RTOS to fly in new Sikorsky S-92 helicopter

Citation

(2003), "RTOS to fly in new Sikorsky S-92 helicopter", Aircraft Engineering and Aerospace Technology, Vol. 75 No. 1. https://doi.org/10.1108/aeat.2003.12775aab.007

RTOS to fly in new Sikorsky S-92 helicopter

RTOS to fly in new Sikorsky S-92 helicopter

Keywords: Avionics, Rotorcraft, Software

Rockwell Collins has integrated Green Hills Software’s INTEGRITY-178B real-time operating system (RTOS) into the Sikorsky S-92 helicopter’s new highly-integrated avionics package. The company’s INTEGRITY-178B, along with their GSTART Ada run-time environment, is being used in Rockwell Collins’ new Avionics Management and Display System, which incorporates what is thought to be the most advanced avionics technology available today for rotorcraft (Plate 8).

Rockwell Collins successfully completed its first S-92 test flight of the system on 5 October 2001 and has accumulated over 300 h of company flight tests to date. The new S-92 cockpit is designed for outstanding visibility, and is equipped with an avionics package that provides the core of an open architecture avionics suite for processing aircraft system information. Flight data is shown on four Collins multi-function displays, with a fifth display offered as an option.

Plate 8

Green Hills also announced that Rockwell Collins is using its AdaMULTI Integrated Development Environment (IDE) to develop the flight software for the new S-92 cockpit.

The S-92 is Sikorsky’s newest medium-lift helicopter, designed to meet both civil and military requirements. Featuring a passenger capacity of 19-22, the versatile new helicopter will serve a variety of commercial and international utility needs, including passenger, cargo, aeromedical, search and rescue and resource development support.

A Motorola PowerPC running INTEGRITY-178B and the GSTART Ada run-time environment provides the backbone for the Sikorsky helicopter’s new Collins Avionics Management and Display system. The system provides the display and integrated management of primary flight data, presentation and management of navigation information for the S-92. The system also provides flight management data, a digital map, weather radar, terrain information and engine instrument caution and advisory system processing and display. Rockwell Collins will use INTEGRITY-178B and GSTART to achieve DO-178B Level A certification of the Avionics Management and Display system.

INTEGRITY-178B is an ARINC-653 compliant, hard real-time RTOS optimised for safety-critical and mission-critical applications that require the utmost security and fast, predictable response. Utilising hardware memory protection, and an advanced two-level partition scheduler, INTEGRITY-178B is reported to provide complete time, space, and resource partitioning between applications operating on the same hardware platform. This partitioning is said to effectively build a firewall between applications and the kernel, preventing errors in one application from corrupting other applications or the kernel. INTEGRITY-178B also claims to provide protection and guaranteed resource availability in both the time and space domains, thereby enabling applications that have been assigned different DO-178B safety levels to run concurrently on the same processor (i.e. supports “robust partitioning”) as defined in ARINC 653.

INTEGRITY-178B’s ARINC-653 APplication/EXecutive (APEX) interface provides a recognised standard interface between the operating system of an avionics computer resource (ACR) and the application software.

The software also includes an RTOS simulator (ISIM) that enables programmers to develop and test their code on a PC or workstation without the need for target hardware. INTEGRITY178B also features a real-time event analyser (EventAnalyzer) that enables viewing of system and user events in a graphical display.

INTEGRITY-178B is tightly integrated with Green Hills Software’s AdaMULTI 2000 IDE. AdaMULTI features an advanced code coverage tool (GCOVER) that automates structural coverage analysis for application software, including the analysis of DO-178B Table A-7, Objectives 5, 6, and 7 (statement, decision, and MCDC coverage achievement).

sGreen Hill also reports that its software’s INTEGRITY real-time operating system (RTOS) and AdaMULTI Integrated Development Environment (IDE) has been chosen by NLX to upgrade the B-1 Bomber Weapons System Trainer (WST). The WST is used to train aircrews for missions aboard the B-1 Bomber, providing pilots and weapons systems officers with a true-to-life simulation of the B-1’s flight and weapons systems.

The INTEGRITY RTOS, hosting PowerPC 740 application software developed with Green Hills Software’s AdaMULTIS Integrated Development Environment (IDE), is used in the B-I’s flight control system, which performs all the navigation, guidance, display, and weapons system functions. The WST duplicates the B-1 environment, from the design of the cockpit, to the PowerPC/ INTEGRITY-based software used in the B-l’s flight computers.

NLX selected INTEGRITY and AdaMULTI for the WST in order to create a precise simulation environment for the B-1. However, NLX engineers also cited INTEGRITY’s flexible build environment, noting that INTEGRITY reportedly made it easy for them to add special training software to the WST. Unlike the software used in the actual B-1, NLX engineers had to custom-build code that “listens” for messages from the training instructor. This software, known as trainer hooks, allows instructors to stop the simulator mid-flight and give assistance to trainees.

INTEGRITY is described as a secure, fast, deterministic, real-time operating system optimised for embedded applications that place a premium on safety, reliability, real-time performance, and testability. Utilising a processor’s memory management (MMU) facilities, INTEGRITY is said to build a firewall between the kernel and user tasks that prevents errant or malicious code from corrupting other user tasks or the kernel. INTEGRITY also claims to deliver maximum responsiveness and determinism by running with interrupts continuously enabled and guaranteeing access to the CPU and memory for critical tasks.

INTEGRITY is tightly integrated with the AdaMULTI IDE, which, together with Green Hills Software’s family of Ada95 and C/C++/EC++ optimising compilers, automates all aspects of embedded PowerPC software development.

Details available from: Green Hills Software. Tel: +44 (0) 1844 267950; Fax: +44 (0) 1844 267955; E-mail: sales-uk@ghs.com; Web site: www.ghs.com