Rocket System Research Articles

Optimization pitch angle controller of rocket system using improved differential evolution algorithm

Pitch angle of rocket system is the important parts of the rocket. This part corresponds to the movement of the rocket system. Rocket system is fell into multi-input and multi-output (MIMO) system. The most challenge factor in MIMO system is designing the controller, if the design is not appropriate, it may lead to the unstable condition. Hence, appropriate and robust control design is inevitable. This paper introduces PID controller as pitch angle control of rocket system. Furthermore, PID controller parameter is optimized using improved differential evolution algorithm (IDEA). To analyze the performance of rocket system, time domain simulation is implemented. From the simulation result, it is found by using PID controller based on IDEA, the performance of pitch angle of rocket system is enhanced.

A Concept for Striking Range Improvement of the GROM/PIORUN Man-Portable Air-Defence System

This paper presents a concept for striking distance performance improvement of the GROM/PIORUN Man-Portable Air-Defence System rocket missiles by increasing the rated diameter of the rocket missile propulsion system and its fuel charge weight. A mathematical and physical model of the GROM rocket missile was designed and its enhanced propulsion system was simulated in a computer environment. The computer simulation results were displayed on plot charts.

A New Problem with the Twin Paradox

This paper discusses the “triplet thought experiment” in which accelerated motion is eliminated from the famous twin paradox thought experiment of the special theory of relativity (STR). The author considers the coordinate systems of an inertial frame M and rocket A moving at constant speed relative to each other. First, an observer in inertial frame M performs the triplet thought experiment, and it is confirmed that the delay in time which elapses in the moving system agrees with the predictions of the STR. However, the delay in time predicted by the STR is observed even in the case when an observer A in rocket A carries out the triplet thought experiment. Before starting movement at constant velocity, rocket A experiences accelerated motion. The coordinate system of rocket A cannot be regarded physically as a stationary system. Even so, observer A observes the delay predicted by the STR. If the previous, traditional interpretation is assumed to be correct, observer A will never observe a delay in time agreeing with the predictions of the STR. To avoid paradox, the previously proposed traditional interpretation must be revised.

The duration of non-stationary transitional periods in vacuum systems for mass spectrometric inspection of the leaktightness of large objects in rocket and space systems

The results of analytical investigation of the processes of the non-stationary flow of reference gases in long vacuum sections of equipment for mass spectrometric inspection of the leaktightness of large objects in rocket and space technology (RST) (liquid rocket engines and space systems) are presented. Relationships are derived for evaluating the duration of periods of non-stationary flow of helium in vacuum inspection systems, including long vacuum lines. The experimental results can be used to solve the problems of designing the vacuum system of mass spectrometric inspection of the leaktightness of large objects in RST.

1st International Seminar on Non-Ideal Compressible-Fluid Dynamics for Propulsion & Power

1st International Seminar on Non-Ideal Compressible-Fluid Dynamics for Propulsion & Power

Robust fault reconstruction based on sliding mode observer for a class of uncertain time-varying delay systems: a rocket motor system application

In this paper, we present an extended sliding mode observer (SMO) design method for robust actuator fault reconstruction for a class of linear uncertain delayed systems. The uncertainty considered is matched and bounded. In meantime, the time-varying delay is unknown, bounded and affects simultaneously the input and the state of the system. Using the H1 concept and applying the equivalent output error injection idea from previous works in fault detection and isolation (FDI) scheme, the estimate actuator fault signal is designed with the proposed observer by minimising the uncertainty and the time-varying delay effects. Therefore, this problem is solved via a bounded real lemma (BRL) and the linear matrix inequalities (LMIs) optimisation. A rocket motor system is included to illustrate the efficiency of the proposed method. Even, in the presence of the uncertainty and the time-varying delay, the results of the simulation demonstrate that the proposed schemes can successfully estimate the system states and reconstruct the unknown actuator fault.

