JPH07123762A - Motor drive device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the followability of the motor speed to the position command by matching the increased feedforward correction in the motor drive device with the acceleration of the motor speed. [Configuration] A position loop gain multiplier 2 that outputs a speed command from a position command 1, a small time constant filter 5 and a large time constant filter 6 that delay the position command by different amounts, and a large and small time constant that switches between the filters 5 and 6. Filter change switch 4
And a feedforward differential calculator 7 that outputs a corrected speed signal that is delayed in response to the output of the small time constant filter or the large time constant filter, and adds the speed command and the corrected speed signal to obtain the motor speed command. It is characterized in that the motor speed is accelerated by the increasing portion of the correction speed signal generated and delayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position control device for a motor drive device used in FA (factory automation) equipment and the like.

[0002]

2. Description of the Related Art Conventionally, in a motor drive device, a feedforward correction function has been used to improve the followability of the motor. Hereinafter, such a motor drive device will be described with reference to the drawings. FIG. 4 is a block diagram showing an example of a conventional motor drive device.

In FIG. 4, 1 is a position command for driving a motor to a certain position, 2 is a position loop gain multiplier which receives the position command 1 and multiplies it by a position loop gain to output a speed command 2 ', Reference numeral 7 is a feedforward differential calculator that differentiates the position command 1 and multiplies the feedforward gain to output a correction signal for the speed command (feedforward correction signal), that is, a corrected speed signal 7'for the speed command 2 ', and 8 is a position An adder that calculates a speed command 2 ′ that is the output of the loop gain multiplier 2 and a corrected speed signal 7 ′ that is the output of the feedforward differential calculator 7 and outputs a speed command 8 ′, and 9 is an adder 8. It is a speed control calculator that calculates a speed command 8 ', which is an output, and outputs a torque command 9'to the next stage.

Continuing with FIG. 4, 10 is an encoder 1.
A magnetic pole detector for detecting the magnetic poles of the motor from the output of 4 (described later), 11 multiplies the torque command 9'which is the output of the speed control calculator 9 by the magnetic pole data detected by the magnetic pole detector 10. A multiplier for transmitting the output to the subsequent stage as a current command 11 '; 12 is a D / A converter for converting the current command 11', which is the output of the multiplier 11, into analog data by D / A conversion to be a current command; Reference numeral 13 is a current amplifier that amplifies a current command that has been D / A converted by the D / A converter 12 and becomes analog data to supply a drive current to the motor, 14 is an encoder that detects the rotational position of the motor, 15 is the motor, Reference numeral 16 is a speed detector that detects the speed from the encoder signal output from the encoder 14.

FIG. 5 shows a timing chart at the time of a large movement amount when the motor drive device of FIG. 4 is used, and FIG. 6 similarly shows a timing chart at the time of a small movement amount when the motor drive device of FIG. 4 is used. Indicates. 5 and 6A show the voltage waveform of the position command signal, FIG. 5B shows the correction amount of the feedforward correction signal, and FIG. 5C shows the speed of the motor.

The operation of the conventional motor drive device configured as described above will be described below. In the conventional example shown in FIG. 4, first, when the position command 1 is input to the feedforward differential calculator 7, the feedforward differential calculator 7 differentiates the position command 1 and then multiplies the internal feedforward gain. Feed forward gain multiplication, and outputs it to the adder 8 as a corrected speed signal 7'of the speed command. At the same time, the position command 1 is input to the position loop gain multiplier 2, multiplied by the position loop gain, and output to the adder 8 as a speed command 2 '. In the adder 8, the speed command 2 ′ that is the output of the position loop gain multiplier 2 and the corrected speed signal 7 ′ that is the output of the feedforward differential calculator 7 are calculated, and the speed control calculator 8 is calculated as the speed command 8 ′. Output to 9.

Further, the speed control calculator 9 calculates the speed command 8'which is the output of the adder 8 and the output of the speed detector 16 and multiplies the speed loop gain to generate the torque command 9 '.
Output to the multiplier 11. The multiplier 11 is the speed control calculator 9
Of the torque command 9 ', which is the output of the magnetic field detector, is multiplied by the magnetic pole data detected by the magnetic pole detector 10 to obtain a current command 11'.
Is input to the D / A converter 12 in the subsequent stage. D / A
The converter 12 outputs the current command 1 which is the output of the multiplier 11.
1'is D / A converted to generate an analog data current command, which is transmitted to the current amplifier 13 in the subsequent stage. Current amplifier 13
Drives the motor 15 by amplifying the current command of the analog data D / A converted by the D / A converter 12 and supplying a drive current to the motor 15.

