D. Marioli

Bio: D. Marioli is an academic researcher from Brescia University. The author has contributed to research in topics: Wireless sensor network & Ethernet. The author has an hindex of 19, co-authored 65 publications receiving 1338 citations. Previous affiliations of D. Marioli include University of Brescia.

Digital time-of-flight measurement for ultrasonic sensors

Abstract: Ultrasonic sensor measurements are mostly based on the determination of the time of flight (TOF). The authors present the development of a digital algorithm for pulse-echo measurement applications, based on the use of a cross-correlation function to determine the TOF. Some experimental results are presented, and the possibility of realizing a low-cost real-time measurement system is considered. >

Modeling, Fabrication and Performance Measurements of a Piezoelectric Energy Converter for Power Harvesting in Autonomous Microsystems

Abstract: This paper deals with the energy conversion via the piezoelectric effect. A mechanoelectrical energy converter based on piezoelectric thick films of lead zirconate titanate (PZT) deposited on a steel cantilever by a low-temperature process is presented. Modeling and measurement results on the performances of the piezoelectric converter are reported, and its potential use in self-powered autonomous sensor devices is proposed

IEEE 1588-Based Synchronization System for a Displacement Sensor Network

Abstract: Distribution of precise time reference in an Ethernet network allows the implementation of distributed measurement systems, overcoming the limitations of a complex architecture. This paper deals with a displacement sensor network that is built over Ethernet and synchronized according to IEEE 1588. Measurement devices share the same time reference, enabling accurate calculation of cross-derived quantities (multidimensional speed and acceleration). In this paper, a description of the sensor architecture is given, and attention is focused on the IEEE 1588 implementation. In particular, the proposed low-cost system does not use any dedicated synchronization hardware, but it can reduce the deviation from time reference down to 20 .

Ultrasonic distance measurement for linear and angular position control

Abstract: A robot-arm positioning control is described. It makes use of a microprocessor-based ultrasonic system and of a novel time-of-flight measurement technique. The experimental system consists of a three aligned ultrasonic transducers mounted on a rod. Two transducers work as receivers, while the third works both as a transmitter and a receiver. The system achieves a positioning accuracy of +or-0.1 degrees in the field of +or-10 degrees of misalignment for a distance ranging from a few centimeters up to 200 mm. For a higher distance range up to 300 mm, the position accuracy is +or-0.4 degrees . The system also performs distance measurement, using the same group of transducers. The system can be used in robotic applications in industrial environments, such as for orientation control or object grasping. >

Measurement of small capacitance variations

Abstract: A technique for measuring low-frequency and low-level capacitance variations is proposed. It is based on a lock-in detection circuit with a feedback loop, containing an integrator and a modulator for zeroing the capacitance mean value. This approach provides a good signal-to-noise ratio and high sensitivity. Capacitance variations can be on the order of 100 p.p.m. of the mean value, and the frequency of the variations can be as low as 0.1 Hz. Stray capacitances and the drift due to the environmental conditions are automatically compensated. The measurement technique, experimental apparatus, and initial results are described. Small variations, about 10 fF, have been measured in the presence of 10-pF mean value. >

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

Abstract: Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art in motion-driven miniature energy harvesters and discusses trends, suitable applications, and possible future developments.

Energy harvesting in wireless sensor networks: A comprehensive review

Abstract: Recently, Wireless Sensor Networks (WSNs) have attracted lot of attention due to their pervasive nature and their wide deployment in Internet of Things, Cyber Physical Systems, and other emerging areas. The limited energy associated with WSNs is a major bottleneck of WSN technologies. To overcome this major limitation, the design and development of efficient and high performance energy harvesting systems for WSN environments are being explored. We present a comprehensive taxonomy of the various energy harvesting sources that can be used by WSNs. We also discuss various recently proposed energy prediction models that have the potential to maximize the energy harvested in WSNs. Finally, we identify some of the challenges that still need to be addressed to develop cost-effective, efficient, and reliable energy harvesting systems for the WSN environment.

Improved Energy Harvesting from Wideband Vibrations by Nonlinear Piezoelectric Converters

Abstract: Vibration harvesters typically are linear mass-spring devices working at resonance. A different approach is here proposed based on nonlinear converters that exploit stochastic resonance with white-noise excitation. It consists of a piezoelectric beam converter coupled to permanent magnets to create a bistable system. Under proper conditions, the system bounces between two stable states in response to random excitation, which significantly improves energy harvesting from wide-spectrum vibrations. The background theory is discussed based on a simplified monodimensional model which includes nonlinearity. A cantilever beam with added nonlinearity was simulated by using a MATLAB® Stochastic Differential Equation (SDE) Toolbox demonstrating the expected improvement under white-noise vibrations. Nonlinear converters were then realized by screen printing low-curing-temperature lead zirconate titanate (PZT) films on steel cantilevers equipped with magnets. Experimental tests were performed by measuring both the beam deflection and the output voltage under excitation by random vibrations at varying degree of nonlinearity added to the system. The obtained results show that the performances of the converter in terms of output voltage at parity of mechanical excitation are markedly improved when the system is made bistable. Furthermore, the principle was also preliminarily validated on a MEMS U-shaped cantilever beam that was purposely designed and fabricated in SOI technology. This demonstrates the possibility to downscale the principle here proposed in the perspective of a MEMS harvester based on nonlinear piezoelectric converters.