JP2000166282A - Rotor position-detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the position detection accuracy of a rotor, by calculating the exclusive OR of each phase of a group of odd sensors as a first operation phase and the exclusive OR of each phase of a group of even sensors as a second operation phase, and setting the generation pulse of the first or second operation phase as a rotor detection signal. SOLUTION: When the electrical angle between two poles is set to 360 deg., the electrical angle of a group of odd sensors becomes an interval of 1200, while that of a group of even sensors becomes an interval of 120 deg. since the group of even sensors are shifted from the group of odd sensors by 30 deg.. By calculating the exclusive OR of first and third phases U1 and V1 and then calculating that of the result and fifth phase W1 using a first operation means 41, an ON/OFF digital signal with a period of 120 deg. can be obtained for the first operation phase A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a rotor position of a rotor having a magnet in a motor.

[0002]

2. Description of the Related Art In a conventional rotor position detecting device for a rotor having a magnet in a brushless motor, a Hall IC is provided on a stator having a winding, and the Hall IC digitally detects a change in the dipole magnetic force of the rotor. The control circuit cumulatively counts the count per unit time to detect the position of the rotor with respect to the reference position.

Here, in order to improve the position accuracy of the rotor, the number of the dipole magnetic forces of the magnets provided on the rotor for generating the pulse is increased to make the angle of the dipole magnetic force smaller, and the rotor is rotated during one rotation. How to generate many pulses on the
Alternatively, a method of increasing the number of Hall ICs, which are detection devices, may be considered.

[0004]

In the above-mentioned conventional configuration, if the polarity of the magnet is increased or the number of Hall ICs is increased, the number of components is increased, which is not preferable in manufacturing. In addition, as a result of increasing the number of parts, a circuit for connecting them is further required, which causes a problem that the entire apparatus becomes complicated. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a rotor position detecting device having a simple configuration and improved rotor position detecting accuracy in a motor.

[0005]

According to a first aspect of the present invention, there is provided a rotor position detecting device for achieving the above object.
A first digital discrimination sensor (31) and a first digital discriminating sensor (31) for emitting a first phase (U1) arranged at equal intervals in the stator (3) sequentially with respect to an electric angle of the motor (2) generating a two-pole magnetic force; An odd-numbered sensor group which is a third digital discriminating sensor (32) emitting three phases (V1) and a fifth digital discriminating sensor (33) emitting fifth phase (W1); and the odd-numbered sensor group arranged on the stator (3) 30 ° to
A second digital discriminating sensor (34) for emitting a second phase (U2) and a fourth for emitting a fourth phase (V2)
An exclusive OR of each of the odd number sensor group and the even number sensor group which is a digital judgment sensor (35) and a sixth digital judgment sensor (36) which emits a sixth phase (W2) is calculated in a first operation phase (A). And a second operation means (42) for calculating an exclusive OR of each phase of the even-numbered sensor group as a second operation phase (B), the first operation phase (41). A) or the pulse generated in the second operation phase (B) is used as a rotor detection signal.

In order to achieve the above object, the rotor position detecting device (1) according to the second aspect of the present invention further includes the first arithmetic phase (A) and the second arithmetic phase (A). B)
A third operation means (43) for calculating an exclusive OR of the third operation phase as a third operation phase (P), and generating pulses of the third operation phase (P) as a rotor position detection signal. .

[0007]

