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Tools for the Conceptual Design of a Stratospheric Hybrid Platform

CIRA - Italian Aerospace Research Centre-Vincenzo Rosario Baraniello, Giuseppe Persechino, Roberto Borsa
  • Technical Paper
  • 2020-01-0025
To be published on 2020-03-10 by SAE International in United States
The Italian Aerospace Research Center is currently developing the design of a HAPS (High Altitude Pseudo Satellite). Different HAPS configurations have been proposed in recent years. Airbus Zephyr family and Aurora Odysseus are based on the flying wing configuration. Thales Stratobus is an airship, while Google Loon project is based on balloons. Our proposal concerns a hybrid configuration where the weight is balanced by both aerodynamic and aerostatic forces. In this paper we present the tools we have implemented to develop the conceptual design of our platform. The tools have been implemented in Mathworks Matlab® and Grasshopper® integrated with Rhino 3-D. In the Matlab environment, we have developed an optimization algorithm which can estimate some geometric and energetic global parameters of the platform (weight, surface, volume, required power, width, length and height) using as input the desired speed, altitude and period of the year in which the mission will be performed. In this algorithm, we have included a modelling of the principal subsystems affecting the overall platform weight and energy consumption and availability, the aerodynamic…
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Real Time Simulated Test Platform for Electric Power Line Replaceable Unit Closed Loop Testing

Honeywell Technology Solutins Lab., Pvt.-Davendar Kashireddy, Kumar Sakinala
  • Technical Paper
  • 2020-01-0018
To be published on 2020-03-10 by SAE International in United States
Aerospace application Line Replaceable Unit (LRU) development is tedious process involving hardware development and software development. Detail testing to be performed as per design assurance level (DAL) level of the system in which the LRU used. LRU design and developed for control application of a system to be tested on the real plant/system. Early system requirements validation during development stage using real plant / system involves high risk causing damage to system impacts high lead time to fix the system or most of time system itself is not built yet or system not available at the location of LRU design and development for system functional testing. However real-time simulation environment can address these limitations of system testing. Real time simulation environment is one platform extensively used for control system validation during initial stage of LRU design and development by simulating plant model / system. Correctness of the control algorithm, software implementation, hardware design can be checked during design and development stage which reduces the errors later during system integration lab (SIL) test. Any real-time simulation…
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Development of Drive Cycle using Fleet Data for Two-Wheelers in Indian Market

Bosch Limited, India-Arvind Satish, Abhijith Sabu, Johnson Xavier Saldanha, Nagesh A P
  • Technical Paper
  • 2019-32-0545
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Generally, to produce reliable two-wheelers, manufacturers resort to intense engineering efforts to make sure the two-wheeler can withstand the most harsh testing conditions and requirements. This sometimes leads to a higher cost in realizing such outlier requirements. Thus, a drive cycle matching the actual riding characteristics will enable better understanding of the requirements and an optimized engineering effort. There have been several attempts by governmental and non-governmental organizations to realize a real drive cycle for various cities and countries, trying to capture the typical riding style in those regions. But the drive patterns observed in most representative cycles do not match with the scenario in India with frequently dense traffic, constrained roads and slow driving speeds.To understand the driving pattern in India, a drive cycle generation algorithm is developed which uses real time on-road data captured from a fleet of vehicles in India and creating a database of micro-trips. These micro-trips are first categorized based on their average speeds. The algorithm concatenates these micro-trips to make a drive cycle, such that the average speed of…
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Two-Speed Transmission Gear Shift Process Analysis and Optimization Using Genetic Algorithm

