JPS6066679A - Irregular speed controller of motor - Google Patents

Abstract

PURPOSE:To enable to stably control an irregular speed control of a motor by deviating the speed detection data to be fed back from the true motor speed in response to the rotating position of the motor in the prescribed characteristics. CONSTITUTION:A rotary position detector 3 outputs nonlinear absolute rotary position detection data Dtheta of the prescribed characteristics with respect to the actual rotary position theta of a motor 1. A speed detector 4 calculates the variation per the prescribed unit time of the position detection data Dtheta to obtain a speed detection data wf, thereby applying it through a D/A converter 5 to a deviation input unit 6. A servo amplifier 2 applies a drive signal in response to a deviation between a speed command value wm and the speed detection data wf to the motor 1. The nonlinear characteristic of the detector 3 is suitably set in response to the irregular speed characteristic of the motor to be achieved.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an inconstant speed control device for a motor, and particularly relates to inconstant speed control synchronized with rotational position, and can be used in a wide range of fields where inconstant speed control of a motor is required. It is something.

For example, by using a motion conversion mechanism as shown in FIG.
When converting rotational motion into reciprocating stroke motion and transmitting it, it depends on the transmission characteristics of the conversion mechanism, but in general,
The reciprocating stroke motion is non-uniform in contrast to the constant speed rotational motion of the motor M, which causes various inconveniences. Such rotary/reciprocating motion conversion mechanisms are used in the field of automatic painting machines, spindle machines, and various other automatic machines, and in any case, it is possible to obtain as uniform a motion as possible over a wide range of stroke strokes. required. This is because it is desirable that the stroke motion be as uniform as possible in order to prevent uneven coating and spindle amount as much as possible. In order to meet such demands, conventional measures have been taken such as expanding the approximately constant velocity stroke range through complex mechanical improvements, or using only a narrow approximately constant velocity stroke range for work. That's all I could do.

In such a case, in order to achieve a stroke motion that is as uniform as possible over a wide range of stroke stroke, it is necessary to take measures according to the transmission characteristics of the conversion mechanism (for example, in the direction of modifying its output inconstant velocity characteristics). ) Inconsistent speed control of the rotational motion of the motor may be considered as an effective countermeasure. This invention was made in view of these problems.

By the way, if we simply think about rotating a motor at non-uniform speeds, it is easy to think of giving the speed command value a desired characteristic such as a sine curve, as seen in vibrators (vibration generators). It is.

However, such non-uniform speed control is not applicable to the rotational position of the motor, and therefore is unrelated to the problem of the present invention. Therefore, the rotational position of the motor M is detected by a low-return encoder E through a speed → no-vo loop as shown in FIG. It is conceivable to change the command value Vi. In this way, inconstant speed control of the motor in synchronization with the rotational position is possible, but it is unstable because the speed command value v1 is constantly changed, and problems such as speed divergence may occur.
Like 1. (1) - Object of the Invention Therefore, it is an object of the present invention to provide an inconstant speed control device for a motor that does not have the above-mentioned drawbacks.

Summary of the Invention An inconstant speed control device for a motor according to the present invention incorporates in a feedback loop means for generating speed detection data that deviates from the true motor speed with predetermined characteristics according to the rotational position of the motor, and generates a speed command value. The speed of the motor is controlled according to the deviation between the speed detection data and the speed detection data, and as a result, the motor is operated at an inconstant speed according to a characteristic corresponding to the predetermined deviation characteristic. . The true speed of the motor is changed according to predetermined characteristics and fed back, and the feedback loop is controlled so that the speed command value and the changed speed detection data apparently match, resulting in stable control. Instability problems such as speed divergence do not occur.

Embodiment FIG. 3 is a block diagram showing an embodiment of an inconstant speed control device for a motor according to the present invention, in which 1 is a motor, 2 is a servo amplifier for driving the motor 1, and 3 is a rotational position of the motor 1. This is a rotational position detector for detecting (angle) θ. The rotational position detector 6 outputs nonlinear absolute rotational position detection data Dθ having predetermined characteristics with respect to the actual rotational position θ of the motor 1. The non-linear detection characteristics of the rotational position detector 6 are appropriately set depending on the non-uniform velocity characteristics of the motion to be achieved. The speed detection circuit 4 is
The speed detection data ωf is calculated by calculating the change (time differential value) of the position detection data Dθ per predetermined unit time. This speed detection data ωf is sent to the D/A converter 5 to send a drive signal according to the deviation of the analog to the servo amplifier 2.
is applied to motor 1 via. Since the position detection data Dθ shows a predetermined non-linear characteristic with respect to the actual motor rotational position 0, the speed detection data ω" determined based on this detection data DO is a characteristic corresponding to the non-linear detection characteristic and is a true motor. It is a deviation from the speed.Here, if the speed command value "+11" indicates a constant speed, then the value is ω14. If the speed of motor 1 is controlled so that the deviation of This results in an inconstant motion according to the bias characteristics (that is, the characteristics corresponding to the nonlinear detection characteristics of the detector 6).

