Then, for example, when the subroutine illustrated in FIG. 11 is used, if the value of the edge number E is 0, the process proceeds to step 820; otherwise, the process proceeds to step 845.

When the edge number E is set to a value other than 0, S0 ≠ S, and the phase signal S0
Has an adjacent relationship with the angle region indicated by the phase signal S. This adjacency is guaranteed because the waiting time set in step 834 is sufficiently small. The algorithm shown in FIG. 11 is configured such that when S0 ≠ S, an integer matching the phase signal of the angle region located on the right side in FIG. 1 among the phase signals S and S0 of two adjacent angle regions is obtained. The selection is made as the edge number E.

In other words, as shown in the definition table of array Θ (E) in FIG. 12, in this embodiment, each edge number E
Are defined so that the electrical angle の of the angle coincides with the lower limit value (left boundary value) of the electrical angle in each angle region where S = E. Thereafter, in step 845, the edge number E of the edge detected as described above is stored in the save area E0.
To save.

On the other hand, in step 820 of FIG.
When the reference point θ0 is detected, after executing step 825 as described above, a series of processing from step 870 to step 885 described below is executed. That is, in step 870, the value of the energization method control flag sw1 is switched to 1 (sine wave energization mode), and the phase measurement I
The value of the phase B of FIG.
Is stored in the save area C0. The values of B0 and C0 stored here are used as initial values in a subroutine (FIG. 14) described later.

C0 = 2A + B (5)

Next, in step 872, the current value of the electrical angle θ to be output in the sine wave conduction mode (sw1 = 1) is set to 0 °. With this setting, the electrical angle of the reference point detected in step 820 is determined to be 0 °, and in the output of the electrical angle θ described below, each reference point is defined as the origin (θ = 0 °). The value of the electrical angle θ of the position is output.

Next, in step 874, a subroutine SUB1 (FIG. 13) described later is executed. This subroutine SUB1 executes processing for outputting the energization method control flag sw1 and the electric angle θ, processing for calculating the electric angle θ based on the pulse input, and the like. In steps 880 and 885, the same processing as in steps 840 and 845 described above is executed. If no edge of the divided phase S is detected, the processing returns to step 874. Therefore, the execution time of this processing (step 885 or 845) substantially corresponds to the event occurrence time of the edge detection event evI.

Therefore, the processing described below and shown in FIG. 10 is the same as that of the divided phase S first detected by the above processing.
Is executed in a state where the edge number E of the edge is stored in the save area E0. After executing the above step 845, step 850 is executed. In step 850,
The processing exactly the same as that in step 870 is executed. That is, in step 850, the variables accessed by the lower-order programs below the subroutine SUB1 (FIG. 13) are initialized just like step 870 described above.

In step 852, the current value θ of the electrical angle is changed to Θ (E0) using the array 例 示 illustrated in FIG.
Set to the same value as. However, this value is determined in step 84.
This is for temporarily determining the electrical angle θ (= current value θ of electrical angle) of the edge of the divided phase S detected at 0.
This setting process is performed temporarily assuming that Δθ = 0 until the value of the origin offset Δθ is measured. By this setting process, the “sine wave energization 1” described above is started. Becomes possible.

At step 854, the above-mentioned "sine wave energization 1" is executed by executing a subroutine SUB1 (FIG. 13) which will be described in detail later. This subroutine SUB
Reference numeral 1 denotes output processing of the energization method control flag sw1 and the electrical angle θ, and calculation processing of the electrical angle θ based on the pulse input.

In steps 860 and 862, the same processes as those in steps 820 and 825 are executed.
However, if the origin is not detected, step 8
The process returns from step 60 to step 854. Therefore, the execution time of this process (step 862 or step 825) substantially corresponds to the event occurrence time of the origin detection event evII. After executing step 862, in step 864, the same processing as in step 872 is executed.

In step 866, the sign of the position D of the edge E0 detected in step 840 is inverted. However, the “position D of the edge E0” here is the content (count value) of the variable D initialized to 0 as a counter used to measure the origin offset Δθ in the above-described step 816. This value is obtained by executing a subroutine SUB1 (FIG. 13), which will be described in detail later, to obtain the measured phase I (AB phase constituting the incremental phase in FIG. 3).
Is updated based on the state transition of the phase.

At step 866, the position D of the edge E0 is determined.
Is reversed, the origin offset Δθ is a numerical value that should be expressed with the origin (reference point θ0) as the starting point. In the above step 854, the edge (E0) detected in step 840 is detected. This is because the displacement amount from the starting point to the origin (reference point θ0) detected in step 860 is counted by the variable D. This displacement amount (D) is such that the rightward direction in FIG. 1, FIG. 3, or FIG. 4 is a positive direction, and the subroutine SUB1 (FIG.
It is measured by steps 125, 130, and 135 of 3).

FIG. 13 is a flowchart illustrating the main processing of a subroutine SUB1 for outputting the electrical angle θ with respect to the sine wave output program. This subroutine SUB
First, in step 110, the means for executing the energization control (control of the drive current of the brushless DC motor 100) is controlled by the energization method control flag sw
1 and the value of the electrical angle θ are output. A known means may be used as a means for performing the energization control. Such an energization control means is usually often embodied by software such as a motor control device as illustrated in FIG. 7, but can be more generally realized by hardware.

