Avionics Design Research Articles

Design of 2-DOF Thrust vector control system for Rockets and Missiles

This paper outlines the development and implementation of a Thrust Vector Control (TVC) system tailored specifically for solid propellant rocket engines, aimed at enhancing the portability of hybrid and liquid propellant rocket systems. The proposed system ensures trajectory stability and rapid response to flight emergencies by effectively addressing external perturbations like wind. Key components are Gyroscopic (GYRO) sensors, good micro-controller, and Servo motors, collectively referred to as Thrust vectoring components, which dynamically adjust thrust direction opposite to the rocket's trajectory to maintain stability. Drawing from an extensive literature review analyzing existing TVC system designs, with a focus on thrust characteristics and engine combustion timings, the design integrates considerations of geometric properties, kinematics, forces, energy requirements, safety, cost, and control methods, aligning with both mechanical and avionic design principles. The anticipated outcome is an advancement in rocket propulsion technology, characterized by improved angular speed control, trajectory linearity, and rapid response capabilities.

Time-triggered scheduling of mixed-critical flows at end-system in asynchronous AFDX avionic network

Avionics Full-DupleX (AFDX) is a switched Ethernet-based network used in modern commercial airplanes for the transmission of command and control avionics flows. These critical flows require deterministic guarantees leading to a lightly loaded network. Aircraft manufacturers envision to carry additional non avionics flows (i.e. video, audio, service) to take advantage of the spare bandwidth. However, it is then compulsory to preserve the real-time guarantees of avionics flows in terms of bounded jitter at the transmitter output and of bounded end-to-end latency. Depending on the type of additional traffic, Quality of Service (QoS) end-to-end guarantees may be offered to the additional flows of lower criticality in terms of reduced delay or bounded jitter for instance. These guarantees can be ensured by scheduling policies at transmitter and switch level. However, an important safety-related constraint is the asynchronous design of avionics distributed systems that prohibits the use of a network-wide synchronization of end systems and switches. Thus, time-triggered networking such as emerging Time-Triggered Ethernet (TTEthernet) or Time-Sensitive Networking (TSN) cannot be leveraged. This paper underlines the benefits of only scheduling flows at the transmitter, which is compatible with the asynchronous safety constraint of avionics systems. We show that it is possible to build a table schedule that carries both critical avionics flows and additional video flows that meet their timing and bandwidth allocation constraints. Therefore, we design scheduling strategies for efficient distribution of flows in the table scheduling whose performance is compared to the optimal schedule minimizing the emission lag of additional flows. Proposed heuristics are constructed such as to favor the network responsiveness for avionics flows thanks to slot over-provisioning. Extensive results on an A350 AFDX industrial configuration show that for a transmitter load of up to 70% of the available bandwidth, the uniform allocation heuristic provides a performance close to optimal in terms of minimum emission lag for additional flows, so offering a practical configuration heuristic to industry.

Electronics Design and Testing of the KREPE Atmospheric Entry Capsule Avionics

Electronics Design and Testing of the KREPE Atmospheric Entry Capsule Avionics

Modeling and optimal design of liquid cooling system of electronic module

Formulation of the problem. Optimal design of avionics (avionics) structures is impossible without the development of new complex methods for modeling thermal processes in their designs and verification based on the results of a full-scale experiment, as well as the creation of methods for the justified use of existing and creation of new mathematical algorithms for optimization procedures. When designing modern RES, it is important to provide a temperature regime for the functioning of power elements of the equipment, in our case, we will consider an electronic module. To ensure normal thermal conditions, cooling systems are used, most often heat sinks (radiator) are used, but in some cases it is not possible to install it. To solve this problem, it is proposed to develop a liquid and air cooling system for the electronic module using an expanded set of elements of cooling systems, including a submersible cooling system. Purpose. Develop a comprehensive methodology for modeling and optimal design of a liquid cooling system for an electronic module, the reliability of which is confirmed by the results of analytical calculations and experimental data. Results. On the basis of the developed 3D model of the electronic module, the procedures for multivariate analysis of the laboratory stand unit were implemented using modern computer-aided design tools. A mathematical formulation was formed and procedures for optimizing the thermal regime were performed: modeling and optimization of the coolant; block topology optimization; optimization by body material and coolant type. Graphs and tables of simulation results are presented, on the basis of which it is possible to draw conclusions about the influence of a particular parameter on the distribution of heat fluxes. All the difficulties that the authors encountered in the course of design optimization in the modeling environment are described in detail, as well as ways to solve them. Practical significance. The results obtained make it possible to apply the proposed method for numerical simulation of thermal processes in REM designs, verification based on the results of a full-scale experiment, as well as the creation of methods for the justified application of existing and the development of new mathematical algorithms for optimization procedures.