SAE International Journal of Alternative Powertrains

China-Zhan Cao
China Automotive Technology and Research Center Co., Ltd., China-Jiansen Yang, Xinyu Wang
  • Journal Article
  • 08-09-01-0001
Published 2020-01-16 by SAE International in United States
Electric Vehicle (EV) equipped with two-speed transmission has benefit in improving dynamic performance and saving battery consumption. However, during gear shift process, torque interruption and shift impact may lead to a bad shift quality. This work investigates gear shift process in an Automated Manual Transmission (AMT) configuration-based two-speed transmission. First of all, a typical gear shift process is analyzed. Parameters like motor speed, shift force, motor torque change rate, and speed difference between synchronizer and target engage gear are all included to find the relationships with shift duration. Then vehicle jerk is introduced as a criterion to evaluate shift impact. Besides, a comprehensive shift control strategy is developed. While keeping the output torque at wheels unchanged, the shift strategy also improved motor working efficiency after gear shift. Therefore, to determine an optimum shift strategy and achieve a balance among different parameters, Genetic Algorithm (GA) multi-objective optimization method is implemented. Through GA optimization, several solutions are presented and discussed. The final results can well satisfy the requirements of different objectives. This work provides a novel and…
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A discussion on algorithms for health monitoring, fault prognosis and RUL prediction of aerospace and automotive equipment

National Institute for Space Research – INPE-Roberta de Cássia Ferreira Porto, Marcelo Lopes de Oliveira e Souza
  • Technical Paper
  • 2019-36-0264
Published 2020-01-13 by SAE International in United States
Companies are gradually developing: 1) complex and/or highly integrated systems including vehicles (as satellites, airplanes, cars, etc.) or equipment (as computers, cell phones, no breaks, etc.) to use under 2) increasingly varied or inhospitable environments, and to survive under 3) increasingly long life cycles and unavoidable changes in staff & facilities & technologies. The overall decision to use (by time, cost, quality, of functions, services, etc.) such end systems under 2 require 4) high Dependability (Reliability, Maintainability, Availability, Correction, Safety, Security, etc.) of them. The overall survival in use (by health monitoring, housekeeping, retrofit, upgrade, etc.) of such end systems under 3 require 5) high Suportability (Maintainability, Adaptability, Availability, Robustness, etc.) of them coupled with the support systems. To meet the requirements and expectations 4 and 5, there is a need to even treat a growing number of faults, arising from 1, 2 and 3 in components, equipment, subsystems or systems used. In particular, health monitoring, fault prognosis and Remaining Useful Life (RUL) prediction have been used to reach 4 and 5 and treat faults…
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Mathematical Model of Heat-Controlled Accumulator (HCA) for Microgravity Conditions

National Aerospace University Kharkov Aviation Institute, Ukraine-Gennadiy Olexandrovich Gorbenko, Polina Sergeevna Koval, Konstantin Sergeevich Yepifanov, Pavlo Grigorovich Gakal, Rustem Yusufovich Turna
  • Journal Article
  • 01-13-01-0001
Published 2020-01-09 by SAE International in United States
It is reasonable to use a two-phase heat transfer loop (TPL) in a thermal control system (TCS) of spacecraft with large heat dissipation. One of the key elements of TPL is a heat-controlled accumulator (HCA). The HCA represents a volume which is filled with vapor and liquid of a single working fluid without bellows. The pressure in a HCA is controlled by the heater. The heat and mass transfer processes in the HCA can proceed with a significant nonequilibrium. This has implications on the regulation of TPL. This article presents a mathematical model of nonequilibrium heat and mass transfer processes in an HCA for microgravity conditions. The model uses the equations of mass and energy conservation separately for the vapor and liquid phases. Interfacial heat and mass transfer is also taken into account. It proposes to use the convective component k for the level of nonequilibrium evaluation. The experiments were carried out in microgravity conditions for the estimation of the k value. The heating of the HCA was investigated in the flight experiments. The working…
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Nonlinear IMM-SUKF Algorithm for Maneuvering Target Tracking with Bearings-Only Measurement