In step 115, the value of the phase signal S is stored in the save area S0. In step 120, processing for waiting for the next pulse input time is performed so that the pulse input processing (step 125) is periodically executed at a predetermined period ΔT. In step 125, step 814
A pulse input process similar to the above is executed.

In step 130, the change amount of the current electrical angle θ in the above-mentioned cycle ΔT is determined by the measurable minimum unit α in FIG.
Is determined as a quantized (digitized) change amount d as a unit. That is, in step 130, the "subroutine for counting the increase / decrease of the phase fluctuation of the incremental phase (measurement phase I) of the sensor rotor R", which is exemplified in the flowchart in FIG. 14, is called and executed. However, this subroutine operates so as to satisfy the “output determination table” shown in FIG.
5) is created on the premise that the absolute value of the amount of change in the electrical angle θ that can change during the period ΔT is less than the minimum measurable unit α. “XOR” in step 720 in FIG. 14 represents an operator for calculating exclusive OR corresponding to each bit by using the variable C0 and the variable C as operation targets.

In step 135, the position D is updated based on the value of the change amount d calculated by the above subroutine (FIG. 14). Therefore, this position D is also a value that is quantized (digitized) with the minimum measurable unit α in FIG. 4 as one unit. In step 140, the current value of the electrical angle θ is updated based on the value of the change amount d. However, if the following equation (6) is not satisfied as a result of this update processing, addition processing or subtraction processing in 360 ° units
It is assumed that adjustment processing is performed so that the following equation (6) is satisfied.

## EQU6 ## 0 ° ≦ θ <360 ° (6)

In step 145, according to equation (3),
The latest value of the phase signal S is obtained. In step 150,
The value of the error width δ0 set in step 816 according to equation (4) is taken over to a region that can be referenced by a subroutine (FIG. 17) for executing the abnormality detection processing. That is, the error width δ0
Is assigned to the variable δ. In step 155, the variable δ
The subroutine (FIG. 17) for executing the abnormality detection process described above will be called and executed based on the numerical value (error width) assigned to.

In step 160, the presence or absence of an abnormality is determined based on the value of the return code (RC) set by the abnormality detection subroutine. As a result, if an abnormality is detected, “abnormality processing (not shown)” in step 165 is executed, and the processing of the motor control device ends. If no abnormality is detected, the subroutine SUB1 is executed.
Is completed once, and control is returned to this subroutine SUB1.
Return to the caller of

As the above abnormal processing, for example, various measures such as gradually or instantaneously changing the torque adjustment coefficient R (FIG. 7) from 1 to 0 can be considered. Further, the return code (RC) is, for example, “RC
For example, when the value of “= 12, 16” is taken, measures such as restarting the above-described rectangular wave energization (initial control) as so-called “alternative control” at the time of abnormality may be performed. According to these various measures, it is possible to smoothly or safely change the power supply control method even in the event of an abnormality.

After executing Step 885 of FIG. 9 or Step 866 of FIG. 10, Step 890 of FIG. 10 is executed. In step 890, according to the following equation (7),
Find the value of the origin offset Δθ.

Δθ = f (E0, αD) = αD−Θ (E0) (7) However, if “−180 ° ≦ Δθ <180 °” is not satisfied, addition processing or subtraction processing in units of 360 ° is performed. , An adjustment is made so as to satisfy “−180 ° ≦ Δθ <180 °”.

In order to enable the rectangular wave energization (initial motion control) when sw1 = 0, it is necessary to set “| Δθ | <90
The condition “°” is a necessary condition, but this condition in the present embodiment is guaranteed by the assembly accuracy in the assembly process of the brushless DC motor 100 described above.

Next, at step 892, the error width δ provisionally set at step 816 is calculated according to the following equation (8).
Correct the value of 0.

Δ0 = φ1− | Δθ | (8)

In step 894, according to the following equation (9), the value of the array C (S) (FIG. 18) referred to in the above-described "subroutine for executing the abnormality detection processing (FIG. 17)" Is corrected.

(9) C (∀I) = C (I) −Δθ (I = 1, 2,..., 6) (9) By the correction processing of these equations (8) and (9), In the abnormality detection processing in step 155 of the subroutine SUB1, more accurate abnormality detection processing can be performed.

At step 895, the value of the variable ε (parameter defining the “permissible range”) is changed to the value of the constant φ3. The optimum value of the constant φ3 will be described in detail later in the description of the abnormality detection processing.

In step 896, the aforementioned subroutine SUB1 (FIG. 13) is executed. Note that this subroutine SUB1 is periodically and repeatedly executed in the present step 896 at the above-described cycle ΔT by the operation of the above-mentioned step 120.

The above angle calculation processing for the motor control device for controlling the brushless DC motor 100 (FIGS. 6 and 7) enables the angle calculation processing in the angle calculation processing section in FIG. 7 to be executed. For example, if the rotation angle difference Δθ is obtained as described above, it is possible to provide each edge of the divided phase S with information (origin information or phase information) equivalent to the origin mark.

