RU2207309C2 - Method of optimization of spacecraft angular motion control system and device for realization of this method - Google Patents

Abstract

FIELD: testing spacecraft control systems. SUBSTANCE: proposed method includes physical simulation of angular motion of spacecraft on test stand. Center of mass of spacecraft simulator is matched with center of its rotation and energy fluxes from stars, Sun and earth are simulated for external information sensors. Angular motion of spacecraft simulator is controlled in turn by means of system under test and technological system. Swivel platform with Earth energy flux simulator is set in rotation at orbital angular velocity and possibility of holding the spacecraft simulator within tolerable range of deviation from vertical in the course of control by means of system under test is estimated. In case deviation is beyond tolerable limits, optimization of control system is discontinued. EFFECT: enhanced accuracy of ground tests and enhanced operational reliability. 3 cl, 3 dwg

Description

 The invention relates to techniques for testing, testing and researching the characteristics of angular motion control systems, in particular to techniques for testing, testing and researching the characteristics of angular motion control systems of spacecraft in ground conditions.

 A known method of testing, testing and researching the characteristics of spacecraft motion control systems in ground conditions by means of physical modeling with small disturbing angular momentum of the spacecraft by the spacecraft simulator, combining the center of mass of the spacecraft simulator with its rotation center by appropriate installation of the equipment of the worked out control system and balancing cargo on a simulator, creating energy flows for external inf sensors formations of the system being worked out by simulators installed motionless relative to the Earth, measuring the parameters of the angular motion of the spacecraft simulator and transmitting information from the simulator to the control system of the system being worked out motionless on the Earth, controlling the angular movement of the simulator by the control system by control commands to the executive bodies installed on the spacecraft simulator apparatus, with a ground control device.

 This method is implemented by a device for testing, testing and studying the characteristics of control systems for the angular motion of spacecraft in ground conditions, containing a dynamic stand simulating the angular motion of the spacecraft and made in the form of an instrument platform mounted on a spherical air bearing, a system for measuring the parameters of the angular motion of the instrument platform communication systems, for example, telemetry for transmitting information from the equipment of the system being worked out and technological paratus disposed on the instrument platform, receive control commands from the fixedly located on Earth control device fulfills system installed on the territory of the stand still relative to the earth simulators energy flows to the external information management system fulfills the sensors installed on the instrument platform [1].

 The disadvantage of this method is the impossibility of developing systems for controlling the angular motion of spacecraft in all modes of their operation. This method allows testing only stabilization systems and orientation determination systems only in coordinate systems associated with the Earth.

 There is also a known method for developing control systems for the angular motion of spacecraft in ground conditions, including physical modeling with small disturbing moments of the angular motion of the spacecraft relative to its center of mass by the spacecraft simulator, combining the center of mass of the simulator with its center of rotation, for example, by moving balancing weights along the guides booms, the creation of energy flows for sensors of external information of the processed system by simulators installed motionless relative to the Earth, control of the angular motion of the spacecraft simulator by the worked out control system, visual control and evaluation of the characteristics of the worked out system on the ground device using telemetry information from the measurement system of the spacecraft simulator.

 This method is implemented by a device for testing, testing and researching the characteristics of spacecraft angular motion control systems, comprising a dynamic stand simulating the angular motion of a spacecraft and made in the form of an instrument platform with a pneumatic system and gas jet engines mounted on a spherical gas bearing, a center of mass combining device instrument platform with its rotation center, made, for example, in the form of a stepper motor moving balancing g loads along the guide rods, a reference system for the angular position of the instrument platform and a communication system made, for example, in the form of a radio modem of the instrument platform and a radio modem of a ground-based device for receiving telemetric information and visual control, made, for example, in the form of a personal computer, energy flow simulators installed on Earth in the booth [2] (prototype).

The disadvantages of this method implemented by the known device are:
- the impossibility of developing control systems for spacecraft in all modes of their operation, including when creating the initial angular position and initial angular velocity before turning on the worked out system, correcting gyroscopic devices from external information sensors in control systems built on the basis of tracking the Earth’s energy flows in the process of orbital motion, because Earth simulator is fixed motionless on Earth;
- a sharp increase in the disturbing moment acting on the instrument platform during its turns relative to the stator of the air bearing, caused both by manufacturing errors of the stand elements and temperature deformations of the rotor of the air bearing when it turns around the stator in the horizontal plane, and, as a result, deterioration in test accuracy;
- failure of expensive equipment of the dynamic stand and equipment of the developed system due to impacts of the instrument platform on the stator of the air bearing during equipment failures or abnormal operation of the developed control system.

