New Approach to Airborne Software verification Using Real-Time Emulator of Integrated Navigation System

摘要

The current practice of navigation system (NS) software evaluation envisages the testing of the integral unit. With such an approach it's rather difficult to isolate the causes of faults and errors. This paper presents the new approach to the software evaluation despite of the airborne computer type. Perm Scientific-Industrial Instrument Making Company (PNPPK) in co-operation with Perm State Technical University has made an emulation system for the development, debugging and validation of the software for navigation systems. This emulator was used in the development of the Strapdown Attitude Head Reference System (AHRS). Airborne computer of AHRS has a DSP processor. The proposed emulator is practically the only means for this type of a computer with the help of which system algorithms for different modes of the object motion are validated in real time. Within the frames of this project the investigation of the possibility of creation of a universal interface capable to operate with all airborne computers used in navigation systems produced by PNPPK was carried out. The emulator hardware includes: -Personal computer; -Target airborne computer; -Airborne computer/personal computer interface device; -Simulator of navigation system interfaces; -Switching devices; The emulator software contains: -Module that implements computational and functional algorithms of - navigation system operation; -Module that sets the mode of object motion and positioning; -Module that generates sensor errors in accordance with preset models; -Module that simulates reading of navigation system sensors; -Module that displays test results; -Interface card drivers. The paper describes a method of the airborne software verification. Navigation parameters of an object and its positing are preset by the simulation program, it also generates reading of navigation system sensors. Based on the generated values the airborne computer calculates the navigation system outputs. Preset navigation and positioning parameters are compared with those received from the airborne computer. Results of comparison are used for the comprehensive analysis of the airborne computer software and hardware operation. This approach can be used in the development of a reliable airborne software.