RU2711487C1 - Method for safe approach of a service spacecraft to a serviced spacecraft - Google Patents

Abstract

FIELD: astronautics.SUBSTANCE: invention relates to observation or tracking of flight of space vehicles and can be used for autonomous safe approach of service spacecraft with serviced spacecraft. Practical use of the proposed invention is related to performing orbital servicing in near-Earth space and beyond. For safe approach of service spacecraft with serviced spacecraft, approach is performed based on data of lidar and video recorder installed on service spacecraft. On the flat screen of the video recorder, a fragment of the image of the serviced spacecraft is selected, controlled approach to multiple magnifications of the size of the selected fragment is performed. In controlled approaches, size of selected fragment is determined based on lidar data and distance between space vehicles as per data of video recorder. Next controlled approaches are performed at a lower speed when observing fragments of a smaller size until a safe rate of mechanical contact is achieved.EFFECT: safe approach of a service space vehicle to a serviced spacecraft is provided.1 cl

Description

The invention relates to the field of observation or tracking the flight of spacecraft (SC) and can be used for autonomous safe approach of a service spacecraft (SKA) with a serviced spacecraft (OKA). The practical use of the alleged invention is associated with the implementation of orbital services in near-Earth space (OKP) and beyond.

Known invention protected by patent - analogue: application No. 95115874/11, IPC B64G 9/00, 1995 “Method for the selection of space objects” (Atnashev AB, Atnashev VB, Dokukin VF, Zemlyanov A.B ., Chuev V.I.), intended for the selection of passive space objects and detection from the space station (SC) of fragments of particles moving along the trajectories of a dangerous approach. The essence of the invention lies in the fact that they conduct direction finding of space objects located near the CS (in the area of the direction finder). In this case, two parameters are measured: the current relative position of the CS and the bearing to be detected, as well as the relative radial velocity. Based on these data, a space object is identified. The disadvantages of the method include the need to use radar equipment onboard the CS, which leads to an increase in the mass and overall characteristics of the CS, as well as to an increase in on-board power.

Known invention protected by patent - analogue: application No. 2012104591/11, IPC B64G, 2012 "Method for the exact positioning and monitoring of moving objects" (V. Zarenkov, D. Zarenkov, V. Dikarev, B. Koinash). The method is based on the use of satellite navigation, allows you to determine the mobile coordinates of the object and control the object in flight. The method is implemented using a system of technical equipment, including navigation spacecraft, correction stations, hardware of a television center, hardware for space communications, hardware for a controlled moving object, and a space flight monitoring station. All of these tools operate simultaneously using specially developed algorithms. EFFECT: high reliability and accuracy of discrete signals exchanged between television centers and space objects, which, in turn, provides high accuracy of positioning and monitoring of moving objects. The disadvantages of the method include the high complexity of its implementation.

A patent-protected invention is known as a prototype: Application No. 2008133984/09, IPC B64G 4/00, 2007, “A device for monitoring the relative position (s) by measuring power for a spacecraft of a group of spacecraft during flight operation”, designed to control space devices when they are moving in formation. The device monitors the relative positions of spacecraft in relation to each other and contains:

• a complex of at least three receiving-emitting antennas mounted on at least three sides of different directions relative to a given spacecraft and capable of emitting / receiving radio frequency signals;

• measuring instruments designed to determine the power of the signals received by each of the antennas, and to issue sets of powers, each of which is associated with one of the spacecraft of the group located around the spacecraft;

• storage means designed to store sets of cartographic data, each of which characterizes the normalized power of the signals received by each of the antennas depending on the selected transmission directions;

• processing tools designed to compare each set of capacities issued by measuring instruments with the totality of stored cartographic data.

As a result of the operation of the device, each of the directions of transmission of signals emitted by other spacecraft of the group is determined with respect to the coordinate system associated with this spacecraft. The technical result of using the prototype method is to ensure the positioning of a group of spacecraft relative to each other with the accuracy necessary for the joint execution of the task. The disadvantages of the device include the need to place radio transmitting equipment onboard the spacecraft, which increases the mass and overall characteristics of the spacecraft and requires additional costs for onboard power.

A patented invention is known as a prototype: patent No. 2669763, IPC B64G, 2017 “Device for automatically docking spacecraft in orbital maintenance operations” (M. Yakovlev and others). The automatic docking device of the spacecraft in orbital maintenance operations includes a pin on the serving spacecraft and a conical socket on the served spacecraft. In the center of the conical socket there is a movable rod, on the outer end of which a radiation source is installed. The radiation receivers are located symmetrically and at the same distance from the longitudinal axis of the rod on the serving spacecraft. The mutual position of the spacecraft is monitored according to the readings of the radiation receivers located on the serving spacecraft. The technical result of the invention is to increase the reliability of the automatic docking of the spacecraft during orbital maintenance operations. The disadvantage of this method is the lack of control of the speed of approach of spacecraft at the time of docking, which can lead to mechanical damage to interface parts.

