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Technical Paper

Utilizing Vehicle Seat Adjustment Motor to Detect, Weigh and Classify the Seat Occupants

2016-04-05
2016-01-0100
High-end vehicles with latest technology and autonomous driving experience have to bear the cost of increasing number of sensors on-board. It would be beneficial to reduce some of the sensors in the vehicle and make use of other available resources, retaining the same functionality. This paper discusses a novel technique of estimating the weight of seat occupant from an already existing DC motor without using additional pressure sensors. Passenger weight information is important for seat-belt reminder system as well as supplemental restraint system that will decide the air-bag deployment. The mathematical model for a series-type DC motor is analyzed and simulated using MATLAB. Further, results of the experiment performed on a lower capacity motor are shared and compared with the simulation results. Formulating a linear relation gives a possibility to develop a device for occupant weight measurement inside the high-end vehicles.
Technical Paper

Guaranteed Timing Behavior Begins with an Established Ethernet Backbone

2016-04-05
2016-01-0061
Increasingly, Ethernet is being used in automotive as a vehicle network backbone. It is ideal for service-oriented communications; streamed communications, such as Audio/Video Bridging (AVB) [1]; and Diagnostics over Internet Protocol (DoIP) [2] communications - areas in which high-bandwidth and reliable performance are essential. Designers are accustomed to network communication systems CAN, LIN, and FlexRay, but how will the timing performance be verified in an Ethernet network? This paper looks at network-wide timing analysis challenges where a mixture of CAN, FlexRay, and Ethernetbased busses co-exist. It is also worth noting that the AUTOSAR standard [3] supports timing definition for all elements in a mixed topology network, but again, accounting for the many different timing paths is a non-trivial process. Figure 1 The Ethernet backbone serving different domains.
Technical Paper

A Novel Design of Pneumatic Actuator for Camless Engines

2016-04-05
2016-01-0099
The concept of camless engines enables us to optimize the overall engine efficiency and performance, as it provides great flexibility in valve timing and valve displacement. This paper deals with design of camless engines with pneumatic actuator. The main objective is to build a prototype and test its performance at different engine speeds. Also an extensive research on the sensors is done to detect the various sensors that could be used to identify the crankshaft position. Here the features and advantages over conventional engines are discussed. In addition the overview of the camless system in the engine is focused along with the design principle and the components used. The system thus designed is capable of actuating at 1500 rpm and demonstrates the ability of pneumatic actuators to be used in an internal combustion engine with low rpm needs.
Technical Paper

Robust Prediction of Lane Departure Based on Driver Physiological Signals

2016-04-05
2016-01-0115
Lane change events can be a source of traffic accidents; drivers can make improper lane changes for many reasons. In this paper we present a comprehensive study of a passive method of predicting lane changes based on three physiological signals: electrocardiogram (ECG), respiration signals, and galvanic skin response (GSR). Specifically, we discuss methods for feature selection, feature reduction, classification, and post processing techniques for reliable lane change prediction. Data were recorded for on-road driving for several drivers. Results show that the average accuracy of a single driver test was approx. 70%. It was greater than the accuracy for each cross-driver test. Also, prediction for younger drivers was better.
Technical Paper

Development of Lane Keeping Assist System Using Lateral-Position-Error Control at Forward Gaze Point

2016-04-05
2016-01-0116
Mitsubishi Electric has been developing a lane keeping assist system (LKAS). This system consists of our products such as an electric power steering (EPS), a camera, and an electronic control unit (ECU) for ADAS. In this system, the camera detects a lane marker, the ECU estimates reference path and vehicle position, and calculates reference steering wheel angle, and the EPS controls a steering wheel angle based on reference steering wheel angle. In this paper, we explain the calculation method of reference steering wheel angle for path tracking control. We derive a formula of reference steering wheel angle calculation that converges lateral position deviation in desired time by using lateral position deviation change rate control on forward gaze point as path tracking control algorithm. Since the formula is obtained from the vehicle model, we can easily design a controller depending on the vehicle type, by using known vehicle specifications.
Technical Paper

