SU1767477A1 - Device for control of dynamic objects with attached flexible member - Google Patents

Abstract

The invention relates to the management of dynamic objects, namely to the management of objects with attached elastic elements. The aim of the invention is to reduce the duration of the transient reorientation of a dynamic object with an attached elastic element. For this purpose, a device containing a control object with an attached elastic element, a block of actuators, angular position and velocity sensors, a control torque sign generator and a control interval calculator are additionally equipped with two time interval calculators that are cracked to the elastic wave period, the generator of the elastic wave period. , shaper level control torque and the switching unit control torque. 1 il. SO with

Description

The invention relates to the management of dynamic objects, namely to the management of objects with attached elastic elements.

A device is known that provides control of the orientation of a control object by implementing a proportional control law. Its main drawback is the non-optimal time spent on the management process.

The known orientation and stabilization system, selected as a prototype, contains serially connected block of actuators, control object, angular velocity sensor, amplifier-converter, first adder, first relay element, the output of which is connected to the inputs of two coincidence systems, the second inputs of which are connected to the output of the second relay element, the second output of the control object is connected to the input of the angle sensor, the output of which is connected to the inputs of two adders, the second input of the second adder is connected through an amplifier with an output of the converter converter, and an output to the input of a second relay element, the outputs of the coincidence circuit are connected to the inputs of the block of executive elements.

A disadvantage of the known device is the possibility of exciting significant vibration amplitudes of the elastic element. This leads to the need for long-term stabilization and damping of the vibrations of the elastic element excited in the process of orientation.

The aim of the invention is to reduce the duration of transients.

IV

About v |

4 vl

vl

reorientation of a dynamic object with an attached elastic element.

The goal is achieved in that a device containing a block of executive bodies, connected by an output to an input of a control object with an attached elastic element, an angular deflection sensor and a speed sensor, whose inputs are respectively connected to the first and second outputs of the control object with an attached elastic element, and their outputs are connected respectively to the information inputs of the first and second keys, the control inputs of which are connected to the output of the start-up unit, the outputs of the first and second keys are associated respectively with the first and second inputs of the control moment sign maker and the first and second inputs of the control interval calculator, the third input and the first output of which are connected respectively to the first output and the third input of the control moment sign generator, additionally introduced the first and second time calculators that are multiples the period of elastic oscillations, the unit of the period of elastic oscillations, the driver of the control torque levels and the control switching unit of the control moment, the second and third outputs of the calculator control intervals are connected respectively to the first inputs of the first and second time interval calculators that are multiples of the elastic oscillation period, the second inputs of which are connected to the first output of the elastic oscillation period generator, the output of the first time intervals calculator that are multiples of the elastic oscillation period, are connected to the first inputs of the control switching unit moment and shaper levels governing mo-. The output of the second calculator of control intervals, multiple to the period of elastic oscillations, is connected to the second inputs of the control torque switching unit and the control torque level generator, the first and second inputs of the control moment sign maker are associated with the third and fourth controls level generator moment, the first output of the setter of the period of elastic oscillations is connected with the third input of the control moment switching unit and with the fifth input of the driver level controller coagulant, the first and second outputs of which are coupled respectively to the fourth and fifth inputs of the switching unit of the control points, the second output setpoint period elastic oscillations coupled to a sixth input

0

five

0

five

0

five

0

five

0

five

the control torque generator, the sixth and seventh inputs of the control torque switch block are connected to the second and third outputs of the control torque sign generator, respectively; the output of the start block is connected to the third inputs of time slot calculators and the eighth input The control torque switch block, the first, second, third and fourth outputs of the control torque switch block are connected to the first, second, third, and fourth inputs of the block, respectively. executive bodies.

The proposed device provides a reduction in the duration of the transient reorientation of a dynamic object with an attached elastic element and thus the achievement of the objective of the invention.

Comparison of the proposed technical solution with the prototype made it possible to establish compliance with the novelty criterion. When studying other known technical solutions in this field of technology, the features that distinguish the invention from the prototype have not been identified and therefore they provide the claimed technical solution with the criterion of significant differences.