Universite 8 Mai 1945 Guelma-Abdennour Sebbagh, Sihem Kechida
  • Technical Paper
  • 2019-01-6005
Published 2019-12-30 by SAE International in United States
In this paper, we present an efficient filtering algorithm to perform accurate estimation in jump Markov nonlinear systems, which we aim to contribute in solving the problem of model-based body motion estimation using bearings-only measurement, the Interacting Multiple Model (IMM) algorithm is specially designed to track accurately maneuvering targets whose state and/or measurement (assumed to be linear) models change during motion transition. However, when these models are nonlinear, the IMM algorithm must be modified in order to guarantee an accurate track. In this paper we propose to avoid the Extended Kalman Filter (EKF) because of its limitations and substitute it with the Scaled Unscented Kalman Filter (SUKF) which seems to be more efficient especially according to the simulation results obtained with the Interacting Multiple Model Scaled Unscented Kalman Filter (IMM-SUKF).
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A proposal for semi-analytical model of teeth contact with application to gear dynamics

Politecnico di Torino, Department of Mechanical and Aerospac-Carlo Rosso, Fabio Bruzzone, Tommaso Maggi, Claudio Marcellini
  • Technical Paper
  • 2019-01-2269
Published 2019-12-19 by SAE International in United States
In this paper a semi-analytical (SA) algorithm developed for the solution of the contact problem between two mating spur gears is presented and its application to the study of engagement dynamics is shown. Firstly, a quasi-static two-dimensional (2-D) approach is implemented to solve the contact taking into account several flexibility contributions related to the mating gears. In detail, a modified Hertzian model for the investigation of the real contact area considering the variable curvature of the profiles is developed. A comparison between this model and the classical Hertzian model is shown: the limitations of the classical method, for instance the possibility of analyzing bodies with varying curvatures and the peaks of pressure due to corner contact are therefore overcome. Furthermore, all the different tooth and gear deformations due to the meshing interaction are shown. This allows the computation of the Static Transmission Error (STE), main source of vibration and noise. The influence of tooth profile modifications is also highlighted. A comparison of the calculation of the STE with a Finite Element Method (FEM) model and…
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Active Damping Control of Torsional Vibration in a Diesel Hybrid Powertrain

Tsinghua University-Lei Du, Fuyuan Yang, Yaodong Hu, Liangfei Xu
  • Technical Paper
  • 2019-01-2342
Published 2019-12-19 by SAE International in United States
This paper has designed a real time control algorithm to use ISG motor actively compensate the torque ripple produced by the engine, to reduce torsional vibration. This paper consists of 3 parts. In the first section, this paper has introduced the research object and its modification for experiments. Then the development of control strategy is presented. The engine dynamic model is built, and real-time control with a feedforward unit and a feedback unit is derived. Encoder and cylinder pressure is used for engine torque estimator. Then the ISG motor output the counter-waveform to make the overall output smooth. In order to verify the effectiveness of the control strategy, the final section has established a test bench, where two experiments are carried out. One of the experimental conditions is to set the engine at a constant operating point, while the other is to crank the engine from 0 rpm to idle speed with ISG motor. At constant operating point, speed fluctuation decreases by as much as 79.15%. In terms of vibration index, the vibration is decreased…
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Semiconductor Safety Concepts for the Power Distribution of Automated Driving

SAE International Journal of Connected and Automated Vehicles

Infineon Technologies AG, Germany-Stefan Schumi
University of Technology Graz, Austria-Daniel Watzenig
  • Journal Article
  • 12-02-04-0017
Published 2019-12-18 by SAE International in United States
Automated driving is a highly complex idea. It involves mechanics, electronics and chemistry, artificial intelligence, human intelligence and high computational efforts. Apart from those aspects, the automated intelligence is run using electricity. An unintended interrupt can easily lead to a hazard. Therefore, a highly reliable power distribution has to be developed. This work focuses on the reliability calculation of such a power distribution concept. It points out what is required and will be in future such that the algorithms for the path planning and control are running in a safe environment according to the ISO 26262 standard.
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