JPH1198876A - Position and speed detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce sensitivity due to noise and enable position and speed detection with accuracy, by making a rotational position signal, calculated from an inducing signal having the frequency of an exciting signal as a fundamental wave and the exciting signal having phase difference through sum of products operation, follow phases through software PLL processing. SOLUTION: For a microcomputer 102, an arithmetic operation is performed at a position and speed detecting section 101 using timing pulses output from a timing pulse generating section as an interrupt signal. The voltage of inducing signals Vr1 , Vr2 and exciting signals Vs1 , Vs2 is input to the microcomputer 102 from A-D converters 103-106. A signal varying with a rotational frequency obtained by expressing rotational position signals Ve1 , Ve2 in first sum of products operation as rotational position θr, and subtracting an exciting frequency component from the frequency of the inducing signals, is used in the software PLL processing on the microcomputer. The rotational speed is detected by determining the change in the position detected through software PLL processing on the microcomputer 102 using a differentiation element 120. Thus, the phase can be PLL-processed on software for a microcomputer or the like, and can be sufficiently followed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position / speed control device for a motor, and more particularly to a position / speed control device suitable for detecting a rotation position and a rotation speed of a motor using a resolver as a position detector or a speed detector. The present invention relates to a speed detecting device.

[0002]

2. Description of the Related Art Conventionally, as a method of obtaining the rotation speed of a motor using a resolver, a method of detecting the rotation frequency of an induced signal output from a resolver by a PLL and obtaining the rotation speed is disclosed in Japanese Patent Laid-Open No. 57-33355. It is known in the gazette. Also,
As a method of detecting the rotational position of the electric motor, a two-phase signal corresponding to the rotational position is calculated by a product-sum operation of an induced signal output from the resolver and an excitation signal applied to the resolver,
A method of detecting the rotational position of the electric motor by calculating the tan ^{-1 of the} two-phase signal is known from Japanese Patent Laid-Open No. 59-13708.

[0003]

The first prior art is a method of detecting only the rotation speed of a motor by using a PLL, and requires a separate circuit for detecting the rotation position of the motor. In addition, in order to detect the rotation speed, the rotation frequency of the induced signal is tracked by the PLL. However, since the frequency of the induced signal is high, the operation of the PLL must be performed at a high speed. This constitutes a PLL. Therefore, there is a problem that adjustment of the PLL is not easy. In the second prior art, the rotation speed can be detected from the obtained rotation position in addition to the rotation position. However, in the above prior art, the rotational position is detected by the tan ^-1 operation by performing the product-sum operation of the induced signal and the excitation signal, and if the induced signal is affected by noise or the like, the influence is not changed. There is a problem that a detection error occurs.

An object of the present invention is to reduce the sensitivity due to noise even if the induced signal is affected by noise, and to enable position detection and speed detection with high accuracy. In addition, by performing the operation of the PLL constituted by the hardware by software processing on the microcomputer, the adjustment of the PLL becomes easy, and the position / speed detecting device can be constructed at low cost without using a high-speed microcomputer. In addition, by eliminating the offset error generated in the position detection when the motor accelerates / decelerates in a ramp shape, the position detection accuracy is further improved, and any cycle corresponding to the position control or the speed control is achieved. The detection can be performed with.

[0005]

As a method for achieving the above object, a rotational position signal corresponding to a rotational position is calculated by performing a product-sum operation of an induced signal and an excitation signal, and this rotational position signal is stored in a microcomputer. The phase is followed by a PLL process (software PLL process) performed by software, and the rotational position and the rotational speed are detected. The induced signal is output at a frequency obtained by modulating the rotation frequency of the rotator with the frequency of the excitation signal (several KHz) as a fundamental wave. Therefore, if the excitation frequency component can be subtracted from the frequency of the induced signal, it is the rotation frequency. It can be a rotational position signal of several tens Hz, and software PL
The tracking can be sufficiently performed by the L processing. The subtraction of the excitation frequency from the frequency of the induced signal can be obtained by a product-sum operation of the induced signal and the excitation signal. By this product-sum operation, the rotation position can be detected by the PLL without using a high-speed microcomputer by using the rotation position signal without following the induced signal having a high frequency as in the related art. In order to improve the position detection accuracy, the software PLL processing is configured by a double integration system using integration and proportional integration, and an offset error generated in position detection when the rotation speed of the rotating body is accelerated or decelerated in a ramp shape. lose.

