Sunhapos Chantranuwathana

Driver Behavior Detection Based on Multi-GNSS Precise Point Positioning Technology

Driver behavior is the key to safe mobility. In general, vehicle 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. 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). With decimeter precision and the update rate scale up to 10-Hz, the GNSS could be an alternative solution for driver behavior detection. In this paper, advance Multi-GNSS with precise point position (PPP) technique was presented with a simple maneuver detection algorithm. The advantage of PPP over conventional navigation is decimeter accuracy without direct connection to any reference base station. The experimental Multi-GNSS receiver was JAVAD Delta G3T that installed on a utility vehicle. This high performance multi-GNSS navigation system was investigated with the driving behavior detection algorithm. The precise point positioning (PPP) technique in combination with multiple satellite navigation system (GPS+GLONASS+GALOLEO+QZSS) were applied in this study. The PPP technique improved the output of detection algorithm in acceleration limit from 260% error in conventional navigation system (GPS) to 20% of incidents with PPP.

Driver Behavior Detection based On PPP-GNSS Technology

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, its 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. In previous studies, it was found that dangerous behaviors such as aggressive lane change required decimeter accuracy from GNSS. Consequently, in this article, the PPP (Precise Point Positioning) technique was applied to develop a behavior detection system. Vehicle maneuvers such as cornering and lane change detected by IMU and Multi-GNSS were collected and compared. The JAVAD Delta TRE_G3TH experimental Multi-GNSS receiver installed on a utility vehicle was used in this work. The navigation data were post-processed with the open source RTKLIB software. On the other hand, the reference vehicle dynamic measurement system was VBOX 3LSi with integrated IMU. A simple curvature model was proposed and applied to estimate the lateral acceleration. In conclusion, experimental results show that driver behavior detection is feasible with the Multi-GNSS PPP. The results revealed that with PPP solution the estimated lateral acceleration could be manipulated within 10% deviation.

In-vehicle carbon dioxide concentration in commuting cars in Bangkok, Thailand

ABSTRACT It is known that in-vehicle carbon dioxide (CO2) concentration tends to increase due to occupant exhalation when the HVAC (heating, ventilation, and air conditioning) air is in recirculation mode. Field experiments were conducted to measure CO2 concentration during typical commute in Bangkok, Thailand. The measured concentrations agreed with the concentration predicted using first-order mass balance equation, in both recirculating and outside air modes. The long-term transient decay of the concentration when the vehicle was parked and the HVAC system was turned off was also studied. This decay was found to follow Fickian diffusion process. The paper also provides useful operational details of the automotive HVAC system and fresh air ventilation exchange between cabin interior and exterior. Implications: Drivers in tropical Asian countries typically use HVAC recirculation mode in their automobiles. This behavior leads to excessive buildup of cabin CO2 concentration levels. The paper describes the CO2 buildup in a typical commute in Bangkok, Thailand. Auto manufacturers can potentially take measures to alleviate such high concentration levels. The paper also discusses the diffusion of CO2 through the vehicle envelope, an area that has never been investigated before.

On-line Ladle Lining Temperature Estimation by Using Bounded Jacobian Nonlinear Observer

The knowledge of transient temperature of the ladle wall is a key factor in optimizing energy consumption in steelmaking process. The transient temperature needs to he estimated. A nonlinear lumped parameter model was used to model the thermal dynamics of the ladle. Then, the bounded Jacobian nonlinear observer was utilized to estimate the temperature. With this method, the estimation model became a closed-loop model and the observer gains were obtained by solving linear matrix inequalities and simply implemented to the system. Comparison between the simulation and recorded data at a participating steel plant in Thailand showed that the nonlinear observer accurately estimated the temperature of the ladle lining. This estimated temperature was very useful in determining suitable tapping temperature for energy conservation and steel quality.

Evaluation of Deadband Effect in Steer-by-Wire Force Feedback System by Using Driving Simulator

This paper presents an evaluation of dead band in force feedback which affects on driving precision with Steer-by-Wire System by using Driving Simulator. Dead band is considered as a zero zone of a relation between Force feedback torque and hand wheel angle. Experimental was designed to focus on dead band size from 0 to ±10 degrees of Force feedback model. The result has shown that the driver has the best driving precision with dead band size of ±4 to ±6 degrees.

Eco-Driving Rating Based on Average Trip Speed and Evaluation

In this work, an eco-driving rating based on the relation between fuel consumption and average trip speed commonly used in traffic engineering is presented. A car following experiment with a driving simulator was used to make an eco-rating chart. The leading car was used to control average speed of each experiment. To calculate the rating, the resulting driving data was divided into trips. For each trip, low level of fuel consumption was given high score while high level was given low score. Rating was given as average of the trip scores. Actual driving data was then used for the leading car for evaluation of the rating. One of the desirable properties of the rating proposed by this work is consistency regardless of traffic conditions. As suggested by the rating chart, it was found that the proposed eco-rating is consistent in terms of ranking drivers around when average trip speed is around 50-70 km/h.