RU2117915C1 - Indicator gyrostabilizer - Google Patents

Abstract

FIELD: gyroscopes, design of tracking systems. SUBSTANCE: indicator gyrostabilizer is composed of platform with single-axis suspension with which axis stabilizing motor is coupled kinematically. Platform carries two-degree-of-freedom gyro with transmitters of angle and moment along each axis of suspension. One transmitter of angle is connected via locking amplifier to transmitter of moment. Transmitter of angle put on axis parallel to axis of suspension of platform is connected to one of inputs of stabilization amplifier. Stabilization amplifier incorporates preamplifier, phase-sensitive rectifier, voltage and power amplifiers connected in series. Its output is connected to control winding of stabilizing motor. Increased stability and reliability of operation of gyroplatform are achieved thanks to insertion of adder into stabilization amplifier between phase-sensitive rectifier and power amplifier and of resistor into control winding of stabilizing motor. Resistor of positive feedback is connected via scaling amplifier to noninverting input of adder. Inverting input of adder is connected to output of phase-sensitive rectifier. Description gives relation to determine gain factor of scaling amplifier. EFFECT: increased stability and reliability of operation of gyroplatform. 1 dwg

Description

 The invention relates to precision instrumentation, namely to gyroscopic technology, and can be used in indicator gyrostabilizers and servo systems.

 Known indicator gyrostabilizers (uniaxial, biaxial and triaxial) built on three-stage gyroscopes (the gyroscope can be in a gimbal, with a ball bearing, dynamically adjustable or float), stabilization contours of which include a gyroscope angle sensor connected in series, a preliminary amplifier, a phase-sensitive rectifier, and phase-sensitive rectifier, correction filter (corrective link), voltage amplifier, power amplifier and stabilizing motor (unloading motor or torque sensor) (Indicator iroskopicheskie platform. p / p. M. Alexandrov, AD, Mechanical Engineering, 1978). In this case, the stabilizing motor in order to eliminate the backlash can be performed according to the twin-engine scheme based on the gear drive. However, having positive qualities, such schemes have significant dimensions, and gear drives are also sources of additional disturbing moments due to the running-in gears.

 Gyrostabilizers on two-stage gyroblocks are also known, when stabilizing motors are gearless, which are direct current torque motors (type DM-3, DM-10) with excitation from constant moments (Inertial course vertical IKV-1. Technical description. 1977, p. 102 - 102 109).

 Indicator gyrostabilizers manufactured by the domestic industry are also known, which are built on three-stage gyroscopes, the stabilizing motors of which are made according to a direct-drive circuit and are direct current torque motors with excitation from permanent magnets (Gyroscopic stabilizer B-51. Technical description 6Sh2.564.005 TO 1975).

 When constructing indicator gyrostabilizers (IHS) of this class, it is necessary to solve the problem of ensuring stability at a given stabilization accuracy (with a large steepness of the stabilization loop), when the proper damping relative to the stabilization axis due to the stabilizing motor is small (since there is no gearbox).

 Ensuring the specified accuracy of stabilization and stability of the IHC is achieved by selecting the appropriate corrective links included in the stabilization circuit. However, with increasing stabilization accuracy (reducing stabilization error), ensuring the stability of the stabilizer is becoming an increasingly difficult task.

 Sometimes, to increase damping relative to the stabilization axis, a tachogenerator is used, which is kinematically connected to the stabilization axis, and is electrically connected to one of the inputs of the stabilization amplifier (see Bessekersky V.A., Fabrikant E.A., Dynamic synthesis of gyroscopic stabilization systems. L., Publishing House Shipbuilding 1968).

 However, in most cases, such a constructive solution is unacceptable due to the increase in the size of the gyrostabilizer or simply because of the impossibility of introducing any design changes in the device. In the proposed technical solution, it is planned to use only electrical signals existing in the stabilization circuit with minimal hardware overhead on electronics.

 For the prototype, we choose an indicator gyrostabilizer, consisting of a platform in a uniaxial suspension, with an axis of which a stabilizing motor is kinematically connected and on which a three-stage gyroscope is installed with angle and moment sensors on each axis of the suspension, and one of the angle sensors is connected to the corresponding correction motor through a locking arm, and the angle sensor mounted on an axis parallel to the axis of the platform is connected to one of the inputs of the stabilization amplifier, containing a series-connected preliminary an amplifier, a phase-sensitive rectifier, voltage and power amplifiers, the output of which is connected to the control winding of a stabilizing motor (GTI gyrostabilizer 54. Technical description 6Sh2.564.009 TO. 1984).