In the software PLL processing, a phase difference is obtained by performing a product-sum operation again with a product-sum operation result as an input value and a feedback value as an output of the PLL, and this phase difference is obtained by a double integration system. The integration is performed so that the input value matches the feedback value. In the first position detection, since the feedback value used for the product-sum operation performed in the PLL process is indefinite, the tan ^-1 operation is performed using the product-sum operation result of the excitation signal and the induced signal, and the initial value of the PLL is calculated. That is, it is a feedback value. Further, the timing pulse generation circuit for generating the timing of position detection has a configuration in which the position detection timing can be arbitrarily set.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a position / speed detecting device using the present invention will be described below. FIG. 2 is an overall configuration diagram of a motor drive system using the present invention. The control unit 201 performs position / speed control processing, a main converter 202 that outputs an AC voltage according to a speed command to a motor 203, and a detector. A resolver 301 includes a position / speed detection unit 101 that detects the rotation position and rotation speed of the electric motor 203. The control unit 201 is configured by means having an arithmetic function such as a microcomputer, and inputs a detected value of the rotational position and a detected value of the rotational speed from the position / speed detecting unit 101 at every predetermined sampling period. The control unit 201 controls the rotation speed by adjusting the three-phase AC voltage and frequency output from the main converter 202 based on the input rotation speed and rotation position. Position / speed detector 10
Reference numeral 1 denotes a two-phase excitation signal applied to a resolver 301 mechanically attached to the electric motor 203 and a two-phase induction signal induced by the resolver 301. The motor 2
The rotation position and the rotation speed of 03 are detected.

Next, the resolver 301 will be described with reference to FIG. The resolver 301 is composed of primary windings 302 and 303 mechanically arranged at an angle of 90 degrees, and a secondary winding 30 mechanically arranged at an angle of 90 degrees.
It is a two-phase excitation two-phase output type composed of 4,305. First, a two-phase excitation signal V having a 90-degree phase difference output by an excitation signal generation unit 401 described later is applied to primary windings 302 and 303.
_{When S1} and _VS2 are applied

[0009]

V _S1 = V sin θ _S (1)

[0010]

V _S2 = V cos θ _S (2) The following two-phase induction signals V _r1 and V _r2 corresponding to the rotational position θ _r are output (induced) to the secondary windings 304 and 305 by the transformer effect. You.

[0011]

V _r1 = K (V _S1 cos θ _r −V _S2 sin θ _r ) (3)

[0012]

Equation 4] _{V r2 = K (V S1 sinθ} r + V S2 cosθ r) ... (4) where, V _S1, V _S2: excitation signal, K: where transformation ratio, the two-phase excitation signals V _S1, V _S2 Will be described with reference to FIG. The excitation signal generation unit 401 includes a crystal oscillator 402, a counter 403 that counts pulses output from the crystal oscillator 402, a ROM 404 that records an instantaneous value of the excitation signal V _S1 , a ROM 405 that records an instantaneous value of the excitation signal V _S2 , and each ROM 404. D / A converters 406 and 4 for converting the digital values from,.
07, voltage control units 408 and 409 for controlling (AVR) the voltage levels of the two-phase excitation signals V _S1 and V _S2 applied to the primary winding of the resolver 301 to a desired value, and a timing pulse trg for position detection. And a timing pulse generator 410 for outputting the same.

First, the pulses of the crystal oscillator 402 are counted by the counter 403, and the count value is read from the ROMs 404 and 405.
Of the D / A converter 40
6, 407 output excitation signals V _S1 and V _S2 having constant frequencies represented by the equations (1) and (2). Therefore, the excitation signal V _S1 is applied to the primary winding 302 of the resolver 301, and the excitation signal V _S2 is applied to the primary winding 303.

The timing pulse generator 410 generates a timing pulse trg which is a timing of position detection with a predetermined count value of the counter 403, and outputs a timing pulse trg to be described later.
As an interrupt signal to the microcomputer 102 of the speed detecting unit 101, and A / D converters 103, 104, 105, 106
Is supplied with a timing as a start signal. The predetermined count value serving as the timing of position detection can be set arbitrarily, and can be set to a detection cycle suitable for position or speed control.

