JP2013172602A - Motor control device and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor control device and a motor control method capable of enhancing versatility without causing increase in circuit scale.SOLUTION: It is determined whether or not mechanical angle data is equal to or more than a value obtained by multiplying electric angle one cycle data by 2. When the determination is negative, first temporary electric angle data is set to be equal to the mechanical angle data. When the determination is affirmative, the first temporary electric angle data is set to be equal to a value obtained by subtracting a value obtained by multiplying the electric angle one cycle data by 2from the mechanical angle data. Then, it is determined whether or not (k-1)th temporary electric angle data is equal to or more than a value obtained by multiplying the electric angle one cycle data by 2. When the determination is negative, k-th temporary electric angle data is set to be equal to the (k-1)th temporary electric angle data. When the determination is affirmative, processing for setting the k-th temporary electric angle data to be equal to a value obtained by subtracting a value obtained by multiplying the electric angle one cycle data by 2from the (k-1)th temporary electric angle data is repeated while k is 2 to n. Electric angle data is set to be equal to n-th temporary electric angle data, and sine/cosine wave data is set on the basis of this electric angle data.

Description

  The present invention relates to a motor control device and a motor control method for driving and controlling a motor according to a detected motor current value and positive cosine wave data corresponding to electrical angle data at the time of detecting the current.

  Conventionally, a motor control device drives and controls a motor according to a detected motor current value and positive cosine wave data corresponding to electrical angle data at the time of detecting the current. In this drive control, for example, the motor control device calculates electrical angle data from a count value (mechanical angle) of an encoder directly connected to the brushless motor, and the calculated electrical angle data is stored in a sine wave table in which cosine wave data is stored. As a result, the cosine wave data corresponding to the electrical angle data is acquired.

  By the way, when only a motor having a specified number of pole pairs is to be controlled, an electrical angle calculation block for calculating electrical angle data, and a sine wave table for obtaining positive cosine wave data corresponding to the calculated electrical angle data, However, one type is prepared corresponding to the number of pole pairs specified above. However, there is a problem that an electrical angle calculation block and a sine wave table are required for each number of pole pairs in order to improve versatility by controlling motors with different pole pairs, assuming motor version upgrades and the like. In particular, when the types of electrical angle calculation blocks and sine wave tables increase, the number of necessary circuits increases and the circuit scale increases.

JP 07-123768 A

  Therefore, a digital AC servo device disclosed in Patent Document 1 is known as a motor control device that improves versatility. In this digital AC servo apparatus, the counter block outputs a triangular wave having an amplitude 1 / (2i-1) times the basic triangular wave f (x) and a frequency (2i-1) according to the counter limit value of each counter. Then, the output of each counter of the counter block is multiplied by 1 / (2i-1) times the amplitude of the triangular wave by the gain multiplication block. Next, sine wave data is calculated by adding / subtracting the values of the N triangular waves so that the harmonic component becomes zero in the addition / subtraction block. That is, by using a plurality of triangular wave counter blocks, a gain multiplication block, and an addition / subtraction block, a triangular wave composed of a plurality of counters is synthesized to generate sine wave data. In this configuration, by resetting the counter limit according to the number of pole pairs, the same sine wave table can be used for motor control of each pole pair.

  However, since the sine wave data is generated by combining a plurality of triangular waves, the accuracy of the sine wave data is lowered. As described above, when the accuracy of the sine wave data is lowered, there is a problem that the efficiency of the motor control using the sine wave data is deteriorated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor control device and a motor control method capable of enhancing versatility without causing an increase in circuit scale. is there.

In order to achieve the above object, a motor control device according to claim 1 of the present invention is directed to a motor in which a motor (1) having a pole pair number (Pn) of 1 to 2 ⁿ (n is a positive number) is detected. A motor control device (10) for controlling driving according to a current value and positive cosine wave data corresponding to electrical angle data (θe) at the time of detecting the current, wherein the number of pole pairs and the electrical angle of the motor to be controlled are An acquisition means (11) for acquiring electrical angle one period data (Te) corresponding to one period, and a mechanical angle data detection means (11, 2) for detecting mechanical angle data (θm) corresponding to the mechanical angle of the motor. , 14), electrical angle data setting means (11, 15) for setting the electrical angle data based on the mechanical angle data detected by the mechanical angle data detection means, and the electrical angle data setting means. Based on the electrical angle data And a positive cosine wave data setting means (11, 16) for setting the positive cosine wave data, wherein the electrical angle data setting means has the mechanical angle data detected by the mechanical angle data detection means as the electrical angle data. It is determined whether or not it is equal to or greater than the value obtained by multiplying the angular period data by 2 ⁿ⁻¹ , and the first provisional electrical angle data (θe ₁ ) is set so as to be equal to the mechanical angle data at the time of negative determination. First temporary electrical angle data (θe ₁ ) is set to be equal to a value obtained by subtracting a value obtained by multiplying the electrical angle single cycle data by 2 ⁿ⁻¹ from the mechanical angle data at the time of affirmative determination. The electrical angle data setting means (11, 15) and whether or not the k-1th provisional electrical angle data is equal to or greater than a value ^obtained by multiplying the electrical angle one-cycle data by 2 ^nk , and a negative determination Sometimes the k-1th provisional electrical angle data (θe _k-1 provisional electrical angle data (θe _k ) is set so as to be equal to _k−1 ), and from the k−1th provisional electrical angle data (θe _k−1 ) to the electrical angle one-period data when an affirmative determination is made. 2nd temporary electrical angle data setting means for repeating the process of setting the _kth provisional electrical angle data (θe _k ) so as to be equal to the value obtained by subtracting the value ^obtained by multiplying 2 ^n−k from k to 2 to n. 11 and 15), and the electrical angle data is set to be equal to the nth provisional electrical angle data.
In addition, the code | symbol in the parenthesis of a claim and the said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

