JP4694238B2 - Servo motor control device - Google Patents

Description

  The present invention relates to a servo motor control device that can suitably perform gain adjustment in accordance with a load inertia moment.

  As a servo motor control device that controls a servo motor, a device that automatically switches a control gain using a detection result that estimates a load inertia moment has been proposed (see, for example, Patent Document 1).

  On the other hand, when it is desired to easily adjust the control gain at the work site and to construct a system at a low cost, the control gain is not automatically adjusted as described above, but the servo motor is connected to the driver that controls the servo motor. It is preferable to provide an adjustment switch for adjusting the control gain according to the load inertia moment to be driven.

  The adjustment switch is composed of, for example, a rotary switch that can be switched in 16 steps. In order to make it possible to adjust the gain within the range of load magnification (for example, load inertia moment / rotor inertia moment) of 1 to 100 times using this adjustment switch, the load magnification of 1 to 100 times is 16 in a geometric sequence. Allocated to The reason for the allocation in the geometric sequence is that, in general, as the load magnification becomes smaller, high-accuracy high-speed settling is required. When the adjustment switch is switched to any one of 16 stages, the load magnification is uniquely determined by the switching position, and the gain is determined by the load magnification. After adjustment by the adjustment switch, the servo motor is controlled based on the determined gain.

  However, depending on the load to be driven, the gain adjustment may be performed only within a specific range in the load magnification of 1 to 100 times. In such a case, the gain adjustment within the specific range cannot be finely performed. In particular, when allocating in a geometric sequence as described above, fine adjustment is possible where the load magnification is small, but the adjustment becomes rough as the load magnification increases. Therefore, when gain adjustment is necessary within a specific range where the load magnification is large, the gain can be adjusted only to a gain deviated from a desired gain.For example, the overshoot is enlarged during positioning and the settling is deteriorated. there were.

In view of this, it is conceivable to use a rotary switch that can switch the adjustment switch to 16 stages or more, for example, 32 stages, in order to finely adjust the gain. However, increasing the number of adjustment steps results in an increase in the number of contacts of the adjustment switch, which is not a good solution in terms of cost and operation.
JP 2000-222004 A

  The main object of the present invention is to enable fine adjustment of gain in a servo motor control apparatus that performs gain adjustment in accordance with a load by switching an adjustment switch that adjusts gain in a plurality of stages.

  Hereinafter, effective means for solving the above-described problems will be described while showing effects and the like as necessary. In the following, in order to facilitate understanding, the corresponding configuration in the embodiment of the invention is appropriately shown in parentheses, but is not limited to the specific configuration shown in parentheses.

Means 1. An adjustment switch (adjustment switch 14) for switching and adjusting the control gain according to the drive load of the servo motor (servo motor 10) in a plurality of stages (16 stages of 0 to 15) is provided, and the reference load is changed by switching the adjustment switch A servo motor control device in which a load magnification for is selected and adjusted to a gain corresponding to the selected load magnification,
The user can change and set at least one of the minimum value and the maximum value of the range of the load magnification that can be selected by the adjustment switch, and the changed range of the load magnification is allocated by the number of switching of the adjustment switch, A servo motor control device comprising gain adjusting means (control circuit 12, setting device 16) for adjusting to a gain corresponding to the load magnification selected by an adjustment switch.

  According to the means 1, when at least one of the minimum value and the maximum value of the load magnification range in the driving load of the servo motor is changed and set by the user, the changed load magnification range is allocated by the number of adjustment switches. The gain corresponding to the load magnification selected by the adjustment switch is adjusted. As a result, by changing the load magnification range so that the load magnification change range near the load driven by the servomotor is reduced, the gain adjustment range near the drive load is reduced, and fine adjustment of the gain by the adjustment switch is possible. It becomes possible. In other words, in a servo motor control device that requires selection of the load magnification by the adjustment switch, it is possible to perform a suitable gain adjustment according to the servo motor drive load, so overshoot can be suppressed during servo motor positioning. The settling time can be shortened.

