March 21, 2018

Archives for May 2012

7th ICCSM in Zadar

Members of Precision Engineering Laboratory participated at the 7th International Conference of the Croatian Society of Mechanics (7ICCSM2012) which was held from May 22nd to 25th 2012 in Zadar, Croatia. Two papers were presented with poster on Wednesday, May 23rd, 2012.

The first paper is „Vibration energy scavenging powered wireless tire pressure monitoring sensor“ from autors David Blažević, Ervin Kamenar and Saša Zelenika. In this work an original solution of a Wireless Tire Pressure Monitoring Sensor (WTPMS), powered by a piezoelectric bimorph scavenger is presented.

The second paper is „Precision and stability analysis of Maxwell-type kinematic mounts“ from autors Saša Zelenika, Kristina Marković and Josipa Rubeša. Kinematic mounts (KMs) are often used in high-precision applications since they are self-locating and free from backlash, allow sub-micrometric re-positioning in static and dynamic applications, can accommodate differential thermal expansions, are not sensitive to contamination, are characterized by limited costs and their behaviour can be represented in closed form. Their main drawback is constituted by the high contact stresses that are to be analysed via the non-linear Hertz theory. The most common KM design configuration is designated as the Maxwell-type KM and is constituted by 3 V-grooves on one end (typically the support) and 3 spherical tops (typically balls) on the other end of the mount (typically supported piece) so as to achieve an exact constraint of all 6 spatial degrees of freedom (DOFs). The aim of this work is to analyse the influence of mechanical parameters on KMs’ behaviour and especially on their positioning precision and stability. An example of a KM used to support a large structure is considered.

The conference coverd recent developments and applications in solid and structural mechanics, fluid mechanics, heat and mass transfer using numerical, analytical, and experimental methods.

Festival of Science 2012

At the 10th Festival of Science in the City Hall of Rijeka on the April 27th a lecture titled “10 batteries less for a cleaner environment and safe driving” was presented by David Blažević & Ervin Kamenar.

Festival of Science is an event which aims to inform the public on activities and results in science, to improve public perception of scientists and and to motivate young people to research new fields and acquire new knowledge.

The lecture topic was related to the previous project named “Wireless Autonomous Tire Pressure Sensor (WATPS)” which was successfully completed in August 2011. WATPS is battery-less tire pressure sensor based on the harvesting of kinetic energy produced by environmental vibrations.

This years Festival of Science event was celebrating its 10th anniversary and the lecture topic was related to the number ten since in the working lifetime of a car, 10 batteries should be replaced in wireless pressure sensors for them to function properly (Battery lasts for about 7 years, car lifetime is about 13 years and it has 5 wheels including the spare wheel).

Opening ceremony of this event was held at City Hall Korzo on Monday, April 23rd, 2012.