The Airplane Pitching Angle Without Overshoot Control Algorithm Design And Implementation

In the longitudinal motion control of aircraft, the pitch-angle control is animportant mode control of the flight control, which is often used in climb segment andglide segment. In the control system design, overshoots is an important dynamic timedomain index. In order to ensure flight safety, when design the high accuracy attitudecontrol law, we often hope the attitude response of the closed-loop system has a smallovershooting, even nonovershooting. In particular, for the plane’s take-off and landingsegment, and aerial refueling quest, it has the strict request for overshoots of tackingpitch-angle.The aircraft’s six degrees of freedom equation， by decoupling and smalldisturbance linearization, get a4-th order system of pitch-angle and a double integralsystem of pitch-angle. For the4-th order model, because of the closed-loop systemorder number is higher, by using analytical method analysis without overshootcondition is more complex, so this paper will make use of state space analysis methodto design control algorithm based on state feedback and output feedback respectively;for the double integral model, because of the influence of the loop in integral link,linear PID control can’t achieve nonovershooting tracking, so this paper will make useof switching system theory to design control algorithm based on switching logic. Bothachieve the nonovershooting tracking of pitch-angle.More specifically, the main research results are as follows:1. Establish the aircraft’s pitch-angle model, and put nonovershooting trackingcontrol problem. From the six degrees of freedom equation of the aircraft, bydecoupling and linearization, we get the dynamic4-th order model and the simplifieddouble integral model of pitch-angle. And make the analysis of the shortcomings of theexisting methods.2. For the4-th order model, we design control law algorithms respectively basedon state feedback and output feedback. The former includes error feedback andfeed-forward control, the latter can be seen as the state feedback with a Luenbergerobserver. In theory, analyze the feasibility of realizing the algorithms, and give Matlab simulation results.3. For the double integral system of pitch-angle, we design the control lawalgorithm based on switching logic. The basic idea is that using two different linear PDcontrollers working in stage to overcomes the shortcomings of linear PID control andget an effect of nonlinear control. Simulation results shows it.4. Set up the comprehensive numerical simulation platform, using the F-16fighters of the pitch-angle control model, to the traditional algorithm and the design ofthis paper algorithm simulation and verification and contrast. First, realize the currentengineering method based on internal and external loop in flight control, and give thesimulation results of the pitch-angle control; And then, make the analysis and contrastto control laws algorithm based on state feedback designed in this paper.