JPH09140193A - Driver for stepping motor and indicating instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent resonance of a load member by making a decision whether an input indicating angular speed is within the range of resonance angular speed of pointer or not and varying the driving force of a stepping motor when it is within the range of resonance angular speed. SOLUTION: A decision is made whether an input indicating angular speed is within a specified range of resonance angular speed of pointer or not. When it is not within the specified range, a drive circuit 70 feeds a current to coils 24, 34 thus driving a stepping motor with a driving force corresponding to SIN, COS signals having amplitude of 40 mA. When it is within the specified range, driving force of the stepping motor decreases from a level corresponding to the SIN, COS signals having amplitude of 40 mA to a level corresponding to the SIN, COS signals having amplitude of 20 mA and the input indicating angular speed on the current stage deviates from the specified range of resonance angular speed. Consequently, resonance of the pointer is prevented on the current stage and high visibility is sustained along with high actual pointing accuracy and response of the pointer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a step motor used as a drive source for a load member in vehicles, ships, aircrafts, industrial equipment and the like, and various indicator instruments suitable for adopting this drive device. .

[0002]

2. Description of the Related Art Conventionally, for example, some vehicle indicating instruments employ a PM type step motor which is driven by a two-phase excitation system in which a magnet rotor is rotatably assembled in a pair of stators. In such an indicating instrument, a sine wave current and a cosine wave current are respectively applied to the coils wound around each stator, and the magnet rotor is driven by a driving force corresponding to the rotating magnetic field generated by combining the magnetic fields generated based on the both currents. It is designed to rotate and to swing the pointer in conjunction with this rotation.

[0003]

By the way, in such an indicating instrument, the pointer causes a resonance phenomenon to cause needle shake at an actual pointing angular velocity during the swing operation of the pointer, and thus the pointing accuracy and the visibility are improved. There is a problem in that On the other hand, it is also possible to suppress the above-mentioned resonance phenomenon of the pointer by using damper oil or the like. However, due to the viscous resistance of the damper oil, the response speed decreases due to the deflection of the pointer.

Therefore, the present inventors have made various studies on the cause of the resonance phenomenon of the above-mentioned pointer. As a result of this study, it has been found that such a resonance phenomenon occurs because the indicated angular velocity is affected by the torque of the step motor and the load (weight of the pointer, moment of inertia, frictional resistance, etc.). For example, if the driving torque of the step motor is Kt, and the resonance angular velocity and the moment of inertia of the pointer are ω and J, the following formula 1 is established. However, the static friction of the pointer is ignored.

[0005]

[Number 1] Kt = ω ² · J According to this, the driving torque Kt is seen to have a constant relationship with the resonance angular velocity omega. Moreover, the drive torque Kt changes according to the inflow current to the step motor.

Here, the actual indicated angular velocity of the pointer (hereinafter,
The relationship between the actual instructed angular velocity) and the instructed angular velocity input to the step motor based on the temporal change of the input signal was investigated. According to this, as illustrated in FIG. 8, the input instruction angular velocity is 15n ± 2n (r.
p. m. ) The resonance phenomenon of the pointer was observed in the resonance angular velocity range. However, the inflow current to the step motor was a sine wave current and a cosine wave current having an amplitude value of 40 mA. In 15n ± 2n, the symbol n represents a natural number.

On the other hand, when the amplitude of the sine wave current and the cosine wave current is reduced to 20 mA and the step motor is driven, the resonance angular velocity range is as shown in FIG.
The range was changed from the range of the amplitude value of 40 mA to the range of the amplitude value of 20 mA. As a result, the resonance phenomenon of the pointer, which would occur when the amplitude value is 40 mA, can be prevented. This was also the case when the resonance angular velocity range was changed from the range of the amplitude value of 40 mA to the range of the amplitude value larger than 40 mA.

From the above, it has been found that the resonance of the pointer can be prevented in advance by controlling so that the driving force of the step motor is changed when the input instruction angular velocity reaches the resonance angular velocity range. Therefore, the present invention pays attention to such a point, and effectively utilizes the resonance angular velocity range of the load member that changes according to the driving force of the step motor to suppress the resonance of the load member. It is an object of the present invention to provide an indicating instrument that employs this driving device.

