Publications in ./ValenteWeb.bib [rss]
Books
[2010] António Valente, Salviano F.S.P. Soares, José Manuel Baptista, "Projecto em Engenharia Electrotécnica e de Computadores", UTAD, Vila Real, Portugal, 2010. [bib] [pdf]
[2005] "EFITA/WCCA 2005 Book of abstracts", UTAD, Vila Real, Portugal, 2005. [bib]
[2005] Raul Morais dos Santos, José Manuel Ribeiro Baptista, António Luís Gomes Valente, Salviano Filipe Pinto Soares, "Práticas Laboratoriais I", UTAD, no. 282, Vila Real, Portugal, 2005. [bib]
Refereed Articles and Book Chapters
[2012] M. Reis, R. Morais, E. Peres, C. Pereira, O. Contente, S. Soares, A. Valente, J. Baptista, P. Ferreira, J. Bulas Cruz, "Automatic detection of bunches of grapes in natural environment from color images", In Journal of Applied Logic, Elsevier, 2012. [+ abstract]
Despite the benefits of precision agriculture and precision viticulture production systems, its rate of adoption in the Portuguese Douro Demarcated Region remains low. We believe that one way to raise it is to address challenging real-world problems whose solution offers a clear benefit to the viticulturist. For example, one of the most demanding tasks in wine making is harvesting. Even for humans, the environment makes grape detection difficult, especially when the grapes and leaves have a similar color, which is generally the case for white grapes. In this paper, we propose a system for the detection and location, in the natural environment, of bunches of grapes in color images. This system is able to distinguish between white and red grapes, and at the same time, it calculates the location of the bunch stem. The system achieved 97% and 91% correct classifications for red and white grapes, respectively.
[bib] [pdf] [doi]
[2011] Manuel Reis, Raul Morais, Carlos Pereira, Olga Contente, Miguel Bacelar, Salviano Soares, António Valente, José Baptista, Paulo Ferreira, José Bulas-Cruz, "A Low-Cost System to Detect Bunches of Grapes in Natural Environment from Color Images", Chapter in Advances Concepts for Intelligent Vision Systems (, ed.), Springer Berlin / Heidelberg, vol. 6915, pp. 92-102, 2011. [+ abstract]
Despite the benefits of precision agriculture and precision viticulture production systems, its adoption rate in the Portuguese Douro Demarcated Region remains low. One of the most demanding tasks in wine making is harvesting. Even for humans, the environment makes grape detection difficult, especially when the grapes and leaves have a similar color, which is generally the case for white grapes. In this paper, we propose a system for the detection and location, in the natural environment, of bunches of grapes in color images. The system is also able to distinguish between white and red grapes, at the same time, it calculates the location of the bunch stem. The proposed system achieved 97% and 91% correct classifications for red and white grapes, respectively.
[bib] [pdf] [doi]
[2011] Manuel Reis, Raul Morais, Carlos Pereira, Salviano Soares, A. Valente, J. Baptista, Paulo Ferreira, J. Cruz, "Automatic Detection of White Grapes in Natural Environment Using Image Processing", Chapter in Soft Computing Models in Industrial and Environmental Applications, 6th International Conference SOCO 2011 (, ed.), Springer Berlin / Heidelberg, vol. 87, pp. 19-26, 2011. [+ abstract]
The rate of adoption of Precision Agriculture and Precision Viticulture production systems in the Douro Demarcated Region remains low. We believe that one way to raise it is to address challenging real-world problems whose solution offers a clear benefit to the viticulturist. For example, one of the most demanding tasks in wine making is harvesting. Even for humans, the detection of grapes in their natural environment is not always easy. White grapes are particularly difficult to detect, since their color is similar to that of the leafs. Here we present a low cost system for the detection of white grapes in natural environment color images. The system also calculates the probable location of the bunch stem and achieves 91% of correct classifications.
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[2011] A. Leal, A. Valente, A. Ferreira, S. Soares, V. Ribeiro, O. Krushinitskaya, E.A. Johannessen, "Glucose Monitoring System Based on Osmotic Pressure Measurements", In Sensors & Transducers, International Frequency Sensor Association, 46 Thorny Vineway Toronto ON M 2 J 4 J 2 Canada, vol. 125, no. 2, pp. 30-41, 2011. [+ abstract]
This paper presents the design and development of a prototype sensor unit for implementation in a long-term glucose monitoring system suitable for estimating glucose levels in people suffering from diabetes mellitus. The system utilizes osmotic pressure as the sensing mechanism and consists of a sensor prototype that is integrated together with a pre-amplifier and data acquisition unit for both data recording and processing. The sensor prototype is based on an embedded silicon absolute pressure transducer and a semipermeable nanoporous membrane that is enclosed in the sensor housing. The glucose monitoring system facilitates the integration of a low power microcontroller that is combined with a wireless inductive powered communication link. Experimental verification have proven that the system is capable of tracking osmotic pressure changes using albumin as a model compound, and thereby show a proof of concept for novel long term tracking of blood glucose from remote sensor nodes.
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[2011] J. Baptista, R. Morais, A. Valente, S. Soares, M. Candeias, M. Reis, "HarmoSim: A tool for harmonic distortion simulation and assessment of nonlinear loads", In Computer Applications in Engineering Education, Wiley Online Library, 2011. [+ abstract]
Electrical power quality (PQ) is a crucial competitive and developing factor to all economic activities. The economic impact resulting from a bad PQ would be drastic on all consumers. Computers, uninterruptible and switched power supplies (UPS), and fluorescent lamps/tubes are examples of nonlinear loads that have the consumption of a nonsinusoidal current, which cause disturbances in the power supply system (that may be severe or not). This study discusses residential generic power circuitry analysis and simulation, under nonlinear loads, in connection with undergraduate electrical engineering education. It briefly reviews some of the basic techniques, and presents a software tool that has been found to be very useful in the context. The tool has an easy-to-use, friendly interface, and can be used to teach design techniques or as a laboratory support to study the applicability of known methods to real situations. The students can perform simulations with their own data on Microsoft(TM) Windows(R)-based platforms
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[2010] M. G. A. D. Reis, L. Cabral, E. Peres, M. Bessa, A. Valente, R. Morais, S. Soares, J. Baptista, A. Aires, J. J. Escola, J. A. Bulas-Cruz, M. J. C. S. Reis, "Using Information Technology Based Exercises In Primary Mathematics Teaching of Children With Cerebral Palsy and Mental Retardation: A Case Study", In Turkish Online Journal of Educational Technology, Turkish Online Journal Educational Tech-tojet, vol. 9, no. 3, pp. 106-118, 2010. [+ abstract]
Technology has profoundly changed the way we learn and live. Indeed, such relationship appears to be quite complex, within IT contexts, and especially in socially and technologically rich learning environments, where related skills and learning are progressively required and fostered. Thus, if a satisfactory level of intellectual performance and social competence of a primary school pupil is indeed highly dependent on the type of participation that parents offer their children, IT, in general, and Internet, in particular, may well provide a new paradigm, setting forth that education and communication approach is truly more complex than ever before. It is on the basis of such paradigm that we therefore present a case study where a set of multimedia exercises were used in order to possibly improve the mathematical skills of pupils, one with mental retardation and another with cerebral palsy. Being part of a Web-based system to support students' learning, the referred set of multimedia exercises proved to be the children's favorite, rather than exercises in paper form, which also led the children to show a fair more positive attitude towards learning. Also, we observed that through the mentioned multimedia exercises, the children became far more autonomous, interested, persistent, happy, and able to easily absorb the material as well as more willingly to continue on working.
