F.J. Jiménez

Virtual instrument for measurement, processing data, and visualization of vibration patterns of piezoelectric devices

This article describes a virtual instrument that automates the obtaining of real vibration patterns of a piezoelectric device, based upon a set of displacement measurements collected for a discreet group of points of its surface. The real vibration pattern information is not easy to model when nonlinear effects appear in the piezoelectric devices. A program in Labview language has been developed for the system control and data acquisition in the sample. Another program, also in Labview language, has been developed to perform the analysis and treatment of the collected data, with the final goal of obtaining a three-dimensional (3D) image representative of the vibration pattern of the sample. A description of the control, measurement, and data processing software and hardware of the developed system is included in this article. Finally, experimental results are shown for a PZT5 working in resonant pattern and with nonlinear effects.

Noncontact inspection laser system for characterization of piezoelectric samples

In this work measurements on a piezoelectric sample in dynamic behavior were taken, in particular, around the frequencies of resonance for the sample where the nonlineal effects are accentuated. Dimension changes in the sample need to be studied as that will allow a more reliable characterization of the piezoelectric samples. The goal of this research is to develop an inspection system able to obtain measurements, using a noncontact laser displacement transducer, also able to visualize, in three-dimensional graphic environment, the displacement that takes place in a piezoelectric sample surface. In resonant mode, the vibration mode of the sample is visualized.

Energy harvesting input stage model for piezoelectric materials involved in road traffic applications

Practical models of the input stage energy harvesting circuits, based on piezoelectric elements involved in road traffic environments, were obtained and optimized. The availability of power harvested at the optimal point of operation is determined assuming regular traffic, generated using a test bench designed to emulate the real road traffic. In order to compare the measured response from the simulation test bench, data were collected from a real traffic sensing installation, build in an inner road of our University Campus. Experimental results are presented for piezoelectric cable, although the results obtained from a commercial piezoelectric are presented to explore the effect of mechanical amplification in order to improve the previous results.

Optimal linear model for piezoelectric materials involved in road traffic energy harvesting applications

The optimal topological structure of the piezoelectric materials involved in road traffic harvesters is covered with the linearized models obtained using practical measurements. The behavior of that harvesters is analyzed in order to obtain practical results that guarantees the optimal tracked maximum power point of operation. Our specifically designed (patent pending) test bench generates regular traffic that emulates the real road traffic. In order to compare the measured response from the simulation test bench, data were collected from a real traffic sensing installation, build in an inner road of our University Campus. Experimental results are presented for piezoelectric cable, although the results obtained from a commercial piezoelectric are presented to explore the effect of mechanical amplification in order to improve the previous results.

STUDY OF MISCIBILITY IN MIXED SYSTEMS OF PRESINTERED PZT

ABSTRACT In this work, we present a compositional and electrical study of mixed presinterized systems following a solid-state and sol-gel rule in order to achieve mixed morphotropic PZT compositions with other compositions in different proportions. A complete characterization of the electrical response of the different PZT compositions is presented, as is the degree of reactivity of the powder according to the route followed and the capacity to mix phases indicating the greater or lesser miscibility between compositions.

Virtual instrument to obtain electrical models of piezoelectric elements used in energy harvesting

ABSTRACT A new virtual instrument (VI) has been designed to obtain the Fourier model of piezoelectric devices under test (PDUT) in road traffic environments, and the linear electrical model of the piezoelectric harvester circuit involved in energy harvesting applications. The VI provides a high grade of automatisation and high accuracy in the characterisation procedure of a piezoelectric harvesting system. The maximum power can be predicted and the number of piezoelectric elements can be calculated to achieve a given power value. The VI system controls the test bench (patent protected), which simulates the effect of the road traffic, and obtains the Fourier model of the PDUT. The VI controls the switched circuit’s matrix of the harvesting electronic hardware (HEH) to select the PDUTs and the rectifier topology. The VI also connects capacitors and load resistors of the HEH and computes the key parameters of the piezoelectric harvester model.

Automatic verification system for Doppler kinemometers

We have developed a system to verify that the Doppler kinemometers installed on the highway system are functioning correctly. An EMBEDDED SERVER is installed next to the test kinemometer (subject of the study) and the verification tasks are programmed and sequenced (in minutes, hours, days, months, etc) through a remote CLIENT subsystem. As the tasks are carried out, the vehicle speed data is collected and stored. The speed measurements are carried out by the verifying system and by the Doppler kinemometer. The system then automatically pairs the measurements collected by both systems. The system generates a report with the speed data and estimates the errors and possible problems with the test kinemometer. The system has been patented (P200901618).