This paper describes an algorithm that determines the reference vehicle trajectory for autonomous lane changing maneuver. The algorithm employs potentially acquired on-board vehicle sensing signals like the velocity of each vehicle, the relative distance between vehicles as variables and estimates the positions of host and surrounding vehicles after finishing lane change maneuver. The lane change timing and reference lateral/longitudinal acceleration are derived theoretically and compared with the data which is obtained from human driver experiments carried out on driving simulator. The longitudinal and lateral accelerations are determined as the reference model. The paper describes algorithm details,following by simulation results which show the feasibility of the proposed algorithm.
Over four thousand data sets of 6 DOF (degree of freedom) (3 linear + 3 angular) accelerations measured at the head CG (center of gravity) were obtained from 19 college football players who voluntarily participated. Of these impacts, one hundred cases with high angular velocity were selected, and the set of 6 DOF head accelerations was applied to a detailed human head brain FE model. This study predicted the maximum 1st principal strain and CSDM (Cumulative Strain Damage Measure) for each set and found significant correlations between CSDM and a proposed criterion with angular velocity and acceleration of the head CG.
The Southwest Research Institute (SwRI) Mobile Autonomous Robotics Technology Initiative(MARTI)program has enabled the development of a fully-autonomous passenger-size vehicle, as well as the development of cooperative vehicle behaviors, such as cooperative sensor sharing and cooperative convoy operations. The program has also developed behaviors to interface intelligent vehicles with intelligent road-side devices. Development of intelligent vehicle behaviors must be understood within the context of broader traffic system dynamics. This paper examines aspects of behavioral stability for traffic systems that are comprised of intelligent vehicles and other intelligent devices that will enable stability in the emergent
A child restraint system (CRS) is installed in various vehicles with different seat, seatbelt routing paths, and
seatbelt characteristics. In this research, a series of sled tests were conducted using the ECE R44 seat bench utilizing various CRS models under the same crash pulse specified by JNCAP. During the impact in JNCAP, the cushion of the multi-purpose vehicle seat was soft and the CRS rotated, which led to large forward excursions of the CRS and dummy. A trend was observed that there is a linear relationship of the assessment values between the JNCAP tests and the ECE base tests.
Changes in the driver's posture and velocity caused by inertia during an emergency braking are believed to
affect the injury outcome in front impact collisions. Moreover, at equivalent impact conditions, the results from real-world data analysis show the increased risk of injury in the cases in which an emergency braking preceded the accident. The objective of this study is to further investigate the relationship between such driver's pre-crash conditions and the injury outcome by using a computer human model. A finite element human model (JAMA model) and the results of the pre-impact experiments with volunteers were employed for this purpose. By simulating the same two accidents after different pre-impact conditions it was concluded that the presence of a pre-impact emergency braking increased the severity of the loading mechanism sustained by the driver, especially on the thoracic region.
We have developed a new steering control system in order to reduce the driver's burden during parking
manoeuvres. In this paper, first of all, the concept of this system and an outline of the steering control method are presented. Then, results of simulation and actual vehicle tests are described to verify the control logic which was applied to solve characteristic problems of the system.
Experimental and numerical studies are performed to evaluate and analyze the influence of the notchback rear diffuser angle on aerodynamic drag and wake structure. The relationship between aerodynamic drag and rear diffuser angle is summarized, and the flow mechanism are analyzed and discussed. A speculation regarding lower trailing vortices is proposed, and is verified in the present research model. Rear diffuser angle is an important factor influencing the wake structure, and optimizing the vehicle rear diffuser at a favorable angle can contribute to reduce the drag force and improve the wake structure.