Browse Topic: Reaction and response times

Items (813)

Determining Worst-Case Execution Time Bounds for Multi-core Processors

2025-01-0155To be published on 05/02/2025

Demonstrating deadline adherence for real-time tasks is a common requirement in all safety norms, including ISO 26262 and DO-178C. Timing verification has to address two levels: the code level (worst-case execution time) and the scheduling level (worst-case response time). Determining which methodology is suited best depends on the characteristics of the target processor. All contemporary microprocessors try to maximize the instruction-level parallelism by sophisticated performance-enhancing features that make the execution time of a particular instruction dependent on the execution history. On multi-core systems, the execution time additionally is influenced by interference effects on shared resources caused by concurrent activities on the different cores, which are not controlled by the scheduling algorithm. In the avionics domain, the new FAA AC 20-193 / EASA AMC 20-193 guidance documents formalize predictability aspects of multi-core systems and derive adequate measures for timing

Kaestner, Daniel, Gebhard, Gernot, Huembert, Christian, Pister, Markus, Wegener, Simon, Ferdinand, Christian

A Proactive System to Anticipate and Store the Damage Information on a Parked Car Using Machine Learning Algorithm

2025-01-8211

04/01/2025

Vehicle ADAS Systems majorly comprises of two functions: Driving and Parking. The most common form of damage to the vehicle which goes unnoticed with unidentified cause are parking damages. A vehicle once parked at a certain location may get damaged without knowledge of the user. In this work developed a solution that not only pre-warns the driver but also prepares the vehicle beforehand if it suspects a damage may occur. This eliminates the latency between damage and information capture, detects small damages such as scratches, classifies the type of damage and informs the user beforehand. This is solution is different from our competitors as the existing solutions informs the user about the scratches/damages, but these solutions are expensive, have high response time, and the damage information is captured after the damage has occurred. The solution consists of the following check blocks: Precondition, Sensor Control and Action Module. The Precondition Module observes the vehicle

Debnath, Sarnab, Patil, Prasad, Belur Subramanya, Sheshagiri, Govinda, Shiva Prasad

Assessing the Impact of Mirror Technology on Driver Perception and Safety: Traditional vs. Camera-Based Systems

2025-01-8664

04/01/2025

Camera-based mirror systems (CBMS) are being adopted by commercial fleets based on the potential improvements to operational efficiency through improved aerodynamics, resulting in better fuel economy, improved maneuverability, and the potential improvement for overall safety. Until CBMS are widely adopted it will be expected that drivers will be required to adapt to both conventional glass mirrors and CBMS which could have potential impact on the safety and performance of the driver when moving between vehicles with and without CBMS. To understand the potential impact to driver perception and safety, along with other human factors related to CBMS, laboratory testing was performed to understand the impact of CBMS and conventional glass mirrors. Drivers were subjected to various, nominal driving scenarios using a truck equipped with conventional glass mirrors, CBMS, and both glass mirrors and CBMS, to observe the differences in metrics such as head and eye movement, reaction time, and

Siekmann, Adam, Prikhodko, Vitaly, Sujan, Vivek

Dynamics Modeling and Lateral Stability of Tank Transport Vehicles

2025-01-8075

04/01/2025

In this paper, the equivalent elliptic gauge pendulum model of liquid sloshing in tank is established, the pendulum dynamic equation of tank in non-inertial frame of reference is derived, and the dynamics model of tank transporter is constructed by force analysis of the whole vehicle. A liquid tank car model was built in TruckSim to study its dynamic response characteristics. Aiming at the problem that the coupling effect between liquid sloshiness in tank and tank car can easily affect the rolling stability of vehicle, the roll dynamics model of tank heavy vehicle is established based on the parameterized equivalent elliptic gauge single pendulum model, and the influence of different lateral acceleration and suspension system on the roll stability is studied. The results show that the coupling effect between the motion state of the tank car and the liquid slosh lengthens the oscillation period of the liquid slosh in the tank, and the amplitude of the load transfer rate of the tank car

Yukang, Guo

Operational Evaluation of a Pre-Production L2 System HMI

2025-01-8050

04/01/2025

The study analyzed data from on-road drives with a pre-production Level 2 (L2) partial automation system using a sample of 27 drivers ranging from 21 to 75 years of age. The system provides continuous automatic lateral and longitudinal control but requires the driver to remain attentive and intervene when necessary. The L2 system was equipped with a Driving Monitoring System (DMS) that issued escalating alerts to remind the driver to pay attention or take over when needed. During the 14-month study period, drivers completed 354,768 miles of travel with the L2 system engaged, totaling 5,913 trips. The results of the study showed that drivers were highly responsive to attention reminders and takeover alerts, with high compliance rates and quick response times. Importantly, there was no evidence of habituation to these alerts over time. These findings support the effectiveness of the system's DMS and alert HMI (Human-Machine Interface) strategy in promoting the proper use of the system

Llaneras, Robert, Glaser, Yi, Green, Charles, August, Maureen, Landry, Steven

Leveraging Triggering Conditions for Efficient Scenario-Based Testing of Automated Vehicles

12-08-04-0035

02/19/2025

Scenario-based testing has become a central approach of safety verification and validation (V&V) of automated driving. The standard ISO 21448: Safety of the intended functionality (SOTIF) [1] proposes triggering conditions (e.g., an occluded traffic sign) as a new aspect to be considered to organize scenario-based testing. In this contribution, we discuss the requirements and the strategy of testing triggering conditions in an iterative, SOTIF-oriented V&V process. Accordingly, we illustrate a method for generating test scenarios for evaluating potential triggering conditions. We apply the proposed method in a two-fold case study: We demonstrate how to derive test scenarios and test these with a virtual automated driving system in simulation. We provide an analysis of the testing result to show how triggering condition-based testing facilitates spotting the weakness of the system. Besides, we exhibit the applicability of the method based on multiple triggering conditions and nominal

