CN105242543A - Relay self-setting method of servo system - Google Patents

Abstract

Provided in the invention is a relay self-setting method of a servo system. Delay time is calculated based on iteration; and setting values of a proportional gain of a PI controller and an integral time constant are calculated. According to the invention, setting of the proportional gain of the PI controller and the integral time constant of the servo system can be realized automatically; and automatic calculation of a PI controller parameter of an expected index can be realized under the circumstances that the load is unknown of the servo system, so that time and effort are saved. And the debugging efficiency of the servo system is improved.

Description

A kind of relay autotuner method of servomechanism

Technical field

The present invention relates to following control system, particularly relate to the controling parameters setting method of servomechanism.

Background technology

Along with the development of modernized war, the tracer request of armament systems to target is more and more higher, therefore higher requirement be it is also proposed to the servomechanism in armament systems, mainly contain rapidity and the tracking accuracy of tracking, this needs the adjustment of the controller parameter to servomechanism suitable, just can obtain satisfied control effects.The adjustment of traditional servomechanism controling parameters greatly number is determined by the commissioning experience of commissioning staff, and the consistance of debugging effect is poor; Another is the principle of design of model according to servomechanism and regulator, the parameter of carrying out controller is estimated roughly, and carry out trickle adjustment, this control grounding in basic skills to commissioning staff requires higher, and the parameter of having debugged changes along with the load of system, need adjustment again, just can reach satisfied control effects.

Summary of the invention

In order to overcome the deficiencies in the prior art, the invention provides a kind of relay autotuner method, without the need to commissioning staff to the commissioning experience of servomechanism and to the requirement controlling grounding in basic skills, can automatically complete asking for of servomechanism controller parameter, facilitate the debugging of servomechanism, effectively improve its production efficiency.

The technical solution adopted for the present invention to solve the technical problems comprises the following steps:

The first step, gets θ time delay _afor θ ₀, 0ms≤θ ₀≤ 200ms, the oscillation frequency that test servomechanism position exports is ω ₀;

Second step, gets θ time delay _afor θ ₁, 0ms≤θ ₁≤ 200ms, and θ ₁≠ θ ₀, the oscillation frequency that test servomechanism position exports is ω ₁;

3rd step, makes θ _n-2=θ ₀, θ _n-1=θ ₁, ω _n-2=ω ₀, ω _n-1=ω ₁, then wherein, ω _cfor servomechanism open loop cross-over frequency, span is 8rad/s≤ω _c≤ 12rad/s, and to get time delay be θ _n, test the oscillation frequency ω that at this moment servomechanism position exports _nwith oscillation amplitude A _n;

4th step, judges | ω _n-ω _c| whether < ε sets up, and wherein, ε span is ε≤0.2rad/s, if be false, then by θ _n-1value be assigned to θ _n-2, then by θ _nvalue be assigned to θ _n-1, then by ω _n-1value be assigned to ω _n-2, then by ω _nvalue be assigned to ω _n-1, calculate new θ _nvalue is and get θ _a=θ _n, then test the new oscillation frequency ω of now servomechanism position output _nwith oscillation amplitude A _n, repeat the deterministic process of the 4th step; If set up, then enter next step;

5th step, calculates the setting valve of PI controller proportional gain and integration time constant with wherein for the phase margin of the expectation of servomechanism, span is

The invention has the beneficial effects as follows: the proportional gain of PI controller and the adjusting of integration time constant that automatically can be realized servomechanism by servomechanism relay autotuner method of the present invention, when servo system load the unknown, adopt this method can realize the automatic calculating of the PI controller parameter of expectation index, time saving and energy saving, improve the debugging efficiency of servomechanism.

Embodiment

Below in conjunction with embodiment, the present invention is further described, the present invention includes but be not limited only to following embodiment.

The invention discloses a kind of servomechanism relay autotuner method, realize the proportional gain of position proportional-integration (PI) controller and the Self-tuning System of integration time constant of servomechanism, wherein, the transport function expression formula of PI controller is wherein k _pfor proportional gain, T _ifor integration time constant, when carrying out PI controller parameter k _pand T _iwhen adjusting, " relay adds delay " link is replaced the position PI controller of servomechanism, make servomechanism input set to 0, and the function expression of " relay adds delay " link is simultaneously:

$u\left(t\right)=\left\{\begin{array}{cc}d& e(t-{\mathrm{\&theta;}}_a)\&GreaterEqual;0\\ -d& e(t-{\mathrm{\&theta;}}_a)<0\end{array}\right.$

Wherein, e (t) is the output of t " relay adds delay " link, the site error of the servomechanism that e (t) is t, θ _afor time delay, and e (t-θ _a) be t-θ _athe site error of the servomechanism in moment, d is the output amplitude of " relay adds delay " link, and the span of d is 0.05 ω _max≤ d≤0.2 ω _max, ω _maxfor the maximum speed that servomechanism actuating motor exports.After adding " relay adds delay " link, the position of servomechanism exports and produces continuous oscillation.