[0009]

In order to achieve the above object, according to the invention described in claims 1 and 2, the input instruction angular velocity calculating means calculates the input instruction angular velocity based on the change of the input signal, and the determining means. However, it is determined whether or not the input instruction angular velocity is a value within the resonance angular velocity range of the pointer. When the determination means determines that the value is within the resonance angular velocity range, the drive control means changes the drive force for rotating the step motor.

As a result, the input instruction angular velocity deviates from the corresponding resonance angular velocity range, and the resonance phenomenon of the pointer can be prevented in advance. According to the third and fourth aspects of the present invention, the input indicated angular velocity calculation means calculates the input indicated angular velocity based on the temporal change of the input signal, and the determination means determines that the input indicated angular velocity is the resonance angular velocity range of the pointer. Is determined. When the determining means determines that the value is within the resonance angular velocity range, the AC control signal generating means changes the amplitude value of the AC control signal, and the driving means causes the driving force corresponding to the AC control signal of the changed amplitude value. To rotate the step motor.

By changing the amplitude value of the AC control signal as described above, the same operational effect as that of the first and second aspects of the invention can be achieved. According to the invention of claim 5, the first AC control signal generating means generates the AC control signal of the first amplitude value so as to swing the pointer toward the target deflection angle corresponding to the input signal, The second AC control signal generating means generates an AC control signal having a second amplitude value different from the first amplitude value so as to swing the pointer toward the target swing angle. Then, the input instructed angular velocity calculation means calculates the input instructed angular velocity based on the temporal change of the input signal, and the determination means determines whether or not the input instructed angular velocity is a value within the resonance angular velocity range of the pointer corresponding to one of the AC control signals. To judge.

When the determining means determines that the value is within the resonance angular velocity range corresponding to one of the AC control signals, the driving means rotates the step motor with a driving force corresponding to the other AC control signal. Further, when the determining means determines that the value is not within the resonance angular velocity range corresponding to the one AC control signal, the driving means rotates the step motor with the driving force corresponding to the one AC control signal.

With such a structure, the same operational effects as those of the first and second aspects of the invention can be achieved. Also,
According to the invention of claim 6, the input instruction angular velocity calculation means calculates the input instruction angular velocity based on the change of the input signal,
The determining means determines whether or not the input instruction angular velocity is a value within the resonance angular velocity range of the pointer.

When the determination means determines that the value is within the resonance angular velocity range, the control signal generation means causes the amplitude values of the SIN signal and the COS signal to correspond to the input indicated angular velocity different from the input indicated angular velocity. The values are changed at the same ratio so that the values are in the angular velocity range. Like this SIN
Even if the amplitude values of the signal and the COS signal are changed at the same ratio, the resonance of the pointer can be prevented in advance as in the inventions according to the first and second aspects.

According to the seventh and eighth aspects of the invention, the output calculating means sets the predetermined amplitude value and the target rotation angle of the step motor so as to swing the pointer toward the target deflection angle corresponding to the input signal. The driving means calculates an AC control signal based on the predetermined amplitude value and the target rotation angle, and the stepping motor is rotated by a driving force corresponding to the AC control signal.

Here, the input instructed angular velocity calculation means calculates the input instructed angular velocity based on the change in the input signal, and the determination means determines whether or not the input instructed angular velocity is within the resonance angular velocity range of the pointer. When the determining means determines that the value is within the resonance angular velocity range, the output calculating means processes the predetermined amplitude value to change, and the driving means converts the AC control signal into the AC control signal having the changing amplitude value. The step motor is changed and the step motor is rotated by the driving force according to the changed AC control signal.

As a result, the predetermined amplitude value and its change,
The output control means and the drive means share the role of the generation of the AC control signal based on this. Therefore, a change in the amplitude value of the AC control signal can be realized with good responsiveness, and as a result, the function and effect of the invention described in claim 1 can be achieved more reliably. According to the invention described in claim 9, the input instruction angular velocity calculation means calculates the input instruction angular velocity for rotating the load member toward the target angle according to the input signal, and the drive control means causes the step motor to operate. A driving pattern representing a non-resonant state of the load member is selected from a plurality of driving patterns representing the driving force of the step motor, and the driving force of the step motor is changed according to the driving pattern.

