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Aiming at the demand for subjective evaluation of driveability for fuel cell vehicles, the modeling and evaluation method of driveability for fuel cell vehicles were studied in this paper. Firstly, a real-time model of the fuel cell vehicle powertrain system was established, which included the fuel cell model, power battery model, DC/DC converter model and drive motor model. Secondly, it was integrated with the vehicle dynamics model to form a virtual prototype of a fuel cell vehicle. And a virtual subjective evaluation platform for fuel cell vehicles was built by combining the virtual prototype and high-fidelity driving simulator. Thirdly, a subjective evaluation method of driveability for fuel cell vehicles was proposed, which included the starting performance, acceleration performance, uniform speed performance and tip-in/tip-out performance. Finally, the paper used the platform and method mentioned above to conduct subjective evaluations of the fuel cell vehicles.

The increasing complexity of driving functions at the overall vehicle level results in a corresponding increase in complexity in the validation process. To expedite this process, validating overall vehicle characteristics at the subsystem level is also beneficial. Validating on subsystems is discussed using the example of the characteristic longitudinal vehicle shuffle as an overall vehicle property concerning the powertrain subsystem. The publication aims to demonstrate, through a literature review, the extent to which consideration of driveability-relevant properties already occurs at the physical subsystem level, with a focus on the frequency range of up to 30 Hz. The literature research shows that the considerations concerning driveability at the subsystem level are currently neither state of the art nor scientific, especially about the increasing number of electric vehicles; the level of knowledge is low. In the second step, this theoretical use case will be presented, in which a physical prototype (powertrain) is used to examine superimposed overall vehicle characteristics (longitudinal vehicle oscillation frequency (shuffle frequency)). For this purpose, a Hardware-in-the-Loop (HiL) approach is presented, which consists of a device under test (DUT) and two highly dynamic, permanently excited synchronous machines as load machines. A suitable manoeuvre (Tip-In) is shown, which makes it possible to evaluate the longitudinal vehicle shuffle. The analysis of the results of a coupled vehicle simulation in the HiL shows evident discrepancies in the verification of the demand values. Concerning a Tip-in, deviations of at least 70% can be determined for the speed required by the whole vehicle simulation and the system response (actual speed signal of the load machines) as a result of the step function. The wheel slip calculated from this propagates the error in the calculation of the virtual vehicle’s longitudinal shuffle frequency. Analyzing the results makes it currently impossible to validate the longitudinal vehicle shuffle at the subsystem level. Finally, there is a discussion about what significant changes are needed to achieve the required goal of vehicle driveability characterization at the powertrain level.

This paper investigates the applicability of Cone Penetration Test (CPT)-based axial capacity approaches, used for estimating pile static capacity, to the prediction of pile driveability. An investigation of the influence of various operational parameters in a driveability study is conducted. A variety of axial capacity approaches (IC-05, UWA-05 and Fugro-05) are assessed in unmodified and modified form to appraise their ability to be used in estimating the driveability of open-ended steel piles used to support, for example, offshore jackets or bridge piers. Modifications to the CPT-based design approaches include alterations to the proposed base resistance to account for the resistance mobilized under discrete hammer impacts and the presence of residual stresses, as well as accounting for the effects of static capacity increases over time, namely ageing. Furthermore, a study on the influence of various operational parameters within a wave equation solver is conducted to ascertain the relative impact of uncertain data in this respect. The purpose of the paper is not to suggest a new design procedure for estimating pile driveability, rather to investigate the influence of the various operating parameters in a driveability analysis and how they affect the magnitude of the resulting predictions. The study will be of interest to geotechnical design of piles using CPT data.

Aftermarket diagnostics combines system knowledge, TSBs, service manuals, training materials and other information sources. Next time we'll cover the final steps in the factory process and then look at my possibilities and thought process and cover more testing procedures.\" The factory chart also left out the initial visual check, TSBs and basic battery and power and ground tests.

Spark-ignition engine fuel standards have been put in place to ensure acceptable hot and cold weather driveability (HWD and CWD). Vehicle manufacturers and fuel suppliers have developed systems that meet our driveability requirements so effectively that drivers overwhelmingly find that their vehicles reliably start up and operate smoothly and consistently throughout the year. For HWD, fuels that are too volatile perform more poorly than those that are less volatile. Vapor lock is the apparent cause of poor HWD, but there is conflicting evidence in the literature as to where in the fuel system it occurs. Most studies have found a correlation between degraded driveability and higher dry vapor pressure equivalent or lower TV/L= 20, and less consistently with a minimum T50. For CWD, fuels with inadequate volatility can cause difficulty in starting and rough operation during engine warmup. The Driveability Index (DI)-a function of T10, T50, and T90-is well correlated with CWD in hydrocarbon fuels. For ethanol-containing fuels, a correction factor to the DI equation improves the correlation with CWD, although the best value for that factor has still not been determined. Ethanol increases the heat of vaporization. However, this is likely insignificant for E15 and lower concentration fuels. The impact of ethanol on driveability is likely due to its direct effect on vapor pressure at cold temperatures. For E51-E83 or flex-fuel blends, ASTM sets a minimum vapor pressure; however, published data suggest that a correction for the amount of ethanol in the fuel is needed to accurately predict CWD, possibly because ethanol has a higher lower-flammability limit.