Zhu, Zhijing, Philipp, Robin, Howar, Falk

Deep Learning-Enhanced Direct Torque Control of BLDC Motors for Optimized Electric Vehicle Performance

12-08-04-0036

02/12/2025

Electric vehicles (EVs) represent a promising solution to reduce environmental issues and decrease dependency on fossil fuels. The main drawback associated with the direct torque control (DTC) scheme is that it is incapable of improving the efficiency and response time of the EVs. To overcome this problem, integrating deep learning (DL) techniques into DTC offers a valuable solution to enhance the performance of the drive system of EVs. This article introduces three control methods to improve the output for DTC-based BLDC motor drives: a traditional proportional–integral for speed controller (speed PI), a neural network fitting (NNF)-based speed controller (speed NNF), and a custom neural (CN) network-based speed controller (speed CN). The NNF and CN are DL techniques designed to overcome the limitations of conventional PI controllers, such as retaining the percentage overshoot, settling times, and improving the system’s efficiency. The CN controller reduced the torque ripple by 15

Patel, Sandesh, Yadav, Shekhar, Tiwari, Nitesh

Optimization of Biodiesel Production from Tannery Industry Fleshing Wastes Using Response Surface Methodology

2025-28-0115

02/07/2025

In response to rising emissions and pollutants, an alternative and environmentally friendly synthesis is gaining prominence on the energy sources. The leather industries generate substantial amount of waste and fleshing oil extracted from fleshing which is rich in lipids and presents a viable feedstock for biodiesel production. In this research work, Response Surface Methodology (RSM) is used to optimize the conversion of leather fleshing oil into biodiesel using three parameters such as operating temperature, reaction time, and molar ratio. Experiments were carried out to determine the most optimal conditions and the response on yield (%) and viscosity (mm2/s) based on a 17-run Box–Behnken Design matrix. Stochastic model parameters such as R2 (0.9715 and 0.9793), adjusted R2 (0.9349 and 0.9527), predicted R2 (0.8327 and 0.7656), and high F-values (26.52 and 36.78) of both responses (yield and viscosity) were found to be statistically significant and warranted model adequacy. ANOVA and

P, Kanthasamy, Selvan, Arul Mozhi, P, Shanmugam

Research on the Intelligent Vehicle Trajectory Tracking Control Based on Optimal Preview Distance

02-18-01-0005

01/03/2025

Accurate and responsive trajectory tracking is a critical challenge in intelligent vehicle control system. To improve the adaptability and real-time performance of intelligent vehicle trajectory tracking controllers, we propose a genetic algorithm adaptive preview (GAAP) scheme that offline optimizes the preview distance based on vehicle speed and reference path curvature. The goal is to obtain the optimal preview distance that balances tracking accuracy, stability, and real-time performance. By establishing a relationship between optimal preview distance, speed, and curvature, we enhance real-time performance through online table checking during trajectory tracking. Our trajectory tracking error model takes into account not only position errors but also heading errors. A feedback–feedforward trajectory tracking controller is then designed to achieve rapid responses without compromising robustness. Simulation tests conducted under straight circular arc condition and double lane change

Cheng, Kehan, Zhang, Huanhuan, Hu, Shengli, Ning, Qianjia

Modeling and Simulation of an Electromagnetic Brake-by-Wire System for Formula SAE Vehicles

2024-36-0169

12/20/2024

Electric vehicles represent a shift towards sustainability in the automotive industry, with the Brake-by-Wire (BBW) system as an innovation to enhance safety, and performance. This study proposes an electromagnetic BBW system for Formula SAE vehicles, optimizing an electromagnet with a genetic algorithm as the actuator. Through a selection process from a million individuals, the system was modeled. Integrated with electric motors using CarMaker® software, the optimized electromagnet surpassed the minimum required force of 228.08 N without reaching its nominal current of 12.5 A, achieving a force of 231.1 N for 150 W power, indicating an energy efficiency of 0.706 N/Watt. The system also exhibited a response time of 17.92ms for an 80 bar increase, 1.52 times better than compared systems. Simulation under varying braking intensities demonstrated dynamic behavior, with settling times for slow, moderate, and sharp braking at 193 ms, 62 ms, and 21 ms, respectively. Efficiency during

Salgado, Vinícius Batista Alves, Gomes, Deilton Gonçalves, Andrade Lima, Cláudio

Trailer Disengage Confirmation Alarm System for Electric Subsystems

2024-28-0213

12/05/2024

The truck industry's primary focus is on global transportation, necessitating the efficient movement of goods and materials. There are many types of trucks designed for different purposes, and one of the most significant ones is the tractor trailer which offers great flexibility and can carry heavy loads. The tractor-trailer assembly unit consists of a complex integration of mechanical, electrical, and pneumatic connections, each serving a critical role in the overall functionality and performance of the vehicle. The disconnection of electrical interconnections between the truck trailer and tractor is crucial to prevent damage to the connectors within the wiring harness, which can lead to hazardous situations on the road. The tractor unit serves as the power source, while the trailer is responsible for carrying cargo, with the wiring harness being a crucial yet vulnerable component. When the trailer disengages from the fifth wheel coupling, it is vital to ensure that the electrical

Singh, Amandeep, Kumar, Pradeep, Suresh, Karthikrajan, Kotian, Pradeep, T, Thirunavukkarasu, Chitreddy, Bharath, R, Sunilkumar

ZF's latest safety advances open up, tighten up and DOUBLE DOWN

24AUTP08_02

08/01/2024

ZF rethinks safety with new airbags, belt tensioner. ZF knows that the steering wheel remains one of the most relevant components in an automotive interior, because this is where drivers have direct contact to the vehicle. As steering wheels become adorned with more functions than some drivers know what to do with, ZF put Marc Schledorn in charge of the teams rethinking how the driver airbag could operate in a world with ever-busier steering wheels. The solution is a new type of steering wheel airbag that ZF Lifetec (ZF's renamed Passive Safety Systems division) announced in June. Instead of moving through a thermoplastic airbag cover mechanically fixed in the center of the wheel, Schledorn told SAE Media, the new design positions the airbag on the top side of the steering wheel and then expands through the upper rim of the wheel when needed.