 The objective of the present invention is to expand the capabilities of the proposed technical solution and the accuracy of the tests by reducing the disturbing moment, preserving the equipment in case of failures and abnormal operation of the worked out control system.

 The problem is solved in that in a method for developing control systems for the angular motion of spacecraft, including physical modeling with small disturbing moments of the angular motion of the spacecraft relative to its center of mass by the spacecraft simulator, combining the center of mass of the simulator with its center of rotation by moving balancing weights along the guide rods , creation of energy flows for sensors of external information of the system being worked out by simulators, control of angular motion by simulating the spacecraft simulator by the control system that is being worked out, evaluating the characteristics of the system being worked out on the ground device using telemetry information from the spacecraft simulator measurement system, the simulator of the Earth’s energy flows and the base of the spacecraft simulator rotate in the horizon plane with orbital angular velocity, control the angular motion of the spacecraft simulator before switching on the worked-out control system, technological control system I am a simulator, create the initial parameters of the angular motion of the simulator of the spacecraft, turn off the control of the angular motion of the simulator by the technological control system after setting the initial conditions and turn on the control of the angular motion of the simulator by the worked out system, calculate the angle of deviation of the simulator of the spacecraft from the vertical when emergency braking of the angular motion of the simulator workings out by the worked-out control system and when exceeding the calculated angle of deviation from the vertical and the allowable value of the angle of pumping disable control fulfills angular motion simulator system include emergency braking angular motion simulator process control system, and return the spacecraft simulator to zero.

 This method is implemented by a device that is a dynamic stand simulating the angular motion of a spacecraft and made in the form of an instrument platform with a pneumatic system and gas jet engines mounted on a spherical gas bearing, a device for combining the center of mass of the instrument platform with its center of rotation, made in the form of a stepper motor moving balancing weights along the guide rods, the reference system of the angular position of the instrument platform, the communication system and the device telemetry information and visual control in the form of a ground personal computer, an instrument platform radio modem and a ground personal computer radio modem, energy simulators of the Sun, Star and Earth, in which a stator of a spherical air bearing and an Earth energy simulator are mounted on a common rotary platform, movable relative to the vertical axis and equipped with a rotation drive made in the form of an electric motor with a gearbox, a control unit is introduced the odom connected to the input of the rotation drive electric motor, the first input connected to the output of the command device, the second input to the output of the angle sensor and the third input to the output of the angular velocity sensor, the angular velocity sensor installed on the instrument platform, the output connected to the first input of the control computing device, the second input of which is connected to the output of the reference system of the angular position of the instrument platform, the first output of the control computing device is connected to the input of the stepper motor, sec the second and third outputs are connected to the switching unit, and the fourth is connected to the control device of the worked out control system, the output of which is connected to the switching unit, the output connected to the inputs of gas jet engines, and the fifth output is connected to the input of the radio modem of the instrument platform.

 Figure 1 shows a General view with a functional diagram of a device for implementing the method, figure 2 is a kinematic diagram of a dynamic test bench, figure 3 is a functional block diagram of a device.

 The device includes a dynamic stand (figure 1), made in the form of an instrument platform (1) with a pneumatic system (2) and gas jet engines (3) mounted on a spherical gas bearing (4) (figure 2), a device for combining the center of mass of the instrument platform (1) with its center of rotation, made in the form of a stepper motor (5), moving balancing weights (6) along the guide rods, a reference system of the angular position (7) of the instrument platform (1), a communication system and a device for receiving telemetric information and visual control In the form of a ground-based personal computer (8), a radio modem (9) of the instrument platform (1) and a radio modem (10) of a ground-based personal computer (9), simulators of the energy fluxes of the Sun (11), Stars (12) and the Earth (13), mobile relative to the vertical axis, the platform (14), equipped with a rotation drive made in the form of an electric motor (15) with a gearbox (16), a control unit (17), an output connected to the input of the rotation drive electric motor (15), connected to the output of the command device by the first input ( 18), the second input to the output of the angle sensor (19) and tr the angular velocity sensor (21) installed on the instrument platform (1) has an input to the output of the angular velocity sensor (21), the output is connected to the first input of the control computing device (22), the second input of which is connected to the output of the angular position reference system (7) instrument platform (1), the first output of the control computing device (22) is connected to the input of the stepper motor (5), the second and third are connected to the switching unit (23), and the fourth is connected to the control device of the developed control system (24), the output to the second is connected to the switching unit (23), the output of the jet engines connected to the inputs of the gas engine (3), and the fifth - to the input of the radio modem (9) of the instrument platform (1) (PrP). Angular motion control PrP (1) is carried out using a technological control system (TSU) (25), which includes gas jet engines (3), a radio modem (9), an angular position reference system (7), a center alignment device mass PrP (1) with a center of rotation, consisting of a stepper motor (5) moving balancing weights (6), an angular velocity sensor (DLS) (21), a control computing device (UVU) (22), a switching unit (23) .

