Search Results (11)

Modern passenger vehicles can indicate the speed limit for a given road section using GPS, cameras, or both. Sign recognition systems must comply with specified testing procedures before operation. Our goal is to create a cost-effective lab environment for vehicle-level tests of these systems. Image recognition can be tested with various traffic signs in a simulation video placed in front of the vehicle’s camera while it runs on a chassis dyno. We tested this environment with factory-built systems, displaying recognized signs on the dashboard. The simulation software allows unlimited signs, eliminating the need for long-distance driving or extensive test track setups. While the lab environment does not replace final public road testing, it is a cost-effective solution for the development and testing of traffic sign recognition systems. Full article

Electric and hybrid vehicles, similarly to combustion engine ones, can experience malfunctions, yet preventive diagnostics for their electric motors are underdeveloped. While many methods exist for testing electric motors in heavy industry, they are not commonly applied in the vehicle industry. Our study aims to develop a real-time, non-invasive fault detection procedure for electric motors in these vehicles. Previous research has focused on simulations, but our work involves real measurements conducted in a controlled laboratory using a two-axle chassis dyno. We present the hybrid vehicle’s drivetrain, our equipment, and the feasibility of simulated methods, and we also detail the evaluation method used. Full article

Electric cars, like internal combustion vehicles, emit particulate pollution from non-exhaust systems, i.e., tires and brakes, which is included in the Euro 7 emission standard planned for implementation. Tests conducted on chassis dynamometers are accompanied by particulate emissions from non-exhaust systems, which are introduced into the ambient air on the test bench. Particulate emissions tests from non-engine systems on chassis dynamometers are mainly aimed at measuring the mass or number of particulates from tires and brakes. In contrast, little attention is paid to the immission of particulate matter from tires and brakes on the dynamometer during tests, which in the case of electric cars include, for example, measurements of energy consumption or range. Therefore, in order to draw attention to the problem of these emissions, the authors carried out measurements of PM2.5 and PM10 immissions into the air in the climatic chamber during tests of an electric car on a chassis dynamometer. The car tests were carried out in accordance with the WLTC (Worldwide harmonized Light duty Test Cycle) and at constant speed. Based on the test results, a model was proposed for the immission of particulate matter in laboratory air from tire and brake abrasion, taking traffic parameters into account. The results and the developed model show that air quality, in terms of particulate content, deteriorates significantly during testing. Full article

The article presents the justification for the necessity to use chassis dynamometers in the tuning process of dual-fuel trucks. The research system used and the research methodology are presented. The research results present the approach to solving problems related to setting the technical (physical) data of the tested vehicle on the dynamometer, selection of the vehicle engine operation range, the impact of the value of the forced load on the vehicle drive axle, selection of the dyno operation mode for the expected tasks and the impact of the correctness of the selection of the scope of the analysis of data on losses in the drive system. The article shows the above-mentioned influence on the test results on the dynamometer and on the tuning results. The article closes with a conclusion detailing prospects for developing the presented results. Full article

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, NO_x, 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, NO_x 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, NO_x 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. Full article

Substantial advances in European road vehicle emissions have been achieved over the past three decades driven by strengthening revisions in emissions legislation and enabled by advances in fuel, vehicle engine and emissions control technologies. As both vehicle technology and emissions legislation in Europe continue to evolve, Concawe has conducted a study to examine the effects that fuels can have on emissions, in this case from commercial road vehicles. A bus certified to Euro VI emissions level and a delivery truck certified to Euro V emissions level have been tested on a chassis-dyno over the World Harmonized Vehicle Cycle (WHVC) and Transport for London Urban Inter-Peak (TfL UIP) test cycles with six fuels: an EN590-compliant B5 (petroleum diesel containing 5% biodiesel by volume), a bioderived paraffinic diesel, a 50:50 blend of the aforementioned fuels, a low-density petroleum-derived B5, a B30 and the same B30 additized with a high dose of cetane number improver (CNI). Results show reduced NO_x reductant (AdBlue) consumption with paraffinic diesel in the Euro VI bus due to lower engine-out NO_x emissions. More surprisingly, higher hydrocarbon emissions were observed with some low-density hydrocarbon fuels in the Euro V truck. Compared to B5, B30 with and without CNI did not affect tank-to-wheel (TTW) CO₂, volumetric fuel consumption or NO_x by statistically significant margins. When considered with the findings of a complementary light-duty study, it is apparent that low-density diesel fuels could offer overall benefits to both emissions affecting local air quality and to greenhouse gas emissions on a TTW basis. The addition of higher fatty acid methyl ester (FAME) levels to fuels can be used to increase renewable fuel contribution resulting in no penalty in NO_x emissions from modern technology vehicles. Compatibility of these fuels with the existing vehicle fleet would require further specific consideration. Outside of fuel properties considerations, Euro VI aftertreatment systems can increase N₂O emissions at the tailpipe through chemical reactions in the catalyst. This can translate into about 10% contribution of N₂O emissions to the overall GHG emissions of the vehicle. Full article