 The disadvantage of the prototype is the small static and dynamic accuracy relative to the axis of stabilization, and the desire to increase it by increasing the steepness of the stabilization loop leads to a significant decrease in stability margins in phase and amplitude and even to unstable operation of the IHS. At the same time, significant difficulties arise in the selection of the type of corrective links.

 The objective of the present invention is to improve the accuracy of stabilization and stability of the IHC.

This task is achieved by the fact that an adder is introduced into the stabilization amplifier between the phase-sensitive rectifier and the voltage amplifier, and a resistor is connected in series with the control winding of the stabilizing motor, which is connected to the non-inverting input of the adder by the type of positive feedback through an additionally introduced large-scale amplifier, the inverting input of which is connected to the output phase-sensitive rectifier, while the gain of the scale amplifier is determined from the ratio
((N-1) r + Nr ₁ ) / NSr ₁ ,
Where
N is the coefficient of increase of static accuracy and damping relative to the axis of suspension of the platform;
r, r ₁ - active resistance of the control winding of the stabilizing motor and resistor;
S is the gain from the point of connection of the large-scale amplifier to the stabilization amplifier to its output.

The kinematic diagram of the GCI with a block diagram of the circuit of the stabilization amplifier is shown in the drawing, where the following notation is adopted:
1 - platform on which the payload is installed;
2 - three-degree gyroscope;
3 - the outer frame of the gyroscope;
4 - gyro;
5 - angle sensor of the stabilization circuit;
6 - angle sensor circuit electric arresting (EA);
7 - amplifier circuit EA;
8 - torque sensor EA;
9 - platform control torque sensor;
10 - stabilization amplifier;
11 - pre-amplifier;
12 - phase-sensitive rectifier;
13 - adder;
14 - voltage amplifier;
15 - power amplifier;
16 - scale amplifier;
17 - stabilizing motor (SM);
17.1 - SM rotor;
17.2 - stator SM;
18 - a resistor that is included in the control winding circuit of the CM;
19 - output sensor angle gyrostabilizer.

- угол и угловая скорость относительно оси стабилизации;
r - активное сопротивление обмотки управления СМ;
r₁ - дополнительное эталонное сопротивление в цепи обмотки управления СМ;
i - ток в обмотке управления СМ;
K₁, K₂, K₃, K₄, K₅, K₆ - коэффициенты передачи датчика угла 5, предварительного усилителя 11, фазочувствительного выпрямителя 12, усилителя напряжения 14, усилителя мощности 15, масштабного усилителя 16.The drawing has the following letter images:
H is the kinetic moment of the gyroscope;
OX - axis of suspension of the platform (axis of stabilization);

- angle and angular velocity relative to the axis of stabilization;
r is the active resistance of the control winding SM;
r ₁ - additional reference resistance in the circuit of the control winding SM;
i - current in the control winding SM;
K ₁ , K ₂ , K ₃ , K ₄ , K ₅ , K ₆ - transmission coefficients of the angle sensor 5, pre-amplifier 11, phase-sensitive rectifier 12, voltage amplifier 14, power amplifier 15, scale amplifier 16.

 Explanation of the operation of the indicator gyrostabilizer.

 An explanation will be made from the standpoint of evaluating the slope and the reduced damping coefficient of the stabilization loop. At the same time, we assume that the stabilization amplifier 10 and the stabilizing motor 17 are inertialess. In this case, we consider two cases: with the absence and presence of positive current feedback.