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[2010] C. Ferreira, P. Ventura, C. Grinde, R. Morais, A. Valente, C. Neves, M. Reis, "Characterization and testing of a shock absorber embedded sensor", In Procedia Engineering, Elsevier, vol. 5, pp. 319-322, 2010. [+ abstract]
This article presents the characterization of a shock absorber embedded sensor (SAES) for real-time monitoring of the condition of vehicle shock absorbers in everyday use. A prototype system was built using a custom designed monolithic silicon combined accelerometer, pressure and temperature sensors. The characterization of the SAES was performed and the obtained results meet and even outperform the specification requirements. The SAES was installed in a shock absorber, with adjustable damping properties, and submitted to road tests. Results show that the condition of a shock absorber can be effectively assessed with the presented SAES. Ensuring that shock absorbers are replaced before reach unacceptable condition, this system will increase onboard comfort and vehicle safety.
[bib] [pdf] [doi]
[2010] J. Baptista, R. Morais, A. Valente, S. Soares, J. Bulas-Cruz, M. Reis, "A Software Tool for Harmonic Distortion Simulation Caused by Non-linear Household Loads", Chapter in Soft Computing Models in Industrial and Environmental Applications, 5th International Workshop (SOCO 2010) (, ed.), Springer Berlin / Heidelberg, vol. 73, pp. 31-38, 2010. [+ abstract]
In this paper we present a software tool to be used in residential/household generic power circuitry analysis and simulation, under non-linear loads. This tool can both be used by electrical engineers and by students of electrical engineering. It has an easy-to-use, friendly interface, and can be used to teach design techniques or as a laboratory tool to study the applicability of known methods to real world practical situations. Also, the users may supply their own data. The simulated results are very close to the measured ones.
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[2009] C. Ferreira, P. Ventura, C. Grinde, R. Morais, A. Valente, C. Neves, M.J.C.S. Reis, "A novel monolithic silicon sensor for measuring acceleration, pressure and temperature on a shock absorber", In Procedia Chemistry, Elsevier, vol. 1, no. 1, pp. 88-91, 2009. [+ abstract]
A fabricated micro-mechanical sensor to assess the condition of automotive shock absorbers is presented. The monolithic sensor, measures the oil temperature, acceleration and internal pressure of the shock absorber. A dual mass accelerometer with optimized beam geometry is used for acceleration readout. In addition, a 23.1 [mu]m thickness square membrane and two buried resistors are used for pressure and temperature sensing respectively. The proposed miniaturized sensor can be effectively integrated with standard single- and dual-tube shock absorbers. The data acquired during normal vehicle operation can be continuously used to monitor the condition of the shock absorbers, allowing shock absorbers to be replaced before their degradation significantly reduce the comfort, performance and safety of the vehicle.
[bib] [pdf] [doi]
[2009] Carlos Ferreira, Paulo Ventura, Raul Morais, António L.G. Valente, Carlos Neves, Manuel C. Reis, "Sensing methodologies to determine automotive damper condition under vehicle normal operation", In Sensors and Actuators A: Physical, Elsevier, vol. 156, no. 1, pp. 237-244, 2009. (cited by 1) Journal IF:1.674 [+ abstract]
Vehicles rely on the efficiency of dampers to dissipate energy from the motion of vehicle body and wheels, maintaining the vehicle more stable, and improving the contact between tires and the road surface. To achieve an effective monitoring of dampers (or shock absorbers), two different methodologies, capable of assessing, under vehicle normal operation, the condition of the automotive dampers are presented. The proposed methodologies are based in acceleration, temperature and pressure sensing to determine the shock absorber condition, and are therefore suitable for future implementation in low cost fabrication technologies. The results shown that it is possible to have an effective monitoring device, installed in the damper body, capable of continuously determining shock absorber status, and therefore enabling real time diagnosis. Such a diagnosis system can reduce the number of vehicles riding with defective suspension systems and increase the overall vehicle safety.
[bib] [pdf] [doi]
[2008] Raul Morais, Samuel G. Matos, Miguel A. Fernandes, António L.G. Valente, Salviano F.S.P. Soares, P.J.S.G. Ferreira, M.J.C.S. Reis, "Sun, wind and water flow as energy supply for small stationary data acquisition platforms", In Computers and Electronics in Agriculture, Elsevier, vol. 64, no. 2, pp. 120 - 132, 2008. (cited by 8) Journal IF:1.312 [+ abstract]
The deployment of large mesh-type wireless networks is a challenge due to the multitude of arising issues. Perpetual operation of a network node is undoubtedly one of the major goals of any energy-aware protocol or power-efficient hardware platform. Energy harvesting has emerged as the natural way to keep small stationary hardware platforms running, even when operating continuously as network routing devices. This paper analyses solar radiation, wind and water flow as feasible energy sources that can be explored to meet the energy needs of a wireless sensor network router within the context of precision agriculture, and presents a multi-powered platform solution for wireless devices. Experimental results prove that our prototype, the MPWiNodeX, can manage simultaneously the three energy sources for charging a NiMH battery pack, resulting in an almost perpetual operation of the evaluated ZigBee network router. In addition to this, the energy scavenging techniques double up as sensors, yielding data on the amount of solar radiation, water flow and wind speed, a capability that avoids the use of specific sensors.
[bib] [pdf] [doi]
[2006] A. Valente, R. Morais, A. Tuli, JW Hopmans, GJ Kluitenberg, "Multi-functional probe for small-scale simultaneous measurements of soil thermal properties, water content, and electrical conductivity", In Sensors and Actuators A: Physical, Elsevier, vol. 132, no. 1, pp. 70-77, 2006. [+ abstract]
In studies of vadose zone flow and transport processes, there is a need for a multi-functional probe for small-scale measurements of different soil properties measured within identical soil volumes. The proposed multi-functional probe was designed for simultaneous measurement of temperature, volumetric water content, water flow,and salinity in small-scale soil volumes. The probe, without the heater element, will be a 21.4 mm diameter by 50 mm long cylinder. The proposed system includes signal processing circuits, a microcontroller, and a RF transceiver with ZigBee(TM) protocol. Heat-pulse simulations results showed a reasonably good agreementbetween measured and fitted data with small deviations at the tail of temperature response curves. In addition, results indicate that the Wenner array configuration provides an excellent tool for EC measurements in soil. In conclusion, results also show that it is possible to implement the multi-functional in a small-scale microsystem.