For example, the inconstant velocity control device of the present invention is applied to a device that converts the rotational motion of the motor 1 into a reciprocating rocking motion using a motion conversion mechanism as shown in FIG. In order to perform oscillating motion at a speed close to the same speed as when moving over a wide range, the non-linear detection characteristics of the rotational position detector 6 are set as follows, and the motor is adjusted accordingly. 1 should move at an inconstant velocity.

D(7CKθ+K sin 2θ ·= (1) Here, K is a coefficient appropriately selected in order to adjust the degree of nonlinearity. Next, this point will be explained.

Figure 4 shows, for example, a spray can 10 in an automatic painting machine.
This is a motion conversion mechanism that can be used when making a rocking motion. Motor 1 shown from the side in Figure (a)
A rotating plate 11 is connected to the rotating shaft of the semi-circular arc link 13.
A disc-shaped swinging plate 14 is located inside both ends of the pivot shafts 15a, 1.
51), and the rocking plate 14 is supported via pivots 15a, 1
51] is pivoted to the frame 17 via pivots 163 and 161) perpendicular to the frame 17. Spray can 10 is rocking plate 1
Attached to 4. Therefore, when the rotary plate 11 rotates in accordance with the rotation of the motor 1, the link 16 rotates conically around the virtual intersection of its pivot 3 and the other pivots 15a, 15b, 16a, 16b, and its end glK15 a
, 15b) move back and forth, and the swing plate 14 swings in the direction of the arrow.

When plotted, it looks like a trajectory 30 in FIG. 5 (aJ), and when the corresponding movement of the swing plate 14, that is, the movement of the spray gun 10 is plotted, it looks like a trajectory 61 in the same figure.

Rotation angle θ of motor 1 that rotates this oscillating motion at a constant speed =
When plotted using a function of 01nt, it becomes Sc in FIG. 5(b), which is the amount of movement S in the swing motion when the center of the stroke is set to 0. is roughly approximated to a sine function. The moving speed V of the rocking motion corresponding to this. When plotted, it looks like V in Figure 5 (bJ), which roughly approximates a cosine function. Here, ω111 is the rotational angular velocity of the motor 1. (1) is the angle θ and the time t. The relationship is linear.

When the motor 1 is rotated at a constant speed ω1,1 in this way, the converted rocking motion exhibits inconstant velocity characteristics of a cosine or sine function, and is high speed near the center of the stroke (5o=O). However, as the stroke end approaches, the speed gradually decreases, and unless the amount of paint ejected is adjusted according to the stroke position, uneven painting will occur, which is not desirable.

The present invention is implemented in the above equation (1), and as a result, the motor speed is periodically biased by an angular velocity component 2ω111 that is twice the steady rotational speed ωIn of the motor 1. It turns out that good results can be obtained by doing this. This point will be further explained.

As shown in FIG. 6 (1), the radius of the locus 60 of rotational movement is R, and the distance between the center of swing and the center of rotational movement is also R (this does not necessarily have to be the same, but for ease of explanation). ).

The angle of the rocking motion corresponding to the rotation angle θ is assumed to be 01. This θl corresponds to the moving distance (stroke position) from the stroke center in the locus 31 of the reciprocating motion. If the rotation angle 0 is realized at a constant velocity with an angular velocity ωI11, then
In other words, if θ=ωnlt, then it can be expressed by the function Or=fan-'(sin O)-(2). This is S in Figure 5(b). corresponds to the curve of

Here, when the rotation angle θ moves with the following inconstant velocity characteristic in which an arbitrary steady angular velocity ω□ is periodically biased by an angular velocity component 2ω1n, which is twice that, 0=ω, n t−K
sin2 ω,, t = - (3) The above equation (2) is expressed as (3
) can be rewritten as follows.