According to the present invention, there is provided a rotor position detecting device according to the present invention.
According to the invention, the digital discrimination sensor discriminates one polarity of the N pole and the S pole, and the accuracy is the lowest since the magnitude of the magnetism is not observed. The first to sixth digital discrimination sensors (31, 32, 33, 34, 3
5, 36), if the electrical angle of the dipole magnetic force is 360 ° in the odd-numbered sensor group as the first, third, and fifth digital discriminating sensors, the odd-numbered sensor group has an electrical angle of 120 °. In addition, since the second, fourth, and sixth digital discrimination sensors are shifted by 30 ° with respect to the odd-number sensor group, the intervals are 120 °. Then, each interval from the first to the sixth digital discrimination sensors to the return to the first digital discrimination sensor is 3
0 °, 90 °, 30 °, 90 °, 30 °, 90 °. In each of the digital determination sensors, the first phase (U1), the second phase (V1), the third phase (W1), and the third phase (W1) perform on / off switching at a cycle of 180 °.
A fourth phase (U2), a fifth phase (V2), and a sixth phase (W2) are generated. First, the exclusive OR is calculated for the first phase (U1) and the third phase (V1), and the result is calculated by the first arithmetic means (41) for the result and the fifth phase (W1). Is performed, a digital signal which is turned on and off with a period of 120 ° is obtained in the first operation phase (A) as a result. Therefore, more accurate motor speed control can be performed by using this digital signal. Similarly, the second phase (U2) and the fourth phase (V2)
Then, first, the exclusive OR is calculated by the second operation means (42), and the exclusive OR is calculated by the result and the sixth phase (W2). A digital signal with an on-off of a period is obtained. Therefore, accurate rotor position detection can be performed by using this digital signal as a rotor position detection signal.

According to the second aspect of the rotor position detecting device of the present invention, in addition to the effects of the first aspect, the first phase (U1), the third phase (V1), and the fifth phase of the odd-number sensor group are provided. The second operation phase obtained from the second phase (U2), the fourth phase (V2), and the sixth phase (W2) of the even-number sensor group which is shifted by 30 ° with respect to the first operation phase (A) obtained from (W1). Since the digital signal of (B) is obtained at the same time, the exclusive OR of the first operation phase (A) and the second operation phase (B) is calculated by the third operation means (4).
If performed in 3), a digital signal of ON / OFF with a 60 ° cycle is obtained as a result of the third operation phase (P). Therefore, accurate rotor position detection can be performed by using this digital signal as a rotor position detection signal.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to an embodiment shown in FIGS. FIG. 1 is a block diagram showing an embodiment of a rotor position detecting device according to the present invention. FIG. 2 is a diagram showing first to sixth phases (U1, V1,.
FIG. 4 is a waveform diagram showing waveforms of pulse signals in W1, U2, V2, W2) and first to third operation phases (A, B, P). This will be described below with reference to the drawings.

First, a description will be given with reference to FIG. The rotor position detecting device 1 according to the present invention is provided in a motor having a rotor and a stator 3. The rotor 2 converts the dipole magnetic force into an electric angle of 3
It has a magnet generated as 60 °.
A winding is wound around a stator core (not shown) in a plurality of phases on the stator 3, and a current is supplied to the winding while sequentially changing the phase, thereby rotating the rotor 2 as a magnet. . Further, the first to sixth digital discriminating sensors 3 all reacting to the N pole are provided on the stator 3.
1, 32, 33, 34, 35, 36 are provided.
The digital discriminating sensors 31 to 36 are responsive to the N pole, but may be responsive to the S pole and have a simple structure. Then, the control circuit 4 obtains signals from the digital discrimination sensors 31 to 36, detects the rotational position of the rotor 2, and controls the rotor 2 by changing a current value supplied to a stator winding (not shown).

The stator includes a first digital discriminating sensor 31 for generating a first phase (U1), and a second phase (V1).
The second digital discriminating sensor 32 that generates the
The third digital discrimination sensor 33 that generates 1), the fourth digital discrimination sensor 34 that generates the fourth phase (U2), and the fifth digital discrimination sensor 35 that generates the fifth phase (V2)
And a sixth digital discriminating sensor 36 for generating a sixth phase (W2). The electrical angle between the first discriminating digital sensor and the first discriminating digital sensor through the sixth discriminating digital sensor is 30 ° in electrical angle. , 90 °, 30 °, 90 °, 3
They are arranged at intervals of 0 ° and 90 °.

The output line of the first digital determination sensor 31 and the output line of the third digital determination sensor 33 are EXO
The output line of the output signal and the output line of the fifth digital determination sensor 35 are connected by an EXOR digital logic circuit (exclusive OR circuit). This is the first operation means 41, and the first operation phase (A) is finally generated.

The output line of the second digital discrimination sensor 32 and the output line of the fourth digital discrimination sensor 34 are EXO
An R digital logic circuit (exclusive OR circuit) is connected, and an output line of the output signal thereof and an output line of the sixth digital determination sensor 36 are connected by an EXOR digital logic circuit (exclusive OR circuit). This is the second operation means 42, and the second operation phase (B) is finally generated.