 The device operates as follows.

 In the initial state, gas jet engines (GRD) (3) are connected to the output of the control computing device (UVU) (22) by the switching control unit (PSU) (23) of the technological control system (TSU) (25) by the angular movement of the instrument platform (PrP) (1). According to the operator’s commands, from the ground-based personal computer (NPK) (8), through the radio modem (10) NPK (8) and the radio modem (9) PrP (1), the operation program of the TSU is transmitted to the UVU (22). In the work program, the operating modes of the TCU, the time points at which these modes should be included, and the initial data for the operation of the software of the TCU are set. In accordance with the work program UVU (22) fulfills the set modes.

The device has three operating modes:
1) setting and adjustment mode;
2) the mode of providing conditions for the work of the worked out control system;
3) the mode of monitoring the development and management in emergency situations.

 In the setup and adjustment mode, the device provides an estimate of the projections of the disturbing moment acting on the PrP (1), and automatic balancing, i.e., the movement of balancing weights (6), compensating for the disturbing moment.

 The projection of the perturbing moment and the automatic balancing of PrP (1) are estimated as follows.

 According to information from the angular velocity sensors (DLS) (21) and the measurement system (7), the UVU (22) generates and issues control signals through the switching unit (23) to the engine (3), providing control of the angular motion of the transducer (1). After bringing PrP (1) to the zero position of the UVU (22), the angular motion control of PrP (1) ceases. PrP (1) makes an uncontrolled movement under the influence of only the disturbing moment of imbalance. The angular position of the PrP (1) in the process of uncontrolled movement is measured by the measuring system (7) and enters the UVU (22). UVU (22) determines the unbalance vector, its position in the coordinate system associated with PrP (1). Further, the UVU (22) calculates the turn-on times and the direction of rotation of the stepper motors (5), turns on and off the stepper motors (5), thereby ensuring that the balancing weights (6) are displaced over a distance that compensates for the unbalance vector acting on PrP (1).

 In the mode of providing conditions for the work out of the developed control system, the device operates as follows.

 The operator with the NPC (8) through the radio modem (10) NPC and the radio modem (9) PrP (1) transmits to the UVU (22) a work program in which it sets the time of switching on the mode and the values of the angular velocity and angular position of PrP (1) at the moment inclusion of the worked out control system (24).

 At the time point specified in the work program of the UVU (22) according to the measurements from the angular velocity sensor (21) and the measurement system (7), we form and issue control signals to the main engine (3) through the switching unit (23), thereby ensuring the reversal of the pressure transformer (1) ) to the angular position specified in the work program and the given angular velocity of its rotation. After turning PrP (1) into a predetermined angular position and reaching a predetermined angular velocity of its movement, the UVU (22) issues a command to the switching block (23), according to which in the switching block (23), the inputs of the main engine (3) are switched from the output of the UVU (22) to the output of the worked out control system (24), which further ensures the determination of the angular position of PrP (1) by its hardware from the simulators of the Star (12), the Sun (11) and the Earth (13) and the control of its angular movement. This ensures the creation of conditions for the angular motion of the spacecraft (1), corresponding to those acquired by the spacecraft after it is separated from the last stage of the launch vehicle, and thereby allows to increase the number of working modes of operation of the systems for controlling the angular motion of spacecraft in ground conditions, in particular, bringing the spacecraft into an oriented position.

 From the moment angular motion control PrP (1) begins, the control system (24) is worked out if a control system is being worked out that ensures the spacecraft is oriented in the orbital coordinate system, the control unit (17), according to information from the angular velocity sensor (20) and the angle sensor (19) begins to form and issue control signals to the drive (15) of the turntable (14). The drive (15) through the gearbox (16) provides rotation of the turntable (14) with the Earth simulator (13) located on it with the orbital angular velocity set by the operator through the command device (18).