According to the first and fourth aspects of the present invention, it is determined whether or not the mechanical angle data is equal to or greater than the value obtained by multiplying the electrical angle one period data by 2 ^n−1, and ¹ is set so as to be equal to the mechanical angle data when a negative determination is made. The first temporary electrical angle data is set, and the first temporary electrical angle data is set to be equal to a value obtained by subtracting the value obtained by multiplying the mechanical angle data by 2 ^n-1 from the mechanical angle data at the time of affirmative determination. The Then, it is determined whether or not the (k−1) th temporary electrical angle data is equal to or greater than a value ^obtained by multiplying the electrical angle 1 period data by 2 ^n−k. The kth provisional electrical angle data is set so as to be equal, and is equal to the value obtained by subtracting the value ^obtained by multiplying one cycle of electrical angle data by 2 ^n−k from the k−1th provisional electrical angle data at the time of affirmative determination. The process of setting the kth provisional electrical angle data in k is repeated from 2 to n. Then, the electrical angle data is set to be equal to the nth temporary electrical angle data, and the positive cosine wave data is set based on the electrical angle data.

Thus, the electrical angle data can be calculated for any number of pole pairs as long as the ^number of pole pairs is 1 to 2 ⁿ , without employing an electrical angle calculation block for calculating electrical angle data for each number of pole pairs. it can. In particular, since it is not necessary to use a circuit having a large scale such as a multiplication block, the circuit scale can be reduced. In addition, since the positive cosine wave data is not created by combining a plurality of triangular waves, the accuracy of the positive cosine wave data is not lowered.
Therefore, versatility can be improved without increasing the circuit scale.

According to the second and fifth aspects of the present invention, the electrical angle data is binary data, and the electrical angle data and the positive cosine when the number of pole pairs is 2 ^nm (m is a positive number equal to or less than n). A table showing the relationship with the wave data is provided. Then, when the number of pole pairs is Pn, normalized electrical angle data obtained by adding Pn / 2 ^nm to the electrical angle data is calculated by using digit shift and addition / subtraction of the electrical angle data, and this normalization is performed. Positive cosine wave data is set from the table based on the electrical angle data.
Here, the normalized electrical angle data is a common table corresponding to the ^{number of} pole pairs of 2 ^nm , by multiplying the calculated electrical angle data by the number of pole pairs Pn / 2 ^nm. This data is normalized so that it can be used.

For example, when controlling a motor having n = 3, m = 1 and a pole pair number of 1 to 8 and having a pole pair number Pn of 2, the electrical angle data is shifted to the right by one digit. Thus, normalized electrical angle data obtained by adding 2/2 ^nm , that is, 2/4, to the electrical angle data is calculated. Further, for example, when controlling a motor having a pole pair number Pn of 5, 5/2 ^nm is added to the electrical angle data by adding the electrical angle data to the right-shifted electrical angle data by 2 digits. That is, normalized electrical angle data obtained by integrating (1 + 4) / 4 is calculated. Also, for example, when controlling a motor having a pole pair number Pn of 7, the electrical angle data is shifted by 1 digit to the left by subtracting the electrical angle data shifted by 2 digits to the electrical angle data. 7/2 ^nm , that is, normalized electrical angle data obtained by integrating (8-1) / 4 is calculated.

Here, right shift is a calculation method of dividing a binary number by 2 ^α (α is a positive number), and when “1000” is shifted right by one digit to “0100”, it is divided by 2. results and equal, when two digits right shift to "1000" in binary number "0010", and equal to the result of dividing by 2 ^2. Also, the left shift, a calculation method of multiplying 2 ^alpha to binary numbers, when 1 Ketahidari shifted to "0100" in a binary number "1000", and equal to 2 result of multiplying. In other words, the normalized electrical angle data is calculated only by the connection state of the signal lines in the circuit without using a multiplier or a subtracter by the calculation method using the shift described above, so that it does not increase the circuit scale. The table can be used, and the circuit can be further reduced in size.

According to the third and sixth aspects of the invention, a motor whose mechanical angle / cycle data is data obtained by multiplying specific mechanical angle / cycle data by 2 ^x (x is an integer) is a control target, and the table includes the table It is set based on specific mechanical angle data. Then, the electrical angle data is divided by 2 ^x by using the shift digit of the electrical angle data set as described above, positive cosine wave data is set using the division is the electrical angle data.

As a result, even if a motor whose mechanical angle / cycle data is different from the specific mechanical angle / cycle data by 2 ^× is controlled, positive cosine wave data can be set using a common table. In particular, by the calculation method using the shift described above, it is possible to suppress an increase in circuit scale resulting from the control of a motor having a plurality of mechanical angle / cycle data.

