Multirotor Motor Failure Detection with Piezo Sensor

Failure detection of Unmanned Aerial Vehicle (UAV) motors and propulsion systems is the most important step in the implementation of active fault-tolerant control systems. This will increase the reliability of unmanned systems and increase the level of safety, especially in civil and commercial applications. The following paper presents a method of motor failure detection in the multirotor UAV using piezo bars. The results of a real flight, in which the failure of the propulsion system caused the crash of a hybrid VTOL UAV, were presented and analyzed. The conclusions drawn from this flight led to the development of a lightweight, simple and reliable sensor that can detect a failure of the UAV propulsion system. The article presents the outcomes of laboratory tests concerning measurements made with a piezo sensor. An extensive analysis of the obtained results of vibrations recorded on a flying platform arm with a propulsion system is presented, and a methodology for using this type of data to detect failures is proposed. The article presents the possibility of using a piezoelectric sensor to record vibrations on the basis of which it is possible to detect a failure of the UAV propulsion system

Parameter Optimization of a Magnetic Coupled Piezoelectric Energy Harvester with the Homogenized Material—Numerical Approach and Experimental Study

This paper presents the process optimization of some key parameters, such as beam spacing, flux density and optimal impedance load matching of magnetic coupled piezoelectric harvesters. In order to do this, the distributed parameters model of this structure, containing macro-fiber components (MFC) with homogenous material in the piezoelectric fiber layer, was determined. Next, the computational model of this structure was designed on the basis of the first-order shear theory (FOST). The performed analysis of the calculated voltage outputs on the basis of the theoretical approach and finite element model by various beam spacing allowed us to indicate that optimized parameters play an important role in enhancing the efficiency of the system. Experiments carried out in a laboratory stand for this structure, allowed for the verification of the numerical results. In the effect, it can be noted that magnetic coupled harvesters will be relevant for a wide range of application sectors, as well as useful for the evolving composite industry

Development and Evaluation of a Tethered Class C3 Hexacopter in Maritime Conditions on the Helipad of a Ferry

Various unmanned aerial vechicle (UAV) applications, especially those based on reconnaissance and observation missions, often require an unlimited time of flight. This is possible only when a UAV is continuously supplied with power from a ground-based power source, which is why tethered UAV systems were developed. Tethered UAV systems are based on multicopters, which can hover above a landing pad or track its position if it is movable. The presented research concerned the development of a large C3 class hexacopter with a maximal payload of about 1 kg and a takeoff mass of 16 kg, which was tested in maritime conditions during a ferry’s cruise. The main purpose of the hexacopter was to continuously observe the area ahead of the vessel to detect and localize obstacles in the water. During the experimental tests, critical phases of flight were identified, the AC/DC power supply unit and power cord unwinder were tested, and the power required by six brushless direct current (BLDC) motors was registered. The obtained results could be useful in future work on tethered UAV systems applied in windy maritime conditions