Browse Topic: Avionics
To solve a problem that ignition anomaly can’t be detected in time, based on the thermal equilibrium equation, the space heat flow, heater heating, propellant combustion, and thermal radiation to cryogenic space are considered to build an accurate ignition temperature method for the 10 N thruster by using on-orbit true temperature. Further, considering the error of measuring the thermistor, an envelope model for the 10 N thruster ignition temperature is established. Based on the above, a detection method for the 10 N thruster ignition anomaly of on-orbit satellites is proposed. The accuracy of the method is relatively high, and the absolute error is less than 3 degrees Celsius. An anomaly can be quickly detected when the 10N thruster ignition temperature deviates from the normal trend by 3–5 degrees celsius. The method is applied to a DFH-3 satellite, and the maximum difference of 10 N thruster ignition temperature between the theoretical values calculated by the proposed method and the measured values is only 2.72 degrees celsius. It has been proven that the prediction accuracy of the proposed method is high. It plays an important role in discovering the 10N thruster ignition anomaly in time and ensuring the success of satellite orbit or attitude control.
This document presents criteria for flight deck controls and displays for Airborne Collision Avoidance Systems.
This paper presents enhancements to the supervisory controller developed for the National Research Council Canada's Bell 412 autonomous helicopter. Building on a Discrete Event System Specification (DEVS)-based framework, the updated Supervisor introduces two new operational modes-Knobs Mode and Sticks Mode-and a structured approach for managing transitions between them and the existing modes. Drawing inspiration from NASA's Flight Guidance System philosophy, the proposed design emphasizes consistency, scalability, and flexibility in handling multiple autonomy modes. Implementation results demonstrate the effectiveness of the updated architecture in supporting future expansion of autonomous mission operations in complex and dynamic environments.
Developing a comprehensive autonomy solution for the Army's current and future aircraft fleet requires a robust computational and perception capability for decision-making across the entire flight envelope without a pilot. This also requires a flight control system and infrastructure capable of executing autonomous decisions in complex mission environments. Ongoing development of automation and autonomy, utilizing a wide range of perception sensors, has been conducted on platforms such as Sikorsky's S-70 and the Army's UH-60Mx aircraft. This work builds upon previous efforts and leverages ongoing collaborations with industry, the Department of War (DoW), and the Defense Advanced Research Projects Agency (DARPA) to advance autonomous capabilities for both optionally piloted and uncrewed aircraft.
The proliferation of Autonomous Aerial Vehicles (AAVs) necessitates robust solutions for dynamic obstacle avoidance, particularly against non-cooperative intruders whose trajectories are unpredictable. While traditional path-planning algorithms excel in static environments, they struggle with dynamic obstacles due to the inherent difficulty in accurately estimating and registering their real-time depth and velocity into a world model. This paper presents a novel two-stage vision-based framework that leverages deep learning for reactive avoidance of non-cooperative dynamic intruders. Our approach decouples the perception and decision-making processes: an object detection deep neural network first processes monocular camera images to detect and track the 2D pixel coordinates of intruders. This perceptual output is then fed into a deep reinforcement learning agent, which learns a mapping from the intruder's image-space location to a high-level avoidance maneuver. This leads to more efficient learning, as the RL agent focuses solely on the policy without the burden of learning visual features. The advantage of using RL lies in its ability to handle partially observable situations—because reliable depth or full 3-D position information is not always readily available from monocular imagery, the RL agent learns to act based on the observable visual cues. Simulation results confirm that our proposed framework provides an effective solution for vision-based, non-cooperative intruder avoidance.
An automatic clear area takeoff mode is developed and initial flight tested for the Airbus Helicopters 5-bladed H145, certification name BK117 D-3, equipped with the Helionix® avionic system and a 4-axis automatic flight control system. While the automatic rearward and vertical takeoff modes are already certified up to the maximum Cat A weight, the clear area procedure - often providing the highest performance in terms of gross weight - currently requires manual execution. The introduction of an automatic clear area takeoff mode ensures a repeatable, procedure conform clear area takeoff profile while respecting engine limits and reducing overall pilot workload. The paper details the integration of the automatic clear area takeoff mode into the existing automatic flight control system, covering automatic clear area normal, continued, and rejected takeoff procedures. Initial flight test results are presented to demonstrate the consistency of the automated flight path and the ability to provide timely and correct responses to simulated engine failures, thereby enhancing overall operational safety.
