Flight Control Algorithms Research Articles

Control and simulation of an autonomously flying model helicopter

MARVIN is a model-helicopter based flying robot, which is able to operate completely autonomously. It has been designed to fulfill the demands of the International Aerial Robotics Competition (IARC) Millennial Event 1998-2000. To improve the flight behavior, a mathematical model of the flight characteristics has been developed, which is used for simulation. The flight control algorithm is based on a hierarchy of PID controllers. The results of simulation and real flight experiments show similar behavior in many points but also that not all effects are taken into account, yet.

Dynamics of Micro-Air-Vehicle with Flapping Wings

Small (approximately 6 inch long, or hand-held) reconnaissance micro air vehicles (MAVs) will fly inside buildings, and require hover for observation, and agility at low speeds to move in confined spaces. For this flight envelope insect-like flapping wings seem to be an optimal mode of flying. Investigation of the aerodynamics of flapping wing MAVs is very challenging. The problem involves complex unsteady, viscous flow (mainly laminar), with the moving wing generating vortices and interacting with them. At this early stage of research only a preliminary insight into the nature of the little known aerodynamics of MAVs has been obtained. This paper describes computational models for simulation of the controlled motion of a microelectromechanical flying insect – entomopter. The design of software simulation for entomopter flight (SSEF) is presented. In particular, we will estimate the flight control algorithms and performance for a Micromechanical Flying Insect (MFI), a 80–100 mm (wingtip-to-wingtip) device capable of sustained autonomous flight. The SSEF is an end-to-end tool composed of several modular blocks which model the wing aerodynamics and dynamics, the body dynamics, and in the future, the environment perception, control algorithms, the actuators dynamics, and the visual and inertial sensors. We present the current state of the art of its implementation, and preliminary results.

Enhanced space integrated GPS/INS (SIGI)

Safe, reliable, and low cost space-based navigation is being provided with embedded INS/GPS systems such as the space integrated GPS/INS (SIGI). The SIGI is being used for various space vehicle applications such as launch vehicles, orbital vehicles, and re-entry vehicles. This paper describes current space vehicle navigation capabilities. The SIGI is being enhanced to provide additions to these existing capabilities with such items as higher processing and a commercial-off-the-shelf operating system. This will allow hosting of various software applications such as advanced navigation functions, flight control, guidance and vehicle management algorithms. The SIGI can host redundancy management functions by incorporating a cross channel data link card (CCDL) using a high speed firewire bus. The SIGI can then be used as a redundancy management platform which has application to current space vehicle avionics topologies incorporating distributed processing architectures.

State-space multivariable non-linear identification and control of aircraft

In the design of commercial and military aircraft, flying and handling qualities, as well as performance (agility and manoeuvrability, controllability and stability) and safety, have received increased emphasis. The aircraft must exhibit acceptable handling qualities while performing manoeuvres, and different flight management systems have been designed. For advanced aircraft, the assumption that longitudinal and lateral dynamics can be decoupled leads to poor flying and handling characteristics owing to longitudinal-lateral cross-coupling. Aircraft stability severely degraded at low speed, high-angle-of-attack flight and gain-scheduled linear control algorithms cannot provide the desired performance (gain-scheduled control laws are used because they are certifiable). These have resulted in the critical need for significant improvements in flying and handling qualities as well as expansion of the flight envelope at low-speed, high-angle-of-attack flight by using robust non-linear controllers. Military aircraft must be capable of performing a diverse range of operational missions, which include air-to-ground and air-to-air combat. Mission effectiveness relies on flight management systems and control algorithms. Control system effectiveness can be achieved as the designer integrates non-linear flight dynamics and advanced optimization methods to design multivariable control algorithms. In this paper a study is made of non-linear identification and control methods which can be applied to multivariable aircraft using measured variables. By performing non-linear modelling, it is shown that the methods reported lead to very encouraging results.

Mission Planning and Flight Control: Meeting the Challenge with Intelligent Techniques

This paper presents a hybrid hardware/software platform that supports flight control and mission planning algorithms for an autonomous helicopter. The emphasis is on the use of intelligent fuzzy logic based techniques and an object-modeling approach to account for unmodeled dynamics to address uncertainty issues and to provide a flexible platform for development purposes and an operator interface. Fuzzy logic routines are implemented in such critical vehicle modules as the route planner the fuzzy navigator the fault-tolerant tools and the flight controller.

Verification of the Space Shuttle Ascent Flight Control

The Space Shuttle vehicle consists of a reusable Orbiter vehicle, reusable SRB's (solid rocket boosters) that burn in parallel with the Orbiter main engines, and an expendable main propellant tank (external tank).During the critical flight phases such as ascent, primary flight control is provided by four onboard digital computers operating as a redundant set with each computer processing the same sensor data set, solving the same set of flight control algorithms, and independently driving via a digital data bus a secondary servo valve on each hydraulic actuator employed in gimballing the propulsion engines.This paper describes the unique avionics design features associated with Space Shuttle ascent flight control, and the test article, test equipment, and test techniques used to verify the ascent flight control prior to commitment to the first orbital flight test.