Abstract: Temperature inconsistency is inevitable during the battery operation, which has a significant impact on its performance. To quickly predict the temperature distribution in a battery cell, a three-heat-source electro-thermal coupled model is proposed in this article. The temperature of four feature regions in a battery cell can be determined in short time, which is potential to be implemented online. In addition, the distributed equivalent circuit model is proposed to calculate the heat generated by different heat sources. To identify the parameters of the electrical and thermal submodels, the experimental test bench is established, and the parameterizations under different conditions are carried out. In addition, the transient parameters, including the internal resistance and entropy coefficient, are adjusted with different state of charges (SOCs) and temperature. Finally, the validity and robustness of the proposed model are demonstrated through various tests of different operating conditions. The results illustrate that the uneven surface temperature distribution of the battery cell can be estimated fast, in less than 1 s. The error deviation of the proposed model is less than 1.4 °C under different conditions.

Abstract: : The presented article aims to design an educational test bench setup for smart grids and renewable energies with multiple features and techniques used in a microgrid. The test bench is designed for students, laboratory engineers, and researchers, which enables electrical microgrid system studies and testing of new, advanced control algorithms to optimize the energy efficiency. The idea behind this work is to design hybrid energy sources, such as wind power, solar photovoltaic power, hydroelectric power, hydrogen energy, and different types of energy storage systems such as batteries, pumped storage, and flywheel, integrating different electrical loads. The user can visualize the state of the components of each emulated scenario through an open-source software that interacts and communicates using OPC Unified Architecture protocol. The researchers can test and validate new solutions to manage the energy behavior in the grid using machine learning and optimization algorithms integrated in the software in form of blocks that can be modified and improved, and then simulate the results. A model-based system of engineering is provided, which describes the different requirements and case studies of the designed test bench, respecting the open-source software and the frugal innovation features in which there is use of low-cost hardware and open-source software. The users obtain the opportunity to add new sources and new loads, change software platforms, and communicate with other simulators and equipment. The students can understand the different features of smart grids, such as defect classification, energy forecasting, energy optimization, and basics of production, transmission, and consumption. Author Contributions: Conceptualization, O.L., H.E.H. and N.G.; state of art, O.L. and N.G.; simulations, O.L. and H.E.H.; design, O.L.; formal analysis, M.B. and A.C; investigation, O.L., M.B. and A.C.; resources, O.L.; model-based system engineering, H.E.H. and O.L.; writing—original draft preparation, writing, and editing, O.L., H.E.H. N.G.; supervision, M.B. and A.C.;

Abstract: In order to reduce the impact of aviation on climate, new technologies like fuel cell and battery hybrids are needed. To develop a hybrid electric aircraft, a flexible and adaptable laboratory test setup of the power train is a cost- and time-effective solution. Replacing the fuel cell and battery with DC sources simplifies the setup, but the characteristics of the fuel cell and the battery must be reproduced. This study presents a test setup for direct hybrid electric power trains with an emulated fuel cell and battery. Two DC (Direct Current) sources are controlled with the help of a database to mirror the behavior of the fuel cell and battery. The setup allows the investigation of the drive train behavior of a direct hybrid consisting of a variety of fuel cells and batteries. The hybrid behavior for different battery state of charge as well as different battery sizes are examined their the influence on the voltage variation within the system is analyzed. The more the fuel cell contributes to the hybrid power, the greater the voltage difference within the entire system. A higher power contribution from the battery reduces the system voltage variation at high power. At a rated power of 5kW, the voltage variation is lowered by 37.2% when the fuel cell share is reduced from 90% to 50%. A lower state of charge of the battery increases the voltage variation.

Abstract: With the rapid development of the sustained economy, the sales of electric vehicles are increasingly pressing, and today the maintenance has severely impeded the marketing and usage of electric vehicles. The maintenance procedure for electric vehicles is considered a critical process, tell its affect the security and availability directly with the passengers. Many of research efforts are still devoted to develop and innovate on electric traction systems diagnostic and prognostic. Furthermore, in high-quality education, especially engineering education, topics concerning the vital and actual concerns should comprise more than theoretical knowledge, in purpose to close the relationship between the present technology and the student’s environment and provides hands-on engineering experience and training of general engineering skills, in order to avoid non-standard, unskilled maintenance work. The paper presents a first step towards designing a test bench of a fully electric vehicle’s Powertrain used for research and educational purposes using model-based systems engineering (MBSE) and systems modelling language (SysML) thorough the CESAM architecting and modelling framework. As the first step of the system’s design, an operational perspective layout of the diagnostic and prognostic’s test bench is built and presented using this technique.