θ, = tan-' (Sin (ω14.t K
s+n 2 ωrn t ) l − (4) where K
is the velocity deviation component 2ω14. is an arbitrary coefficient that sets the size of [. The above equation (4) can be expressed by the following approximate equation.

θ +=asin 0m t + b stn 3 0
m' + c sin 5 ωIl]1 + d sin
7ωIn' (5) Here, coefficients a, b, c, and d are speed deviation components 2ω, 1.
It has been confirmed that it takes a specific value depending on the magnitude of the coefficient of t. By the way, in order to make θX, which corresponds to the displacement of the rocking motion, move at a constant speed over a wide range as possible, the motion of 01 should be close to a triangular wave like S in Fig. 6 (1)). I wish I could. Therefore, the ideal motion function of 01 is obtained from the Fourier expansion formula of the triangular wave as follows: θ+ = sin ω n 1 t - sin 3 ω m t + -! −
5lo5ωmt-...25...(It would be sufficient if it were 6n, but the coefficient K of the velocity deviation component
If properly determined, the coefficients a and b of each term in equation (5).

It was confirmed that c and d were quite close to the ideal values of equation (6). Therefore, the motion function of motor 1 at rotation angle 0 is K
It is preferable to set the value of to an appropriate value other than O to achieve inconstant motion as expressed in equation (3) above. What corresponds to the inconstant velocity characteristic of this equation (3) is the nonlinear detection characteristic of the (υ equation).

In other words, the non-linear detection characteristic of the (υ equation) is shown in Fig. 7. In this way, since the position detection data Dθ itself exhibits non-linear characteristics with respect to the actual rotational position 0, the time of this position detection data Dθ As mentioned above, the speed detection data ωf determined by differentiation has characteristics that correspond to the nonlinear characteristics described above and is deviated from the true motor speed.In the servo loop, this false speed detection data ωf is used as the speed command value ωln (however, Assume that ω□ is an arbitrary constant value) 1, +T4r-1-Z +-, :, -w /J 4
Second year of elementary school! t&++lG+++J-7 hub ω□ and ω
In a stable state where the deviation of f is O, as shown in FIG. 8, the rotational position detection data Dθ changes at an apparently constant speed in the relationship D0oCωInt. At this time, from the relationship in equation (1) above, the true rotational position 0 of the motor 1 is [θ=ω] in equation (3) as shown in FIG. , 1-K sin 2ωnl'J
This results in an inconstant motion roughly equivalent to . As is clear from FIG. 9, the speed change pattern is synchronized with the rotational position θ.

Next, a case will be considered in which the present invention is applied to a motion conversion mechanism as shown in FIG. 1 that converts motor rotational motion into reciprocating linear motion, and the reciprocating linear motion is made to be as close to constant velocity as possible over a wide range as possible. In FIG. 1, heat is the radius of rotational movement, θ is the rotation angle, D is the length of the connecting rod 32,
33 is a slide rod that is supported by a bearing 64 and performs reciprocating linear motion, α is the angle of the connecting rod 62 with respect to the sliding direction, and X
is the amount of linear displacement of the slide rod 33. In the mechanism shown in FIG. 1, the following relationship holds true.

x == −r 5ino+D CO5α−, 1coS
O = −r sinθ+D cos(stn) −(7
) Expressing equation (7) as an approximation, x = A −B sinθ−Cars 2θ =−(
8). A, B, and C are predetermined coefficients. Here, as described above, the rotation angle θ is an arbitrary steady angular velocity ω1
1. Suppose that it moves with inconstant velocity characteristics as shown in equation (3) above, in which it is periodically biased with twice the angular velocity component 2ωII+, then by substituting equation (3) into equation (7), we get X=- rsin(
ω,,j-Ksin2ω,11L)+D CO3(5
in-'rCO3(ω,, t-K sin 2 o
r11. t ) )...(9) This is expressed as an approximate expression: x = a - b sin ω,,, t - c cos2ω
m [+d sin 3 ωm' (10). a, b, c, and d are coefficients.

Similarly to the above, the ideal possible uniform motion of X is the above (6
), so if we compare Equations 8 and 10, we can see that if Equation (8) is left as is (uniform motor motion), it is far from being a triangular wave function, but Equation (10) (
In the case of constant velocity motion of the motor as shown in equation (3), a third harmonic component is generated, which is close to a triangular wave function.