The concrete steps realizing servomechanism relay autotuner method are:

The first step: get θ _avalue θ _a=θ ₀(0ms≤θ ₀≤ 200ms), the oscillation frequency that test servomechanism position exports is ω ₀;

Second step: get θ _avalue θ _a=θ ₁(0ms≤θ ₁≤ 200ms, and θ ₁≠ θ ₀), the oscillation frequency that test servomechanism position exports is ω ₁;

3rd step: make θ _n-2=θ ₀, θ _n-1=θ ₁, ω _n-2=ω ₀, ω _n-1=ω ₁, calculate iteration expression formula below

${\mathrm{\&theta;}}_n=\frac{{\mathrm{\&omega;}}_c-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

Wherein, ω _cfor servomechanism open loop cross-over frequency, span is 8rad/s≤ω _c≤ 12rad/s, and get θ _a=θ _n, test the oscillation frequency ω that at this moment servomechanism position exports _nwith oscillation amplitude A _n;

4th step: judge | ω _n-ω _c| whether < ε sets up, and wherein, ε span is ε≤0.2rad/s, if be false, then by θ _n-1value be assigned to θ _n-2, then by θ _nvalue be assigned to θ _n-1, then by ω _n-1value be assigned to ω _n-2, then by ω _nvalue be assigned to ω _n-1, be calculated as follows new θ _nvalue:

${\mathrm{\&theta;}}_n=\frac{{\mathrm{\&omega;}}_c-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

And get θ _a=θ _n, then test the new oscillation frequency ω of now servomechanism position output _nwith oscillation amplitude A _n, repeat the deterministic process of the 4th step, if set up, then enter next step;

5th step, calculates PI controller parameter k _pand T _isetting valve:

$k_p=\frac{4{\mathrm{dT}}_i{\mathrm{\&omega;}}_c}{{\mathrm{\&pi;A}}_n\sqrt{1+{\left(T_i{\mathrm{\&omega;}}_c\right)}^2}},$

Wherein for the phase margin of the expectation of servomechanism, span is

Embodiment 1:

When carrying out servomechanism position PI controller parameter k _pand T _iduring Self-tuning System, " relay adds delay " link is replaced the position PI controller of servomechanism, make servomechanism input set to 0 simultaneously, get d=0.05 ω _max, then the function expression of " relay adds delay " link is:

$u\left(t\right)=\left\{\begin{array}{cc}0.05{\mathrm{\&omega;}}_{max}& e(t-{\mathrm{\&theta;}}_a)\&GreaterEqual;0\\ -0.05{\mathrm{\&omega;}}_{max}& e(t-{\mathrm{\&theta;}}_a)<0\end{array}\right.$

Get θ ₀=10ms, θ ₁=20ms, ω _c=8rad/s, ε=0.05rad/s, the concrete steps then realizing servomechanism relay autotuner method are:

The first step: get θ _avalue θ _a=θ ₀=10ms, the oscillation frequency that test servomechanism position exports is ω ₀;

Second step: get θ _avalue θ _a=θ ₁=20ms, the oscillation frequency that test servomechanism position exports is ω ₁;

3rd step: make θ _n-2=θ ₀, θ _n-1=θ ₁, ω _n-2=ω ₀, ω _n-1=ω ₁, calculate iteration expression formula below

${\mathrm{\&theta;}}_n=\frac{8-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

And get θ _a=θ _n, test the oscillation frequency ω that at this moment servomechanism position exports _nwith oscillation amplitude A _n;

4th step: judge | ω _n-ω _c| whether < 0.05rad/s sets up, if be false, then by θ _n-1value be assigned to θ _n-2, then by θ _nvalue be assigned to θ _n-1, then by ω _n-1value be assigned to ω _n-2, then by ω _nvalue be assigned to ω _n-1, be calculated as follows new θ _nvalue:

${\mathrm{\&theta;}}_n=\frac{8-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

And get θ _a=θ _n, then test the new oscillation frequency ω of now servomechanism position output _nwith oscillation amplitude A _n, repeat the deterministic process of the 4th step, if set up, then enter next step;

5th step, calculates PI controller parameter k _pand T _isetting valve:

