CN103792936B - Based on the linear servo system characteristic analysis method of saturation activation signal - Google Patents

Abstract

The invention provides a kind of linear servo system characteristic analysis method, according to the electric of linear servo system and mechanical features, select saturation activation signal, amplitude and duration; Under amplitude and duration, carry out the saturation activation experiment of linear servo system, and record the actual displacement data in linear servo system direction of motion; Analyze actual displacement data by difference method, obtain the speed data of linear servo system under extreme sport situation in linear servo system direction of motion and acceleration information; By Morlet wavelet transformation analysis acceleration information, obtain the frequency data of linear servo system under extreme sport situation; For motion Controller Design and exploitation, and motion planning and control method research provide direct data reference frame.The invention provides a kind of linear servo system characteristic analysis method simple experiment, algorithm operation quantity is little, and be easy to on-the-spot and realize, debug process is flexible.

Description

Based on the linear servo system characteristic analysis method of saturation activation signal

Technical field

What the present invention relates to is the system features analytical approach in movement control technology field, specifically a kind of linear servo system characteristic analysis method based on saturation activation signal.

Background technology

Compare traditional electric rotating machine, the revolutionary feature of linear electric motors is the mechanical energy directly converting electrical energy into rectilinear motion, eliminates the intermediate link that rotary motion is changed to rectilinear motion.Linear electric motors rely on the features such as its high thrust-weight ratio, high rigidity, high acceleration and high precision, become the main flow core component that height accelerates high-speed, high precision kinematic system equipment, be widely used in high-end numerical control machine, IC encapsulation and the field such as manufacture and microelectronics.Along with improving constantly of production efficiency and the quality of production, the requirement of the acceleration of relevant production units, speed and positioning precision is more and more higher.This brings stern challenge to motion control developer, and it needs the motion controller designed and developed under the prerequisite of Appropriate application linear servo system feature, can realize the high production requirement accelerating high-speed, high precision kinematic system equipment.

Linear servo system be one integrate mechanical, electrical, the complication system of the multiple kinds of energy form such as magnetic and heat energy.Linear electric motors are as the chief component of system, and its performance is not only relevant to the characteristic such as mechanical, electrical, magnetic itself, and closely bound up with mechanical system.Therefore traditional research separately for motor or mechanical system is difficult to realize entire system signature analysis.At control field, the linear servo system feature that researchist is concerned about refers to velocity information, acceleration information and frequency information etc. in its system limits motion process.In motion controller performance history, how to determine that the velocity information of linear servo system in extreme sport process, acceleration information and frequency information become primarily dealing with problems of the personnel of designing and developing.

In control field, often adopt natural frequency that is linear or logarithm frequency sweeping method mensuration servo-drive system, in order to characterize the frequency information of servo-drive system in motion process.But these methods, while acquisition frequency information, are difficult to obtain more system features, as velocity information and acceleration information.In order to obtain velocity information and the acceleration information of servo-drive system, tester needs more method and experiment to measure.In addition, the natural frequency obtained by these class methods, directly can not represent the frequency information of servo-drive system in motion process.

Find through retrieval, Kim etc. are at document " Designandperformancetuningofsliding-modecontrollerforhig h-speedandhigh-accuracypositioningsystemsindisturbanceob serverframework " (IEEETransactionsonIndustrialElectronics, 2009, 56 (10): 3798-3809.) natural frequency obtaining controlled device in by calculating the mode of dynamic model parameters carrys out the frequency information in characterizing motility process, but this method needs dynamic model parameters accurately, operability is in actual applications not strong.

In sum, in prior art, adopt the frequency information that natural frequency is come in characterizing motility process, be difficult to the frequency information in accurate characterization motion process; In addition, while obtaining frequency information, be difficult to obtain other system features, as velocity information and acceleration information, thus affect motion Controller Design and exploitation.

Summary of the invention

For prior art above shortcomings, the invention provides a kind of linear servo system characteristic analysis method based on saturation activation signal.The method effectively can not only obtain velocity information and the acceleration information of linear servo system under extreme sport situation, and can the frequency information of accurate analysis linear servo system under identical limit moving condition, for motion Controller Design and exploitation, and motion planning and control method research provide direct data reference frame.