ОРГАНИЗАЦИЯ ПЕРЕДАЧИ СИГНАЛЬНЫХ СООБЩЕНИЙ В ВЫЧИСЛИТЕЛЬНЫХ СЕТЯХ ЛЕТАТЕЛЬНОГО АППАРАТА

This article considers the problem of transmitting signal text messages in the onboard computer networks of an aircraft. The article provides a brief overview of promising areas in the design of modern avionics, such as integrated modular avionics and Avionics Full Duplex Ethernet. The text of the article provides a protocol that allows you to generate the text of the signal zone on the multifunctional indicator in the cockpit, as well as to transmit the encoded text using the Arinc 664 (AFDX) protocol. The use of this protocol makes it possible to transmit to the multifunctional indicator in the cockpit the zone of signal messages completely formed in the computing unit. The advantage of this approach is the absence of information fragmentation, and therefore an increase in the frequency of updating information on the indicator screen.

Впровадження DO-254 в процес розробки регуляторів авіадвигунів

The experience of JSC Element, a certified developer and manufacturer of components for aviation equipment, is described in terms of introduction into the product development process, namely, their hardware, the requirements and recommendations of the RTSA DO-254 avionics design assurance manual, similarly earlier implemented RTSA DO-178 for the firmware of said products. The need to introduce these documents developed by the Radio Technical Commission for Aeronautics is due to the desire of domestic developers and manufacturers of aircraft products to integrate into the system of international cooperation in the field of aircraft manufacturing. Brief results of the comparison of the requirements of DO-254 with the requirements of the national standard DSTU 3974–2000 for development in terms of the sequence of stages and the content of work are given. It is shown that, working in accordance with the requirements of the current domestic system of standards, Ukrainian development enterprises (including Element JSC) sufficiently ensure the completeness of the passage of what is called in the implemented Guide DO-254 "life cycle of hardware design" and that the main differences are in the form of documentation of development processes and results. Differences in the concept of planning according to DO-254 and in domestic practice are considered, and analogies are redrawn between plans in the interpretation of DO-254 and documents traditional for the system of domestic standards. In terms of the practical development of the forms and methods for documenting the life cycle processes of the development of onboard equipment, the company JSC "Element" is currently at the initial stage, introducing them for the first in the development of the RDC-450M-117V regulator for the aircraft engine TV3-117VMA-SBM1V. The prospects for the work of the enterprise in this direction are outlined, including the integration of the requirements and recommendations of DO-254 into the system of enterprise standards operating within the framework of a certified quality management system.

Application of prognostic and health management in avionics system

Currently, most aircraft avionics systems are maintained based on reported failures or periodic system replacement. However, the evolution of prognostic and health management (PHM) concepts from mechanical to electronic systems and further to avionics system maintenance has been driven by changes in weapon platform procurement and support requirements. At the same time, with the increasing complexity of avionics design, integrated modular avionics (IMA) came into being. The appearance of IMA design concept marks the gradual transition of avionics system from distributed joint architecture to integrated architecture, which also provides the foundation for PHM technology to be applied to avionics system. This paper reviews the application and research status of predictive and health management system technology in avionics system.

