JPS5958314A - Digital rotation detector - Google Patents

Abstract

PURPOSE:To highly accurately detect the position of digital rotation by installing a pair of Hall elements which detect the magnetic flux of a rotor made of permanent magnet at a phase difference of pi/2-interval to an armature core. CONSTITUTION:A rotation detector is constituted in such a way that Hall elements 10 and 11 which detect the magnetic flux of a rotor R made of permanent magnet are installed at a phase difference of pi/2-interval to an armature and, at the same time, sin generator 17 and cos generator 16 are connected to the current terminals 10i and 11i of the Hall elements 10 and 11, respectively, and a control circuit 12 which operates the output values of the voltage terminals 10v and 11v of the elements 10 and 11 and controls so that the operated value goes to zero, voltage controlling oscillator 13 which generates a pulse in accordance with the output value, counter 15, etc., are connected to the voltage terminals 10v and 11v. Since the control circuit 12 controls so that the difference in rotational angle, theta-theta', goes to zero, the angle of the rotor R becomes almost equal to the output value theta' of the counter 15 and a rotational position signal is easily obtained. Therefore, the position of digital rotation can be detected with high accuracy.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention t"2. Detects the rotational position of a commutatorless motor with high accuracy. This invention relates to a digital rotation detector designed to

[Technical background of the invention]

Electronic rectifier type (brushless)'? I'i, Dotsuki ν'' 2,
Position detector (ps) on permanent magnet type synchronous motor
It is common to use a combination of a semiconductor switch impeller and a semiconductor switch impeller.

FIG. 1 shows the principle of this commutatorless motor, which is composed of a two-pole synchronous motor and a three-phase half-boyfriend inverter. Further, FIG. 2 shows a time diagram of the inverter. In Figure 1, the direct current voltage I
The positive side of C (transistor Q, which is a semiconductor switch)
ll Connected to the collector side of Q2 and Q3, respectively,
The emitter side of the transistor QI P Q2 + Q3 is an electric machine j'-winding net WI r w, , W3's -)'1i, which is arranged with a phase difference of 120°, respectively.
j respectively connected IrA; and this armature winding W
The other ends of H+W2+W3 are all commonly connected to the negative side of the DC power supply E. In addition, the base sides of the transistors Q+ rQ2 and Q3 are connected to each other in order to detect the position of the magnetized permanent magnet rotor R as shown in the figure.
The output ψi of Hall ICH, H2, ■■3, which are arranged with a phase difference of 120°, respectively
's Kta continues. these nj neil ic
H.

The output waveforms of H2 and H, respectively, are 81 t in Fig. 2.
It will be like 82 + 83.

In the duck configuration, the rotor R is at the position It? shown in FIG. , i9. As shown in FIG. 2, sl turns on the transistor Q1 and turns off the transistor Q3. Therefore, a current flows through the child windings W and K'Tf, and the armature magnetomotive force is generated as shown in the 10th diagram. Then, due to the interaction of this force (c) J-■ and the rotation -J)
Rotate in the direction of the arrow shown. In this way, 111
, when rotated by 2π/3 dinoan in the gas phase, Hall ■C
The output 4- of lI2 is applied to signal 52Ii, which turns on transistor Q2 and turns off transistor Q l as shown in FIG.

As a result, frost and current flow to approximately W2 in 11-1, thereby generating an armature magnetomotive force in the armature winding W2, and the rotor R further rotates in the direction of the arrow shown in the figure. Then, from the first digit, it is rotated by 4π Harajian in electrical angles to obtain 7.
At the position where the output of the Hall IC is +jS 3 ti
t: As shown in FIG. 2, transistor Q3 is turned on and L-Rannosk Q2 is turned off. Therefore, 'rf,i:
↑11. As the current flows, an armature magnetomotive force A is generated in the armature winding W3, and the rotor R rotates in the direction of the arrow shown in the figure, and then returns to the position shown in FIG. 1 by one rotation. The rotor R continues to rotate in the same manner 11
do.

By the way, in order to accurately perform positioning control or speed control in such a commutatorless motor, it is generally necessary to constantly detect the position of the rotor R of the electric motor. A rotation detector using a photosensor or a magnetic sensor is used to detect the rotational position of the rotor R. FIG. 3 shows the configuration of a rotation detector using a photosensor.