Reducing Automotive Wire Harness Design Time and Cost Using Simulation

2016-04-05
2016-01-0106
One of the many critical design criteria for vehicle harness design is circuit protection. This process typically involves calculating the maximum load on each wire manually and then comparing the result to a spreadsheet that may be quite old. Testing physical prototypes occurs so late in the design process that problems found can be very expensive to rectify. Using simulation to detect faults, such as short circuits or the time for the fuse to blow vs. the time for the wire to smoke is an effective solution that can not only save a great deal in costs, but shorten the development cycle as well.
Technical Paper

The Detection of Visual Distraction using Vehicle and Driver-Based Sensors

2016-04-05
2016-01-0114
Distracted driving remains a serious risk to motorists in the US and worldwide. Over 3,000 people were killed in 2013 in the US because of distracted driving; and over 420,000 people were injured. A system that can accurately detect distracted driving would potentially be able to alert drivers, bringing their attention back to the primary driving task and potentially saving lives. This paper documents an effort to develop an algorithm that can detect visual distraction using vehicle-based sensor signals such as steering wheel inputs and lane position. Additionally, the vehicle-based algorithm is compared with a version that includes driving-based signals in the form of head tracking data. The algorithms were developed using machine learning techniques and combine a Random Forest model for instantaneous detection with a Hidden Markov model for time series predictions.
Technical Paper

Virtual Multi-ECU High Fidelity Automotive System Simulation

2016-04-05
2016-01-0013
Automotive vehicles today consist of very complex network of electronic control units (ECU) connected with each other using different network implementations such as Controller Area Network (CAN), FlexRay, etc. There are several ECUs inside a vehicle targeting specific applications such as engine, transmission, body, steering, brakes, infotainment/navigation, etc. comprising on an average more than 50 ECUs executing more than 50 million lines of software code. It is expected to increase exponentially in the next few years. Such complex electric/electronic (E/E) architecture and software calls for a comprehensive, flexible and systematic development and validation environment especially for a system level or vehicle level development. To achieve this goal, we have built a virtual multi-ECU high fidelity cyber-physical multi-rate cosimulation that closely resembles a realistic hardware based automotive embedded system.
Technical Paper

A Study of the Dynamics of the Rolling Element and its Effect on Outer Race Creep

2016-04-05
2016-01-0011
Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. In high speed applications, rolling element forces and gyroscopic moments can be significantly high compared to the applied forces acting on a bearing. Such moments create a “driving” torque causing outer race to creep. In this paper a mathematical model for the dynamics of a rolling element in a high speed bearing is derived. Preload values counterbalancing the torque driving the outer race to rotate can be predicted from this model. An attempt to experimentally measure this torque using a specially designed apparatus with integrated strain gauge torque sensor is also described. Both model and experimental measurements are aimed at understanding, and therefore preventing bearing failures due to outer race (creep) rotations.
Technical Paper

Implementation of a Local Interconnect Network over a DC-Bus for Reduction of a Vehicle Wiring Harness

2016-04-05
2016-01-0059
The paper discusses the development and implementation of a form of in-vehicle communications for the body control in an Ariel Atom niche sports car. A Local Interconnect Network (LIN) bus has been developed that runs the LIN signals over the power lines of the vehicle wiring harness. The LIN system has one master and up to 15 slave ECUs. LIN is normally run at a maximum bit rate of 20 Kbit/s, however this system has been implemented at 57.6 Kbit/s by modulating over the power lines. Benefits of this approach include weight reduction, reduction in the number wires, ease in retro-fitting to existing vehicle architectures as only requires a connection to power lines and the ability to monitor the signals via the battery pins of the OBD connector of the vehicle. The approach has resulted in a reduction in weight due to wiring and electronic control unit reduction.
Technical Paper

The Potential of Key Process/Performance Indicators (KPIs) in Automotive Software Quality Management

