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Drowsiness has been one of the major reasons of road fatality over a decade because the effect of drowsiness is trying to shut down both mind and body. That means drivers are unable to completely control the car while trapped in an unconscious state. It will lead to a several number of casualties on road. In this research, two sets of people, partial sleep-deprivation and non-sleep-deprivation, are tested on the driving simulator. Two methods were used in this study to identify driver drowsiness. First, driving behavior focusing on steering pattern. And secondly, vehicle offset from the lane center. The tests were carried out on the designed scenarios in the Driving Simulator. The scenarios are such as following straight lane with vehicle along the road, following curve lane without other cars, car following on a single lane and following straight lane without other cars. From the results, there are significant results that can roughly separate drowsy driver from regular driver.

It is common for users of commuting passenger cars in Thailand to use the vehicle’s HVAC (Heating, Ventilating and Air Conditioning) system predominantly in recirculation (REC) mode. This minimizes the compressor work, thereby saving fuel, and reduces dust and odor infiltration into the vehicle cabin. The car windows are rarely opened for ventilation purposes, except for exchanges at service stations such as garage entrances and tollway booths. As such, there are few opportunities for fresh air to enter the cabin with the consequent accumulation of CO2 in vehicle cabins due to occupants’ exhalations being well documented. Field experiments conducted showed that the in-vehicle CO2 concentrations could reach up to 15 times that of the ambient concentration level during typical city commutes. Preliminary experiments were also conducted to quantify the air exchanges between the cabin and the ambient when the doors are opened for occupant egression.

The world is aging rapidly. Many countries can already be categorized as aging or aged societies while a few are becoming super-aged societies. In Thailand as well as in other countries, traffic accidents caused by elderly drivers will continue to rise as a significant percentage of elderly people still prefer to drive. Accidents may be prevented with driving tests and screening methods for elderly drivers. However, it is also necessary to understand the effect of aging on driving ability. With this understanding, driver training, driver assistant systems, and improvements on infrastructure may be designed accordingly. Among various physical changes, cognitive ability of the brain is one of the most significant factors affecting driving ability. In this paper, correlation between various cognitive functions of the brain and car following skill of drivers are considered.

According to the recent study, Thailand has the 2nd most dangerous road in the world. Based on many researches, the driver is the main influencers of the traffic fatalities. Since the more dangerous the driver drive, the more chance of accident become. Therefore, driver’s monitoring system become one of the solutions that acceptable and reliable, especially for fleet management and public transportation. This paper’s goal is to find an algorithm that can distinguish driving behaviour based on cars’ acceleration and velocity, calling it as Risk Driving Score (RDS). The algorithm was tested by driving test by volunteers on highways with observers, who were told to rank the drivers in terms of driving risk from the 1-5 point. Meanwhile, the drivers were asked to drive in 3 different styles, normal, safety, and hurry. All drives were recorded by satellite and video data then filtered and used for the algorithm calculation.

The road accident is major problem around the world and also in Thailand, The main cause is concerning the driving behavior e.g. uncarefulness, aggression, drowsiness and etc. Dangerous driving is categorized by means of lateral vehicle dynamics when the turning or lane changing is performed, and longitudinal one if the braking or rapid acceleration is occurred. For this reason, we developed the vehicle monitoring system based on novel consumer grade multi-satellite navigation receivers and proposed the lateral acceleration estimation from these data. The system were tested within controlled condition tested track. The multiple satellite system, GPS and multi-GNSS: GPS+Glonass and GPS+Beidou were tested and compared to the reference inertial measurement unit (IMU) As results, the maximum lateral acceleration in tested track were chosen and compared with reference IMU.