Abstract: This paper presents the results of tests on the railway disc brake with regard to the weight wear of friction pads. The tests were carried out at a certified brake test bench where the friction-mechanical characteristics of the railway brake were determined. The test stand was additionally equipped with a thermal imaging camera to observe the contact between the brake pads and the brake disc. The scientific goal of the test is to evaluate the relationship between the weight wear of friction pads and the quantities characterizing the braking process. The quantities characterizing the braking process included pad-to-disc contact area, friction pad thickness, pad-to-disc pressure, and braking speed. A regression model to estimate the friction pad wear on the basis of a single braking with the given input quantities was determined. The greatest influence on the increase in weight wear of friction pads has the braking velocity, which was confirmed by the value of the correlation coefficient of the regression model at value 0.81. The pressure of the friction pad to the disc and the friction pad thickness do not have a significant effect on the weight wear described by the regression model, and the obtained correlation coefficient for these parameters was lower than the value of 0.2.

Abstract: A detailed benchmark analysis is presented to compare the efficient evaluation of ADAS/AD functions in conventional real driving and SiL/HiL environments with a novel Vehicle-in-the-Loop (ViL) test bench solution. Two ViL installations have been set up in Germany and Japan with highly-dynamic wheel dynamometers, a novel steering force emulator in combination with a validated vehicle model and a detailed environment simulation. Selected test scenarios from vehicle dynamics, NCAP, highway and urban driving have been configured and executed in manual, assisted and automated driving mode. It can be shown that the unique integration of Powertrain-, Steering- and Brake-in-the-Loop together with Sensor-in-the-Loop allows highly realistic tests in the complete vehicle operation range up and beyond the dynamic limits. For the implemented prototypical ADAS functions several sensor and function weaknesses within critical driving maneuvers have been detected in the same way on the bench as in the real test. A key success factor has been to establish a novel process to validate standardized sensor and environment models against the real world, this being the precondition for any simulation-based homologation of ADAS/AD systems. This enables a much more efficient optimization and validation of ADAS/AD functions in the lab compared to real track testing.

Abstract: A new reflected shock tunnel has been commissioned at Sandia capable of generating hypersonic environments at realistic flight enthalpies. The tunnel uses an existing free-piston driver and shock tube coupled to a conical nozzle to accelerate the flow to approximately Mach 9. The facility design process is outlined and compared to other ground test facilities. A representative flight enthalpy condition is designed using an in-house state-to-state solver and piston dynamics model and evaluated using quasi-1D modeling with the University of Queensland L1d code. This condition is demonstrated using canonical models and a calibration rake. A 25 cm core flow with 4.6 MJ/kg total enthalpy is achieved over an approximately 1 millisecond test time. Analysis shows that increasing piston mass should extend test time by a factor of 2-3.

Abstract: Abstract During the braking process, a large amount of heat energy is generated at the friction surfaces between the brake disc and pads and rapidly dissipates into the disc volume. In this paper, a three-dimensional thermo-mechanical coupling model of high-speed wheel-mounted brake discs containing bolted joints and contact relationships is established. The direct coupling method is used to analyze the temperature and stress of the brake discs during an emergency braking event with an initial speed of 300 km/h. A full-scale bench test is also conducted to monitor the temperatures of the friction ring and bolted joints. The simulation result shows that the surface temperature of the friction ring reaches its peak value of 414 °C after 102 s of braking, which agrees well with the bench test result. The maximum alternating thermal stress occurs in the bolt hole where the maximum circumferential compressive stress is − 658 MPa and the maximum circumferential tensile stress is 134 MPa. During the braking process, the out-of-plane deformation of the middle part of the friction ring is larger than that of the edge, which increases the axial tensile load of the connecting bolt. This work provides support for the design of brake discs and connecting bolts.

Abstract: For a 120kW hydrogen fuel cell system, a centrifugal air compressor with fixed power of 22kW fuel cell is designed. Firstly, the theoretical calculation is carried out for the aerodynamic characteristics of a ultra-high-speed permanent magnet synchronous motor, an air compressor, and an aerodynamic foil bearing. Then, a prototype is trial-produced and a related test bench is built for test verification. Finally, both the simulation and test results indicate that the designed centrifugal air compressor meets the overall requirements of the hydrogen fuel cell system, and the relevant conclusions provide both theoretical and experimental references for the subsequent series development and design of the centrifugal air compressor.