The "subroutine for executing abnormality detection processing (FIG. 17)" mentioned above will be described in detail. The subroutine for executing the abnormality detection processing illustrated in FIG. 17 is configured based on the consistency determination criterion table in FIG.

In this subroutine, first, at step 605, the above-mentioned return code RC is reset to 0. In step 610, the variable x is set to the electrical angle θ.
Inherit (copy) the value of Next, in step 615, the current value of the divided phase S is determined. If S = 1, the process proceeds to step 620; otherwise, the process proceeds to step 630. In step 620, it is determined whether or not the following expression (10) is satisfied. If it is satisfied, the process proceeds to step 625; otherwise, the process proceeds to step 630.

C (1) + 360 ° −δ <x <360 ° (10) where the value of C (1) on the left side is the array C (S) in FIG.
Defines its initial value.
The image has been subjected to correction processing by 94.

In step 625, 360 ° is calculated from the value of x.
Is subtracted to reset the value of x. However,
A series of processes from step 615 to step 625 is a pre-process for performing step 640 or step 670 described later, and the absolute value | Δθ |
The processing is based on the premise that it is less than Therefore, "|
If “Δθ | <30 °” does not hold, these related processes require a slight change. Note that at least in the present embodiment, it is assumed that “| Δθ | <30 °” is satisfied. Therefore, step 81 in FIG.
The constant φ2 used in 6 may be set to 30 °. Such a premise can be sufficiently ensured in the same manner as described above by the assembling accuracy in the assembly process of the brushless DC motor 100.

In step 630, the value of the divided phase S (phase signal S) is determined, and if S = 0 or 7, step 650 is executed.
Otherwise, the process proceeds to step 640. At step 640, it is determined whether or not the following equation (11) is satisfied. If so, control is returned to the caller of this subroutine. If the condition is not satisfied, the return code RC is set to code 8 (step 645), and control is returned to the caller of this subroutine. By these determination processes, S =
1, 2,. . , 6, the criterion in the above-described consistency judgment criterion table (FIG. 16) is checked.

C (S) −δ <x <C (S) + 60 ° + δ (11)

In step 650, it is determined whether the value of the origin signal saving area GM set to "1" in step 810 (FIG. 9) has been updated. Here, if the save area GM has not been updated (if GM = 1), step 854 (FIG. 9) is currently being executed and the origin (S = 0 or 7) has not yet been detected. is there. In this case, control is returned to the caller as it is. Thus, the above-described steps 860 to 866 are sequentially and unconditionally executed.

On the other hand, as a result of the determination in step 650,
If GM ≠ 1, the origin signal saving area GM has been updated to a predetermined origin signal (0 or 7) in step 825 or step 862 in FIG. In this case, the process proceeds to step 660. In step 660, it is determined whether or not the current value of the divided phase S (phase signal S) matches the value stored in the origin signal save area GM, and if they match, the process proceeds to step 670. Step 66
Move the processing to 5. In step 665, the value of the return code RC is set to code 16, and then control is returned to the caller.

At step 670, it is determined whether or not the following equation (12) is satisfied. If so, the control is returned to the calling source. If not, return code RC
(Step 675), and control is returned to the caller.

| X | ≦ ε (12)

FIGS. 19 and 20 are explanatory diagrams for explaining the setting criteria for determining the upper limit ε used in the above-described abnormality detection processing (FIG. 17). For example, if the magnetization width h of the origin signal is limited to the range of “2α ≦ h <3α” using the minimum measurable unit α of the positioning amount (electrical angle θ), FIG.
As shown in FIG. 20, when the origin signal is detected over a range of two pulses of the AB phase, as shown in FIG.
A case where detection is performed over a range of a pulse may occur.
Therefore, in such a case, the origin signal is the true origin θ0
Can be detected only within a range of 3α from. That is, in such a case, the value of the constant φ3 in step 895 may be set to three times α.

More generally, it is desirable to select the minimum value of y that satisfies “h _MAX <y” as ε in consideration of the variation of the magnetization width h of the origin mark. However, here, h _MAX is the maximum value of the magnetization width h when the magnetization width h can vary. Also, origin mark (origin signal)
Is constituted by the exception signal, and in order to detect the original abnormality more reliably and accurately, it is desirable that the value of ε be as small as possible within a range where the origin mark can be surely detected. Therefore, it is desirable that the magnetization width h of the origin mark or the maximum value h _MAX of the magnetization width h be smaller within a range in which the origin mark can be reliably detected.

For example, if it is possible to set “h _MAX <1.8α”, the value (φ3) of the upper limit ε of | x | can be set smaller, such as “φ3 = 2α”. However, care must be taken because the value of α is directly related to the measurement accuracy of the measurement phase I (incremental phase). From the above, the magnetization width h of the origin mark or its maximum value h _MAX is α
程度 3α is considered to be the most reasonable. In addition, these circumstances are the same when general phase information is configured by an arbitrary physical quantity.