Blanco, Sebastian

Test Cycle Simulation of Bench Based on Deep Reinforcement Learning

15-17-03-0015

07/31/2024

Test cycle simulation is an essential part of the vehicle-in-the-loop test, and the deep reinforcement learning algorithm model is able to accurately control the drastic change of speed during the simulated vehicle driving process. In order to conduct a simulated cycle test of the vehicle, a vehicle model including driver, battery, motor, transmission system, and vehicle dynamics is established in MATLAB/Simulink. Additionally, a bench load simulation system based on the speed-tracking algorithm of the forward model is established. Taking the driver model action as input and the vehicle gas/brake pedal opening as the action space, the deep deterministic policy gradient (DDPG) algorithm is used to update the entire model. This process yields the dynamic response of the output end of the bench model, ultimately producing the optimal intelligent driver model to simulate the vehicle’s completion of the World Light Vehicle Test Cycle (WLTC) on the bench. The results indicate that the

Gong, Xiaohao, Li, Xu, Hu, Xiong, Li, Wenli

Experimental Analysis of Force Recovery and Response Time Using Strain Measurement Sensors in Stress Wave Force Balance

2024-26-0451

06/01/2024

Severe problem of aerodynamic heating and drag force are inherent with any hypersonic space vehicle like space shuttle, missiles etc. For proper design of vehicle, the drag force measurement become very crucial. Ground based test facilities are employed for these estimates along with any suitable force balance as well as sensors. There are many sensors (Accelerometer, Strain gauge and Piezofilm) reported in the literature that is used for evaluating the actual aerodynamic forces over test model in high speed flow. As per previous study, the piezofilm also become an alternative sensor over the strain gauges due to its simple instrumentation. For current investigation, the piezofilm and strain gauge sensors have mounted on same stress force balance to evaluate the response time as well as accuracy of predicted force at the same instant. However, these force balance need to be calibrated for inverse prediction of the force from recorded responses. A reliable multi point calibration

Kamal, Abhishek, Deka, Sushmita, Sahoo, Niranjan, Kulkarni, Vinayak

PRODUCT BRIEFS

24AUTP06_13

06/01/2024

Gap Adjustment Strategy for Electromechanical Brake System Based on Critical Point Identification

2024-01-2320

04/09/2024

Abrasion of the Electromechanical brake (EMB) brake pad during the braking process leads to an increase in brake gap, which adversely affects braking performance. Therefore, it is imperative to promptly detect brake pad abrasion and adjust the brake gap accordingly. However, the addition of extra gap adjustment or sensor detection devices will bring extra size and cost to the brake system. In this study, we propose an innovative EMB gap active adjustment strategy by employing modeling and analysis of the braking process. This strategy involves identifying the contact and separation points of the braking process based on the differential current signal. Theoretical analysis and simulation results demonstrate that this gap adjustment strategy can effectively regulate the brake gap, mitigate the adverse effects of brake disk abrasion, and notably reduce the response time of the braking force output. Monitoring is critical to accurately control EMB clamping force. Pressure transducers are

Zhang, Yilong, Chen, Zixuan, Wu, Jinglai, Zhang, Yunqing

Trends in Driver Response to Forward Collision Warning and the Making of an Effective Alerting Strategy

2024-01-2506

04/09/2024

This paper compares the results from three human factors studies conducted in a motion-based simulator in 2008, 2014 and 2023, to highlight the trends in driver's response to Forward Collision Warning (FCW). The studies were motivated by the goal to develop an effective HMI (Human-Machine Interface) strategy that enables the required driver's response to FCW while minimizing the level of annoyance of the feature. All three studies evaluated driver response to a baseline-FCW and no-FCW conditions. Additionally, the 2023 study included two modified FCW chime variants: a softer FCW chime and a fading FCW chime. Sixteen (16) participants, balanced for gender and age, were tested for each group in all iterations of the studies. The participants drove in a high-fidelity simulator with a visual distraction task (number reading). After driving 15 minutes in a nighttime rural highway environment, a surprise forward collision threat arose during the distraction task. The response times from the

Nasir, Mansoor, Kurokawa, Ko, Singhal, Neha, Mayer, Ken, Chowanic, Andrea, Osafo Yeboah, Benjamin, Blommer, Michael

Inherent Diverse Redundant Safety Mechanisms for AI-Based Software Elements in Automotive Applications

2024-01-2864

04/09/2024

This paper explores the role and challenges of Artificial Intelligence (AI) algorithms, specifically AI-based software elements, in autonomous driving systems. These AI systems are fundamental in executing real-time critical functions in complex and high-dimensional environments. They handle vital tasks like multi-modal perception, cognition, and decision-making tasks such as motion planning, lane keeping, and emergency braking. A primary concern relates to the ability (and necessity) of AI models to generalize beyond their initial training data. This generalization issue becomes evident in real-time scenarios, where models frequently encounter inputs not represented in their training or validation data. In such cases, AI systems must still function effectively despite facing distributional or domain shifts. This paper investigates the risk associated with overconfident AI models in safety-critical applications like autonomous driving. To mitigate these risks, methods for training AI

Pitale, Mandar Manohar, Abbaspour, Alireza, Upadhyay, Devesh

System Level Modelling, Evaluation, and Trade-Off/Optimization of Solid-State & Hybrid DC Circuit Breakers for an EV Eco-System Using AI/ML in an MBSE Framework

2024-01-2657

04/09/2024

With the increasing demand for efficient & clean transport solutions, applications such as road transport vehicles, aerospace and marine are seeing a rise in electrification at a significant rate. Irrespective of industries, the main source of power that enables electrification in mobility applications like electric vehicles (EV), electric ships and electrical vertical take-off & landing (e-VTOL) is primarily a battery making it fundamentally a DC system. Fast charging solutions for EVs & e-VTOLs are also found to be DC in nature because of several advantages like ease of integration, higher efficiency, etc. Likewise, the key drivers of the electric grid are resulting in an energy transition towards renewable sources, that are also essentially DC in nature. Overall, these different business trends with their drivers appear to be converging towards DC power systems, making it pertinent. However, DC circuit protection poses serious challenges compared to AC due to the absence of natural

