JPH10281809A - Position sensor and motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sense the position of an object without malfunction even where the object moves at high speed, by installing an interpolating processing circuit, and first and second generators for generating carry and digit lowering pulses from the signals generated by shaping first and second position signals into rectangular waveforms, and by switching the carry and digit lowering pulses according to the travel speed of the object. SOLUTION: A position signal generator 102 outputs first and second position signals MR1 and MR2 of which the phases differ from each other by an angle of 90 deg according to the turning angle of a motor 101. An interpolation processing circuit 126 divides one period of the position signals MR1 and MR2. A first pulse generating circuit 116 generates carry and digit lowering pulses from the output signals of the interpolation processing circuit 126. A second pulse generating circuit 118 generates carry and digit lowering pulses from the output signals of a waveform transforming circuit 114. A pulse change-over circuit 121 selects carry and digit lowering pulses of, if L level, the first and, if H level, the second pulse generators 116 and 118, and the pulses subjected to carry and digit lowering pulses are counted by an up-down counter 122.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for detecting the position of an object such as a motor, and which can be used in a motor control device to control the rotation position or rotation speed of the motor. It is.

[0002]

2. Description of the Related Art An example of a position detecting device applied to a motor control device is disclosed in Japanese Patent Application No. 8-201621. Hereinafter, a conventional position detecting device will be described with reference to the drawings. FIG. 10 is a configuration diagram of a conventional position detection device.

In FIG. 10, reference numeral 101 denotes a motor;
Is a position signal generator. The position signal generators 102 have a phase of 90 ° according to the rotation angle position of the motor 101.
It outputs different first and second position signals MR1 and MR2. In this conventional example, MR1 = cos θ, MR2 = sin
θ. MR1 and MR2 are one of the motors 101.
Assume that 512 waves are generated per rotation.

[0004] Reference numerals 1103 and 1104 denote amplifying circuits, and the first and small amplifiers output from the position signal generator 102 have small amplitudes.
This circuit amplifies the second position signals MR1 and MR2 by a predetermined gain so as to have an amplitude sufficient for the subsequent signal processing, and outputs the amplified signals. A position detection circuit 1105 in the broken line frame outputs a rotation position in one rotation as a digital value, and includes an interpolation processing circuit 1126 (inside the broken line frame 1126) that divides one cycle of the position signals MR1 and MR2 more finely. ing.

Next, the position detection circuit 1105 and the interpolation processing circuit 1126 will be specifically described. 1106,11
07 is a multiplication circuit, and 1111 is a position detection signal MR.
1, phases of 90 ° which are sufficiently higher than the frequency of MR2 (for example, several tens kHz to several hundred kHz) are different from each other by 90 °.
A multiplying circuit 1106, 1107 is a carrier signal generating circuit for generating a phase carrier signal.
104, the position signals MR1 and MR amplified respectively.
2 is multiplied by each carrier signal, and the carrier signal is modulated by the position signal. That is, the carrier signal generation circuit 1111 generates two-phase carrier signals having phases different from each other by 90 °, and if one of the signals is + sinωt (ω: angular velocity, t: time), the other is cosωt or −cosωt. (To be explained in the former).

[0006] One multiplication circuit 1106 has one phase position signal MR1 (cos θ) and one carrier signal (+ s
inωt), and the other multiplication circuit 1107 multiplies the position signal MR2 (sin θ) of the other phase by the other carrier signal (+ cosωt). Multiplication circuit 110
6,1107 outputs (+ sin ωt · cos θ),
(+ Cosωt · sin θ) is introduced into the adder circuit 1108 and added to obtain sin (ωt + θ).

[0007] The added signal is input to a waveform shaping circuit 1110 for converting unnecessary signals into high-frequency components in a filter 1109 and then converting the signal into a square wave.
The output of 0 is input to the phase detector 1113. The phase detector 1113 outputs the output signal s from the waveform shaping circuit 1110.
In (ωt + θ) is compared with the output signal sinωt from the carrier signal generation circuit 1111 to detect the phase θ. The detected phase θ is converted into a digital signal, and is output as 7-bit data, for example.

The pulse generation circuit 1116 and the up / down counter 1122 carry out and carry out the above-mentioned phase θ, and detect the result as a position larger than one cycle of the position signals MR1 and MR2. As the output.

Assume that the position signal generator 102 outputs 512 position signals MR1 and MR2 per rotation, and further divides one wave of the MR1 and MR2 into 128. That is, the rotation position of the motor 101 is set to 51
It is divided into 2 × 128 = 65536 and represented as 16-bit position data. In this case, the format of the position data is such that the upper 9 bits are 5 bits of the position signals MR1, MR2.
The lower 7 bits are assigned to the position signal MR.
It is assumed that one wave of 1, MR2 is assigned to 128 divisions. The upper 2 bits of the lower 7 bits are used as carry / borrow data.

[0010] That is, with the rotation of the motor 101, the lower 7
The bit is, for example, 000000, 0000001, 0
...,..., And then, when the overflow occurs and the upper 2 bits of the lower 7 bits change from 11 to 00, a carry occurs. That is,
The pulse generation circuit 1116 outputs a carry pulse, and the up / down counter 1122 adds one bit.