The road accident is major concern around the world, so do Thailand. It is caused by three main factors: man, vehicle and infrastructure. The most important part that accounts the safety of vehicle is human. With experiences and careful driver, the accident could be diminished. So that the vehicle monitoring systems are the vital tools to screen out the inexperience or aggressive driver. In this paper, we state the problem about the dangerous driving behavior by monitoring lateral and longitudinal acceleration. For this purpose, the inertial measurement unit should be applied but it is inconvenient to install in the vehicle. Consequently, the vehicle monitoring system were developed based on novel consumer grade multi-satellite navigation receivers and were compared to Racelogic Video V-Box system in controlled condition tested track. The incidents were virtually detected and reviewed. The incident detection algorithm were proposed and tested alongside with receivers.

Driver behavior is one of the most important factors in safe mobility. In general, various driver maneuvers can be determined from acceleration of the vehicle. Physically, the acceleration and brake can be detected with longitudinal acceleration while turning and lane change can be detected with lateral acceleration. Normally, IMU (inertia measurement unit) has been designated to get these data. However, the IMU is not convenience to install in the vehicles especially as aftermarket parts. Nowadays, navigation system technologies have been much improved, both on availability and accuracy with combination of multiple navigation satellite systems. Normally, it's called Multi-GNSS (multiple global navigation satellite system). In particular, the satellite navigation systems available in this work are GPS, GLONASS, and QZSS. With decimeter precision and the update rate scale up to 10-Hz, the GNSS can be a viable alternative for driver behavior detection.

This paper presents the development and simulation results of dynamic model for electric Tuk-tuk that can be used to predict energy consumption in Bangkok driving condition by using MATLAB/Simulink. The major components of this model are battery, motor, controller, transmission and tractive effort. The model consider in dynamics of motor and battery. The driving cycle which is employed is consist of Bangkok driving cycle (BDC). The simulation results were verified with collected data from real condition driving test. It shown that the simulation results of the model can represent accurately the actual electric Tuk-tuk behavior during both steady state and transient and can indicate the energy consumption from battery. The energy consumption required is 6.85 kWh with 20.04km distance along the urban Bangkok driving route before the battery cannot supply adequate power.

This paper presents an investigation on fuel consumption in Bangkok traffic condition with an application of idle stop system. Collected data is evaluated by cutoff the fuel usage while the vehicle is in stationary condition. The vehicles in this study are ordinary vehicle which is not the vehicle with idle-stop system. The study includes four levels of congestion and three road side conditions. With idle stop system, for spark ignition engine 40% of fuel consumption rate could be improved in severe condition and 10% improvement in free flow traffic. In addition, the fuel consumption can be improved by 30% for compression ignition engine. Furthermore, the idle stop system improves fuel efficiency in severe congestion to the same level as the free flow traffic

This paper presents a Tire-Suspension-Steering Hardware-In-the-Loop Simulator (HILS) system for using in a development of a student formula car suspension. The HILS system was modified from an existing Tire-Suspension-Steering Hardware-In-the-Loop Simulator developed in Chulalongkorn University. The system can be used to reduce the development time and cost when comparing to testing a real prototype car on a test track. Firstly, we designed and built the adjustable support for the student formula car suspension on the HILS such hat wheel parameters such as camber and toe can be adjusted. CATIA V5 was used to design and test the structural strength. On the other hand, the HILS system is used to simulate and test vehicle dynamics by replacing the front wheel of a bicycle model with a real student formula wheel and suspension. The wheel is running on a rotating drum whose speed and orientation can be controlled to simulate the car speed and the tire side slip angle.

Biodiesel is widely used as a diesel component worldwide as well as in Thailand. Even there are so many research papers studied about biodiesel combustion, performance and emission, the various sources of biodiesel and engine technologies makes it more complicated to conclude how biodiesel combustion react to the engine behavior, especially for transient state operation. Some of biodiesel user feels that the presence of biodiesel component in diesel fuel influence on poor engine driveability even only 5% V/V. While, there is a few publications comment on the low sensitivity of diesel fuel ignition delay quality when running with advance diesel common-rail DI engine. The first experiment was done on low pressure diesel combustion which represented the conventional diesel technology, aiming to study the effect of fuel injection pressure on biodiesel combustion. The results shown that, the higher content of biodiesel blended fuel has no significant effect on diesel combustion.