It is a block diagram which shows schematic structure of the motor control apparatus which concerns on 1st Embodiment. It is a flowchart which shows the flow of a positive cosine wave data calculation process. It is explanatory drawing explaining an example of the electrical angle data calculated when the number of pole pairs is 5 in an electrical angle calculation process. It is explanatory drawing explaining an example of the electrical angle data calculated when the number of pole pairs is 3 in an electrical angle calculation process. It is a graph which shows the relationship between the number of pole pairs and the normalization magnification. It is explanatory drawing for demonstrating the address normalization process in a positive cosine wave data calculation process. It is a flowchart which shows the flow of the positive cosine wave data calculation process in 2nd Embodiment.

[First Embodiment]
Hereinafter, a motor control device and a motor control method according to a first embodiment of the present invention will be described with reference to the drawings.
The motor control device 10 shown in FIG. 1 has a pole pair number of 1 to 2 ⁿ (n is a positive number), specifically, for example, a brushless motor 1 having a pole pair number of 1 to 8 is a control target, and the brushless The motor 1 is driven and controlled according to a detected motor current value and positive cosine wave data corresponding to electrical angle data at the time of detecting the current. When the motor control device 10 obtains the count value (mechanical angle) of the encoder 2 directly connected to the brushless motor 1, the motor control device 10 calculates the electrical angle data by the positive cosine wave data calculation process described later, and the calculated electrical angle data is corrected to the positive value. The positive cosine wave data is calculated by inputting as an address of a sine wave table (sine wave map) in which the cosine wave data is stored. The encoder 2 and the counter / latch circuit 14 may correspond to an example of “mechanical angle data detecting means” recited in the claims.

  The motor control device 10 includes a control controller 11 that performs overall control, a current detector 12 that detects a motor current of the brushless motor 1, and an A / D converter 13. The motor current of the brushless motor 1 is converted into a voltage by the current detector 2, converted into a digital quantity by the A / D converter 3, and taken into the controller 11 as motor current data Iu, Iv, Iw.

  Further, in synchronization with the control cycle of the controller 11 independent of the current capture timing, an encoder pulse corresponding to the rotation amount of the brushless motor 1 output from the encoder 2 is sent to the counter / latch circuit 14 as mechanical angle data θm. It is captured. When the electrical angle calculation block 15 outputs the electrical angle data θe of the brushless motor 1 according to the acquired encoder pulse value, for example, the positive cosine wave data when the pole pair number Pn is 4 is stored. The sine wave table 16 is used to output positive cosine wave data corresponding to the input electrical angle data θe to the controller 11. The encoder pulse from the encoder 2 may be taken into the counter / latch circuit 14 as the mechanical angle data θm in synchronization with the current take-in timing.

  The controller 11 performs two-phase three-phase conversion based on the positive cosine wave data corresponding to the electrical angle data θe read at the respective timings described above and the motor current data Iu, Iv, Iw, and the motor invalid efficiency. A d-axis current value that is a component and a q-axis current value that is a motor effective efficiency component are calculated. The brushless motor 1 is vector-controlled so that the deviation between the actual current value and the command value calculated in the controller 4 is small.

  Next, the positive cosine wave data calculation process, which is a characteristic part of the present invention, will be described with reference to FIGS. FIG. 2 is a flowchart showing the flow of the positive cosine wave data calculation process. FIG. 3 is an explanatory diagram illustrating an example of electrical angle data θe calculated when the pole pair number Pn is 5 in the electrical angle calculation process. FIG. 4 is an explanatory diagram illustrating an example of the electrical angle data θe calculated when the pole pair number Pn is 3 in the electrical angle calculation process. FIG. 5 is a chart showing the relationship between the number of pole pairs Pn and the normalized magnification. FIG. 6 is an explanatory diagram for explaining an address normalization process in the positive cosine wave data calculation process.

The positive cosine wave data calculation process can simplify the electrical angle calculation block 15 and sine wave even when a plurality of brushless motors 1 having pole pairs of 1 to 2 ⁿ (n is a positive number) are controlled. This is for realizing sharing of the table 16. This positive cosine wave data calculation process mainly includes an electrical angle calculation process for calculating the electrical angle data θe based on the detected mechanical angle data θm, and a normalized electrical angle data obtained by normalizing the calculated electrical angle data θe. and address normalization processing for calculating θn. In the positive cosine wave data calculation process, data such as mechanical angle data θm and electrical angle data θe are handled as binary data.

Hereinafter, the positive cosine wave data calculation process will be described in detail with reference to the flowchart shown in FIG.
First, the acquisition process shown in step S101 of FIG. 2 is performed, and the number of pole pairs Pn of the brushless motor 1 to be controlled, the electrical angle cycle data Te corresponding to one cycle of the electrical angle, and the mechanical angle data θm are acquired. The The acquisition process may correspond to an example of “acquiring means” and “first and second steps” recited in the claims.

Subsequently, in the determination process shown in step S103, it is determined whether or not the mechanical angle data θm is equal to or greater than a value obtained by multiplying the electrical angle one period data Te by 2 ⁿ⁻¹ . If the determination is negative in the determination process of step S103 (No at S103), at step S105, 1-th provisional electrical angle data .theta.e ₁ is set to be equal to the mechanical angle data .theta.m. On the other hand, if an affirmative determination is made in the determination processing in step S103 (Yes at S103), at step S107, 1-th provisional electrical angle data .theta.e ₁ is the electrical angle one cycle data Te from the mechanical angle data θm 2 It is set to be equal to a value obtained by subtracting a value obtained by multiplying ⁿ⁻¹ . The processing shown in steps S103 to S107 may correspond to an example of “first provisional electrical angle data setting unit” recited in the claims. The determination process shown in step S103 corresponds to an example of the “third step” described in the claims, and the processes shown in steps S105 and S107 are the “fourth step” described in the claims. It can correspond to an example.