As a result, the least significant bit of the upper bit changes from 0 to 1, and shifts to the next wave of the position signal MR1 or MR2. By repeating the above, all 16-bit data changes at every minute rotation angle according to the rotation angle of the motor 101, and after one rotation, all 16-bit data returns from the state of all 1 to the initial value of all 0.

In the case of reverse rotation, it is assumed that when the upper 2 bits of the lower 7 bits change from 00 to 11, a carry down occurs. That is, the pulse generation circuit 11
16 outputs a carry pulse, and the up / down counter 1122 subtracts 1 bit.

The data register 1123 stores the output signal of the up / down counter 1122 as upper data, and the data register 1124 stores the output signal of the phase detector 1113 as lower data. Is output.

By performing the above operation, the position during one rotation is subdivided into 16 bits, that is, 65536 data, and the rotational position of the motor can be detected with high resolution.

[0015]

However, in the above-described method, the rotational position of the motor can be detected with high resolution, but the frequency of the carrier signal is constant, so that the rotational speed of the motor increases and the position of the motor increases. If the frequency of the signal becomes about 1/5 or more of the frequency of the carrier signal, the carry-carry processing is not performed properly, and a malfunction occurs. Further, when the frequency of the position signal is further increased, there is a problem in that a detected value of a position finer than one cycle of the position signal detected by the interpolation processing circuit does not show a correct value. For example, if the carrier frequency is 125 kHz, the upper limit of the frequency of the position signal is about 25 kHz,
Assuming that the position signal is 512 waves in one rotation of the motor, the upper limit of the rotation number of the motor is about 2900 rotations / minute.

If the frequency of the carrier signal is increased, the upper limit of the rotational speed of the motor can be increased, but on the contrary, the phase detection resolution of the phase comparator is lowered, and the position detection accuracy is reduced. .

The present invention has been made in view of the above problems, and when the moving speed of an object (or the rotation speed of a motor) is relatively low, the position of the object is detected with high resolution using an interpolation processing circuit. An object of the present invention is to provide a position detecting device capable of correctly detecting the position of an object (or the rotational position of the motor) without malfunction even when the moving speed (or the rotational speed of the motor) is relatively high.

[0018]

In order to solve the above-mentioned problems, a position detecting apparatus according to the present invention generates a position signal for outputting first and second position signals having different phase differences according to the position of an object. And an interpolation processing circuit for detecting a position of the object finer than one cycle of the first and second position signals;
A first pulse generation circuit that generates and outputs a first carry pulse and a first carry pulse from a signal output by the interpolation processing circuit, and converts the first or second position signal into a square wave, respectively. A waveform conversion circuit for converting and outputting a second carry pulse and a second carry pulse based on an output signal of the waveform conversion circuit;
A second pulse generating circuit for generating and outputting a carry pulse of the first and second carry pulses, a first carry pulse, and a second carry pulse and a second carry pulse. A pulse switching circuit that switches at a predetermined phase of the first and second position signals in accordance with the moving speed of the object, and a third carry pulse and a third carry pulse output from the pulse switching circuit, respectively. And an up / down counter for counting and outputting as a position of the object that is longer than one cycle of the first and second position signals.

With the above arrangement, the first carry pulse and the first carry pulse are selected when the moving speed of the object is relatively low, and when the moving speed of the object is relatively high, , The second carry pulse and the second carry pulse are selected and the carry carry processing described above is performed. Therefore, when the moving speed of the object is relatively low, the position of the object is detected with high resolution. On the contrary, even when the moving speed of the object is relatively high, the position of the object larger than one cycle of the position signal can be correctly detected.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, a position detecting device according to a first aspect of the present invention provides a position signal for outputting first and second position signals having different phase differences according to the position of an object. A generator, an interpolation processing circuit for detecting a position of the object finer than one cycle of the first and second position signals,
A first pulse generation circuit that generates and outputs a first carry pulse and a first carry pulse from a signal output by the interpolation processing circuit, and converts the first or second position signal into a square wave, respectively. A waveform conversion circuit for converting and outputting a second carry pulse and a second carry pulse based on an output signal of the waveform conversion circuit;
A second pulse generating circuit for generating and outputting a carry pulse of the first and second carry pulses, a first carry pulse, and a second carry pulse and a second carry pulse. A pulse switching circuit that switches at a predetermined phase of the first and second position signals in accordance with the moving speed of the object, and a third carry pulse and a third carry pulse output from the pulse switching circuit, respectively. And an up / down counter for counting and outputting as a position of the object that is longer than one cycle of the first and second position signals.

With the above structure, the position detecting device of the first invention of the present application selects the first carry pulse and the first carry pulse when the moving speed of the object is relatively low, and conversely, When the moving speed of the object is relatively high, the second carry pulse and the second carry pulse are selected and the above-mentioned carry carry processing is performed, so that the moving speed of the object is relatively low. In this case, the position of the object can be detected with high resolution, and conversely, even when the moving speed of the object is relatively high, the position of the object larger than one cycle of the position signal can be correctly detected.

Further, the position detecting device of the second invention of the present application is:
With respect to the position detecting device of the first invention of the present application, the position of the object is detected from the two-phase signal output from the waveform conversion circuit with a resolution of 1/4 of one cycle of the first and second position signals. A multiplication circuit and a lower data switching circuit for switching and outputting an output signal of the multiplication circuit and an output signal of the interpolation processing circuit in conjunction with a pulse switching circuit are added.

