Mechatronics Application to Solar Tracking

The purpose of this was to design and implement a two-axis solar tracking system utilizing the National Instruments C-Rio real time controller. In order to accomplish this a prototype was modeled in CAD. This prototype used two 12 V DC motors to change a solar panel\u27s rotation and tilt based on feedback data from three cadmium sulfide photoresistors. This configuration was chosen for its ability to create both a left-right rotational and an up/down tilt differential. In Addition this approach uses National Instruments Labview to control a solar tracking system. Using Labview add uniqueness to this project by adding a graphical programming approach instead of conventional text based coding. Solar collection data was taken for seven days. During the energy collection performed on the first day and the second day the sensitivity was calibrated for outdoor conditions. The results have shown that a 28% increase in energy collected with solar tracking, however due to the energy demands of C- Rio controller and motors the net energy gains were less than a stationary collector. This project has resulted in a working solar tracking prototype. With a few design modifications an upgrade to this system may prove useful in future research. With the growing complexity of technology, interest in mechatronics will continue to develop requiring further research will be necessary. Therefore, this project provides Purdue University with demonstration prototype in the up and coming field of mechatronics

Functionality analysis of electric actuators in renewable energy systems - A review

Various mechanical, hydraulic, pneumatic, electrical, and hybrid actuators can alter motion per the requirements of particular applications. However, except for electrical ones, all actuators are restricted due to their size, complex auxiliary equipment, frequent need for maintenance, and sluggish environment in renewable applications. This brief review paper highlights some unique and significant research works on applying electrical actuators to renewable applications. Four renewable energy resources, i.e., solar, wind, bio-energy, and geothermal energy, are considered to review electric actuators applicable to renewable energy systems. This review analyses the types of actuators associated with the mentioned renewable application, their functioning, their motion type, present use, advantages, disadvantages, and operational problems. The information gathered in this paper may open up new ways of optimization opportunities and control challenges in electrical actuators, thereby making more efficient systems. Furthermore, some energy-efficient and cost-effective replacements of convectional actuators with new innovative ones are suggested. This work aims to benefit scientists and new entrants working on actuators in renewable energy systems.Web of Science2211art. no. 427

Assess the Efficacy of an Aerial Distant Observer Tool Capable of Rapid Analysis of Large Sections of Collector Fields, FY 2008 CSP Milestone Report, September 2008

We assessed the feasibility of developing an aerial Distant Observer optical characterization tool for collector fields in concentrating solar power plants

Practical strategies to stabilize a nanosatellite platform with a space camera and integrated mechanical parts

The growth and speed of nanosatellite capabilities has led to an increasing demand on the respective attitude control systems. Typically, nanosatellites utilise minaturised reaction wheels for 3-axis stabilisation/manoeuvres, which are desaturated using magnetorquers. Small space telescopes have been deployed from nanosatellites in the past with capability ever increasing to push the limit of detectors. Previous work has established the feasibility of achieving GSD of 0.7 m in low Earth orbit for a 2.5 U CubeSat using deployable mirrors from a 400 km orbit. The dynamic model of nanosatellite with the telescope + the deployed mirror systems will be built in this research work. The deployed mirror system will use a diamond turned mirror - it's an off axis paraboloid. The mirror would be light-weighted as much as possible, i.e. the back surface would be carved away with good thermal stability. The mechanisms for mirror systems may use methods like minature geared motors, stiction motors and shape memory alloy hinges. The sensoring and directing of the mirror surface will use an image based detection methods. A closed loop control of the mirror position will be used to iterate to a fully aligned system. This work also considers control strategies to stabilise such a platform against the effects of firstly, the external aerodynamics and secondly, any internal disturbances induced by and the movement of focussing elements. A pointing accuracy of 5-10 arcsec for a 20 min observation over the UK is targeted at a baseline orbit of 350 km sun-synchronous. Following an initial baseline to establish current state-of-art both based on in-orbit performance and off-the-shelf subsystems available to the market within the constraints of a 3U nanosatellite system, a number of feed-forward/feedback control loops and sensor systems are studied to determine a simple process for compensating for the motion

MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics

El libro de actas recoge las aportaciones de los autores a través de los correspondientes artículos a la Dinámica de Sistemas Multicuerpo y la Mecatrónica (Musme). Estas disciplinas se han convertido en una importante herramienta para diseñar máquinas, analizar prototipos virtuales y realizar análisis CAD sobre complejos sistemas mecánicos articulados multicuerpo. La dinámica de sistemas multicuerpo comprende un gran número de aspectos que incluyen la mecánica, dinámica estructural, matemáticas aplicadas, métodos de control, ciencia de los ordenadores y mecatrónica. Los artículos recogidos en el libro de actas están relacionados con alguno de los siguientes tópicos del congreso: Análisis y síntesis de mecanismos ; Diseño de algoritmos para sistemas mecatrónicos ; Procedimientos de simulación y resultados ; Prototipos y rendimiento ; Robots y micromáquinas ; Validaciones experimentales ; Teoría de simulación mecatrónica ; Sistemas mecatrónicos ; Control de sistemas mecatrónicosUniversitat Politècnica de València (2011). MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/13224Archivo delegad

Space Exploration Robotic Systems - Orbital Manipulation Mechanisms

In the future, orbital space robots will assist humans in space by constructing and maintaining space modules and structures. Robotic manipulators will play essential roles in orbital operations. This work is devoted to the implemented designs of two different orbital manipulation mechanical grippers developed in collaboration with Thales Alenia Space Italy and NASA Jet Propulsion Laboratory – California Institute of Technology. The consensus to a study phase for an IXV (Intermediate eXperimental Vehicle) successor, a preoperational vehicle called SPACE RIDER (Space Rider Reusable Integrated Demonstrator for European Return), has been recently enlarged, as approved during last EU Ministerial Council. One of the main project task consists in developing SPACE RIDER to conduct on orbit servicing activity with no docking. SPACE RIDER would be provided with a robotic manipulator system (arm and gripper) able to transfer cargos, such as scientific payloads, from low Earth orbiting platforms to SPACE RIDER cargo bay. The platform is a part of a space tug designed to move small satellites and other payloads from Low Earth Orbit (LEO) to Geosynchronous Equatorial Orbit (GEO) and viceversa. The assumed housing cargo bay requirements in terms of volume (<100l) and mass (<50kg) combined with the required overall arm dimensions (4m length), and mass of the cargo (5-30kg) force to developing an innovative robotic manipulator with the task-oriented end effector. It results in a seven degree-of-freedom arm to ensure a high degree of dexterity and a dedicate end-effector designed to grasp the cargo interface. The gripper concept developed consists in a multi-finger hand able to lock both translational and rotational cargo degrees of freedom through an innovative underactuation strategy to limit its mass and volume. A configuration study on the cargo handle interface was performed together with some computer aided design models and multibody analysis of the whole system to prove its feasibility. Finally, the concept of system control architecture, the test report and the gripper structural analysis were defined. In order to be able to accurately analyze a sample of Martian soil and to determine if life was present on the red planet, a lot of mission concepts have been formulating to reach Mars and to bring back a terrain sample. NASA JPL has been studying such mission concepts for many years. This concept is made up of three intermediate mission accomplishments. Mars 2020 is the first mission envisioned to collect the terrain sample and to seal it in sample tubes. These sealed sample tubes could be inserted in a spherical envelope named Orbiting Sample (OS). A Mars Ascent Vehicle (MAV) is the notional rocket designed to bring this sample off Mars, and a Rendezvous Orbiting Capture System (ROCS) is the mission conceived to bring this sample back to Earth through the Earth Entry Vehicle (EEV). MOSTT is the technical work study to create new concepts able to capture and reorient an OS. This maneuver is particularly important because we do not know an OS incoming orientation and we need to be able to capture, to reorient it (2 rotational degrees of freedom), and to retain an OS (3 translational degrees of freedom and 2 rotational ones). Planetary protection requirements generate a need to enclose an OS in two shells and to seal it through a process called Break-The-Chain (BTC). Considering the EEV would return back to Earth, the tubes orientation and position have to be known in detail to prevent any possible damage during the Earth hard landing (acceleration of ∼1300g). Tests and analysis report that in order for the hermetic seals of the sample tubes to survive the impact, they should be located above an OS equator. Due to other system uncertainties an OS presents the potential requirement to be properly reoriented before being inserted inside the EEV. Planetary protection issues and landing safety are critical mission points and provide potential strict requirements to MOSTT system configuration. This task deals with the concept, design, and testbed realization of an innovative electro-mechanical system to reorient an OS consistent with all the necessary potential requirements. One of these electro-mechanical systems consists of a controlled-motorized wiper that explores all an OS surface until it engages with a pin on an OS surface and brings it to the final home location reorienting an OS. This mechanism is expected to be robust to the incoming OS orientation and to reorient it to the desired position using only one degree of freedom rotational actuator