Next, the detailed configuration of the position / speed detecting unit 101 will be described with reference to FIG. The configuration of the position / speed detection unit 101 includes a microcomputer 102 that performs position and speed calculations, an excitation signal generation unit 401 that outputs two-phase excitation signals V _S1 and V _S2 to the primary winding of the resolver 301, Induced signals V _r1 , V
A / D converters 103 and 104 for taking in the voltage of _r2 , and A / D converters 105 and 106 for taking in the voltages of the two-phase excitation signals V _S1 and V _S2 . A / D converter 103, 1
04, 105, and 106 are timing pulses output by the timing pulse generator 410 of the excitation signal generator 401.
The excitation signals V _S1 and V _S2 and the induced signal V
Conversion of _r1 and _Vr2 is performed.

The microcomputer 102 uses the timing pulse trg output from the timing pulse generator 410 as an interrupt signal, and executes a position detection calculation and a speed detection calculation by processing generated by the interrupt. In the position detection calculation processing, first, the A / D converters 103, 104, 105, 1
From step 06, the voltages of the induced signals V _r1 and V _r2 and the excitation signals V _S1 and V _S2 are fetched, and the position and speed are detected in the following procedure.

In the position detection calculation processing, first, the induced signals V _r1 and V _r2 at the position detection timing are converted into A / D converters 1.
03 and 104, and input the excitation signals V _S1 and V _S2 to the A / D converters 105 and 106 in the same manner.
To enter through. Here, the induced signals V _r1 and V _r2 are represented by the equations (3) and (4), but since the excitation signals V _S1 and V _S2 are represented by the equations (1) and (2), (3) and (4) The expression can be modified as follows.

[0018]

[Number 5] _{V r1 = VKsin (θ S -θ} r) ... (5)

[0019]

V _r2 = VK cos (θ _S −θ _r ) (6) where V: excitation voltage, K: transformation ratio (5) As can be seen from equations (6), induced signals V _r1 , V
_r2 is expressed by a phase difference of the rotational position theta _r and theta _S is the phase of the excitation signal. Here, the phase θ _S changes at a frequency of several KHz which is the frequency of the excitation signal, and the rotational position θ _r changes at several tens Hz which is the rotation frequency. Therefore, the induced signal is output at a frequency modulated by the rotation frequency with the frequency of the excitation signal as a fundamental wave, and can be regarded as substantially the frequency of the excitation signal. In the prior art, the phase or rotation frequency of the induced signal is obtained by following the PLL.
The rotation position and rotation speed were detected. In order to follow the phase or frequency of the induced signal by the PLL, it is necessary to perform the operation at a high speed. Conventionally, the PLL is configured and realized by hardware. When the position detection or the speed detection processing by the PLL is realized on a microcomputer, the speed of the PLL processing becomes a problem. However, even when a high-speed microcomputer is used, the induced signal having a high frequency as in the related art is used. There is a limit to follow.

Therefore, as a method of obtaining the rotation position and the rotation speed by the PLL processing on the microcomputer, a rotation position signal as a rotation frequency is generated by signal processing described later instead of using a high-speed microcomputer. Is followed by software PLL processing on the microcomputer. That is, by performing a product-sum operation of the excitation signal and the induced signal, the excitation frequency component is removed from the frequency of the induced signal, and a signal that changes with the rotation frequency is generated. The instantaneous values of the induced signals V _r1 , V _r2 and the excitation signals V _S1 , V _S2 at the position detection timing are converted by the microcomputer 1 through the A / D converters 103, 104, 105, 106.
02, and performs a product-sum operation (hereinafter referred to as a first product-sum operation) between the induced signals V _r1 and V _r2 and the phases of the excitation signals V _S1 and V _S2 represented by the following equations.

