In this paper, a tracking controller is formulated for a quadrotor to track a moving ground target. The quadrotor exhibits distinct hierarchical dynamics that allows its position to be controlled by its attitude. This motivates the use of backstepping control on the underactuated quadrotor. Most backstepping architecture controls the quadrotor position and attitude independently, and couples th...

In this paper, we describe an algorithm, based on the well-known Unscented Quaternion Estimator, to estimate external forces and torques acting on a quadrotor. This formulation uses a non-linear model for the quadrotor dynamics, naturally incorporates process and measurement noise, requires only a few parameters to be tuned manually, and uses singularity-free unit quaternions to represent attit...

Tools for quadrotor trajectory design have enabled single videographers to create complex aerial video shots that previously required dedicated hardware and several operators. We build on this prior work by studying film-maker’s working practices which informed a system design that brings expert workflows closer to end-users. For this purpose, we propose WYFIWYG, a new quadrotor camera tool whi...

BACKGROUND Following the introduction of Helicopter Emergency Ambulance Services (HEAS) in the United Kingdom in the last ten years this paper examines the costs and benefits of three contrasting services in Cornwall, London and Sussex. METHODS Pre-hospital processes of care were compared between helicopter attended patients and land ambulance patients in all three studies, and health outcome...

Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control ...

In this paper, a neuro-fuzzy system identification using measured input and output data are carried out. A model-free learning from “examples” methodology is developed to train a neuro-fuzzy model of a smallsize helicopter. The helicopter model is obtained and tuned using training data gathered while a teacher operates the helicopter. Behavior-based model architecture is used, with each behavio...

Over last 10-years period there has been just one helicopter accident (with no fatalities) in the Norwegian sector of helicopter offshore operations. In this case, safety monitoring cannot be based on the absence of accidents. The main objective of this paper is to suggest a combination of leading and lagging indicators to monitor safety performance for helicopter offshore operations. An approa...

DASC Time-delayed anti-swing controller FHL Force transferred from the load to the helicopter kd Gain of the delayed feedback controller L Load cable length mL Load mass MHL Moment transferred from the load to the helicopter N Number of particles in the PSO PSO Particle swarm optimization algorithm RH Hook position vector RL Load position vector p,q,r Helicopter angular velocities Vmax Maximum ...

SUMMARY This work first describes the development of a real-time flight simulator for an R-50 experimental model helicopter. A mathematical model of the helicopter is developed to represent the dynamics of the real system. This simulation model is used to investigate and analyze the helicopter dynamics in a hovering flight condition. The importance of a control rotor used for stability augmenta...

We propose and investigate a system in which teams of quadrotor helicopters assemble 2.5-D structures from simple structural nodes and members equipped with magnets. The structures, called Special Cubic Structures (SCS), are a class of 2.5-D truss-like structures free of overhangs and holes. Grippers attached to the bottom of each quadrotor enable them to pick up, transport, and assemble the st...