When the first provisional electrical angle data θe ₁ is set in this way, k indicating the order of the provisional electrical angle data is incremented in step S109. Note that k is initialized and set to 1 each time the positive cosine wave data calculation process is started.

Subsequently, in the determination process shown in step S111, it is determined whether or not the (k−1) th temporary electrical angle data θe _k−1 is equal to or greater than the value ^obtained by multiplying the electrical angle one period data Te by 2 ^n−k. The When a negative determination is made in the determination process in step S111 (No in S111), in step S113, the kth provisional electrical angle data θe _k is changed to the k−1th provisional electrical angle data θe _k−1 . Set to be equal. On the other hand, when an affirmative determination is made in the determination process in step S111 (Yes in S111), in step S115, the k-th temporary electrical angle data θe _k is converted into the (k-1) th temporary electrical angle data θe _k−. It is set to be equal to a value obtained by subtracting a value ^obtained by multiplying ₁ electrical angle cycle data Te by 2 ^nk from ₁ .

When the k-th provisional electrical angle data θe _k is set in this way, it is determined in step S117 whether k is n or more. If k is not n or more (No in S117), step S109 is performed. K is incremented, and the processes after step S111 are repeated. The processing shown in steps S111 to S115 can correspond to an example of “second provisional electrical angle data setting means” described in the claims. Further, the determination process shown in step S111 corresponds to an example of “fifth step” described in the claims, and the processes shown in steps S113 and S115 correspond to “sixth step” described in the claims. It can correspond to an example.

When the incremented k becomes n or more (Yes in S117), electrical angle data setting processing is performed in step S119. In this process, the electrical angle data θe is set to be equal to the _nth provisional electrical angle data θen. The electrical angle data setting process shown in step S119 may correspond to an example of “seventh step” recited in the claims.

  The processing from step S101 to step S119 described above constitutes an electrical angle calculation process, and this electrical angle calculation process will be described using specific numerical values exemplified in FIG. The electrical angle calculation process may correspond to an example of “electrical angle data setting unit” recited in the claims.

  First, since n = 3, the brushless motor 1 having 1 to 8 pole pairs is controlled, and in step S101, the pole pair number Pn = 5, mechanical angle data θm = 7600, and electrical angle one period data Te =. The electrical angle data θe calculated when 1638 is acquired will be described.

First, in step S103, it is determined whether or not the mechanical angle data θm is equal to or greater than a value obtained by multiplying the electrical angle one period data Te by 2 ⁿ⁻¹ . θm (= 7600) ^{is, Te × 2 n-1 (} = 1638 × 2 2 = 6552) (Yes in S103) from greater than, the first temporary electrical angle data .theta.e ₁ is ^θm-Te × ^{2 n- 1} (7600-1638 × 2 ² ) = 1048 is set.

Then, after k is incremented from the initial value 1 to k = 2 in step S109, in step S111, the first provisional electrical angle data θe ₁ multiplies the electrical angle one period data Te by 2 ⁿ⁻² . It is determined whether or not the value is greater than or equal to the value. θe ₁ (= 1048) is, (No in ^{S111) Te × 2 n-2} (= 1638 × 2 1 = 3276) from less than, the second temporary electrical angle data .theta.e ₂ is temporary electrical angle of the first It is set to 1048 so as to be equal to the data θe ₁ .

Then, k = (No in S117) since it is not a 2 a and k ≧ n, after being incremented k = 3 in step S109, in step S 111, 2 th temporary electrical angle data .theta.e ₂ electrical angle one It is determined whether or not the value is equal to or greater than the value obtained by multiplying the periodic data Te by 2 ⁿ⁻³ . θe ₂ (= 1048) is, (No in ^{S111) Te × 2 n-3} (= 1638 × 2 0 = 1638) from less than, the temporary electrical angle third temporary electrical angle data .theta.e ₃ is the second is set to 1048 be equal to the data .theta.e _2.

Since k = 3 and k ≧ n (Yes in S117), an electrical angle calculation process is performed in step S119, and the electrical angle data θe is changed to 1048 which is the _third provisional electrical angle data θe3. Set to be equal.

  Here, the electrical angle data θe set as described above is compared with the calculation result actually calculated using the numerical value of the mechanical angle data θm. Since mechanical angle data θm = 7600, dividing this mechanical angle data θm = 7600 by electrical angle one-cycle data Te = 1638 results in a quotient of 4 and a remainder of 1048. Since the remainder is the calculation result of the electrical angle data θe, it can be seen that the electrical angle data θe set as described above is a correct numerical value.

  The electrical angle calculation process described above will be described using specific numerical values illustrated in FIG. First, since n = 3, the brushless motor 1 having 1 to 8 pole pairs is controlled, and in step S101, the pole pair number Pn = 3, mechanical angle data θm = 7600, and electrical angle one period data Te =. The electrical angle data θe calculated when 2730 is acquired will be described.