[0008]

However, in the conventional motor drive device as described above, the first problem is that the position command 1 is applied to the position loop gain multiplier 2 and the feedforward differential calculator 7 at the same time. As a result, the feedforward differential calculator 7 outputs the same as the position command as shown in FIGS. 5 (a) and 5 (b) or FIGS. 6 (a) and 6 (b). Feedforward correction will be applied in phase.

Moreover, as shown in FIGS. 5 (c) and 6 (c), there is a delay in the motor speed. Therefore, when the motor speed should be increased (T7, T8), as shown in FIG.
(B) of FIG. 6 and feedforward correction for reducing the speed as shown in FIG. 6 (b) are applied, and the peaks V3 ((c) of FIG. 5) and V4 ((c) of FIG. 6) of the motor speed are suppressed. As a result, the acceleration and deceleration time becomes long, and as a result, not only the effect of feedforward correction for improving the followability is lost, but also the followability is deteriorated.

As a second problem, the cycle of the position command for the large movement amount and the small movement amount is shorter at the small movement amount than at the large movement amount, as shown below. That is, T3> T5, where T3 is the position command cycle when the amount of movement is large (see FIG. 5).
(A)) T5 is the cycle of the position command when the movement amount is small ((a) in FIG. 6).

For this reason, the feedforward correction also has a shorter cycle at the time of the small movement amount than at the time of the large movement amount, so that the time at the small movement amount is earlier than that at the time of the large movement amount. At this point, the feedforward correction for acceleration of the motor speed is applied, and the deceleration correction is applied where the speed should be accelerated. Therefore, as shown in the following equation, the peak of the motor speed is suppressed, and the motor speed with respect to the peak of the position command is smaller than that with the large travel amount when the small travel amount is delayed with respect to the position command. There is a problem that the time difference between the peaks becomes large, and the followability of the motor speed is poor when the travel distance is small and when the travel distance is large. (Details will be described later.) T7 <T8 Here, T7 is the time difference between the peak of the motor speed and the peak of the command when the amount of movement is large ((c) in FIG. 5) T8 is the peak of the command when the amount of movement is small. Difference of the peak of motor speed with respect to ((c) of FIG. 6)

As a third problem, the phase difference of the motor speed with respect to the position command at the time of the large movement amount and the small movement amount is 360 ° × when the large movement amount is as shown in FIG.
(T7 / T3) degrees, when the amount of movement is small, it becomes 360 ° × (T8 / T5) degrees, as shown in FIG. However, since the relationship between T8 and T7 is T8> T7, comparing the phase difference of the motor speed with respect to the position command at the time of a large movement amount and at the time of a small movement amount, it is apparent that the phase difference at the small movement amount is larger. The phase difference with respect to the position command becomes large, so
In particular, there is a problem that the followability to the position command is worse when the moving amount is small than when the moving amount is large.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and delays the correction of the motor speed based on the command to increase the acceleration of the motor speed.
The purpose is to improve the followability of the motor speed.

Further, the present invention has been made in view of the above-mentioned problems of the prior art, and delays the correction of the motor speed based on the command at the time of the small movement amount to a greater extent than that at the time of the large movement amount, and the small movement amount. In order to improve the followability of the motor speed by making a time difference between the peak of the motor speed and the peak of the command at the time of a small amount of movement, by appropriately performing the correction to increase the acceleration of the motor speed at With the goal.

Further, the present invention has been made in view of the above-mentioned problems of the prior art, and by appropriately increasing the acceleration of the motor speed by a correction when the amount of movement is small, the command for the amount of movement is small. The object is to improve the followability of the motor speed by reducing the phase difference of the motor speed.