Thus, it is possible to provide a step motor drive device capable of suppressing the resonance of the load member.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration of a vehicle indicating instrument according to the present invention. The indicating instrument shown in FIG.
As shown in FIG. 3, a two-phase excitation PM type step motor M is used as a drive source.

As shown in FIG. 2, the step motor M has a cylindrical casing 10 in which a pair of upper and lower annular stators 20, 30 are provided.
However, as shown in FIG. 3, they are assembled coaxially. The stator 20 has a ring-shaped coil 2 with a bobbin 23 between two ring-shaped yokes 21 and 22 combined in a substantially U-shape.
4 are accommodated in the two yokes 21, 2 and
Magnetic pole teeth 21a and 22a are formed so as to extend alternately from each other on each inner peripheral edge of 2. It should be noted that the circumferential intervals between the magnetic pole teeth 21a and 22a that are alternately positioned are equiangular pitches.

On the other hand, the stator 30 is constructed by accommodating an annular coil 34 between two annular yokes 31 and 32 combined in a substantially U shape with a bobbin 33 interposed therebetween. The magnetic pole teeth 31a, 3 are provided on the periphery.
2a are alternately extended from each other. In addition, the magnetic pole teeth 31a and 32a are separated from the magnetic pole teeth 21a and 22a by 1 /
It is offset by 2 pitches.

Further, the step motor M is provided with a magnet rotor 40, and the magnet rotor 40 is coaxially assembled in both the stators 20 and 30. The magnet rotor 40 is rotatably supported by its output shaft 41 by the central bearing portion of the upper wall 11 of the casing 10 and the central bearing portion of the bottom wall. A number of magnetic poles are formed on the outer peripheral surface of the magnet rotor 40 in the circumferential direction.

Further, the indicating instrument is provided with a pointer 50, and the pointer 50 is coaxial with the upper end portion of the rotary shaft 41 extending upward from the upper wall 11 of the casing 10 by the pointer boss 51. It is pivotally supported. As a result, the pointer 50
Rotates along the surface of a scale plate (not shown) in conjunction with the rotation of the magnet rotor 40. In addition, in FIG.
2 indicates a stopper.

The indicating instrument is, as shown in FIG.
The microcomputer 60 is provided with its power supply terminal connected to the positive terminal of the battery Ba via the ignition switch IG of the vehicle. This microcomputer 60
4 starts execution of the computer program according to the flowcharts shown in FIGS. 4 and 5, and during this execution, performs arithmetic processing necessary for drive control of the drive circuit 70 connected to the coils 24 and 34 of the step motor M. To do.

The drive circuit 70 is the microcomputer 6
Under the control of 0, a sine wave current (hereinafter referred to as SIN current) is passed through the coil 24 and a cosine wave current (hereinafter referred to as COS current) is passed through the coil 34. In the present embodiment having such a configuration, when the indicating instrument is in an operating state, the microcomputer 60 starts executing the computer program according to the flowchart of FIG.

At step 100, when an analog quantity such as the vehicle speed of the vehicle is read as an input signal into the microcomputer 60, at next step 110,
The target deflection angle θo of the pointer 50 is calculated based on the input signal. Then, in step 120, the temporal change of the input signal, that is, the input instruction angular velocity α with respect to the step motor M is calculated based on the difference between the present target deflection angle θo and the previous target deflection angle θo. The input instruction angular velocity α may be directly obtained from the temporal change of the input signal.

Then, the current deflection angle θ _a of the pointer 50 and the current target deflection angle θ o are compared and determined in step 130. Here, if the current shake angle θ _a is smaller than the target shake angle θ o, the process of the normal rotation process routine 140 is performed (see FIGS. 4 and 5). Then, step 14 in FIG.
At 1, it is determined whether or not the input instruction angular velocity α is a value within a predetermined resonance angular velocity range of the pointer 50. Here, the predetermined resonance angular velocity range is within the above-described resonance angular velocity range of FIG. 8, that is, a range of (15n + 2n) (r.p.m.) to (15n-2n) (r.p.m.). Equivalent to.

Here, the input instruction angular velocity α is (15n + 2)
If it is larger than (n) or smaller than (15n-2n), it is determined that the input instruction angular velocity α is not within the resonance angular velocity range of the pointer 50, and the determination in step 141 is NO. Then, in step 142, the sine wave signal I _S1 and the cosine wave signal I _C1 shown in the following equation 2 are output to the drive circuit 70.