The invention is based on the following. The dynamics of an object with an attached elastic element can be described by a system of equations

-I for bs + and;

m s + m v a) i / + m or2 s - by, where I is the mass-inertia parameter of the control object;

b is the coefficient of mutual interaction between the body of the object and the elastic element;

m is the reduced mass of the elastic element;

w is the oscillation frequency of the elastic element;

v is the logarithmic decrement decrement;

y is the coordinate of the body of the control object;

s is the generalized coordinate of the elastic element.

The idea of controlling such an object is based on independence from the magnitude of the control of the oscillation period of the elastic element, which is equal to

Tk 2 T, where T 1 / w.

If the control action is maintained equal and on a time interval that is a multiple of the oscillation period T, then at the end of this

the coordinate interval of the elastic element will be at the same point as at the time the control started (s 0, s 0).

For a speed-optimal turn of the control object as a solid (without taking into account the elastic element), it is necessary to attach a control action of a relay type to it, which has two constant intervals, the durations of which are determined by the expressions

 :YU

"-TR

where ti, t2 - the duration of the first and second intervals;

y (0), y (0) - the initial value of the phase coordinates;

and - maximum control torque;

I is the moment of inertia of the control object.

The duration q, ta may not be a multiple of the oscillation period of the elastic element (the case of multiplicity is special and improbable).

M Mk + Ati;

t2 t2k + At2,

where tr ti / 2 T, t2k 12/2 nJ, is part of a number;

DM 2 T,. This can lead to the excitation of large amplitude oscillations of the elastic element when switching the control action. However, if Ati, At2 is stretched to a value equal to Tk, then at the end of the control intervals the phase coordinates of the elastic element will in this case also be at the point (s 0, s 0), but then the coordinates of the solid body will not fall into the control target. The combination of these two moments can be accomplished by reducing the magnitude of the control action at intervals of Dm, At2 extended to Tk. The values of u, u2 at these intervals are easy to determine from the expressions

U1

-T G O-tlT - X ®

U2 {I Y (0) + I Y (OX YT + t1k) + U (I T (+ t2k) + (+ t2k2))} / (- 2 l T (2 L T + T2k), (4)

which are derived from the system of equations for the duration of the intervals when taking into account that

DM At2.

ten

15

20

25

3Q

gg o

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55

The sign of the control torque in the first interval is determined in accordance with the expression

and - lulsign

). (five)

As a result, at the end of the control, all phase coordinates will satisfy the final conditions (y 0, y 0, s 0, s 0). The duration of the turn will be more than optimal for no more than two periods of oscillation of the elastic element.

To evaluate the advantages of the proposed method, a number of mathematical experiments were carried out. The control object was turned with parameters:

The moment of inertia of the object I is 1400 kg-m-s2;

The maximum control torque is 48.57 kg-m;

The reduced mass of the elastic element is 3.5 kgf / m:

The ratio of the elastic element and the body of the object is 10 kgf;

The natural frequency of oscillation of the elastic element W 51 / s;

Dtina elastic element h 2m;

Logarithmic damping decrement, 05;

10 degrees with zero values of the remaining phase coordinates. The duration of the control intervals of an object as a solid body is m T2 2.2657 s,

moreover, their multiple parts to the period of oscillations of the elastic element are equal to tik t2k 1.2551 s. Control torque levels

і U2 41.68 kg-m

At the end of the control, all phase coordinates turned out to be zero, which corresponds to the control goal. At the same time, the control duration was tynp 5.0205 s, while the control duration, optimal in speed, the object as a solid is equal to tonr 4.5314 s, however, it is necessary to add to it the time required for damping (or stabilizing) the residual oscillations of the elastic an item.

The drawing shows a block diagram of the proposed device.

The device consists of a control object 1 with an attached elastic element 2, a block of executive bodies 3 capable of creating a control action of different characters, adjustable in magnitude, angle sensors 4 and angular velocity 5, two keys 6 and 7, start block 8, a calculator of control intervals 9, the generator of the control moment sign 10, two time interval calculators that are multiples of the elastic oscillation period, 1 and 12, the initial generator of the elastic oscillation period 13, at the first output of which the signal is proportional to Tk, and at the second output Tk / 2, control level timing pulley 14, control torque switching unit 15.

The device works as follows.