According to the position detecting device of the second invention of the present application, when the moving speed of the object is relatively low, the output signal of the interpolation processing circuit is selected and the moving speed of the object is compared. If the speed is very high, select the output signal of the multiplier circuit,
Since the position of the object is output as a position finer than one cycle of the position signal, when the moving speed of the object is relatively low, the position of the object is detected with high resolution similarly to the position detection device of the first invention of the present application described above. On the contrary, even when the moving speed of the object is relatively high, not only the position of the object larger than one cycle of the position signal, but also the position of the object finer than one cycle of the position signal, one cycle of the position signal. The position of the object can be correctly detected with a resolution of 1/4 of the following.

Further, the position detecting device of the third invention of the present application is:
First and second phase differences different from each other according to the position of the object
A position signal generator that outputs a position signal of the first and second position signals; an interpolation processing circuit that detects a position of the object finer than one cycle of the first and second position signals; A waveform conversion circuit for converting the signal into a square wave and outputting the first and second signals based on a two-phase signal output from the waveform conversion circuit;
A multiplying circuit for detecting the position of the object with a resolution of 1/4 of one cycle of the position signal, and an output signal of the interpolation processing circuit and an output signal of the multiplying circuit according to the moving speed of the object.
A lower data switching circuit for switching and outputting; a first pulse generating circuit for generating and outputting a first carry pulse and a first carry pulse from a signal output from the lower data switching circuit; An up / down counter configured to count a first carry pulse and a first carry pulse output from the pulse generating circuit and output the counted number as a position of the object that is longer than one cycle of the first and second position signals. It is a thing.

According to the position detecting device of the third invention of the present application, when the moving speed of the object is relatively low, the output signal of the interpolation processing circuit is selected and the moving speed of the object is compared. If the speed is very high, select the output signal of the multiplier circuit,
Since the position of the object is output as a position finer than one cycle of the position signal, when the moving speed of the object is relatively low, the object is detected with high resolution similarly to the position detecting device of the first and second inventions of the present invention. The position can be detected. Conversely, even when the moving speed of the object is relatively high, not only the position of the object larger than one cycle of the position signal, but also the position of the object finer than one cycle of the position signal. 1 / one of one cycle of signal
The position of the object can be correctly detected with a resolution of 4. Further, the first pulse generation circuit generates and outputs the first carry pulse and the first carry pulse from the signal selected and output by the lower data switching circuit, and therefore, regardless of the moving speed of the object. Also, the position of an object larger than one cycle of the position signal can be correctly detected.

Further, the position detecting device of the fourth invention of the present application is:
A second carry pulse and a second carry pulse are generated and output from the output signal of the waveform conversion circuit to the position detecting device of the first, second, or third invention of the present application. And an offset for detecting an offset included in an output signal of the interpolation processing circuit by storing an output signal of the interpolation processing circuit when the second carry pulse and the second carry pulse are generated. A detection circuit and offset correction means for correcting an offset included in an output signal of the interpolation processing circuit based on an output signal of the offset detection circuit are added.

According to the position detecting device of the fourth invention of the present application, when the pulse switching circuit or the lower data switching circuit switches the signal to be selected, the signal is included in the signal of the detected position of the object. Since the offset is corrected, the position of the object can be correctly detected regardless of whether the moving speed is relatively low or relatively high, without including the offset in the detected position signal of the object.

Further, the motor control device of the present invention comprises a position detecting device according to the first, second, third or fourth invention of the present application for detecting a rotational position of a motor, and a reference position indicating a target position of the motor. A position control means for detecting an error between a signal and a rotational position signal output from the position detection device, and outputting a position control signal for applying feedback so that the position error is minimized; and a target speed of the motor. Speed control means for detecting an error between a reference speed signal shown and a rotation speed signal obtained by time-differentiating the rotation position signal, and outputting a speed control signal for applying feedback so that the speed error is minimized; Mixing means for mixing the position control signal and the speed control signal at a predetermined ratio, and controlling the rotational position and / or the rotational speed of the motor by the output of the mixing means. Those configured to.

According to the motor control device of the present invention, when the rotation speed of the motor is relatively low, the rotation position or the rotation speed of the motor can be controlled with high resolution. Even when the speed is relatively high, the rotation position or the rotation speed of the motor can be controlled without malfunction although the resolution is not high.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In this embodiment, a position detecting device for detecting the rotational position of a motor as a 16-bit digital value will be described. FIG. 1 shows a configuration diagram of a position detecting device according to a first embodiment of the present invention.

In FIG. 1, 101 is a motor, and 102 is a position signal generator. The position signal generator 102 outputs first and second position signals MR1 and MR2 whose phases are different from each other by 90 ° according to the rotation angle position of the motor 101.
In this embodiment, MR1 = cos θ and MR2 = sin
θ. MR1 and MR2 generate, for example, 512 waves per rotation of the motor 101.

Reference numerals 103 and 104 denote amplification circuits, which are first and second small amplitude signals output from the position signal generator 102.
Is a circuit that amplifies the position signals MR1 and MR2 by a predetermined gain so as to have an amplitude sufficient for the subsequent signal processing, and outputs the amplified signals.

A position detection circuit 105 for outputting a rotation position in one rotation as a digital value is indicated by reference numeral 105 in the broken line frame.
An interpolation processing circuit 126 (within a broken line frame 126) for finely dividing one cycle of the position signals MR1 and MR2 is included.