If there is one edge of the divided phase S near the point where the origin mark should be formed or in the vicinity of the minimum magnetization width (≒ 2α), the edge number of the edge is not formed without forming the origin mark. E and the like may be stored in a predetermined external storage device or the like. By using such means, it is not necessary to write the origin mark on or near the edge, and the edge can be handled as the origin without forming the origin mark.

For example, with the configuration of the first embodiment as described above, the operation and effect of the present invention can be greatly obtained while sufficiently securing the abnormality detection accuracy. That is, by performing the above-described logical correction processing as an alternative, it is not necessary to perform the “physical positioning” such as the origin adjustment based on the “matching mark” or the like, which has been conventionally performed, As a result, the manufacturing time is shortened, the productivity of the apparatus is improved, and an adjusting mechanism is not required. Therefore, the apparatus can be manufactured at low cost or in a shorter time than before.

In the first embodiment, S = 1
The center point of the angle region is defined as the temporary origin (θ = 0 °) in sine wave energization 1 (control temporarily assuming Δθ = 0 °)
However, if the array Θ of the equation (7) and the array C of the equation (11) are appropriately redefined, the position of the provisional origin in the sine wave energization 1 used for the initial movement control at the time of starting, etc. Can also be taken freely. Therefore, for example, an appropriate arbitrary position such as the position of a certain edge itself can be adopted as the temporary origin.

(Second Embodiment) A motor control device (not shown) according to a second embodiment of the present invention uses a motor substantially the same as the brushless DC motor 100 (FIG. 6) according to the first embodiment described above, as a sensor rotor. After configuring without writing the origin mark on R,
Drive control is performed. This motor of the second embodiment is otherwise identical to the brushless DC motor 10 described above.
0, the drawing of this motor is omitted, but this motor is hereinafter referred to as “motor 200”.
I may say.

The second control for driving the motor 200
The greatest feature of the motor control device of the embodiment is that the "electric lock" operation is performed at the time of starting the motor, so that the "origin information"
Is stored only in the volatile storage device. The logical configuration of the motor control device of the second embodiment is the same as the control block diagram of the first embodiment (FIG. 7).
Although it is very similar to the logical configuration shown in FIG. 1, the point that the above-mentioned rectangular wave conduction mode (sw1 = 0) is not provided in the initial operation control at the time of starting the motor is greatly different from the first embodiment.

FIG. 21 is a flowchart illustrating the main processing of the angle calculation processing unit of the motor control device according to the second embodiment. This flowchart is based on the series of processes shown in FIGS. 9 and 10 described above.
6 "and a slight change.
Therefore, for example, in FIG.
996 "is composed of the same processing as the series of processing consisting of" step numbers 870 to 896 "in FIGS. 9 and 10, and the same subroutine is used for each lower-level subroutine. .

In the main processing of the angle calculation processing section, first, at step 902, a pulse test equivalent to that of the first embodiment is executed. Steps 904 and 906 are also performed in step 80 of the first embodiment.
4. The same processing as in step 806 is executed. However,
The above processing can be omitted. In the second embodiment, since the origin signal constituted by the exception signal such as “S = 7/0” of the first embodiment is not used, step 90 is executed.
Steps 2 to 906 may be omitted.

In step 910, the origin signal saving area G
Set the numerical value “2” to M. This value means that the system does not use the origin mark. However, as will be described in detail later, this step 910 can also be omitted depending on the configuration (correction) of the abnormality detection processing (FIG. 17).

At step 912, the above-mentioned "electric lock" processing is performed. That is, a predetermined DC current is supplied to the motor 200, and the angle of the sensor rotor R is fixed at a predetermined position. In step 914, pulse input processing is executed as in step 814 of the first embodiment. Step 9
At 15, the "electric lock" is released.

In step 916, initialization of three variables D, S, and δ0 is performed in accordance with equations (2), (3), and (4), as in step 816 of the first embodiment. After that, in a series of processing consisting of “step numbers 970 to 996”,
The same processing as the series of processing consisting of “step numbers 870 to 896” in FIGS. 9 and 10 is executed.

According to the above operation, when the motor 200 is started, the rotor sensor R is forcibly positioned at the origin, and therefore, according to the present motor control device, the "sine wave energization 2" must be performed from the beginning. Can be. The motor control device having such a control method is effective under a system configuration in which an “electric lock” operation is allowed when the motor is started.

In the motor control device of the second embodiment, since the origin mark is not used, in the manufacturing process of the motor 200, the process of writing the origin to the sensor rotor R (the manufacturing process S30 in FIG. 5), Alternatively, the step of exchanging the origin signal writing device 5 and the sensor signal reading unit 1 as in the manufacturing step S40 of FIG. 5 is not required.
Therefore, according to the configuration of the present embodiment, instead of performing these steps, it is only necessary to assemble the sensor signal reading unit 1, so that the manufacturing time can be further reduced, and the production efficiency of the motor 200 is further improved. it can.

According to the structure of this embodiment, even when the motor 200 is reassembled for repair or the like, it is not necessary to rewrite the origin mark using the origin signal writing device 5 or the like. It can be used as it is.