The aerospace industry is undergoing a profound transformation driven by emerging aviation technologies, including Advanced Air Mobility (AAM), electric vertical takeoff and landing (eVTOL) aircraft, and highly automated flight control systems. These complex systems often feature tightly coupled flight controls and power plants where traditional methods of compliance — relying heavily on physical ground and flight testing — are becoming increasingly impractical due to the vast number of potential interaction cases. To address this challenge, the SAE G-35 Modeling, Simulation, and Training for Emerging Aviation Technologies and Concepts Committee was formed to develop industry consensus standards. This presentation discusses the landmark release of SAE ARP7094, "Recommended Practice for Using Modeling and Simulation for Certification of Aircraft, Products, and Systems" and its role in establishing a standardized, simulation-based path to certification. The SAE G35C group is responsible for developing standards and procedures for using modeling and simulation as a method of compliance for the certification of AAM aircraft similar to the RCbS project conducted in collaboration between EASA, academia and industry in Europe.
This paper presents the development, optimization, and flight test validation of a Trajectory Control System (TCS)-based flight control system for a tiltwing unmanned aerial vehicle. The TCS is a configuration-independent middle-loop longitudinal controller for vertical takeoff and landing aircraft and is integrated here with explicit model following inner-loop controllers, inverse propulsor models, and a tiltwing-specific control allocation scheme. The resulting flight control system provides coordinated control across vertical flight mode, hybrid flight mode, transition flight mode, and forward flight mode while relying on a concise feedback set and requiring only airspeed from the air data system. The control laws are obtained using a formal constrained optimization framework and transferred directly from simulation to flight without additional on-site retuning. Flight test results from piloted, semi-autonomous, and fully autonomous operations demonstrate stable and predictable behavior throughout the flight envelope, including tight hover performance, simultaneous climb rate and speed tracking in hybrid flight, and successful departure and arrival transitions at multiple speeds. Selected simulation-versus-flight comparisons further show that the nonlinear model captures the dominant trends in the measured response while also identifying specific aerodynamic and transition regime effects that warrant further refinement. Overall, the results demonstrate that the TCS + EMF architecture provides a practical and effective control solution for tiltwing VTOL aircraft.
This work describes the flight control system architecture of the VSDDL VT-03-s Shadow, a cost-effective subscale aircraft used as a testbed for novel flight control schemes. The highlight is the Maneuver Control System comprising the Trajectory Control System, which facilitates Simplified Vehicle Operations, and the Tactical Maneuvering System, which permits more aggressive maneuvering. The control laws permit the selection of both vertical takeoff and landing and conventional takeoff and landing modes of operation. Flight test results shown include transitions between vertical and forward flight modes performed using both Trajectory Control System and Tactical Maneuvering System, limited aerobatic maneuvering performed using the Tactical Maneuvering System, and demonstration of some of the automatic flight functions and capabilities.
Developing high-integrity software is a complex process that involves meeting strict standards across various industries. For instance, in the avionics sector, the DO-178C Design Assurance Level A (DAL-A) sets the highest level of rigor, requiring comprehensive evidence that the software will perform its intended safety functions. Modern avionics systems are made up of hardware and software from different vendors, all integrated by prime contractors. By achieving modularity in these systems, we can reduce interface complexity, manage version control, address supply chain vulnerabilities, and significantly lower recertification costs. To support a high degree of integration and software reuse in avionics systems, certain architectural elements are necessary. These include a certified Real-Time Operating System (RTOS), open standards consortia like FACE® and MOSA, multicore partitioning strategies, deterministic networking, and hypervisor-based virtualization. The role of a certified RTOS, for example, is crucial in ensuring the reliable and efficient operation of safety-critical software components. Open standards consortia, on the other hand, facilitate the development of interoperable systems, while multicore partitioning strategies enable the efficient use of system resources. The use of deterministic networking and hypervisor-based virtualization also plays a key role in enabling the integration of multiple systems and reducing the complexity of system design. By leveraging these technologies, we can create a 'certify once, deploy anywhere' paradigm, which reduces development timelines, lowers lifecycle costs, and positions safety-critical software components for reuse across heterogeneous platforms. This approach not only improves the efficiency of system development but also enhances the reliability and safety of the resulting systems. In essence, the development of high-integrity software for avionics systems requires a comprehensive approach that considers the complex interactions between hardware and software components. By adopting modular architectures and leveraging open standards, certified RTOS, and advanced networking and virtualization technologies, we can create systems that are not only safe and reliable but also efficient and cost-effective. This, in turn, can help reduce the risks associated with system development and deployment, while also improving the overall performance and safety of the resulting systems.
