Distributed simulation and testing for the design of a smart suspension. - In: SAE international journal of connected and automated vehicles, ISSN 2574-075X, Volume 3 (2020), issue 2, Article ID 12-03-02-0011, Seite 129-138
https://doi.org/10.4271/12-03-02-0011
Comparison of particulate matter and number emissions from a floating and a fixed caliper brake system of the same lining formulation. - In: SAE technical papers, ISSN 2688-3627, (2020), SAE technical paper 2020-01-1633, S. 1-11
The particulate emissions of two brake systems were characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust PN regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a section (trip-10) novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of trip-10 tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle. PM2.5 emissions of burnished pads averaged at 2.6 mg/km/brake and 4.1 mg/km/brake for the FLC and the FXC system, respectively. A large fraction of the airborne PM was found to be larger than 2.5 [my]m, leading to 2.7 times higher PM10 emissions. Therefore, proper PM10 measurements will require careful considerations on the operating tunnel parameters to minimize particle losses. The FXC system yielded ˜50% higher PM and two times higher PN emissions despite the 22% lower disc temperatures measured with an embedded thermocouple. No indication of volatile particle formation was observed, with more than 80% of total PN having an optical diameter larger than 300 nm. The results illustrate the challenges associated with the use of disc temperature measurements for the control of a representative braking procedure.
https://doi.org/10.4271/2020-01-1633
Addressed fiber bragg structures in load-sensing wheel hub bearings. - In: Sensors, ISSN 1424-8220, Bd. 20 (2020), 21, 6191, insges. 14 S.
The work presents an approach to instrument the load-sensing bearings for automotive applications for estimation of the loads acting on the wheels. The system comprises fiber-optic sensors based on addressed fiber Bragg structures (AFBS) with two symmetrical phase shifts. A mathematical model for load–deformation relation is presented, and the AFBS interrogation principle is described. The simulation includes (i) modeling of vehicle dynamics in a split-mu braking test, during which the longitudinal wheel loads are obtained, (ii) the subsequent estimation of bearing outer ring deformation using a beam model with simply supported boundary conditions, (iii) the conversion of strain into central frequency shift of AFBS, and (iv) modeling of the beating signal at the photodetector. The simulation results show that the estimation error of the longitudinal wheel force from the strain data acquired from a single measurement point was 5.44% with a root-mean-square error of 113.64 N. A prototype load-sensing bearing was instrumented with a single AFBS sensor and mounted in a front right wheel hub of an experimental vehicle. The experimental setup demonstrated comparable results with the simulation during the braking test. The proposed system with load-sensing bearings is aimed at estimation of the loads acting on the wheels, which serve as input parameters for active safety systems, such as automatic braking, adaptive cruise control, or fully automated driving, in order to enhance their effectiveness and the safety of the vehicle.
https://doi.org/10.3390/s20216191
Recent advancements in continuous wheel slip control. - In: Advances in dynamics of vehicles on roads and tracks, (2020), S. 1525-1535
The paper presents an overview of continuous wheel slip control (WSC) methods as the part of anti-lock braking system (ABS) for the several vehicles configurations with friction brakes and electric motors. Performance of proposed WSC design variants using several control techniques has been experimentally evaluated for three different test vehicles: Sport Utility Vehicle (SUV) with decoupled electro-hydraulic brake (DEHB) system, SUV with four individual on-board electric motors (OBM), and compact vehicle with four individual in-wheel motors (IWM). Obtained results demonstrated that proposed continuous WSC variants provide a simultaneous effect on braking efficiency and ride quality as well as robust operation in various road conditions. Presented summary provides outlook on future perspectives of the continuous WSC and compares its status with conventional rule-based ABS systems.
Torque vectoring control on ice for electric vehicles with individually actuated wheels. - In: Advances in dynamics of vehicles on roads and tracks, (2020), S. 1543-1551
Recent studies on torque vectoring control for electric vehicles proposed various efficient solutions demonstrating improvement of vehicle stability for evasive manoeuvres. However, the torque vectoring on very low friction surfaces such as black ice or wet snow is rarely investigated, especially for the electric vehicles with off-road capability. The presented study contributes to this topic by laying the groundwork for further advanced torque vectoring designs. Within the framework of this paper, the target vehicle is a sport utility vehicle equipped with four on-board electric motors controlling each wheel separately. The functionality of the developed controllers is tested under hardware-in-the-loop simulations for icy road conditions. For this purpose, the tyre model has been parameterized and validated based on the experimental data conducted on a unique terramechanics test rig at Virginia Polytechnic Institute and State University. The test results confirm very good functionality of the developed controllers and demonstrate an improvement of the electric vehicle driving performance.
Real-time simulation of microwave-photonic system for estimating the tangential deformation of tire. - In: 2020 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO), (2020), insges. 7 S.
https://doi.org/10.1109/SYNCHROINFO49631.2020.9166028
Wheel slip control for the electric vehicle with in-wheel motors: variable structure and sliding mode methods. - In: IEEE transactions on industrial electronics, Bd. 67 (2020), 10, S. 8535-8544
https://doi.org/10.1109/TIE.2019.2942537
Optimization based sliding mode control in active suspensions: design and hardware-in-the-loop assessment. - In: European Control Conference 2020, (2020), S. 1607-1612
https://ieeexplore.ieee.org/document/9143835
Tire particle emissions: demand on reliable characterization. - In: Tire science and technology, ISSN 0090-8657, Bd. 48 (2020), 2, S. 107-122
Tire emissions are recently becoming an important topic in environmental science and among visionary automotive engineers. Deep understanding of the mechanisms involved in tire wear and emissions and their reliable physical/chemical characterization should be assumed as an urgent task. With the aim to contribute to a trustworthy characterization of tire wear and emissions, this paper presents both (i) analysis of state-of-the-art in this field and (ii) a first experimental approach to the collection of particles from a rotating tire in a new developed test box.
https://doi.org/10.2346/tire.19.170181
Modeling of microwave-photonic system for assessing the tangential component of tire deformation. - In: 2020 Wave Electronics and its Application in Information and Telecommunication Systems, (2020), insges. 7 S.
https://doi.org/10.1109/WECONF48837.2020.9131541