Therefore, by the non-uniform motion of the motor as shown in equation (3), it is possible to perform the linear reciprocating motion as shown in FIG. 1 at as uniform a speed as possible over as wide a range as possible. Similarly to the above, in order to achieve non-uniform motion as expressed in equation (3), the detection characteristic of the rotational position detector 3 may be made non-linear as expressed in equation (1). Furthermore, (10
In order to reduce the second harmonic component 20J Ill of the equation and make it more similar to a triangular wave function, D/r may be increased.

Incidentally, the apparatus in which the conversion mechanism as shown in FIG. There are automatic painting machines such as 35 is a conversion mechanism that converts the rotational motion of the motor 1 into a reciprocating linear motion, and in FIG. In FIG. 11, the painting spray gun 39 is moved in a reciprocating linear motion.

As the rotational position detector 6, for example, Japanese Patent Application Laid-Open No. 57-704
Variable magnetic resistance type ABUN+J as shown in No. 06,
- It is better to use a rotational position detector.

An example of this type of detector 3 is shown in FIG.

The position detector-11-6 shown in FIG.
Output signal Y = sin, which is obtained by phase-shifting the reference AC signal 5ilIωt or cosω1 according to the rotational position θ of 9.
(ωt-θ) and the amount of phase shift between this output signal Y and the reference AC signal sinωt is 0.
The converter 21 includes a converter 21 that measures θ and generates digital absolute rotational position data Dθ corresponding to this θ. The sensor unit 20 includes a stator 22 in which a plurality of poles A-D are provided at predetermined intervals (for example, 90 degrees) in the circumferential direction;
It includes a rotor (movable core) 19 inserted into a stator space surrounded by various types A-D. Rotor 19
has a shape that changes the reluctance of various A-D depending on the rotation angle, - for example, an eccentric cylindrical shape. The various A-D of the stator 22 have primary coils 18 to 1D.
and secondary coils 28 to 2D are wound respectively. The two poles A and C facing each other in the radial direction are wound with coils so as to operate differentially, and differential reluctance changes occur.

The same goes for the other pair of poles B and D. One pole A,
The primary coils IA and IC of C are excited by a sine signal sinωt, and the other pole pair B and D's primary coil 1B.

1D is excited by a cosine signal. As a result, as the composite output Y of the secondary coils 2A to 2D, the reference signal sinω
A signal Y=si++ (ω[
-0) can be obtained. Note that when the rotor 19 is rotating at a speed equal to .theta., .theta. is expressed by .theta.(1). In other words, θ changes from moment to moment.

In the converter 21, a predetermined high speed clock pulse CP
is counted by a counter 23, and based on the output of this counter 23, a sine/cosine generating circuit 24 generates a sine signal s.
inω[ and cosine signal cosω] are generated, respectively, and these are sent to the primary coil 1A as described above.

Apply to IC, IB, and ID respectively. Secondary coil 2A~2
The output signal Y = sin (ω = - θ) of D is given to the zero cross detection circuit 25, and a pulse L is output in synchronization with the timing of the upper end of the electrical phase angle of this signal Y. The output pulse L of this circuit 25 is used as a latch pulse of the latch circuit 26. The latch circuit 26 latches the count output of the counter 23 in response to the rise of the pulse L applied from the circuit 25. The count value of counter 23 is 1
It is possible to synchronize the cycle of the sine signal 3i16) t with one cycle of the sine signal 3i16) t, and the latch circuit 26 receives the reference AC signal sinωt and the output signal Y = s of the two sensor sections.
A count value corresponding to the phase difference θ with in (ωt−θ) is latched, and this is output as position data Dθ.

In the phase shift type rotational position detector 3 as described above, the primary alternating current signal sinωl, l;O2O3 is normally used.
By making the amplitudes equal and the phase difference between the two properly 90 degrees, an electrical phase shift θ having a linear characteristic with respect to the mechanical rotational position θ is generated in the secondary output signal Y. However, the primary AC signals sinωt, cosω[
By varying the amplitude of the signal by a predetermined ratio, or by adjusting the phase difference between the two to some extent from 90 degrees, an electrical phase shift with a non-linear characteristic with respect to the rotational position θ can be made into the secondary output signal Y. It has been found that it is possible to cause this to occur. Therefore, it is advantageous to use a rotational position detector of the type shown in FIG. 12, since desired nonlinear detection characteristics can be obtained very easily.

To explain this point, the primary AC signal sinωi
, If the amplitudes of CO5ωt are different, an electrical phase shift with an error of △θ will occur in the secondary output signal Y with respect to the true rotational position θ, and this error/\θ has the characteristic of △θ-K 5in2θ. It turns out that. - For example, the ratio of the amplitude difference of the primary signal is 1%, 2%.

