System Modeling and Controller Design for Lateral and Longitudinal Motion of F-16

Abstract

Classical control laws are still widely used in aviation industry because of their good structural understanding, simplicity, and better tracking control performance. However in recent decades the application of such controllers are getting substantial interest of researchers. This paper addresses controller design method for longitudinal and lateral motion autopilots of F-16. Aircraft complete mathematical model was obtained using Newton-Euler formulism. The non-linear model was linearized around equilibrium points at certain trim conditions to obtain state space model of the system. Comparative analysis of two linear controllers, Proportional-Integral-Derivative (PID) and Linear-Quadratic-Regulator (LQR) is investigated and control algorithm is proposed. Both the control schemes use feedback control laws and a careful selection of tuning parameters for controllers is carried out to track the desired input reference. Effectiveness of both controllers is illustrated with the help Matlab/Simulink figures and results.

Finite-time SDRE control of F16 aircraft dynamics

“…where coefficients 𝑐 𝑙1 , 𝑐 𝑙2 , 𝑐 𝑚1 , 𝑐 𝑛1 , 𝑐 𝑛2 are derived from the density of air flowing in and Mach number, the geometry of the wing structure including its span, the mean aerodynamic chord and wing area. The F16 aircraft properties [1,23] used with certain assumptions and indicated values to be able to perform further calculations in the chapter due to the model (5)-( 6) and ( 26)-( 27) are presented in Table 2. Employing described aircraft model, the SDRE control method is applied to control the flight stabilization problem, considering two values of finite control times: 𝑡 𝑓 = 3 s and 𝑡 𝑓 = 5 s. As mentioned in introduction, the time is very important, because the aircraft should rapidly answer for pilot commands.…”

“…But, the primary purpose of a flight control system is to provide the appropriate interface between a pilot and the aircraft responses. Although stabilization is a requirement of a typical modern FCS (Flight Control Systems), it is stabilization with a pilot in the loop, or flying qualities, that is the design challenge and has caused most problems [1,29,36]. The relationship between pilot action and aircraft reaction should be fast, performed in finite time, eliminating aerodynamics nonlinearities, uncertainties or uncontrollable oscillations resulting from efforts of the pilot to control the aircraft and occur when the pilot of an aircraft inadvertently commands an often increasing series of corrections in opposite directions, known as PIO (Pilot Involved Oscillations) [19,36].…”

“…Figure 1: F16 multirole fighter aircraft [37] Many papers deal with the F16 aircraft dynamics, where finite-time optimal control methods used to flight control systems is still a challenge for many engineers and researchers [1,18,22,23,29,34,35]. Literature provide some interesting works related to finite-time problems.…”

Aircraft pitch control design using LQG controller based on genetic algorithm

“…However, the controllers design is not optimized utilizing optimization algorithms. Ahmed et al [16] presented a classic PID controller and optimal LQR controller to control longitudinal and lateral motion in F-16 airplane system. A complete mathematical modeling of the system using Newton-Euler formulas.…”

Adaptive Control and Estimation of the Condition of a Small Unmanned Aircraft Using a Kalman Filter

“…The second part of closed loop control system is state estimate part, where the sensor data along with the GPS position information is passed to a filter to make an estimate of the current state, which is needed for later use in driving. This closed-loop system can be presented using the block diagram in Figure 3 [15][16][17]. Primary stabilization performed by an inner loop.…”