The abnormality detection processing (FIG. 17) can be used as it is in the first embodiment, but steps 650 to 675 can be deleted, leaving only step 665. That is, if steps 650 to 675 are configured so as to leave only step 665, step 910 in FIG. 21 is not necessary only in this case. In this case, the exception signal (S = 7 /
If 0) is detected, the code 16 is unconditionally set to the return code RC in step 665, and the subsequent control is returned to the caller of the abnormality detection processing routine.

According to such a configuration, not only the exception processing of the abnormality detection processing (FIG. 17) can be simplified, but also step 6
By eliminating 70, etc., the abnormality detection can be correctly performed even when a true abnormality (S = 7/0) occurs within the range where the above equation (12) holds, so that the abnormality detection accuracy or responsiveness (abnormality) The detection time is also slightly improved. Further, in such a configuration, since there is no magnetization width h of the origin mark, the measurement error caused by the magnitude of the magnetization width h is also eliminated.

Further, in the motor control device according to the second embodiment, not only the manufacturing cost of the motor 200 can be reduced, but also the amount of program development is smaller than that of the first embodiment, which is advantageous in terms of development cost. It is.

(Third Embodiment) In the manufacturing process S30 of FIG. 5, instead of writing the origin mark on the sensor rotor R of the brushless DC motor 100, the phase of the divided phase S (uvw phase) is calculated from the zero-adjusted position. A method of writing all information from the beginning may be adopted. In this case, only the phase information of the measurement phase I (incremental phase) needs to be formed (magnetized) on the sensor rotor R before the manufacturing process S10 is performed.

In the case of employing such a method, since the positioning is correctly performed at the predetermined position in the manufacturing process S20, the phase information of the divided phase S (uvw phase) always includes the value of Δθ described above. Is written to be 0 °. In other words, this method does not use the origin mark as in the first embodiment, and is configured such that the phase information itself of the divided phase S recorded by adjusting the zero point essentially has the origin information. is there.

By using this method, it is not necessary to find or use the value of Δθ, and the program is simplified. That is, according to the configuration of the third embodiment,
The functions and effects of the first embodiment can be obtained, and at the same time, the motor control can be executed by the same control method as the conventional one.

It should be noted that such a divided phase S is not limited to three phases, and n
It may be composed of phases (n is an arbitrary natural number). As practical values, n = 1, 2, 3, 4 and the like are particularly effective because the number of sensors can be reduced. Further, when such a divided phase S is used for the initial movement control at the time of starting, an appropriate natural number n may be selected according to the number of phases of the motor and the like.

For example, when the configuration of n = 1 is adopted, for example, a method of forming the origin mark by the following local magnetization (magnetization) or the like (Example 1), It is possible to consider a method (example 2) in which the width of (magnetization) is relatively wide and an origin mark is formed by an edge or the like. (Example 1) Phase information (1) between the origin mark and other parts
/ 0), the origin mark is formed. That is, for example, the point of S = 1 is set as the origin (reference point θ0).
The other part (the point where S = 0) is set as a general most angle area other than the origin.

(Example 2) The point at which the phase information (1/0) changes is defined as the origin (reference point θ0). That is, for example, “0 ° ≦
In the angle region where θ <180 °, S = 0 and “180
S = 1 in an angle region where “° ≦ θ <360 °”. Since the rotation direction can be determined from the phase measurement I, it is possible to selectively recognize the side of 0 ° = θ among the two edges as the origin.

According to the means of (Example 1), since the origin mark can be easily formed, it is effective in shortening the manufacturing time. Further, according to the means of (Example 2) above,
It is also possible to execute rectangular wave energization with a rectangular wave of binary (± 1) based on the phase information of the divided phase S.

(Fourth Embodiment) In each of the above embodiments, the phase measurement I (incremental phase) has a two-phase configuration of the AB phase. A configuration may be used. For example, the measurement phase I is made into a three-phase configuration of the uvw phase, and an origin mark (eg: (u, v, w) = (1, 1, 1) or (0, 0) ,
0)) may be written.

According to such a configuration, the exceptional signal is included in the phase measurement I of the brushless DC motor having only the phase measurement I and not having the divided phase S as in each of the above embodiments. In addition, it becomes possible to write the “origin mark”.

The exception signal constituting the above-mentioned "origin mark" is not limited to (u, v, w) = (1, 1, 1) or (0, 0, 0). Absent. For example,
The origin mark may be formed by inverting the phase information (of three phases of uvw) of all the phases of the phase information already provided at the position where the “origin mark” is to be written.

More generally, if the sampling period ΔT of the pulse signal is made sufficiently short so as to prevent the so-called “phase skipping (phase skipping)”, the “angle domain (phase area) to which the point to which the origin mark should be written belongs” can be obtained. The origin mark can be formed by an arbitrary phase signal other than the phase signal and the phase signal of the angle region adjacent to the angle region. These exception signals are determined to be exception signals (origin marks) because the value of the phase information itself or the state transition of the phase information is exceptional. As exemplified in the second embodiment,
It is more desirable to employ an exception signal having the least effect on the abnormality detection processing as the origin mark or the like.