[bib] [pdf] [doi]
[2006] R. Morais, A. Valente, J. C. Almeida, A. M. Silva, S. Soares, M. J. C. S. Reis, R. Valentim, J. Azevedo, "Concept study of an implantable microsystem for electrical resistance and temperature measurements in dairy cows, suitable for estrus detection", In Sensors and Actuators A: Physical, Elsevier, vol. 132, no. 1, pp. 354-361, 2006. (cited by 2) Journal IF:1.674 [+ abstract]
In cattle breeding industry, where artificial insemination techniques are employed, the successful detection of estrus onset leads to considerable cost-saving in herd management. One of the most reliable approaches is based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate is used in a chemical-binding reaction to directly or indirectly produce some effect (electrical or light) that is used at the transducer level. These methods present several drawbacks concerning real-time measurements due to the complexity of the reactions involved and reagent/waste handling. Another approach is to combine measurements of temperature and electrical resistance of reproductive tissues to predict estrus. Using a low-power microsystem with wireless capabilities it is possible to take these measurements in situ and more frequently. The proposed microsystem comprises a second-order delta-sigma modulator for analog-to-digital conversion and a class-E radio-frequency (RF) transmitter operating in the ISM-band of 433 MHz to transfer acquired data to a collar. Electrical resistance is measured by using a modified Wenner array and temperature by the on-chip temperature sensor. System (including battery and antenna) package is made of a tissue-compatible material to allow implantation in the cow's vulvar muscle. Since estrus prediction is based on relative changes of the two correlated parameters, calibration is not necessary. Some preliminary results regarding the measuring concept are presented. (c) 2006 Elsevier B.V. All rights reserved.
[bib] [pdf] [doi]
[2004] R. Morais, A. Valente, C. Couto, J. H. Correia, "A wireless RF CMOS mixed-signal interface for soil moisture measurements", In Sensors and Actuators A: Physical, Elsevier, vol. 115, no. 2-3, pp. 376-384, 2004. (cited by 6) Journal IF:1.674 [+ abstract]
This paper describes a wireless RF CMOS interface for soil moisture measurements. The interface basically comprises a Delta-Sigma (DeltaSigma) modulator for acquiring an external sensor signal, and a RF section where data is transmitted to a local processing unit. The DeltaSigma modulator is a single-bit, second-order modulator and it is implemented using switched-capacitors techniques in a fully-differential topology. With a sampling frequency of 423.75 kHz and an oversampling ratio (OSR) of 256, the modulator achieves a dynamic range of 98.7 dB (16.1 bit). The output of the modulator is applied to a counter, as a first-order decimation filter, and the result is stored. Prior to transmission, data is encoded as a pulse width modulated signal and assembled in a frame containing preamble and checksum control fields. This frame is then transmitted through a power amplifier operating at 433.92 MHz in class-E mode. To evaluate the DeltaSigma modulator performance, the bitstream was acquired and transferred to a personal computer to perform digital filtering and decimation using MATLAB. The soil moisture sensor is based on dual-probe heat-pulse (DPHP) method and is implemented by using an integrated temperature sensor and a heater. After applying a heat-pulse for a fixed period of time, the temperature rise, that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless sensors network. The CMOS mixed-signal interface has been implemented in a single-chip using a standard CMOS 0.7 mum process (AMI C07M-A, n-well, 2 metals and 1 poly). (C) 2004 Elsevier B.V. All rights reserved.
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[2000] M. Cordeiro, A. Valente, S. Leitão, "Wind energy potential of the region of Trás-os-Montes and Alto Douro, Portugal", In Renewable Energy, Elsevier, vol. 19, no. 1, pp. 185-191, 2000. (cited by 0) Journal IF:2.226 [+ abstract]
The main objective of this paper is to present a study on the wind energy potential that is being developed in the Region of Trás-os-Montes and Alto Douro. This study started in July 1996 and will continue until the end of 1998. In order to have an adequate characterisation of the wind energy potential in this region it is necessary to measure the wind speed and direction in several places. At this moment the data are being collected at nine places. Due to lack of space, only four places will be addressed in this article. The Region of Douro and Alto Trás-os-Montes has an area of 12,235 km2. It is located in the Northeast part of Portugal and represents 57.7% of the North Region. Other projects refer to this region as having great potential in the field of renewable energies. From the analysis of the collected data, it seems that wind energy in Marão and Alvão mountains is one of the most interesting renewable energies.
[bib] [pdf] [doi]
[1998] A. Valente, J. Boaventura Cunha, C. Couto, "Integrated Management System", In Computes in Agriculture (, ed.), Amer Soc Agricultural Engineers, pp. 54-60, 1998. [+ abstract]
Soil water content has a direct influence on the cooling and growth mechanisms of the plants. Crop evapotranspiration is majoring influenced by solar radiation and the air temperature, humidity and movement. An efficient irrigation system must supply and maintain, at soil root zone of the plants, the adequate amount of water that best regulate the physiological mechanisms of the plant. For this purpose, an intelligent real-time greenhouse irrigation system was implemented which uses accurate sensors for measuring soil moisture, as well to determinate the crop evapotranspiration. To avoid loss of control, it was provided fault-detection capabilities to the soil moisture sensor and used a knowledge-based approach to estimate replacement values for the faulty sensors. A model-based controller was implemented to regulate the water content at the root zone of the plants. These tasks are very complex and difficult to meet, unless microcontroller and microprocessor systems are employed, such as in the integrated management irrigation system. The system comprises four modules: Sensor/Actuation, Acquisition and Data Validation, Data Correction, Model Based Controller, and Control Signals Generation. All the modules are linked and supervised by a higher-level supervision module to achieve an intelligent irrigation.
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Refereed Conference Papers
[2011] M.J.C.S. Reis, M. Bacelar, M.G.A.D. Reis, D. Meira, M. Bessa, E. Peres, R. Morais, A. Valente, S. Soares, J. Bulas-Cruz, "Internet-based collaborative E-exercisebook system for primary math teaching", In Telecommunications (CONATEL), 2011 2nd National Conference on, pp. 1 -7, 2011. [+ abstract]
The academic performance and social competence of a child in school is positively associated with the involvement of their parents. However, the researches about educational learning models often ignore the parents' part. Internet opens a new paradigm: education and communication approach is more complex than ever. Here, we would like to present an Internet based system to support students' homework. We believe that one of the major advantages of our system is time saving, particularly from the teacher's point of view. Also, this system gathers statistical data concerning different groups of students selected by the teacher. From these data on, the teacher can easily see where the students are having problems and decide what to do next. From the student (or parent) point of view, the prompt feedback about the exercises correctness, added to the training with different exercises sets about the same subject, besides the utilization of video, color, sound, etc., that positively reinforce child's senses, are elected as the main advantages.
