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Enhancement of Occupant Ride Comfort by GA Optimized PID Control Active Suspension System

Anna University-Arivazhagan Anandan, Arunachalam K
  • Technical Paper
  • 2020-01-1532
To be published on 2020-06-03 by SAE International in United States
The main objective of this work is to enhance the occupant ride comfort. Ride comfort is quantified in terms of measuring distinct accelerations like sprung mass, seat and occupant head. For this theoretical evaluation, a 7- degrees of freedom (DOF) human-vehicle-road model was established and the system investigation was limited to vertical motion. Besides, this work also focused to guarantee other vehicle performance indices like suspension working space and tire deflection. A proportional-integral-derivative (PID) controller was introduced in the vehicle model and optimized with the aid of the genetic algorithm (GA). Actuator dynamics is incorporated into the system. The objective function for PID optimization was carried out using root mean square error (RMSE) concept. The severity of various suspension indices and biomechanics responses of the developed model under proposed approach were theoretically analyzed using various road profiles and compared with conventional passive system. Furthermore, this work discussed the seat to head transmissibility ratio (STH) response to examine the severity of whole-body vibration (WBV). Subsequently, the respective performance measures were statistically analyzed using root mean square…
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Sliding Mode Controlled Half Car Suspension System with Magnetorheological Damper

Anna University-AROCKIA SUTHAN SOOSAIRAJ, ARUNACHALAM K
  • Technical Paper
  • 2020-01-1540
To be published on 2020-06-03 by SAE International in United States
Attenuation of vibrations caused by the road undulance conditions are tedious and very much related to human health and vehicle handling problems. One of the promised approaches to solving these problems in a vehicle suspension system is the use of effective controllers. In this paper, the sliding mode controller (SMC) is designed and used to control the magnetorheological (MR) damper. The performance of the proposed controller is verified by incorporating the controller in a half car vehicle suspension model. In a suspension damper design, Modified Bouc-Wen model is used to characterize the hysteretic behaviour of MR damper parameters. The voltage control algorithm is used to convert the desired force into the varied voltage input to the MR damper. The fail-proof advantage of MR damper is analysed by comparing the results of uncontrolled MR suspension with a passive system. In order to limit the pitch angle and to achieve the improved ride comfort and stability of the vehicle, the vertical displacement of the front and rear body of the half-car model is controlled by the SMC…
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Real-Time Capable Wind and Rolling Noise Synthesis for a More Realistic Vehicle Simulator Experience

Institute of Electronic Music & Acoustic-Julian Koch, Alois Sontacchi
MAGNA STEYR Fahrzeugtechnik AG & CO KG-Thorsten Bartosch, Werner Reinalter
  • Technical Paper
  • 2020-01-1546
To be published on 2020-06-03 by SAE International in United States
Nowadays a large proportion of the overall acoustic vehicle development takes place within virtual phases. Increasingly, projects require the auralization of virtual developed acoustics measures, e.g. from the disciplines of electro-acoustic, ride comfort, rolling noise or passive acoustic on dynamic or static driving simulators. In practice it turns out that in addition to engine noise also a realistic reproduction of rolling and wind noise is important. In this article, approaches to synthetic rolling and wind noise generators are discussed. We developed such real-time capable sound generators that are parametrizable according to arbitrary driving conditions. Furthermore, spacial reproduction of the driving sounds is achieved for binaural headphone, as well as for other arbitrary loudspeaker setups, like often found in driving simulators. Derived models and parametrization are based on measurements and recordings from several real vehicles. In order to facilitate the adjustment on specific vehicles and designing rolls thereof, the suggested parametrization is guided by a defined procedure. The influence of these noise components on an improved perception of the overall driving experience is objectified by means…
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Asian Consumers Challenging the NVH Performance of European Cars – Implications on the Product Development in the 2020ies