[0021]

V _e1 = sin θ _S × V _r2 −cos θ _S × V _{r1 = sinθ S × VKcos (θ S} -θ r) -cosθ S × VKsin (θ S -θ r) = VKsinθ r ... (7)

[0022]

V _e2 = cos θ _S × V _r2 + sin θ _S × V _{r1 = Cosθ S × VKcos (θ S} -θ r) + sinθ S × VKsin (θ S -θ r) = VKcosθ r ... (8) (7) (8) Equation multiplication over microcomputer 102 107,10
The calculation is performed by 8, 110, 111 and additions 109, 112. As can be seen from equations (7) and (8), the rotation position signals V _e1 and V _e2 that are the results of the first sum-of-products operation are represented by the rotation position θ _r , and the rotation obtained by removing the excitation frequency component from the frequency of the induced signal. It is a signal that changes with frequency. Since the signal that changes with the rotation frequency can be sufficiently followed by software PLL processing, the rotation position signals V _e1 and V _e2 are
This is input to the LL process. Next, PL performed by software
The L processing will be described.

The software PLL process of the microcomputer 102 receives both the rotational position signals V _e1 and V _e2 as inputs and
The output of the L processing is the detected position θ _r ^* . Software PL
Multiplications 113 and 114 and addition 115 as the configuration of the L processing
, A proportional integral element 117, an integral element 118, and a table 116. Since a feedback loop is formed by these configurations, in a steady state, the input / output relationship operates so that the rotational position θ _r = the detected position θ _r ^* . The reason for inputting both of the rotational position signals V _e1 and V _e2 is that a product-sum operation (hereinafter referred to as a second product-sum operation) represented by the following equation is performed to detect the output of software PLL processing. This is for calculating the phase difference between the position θ _r ^* and the input rotation position signal (rotation position θ _r ).

[0024]

Equation 9 Δθ = V _e1 × cos θ _r ^* −V _e2 × sin θ _r ^{* _{= VKsinθ r × cosθ r * -VKcosθ}} × sinθ r * = VKsin (θ r -θ r *) ... (9) sinusoidal signal at the detection position theta _r ^* in the calculation sin [theta _r ^*,
The instantaneous value of the cosine signal cos θ _r ^* is output from the table 116, and the above operation is performed by multiplication 113, 114 on the microcomputer 102.
And addition 115. Further, the phase difference Δθ, which is the calculation result of the equation (9), is input to an integration element 118 via a later-described proportional integration element 117, and the integration of the phase difference Δθ, that is, the addition of the phase difference Δθ is calculated by the integration element 118. , The detection position θ _r ^* which is the sum of the phase differences Δθ is a software PLL.
Output value of the process. Here, in the software PLL process, since the feedback loop is formed by the above configuration, the detection position θ _r ^* is adjusted so that the phase difference Δθ always becomes 0, that is, the rotational position θ _r = the detection position θ _r ^*. Is calculated. Proportional integral element 11 which is one of the configurations of PLL
7, when the motor 203 performs ramp-shaped acceleration / deceleration,
Since an offset error occurs in position detection only by the integration element 118, the offset error is provided to eliminate the offset error.

As a result, the position detection accuracy is further improved. Note that, at the first position detection timing, the detection position θ _r ^* required when performing the calculation of the equation (9) ^.
Since it is indefinite, the detection position theta _r ^* sine signal sin [theta _r ^*,
The cosine signal cosθ _r ^* cannot be read from the table 116. Therefore, using the rotational position signals V _e1 and V _e2 ,
The detection position θ _r ^* is obtained by the following tan ⁻¹ calculation, and is used as the initial value of the output of the PLL. In the second and subsequent calculations of Expression (9), the table 116 is referred to using the value of the detection position θ _r ^* , which is the output of the software PLL processing.

[0026]

(Equation 10)

However, performing the above calculation by a microcomputer causes problems such as an increase in program capacity. Therefore, the above calculation formula may be a rough calculation such as a linear approximation formula. However, the error is within 180 degrees. This is merely read from the table 116 detected position theta _r ^* sine signal sin [theta _r ^* and the cosine signal cos [theta] _r ^* in the position detection of the first, the error generated in the approximate expression in the position detection of the second and subsequent This is because the error is corrected by the software PLL processing. Detection of the rotation position theta _r is performed in software PLL process by the above configuration.

Next, the speed detection calculation process for detecting the rotation speed will be described.

The rotational speed is calculated by the differential element 120 shown in FIG. 1 and the derivative of the detected position θ _r ^* detected by the software PLL processing on the microcomputer 102, that is, the detected position θ _r ^* per position detection cycle shown in the following equation Is detected by calculating the change in Expression (11) is calculated by the calculation function of the microcomputer 102.

