JP2772407B2 - Motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control amount adjusting device such as a speed adjusting device or a current adjusting device and a motor control device having the same. The present invention relates to a control amount adjusting device that is dynamically variably set.

[0002]

2. Description of the Related Art A motor control device and the like are provided with speed adjusting means for adjusting the speed of a motor, current adjusting means for adjusting a torque current and an exciting current, and the like. Is operated, the input of the motor is controlled to drive the motor according to target values such as speed and torque.

The control characteristics such as the speed response and current response of the motor in such a motor control device depend on the characteristics of a control loop related to each control amount adjusting means. Generally,
By setting the control constant of each control amount adjusting means to an appropriate value, desired control characteristics are realized.

The control constant of such a control amount adjusting means is as follows:
A constant is determined in advance at the design stage, and is confirmed by a trial operation or the like, and then applied to an actual operation. Conventionally, the following method is known as a method for determining such a control constant.

(1) Each control amount adjusting means is regarded as an independent control loop, and each control constant is determined based on classical theory or modern theory so that the system becomes stable.

(2) The plurality of control amount adjusting means are regarded as one system, and respective control constants are determined so that the entire loop becomes stable.

(3) The control constant is determined by the host controller according to the method (1) or (2) according to the change of the system such as the motor load, and the control constant of the control amount adjusting means is variably set accordingly. (Japanese Unexamined Patent Publication No. 4-856)
04 publication).

[0008]

However, the above-mentioned prior art (1) cannot avoid a setting error of a control constant caused by a difference between a design value and a constant of an actual machine. There arises a problem that followability and the like are reduced.

Also, in the case of the prior art (2), the difference in the condition between the test operation and the actual operation, for example, the setting error of the control constant due to the loss of the machine or the load condition causes the same deterioration in the control characteristics as described above. There is a problem of bringing.

In the case of the prior art (3),
Basically, the change values of the control constants are determined by the above methods (1) and (2).

In other words, according to the above-mentioned conventional technique, the conditions for determining the control constant and the actual conditions for the control constant are set, for example, under the ideal condition that the plurality of control amount adjusting means are mutually independent. This is because there are unavoidable differences, such as design.

Further, the problems of the prior art described above are not limited to motor control devices, but are common to various control amount adjusting devices such as attitude control, position control, and various controls using hydraulic pressure.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, in other words, it is possible to dynamically change and set a control constant in accordance with an operating state, and to reduce a characteristic or the like due to a setting error of the control constant. An object of the present invention is to provide a control amount adjusting device that can be avoided and a motor control device including the same.

[0014]

In order to achieve the above-mentioned object, the present invention provides a method of controlling a controlled object to be controlled by at least one control variable based on a deviation between a plurality of types of control target values and a corresponding control feedback value. In a control amount adjustment device including a plurality of types of control amount adjustment units that adjust according to a control operation having two control constants, a control constant determination unit that variably sets control constants of the control amount adjustment units is provided,
The control constant determining means inputs the respective deviations, and changes the respective control constants based on the relationship between the type of the deviations affected by the previously set control constants and the degree of influence thereof. I do.

Further, the motor control device of the present invention includes a speed adjusting means for adjusting the input of the motor in accordance with a control operation having at least one control constant so as to eliminate a speed deviation between the speed target value and the speed feedback value. A current adjusting means for adjusting an input of a motor in accordance with a control operation having at least one control constant so as to remove a current deviation between a current target value and a current feedback value. Control constant determining means for variably setting each control constant of the current adjusting means is provided. The control constant determining means inputs the speed deviation and the current deviation, and controls the influence of each of the deviations and each of the deviations previously set variably. It is characterized in that the control constants are changed in accordance with the degree.

In this case, the current adjusting means includes:
The present invention is also applicable to a device including a torque current adjusting unit and an exciting current adjusting unit.

[0017]

According to the present invention, the above object can be achieved by the following operation.