Milind, T. R., Thomas, Amal, Rastogi, Sarthak, K, Satyadeep

Enhanced Safety of Heavy-Duty Vehicles on Highways through Automatic Speed Enforcement – A Simulation Study

2024-01-1964

04/09/2024

Highway safety remains a significant concern, especially in mixed traffic scenarios involving heavy-duty vehicles (HDV) and smaller passenger cars. The vulnerability of HDVs following closely behind smaller cars is evident in incidents involving the lead vehicle, potentially leading to catastrophic rear-end collisions. This paper explores how automatic speed enforcement systems, using speed cameras, can mitigate risks for HDVs in such critical situations. While historical crash data consistently demonstrates the reduction of accidents near speed cameras, this paper goes beyond the conventional notion of crash occurrence reduction. Instead, it investigates the profound impact of driver behavior changes within desired travel speed distribution, especially around speed cameras, and their contribution to the safety of trailing vehicles, with a specific focus on heavy-duty trucks in accident-prone scenarios. To conduct this analysis, we utilize SUMO, an open-source microscopic traffic

Shiledar, Ankur, Sujan, Vivek, Siekmann, Adam, Yuan, Jinghui

Enhancing Safety Features of Advanced Driver Assistance System Warnings by Using Head-Up Displays

2024-01-2058

04/09/2024

ADAS (Advanced Driver Assistance Systems) is a growing technology in automotive industry, intended to provide safety and comfort to the passengers with the help of variety of sensors like radar, camera, LIDAR etc. Though ADAS improved safety of passengers comparing to conventional non-ADAS vehicles, still it has some grey areas for safety enhancement and easy assistance to drivers. BSW (Blind Spot Warning) and LCA (Lane Change Assist) are ADAS function which assists the driver for lane changing. BSW alerts the driver about the vehicles which are in blind zone in adjacent lanes and LCA alerts the driver about approaching vehicles at a high velocity in adjacent lanes. In current ADAS systems, BSW and LCA alerts are given as optical and acoustic warnings which is placed in vehicle side mirrors. During lane change the driver must see the side mirrors to take a decision. Due to this, there is a reaction time for taking a decision since driver must divert attention from windshield to side

R, Manjunath, Saddaladinne, Jagadeesh Babu, D, Gopinath

Responses to Flashing Warning Lights and Colors of Service Vehicles

2024-01-2229

04/09/2024

Flashing warning lights and vehicle markings of various colors are used on a wide range of emergency and other service vehicles to help inform drivers about the presence of these vehicles and the types of situations that drivers are approaching. Although not applied consistently among all jurisdictions, the colors and performance of these visual elements are often selected to help communicate the type of scenario (such as red flashing lights to indicate an emergency vehicle, or yellow flashing lights to indicate a non-emergency service vehicle). Previous investigations have shown that flashing light colors, vehicle and marking colors, and flashing temporal characteristics (e.g., rapid versus slower flashing) can all affect a driver’s perception of whether a vehicle along the road is responding to an emergency situation or not. Building on previous research, a laboratory study was carried out to investigate how drivers perceive scale-model roadway scenarios including different numbers

Bullough, John D., Skinner, Nicholas P., Rea, Mark S.

Vehicle Braking Performance Improvement via Electronic Brake Booster

10-08-01-0005

02/10/2024

Throughout the automobile industry, the electronic brake boost technologies have been widely applied to support the expansion of the using range of the driver assist technologies. The electronic brake booster (EBB) supports to precisely operate the brakes as necessary via building up the brake pressure faster than the vacuum brake booster. Therefore, in this article a novel control strategy for the EBB based on fuzzy logic control (FLC) is developed and studied. The configuration of the EBB is established and the system model including the permanent magnet synchronous motor (PMSM), a two-stage reduction transmission (gears and a ball screw), a servo body, reaction disk, and the hydraulic load are modeled by MATLAB/Simulink. The load-dependent friction has been compensated by using Karnopp friction model. Due to the strong nonlinearity on the EBB components and the load-dependent friction, FLC has been used for the control algorithm. The control concept focused on transforming the

Soliman, Amr M.E., Kaldas, Mina M., Soliman, Aref M.A., Huzayyin, A.S.

Model Based Charge Control for 3-Cylinder TGDI Miller Engine Containing Variable Geometry Turbocharger

2024-26-0043

01/16/2024

For ensuring environmental safety, strong emphasis on CO2 pollution reduction is mandated which led to evolution of miller cycle engines. However, the inherent Miller engine characteristic is the lower volumetric efficiency when compared to otto engines because of which small turbo chargers with variable geometry turbines are used to induct air into the engine. With miller engine and VGT turbo charger combination arises the challenges of charge controllability because of lower inertia and reduced vane control area. With conventional turbo charger control methods, the response time is slow thereby leading to turbo lag or severe over boosting, this is overcome by accurate engine modelling and using the same as input for charger control. In this study, model-based calibration approach was performed on a 3-cylinder Miller GDI 1.2L engine to model the charge exchange of the engine and use the same for determination required turbine vane positions to achieve the desired airflow induction

Veeramani, Vivekanand, Karthi, Ramanathan, Shanmugam Ramakrishnan, Muthu

Exploring Capabilities of Hydraulic Actuators to Achieve Vehicle Ride Targets in Frequency Range beyond Their Operational Bandwidth

