OBJECTIVE To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. METHODS We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 ...

This paper describes the development of a parameterized model for a small-scale unmanned helicopter (Yamaha R-50 with 10 ft rotor diameter) and its identification using a frequency domain identification technique. The model explicitly accounts for the stabilizer bar, which has a strong influence on the flight dynamics characteristics. The accuracy of the identified model is verified by comparin...

Robust attitude tracking control of a small-scale aerobatic helicopter using geometric and backstepping techniques is presented in this article. A nonlinear coupled rotor-fuselage dynamics model of the helicopter is considered, wherein the rotor flap dynamics is modeled as a first order system, while the fuselage is as a rigid body dynamically coupled to the rotor system. The robustness of the ...

The compound helicopter design could potentially satisfy the new emerging requirements placed on the next generation of rotorcraft. The main benefit of the compound helicopter is its ability to reach speeds that significantly surpass the conventional helicopter. However, it is possible that the compound helicopter design can provide additional benefits in terms of maneuverability. The paper fea...

In this paper, nonlinear rigid body dynamics for rotorcraft mathematical model is studied. A linearization of helicopter flight dynamics is evaluated. Automatic Flight Control System (AFCS) with gain scheduled LQ optimal control is designed based on look-up tables. Stability analyses are performed and results are illustrated graphically for open and closed-loop systems. As seen from results, LQ...

In this study, attitude control is proposed for helicopters with actuator dynamics. For the nominal helicopter dynamics, model-based control is firstly presented to keep the desired helicopter attitude. To handle the model uncertainty and the external disturbance, radial basis function neural networks are adopted in the attitude control design. Using neural network approximation and the backste...

In this paper we propose a vision-based stabilization and output tracking control method for a model helicopter. A novel two-camera method is introduced for estimating the full six-degrees-of-freedom pose of the helicopter. One of these cameras is located on-board the helicopter, and the other camera is located on the ground. Unlike previous work, these two cameras are set to see each other. Th...

Abstract: In this paper we present the application of the adaptive neural-networktechnique in (Calise, Hovakimyan and Idam, 2001) to the control of the 3DoF model helicopter in (Avila, Brogliato, Dzul and Lozano, 2003). The technique uses feedback linearization, linear (coarse) compensation and adaptive-neural-network (fine) compensation. The description of the technique is presented in a way a...

In this paper, we address the design of a controller that accomplishes stabilization and reference tracking at various flight conditions by using linear helicopter models. The suggested controller is in the form of an H-infinity gain-scheduler, and is used for stabilization and reference tracking for the 4 axis (heave, pitch, roll and yaw) autopilot. Based on the linear models given for the Pum...