Curvy Road Research Articles

Pediatric cardiac surgery in the hills: A curvy road

Pediatric cardiac surgery in the hills: A curvy road

System Attributes that Influence Reported Improvement in Drivers’ Experiences with Adaptive Cruise Control and Active Lane Keeping after Daily Use in Five Production Vehicles

ABSTRACTDriving automation technology must be used to benefit safety, but little is known about real-world experiences with the technology. Fifty-one Insurance Institute for Highway Safety employees used an Audi A4 or Qty 7, Honda Civic, Infiniti QX60, or Toyota Prius for up to several weeks and completed surveys about their experiences. Each vehicle had adaptive cruise control (ACC), and the Audis and Honda had active lane keeping (ALK). Drivers agreed ACC improved the driving experience more than ALK, but this was not true for all vehicles. Drivers were most comfortable using automation on interstates, and least comfortable using ACC on local roads and ALK on curvy roads. Increased agreement that the technology made gentle, smooth changes to vehicle control predicted increased agreement that it improved the driving experience. Designers should implement automation that makes smooth and gentle changes to steering or speed to improve perceptions of the technology and encourage use.

Shared steering control combined with driving intention for vehicle obstacle avoidance

This paper presents a framework of shared steering control for vehicle obstacle avoidance, which is combined with the driver’s driving intention and risk assessment. The driving intention is recognized by a support vector machine model through the steering wheel angle, the relative lateral offset, and lateral velocity to the road center line. The elastic band theory is adopted to plan the obstacle avoidance path, which takes the driving intention and environment information into consideration. A linear model predictive control algorithm based on a bicycle vehicle model is used to realize path following. The risk assessment of current traffic situation is calculated by time to collision and the time required from the starting position of lane changing to the obstacle to collide. The shared steering control strategy is designed by the risk assessment and driving intention, simultaneously, so that the cooperative coefficient and the driving mode would be determined. In order to validate the framework proposed in this paper, the shared steering control system is tested on four obstacle avoidance scenarios, including the static and moving obstacles on a straight road and a curvy road. The results show that the shared steering control system could help the human driver avoid obstacles safely. Besides, both the path and steering wheel angle curve of the shared steering control system are smooth, and the vehicle stability performance also maintains well through a suitable shared strategy.

Age-Related Differences in Pro-active Driving Behavior Revealed by EEG Measures.

Healthy aging is associated with a decline in cognitive functions. This may become an issue when complex tasks have to be performed like driving a car in a demanding traffic situation. On the other hand, older people are able to compensate for age-related deficits, e.g., by deploying extra mental effort and other compensatory strategies. The present study investigated the interplay of age, task workload, and mental effort using EEG measures and a proactive driving task, in which 16 younger and 16 older participants had to keep a virtual car on track on a curvy road. Total oscillatory power and relative power in Theta and Alpha bands were analyzed, as well as event-related potentials (ERPs) to task-irrelevant regular and irregular sound stimuli. Steering variability and Theta power increased with increasing task load (i.e., with shaper bends of the road), while Alpha power decreased. This pattern of workload and mental effort was found in both age groups. However, only in the older group a relationship between steering variability and Theta power occurred: better steering performance was associated with higher Theta power, reflecting higher mental effort. Higher Theta power while driving was also associated with a stronger increase in reported subjective fatigue in the older group. In the younger group, lower steering variability came along with lower ERP responses to deviant sound stimuli, reflecting reduced processing of task-irrelevant environmental stimuli. In sum, better performance in proactive driving (i.e., more alert steering behavior) was associated with increased mental effort in the older group, and higher attentional focus on the task in the younger group, indicating age-specific strategies in the way younger and older drivers manage demanding (driving) tasks.