  Mean 2. 2. The servo motor control apparatus according to claim 1, wherein the gain adjusting means allocates the range of the load magnification by the number of switching of the adjustment switch using a geometric sequence.

  According to the means 2, since the range of the load magnification is allocated by the number of adjustment switches using the geometric sequence, the fine adjustment is possible where the load magnification is small. The adjustment gets rougher as it gets larger. In general, fine adjustment is required where the load magnification is low, and fine adjustment is not required where the load magnification is high, so there is no problem, but there is a need to improve positioning accuracy when using only where the load magnification is high. There was a conventional problem that could not be answered. In this regard, in this means, even if allocation is performed using a geometric sequence, positioning accuracy is set even at high load magnification by setting the load magnification range at a relatively high position and narrowing the range. Can be improved.

  Means 3. The servo motor control apparatus according to means 1 or 2, wherein the gain adjustment means includes a setting means (setting device 16) that is input by a user to change the range of the load magnification.

  According to the means 3, when the user operates the setting means, the range of the load magnification is changed. If the setting means is not provided in the control device main body but is detachably connected to the control device main body, the setting means can be shared by a plurality of servo motor control devices.

Means 4. An adjustment switch (adjustment switch 14) for switching and adjusting the control gain according to the drive load of the servo motor (servo motor 10) in a plurality of stages (16 stages of 0 to 15) is provided, and the reference load is changed by switching the adjustment switch Is a servo motor control device in which a load magnification for is selected and adjusted to a gain corresponding to the selected load magnification,
A setting means (setting device 16) for inputting and setting the base and the width of the load magnification;
According to the radix and the load magnification width input and set by the setting means, the load magnification width is allocated by the switching number of the adjustment switch using a geometric sequence, and the radix is the minimum of the load magnification width. By using an addition element that fluctuates the value, the range of the changed load magnification is allocated for each switching position of the adjustment switch (calculation expression “A + B ^ (X / 15)”), and each assigned load magnification is Gain adjustment means (control circuit 12) for adjusting to a gain corresponding to the selected load magnification by selecting the adjustment switch (load magnification corresponding to 0 to 15 in FIG. 2) with the adjustment switch is provided. Servo motor control device characterized by.

  According to the means 4, when the radix and the load magnification width are input and set by the setting means, the gain adjustment means allocates the load magnification width by the number of adjustment switches using the geometric sequence, and the radix. Is used as an addition element that varies the minimum value of the width of the load magnification. Then, the changed range of the load magnification is allocated for each switching position of the adjustment switch. After that, when the adjustment switch is switched to a predetermined position, the gain adjusting means adjusts the gain corresponding to the load magnification selected for switching. In other words, in a servo motor control device that requires selection of the load magnification by the adjustment switch, it is possible to perform a suitable gain adjustment according to the servo motor drive load, so overshoot can be suppressed during servo motor positioning. The settling time can be shortened. At that time, the setting means may change the radix when it is desired to change the minimum value, and input to change the width of the load range when it is desired to change the width between the minimum value and the maximum value or the maximum value itself. Since the arithmetic processing using the radix and the width is an extremely simple process, the processing load can be reduced while reducing the number of memories.

  Means 5. 5. The servo motor control device according to claim 1, wherein the adjustment switch is a rotary switch having a plurality of contacts in the circumferential direction.

  According to the means 5, since the adjustment switch is constituted by a rotary switch having a plurality of contacts in the circumferential direction, there is a limit to the number of load magnification ranges to be allocated. As an adjustment switch, one having 8 or 16 contacts is common. When such a hardware configuration is to be used as it is, the effect of making it possible to change the load magnification range as described above is significant.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS An embodiment of the invention will be described below with reference to the drawings. In the present embodiment, a load (for example, a rotary table for indexing work equipment) is applied to a control device for a direct drive motor (DD motor) as a servo motor that directly rotates and drives without a reduction gear. is there.