In Memoriam

In Memoriam

Investigation of the automation level of designing the software and hardware structure of the on-board equipment integrated modular avionics

This article shows the complexity of the integrated modular avionics design of on-board equipment of large aircraft. A modern image of the integrated modular avionics of on-board equipment is presented on the basis of existing samples. The design process of the software and hardware of the integrated modular avionics of on-board equipment is analysed. The main tasks of its design are listed. The existing and currently used methods for solving design problems of integrated modular avionics of on-board equipment are described. The level of the design automation process is reviewed. Modern means of computer-aided design are presented and their comparative analysis is carried out. An assessment of the existing level of design automation is given. The design stage with the lowest level of automation is defined. Appropriate conclusions are given.

Language for Unified Verification and Implementation for Distributed Avionics

In designing, verifying, and validating distributed systems today, an engineer is often faced with having to specify a system multiple times. For example, the engineer might specify it once in a model-checker for formal analysis, in an architectural description language for requirements analysis, and in a programming language for testing. By specifying the same system multiple times, there is risk that each specification has different semantics, so that the system tested differs from the one verified, for example. To help solve this problem, we envision an architectural domain-specific language (ADSL), or a unified language from which formal models, executable code, and architectural models can be synthesized. To make our problem tractable, we focus on distributed fault-tolerant systems. We present the Language for Integrated Modeling and Analysis (LIMA), a particular ADSL that we have designed. We describe LIMA and its application to case studies motivated by avionics design.

Analysis on the Grounding Architecture of a Technology Demonstrator Vehicle

ABSTRACT In launch vehicles, Inter system and intra system interfaces exist among various onboard avionic modules. In addition to that, the on-board systems are interfaced to ground checkout system also which is yet another complex system. Isolation of grounds is an important concept in launch vehicle avionics system integration and design. Understanding ground loops and chassis potential is essential for achieving accuracy in measurements and prevention of failure propagation. This paper is a study of the grounding architecture of a Technology Demonstrator Vehicle (TDV). For this purpose, simulation models of on-board and checkout systems have been generated in ORCAD PSPICE. An attempt is made to understand the causes of chassis potential and ground loops. Monitoring networks are analyzed to determine its robustness against ground potential lift. The paper also discusses the grounding-related issues faced during the testing TDV and the methods adopted to overcome them.

FPGA-Centric Design Process for Avionic Simulation and Test

Real-time computing systems are increasingly used in aerospace and avionic industries. In the face of power challenge, performance requirements and demands for higher flexibility, hardware designers are directed toward reconfigurable computing using field programmable gate arrays (FPGAs) that offer high computation rates per watt and adaptability to the application constraints. However, considering reconfigurable computing in the avionic design process leads to several challenges for system developers. Indeed, such technology should be validated along the verification & validation cycle starting with simulation tools, passing through the test benches and finishing with the integration phase. For each step, the FPGA can play an essential role to achieve better performances, more adaptive systems, and cost-effective solutions. In this paper, we present a seamless FPGA-centric design process for avionic equipments. Along this process, we redefine the role of the FPGA circuits to cover the simulation, the test, and the integration steps. First, reconfigurable logics are used in the frame of heterogeneous CPU/FPGA computing in order to obtain high speed-up for real-time avionic simulation. The proposed environment supports dynamic execution model enabling reconfiguration during runtime to avoid the timing constraint violation. Second, the FPGA is used as a key solution to offer versatile test benches and to converge toward unified test and simulation tools. We have designed several commercial input output intellectual property systems with dynamic runtime reconfiguration capabilities, in order to mitigate component obsolescence and to provide increased flexibility and decreased design time. Third, at the integration phase, we use the conventional tools to make profit from reconfigurable technology in embedded avionic applications in order to deliver high computation rates and to adapt their functioning mode to provide reliability, fault tolerance, deterministic timing guarantees, and energy efficiency.

