The DRIVE-SAFE project: signal processing and advanced information technologies for improving driving prudence and accidents

In this paper, we will talk about the Drivesafe project whose aim is creating conditions for prudent driving on highways and roadways with the purposes of reducing accidents caused by driver behavior. To achieve these primary goals, critical data is being collected from multimodal sensors (such as cameras, microphones, and other sensors) to build a unique databank on driver behavior. We are developing system and technologies for analyzing the data and automatically determining potentially dangerous situations (such as driver fatigue, distraction, etc.). Based on the findings from these studies, we will propose systems for warning the drivers and taking other precautionary measures to avoid accidents once a dangerous situation is detected. In order to address these issues a national consortium has been formed including Automotive Research Center (OTAM), Koç University, Istanbul Technical University, Sabancı University, Ford A.S., Renault A.S., and Fiat A. Ş

Autonomous Road Vehicle Emergency Obstacle Avoidance Maneuver Framework at Highway Speeds

An Autonomous Road Vehicle (ARV) can navigate various types of road networks using inputs such as throttle (acceleration), braking (deceleration), and steering (change of lateral direction). In most ARV driving scenarios that involve normal vehicle traffic and encounters with vulnerable road users (VRUs), ARVs are not required to take evasive action. This paper presents a novel Emergency Obstacle Avoidance Maneuver (EOAM) methodology for ARVs traveling at higher speeds and lower road surface friction, involving time-critical maneuver determination and control. The proposed EOAM Framework offers usage of the ARV's sensing, perception, control, and actuation system abilities as one cohesive system, to accomplish avoidance of an on-road obstacle, based first on performance feasibility and second on passenger comfort, and is designed to be well-integrated within an ARV high-level system. Co-simulation including the ARV EOAM logic in Simulink and a vehicle model in CarSim is conducted with speeds ranging from 55 to 165 km/h and on road surfaces with friction ranging from 1.0 to 0.1. The results are analyzed and given in the context of an entire ARV system, with implications for future work.Comment: 50 pages, 25 figures, 2 table

Modeling and rule based control of hybrid electric vehicles

Hibrid elektrikli araçlar, atmosferi kirletmeyen taşıtların geliştirilmesinde ara çözüm olarak karşımıza çıkmaktadır. Global ısınmaya neden olduğu ve insan sağlığına zarar veren kirletici gazlar açığa çıkartmaları nedeniyle içten yanmalı motorlar ile çalışan yol taşıtlarında emisyonlara sıkı sınırlamalar getirilmekte, yenilenebilir ve temiz enerji üzerine yapılan çalışmalar giderek yoğunlaşmaktadır. Yakıt hücresi ve hidrojen enerjisi ile çalışan araç teknolojilerinde, hidrojen yakıtının doğada saf halde elde edilememesi ve bu nedenle hidrojen elde ediniminde fosil yakıtlar ile çalışan santrallerin kullanılması, daha az ya da hiç karbon içermeyen yakıtların yol taşıtlarında kullanılmasında engel teşkil etmektedir. Bataryaların fosil yakıtlara göre enerji kapasitelerinin ve sağladıkları menzil miktarının çok düşük olması nedeniyle, hibrid elektrikli araçlarda, içten yanmalı motorların düşük verim ile çalıştığı bölgelerde bataryalar yardımcı güç kaynağı olarak kullanılmakta, dolayısı ile araç seyahati süresince içten yanmalı motorların ortalama verimleri daha yüksek tutularak yakıt tasarrufu sağlanmaktadır. Hibrid elektrikli araçlar üzerine yapılan çalışmalar, sıfır emisyonlu araç teknolojilerinin alt yapısını da güçlendirmektedir. Hibrid elektrikli araçlarda ana problem, bir araya getirilen bileşenler arasındaki güç dağılımının, araç seyahati esnasında gerçek zamanlı olarak hesaplanabilmesi problemidir. Ticari hibrid elektrikli araçlarda, kural tabanlı kontrol yöntemleri ve mekanizmaları kullanılmaktadır. Hibrid elektrikli araçlarda bu kısıtlamaların giderilebilmesi için, gerçek zamanlı kullanılabilecek optimizasyon yöntemleri üzerinde çalışmalar yoğunlaşmıştır.  Anahtar Kelimeler: Hibrid elektrikli araçlar, modellenmesi, kural tabanlı kontrol.The increase in temperature of atmosphere is mostly attributed to human activity due to the combustion products of excessively used fossil fuels.These products create greenhouse effect whereby the planet's surface temperature increases. Use of renewable and clean energy sources is the best solution to reduce increase rate of warming, to mitigate the results of climate change and not to go beyond the irreversible point for the sustainability of life on the planet. The second major source of green house gases comes after electricity generation is transportation sector due to increasing traveling demand as well as its fastest growing rate. There are stringent emission limits stipulated by governors. The proposed emission limits for near future can no longer be satisfied by Internal Combustion Engines (ICE) despite the good advancements in engine technologies. There are numerous studies to adapt clean energy sources on road vehicles. Hydrogen and pure electric energy is seen as an excellent solution for zero emission vehicles. But there are some obstacles for both power sources. The use of hydrogen as common fuel in internal combustion is seen to be unfeasible in immediate future, due to storage, production and availability problems. Hydrogen is not an energy source but it is an energy carrier.  Besides this its well-to-wheel efficiency is low with respect to fossil fuels. As to batteries, their poor energy density and long charging time hampers the use of batteries as main power source in on road vehicles. The best solution is to use less or carbon intensive fuels or increasing average efficiency of ICE by using secondary power source in the vehicle. Hybrid vehicles which combine at least two power sources are temporary solution on the way of zero emission vehicles. Hybridization provides means of fuel consumption and emission reduction. Using secondary power source allows down-sizing the engine. Smaller engines operate more efficiently than bigger ones since internal combustion engines are designed to operate efficiently at high loads.  Recuperation of the thrown energy and engine stop option are another advantages of hybrid vehicles in fuel economy. Power distribution strategy between energy sources and wheels is of great importance to exploit hybrid vehicles features and this may give satisfactory results even in the situations where engine down-sizing and idle stop cannot be implemented. Power management is a complicated global optimum problem since it involves too many objectives such as fuel consumption and emission reductions as well as drive-ability and acceleration performance of hybrid vehicle. Dynamic Programming (DP) technique generally is used to solve global optimum problems with non-linear constraints. Due to the computational burden and uncertainty in driver's power demand, dynamic programming technique cannot be handled real-time with available computation technologies. Optimum power split strategy is determined offline for a given drive cycle and control rules are extracted at the end of DP solution.There are alternative techniques developed that give sub-optimal solutions approaching global optimum results and can be implemented real-time. These methods are based on finding optimum power split ratio in a time interval by applying predictive control or finding instantaneous optimum power split by using equivalent fuel consumption methods. The vehicle speed profile in shorter time intervals is estimated and DP solution is computed for optimum power split in model predictive control methods. Equivalent fuel quantity of battery energy is converted by using mean efficiencies for a defined cycle and then best power split ratio is chosen. Modeling and rule based control methodology of a converted vehicle is explained in this study. The Ford Transit light commercial vehicle is converted to a hybrid electric vehicle. Since it has front and rear wheel drive versions are available in the market, mounting an electric motor to rear axle of front wheel drive version resulted in a parallel hybrid electric vehicle. The construction of longitudinal hybrid electric vehicle models is given. The use of these models to develop rule based control and simulation results are given. Keywords: Hybrid electric vehicles, rule based control

