Control de power take-off para aprovechamiento de energía marina

262 p.Esta tesis describe un nuevo PTO hidráulico basado en un array de cilindros de doble efecto cuya fijación mecánica es variable, siendo todos ellos manipulables independientemente. Este PTO no lineal se modela cinemática y dinámicamente en detalle, incluyendo gran parte de las pérdidas y efecto hidráulicos, como las tuberías de transmisión o el aire atrapado en el fluido hidráulico. El comportamiento del PTO se verifica ante varios estados característicos de un componente principal del PTO, la válvula de control, mostrando la versatilidad del PTO diseñado. El modelo se ajusta al comportamiento real del PTO fabricado a través de ensayos experimentales en un banco de ensayos desarrollado a tal efecto. Para comprobar la extracción de energía del dispositivo PTO se incluye éste en un modelo de captador tipo absorbedor puntual aplicando varias estrategias de control. Las estrategias analizadas se corresponden con estrategias por amortiguamiento lineal, amortiguamiento de Coulomb y amortiguamiento basado en el auto bloqueo del captador por el propio PTO, ya sea a través del control del desplazamiento o del control del desplazamiento y velocidad del convertidor. Estas estrategias de control se analizan para condiciones de mar regular

Assembled PTO based on an array of double-acting hydraulic cylinders for WECs: From Conceptual Design to an Adjusted Detailed Model

All Wave Energy Converters (WECs) based on wave activated bodies comprises a Power Take- Off (PTO) system among other subsystems like the reaction mechanism, the supervisor of the system and the electrical generator. One of the most applied PTO systems consists of oil high pressure hydraulic devices. These devices are able to apply high forces, to store large quantities of energy through accumulators and to provide smoother power output to the motor coupled to a generator. In these systems the poor efficiency and the oil leakages contaminating the environment are considered main drawbacks. Despite of this, they are widely used in several promising WECs with the aim of optimizing the harvested wave energy along the time. The initial challenge to absorb an oscillating movement of ±30º at 5rad/s as a maximum angular speed absorbing up to 16000Nm from a specific WEC, led to the development of a simplified hydraulic model before manufacturing a PTO prototype to be verified in a Test Bench (Figure 1). The experimental results of PTO under different conditions have been used to adjust a full detailed PTO Model using Mathworks® software platform. This work presents a patented oil high pressure hydraulic PTO prototype based on an array of four double-acting hydraulic cylinders. This prototype has been designed and completely modelled as a proof concept at 1:4 scale being able to apply a variable Coulomb type damping torque through the activation of each hydraulic cylinder independently and through the modification of geometrical parameters easily. The complete model of the PTO has been accurately tuned up through adjustment of model parameters using the results of the experimental tests. This will allow the study of control strategies to optimize the extracted wave energy from a specific WEC, like point-absorbers

MOLDAM additive manufacturing robotic cell for extruding thermoplastic pellets

[Resumen] Durante los últimos años la fabricación aditiva se está posicionando como una tecnología atractiva por su sencillez y accesibilidad en el mercado, posibilitando la extrusión de diferentes materiales. Sin embargo, las dimensiones del área de trabajo y las limitadas capacidades de extrusoras comerciales de pequeñas dimensiones están derivando en la investigación y puesta en marcha de máquinas más grandes con una mayor tasa de deposición de material. Este artículo describe una nueva celda robótica automatizada para la extrusión de materiales termoplásticos en formato de granza o pellet siendo posible la extrusión de material a alta tasas de deposición. En este sentido, el artículo define la arquitectura de la celda robótica, el interfaz de usuario y los resultados preliminares. Además, se ha desarrollado el gemelo digital para la monitorización del proceso de una manera virtual. Finalmente, el artículo describe un nuevo software registrado en el que se puede analizar las variables del proceso o el comportamiento del material impreso.[Abstract] During the last years, the additive manufacturing is becoming an attractive technology due to simplicity and market accessibility enabling the extrusion of different materials. However, the workspace requirements and the limitation of the small commercial extruders, are leading to research and develop big machines with higher material feed rate. This article describes a new robotic cell for extruding thermoplastic material in pellet format, being able to deposit high material feed rate. In this sense, this article defines the architecture of the cell, the user interfaces for controlling and monitoring the robotic cells and the preliminary results. Furthermore, a digital twin (DT) has been developed to monitor the process virtually. Finally, the paper describes a new registered software in which the data process or the behaviour of the printed material after testing can be shown

