Flight control clearance of the Cessna Citation X using evolutionary algorithms

Abstract

In this paper, an Aircraft Research Flight Simulator equipped with Flight Dynamics Level D (highest level) was used to collect flight test data and develop new controller methodologies. The changes in the aircraft's mass and center of gravity position are affected by the fuel burn, leading to uncertainties in the aircraft dynamics. A robust controller was designed and optimized using the H 1 method and two different metaheuristic algorithms; in order to ensure acceptable flying qualities within the specified flight envelope despite the presence of uncertainties. The H 1 weighting functions were optimized by using both the genetic algorithm, and the differential evolution algorithm. The differential evolution algorithm revealed high efficiency and gave excellent results in a short time with respect to the genetic algorithm. Good dynamic characteristics for the longitudinal and lateral stability control augmentation systems with a good level of flying qualities were achieved. The optimal controller was used on the Cessna Citation X aircraft linear model for several flight conditions that covered the whole aircraft's flight envelope. The novelty of the new objective function used in this research is that it combined both time-domain performance criteria and frequency-domain robustness criterion, which led to good level aircraft flying qualities specifications. The use of this new objective function helps to reduce considerably the calculation time of both algorithms, and avoided the use of other computationally more complicated methods. The same fitness function was used in both evolutionary algorithms (differential evolution and genetic algorithm), then their results for the validation of the linear model in the flight points were compared. Finally, robustness analysis was performed to the nonlinear model by varying mass and gravity center position. New tools were developed to validate the results obtained for both linear and nonlinear aircraft models. It was concluded that very good performance of the business Cessna Citation X aircraft was achieved in this research.

Cessna Citation X Business Aircraft Eigenvalue Stability – Part2: Flight Envelope Analysis

“…In this paper, 5 th order discretization was applied. Future work will evaluate the eigenvalue stability of the Cessna Citation X longitudinal closed loop aircraft model by using H-infinity, and optimal controllers developed during earlier researches [8], [34]- [36] to show if the interaction of the flight controller with the Cessna Citation X would induce any instability.…”

Review and Comparison of Clearance Control Strategies

“…Clearance exists widely between the driving and driven parts, which are not directly connected in mechanical transmission. The existence of clearance nonlinearity causes phase lag, input saturation, limited cycle oscillation, and other phenomena [18], which significantly reduce the stability of the system and limit the static and dynamic control performance. When mechanical resonance is induced by the limited stiffness of the transmission, the existence of clearance nonlinearity further aggravates mechanical resonance, which has three manifestations in the servo system: axial, lateral, and torque [19].…”

Automatic Control of Aircraft Landing by Using the H2/H∞ Control Technique

“…Other structures of ALSs use optimal controllers consisting of state observers [4]. Also, the use of optimal control laws (H 2 , H ∞ , H 2 /H ∞ ) together with full-or reduced-order observers, provide good results [5,6]. For a safety landing, the required information is obtained by means of gyro transducers, accelerometers, or radio-technical transducers whether or not the landing control architecture includes an observer [7].…”