[0029]

[Equation 2] I_S1= I₄₀SIN (ωt) I_C1= I₄₀COS (ωt) where I₄₀Is the amplitude value corresponding to the current value of 40 mA.
is there. Thus, the sine wave signal I_S1(Hereinafter, SIN signal I
_S1And cosine wave signal I _C1(Hereinafter, COS signal I_C1
Is output to the drive circuit 70, this drive circuit
70 applies a SIN current having an amplitude value of 40 mA to the coil 24.
As it flows, the coil 34 has a COS with an amplitude value of 40 mA.
Apply current. As a result, the step motor has an amplitude value of 40
SIN signal I with mA_S1And COS signal I_C1According to
It is driven by the driving force. Therefore, the deflection angle of the pointer 50
Is the current deflection angle θ_aChanges toward the target deflection angle θo
You. When the process in step 142 ends,
If NO in step 160, the computer program
Gram returns to step 100.

After that, the determination in step 141 is Y.
When ES is reached, in the next step 143, the next number 3
The SIN signal I _S2 and the COS signal I _C2 indicated by are output to the drive circuit 70.

[0031]

## EQU3 ## I _S2 = I ₂₀ SIN (ωt) I _C2 = I ₂₀ COS (ωt) where I ₂₀ is an amplitude value corresponding to a current value of 20 mA. When the SIN signal I _S2 and the COS signal I _C2 are output to the drive circuit 70 as described above, the drive circuit 70 causes the coil 24 to pass the SIN current having the amplitude value of 20 mA and the coil 34 having the amplitude value of 20 mA. Apply COS current.

As a result, the step motor has an amplitude value of 2
It is driven by a driving force corresponding to the SIN signal I _S2 and COS signal I _C2 having 0 mA. In this way, when the input instruction angular velocity reaches the value within the resonance angular velocity range, the driving force of the step motor is changed to the SIN signals I _S1 and CO having the amplitude value of 40 mA.
SIN with an amplitude value of 20 mA from the driving force corresponding to the S signal I _C1
Since the driving force corresponding to the signal I _S2 and the COS signal I _C2 is reduced at the same time, the input instruction angular velocity at the present stage deviates from the value within the predetermined resonance angular velocity range.

When this is illustrated with reference to FIGS. 8 and 9, if the input indicated angular velocity is in the resonance angular velocity range 30 ± 4 (r.p.m.) when the amplitude value is 40 mA, the amplitude value is 20.
By reducing to mA, the resonance angular velocity range becomes
Both resonance angular velocity ranges 15 ± 2 (r.p.m.) and 30 ±
4 (r.p.m.), that is, an amplitude value of 20 m
The resonance angular velocity range at A is deviated.

As a result, the resonance of the pointer 50 at the present stage is prevented. As a result, the actual indication accuracy and responsiveness of the pointer 50 can be kept high and the visibility can be kept good. Also,
Even when the computer program shifts from step 130 to step 150, it is processed according to the flowchart of FIG. 5 as in the case of the normal rotation processing routine 140. This makes it possible to achieve the same effect as that of the normal rotation processing routine 140.

By the way, the relationship between the indicated input angular velocity and the current to the step motor was examined by an experiment. here,
When the input instructed angular velocity reaches the value in the resonance angular velocity range, the step motor, which was driven by the COS current and the SIN current with the amplitude value of 40 mA, is driven by the C with the amplitude value of 20 mA.
When driving was performed with the OS current and the SIN current, the results shown in FIGS. 6 and 7 were obtained.

However, in FIGS. 6 and 7, reference numerals L1 and L3 respectively indicate the relationship between the current and the input instruction angular velocity when the drive current of the step motor M is the COS current and the SIN current having the amplitude value of 20 mA. , And the symbol L2
And L4 respectively show the relationship between the current and the input instruction angular velocity when the drive current of the step motor M is the COS current and the SIN current having the amplitude value of 40 mA.