Modeling Innovative Power Take-Off Based on Double-Acting Hydraulic Cylinders Array for Wave Energy Conversion

One of the key systems of a Wave Energy Converter for extraction of wave energy is the Power Take-Off (PTO) device. This device transforms the mechanical energy of a moving body into electrical energy. This paper describes the model of an innovative PTO based on independently activated double-acting hydraulic cylinders array. The model has been developed using a simulation tool, based on a port-based approach to model hydraulics systems. The components and subsystems used in the model have been parameterized as real components and their values experimentally obtained from an existing prototype. In fact, the model takes into account most of the hydraulic losses of each component. The simulations show the flexibility to apply different restraining torques to the input movement depending on the geometrical configuration and the hydraulic cylinders on duty, easily modified by a control law. The combination of these two actions allows suitable flexibility to adapt the device to different sea states whilst optimizing the energy extraction. The model has been validated using a real test bench showing good correlations between simulation and experimental testsSpanish Government PS-440000-2008-1, Regional Government of the Basque Country IT719-13, UPV/EHU UFI11/2

Control de power take-off para aprovechamiento de energía marina

262 p.Esta tesis describe un nuevo PTO hidráulico basado en un array de cilindros de doble efecto cuya fijación mecánica es variable, siendo todos ellos manipulables independientemente. Este PTO no lineal se modela cinemática y dinámicamente en detalle, incluyendo gran parte de las pérdidas y efecto hidráulicos, como las tuberías de transmisión o el aire atrapado en el fluido hidráulico. El comportamiento del PTO se verifica ante varios estados característicos de un componente principal del PTO, la válvula de control, mostrando la versatilidad del PTO diseñado. El modelo se ajusta al comportamiento real del PTO fabricado a través de ensayos experimentales en un banco de ensayos desarrollado a tal efecto. Para comprobar la extracción de energía del dispositivo PTO se incluye éste en un modelo de captador tipo absorbedor puntual aplicando varias estrategias de control. Las estrategias analizadas se corresponden con estrategias por amortiguamiento lineal, amortiguamiento de Coulomb y amortiguamiento basado en el auto bloqueo del captador por el propio PTO, ya sea a través del control del desplazamiento o del control del desplazamiento y velocidad del convertidor. Estas estrategias de control se analizan para condiciones de mar regular

Challenges of digital industrial furnaces for energy efficiency using syngas from biomass

Industrial furnaces, as part of intensive industries, are facing new challenges to increase the efficiency, reliability and flexibility of their processes. They require a considerable amount of energy to accomplish heating and melting processes. Thus, multiple types of research have been focused on the optimisation of the energy consumption to address radical improvements in the competitiveness and energy, environmental, and cost performances at the system level. Furthermore, from a renewable energy perspective, a progressive substitution of natural gas by syngas from gasified biomass require an optimal monitoring and control system to regulate new burners as well as, an appropriate adaptation of existing ones. The use of syngas derived from biomass is not a widespread practice in industrial furnace scenarios. Therefore, this paper shows a brief review of creating a digital pre-heating industrial furnace, addressed from the perspective of monitoring and control system. Also, a precise analytical model divided into four primary sections is proposed: (i) burners system, (ii) isolation structure, (iii) energy recovery system, and (iv) load to be pre-heating. These models provide the foundation for a future hybrid models development to achieve higher efficiency levels using an accurate parametrisation of operational process variables, and a precise maintenance operation strategy. Finally, a broad discussion is exposed.The authors wish to acknowledge the financial support from the European Union under grant agreement n° 723803-VULKANO H2020-IND-CE-2016-17/H2020-SPIRE-2016

A Power Take-Off Behaviour at High Pressure Operation Point, Using Four Double-acting Hydraulic Cylinders Modelled by a Port-based Approach

