RU2293691C2 - Method for forming payload separation system - Google Patents

Abstract

FIELD: coupling of space payloads having unbalance in mass in transversal direction and separation from launch vehicles.

SUBSTANCE: proposed method includes determination of initial forces of operation of each spring-loaded pusher by calculation method ; spring-loaded pushers are mounted on payload separation system. Pushers are mounted in pairs and are located along lateral axes of payload. Pusher forces are so selected that their total static moment relative to any lateral axis passing through projection of actual position of payload mass is equal to zero. Forces of pushers located along one of lateral axes depend on shift of payload center of mass along this axis and do not depend on shift of payload center of mass along other axis.

EFFECT: reduction of angular disturbance of item relative to its lateral axes at separation from launch vehicle; avoidance of collision of separated item with last stage of launch vehicle.

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Description

The invention relates to systems for dumping or separating objects, mainly spacecraft (SC) and other payloads (PN), from supporting structures (adapters or instrument compartments) of launch vehicles (LV) when they are put into the calculated orbit and can be used in the field rocket and space technology. A feature of the method of forming a separation system (CO) is its use for separating monitors with a large mass imbalance in the transverse direction.

As a result of the analysis of patent and scientific and technical literature, as a prototype of the claimed method, a technical solution was made according to patent RU 2151086 C1 of 06/20/2000, registration number of the application 99114863/28 of 07/07/1999, "Device for transporting and separating PN from space objects ”, which presents the device for separation of monitors and the method of formation of monolithic monitors implemented by him.

A known method for the formation of CO is to install the fixing mechanism (holding device) of the load cell and means for separating the load cell - spring pushers between the load cell and the supporting structure. The locking mechanism is made in the form of rotary hooks interacting with the PN, the drive of their disclosure and pirozamka. Each of the spring pushers is made in the form of a rod placed in the housing, and a spring with an adjusting screw. Pushers are installed symmetrically with respect to the longitudinal axis of the PN passing through its geometric center. When installing the longitudinal axis of the spring pushers are parallel to the longitudinal axis of the detachable PN. At the same time, at the moment of separation of the PN with a pyro lock and a spring-loaded opening drive, the rotary hooks of the PN fixing mechanism are simultaneously triggered and the separation means (spring pushers) are included in the operation.

At the stage of initial preparation and docking of the PN with the SO (before fixing the PN using the locking mechanism), calibration (setting of the pushers to the calculated forces necessary to separate the PN at a given speed) of the efforts of the rods of the spring pushers and, during the installation of the PN, simultaneously compress the pusher springs by the rods . Such adjustment of the forces of the pusher rods and their adjustment to the calculated forces (nominal within the tolerance for each pusher) provides, after the MON fixing mechanism is activated, an insignificant calculated initial linear velocity ranging from 0.02 to 0.1 m / s, but does not exclude angular velocities rotation relative to the transverse axes, which are 0.5 deg / s, because The calibration of the efforts of the rods of the spring pushers is carried out without taking into account the actual displacement of the position of the center of mass of the payload and the specific location of the position of the pushers with respect to this displacement. As a result, the PN rotates (twists) relative to the transverse axes when it is separated from the supporting structure.

The perturbations in angular velocity during separation worsen the conditions for subsequent stabilization and orientation of the PN in the orbit of functioning in outer space, and can also lead to the approach and mutual collision of the separated PN with the last stage of the LV.

The usual compensation in these cases of unbalanced mass of the payload due to the installation of additional balancing weights on it, on the one hand, is not always possible due to the high density of the arrangement of instruments and equipment in limited volumes of payload housings, for example, small spacecraft, on the other hand, an increase in the mass of monitors and loads on elements of CO

The goal (task) of the proposed method for the formation of CO for the separation of STs is the elimination (reduction) of twisting of STs (without increasing the mass of STs) with the center of mass displaced in the transverse direction when it is separated from the ST.

The goal in the proposed method for the formation of CO is achieved by introducing the following operations:

- before fixing (with the help of a holding device) the payload on the separation system, the projection along the X axis of the actual position of the center of mass of the separated payload on its separation plane, characterized by the displacements Δу and Δz of the center of mass along the transverse axes Y and Z, passing through the geometric center, is determined payload;

- pushers in an amount of four, arranged in pairs along the indicated transverse axes, adjust to the calculated forces depending on their position with respect to the specified projection;

- at the same time choose the efforts of the pushers located along the axis Y, according to the ratios

moreover, the pusher with a force P ₁ is located closer to the specified projection of the center of mass than the pusher with a force P ₃ ;

- choose the efforts of the pushers located along the axis Z, according to the ratios

moreover, the pusher with a force of P ₂ is located closer to the specified projection of the center of mass than the pusher with a force of P ₄ ,

where P is the nominal setting force of the adjustable pushers necessary to ensure a linear speed of departure of the load cell in the absence of a displacement of the center of mass;

R is the radius of the circumference of the installation of the pushers around the axis X.

The values of the initial efforts of each pusher are preliminarily determined by calculation from the known equilibrium condition for an object (body) under the action of forces applied to it. The adjustment of each pusher to the calculated initial efforts is carried out in the process of their adjustment before installing and securing the payload using the holding device on the CO.

