LQR CONTROL FOR A SMALL SCALE HELICOPTER IN HOVER FLIGHT CONDITION

Small scale helicopters have been used as unmanned aerial vehicle (UAV) because they have agility and maneuverability that make them as an ideal option for various missions ranging from weather research, agriculture, aerial surveillance to power line inspection. Small scale helicopter posses a higher bandwidth of dynamics and a greater sensitivity to control inputs which make them more difficult to control. This paper deals with the control system design using Linear Quadratic Regulator (LQR) for an autonomous small scale helicopter in hover flight condition. A nonlinear dynamics model of the small scale helicopter is derived from the Euler-Newton equations of motion. Linear model at hover flight condition is numerically extracted using MATLAB/Simulink. Linear control system is then designed for the small scale helicopter with the following predefined hover position and external disturbances such as longitudinal doublet input and gust. The Virtual Reality model in Matlab/Simulink is used to show the 3 D view of the simulation results. Kata kunci: LQR, hover, small scale helicopter

Control synthesis for an unmanned helicopter with time-delay under uncertain external disturbances

This paper presents the controller synthesis for an unmanned helicopter with minimum initial information about the parameters of its mathematical model with time-delays of measured and control signals. The unknown parameters, wind disturbances, and system nonlinearity are considered as external disturbances that are estimated using a multi-gap observer. The estimates obtained are used in the control law to improve the stability rate for flight regimes

Modelling and Control of Small-Scale Helicopter on a Test Platform

The helicopter is a Multiple-Input Multiple-Output (MIMO) system with highly coupled characteristics, which increases the complexity of the system dynamics. In addition, the system dynamics of the helicopter are unstable, referring to its tendency to deviate from an equilibrium when disturbed. Despite the complexity in its modelling and control, the benefit of using a helicopter for unmanned, autonomous applications can be tremendous. One particular application that motivates this research is the use of an unmanned small-scale helicopter in an autonomous survey mission over an area struck by disaster, such as an earthquake. The work presented in this thesis provides a framework for utilizing a platform system for research and development of small-scale helicopter systems. A platform system enables testing and analysis to be performed indoor in a controlled environment. This can provide a more convenient mean for helicopter research since the system is not affected by environmental elements, such as wind, rain or snow condition. However, the presence of the platform linkages poses challenges for analysis and controller design as it alters the helicopter system flight dynamics. Through a six degree-of-freedom (6 DOF) platform model derived in this research, the criteria for matching the trim conditions between the platform system and a stand alone helicopter have been identified. With the matched trim conditions, linearization is applied to perform analysis on the effects that the platform has on the system dynamics. The results of the analysis provide insights into both the limitations and benefits of utilizing the platform system for helicopter research. Finally, a Virtual Joint Control scheme is proposed as an unified control strategy for both the platform and the stand alone helicopter systems. Having a consistent control scheme between the two systems allows for comparisons between simulation and experimental results for the two systems to be made more readily. Furthermore, the Virtual Joint Control scheme represents a novel flight control strategy for stand alone helicopter systems

Decentralized Hybrid Formation Control of Unmanned Aerial Vehicles

This paper presents a decentralized hybrid supervisory control approach for a team of unmanned helicopters that are involved in a leader-follower formation mission. Using a polar partitioning technique, the motion dynamics of the follower helicopters are abstracted to finite state machines. Then, a discrete supervisor is designed in a modular way for different components of the formation mission including reaching the formation, keeping the formation, and collision avoidance. Furthermore, a formal technique is developed to design the local supervisors decentralizedly, so that the team of helicopters as whole, can cooperatively accomplish a collision-free formation task