[bib] [pdf] [doi]
[2011] M. Reis, L. Cabral, D. Meira, E. Peres, M. Bessa, A. Valente, R. Morais, S. Soares, J. Baptista, A.P. Aires, others, "Um Estudo de Caso do Ensino da Matemática em Crianças com Paralisia Cerebral e Deficiência Mental no 1\textordmasculine CEB", In XIII CONFERÊNCIA INTERAMERICANA DE EDUCAÇÃO MATEMÁTICA, Recife, Brasil, pp. 1-12, 2011. [+ abstract]
O desenvolvimento exponencial da técnica e tecnologia transformou profundamente o modo como aprendemos, conhecemos, interagimos e vivemos. Se um nível satisfatório de desempenho intelectual e competências sociais de um aluno do 1º Ciclo do Ensino Básico (escola primária) está de facto grandemente dependente do tipo de acompanhamento que os pais disponibilizam aos seus filhos, as TI (em geral) e a Internet (em particular) podem muito bem proporcionar novos contextos de aprendizagem e um novo paradigma, comprovando que a educação e os processos comunicacionais se tornaram processos mais complexos do que nunca. É neste contexto que realizámos uma investigação apresentando um estudo de caso, onde um conjunto de exercícios multimédia foi concebido e aplicado com o objectivo de melhorar as competências matemáticas das crianças com necessidades educativas especiais (NEE), no caso concreto, uma com deficiência mental e outra com paralisia cerebral. Este conjunto de exercícios multimédia provou ser o favorito das crianças, ao invés de exercícios em formato de papel, e também conduziram uma atitude mais positiva em relação à aprendizagem. Além disso, observou-se que as crianças se tornaram mais autónomas, interessadas, persistentes, alegres, e capazes de absorver mais facilmente o material, demonstrando ainda mais vontade de continuar a trabalhar.
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[2010] António Valente, Salviano Soares, Raul Morais, José Manuel Baptista, Manuel Cabral, "Button Heat-pulse Sensor for Soil Water ContentMeasurements", In First International Conference on Sensor Device Technologies and Applications - SENSORDEVICES 2010, Venice--Mestre, Italy, pp. 180-182, 2010. [+ abstract]
Recent developed button heat pulse probes (BHPP) demonstrated a great potential for soil water content measurements. This new probe compared to conventional heat pulse probes (HPP), does not use needles, and measurement accuracy is significantly improved. This new design, with the possibility to assembly the probe and electronics in the same package, with low-cost, and with less power consumption compared to conventional HPP, make it suitable to be connected to wireless data acquisition systems in precision agriculture. The probe was tested in agar to demonstrate the potential advantages of the button heat pulse sensor for soil water content measurements. It was possible to have an 0.5 x00B0;C temperature rise with only 156 mW of power consumption, a ten times power reduction in heat-pulse soil water content measurements. These tests showed the potential use of the button heat pulse sensor for the determination of soil water content.
[bib] [doi]
[2010] Carlos Ferreira, Paulo Ventura, Nuno Pires, Christopher Grinde, Raul Morais, António Valente, Carlos Neves, Manuel Reis, "A Self-Powred Embedded System for Shock Absorber Diagnosis During Vehicle Motion", In Proc. FISITA 2010 World Automotive Congress, GTE (Scientific Society of Mechanical Engineers), June 2010, Budapest, Hungary, pp. F2010-D-085, 2010. [+ abstract]
Shock absorbers (or dampers) are key components in a vehicle suspension system and play an important role in braking performance, manoeuvring stability and onboard comfort. However they are subject to wear and suffer damages like oil leak, affecting vehicle comfort, drivability, safety and increasing the breaking distances. Dampers are difficult to visually inspect, and common examinations on ground suspension platforms give inaccurate results regarding the shock absorber condition. More precise testing can be performed on a dynamometer, where a shock absorber velocity-force diagram can be collected, but because shock absorbers must be removed from the vehicle in order to be tested, these examinations are seldom used. A theoretical analysis of the vehicle suspension and of dampers internal working principles was used to confirm the possibility of determining damper condition during normal vehicle operation. By knowing unsprung mass acceleration, and damper internal pressure, or alternatively, sprung and unsprung mass acceleration, damper status can be computed in order to alert when dampers replacement is necessary. In order to increase the accuracy, also the oil temperature should be monitored. A wireless solution can reduce wiring cost and reduce weight, but requires the use of internal energy sources. Harvesting available energy and converting it into electricity, makes the system independent in terms of power supply, becoming a maintenance free device. A piezoelectric generator is proposed as an energy harvesting device for this application, its energy being stored in an external energy reservoir. The proposed system can be fabricated using low cost technologies (CMOS and MEMS) allowing batch fabrication of small dimensions and high reliability systems, that are suitable for embedding in the shock absorber. A monolithic micro-sensor for measuring acceleration, pressure and temperature was fabricated with the SensoNor MultiMEMS process. Multi road experiments done with instrumented dampers, under various conditions, validated the proposed methods. A piezoelectric cantilever tuned to resonate at 12 Hz (unsprung mass resonance frequency) was installed in the vehicle suspension and energy obtained confirmed the feasibility of a self-powered system. The experimental results validate the possibility of deciding the need for shock absorber service or replacement, by comparison with reference parameters, even in a random multi-road scenario. The proposed self powered embedded system, with measurement, signal conditioning and wireless communication capabilities, can easily be integrated in a shock absorber to enhance vehicle diagnosis. Such device can be a major improvement in vehicle safety without significant added complexity and cost.
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[2010] J. Baptista, J. Gonç andalves, S. Soares, A. Valente, R. Morais, J. Bulas-Cruz, M.J.C.S. Reis, "Induction motor response to periodical voltage fluctuations", In Electrical Machines (ICEM), 2010 XIX International Conference on, pp. 1-6, 2010. [+ abstract]
The main aim of this paper is to analyze the behavior of the three-phase squirrel cage induction motor under different voltage fluctuation levels. To achieve this goal several simulations were performed using the EMTP/ATP tool. Here we present how mechanical torque, speed and efficiency parameters varied with different levels of voltage fluctuation and modeling frequencies. As it was expected, the induction motor is sensitive to voltage fluctuations within certain amplitude levels and frequencies. Also, the speed is more affected by low frequencies and high amplitudes of voltage fluctuations, while the torque and efficiency are more affected by middle and high frequencies and amplitudes.
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[2008] P. J. C. Ventura, C. D. H. Ferreira, C. F. C. Neves, R. M. P. Morais, A. L. G. Valente, M. J. C. Reis, "An embedded system to assess the automotive shock absorber condition under vehicle operation", In Proc. IEEE Sensors 2008, pp. 1210-1213, 2008. [+ abstract]
The automotive suspension plays a crucial role in vehicle safety and driving comfort. One of the most important components in vehicle suspensions is the damper (or shock absorber). Because there is no precise method to perform shock absorber test within the vehicle, an embedded autonomous system, powered by the energy harvested from the shock absorber itself, capable of monitoring shock absorber parameters and transmitting these values throughout a wireless interface to the vehicle central diagnostic unit, is presented. Such a device will permit the shock absorber condition assessment under vehicle operation, which to our best knowledge is considered a breakthrough in vehicle safety.