Next, the details of the position detection circuit 105 and the interpolation processing circuit 126 will be specifically described. Reference numeral 114 denotes a waveform conversion circuit which includes two zero-cross comparators, and converts and outputs the signal MR1 to the signal FG1 and the signal MR2 to the signal FG2. Signal MR1
Alternatively, FIGS. 3A to 3D show the respective signal waveforms when the phase θ (unit is radian) of the MR2 is set on the horizontal axis. 3A shows the signal MR1, and FIG. 3B shows the signal MR.
2, FIG. 3 (c) shows the signal FG1, and FIG. 3 (d) shows the signal FG2.
It is. 117 is a frequency multiplier, 118 is a second pulse generator, and 119 is a switching signal generator. FIG.
This shows a specific circuit configuration of the multiplication circuit 117, the second pulse generation circuit 118, and the switching signal generation circuit 119. In FIG. 2, 201, 202, and 206 are D flip-flops, and 203 and 204 are inverters,
05 is an exclusive OR circuit.

The multiplying circuit 117 is a circuit that detects the phase θ from the signals FG1 and FG2 with a resolution of １ ／ of one cycle and outputs it as a 7-bit signal. Since the resolution is 1/4, it can be represented by 2 bits.
Since the data is divided into 28 and handled as 7-bit data, a 2-bit signal is converted into a 7-bit signal and output in order to match this. Assuming that each bit of the 7-bit signal output from the multiplying circuit 117 is B0 to B6 (B0 is lower order), the relationship between the phase θ, the levels of the signals FG1 and FG2 and the respective bits B0 to B6 of the output signal of the multiplying circuit 117 is as follows. , (Table 1).

[0037]

[Table 1]

The second pulse generation circuit 118 outputs the signal FG
1 and a circuit for generating and outputting a second carry pulse and a second carry pulse from FG2. A switching command circuit 120 detects the rotational speed of the motor 101 by time-differentiating the position data output from the data registers 123 and 124, and compares the detected rotational speed with a predetermined switching speed. If the level signal is higher than the switching speed, the H level signal is output as the switching command signal CHG. The switching signal generation circuit 119 synchronizes the switching command signal CHG output from the switching command circuit 120 with the rising edge of the signal FG1, and outputs the same as the switching signal CSG.

Reference numeral 121 denotes a pulse switching circuit, which is a switching signal CS output from the switching signal generation circuit 119.
If it is at L level according to G, the first pulse generation circuit 1
The first carry pulse and the first carry pulse output by the second pulse generator circuit 118 are selected. Select and output as a third carry pulse and a third carry pulse. The third carry pulse and the third carry pulse are counted by the up / down counter 122, and the count value is stored in the data register 123.

Reference numeral 115 denotes a lower-order data switching circuit, which is in accordance with the switching signal CSG output from the switching signal generating circuit 119, if the L level, the interpolation processing circuit 12
6 is selected and if it is at the H level, the multiplication circuit 11
7 is selected and output. Data register 12
4 stores an output signal of the lower data switching circuit 115. The values stored in the data registers 123 and 124 are output to the outside as position data of the rotational position of the motor 101.

Reference numeral 125 denotes an offset detection circuit which stores an output signal of the interpolation processing circuit 126 when either the second carry pulse or the second carry pulse output from the pulse generation circuit 118 is generated. And output to the outside.

The interpolation processing circuit 126 is almost the same as that of FIG. 10, but only different parts will be described. Reference numeral 112 denotes a delay circuit. The delay circuit 112 delays the input carrier signal by a phase α and outputs the delayed carrier signal. This output signal is input to the phase detector 113 and the waveform shaping circuit 110
Is compared with the output signal.

The output signal of the waveform shaping circuit 110 should be sin (ωt + θ) as described above. However, since a delay phase (or delay time) occurs in the process of each signal processing including the filter 109, the output signal becomes sin (ωt + θ). If the delay phase is β, the actual signal is sin (ωt + θ−β). Therefore, this is converted to sinω which is the first carrier signal.
When the phase is compared with t, the phase difference becomes (θ−β) and the phase θ
Produces an offset value β. The delay circuit 112
This is for correcting the offset value β. Assuming that the delay phase of the delay circuit 112 is α, the output signal is s
In (ωt−α), the phase detected by the phase detector 113 is θ− (β−α). Here, the set value of the delay phase α is set so as to supplement the delay phase β. That is,
If (β−α) << 0, θ− (β−α) ≒ θ, and the detection error of the phase θ decreases.

FIGS. 4A to 4G show signal waveforms at various parts in FIG. Here, the horizontal axis is the phase θ (unit is radian) of the position signal MR1 or MR2. 4A shows the signal FG1, FIG. 4B shows the signal FG2, FIG. 4C shows the second carry pulse, and FIG. 4D shows the second carry pulse. FIG. 4 (e) shows the first carry pulse or the first carry pulse in FIG.
(F) and FIG. 4 (g) show the third carry pulse. Here, the pulses P1, Q1, R1 and the pulses P2,
Q2, R2 and pulses P3, Q3, R3 are groups of pulses corresponding to the same rotational position of the motor 101, respectively.