Whether or not the control constant of the control amount adjusting means is appropriate can be basically determined by the magnitude of the deviation between the feedback value of the control loop and the target value. Therefore,
Basically, the control constant is changed according to the deviation. For example, in the case of a control constant relating to speed response, the gain is increased when the deviation is large, and the gain is decreased when the deviation is small.

However, when there are a plurality of control loops such as the speed control and the current control of the motor control, the control characteristic of one control loop and the control characteristic of another control loop interact with each other. Therefore, in changing one control constant, the influence of another control loop must be considered. For example, when changing the speed response gain, it is desirable to reduce the disturbance by transiently lowering the speed response according to the deviation of the torque current. Further, it is preferable to transiently increase the speed response according to the deviation of the exciting current so as to cancel the interference between the current controls.

In view of such a background, the control constant determining means of the present invention uses the relation between the type of deviation and the degree of influence (influence degree) of each control amount adjusting means which is affected by each of the control constants set in advance. ), Each control constant is changed, so that an appropriate control constant can be set. Further, since the control constant is set according to the deviation, the control constant can be dynamically determined in accordance with the operating state, and the deterioration of the characteristics due to the setting error of the control constant can be avoided.

Further, the speed adjusting means, the current adjusting means, and the control constant determining means are formed by using a microcomputer, and the control constant determining means is executed at an operation cycle synchronized with an operation cycle of the speed adjusting means and the current adjusting means. Then, the control constants can be changed more quickly to the actual conditions.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is an overall configuration diagram of an embodiment of a motor control device to which the control amount adjusting device of the present invention is applied.
As shown in the figure, a difference Δωr between the target speed value ωr and the feedback value ωf is obtained by the adding means 1, and the difference is input to the speed adjusting means 2. The speed adjusting means 2 outputs a torque current target value Itr by, for example, performing a proportional integral process on the deviation so that the deviation becomes zero. The deviation ΔIt from the torque current target value Itr and the feedback value Itf is obtained by the adding means 3 and input to the torque current adjusting means 4. The torque current adjusting means 4 outputs a torque current command to the command synthesizing means 5 by, for example, performing a proportional integration process on the input error so that the input error becomes zero. On the other hand, the exciting current target value Im given from the exciting current setting means 6 is used by the adding means 7 to calculate a deviation ΔI from its feedback value Imf.
m is obtained and input to the exciting current adjusting means 8. The exciting current adjusting means 8 controls the input deviation so that the input deviation becomes zero.
For example, the deviation is proportionally integrated and an excitation current command is output to the command synthesizing means 5. The frequency adjusting means 9 operates to output a frequency corresponding to the speed target value to the command synthesizing means 5, and is a proportional-integral control system. The command synthesizing means 5 includes a torque current adjusting means 4 and an exciting current adjusting means 8
And the outputs of the frequency adjusting means 9 are combined, and the combined output controls the inverter 10. This allows
The input power of the motor 11 is controlled according to the target speed.
The input current of the motor is detected by the current transformer 12,
The speed of the motor is detected by a speed sensor 13,
Each is input to the feedback detecting means 14. The feedback detecting means 14 determines the speed feedback value ωf and the torque current feedback value It based on the input signal.
f, an excitation current feedback value Imf is generated, and is negatively fed back to the adding means 1, 3, 7 respectively.

The control constant determining means 15 determines each deviation Δωr,
ΔIt and ΔIm are input, and control constants (proportional constants,
Integral constant) is obtained, and a change command is output to each adjusting means. The timing generating means 16 includes the adjusting means 2, 4,
The control periods of 8 and 9 and the operation timing of the control constant determining means 15 are set, and each adjusting means operates in synchronization. For example, in response to a request from the motor control system, the torque current adjusting unit 4 and the exciting current adjusting unit 8 are set to operate at a speed two to five times faster than the speed adjusting unit 2.