MAGNA STEYR Automotive Technologies-Paulo Padilha
NVH Experts-Christoph Fankhauser
  • Technical Paper
  • 2020-01-1552
To be published on 2020-06-03 by SAE International in United States
Sales of SUV and luxury cars on the largest market of the world – China – are growing at a high rate. The highways in large cities like Beijing or Shanghai are increasingly populated with cars from all over the world like Japan, USA, Europe and Korea and even some refined domestic brands. More than 10 million rich people can afford those cars and are skilled drivers. This huge group of potential consumers is targeted by luxury brand OEMs and by startup companies. It has been understood, that these people have a strong attitude towards comfort. The twistbeam rear axle was replaced by multilink, double clutch transmissions were improved by comfort-mode drive programs, interior trims raised to Western standard performance levels, tyres specially developed for comfort in China, localized insulation materials and packages engineered to a one vehicle class higher level. The European avant-garde is capable of such high levels of complete vehicle NVH performance, whereas premium brands often compromise NVH with respect to high vehicle dynamics performance and passive safety requirements. At the same…
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Simulating and Optimizing the Dynamic Chassis Forces of the Audi e-tron

Audi AG-Stefan Uhlar
  • Technical Paper
  • 2020-01-1521
To be published on 2020-06-03 by SAE International in United States
With battery electric vehicles (BEV), due to the absence of the combustion process, the rolling noise comes even more into play. The BEV technology also leads to different concepts of how to mount the electric engine in the car. Commonly, also applied with the Audi e-tron, the rear engine is mounted on a subframe, which again is connected to the body structure. This concept leads to a better insulation in the high frequency range, yet it bears some problems in designing the mounts for ride comfort (up to 20Hz) or body boom (up to 70Hz). Commonly engine mounts are laid-out based on driving comfort (up to 20Hz). The current paper presents a new method to find an optimal mount design (concerning the stiffness) in order to reduce the dynamic chassis forces which are transferred to the body up to 100Hz. This directly comes along with a reduction of the sound pressure level for the ‘body boom’ phenomena. Here we use multibody simulation along with a sophisticated tire model in the time domain in order to…
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Research on the Subjective Rating Prediction Method for the Ride Comfort with Deep Learning

Hitachi Automotive Systems, Ltd-Ryusuke Hirao
Hitachi Automotive Systems, Ltd.-Nobuyuki Ichimaru
  • Technical Paper
  • 2020-01-1566
To be published on 2020-06-03 by SAE International in United States
Suspension is an important chassis part which is vital to ride comfort. However, it is difficult to achieve our targeted comfortability level in a short time. Therefore, improving efficiency of damper development is our primary challenge. We have launched a project which aims to reduce the workload on developing dampers by introducing analytical approaches to the improvement of ride comfort. To be more specific, we have been putting effort into developing subjective rating prediction, vehicle dynamics prediction, the damping force prediction. This paper describes the subjective rating prediction method which output a subjective rating corresponding to the physical value of the vehicle dynamics with Deep Learning. As a result of verifying with the unlearning data, DNN(Deep Neural Network) prediction method could almost predict the subjective rating of the expert driver.
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Effects of a Probability-Based Green Light Optimized Speed Advisory on Dilemma Zone Exposure

Indiana Department of Transportation-James Sturdevant
Purdue University-Enrique Saldivar-Carranza, Howell Li, Woosung Kim, Jijo Mathew, Darcy Bullock
  • Technical Paper
  • 2020-01-0116
To be published on 2020-04-14 by SAE International in United States
Green Light Optimized Speed Advisory (GLOSA) systems have the objective of providing a recommended speed to arrive at a traffic signal during the green phase of the cycle. GLOSA has been shown to decrease travel time, fuel consumption, and carbon emissions; simultaneously, it has been demonstrated to increase driver and passenger comfort. Few studies have been conducted using historical cycle-by-cycle phase probabilities to assess the performance of a speed advisory capable of recommending a speed for various traffic signal operating modes (fixed-time, semi-actuated, and fully-actuated). In this study, a GLOSA system based on phase probability is proposed. The probability is calculated prior to each trip from a previous week’s, same time-of-day (TOD) and day-of-week (DOW) period, traffic signal controller high-resolution event data. By utilizing this advisory method, real-time communications from the vehicle to infrastructure (V2I) become unnecessary, eliminating data-loss related issues. The effects of three different advice approaches (conservative, balanced, and aggressive) on dilemma zone exposure are analyzed. Proof of concept is carried out by virtually driving through a test-route composed of an arterial that…
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A Dynamic Trajectory Planning for Automatic Vehicles Based on Improved Discrete Optimization Method