= M + M_в; (1)
M = C_мi; (2)
U = (r+r₁)i+C_e

; (3)
U = (-K₁K₂K₃ α + K₆r₁i)K₄K₅, (4)
где
(1) - уравнение относительно оси стабилизации;
(2) - уравнение моментов СМ;
(3) - уравнение напряжений для СМ;
(4) - уравнение усилителей стабилизации;
I - момент инерции относительно оси стабилизации;
C_м, C_e - коэффициенты момента и противоэдс СМ;
M - момент на валу СМ;
M_в - возмущающий момент;
U - напряжение на выходе усилителя стабилизации.For proof, we write equations explaining the operation of the IHC when forming the moment of SM
I

= M + M _in ; (1)
M = C _m i; (2)
U = (r + r ₁ ) i + C _e

; (3)
U = (-K ₁ K ₂ K ₃ α + K ₆ r ₁ i) K ₄ K ₅ , (4)
Where
(1) - equation with respect to the stabilization axis;
(2) - equation of moments of SM;
(3) - stress equation for SM;
(4) - equation of stabilization amplifiers;
I - moment of inertia relative to the axis of stabilization;
C _m , C _e - moment coefficients and CM countermeasures;
M is the moment on the SM shaft;
M _in - disturbing moment;
U is the voltage at the output of the stabilization amplifier.

)/((r+r₁)-K₄K₅K₆r₁), (5)
подставляя которое в (1), получим

где
K= C_м(K₁K₂K₃K₄K₅)/ (r+r₁(1-K₄K₅K₆)) - крутизна контура стабилизации по моменту;
K_д=C_e/(r+r₁(1-K₄K₅K₆)) - коэффициент демпфирования относительно оси стабилизации.For analysis, it is enough to find the expression for the current of the stabilizing motor
i = - (K ₁ K ₂ K ₃ K ₄ K ₅ α + C _e

) / ((r + r ₁ ) -K ₄ K ₅ K ₆ r ₁ ), (5)
substituting which in (1), we obtain

Where
K = C _m (K ₁ K ₂ K ₃ K ₄ K ₅ ) / (r + r ₁ (1-K ₄ K ₅ K ₆ )) - the slope of the stabilization circuit in time;
K _d = C _e / (r + r ₁ (1-K ₄ K ₅ K ₆ )) is the damping coefficient relative to the stabilization axis.

где
T = I/K_д - постоянная времени платформы;
K_w= K/K_д= (C_мK₁K₂K₃K₄K₅)/ C_e - добротность ИГС, как следящей системы по скорости;
α_y = M_в/K - статическая ошибка, характеризующая точность стабилизации при действии постоянного возмущающего момента.If we divide all the terms of equation (6) by K _d , we get a different form of writing equation (6), often used in the study of such systems

Where
T = I / K _d - platform time constant;
K _w = K / K _d = (C _m K ₁ K ₂ K ₃ K ₄ K ₅ ) / C _e - Q factor of the IHS as a tracking system in speed;
α _y = M _in / K is a static error characterizing the accuracy of stabilization under the action of a constant disturbing moment.

 Further estimates will be made for two cases when there is no and when there is a positive current feedback.

Case 1. The resistance r ₁ = 0 and, accordingly, there is no scale amplifier (16) (corresponds to the prototype).

The corresponding parameters of equations (6) and (7) in this case take the form (the condition is indicated in brackets):
K (r ₁ = 0) = (C _m K ₁ K ₂ K ₃ K ₄ K ₅ ) / r; (eight)
K _d (r ₁ = 0) = C _e / r; (nine)
K _w (r ₁ = 0) = C _m / (C _e K ₁ K ₂ K ₃ K ₄ K ₅ ); (ten)
T (r ₁ = 0) = Ir / C _e ; (eleven)
Case 2. The resistance r ₁ ≠ 0 and the positive current feedback are organized through a scale amplifier (16).

K (r ₁ ≠ 0) = (C _m K ₁ K ₂ K ₃ K ₄ K ₅ ) / (r + r ₁ (1-K ₄ K ₅ K ₆ )); (12)
K _d (r ₁ ≠ 0) = C _e / (r + r ₁ (1-K ₄ K ₅ K ₆ )); (13)
K _w (r ₁ ≠ 0) = C _m / (C _e K ₁ K ₂ K ₃ K ₄ K ₅ ); (fourteen)
T (r ₁ ≠ 0) = (I (r + r ₁ (1-K ₄ K ₅ K ₆ ))) / C _e ; (15)
From a comparison of parameters (8) - (11) and (12) - (15), we can draw the following conclusions:
1. The steepness K of the stabilization circuit and the damping coefficient substantially depend on the presence of positive feedback and, accordingly, its parameters r ₁ and K ₆ .