A device under test, when applied to the test rig, often does not come with much information about its mechanical properties to the user. There are different applications in which specific properties of the device under test are of interest to the user. Therefore, a suitable model approach and a parameterisation method are required. If there is a torsional model of the plant, including the device under test and the load machines, it can, for example, be used in a model predictive control architecture. The focus of the publication is on the frequency range of driveability (f< 30 Hz) and, in particular, on the phenomenon of the vehicle shuffle mode, which is important for driving comfort. The model approach has to map these characteristics. To make this possible, the publication presents a suitable, simplified modelling approach for electric powertrains in the hardware-in-the-loop environment and the possibility of indirect parameterisation for the moment of inertia and stiffness. The investigations demonstrate that the model possesses the essential eigenmodes and frequencies observed in the measurements on the test rig. Taking into account extensions, the model enables the incorporation of the properties of an open differential, including delta speeds. The natural frequency matches the measured one with deviations less than 1%. The results also show that the parameters are smaller than assumed. The authors will revise the developed method on this basis to achieve higher information value and a better confidence interval. This further work will discuss the influence of the confidence interval on the resulting parameters.

Vehicle driveability is one of the important attributes in range-extender electric vehicles due to the electric motor torque characteristics at low-speed events. Physical vehicle prototypes are typically used to validate and rectify vehicle driveability attributes. However, this can be expensive and require several design iterations. In this paper, a model-based energy method to assess vehicle driveability is presented based on high-fidelity 49 degree-of-freedom powertrain and vehicle systems. Multibody dynamic components were built according to their true centre of gravity relative to the vehicle datum to provide an accurate system interaction. The work covered a frequency of less than 20 Hz. The results consist of the components’ frequency domination, which was structured and examined to identify the low-frequency resonances sensitivity based on different operating parameters such as road surface coefficients. An energy path method was also implemented on the dominant component by decoupling its compliances to study the effect on the vehicle driveability and low-frequency resonances. The outcomes of the research provided a good understanding of the interaction across the sub-systems levels. The powertrain rubber mounts were the dominant component that controlled the low-frequency resonances (<15.33 Hz) and can change the vehicle driveability quality.

In this paper, a cylindrical cavity sensor based on microwave resonant theory is proposed to distinguish between various driveability index gasolines under temperature variations. The working principle of the proposed sensor is based on the fact that the change in permittivity of gasoline samples inside cavity sensor will also cause a change in resonant frequency. The proposed sensor has good sensitivity in terms of resonant frequency separation, which enables it to capture the minute permittivity changes and distinguish different gasolines. By using a normal gasoline permittivity of 2.15 and changing sensor dimension parameters, the sensor was designed by high-frequency structure simulator (HFSS). The designed sensor has a resonant frequency of 7.119 GHz for the TM012 mode with a 19.2 mm radius, a 35 mm height, and one-port coupling probe of 8 mm height. The proposed cylindrical cavity sensor shows advantages of excellent resonant characteristics of small cavity size and small sample amount. To optimize and verify the parameters of the sensor, many experiments have been carried out using HFSS and a vector network analyzer (VNA). Consequently, the proposed sensor is proven to be robust to temperature changes in terms of resonant frequency separation. The minimum frequency separation to distinguish gasoline samples is found to be larger than 29 MHz with reflection coefficients under −11 dB for temperature changes from −35 °C to 0 °C. The consistency of experimental and theoretical results also are presented, which guarantees accuracy of the sensor for the distinction of gasoline.

Automobile manufacturers face challenges in detecting errors due to the complexity of interconnected vehicle components and rely on rapid analysis of large datasets. During endurance testing, vehicle fleets are driven under various conditions while measurement data is collected. These measurements help experts develop engines and components with precision. Data mining methods compress large datasets, extract key information for anomaly detection, and save analysis time. This article introduces the use of the Dynamic Time Warping (DTW) approach for analyzing measurement signals, enabling insights into event curve shapes. A novel artifact was developed to integrate this approach into the engine development process, streamlining anomaly detection for practical application. Individual events are stored in subsets, allowing them to be used for further training in supervised learning approaches. The study focuses on unlabeled time series data from Mercedes-Benz endurance testing, particularly on anomalous decelerations (hesitations), using clustering-based anomaly detection.

The backlash between engaging components in a driveline is unavoidable, especially when the gear runs freely and collides with the backlash, the impact torque generated increases the vibration amplitude. The power-split hybrid electric vehicle generates output torque only from the traction motor during the launching process. The nonlinear backlash can greatly influence the driveability of the driveline due to the rapid response of the traction motor and the lack of the traditional clutches and torsional shock absorbers in the powertrain. This paper focuses on the launch vibration of the power-split hybrid electric vehicle, establishes a nonlinear driveline model considering gear backlash, including an engine, two motors, a Ravigneaux planetary gear set, a reducer, a differential, a backlash assembly, half shafts, and wheels. For easier control, some components of the power-spilt system are simplified, after verifying the reliability of the simplified model, a linear observer(LSO) and a nonlinear observer(ESO) are designed to estimate the system state variables respectively. Based on the estimated information a dynamic matrix controller(DMC) is designed to correct the motor output torque. Through the feedback torque of the motor, the active control system can reduce the shock and vibration of the nonlinear driveline caused by the transient change of the motor torque during launch conditions.