First, the case where the motor 101 is rotating in the forward direction, that is, the case where the phase θ increases with time will be described. At this time, the second pulse generation circuit 118 outputs a second carry pulse as shown in FIG. This pulse is applied to a pulse switching circuit 121
, The rising edge is counted in the up / down counter 122, and the phase at which the rising edge occurs is 2nπ (n is an integer). If α
= 0, -2 <β <θ1, the first carry pulse is generated at the phase (2nπ + β) as shown in FIG.

Here, a case is considered where the first carry pulse and the second carry pulse are switched by the switching signal CSG output from the switching signal generating circuit 119. The switching signal CSG changes at the rising edge of the signal FG1, and in this case, changes at the phase (2nπ + θ1). The rotation speed of the motor 101 increases, and the switching command signal CHG output from the switching command circuit 120 changes from the L level to the H level.
Assuming that SG changes from L level to H level at the phase θ1, the third carry pulse output from the pulse switching circuit 121 includes both the pulse R2 and the pulse P2 as shown in FIG. Will be included. In this case, the up / down counter 122 counts the pulses doubly, and the count value does not indicate the correct rotational position of the motor 101. Conversely, the rotation speed of the motor 101 becomes low,
Switching command signal C output from switching command circuit 120
Assuming that HG changes from H level to L level, and accordingly, the switching signal CSG changes from H level to L level at the phase θ 1, the third carry pulse includes the signal shown in FIG.
As shown in (g), neither pulse R2 nor pulse P2 is included. This means that the pulse is missing,
Also in this case, the count value of the up / down counter 122 does not indicate a correct rotational position.

Next, a case where the motor 101 is rotating in the reverse direction, that is, a case where the phase θ decreases with the passage of time will be described. 5 (a) to 5 (g) show FIG.
(A) to (g) respectively. However, FIG.
(F) and FIG. 5 (g) show the third carry pulse. At this time, the second pulse generation circuit 118 outputs a second carry pulse as shown in FIG. The rising edge of this pulse is counted by the up / down counter 122 through the pulse switching circuit 121. The phase at which the rising edge occurs is 2nπ (n
Is an integer). If α = 0 and θ2 <β <+ 2π, the first carry pulse is generated at the phase (2nπ + β) as shown in FIG.

Here, as described above, the switching signal CS
Consider a case where G switches between the first carry pulse and the second carry pulse. The switching signal CSG is the signal FG
In this case, it changes at the phase (2nπ + θ2). The number of rotations of the motor 101 increases, and the switching command signal CHG output from the switching command circuit 120 changes from L level to H level,
Accordingly, assuming that the switching signal CSG changes from L level to H level at the phase θ2, the third carry pulse output from the pulse switching circuit 121 includes FIG.
As shown in (f), both the pulse R2 and the pulse Q2 are included. In this case, the up-down counter 12
2 means that the pulses are counted twice, and the counted value does not indicate the correct rotation position of the motor 101. Conversely, the rotation speed of the motor 101 becomes low, and the switching command circuit 12
0 is output from the H level to the L level.
Assuming that the switching signal CSG changes from H level to L level at the phase θ2,
The third carry pulse has a pulse R as shown in FIG.
2 and the pulse Q2 are not included. This means that the pulse has been missed, and the count value of the up / down counter 122 does not indicate the correct rotational position in this case as well.

In particular, when the switching command signal CHG repeatedly changes from L level to H level or from H level to L level a plurality of times, the up / down counter 12
The error of the count value of 2 is accumulated, and a large error occurs in the position data output from the position detection circuit 105.

Next, consider the case where the value of α is set to supplement β and the offset value (β-α) is set to (β-α) << 0. 6 (a) to 6 (g) are FIGS. 4 (a) to 4
(G) respectively. In this case, the first carry pulse or the first carry pulse is generated at a phase 2nπ (n is an integer) as shown in FIG. Regardless of whether the motor 101 is moving in the forward direction or the reverse direction, and with the change in the number of revolutions of the motor 101, the switching signal CSG becomes L at the phase θ1 or the phase θ2.
In either case where the level changes from the H level to the H level or from the H level to the L level, the third carry pulse or the third carry pulse output by the pulse switching circuit 121 is output.
6 (f) and FIG. 6 (g), neither the pulse R2 nor the pulse P2 (or the pulse Q2) is included at the same time, or neither is included. . Accordingly, the carry / carry processing is correctly performed, and the count value of the up / down counter 122 is
1 would indicate the correct rotational position.

In practice, the value of the phase β changes depending on the frequency of the signal passing through the filter 109 and further varies due to factors such as the accuracy of the components constituting the filter 109, so that the offset value is (β−α ) << 0 in some cases. However, also in this case, if the offset value is in the range of θ1 <(β−α) <θ2, the carry-carry processing can be correctly performed without malfunction.

However, this offset is calculated by the interpolation processing circuit 1
26, but not in the output signal of one of the multiplying circuits 117, the offset value (β−α)
If is a value that cannot be ignored in practical use, it is necessary to correct this. The offset detection circuit 125 is a circuit for detecting the offset value. Offset detection circuit 1
Numeral 25 stores the output signal of the interpolation processing circuit 126 when either the second carry pulse or the second carry pulse is generated, and stores the second carry pulse and the second carry pulse. Are generated when θ = 0, the output signal of the interpolation processing circuit 126 at this time is θ− (β−α) = − (β
−α), and the offset value (β−α) is stored in the offset detection circuit 125.

