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Start Over Publication Year Range Last 50 years Publisher society of automotive engineers of japan
525 results

1. Continuous Risk Measures for Driving Support

Author

Eggert, Julian, Puphal, Tim, Eggert, Julian, and Puphal, Tim

Abstract

In this paper, we compare three different model-based risk measures by evaluating their stengths and weaknesses qualitatively and testing them quantitatively on a set of real longitudinal and intersection scenarios. We start with the traditional heuristic Time-To-Collision (TTC), which we extend towards 2D operation and non-crash cases to retrieve the Time-To-Closest-Encounter (TTCE). The second risk measure models position uncertainty with a Gaussian distribution and uses spatial occupancy probabilities for collision risks. We then derive a novel risk measure based on the statistics of sparse critical events and so-called “survival” conditions. The resulting survival analysis shows to have an earlier detection time of crashes and less false positive detections in near-crash and non-crash cases supported by its solid theoretical grounding. It can be seen as a generalization of TTCE and the Gaussian method which is suitable for the validation of ADAS and AD.

Published
2022

2. Safety Analysis of Cooperative Adaptive Cruise Control in Vehicle Cut-in Situations

Author

Aramrattana, Maytheewat, Englund, Cristofer, Jansson, Jonas, Larsson, Tony, Nåbo, Arne, Aramrattana, Maytheewat, Englund, Cristofer, Jansson, Jonas, Larsson, Tony, and Nåbo, Arne

Abstract

Cooperative adaptive cruise control (CACC) is a cooperative intelligent transport systems (C-ITS) function, which especially when used in platooning applications, possess many expected benefits including efficient road space utilization and reduced fuel consumption. Cut-in manoeuvres in platoons can potentially reduce those benefits, and are not desired from a safety point of view. Unfortunately, in realistic traffic scenarios, cut-in manoeuvres can be expected, especially from non-connected vehicles. In this paper two different controllers for platooning are explored, aiming at maintaining the safety of the platoon while a vehicle is cutting in from the adjacent lane. A realistic scenario, where a human driver performs the cut-in manoeuvre is used to demonstrate the effectiveness of the controllers. Safety analysis of CACC controllers using time to collision (TTC) under such situation is presented. The analysis using TTC indicate that, although potential risks are always high in CACC applications such as platooning due to the small inter-vehicular distances, dangerous TTC (TTC < 6 seconds) is not frequent. Future research directions are also discussed along with the results.

Published
2017

3. Development of a safe driving guidance system that targets 30 km/h zones

Author

Strand, Niklas, Suzuki, Keisuke, Peters, Björn, Strand, Niklas, Suzuki, Keisuke, and Peters, Björn

Abstract

Traffic accidents between vehicles and vulnerable road users, and the senior part of the population particularly, is a traffic safety problem that must be addressed continuously. A safe driving guidance system such as an intelligent speed adaptation system that suppress the speed to prevent and mitigate accidents is an important measure that can address this traffic safety problem. In specific, the accidents targeted in this paper are those that appear in intersections. An intelligent speed adaptation system with acoustic and graphical information that is adapted to the driver’s characteristics to increase the compliance with the guidance provided by the system is developed. Two driving simulator studies were conducted as part of the development procedure. The results of these experiments indicated that a speed restraining effect could be determined of the system and different human-machine-interfaces were compared. The safe driving guidance system was also optimized to driver characteristics and a target value was presented with an optimal value. Implications for system design and human-machine-interaction is discussed.

Published
2017

4. Magnetic Field Emission Comparison for Series-Parallel and Series-Series Wireless Power Transfer to Vehicles – PART 1/2

Author

Tushar Batra and Erik Schaltz

Subjects
EV and HV systems, Magnetic fields, Wireless power transfer, Series-series topology, Series-parallel topology
Abstract

Resonant circuits of wireless power transfer system can be designed in four possible ways by placing the primary and secondary capacitor in a series or parallel order with respect to the corresponding inductor. The two topologies series-parallel and series-series under investigation have been already compared in terms of their output behavior (current or voltage source) and reflection of the secondary impedance on the primary side. In this paper it is shown that for the same power rating series-parallel topology emits lesser magnetic fields to the surroundings than its series-series counterpart at steady state resonant operation. First of all analytical expressions for the above mentioned statement are presented and is later substantiated with simulations on a finite element solver (Comsol). Results for variation of the magnetic emissions ratio for the two topologies are presented in this paper for different gap distance between the two inductors, horizontal distance from the coils and turn ratio.

Published
2014