Integrated Steering and Braking Control System for Collision Avoidance by Using Virtual Repulsive Force Field Method

Author(s):  
Atsushi Yokoyama ◽  
Pongsathorn Raksincharoensak ◽  
Naoto Yoshikawa

Advanced Driver Assistance Systems (ADAS) and autonomous driving systems are being enhanced to deal with various types of collision avoidance use-case scenarios. To handle those complicated scenarios, a unified two-dimensional planar motion control methodology assuming virtual repulsive force from obstacles is introduced, which is physically interpretable and comprehensible. The direction and magnitude of virtual repulsive force are determined considering the orientation of obstacle surface planes and the friction limit between tires and road surface respectively. Applying the concept of virtual repulsive force field, the collision avoidance path can be derived from geometrical relationship and the control activation points can be obtained as algebraic solutions. By using a simple particle mass model, the formulation for path and control activation point is described. The simulation is conducted against not only in the case of a straight roadway but also in the case of a curve roadway. By designing feedforward and feedback controllers based on a two-wheel vehicle dynamics model, the effectiveness of the proposed method is verified and the feasibility of controller implementation for actual vehicle is also investigated.

2020 ◽  
Vol 73 (6) ◽  
pp. 1306-1325
Author(s):  
Xinli Xu ◽  
Wei Pan ◽  
Yubo Huang ◽  
Weidong Zhang

A dynamic collision avoidance algorithm via layered artificial potential field with collision cone (LAPF-CC) is proposed to overcome the shortcomings of the traditional artificial potential field method in dynamic collision avoidance. In order to reduce invalid actions for collision avoidance, the potential field is divided into four layers, and a collision cone with risk detection function is introduced. Relative distance and relative velocity are used as variables to establish the risk of collision, and a torque named ‘speed torque’ is constructed. Speed torque, attractive force and repulsive force work together to change the speed and heading of the unmanned surface vehicle (USV). Driving force and torque are controlled separately, which makes it possible for the LAPF-CC algorithm to be used for real-time collision avoidance control of underactuated USVs. Simulation results show that the LAPF-CC algorithm performs well in dynamic collision avoidance.


2020 ◽  
Vol 10 (9) ◽  
pp. 3289
Author(s):  
Hanwool Woo ◽  
Mizuki Sugimoto ◽  
Hirokazu Madokoro ◽  
Kazuhito Sato ◽  
Yusuke Tamura ◽  
...  

In this paper, we propose a novel method to estimate a goal of surround vehicles to perform a lane change at a merging section. Recently, autonomous driving and advance driver-assistance systems are attracting great attention as a solution to substitute human drivers and to decrease accident rates. For example, a warning system to alert a lane change performed by surrounding vehicles to the front space of the host vehicle can be considered. If it is possible to forecast the intention of the interrupting vehicle in advance, the host driver can easily respond to the lane change with sufficient reaction time. This paper assumes a mandatory situation where two lanes are merged. The proposed method assesses the interaction between the lane-changing vehicle and the host vehicle on the mainstream lane. Then, the lane-change goal is estimated based on the interaction under the assumption that the lane-changing driver decides to minimize the collision risk. The proposed method applies the dynamic potential field method, which changes the distribution according to the relative speed and distance between two subject vehicles, to assess the interaction. The performance of goal estimation is evaluated using real traffic data, and it is demonstrated that the estimation can be successfully performed by the proposed method.


2021 ◽  
Vol 9 (4) ◽  
pp. 405
Author(s):  
Raphael Zaccone

While collisions and groundings still represent the most important source of accidents involving ships, autonomous vessels are a central topic in current research. When dealing with autonomous ships, collision avoidance and compliance with COLREG regulations are major vital points. However, most state-of-the-art literature focuses on offline path optimisation while neglecting many crucial aspects of dealing with real-time applications on vessels. In the framework of the proposed motion-planning, navigation and control architecture, this paper mainly focused on optimal path planning for marine vessels in the perspective of real-time applications. An RRT*-based optimal path-planning algorithm was proposed, and collision avoidance, compliance with COLREG regulations, path feasibility and optimality were discussed in detail. The proposed approach was then implemented and integrated with a guidance and control system. Tests on a high-fidelity simulation platform were carried out to assess the potential benefits brought to autonomous navigation. The tests featured real-time simulation, restricted and open-water navigation and dynamic scenarios with both moving and fixed obstacles.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Guo Lie ◽  
Ren Zejian ◽  
Ge Pingshu ◽  
Chang Jing

Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian.


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