[0016]

In order to solve the above-mentioned problems of the prior art, a motor drive device according to the present invention includes an encoder for detecting the rotational position of a motor, and a magnetic pole detector for detecting a motor magnetic pole from the encoder. A position loop gain multiplier that multiplies a position command by a position loop gain and outputs a speed command; a feedforward differential calculator that differentiates the position command and feedforward multiplies it to output a corrected speed signal that corrects the speed command; An adder for adding a speed command and a corrected speed signal to output a second speed command; a torque command value generated from the second speed command and the output of the speed detection; and a magnetic pole detector. A motor drive device comprising a current amplifier that supplies a product to a magnetic pole detection value as a current command to the motor, wherein the position command is input for a predetermined time. A position command delay means for outputting to the feedforward differential calculator as a delayed and delayed position command, the position command delay means sending the delayed position command to the feedforward differential calculator, and based on it, the feedforward differential calculator It is characterized in that the arithmetic unit outputs a corrected speed signal delayed by a predetermined time.

Further, in order to solve the above-mentioned problems of the prior art, the motor drive device according to the present invention uses, as the position command delay means, a plurality of delay means having different delay times and one of the plurality of delay means. And a changeover switch for changing the delay of the correction speed signal.

Further, in the motor drive device according to the present invention, in order to solve the above-mentioned problems of the prior art, the position command delay means includes a time constant large filter having a large delay amount and a time constant small filter having a small delay amount. It is characterized in that it is constituted by a time constant large / small filter changeover switch for switching between a large time constant filter and a small time constant filter according to a large / small movement amount switching signal indicating a movement amount of a motor.

[0019]

The present invention is configured as described above, and in particular, the position command delay means is provided in the preceding stage of the feedforward differential calculator to delay the correction speed signal for correcting the motor speed, which accelerates the motor speed. By increasing the number, the peak voltage of the motor speed can be increased, the followability of the motor speed to the position command can be improved, and the phase difference between the position command and the motor speed can be shortened.

Further, the position command delay means is switched to a time constant large filter, a time constant small filter, and a time constant large filter or a time constant small filter according to a large / small movement amount switching signal indicating the magnitude of the motor movement amount. It consists of a large and small filter changeover switch to switch between a small time constant filter for large movements and a large time constant filter for small movements. Especially for small movements, motor speed acceleration is equivalent to that for large movements. Because of the delay, a large time constant filter is used to delay the correction speed signal that accelerates the motor speed so that it matches the acceleration of the motor speed. In addition to reducing the peak time difference, the phase difference of the motor speed with respect to the position command is improved to improve the followability of the motor speed with respect to the position command. It can be.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of a three-phase synchronous motor drive device according to an embodiment of the present invention.

In FIG. 1, 1 is a position command for driving a motor to a certain position, and 2 is a position loop gain multiplier which receives the position command 1 and multiplies it by a position loop gain to output a speed command 2 '. Reference numeral 3 denotes a large / small movement amount switching signal for discriminating whether the movement amount of the motor is a large movement amount or a small movement amount and switching the input of the position command to the time constant small filter or the time constant large filter.

Further, 4 is a time constant large / small filter changing switch for switching between inputting the position command 1 to the time constant small filter or the time constant large filter in response to the large / small movement amount change signal 3. If command 1 indicates a large amount of movement,
A time constant small filter that receives the position command 1 and filters it by operating the time constant large / small filter changeover switch 4 by the large / small movement amount switching signal 3, 6 is a large / small movement amount switching when the position command 1 indicates a small movement amount. This is a large time constant filter that receives the position command 1 and filters it by operating the time constant large / small filter changeover switch 4 by the signal 3. The time constant large / small filter changeover switch 4, the small time constant filter 5, and the large time constant filter 6 form the features of the present invention, and have a position command having an effect of delaying the input position command 1 by a predetermined time. The delay means 17 is formed.

Further, 7 differentiates the position command 1'after being filtered by the small time constant filter 5 or the large time constant filter 6 and multiplies the feed forward gain to multiply the speed command correction signal (feed forward correction signal), That is, the feedforward differential calculator that outputs the corrected speed signal 7 ″ for the speed command 2 ′, and 8 is the speed command 2 ′ that is the output of the position loop gain multiplier 2 and the corrected speed that is the output of the feedforward differential calculator 7. Addition period for calculating signal 7 ", 9 is speed command 8" which is the output of addition period 8
Is a magnetic pole detector for detecting the magnetic pole of the motor from the output of the encoder 14.