2024-26-0060

01/16/2024

Active suspension systems employ sophisticated control algorithms to deliver superior comfort in vehicles. However, the capabilities of these algorithms are limited by the physical constraints of actuators. Many vehicles use hydraulic actuators in their active suspension system, which use fluid movement to control suspension motion. These systems inherently have slower response times due to the nature of fluid flow and the time required to build up or release pressure within the hydraulic system. Typically, hydraulic systems operate in a low bandwidth of 0-5 Hz. This limits their capability to only meeting vehicle’s primary ride targets which typically lie below 5 Hz. Although they can be tuned to operate at a slightly higher frequency range (up to 10 Hz), they perform poorly in attenuating the secondary ride vibration, i.e., 5 – 25 Hz. This paper focuses on investigating the possible hardware and subsequently control capabilities that can allow us to affect the vehicle ride well

Agrawal, Ayush, Negi, Ayush, Joshi, Divyanshu

Critical Scenarios Based on Graded Hazard Disposal Model of Human Drivers

2023-01-7054

12/20/2023

In order to improve the efficiency of safety performance test for intelligent vehicles and construct the test case set quickly, critical scenarios based on graded hazard disposal model of human drivers are proposed, which can be used for extraction of test cases for safety performance. Based on the natural driving data in China Field Operational Test (China-FOT), the four-stage collision avoidance process of human drivers is obtained, including steady driving stage, risk judgment stage, collision reaction stage and collision avoidance stage. And there are two human driver states: general state and alert state. Then the graded hazard disposal model of human drivers is constructed. According to the parameter distribution of natural driving data, the risk perception point, risk response point and collision reaction time of deceleration scenario and cut-in scenario are obtained, and the deceleration gradient and the maximum deceleration of each collision avoidance difficulty level are

Fang, Xiaowei, Ma, Zhixiong, Zhu, Xichan, Yin, Qi

Predictive 3D-CFD Model for the Analysis of the Development of Soot Deposition Layer on Sensor Surfaces

2023-24-0012

08/28/2023

After-treatment sensors are used in the ECU feedback control to calibrate the engine operating parameters. Due to their contact with exhaust gases, especially NOx sensors are prone to soot deposition with a consequent decay of their performance. Several phenomena occur at the same time leading to sensor contamination: thermophoresis, unburnt hydrocarbons condensation and eddy diffusion of submicron particles. Conversely, soot combustion and shear forces may act in reducing soot deposition. This study proposes a predictive 3D-CFD model for the analysis of the development of soot deposition layer on the sensor surfaces. Alongside with the implementation of deposit and removal mechanisms, the effects on both thermal properties and shape of the surfaces are taken in account. The latter leads to obtain a more accurate and complete modelling of the phenomenon influencing the sensor overall performance. The evolution of the fouling thickness is evaluated by means of the implementation of a

D'Orrico, Fabrizio, Cicalese, Giuseppe, Breda, Sebastiano, Fontanesi, Stefano, Cozza, Ivan, Tosi, Sergio, Gopalakrishnan, Venkatesh

Analytical and Experimental Handling Performance of Ultra-Efficient Lightweight Vehicles

2023-24-0135

08/28/2023

The rising environmental awareness has led to a growing interest in electric and lightweight vehicles. Four-wheeled Ultra-Efficient Lightweight Vehicles (UELVs) have the potential to improve the quality of urban life, reduce environmental impact and make efficient use of land. However, the safety of these vehicles in terms of dynamic behaviour needs to be better understood. This paper aims to provide a quantitative assessment of the handling behaviour of UELVs. An analytical single-track model and a numerical simulation by VI-CarRealTime are analysed to evaluate the dynamic performance of a UELV compared to a city car. This analysis shows that the lightweight vehicle has a higher readiness (i.e. lower reaction time to yaw rate) for step steering and lower steering effort (i.e. higher steady-state value). Experimental analysis through real-time driving sessions on the Dynamic Driving Simulator assesses vehicle responses and subjective perception for different manoeuvres. The driving

Musso, Emanuele, Previati, Giorgio, Mastinu, Gianpiero

Designing an Interactive Mixed Reality Cockpit for Enhanced Soldier-Vehicle Interaction

2024-01-4028

08/10/2023

ABSTRACT This paper discusses the design and implementation of an interactive mixed reality cockpit that enhances Soldier-vehicle interaction by providing a 360-degree situational awareness system. The cockpit uses indirect vision, where cameras outside the vehicle provide a video feed of the surroundings to the cockpit. The cockpit also includes a virtual information dashboard that displays real-time information about the vehicle, mission, and crew status. The visualization of the dashboard is based on past research in information visualization, allowing Soldiers to quickly assess their operational state. The paper presents the results of a usability study on the effectiveness of the mixed reality cockpit, which compared the Vitreous interface, a Soldier-centered mixed reality head-mounted display, with two other interface and display technologies. The study found that the Vitreous UI resulted in better driving performance and better subjective evaluation of the ability to actively

Hansberger, Jeffrey T., Wood, Ryan, Conner, Ty, Hansen, Jayse, Nix, Jacob, Torres, Marco

Occupant Kinetics and Muscle Responses of Relaxed and Braced Small Female and Midsize Male Volunteers in Low-Speed Frontal Sled Tests

09-11-03-0012

07/28/2023

Previous volunteer studies focused on low-speed frontal events have demonstrated that muscle activation (specifically pre-impact bracing) can significantly affect occupant response. However, these tests do not always include a sufficient number of small female volunteers to compare their unique responses to the typically studied midsize male population. The purposes of this study were to quantify the occupant kinetics and muscle responses of relaxed and braced small female and midsize male volunteers during low-speed frontal sled tests and to compare between muscle states and demographic groups. Small female and midsize male volunteers experienced multiple low-speed frontal sled tests consisting of two pulse severities (1 g and 2.5 g) and two muscle states (relaxed and braced) per pulse severity. The muscle activity of 30 muscles (15 bilaterally) and reaction forces at the volunteer-test buck interfaces and seat belt were measured before and during each sled test. Compared to the

Chan, Hana, Albert, Devon L., Gayzik, F. Scott, Kemper, Andrew R.