According to this, when the input indicated angular velocity falls within the resonance angular velocity range (17 to 13) (r.p.m.), in FIG. 6, the current is changed from the current specified by the curve L1 to the curve L1.
It decreases to the current specified in 2. On the other hand, in FIG. 7, the current specified by the curve L3 changes to the current specified by the curve L4. Along with this, the driving force of the step motor decreases, and the input instruction angular velocity falls within the resonance angular velocity range (17 to 13).
(R.p.m.).

That is, if the input instruction angular velocity is (17 to 13)
When it is within the resonance angular velocity range of (r.p.m.), the resonance angular velocity range of the pointer 50 deviates from the range of 40 mA to the range of 20 mA due to the decrease of the driving force as described above. The occurrence of the resonance phenomenon of the pointer 50 is prevented in advance. In the above embodiment, the amplitude values of the SIN signal and the COS signal in step 143 (see FIG. 5) are compared with the SIN signal and C in step 142.
I tried to reduce it to half of each amplitude value of OS signal.
Instead, it may be increased. In short, if the input instruction angular velocity is changed so as to be out of the actual resonance angular velocity range of the pointer 50, the same operational effect as described in the above embodiment can be achieved.

Further, in the above embodiment, the microcomputer 60 determines in step 142 that I _S1 = I ₄₀ S
IN (ωt) and I _C1 = I ₄₀ COS (ωt) are output, and I _S2 = I ₂₀ SIN in step 143.
Output processing (ωt) and I _C2 = I ₂₀ COS (ωt),
The example in which the drive circuit 70 supplies the SIN current and the COS current corresponding to each output of the microcomputer 60 to each coil of the step motor M to drive the step motor M has been described, but instead of this, the following is performed. It may be modified to be implemented.

That is, in this modification, the microcomputer 60 outputs the target rotation angle of the step motor M together with the amplitude value I ₄₀ in step 142, and
In step 143, the target rotation angle of the step motor M is modified to be output together with the amplitude value I ₂₀ . Further, instead of the drive circuit 70, the SIN stored in advance is stored.
Based on the waveform data and the COS waveform data, the SIN is output according to each target rotation angle output from the microcomputer 60.
Signal and COS signal are formed, and the SIN current and the COS current are generated on the basis of these formation signals.
Another drive circuit configured to output to both coils of the step motor M with the output amplitude value of is used.

As a result, the microcomputer 60 outputs the output processing of each amplitude value of the SIN signal and the COS signal and the target rotation angle of the step motor M, and the other drive circuit outputs the output amplitude value and the output target rotation. The SIN current and the COS current are formed based on the angle and output to the step motor M. In this way, in forming the SIN current and the COS current, the microcomputer 60 and the other driving circuit described above share the roles to change the current having the amplitude value I _{40 from} the current having the amplitude value I ₂₀ with good responsiveness. You can As a result, the function and effect described in the above embodiment can be achieved more reliably.

In implementing the present invention, the drive control circuit (60, 70) for driving the step motor M so as to rotate the load member (corresponding to the pointer 50) toward the target angle corresponding to the input signal. The present invention may be applied to and implemented in a drive device having a. In this case, the input instruction angular velocity for rotating the load member toward the target angle according to the input signal is calculated in steps 100 to 120.
Then, the drive control circuit selects a drive pattern representing the non-resonant state of the load member based on the input instruction angular velocity from a plurality of drive patterns representing the driving force of the step motor M,
The driving force of the step motor is changed according to this driving pattern.

According to this, with respect to the suppression of resonance of the load member, it is possible to achieve substantially the same effects as those described in the above embodiment. Further, in carrying out the present invention, the absolute value of the difference between the target shake angle θo and the current shake angle θ _a is calculated without being limited to the process of step 130 of FIG. 4, and the target shake angle θo and the current shake angle θ _a are calculated. depending on the magnitude of _a, so as to forward reversed by the step motor M instruction angle corresponding to the absolute value, in this process, it may be performed the processing according to the flow chart in FIG.

Further, the present invention is not limited to the two-phase excitation step motor M, but may be a three-phase excitation or higher PM type step motor. In this case, the step motor is not limited to the PM step motor, but may be a hybrid step motor. Further, in carrying out the present invention, as described in the above embodiment, not limited to the SIN current and the COS current, various pairs of alternating currents such as a pseudo SIN current, a pseudo COS current or an AC trapezoidal wave current ( The step motors may be driven by mutually different phases (for example, half phases).