  As shown in FIG. 1, a driver 11 as a control device that controls the DD motor 10 includes a control circuit 12, a drive circuit 13, and an adjustment switch (adjustment SW) 14. The control circuit 12 is provided with a memory 15 such as an EEPROM or a RAM, for example, in addition to a CPU that executes arithmetic processing. The control circuit 12 outputs a control signal to the drive circuit 13 in accordance with the control program stored in the memory 15 and the calculation processing result. The drive circuit 13 outputs a drive current based on the control signal from the control circuit 12 to the DD motor 10 and operates the DD motor 10 according to the control program.

  The DD motor 10 is integrally provided with a resolver 10a for detecting the rotation angle of the rotating shaft. The resolver 10 a detects the rotation angle of the rotation shaft of the motor 10 and outputs a detection signal (resolver signal) to the control circuit 12. Although not shown, a converter for converting a resolver signal into a digital signal is connected between the resolver 10a and the control circuit 12. The control circuit 12 detects the rotation angle of the rotation shaft of the motor 10 based on the detection signal from the resolver 10a, and executes a control program based on the detected rotation angle.

  The adjustment SW 14 is composed of a rotary switch. In this embodiment, the adjustment SW 14 formed of a rotary switch can be switched to 16 stages with 16 contact points in the circumferential direction.

  In the memory 15, the maximum value of the load magnification (= load inertia moment / rotor inertia moment) assumes that the allowable load inertia moment is 100 times the rotor inertia moment, and ranges from 1 to 100 in a geometric sequence. 16 is stored in advance (see the upper part of FIG. 2). In the reference gain adjustment table, the load magnification is determined in association with the rotation adjustment position (16 stages of 0 to 15) of the adjustment SW 14, and the gain value is set in association with each load magnification. Therefore, the rotation adjustment position and each gain value are also stored in the memory 15. The gain with respect to the load magnification is set in advance from measurement and calculation so that the settling time when the motor 10 drives each load is within an allowable range.

  Instead of storing all the gains corresponding to each load magnification, the gain for the reference load (load magnification = 1) is stored in the memory 15, and the gain is derived by calculation according to each load magnification. May be.

  When the adjustment SW 14 is switched, the control circuit 12 detects the switching position of the adjustment SW 14 and determines that the load magnification corresponding to the switching position is selected. For example, if the switching position of the adjustment SW 14 is “4”, it is determined that the load magnification is “3.41”. Then, the control circuit 12 reads a gain corresponding to the selected load magnification from the memory 15 and reflects the read gain on the control of the DD motor 10.

  Here, the setting device 16 can be brought into and out of contact with the driver 11. When the setting device 16 is connected to the driver 11, the setting device 16 and the control circuit 12 can communicate with each other. The setting device 16 can set various parameters to teach the operation of the DD motor 10 by the user (for example, an index operation for reciprocating the DD motor 10 between a specific rotation position and another rotation position). The various parameters set by the user are stored in the memory 15 of the control circuit 12.

  In addition, the setting device 16 according to the present embodiment has a function for newly setting the range of the adjustment SW 14 to be switched. As shown in FIG. 2, the load magnification range with respect to the operation range of the adjustment SW 14 is typically set to 1 to 100 times. However, with this setting device 16, the load magnification range is, for example, 1 to 50 times, 1 The maximum value can be changed such as -20 times, 1-5 times, and the like. Further, although these have a radix of 0, the radix can also be changed by the setting device 16. For example, the radix is 50, and the load magnification range can be changed to 51 to 100 times. The load magnification range thus changed is stored in the memory 15.

  A function for performing the range switching setting of the adjustment SW 14 will be described in more detail. The arithmetic expression “A + B ^ (X / 15)” is stored in the memory 15 of the control circuit 12 for setting the range switching. The symbol “^” represents a power. A indicates the radix, B indicates the load magnification width (maximum value−minimum value), and X indicates the switching position of the adjustment SW 14. That is, X is a numerical value from “0” to “15”. Further, in the reference gain adjustment table described above, since the radix A = 0 and the width B = 100, the load magnification corresponding to the adjustment position of each adjustment SW 14 is set as “100 ^ (X / 15)”.