Given the necessity of performing System Certification according to SAE ARP4754, accepted as guideline by aeronautics certification authorities for development of aircrafts and complex systems, the need to define a robust and adaptable system requirements Validation and Verification (V&V) process has become a priority. SAE ARP4754 compliant processes shall be applied for certification of new complex systems, as well as to existing ones. Defining suitable and compliant processes for projects that were already in an advanced development stage when compliance to ARP4754 became mandatory is even more challenging with respect to the application to new projects, as the need of rearranging existing certification documentation naturally arises. This paper illustrates a process compliant with ARP4754 guidelines to achieve the System level requirement V&V. The presented process – based on the Function-Based Systems Engineering (FuSE) – has been applied to the civil certification of the Fly-By-Wire Flight Control System (FCS) of the AW609 tiltrotor by Leonardo Helicopters and has been reviewed by the Federal Aviation Administration (FAA).
When surveying the current landscape of Deterministic Ethernet avionics solutions in the aerospace industry, the three main technologies in the market are ARINC 664 part 7 rate-constrained Ethernet (commonly known by its trademark name "AFDX®"), TTEthernet (which combines ARINC 664 part 7 with Best-Effort Ethernet, while adding a new class of synchronous determinism defined in SAE AS6802 [Time-Triggered Ethernet]), and IEEE 802.1 Time-Sensitive Networking (TSN). No single deterministic Ethernet technology optimally satisfies certification, MOSA, and lifecycle goals across all avionics domains. Instead, successful digital backbones require intentional partitioning of responsibilities across technologies. This paper will seek to identify a number of those considerations and provide guidance on which technologies offer the best fit. After first opening with an explanation of the market forces driving the trends towards these technologies, this paper will delve into a short outline of each of these Ethernet standards. Following that, this paper will compare a variety of characteristics of each of the above Ethernet technologies pertaining to certifiability, MOSA conformance for DoD use cases, and supply chain considerations. Finally, the paper will synthesize those comparisons into a number of recommendations regarding the most appropriate uses for each Ethernet technology.
This paper presents the development flight test campaign of autopilot Upper Modes for T-625 Gökbey helicopter. The primary objective of the test campaign is to evaluate the newly developed Upper Modes in the frequency and time domain across the operational flight envelope. For quantification of performance and stability, various metrics are selected from the literature. Flight tests are designed to extract the metrics from time domain data and tests are conducted. Initial flight tests revealed discrepancies between theoretical design models and actual aircraft dynamics, requiring iterative control law gain optimizations. Furthermore, combined mode engagements required targeted simultaneous tuning of different modes to maintain stability margins in combined engagement. By integrating quantitative data analysis with qualitative pilot feedback, engagement logic and control parameters were successfully refined.
The certification of highly integrated electric Vertical Take-Off and Landing (eVTOL) aircraft requires a rigorous bridge between simulation and flight reality. This paper presents the Joby Disturbance Generator, a high-integrity software framework natively integrated into the aircraft flight control system. The system utilizes a deterministic state machine to inject a library of signals, ranging from standard doublets and chirps to complex waveforms, directly into internal control loops. Applications include frequency sweeps for stability margin extraction and structural mode identification, time-domain inputs for handling qualities assessment, synthetic fault injection for redundancy management verification, and precise loads model validation. The system continuously monitors vehicle health, automatically aborting test points upon detecting genuine failures. For loads validation, it coordinates temporary relaxation of flight envelope protections with precise disturbance injection. This methodology accelerates development by shifting risk from flight execution to software verification, providing deterministic, data-driven evidence for certification. Flight test results demonstrating these capabilities are presented.