Reducing air pollution caused by emissions from road traffic, especially in urban areas, is an important goal of legislators and the automotive industry. The introduction of so-called “Real Driving Emission” (RDE) tests for the homologation of vehicles with internal combustion engines according to the EU6d legislation was a fundamental milestone for vehicle and powertrain development. Due to the introduction of non-reproducible on-road emission tests with “Portable Emission Measurement Systems” (PEMS) in addition to the standardized emission tests on chassis dynamometers, emission aftertreatment development and validation has become significantly more complex. For explicit proof of compliance with the emission and fuel consumption regulations, the legislators continue to require the “Worldwide Harmonized Light Duty Vehicle Test Cycle” (WLTC) on a chassis dynamometer. For calibration purposes, also various RDE profiles are conducted on the chassis dynamometer. However, the combination of precisely defined driving profiles on the chassis dynamometer and the dynamics-limiting boundary conditions in PEMS tests on the road still lead to discrepancies between the certified test results and the real vehicle behavior. The expected future emissions standards to replace EU6d will therefore force even more realistic RDE tests. This is to be achieved by significantly extending the permissible RDE test boundary conditions, such as giving more weight to the urban section of an RDE test. In addition, the introduction of limit values for previously unregulated pollutants such as nitrogen dioxide (NO₂), nitrous oxide (N₂O), ammonia (NH₃) and formaldehyde (CH₂O) is being considered. Furthermore, the particle number (for diameters of solid particles > 10 nm: PN₁₀), the methane (CH₄) emissions and emissions of non-methane organic gases (NMOG) shall be limited and must be tested. To simplify the test procedure in the long term, the abandonment of predefined chassis dyno emission tests to determine the pollutant emission behavior is under discussion. Against this background, current testing, validation, and development methods are reviewed in this paper. New challenges and necessary adaptations of current approaches are discussed and presented to illustrate the need to consider future regulatory requirements in today’s approaches. Conclusions are drawn and suggestions for a robust RDE validation procedure are formulated. Full article

A vehicle’s air drag coefficient (Cd) and rolling resistance coefficient (RRC) have a significant impact on its fuel consumption. Consequently, these properties are required as input for the certification of the vehicle’s fuel consumption and Carbon Dioxide emissions, regardless of whether the certification is done via simulation or chassis dyno testing. They can be determined through dedicated measurements, such as a drum test for the tire’s rolling resistance coefficient and constant speed test (EU) or coast down test (US) for the body’s air Cd. In this paper, a methodology that allows determining the vehicle’s Cd·A (the product of Cd and frontal area of the vehicle) from on-road tests is presented. The possibility to measure these properties during an on-road test, without the need for a test track, enables third parties to verify the certified vehicle properties in order to preselect vehicle for further regulatory testing. On-road tests were performed with three heavy-duty vehicles, two lorries, and a coach, over different routes. Vehicles were instrumented with wheel torque sensors, wheel speed sensors, a GPS device, and a fuel flow sensor. Cd·A of each vehicle is determined from the test data with the proposed methodology and validated against their certified value. The methodology presents satisfactory repeatability with the error ranging from −21 to 5% and averaging approximately −6.8%. A sensitivity analysis demonstrates the possibility of using the tire energy efficiency label instead of the measured RRC to determine the air drag coefficient. Finally, on-road tests were simulated in the Vehicle Energy Consumption Calculation Tool with the obtained parameters, and the average difference in fuel consumption was found to be 2%. Full article

The octane number is a measure of the resistance of gasoline fuels to auto-ignition. Therefore, high octane numbers reduce the engine knocking risk, leading to higher compression threshold and, consequently, higher engine efficiencies. This allows higher compression ratios to be considered during the engine design stage. Current spark-ignited (SI) engines use knock sensors to protect the engine from knocking, usually adapting the operation parameters (boost pressure, spark timing, lambda). Moreover, some engines can move the settings towards optimized parameters if knock is not detected, leading to higher performance and fuel economy. In this work, three gasolines with different octane ratings (95, 98 and 100 RON (research octane number)) were fueled in a high-performance vehicle. Tests were performed in a chassis dyno at controlled ambient conditions, including a driving sequence composed of full-load accelerations and two steady-state modes. Vehicle power significantly increased with the octane rating of the fuel, thus decreasing the time needed for acceleration. Moreover, the specific fuel consumption decreased as the octane rating increased, proving that the fuel can take an active part in reducing greenhouse gas emissions. The boost pressure, which increased with the octane number, was identified as the main factor, whereas the ignition advance was the second relevant factor. Full article

Although Hybrid Electric Vehicles (HEVs) represent one of the key technologies to reduce CO₂ emissions, their effective potential in real world driving conditions strongly depends on the performance of their Energy Management System (EMS) and on its capability to maximize the efficiency of the powertrain in real life as well as during Type Approval (TA) tests. Attempting to close the gap between TA and real world CO₂ emissions, the European Commission has decided to introduce from September 2017 the Worldwide Harmonized Light duty Test Procedure (WLTP), replacing the previous procedure based on the New European Driving Cycle (NEDC). The aim of this work is the analysis of the impact of different driving cycles and operating conditions on CO₂ emissions and on energy management strategies of a Euro-6 HEV through the limited number of information available from the chassis dyno tests. The vehicle was tested considering different initial battery State of Charge (SOC), ranging from 40% to 65%, and engine coolant temperatures, from −7 °C to 70 °C. The change of test conditions from NEDC to WLTP was shown to lead to a significant reduction of the electric drive and to about a 30% increase of CO₂ emissions. However, since the specific energy demand of WLTP is about 50% higher than that of NEDC, these results demonstrate that the EMS strategies of the tested vehicle can achieve, in test conditions closer to real life, even higher efficiency levels than those that are currently evaluated on the NEDC, and prove the effectiveness of HEV technology to reduce CO₂ emissions. Full article

This paper describes a two-fold approach carried out in collaboration between IFPEN and the French ADEME with the aim to evaluate a Plug-in Hybrid vehicle according to its conditions of use. The vehicle considered, an Opel Ampera, has been widely tested on a chassis dyno and simulated using IFPEN LMS.IMAGINE.Lab AMESim^® platform. The software principles and its validation on different specific cases, thanks to experimental results, are described. The PHEV simulation tool is used to evaluate the influence of two European standard procedures and the influence of their parameters on the weighed CO₂ emission. Full article