(Fifth Embodiment) FIG. 22 (b) shows the "origin mark" of the brushless DC motor (not shown) of the fifth embodiment.
FIG. FIG. 22 (a) is the same figure as FIG. 4 (a), and is drawn for comparison with FIG. 22 (b). Origin mark (exception signal) in FIG.
Are configured exclusively for the AB phase, and the AB phase changes simultaneously only at the origin (reference point θ0). Therefore, if such an AB phase is used, when there is a predetermined exceptional transition in the phase transition form, that point can be determined as the origin (reference point θ0).

However, when using the origin mark as shown in FIG. 22B, it is necessary to slightly change the subroutine for obtaining the displacement d in FIG. FIG. 23 has logic for detecting the “origin mark” of the brushless DC motor (not shown) of the fifth embodiment, and counts the increase / decrease of the phase fluctuation of the incremental phase (measuring phase I) of the sensor rotor R. It is a flowchart of a subroutine. For example, in FIG.
The origin mark can be detected by, for example, inserting an origin mark detection logic as embodied in Steps 790 to 796 of Step 3 immediately before Step 740 of the subroutine for obtaining the displacement d in FIG.

Further, if such a logic is used, | d | =
It can be determined that the origin has been confirmed at the time when the number 2 is established.
Therefore, for example, when executing step 140 (FIG. 13) of the above-described subroutine SUB1, if "| d | =
If “2”, the setting “θ = 0 °” may be exceptionally executed only at that time. It is sufficient to perform such processing only once in the initial stage, but it may be performed every time. However, similar to such a program change, in other related programs, program change, extension, module replacement, etc. are performed as necessary in accordance with the specification change from the related embodiment described above. It shall be.

In the fifth embodiment, the "origin mark" constituted exclusively for the AB phase is exemplified. However, in general, it is assumed that the phases of a plurality of phases simultaneously change only at the origin (reference point θ0). These origin marks (exception signals) can be configured by means such as In addition, these means are not limited to the phase configuration (the number of phases) such as the AB phase and the uvw phase, and can be introduced irrespective of the role of the phase such as the phase measurement I and the split phase S. .

Further, even more generally, when there is a predetermined exceptional transition in the phase transition form, the above point is determined by adopting the “origin mark detection method” for determining that point as the origin (reference point θ0). The same operation and effect can be obtained.

(Other Modifications) In the first, second and fourth embodiments, (u, v, w) =
Although a unique “origin mark” is formed (defined) by expressions such as (1,1,1) or (0,0,0), it corresponds to the reference point θ0 based on a predetermined positional relationship, and corresponds to the origin mark. A substantially similar “reference point mark” similar to the origin mark may be provided.

For example, when the origin mark is written, the direction of the "electric lock" is further reversed and the "electric lock" is carried out again. The "point mark" may be written at the fixed position of the second electric lock. That is, for example, when the origin mark is represented by “S = 0”, the “reference point mark” represented by “S = 7” is written at a position where the electrical angle θ is shifted by 180 ° from that point. You may do.

That is, the number of positions where the “origin mark” and “reference point mark” of the present invention are written is arbitrary, and accordingly,
For example, in the case of a brushless DC motor having 16 magnets, a configuration may be adopted in which “origin marks” are provided at eight locations and “reference point marks (back signals)” are further provided at eight locations.

According to these means, since the average time until the origin mark or the reference point mark is first detected at the time of initial movement is shortened, an accurate positioning amount θ is output from an earlier stage immediately after the positioning device is started. It becomes possible to do.
That is, if the formation positions of these exception signals are not unevenly distributed, the time required to obtain Δθ becomes short, and the transition to the sine wave energization can be executed early.

In the second embodiment, the sensor rotor R having the divided phase S (uvw phase) is used.
When the "electric lock" is performed at the time of startup as in the second embodiment, the split phase S may not be provided. The role of the split phase S in the second embodiment and the like is used to obtain phase information serving as a criterion at the time of abnormality detection processing and to obtain phase information for performing alternative control at the time of abnormality. Yes, when configuring a device that does not require high reliability,
The split phase S in a positioning device, a motor, or the like that performs “electric lock” at the time of startup is not always necessary.

Instead of performing the above-described “electric lock”, a desired stationary magnetic field can be formed using a permanent magnet. For example, the rotor and the moving body can be positioned by such means. Such means is particularly effective when manufacturing a brushless DC motor, or when manufacturing or operating a linear scale.

In the above-described embodiment, the processing of various phase information in the motor control device is realized by software. However, at least a part of the information processing may be configured using a hardware circuit or the like. It is possible.
For example, the algorithm most suitable for hardware implementation may be the algorithm shown in FIGS. 11, 14, 23, and the like. Further, in particular, instead of executing the edge determination process using the program in FIG. 11 or the like, the edge determination process may be performed using an ECU (electronic control device) having an “edge interrupt mechanism” or the like. good.