Further, 11 is a multiplier for multiplying the torque command 9 "which is the output of the speed control calculator 9 by the magnetic pole data detected by the magnetic pole detector 10 and transmitting the output as a current command to the subsequent stage, 12 Is a D / A converter that D / A converts the current command 11 ′ output from the multiplier 11 into a current command for analog data, and 13 is a current that is D / A converted by the D / A converter 12 and becomes analog data. A current amplifier that amplifies the command and supplies the drive current to the motor,
Reference numeral 14 is an encoder that detects the rotational position of the motor, 15 is a motor, and 16 is a speed detector that performs speed detection based on the encoder signal output from the encoder 14.

FIG. 2 shows a timing chart at the time of a large movement amount in the embodiment of FIG. 1, and FIG. 3 also shows a timing chart at the time of a small movement amount in the embodiment of FIG. Therefore, FIG. 2A and FIG. 3A show the voltage waveform of the position command signal, FIG. 2B shows the correction amount (voltage) of the feedforward correction signal, and FIG. ) Indicates the speed of the motor.

The operation of the motor drive device of the present invention constructed as above will be described below. First, when the position command 1 indicates a large moving amount, the large / small moving amount switching signal 3 determines that the position command 1 indicates a large moving amount and switches the time constant large / small filter changing switch 4. , Position command 1 is transmitted to the small time constant filter 5 side. The position command 1 transmitted to the small time constant filter 5 is processed and filtered inside the small time constant filter 5, and is input to the feedforward differential calculator 7 as a delayed position command 1 '. The feedforward differential calculator 7 differentiates the delayed position command 1 ′ filtered by the small time constant filter 5, and further multiplies the feedforward gain by the internal feedforward gain to correct the speed command, that is, the speed command 2 ′. Is output to the adder 8 as a corrected speed signal 7 ″.
The corrected speed signal 7 ″ (feedforward correction value) for the speed command 2 ′ which is the output of the feedforward differential calculator 7 is, as shown in FIG. Has a delay time of T1.

At the same time, the position command 1 is input to the position loop gain multiplier 2, multiplied by the position loop gain, and output to the adder 8 as a speed command 2 '. In the adder 8, the speed command 2 ′ that is the output of the position loop gain multiplier 2 and the corrected speed signal 7 ″ that includes the delay time that is the output of the feedforward differential calculator 7 are calculated, and the second speed command 8 "to the speed control calculator 9.
Further, the speed control calculator 9 calculates the second speed command 8 ″ including the delay time which is the output of the adder 8 and the speed feedback which is the output of the speed detector 16, and multiplies the speed loop gain to obtain the torque command. 9 ″ is generated and output to the multiplier 11.

The multiplier 11 multiplies the torque command 9 "output from the speed control calculator 9 by the magnetic pole data detected by the magnetic pole detector 10 and uses it as a current command to output D / in the subsequent stage.
Input to the A converter 12. The D / A converter 12 D / A-converts the current command 11 ″ that is the output of the multiplier 11 to generate a current command of analog data, and transmits the analog data current command to the current amplifier 13 in the subsequent stage. The current command of the analog data D / A converted by 12 is amplified and a drive current is supplied to the motor 15. The drive current output from the current amplifier 13 is the motor 15
To drive the motor 15.

In the present embodiment, the feedforward correction signal has a delay time T1 with respect to the position command signal as shown in FIG. 2B, so that as shown in FIG. Since the feedforward correction of the acceleration is performed more than before when the motor speed is accelerated, the acceleration of the rotation of the motor 15 can be increased. Motor 1
As the acceleration of 5 increases, the phase difference T4 between the peak of the motor speed and the peak of the position command can be made smaller than the conventional phase difference T7, as shown below. T4 ((c) of FIG. 2) <T7 ((c) of FIG. 5)

Further, as the acceleration of the motor is increased, the peak value V1 of the speed is increased as shown below, and the followability of the motor can be further improved. V1 ((c) in FIG. 2)> V3 ((c) in FIG. 5) Further, as the motor speed increases, the position command ((a) in FIG. 2) and the motor speed ((c) in FIG. 2) Phase difference (36
0 ° × (T4 / T3) [degree]) is also shortened, and when this is compared with the phase difference in the conventional case ((a) and (c) of FIG. 5), the following relationship is established and the position command The phase difference between the motor speed and the motor speed can be improved. 360 ° x (T4 / T3) [degree] <360 ° x (T7 /
T3) [degree]