In other words, when the rotating disk 4, which is fixed to the shaft 2 on the opposite side of the electric motor 1 and has the ζ slits 3 carved on the circumference, rotates due to the rotation of the electric motor 1, The light emitting element 5 and the light receiving element 6 are supported by the support 7 F+'
In the L, 7'ζ photo sensor, a light receiving element 6 receives light from a light emitting element 5 passing through a slit 3 and outputs a rotation pulse. On the other hand, rotation detectors using magnetic sensors have almost the same configuration, and both have rotating disks 4
A sensor is provided opposite the slit 3 cut in the slit 3 . In order to increase the amount W (fil '<c) per rotation, increase the center sensitivity and narrow the slit width. There is a must-do.

[I''() point in the background art] As a result, a rotation detector with high JW performance and a small one-piece shape is necessarily expensive; Rotating detector C1,) "There is a large rotating detector missing an extra issue, 1 (: j, !'+r'J Jib
, J. Rotation detectors are more expensive, which is a practical limitation. In other words, it is necessary to use an expensive rotation detector when there are legal restrictions, such as when it is built into a small sensor, and when there are legal and price restrictions. 6",? 11: Work, (
There is a problem in that the position detection performance must be determined by r71.

[Purpose of the invention]

The present invention was made in order to solve the problems mentioned above.
Is the rotational position of the four-flow electric motor high 'Ai'? An object of the present invention is to provide a small, lightweight, and inexpensive digital rotation detector for a commutatorless motor that can detect the rotation of a commutatorless motor.

[Summary of the invention]

- In order to achieve target 1, the present invention (bow 2, front 81
2 Hall ICH1+ ) 12 r Apart from H3, Hall elements are installed with a phase difference of π/2, and the current of each Hall element, 7jAj, is a sine wave with a phase difference of π/2, tiiL.
The output value of each Hall element is inputted to the Sll+ generator and the sludge generator that flow the current, and a control circuit that subtracts n by 2 and controls the subtracted value to become zero, and the output value of this control circuit is a voltage-controlled oscillator that outputs pulses of a corresponding frequency, and a sine generator that counts this output/thousands.
μs generator”? and a counter that outputs to the rotational position IK6 output terminal to obtain a highly accurate digital rotational position signal! It is considered a conker sign.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described and explained with reference to the drawings. FIG. 4 is a block diagram showing an example of the configuration of a digital rotation detector according to the present invention. In the figure, R
H1 As shown in the diagram, the permanent magnet rotor of the non-commutator motor is magnetized, and the 10°1 angle faces the rotor R with a phase difference of π intervals. Located on the 111 machine, current terminal 1θ♂.

11i and a Hall element having voltage terminals 10υ and 11v,
12 is the voltage terminal 10υ, 11υ of the Hall element 10.11
This is a control circuit made up of an operational amplifier, etc., which inputs the output value from the controller, performs proportional integration on the difference value, and outputs the result. Also, 1
3 is a voltage controlled oscillator that outputs a signal with a frequency corresponding to the output 1f1 of the control circuit 12; 14 is a level "1" when the output value of the control circuit 12 is positive; 2 a level "0" when it is negative; 15 is a voltage controlled oscillator 1
The output level of the polarity discrimination circuit 14 is determined by the number of output pulses of 3.
Count up when it is 1.

This counter counts down when the output level is 0'' and outputs this counted value θ' as a rotational position signal.

Furthermore, 16 and 17 are the divisor values θ of the counter 15, respectively.
A read-only memory (ROM) or the like that inputs the value of θ' and outputs the value of θ' and the value of slnθ', The digital output value from the generator 17 is inputted 2 and converted into an analog value, and the respective Hall elements 1
This figure shows a digital analog (D/A) converter that outputs 0.11 current to terminals 1θi and 11i.

Next, the operation of the +1q digital rotation detector as described above will be described.

Unfortunately, when the rotor R rotates by a rotation angle θ, the magnetic flux density B1 applied to the Hall element 10.11.

B2 is expressed by the following formula.

n 1 = B sinθ
...(1,)B2=B2θ
...(2) Here, B is a constant.

Current terminal 10i of this Hall element 10.11.

When a current 'I+'2 is applied to each jJl, since the Hall element has a multiplication function, its voltage terminal 10v,
l1j) respectively B■×i1.