Abstract: The coefficient of friction (COF) is one of the core factors in the evaluation of brake system performance. It is challenging to predict the COF, since it is strongly influenced by several parameters such as contact pressure (p), slip rate (v) and temperature (T) that depend on the driving conditions. There is a need for better models to describe how the brake friction varies under different driving conditions. The purpose of this research is to study the possibility of using 3D friction pvT-maps to estimate the COF of a disc brake system under different driving conditions. The 3D friction pvT-maps are created by filtering results of material tests conducted in a mini-dyno inertia bench. The COF measured under different driving cycles in an inertia dyno bench with the full brake system are compared with the COF estimated by the friction maps coming from the reduced scale dyno bench to investigate the validity of the simulation approach. This study shows that mini dyno bench is suitable to obtain a tribological characterization of the friction pad–disc rotor contact pair and is able to replace the full inertia dyno bench to investigate the brake system performance.

Abstract: This paper studies the behavior of a Euro 6 diesel engine tested under dynamic conditions corresponding to different real driving emissions (RDE) scenarios. RDE cycles have been performed in an engine test bench by simulating its operation in a long van application. A computer tool has been designed to define the cycle accounting for different dynamic characteristics and driver behaviors to study their influence on CO2 and pollutant emissions, particularly CO, THC, and NOX. Different dynamic parameters have been established in terms of power, torque, engine speed, or vehicle speed. Additionally, a tool to estimate the emission of an RDE cycle from steady-state maps has been developed, helping to identify emission trends in a clearer way. Finally, the conclusions suggest that driving patterns characterized by lower engine speeds lead to fewer emissions. In addition, the analysis of RDE cycles from stationary maps helps to estimate the final tailpipe emissions of CO2 and NOX, offering the possibility to rely on tests carried out on engine test bench, dynamometer, or on the road.

Abstract: To successfully launch automated vehicles into the consumer market, there must be credible proof that the vehicles will operate safely. However, finding a method to validate the vehicles' safe operation is a challenging problem. While scenario-based test approaches seem to be possible solutions, they require execution of a large number of test cases. Several test benches, ranging from actual test vehicles to partly or fully simulated environments, are available to execute these test cases. Each test bench provides different elements, which in turn, have different parameters and parameter ranges. The composition of elements with their specific parameter values at a specific test bench that is used to execute a test case is referred to as a test bench configuration. However, selecting the most suitable test bench configuration is difficult. The selected test bench configuration determines whether the execution of a specific test case provides sufficiently valid test case results with respect to the intended purpose, for example, validating a vehicle's safe operation. The effective and efficient execution of a large number of test cases requires a method for systematically assigning test cases to the most suitable test bench configuration. Based on a proposed method for classifying test bench configurations, we propose and illustrate a method for systematically assigning test cases to test bench configurations in a scenario-based test approach for automated vehicles. This assignment method allows for the effective and efficient execution of a large number of test cases while generating sufficiently valid test case results.

Abstract: Shorter development times, increased standards for vehicle emissions and a greater number of vehicle variants result in a higher level of complexity in the vehicle development process. Efficient development of powertrain and driver assistance functions under comparable and reproducible operating conditions is possible on vehicle test benches. Yet, the realistic simulation of real driving environments on test benches is a challenge. Current test procedures and new technologies, such as Real Driving Emission tests and Autonomous Driving, require a reproducible and even more detailed simulation of the driving environment. Due to this, the simulation of curve driving in particular is gaining in importance. This results from its significant influence on energy consumption and Autonomous Driving functions with lateral guidance, such as lane departure and evasion assistance. Reproducibility can be additionally increased by using a driving robot. At today’s vehicle test benches, pedal and shift robots are predominantly used for longitudinal dynamic tests in the performed test procedures. In order to meet these new test automation requirements for vehicle test benches, the cooperative operation of pedal and steering robots is needed on a test bench setup suitable for this purpose. In this publication, the authors present the setup of a vehicle test bench to be used in automated and reproducible vehicle-in-the-loop tests during steering events. The focus is on the test-bench-specific setup with steerable front wheels, the actuators for simulating the wheel steering torque around the steering axle and the robots used for pedals and steering wheel. Results from various test series are presented and the potential of the novel test environment is shown. The results are reproducible in various test series due to the closed-loop operation without human driving influences at the test bench.