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[2008] I. M. M. Faria, P. X. S. Freitas, J.T.Q.S. Pinto, A. M. P. Jesus, A. L. G. Valente, R. M. P. M. Santos, J. J. L. Morais, "Estrutura de Madeira da Cobertura as Piscinas Municipais de Mirandela", In 4o CIMPAR – Congresso Internacional sobre Patologia e Reabilitação de Estruturas, 2008. [bib]
[2007] A. Valente, R. Morais, C. Serodio, P. Mestre, S. Pinto, M. Cabral, "A ZigBee Sensor Element for Distributed Monitoring of Soil Parameters in Environmental Monitoring", In Proc. IEEE Sensors 2007, pp. 135-138, 2007. [+ abstract]
This work describes the development and implementation of a grid of self-powered multi-functional probes (MFPz) for small-scale measurements of different soil properties, as being part of a wireless sensor network. The measurement principle is based on the heat-pulse method for soil moisture and water flux measurements and in a Wenner array for soil electrical conductivity. To promote the deployment of these sensing devices across large areas, such as irrigation fields, the ZigBee standard has been adopted as a multi-hop, ad-hoc network enabler. The core of the MTPz device is a wireless microcontroller (with a built-in ZigBee stack) that builds upon an IEEE 802.15.4 radio device. A 7.2Ah NiHM battery that is charged by a solar panel powers the MFPz device. Experimental results have proofed the reliability of the MFPz, regarding power consumption, connectivity and data agreement with known soil samples, as a cost-effective solution for environment monitoring.
[bib] [pdf] [doi]
[2006] A. Valente, R. Morais, A. Tuli, J.W. Hopmans, G.J. Kluitenberg, "Multi-functional probe for small-scale simultaneous measurements of soil thermal properties, water content, and electrical conductivity", In EUROSENSORS XIX – The 19th European Conference on Solid-State Transducers, pp. 70-77, 2006. [bib]
[2006] R. Morais, A. Valente, J.C. Almeida, A.M. Silva, S. Soares, M.J.C.S. Reis, R. Valentim, J. Azevedo, "Concept study of an implantable microsystem for electrical resistance and temperature measurements in dairy cows, suitable for estrus detection", In EUROSENSORS XIX – The 19th European Conference on Solid-State Transducers, pp. 354-361, 2006. [bib]
[2006] Jan Hopmans, Yasushi Mori, Annette P. Mortensen, Gerard Kluitenberg, Atac Tuli, Antonio Valente, "Multi-Functional Heat Pulse Probe Measurements of Water, Heat, and Solute Transport in the Vadose Zone", In 18th World Congress of Soil Science, 2006. [bib] [pdf]
[2005] C. Nogueira, R. Costa, A. Valente, S. Soares, R. Morais, M. Cabral, C. Amaro, A.F.V.C.C. Coelho, "Dispositivo de baixo peso para estimação de trajectórias aéreas de aves", In Proceedings of the Congreso Interamericano de Computacion Aplicada a la Industria de Processos, UTAD, pp. 311-314, 2005. [bib]
[2005] Cesário Nogueira, Raúl Costa, Carlos Amaro, António Coelho, Maximino Bessa, Manuel Cabral, António Valente, Raul Morais, Salviano Soares, "Simulação visual de trajectórias aéreas", In 13º Encontro Português de Computação Gráfica, pp. 223-226, 2005. [+ abstract]
A realidade virtual é uma área da computação gráfica que engloba a síntese de ambientes imersivos com o intuito de proporcionar a sensação de estar noutro lugar. Neste projecto foi criado um sistema de realidade virtual, projectado para trabalhar com informação referenciada por coordenadas espaciais ou geográficas, aliado a uma modelação tridimensional do terreno para recriar trajectórias aéreas. Neste artigo apresentamos a arquitectura e capacidades desenvolvidas, bem como potenciais aplicações.
[bib]
[2005] R. Morais, A. Valente, C. Serôdio, "A wireless sensor network for smart irrigation and environmental monitoring: A position article", In 5th European federation for information technology in agriculture, food and environement and 3rd world congress on computers in agriculture and natural resources (EFITA/WCCA), pp. 845-850, 2005. [bib]
[2003] A. Valente, R. Morais, C. Couto, J. H. Correia, "Modeling and simulation of a silicon soil moisture sensor based on the DPHP method for agriculture", In EUROSENSORS XVII – The 17th European Conference on Solid-State Transducers, University of Minho, pp. 332-333, 2003. [bib]
[2003] A. Valente, R. Morais, J. Boaventura Cunha, J. H. Correia, C. Couto, "A multi-chip-nodule micro-system for soil moisture measurements", In Proceedings of 4th Conference of the European Federation for Information Technology in Agriculture, Food and Environment, pp. 547-551, 2003. [bib]
[2003] R. Morais, A. Valente, C. Couto, J. H. Correia, "A wireless RF CMOS interface for a soil moisture sensor", In EUROSENSORS XVII – The 17th European Conference on Solid-State Transducers, University of Minho, pp. 268-269, 2003. [bib]
[2003] R. Morais, A. Valente, J. H. Correia, C. Couto, "A CMOS mixed-signal interface with a RF transmitter for a micromachined soil moisture sensor", In Proc. IEEE Int. Symp. Industrial Electronics ISIE 2003, pp. 952-955, 2003. [+ abstract]
This paper describes a CMOS mixed-signal interface with a RF transmitter. This die is assembled in a Multi-Chip-Module (MCM) micro-system together with the micromachined soil moisture sensor to achieve a cost-effective solution with accurate and reliable measurements for soil moisture in agriculture. The soil moisture probe, based on Dual-Probe Heat-Pulse (DPHP) method, is fabricated in bulk-micromachining technology. The DPHP method is based on the measurement of the maximum temperature rise at some distance from the heater, after applying a heat-pulse. The measurement of the temperature rise is obtained by subtracting soil temperature from the probe temperature. The mixed-signal interface is based on a pre-amplification stage and first-order sigma-delta modulator. The bit-stream output of the modulator is then applied to a counter as a first order decimation filter thus providing a 12-bit readout sample. Prior to transmission, data is encoded as a pulse width modulated (PWM) signal and then transmitted by means of an amplitude shift-keying (ASK) modulation. ne transmitter features a VCO phase locked to the quartz crystal reference of 13.56 MHz to achieve a carrier frequency of 433.92 MHz. A RF power amplifier based on class E topology was chosen. The CMOS mixed-signal interface with a RF transmitter has been implemented in a single-chip using a standard CMOS process (AMI 0.7 mum, n-well, 2 metals and I Poly).