[0030]

[Equation 11]

Next, the position detection calculation processing performed by the microcomputer 102 will be described with reference to the flowchart of FIG. The position detection arithmetic processing is started by an interrupt by a timing pulse trg supplied from the timing pulse generator 410. In step 501, the induced signals V _r1 and V _r2 are converted by the A / D converter 1.
03, 104, and the excitation signals V _S1 , V
_{S2 is} also connected to the microcomputer 10 via the A / D converters 105 and 106.
Take in 2.

Next, at step 502, the first sum of products operation represented by the equations (7) and (8) is performed. In step 503, it is determined whether the position detection processing is the first time. If it is the first time, since the detection position θ _r ^* is indefinite, the detection position θ _r ^* is calculated in step 504 by the tan ^-1 operation of the equation (10). In step 505, the detected position θ _r ^* calculated in step 504 is recorded as an initial value (previous value) of the PLL. If the position detection calculation processing is performed for the second time or later, a sine signal sin θ _r ^* of the detection position θ _r ^* and a cosine signal
The value of cosθ _r ^* is read from the table 116, and the second sum-of-products calculation represented by the equation (9) is performed in step 507. In steps 508 and 509, a proportional integral element and an integral element are performed to detect a detection position θ _r ^* . Then, the detected position θ _r ^* detected in step 510 is stored as the previous value, and the process is completed.

Next, the speed detection calculation processing performed by the microcomputer 102 will be described with reference to the flowchart of FIG. In the speed detection calculation process, the calculation is performed subsequent to the position detection calculation process, which is an interrupt process generated by the timing pulse trg supplied from the timing pulse generator 410. First, in step 601, the current position detection timing i
Of the detected position θ _r ^* (i). Step 60
2, the detected position θ _r ^* (i−1) at the previous position detection timing i−1 is read, and at step 603 (1
1) The operation of the expression is performed, and the process is completed.

In the embodiment described above, the timing of the position detection generated by the timing pulse generator 410 is set arbitrarily, and the detection is performed at a detection cycle suitable for position or speed control. An embodiment in which the cycle is performed in synchronization with the excitation cycle will be described.

FIG. 7 shows the configuration of the present embodiment. The same reference numerals as those in FIG. 1 denote the same elements, and the excitation signals V _S1 and V
Instead of the A / D converter for taking in _S2 , square pulse generating circuits 121 and 122 are added, and the excitation signal supply unit 12
3 is newly added. First, the timing of position detection in the present embodiment will be described with reference to FIG.

In this embodiment, the position detection timing is
In synchronization with the excitation signal, N times (N
= 1, 2, 4).
10 outputs a timing pulse trg. However, the excitation signal to be synchronized is determined by the number of position detections (N) in one cycle of the excitation signal. That is, as shown in FIG. 8, if N = 1, it is only necessary to perform position detection once for one cycle of the excitation signal. Therefore, the time when the phase of the excitation signal V _S1 is 0 degree is set as the position detection timing. If N = 2, the position detection timing is set every half cycle of the excitation signal V _S1 (phase: 0 degree, 1 degree).
80 degrees), and N = 4, the timing pulse trg every half cycle of the excitation signal V _S1 (phase: 0 degrees, 180 degrees) and every half cycle of the excitation signal V _S2 (phases: 90 degrees, 270 degrees). Generate.

Next, the added square pulse generating circuit 121,
Reference numeral 122 denotes a comparator which converts the excitation signals V _S1 and V _S2 into rectangular pulses P _S1 and P _S2 .
When an input signal as shown in FIG. 9 is input, the input signal is converted into a square pulse and output. Although a detailed description of the excitation signal supply unit 123 will be described later, the excitation signals V _S1 ,
It outputs the value of V _S2 . Synchronizing the position detection with the excitation signal is based on the excitation signal V at the position detection timing.
The instantaneous values of _S1 and V _S2 are known in advance, and the excitation signals V _S1 and V _S2 can be calculated without using an A / D converter. For example, assuming that the position detection cycle is once per excitation cycle (N = 1),
Excitation signals V _S1 and V _S2 when position detection timing occurs
Are constant, that is, the phase is 0 degree, so that the excitation signals V _S1 and V _S2 can be regarded as constants as shown below.

