Low-speed longitudinal controllers for mass-produced cars: A comparative study

Four longitudinal control techniques are compared: a classical Proportional-Integral (PI) control; an advanced technique-called the i-PI-that adds an intelligent component to the PI; a fuzzy controller based on human experience; and an adaptive-network-based fuzzy inference system. The controllers were designed to tackle one of the challenging topics as yet unsolved by the automotive sector: managing autonomously a gasoline-propelled vehicle at very low speeds. The dynamics involved are highly nonlinear and constitute an excellent test-bed for newly designed controllers. A Citroën C3 Pluriel car was modified to permit autonomous action on the accelerator and the brake pedals-i.e., longitudinal control. The controllers were tested in two stages. First, the vehicle was modeled to check the controllers' feasibility. Second, the controllers were then implemented in the Citroën, and their behavior under the same conditions on an identical real circuit was compared.

Using array based techniques for noise source identification in cars

Una de las principales causas del ruido en nuestras ciudades es el tráfico rodado. El ruido generado por los vehículos no es sólo debido al motor, sino que existen diversas fuentes de ruido en los mismos, entre las que se puede destacar el ruido de rodadura. Para localizar las causas del ruido e identificar las principales fuentes del mismo se han utilizado en diversos estudios las técnicas de coherencia y las técnicas basadas en arrays. Sin embargo, en la bibliografía existente, no es habitual encontrar el uso de estas técnicas en el sector automovilístico. En esta tesis se parte de la premisa de la posibilidad de usar estas técnicas de medida en coches, para demostrar a la largo de la misma su factibilidad y su bondad para evaluar las fuentes de ruido en dos condiciones distintas: cuando el coche está parado y cuando está en movimiento. Como técnica de coherencia se elige la de Intensidad Selectiva, utilizándose la misma para evaluar la coherencia existente entre el ruido que llega a los oídos del conductor y la intensidad radiada por distintos puntos del motor. Para la localización de fuentes de ruido, las técnicas basadas en array son las que mejores resultados ofrecen. Statistically Optimized Near-field Acoustical Holography (SONAH) es la técnica elegida para la localización y caracterización de las fuentes de ruido en el motor a baja frecuencia. En cambio, Beamforming es la técnica seleccionada para el caso de media-alta frecuencia y para la evaluación de las fuentes de ruido cuando el coche se encuentra en movimiento. Las técnicas propuestas no sólo pueden utilizarse en medidas reales, sino que además proporcionan abundante información y frecen una gran versatilidad a la hora de caracterizar fuentes de ruido. ABSTRACT One of the most important noise causes in our cities is the traffic. The noise generated by the vehicles is not only due to the engine, but there are some other noise sources. Among them the tyre/road noise can be highlighted. Coherence and array based techniques have been used in some research to locate the noise causes and identify the main noise sources. Nevertheless, it is not usual in the literature to find the application of this kind of techniques in the car sector. This Thesis starts taking into account the possibility of using this kind of measurement techniques in cars, to demonstrate their feasability and their quality to evaluate the noise sources under two different conditions: when the car is stopped and when it is in movement. Selective Intensity was chosen as coherence technique, evaluating the coherence between the noise in the driver’s ears and the intensity radiated in different points of the engine. Array based techniques carry out the best results to noise source location. Statistically Optimized Near-field Acoustical Holography (SONAH) is the measurement technique chosen for noise source location and characterization in the engine at low frequency. On the other hand, Beamforming is the technique chosen in the case of medium-high frequency and to characterize the noise sources when the car is in movement. The proposed techniques not only can be used in actual measurements, but also provide a lot of information and are very versatile to noise source characterization.

