ALSs with Conventional and Fuzzy Controllers Considering Wind Shear and Gyro Errors

Abstract

The paper presents the automatic control of the aircrafts in the longitudinal plane during the landing process, taking into account the wind shears and sensor errors. Two automatic landing systems (ALS) are designed: the former uses an Instrumental Landing System (ILS), while the latter controls the flight altitude using the state vector. Both systems have a subsystem for the c    = calculated pitch angular acceleration of the aircraft

Application of H 2 /H ∞ and dynamic inversion techniques to aircraft landing control

“…The problem of landing has also been discussed in other papers, different types of ALSs being designed [2,3,5,23]. If we briefly compare our new ALS with the ones based on an Instrumental Landing System or conventional/fuzzy control of flight altitude by using the system's state [3], we remark that from the system transient regime period and overshoot point of view, the ALS based on the H 2 /H ∞ technique and the dynamic inversion works slightly well.…”

“…The dynamics associated to the flare phase (H < H 0 ) has been presented in detail in [2]; the form of the calculated altitude H c …”

“…The dynamics used in this paper belongs to a Boeing 747; the linear model of the aircraft motion, in longitudinal plane, is described by the state equation [2,3]:…”

“…Using the equation [2][3][4]: w = V 0 sin α or w ∼ = V 0 α for small values of the attack angle (sin α ∼ = α), for the aircraft control during the glide slope phase, the following state x ∈ R 8×1 is chosen:…”

“…Furthermore, these ALSs must consistently control an aircraft to an accurate touchdown point and a smooth touchdown to prevent its damage. In the design process, one can use different conventional control laws as: proportional-derivative (PD), proportional-integral (PI), proportional-integral-derivative (PID) for the altitude and descent velocity control [2][3][4][5], PD or PID conventional laws for the pitch angle and pitch rate control, as well as different laws based on the state vector, dynamic inversion concept, with command filters, dynamic compensators, and state observers [1,[6][7][8]. The PID controllers designed for landing are easy to software implement, but these controllers have not satisfying performances and robustness, especially in the cases of flight dynamics affected by disturbances and uncertainties [9]; therefore, to increase the robustness of the landing controllers and the safety of landing, these con-* Corresponding author.…”