Collision Avoidance Behavior Research Articles

Navigation of multiple mobile robots with cooperative collision avoidance

This paper presents a new collision avoidance technique, called cooperative collision avoidance, for multiple mobile robots. The detection of the danger of collision between two mobile robots is discussed with respect to the geometric aspects of their paths as are cooperative collision avoidance behaviors. The proposed cooperative collision avoidance between two mobile robots is then extended to cases in which the number of mobile robots is greater than two. The effectiveness of the proposed technique was demonstrated by numerical simulation examples.

Collision Avoidance Behavior of Unalerted Drivers Using a Front-to-Rear-End Collision Warning Display on the Iowa Driving Simulator

This study investigated whether drivers who operate a vehicle equipped with a front-to-rear-end collision warning system can avoid crashing when a lead vehicle brakes at its maximum potential (e.g., -0.85 g). Drivers in the experimental condition drove a 1993 General Motors Saturn mounted on the Iowa Driving Simulator’s six-degree-of-freedom motion base. The simulator cab was equipped with a collision warning display that provided a primary auditory warning and secondary visual warning based on a time-to-collision algorithm between the subject’s vehicle and the lead vehicle. Two headway distances were tested (2.7 sec and 3.2 sec). The collision avoidance performance of subject drivers was compared to the behavior of drivers in a baseline condition where no collision warning display was present. Relative to the baseline condition, results indicate that drivers using the collision warning display ( a) showed significantly fewer crashes in the shorter headway condition, ( b) collided with the lead vehicle at significantly slower impact speeds, ( c) released the accelerator significantly faster, and ( d) had longer headways both at accelerator release and brake initiation.

Behavior-based map representation for a sonar-based mobile robot by statistical methods

Many conventional methods for map generation by mobile robots have tried to reconstruct a 3D geometric representation of the environment, which is time-consuming, error-prone and necessary to transform the map into the information available for the given task. This paper proposes a method to acquire a statistical map representation robust to sensor noise and directly usable for a navigation task. The robot is equipped with a ring of ultrasonic ranging sensors and a collision avoidance behavior is embedded in it. First, the mobile robot explores the environment in order to store a set of sequences of sonar data and principle component analysis is applied to reduce the dimensionality of the sonar data. As a result, each sequence of sonar data can be described as a score pattern of principal components. Next, these patterns are classified into typical local structures of the environment in order for the robot to discriminate them. Finally, a graph representation of the environment is constructed in which the...

Obstacle Avoidance Using Tactile Sensing for an Autonomous Mobile Robot

Abstract A tactile sensor-ring is built around an autonomous mobile robot to measure the force and torque acting on the robots body. The computed force/torque are then used to aid the collision avoidance behaviour. This behaviour can be described as follows: Push the obstacles away if it is light enough. Repel-away from the obstacle if it acts aggressively such that the force felt by the robot exceeds a given threshold. Finally, if the obstacle is neither movable nor aggressive, round-about it when a prescribed time has elapsed. The implementation of this strategy is described and experiments are documented which demonstrate the fruitfulness of this design.

Reflexive collision avoidance in a recursive architecture

The collision avoidance behavior in a Recursive Nested Control Structure Design is discussed. A formulation of a repulsion force based on measurements of ultrasonic range and tactile force and moment is given. The avoidance behavior adapts to the dynamics of the mobile robot. The realization details emphasize the importance of keeping the system land width as large as possible to increase the reflexiveness of the avoidance behavior. Real-world experiments confirm the effectiveness and robustness of the proposed procedure.

閉塞領域についての一考察

As one of techniques with which the congestion intensity of marine traffic is studied, there is the calculation model proposed by Y. Fujii which avails itself of the frequency of collision avoidance in a geometric pattern. The model basically regards, from a functional viewpoint, a ship safety domain as a bumper, and calculates the frequency at which such fictitious bumpers of ships would overlap each other when they proceed to the same direction without changing their navigation routes, hence being named "bumper method." This study first calculates the frequency of bumpers being overlapped and time-sequential distribution of collision avoidance, and then examines the collision avoidance behaviors; and finally, based on those study results, proposes a calculation method for obtaining the size of a bumper in correlation with the ship speeds, etc.

Collision Avoidance Behaviour and Uncertainty

When radar was first introduced to the merchant fleets of the world, many people felt that a practical solution to the collision avoidance problem had been found. However, a review of worldwide collision statistics of the past 20 years indicates that, in spite of the expanded use of radar, the over-all collision rate remains alarmingly high. Because of radar's less than perfect record for preventing ship collisions, development of various types of collision avoidance systems has taken place. The implied promise in this development is that the computer-aided radar will provide a lasting answer to the collision avoidance problem.

Human Collision Avoidance Behavior as a Function of Visibility, Traffic Density Electronic Aiding and Type of Information Displayed

Licensed Captains of 80,000 DWT oil tankers were tested on a real time computerized simulator in order to evaluate their collision avoidance behavior in the open sea. Visibility, Traffic density, Navigational aid, and Type of information displayed were manipulated experimentally in order to assess the effects of these variables upon the human's performance in potential collision situations. The findings indicated that a computerized collision avoidance system greatly reduced the danger of collision in poor visibility and in high traffic density whereas the possibility of collision was increased using radar in poor visibility and high traffic density. Furthermore, it was found that a meaningful graphic display of information was responsible for the improved performance as compared to a visual alphanumeric display of target ship information.