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This paper presents the development of an obstacle mapping system based on the concept of a Probabilistic Threat Exposure Map (PTEM). The paper also discusses the realtime embedded implementation of this obstacle mapping system on a small Unmanned Ground Vehicle (UGV) to support realtime obstacle avoidance. These activities are a part of a larger effort to establish a theoretical foundation for autonomous...
Established the computational model about the safe distance of vehicles. In order to simulate the dynamic model of rear-end, based on VB software to build a freeway rear-end simulation system. Simulation system provides an important means for in-depth study on rear-end probability. To investigate the non-linear relationship of probability and impact factors of rear-end, established probability of...
Advances in wireless communication technologies have enabled vehicles on a highway to communicate in order to share state information and provide drivers with potential collision warnings. This paper proposes a protocol to support such a vehicle collision warning system. By sharing vehicle state information, the protocol is able to predict potential collisions and deliver warning messages to address...
This thesis describes a new method that in real time predicts fall and collision in order to support remote control of a tracked vehicle with sub-tracks. A tracked vehicle has high ability of getting over rough terrain. However, it is difficult for an operator at a remote place to control the vehicle's moving direction and speed. Hence, we propose a new path evaluation system based on the measurement...
This paper considers the path planning problem for an autonomous vehicle in an urban environment populated with static obstacles and moving vehicles with uncertain intents. We propose a novel threat assessment module, consisting of an intention predictor and a threat assessor, which augments the host vehicle's path planner with a real-time threat value representing the risks posed by the estimated...
Vehicles in Intelligent Transportation System employ IEEE 802.11p/1609 protocols to communicate with other vehicles or roadside infrastructure within a specific area. Messages related with traffic safety can be delivered timely for collision avoidance and etc. Meanwhile, non-safety related infotainment messages can also be transmitted besides safety-critical information. Many of the safety critical...
This paper presents the design and simulation tests of a steering assistance for passenger vehicles based on a dynamic state feedback controller. Its main purpose is to avoid unintended lane departure and collisions. The design of the proposed lane keeping system takes into account the road curvature, considered as an exogenous input, into its internal model. The computation of the control law has...
In this paper, a motion planning algorithm based on differential flatness for an autonomous vehicle driving in a structured environment with moving obstacles is presented. A descriptions of the structured environment and definitions of safety and availability of the lane are proposed. In order to ensure that the trajectory is feasible and effective, dynamic longitudinal and lateral acceleration constraints...
In this study, a collision avoidance method with model predictive control is proposed for a nonlinear model of a four-wheeled vehicle. The C/GMRES algorithm is used for solving the nonlinear model predictive control (NMPC) problem within a short sampling period. A nonlinear tire model is employed to represent the realistic behavior of a vehicle. Here, to consider whether it is possible to avoid an...
A Fuzzy approach to backward movement control for trailers in a dynamic environment is presented in this paper. The approach is then extended and employed for conditions where obstacles are placed on the trailer pathway. In the first case, obstacles are assumed to be fixed, while the second condition includes moving obstacles through which the trailer should be directed toward the parking dock. The...
We define an ad hoc transportation system as one that has no infrastructure such as roads (and lanes), traffic lights etc. We assume that in such a system the vehicle are autonomic and can guide and direct themselves without a human driver. In this paper we investigate how a safe distance can be maintained between vehicles. A vehicle which has been compromised by an adversary can cause serious chaos...
In this paper, a new type of autonomous vehicle is developed. This vehicle consists of three sets of control systems to regulate the direction, brake and fuels. The sensing system is a combination of laser radar and camera. The localization system is constructed with GPS device and electronically compass. Currently, three tasks, including lane detection and following, object detection, and obstacle...
Vehicle is a complex uncertain system with parameter perturbations and external disturbances; these uncertainties will easily result in the loss of vehicle driving stability. Tire cornering stiffness is a key influencing factor on maneuverability of vehicle. In order to maintain driving stability in vehicle cornering, through regarding tire cornering stiffness and outer disturbances as bounded uncertain...
In this study, we develop an low-cost Advanced Safety Vehicle (ASV) onboard unit that integrates driving warning and car-following control systems on a vision-based platform for laboratory and real-time experiments. This onboard unit mainly consists of three systems including the lateral departure warning System (LDWS), the forward vehicle collision warning system (FVCWS), and the adaptive car-following...
This paper describes a method for an object related reactive offset maneuver increasing the number of action alternatives for an autonomous ground vehicle. The method improves a variety of time-critical maneuvers as for example merging into moving traffic, changing lanes, passing other traffic participants as well as emergency obstacle avoidance without having to replan a path using high-level planning...
Advanced systems for driver assistance in combination with new preventive safety systems offer great potential for collision avoidance, reducing accident severity and increasing occupant protection. This paper presents the development and evaluation of a system targeting to vehicle collision avoidance in emergency situations. The proposed system provides the nearby vehicles with information about...
Steering control systems have been used to develop vehicle automated lane change maneuvers or evasive maneuvers for collision avoidance. Most of these systems have used predetermined desired trajectories to perform the required maneuvers. In this study, an optimal trajectory is found while ensuring minimization of lateral acceleration throughout the maneuver. Collocation technique was used to numerically...
The control of car following is essential to its safety and its operational efficiency. For this purpose, this paper builds a linear, continuous and time-delay model of car following. And then, presents a controller based on an adaptive network fuzzy inference system (ANFIS) for the car-following collision avoidance system to adaptively control the speed of the vehicle. The relative distance and relative...
Safe handling of dynamic highway and inner city scenarios with autonomous vehicles involves the problem of generating traffic-adapted trajectories. In order to account for the practical requirements of the holistic autonomous system, we propose a semi-reactive trajectory generation method, which can be tightly integrated into the behavioral layer. The method realizes long-term objectives such as velocity...
We address the minimal risk motion planning problem in a two dimensional environment in the presence of both moving and static obstacles. Our approach is inspired by recent results due to Vladimirsky in which path planning on time-varying maps is addressed using a new level-set approach, and for which computational costs are remarkably low. Toward practical implementation of these results for path...
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