 The introduction of rotation of the Earth simulator with an arbitrary angular velocity allows us to refine not only control systems that ensure the orientation of spacecraft in an inertial coordinate system, but also correction modes of gyroscopic control systems that provide orientation of spacecraft in an orbital coordinate system, and also work out non-gyroscopic control systems, determining the orientation of spacecraft relative to the orbital system in the infrared field of the Earth.

 The introduction of the rotation of the stator of a ball gas bearing with an orbital angular velocity ensures the balancing of PrP (1) with an unlimited angle of rotation of PrP (1) relative to the Earth during the development of orbital motion, and therefore improves the quality of development of control systems.

 In the control mode of mining and control in emergency situations, the device operates as follows.

 After setting the initial parameters of the angular motion PrP (1), disabling the angular motion control PrP (1) by the commands of the control gear (22) and turning on the control by the commands of the worked out control system (24), the control gear (22) provides information with a given resolution from the angular velocity sensor (21) and measurement systems (7) on the angular position and angular velocity of the receiver (1), storing it and transmitting it via the radio modem (9) to the receiver (1) and the radio modem (10) of the receiver in the receiver (8) for registration and subsequent processing. In addition, the UVU (22) at each step of its operation provides a calculation of the angular position of PrP (1), which it would have occupied if emergency braking of its angular movement had been included.

где γ_T,ψ_T,ϑ_T - угловое положение ПрП (1) по каналам крена, рыскания и тангажа;
γ_изм,ψ_изм,ϑ_изм - измеренные на текущем такте работы значения углового положения ПрП (1) по каналам крена, рыскания и тангажа,
ω $\genfrac{}{}{0ex}{}{\text{x}}{\text{изм}}$ ,ω $\genfrac{}{}{0ex}{}{\text{y}}{\text{изм}}$ ,ω $\genfrac{}{}{0ex}{}{\text{z}}{\text{изм}}$ - измеренные на текущем такте работы значения угловой скорости ПрП (1) относительно связанных осей ОХ, OY, OZ,
ε_x,ε_y,ε_z - ускорения ПрП (1), создаваемые газовыми реактивными двигателями (3) по каналам крена, рыскания и тангажа,

- время торможения ПрП (1) по каналам крена, рыскания и тангажа;

По расчетным значениям углов γ_T и ψ_T УВУ (22) рассчитывает величину угла отклонения (угла прокачки ПрП (1)) вертикальной оси ПрП (1) φ относительно вертикальной оси статора устройства в соответствии с выражением:
φ = arccos(cosγ_Tcosψ_T).
После расчета величины угла прокачки ПрП (1) (φ) УВУ (22) сравнивает φ с величиной допустимого угла прокачки ПрП (1). При нахождении φ в рабочей зоне углов прокачки УВУ (22) осуществляет только регистрацию и передачу информации о текущем положении ПрП (1) в НПК (8).During braking, the angular position of PrP (1) changes in accordance with the expressions:

where γ _T , ψ _T , ϑ _T is the angular position of PrP (1) along the roll, yaw, and pitch channels;
γ _ISM , ψ _ISM , ϑ _ISM - the values of the angular position PrP (1) measured at the current cycle of operation along the roll, yaw, and pitch channels,
ω $\genfrac{}{}{0ex}{}{\text{x}}{\text{ism}}$ , ω $\genfrac{}{}{0ex}{}{\text{y}}{\text{ism}}$ , ω $\genfrac{}{}{0ex}{}{\text{z}}{\text{ism}}$ - the values of the angular velocity PrP (1) measured at the current cycle of operation relative to the associated axes OX, OY, OZ,
ε _x , ε _y , ε _z are accelerations of PrP (1) created by gas jet engines (3) along the channels of roll, yaw and pitch,

- braking time PrP (1) through the channels of roll, yaw and pitch;

Using the calculated values of the angles γ _T and ψ _{T, the} UVU (22) calculates the deviation angle (pumping angle PrP (1)) of the vertical axis PrP (1) φ relative to the vertical axis of the stator of the device in accordance with the expression:
φ = arccos (cosγ _T cosψ _T ).
After calculating the value of the pumping angle PrP (1) (φ), the UVU (22) compares φ with the value of the permissible pumping angle PrP (1). When φ is located in the working zone of the pumping angle of the UVU (22), it only registers and transfers information about the current position of PrP (1) to the NPC (8).