Chongqing University-Pengyun Zeng, Zheng Ling
  • Technical Paper
  • 2020-01-0120
To be published on 2020-04-14 by SAE International in United States
The dynamic trajectory planning problem for automatic vehicles in complex traffic scenarios is investigated in this paper. A hierarchical motion planning framework is developed to complete the complex planning task. An improved dangerous potential field in the curvilinear coordinate system is constructed to describe the collision risk of automatic vehicles accurately instead of the discrete Gaussian convolution algorithm. At the same time, the driving comfort is also considered in order to generate an optimal, smooth, collision-free and feasible path in dynamics. The optimal path can be mapped into the Cartesian coordinate system simply and conveniently. Furthermore, a velocity profile considering practical vehicle dynamics is also presented to improve the safety and the comfort in driving. The effectiveness of the proposed dynamic trajectory planning is verified by numerical simulation for several typical traffic scenarios.
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Multi-zone HAVC Development and Validation with Integrated Heated/Vented Seat Control

FCA US LLC-Murad Maghaireh, Michael Hoppe
  • Technical Paper
  • 2020-01-1247
To be published on 2020-04-14 by SAE International in United States
Vehicle multi zone automatic Heating , Venting and Air Conditioning (HVAC) is the advanced form of the traditional air conditioning, the advantage of multi zone automatic HVAC is that it allows the passengers of a vehicle to set a desired temperature for their own zone within the vehicle compartment. This desired temperature is then maintained by the HVAC system, which determines how best to control the available environment data that leads to a higher comfort for the passengers. To achieve ultimate thermal comfort of the occupants in a vehicle, multi zone HVAC takes things a step further by adding heated, vented seats and, steering wheel to the HVAC controller hardware as well as strategies. The heating and cooling of the occupants by this more advance one integrated system is performed by complex control algorithms in form of embedded software programs and private LIN network. This paper describes the approach and tools used to develop, simulate and validate the one integrated climate control system. Included are 1- introduction of an integrated HVAC , steering wheel and…
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Decision Making and Trajectory Planning of Intelligent Vehicle’ s Lane-Changing Behavior on Highways under Multi-Objective Constrains

Wuhan University of Technology-Linzhen Nie, Zhishuai Yin, Haoran Huang
  • Technical Paper
  • 2020-01-0124
To be published on 2020-04-14 by SAE International in United States
Discretionary lane changing is commonly seen in highway driving. Intelligent vehicles are expected to change lanes discretionarily for better driving experience and higher traffic efficiency. This study proposed to optimize the decision-making and trajectory-planning process so that intelligent vehicles made lane changes not only with driving safety taken into account, but also with the goal to improve driving comfort as well as to meet the driver’ s expectation. The mechanism of how various factors contribute to the driver’s intention to change lanes was studied by carrying out a series of driving simulation experiments, and a Lane-Changing Intention Generation (LCIG) model based on Bi-directional Long Short-Term Memory (Bi-LSTM) was proposed. The inputs of the Bi-LSTM were data fragments of several influencing factors including the relative velocity and the distance between the relative vehicles, the type of the preceding vehicles, and the average velocity of the adjacent traffic flows, that over a certain period of time, which was determined via examining subjects’ visual behaviors of the left view mirror or the right view mirror. By combining the…