[bib]
[2002] A. Valente, R. Morais, C. Couto, JH Correia, "A MCM-based microsystem for soil moisture measurements", In EUROSENSORS XVI - The 16th European Conference on Solid-State Transducers, Czech Technical University, Prague, Czech Republic, 2002. [bib]
[2002] A. Valente, R. Morais, C. Couto, J. H. Correia, "A MCM-based Micro-system for Soil Moisture Measurements", In Proc.EUROSENSORS XVI – The 16th European Conference on Solid-State Transducers, pp. 447-448, 2002. [bib]
[2002] A. Valente, Raul Morais, Carlos Couto, J. H. Correia, "A Bulk-Micromachined Soil Moisture Probe with a Mixed-Signal Interface", In Proceedings of Controlo 2002, 5th Portuguese Conference on Automatic Control, pp. 429-433, 2002. [bib]
[2002] C. Ferreira, P. Ventura, R. Morais, A. Valente, C. Neves, M.J.C.S.Reis, "An Embedded Monitoring Device for an Automotive Shock Absorber", In EUROSENSORS 2002 – The 22th European Conference on Solid-State Transducers, 2002. [bib]
[2001] A. Valente, J. Boaventura Cunha, J.H. Correia, C. Couto, "Sensor de Humidade do Solo Micromaquinado no Silício com Integração do Sensor, Electrónica e Interface", In II Congresso Luso-Moçambicano de Engenharia, pp. J97-J103, 2001. [bib]
[2001] A. Valente, Raul Morais, C. Couto, J. H. Correia, "Sensor de Humidade do Solo Micromaquinado no Silício com Transmissão por Rádio Frequência", In 3as Jornadas do ICETA-UTAD, 2001. [bib]
[2001] A. Valente, J. B. Cunha, J. H. Correia, C. Couto, "A silicon probe with integrated microelectronics for soil moisture measurements", In Proceedings of The World Congress on Computers in Agriculture and Natural Resources, pp. 440-446, 2001. [+ abstract]
This work presents an on-chip silicon bulk-micromachined Soil Moisture Sensor (SMS) suited for irrigation control and management applications. The same basic fabrication concepts and materials, which made microelectronics successful, are now being adapted to making low-cost, small, high-performance sensor systems with integrated electronics on the same chip. As a result, this system-on-a-chip includes the SMS, readout electronics, self-test, calibration facilities and a digital bus interface for external data transmission, Moreover, since this sensor has low-cost, it could be employed several sensors networked together with the 1-wire bus, to achieve an accurate measure of the soil moisture at the plant root level. A heat-pulse technique is used (for measuring the maximum temperature on a distant point) to determine the volumetric heat capacity and hence the water content of a porous media, such as soil. This method is based on the Joule effect (heater probe shank) and in Seebeck effect (thermopile - temperature probe shank). The heater and the thermopile are suspended on a dielectric window to reduce undesired heat conduction to the substrate (silicon is a good heat conductor). Thermal simulations of the bulk-micromachined SMS are performed to test sensor performance. In order to validate the method, simulations are made and experimental results were achieved with a macrosensor based on this technique. The results were compared with the measurements performed by the conventional thermo-gravimetric method.
[bib]
[2001] A. Valente, C. Couto, J. H. Correia, "On-chip integrated silicon bulk-micromachined soil moisture sensor based on the DPHP method", In Transducers’01 and EUROSENSORS XV, Digest of Technical Papers, Springer, pp. 316-319, 2001. [+ abstract]
This paper reports the design, modelling, fabrication and assembly of a silicon bulk-micromachined soil moisture microsensor using the Dual-Probe Heat-Pulse (DPHP) method. Soil humidity measurement is essential to study soil preservation and control the development of plants, namely in closed ecosystem. The DPHP method uses a heater (Peltier effect) and a temperature probe (Seebeck effect) to determine the volumetric heat capacity of the soil and hence water content (theta (v)). This is the first time that the DPHP method is implemented in a microdevice and the first integrated sensor for soil moisture. This microdevice is more suited to measure at different soil depths in a non-destructive and automated manner.
[bib]
[2000] A. Valente, C. Coute, J.H. Correia, "On-chip integrated silicon bulk-micromachined soil moisture sensor with electronics and bus interface", In Industrial Electronics, 2000. ISIE 2000. Proceedings of the 2000 IEEE International Symposium on, vol. 2, Cholula, Puebla, Mexico, pp. 576-579, 2000. [+ abstract]
This paper presents an on-chip silicon bulk-micromachined soil moisture sensor (SMS) for irrigation control in greenhouses. The system-on-a-chip includes the SMS, readout electronics, self-test, calibration facilities and a digital bus interface for external data transmission. Moreover, this low-cost device can be applied in several locations (e.g. per each plant root), and networked together with the 1-wire bus. The heat-pulse technique is used (for measuring the maximum temperature on a distant point) to determine the volumetric heat capacity and hence the water content of a porous media, such as soil. In order to validate this method, experimental results were achieved with a macrosensor based on the heat-pulse and capacitance methods. The capacitance method relates the volumetric water content with the capacitance change (dielectric properties) of a probe, inserted in the soil and water contents. These results are compared with the measurement achieved using the conventional thermogravimetric method
[bib] [pdf] [doi]
[2000] A. Valente, C. Couto, J. H. Correia, "On-chip integrated silicon bulk-micromachined soil moisture sensor with electronics and bus interface", In Proc. IEEE Int. Symp. Industrial Electronics ISIE 2000, vol. 2, pp. 576-579, 2000. [+ abstract]
This paper presents an on-chip silicon bulk-micromachined Soil Moisture Sensor (SMS) for irrigation control in greenhouses. The system-on-a-chip includes the SMS, readout electronics, self-test, calibration facilities and a digital bus interface for external data transmission. Moreover, this low-cost device can be applied in several locations (e. g. per each plant root), and networked together with the 1-wire bus. The heat-pulse technique is used (for measuring the maximum temperature on a distant point) to determine the volumetric heat capacity and hence the water content of a porous media, such as soil. In order to validate this method, experimental results were achieved with a macrosensor based on the heat-pulse and capacitance methods. The capacitance method relates the volumetric water content with the capacitance change (dielectric properties) of a probe, inserted in the soil. Several tests were performed for different type of soils and water contents. These results are compared with the measurements achieved using the conventional thermogravimetric method.