[0038]

V _S1 = V sin θ _S = 0, V _S2 = V cos θ _S = V (12) Similarly, if N = 2, every half cycle of the excitation signal V _S1 (phase: 0 degree, 180 degrees) Since the position detection timing occurs, the excitation signals V _S1 and V _S2 can be regarded as the following two constants.

[0039]

[Number 13] θ _S = 0 degrees _{when: V S1 = Vsinθ S = 0} , V S2 = Vcosθ S = V ... (13)

[0040]

Equation 14] theta _S = 180 degrees _{when: V S1 = Vsinθ S = 0} , V S2 = Vcosθ S = -V ... (14) Moreover, if N = 4, every half cycle of the excitation signal V _S1 ( Since the position detection timing occurs every half cycle of the excitation signal V _S1 (phase: 0 degrees, 180 degrees) and the excitation signal V _S1 (phases: 90 degrees, 270 degrees), the excitation signals V _S1 and V _S2 are regarded as the following four constants. Can do things.

[0041]

[Number 15] θ _S = 0 degrees _{when: V S1 = Vsinθ S = 0} , V S2 = Vcosθ S = V ... (15)

[0042]

[Number 16] θ _S = 90 degrees _{when: V S1 = Vsinθ S = V} , V S2 = Vcosθ S = 0 ... (16)

[0043]

[Number 17] θ _S = 180 degrees _{when: V S1 = Vsinθ S = 0} , V S2 = Vcosθ S = -V ... (17)

[0044]

When θ _S = 270 degrees: V _S1 = V sin θ _S = −
V, V _S2 = V cos θ _S = 0 (18) As described above, the excitation signals V _S1 and V _S2 are regarded as constants at each position detection timing, and the values of the excitation signals V _S1 and V _S2 at each position detection timing are excited. It is recorded in the signal supply unit 123. However,
When performing the position detection calculation processing (excluding the position detection timing when N = 1), it is necessary to determine the timing (phase) of the position detection timing and then use the excitation signals V _S1 and V _S2 of each phase. is there. This determination is made by the square pulse generation circuit 12
The quadrant determination is performed based on the signal levels of the square pulses P _S1 and P _S2 output from 1,122. The actual position detection calculation processing in the microcomputer 102 is almost the same as the calculation processing shown in FIG. 5, but only the step 501 is different.

In this embodiment, in addition to the induced signals V _r1 and V _r2 , square pulses P _S1 and P _S2 from the square pulse generation circuits 121 and 122 are fetched. The quadrant at the time of position detection is determined by the square pulses P _S1 and P _S2 , and the values of the excitation signals V _S1 and V _S2 in the quadrant are determined by the excitation signal supply unit 123,
Read from 124. Subsequent processing is the same as the arithmetic processing shown in FIG. In this embodiment, the timing pulse trg is generated using the polarity of the excitation signal.
It is also possible to use the count value of the counter 403 for determining the addresses of 04 and 405.

According to the present embodiment, the adjustment of the PLL section is performed by software, so that only the integration of the PLL and the constant of the proportional integration are changed, so that the adjustment is easy. In addition, by synchronizing the position detection cycle with the excitation cycle, the number of A / D converters that take in the excitation signal can be reduced, and the multiplication of the first product-sum operation and the second product-sum operation can be omitted. Therefore, there is an effect that arithmetic processing can be performed without using a high-speed microcomputer.

[0047]

According to the present invention, position detection or speed detection can be performed at a detection cycle suitable for position control or speed control of a motor. Conventionally, a PLL is configured by hardware in order to follow an induced signal having a frequency as high as several KHz, and it is not easy to adjust the PLL. However, according to the present invention, by performing a product-sum operation of the excitation signal and the induced signal to generate a signal that is the rotation frequency of the rotating body, it is possible to sufficiently follow the PLL processing on software such as a microcomputer, thereby achieving high-speed operation. A system can be realized at low cost without using a microcomputer. Also,
Since the PLL implemented by software is constituted by a double integration system, even when the rotating body is accelerated or decelerated in a ramp shape, the position can be accurately detected without generating an offset error in the position detection.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a position / speed detection unit according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a system using the position / speed detection device of the present invention.

FIG. 3 is a configuration diagram of a resolver of the present invention.

FIG. 4 is a configuration diagram of an excitation circuit according to the present invention.

FIG. 5 is a flowchart of a position detection calculation process according to the present invention.