The proposed adjustment of each pusher to a specific initial force depends on the actual position of the center of mass of the carrier (more precisely, on the projection of the actual position of the center of mass of the carrier on the plane of its separation from the carrier). The actual position of the center of mass of the PN is determined by the results of balancing work and the determination of the mass-centering characteristics of the PN (during balancing, the mass, the position of the center of mass along the three axes of the PN, the mass moments of inertia of the PN are determined) and is a mandatory operation in the pre-flight preparation of any PN (SC, small CRs, satellites, detachable associated loads from the base SC) to launch.

It should be noted that the mass-centering characteristics of a truly manufactured PN in most cases differ from the corresponding characteristics determined by calculation, due to errors in the masses of the components of the PN devices, equipment, power design of the PN, as well as due to errors in their spatial arrangement on really made PN.

But the conditions for separation of the PN are installed on the supporting structure of the LV in a certain position, therefore the direction (orientation) of the projection of the actual position of the center of mass of the PN on the plane of its separation is known, as well as the magnitude of this displacement relative to the geometric center through which the longitudinal axis of the PN passes. This means that the position of each pusher with respect to the projection of the actual position of the center of mass of the PN is defined. Therefore, in order to compensate for the unbalanced effect from the imbalance in the mass of the load cell and to prevent twisting of the load cell after its separation, it is necessary to adjust the adjustable pushers to the calculated initial actuation forces of the corresponding value (taking into account their symmetrical location on the CO and taking into account the parallelism of their longitudinal axes of the longitudinal axis of the separated load cell).

For the operation of the CO formed and tuned by the proposed method, a prerequisite is the simultaneous release and inclusion of all pushers in the work, which can be accomplished by installing on the CO one holding device (lock) or a group of locks synchronously unlocked from one mechanical drive or pyromedicine.

Figure 1 shows a side view of the CO.

The figure 2 presents a view of the CO from above (view A in figure 1), shows the relative position of the holding device and the group of four pushers in plan, while the PN is conventionally not shown. The projection of the actual (shifted in the transverse direction relative to the longitudinal axis of the ST) position of the center of mass of the ST on the separation plane — point C.

WITH consists of four spring pushers 1, 2, 3, 4 and a holding device 5, made, for example, in the form of a mechanical lock. Spring pushers 1, 2, 3, 4 are installed around a circle of radius R, and a holding device (lock) 5 is installed in the center of the circle (point O, see figure 2) between the supporting structure 6 and PN 7. Spring pushers 1, 2, 3 , 4 and the holding device 5 are fixed on the supporting structure 6, ensuring their interaction (contact) with the PN 7. The pushers are placed symmetrically with respect to the geometric center of the PN (point O, see figure 2), through which its longitudinal axis X passes. The holding device ( lock) 5 provide simultaneous operation of all four pushers after it is released during the separation of the PN. It should be noted that a CO containing four spring-type pushers is the most typical and most common in the practice of developing CO for separating PN. When forming such a CO, the pushers are placed symmetrically (in increments of 90 °) with respect to the projection of the geometric center of the PN on the separation plane (relative to the longitudinal axis X of the PN). In this case, the pushers are installed in such a way that their longitudinal axes are parallel to the longitudinal axis of the PN. With this installation of the separation means, a group of at least four pushers allows you to compensate for the unbalanced effect of the mass unbalance of the payload simultaneously along two transverse axes by adjusting the pushers to the calculated forces in accordance with the above-proposed relations (1), (2), (3), (4) .

These relations were obtained by the authors from the well-known condition on the equality of static moments (equal to zero of the total static moment) of the pusher forces relative to any axis passing through the projection along the X axis of the actual position of the center of mass of the gravitational force on the separation plane (the known equilibrium condition of an object (body) under forces applied to it), while maintaining the total force of the four pushers equal to 4P (where P is the nominal force required to separate the PN in the absence of mass imbalance).

For presented on figures 1 and 2 of the separation system, the distribution of efforts to adjust the pushers is shown below:

P ₁ = P (1 + 2 Δу / R) - setting force of the pusher 1,

P ₂ = P (1 + 2 Δz / R) is the force setting pusher 2,

P ₃ = P (1-2 Δy / R) - force setting pusher 3,

P ₄ = P (1-2 Δz / R) - force setting pusher 4,

where P is the nominal force setting of the pushers, necessary to ensure a linear speed of departure of the ST in the absence of a displacement of the center of mass;

Δy and Δz are the actual displacement of the center of mass of the PN along the transverse axes Y and Z, respectively (see figure 2);

R is the radius of the circumference of the installation of the pushers around the X axis (see figure 2).

