The use of UAVs in areas ranging from agriculture over urban services to entertainment or simply as a hobby has rapidly grown over the last years. Regarding serious/commercial applications, UAVs have been considered in the literature, especially as mobile sensing/actuation platforms (i.e., as a delivery platform for an increasingly wide range of sensors and actuators). With regard to timely, cost-effective and very rich data acquisition, both, NEC Research as well as TNO are pursuing investigations into the use of UAVs and swarms of UAVs for scenarios where high-resolution requirements, prohibiting environments or tight time constraints render traditional approaches ineffective. In this review article, we provide a brief overview of safety and security-focused application areas that we identified as main targets for industrial and commercial projects, especially in the context of intelligent autonomous systems and autonomous/semi-autonomously operating swarms. We discuss a number of challenges related to the deployment of UAVs in general and to their deployment within the identified application areas in particular. As such, this article is meant to serve as a review and overview of the literature and the state-of-the-art, but also to offer an outlook over our possible (near-term) future work and the challenges that we will face there.

Review: Using Unmanned Aerial Vehicles (UAVs) as Mobile Sensing Platforms (MSPs) for Disaster Response, Civil Security and Public Safety

Deterministic and band-limited stochastic energy harvesting scenarios using a multilayer piezoelectric stack configuration are investigated for uniaxial dynamic pressure loading. The motivation for exploring this off-resonant energy harvesting problem derives from typical civil infrastructure systems subjected to dynamic compressive forces in deterministic or stochastic forms due to vehicular or human loads, among other examples of compressive loading. Modeling of vibrational energy harvesters in the existing literature has been mostly focused on deterministic forms of mechanical vibration as in the typical case of harmonic excitation, while the efforts on stochastic energy harvesting have thus far considered second-order systems such as piezoelectric cantilevers. In this paper, we present electromechanical modeling, analytical and numerical solutions, and experimental validations of piezoelectric energy harvesting from harmonic, periodic, and band-limited stochastic excitation of a multilayer piezoelectric stack under axial compressive loading in the off-resonant low-frequency range. The deterministic problem employs the voltage output-to-pressure input frequency response function of the harvester for a given electrical load, which is also extended to periodic excitation. The analytical stochastic electromechanical solution employs the power spectral density of band-limited stochastic excitation to predict the expected value of the power output. The first one of the two numerical solution methods uses the Fourier series representation of the excitation history to solve the resulting ordinary differential equation, while the second method employs an Euler–Maruyama scheme to directly solve the governing electromechanical stochastic differential equation. The electromechanical models are validated through several experiments for a multilayer PZT-5H stack under harmonic and band-limited stochastic excitations at different pressure levels. The figure of merit is also extracted for this particular energy harvesting problem to choose the optimal material. Soft piezoelectric ceramics (e.g. PZT-5H and PZT-5A) offer larger power output as compared to hard ceramics (e.g. PZT-8), and likewise, soft single crystals (e.g. PMN-PT and PMN-PZT) produce larger power as compared to their hard counterparts (e.g. PMN-PZT-Mn); and furthermore, single crystals (e.g. PMN-PT and PMN-PZT) generate more power than standard ceramics (e.g. PZT-5H and PZT-5A) for low-frequency, off-resonant excitation of piezoelectric stacks.

Deterministic and band-limited stochastic energy harvesting from uniaxial excitation of a multilayer piezoelectric stack

Unmanned aerial vehicles (UAVs) or Drones technology has a huge potential for supporting different efficient solutions for the smart applications in our world. The applications include sma...

A survey on recent optimal techniques for securing unmanned aerial vehicles applications

In precision agriculture, activities such as selective spraying of agrochemicals are essential to maintaining high productivity and quality of agricultural products. The use of unmanned aerial vehicles (UAVs) to perform this activity reduces soil compaction, compared to the use of heavy machinery, and helps to reduce the waste of these artificial substances through a punctual and self-regulating application. This work proposes an entire guiding system for use on UAVs (hardware and software) based on image processing techniques. The software part consists of two algorithms. The first algorithm is the Crop Row Detection which is responsible for the correct identification of the crop rows. The second algorithm is the Line Filter that is responsible for generating the driving parameters sent to the flight controller. In the field experiments performed on the proposed hardware, the algorithm achieved a detection rate of 100% of the crop rows for images with resolutions above 320 × 240. The system performance was measured in laboratory experiments and reached 31.22 FPS for images with small resolution, 320 × 240, and 1.63 FPS for the highest resolution, 1920 × 1080. The main contribution of this work is the design and development of an entire embedded guidance system composed of a hardware and software architectures. Other contributions are: the proposed filter for the image pretreatment; the filter to remove the false positive lines; and the algorithm for generating the guiding parameters based on detected crop rows.