Point of View: The Curvy Road to Student Success in Underserved Populations

Point of View: The Curvy Road to Student Success in Underserved Populations

Estimation of Steering Model depending on Gazing Distance in a Curvy Road

To analyze the driving behavior, the steering model is important for designing a comfortable automatic driving. It is known that the PID gain of the model is assumed to be modified depending on driver's gazing distance. The aim of this study is to design a steering model with the gazing distance using Particle Swarm Optimization (PSO). The steering model was estimated well in a single curve, however, the steering model in a curvy road have not estimated yet, because it is expected the drivers changes according the situation. In this paper, the estimated method of the steering model is considered in a curvy road. For this, the switching of a hybrid model based on effective visual field is proposed, that consists of PD control and on-off control models. The effectiveness of proposed method is evaluated by simulation using Honda driving simulator.

Driver Acceptance of Adaptive Cruise Control and Active Lane Keeping in Five Production Vehicles

Little is known about how consumers interact with driving automation technology that controls steering, speed, or headway in production vehicles. Forty-eight Insurance Institute for Highway Safety employees used a Honda Civic, Infiniti QX60, Toyota Prius, or Audi A4 or Q7 as a personal vehicle for up to several weeks and completed surveys about their experiences. Agreement about whether adaptive cruise control (ACC) or active lane keeping (ALK) improved driving experience varied significantly among vehicles. The Q7’s ACC improved the driving experience significantly more than its ALK. The Civic’s ALK improved the driving experience more than the Q7’s system, but this effect only approached significance. Drivers were most comfortable using systems on free-flowing interstates and least comfortable using ACC in stop-and-go traffic and ALK on curvy roads. The findings show a range of qualitative differences in driving automation technologies and that use of current technologies likely is limited to low-demand conditions.

Lane Characterization Under Challenging Scenarios for Autonomous Driving System

Advanced Driver Assistance systems (ADAS) have seen increasing popularity due to their importance in automotive driver safety and autonomous driving. These systems analyze data from several sensors mounted on the vehicle to detect lanes, obstacles and traffic conditions to ensure safe driving. Lane markings on road with different color and structure provide information on safe drive zone and other traffic restrictions on road. Typical ADAS solutions depend on vision based sensors for lane detection. Here we propose an efficient algorithm for detecting type and color of the lane marks as this information plays critical role in taking the decision for safety features such as lane change and lane keep assist. Our algorithm is pluggable to any state-of-art lane detection algorithm and provides lane type and color for straight, curvy roads. The proposed method is tested on various challenging scenarios and results are promising.

Model reference-based vehicle lateral control for lane departure avoidance

This paper presents the design and practical implementation of a lane departure avoidance assistance for passenger vehicles based on a state feedback dynamic controller. The road curvature is taken into account as an internal model to ensure convergence of the lateral offset to zero at steady state, even on curvy roads. Lyapunov theory and bilinear matrix inequalities including bounds in the control input and constraints for poles clustering are used to minimise the reachable set of the vehicle after activation of the assistance. The proposed control strategy is simulated in CarSim environment and successfully tested on a prototype vehicle.

Drivers' Understanding of Adaptive Cruise Control Limitations

Adaptive cruise control (ACC) is one system that is changing the driver-vehicle relationship. However, not all drivers are aware of the systems' capabilities or limitations. In this study, a cluster analysis was used to classify drivers based on how aware they were of the limitations associated with ACC. Three cluster groups emerged: those who are aware, unaware, and unsure of ACC limitations. Further examination revealed that drivers who were unaware or unsure exhibited potentially hazardous behavior when compared to the aware group. These two groups were more willing to use ACC when tired or on curvy roads. The unaware and unsure groups were also more likely to use conventional cruise control (CCC) in the absence of ACC. All three cluster groups reported high levels of trust in ACC. This may be problematic for the unaware and unsure groups since they may trust the system based on inappropriate expectations which can impact driver safety. Lower levels of awareness coupled with high levels of trust in ACC may correspond to potential misuse of the system. However, the findings suggest that this could be potentially mitigated through extended use of ACC.