Using this as correction data, the offset included in the position data can be corrected by configuring the offset correcting means by software in a microprocessor (or microcomputer).
That is, the correction data is stored in the data registers 123 and 124.
The correction data is added to (or subtracted from) the position data while determining which signal is selected by the lower data switching circuit 115 by simultaneously taking in the position data output from the control circuit and by taking in the level of the switching signal CSG. The processing may be programmed by software.

In this embodiment, the offset correcting means is constituted by software by a microprocessor, but the offset correcting means may be constituted by providing an adding circuit or the like by hardware in the position detecting circuit. .

In the interpolation processing circuit 126, the offset is corrected by using the delay circuit 112. However, the delay value is not provided, and for example, the output value of the phase detection circuit 113 is added to the output value by using an addition circuit. Even if α is added, the same operation as described above is performed.

Further, consider the case where the motor 101 accelerates and rotates at high speed. In this case, the phase θ of the position signal output from the interpolation processing circuit 126 (or θ− (β−α))
No longer shows the correct value. But,
The value output from the multiplying circuit 117 always outputs a correct value corresponding to the phase θ of the position signal even when the motor 101 is rotating at high speed.

The lower data switching circuit 115 is a circuit that, in conjunction with the pulse switching circuit 121, switches and outputs a signal corresponding to the phase θ of the position signal according to the rotation speed of the motor 101. That is, when the motor 101 is rotating at a low speed, the output signal of the phase detection circuit 113 is selected and when the motor 101 is rotating at a high speed, the output signal of the multiplication circuit 117 is selected and output. The circuit 115 always outputs a correct value corresponding to the phase θ of the position signal regardless of the rotation speed of the motor 101.

It is to be noted that the configuration of the multiplication circuit 117 and the lower data switching circuit 115 may be omitted, and the output signal of the interpolation processing circuit 126 may be directly input to the data register 124. In this case, a position finer than one cycle of the position signal cannot be correctly detected, but a carry-carrying process is correctly performed, so that a position larger than one cycle of the position signal can be correctly detected.

In the present embodiment, the switching command circuit 12
0 is configured by hardware. For example, the position data output from the data registers 123 and 124 is fetched by an external microprocessor, and the position data fetched in the microprocessor is time-differentiated and converted into a moving speed. Compared with a predetermined switching speed, the same operation as described above is possible even if a switching command signal is output to the switching signal generation circuit 119 depending on the magnitude of the switching speed.

As described above, according to this embodiment, when the motor is rotating at a relatively low speed, the position of a high resolution can be detected by the operation of the interpolation processing circuit, and the rotation at a relatively high speed can be performed. In this case, the rotational position can be correctly detected without malfunction although the resolution is reduced.

(Embodiment 2) FIG. 7 shows a configuration diagram of a position detecting device according to a second embodiment of the present invention. FIG.
In the position detecting device according to the second embodiment of the present invention shown in FIG.
The components constituting the position detecting device of the first embodiment of the present invention shown in FIG. 1 are common, and the number of components constituting FIG. 7 is smaller than that of FIG. Also,
Components common to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, only different configurations will be described.

The lower data switching circuit 115 uses the switching command signal CHG output from the switching command circuit 120 as a switching signal CSG and outputs the output signal of the interpolation processing circuit 126 and the multiplication circuit 117 according to the level of this signal.
The output signal is switched and output. The first pulse generating circuit 116 generates and outputs a first carry pulse and a first carry pulse from the output signal of the lower data switching circuit 115 in the same manner as in the above-described first embodiment of the present invention. The up / down counter 122 counts the first carry pulse and the first carry pulse and counts the data register 123
Output to

FIG. 8 shows the waveform of each signal in FIG. Here, the horizontal axis is the phase θ of the position signal MR1 or MR2. Here, FIG. 8A shows the signal FG.
8 (b) shows the signal FG2, FIG. 8 (c) shows the output signal of the multiplication circuit 117, and FIG.
8 (e) shows the output signal of the lower data switching circuit, and FIG. 8 (f) and FIG.
5 shows a first carry pulse and a first carry pulse output from the pulse generation circuit 116 of FIG. Here, the signals shown in FIGS. 8C, 8D, and 8E indicate the upper two bits required for carry-carry processing by a binary number (the upper left is the upper one).

Now, assuming that the offset included in the output signal of the interpolation processing circuit 126 is (β−α) as described above,
As shown in FIG. 8D, the output signal of the interpolation processing circuit 126 is a signal whose phase is shifted by (β−α) with respect to the output signal of the multiplication circuit 117 of FIG. 8C. . It is assumed that the motor 101 is rotating in the forward direction, that is, the phase θ is increasing with time. Here, 0 <γ <
As (β−α) <+ π / 2, the switching signal CSG changes from the H level to the L level in the phase γ as the rotation speed of the motor 101 changes, and the lower data switching circuit 1
Reference numeral 15 denotes the interpolation processing circuit 12 based on the output signal of the multiplication circuit 117.
It is assumed that the output signal is switched to the output signal No. 6. At this time, the output signal of the lower data switching circuit 115 changes as shown in FIG. The first pulse generation circuit 116 is configured as shown in FIG.
FIG. 8 (g) shows a first carry pulse as shown in FIG.
A carry pulse as shown in is output.