Figure 13 shows the waveform of the error △θ when there are 3 hits (however,
In this example, sinωt has a larger amplitude).

The coefficient increases as the ratio of amplitude differences increases.

In this way, by appropriately setting the amplitude ratio of the primary signal sinω[, (2) Sωt in the variable magnetic resistance type position detector B as shown in FIG. characteristics can be obtained.

In position detectors 6 of the same type, if the amplitudes of the primary signals are made equal and the phase difference between the two is shifted from 90 degrees, an error △θ as shown in Fig. 14 will occur depending on the amount of shift α. It is clear that Therefore, the primary AC signal sinωt,c
By suitably finely adjusting the phase difference of osωt from its original value of 90 degrees, it is possible to obtain a desired nonlinear detection characteristic different from the above equation (1). Furthermore, the phase difference is 90
It is also possible to control both the degree deviation amount α and the amplitude ratio, and the waveform of the error △θ can be created in any pattern depending on how they are combined as shown in Figure 15. Depending on the combination, a desired non-linear detection characteristic different from the above equation (1) can be appropriately set.

The absolute 1/rotational position detector 6 with the same non-linear detection characteristics as described above uses a variable magnetic coupling type phase shift type sensor such as a resolver instead of the variable magnetic resistance type sensor as shown in Fig. 12. can also be configured.

Furthermore, as in the example shown in FIG. 16, a type that generates incremental pulses may be used as the rotational position detector 6 with non-linear detection characteristics. That is, a pulse generation pattern is formed with a predetermined non-linear characteristic (non-uniformly spaced pinch), an incremental rotary encoder is used as the rotational position detector 6, and this output pulse INCP is input to the frequency-voltage converter 7 to convert it into an analog signal. Find the speed detection data ωf and apply it to the deviation input section B. in this case,
The pulse generation pattern with respect to the actual rotational displacement θ is made non-linear so that the generation time intervals of the incremental pulses INCP are equal when the motor 1 is performing a desired non-uniform motion.

FIG. 17 shows the actual rotational position θ as the rotational position detector 3a.
This detection data is converted into a predetermined nonlinear characteristic using a nonlinear conversion table 8, and the subsequent processing is performed in the same manner as shown in FIG. 3.

The rotational position detector 3a in FIG. 18 also has linear detection characteristics as in FIG. 17, and is also provided with a speed detector TG for detecting the true motor speed (rl). , the true motor speed ω is changed according to a predetermined characteristic in accordance with the rotational position detection data from the detector 6, and false speed detection data ωr is created.

The true motion speed ω may be calculated based on the time change in the output of the position detector 6a using the speed detection circuit 4 without providing a special speed detector TG.

The rotational position detectors 3, 3a are not limited to those described above, and any other arbitrary device such as an optical absolute encoder can be used. Further, the predetermined bias characteristic of the speed detection data to be hacked with respect to the true motor speed is not limited to the above-mentioned one, and may be freely set depending on the application.

In addition, C.
Of course, the present invention can also be applied to cases in which a motor is moved at an inconstant speed for the purpose of moving a mechanical system at an inconstant speed with predetermined characteristics. An example is a vibrator (vibration generator).