Drivers' Understanding of Adaptive Cruise Control Limitations

Adaptive cruise control (ACC) is one system that is changing the driver-vehicle relationship. However, not all drivers are aware of the systems' capabilities or limitations. In this study, a cluster analysis was used to classify drivers based on how aware they were of the limitations associated with ACC. Three cluster groups emerged: those who are aware, unaware, and unsure of ACC limitations. Further examination revealed that drivers who were unaware or unsure exhibited potentially hazardous behavior when compared to the aware group. These two groups were more willing to use ACC when tired or on curvy roads. The unaware and unsure groups were also more likely to use conventional cruise control (CCC) in the absence of ACC. All three cluster groups reported high levels of trust in ACC. This may be problematic for the unaware and unsure groups since they may trust the system based on inappropriate expectations which can impact driver safety. Lower levels of awareness coupled with high levels of trust in ACC may correspond to potential misuse of the system. However, the findings suggest that this could be potentially mitigated through extended use of ACC.

The impact of in-car displays on drivers in neighbouring cars: Survey and driving simulator experiment

Legislation against drivers seeing an audiovisual display in their own vehicle does not prevent them from seeing audiovisual displays (such as those used with entertainment systems) in neighbouring vehicles. Resulting cognitive and visual distraction is likely to impair driving, but research is lacking. We conducted a survey ( N = 61) assessing whether drivers have seen and attended to audiovisual entertainment displays in other vehicles. In order to assess the effect of any such distraction on driving, we conducted a driving simulator experiment ( N = 28) in which each participant completed drives under four conditions: (1) while a laptop computer positioned as if in a neighbouring vehicle displayed no audiovisual entertainment materials; (2) while the laptop displayed entertainment materials, and given instructions to attend the materials; (3) while the laptop displayed entertainment materials, and given instructions to ignore the materials; (4) while the laptop displayed entertainment materials, and given no instructions. Thirty-one percent of survey respondents reported having ever seen an entertainment display. Amongst those who were driving at the time of last sighting, 87.5% reported having paid at least “a little” attention to the display. In the simulator experiment, drivers in the “attend” condition demonstrated lower mean speeds, lower variability in throttle input, greater variability in lane position on a curvy road section, and slower deceleration in response to a pedestrian, than those in the baseline condition. Results suggest that drivers pay attention to displays in neighbouring vehicles and this may impair driving. The negative impacts of audiovisual displays as external-to-vehicle distractors might by reduced by design innovations, and legislation limiting visibility of audiovisual displays to the drivers of other vehicles should be considered.

Measuring Divided-Attention Capability of Young and Older Drivers

A divided-attention task was used to measure the ability of young and older drivers to obtain information from an in-vehicle display. Performance with the in-vehicle display was compared with performance with information superimposed on the driving scene. Ten young and 10 older drivers drove on a curvy road by using a fixed-based driving simulator. Older drivers were less accurate in obtaining information from the in-vehicle display, the average lane-position error of older drivers was greater, and older drivers spent more time driving outside their lanes. These results suggest that the use of in-vehicle displays, in their present configuration, is not appropriate for older drivers. When viewing information superimposed on the driving scene, older drivers were much more accurate and controlled their vehicles better. This indicates that the poor performance of older drivers with the in-vehicle display was due to vision-related changes, such as longer eye accommodation times, rather than cognitive processes.

Analysis of Lateral Stability with Integrated Control of Suspension and Steering Systems.

The integrated control of suspensions and steering systems in cornering on uneven roads is analyzed by means of LQR control theory, assuming that cornering forces depend on normal tire loads in addition to tire slip angles. The effectiveness of parametric design for the integrated control is discussed in the vehicle stability on curvy road. By simulations of this control system under a preview driver control, it is furthermore confirmed that maneuverability is much improved for safer cornering along a desired curve on uneven roads, and it is necessary to design the integrated control with saturation condition of individual control systems.