2016-04-05
2016-01-0046
A steady increasing share and complexity of automotive software is a huge challenge for quality management during software development and in-use phases. In cases of faults occurring in customer’s use, warranty leads to product recalls which are typically associated with high costs. To avoid software faults efficiently, quality management and enhanced development processes have to be realized by the introduction of specific analysis methods and Key Process/Performance Indicators (KPIs) to enable objective quality evaluations as soon as possible during product development process. The paper introduces an application of specific analysis methods by using KPIs and discusses their potential for automotive software quality improvement. Target is to support quality evaluation and risk-analysis for the release process of automotive software.
Technical Paper

A BCI-Test Simulation Model for In-Vehicle Equipment

2016-04-05
2016-01-0045
In this paper, consideration is made to create a simulation model of the BCI test method, which is one of the EMC evaluation methods for in-vehicle electronic devices, and an intrinsic model of a BCI probe is provided. Using this model, it is demonstrated that when the impedance of the BCI probe is sufficiently high, the BCI probe serves as a transformer with a winding ratio of 1:1, and the admittance of a line or a load connected to each wire becomes proportional to the magnitude of current flowing in each wire. This model can also be applied when the leakage inductance inside the BCI probe is taken into consideration. The validity of this model is verified by experiment using a jig which can clamp multiple wires. In addition, by using this model, it is demonstrated that the S-parameters for dozens of wires clamped in the BCI probe can be generated using the S-parameter measurement results from when one wire is in the BCI probe.
Technical Paper

A Feasibility Demonstration of a Sensing Control Unit for Measurement of Large Capacitance for Particulate Matter Sensor

2016-04-05
2016-01-0044
On-board diagnostics (OBD) of diesel vehicles require various sensors to detect system malfunctions. The Particulate Matter (PM) sensor is one of OBD devices which gather information which could be critical in determining a crack in the diesel particulate filters (DPFs). The PM sensor detects PM which penetrates cracked DPFs and converts the amount of PM into electrical values. The PM sensor control unit (SCU) receives those analog signals and converts them to digital values through hardware and software solutions. A capacitive sensing method would be a stable solution because it detects not raw analog signals but electrical charges or a time constant going through the capacitive load. Therefore, amount of PM would be converted reasonable value of capacitance even though there is a little amount of PM.
Technical Paper

Analytical and Numerical Structural Evaluation of a Baja

2015-09-22
2015-36-0516
This paper aims at analytical and numerical evaluation of the structure of a Baja. It will be described some load conditions to analyze the overall structure of Baja well as localized elements, in order to prevent premature failure of the vehicle during the competition and improvements in the design phase. The numerical analysis will be conducted via finite elements to establish the optimization of weight and gain performance of the vehicle. Analytical evaluation it will conducted via propositions of physics. Results obtained for the initial concept of the project and compared with the structural changes after the trial proposition will be presented. Analysis of study resulted in improvements in manufacturing reducing weight. Also it was expected to increase the structural performance associated to a better understanding of the vehicle as a whole.
Technical Paper

Influence of CFD Setup and Brief Analysis of Flow Over a 3D Realistic Car Model

2015-09-22
2015-36-0513
Fuel consumption of road cards has been a main issue for the global automotive industry. Engineering tools, such as wind tunnels and computational fluid dynamics (CFD), have been employed for vehicle design, intending to achieve more aerodynamic efficiency. However, wind tunnels are very expensive facilities. Conversely, CFD technique rises as the best cost-effective tool for solutions on aerodynamics. This paper presents the influences of numerics and brief analysis of the intrinsic turbulent flow over a 3D realistic car model. The objective is to provide a significant cost-benefit of numerical parameters to the automotive industry in the development of road cars. Besides the validation from an unsteady-state simulation over a full car domain, the simplification of the domain by half and the steady-state regime were found to provide an acceptable approach for automotive simulation.
Technical Paper