Real-time controller design for a parallel hybrid electric vehicle using neuro-dynamic programming method

The use of the neuro-dynamic programming method for real-time control of a parallel hybrid electric vehicle is addressed in this study. The validated model of a research prototype parallel hybrid electric light commercial vehicle, FOHEV I, is used in the numerical parts of this paper. A diesel engine and an electric motor power the front and rear axles, respectively. Due to the computational complexity and resulting burden for optimum power distribution in the hybrid electric powertrain, real-time computation using dynamic programming is not feasible. Sub-optimal optimization techniques are available for pre-defined speed profiles, however, the vehicle speed profile depends on the driver input and vehicle and road conditions and is not known a priori. A neuro-dynamic programming method is proposed here to solve this problem. The results are compared with and found to be quite close to the optimal ones computed using dynamic programming.7 page(s

Taşıt savrulma dinamiği kontrol sistemlerinde zaman gecikmesi etkisinin zaman gecikmesi gözleyicisi kullanılarak telafi edilmesi

Zaman gecikmesi kontrol sistemleri tasarımında dikkate alınması gereken sistemin performansını azaltan ve en kötü durumda da sistemi kararsız yapan etkenlerden birisidir. Zaman gecikmesi telafisi için literatürde pek çok yöntem önerilmiştir. Bunlardan en yaygın olarak kullanılanı Smith tahmincisidir. Smith tahmincisi kolaylıkla uygulanabilse de tahmincinin kullandığı zaman gecikmesi modeli ile sistemdeki gerçek zaman gecikmesi farklılaştıkça gecikme telafisi performansı düşmektedir. Bu metodun alternatifi olarak zaman gecikmesi gözleyicisi önerilmiş ve literatürde daha önce bilateral teleoperasyon sistemlerine, robotik manipülatörlere ve iletişim ağı tabanlı yürüyüş şekli rehabilitasyon cihazlarına uygulanmıştır. Bu çalışmada ise zaman gecikmesi gözleyicisinin taşıt savrulma dinamiği kontrolüne uygulanması ele alınmıştır. Zaman gecikmesi gözleyicisinin performansı zamanla değişen gecikmeler için çeşitli simülasyon çalışmalarıyla test edilmiş, ayrıca sonuçlar Smith tahmincisiyle karşılaştırılmıştır