The invention provides a kind of linear servo system characteristic analysis method, comprising:

(1) according to the electric of linear servo system and mechanical features, saturation activation signal, amplitude and duration is selected;

(2) under amplitude and duration, carry out the saturation activation experiment of linear servo system, and record the actual displacement data in linear servo system direction of motion;

(3) analyze actual displacement data by difference method, obtain the velocity information of linear servo system under extreme sport situation in linear servo system direction of motion and acceleration information;

(4) acceleration information by obtaining in Morlet wavelet transformation analysis step (3), obtains the frequency information of linear servo system under extreme sport situation;

Extreme sport situation is the moving situation of linear servo system when adding saturation activation signal.

Further, in step (1), saturated pumping signal is saturation voltage pumping signal or saturation current pumping signal.

Further, linear servo system comprises motion controller, driver element, topworks and auxiliary equipment.

Further, carry out the saturation activation experiment of linear servo system in step (2), comprise the following steps:

(21) send saturation activation signal by motion controller, drive linear servo system motion;

(22) record contactless grating chi feedback signal, contactless grating chi feedback signal is corresponding actual displacement data.

Further, in step (22), saturated pumping signal is saturation voltage pumping signal, and the amplitude of saturation voltage pumping signal is ± 10V, and the duration of positive and negative saturation voltage is 5ms.

Further, when recording contactless grating chi feedback signal in step (22), select effectively to preserve length.By selecting effectively to preserve length, under the condition that memory capacity is certain, the quantity of preserving displacement data can be determined.

Further, effectively preserving length is 200.

Further, step (4) comprises step:

(41) continuous wavelet transform is the inner product of signal and wavelet function:

$\mathrm{Wf}(u,s)=\frac{1}{\sqrt{s}}{\∫}_{-\∞}^{+\∞}f\left(t\right)\mathrm{\ψ}\left(\frac{t-u}{s}\right)\mathrm{dt}$

Wherein, for signal, Wf (u, s) is wavelet function ψ _u,scorresponding wavelet coefficient, describes signal near the u of position with the vibration of yardstick s;

(42) analysis frequency lower limit and upper frequency limit are set, and select frequency to count, obtain corresponding time-frequency distributions;

(43), in the time-frequency distributions obtained from step (42), first is obtained by the frequency evoked.

Further, the formula of the Morlet wavelet transformation adopted in step (41) is:

$\mathrm{\ψ}\left(t\right)={\mathrm{\π}}^{-1/4}(e^{-{\mathrm{j\ω}}_{0}t}-e^{-{\mathrm{\ω}}_0^2/2})e^{{-t}^2/2}.$

Further, step (42) medium frequency lower limit is 100Hz, and upper frequency limit is 5000Hz, and it is 256 that frequency is counted.

Compared with prior art, linear servo system characteristic analysis method provided by the invention has following beneficial effect:

(1) adopt based on saturation activation signal, carry out the saturation activation experiment of linear servo system, the Obtaining Accurate displacement information of linear servo system;

(2) adopt difference method to analyze actual displacement data, obtain velocity information and the acceleration information of linear servo system;

(3) adopt Morlet wavelet transformation, have good Time-Frequency Localization characteristic, the time-frequency characteristic of energy reflected well analyzed signal, effectively analyzes the frequency information of linear servo system under extreme sport condition;

(4) simple experiment, algorithm operation quantity is little, and be easy to on-the-spot and realize, debug process is flexible.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of the linear servo system characteristic analysis method in one embodiment of the present of invention;

Fig. 2 is saturation voltage pumping signal figure;

Fig. 3 is the actual displacement figure of the linear servo system Y-axis in one embodiment of the present of invention;

Fig. 4 is the velocity information figure of the linear servo system Y-axis in one embodiment of the present of invention;

Fig. 5 is the acceleration information figure of the linear servo system Y-axis in one embodiment of the present of invention;

Fig. 6 is the frequency information figure of the linear servo system Y-axis in one embodiment of the present of invention.