Robust fault reconstruction based on sliding mode observer for a class of uncertain time-varying delay systems: a rocket motor system application

Robust fault reconstruction based on sliding mode observer for a class of uncertain time-varying delay systems: a rocket motor system application

Robust optimal stabilization of balance systems with parametric variations

This paper proposes a method of robust optimal stabilization for balance systems such as rocket and missile systems, Segway human transportation systems, and inverted pendulum systems. Constant-gain controllers such as linear-quadratic regulators may not guarantee stability let alone optimality for balance systems affected by parametric variations. The robust stability and robust performance achieved through the proposed variable-gain controller are better than those of the linear-quadratic regulator. The proposed controller consists of two components, one of which is designed offline for nominal values of parametric variations and one of which is updated online for off-nominal values of parametric variations. A salient feature of the proposed method is a linear transformation that converts the vector control input of balance systems into scalar control input for application of the proposed method. A fourth-order linearized model of an inverted pendulum system is simulated to show the efficacy of the proposed method.

Global atmospheric response to emissions from a proposed reusable space launch system

AbstractModern reusable launch vehicle technology may allow high flight rate space transportation at low cost. Emissions associated with a hydrogen fueled reusable rocket system are modeled based on the launch requirements of developing a space‐based solar power system that generates present‐day global electric energy demand. Flight rates from 104 to 106 per year are simulated and sustained to a quasisteady state. For the assumed rocket engine, H2O and NOX are the primary emission products; this also includes NOX produced during reentry heating. For a base case of 105 flights per year, global stratospheric and mesospheric water vapor increase by approximately 10 and 100%, respectively. As a result, high‐latitude cloudiness increases in the lower stratosphere and near the mesopause by as much as 20%. Increased water vapor also results in global effective radiative forcing of about 0.03 W/m2. NOX produced during reentry exceeds meteoritic production by more than an order of magnitude, and along with in situ stratospheric emissions, results in a 0.5% loss of the globally averaged ozone column, with column losses in the polar regions exceeding 2%.

THE CAPABILITIES OF OPEN SOURCE CFD CODE FOR MODELING THE STAND TANK FILLING PROCESS WITH LIQUID HYDROGEN

The paper analyzes the functioning and launching of the cryogenic propulsion upper stages and the stages of rocket-space systems, which are largely determined by heat and mass exchange processes in the elements of supply systems. This is due to the fact that in ground conditions, there are no possibilities of flight conditions simulation during cooling of feed lines and starting the engine. Therefore, the simulation of the flow of cryogenic components with respect to heat and mass exchange processes in supply systems of the units and the test stand is important. The paper gives data that booster pump aggregates of oxidant and fuel, as a rule, are located in the corresponding fuel tanks. This makes it possible to significantly reduce the costs of the component for carrying out the operations of cooling and filling fuel lines and the tank, and to optimize the process of starting the engine when it is switched on repeatedly. It is also noted that in complex ground tests of upper stages there are usually no possibilities to simulate flight conditions during launching operations in complex ground tests of upper stages, therefore the use of physical and mathematical models for the calculation of nonstationary multiphase processes with intensive phase transformations makes it possible to determine the characteristics and to forecast the parameters of supply systems. The following tasks have been accomplished: the development of open source code based on CFD program OpenFoam for simulation of cryogenic flows in conjunction with heat exchange processes with the wall of the tank; the verification of open source code on a simple two-dimensional model of the tank for determination the main mechanisms that arise in the process of cooling and filling the stand tank; the implementation of open source code for simulation the initial stage of the refilling of the stand fuel tank taking into account the evaporation of the cryogenic liquid and heat exchange with the walls. The paper shows that the processes of flow and evaporation can be modeled in the framework of models with a free surface flow. The results of calculations of basic parameters of two-phase flows in the process of cooling the liquid hydrogen fuel tank are presented. The results of the study are expected to be used in the methodology for estimating the parameters of two-phase flows during testing of the advanced space rocket systems.