A UAV Guidance System Using Crop Row Detection and Line Follower Algorithms

Accurate predictions of the amount of harvestable energy available from ambient vibrations are important for design of energy harvesters and for their integration in specific applications. This need has motivated the development of many mathematical models for piezoelectric energy harvesters (PEHs). Existing models, however, require material and geometric PEH data that are often incorrect and/or unavailable. As a more accurate and practical means to meet this need, we propose an energy conversion model of a cantilevered PEH that requires only geometric data and modal parameters that can be directly measured using a standard vibration test. The newly proposed model facilitates calculation of the maximum output power and thus enables visualization of the harvestable energy from the target vibrating structure. Prediction accuracy of the proposed model was confirmed in our study through finite element analysis and experimental results. Practical use of the proposed energy conversion model was demonstrated by applying it to a cooling fan unit of a boiler facility in a power plant.

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An Energy conversion model for cantilevered piezoelectric vibration energy harvesters using only measurable parameters

Drone technology has advanced to aid applications in field of defense, emergency, disaster relief and digital imaging Inheriting all such applications for Unmanned Aerial Vehicle (UAV) in low cost scale to make system for ubiquitous for all domains is the motive for our system Hence, embedding high quality video feed and controlling flight data characteristics to execute several applications Our system has been devised specifically for air navigation and hence, seamless performance of all the components placed on-board is maintained with high compactness in form factor First Person View (FPV) is provided for pilots for to achieve long distance mission execution along with image processing for accurate data analysis of flight characteristics Along with this, the telemetry data procured from Arduino integrated with sensors viz, GPS, Altimeter, IMU assists the pilot for maintaining steady flight characteristics Our system has been rigorously tested and has also been presented for Society of Automotive Engineers (SAE) Aero Design competition to accomplish humanitarian relief operation The low-cost general processing boards like Raspberry Pi and Arduino facilitates versatility in embedding various sensors based on requirements of the pilot Along with the on-board the telemetry system, the Ground Control System (GCS) provides first person visual aid on base station The JavaFx interface is platform independent with features like FPV video streaming in real-time, representation of UAV's altitude, orientation and position at every instance of time Moreover, the trans-receiver communication allows controlling flight characteristics from the interface, increasing the scope of applications with UAV

Embedded video processing and data acquisition for unmanned aerial vehicle

Our idea describes an approach to harvest electrical energy from mechanically excited piezoelectric elements. In the wake of depleting fossil fuels and the damage it inflicts on mother earth, makes it a compelling case for a renewable and sustainable source of energy. Our project is a step in that direction. The basic idea is to put back into use the energy expended by us in daily course of life. Specifically, we attempted to convert pressure exerted on the ground by individuals while walking or by vehicles travelling on the road to excite piezoelectric elements. While the phenomenon of piezoelectricity is well known for decades, to harness its potential we have come about with a novel methodology of connecting piezoelectric elements with an apt circuitry to yield maximum power. The Piezoelectric sensor which gives voltage on the application of pressure is unregulated DC Voltage. The DC Voltage obtained is passed through a power conditioning source and then given to a storage source (rechargeable Lithium-Ion battery). The rate at which the storage source gets charged is where our module stands out as an efficient and innovative module to harness the plenteous potential energy. There is a paucity of power generated from a single Peizo-Electric transducer. We have developed a prototype wherein we connect a couple hundreds of Piezoelectric sensors followed by a combination of well designed circuitry that involves efficiently designed DC-DC converters, (schottky) diodes, charging circuit. In this paper we have given a unique scheme of harnessing and taking this iota of power and converting it into a substantial amount of power which in-turn will charge a Lithium Ion battery in couple of hours. This makes our innovation industrially relevant particularly in remote areas where it is uneconomical to transmit electricity by traditional means. Cellular phone towers located in the remote areas is a case in point.

Energy harvesting using piezoelectricity

http://www.ijste.org/articles/IJSTEV1I11117.pdf

Akshay Patil

Papers

Embedded video processing and data acquisition for unmanned aerial vehicle

Energy harvesting using piezoelectricity

Data Acquisition System for an Unmanned Aerial Vehicle