The difference between the maximum and minimum actuating forces of a pair of pushers installed on the CR at diametrically opposite points along the Y axis (pairs of pushers 1 and 3) is determined by the ratio

The difference between the maximum and minimum actuating forces of a pair of pushers installed on the CR at diametrically opposite points along the Z axis (pairs of pushers 2 and 4) is determined by the ratio

The total actuation force of all four CO pushers configured in accordance with relations (1), (3), (2), (4) is equal to

The analysis of relations (1) through (7) shows that the pairs of pushers can be adjusted for various forces that vary over a wide range, namely from 0 to 2P, while setting the pushers 1 and 2 for maximum forces equal to 2P, and pushers 3 and 4, with minimum efforts equal to 0, it is possible to compensate (to prevent twisting during separation of the ST) significant displacements of the position of the center of mass of the ST, reaching a value equal to half the radius (0.5 R) of the pushers, which is an order of magnitude higher than the transverse ST eccentricities, usually constituting no more than 5% p Fitting radius pushers, i.e. 0.05 R. Structurally, in this case, instead of the pushers 3 and 4, you can install unregulated stops.

The distribution of forces among the four pushers in accordance with the ratios given above, while maintaining the total force equal to 4P, eliminates (reduces) the rotation of the load cell after separation and ensures the departure of the load cell from the launch vehicle with a given linear speed.

To implement the method of forming CO, adjustable spring-loaded pushers are installed with the possibility of setting their operating response forces in the range from 0 to 2P (where P is the nominal force required to separate the PN with a given linear speed in the absence of an unbalance in the mass of the PN).

The formation of CO by the claimed method in the process of installation and fastening of the MO on the supporting structure of the LV is carried out as follows (with the orientation of the transverse displacement of the center of mass of the MON, for example, between the pushers 1 and 2 - the projection onto the separation plane at point C, as shown in figure 2):

- for installation on CO using pushers with adjustable working force;

- pushers 1, 2, 3, 4 autonomously adjust to the forces previously determined by calculation by the ratios (1), (3), (2), (4), respectively, and install in zones (places) intended for their placement on supporting structure 6;

- install PN 7 on the supporting structure 6 and fix it with a lock 5;

- configured pushers 1, 2, 3, 4 down to contact with PN 7 (see figure 1), while maintaining the efforts of their settings, and fix the pusher bodies relative to the supporting structure 6.

The separation system formed by the proposed method operates as follows.

After the actuation of the holding device (lock) 5, all four pushers 1, 2, 3, 4 are simultaneously released and put into operation, each of which is configured for the actual adjusted actuation force. Pushers act on PN 7 with different forces, but the total force of a group of four pushers is 4P, which ensures separation of PN 7 (departure of PN 7 from the load-bearing structure 6 of the PH) with a given linear speed. Because the initial actuating forces of the pushers are determined taking into account that the static moment of effort is equal to zero with respect to any transverse axis passing through the projection of the actual position of the center of mass of the PN 7 on the separation plane, the process of separation of the PN 7 from the supporting structure 6 will occur without twisting the PN 7.

The proposed adjustment of the adjustable pushers for various design efforts (determined taking into account the direction and magnitude of the displacement of the center of mass of the load cell) allows the use of mass-produced CO equipped with adjustable pushers to separate the load transfer system, having an eccentricity of the center of mass along the transverse axes to half the radius of the circumference of the plunger installation. An increase in the loads on individual pushers and on the zones of their contact with the PN due to the adjustment of the pusher springs to the increased actuation force during the separation of the PN is not critical, because the load on the LV elements in the areas of its fastening on the supporting structure with the help of holding devices (locks) is significantly higher during flight at the launch site and in cases of ground operation as part of the LV.

The proposed method for the formation of CO has significant differences compared with the prototype and allows you to separate the ST with the eccentricity of the center of mass in the transverse direction with minimal angular perturbations and without the usual increase in mass of the ST in such cases (there is no need to install additional balancing weights to compensate for the existing mass imbalance).

Claims (1)

A method of forming a payload separation system with a transverse mass imbalance consisting of a holding device and separation means made in the form of a group of spring pushers with adjustable forces parallel to the longitudinal axis X of the payload passing through its geometric center, namely, that the holding device and pushers are installed between the payload and the supporting structure symmetrically with respect to the specified longitudinal axis, and before fixing the payload the pushers adjust the design forces by the living device, ensuring that the pushers simultaneously trigger all the pushers, characterized in that before fixing the payload, the projection along the X axis of the actual position of the center of mass of the payload on its separation plane, characterized by displacements of the center of mass Δу and Δz along the transverse, is determined the Y and Z axes passing through the geometric center of the payload, and the pushers in the amount of four, pairwise located along the indicated points axes, set to design forces depending on their position relative to the specified projection, choosing the efforts of the pushers located along the Y axis, according to the ratios P ₁ = P (1 + 2 Δy / R), P ₃ = P (1-2 Δy / R), moreover, the pusher with a force P ₁ is located closer to the specified projection of the center of mass than the pusher with a force P ₃ , and the efforts of the pushers located along the Z axis - according to the relations P ₂ = P (1 + 2 Δz / R), P ₄ = P (1-2 Δz / R), moreover, the pusher with a force of P ₂ is located closer to the specified projection of the center of mass than the pusher with a force of P ₄ , where P is the nominal force setting of the pushers, necessary to ensure a linear speed of departure of the load cell in the absence of a displacement of the position of the center of mass; R is the radius of the circumference of the installation of the pushers around the axis X.

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