In FIGS. 8 (f) and 8 (g), the pulses P2 and S2 or the pulses R2 and S2 act so as to cancel each other out in the up / down counter 122. The numerical value is 1 of the position signals MR1 and MR2 of the motor 101.
A rotation position larger than the period will be correctly indicated. In addition, the same result as described above is obtained when the motor 101 is rotating in the reverse direction or when the switching signal CSG changes from L level to H level.

However, the offset value (β−α) is −π
If the value does not fall within the range of / 2 <(β−α) <+ π / 2, the method of generating the first carry pulse or the first carry pulse is different. Does not necessarily indicate a correct count value.

As described above, the lower data switching circuit 11
Even if 5 outputs a signal switched according to the rotation speed of the motor 101, carry-down processing is performed without malfunction and the output signals of the data registers 123 and 124 correctly indicate the rotation position of the motor 101. become.

Also, in the second embodiment of the present invention,
Second pulse generating circuit 1 as in the first embodiment of the present invention.
18. By providing the offset detection circuit 125 and the offset correction means, the offset included in the output signal of the interpolation processing circuit 126 can be corrected.

As described above, according to this embodiment, as in the first embodiment, when the motor is rotating at a relatively low speed, the position of high resolution can be detected by the operation of the interpolation processing circuit. It is possible, and even when rotating at a relatively high speed, the rotational position can be correctly detected without malfunction although the resolution is reduced.

In the second embodiment of the present invention,
Compared to the first embodiment, the position detection function or performance is substantially the same, but the number of components is smaller and the circuit size of the entire position detection circuit is smaller. Can be.

In this embodiment, the position detection of a rotary motor has been described. However, a linear motor (linear motor) can be similarly applied to the position detection.

Next, a motor control device according to the present invention will be described with reference to the drawings. FIG. 9 shows an overall configuration diagram of a motor control device according to the embodiment of the present invention.

In FIG. 9, a motor 101, a position signal generator 102, amplification circuits 103 and 104, a position detection circuit 1
05 has the same configuration as that of FIG. 1, and a description thereof will be omitted. The area 901 inside the broken line is the above-described position detecting device of the present invention.

A portion 902 in a broken line frame indicates a portion processed by software by the microprocessor. Reference numeral 910 denotes an offset correction unit, which determines the position of the position detection circuit 10 according to the level of the switching signal output from the position detection circuit 105.
The correction data is added to the position data output from No. 5 and output as a rotation position signal. Reference numeral 905 denotes a reference speed signal generating unit that outputs a reference speed signal indicating the target speed of the motor 101. Reference numeral 906 denotes an integration unit that generates and outputs a reference position signal indicating a target position of the motor 101 by time-integrating the reference speed signal output from the reference speed signal generation unit 905. Reference numeral 907 denotes a speed control unit that compares a reference speed signal with a rotation speed signal obtained by time-differentiating a rotation position signal output from the offset correction unit 910,
A speed control signal corresponding to the speed error is output. 908
Is a position control means for comparing the reference position signal with the rotational position signal output from the offset correction means 910 and outputting a position control signal corresponding to the position error.

The speed control signal corresponding to the speed error and the position control signal corresponding to the position error are added by the mixing means 909 at a predetermined ratio. The output of the mixing means 909 is input to a drive circuit 903 via a D / A converter 902, and the rotation position or rotation speed of the motor 101 is controlled so that the above-described position error or speed error is minimized.

In the motor control device of the present invention configured as described above, the position detecting device 901 is
Irrespective of the rotation speed of the motor 101, a rotation position signal corresponding to a correct rotation position is output without malfunction.
Can control the rotation position or rotation speed of the motor 101 from stop to a relatively low rotation speed with high resolution, and also control the rotation position or rotation speed without deviation from the target position or target speed even at high speed rotation. can do.

[0077]

As described above, the position detecting device of the present invention has the following effects.

According to the first aspect of the present invention, when the moving speed of the object is relatively low, the position of the object can be detected with high resolution. Conversely, when the moving speed of the object is relatively high, Also, the position of the object larger than one cycle of the position signal can be correctly detected.

According to the second aspect of the present invention, when the moving speed of the object is relatively low, the position of the object can be detected with high resolution as in the first aspect of the present invention.
Conversely, even when the moving speed of the object is relatively high, the position of the object can be correctly detected with a resolution of 1/4 of one cycle of the position signal.

According to the third aspect of the present invention, similarly to the second aspect of the present invention, when the moving speed of the object is relatively low, the position of the object can be detected with high resolution. Conversely, even when the moving speed of the object is relatively high, the position of the object can be correctly detected with a resolution of 1/4 of one cycle of the position signal. Further, the circuit can be constituted by a circuit smaller than that of the second aspect.

According to the sixth aspect of the present invention, the detected position signal of the object is correctly included in both the case where the moving speed is relatively low and the case where the moving speed is relatively high, without including an offset in the detected position signal of the object. Can be detected.

According to the present invention, when the rotation speed of the motor is relatively low, the rotation position or rotation speed of the motor can be controlled with high resolution. Even at a high speed, the rotational position or the rotational speed of the motor can be controlled without malfunction although the resolution is not high.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a position detection device according to a first embodiment of the present invention.

FIG. 2 shows a second pulse generation circuit, a multiplication circuit,
Circuit diagram of switching signal generation circuit

FIG. 3 is an operation explanatory diagram of the waveform conversion circuit shown in FIG. 1;

FIG. 4 is an explanatory diagram of an operation of the position detecting device according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of the operation of the position detecting device according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of an operation of the position detecting device according to the first embodiment of the present invention.