This paper deals with the behaviour at high pressure operation points of a hydraulic Power Take-Off (PTO) using a highly detailed model based on four double-acting hydraulic cylinders modelled by a port-based approach. The developed model takes advantage of the availability of basic hydraulic components which can be parameterized based on real ones, including most of the hydraulic losses. With the aim of optimizing the extraction of wave energy, this PTO is able to modify its restraining torque through the independent activation of the hydraulic cylinders located in the primary transmission and modifying some geometrical parameters related to their fixation points respecting to the axis torque. The ultimate objective of this PTO is to provide a wide range of torques that can be modulated by modifying the operating high pressure of the HP accumulator, the combination of the available areas of the double-acting hydraulic cylinder and the location of their fixation points with respect to the applied movement. This factor can help to improve the control of WEC based on activated bodies with the aim to optimize the extraction of wave energy. In this paper an extended simulation results at different operation points and input movements are presented.Regional Government of the Basque Country IT719-B, UPV/EHU UFI11/2

Innovative Hydraulic Power Take-Off Construction and Performance Tests for Wave Energy Conversion

This document describes and demonstrates the features of a new innovative hydraulic Power take-Off (PTO) to be used for Wave Energy Conversion. This device is able to transform low frequency oscillating movement into a continuous high frequency angular speed, absorbing high fluctuated torque at the input shaft, which can reach up to 8000Nm. Moreover, the major breakthrough of this device is that it can control the braking torque through the modification of some geometrical parameters, L and R, and through the activation of more than one hydraulic cylinder together with the pressure. The output shaft of the PTO is able to rotate at different continuous rated speed through the actuation on a specific control valve at the inlet of the hydraulic motor. Tests to check the behavior of the PTO related to the smoothening of the power output and concerning the time needed to increase the high pressure and the time available after the accumulation of some quantity of energy in different initial conditions are presented.Spanish Government PS-440000-2008-

Construction of a Universal Hydraulic Power Take-Off for Wave Energy Converters. Mathematical Modelling and Validation Testing

This paper presents the construction, mathematical modelling and validation testing of a scaled universal hydraulic Power Take-Off (PTO) device for Wave Energy Converters (WEC). A specific prototype and test bench were designed and built to carry out the validation tests. The results obtained by these tests were used to adjust an in-house mathematical model. The design of the PTO device led to an international patent application. The PTO was initially designed to be coupled to a scaled wave energy capture device with a low speed and high torque oscillating motion and high power fluctuations. Any energy capture device (ECD) that fulfils these requirements can be coupled to this PTO, provided that its scale is adequately defined depending on the rated power of the full scale prototype. The initial calibration included estimation of the pressure drops in the different components, the pressurization time of the oil inside the hydraulic cylinders and the volumetric efficiency of the complete circuit. Since the overall efficiency measured during the tests ranged from 0.69 to 0.8 and the dynamic performance of the PTO was satisfactory, the results are really promising and it is believed that this solution might prove effective in real devices.Spanish Government PS-440000-2008-

End-effector for automatic shimming of composites

Gaps in composite structures are a risky factor in aeronautical assemblies. For mechanically joined composite components, the geometrical conformance of the part can be problematic due to undesired or unknown re-distribution of loads within a composite component, with these unknowns being potentially destructive. To prevent unnecessary preloading of a metallic structure, and the possibility of cracking and delamination in a composite structure, it is important to measure all gaps and then shim any gaps greater than 127 microns. A strategy to overcome the high relative tolerances for assemblies lies in the automated manufacturing of shims for the gaps previously predicted through the evaluation of their volumes via a simulation tool. This paper deals with the development of a special end-effector prototype to enable the shimming of gaps in composites structures using a pre-processed geometry. The aim of this end-effector is to provide movement to a temperature controlled hot-end in order to generate a solid shim of ABS on the target composite surface. This process is defined according to the trajectories and velocities marked by the 3D printing process using standard G-code. The geometry and material volume to be printed are indicated by the simulated gap volume which is based on previous metrological measurements. The final objective will be to attach this end-effector to an anthropomorphic robot to enable autonomous manufacturing. This work is part of the EU FP7 funded LOCOMACHS project, under grant agreement n◦314003.European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° 314003; Basque program Elkartek Basqtech 201