Effects of the Invention As described above, according to this FJAlζ, the speed detection data to be fed back is biased from the true motor speed 75) according to a predetermined characteristic according to the motor rotational position, and the deviation between this and the speed command value ζζ is Since the motor speed is controlled by 1, the desired non-uniform speed control is realized in a stable state of the servo loop, and the non-uniform speed control of the motor is executed extremely stably. Furthermore, by making it possible to control the motor at non-uniform speed in synchronization with the rotational position, it becomes possible to expand the range of applications of morph control. Therefore, control that has been difficult in the past can be achieved extremely easily in various motor application fields. For example, in the motion conversion mechanism as described in the embodiment, the problem of making reciprocating rocking motion or linear motion as equal as possible can be achieved extremely easily by applying the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a mechanism for converting rotational motion into reciprocating stroke motion for detailed explanation of this invention, and FIG. A block diagram showing a control method for changing command values,
FIG. 3 is a block diagram showing an embodiment of the motor inconstant velocity control device according to the present invention, and FIG. 4(a) shows rotary motion/reciprocating rocking motion to which the morph inconstant velocity control according to the present invention can be applied. 5(a) is a front view showing an example of the conversion mechanism; FIG. 5(b) is a right side view of the same mechanism; FIG. (b) is a graph schematically showing the function of the movement amount and speed of the output swing motion during the morph constant rotation motion of the same mechanism, and FIG. 6 (a) is the graph shown in FIG.
Figure 7 is a graph similar to a), Figure 7 is a graph schematically showing the function of the movement amount and speed of the output oscillation motion during the ideal constant speed rotational motion of the motor, and Figure 7 is the rotation of the embodiment shown in Figure 3. A graph showing an example of the non-linear characteristics of the input rotation angle versus output detection data in a position detector. Fig. 8 is a graph showing changes in the apparent rotational position detection data when the servo loop in Fig. 3 is stable. Fig. 9 is a graph showing an example of the nonlinear characteristics of the input rotation angle versus output detection data. Figure 8 is a graph showing actual changes in motor rotational position corresponding to changes in apparent position detection data, that is, inconstant motion, and Figure 30 is an example of a spindle using the conversion mechanism shown in Figure 1. FIG. 11 is a schematic diagram showing an example of an automatic coating machine using the conversion mechanism shown in FIG. block diagram, 1st
3 is a graph showing the output error Δθ (nonlinear component) with respect to the input rotation angle θ when the amplitude of the primary AC signal sin (IJ t , cos ωt is varied in the rotational position detector of FIG. 12, The figure shows the phase difference between the primary AC signals sinωt and ωSωt in the same rotational position detector.
Graph showing output error Δθ (non-linear component) against input rotation angle θ1 when slightly shifted from 0 degrees, No. 15
The figure shows the primary AC signal sinω[
, (the amplitude of the force Sω1 is different and the phase difference is 90
A graph showing the output error Δθ (non-linear component) with respect to the input rotation angle θ when the input rotation angle θ is slightly shifted from the degree, FIGS. 16, 17, and 18 are block diagrams showing other embodiments of the invention, It is. ML・Motor, 2. Servo amplifier, 3. Rotational position detector with non-linear detection characteristics, 3a... Rotational position detector with linear detection characteristics, 4. Speed detection circuit, 7. Frequency voltage converter, 8. Non-linear conversion. Table, 9...Speed change table, TG/speed detector. Applicant Nisgy Co., Ltd. Agent Yoshihito Iizuka Figure 1 Figure 4 Figure 7 Figure 8 Figure 9-↑

Claims (1)

[Claims] 1. Rotational position detection means for detecting the rotational position of the motor;
speed feedback means for generating speed detection data that deviates from the true motor speed with predetermined characteristics according to the rotational position detection data; and controlling the speed of the motor according to the deviation between the speed command value and the speed detection data. 1. An inconstant speed actual control device for a motor, comprising means for controlling the motor. 2. The rotational position IA detection means outputs nonlinear rotational position detection data with predetermined characteristics with respect to the actual rotational position of the motor, and the speed feedback means outputs nonlinear rotational position detection data with respect to the actual rotational position of the motor. The rotational position detection means includes a plurality of primary coils and corresponding secondary coils, and the rotational position detection means includes a plurality of primary coils and corresponding secondary coils, and the rotational position detection means includes a plurality of primary coils and corresponding secondary coils, and the rotational position detection means includes a plurality of primary coils and corresponding secondary coils, and the Excitation is carried out by an alternating current signal with a phase shift between the two, and the alternating current signal is output to the secondary coil with a phase shift of an electrical angle corresponding to the rotational position according to changes in magnetic resistance or magnetic coupling accompanying rotation. By generating a signal and measuring the amount of phase shift, the abunlute rotational position detection data is obtained, and by varying the amplitude level between the primary side AC signals at a predetermined ratio, or The motor inequality according to claim 2, characterized in that by adjusting the phase difference between the alternating current signals, position detection data having linear characteristics with respect to the actual rotational position is obtained. Speed control device. 4. The rotational position detection means generates incremental pulses at non-linear intervals with predetermined characteristics with respect to the actual rotational displacement of the motor, and the speed detection circuit is the incremental pulses. Second
Inconstant speed control device for the motor described in Section 1. 5. The rotational position detection means outputs rotational position detection data with linear characteristics with respect to the actual rotational position of the motor, and the speed feedback means detects the actual rotational speed of the motor. The motor according to claim 1, comprising a speed detector and means for changing the speed detected by the speed detector with a predetermined characteristic according to the rotational position data and outputting the changed speed as the speed detection data. Inconstant velocity control device.