Veli Heikkinen

Abstract: In this paper, an energy efficient streetlight for pedestrian roads is introduced. Energy efficiency is achieved via up-to-date light-emitting diode (LED) technology and added intelligence utilising integrated sensors and wireless control. Thermal and electrical design of the luminaire contributed to good technical functionality. The performance of the luminaire was validated with testing. The luminaire was compared with commercial lamp and LED-based street lighting technology by technical values and user acceptance. Energy savings of 19–44% through improved luminous efficacy was demonstrated without added intelligence. With smart control further power saving potential of 40–60% was shown depending on the lighting environment and pedestrian presence. User feedback of a pilot installation comparing commercial luminaires with the newly developed streetlight revealed that on average the users preferred the developed streetlight over the commercial luminaires.

TL;DR: In this paper, a prototype imaging pulsed time-of-flight laser range finder is presented, which produces an image with 36 pixels, each containing distance and reflectivity information.

TL;DR: In this paper, the authors show how the traditional optomechanical design of the IR temperature measuring systems produce inaccurate results when used in handheld mobile devices, when the mobile device is not thermally stable and measured targets are significantly colder than the device, the measurement error can be several degrees.

TL;DR: In this article, a copper-core metal core printed circuit board (MCPCB) substrate with copper filled microvias is introduced to improve thermal performance of high-power chip-on-board multichip LED module.

TL;DR: In this article, the thermal performance of high-power LED modules made with two types of circuit boards: novel substrates based on insulated aluminum material systems (IAMSs) technology that inherently allows using thermal vias under the LEDs and traditional metal core printed circuit boards (MCPCBs) commonly used with high power LED applications.