This paper presents an initial handling qualities analysis of an Electric Vertical Take-Off and Landing (eVTOL) hexacopter. The analysis uses the Distributed Electric Propulsion Simulation (DEPSim), developed by Penn State University (PSU) and the Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM), developed by Continuum Dynamics, Inc. (CDI). The study focuses on evaluating a generic AAM hexacopter performing Handling Qualities Task Elements (HQTE) as defined by the DOT / FAA. A trajectory controller was developed to enable simulation of prescribed flight paths, allowing automated simulation of four HQTEs: Heliport Approach, Hovering Turn and Hold, Pirouette, Lateral Reposition and Hold. Design modifications incorporating lateral mast tilt and Direct Side Force Control (DSFC) were implemented to enhance yaw control and ride qualities. Piloted simulations were conducted at the PSU rotorcraft flight simulation facility using DEPSim, employing an Attitude Command Attitude Hold (ACAH) architecture with mode switching to Translational Rate Command / Position Hold (TRC / PH) and TRC plus DSFC modes. Two of the four HQTEs were tested in piloted simulations. Though formal ratings were not collected at this time, pilot commands and performance indicated that TRC / PH and TRC plus DSFC modes enhance handling qualities over ACAH mode. The DSFC control law was found to have substantially reduced roll attitude, which could potentially enhance visual cueing, pilot comfort, and pilot-perceived handling qualities.
With the continuous development of avionics systems towards greater integration and modularization, traditional aircraft buses such as ARINC 429 and MIL-STD-1553B are increasingly facing challenges in meeting the demanding requirements of next-generation avionics systems. These traditional buses struggle to provide sufficient bandwidth efficiency, real-time performance, and scalability for modern avionics applications. In response to these limitations, AFDX (Avionics Full-Duplex Switched Ethernet), a deterministic network architecture based on the ARINC 664 standard, has emerged as a critical solution for enabling high-speed data communication in avionics systems. The AFDX architecture offers several advantages, including a dual-redundant network topology, a Virtual Link (VL) isolation mechanism, and well-defined bandwidth allocation strategies, all of which contribute to its robustness and reliability. However, with the increasing complexity of onboard networks and multi-tasking scenarios, the existing AFDX protocol still faces challenges in certain areas. Notably, there are issues related to latency jitter control under extreme network loads, efficiency in redundant link dynamic switching, and the assurance of timely and safe transmission of mixed criticality data. To address these challenges, this paper proposes an enhanced data transmission mechanism that builds upon an improved AFDX architecture. This mechanism introduces the construction of Virtual Links, creating a point-to-point network that provides deterministic Quality of Service (QoS) guarantees. Furthermore, a parallel redundant structure is incorporated to further enhance the reliability and fault tolerance of data transmission, ensuring that critical data is transmitted accurately and efficiently in complex, high-demand environments. This research aims to optimize the overall performance of AFDX systems, supporting the evolving needs of modern avionics networks.
This document establishes re-certification guidelines applicable to fiber optic fabricator technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Production
Modern military aircraft represent some of the most complex electronic environments ever engineered. These platforms integrate advanced avionics, radar systems, data links, and communication networks that must function seamlessly in hostile, high-frequency environments. In these mission-critical contexts, electromagnetic interference (EMI) poses a silent but serious threat that can degrade signal integrity, cause crosstalk between systems, or even lead to mission failure. The combination of increasing data rates, higher frequencies, and more complex electromagnetic environments demands shielding solutions that can deliver superior performance while contributing to overall system weight reduction. This challenge has driven innovation toward advanced materials that maintain electrical effectiveness while dramatically reducing mass.
The multinational EPIIC programme, involving Airbus Defence and Space, is exploring multiple exciting innovations to strengthen Europe's defense capabilities and technological sovereignty. Airbus, Toulouse, France Imagine Tony Stark soaring through the skies in his iconic Iron Man suit, each command answered with a seamless blend of futuristic technology. Now imagine the cockpit of tomorrow's fighter jet.
Advancements in embedded processing, software, new product introductions, partnerships and recent demonstration flights reflect the growth in development of artificial intelligence (AI) and machine learning (ML) for military aircraft avionics systems occurring in the aerospace industry. This article highlights trends across several industry partnerships, demonstration flights and the enabling elements that are providing opportunities to integrate AI and ML into military avionics systems. In a June press release, Helsing, the Munich, Germany-based native software company and Saab, the Swedish defense manufacturer, announced their completion of a series of test flights where Helsing's “Centaur” AI agent controlled the aerial movements of a Gripen E fighter jet. AI agents are growing in popularity across many different industries for a variety of use cases. In a November 2024 blog about the topic, Microsoft described them as taking “the power of generative AI a step further, because instead of just assisting you, agents can work alongside you or even on your behalf. Agents can do a range of things, from responding to questions to more complicated or multistep assignments. What sets them apart from a personal assistant is that they can be tailored to have a particular expertise.”
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