A patent-protected invention is known as a prototype: Patent No. 2603301, IPC B64G, 2015. “A method for synchronizing the angular velocities of an active spacecraft with a passive spacecraft” (M. Yakovlev and others). The method includes controlling the angular velocities of the active spacecraft according to observations from its side of the passive spacecraft. At the same time, the figure of a triangle is observed, the vertices of which are images of three reflective elements mounted on a passive spacecraft at the maximum distance from its center of mass. Control is performed before registration on an active spacecraft of a stable stationary figure of a triangle. The technical result of the invention is the implementation of the synchronization of the angular velocity of the spacecraft with relatively simple means. The disadvantage of this method is the need for preliminary equipment of a passive spacecraft installed at a maximum distance from its center of mass of three reflective elements forming the shape of a triangle.

The aim of the invention is the safe approximation of the service spacecraft with the served spacecraft.

This goal is achieved in the inventive method for the safe approach of a service spacecraft (SCA) to a serviced spacecraft (OKA), according to which the approach of spacecraft is performed according to the lidar and video recorder installed on the service spacecraft. On the flat screen of the DVR, a fragment of the image of the served spacecraft is isolated. Perform controlled convergence to a multiple increase in the image size of the selected fragment. In controlled proximity, the size of the selected fragment is determined according to the lidar and the distance between the spacecraft according to the data of the DVR. The next controlled approach is performed at a lower speed when observing fragments of a smaller size until a safe speed of mechanical contact is achieved.

The proposed method is implemented as follows. The presence of a lidar allows you to determine the distance between the approaching SKA and OKA. At small distances commensurate with the characteristic dimensions of spacecraft, the lidar readings may not be accurate enough due to the smallness of the measured time intervals (less than ten nanoseconds). In this case, the distance between the spacecraft is determined using a DVR installed on board the SKA. The image of the approaching OKA is projected onto the flat screen of the DVR.

Before starting work at short distances, a certain observable fragment is isolated on the image surface of the OKA and its linear size is determined with a controlled approach to a multiple increase in the image size of this fragment. Controlled proximity means using a lidar to measure the distance between spacecraft in two positions. In the first measurement, the distance, L, between the SKA and the OKA is determined at the moment of separation of the observed fragment. The second measurement determines the distance, B, between the SKA and the OKA at the time of reaching the specified multiple increase in the size of the selected fragment. During the first and second measurements, the angle of view of the selected fragment, α, should remain small enough so that the condition is satisfied:

sin (n⋅α) ~ n⋅α,

where n is the specified magnification of the size of the selected fragment. This condition is always fulfilled, since any identifiable portion of the OKA image on the recorder screen can be selected as the selected fragment. In the above approximation, the variables L, B, n are associated with the linear size of the selected fragment, and , by the following relation:

Formula (1) determines the desired linear size of the observed fragment. By the known value of a and the proportions, the size of any other selected fragment in the image of the OKA on the recorder screen is found.

When working at short distances, the distance, L, between spacecraft is determined by the data of controlled approach to a multiple increase in the image size of the selected fragment. In this case, controlled approach means controlling the distance, S = (L-B), by which the SKA has moved in the direction of the OKA from the moment the observed fragment is selected to the moment the specified multiple increase in the size of this fragment is achieved on the recorder screen. The distance, S, is determined by the known relative speed of the SKA and the duration of the time interval between the two time points indicated above. The linear size, and , of the selected fragment is determined by the data of previously performed operations. The desired value of L is determined by the formula:

After the next controlled approach at short distances, a new fragment with a smaller size is isolated on the observed surface of the serviced spacecraft and another controlled approach is performed at a lower speed. In this case, the speed of approaching the SKA with the OKA is chosen so that the time for moving the SKA to the remaining distance to the OKA exceeds the duration of the operations to prepare for the next iteration of the selection of a new fragment with a smaller size and the approach of spacecraft with a lower speed. The SKA is slowed down until a safe mechanical contact speed of the spacecraft is reached.

Thus, the practical relevance and feasibility of the technical implementation of the proposed method for the safe approximation of a service spacecraft with a serviced spacecraft is not in doubt.

Claims (1)

A method of safely approaching a service spacecraft with a serviced spacecraft, according to which the approach of spacecraft is performed according to the lidar and the DVR installed on the service spacecraft, whereby a fragment of the image of the served spacecraft is isolated on the flat screen of the DVR, controlled proximity is performed until the image size is highlighted fragment, in controlled proximity determine the size of the selected fragment of lidar data and the distance between the spacecraft according DVR next controlled convergence operate at a slower speed when observed fragments of smaller size to achieve a secure mechanical contact speed.