2. The time constant T also substantially depends on r ₁ and K ₆ .

 3. The quality factor in speed does not depend on the presence of positive feedback.

 4. Static accuracy (error) and, accordingly, dynamic accuracy also significantly depend on the introduction of positive current feedback.

5. Selecting r ₁ and K ₆ , it is possible to obtain the desired accuracy characteristics and greatly simplify the task of finding the type of corrective links, which are usually included in the voltage amplifier (14) and power amplifier (15), to ensure the given stability margins in phase and amplitude.

When constructing an IHC stabilization loop with positive current feedback CM, K ₄ and K ₅ can be considered set, and r ₁ and K ₆ should be set from additional conditions, for example, from the value of the slope increase coefficient and damping coefficient, which we denote by N
N = (K (r ₁ ≠ 0)) / (K (r ₁ = 0)) = K _d (r ₁ ≠ 0) / (K _d (r ₁ = 0)) = r / (r + (1-K ₄ K ₅ K ₆ ) -r ₁ ). (sixteen)
From expression (16) we find the transfer coefficient of the scale amplifier
K ₆ ((N-1) r + Nr ₁ ) / (Nr ₁ S), (17)
Where
S = K ₄ K ₅ is the gain between the output of the adder and the output of the power amplifier or, more generally, the gain between the point of connection of the large-scale amplifier to the stabilization amplifier and its output.

 Expression (17) is introduced into the claims as an expression of the relationship between the parameters of the stabilization amplifier, the resistances of the control circuit SM and the coefficient of increase in the accuracy of stabilization.

 It should also be noted the purpose of the circuit of electric arresting, which ensures the stability of the gyroscope - arresting gyro 4 relative to the excess axis - the axis of its suspension. In the initial position, the vector H is perpendicular to the plane of the outer frame 3. If for some reason the perpendicularity is violated, the angle sensor 6 provides a signal to the amplifier 7, which controls the torque sensor 8. The torque sensor creates a moment that forces the gyroscope to precess around the axis of the gyro 4 to the side decrease the signal from the angle sensor 6.

 Example. In an example, we consider a uniaxial IHS with a gearless drive, when the SM is a direct current motor with independent excitation from permanent magnets of the DM series. Such IHSs are widely used, for example, in the construction of gyroscopic inclinometers, when accelerometers serve as a payload and strict requirements are imposed on the stabilization accuracy.

Initial data: r = 20 Ohms; r ₁ = Ohm; S = 20.

Given various N, we get:
N = 2, K ₆ = 0.3.

N = 5, K ₆ = 0.45.

N = 10, K ₆ = 0.5.

Since it follows from (11) and (15) that T (r ₁ = 0) = T (r = 0) / N, the time constant T will decrease by 2, 5, and 10 times, respectively.

In a laboratory specimen of IHS, the coefficient N = 7. This turned out to be enough to ensure the given stabilization accuracy and to select an effective correction that provides a phase margin of at least 40 ^o , and an amplitude margin of about 18 dB.

Claims (1)

Gyrostabilizer, consisting of a platform in a uniaxial suspension, with the axis of which a stabilizing motor is kinematically connected, mounted on the platform of a three-stage gyroscope with angle sensors and torque sensors on each axis of its suspension, and one of the angle sensors is connected to the corresponding torque sensor through an arresting amplifier, an angle sensor mounted on an axis parallel to the suspension axis of the platform is connected to one of the inputs of the stabilization amplifier, the output of which is connected to the control winding of the stabilizing motor, the stabilization amplifier contains a series pre-amplifier, a phase-sensitive rectifier, a voltage amplifier and a power amplifier, characterized in that an adder is inserted into the stabilization amplifier between the phase-sensitive rectifier and the voltage amplifier, and a resistor is connected in series to the control winding of the stabilizing motor, which is additionally positively coupled via an additional feedback the entered scale amplifier is connected to the non-inverting input of the adder, the inverting input otorrhea connected to the output of phase-sensitive rectifier, the transmission coefficient scaling amplifier is determined by the relation
(N - 1) r + Nr ₁ ) / Nsr ₁ ,
where N is the coefficient of increase of static accuracy and damping relative to the axis of suspension of the platform;
r, r ₁ - active resistance of the control winding of the stabilizing motor and resistor;
S is the gain from the point of connection of the large-scale amplifier to the stabilization amplifier to its output.