In each of the above embodiments, means for expressing phase information using a magnetized magnetic material is mainly described. Physical means for expressing the phase information include: Arbitrary means such as a method using a light emitting element and a photoelectric element, a mirror surface or a reflecting surface, a Hall element, an uneven surface such as a CD or MD, or the like can be adopted. O these physical quantities
The present invention can be applied irrespective of a phase signal forming means, a transmitting means, or a detecting means as long as it is recognized as phase information composed of an N / OFF signal (1/0 signal).

The present invention also relates to a process unique to motor control such as an adjustment process using the equation (6) shown in step 140 in FIG. 13, for example. If a simple change to the above-described algorithm is performed by appropriately deleting or changing the normalization process), the algorithm can be applied to the linear scale.

The phase information setting medium may be fixed to a housing or the like, and a sensor for reading the phase information may be provided on the rotating body (moving body). When a linear scale or the like is configured, such a configuration is more general. More generally, the positioning amount θ such as the rotation angle and the translation amount
Is a quantity measured based on the relative displacement between the sensor side and the measured object. Therefore, even if a sensor (pulse detector) is provided on either the moving or stationary body, By providing the measured object, these positioning devices can be configured.

[Brief description of the drawings]

FIG. 1 is a graph (a) showing a relationship between an electrical angle θ and a phase signal S (divided phase S) according to each embodiment of the present invention, and a definition table (b) of the phase signal S.

FIG. 2 is a brushless DC motor 1 according to a first embodiment of the present invention.
Sectional view in the manufacturing process of 00.

FIG. 3 shows a sensor rotor R of the brushless DC motor 100;
FIG.

FIGS. 4A and 4B are a graph (a) showing a relationship between a measurable minimum unit α of an incremental phase (measurement phase I) of a sensor rotor R and a phase signal (region signal C), and a definition table (b) of the phase signal C.

FIG. 5 is a flowchart illustrating an outline of an assembly procedure of the brushless DC motor 100;

FIG. 6 is a cross-sectional view of the brushless DC motor 100.

FIG. 7 is a control block diagram illustrating a logical configuration of a motor control device that drives and controls the brushless DC motor 100;

FIG. 8 is a time chart exemplifying a timing of switching of an energization method when driving the brushless DC motor 100;

FIG. 9 is a flowchart (first half) illustrating main processing of an angle calculation processing unit of a motor control device that drives and controls the brushless DC motor 100;

FIG. 10 is a flowchart (second half) illustrating main processing of an angle calculation processing unit of the motor control device that drives and controls the brushless DC motor 100;

FIG. 11 is a flowchart of a subroutine that can be used for the edge determination processing in FIG. 9;

FIG. 12 is a definition table of an array Θ (E) that defines a relationship between an edge number E and an electrical angle θ.

FIG. 13 is a flowchart illustrating a main process of a subroutine SUB1 for outputting an electrical angle θ with respect to a sine wave output program.

FIG. 14 is a flowchart of a subroutine for counting the increase / decrease of the phase fluctuation of the incremental phase (measurement phase I) of the sensor rotor R.

FIG. 15 is an output determination table that defines the operation of the subroutine in FIG. 14;

FIG. 16 is a consistency determination criterion table that defines the operation of the abnormality detection processing (step 155, FIG. 17).

FIG. 17 is a flowchart of a subroutine for executing an abnormality detection process.

FIG. 18 is an initial value table of an array C (S) used in the abnormality detection processing (step 155, FIG. 17).

FIG. 19 is an explanatory diagram (1) illustrating a setting criterion when determining the upper limit value ε used in the abnormality detection processing (step 155, FIG. 17).

FIG. 20 is an explanatory view (2) illustrating a setting criterion for determining the upper limit ε used in the abnormality detection processing (step 155, FIG. 17).

FIG. 21 is a flowchart illustrating a main process of an angle calculation processing unit of the motor control device according to the second embodiment of the present invention for controlling the drive of the brushless DC motor 100 (FIG. 6).

FIG. 22 is a graph illustrating an “origin mark” of a brushless DC motor (not shown) according to a fifth embodiment of the present invention.

FIG. 23 shows an incremental phase (measurement phase I) of the sensor rotor R having logic for detecting an “origin mark” of the brushless DC motor (not shown) according to the fifth embodiment of the present invention
9 is a flowchart of a subroutine for counting the increase / decrease of the phase fluctuation of the subroutine.

[Explanation of symbols]

100 ... brushless DC motor 1 ... sensor signal reading section R ... sensor rotor (measured object (rotating body) 3 ... motor shaft 4 ... motor housing 5 ... origin signal writing device I ... incremental phase (measuring phase) S ... split phase Or its phase signal θ: positioning amount (rotation angle or position) α: minimum unit of positioning amount θ (θ = θ0 + dα: d is an integer) Δθ: origin offset (temporary based on the phase of the divided phase S) Of the positioning amount θ between the original origin and the true origin θ0)

Continued on the front page (72) Inventor Kenji Mori 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 2F077 AA38 AA49 CC02 QQ11 VV01 VV30 VV33 3D033 CA28 CA29 5H019 AA10 BB01 BB10 BB19 BB23

Claims (24)