  When the maximum value is to be changed such that the load magnification is 1 to 50 times, the base A = 0 and the width B = 50 may be set by the setting device 16, and in this case, the second of FIG. As in the second row, an arithmetic expression “50 ^ (X / 15)” is set, and the load magnification with respect to the switching position as in the second row is set to be distributed. Similarly, when settings such as width B = 20 and width B = 5 are made, the load magnification is set to be distributed as in the third and fourth stages in FIG. Furthermore, when it is desired to set the load magnification range to a high position, for example, the radix A = 50 and the width B = 50 may be set by the setting device 16. In this case, as shown in the lowermost part of FIG. 50 + 50 ^ (X / 15) "is set.

  Along with this, the control circuit 12 uses the gain corresponding to the load magnification of 1 to 100 times stored in advance in the memory 15, and calculates the gain according to the changed range of the load magnification. In this case, each gain may be calculated on the setting device 16 side in accordance with the range of the changed load magnification, and these may be associated and stored in the memory 15.

  Thus, by changing the range of the load magnification so that the change width of the load magnification near the load driven by the DD motor 10 is small (so that the change rate is small in FIG. 3), the gain adjustment width near the driving load is changed. Becomes smaller, and fine adjustment of the gain by the adjustment SW 14 becomes possible. As a result, the control gain of the DD motor 10 can be matched or extremely approximated to a desired gain, so that overshoot is suppressed during positioning of the DD motor 10 and high-speed settling (short settling time) is possible. Become.

  According to the embodiment described above in detail, the following excellent effects can be obtained.

  In the present embodiment, by setting at least one of the radix and the load magnification range using the setting device 16, at least one of the minimum value and the maximum value of the load magnification range in the driving load of the servo motor 10 is changed. . Then, the range of the changed load magnification is assigned by the number of switching of the adjustment SW 14 (“16” in the present embodiment) and adjusted to a gain corresponding to the load magnification selected by the adjustment SW 14. As a result, by changing the load magnification range so that the change range of the load magnification near the load driven by the servo motor 10 becomes small, the gain adjustment width near the driving load becomes small, and fine adjustment of the gain by the adjustment SW 14 Is possible. That is, since a suitable gain adjustment can be performed according to the driving load of the servo motor 10, overshoot can be suppressed during positioning of the servo motor 10 and the settling time can be shortened.

  In the present embodiment, the range of the load magnification is assigned by using the equivalence number sequence, and the number of switching of the adjustment SW 14 is used. Therefore, fine adjustment is possible where the load magnification is small due to the nature of this number sequence. The adjustment gets rougher as it gets larger. Therefore, in the case of the present embodiment in which allocation is performed using a geometric sequence, the effect of making the load magnification range changeable is great.

  In the present embodiment, the range of the load magnification is changed by the user operating the setting device 16 that can contact and separate from the driver 11. Therefore, it is not necessary to provide each driver 11 with a means for changing the range of the load magnification. Further, the setting device 16 can be shared by a plurality of control device bodies. Further, since the setting only needs to be input of the radix A and the load magnification width B, the setting operation is easy.

  In the present embodiment, by calculating the gain after changing the load magnification range from the gain in the standard range (1 to 100 times) of the load magnification, the number of gains stored in the memory 15 can be reduced. , The load on the gain calculation can be reduced.

  In the present embodiment, since the adjustment SW 14 is configured by a rotary switch having a plurality of contacts in the circumferential direction, there is a limit to the number of load magnification ranges that can be allocated. Therefore, the effect of making the load magnification range changeable as described above is great.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

  In the above embodiment, by changing and setting the radix A and the load magnification range B based on the arithmetic expression “A + B ^ (X / 15)”, at least one of the minimum value and the maximum value of the load magnification range is Although it is changed, the setting device 16 may be configured to change and set the minimum value and the maximum value directly. In this case, the minimum value and the maximum value are input from the setting device 16, and the driver 12 assigns the load magnification so that the “0” position of the switching SW 14 is the minimum value and the “15” position is the maximum value. Good. This allocation can be performed by setting (minimum value-1) = A and (maximum value-minimum value + 1) = B in the above arithmetic expression.