Next, in the case where the position command 1 indicates a small amount of movement, the problems associated therewith will be described in detail. First,
Looking at the conventional example shown in (a) of FIG. 5 and (a) of FIG.
When comparing the case of the large movement amount and the case of the small movement amount, as shown below, it can be seen that the cycle of the position command is shorter for the small movement amount than for the large movement amount. T5 ((a) in FIG. 6) <T3 ((a) in FIG. 5)

Therefore, as described above, the feedforward correction also has a shorter position command cycle when the movement amount is small than when the movement amount is large. Therefore, the feedforward correction is larger when the movement amount is small. The acceleration of the motor speed is corrected at a time earlier than the movement amount, and the effect is reduced, so the peak of the motor speed is suppressed and the position command On the other hand, it will be considerably delayed in time. Therefore, the time difference between the peak of the position command and the peak of the motor speed is larger when the amount of movement is small than when the amount of movement is large. When the amount of movement is small, the followability of the motor speed is worse than when the amount of movement is large. There was a problem. T8 ((c) of FIG. 6)> T7 ((c) of FIG. 5)

In the present invention, in order to solve this problem, a plurality of time constant filters 5 and 6 (FIG. 1) are provided, and in general, when a large amount of movement is used, a filter having a small time constant is used. The delay of the correction signal of the speed command, which is the delay of the command, is relatively reduced, and the filter of the correction signal of the speed command, which is the delay of the position command, is used to reduce the delay of the correction signal of the position command when the movement amount is small. It was made relatively large to increase the acceleration of the motor. For the control, a time constant large / small filter changeover switch is used to switch between small and large time constant filters based on the amount of movement.

That is, at the time of a small movement amount, a large time constant filter having a large time constant is used, and at the time of a large movement amount such as T2 ((b) of FIG. 3) (T1 ((of FIG. 2)). b))) A larger delayed feedforward correction acceleration portion was used to properly accelerate the motor speed (FIG. 3 (c)). This increases the peak voltage of the motor speed, thereby reducing the time difference between the peak of the motor speed and the peak of the position command, and further shortening the phase difference of the motor speed with respect to the position command. Then, it is possible to improve the followability of the motor speed to the position command, which is particularly problematic when the amount of movement is small.

Next, the operation of the motor drive device in this embodiment when the amount of movement is small will be described. As described above, the small movement amount requires a filter having a larger time constant than the large movement amount. Therefore, the large / small movement amount switching signal 3 indicates that the position command 1 indicates a small movement amount. By operating the indicated time constant large / small filter changeover switch 4, the position command 1 is connected to the large time constant large filter 6 side. The position command 1 transmitted to the large time constant filter 6 is processed and filtered inside the large time constant filter 6, and the delayed position command 1 ′ is supplied to the feedforward differential calculator 7.
Is entered as.

The feedforward differential calculator 7 differentiates the delayed position command 1'which is filtered by the large time constant filter 6 and further multiplies the feedforward gain by the internal feedforward gain to obtain a speed command correction signal, that is, , The corrected speed signal 7 ″ of the speed command 2 ′ is output to the adder 8. In this case, the corrected speed signal 7 ″ (feedforward correction value) for the speed command 2 ′ output from the feedforward differential calculator 7 is Due to the effect of the large time constant filter 6, there is a delay time of T2 with respect to the command value, as shown in FIG. As described above, the relationship between the delay time T2 and the delay time T1 ((b) of FIG. 2) when the amount of movement is large is T2> T1.

The position command 1 is input to the time constant large filter 6 and at the same time, to the position loop gain multiplier 2.
The position loop gain is multiplied and output to the adder 8 as a speed command 2 '. In the adder 8, the speed command 2 ′ that is the output of the position loop gain multiplier 2 and the corrected speed signal 7 ″ that includes the delay time that is the output of the feedforward differential calculator 7 are calculated, and the second speed command 8 "to the speed control calculator 9. Further, the speed control calculator 9 calculates the second speed command 8 ″ including the delay time which is the output of the adder 8 and the speed feedback which is the output of the speed detector 16, and multiplies the speed loop gain to obtain the torque command. 9 ″ is generated and output to the multiplier 11.