Passive Ice Protection Systems Lab Scale Testing Methodology

2023-01-1412

06/15/2023

Aircraft icing is a well-known problem that can have serious consequences for flight safety. To combat this problem, various ice protection systems (IPSs) have been developed and are currently used on most aircraft, including thermal ice protection systems. However, these systems can be costly, heavy and ineffective. Therefore, there is a need to improve the efficiency and response time of these systems. In recent years, research has focused on the development of hybrid systems that combine different ice protection technologies to achieve better performance. In this sense, the use of an active element with a coating on its external part that improve its efficiency would be an important advance, but there is a wide range of active systems and even more of coatings and surface treatments. Therefore it would be helpful to have a test methodology that would allow a simple but thorough assessment of the performance of each passive system, and this is precisely what is proposed in this

García, Paloma, Mora, Julio, Carreño, Francisco, Redondo, Francisco, Rodriguez, Rafael, Rivero, Pedro, Vicente, Adrian, Acosta, Carolina, Larumbe, Silvia, Medrano, Ángel, Lecumberri, Cristina

Experimental and Analytical Evaluation of an Acceleration-Based Semiactive Control Strategy for Automotive Suspension Systems with Magneto-Rheological Damper

15-16-03-0015

06/01/2023

Most of the control strategies presented to date are based on either the velocities or displacement of the vehicle body and the wheel which are derived by filtering and converting the data from the accelerometer. This increases the computational load and therefore directly affects the performance of the semiactive suspension system. This study presents a control strategy purely based on the acceleration for semiactive control of vehicle suspension with a magneto-rheological MR damper. The effectiveness of the acceleration-based skyhook (ASH) control strategy is compared with the existing velocity-based skyhook (VSH) control strategy based on the vibration response of a single-degree-of-freedom (SDOF) system. The effectiveness of ASH is evaluated experimentally, and the reaction time is evaluated analytically. The experimental results revealed that the ASH reduces the peak displacement and peak acceleration of the mass under the free vibration test and also improves the settling time as

Jamadar, Mohibb e Hussain, Devikiran, Pinjala, Kumar, Hemantha, Joladarshi, Sharnappa

Comparing Visual Fixations between Initially Stopped and In-motion Turn Across Path Hazards

2023-01-0837

04/11/2023

Collisions involving turn-across-path hazards are responsible for a disproportionate number of injuries and fatalities compared to collisions with other orientations. Previous investigations of turn-across-path hazards have found conflicting results regarding hazard detection and response behaviour of drivers, particularly for hazards with different onset conditions. Typically, hazards with abrupt onsets should attract attention more readily, however, the opposite trend for response times has been observed when the abrupt onset is a rapid change in speed, rather than a sudden appearance. This study compared two left-turn-across path hazards with different onsets. The abrupt onset hazard was an initially stopped vehicle that quickly accelerated into the participant drivers’ path, while the gradual onset hazard was already in motion as the participant driver approached. Visual fixations were compared between the two onset types to determine if the sudden speed change was capturing

Caren, Brooklin, Ziraldo, Erika, Oliver, Michele

Evaluating Drivers’ Understanding of Warning Symbols Presented on In-Vehicle Digital Displays Using a Driving Simulator

2023-01-0790

04/11/2023

Since 1989, ISO has published procedures for developing and testing public information symbols (ISO 9186), while the SAE standard for in-vehicle icon comprehension testing (SAE J2830) was first published in 2008. Neither testing method was designed to evaluate the comprehension of symbols in modern vehicles that offer digital instrument cluster interfaces that afford new levels of flexibility to further improve drivers’ understanding of symbols. Using a driving simulator equipped with an eye tracker, this study investigated drivers’ understanding of six automotive symbols presented on in-vehicle displays. Participants included 24 teens, 24 adults, and 24 senior drivers. Symbols were presented in a symbol-only, symbol + short text descriptions, and symbol + long text description conditions. Participants’ symbol comprehension, driving performance, reaction times, and eye glance times were measured. The results of this study suggested that presenting automotive symbols on in-vehicle

Schwambach, Breno, Brooks, Johnell, Jenkins, Casey

Compound Brake Control for Improved Ride Comfort for Dual-rotor In-wheel Motor Electric Vehicles

2023-01-0526

04/11/2023

Aiming at the problem of braking shock caused by the inconsistent response time of the inner motor (IM), the outer motor (OM) and the hydraulic brake when the regenerative braking mode of dual-rotor in-wheel motor (DRIWM) is switched, this paper proposes a U-shaped transition coordinated control strategy for the DRIWM. Ensure that the total braking torque can be smoothly transitioned when any one or more of the hydraulic braking torque, the braking torque of the IM and the braking torque of the OM enter/exit braking. The dynamic model of electric vehicle (EV) with DRIWMs is established, the division of braking mode is based on the principle of optimal DRIWM system efficiency, and the U-shaped transition coordinated controller of DRIWM is designed. Finally, two cases of switching the IM single braking mode to hydraulic braking mode and OM and hydraulic coordinated braking mode switching to compound braking mode are taken as examples to verify. The results show that, compared with the

leng, Fei, He, Ren

A Road Roughness Estimation Method based on PSO-LSTM Neural Network

2023-01-0747

04/11/2023

The development of intelligent and networked vehicles has enhanced the demand for precise road information perception. Detailed and accurate road surface information is essential to intelligent driving decisions and annotation of road surface semantics in high-precision maps. As one of the key parameters of road information, road roughness significantly impacts vehicle driving safety and comfort for passengers. To reach a rapid and accurate estimation of road roughness, in this study, we develop a neural network model based on vehicle response data by optimizing a long-short term memory (LSTM) network through the particle swarm algorithm (PSO), which fits non-linear systems and predicts the output of time series data such as road roughness precisely. We establish a feature dataset based on the vehicle response time domain data that can be easily obtained, such as the vehicle wheel center acceleration and pitch rate. A PSO-LSTM network is built to achieve road roughness estimation and