  In the above embodiment, the gain associated with the standard range (1 to 100 times) of the load magnification is stored in the memory 15, and the gain after the change of the load magnification range is calculated from the stored gain. However, the present invention is not limited to this. For example, only the gain corresponding to the reference load may be stored in the memory 15, and the gain may be calculated each time the load magnification is changed. In this way, the number of gains stored in the memory 15 can be reduced. In addition, gains corresponding to various load magnification ranges may be stored in the memory 15 in anticipation of a certain change in the load magnification. In this way, gain calculation can be reduced as much as possible. Further, instead of storing the reference gain adjustment table in the memory 15, load magnification allocation is performed by arithmetic processing based on the arithmetic expression “A + B ^ (X / 15)” even in the standard state (specifically, A = 0, B = 100). In this case, it contributes to further reduction in storage capacity.

  In the above-described embodiment, the range of the load magnification is assigned by the number of switching of the adjustment SW 14 using the geometric sequence, but the present invention is not limited to this. For example, other number sequences such as an arithmetic difference number sequence may be used for allocation.

  In the above-described embodiment, the range of the load magnification is changed by the setting device 16 connected to the driver 11. However, the driver 11 may include a means for changing the range of the load magnification.

  In the above-described embodiment, the adjustment SW 14 that can be switched to 16 steps is used. However, an adjustment SW that can be switched in other than a plurality of steps, for example, 32 steps, 8 steps, or multiples of 8, may be used. Moreover, although the adjustment SW 14 is constituted by a rotary switch, it may be constituted by other switches such as a numerical value input switch.

  In the above embodiment, the load is applied to the servo motor (DD motor) that directly rotates the load. However, the load may be applied to a servo motor that includes a speed reduction mechanism between the load and the load. Moreover, although it implemented to the servomotor which drives rotationally, you may implement to the linear servomotor which drives linearly.

It is a block circuit diagram of a motor and a motor control device in an embodiment. It is a figure for demonstrating the relationship between an adjustment switch and a load magnification range. It is a figure for demonstrating the relationship between an adjustment switch and a load magnification range.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Servo motor, 11 ... Driver (control apparatus main body), 12 ... Control circuit (gain adjustment means), 14 ... Adjustment switch, 16 ... Setting apparatus (setting means, gain adjustment means)

Claims (4)

An adjustment switch that switches and adjusts the control gain according to the servo motor drive load in multiple stages is selected, and the load magnification with respect to the reference load is selected within the standard range by switching the adjustment switch, and corresponds to the selected load magnification. Servo motor control device adjusted to gain to
The user can change and change at least one of the minimum value and the maximum value of the load magnification range so that the range of the load magnification that can be selected by the adjustment switch is narrower than the standard range. A range of the load magnification is allocated by the number of switching of the adjustment switch, and gain adjustment means for adjusting to a gain corresponding to the load magnification selected by the adjustment switch ,
The servo motor control apparatus according to claim 1, wherein the gain adjusting means includes setting means input by a user to change the range of the load magnification .   2. The servo motor control apparatus according to claim 1, wherein the gain adjusting means allocates the range of the load magnification by the number of switching of the adjustment switch using a geometric sequence. An adjustment switch that switches and adjusts the control gain according to the servo motor drive load in multiple stages is selected, and the load magnification with respect to the reference load is selected within the standard range by switching the adjustment switch, and corresponds to the selected load magnification. Servo motor control device adjusted to gain to
As the range of the load factor after the change is smaller than the normal range, and setting means for inputting the width of base and the load factor by the input operation of the user,
According to the radix and the load magnification width input and set by the setting means, the load magnification width is allocated by the switching number of the adjustment switch using a geometric sequence, and the radix is the minimum of the load magnification width. By using an addition element that fluctuates the value, the range of the changed load magnification is allocated for each switching of the adjustment switch, and each allocated load magnification is selected by the adjustment switch. And a gain adjusting means for adjusting to a gain corresponding to the load magnification. The adjustment switch, the servo motor control apparatus according to any one of claims 1 to 3, characterized in that a rotary switch having a plurality of contacts in the circumferential direction.

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