The blades in a wind turbine are currently manufactured with flexible and light materials, which make them more susceptible to the effects of vibrations when the wind speed is high enough, causing fatigue damage, affecting the functionality of its structure and aerodynamic efficiency. This work presents a comparison of the modal vibration parameters, applied to a cantilever beam, determined with two experimental methods—the use of accelerometers and a proposed optical non-contact method—based on the principle of laser triangulation and photogrammetry techniques. This technique uses the geometric symmetry of the equidistant displacements along the z axis of the beam to obtain the amplitude data. Parameters such as natural frequency and modal form are obtained by fitting the data to a nonlinear equation with a solution which is an exponential/harmonic equation. Also, analytically, these parameters are determined, and a comparison is made between the experimental methods. The result shows that the relative error of the first-order natural vibration frequency is below 1%. The proposed method is simple, efficient, reliable, and it is also a method that has not been applied to the test of wind turbine blades, so its implementation as this type of wind turbine component is an area of opportunity for the validation of modal vibration parameters in the wind industry. An analysis of results is presented showing benefits of the proposed method and its limitations.

This paper shows the design, modeling and control of a micro submarine (Cookie ROV) for inspection tasks in closed areas. The prototype include an embedded system (gumstix) in order to apply the control algorithms. This vehicle is made of materials and devices of low cost. The main goal consists of implementation and the comparison of controllers: PD, PID and saturated PD for stabilizing attitude of vehicle using an IMU (Inertial Measurement Unit). The Dynamic model is described by Newton-Euler equations. It presents vehicle's performance validation with help of MatLab Simulink and experimental results in real time. The contribution of this work is the original and compact design of the prototype to obtain a dynamic uncoupled in orientation and position, as well as its construction and integration of versatile and modular electronic components of small size, besides the implementation and validation of the different strategies of control systems to compare and obtain the best performance.