Li, Zhuoyang, Yang, Shichun, Chen, Yuyi, Nan, Zhaobo, Shi, Runwu, Wang, Rui, Zhang, Mengyue

An Analysis of Software Latency for a High-Speed Autonomous Race Car—A Case Study in the Indy Autonomous Challenge

12-06-03-0018

02/07/2023

Autonomous driving faces the difficulty of securing the lowest possible software execution times to allow a safe and reliable application. One critical variable for autonomous vehicles is the latency from the detection of obstacles to the final actuation response of the vehicle, especially in the case of high-speed driving. A prerequisite for autonomy software is that it enables low execution times to achieve superhuman reaction times. This article presents an in-depth analysis of a full self-driving software stack for autonomous racing. A modular software stack especially developed for high-speed autonomous driving is used and the latency of the software is analyzed in four main autonomy modules: perception, prediction, planning, and control. With the help of a trace point measurement method, it is possible to investigate the end-to-end latency and runtimes of the individual modules. This analysis is conducted for different scenarios (high-speed runs, object avoidance, and multi

Betz, Tobias, Karle, Phillip, Werner, Frederik, Betz, Johannes

Operational Definitions of Driving Performance Measures and Statistics

J2944_202302 (Current)

02/06/2023

This Recommended Practice, Operational Definitions of Driving Performance Measures and Statistics, provides functional definitions of and guidance for performance measures and statistics concerned with driving on roadways. As a consequence, measurements and statistics will be calculated and reported in a consistent manner in SAE and ISO standards, journal articles proceedings papers, technical reports, and presentations so that the procedures and results can be more readily compared. Only measures and statistics pertaining to driver/vehicle responses that affect the lateral and longitudinal positioning of a road vehicle are currently provided in this document. Measures and statistics covering other aspects of driving performance may be included in future editions. For eye glance-related measures and statistics, see SAE J2396 (Society of Automotive Engineers, 2007) and ISO 15007-1 (International Standards Organization, 2002).

Driver Metrics, Performance, Behaviors and States Committee

Humidity Sensing Behavior and Characterization of CuWO ₄ Nanoparticles

2022-28-053712/23/2022

Solution route precipitation technique was opted to synthesize the nanostructured copper tungstate by the incorporation of cupric ion solution to the aqueous sodium tungstate reagent. The size and surface of the synthesized nanostructured material is highly influenced by the concentration of cuprous ion as well as the tungstate solution. The structural pattern and chemical composition of CuWO4 nanoparticles were analysed by powder XRD and FESEM with EDX spectrum. The powder XRD and EDX pattern confirmed the elemental composition of the synthesized samples. FESEM images indicated that the particle was present in random size distribution. At 298 K, water vapour pressure thermostat was achieved in the range from 5% to 98% as a relative humidity (RH). By providing the DC conductance measurement as a relative humidity, the humidity sensing nature of the material was investigated and the sensitivity factor (Sf) value of the prepared CuWO4 was calculated at 298K (Sf=9640±100). It revealed

S, Poovaragan, R, Ganesamoorthy, N, Balaji, K R, Padmavathi, R, Soundararajan

The Effect of Driver’s Response Features on Safety Effectiveness of Autonomous Emergency Braking

2022-01-7131

12/16/2022

The Autonomous emergency braking system (AEB) has been widely equipped in the design and manufacture of vehicles as an active safety system for preventing rear-end collisions. It has shown great safety potential in preventing collisions and reducing collision injuries. However, there are differences in the response characteristics of drivers in emergency scenarios due to individual differences and driving habits. The impact of different driver types on the safety performance of AEB systems has not been evaluated. In this study, the typical driver response model was constructed by selecting driver response features representing alertness and braking. The AEB algorithm of distance and situation awareness was combined with the kinematic of vehicle before the collision to construct a simulation case based on the rear-end collisions in the China in-depth accident study database (CIDAS). The collision avoidance percentage, the impact speed, and the minimum relative distance were used as

Wei, Tianzheng, Kang, Kai, Zhu, Tong, Liu, Haoxue

Implications for Interactions between Micromobility and Autonomous Vehicles

12-06-02-0012

12/08/2022

This article discusses the potential interactions and impacts between autonomous vehicles (AVs) and micromobility users. While fully automated privately owned AVs are not yet commercially available to the public, AVs such as robotaxis, shuttles, and delivery bots are becoming increasingly common, especially in densely populated urban areas. At the same time, new types of micromobility devices, such as e-scooters, are being introduced into the transportation infrastructure, often in the same areas. While extensive research and safety testing are standard in both domains, the potential interactions between these two types of mobility in real-world environments require consideration. By exploring the current state of both technologies and the early evidence currently available, we catalog potential implications of their interactions, particularly with respect to communication, expectations, infrastructure, risky behavior, and the impact of data limitations. Avenues for future research in

Sanders, Tracy, Karpinski, Elizabeth

Analysis of Factors Which Impact Response Timing for OBD Diagnostic Protocol

SAE-PP-0031411/18/2022

The timer P2 is wellknown in the industry for OBD diagnostic protocols, it has been 50ms since the mid of the 90's and the industry has had concerned for it the latest 20 years. This document tries to analyze the factors which impact the P2 timer and also the P6 which is for DoIP.

Pauli, Joakim

On-board Electrostatic PM (ePM) Sensing for Filter IUMPR Compliance

1333210/07/2022

Recent advances in electrostatic sensing of particulates have enabled improvements in sensor response time, sensitivity, and durability. These improvements provide a path to compliance with the recently-approved CARB OBD updates phasing in between 2026 and 2029. This presentation will review the ePM measurement principle, sensor design status, performance data, calibration requirements, cold start performance, and potential applicability to real emissions assessment logging (REAL).