On Qualitative Characteristics of the State Variable Observability in Linear Time-Varying Models of Inertial Navigation Systems

A criterion for the degree of observability of state variables in linear time-varying systems is considered. The qualitative characteristics of the observability of the errors in inertial navigation systems are studied with a change in the aircraft flight altitude, the step of computation and in depending with the type of inertial navigation system, that are characterized by the values of the mean frequency of the random change in the drift of the gyroplatform. The results of simulation of navigation system errors, their degree of observability and estimation by the non-stationary Kalman filter are presented. The problem of determining the achievable accuracy of corrected inertial navigation systems in aircraft is investigated. In the models of the estimation algorithms, different values of the average frequency of the change in drift of the gyroplatform are used. A method for studying the achievable accuracy of corrected navigation systems has been developed, which makes it possible to make an informed decision on the use of the system in the design of the aircraft avionics. Based on the analysis of the state variable observability characteristics of navigation systems, it can be concluded that the accuracy of the estimation is dependent on the variable parameters of the inertial navigation system error model.

A Software Defined Radio Based Airplane Communication Navigation Simulation System

Radio communication and navigation system plays important role in ensuring the safety of civil airplane in flight. Function and performance should be tested before these systems are installed on-board. Conventionally, a set of transmitter and receiver are needed for each system, thus all the equipment occupy a lot of space and are high cost. In this paper, software defined radio technology is applied to design a common hardware communication and navigation ground simulation system, which can host multiple airplane systems with different operating frequency, such as HF, VHF, VOR, ILS, ADF, etc. We use a broadband analog frontend hardware platform, universal software radio peripheral (USRP), to transmit/receive signal of different frequency band. Software is compiled by LabVIEW on computer, which interfaces with USRP through Ethernet, and is responsible for communication and navigation signal processing and system control. An integrated testing system is established to perform functional test and performance verification of the simulation signal, which demonstrate the feasibility of our design. The system is a low-cost and common hardware platform for multiple airplane systems, which provide helpful reference for integrated avionics design.

A study on fabrication of monolithic lightweight composite electronic housing for space application

This paper dealt with an alternative approach of enhancing mass savings in spacecraft avionics design by replacing conventional aluminum alloy housing widely used for various spacecraft avionics with lightweight composite materials. For this purpose, key design requirements were defined to build up composite housing with various functionalities as well as more lightweight characteristics as compared with aluminum alloy housing. The proposed composite housing can be equipped with multiple electronics boards; and it can provide mechanical and electrical interfaces with ease. A fabrication process was also designed to overcome low machinability of CFRP and to minimize the post-treatment such as machining CFRP after curing. In addition, the composite housing with monolithic grid-stiffened frame was fabricated by co-curing through vacuum bag molding method. Its physical properties were also investigated with regard to launch environmental random load, stiffness, thermal conductivity, EMI protection. As a result, it was shown that the composite housing can have good performance comparable to aluminum and provide the mass savings over the aluminum housing having the same dimension. The proposed concept for composite electronic housing will be an effective alternative for lightweight avionics design for space application.

Ethernet-based avionic databus and time-space partition switch design

Avionic databuses fulfill a critical function in the connection and communication of aircraft components and functions such as flight-control, navigation, and monitoring. Ethernet-based avionic databuses have become the mainstream for large aircraft owning to their advantages of full-duplex communication with high bandwidth, low latency, low packet-loss, and low cost. As a new generation aviation network communication standard, avionics full-duplex switched ethernet (AFDX) adopted concepts from the telecom standard, asynchronous transfer mode (ATM). In this technology, the switches are the key devices influencing the overall performance. This paper reviews the avionic databus with emphasis on the switch architecture classifications. Based on a comparison, analysis, and discussion of the different switch architectures, we propose a new avionic switch design based on a time-division switch fabric for high flexibility and scalability. This also merges the design concept of space-partition switch fabric to achieve reliability and predictability. The new switch architecture, called space partitioned shared memory switch (SPSMS), isolates the memory space for each output port. This can reduce the competition for resources and avoid conflicts, decrease the packet forwarding latency through the switch, and reduce the packet loss rate. A simulation of the architecture with optimized network engineering tools (OPNET) confirms the efficiency and significant performance improvement over a classic shared memory switch, in terms of overall packet latency, queuing delay, and queue size.