정성적 및 준-정량적 신뢰성 분석 기법을 이용한 하이브리드 로켓 설계

본 연구에서는 대표적 정성적 신뢰성 분석 기법인 FMEA(고장모드 및 영향 분석)와 준-정량적 분석 방법인 치명도 분석을 이용하여 소형 하이브리드 로켓 설계를 수행하였다. 설계 중인 하이브리드 로켓을 총 31개의 부품으로 나누고 각 부품에서 발생할 수 있는 총 72개의 고장모드를 고려하여 FMEA를 수행하였으며 고장모드의 원인과 영향을 분석하였다. 또한 고장모드들의 정성적인 심각도 평가를 수행하고, 고장모드의 고장률 데이터를 이용하여 치명도 분석을 추가적으로 수행하였다. 분석 결과 설계 시 중점적으로 고려해야 할 고장모드를 파악하였으며 하이브리드 로켓의 신뢰도를 높이기 위해 고장모드들의 설계 및 재질 변경 등의 개선 조치를 설계에 반영하였다.

System Design of Model Rocket Launcher Multi-pose Detection Based on Kinetis K60

In this paper, a model rocket attitude detection system based on K60 was promoted by choosing triaxlal accelerometers and pressure sensors. It mainly includes the detection device, controller, display device, voice alarm module, etc. It can not only implement electronic launch platform, but also accurately obtain model rocket launch specific posture parameters, including the level angle of the launch platform and model rocket's center of gravity position. Besides, it can clear indicators of the rocket launch through a serial port graphical LCD display, and realize the Bluetooth module and dial the code switch to communicate using wireless data transceiver module short adjusting posture. Thus it is easier for man-machine interactive operation. If the test result is beyond the scope of booking reference angle, alarm module will automatically send alarm signal to remind operator manual adjustment, until the rocket launch properly.

СИСТЕМА ПОКАЗАТЕЛЕЙ КАЧЕСТВА МОДЕЛЕЙ ТЕХНОЛОГИЧЕСКИХ ПРОЦЕССОВ ФУНКЦИОНИРОВАНИЯ РАКЕТНО-КОСМИЧЕСКОЙ ТЕХНИКИ

СИСТЕМА ПОКАЗАТЕЛЕЙ КАЧЕСТВА МОДЕЛЕЙ ТЕХНОЛОГИЧЕСКИХ ПРОЦЕССОВ ФУНКЦИОНИРОВАНИЯ РАКЕТНО-КОСМИЧЕСКОЙ ТЕХНИКИ

Approximate Solution to the Angular Speeds of a Nearly-Symmetric Mass-Varying Cylindrical Body

This paper examines the rotational motion of a nearly axisymmetric rocket type system with uniform burn of its propellant. The asymmetry comes from a slight difference in the transverse principal moments of inertia of the system, which then results in a set of nonlinear equations of motion even when no external torque is applied to the system. It is often difficult, or even impossible, to generate analytic solutions for such equations; closed form solutions are even more difficult to obtain. In this paper, a perturbation-based approach is employed to linearize the equations of motion and generate analytic solutions. The solutions for the variables of transverse motion are analytic and a closed-form solution to the spin rate is suggested. The solutions are presented in a compact form that permits rapid computation. The approximate solutions are then applied to the torque-free motion of a typical solid rocket system and the results are found to agree with those obtained from the numerical solution of the full non-linear equations of motion of the mass varying system.

Distributed parallel computing of the recursive eigenvalue search in the context of transfer matrix method for multibody systems

The modeling and solving a transcendental eigenvalue problem are important issues in the transfer matrix method for linear multibody systems. Based on the recursive eigenvalue search algorithm for transfer matrix method for linear multibody system, the distributed parallel approach for assembling overall transfer matrix and searching eigenvalues is proposed. This is achieved based on Message Parallel Interface. The influence of the CPU core number as well as the distributed network environment on the final computational time is analyzed through numerical examples of both a non-uniform beam and a multiple launch rocket system. The results indicate that the computational time is significantly reduced by the proposed parallel computing method, so that the computational efficiency on optimization and design of complex multibody systems can be improved.