Power-over-Tether Unmanned Aerial System Leveraged for Trajectory Influenced Atmospheric Sensing

The use of unmanned aerial systems (UASs) in agriculture has risen in the past decade and is helping to modernize agriculture. UASs collect and elucidate data previously difficult to obtain and are used to help increase agricultural efficiency and production. Typical commercial off-the-shelf (COTS) UASs are limited by small payloads and short flight times. Such limits inhibit their ability to provide abundant data at multiple spatiotemporal scales. In this thesis, we describe the design and construction of the tethered aircraft unmanned system (TAUS), which is a novel power-over-tether UAS configured for long-term, high throughput atmospheric monitoring with an array of sensors embedded along the tether. This was accomplished by leveraging the physical presence of the tether to integrate an array of sensors. With power from the ground station, the TAUS can acquire continuous volumetric data for numerous hours. The system is used to sense atmospheric conditions and temperature gradients across altitudes. We present the development of the prototype system, along with a discussion of the results from field experiments. We discuss the influence that power losses across the tether have on the sensors’ abilities to accurately sense atmospheric temperature. We demonstrate a 6-hour continuous flight at an altitude of 50 feet, and a 1-hour flight at sunset to acquire the gradually decreasing atmospheric temperature from an array of 6 sensors. We then modeled the TAUS and sensor array to computer simulate four trajectories (mower, spiral, star, and flower) for the TAUS and evaluated the system and sensing performance via well-defined factors. We conducted outdoor experiments to characterize system performance while in operation and to inform the development of models and trajectory simulations. From the analysis of the experimental data, we found minimal sensing error with respect to ground truth installations at comparable altitudes. Leveraging the simulated trajectory outcomes we reconstructed the changing input temperature fields. The analysis of the simulated data indicated that the power-tethered Star trajectory performed well with respect to key performance factors when measuring changing atmospheric fields. The TAUS will be improved by incorporating multi-variable sensors and an optimal control algorithm for elevated levels of operational autonomy. Adviser(s): Carrick Detweiler and Francisco Mu˜noz-Arriol

MATLAB

This excellent book represents the final part of three-volumes regarding MATLAB-based applications in almost every branch of science. The book consists of 19 excellent, insightful articles and the readers will find the results very useful to their work. In particular, the book consists of three parts, the first one is devoted to mathematical methods in the applied sciences by using MATLAB, the second is devoted to MATLAB applications of general interest and the third one discusses MATLAB for educational purposes. This collection of high quality articles, refers to a large range of professional fields and can be used for science as well as for various educational purposes

Язык и мировая культура: взгляд молодых исследователей. Ч. 2

Настоящий сборник объединяет исследовательские проекты студентов Энергетического института Национального исследовательского Томского политехнического университета и содержит материалы, представляющие широ­кий круг научно-учебных интересов в парадигме современных технических знаний. Предназначен для преподавателей, аспирантов и студентов

A steady state tip control strategy for long reach robots

The work presented in this thesis describes the development of a novel strategy for the steady state tip position control of a single link flexible robot arm. Control is based upon a master/slave relationship. Arm trajectory is defined by through 'master' positioning head which moves a laser through a programmed path. Tip position is detected by an optical system which produces an error signal proportional to the displacement of the tip from the demand laser spot position. The error signal and its derivative form inputs to the arm 'slave' controller so enabling direct tip control with simultaneous correction for arm bending. Trajectory definition is not model-based as it is defined optically through movement of the positioning head alone. A critical investigation of vacuum tube and solid state sensing methods is undertaken leading to the development of a photodiode quadrant detector beam tracking system. The effect of varying the incident light parameters on the beam tracker performance are examined from which the optimum illumination characteristics are determined. Operational testing of the system on a dual-axis prototype robot using the purpose-built beam tracker has shown that successful steady state tip control can be achieved through a PD based slave controller. Errors of less than 0.05 mm and settling times of 0.2 s are obtained. These results compare favourably with those for the model-based tip position correction strategies where tracking errors of ± 0.6 mm are recorded