A pressure proportional to B2×♂2 is generated. for example,"
1 = A c+1<θ', F', 2 = A 5i
When a sinusoidal waveform 11c (A is a constant) of 11θ' is applied, j
Jl, pressure) Benito j'10 v, dl to 11v, 1) l = n l X Z H”
” A B sin θ・(shiro r; θ'
-1:1)vl? -112X Z 2
= AI(cryθ・<il+θ′ ゛(4) An output 11j, II: is generated.

These output voltages v1. uz is control i′lIj circuit 1
2, the difference is taken, and this value is proportionally integrated and output. That is, υ=υ, −? J2: A IS siq (θ-
θ') - (5), the difference V, l, the angle difference (θ
-θ′) is determined by IE Genkichi. :The output value t=11 of the If control circuit I2 is output to the counter 15 as a pulse converted into a frequency according to the value in the voltage controlled oscillator 13.

In addition, the polarity determining circuit 14 determines whether the vi force value of the control circuit I2 is negative or not, and when it is positive, the level of the forward rotation signal is set to "1", and when it is negative, the level of the reverse rotation signal is set to "0". is output to the counter 15. Voltage controlled oscillation i!:y, 7
The counter 15 counts up when the output level of the polarity determining circuit 14 is 1'', and counts down when the output level is 0''. This division value θ' is output as a rotational position signal, and is also outputted as a rotational position signal.
+'i becomes the address signal of the generator 17, and the corresponding atl
The data 40′ and sinθ′ stored in the scalpel are respectively D
/A converters 18 and 19. Value C of Acos θ′ converted into an analog value multiplied by a constant by the D/A converters 18 and 19: current ψ of Hall element 10;
The value of A sin θ' is input to the current terminal 11i of the Hall element 1 to the 14 children 1oi, respectively, and the value of A sin θ' is input to the current terminal 11i of the Hall element 1
and 11, the magnetic flux densities B and B2 are multiplied to obtain equations (3) and (4).

Configuring loose control in this way is generally referred to as fuse-lock-loop (PLL) control.
The rotation angle difference (θ-θ') is controlled to be zero. As a result, the value fd of the rotation angle θ of the rotor R becomes approximately equal to the output value θ' of the horn rank 15, and a rotational position signal can be easily obtained. (For example, if a 10-bit up/down counter is used as the counter 15, one rotation of the rotor R can be divided into 1024. At this time, the number of revolutions of the uncontrolled 111 Confucius motor is 150 O.
r, p, m, the output frequency of the voltage controlled generator 13 is d, 25. (Adjust the proportional integral constant of the output voltage of control 1 circuit 12 so that i kl17.
Just set it.

Note that the detection of the stop position of the rotor R is based on the rotation angle difference (θ - θ
If the value of n1 becomes zero, the voltage controlled oscillator 13 can easily output a pulse to advance or reverse the n1 value of the counter 15.

Note that the present invention is not limited to the above-mentioned actual Mlj example, but can also be implemented as follows.

(') In J,−,,il,, Hall element 10.1
1 is placed at a location where the magnetic flux of the armature winding of the non-commutator motor is less affected, and the magnetic flux of the permanent magnet rotor R5 is detected. However, as shown in FIG. anti-1
On the shaft 2 on the α-connection side, place a disk L of a permanent magnet magnetized by <X2 as shown in FIG. It may also be arranged using

In this way, the detection of the magnetic flux density by 11015 degrees is improved, and the direction of the detection of the rotational position Tl1i degrees is reduced. Note that the rotating disk and Hall element 10.1
1 is small and does not cause a significant increase in the external dimensions of the motor 1 as a whole.

(1)) Also, the output of Hall elements 10 and 11! If temperature dependence is a problem for samurai characteristics, a temperature sensor is installed in the motor, and based on the output signal, a temperature correction circuit (not shown) consisting of a one-chip microcomputer is installed in the control circuit 12. 1 and correct the value of the difference (t'+-υ2) between the output voltages υl+' and 2 of the Hall element 10.11, and it is sufficient to cope with temperature changes. It is possible.