Embodiment

Elaborate for embodiments of the invention below, give detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

Permanent magnet linear synchronous motor (PermanentMagnetLinearSynchronousMotor is adopted in the present embodiment, PMLSM) Y-axis of Direct driver Mechatronic Systems is as research object, saturation activation experiment is carried out by the linear servo system formed Embedded Motion, driver element, topworks and other auxiliary equipment etc., and then analyze the velocity information of Y-axis and acceleration information under extreme sport situation, and under extreme sport situation the natural frequency of permanent magnet linear synchronous motor

As shown in Figure 1, the linear servo system characteristic analysis method that the present embodiment provides comprises the following steps:

Step one, according to the electric of permanent magnet linear synchronous motor Y-axis and mechanical features, select saturation voltage signal as testing saturation activation signal used, saturation voltage pumping signal as shown in Figure 2, its amplitude is ± 10V, the duration of positive and negative saturation voltage is 5ms, and the sampling period of linear servo system is set to 0.1ms;

Also saturation current pumping signal can be selected as testing saturation activation signal used;

Step 2, the experiment parameter of saturation voltage pumping signal is set, sends by Embedded Motion Control System the voltage saturation pumping signal that duration is 10ms, drive the Y-axis motion of permanent magnet linear synchronous motor, record corresponding contactless grating chi feedback signal, i.e. corresponding actual displacement information;

In order to store more displacement information, select 200 as effectively preserving length, actual displacement as shown in Figure 3.

Step 3, choose length be 200 actual displacement data carry out difference, the actual speed information of permanent magnet linear synchronous motor Y-axis when can obtain saturation voltage exciter response, as shown in Figure 4, as can be seen from Figure 4, permanent magnet linear synchronous motor Y-axis has and reaches the ability that maximal rate is 0.689m/s.By the actual speed information difference again of permanent magnet linear synchronous motor Y-axis, obtain its acceleration information, as shown in Figure 5, by analyzing its acceleration information, the peak acceleration obtaining this permanent magnet linear synchronous motor Y-axis is 220m/s ²be 145m/s with average acceleration ².In addition, also can obtain the acceleration of this permanent magnet linear synchronous motor Y-axis, namely acceleration is 0.5ms from the time that 0 accelerates to average acceleration, and that is, Y-axis has the ability reaching average acceleration at 5 servo periods.

And then the information that the motion planning design of Y-axis can obtain according to this step, carries out rational motion planning, makes Y-axis reasonably play the performance of oneself.

Step 4, by the corresponding actual acceleration data of Morlet wavelet transformation analysis, obtain the frequency information of permanent magnet linear synchronous motor Y-axis under extreme sport situation, concrete steps are as follows:

A) for a given signal continuous wavelet transform is the inner product of signal and wavelet function:

$\mathrm{Wf}(u,s)=\frac{1}{\sqrt{s}}{\∫}_{-\∞}^{+\∞}f\left(t\right)\mathrm{\ψ}\left(\frac{t-u}{s}\right)\mathrm{dt},$

Wherein Wf (u, s) is called small echo ψ _u,scorresponding wavelet coefficient, describe signal with the vibration of yardstick s near the u of position, the formula of the Morlet wavelet transformation adopted in the present embodiment is as follows:

$\mathrm{\ψ}\left(t\right)={\mathrm{\π}}^{-1/4}(e^{-{\mathrm{j\ω}}_{0}t}-e^{-{\mathrm{\ω}}_0^2/2})e^{{-t}^2/2}.$

B) to arrange analysis frequency lower limit be 100Hz and upper frequency limit is 5000Hz, and selecting frequency to count is 256, obtains corresponding time-frequency distributions, as shown in Figure 6.

C) as can be known from Fig. 6: permanent magnet linear synchronous motor Y-axis under extreme sport situation, first by the frequency that evokes greatly about about 290Hz.

And then the control method of Y-axis can be carried out choose reasonable by the size evoking frequency to the cutoff frequency of the low-pass filter that control method relates to according to first.In addition, also can refer to the calculating that this frequency carries out controller parameter, as the parameter of the PID controller based on POLE PLACEMENT USING.

Linear servo system characteristic analysis method provided by the invention can be used for the linear electric motors of other type, and the present invention is not restricted this.

The part that do not elaborate in above-mentioned explanation is knowledge and technology disclosed in this professional domain.