[bib] [doi]
[2000] M. Seixas, G. Igrejas, A. Valente, P. Salgado, C. Couto, "Wine fermenter with an automatic system of monitoring and control", In CONTROLO'2000: 4th Portuguese Conference on Automatic Control, 2000. [bib]
[2000] José Boaventura Cunha, Raul Morais Santos, António Valente, Ana Edite Cunha, "Air Humidity Sensing: Electronic Psychrometer with Built-in Heat Pump and Condenser to Refill the Evaporated Water", In 2000 ASAE Annual International Meeting, no. Paper n. 004061, 2000. [+ abstract]
Psychrometer sensors are widely used for monitoring greenhouse air humidity because of its simplicity, low cost and accuracy. For proper operation the wick, which is immersed in a water reservoir, must maintain a continuous supply of water to the wet bulb temperature sensor. This implies the need to refill periodically the water reservoirs, which is the major limitation of these sensors. To avoid this problem an electronic psychrometric sensor was developed. A microcontroller is used to read the wet and dry bulbs temperatures and compute the vapor pressure and relative humidity. In addition, it controls a micro heat pump to continuously supply water to the reservoir.
[bib]
[2000] M. Cordeiro, A. Valente, S. Leitão, "Wind energy potential of the Trás-os-Montes region, northeast of Portugal", In World Renewable Energy Congress VI (, ed.), Pergamon, vol. IV, Brighton, UK, pp. 2320-2323, 2000. [+ abstract]
Summary This paper has as main objective to present a study on the wind energy potential and was developed in the Region of Trás-os-Montes and Alto Douro, in the Northeast of Portugal.
[bib] [pdf] [doi]
[1999] A. Valente, J. Boaventura Cunha, M. Cordeiro, "Sistema Inteligente de Aquisição de Dados com Vista à Utilização Racional de Energia em Edifícios", In 1º Congresso Luso Moçambicano de Engenharia, 1999. [bib]
[1999] A. Valente, M. Seixas, J. Boaventura Cunha, "Sensor Inteligente de Humidade do Solo", In 2as Jornadas do ICETA-UTAD, 1999. [bib]
[1999] G. Igrejas, A. Valente, J. Boaventura Cunha, M. Cordeiro, "Controlo energético de edif\'\icios com vista à utilização racional de energia", In VI Jornadas Luso-Espanholas de Engenharia Electrotécnica., pp. 87-92, 1999. [bib]
[1998] A. Valente, J. Boaventura Cunha, C. Couto, "Soil moisture sensor with built-in fault-detection capabilities", In Industrial Electronics Society, 1998. IECON '98. Proceedings of the 24th Annual Conference of the IEEE, vol. 3, pp. 1310-1314, 1998. [+ abstract]
A soil moisture sensor (SMS) was built around a RISC-like microcontroller and common peripherals to perform data acquisition, signal processing, configuration, fault-detection and data communication with control/management systems. The SMS employs capacitance and heat-pulse techniques to determine the soil water content. The sensor uses the capacitance technique as the main method while the heat-pulse readings, acquired at a lower rate, are used for calibration and fault detection purposes. The temperature sensors and the heater were assembled in a four-needle probe. Several experiments were conducted for different types of soil. The results showed that this sensor could be applied in an effective way to measure the soil water content. Several tests are being performed to conclude about the sensor dependence with soil temperature and chemical composition as well about its long-term stability
[bib] [pdf] [doi]
[1998] A. Valente, J. Boaventura Cunha, C. Couto, "Integrated Management Irrigation System", In Proceedings of the 7th. International Conference Computers in Agriculture, pp. 54-60, 1998. [bib]
[1998] A. Valente, J. Boaventura Cunha, C. Couto, "Soil moisture sensor with built-in fault-detection capabilities", In Proc. 24th Annual Conf. of the IEEE Industrial Electronics Society IECON '98, vol. 3, pp. 1310-1314, 1998. [+ abstract]
A soil moisture sensor (SMS) was built around RISC-like microcontroller and common peripherals to perform data acquisition, signal processing, configuration, fault-detection and data communication with a control/management system. The SMS employs capacitance and heat-pulse techniques to determine the soil water content. The sensor uses the capacitance technique as the main method while the heat-pulse readings, acquired at a lower rate, are used for calibration and fault detection purposes. The temperature sensors and the heater were assembled in a four-needle probe. Several experiments were conducted for different types of soil. The results showed that this sensor could be applied in an effective way to measure the soil water content. Several tests are being performed to conclude about the sensor dependence with soil temperature and chemical composition as well about its long-term stability.
[bib] [doi]
[1997] C. Serodio, J.B. Cunha, M. Cordeiro, A. Valente, R. Morais, P. Salgado, C. Couto, "MNet-DACS: multi-level network data acquisition and control system", In Industrial Electronics, 1997. ISIE '97., Proceedings of the IEEE International Symposium on, vol. 1, Guimaraes, Portugal, pp. 39 -43, 1997. [bib] [pdf] [doi]
[1997] C. Serodio, J. B. Cunha, M. Cordeiro, A. Valente, R. Morais, P. Salgado, C. Couto, "MNet-DACS: multi-level network data acquisition and control system", In Proc. IEEE Int Industrial Electronics ISIE '97. Symp, vol. 1, pp. 39-43, 1997. [+ abstract]
This paper describes the implementation of a distributed data acquisition network based on the 80C592 microcontroller from Intel. Each station is connected in an hierarchical way to form a tree topology. The lower level network stations, designated by slaves, are dedicate to the data acquisition and the generation of control signals. The upper level, masters, are responsible for the communications control. Both networks use a CAN (controller area network) bus, for data transfer, and the global network is also connected to a PC, via a CAN. A device router, NetManager, was implemented to support total intrinsic requirements at the communication level. This type of connection allows total configuration from a personal computer, PC, which runs a software application developed for Windows(TM) environments. The tests performed at the laboratory, with transmission rates varying from 40 kbits/s to 1 Mbits/s, showed that the communications were performed without errors for cable lengths of 1100 m to 40 m, respectively. This system is now being installed in a set of environmental chambers and greenhouses located on a Portuguese university campus, where it will monitor and control air temperatures and humidities, CO2 and ammonia concentrations and the radiation level
[bib] [doi]
[1997] J. Boaventura Cunha, Manuel Cordeiro, Raul Morais, Paulo Salgado, Carlos Serôdio, A. Valente, "Automação de estufas agrícolas na UTAD", In 1as Jornadas do ICETA-UTAD, pp. 9-10, 1997. [bib]
[1995] António Valente, Paulo Salgado, J. Boaventura Cunha, "Controlador digital de uma câmara climática", In 4as Jornadas Luso-Espanholas de Engenharia Electrotécnica, vol. 3, pp. 1665-1670, 1995. [bib]
[1995] Manuel Martins, Rui Pereira, Miguel Teixeira, Carlos Gomes, J. Boaventura Cunha, António Valente, Raul Morais, Carlos Serôdio, "Rede Distribuída de Aquisição de Dados", In 2º Encontro Nacional do Colégio de Engenharia Electrotécnica, pp. 121-130, 1995. [bib]
[1994] António L. Valente, Paulo J. Moreira, José B. Cunha, Carlos M. Serôdio, "Desenvolvimento de um sistema de aquisição de dados e controlo para estufas agrícolas", In 1º Encontro Nacional do Colégio de Engenharia Electrotécnica, pp. 91-94, 1994. [bib]
[1994] António Valente, Paulo Moreira, José Cunha, Carlos Serôdio, "Desenvolvimento de um sistema de aquisição de dados e controlo para um projecto agrícola", In 1º Encontro Português de Controlo Automático, vol. 1, pp. 251-256, 1994. [bib]