 If the value of the angle φ exceeds the permissible value of the pumping angle, which is possible only in case of failures of the equipment of the system being worked out - its abnormal work or an operator error when setting the work program transmitted from the NPC (8) to the UVU (22), the UVU (22) issues a control command into the switching unit (23), it turns off the control of the angular movement of the PrP (1) by the worked out control system (24) and turns on the control of the technological control system (TSU) (25), i.e. switches the inputs of the hydraulic control valve (3) from the output of the system being worked out (24) to the output of the UVU (22). After switching the control of the angular movement, PrP (1) of the UVU (22) turns on braking and returns the PrP (1) to its initial position according to information from the angular velocity sensor (17) and the measurement system (7) of the technological control system (TSU) (25).

Thus, the proposed invention allows:
- to develop control systems for the angular motion of spacecraft in all modes of their work by introducing control of the angular motion of the spacecraft simulator by the technological control system and introducing the rotation of the Earth simulator with orbital angular velocity;
- to improve the accuracy of mining due to the introduction of rotation (stator) of a ball gas bearing;
- to improve the reliability of the work by continuously determining the ability of executive bodies to keep the spacecraft simulator in the acceptable range of its pumping angles and introduce control of its angular movement by the technological control system when the spacecraft simulator deviations exceed the allowable range.

Sources of information
1.1C10. Modeling complexes for simulating the angular movements of spacecraft and artificial Earth satellites, "Military Aviation and Missile Technology", Issue 11, Moscow, 1972, pp. 37-48.

 2. Stand on a gas spherical bearing for testing satellite control systems for the angular position of the satellite. Rizos I., Arbes J., Raul J. - Sat. "Management in space", Volume 2. M .: Nauka, 1973, pp. 274-278.

Claims (2)

 1. A method for developing systems for controlling the angular motion of spacecraft, including physical modeling of the angular motion of the spacecraft relative to its center of mass by the simulator of the spacecraft, combining the center of mass of the simulator with its center of rotation, creating energy flows for external sensors of the processed system by the simulators, and controlling the angular motion of the simulator the spacecraft by the worked out control system, assessment of the characteristics of the worked out system on the ground a property according to telemetric information from a measurement system of a simulator of a spacecraft, characterized in that they provide rotation of the simulator of the Earth’s energy flows and the base of the simulator of a spacecraft in the horizon plane with orbital angular velocity, control the angular movement of the simulator of the spacecraft until the worked out control system of the technological control system of the simulator is turned on, create the initial parameters of the angular motion of the spacecraft simulator, turn off the control of after the initial conditions are set and the angular motion of the simulator is worked out by the system, the angle of deviation of the spacecraft simulator from the vertical is calculated, provided that emergency braking of the angular motion of the simulator is turned on during operation of the worked-out control system and when the calculated angle exceeds the deviation of the simulator from the vertical permissible values turn off the control of the angular movement of the simulator by the worked out system, in turn on emergency braking of the angular motion of the simulator by the technological control system, returning the simulator of the spacecraft to the zero position.  2. A device for developing systems for controlling the angular motion of spacecraft, comprising a dynamic stand simulating the angular motion of the spacecraft and made in the form of an instrument platform with a pneumatic system and gas jet engines mounted on a spherical gas bearing, a device for combining the center of mass of the instrument platform with its rotation center made in the form of a stepper motor moving balancing weights along the guide rods, the reference system of the angular position of the instrument platforms, a communication system and a device for receiving telemetric information and visual control, made in the form of a terrestrial personal computer, a radio modem of the instrument platform and a radio modem of a terrestrial personal computer, simulators of the energy flows of the Sun, star and Earth, a control computing device and a control device of the system being worked out, characterized in that in it the stator of a spherical gas bearing and the simulator of the Earth’s energy flows are installed on a common rotary platform, relative to the vertical axis and equipped with angle and angular velocity sensors, a rotation drive made in the form of an electric motor with a reducer, moreover, a switching unit, a command device and a rotation drive control unit are introduced, the output connected to the input of the specified motor, the first input connected to the output of the command device, the second input - to the output of the indicated angle sensor and the third input - to the output of the specified angular velocity sensor, as well as the angular velocity sensor installed on the instrument platform output connected with the first input of the control computing device, the second input of which is connected to the output of the reference system of the angular position of the instrument platform, the first output of the controlling computing device is connected to the input of the stepper motor, the second and third outputs are connected to the switching unit, and the fourth is connected to the control device control system, the output of which is connected to the switching unit, the output connected to the inputs of gas jet engines, and the fifth output is connected to the input m radio instrument platform.

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