First, in step S103, it is determined whether or not the mechanical angle data θm is equal to or greater than a value obtained by multiplying the electrical angle one period data Te by 2 ⁿ⁻¹ . θm (= 7600), since smaller than ^{Te × 2 n-1 (=} 2730 × 2 2 = 10920) ( in S103 No), 1-th provisional electrical angle data .theta.e ₁ is the mechanical angle data .theta.m = 7600 Set to be equal.

Then, after k is incremented from the initial value 1 to k = 2 in step S109, in step S111, the first provisional electrical angle data θe ₁ multiplies the electrical angle one period data Te by 2 ⁿ⁻² . It is determined whether or not the value is greater than or equal to the value. Since θe ₁ (= 7600) is larger than Te × 2 ⁿ⁻² (= 2730 × 2 ¹ = 5460) (Yes in S111), the second temporary electrical angle data θe ₂ is θe ₁ −Te × 2 ^n-2 (7600-2730 × 2 ¹ ) = 2140 is set.

Then, k = (No in S117) since it is not a 2 a and k ≧ n, after being incremented k = 3 in step S109, in step S 111, 2 th temporary electrical angle data .theta.e ₂ electrical angle one It is determined whether or not the value is equal to or greater than the value obtained by multiplying the periodic data Te by 2 ⁿ⁻³ . θe ₂ (= 2140) ^{is, Te × 2 n-3 (} = 2730 × 2 0 = 2730) (No in S111) from a smaller than, the temporary electrical angle third temporary electrical angle data .theta.e ₃ is the second It is set to 2140 so as to be equal to the data θe ₂ .

Since k = 3 and k ≧ n (Yes in S117), electrical angle calculation processing is performed in step S119, and the electrical angle data θe is changed to 2140, which is the _third provisional electrical angle data θe3. Set to be equal.

  Here, the electrical angle data θe set as described above is compared with the calculation result actually calculated using the numerical value of the mechanical angle data θm. Since the mechanical angle data θm = 7600, dividing the mechanical angle data θm = 7600 by the electrical angle one period data Te = 2730, the quotient is 2 and the remainder is 2140. Since the remainder is the calculation result of the electrical angle data θe, it can be seen that the electrical angle data θe set as described above is a correct numerical value.

  When the electrical angle data θe is set as described above, the address normalization process shown in step S121 is performed, and the normalized electrical angle data θn is set. Based on the normalized electrical angle data θn, the positive cosine wave data is set using the sine wave table 16 in the positive cosine wave data setting process shown in step S123, and the positive cosine wave data calculation process is completed. The determination process shown in step S121 may correspond to an example of “calculation unit” recited in the claims. The determination processing shown in steps S121 and S123 may correspond to an example of “positive cosine wave data setting means” and “eighth step” recited in the claims.

Here, the address normalization process described above will be described. This process is a process of setting normalized electrical angle data θn obtained by multiplying the calculated electrical angle θe by the pole pair number Pn / 2 ⁿ⁻¹ which is a normalization magnification. That is, the electrical angle θe is a sine wave table address for using the sine wave table, and by setting a normalized address (normalized electrical angle data θn) for the sine wave table 16, the electrical angle θe It can be used in common without distinguishing the number of pole pairs.

Specifically, since the electrical angle data θe is binary data, normalized electrical power obtained by multiplying the electrical angle data θe by a normalization magnification Pn / 2 ^n-1 by using digit shift and addition / subtraction. Angle data θn is calculated. Such an address normalization process will be described in detail with reference to FIGS.

  Since the sine wave table 16 is set based on, for example, the number of pole pairs Pn = 4, as can be seen from FIG. 5, the normalized electrical angle data θn is equal to the electrical angle data θe and Pn / 4 which is a normalized magnification. Is set to be accumulated. In this embodiment, this integration is performed by using digit shift and addition / subtraction as shown in FIG.

Here, the operator “>>” indicates a right shift operation (right bit shift operation), which is a calculation method for dividing a binary number by 2 ^α (α is a positive number), and θe >> 1 is By shifting the electrical angle data θe by one digit to the right, normalized electrical angle data θn obtained by dividing the electrical angle data θe that is a binary number by 2 is calculated. For example, if "1000" is shifted to the right by one digit in binary, it becomes "0100" and is equal to the result obtained by dividing by 2, and if "1000" is shifted by two digits to the right in binary, it becomes "0010" and divided by ² Equal to the result.

Furthermore, operator "<<" represents a left shift operation (left bit shift operation), a calculation method of multiplying 2 ^alpha to binary numbers, .theta.e << 1 is an order of magnitude the electrical angle data .theta.e By shifting leftward, normalized electrical angle data θn obtained by multiplying electrical angle data θe, which is a binary number, by 2 is calculated. For example, if “0100” is shifted by one digit to the left in binary, “1000” is obtained, which is equal to the result of multiplying by 2.