Here, the detailed configuration of the control constant determining means 15 will be described. 2 (a) to 2 (d) show the main parts of the transfer functions of the adjusting means 2, 4, 8, and 9, respectively. In these figures, the control constants of the respective adjusting means are as follows, and are theoretically set in advance at the design stage.

Speed adjusting means 2: Proportional constant Kp, integration constant
Tp torque current adjusting means 4: proportional constant Kt, integral constant ...
Tt exciting current adjusting means 8: proportional constant ... Km, integration constant ...
Tm frequency adjusting means 9: proportional constant Ks, integral constant ...
Change adjustment of Ts each control constants is performed by variably by the control constant determining means 15 a correction factor (gain) k ₁ to k ₈ shown in FIG. Each gain is as follows.

Speed adjusting means 2: proportional constant gain k ₁ , integral constant gain k ₂ torque current adjusting means 4: proportional constant gain k ₃ , integral constant gain k ₄ exciting current adjusting means 8: proportional constant gain k _5, the integration constant gain ... k ₆ frequency adjusting means 9: proportional constant gain ... k _7, the integration constant gain ... k ₈ next, define impact matrix (M) as follows.

[0028] We define the gain k ₁ to k ₈ each adjusting means as follows.

[0029] According to the relationship of the above equation, the proportional constant Kp of the speed adjusting means 2
Taken up as an example, it is described a method of determining the gain k _1. From Equations (1) and (2), the gain k ₁ of the proportionality constant of the speed adjusting means 2 can be expressed by Equation (3).

[0030]

(Equation 3) Therefore, by determining the elements m ₁₁ , m ₁₂ , and m ₁₃ of the influence matrix M, it is possible to define the effects of the deviations Δωr, ΔIt, and ΔIm on k ₁ .

For example, the proportionality constant Kp can be obtained by a conventional open-loop stabilization method. Using the Kp thus obtained, the proportional constant of the speed adjusting means 2 is set to k ₁ * Kp, and the speed is varied by adjusting k ₁ .
For example, if m ₁₁ , m ₁₂ , and m ₁₃ are set to m ₁₁ = 2.0, m ₁₂ = 0.5, and m ₁₃ = 1.0 in consideration of the degree of influence of each deviation, k ₁ = 2.0 * Δωr + from equation (3). 0.5 * ΔIt + 1.0 * ΔIm (4), and the degree of influence on the change in Δωr can be maximized. On the other hand, in the conventional adjusting means, m ₁₁ = 1.0, m ₁₂ = 0.0, and m ₁₃ = 0.0.

FIG. 3 shows operation waveforms of various parts of the motor control device with respect to disturbance. When a load disturbance occurs at t ₁ as shown in FIG. 7A, the speed drops in the prior art as shown in FIG. 7B, and the speed feedback value returns after a certain period of time. On the other hand, as shown in (c), the torque current feedback value increases and decreases due to a decrease in speed, and then calms down after a certain period of time. At this time, as shown in (d), the exciting current feedback value is also slightly varied. On the other hand, when the gains k _{1 to} k ₈ determined by the control constant determining means 15 of the above embodiment are used, the speed feedback value is improved as shown in FIG.
As can be seen from the figure, it is possible to realize speed adjusting means having excellent control performance.

The above operation is the same for the torque current adjusting means 4, the exciting current adjusting means 8 and the frequency adjusting means 9, and even when the control constants of the respective adjusting means are designed as independent control loops. , Control constant determining means 1
5 makes it possible to obtain desirable control performance.

Further, since the control constant determining means 15 operates in synchronization with the operation cycle of each of the adjusting means 2, 4, 8, and 9, it is possible to minimize an adjustment error due to a variation in the operation.

Therefore, according to the present embodiment, it is possible to dynamically determine the control constants of the respective adjusting means 2, 4, 8, and 9 according to the operating conditions, and it is possible to obtain excellent control performance. .

