The Design Of Software For Mathematical-modelled Autopilot

As part of the airborne software, the software of Civil aircraft autopilot must meet airworthiness regulations, it should be in accordance with the development and validation standard of DO178 C. The security and stability of the software is the most important index of the software.The design of software for conventional autopilot have the disadvantages of long cycle,difficult,high risk and high cost,but also requires a tedious verification process of DO178 C.This paper puts forward the design method of mathematical-modeled autopilot, modeling autopilot with mathematical method. Because the expressions of mathematical model have consistency, the automatically generated code based on mathematical model has high security and stability. The design of software for mathematical-modelled autopilot not only has the advantages of short cycle, high efficiency and low cost, but also generates verification documents that in accordance with airborne software DO178 C automatically. It simplifies the tedious process of verification. The main contents are as follows:Firstly, the paper gives the overall design scheme of general aircraft autopilot, then describes the basic components of autopilot and its relation, and defines the basic functions and performance within the autopilot.Secondly, the paper proposes the requirements analysis of autopilot software and also defines the building blocks of autopilot software. These provide the basis for the subsequent preparation of autopilot software. According to the requirements analysis of software, the software is divided into mathematical modeling and manually implement to achieve in two different ways.Thirdly, establish the mathematical model of autopilot by using Matlab/Simulink. According to different functions, the autopilot can be divided into mode choice model and model control law in two parts. Respectively, using Simulink and Stateflow model and control law of model selection on the way. Simulink Coder toolbox can conversion Simulink model to generate standard C code efficiently and stably. This paper using toolbox of mathematical model optimization. And analysis the automatic report generation code detail.In order to verify the design of software for mathematical-modelled autopilot, The MSP430F5438 A chip is used as the processor computer of autopilot flight control and then developed the substrate drivers. The open loop and closed loop verification test is carried out. The desired effect is achieved, it has certain engineering application value.