  As shown in FIG. 6, when the number of pole pairs Pn = 1, the electrical angle data θe is multiplied by ¼, so that the electrical angle data θe is shifted to the right by two digits to calculate the normalized electrical angle data θn. Further, when the number of pole pairs Pn = 2, the electrical angle data θe is shifted by one digit to calculate the normalized electrical angle data θn because the electrical angle data θe is multiplied by 2/4. In addition, when the pole pair number Pn = 3, the electrical angle data θe is multiplied by 3/4, so that the sum of the value obtained by shifting the electrical angle data θe by two digits to the right and the value obtained by shifting the electrical angle data θe by one digit to the right. Normalized electrical angle data θn is calculated so as to be equal to. Further, when the number of pole pairs Pn = 4, the normalized electrical angle data θn is calculated so as to be equal to the electrical angle data θe. Further, when the number of pole pairs Pn = 5, the electrical angle data θe is multiplied by 5/4, so that the normalized electrical value is set so that the electrical angle data θe is equal to the sum of the right-shifted value and the electrical angle data θe. Angle data θn is calculated. In addition, when the number of pole pairs Pn = 6, the electrical angle data θe is multiplied by 6/4. Therefore, the normalized electrical value is set so that the electrical angle data θe is equal to the sum of the right-shifted value and the electrical angle data θe. Angle data θn is calculated. In addition, when the number of pole pairs Pn = 7, the electrical angle data θe is multiplied by 7/4. Therefore, the value obtained by shifting the electrical angle data θe by two digits to the right is subtracted from the value obtained by shifting the electrical angle data θe by one digit to the left. Normalized electrical angle data θn is calculated to be equal to the value. When the number of pole pairs Pn = 8, the electrical angle data θn is multiplied by 8/4, so that the normalized electrical angle data θn is calculated so that the electrical angle data θe is equal to a value shifted left by one digit.

  As described above, the normalized electrical angle data θn is calculated only by the connection state of the signal lines in the circuit without using a multiplier or a subtracter by the above-described calculation method using the shift, resulting in an increase in circuit scale. Thus, a common table can be used without any further reduction in circuit size.

As described above, in the motor control device 10 and the motor control method according to the present embodiment, it is determined whether or not the mechanical angle data θm is equal to or greater than the value obtained by multiplying the electrical angle one period data Te by 2 ^n−1. Thus, the first provisional electrical angle data θe ₁ is set to be equal to the mechanical angle data θm at the time of negative determination, and the value obtained by multiplying the mechanical angle data θm by one electrical angle cycle data Te by 2 ⁿ⁻¹ at the time of positive determination. The first provisional electrical angle data θe ₁ is set to be equal to the value obtained by subtracting. Then, it is determined whether or not the (k−1) th provisional electrical angle data θe _k−1 is equal to or greater than the value ^obtained by multiplying the electrical angle single period data Te by 2 ^n−k . k th temporary electrical angle data .theta.e _k to be equal to the temporary electrical angle data .theta.e _k-1 is set, the k-1 th temporary electrical angle data .theta.e _k-1 to an electrical angle of one cycle data Te when affirmative determination The process of setting the k-th temporary electrical angle data θe _k so as to be equal to the value obtained by subtracting the value ^obtained by multiplying 2 ^n−k is repeated from 2 to n. The electrical angle data θe is set to be equal to the _nth provisional electrical angle data θen, and positive cosine wave data is set based on the electrical angle data θe.

Thus, the electrical angle data θe can be used regardless of the number of pole pairs Pn as long as the ^number of pole pairs Pn is 1 to 2 ⁿ without using an electrical angle calculation block for calculating the electrical angle data θe for each number of pole pairs Pn. Can be calculated. In particular, since it is not necessary to use a circuit having a large scale such as a multiplication block, the circuit scale can be reduced. In addition, since the positive cosine wave data is not created by combining a plurality of triangular waves, the accuracy of the positive cosine wave data is not lowered.
Therefore, versatility can be improved without increasing the circuit scale.

The electrical angle data θe is binary data, and a sine wave table 16 is provided that shows the relationship between the electrical angle data θe and the positive cosine wave data when the pole pair number Pn is 2 ^n−1. Yes. Then, using the digit shift and addition / subtraction of the electrical angle data θe, the normalized electrical angle data θn obtained by adding Pn / 2 ⁿ⁻¹ to the electrical angle data θe is calculated, and the normalized electrical angle data θn is calculated. Based on this, positive cosine wave data is set from the sine wave table 16.

  As described above, the normalized electrical angle data θn is calculated only by the connection state of the signal lines in the circuit without using a multiplier or a subtracter by the above-described calculation method using the shift, resulting in an increase in circuit scale. Thus, a common table can be used without any further reduction in circuit size.

[Second Embodiment]
Next, a motor control device and a motor control method according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of a positive cosine wave data calculation process in the second embodiment.
In the second embodiment, even when the brushless motor 1 having a different mechanical angle cycle data Tm is a control target, the positive cosine wave data calculation process is replaced with the flowchart shown in FIG. The point which implements based on the flowchart shown in FIG. 7 differs from the said 1st Embodiment. Therefore, substantially the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the positive cosine wave data calculation processing according to the first embodiment, the processing is performed on the assumption that the mechanical angle one period data Tm corresponding to one mechanical angle period in the encoder 2 is constant. For this reason, if the mechanical angle one cycle data Tm is changed by upgrading the brushless motor 1 or the like, the sine wave table 16 cannot be shared.

Therefore, in the present embodiment, for example, when 8192 is specified as the specific mechanical angle / cycle data, the mechanical angle / cycle becomes data obtained by multiplying the specific mechanical angle / cycle data by 2 ^x (x is an integer). The brushless motor 1 having data Tm is set as a control target. Here, the sine wave table 16 is set based on the specific mechanical angle cycle data. Then, a positive cosine wave data calculation process, to increase its versatility even if the control target of the brushless motor 1 which mechanical angle one cycle data Tm are different, the calculated electrical angle data θe above 2 ^x Division is performed, and normalized electric angle data θn is set with the divided data as electric angle data θe. Thereby, even when the mechanical angle one-cycle data Tm changes by 2 ^× , the sine wave table 16 and the like can be shared.

