Design Of Automatic Flight Control System Research Articles

Preliminary design of redundancy management for LSA -02 automatic flight control system

The final objective of this paper is to make preliminary design concept of redundancy management, which applied for the automatic flight control system in LAPAN Surveillance Aircraft - 02 (LSA-02). The LSA-02 concept use a certified class I aircraft, which has a MTOW < 6000 pounds and use single reciprocating engine. Then, an automatic flight control system (AFCS) is installed in the aircraft, hence added the aircraft capability to fly autonomously. Although the pilot still onboard and act as safety pilot when the AFCS is going wrong, the design of AFCS shall be safe. The AFCS consist of components where some of them are critical and need redundancy. The identifications of component criticality are come from functional hazard analysis (FHA) where the result are list of critical and non-critical component in AFCS during the automated flight. The FHA is a systematic, comprehensive examination of basic aircraft system to identify potential minor, major, hazardous, and catastrophic conditions that may occur due to a malfunction or a function failure of AFCS. The FHA result shows the critical components of AFCS that may lead to the catastrophic conditions in case of failure are the actuator that connected to the elevator, flaperon, rudder and throttle stick, also the flight control computer. Therefore, they need redundancy and the design of redundancy explained in the redundancy management. The redundancy management suggest eight actuators needed for the critical control surface and the throttle stick. This critical actuator is configured as cold standby redundancy. For non-critical control surface (flap and air break), two actuators are needed and configured with no redundancy. The flight control computer is also a critical component and built in dual modular redundancy (DMR) configuration and one independent communication channel for each flight control computer.

Automatic Flight Control System Design of Level Change Mode for a Large Aircraft

The level change mode is an essential part of large civil aircraft automatic flight control systems. In cruise, with the decrease of the plane's weight caused by fuel consumption and the influence of bad weather, such as thunderstorms, the level change mode is required to solve this problem. This work establishes a nonlinear model of large aircraft, takes level changed from 9500m to 10100m as an example to design control laws for the level change mode in cruise. The classical engineering method is used to design longitudinal and lateral control laws synthetically. The flight qualities are considered in the design process. Simulation results indicate the control laws can meet design requirements and have a good anti- gust performance.

Unfalsified Control; Application to automatic flight control system design

Unfalsified Control Theory has been developed to provide a way for avoiding modeling uncertainties in controller design. It belongs to the class of control methods called Adaptive Supervisory Switching Control, which work by introducing in the control scheme a supervisory unit which chooses, from a set of candidate controllers the one most suited for the current plant. Unfalsified Control works by using a switching logic that dispenses with the need for a-priori knowledge of the dynamic model. At discrete moments of time, using the input/output data recorded up to that point, the supervisory calculates for each candidate controller a performance index, and compares it to a given threshold. Controllers surpassing that threshold are removed from the candidate controller set. This process is called falsification. If the controller in the loop is one such falsified controller it is replaced. In this paper we investigate the suitability of this method for aeronautical control applications. We review the theory behind this control scheme and adapt it to the case of controlling a fighter aircraft. We also provide a case study, where we test this control scheme on a simulated fighter aircraft.

`Unfalsified Control; Application to automatic flight control system design

Unfalsified Control Theory has been developed to provide a way for avoiding modeling uncertainties in controller design. It belongs to the class of control methods called Adaptive Supervisory Switching Control, which work by introducing in the control scheme a supervisory unit which chooses, from a set of candidate controllers the one most suited for the current plant. Unfalsified Control works by using a switching logic that dispenses with the need for a-priori knowledge of the dynamic model. At discrete moments of time, using the input/output data recorded up to that point, the supervisory calculates for each candidate controller a performance index, and compares it to a given threshold. Controllers surpassing that threshold are removed from the candidate controller set. This process is called falsification. If the controller in the loop is one such falsified controller it is replaced. In this paper we investigate the suitability of this method for aeronautical control applications. We review the theory behind this control scheme and adapt it to the case of controlling a fighter aircraft. We also provide a case study, where we test this control scheme on a simulated fighter aircraft.