(c) Furthermore, although the counter 15 that determines the number of divisions per rotation of the rotor R has been described as a 10-bit up/down counter, it is not limited to this and is compatible with the resolution required for a digital rotation detector. It is only necessary to select a counter with the number of bits to be used. However, at this time, the output frequency of the voltage controlled oscillator 13 and the generator 16 + sin
The capacity Fjl- of the ROM constituting the generator 17 must be selected to match the number of bits of the counter 15.

(d) If the non-commutator 1 [base of the transistor Q1 r Q2 t Q3 constituting the three-phase half-wave inverter with the motive] is formed according to the divisor value of the counter 15, the above-mentioned hole ICHL+ H2r11
3 can be omitted, and the control accuracy of the electric motor can be improved.

(e) Commutatorless motors are not limited to the configuration of a two-pole synchronous motor and three-phase half-wave inverter, and trenchless semiconductor switches are not limited to transistors, as shown in Figure 6. 4-pole synchronous motor and 3-phase full-wave in-line motor with zero dirt turn-off risk
It is possible to implement various modifications such as a configuration of 1 to G6 and a configuration in which three sets of Hall elements with a phase difference of π/3 are switched to 11". In FIG. 6, 20 is a changeover switch, 2 is a digital rotation detector, and 22 is a speed control circuit.

(f) If it is necessary to detect the rotational position IC on a rotating shaft other than the motor rotating shaft, attach a permanent magnet disc to the rotating shaft as shown in Figure 264. By arranging the Hall elements 10 and 11 facing each other,
It is possible to perform high-precision digital rotation detection similarly to the motor rotation shaft 2.

〔Effect of the invention〕

As explained above, according to the present invention, a pair of Hall elements for detecting the magnetic flux of a permanent magnet rotor of a non-commutated motor are mounted on the armature core with a phase difference of π, and high precision is achieved. Can detect digital rotational position, small size,
A lightweight and inexpensive De Notal rotation detector can be provided. As a result, it is possible to eliminate the need for a commutator-less detection pole IC for the rotor position of a single moving engine, and to perform highly accurate tracking control and position determination control. ;
If space is limited, the effect will be enormous. The input of the pressure-controlled oscillator is the rotational speed signal, and the output is the rotation (1,
It can be used as a pulse signal, and σ(41.
) i4j output:: and noPrussoenerator are also set to 7. A.

[Brief explanation of drawings]

Fig. 1 is a principle diagram of (1!l commutator movement/;1 te'), Fig. 2 is a time chart showing the 10 operations of the inverter in Fig. 1, Fig. 3 is) A sensor FIG. 4 is a block diagram showing one embodiment of the present invention, and FIGS. 5 and 6 are +111 diagrams showing other embodiments of the present invention. 10.11... Hall element, 12... Control circuit, 13
...Voltage open side 1 lifter, 14...Polarity discrimination circuit, 1
5... Counter, 16... Oscillator, 17... s
ln oscillator, 18.19...D/A converter. Figure 1 Figure 2 Figure 4

Claims (4)

[Claims] (1) A pair of Hall elements arranged with a phase difference of π/2 in response to the magnetic flux of the permanent magnet rotor, and a 5111 generator that flows a sine wave current with a phase difference of π/2 to the current terminal of each Hall element. and a μs generator, a control circuit that inputs and subtracts the voltage output value of each Hall element, and controls the subtracted value to zero, and inputs the output value of this control circuit, and inputs the output value of this control circuit, and A voltage controlled oscillator that outputs a response of the corresponding frequency, and an output of 4 from this voltage controlled oscillator.
1. A digital rotation detector comprising: a counter that outputs the sln generator, the shock generator, and a rotational position output terminal by converting the rotational speed into a Tfl number. (2) Claim No. 1, wherein the voltage output values of three sets of a pair of Hall elements installed at an interval of 120° are sequentially switched with a phase difference of π/3 and inputted to the control circuit.
Digital rotation detector as described in section. (3) None (1) A pair of Hall elements are installed in the armature of a ryuko motor with a phase difference of π/2, and a signal corresponding to the position of the permanent magnet rotor is output. 0)
A digital rotation detector described in Ji'I. (4) No 1 (Ryuko 11 presentation motive l'iii't IL
Patent i in which an L detector is provided and the output value of the control circuit is corrected using the output (iN) to perform temperature control J1.
The digital rotation detector according to item (1), in which the range of j'l'J is determined.