Further, in carrying out the present invention, the judgment criterion of step 141 in FIG. 5 may be changed appropriately according to the specifications of the indicating instrument. Further, in carrying out the present invention, as described in the above embodiment, the SIN signal and COS of each amplitude value corresponding to 20 mA and 40 mA are provided.
In addition to the signal, SIN of the amplitude value corresponding to, for example, 30 mA
A signal and a COS signal may be adopted and implemented.

In this case, with the SIN signal and the COS signal of each amplitude value corresponding to 20 mA and 40 mA, the pointer 50
When the resonance of the pointer cannot be prevented, the resonance of the pointer 50 can be prevented by driving the step motor with the SIN signal and the COS signal having the amplitude value corresponding to 30 mA. Further, in carrying out the present invention, as described in the above-described embodiment, the SIN signal and the COS signal having the continuously changing amplitude values do not depend on the SIN signal and the COS signal having the respective amplitude values corresponding to 20 mA and 40 mA. The signal may be employed to drive the stepper motor to prevent resonance of the pointer 50.

Further, in the above-mentioned embodiment, the example in which the two-phase stepping motor is adopted as the stepping motor has been described, but instead of this, a single-phase excitation type stepping motor may be adopted. Further, in carrying out the present invention, the present invention is not limited to the indicating instrument for a vehicle, and the present invention may be applied to an indicating instrument adopted in a ship, an aircraft or the like.

Further, each step in the flowcharts of the above embodiments may be realized by a hardware logic configuration as a function executing means.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram showing an embodiment of an indicating instrument according to the present invention.

2 is a partially cutaway perspective view of the step motor of FIG. 1. FIG.

3 is a partially cutaway perspective view showing a stator and a magnet rotor of the step motor of FIG.

4 is a flowchart showing the operation of the microcomputer of FIG.

5 is a detailed flowchart of a reverse rotation processing routine and a normal rotation processing routine of FIG.

FIG. 6 is a graph showing a relationship between an input instruction angular velocity to a step motor and a current flowing through the step motor, each parameter having amplitude values corresponding to 20 mA and 40 mA of a COS signal.

FIG. 7 is a graph showing the relationship between the input instruction angular velocity to the step motor and the current flowing in the step motor, with each amplitude value corresponding to 20 mA and 40 mA of the SIN signal as a parameter.

FIG. 8 is a graph showing a relationship between an actual designated angular velocity of a pointer and an input designated angular velocity when the amplitude value corresponds to 40 mA.

FIG. 9 is a graph showing the relationship between the actual indicated angular velocity of the pointer and the input indicated angular velocity when the amplitude value corresponds to 20 mA.

[Explanation of symbols]

Ba ... battery, M ... step motor, 50 ...
..Pointers, 60 ... Microcomputer, 70 ...
-Drive circuit.

Claims (9)