Hereinafter, the positive cosine wave data calculation process in the present embodiment will be described in detail with reference to the flowchart shown in FIG.
Similar to the first embodiment, when the electrical angle θe is set in the electrical angle data setting process, the shift process shown in step S120 of FIG. 7 is performed. In this process, the electrical angle data is divided by 2 ^× by using the shift of the digit of the electrical angle data θ set as described above. The shift process can correspond to an example of “shift means” described in the claims.

Specifically, for example, when x = 1 and the mechanical angle single cycle data Tm is 16384 (= 8192 × 2 ¹ ), the electrical angle data θ is divided by 2 by shifting the electrical angle data θ to the right by one digit. To do. Further, for example, when x = −1 and the mechanical angle one cycle data Tm is 4096 (= 8192 × 2 ⁻¹ ), the electrical angle data θ is shifted to the left by ⁻¹ by shifting the electrical angle data θ by one digit. Divide (multiply by 2).

  Then, using the data divided in this way as the electrical angle data θe, the address normalization process shown in step S121 is performed, and the normalized electrical angle data θn is set.

As described above, in the motor controller 10 and motor control method according to the present embodiment, the brushless motor 1 which is a mechanical angle one cycle data Tm is multiplied by 2 ^x for certain mechanical angle one cycle data data The sine wave table 16 is a control target, and is set based on the specific mechanical angle one cycle data. Then, the electrical angle data θe divided by 2 ^x by using the shift of the digits of the set electrical angle data θe as described above, positive cosine data is set using the division electrical angle data θe Is done.

As a result, even if the brushless motor 1 whose mechanical angle / cycle data Tm is different from the specific mechanical angle / cycle data by 2 ^× is controlled, the cosine wave data is obtained using the common sine wave table 16. Can be set. In particular, by the calculation method using the shift described above, it is possible to suppress an increase in circuit scale due to the brushless motor 1 having a plurality of mechanical angle / cycle data Tm being controlled.

In addition, this invention is not limited to the said embodiment, You may actualize as follows.
(1) The above-described positive cosine wave data calculation process is not limited to the case where the brushless motor 1 is controlled, but the positive cosine corresponding to the detected motor current value and the electrical angle data at the time of detecting the current. This may be employed when a motor that is driven and controlled according to the wave data is a control target.

(2) In the address normalization process described above, not only the normalized electrical angle data θn is calculated by using digit shift and addition / subtraction, but also multiplication according to the usage situation in which the motor control device 10 is used. Even if the normalized electrical angle data θn is calculated by adopting a device or the like, the sine wave table 16 can be shared.

(3) In the address normalization process described above, Pn is added to the electrical angle data θe with respect to the sine wave table 16 indicating the relationship between the electrical angle data θe and the positive cosine wave data when the pole pair number Pn is 2 ^n−1. / 2 The positive electrical cosine wave data is generated by inputting the normalized electrical angle data θn obtained by integrating ⁿ⁻¹ as an address. However, the present invention is not limited to this generation method, and the following processing may be performed.

That is, in the address normalization process described above, the electrical angle when the pole pair number Pn is 2 ^nm (where m is a positive number equal to or less than n), depending on the usage situation in which the motor control device 10 is used. For the sine wave table indicating the relationship between the data θe and the positive cosine wave data, the normalized electrical angle data θn obtained by integrating Pn / 2 ^nm to the electrical angle data θe is input as an address to obtain the positive cosine wave data. A generation method may be adopted.

(4) In the motor control apparatus 10 described above, the encoder 2 is not limited to the position detector that acquires the mechanical angle, and a position detector such as a resolver may be used.

(5) The sine wave table 16 described above is not limited to the sine wave table storing all data in four quadrants (360 degrees) corresponding to one sine wave cycle. A sine wave table storing only one quadrant (90 degrees) sine wave data may be employed on the assumption that a positive cosine wave is generated using a method of performing address inversion or the like.

DESCRIPTION OF SYMBOLS 1 ... Brushless motor (motor) 2 ... Encoder 10 ... Motor controller 11 ... Controller 15 ... Electrical angle calculation block 16 ... Sine wave table Te ... Electrical angle 1 cycle data Tm ... Mechanical angle 1 cycle data θe ... Electrical angle data θe _k : provisional electrical angle data θm: mechanical angle data θn: normalized electrical angle data Pn: number of pole pairs

Claims (6)