Abstract: The aim of this article is mathematical modelling and investigation of chosen parameters of a small energy harvesting system designed for energy harvesting from car tire mechanical vibrations to provide power supply for various sensors, e.g., in tire pressure monitoring system. The energy harvester consists of three permanent magnets inserted into a tube made from polyamide material. Comsol program has been used to calculate the force between the magnets, the stiffness of the magnetic spring, and the natural frequency of the system. MATLAB program has been used to simulate the movement of the moveable magnet to compare it with the measurements. Finally, the parameters of the mathematical model of the energy harvester were investigated and validated on a specially prepared laboratory test bench.

Abstract: High performance vibration measurements are nowadays required to assess the operating performance of modern electrical vehicles, where the increase of motor angular speed leads to the need to measure vibrations at ever higher frequencies. From a perspective of integration in IoT systems, high performance MEMS accelerometers are the solution to perform condition monitoring of roller bearing in modern EV motors. In this work, the authors present the characterization and the possible use of high performances commercial analog MEMS accelerometers for bearing condition monitoring, exploiting a pre-developed test bench able to emulate different kinds of failure of roller bearings. Three uniaxial MEMS accelerometers were mounted on an ad hoc structure to obtain a full triaxial accelerometer and an ad hoc emulation system was designed and used to obtain its response characterization. The experimental results show the astonishing performance of the tested accelerometers, that with a reasonably low cost, show metrological characteristics which are comparable to the one of their expensive piezoelectric counterparts. Moreover, the small size and the low power consumption make the integration of these sensors in an IoT context very easy and promising.

Abstract: Electrochemical impedance spectroscopy (EIS) has been used in various applications, such as metal corrosion monitoring. However, many conventional corrosion monitoring setups are bulky and inconvenient for in-situ testing. The purpose of this work is to reduce the size of the whole corrosion monitoring system. We utilized EIS to design a field deployable impedance-based corrosion sensor (FDICS), capable of performing in-situ EIS analysis. Experiments verified the sensor's accuracy, and the results showed that the sensor performed similarly to a bench-top EIS machine when we tested on circuit models. Furthermore, we used the proposed FDICS to monitor a metal corrosion experiment and performed EIS. The result showed that the proposed FDICS is able to obtain the sample's impedance spectroscopy, which could help researchers test its corrosion severity on a metallic sample in-situ. Compared to other bulky conventional setups, our device eliminates the design complexity while still showing insights into the corrosion reaction.

Abstract: This manuscript proposes a short tuning march algorithm to estimate induction motors (IM) electrical and mechanical parameters. It has two main novel proposals. First, it starts by presenting a normalized-model reference adaptive system (N-MRAS) that extends a recently proposed normalized model reference adaptive controller for parameter estimation of higher-order nonlinear systems, adding filtering. Second, it proposes persistent exciting (PE) rules for the input amplitude. This N-MRAS normalizes the information vector and identification adaptive law gains for a more straightforward tuning method, avoiding trial and error. Later, two N-MRAS designs consider estimating IM electrical and mechanical parameters. Finally, the proposed algorithm considers starting with a V/f speed control strategy, applying a persistently exciting voltage and frequency, and applying the two designed N-MRAS. Test bench experiments validate the efficacy of the proposed algorithm for a 10 HP IM.

Abstract: The experimental investigation of viscoelastic behavior of cyclically loaded elastomeric components with respect to the time and the frequency domain is critical for industrial applications. Moreover, the validation of this behavior through numerical simulations as part of the concept of virtual prototypes is equally important. Experiments, combined measurements and test setups for samples as well as for rubber-metal components are presented and evaluated with regard to their industrial application. For application in electric vehicles with relevant excitation frequencies substantially higher than by conventional drive trains, high-frequency dynamic stiffness measurements are performed up to 3000 Hz on a newly developed test bench for elastomeric samples and components. The new test bench is compared with the standard dynamic measurement method for characterization of soft polymers. A significant difference between the measured dynamic stiffness values, caused by internal resonance of the bushing, is presented. This effect has a direct impact on the acoustic behavior of the vehicle and goes undetected by conventional measurement methods due to their lower frequency range. Furthermore, for application in vehicles with internal combustion engine, where the mechanical excitation amplitudes are significantly larger than by vehicles with electric engines, a new concept for the identification of viscoelastic material parameters that is suitable for the representation of large periodic deformations under consideration of energy dissipation is described. This dissipated energy causes self-heating of the polymer and leads to the precocious aging and failure of the elastomeric component. The validation of this concept is carried out thermally and mechanically on specimen and component level. Using the approaches developed in this work, the behavior of cyclically loaded elastomeric engine mounts in different applications can be simulated to reduce the time spent and save on the costs necessary for the production of prototypes.