The output line of the first operation phase (A) from the first operation means 41 and the output line of the second operation phase (B) from the second operation means 42 are connected to an EXOR digital logic circuit (exclusive OR). Circuit), which is the third operation means 43, and finally a third operation phase (P) is generated.

Next, FIG. 2 shows the first to sixth phases (U1, V
1, W1, U2, V2, W2) and the third
FIG. 3 is a waveform diagram showing a waveform of a pulse signal in a calculation phase (A, B, P). These waveforms are obtained by the first arithmetic means 41, the second arithmetic means 42, and the third arithmetic means 43, which are digital logic circuits. Since the first calculation phase and the second calculation phase (A, B) are digital ON / OFF signals at intervals of 120 °, if the cycle of one rotation is T, the rotor position can be detected with an accuracy of 120 °, which is a time 2T / 6 cycle. I can do it. Also, the third
In the calculation phase (P), since the digital on / off signal is at 60 ° intervals, which is the period of time T / 6, the position of the rotor can be detected with an accuracy of 60 °.

In the embodiment shown in FIGS. 1 and 2, the generation of the dipole magnetic force of the rotor is performed once per rotation of the rotor. Can be set arbitrarily. For example, if a rotor in which a dipole magnetic force is generated 10 times per rotation is used, the angle of the dipole magnetic force becomes 36 ° from the viewpoint of the rotor, and 3 ° → 9 ° → 3
1st to 6th provided at intervals of ° → 9 ° → 3 ° → 9 °
By using the first calculation phase to the second calculation phase by the digital determination sensor, the rotor position can be detected with an accuracy of 12 °.
Further, if the third calculation phase is used, the rotor position can be detected with an accuracy of 6 °. Furthermore, in this case, six first to sixth digital discriminating sensors may be arranged in a concentrated manner in the range of the stator 36 °, or the start position of the stator at every 36 °, (36
°, 72 °, 108 °, 144 °, 180 °, 216
°, 252 °, 288 °, 324 °, 360 °)
The same effect can be obtained by arbitrarily disposing at positions shifted by 3 ° → 9 ° → 3 ° → 9 ° → 3 ° → 9 °.

[0017]

As is apparent from the above description, according to the present invention, the position of the rotor can be accurately detected by using a simple digital discriminating sensor. Therefore, a highly accurate rotor position detecting device can be obtained even with a simple structure.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a rotor position detecting device according to the present invention.

FIG. 2 is a waveform diagram of a first phase to a sixth phase and a first calculation phase to a third calculation phase of the rotor position detection device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor position detection device, 2 ... Rotor, 3 ... Stator,
31 to 36: digital discrimination sensor, 4: control circuit, 41
... first computing means, 42 ... second computing means, 43 ... third computing means,

Claims (2)

[Claims] 1. A first digital discriminating sensor which emits first phases (U1) which are sequentially arranged at equal intervals on a stator (3) with respect to an electric angle of a motor (2) for generating a dipole magnetic force of a motor. (31) and third digital discriminating sensor (32) emitting third phase (V1) and fifth phase (W1)
An odd-numbered sensor group, which is a fifth digital discriminating sensor (33) that emits, and 3 arranged for the odd-numbered sensor group arranged on the stator (3).
A second digital discrimination sensor (34) that emits a second phase (U2) and a fourth digital discrimination sensor (35) that emits a fourth phase (V2) and a sixth phase (W2) that are arranged at 0 ° offset
An even number sensor group that is a sixth digital discriminating sensor (36) that emits, a first operation means (41) that calculates an exclusive OR of each phase of the odd number sensor group as a first operation phase (A), A second operation means (42) for calculating an exclusive OR of each phase of the even-number sensor group as a second operation phase (B), wherein a generated pulse of the first operation phase (A) or the second operation phase (B) is provided. A rotor position detecting device (1) that uses a signal as a rotor detection signal. 2. A third operation means (43) for calculating an exclusive OR of the first operation phase (A) and the second operation phase (B) as a third operation phase (P). The rotor position detection device (1) according to claim 1, wherein the generated pulses of the three calculation phases (P) are used as a rotor position detection signal.