eVTOL Flight Control System: Solutions Using NXP S32G
Introduction to eVTOL Flight Control Systems
Electric Vertical Take-Off and Landing (eVTOL) aircraft, as a key technology in the low-altitude economy, rely on Flight Control Systems (FCS) to implement trajectory planning, attitude control, and flight stabilization. The flight control system ensures eVTOL safety and intelligence through fly-by-wire technology, redundant design, and integrated architecture. NXP is also attempting to adapt the S32G automotive network processor, widely used in automotive electronics, for eVTOL flight control solutions, incorporating features such as high-performance computing, safety certification, network communication, and scalability. The commercialization of Urban Air Mobility (UAM) depends on achieving controlled costs and reliable safety, which are the focus of our discussion.
Technical Architecture and Core Functions of Flight Control Systems
The eVTOL flight control system serves as its core “brain,” responsible for ensuring flight safety and efficiency. Its key function is to implement flight stabilization through advanced control laws, optimizing aircraft dynamic characteristics to enhance maneuverability and stability. Simultaneously, the flight control system precisely manages trajectory and attitude, supporting control of speed, altitude, and heading while enabling advanced functions such as automatic navigation and automatic landing.
The system also incorporates flight envelope protection, limiting critical parameters to prevent operational errors, and can support complex tasks such as terrain following and formation flying. It typically consists of a Primary Flight Control System (PFCS) responsible for stabilization and envelope protection, and an Automatic Flight Control System (AFCS) that implements automated trajectory management through autopilot and flight guidance.
Based on Fly-By-Wire (FBW) technology, the flight control system replaces traditional mechanical connections with electronic signals, significantly improving control precision, reducing system weight, and providing greater flexibility, laying the technical foundation for eVTOL’s high reliability and intelligence.
Safety Design Requirements for eVTOL Flight Control Systems
The design of eVTOL flight control systems must meet extremely stringent safety certification requirements, particularly the airworthiness provision SC-VTOL.2510(a), which states that a single failure must not lead to catastrophic consequences (probability less than 10^-9 per flight hour). This requires designs to follow guidelines such as ARP4754B and DO-254, and to identify potential common mode failures (CMF) through Functional Hazard Analysis (FHA) at the system level.
Traditional methods of reducing CMF impact by procuring components from multiple suppliers introduce inherent diversity to enhance fault tolerance. Achieving high reliability depends on strict design principles, including functional separation and component separation.
Functional separation is reflected in the physical and electrical isolation of high-voltage motor drive power from low-voltage digital processor power (often with redundant power supplies), ensuring that functions are retained even when partial power is lost. At the processor level, even when executing the same algorithms, roles need to be differentiated, and mechanisms such as Digital Simple Voters are used for command arbitration and monitoring between redundant channels to avoid control conflicts.
Component separation requires physical and electrical isolation between internal redundant units (digital, analog, mechanical) to prevent the spread of common cause or cascading failures due to heat, vibration, short circuits, etc.
NXP S32G Applications and Advantages in eVTOL Flight Control Systems
The eVTOL flight control solution developed with NXP’s S32G automotive network processor provides a high-performance, safe, and reliable control platform for the next generation of urban air transportation. S32G is an automotive-grade processor that combines ASIL-D functional safety certification (ISO 26262) with a heterogeneous multi-core architecture, designed for high-performance computing and real-time control. Core features include:
◎ Heterogeneous multi-core architecture: Integrates 4 Arm Cortex-A53 cores and 3 dual-core lockstep Arm Cortex-M7 cores, supporting parallel processing of AI navigation, real-time control, and multi-sensor fusion.
◎ High-speed network communication: Supports CAN FD, TSN Ethernet, and PCIe 3.0, enabling low-latency interaction with propulsion systems, batteries, and ground stations.
◎ Hardware Security Engine (HSE): Ensures data security and reliability of OTA upgrades.