The multiplier 11 multiplies the torque command 9 "which is the output of the speed control calculator 9 and the magnetic pole data detected by the magnetic pole detector 10 and uses it as a current command for D / in the subsequent stage.
Input to the A converter 12. The D / A converter 12 D / A-converts the current command 11 ″ that is the output of the multiplier 11 to generate a current command of analog data, and transmits the analog data current command to the current amplifier 13 in the subsequent stage. The A / D converted analog data current command is amplified to supply a drive current to the motor 15. The drive current output from the current amplifier 13 is supplied to the motor 1.
5 to drive the motor 15.

In this embodiment, as shown in FIG. 3 (b), the feedforward correction has a delay time T2 with respect to the position command, so that the motor speed is changed as shown in FIG. 3 (c). Since the feedforward correction of the acceleration is performed more than in the conventional case, the rotational acceleration of the motor 15 can be increased. When the acceleration of the motor becomes higher, the phase difference T6 between the peak of the motor speed and the peak of the position command can be made smaller than the conventional phase difference T8 as shown in the following equation. T6 ((c) of FIG. 3) <T8 ((c) of FIG. 6)

Further, as the acceleration increases, the peak value V2 of the speed increases as shown in the following equation, and the followability of the motor speed can be improved. V2 ((c) in FIG. 3)> V4 ((c) in FIG. 6) As the motor speed increases, the phase difference between the position command ((a) in FIG. 3) and the motor speed ((c) in FIG. 3) (36
0 ° × (T6 / T5) [degrees] is also shortened, and when this is compared with the phase difference in the conventional case ((a) and (c) of FIG. 6), the following equation is obtained: The phase difference between the position command and the motor speed can be improved. 360 ° x (T6 / T5) [degree] <360 ° x (T8 /
T5) [degree]

Finally, the characteristic part of the present invention in this embodiment described above will be summarized. That is, in the present embodiment, the time constant large / small filter changing switch 4 and the time constant small filter 5 are provided in the preceding stage of the feedforward differential calculator 7.
And a position command delay means 1 including a large time constant filter 6
Connect 7. Then, when the movement amount of the motor 15 is large, the delay is small, and when the movement amount of the motor 15 is small, the position command 1 ′ having a large delay is output to the feedforward differential calculator 7, and each of the feedforward differential calculator 7 outputs the position command 1 ′. A correction speed signal 7 ″ (feedforward correction value) having a delay corresponding to the delay is output.

More specifically, the correction speed signal 7 "corresponds to T1 (FIG. 2) with respect to the position command 1 (in the case of a large movement amount: FIG. 2A, in the case of a small movement amount: FIG. 3A). (B)) or T2 ((b) in FIG. 3), it is necessary to accelerate the motor speed ((c) in FIG. 2 or (c) in FIG. 3) more than in the conventional case. An additional correction amount for acceleration can be applied to increase the acceleration of the motor, resulting in a time difference T4 from the peak of the position command 1 to the peak of the motor speed.
((C) of FIG. 2) and T6 ((c) of FIG. 3) can be made shorter than the same peak intervals T7 ((c) of FIG. 5) and T8 ((c) of FIG. 6) of the prior art. In addition, the peak values V2 and V4 of the motor speed are increased due to the acceleration of the motor.
Is increased, the followability of the motor speed can be improved,
The phase difference between the position command and the motor speed can also be improved.

In addition, the problem that the motor speed following performance is worse when the travel amount is small than when the travel amount is large is that the acceleration of the motor speed is increased by using the large time constant filter as described above. It can be solved by delaying the correction speed signal 7 "so that the correction is matched to the acceleration of the motor speed.

Although the two time constant filters 5 and 6 are used in this embodiment, only one may be used.
In that case, the large / small movement amount switching signal 3 and the time constant large / small filter switching switch 4 are unnecessary. Also, the time constant filter 5
It is also possible to use not only two and six, but also three or more as needed and appropriately switch and use the time constant large / small filter changeover switch 4.

The large / small movement amount switching signal according to the present invention is
It may be a signal indicating the large or small movement amount and already indicating it, or may be a signal for simply activating the time constant large or small filter changeover switch. In the former case, the large / small movement amount switching signal can directly switch the time constant large / small filter switching switch, but in the latter case, the same signal is sent from the position command 1 received by the time constant large / small filter switching switch to the time constant large / small filter switching switch. Can be a gate for determining the amount of movement.