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

FIG. 8 is a diagram illustrating the operation of the position detecting device according to the second embodiment of the present invention.

FIG. 9 is a configuration diagram of a motor control device according to an embodiment of the present invention.

FIG. 10 is a configuration diagram of a conventional position detection device.

[Explanation of symbols]

 Reference Signs List 101 Motor 102 Position signal generator 103, 104 Amplification circuit 105 Position detection circuit 106, 107 Multiplication circuit 108 Addition circuit 109 Filter 110 Waveform shaping circuit 111 Carrier signal generation circuit 112 Delay circuit 113 Phase detector 114 Waveform conversion circuit 115 Lower data switching Circuit 116 First pulse generation circuit 117 Multiplication circuit 118 Second pulse generation circuit 119 Switching signal generation circuit 120 Switching command circuit 121 Pulse switching circuit 122 Up / down counter 123, 124 Data register 125 Offset detection circuit 126 Interpolation processing circuit 907 Speed control means 908 Position control means 909 Mixing means 910 Offset correction means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02P 5/00 H02P 5/00 R

Claims (9)

[Claims] 1. A position signal generator that outputs first and second position signals having different phase differences according to the position of an object,
An interpolation processing circuit for detecting the position of the object finer than one cycle of the first and second position signals, and a first carry pulse and a first carry pulse from a signal output from the interpolation processing circuit A first pulse generation circuit for generating and outputting a signal, a waveform conversion circuit for converting the first and second position signals into a square wave and outputting the same, and a second carry from the output signal of the waveform conversion circuit. A second pulse generating circuit for generating and outputting a pulse and a second carry pulse; the first carry pulse and the first carry pulse; and the second carry pulse and the second carry A pulse switching circuit for switching a pulse at a predetermined phase of the first or second position signal in accordance with the moving speed of the object, a third carry pulse and a third digit output from the pulse switch circuit Apply a lowering pulse Position detecting device and a up-down counter which outputs respective counts as the position of one period is greater than the object of the first and second position signals. 2. A multiplying circuit for detecting the position of an object with a resolution of 1/4 of one cycle of the first and second position signals from a two-phase signal output from the waveform converting circuit, and an output signal of the multiplying circuit. 2. The position detecting device according to claim 1, further comprising a lower data switching circuit for switching and outputting an output signal of the interpolation processing circuit in conjunction with the pulse switching circuit. 3. A position signal generator for outputting first and second position signals having different phase differences from each other according to the position of an object;
An interpolation processing circuit for detecting a position of the object finer than one cycle of the first and second position signals;
And a waveform conversion circuit for converting each of the position signals into a square wave and outputting the square signal. A multiplying circuit for detecting a position, a lower data switching circuit for switching and outputting an output signal of the interpolation circuit and an output signal of the multiplying circuit according to the moving speed of the object, and a lower data switching circuit. A first pulse generation circuit that generates and outputs a first carry pulse and a first carry pulse from a signal to be output, and a first carry pulse and a first carry pulse that are output from the first pulse generation circuit. The carry pulse is counted, and 1 of the first and second position signals is counted.
A position detection device comprising: an up / down counter that outputs the position of the object longer than a period. 4. An interpolation processing circuit comprising: a first and a second position signal having a frequency higher than that of the first and second position signals and having different phases from each other;
Means for generating a carrier signal, means for modulating the first and second carrier signals respectively with the first and second position signals, means for adding each modulated signal, Phase detecting means for detecting a phase difference from the first or second carrier signal, and outputting an output signal of the phase detecting means as a position of an object finer than one cycle of the first or second signal of the position detector. The position detection device according to any one of claims 1 to 3. 5. An interpolation processing circuit comprising means for correcting an offset included in an output signal of the interpolation processing circuit.
The position detecting device as described in the above. 6. A second pulse generating circuit for generating and outputting a second carry pulse and a second carry pulse from an output signal of the waveform conversion circuit, and a second carry pulse and a second carry. An offset detection circuit that detects an offset included in the output signal of the interpolation processing circuit by storing an output signal of the interpolation processing circuit when a pulse is generated, and an output signal of the interpolation processing circuit based on the output signal of the offset detection circuit The position detecting device according to any one of claims 1 to 5, further comprising: an offset correcting unit configured to correct an offset included in the position detecting unit. 7. A position signal generator, comprising: a multipolar magnetized permanent magnet which moves integrally with an object; and a position signal generator which is installed near the permanent magnet and controls a change in magnetic force by the permanent magnet according to the position of the object. The position detecting device according to any one of claims 1 to 6, comprising a magnetoelectric conversion element that converts the electric signal into an electric signal. 8. A position detection device for detecting a rotation position of a motor, and an error between a reference position signal indicating a target position of the motor and a rotation position signal output from the position detection device,
Position control means for outputting a position control signal for performing feedback so that the position error is minimized; a reference speed signal indicating a target speed of the motor; and a rotation speed signal obtained by time differentiating the rotation position signal. Speed control means for detecting a difference between the position control signal and the speed control signal at a predetermined ratio, and outputting a speed control signal for performing feedback so as to minimize the speed error. Means for controlling the rotational position and / or the rotational speed of the motor based on the output of the mixing means. 9. The control device according to claim 8, wherein the position detection device includes the position detection device according to any one of claims 1 to 7.