◎ Rich hardware resources: Includes 64MB QSPI flash, 32GB eMMC, 4GB LPDDR4, as well as multiple Ethernet ports (2×10GBASE-T1, 8×1GBASE-T1, 12×100MBASE-T1), 17×FlexCAN, etc., meeting complex flight control requirements.
◎ Compact design: Uses “S32G SOM + mainboard” architecture, optimizing space and power consumption, suitable for eVTOL lightweight requirements.
Advanced Capabilities of S32G in Flight Control Applications
The S32G high-performance, automotive-grade processor serves as the core computing platform, providing aviation-grade high-performance computing capabilities and critical safety certifications. The S32G processor employs an advanced heterogeneous multi-core architecture, integrating high-performance Arm Cortex-A application processor cores with dual-core lockstep Arm Cortex-M real-time cores for real-time control. The advantage of this architecture is the ability to process multiple complex tasks required by eVTOL flight control systems in parallel:
◎ Cortex-A cores can be responsible for running complex AI navigation algorithms, processing multi-sensor fusion data (such as information from LiDAR and vision systems), and performing path planning and decision-making;
◎ While Cortex-M cores focus on precise millisecond-level real-time control of the aircraft’s control surfaces and motors, ensuring flight stability and response speed.
Crucially, the S32G processor complies with the stringent ISO 26262 ASIL-D functional safety standard, the highest level of functional safety in the automotive industry, with design concepts highly compatible with aviation safety requirements. Combined with aviation-grade redundant design in the solution, it enables highly fault-tolerant operation that meets airworthiness certification requirements, maintaining critical system functions even when partial hardware failures occur, greatly enhancing flight safety.
Integrated System Architecture and Implementation
S32G integrates high-speed network communication interfaces, including CAN FD and TSN (Time-Sensitive Networking) standard Ethernet, ensuring low-latency, high-bandwidth data interaction between the flight control system and other critical subsystems (such as propulsion systems, battery management systems) and ground stations. The built-in Hardware Security Engine (HSE) provides powerful hardware-level security protection for data transmission and increasingly important over-the-air software updates (OTA), defending against potential network threats.
The solution supports multiple real-time operating systems such as QNX and AutoSAR, and accelerates the development, integration, and certification process of avionics systems through NXP’s comprehensive development toolchain. Avnet uses a modular “S32G SOM (System On Module) + mainboard” architecture, which is not only compact and reliable but also has good scalability, allowing the solution to flexibly adapt to eVTOL platforms of different sizes and configurations, providing a powerful foundation for next-generation urban air transportation and autonomous flight applications.
This is a highly integrated compact solution, whose “S32G SOM + mainboard” architecture provides eVTOL developers with an optimized computing platform, particularly suitable for domain control and central computing applications requiring high-performance processing, strict functional safety, and information security. The combination of 4 Arm Cortex-A53 cores and 3 dual-core lockstep Arm Cortex-M7 cores within the processor provides ample computing resources and rich input/output interfaces (including various types of Ethernet, FlexCAN, LIN, FlexRay, PCIe, etc.), sufficient to handle complex flight control algorithms, multi-sensor data processing, network communication management, FOTA updates, and security key management tasks.
Rich hardware resources, such as large-capacity QSPI Flash, eMMC, SDRAM, etc., provide assurance for system software and flight data storage. The VR5510 power management chip’s ASIL D certification further enhances the functional safety level of the entire system. By adopting such a pre-certified, feature-rich, and highly integrated platform, eVTOL manufacturers can significantly shorten development cycles and reduce the complexity and certification risks of system integration. A powerful, safe, and reliable flight control system is a prerequisite for achieving advanced functions such as autonomous flight, formation flying, precise navigation, and landing.
The image above illustrates the eVTOL aircraft with its integrated flight control system architecture utilizing NXP S32G processors, highlighting the heterogeneous computing cores and safety-critical systems that enable reliable autonomous flight operations.
