Research And Design Of Flight Control System

With the growing world population and rising living standards, recently, the number of cars increases continuously. This results in the entire ground transportation burden. Therefore, it is very important to open up the air road as soon as possible. As one of the air transportations, aerocar has atracted a high degree of attention and extensive researchs from scholars. The flight control system as the core of aerocar has the absolute value of research. This thesis initially completed the hardware and software implementations of the flight control system of aerocar. And for the problem of SINS solver in flight control system producing noncommutativity errors and affecting system accuracy under high dynamic environment, this paper proposed a spiral vector algorithm based on dual quaternion. The proposed algorithm guarantees the real-time performance of the system. Meanwhile, the navigation accuracy can be improved with reducing the complexity of the algorithm. In addition, considering the high demands for the reliability and stability of aerocar on flight control system in the complex environment, we design hot backup system based on three microcontrollers. The two of them are responsible for dual hot backup, and the only one left is responsible for arbitration. The designed system greatly improved the mean free error time(MTBF) of the system. By comparing with the stand-alone system, this designed system enhances the stability and reliability of theflight control system of aerocar.The main work of this thesis is embodied as follows:Firstly, the hardware selection and overall design of aerocar control system are derived according to the functional requirements of the speed control system. Taking into account the performance requirements and design costs, we choose C8051F020 chip as the main control system and choose the appropriate sensor module including ADXL345, L3G4200 D, HMC5883 L and BMP085. We introduce principle about the steering gear and steering gear control version.Secondly, according to the software design requirements of flight control system, the paper completed the overall design of the system software, which including CPU serial communication design, C8051F020 initialization parameter initialization and synchronization of the system design. The most critical part is that we design a dual port RAM so that dual-computer communicates with each other by using the dual port RAM.Furthermore, according to the problems of the amount of heavy and large errors in traditional SINS algorithm, this thesis a spiral vector algorithm based on dual quaternion. Through simulation results and comparative study of traditional velocity update algorithm and dual quaternion velocity update algorithm, we determine the reason for the existence of differences in the accuracy of the two algorithms in principle.And we quantitatively characterize the accuracy of the difference between the two algorithms. The testing results showed that spiral vector algorithm based on dual quaternion has obvious advantages in accuracy under the high dynamics and large motorized motion.Finally, since the flight control system demands higher reliability and stability, this thesis designed a hot backup system based on three single-chips, two of which are responsible for hot backup, and the only one left is in charge of arbitration. From the system reliable analysis and reliability calculations, and comparing with the stand-alone system, we can find that the stability and reliability of the designed system have been greatly improved.