ACCURACY AND STABILITY FACTOR OF A ROCKET ROTATION STABILIZATION SYSTEM

Methodology of receipt of the exactness indexes estimations by equalization of a disturbing acceleration is worked out with the use of the linear model of a cosmic rocket rotation stationary in region of the determined trajectory point with taking in account of an actuating device inertia. In terms of quantity they are determined by two vectors of errors the coordinates of that are expressed by simple analytical dependences on coefficients of the motion equations and the law of control. The purpose of the research is to establish a connection between the coordinates of vectors of errors and the system’s stability factor on the plane of roots of characteristic polynomial, that will give a possibility of grounded choice of coefficients of a control law while the initial stage of the control system project development. For the first time, taking in account the cosmic rocket specificity, methodology for establishing of connection between coordinates of error vectors by linear disturbing acceleration, control law coefficients, which include four coordinates of the state vector, and stability factor of stabilizing system of the rotation motion on the plane of a characteristic polynomial roots was developed. We determined three independent coordinates of error vectors, which allows variation coefficient of a control law at the angular velocity of a rocket or a steering body on the basis of the criterion of the largest stability factor without changing the parameters of accuracy. The results of the work can be used by the technical decision-making while designing the rocket control system of rotational motion.

A Study on Friction Noise Reduction of Elevation Clutch in the Multiple Launcher Rocket System

A Study on Friction Noise Reduction of Elevation Clutch in the Multiple Launcher Rocket System

An autonomous receiver/digital signal processor applied to ground‐based and rocket‐borne wave experiments

AbstractThe programmable combined receiver/digital signal processor platform presented in this article is designed for digital downsampling and processing of general waveform inputs with a 66 MHz initial sampling rate and multi‐input synchronized sampling. Systems based on this platform are capable of fully autonomous low‐power operation, can be programmed to preprocess and filter the data for preselection and reduction, and may output to a diverse array of transmission or telemetry media. We describe three versions of this system, one for deployment on sounding rockets and two for ground‐based applications. The rocket system was flown on the Correlation of High‐Frequency and Auroral Roar Measurements (CHARM)‐II mission launched from Poker Flat Research Range, Alaska, in 2010. It measured auroral “roar” signals at 2.60 MHz. The ground‐based systems have been deployed at Sondrestrom, Greenland, and South Pole Station, Antarctica. The Greenland system synchronously samples signals from three spaced antennas providing direction finding of 0–5 MHz waves. It has successfully measured auroral signals and man‐made broadcast signals. The South Pole system synchronously samples signals from two crossed antennas, providing polarization information. It has successfully measured the polarization of auroral kilometric radiation‐like signals as well as auroral hiss. Further systems are in development for future rocket missions and for installation in Antarctic Automatic Geophysical Observatories.

연속발사 충격에 강인한 SDINS 신속 초기정렬기법 설계

연속발사 충격에 강인한 SDINS 신속 초기정렬기법 설계

Dynamics design for multiple launch rocket system using transfer matrix method for multibody system

Dynamics design for complex mechanical systems has become an important research field and development direction at present, capturing attentions of an increasing number of engineers and scientists worldwide. Based on many advantages of the transfer matrix method for multibody system in studying multibody system dynamics, a design problem of a multiple launch rocket system is solved in this paper. Particular attention is addressed to model actions of the exhaust flow on the multiple rocket launcher, which are associated with firing order and firing intervals of rockets. Combined with a genetic algorithm, firing order and firing intervals are optimized to achieve optimum impact point dispersion reduction. The results of numerical simulation and verification tests show good agreement, while the dispersion characteristics of rockets have been improved in a low-cost way.