Methodology to Analyse Thermal and Mechanical Stresses in Friction Material

2015-09-22
2015-36-0512
In engineering development, simulation methods are frequently used to perform thermal and mechanical stress components analysis. In brake systems, where the components are exposed to mechanical and thermal loads, the numerical analysis is very helpful. Once a numerical model for brake assembly is available, it will be possible to understand the effects of successive brake applications on the temperature distribution in drum brake’s friction materials. This is a fundamental aspect to determine, for instance, the thermal stress distribution which is related to the warming and cooling of the brakes. In this work, an analytical solution to calculate stabilized temperature was used to establish a heat flux through a pneumatic S cam drum brake’s friction material applied to a numerical model in a finite element analysis.
Technical Paper

Curve Fits for Thermodynamic Properties of Butanol Fuel

2015-09-22
2015-36-0505
Butanol is an important industrial chemical and a promising biofuel. However, for the butanol applications in engines, studies are not as extensive as the case of ethanol or biodiesel. Therefore, there is a lack of information regarding the thermodynamic and combustion parameters of internal combustion engines operation using butanol fuel. To evaluate the combustion calculations and the thermodynamic simulation of internal combustion engines, several references from the literature can be used to obtain the thermodynamic and combustion routines. The most complete models are based on polynomials curve fits to the thermodynamic data (specific heat, enthalpy and entropy) of the fuels. The goal of this study is to evaluate the coefficients of the thermodynamic property curves of butanol fuel, so that the fuel can be included in the routines for internal combustion engines calculations.
Technical Paper

Advantages of Directive Acoustic Sources for Audible Alert Systems in EV

2015-09-22
2015-36-0560
The rapid growth of Electric Vehicles (EV’s) and Hybrid Electric Vehicles (HEV’s) has increased the concern that the relative silence of these type of vehicles will result in an increased risk to pedestrian safety. A practical solution to this problem is to add artificial sounds to EV's to aid their detection by pedestrians and other vulnerable road users. Acoustic warning systems for EV’s should increase pedestrian safety and simultaneously produce a small impact on environmental noise levels. This paper shows the main advantage of using a directive acoustic source implemented as a beamforming loudspeaker array in an EV to increase pedestrian safety and control the effect on noise pollution. An example of such a system has been implemented in a Nissan Leaf vehicle and its performance in realistic situations has been assessed.
Technical Paper

Analysis of Power Loss by Viscous Dissipation in Hydrodynamic Thrust Bearings

2015-09-22
2015-36-0557
The hydrodynamic thrust bearings has been the subject of several studies in the scientific environment. In the hydrodynamic lubrication the surfaces are completely separated by the lubricating film, and therefore it is the most desirable type of lubrication. The lubricant should be chosen in order to reduce power losses by viscous dissipation. The work aims to analyze the power loss by viscous dissipation for various types of lubricating oils. It was investigated a six pivoted-pad thrust bearing in a rotation range between 1500 rpm and 3000 rpm. Eleven different types of lubricating oils were analyzed. It was possible to observe the net power loss - in function of the lubricant type - for each of the thrust bearings located in an automobile. The cost associated with this loss of potency was also obtained. The results showed that the appropriate selection of the lubricating generates an increase of 50% in power gain.
Technical Paper

A Discussion on the Methods of Thermal Cycling and Power Cycling for Reliability Prediction of Solder Joints of Electronic Components

2015-09-22
2015-36-0553
The increasing use of embedded electronics in aerospace and automotive vehicles increases the designers' concern regarding the reliability of the components as well as the reliability of their interconnections. The discussion about the most appropriate method for assessing the reliability of solder joints for a given application is an ever-present theme in the literature. Several methods of prediction have been developed for assessing the reliability of solder joints. The standard method established by the industries for assessing reliability of solder joints is the thermal cycling. However, when the thermal distributions in real applications are studied, particularly in some electronic components used in on-board electronics of space systems, the thermal cycling does not represent what actually happens in practice in the packaging.
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