Thompson, Patrick

Motorcycle Crash Severity Estimation for Effective Emergency Response

2022-28-0399

10/05/2022

Motorcyclists are about 29 times more likely than passenger vehicle occupants to die in a motor vehicle crash and are 4 times more likely to be injured. Safe motorcycling takes balance, co-ordination, and good judgement. As per NHTSA, per 100,000 registered vehicles motorcycle fatality and injury rate stand at 58.33 and 975 and that of passenger vehicles stand at 9.42 and 1152. With such rates of fatality and injury of motorcyclists, there is strong need for motorcycle solutions that help to minimize traffic fatalities and improve road safety scenarios. Helmets are estimated to be 37% effective in preventing fatal injuries to motorcycle riders and 41% for motorcycle passengers but there is little to no post-crash assistance available on board the motorcycles. Post-crash emergency response is time sensitive and can be broken down into a subset of activities beginning with discovery of crash, notification, and activation of emergency medical service (EMS), response time, on-scene time

Rao, Aditya N, Notani, Vipul, Muralidharan, Vishal

A Collision Avoidance Strategy Based on Inevitable Collision State

2022-01-1170

09/19/2022

This paper proposed a collision avoidance strategy that take over the control of ego vehicle when faced with urgent collision risk. To improve the applicability of collision avoidance strategy in complex scenarios, the theory of ICS (Inevitable Collision State) is introduced to evaluate the collision risk and compute the trigger flag of the system, and vehicle dynamic is taken into account when modeling ego vehicle to predict ego vehicle’s following moving. Vehicle specific characteristics including reaction time of the braking system and the braking force increasing process are taken into account. In order to reduce injury caused by collision accidents and minimize disruption to drivers, slight steering is added on top of emergency braking. The direction of the steering angle is determined according to IM (Imitating Maneuvers) The flow chart of the strategy is presented in the paper. Considering the more serious danger and higher mobility of scenarios involving VRU (Vulnerable Road

Wang, Ruoqi, Yu, Liangyao, Huang, Yong

Hand Held Aircraft Tire Inflation Pressure Gauges

ARP5542A (Current)

05/19/2022

This SAE Aerospace Recommended Practice (ARP) covers the design, construction, performance and testing requirements for hand held aircraft tire inflation pressure gauges with valve stem attachment chuck to be used with all aircraft types. The ground-based gauges in this specification are those which are designed to read the tire inflation pressure from a position adjacent to the tire.

A-5C Aircraft Tires Committee

Predicting Driver Emergency Response Onset using Time-to-Impact

2022-01-0806

03/29/2022

Conventional forensic analyses of collision avoidance behaviours involve assigning a perception and response time (PRT) interval to a driver which precedes the onset of evasive action. This approach relies on the investigator identifying a ‘time zero’ for when to begin the PRT interval, which nominally aligns with the first moment of hazard detection. However, depending on the incident circumstances, identifying the initial moment of hazard detection poses challenges. Recent research has shown the potential of an alternative method of forensic analysis that is based on the relationship between response onset and the projected time-to-impact (TTI). Accordingly, the aim of this research is to further investigate this relationship. Twenty subjects viewed driver-perspective recordings of a simulated vehicle travelling down a major roadway past several two-way stop-controlled minor roads. At various intersections, intruding vehicles entered from the left or right. These intruders were

Erazo, Fabian, Campbell, Adam

Modelling of Switching Characteristics of Hydrogen-Nitrogen Filled DC Contactor Under External Magnetic Field

2022-01-0728

03/29/2022

The electric or hybrid vehicles need fast switching operation in order to ensure the quick-response of the motors. This process is carried out by compact direct-current contactors which are designed to perform the switching over multiple cycles. During the contact separation, the gas between the contacts breaks down and the resulting thermal arc provides a conductive channel that sustains the current. Until the arc is quenched, the current continues to flow through the contacts despite the physical separation. This unintended flow of current could lead to a larger response time than the safe operation limits. We perform high-fidelity simulation of thermal arc in hydrogen-nitrogen mixture environment under external magnetic field of 1 Tesla. The hydrogen enrichment level is kept at 0%, 40%, 50% and 80%. The contacts are separated at 8 m/s. It is demonstrated that the increase in hydrogen concentration leads to smaller arc lifetime thereby improving the circuit interruption performance.

Ranjan, Rakesh, Thiruppathiraj, Sudharshanaraj, Raj, Naveen, Karpatne, Anand, Breden, Douglas, Raja, Laxminarayan

A Novel Method for Displaying Systems Datums Based on “Cognitive Load”

2022-01-0808

03/29/2022

Operator attention has been a significant focus of human factors research in recent years. This research has clarified how electronic devices and other stimuli can become distractions for vehicle operators. The research has defined a condition known as “distracted driving,” characterized by interruption of the sequence of cognitive processes essential for safe operation of a vehicle. Although “attention” has been the most often mentioned of these cognitive processes, they also include perception, memory, cognition, and planful behavior. These processes are the “cognitive demands” of safe vehicle operation. There is another issue, similar to distracted driving, that may hamper safe operation of a vehicle. That issue is the “cognitive load” of human-machine interface devices, including instrument clusters. The present paper explores the effects of cognitive load on operator response speed. It describes a novel method for displaying systems datums designed to manage cognitive load. The

Havins, William

Hydrostatic Torque Modulation

2022-01-0643

03/29/2022

Hydrostatic torque modulation is a new, at moment theoretical approach, to developing advanced AWD4WD transmissions. The basic component is a rotational hydrostatic modulator. It is derived from a low-speed high-torque hydrostatic machine. As such, it can be integrated into a standard mechanical AWD4WD transmission as a replacement for the clutch, where torque is controlled through energy dissipation. Controlled by a simple solenoid valve, it provides torque vectoring with a reaction time shorter than 0.5 s, and it provides additional safety features that result in a more robust AWD4WD transmission. As it can modulate torque with energy flow control/transfer, it offers much more than existing systems based on controlled clutches. Specifically, hydrostatic torque modulation, when it is integrated into the AWD4WD transmission, brings CVT or ICT performance. As torque modulation is performed through the control of the energy flow, it provides torque control from 0 km/h without using a

Bozic, Ante

Items per page:

1 – 50 of 813