FIG. 6 is a flowchart of a speed calculation process according to the present invention.

FIG. 7 is a configuration diagram of a position / speed detection unit according to a second embodiment of the present invention.

FIG. 8 is an operation diagram of the timing pulse generation circuit of the present invention.

FIG. 9 is an operation diagram of the square pulse generation circuit of the present invention.

[Explanation of symbols]

101: position / speed detector, 102: one-chip microcomputer, 103, 104, 105, 106: A / D converter,
301: resolver, 401: excitation signal generation unit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoji Monmino 5-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Omika Plant, Hitachi, Ltd. (2-1) Inventor Akihiro Inogari 5-2-1 Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Omika Plant

Claims (6)

[Claims] 1. A two-phase primary winding mechanically disposed at an angle of 90 degrees and a two-phase secondary winding mechanically disposed at an angle of 90 degrees. In a resolver in which a secondary winding is mechanically coupled to a rotating body, an excitation circuit for applying a two-phase excitation signal having a phase difference of 90 degrees to the primary winding; Sum-of-products calculation function for performing a sum-of-products operation of the two-phase induced signal output from the secondary winding of the phase, and a PLL (phase-locked loop) using a calculation result of the first sum-of-products calculation function as a command value ) Function, the first product-sum operation function outputs a two-phase rotational position signal corresponding to the rotational position of the rotating body, and inputs the two-phase rotational position signal as a command value of the PLL function. By detecting the detected position signal that is the rotational position of the rotating body, and also detected Serial detecting a position signal by differentiating and obtaining the rotational speed of the rotator position and speed detector. 2. An analog-to-digital converter (A / D converter) for taking in the voltage of the two-phase excitation signal and the voltage of the two-phase induced signal, and a microcomputer (microcomputer) according to claim 1, A position / velocity detection device, wherein the first product-sum operation function and the PLL function are realized by software processing of the microcomputer. 3. The PLL function according to claim 1, wherein a second product-sum operation function for outputting a phase error signal between the two-phase rotational position signal and the position detection signal, and a compensation operation for the phase error signal. The second product-sum operation function has a table that outputs a two-phase feedback signal having a 90-degree phase difference corresponding to the detection position signal output by the error compensation function. A phase error signal is output by a product-sum operation of the two-phase rotation position signal and the two-phase feedback signal output by the one-sum operation function, and the error compensation function performs a compensation operation on the phase error signal. As a function to be performed, the phase error signal is integrated by a double integration system composed of a proportional integration element and an integration element to obtain the position detection signal, and the instantaneous values of sin and cos corresponding to the position detection signal are obtained from the table. Position and speed detection device, characterized in that the feedback signal of the two-phase. 4. The PLL function according to claim 3, wherein
Using the two-phase rotational position signal output from the first sum-of-products calculation function at the timing of the first position detection, a position detection value is calculated by performing tan ^-1 calculation by software processing of the microcomputer. The initial value of the position detection signal output from the PLL function is set as an initial value, and at the timing of the second and subsequent position detection, the table is drawn using the position detection signal obtained from the PLL function. Position / speed detector. 5. An exciting circuit according to claim 1, wherein a constant clock oscillator, a counter function for counting pulses from said constant clock oscillator, and sin and cos corresponding to one cycle of said two-phase excitation signal are provided. A semiconductor memory storing each instantaneous value, and a digital / analog converter (D / A
Converter), the counter function repeatedly counts at a cycle corresponding to the two-phase excitation signal, and uses the counted value as an address input of the semiconductor memory, and the semiconductor memory outputs instantaneous data of the excitation signal to the semiconductor memory. The analog sine-wave and cosine-wave signals output from the D / A converter are given to the D / A converter as the two-phase excitation signals, and the counter function generates a timing pulse which is the timing of the position detection cycle. A timing pulse generating function, wherein the timing pulse is supplied to the microcomputer as an interrupt signal and the A
A position / velocity detecting device, which is used as a start signal of a / D converter. 6. A timing pulse generating function according to claim 5, wherein said timing pulse is synchronized with a cycle of said excitation signal, and said timing pulse is generated N times within one cycle of said excitation signal. Performing the first sum-of-products function using the instantaneous value of the two-phase excitation signal in the timing pulse as a constant.
Speed detector.