A motor (1) having a pole pair number (Pn) of 1 to 2 ⁿ (n is a positive number) is converted into a detected cosine wave data corresponding to the detected motor current value and electrical angle data (θe) at the time of detecting the current. A motor control device (10) that performs drive control in response,
An acquisition means (11) for acquiring the number of pole pairs of the motor to be controlled and one electrical angle cycle data (Te) corresponding to one electrical angle cycle;
Mechanical angle data detecting means (11, 2, 14) for detecting mechanical angle data (θm) corresponding to the mechanical angle of the motor;
Electrical angle data setting means (11, 15) for setting the electrical angle data based on the mechanical angle data detected by the mechanical angle data detection means;
Positive cosine wave data setting means (11, 16) for setting the positive cosine wave data based on the electric angle data set by the electric angle data setting means,
The electrical angle data setting means includes
It is determined whether or not the mechanical angle data detected by the mechanical angle data detection means is equal to or greater than a value obtained by multiplying the electrical angle single period data by 2 ⁿ⁻¹ , and is equal to the mechanical angle data when a negative determination is made. The first provisional electrical angle data (θe ₁ ) is set so as to be equal to a value obtained by subtracting a value obtained by multiplying the electrical angle one period data by 2 ⁿ⁻¹ from the mechanical angle data at the time of affirmative determination. First temporary electrical angle data setting means (11, 15) for setting _first temporary electrical angle data (θe ₁ );
It is determined whether or not the (k−1) th provisional electrical angle data is equal to or greater than a value ^obtained by multiplying the electrical angle single cycle data by 2 ^n−k , and the k−1th provisional electrical angle data (θe) is determined when a negative determination is made. _k-1 provisional electrical angle data (θe _k ) is set so as to be equal to _k−1 ), and from the k−1th provisional electrical angle data (θe _k−1 ) to the electrical angle one-period data when an affirmative determination is made. 2nd temporary electrical angle data setting means for repeating the process of setting the _kth provisional electrical angle data (θe _k ) so as to be equal to the value obtained by subtracting the value ^obtained by multiplying 2 ^n−k from k to 2 to n. 11, 15)
The motor control device, wherein the electrical angle data is set to be equal to the nth provisional electrical angle data. The electrical angle data is binary data,
The positive cosine wave data setting means includes:
A table (16) showing a relationship between the electrical angle data and the positive cosine wave data when the number of pole pairs is 2 ^nm (m is a positive number of 0 or less than n);
When the number of pole pairs is Pn, calculating means (11, 11) for calculating normalized electrical angle data obtained by adding Pn / 2 ^nm to the electrical angle data by using digit shift and addition / subtraction of the electrical angle data. 15)
The motor control device according to claim 1, wherein the cosine wave data is set from the table based on the normalized electrical angle data calculated by the calculation unit. A motor whose mechanical angle / cycle data (Tm) corresponding to one cycle of the mechanical angle is data obtained by multiplying specific mechanical angle / cycle data by 2 ^x (x is an integer) is controlled,
The table is set based on the specific mechanical angle / cycle data,
A shift means for dividing the electrical angle data by using a shift of the digits of the electrical angle data set by the 2 ^x (11, 15) by the electrical angle data setting means,
The motor control apparatus according to claim 2, wherein the positive cosine wave data setting means sets the positive cosine wave data using the electrical angle data divided by the shift means. A motor control method for driving and controlling a motor having a pole pair number of 1 to 2 ⁿ (n is a positive number) according to a detected motor current value and positive cosine wave data corresponding to electrical angle data at the time of detecting the current. There,
A first step of acquiring the number of pole pairs of the motor to be controlled and one period of electrical angle data corresponding to one period of the electrical angle;
A second step of detecting mechanical angle data corresponding to the mechanical angle of the motor;
A third step of determining whether or not the mechanical angle data detected in the second step is equal to or greater than a value obtained by multiplying the electrical angle single cycle data by 2 ⁿ⁻¹ ;
The first provisional electrical angle data is set to be equal to the mechanical angle data at the time of negative determination in the third step, and the electrical angle one-cycle data is multiplied by 2 ^n-1 from the mechanical angle data at the time of positive determination. A fourth step of setting the first temporary electrical angle data to be equal to the value obtained by subtracting the value;
a fifth step of determining whether or not the k-1th provisional electrical angle data is equal to or greater than a value ^obtained by multiplying the electrical angle single period data by 2 ^n−k ;
The kth temporary electrical angle data is set to be equal to the k-1th temporary electrical angle data at the time of negative determination in the fifth step, and the electrical angle equals from the k-1th temporary electrical angle data at the time of positive determination. A sixth step of repeating the process of setting the k-th temporary electrical angle data so as to be equal to the value obtained by subtracting the value ^obtained by multiplying the periodic data by 2 ^nk , from k to 2 to n,
A seventh step of setting the electrical angle data to be equal to the nth provisional electrical angle data;
An eighth step of setting the positive cosine wave data based on the electrical angle data calculated in the seventh step;
A motor control method comprising: The electrical angle data is binary data,
A table showing a relationship between the electrical angle data and the positive cosine wave data when the number of pole pairs is 2 ^nm (m is a positive number of 0 or n or less);
The seventh step includes
When the number of pole pairs is Pn, normalized electrical angle data obtained by adding Pn / 2 ^nm to the electrical angle data is calculated by using digit shift and addition / subtraction of the electrical angle data. The motor control method according to claim 1, wherein the positive cosine wave data is set from the table based on angle data. The control object is a motor whose mechanical angle / cycle data corresponding to one cycle of the mechanical angle is data obtained by multiplying specific mechanical angle / cycle data by 2 ^x (x is an integer),
The table is set based on the specific mechanical angle / cycle data,
The eighth step includes
The seventh divided by set the electrical angle data of digits of the the electrical angle data by using a shift 2 ^x in step, the set positive cosine wave data using this division is the electrical angle data were The motor control method according to claim 5.

Images