Understanding single-Event effects in FPGA for Avionic system design

Radiation has proven to cause transient and permanent failures in the semiconductors. When an energetic radiation particle strikes the semiconductor substrate, single-event effects (SEEs) occur. The effects due to SEE are prime areas of research and various experiments have been conducted to study the effects through artificial radiation environment. Radiation effects in avionics systems are gaining more attention since they are used to perform safety critical functions at higher altitudes. In this paper, a comprehensive review on the topic of SEEs on electronics, with special emphasis on its effects on field-programmable gate array (FPGA) is presented. This bibliographical survey covers most of the state-of-the-art technologies used in the prevention and mitigation techniques in FPGA design and also briefs the standards used for managing SEE in avionics. A detailed description of radiation experiments, their test setups and analysis are not included as they are beyond the scope of this review; instead, it gives a design perspective in a radiation environment.

Fully Autonomous Indoor Flight Relying on Only Five Very Low-Cost Range Sensors

Answering what is the bare minimum combination of avionics and vehicle platform design that enables useful autonomous indoor flight without a Global Positioning System (GPS) is required to understand the lower-cost bounds for indoor unmanned aerial system (UAS) technology. The GTLama indoor UAS, capable of autonomously exploring indoor areas in the GPS-denied environment discussed here, was designed in an attempt to answer this question. TheGTLamaweighs around 600 g (1.3 lb), has a diameter of approximately 70 cm (27.6 in.), and costs less than 900 U.S. dollars. Cost and weight savings are realized through development of an innovative indoor guidance, navigation, and control algorithm that uses only five small off-the-shelf low-cost range sensors rather than expensive and sophisticated sensors such as inertial measurement units, scanning laser range sensors, andGPS. The onboard software leverages the inherent stability of the coaxial rotorcraft platform and fuses information from the low-fidelity range sensors to detect and follow walls and other stationary obstacles. The algorithms are designed to encourage maximum exploration of the perimeter of an indoor environment in a reasonable amount of time. The avionics design and the guidance, navigation, and control algorithms used are discussed in detail and validated through flight tests.

Avionics System Simulation of General Aviation Aircraft Based on HLA

Simulation is an effective means for system development. A simulation system of the General aviation (GA) avionics using HLA is designed in this paper. The design and implementation process of federates is also described, taking the Cockpit Display federate as an example. The system has good interoperability, reusability and scalability, which meet the requirements of avionics simulation. The system can be widely used in GA avionics design and the training of pilots.

Scheduling Heterogeneous Flows with Delay-Aware Deduplication for Avionics Applications

An avionics network demands determinism and predictability. This is especially challenging because of the relatively low bandwidth of the on-board network, and the emerging needs of heterogeneous flows due to the proliferation of avionics applications. Redundant transmission and hard real-time scheduling potentially generate many duplicate data, which makes deduplication become more difficult. Many avionic flows further exhibit dynamic workloads which may change abruptly online. Hence, besides the guarantee of transmission delay, modern avionic network design needs to flexibly handle burst flows and efficiently implement data deduplication for bandwidth saving. In order to address these challenges, we propose a DeDuplication-aware Deficit Round Robin (D2DRR)-based scheduling scheme for Avionics Full DupleX (AFDX) networks with the benefits of low complexity and easy implementation. The core idea is to judiciously offer proper “division of labor” between switches and end systems and transform the services for heterogeneous flows to a single representation of utilization, i.e., DRR quantum, which can be flexibly reconfigured. We further leverage Bloom filters to support fast deduplication in order to reduce the load on the AFDX network. D2DRR, hence, offers salient features, elastic scheduling and adept deduplication, to deliver substantial performance improvements. Through both simulations and real implementations, extensive experimental results in an AFDX testbed demonstrate the efficacy and efficiency of our proposed schemes.