The current values of the angle and angular velocity are removed from the angle sensor 4 and the angular velocity sensor 5. If you need to turn the object 1 with the attached elastic element 2, turn on the start block 8 (this can be just a press of the Start button). The enable signal is fed to the logical inputs of keys 6 and 7, to the time interval calculators that are multiples of the elastic oscillation period, 11 and 12, and to the control torque switching unit 15. The initial values of the angle and angular velocity of the object are fed to the inputs of the time interval calculator 9, on the outputs which form signals proportional to the duration of the intervals of controlling the object as a solid ti and ta, calculated in accordance with expressions (1), (2), and to the inputs of the generator of the sign of the control moment 10, from the first output otorrhea control signal determined in accordance with expression (5) corresponding to the maximum mark and a control unit effects switching through control points 16 includes a unit executive bodies 3 which generates the maximum control point corresponding sign. From the first and second outputs of the calculator of control intervals 9, the signals are proportional to. The corresponding ti and t2, respectively, are fed to the inputs of the first and second time interval calculators that are multiples of the elastic oscillation period, 11 and 12. In addition, a signal is received at the inputs of these calculators that is proportional to Tk from the first output of the elastic oscillator of the period 13 oscillator. At the outputs of the time interval calculators that are multiples of the elastic oscillation period, 11 and 12, signals are formed that are proportional to the values of η and ta, respectively. At the outputs of the driver of the control torque levels 14, signals proportional to both T and U2, calculated in accordance with expressions (3) and (4), are generated. Signals proportional to tik, t2k and Tk are fed to the inputs of the control timing switch unit 15. When the control duration corresponding to the maximum control torque is equal to tik, the input of the actuators block 3 will receive a signal through the control timing switch 15, proportional and /, switching it to the creation of a control moment of the same sign, but the value and /. Such a control moment is created over time Tk. Then a switch is made to the creation of the maximum control moment of the opposite sign during the time T2 and the moment ig during the time Tk. The circuit returns to its original state. The management process ends.

The use of the proposed control device for a dynamic object with an attached elastic element makes it possible to significantly reduce the control duration as compared with the known ones, which is confirmed by the results of a mathematical experiment.

At the end of the turn, the described device completely damps the oscillations of the elastic element, while the prototype leaves the elastic element in an excited state. At the same time, disturbing accelerations are created, reaching in magnitude units and even tens of percent of the acceleration transmitted to the object by the executive bodies. Therefore, the process of high-precision stabilization can be significantly inhibited and exceed the duration of a turn in several times (up to 30- 60 s and more).

Claims (1)

Invention Formula A dynamic object control device with an attached elastic element, comprising a block of actuators connected by an output to an input of the control object with an attached elastic element, an angular deviation sensor and a speed sensor, the inputs of which are respectively connected to the first and second outputs of the control object the outputs are connected respectively to the information inputs of the first and second keys, the control inputs of which are connected to the output of the start block, the outputs of the first and The second keys are associated respectively with the first and second inputs of the control torque sign maker and the control interval calculator, the third input and the first output of which are connected to the first output and the third input of the control torque sign maker, respectively, in order to reduce the duration of the transient processes of reorientation of dynamic objects with an attached elastic element, the first and second time interval calculators that are multiples of the elastic period are additionally introduced into it oscillations, the unit of the elastic oscillation period, the control torque level generator and the control torque switching unit, the second and third outputs of the calculator of control intervals are connected respectively to the first inputs of the first and second calculators of time intervals that are multiple to the period of elastic oscillations, the second inputs of which are connected to the first the output of the unit period of elastic oscillations, the output of the first time interval calculator, a multiple of the period of elastic oscillations, is connected to the first inputs of the block lyuchatel control points and levels shaper control point, the second calculator output control slots, multiple elastic vibration period, is coupled to second inputs of the switching unit of the control points and levels shaper control points, the first and the second input of the sign of control points associated respectively, the third and fourth inputs of the control torque level generator, the first output of the setter of the elastic oscillation period is connected to the third input of the control torque switching unit and the fifth input of the control torque level generator, the first and second outputs of which are connected respectively to the fourth and the fifth inputs of the control moment switching unit; the second output of the elastic period setting unit is connected to the sixth input of the control torque level generator; the sixth and seventh inputs of the control unit For switching the control torque, respectively, with the second and third outputs of the control torque generator, the output of the start-up unit is connected to the third inputs of time interval calculators that are multiples of the elastic oscillation period and the eighth input of the control moment switching unit, the first to fourth outputs of the control moment switching unit are connected to the same inputs of the executive unit.