[0047]

The present invention is configured as described above,
In particular, a time constant large filter, a small time constant filter, and a time constant for switching to a large time constant filter or a small time constant filter according to a large / small movement amount switching signal indicating the amount of motor movement amount are provided in front of the feedforward differential calculator. By providing a position command delay unit configured by a large and small filter changeover switch and delaying the correction signal so as to match the increase correction for accelerating the motor speed with the acceleration of the motor speed, the motor speed is increased and the peak position command is generated. By shortening the time difference between the peaks of the motor speed and improving the phase difference between the position command and the motor speed, it was possible to improve the followability of the motor speed.

In addition, when the peak of the motor speed is a small amount of movement which is considerably behind the peak of the position command, the filter is switched to a large time constant filter to further increase the acceleration of the motor speed, so that the position of the small amount of movement is increased. It is possible to reduce the delay in the phase of the motor speed with respect to the command and improve its followability.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a three-phase synchronous motor drive device incorporating an embodiment of the present invention.

2A and 2B are timing charts when a large amount of movement is performed in the embodiment of FIG. 1, where FIG. 2A shows a voltage waveform of a position command signal, and FIG. 2B shows a correction amount (voltage) of a feedforward correction signal. , (C) shows the motor speed

3A and 3B are timing charts when a small amount of movement is performed in the embodiment of FIG. 1, where FIG. 3A shows a voltage waveform of a position command signal, and FIG. 3B shows a correction amount (voltage) of a feedforward correction signal. , (C) shows the motor speed

FIG. 4 is a configuration diagram of a conventional motor drive device.

5 is a timing chart of the conventional motor drive device shown in FIG. 4 when a large amount of movement is performed, in which (a) shows a voltage waveform of a position command signal, and (b) shows a correction amount of a feedforward correction signal ( Voltage) and (c) shows motor speed

6A and 6B are timing charts of the conventional motor drive device shown in FIG. 4 when a small amount of movement is performed. FIG. 6A shows a voltage waveform of a position command signal, and FIG. 6B shows a correction amount of a feedforward correction signal ( Voltage) and (c) shows motor speed

[Explanation of symbols]

 1,1 'Position command 2 Position loop gain multiplier 2'Velocity command 3 Large / small movement amount switching signal 4 Time constant large / small filter changeover switch 5 Time constant small filter 6 Time constant large filter 7 Feed forward differential calculator 7', 7 " Correction speed signal 8 Adder 8'Speed command 8 "Second speed command 9 Speed control calculator 9 ', 9" Torque command 10 Magnetic pole detector 11 Multiplier 11', 11 "Current command 12 D / A converter 13 Current amplifier 14 Encoder 15 Motor 16 Speed detector 17 Position command delay means

Claims (3)

[Claims] 1. An encoder for detecting a rotational position of a motor, a magnetic pole detector for detecting a motor magnetic pole from the encoder, a position loop gain multiplier for multiplying a position command by a position loop gain and outputting a speed command, and a position A feed-forward differential calculator that differentiates the command and feed-forward-multiplies it to output a corrected speed signal that corrects the speed command; and an adder that adds the speed command and the corrected speed signal to output a second speed command. , A motor drive including a current amplifier that supplies a product of a torque command value generated from the second speed command and the output of the speed detection and a magnetic pole detection value from the magnetic pole detector to the motor as a current command A device,
Further, it includes position command delay means for inputting the position command and outputting a position command delayed by a predetermined time to the feedforward differential calculator, and the position command delay means includes the delayed position command for the feedforward differential calculator. The motor drive device is characterized in that a corrected speed signal delayed by a predetermined time is output from the feedforward differential calculator based on the above. 2. The position command delay means comprises a plurality of delay means each having a different delay time, and a changeover switch for switching to use one of the plurality of delay means, and changes the delay of the correction speed signal. The motor drive device according to claim 1, characterized in that. 3. The position command delay means, in accordance with a large time constant large filter having a large delay amount, a small time constant small filter having a small delay amount, and a large / small movement amount switching signal indicating a movement amount of a motor, said large time constant filter. 2. The motor drive device according to claim 1, further comprising a time constant large / small filter changeover switch for switching between the time constant small filter and the time constant small filter.