[Claims] 1. A step motor (M) and a pointer (50) swinging in accordance with the rotation of the step motor.
And a drive control means (60, 70) for rotating the step motor so as to swing the pointer toward a target swing angle corresponding to an input signal, based on a temporal change of the input signal. Input instruction angular velocity calculation means (100 to 120) for calculating the input instruction angular velocity
And a determination means (140, 150, 141) for determining whether or not the input instruction angular velocity is a value in the resonance angular velocity range of the pointer, and when the determination means determines that the value is in the resonance angular velocity range, An indicating instrument characterized in that the drive control means changes the driving force of the step motor. 2. The resonance angular velocity range is determined according to the input designated angular velocity, and the drive control means sets the resonance angular velocity range different from the range corresponding to the input designated angular velocity with respect to the input designated angular velocity. The indicating instrument according to claim 1, wherein the driving force is changed so as to change the range. 3. A step motor (M) and a pointer (50) swinging according to the rotation of the step motor.
An AC control signal generating means (142, 143) for generating an AC control signal having a predetermined amplitude value so as to swing the pointer toward a target deflection angle corresponding to an input signal; and a driving force corresponding to the AC control signal. In an indicating instrument provided with a driving means (70) for rotating the step motor, the input indicating angular velocity calculating means (100 to 120) for calculating the input indicating angular velocity based on the temporal change of the input signal.
And a determination means (141) for determining whether or not the input instruction angular velocity is a value within the resonance angular velocity range of the pointer, and when the determination means determines that the value is within the resonance angular velocity range, the AC control signal generation is performed. A means for changing the amplitude value of the AC control signal, and the driving means rotates the step motor with a driving force according to the AC control signal of the changed amplitude value. 4. The resonance angular velocity range is determined according to the input designated angular velocity, and the drive means sets the resonance angular velocity range different from a range corresponding to the input designated angular velocity with respect to the input designated angular velocity. The indicating instrument according to claim 3, wherein the amplitude value is changed so as to be changed to. 5. A step motor (M) and a pointer (50) swinging according to the rotation of the step motor.
A first AC control signal generating means (142) for generating an AC control signal having a first amplitude value so as to swing the pointer toward the input signal, and swing the pointer toward the target deflection angle. Second AC control signal generation means (143) for generating an AC control signal having a second amplitude value different from the first amplitude value, and input instruction angular velocity calculation means for calculating an input instruction angular velocity based on a change in the input signal. (100 to 120), a determination means (141) for determining whether or not the input instruction angular velocity is a value within the resonance angular velocity range of the pointer corresponding to one of the two AC control signals, and this determination means When it is determined that the value of the resonance angular velocity range corresponding to the AC control signal, the step motor is rotated by the driving force according to the other AC control signal,
Drive means (70) for rotating the step motor with a drive force corresponding to the one AC control signal when the determining means determines that the value is not within the resonance angular velocity range corresponding to the one AC control signal. Indicating instrument equipped with. 6. A two-phase excitation type step motor (M) and a pointer (50) swinging in accordance with the rotation of the step motor.
A control signal generating means (142, 143) for generating a SIN signal and a COS signal having a predetermined amplitude value so as to swing the pointer toward a target deflection angle corresponding to an input signal, and An indicating instrument comprising: a driving unit (70) for rotating the step motor with a different driving force; and an input indicating angular velocity calculating unit (100 to 120) for calculating an input indicating angular velocity based on a change in the input signal, A determination means (141) for determining whether or not the input instruction angular velocity is a value within the resonance angular velocity range of the pointer, and when the determination means determines that the value is within the resonance angular velocity range, the control signal generation means SIN signal and CO
An indicating instrument characterized in that each amplitude value of the S signal is changed at the same ratio so as to be a value in a resonance angular velocity range corresponding to an input instruction angular velocity different from the input instruction angular velocity. 7. A step motor (M) and a pointer (50) swinging in accordance with the rotation of the step motor.
And output calculation means (142, 14) for calculating, as outputs, a predetermined amplitude value and a target rotation angle of the step motor so as to swing the pointer toward a target deflection angle corresponding to an input signal.
An indicator instrument comprising 3) and a drive means (70) for generating an AC control signal based on the predetermined amplitude value and the target rotation angle and rotating the step motor with a driving force corresponding to the AC control signal, Input indicating angular velocity calculating means (100 to 120) for calculating an input indicating angular velocity based on the change of the input signal; and determining means (141) for determining whether or not the input indicating angular velocity is a value within the resonance angular velocity range of the pointer. When the determination means determines that the value is in the resonance angular velocity range, the output calculation means processes to change the predetermined amplitude value, and the drive means changes the AC control signal to the changed amplitude value. Indicating instrument, wherein the step motor is rotated by a driving force according to the changed AC control signal. 8. The resonance angular velocity range is determined according to the input designated angular velocity, and the output calculation means changes the resonance angular velocity range to a range corresponding to an input designated angular velocity different from the input designated angular velocity. The indicating instrument according to claim 7, wherein the predetermined amplitude value is changed. 9. A drive device comprising drive control means (60, 70) for driving a step motor (M) so as to rotate a load member (50) toward a target angle corresponding to an input signal, the input device comprising: An input instruction angular velocity calculation means (100 to 120) for calculating an input instruction angular velocity for rotating the load member toward the target angle according to a signal is provided, and the drive control means controls the driving force of the step motor. Of the plurality of drive patterns represented, a drive pattern representing a non-resonant state of the load member is selected based on the input instruction angular velocity, and the drive force of the step motor is changed according to the drive pattern. Drive.