Abstract. The nanoparticles of some materials can be used successfully to improve tribological properties through decreasing both wear and friction borne out of contact between the contact surfaces of elements in different devices, particularly vehicles. Nanoparticles of TiO2 and ZrO2 were chosen as additives to the lithium grease lubricating the contact surfaces in tie rod ends. The object of study was the steel ball -the component of the tie rod end -mating with the polymer insert and lubricated with the pure lithium grease or containing the addition of pure TiO2, pure ZrO2 nanoparticles, with a 1%wt. Studies on friction were carried out using the tester allowing cyclical rotational motion and different loading of contact. Wear was investigated by driving a car, whose tie rod ends were analysed, on a fixed 'eight'-shape track and with a fixed velocity pattern. The aim of the study was to obtain the values and waveforms of friction moment and wear versus cycles, loading and composition of lubricating grease. The waveforms of friction coefficient were obtained using the FEM model of the analysed contact zone. Based on the obtained waveforms, recommendations for the composition of additives for lithium grease were made.

This paper presents the accuracy investigation results and functionality of Ubisense RTLS positioning system. Three kinds of studies were conducted: test of calibration accuracy, analysis of theoretical accuracy of the coordinates determination as well as accuracy measurements in field conditions. Test of calibration accuracy was made with several different geometric constellation of reference points (tag positions). We determined changes of orientation parameters of receivers and disturbance of positioning points coordinates against chosen reference points constellations. Analysis of theoretical accuracy was made for several receivers spatial positions and their orientations. It allowed to indicate favourable and unfavourable measurement area considering accuracy and reliability. Real positioning accuracy of the Ubisense system was determined by comparison with coordinates measured using precise tacheometer TCRP1201+. Results of conducted experiments and accuracy analysis of test measurement were presented in figures and diagrams.

The amount of hybrid vehicles and their contribution have increased in the global market. They are a promising aspect for a decrease in emissions. Different tests are used to determine the factors of such emissions. The goal of the present study was to compare the emissions of two hybrid vehicles of the same manufacturer: the plug-in version and the HEV version (gasoline + electric engine). These vehicles were chosen because they comprise the largest market share of hybrid cars in Poland. The exhaust emission tests were conducted in the WLTC tests on a chassis dynamometer and under real traffic conditions. Simultaneous testing on a dyno and under real driving is the most adequate test to assess the environmental aspects of vehicles—especially hybrids. The combustion engines of the tested vehicles were supplied with gasoline containing 5% biocomponents. The emissions, including CO2, CO, NOx, THC and PNs, were measured in accordance with the European Union procedure. According to the latter, the resistance to motion of the chassis dyno was adjusted to the road load, allowing the hybrid vehicles to move in electric mode and allowing the dynamometer to operate in energy recovery mode. The obtained emissions of CO2, CO, NOx and THC in the case of the plug-in hybrid vehicle were lower by 3%, 2%, 25%, and 13%, respectively, compared to the case of HEV. Fuel consumption in the case of the plug-in hybrid vehicle was lower by 3%, and PN was lower by 10% compared to the case of HEV (WLTC). In real driving conditions, the differences were more pronounced in favour of the plug-in vehicle: CO2 emissions in the RDE test were 30% lower, NOx emissions were 50% lower, and PN was 10% lower. An increase in emissions was only observed for CO2 emissions—the plug-in vehicle’s on-road emissions were 6% higher compared to the HEV. The obtained emissions for FC and PN varied with actual velocity values due to competitive driving between a combustion engine and an electric motor, as well as existing acceleration and deceleration events during the test and other factors.

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