$T_i=\frac{1}{8}tan(\frac{2\mathrm{\&pi;}}{3}-8{\mathrm{\&theta;}}_n),k_p=\frac{1.6T_i{\mathrm{\&omega;}}_{max}}{{\mathrm{\&pi;A}}_n\sqrt{1+{\left(8T_i\right)}^2}}.$

Embodiment 2:

When carrying out servomechanism position PI controller parameter k _pand T _iduring Self-tuning System, " relay adds delay " link is replaced the position PI controller of servomechanism, make servomechanism input set to 0 simultaneously, get d=0.2 ω _max, then the function expression of " relay adds delay " link is:

$u\left(t\right)=\left\{\begin{array}{cc}0.2{\mathrm{\&omega;}}_{max}& e(t-{\mathrm{\&theta;}}_a)\&GreaterEqual;0\\ -0.2{\mathrm{\&omega;}}_{max}& e(t-{\mathrm{\&theta;}}_a)<0\end{array}\right.$

Get θ ₀=20ms, θ ₁=50ms, ω _c=12rad/s, ε=0.2rad/s, the concrete steps then realizing servomechanism relay autotuner method are:

The first step: get θ _avalue θ _a=θ ₀=20ms, the oscillation frequency that test servomechanism position exports is ω ₀;

Second step: get θ _avalue θ _a=θ ₁=50ms, the oscillation frequency that test servomechanism position exports is ω ₁;

3rd step: make θ _n-2=θ ₀, θ _n-1=θ ₁, ω _n-2=ω ₀, ω _n-1=ω ₁, calculate iteration expression formula below

${\mathrm{\&theta;}}_n=\frac{12-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

And get θ _a=θ _n, test the oscillation frequency ω that at this moment servomechanism position exports _nwith oscillation amplitude A _n;

4th step: judge | ω _n-ω _c| whether < 0.2rad/s sets up, if be false, then by θ _n-1value be assigned to θ _n-2, then by θ _nvalue be assigned to θ _n-1, then by ω _n-1value be assigned to ω _n-2, then by ω _nvalue be assigned to ω _n-1, be calculated as follows new θ _nvalue:

${\mathrm{\&theta;}}_n=\frac{12-{\mathrm{\&omega;}}_{n-1}}{{\mathrm{\&omega;}}_{n-1}-{\mathrm{\&omega;}}_{n-2}}({\mathrm{\&theta;}}_{n-1}-{\mathrm{\&theta;}}_{n-2})+{\mathrm{\&theta;}}_{n-1}$

And get θ _a=θ _n, then test the new oscillation frequency ω of now servomechanism position output _nwith oscillation amplitude A _n, repeat the deterministic process of the 4th step, if set up, then enter next step;

5th step, calculates PI controller parameter k _pand T _isetting valve:

$T_i=\frac{1}{12}tan(\frac{17\mathrm{\&pi;}}{18}-12{\mathrm{\&theta;}}_n),k_p=\frac{9.6T_i{\mathrm{\&omega;}}_{max}}{{\mathrm{\&pi;A}}_n\sqrt{1+{\left(12T_i\right)}^2}}.$

Claims (1)

1. a relay autotuner method for servomechanism, is characterized in that comprising the steps:

The first step, gets θ time delay _afor θ ₀, 0ms≤θ ₀≤ 200ms, the oscillation frequency that test servomechanism position exports is ω ₀;

Second step, gets θ time delay _afor θ ₁, 0ms≤θ ₁≤ 200ms, and θ ₁≠ θ ₀, the oscillation frequency that test servomechanism position exports is ω ₁;

3rd step, makes θ _n-2=θ ₀, θ _n-1=θ ₁, ω _n-2=ω ₀, ω _n-1=ω ₁, then wherein, ω _cfor servomechanism open loop cross-over frequency, span is 8rad/s≤ω _c≤ 12rad/s, and to get time delay be θ _n, test the oscillation frequency ω that at this moment servomechanism position exports _nwith oscillation amplitude A _n;

4th step, judges | ω _n-ω _c| whether < ε sets up, and wherein, ε span is ε≤0.2rad/s, if be false, then by θ _n-1value be assigned to θ _n-2, then by θ _nvalue be assigned to θ _n-1, then by ω _n-1value be assigned to ω _n-2, then by ω _nvalue be assigned to ω _n-1, calculate new θ _nvalue is and get θ _a=θ _n, then test the new oscillation frequency ω of now servomechanism position output _nwith oscillation amplitude A _n, repeat the deterministic process of the 4th step; If set up, then enter next step;

5th step, calculates the setting valve of PI controller proportional gain and integration time constant with wherein for the phase margin of the expectation of servomechanism, span is