Stop cars: “Recuperación de un derecho ciudadano”

Durante el siglo XX, hemos pasado de ser una sociedad activa que disfrutaba de la ciudad a medida que recorría sus calles, a ser una sociedad motorizada cuyo interés principal es transportarse de un punto A a un punto B en el menor tiempo posible. En este siglo XXI, la concepción del espacio urbano y de la vida cotidiana se encuentra en un movimiento de rechazo de esta ideología anterior. Ya no nos interesan esas ciudades funcionales diseñadas solamente para los vehículos y un movimiento de recuperación del espacio urbano se ha iniciado sobre una trama de ciudad todavía anclada en el pasado. Este ensayo pretende analizar los retos provenientes de este cambio ideológico y dar una serie de soluciones a la conversión de espacios públicos de tránsito en espacios de estar al aire libre que den pie a una sinergia comunicativa de sus gentes. Hoy en día nos encontramos con los inicios de este movimiento de cambio que busca una mejora en la salud y la vida cotidiana de los ciudadanos, previamente relegados a espacios libres públicos muy acotados. Ahora, todo el espacio libre se convierte en espacio para sus ciudadanos buscando crear de esta forma una “sala de estar” al aire libre.

Key Issues and Developments in Farmland Rental Markets in EU Member States and Candidate Countries. Factor Markets Working Paper No. 13, February 2012

In this paper, we describe recent developments in the rental market for agricultural land in selected EU member states and candidate countries. The analysis focuses on the importance of the rental market as well as on the evolution of rental prices. It appears that the share of rented land in the total utilised agricultural area varies considerably among member states. In the old member states, the share of rented land ranges between 18% in Ireland and 74% in France, while in the new member states (NMS) it ranges from 17% in Romania to 89% in Slovakia. For the former, different strategies to provide tenure security to tenants can explain differences in the importance of rental markets. Changes in the significance of land rental have also reflected changes in institutions and in economic and political conditions. In the NMS, diverse approaches to land reform have resulted in assorted ownership structures and hence in differences in the share of rented land. Regarding rental prices, governments impose price restrictions on agricultural land rents in some countries, such that large divergences are observed in rental prices between and within member states.

Rental Market Regulations for Agricultural Land in EU Member States and Candidate Countries. Factor Markets Working Paper No. 15, February 2012

In this paper, we describe the regulations governing the rental markets for agricultural land in selected EU member states and candidate countries. The analysis focuses on various kinds of regulations and institutions connected with the land rental market, including price, tenancy duration, quantity and other regulations, as well as transaction costs. The diverse government regulations on price restrictions and tenancy duration are analysed, along with the social norms observed for rental payments and contracts. The paper also examines the type and registration of contracts, the contract enforcement rules, the regulations on the inheritability of contracts and the pre-emptive right of tenants to buy the land.

An Analysis of the Capitalisation of CAP Payments into Land Rental Rates in Ireland. Factor Markets Working Document No. 68, August 2013

EDITED VERSION SOON TO BE PUBLISHED In this paper the effect of decoupling on the capitalisation of agricultural subsidies into agricultural rents in Ireland are analysed using a dynamic rental equations estimated with a two step system GMM estimator that accounts for expectation error and endogenous regressors. The findings illustrate the importance of institutional details in determining the extent to which subsidies are capitalised. In the period prior to decoupling Pillar 1 subsidies were highly capitalised into Irish agricultural rents in both the short and the long run. Depending on the farm system considered between 58 to 80 cents per euro of subsidies were capitalised into agricultural rents. In the post decoupling period the rate at which Pillar 1 subsidies are capitalised into Irish agricultural rents is found to have declined. This change is likely due to short term character of the Irish agricultural land rental market, where 11 month rental periods predominate, and the freedom that the 2003 reform of the CAP offered farmers to consolidate entitlements established on rented land. The generally very short term nature of Irish agricultural rental contracts offered farmers an opportunity to consolidate entitlements that is unlikely to have arisen in other Member States with agricultural land rental markets characterised by long term contracts. The results in both the pre and post decoupling periods highlight the high degree of inertia of agricultural rents in Ireland, and the importance of accounting for dynamics when investigating the capitalisation of agricultural subsidies into land rents. The high degree of inertia in rents means that the impact of previously capitalised agricultural policy persists through time.