Linear servo system characteristic analysis method provided by the invention, adopt based on saturation activation signal, carries out the saturation activation experiment of linear servo system, the Obtaining Accurate displacement information of linear servo system; Adopt difference method to analyze actual displacement data, obtain velocity information and the acceleration information of linear servo system; Adopt Morlet wavelet transformation, have good Time-Frequency Localization characteristic, the time-frequency characteristic of energy reflected well analyzed signal, effectively analyzes the frequency information of linear servo system under extreme sport condition; For motion Controller Design and exploitation, and motion planning and control method research provide direct data reference frame, simple experiment, and algorithm operation quantity is little, and be easy to on-the-spot and realize, debug process is flexible.

More than describe preferred embodiment of the present invention in detail.Should be appreciated that those of ordinary skill in the art just design according to the present invention can make many modifications and variations without the need to creative work.Therefore, all technician in the art, all should by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.

Claims (10)

1. a linear servo system characteristic analysis method, is characterized in that, described method comprises:

(1) according to the electric of linear servo system and mechanical features, saturation activation signal, amplitude and duration is selected;

(2) in described amplitude with under the described duration, carry out the saturation activation experiment of described linear servo system, and record the actual displacement data in described linear servo system direction of motion;

(3) analyze described actual displacement data by difference method, obtain the velocity information in the described linear servo system direction of motion of described linear servo system under extreme sport situation and acceleration information;

(4) the described acceleration information by obtaining in Morlet wavelet transformation analysis step (3), obtains the frequency information of described linear servo system under extreme sport situation;

Described extreme sport situation is the moving situation of described linear servo system when adding described saturation activation signal.

2. linear servo system characteristic analysis method as claimed in claim 1, it is characterized in that, saturation activation signal described in step (1) is saturation voltage pumping signal or saturation current pumping signal.

3. linear servo system characteristic analysis method as claimed in claim 2, it is characterized in that, described linear servo system comprises motion controller, driver element, topworks and auxiliary equipment.

4. linear servo system characteristic analysis method as claimed in claim 3, is characterized in that, carries out the saturation activation experiment of described linear servo system, comprise the following steps in step (2):

(21) send described saturation activation signal by described motion controller, drive described linear servo system to move;

(22) record contactless grating chi feedback signal, described contactless grating chi feedback signal is corresponding actual displacement data.

5. linear servo system characteristic analysis method as claimed in claim 4, it is characterized in that, described in step (22), saturation activation signal is saturation voltage pumping signal, and the amplitude of described saturation voltage pumping signal is 10V, and the duration of positive and negative saturation voltage is 5ms.

6. linear servo system characteristic analysis method as claimed in claim 4, is characterized in that, when recording described contactless grating chi feedback signal in step (22), selects effectively to preserve length.

7. linear servo system characteristic analysis method as claimed in claim 6, it is characterized in that, described effective preservation length is 200.

8. linear servo system characteristic analysis method as claimed in claim 1, it is characterized in that, step (4) comprises step:

(41) continuous wavelet transform is the inner product of signal and wavelet function:

$Wf(u,s)=\frac{1}{\sqrt{s}}{\∫}_{-\mathrm{\∞}}^{+\mathrm{\∞}}f\left(t\right)\mathrm{\ψ}\left(\frac{t-u}{s}\right)dt$

Wherein, for described signal, Wf (u, s) is wavelet function ψ _u,scorresponding wavelet coefficient, describes described signal near the u of position with the vibration of yardstick s;

(42) analysis frequency lower limit and upper frequency limit are set, and select frequency to count, obtain corresponding time-frequency distributions;

(43), in the described time-frequency distributions obtained from step (42), first is obtained by the frequency evoked.

9. linear servo system characteristic analysis method as claimed in claim 8, is characterized in that, the formula of the Morlet wavelet transformation adopted in step (41) is:

$\mathrm{\ψ}\left(t\right)={\mathrm{\π}}^{-1/4}(e^{-{\mathrm{j\ω}}_{0}t}-e^{-{\mathrm{\ω}}_0^2/2})e^{-t^2/2}.$

10. linear servo system characteristic analysis method as claimed in claim 8, it is characterized in that, described in step (42), lower-frequency limit is 100Hz, and described upper frequency limit is 5000Hz, and it is 256 that described frequency is counted.