[Claims] 1. A positioning device for measuring a rotation angle or a position of a moving body by detecting phase information of a “phase measurement I” periodically set on a measured object, wherein the assembling step of the positioning device Characterized by having a recording medium on which the “origin information” indicating the position of the reference point θ0 of the positioning amount θ of the positioning device fixed after the assembly process is recorded. 2. The recording medium according to claim 1, wherein the recording medium is constituted by a recording medium capable of holding at least information represented by a physical quantity that can be converted into an electric signal without power. A positioning device as described. 3. The positioning device according to claim 1, wherein said recording medium is constituted by a volatile storage medium. 4. The positioning device according to claim 1, wherein the recording medium is constituted by at least the object to be measured. 5. The object to be measured has a “divided phase S” that indicates the positioning amount θ stepwise in a predetermined width unit larger than the measurement accuracy of the positioning amount θ. The positioning device according to claim 4. 6. The recording medium includes at least the object to be measured, and the origin information is uniquely represented by phase information of the divided phase S recorded after phase matching or zero point adjustment. The positioning device according to claim 5, wherein: 7. The recording medium includes at least the object to be measured, and the origin information includes the reference point θ.
5. The image data is uniquely represented by an "origin mark" written at a position corresponding to or matching "0".
Or the positioning device according to claim 5. 8. The recording medium is composed of the measured object having a “divided phase S” that indicates the positioning amount θ stepwise in a predetermined width unit sufficiently larger than the measurement accuracy of the positioning amount θ. The positioning device according to claim 7, wherein the origin mark is represented by an exception signal of the divided phase S. 9. The divided phase S is composed of a total of three phases of a u phase, a v phase, and a w phase, and the origin mark is “(u, v, w) = (0, 0, 0)
9. The positioning device according to claim 8, wherein the positioning signal is represented by a phase signal of (u, v, w) = (1, 1, 1). 10. The positioning apparatus according to claim 7, wherein the origin mark is represented by an exception signal of the measurement phase I. 11. The phase measurement I is composed of a total of three phases of a u phase, a v phase, and a w phase, and the origin mark is “(u, v, w) = (0, 0, 0)
11. The positioning device according to claim 10, wherein the positioning device is represented by a phase signal represented by (u, v, w) = (1, 1, 1). 12. The width of the origin mark in the positioning direction of the positioning amount θ is the minimum width in the positioning direction of the phase information of the positioning phase I, the setting accuracy, or the minimum measurable unit α of the positioning amount θ. The positioning device according to claim 7, wherein the positioning device is substantially the same. 13. A reference point mark corresponding to the reference point θ0 based on a predetermined positional relationship and substantially similar to the origin point mark and similar to the origin point mark. The positioning device according to claim 12. 14. The moving object according to claim 1, wherein the origin information indicates a position where a potential energy of the moving body associated with a predetermined stationary magnetic field formed around the moving body is minimum or minimum. Item 14. The positioning device according to any one of items 13. 15. The recording medium comprises at least the object to be measured, and an apparatus for recording the origin information on the object to be measured and an apparatus for reading the origin information from the object to be measured are the same. 15. An apparatus according to claim 4, wherein the apparatus is constituted by an integrated device.
The positioning device according to the paragraph. 16. A linear scale comprising the positioning device according to claim 1, wherein the position of the moving body that translates is measured as the positioning amount θ. 17. The positioning device according to claim 1, wherein the rotation angle of the moving body (rotating body R) that rotates is measured as the positioning amount θ. Characterized encoder. 18. A brushless DC motor comprising the encoder according to claim 17, wherein a rotor is constituted by the rotating body R, and drive is controlled based on a rotation angle detected by the encoder. 19. The method according to claim 18, based on the origin information.
A motor control device for driving and controlling the brushless DC motor according to any one of claims 1 to 4. 20. The motor control device according to claim 19, wherein the phase information of the divided phase S is used in the initial movement control, the substitute control, or the abnormality detection processing. 21. The recording medium and the rotating body R are the object to be measured having the “phase measurement I”, the “split phase S”, and the “origin mark”, and when the brushless DC motor starts operating. 21. The motor control device according to claim 19, wherein an initial process for calculating a rotation angle difference Δθ between a predetermined position of the divided phase S and the origin mark is executed. 22. The recording medium is a volatile storage medium, which forms a predetermined stationary magnetic field around the rotating body R when the brushless DC motor starts operating, and generates a predetermined steady magnetic field around the rotating body R. 21. The motor according to claim 19, wherein an initial process for obtaining the origin information and storing the origin information in the volatile storage medium is executed by detecting a position where the potential energy is minimum or minimum. Control device. 23. Any one of claims 19 to 22.
An electric power steering device mounted on a vehicle, comprising the motor control device described in the above section. 24. Manufacture of a positioning device having means for detecting phase information of “phase measurement I” periodically set on a measured object and applicable to an encoder, a linear scale, a brushless DC motor, or the like. A method, wherein the "origin information" indicating the position of the reference point θ0 of the positioning amount θ of the positioning device fixed in the assembling process of the positioning device is provided on a predetermined recording medium or the measured object after the assembling process. A method of manufacturing a positioning device, comprising: a "origin information recording step" for recording the position information.