Refereed Workshop Papers
[1997] A. Valente, J. Boaventura Cunha, C. Couto, "Intelligent Soil Moisture Sensor Employing Thermal and Capacitive Methods for Irrigation Control", In Preprints of the International Workshop on Robotics and Automated Machinery for Bio-Productions, pp. 177-182, 1997. [bib]
Other Publications
[2004] Antonio Valente, "Sistema senorial para monitorização do teor de água em solos agrícolas utilizando tecnologia CMOS", PhD thesis, Universidade de Trás-os-Montes e Alto Douro, Vila Real, 2004. [bib] [pdf]
[1999] Antonio Valente, "Desenvolvimento de um Sensor de Humidade para Solos", Master's thesis, Universidade do Minho, Guimarães, 1999. [bib] [pdf]
Patents
[2010] Raul Manuel PEREIRA MORAIS DOS SANTOS, Paulo Jorge DA CRUZ VENTURA, Carlos Daniel Henriques FERREIRA, António Luís GOMES VALENTE, "Continuous monitoring system for shock absorbers in motor vehicle, has single integrated circuit or several integrated interconnected circuits incorporated in shock absorber and equipped with identification unit", no. US2010211253-A1, UTAD, Vila Real, Portugal, 2010. [+ abstract]
The present invention relates to a continuous monitoring system for shock absorbers, for use in motor vehicles or in any kind of machine which requires them, which will enable the shock absorbers to be evaluated during normal operation. It is essentially characterised by all the necessary components being embedded into the shock absorber itself, in a single circuit 1 or several integrated interconnected circuits, which are equipped with means of identification which provide the vehicle's or machine's various electronic management systems with the necessary information regarding shock absorbers identification, characteristics and capacity for self- diagnosis. The aforementioned components include acceleration, pressure and temperature sensors 2, signal conditioning and processing circuits 3, a wireless communication system 4, power production 5 and storage system 7 and management electronics 6. NOVELTY - The continuous monitoring system has a single integrated circuit (IC) or several integrated interconnected circuits incorporated in a shock absorber. The integrated circuit has an identification unit for providing necessary information regarding shock absorbers identification, characteristics and self-diagnosis capacity to a vehicle management system. USE - Continuous monitoring system for shock absorbers in motor vehicle. ADVANTAGE - The comfortable and safe driving of the vehicle are possible by providing shock absorber replacement warning at an appropriate time after evaluating the characteristics of the shock absorber in real time during the life time of the shock absorber. DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of the IC system.
[bib] [pdf]
[2010] Raul Manuel PEREIRA MORAIS DOS SANTOS, Paulo Jorge DA CRUZ VENTURA, Carlos Daniel Henriques FERREIRA, António Luís GOMES VALENTE, "Continuous monitoring system for shock absorbers in motor vehicle, has single integrated circuit or several integrated interconnected circuits incorporated in shock absorber and equipped with identification unit", no. EP2197709-A1, UTAD, Vila Real, Portugal, 2010. [+ abstract]
The present invention relates to a continuous monitoring system for shock absorbers, for use in motor vehicles or in any kind of machine which requires them, which will enable the shock absorbers to be evaluated during normal operation. It is essentially characterised by all the necessary components being embedded into the shock absorber itself, in a single circuit 1 or several integrated interconnected circuits, which are equipped with means of identification which provide the vehicle's or machine's various electronic management systems with the necessary information regarding shock absorbers identification, characteristics and capacity for self- diagnosis. The aforementioned components include acceleration, pressure and temperature sensors 2, signal conditioning and processing circuits 3, a wireless communication system 4, power production 5 and storage system 7 and management electronics 6. NOVELTY - The continuous monitoring system has a single integrated circuit (IC) or several integrated interconnected circuits incorporated in a shock absorber. The integrated circuit has an identification unit for providing necessary information regarding shock absorbers identification, characteristics and self-diagnosis capacity to a vehicle management system. USE - Continuous monitoring system for shock absorbers in motor vehicle. ADVANTAGE - The comfortable and safe driving of the vehicle are possible by providing shock absorber replacement warning at an appropriate time after evaluating the characteristics of the shock absorber in real time during the life time of the shock absorber. DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of the IC system.
[bib] [pdf]
[2009] António Valente, Salviano Soares, "SYSTEM FOR MEASURING SOIL PROPERTIES", no. WO/2009/084971, UTAD, Vila Real, Portugal, 2009. [bib] [pdf]
[2009] Raul Manuel PEREIRA MORAIS DOS SANTOS, Paulo Jorge DA CRUZ VENTURA, Carlos Daniel Henriques FERREIRA, António Luís GOMES VALENTE, "Continuous monitoring system for shock absorbers in motor vehicle, has single integrated circuit or several integrated interconnected circuits incorporated in shock absorber and equipped with identification unit", no. WO/2009/048347, UTAD, Vila Real, Portugal, 2009. [+ abstract]
The present invention relates to a continuous monitoring system for shock absorbers, for use in motor vehicles or in any kind of machine which requires them, which will enable the shock absorbers to be evaluated during normal operation. It is essentially characterised by all the necessary components being embedded into the shock absorber itself, in a single circuit 1 or several integrated interconnected circuits, which are equipped with means of identification which provide the vehicle's or machine's various electronic management systems with the necessary information regarding shock absorbers identification, characteristics and capacity for self- diagnosis. The aforementioned components include acceleration, pressure and temperature sensors 2, signal conditioning and processing circuits 3, a wireless communication system 4, power production 5 and storage system 7 and management electronics 6. NOVELTY - The continuous monitoring system has a single integrated circuit (IC) or several integrated interconnected circuits incorporated in a shock absorber. The integrated circuit has an identification unit for providing necessary information regarding shock absorbers identification, characteristics and self-diagnosis capacity to a vehicle management system. USE - Continuous monitoring system for shock absorbers in motor vehicle. ADVANTAGE - The comfortable and safe driving of the vehicle are possible by providing shock absorber replacement warning at an appropriate time after evaluating the characteristics of the shock absorber in real time during the life time of the shock absorber. DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of the IC system.
[bib] [pdf]
[2008] António Valente, Salviano Soares, "Sistema de medição do teor de água, das propriedades térmicas, da condutividade eléctrica e do fluxo de água no solo baseado no impulso de calor", no. PT-103909, UTAD, Vila Real, Portugal, 2008. [bib]
[2007] Raul Morais, Paulo Ventura, Carlos Ferreiraand António Valente, Carlos Neves, Manuel Cabral Reis, "Sistema de Monitorização contínua para aplicação em amortecedores", no. PT-103847, UTAD, Vila Real, Portugal, 2007. [bib]
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