Sliding mode controller based aircraft automatic landing for alternate profiles

In the present paper, different autonomous landing profiles are formulated and simulated. Generic landing is modelled first, wherein, approach and acquired runway heading is considered as same. The second-landing profile involves altitude hold when runway is not clear to land the aircraft. Expedited landing is the third profile modelled with a glide slope-maintained descent to reduce the ground distance required pre-touchdown. In either of the landing profiles, flare is kept the same. The merits and demerits with respect to the practicality of implementation of these profiles are then discussed. Each landing profile has been demonstrated using sliding mode controller (SMC). The asymptotic stability and finite-time proofs of the designed controller are shown using Lyapunov function. F-18 HARV aircraft is considered to test the efficacy of the formulated landing profiles. Expedited landing profile proposed here is a novel approach in which altitude descent gradient is maintained with helical descent path. Additionally, results of this approach show significant improvement in terms of possibility of initiating an unconventional and yet safe as well as economical method much nearer to the runway.