In the embodiment shown in FIG. 1, the part of the control amount adjusting device comprising the adjusting means 2, 4, 8, 9 and the control constant determining means 15 can be formed by using a microcomputer or the like. Further, as shown in FIG. 4, by using a plurality of processor units, the operation speed can be increased and high responsiveness can be realized. That is, as shown in FIG. 4, the control amount adjusting device is composed of five processor units 20a to 20e and timing generating means 16, and each processor unit 20a to 20e
, Thereby enabling bidirectional data transmission.

The processor units 20a to 20e have synchronization detecting means 22a to 22e, respectively. The processor unit 20a mainly controls the operation of the speed adjusting means 2, the processor unit 20b mainly controls the operation of the torque current adjusting means 4, The processor unit 20c mainly controls the operation of the exciting current adjusting means 8, and the processor unit 20c
d mainly controls the input / output processing 23, and the processor unit 20e mainly controls the operation of the control constant determining means 15. The timing signal output from the timing generator 16 is received by each of the synchronization detectors 22a to 22e, and is synchronized with the timing signal to adjust each of the adjusters 2, 2.
4, 8, 15, and 23 are operated. That is, as shown in the timing chart of FIG.
When input to e, the synchronization detecting means 22a to 22e implement a synchronization process with a timing based on a predetermined reference internally. In this embodiment, the synchronization detecting means 22a
Is set to operate the speed adjusting means 2 at a cycle 2T.

[0038]

As described above, according to the present invention,
Since the control constant of the control amount adjusting means can be determined in accordance with the operating condition, and a characteristic decrease or the like due to a control constant setting error can be avoided, a control amount adjusting device and a motor control device with excellent control performance can be realized. .

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a motor control device using a control amount adjusting device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a main configuration of a transfer function of each control amount adjusting unit.

FIG. 3 is an operation waveform diagram of each section for explaining the operation of the embodiment in FIG. 1;

FIG. 4 is a block diagram of an embodiment in which a main part of the embodiment in FIG. 1 is constituted by a plurality of processor units;

FIG. 5 is a timing chart illustrating the operation timing of the embodiment in FIG. 4;

[Explanation of symbols]

 2 speed adjusting means 4 torque current adjusting means 5 command synthesizing means 8 exciting current adjusting means 9 frequency adjusting means 14 feedback value detecting means 15 control constant determining means 16 timing generating means 20 processor unit 21 high-speed transmission path 22 synchronization detecting means 23 input / output Processing means 24 Adjustment means management processing means M Influence matrix

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-22729 (JP, A) JP-A-63-115202 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05B 13/00-13/02 H02P 5/00

Claims (4)

(57) [Claims] 1. Speed adjusting means for adjusting an input of a motor according to a control operation having at least one control constant so as to eliminate a speed deviation between a speed target value and a speed feedback value, and a current target value and a current feedback value. And a current adjusting means for adjusting an input of the motor in accordance with a control operation having at least one control constant so as to remove a current deviation from the speed adjusting means and the current adjusting means. A control constant determining means for variably setting a control constant is provided, and the control constant determining means includes:
A motor control device, wherein the speed deviation and the current deviation are input, and each of the control constants is changed in accordance with a relationship between each of the deviations and a degree of influence of each of the deviations set in advance. 2. The motor control device according to claim 1 , wherein said current adjusting means comprises a torque current adjusting means and an exciting current adjusting means. 3. The speed adjusting means, the current adjusting means, and the control constant determining means according to claim 1 , wherein the speed adjusting means, the current adjusting means, and the control constant determining means are formed by using a microcomputer. A motor control device, wherein the motor control device is executed in a calculation cycle synchronized with a calculation cycle of the adjusting means. 4. The method according to claim 1, wherein at least one
Corresponds to the speed target value according to control calculation with control constant
Frequency adjusting means for outputting the adjusted frequency;
Means for combining the output of the means and the output of the current adjusting means.
Command synthesizing means for controlling the inverter with the output
A motor control device comprising: