Collision avoidance

About: Collision avoidance is a research topic. Over the lifetime, 8014 publications have been published within this topic receiving 111414 citations.

Activity of descending contralateral movement detector neurons and collision avoidance behaviour in response to head-on visual stimuli in locusts.

Abstract: We recorded the activity of the right and left descending contralateral movement detectors responding to 10-cm (small) or 20-cm (large) computer-generated spheres approaching along different trajectories in the locust's frontal field of view. In separate experiments we examined the steering responses of tethered flying locusts to identical stimuli. The descending contralateral movement detectors were more sensitive to variations in target trajectory in the horizontal plane than in the vertical plane. Descending contralateral movement detector activity was related to target trajectory and to target size and was most sensitive to small objects converging on a direct collision course from above and to one side. Small objects failed to induce collision avoidance manoeuvres whereas large objects produced reliable collision avoidance responses. Large targets approaching along a converging trajectory produced steering responses that were either away from or toward the side of approach of the object, whereas targets approaching along trajectories that were offset from the locust's mid-longitudinal body axis primarily evoked responses away from the target. We detected no differences in the discharge properties of the descending contralateral movement detector pair that could account for the different collision avoidance behaviours evoked by varying the target size and trajectories. We suggest that descending contralateral movement detector properties are better suited to predator evasion than collision avoidance.

The influence of in-vehicle speech warning timing on drivers' collision avoidance performance at signalized intersections

Abstract: Collision warning systems have been identified as an effective technique for avoiding accidents. In such a system, the delivery time of warning messages is a crucial factor that influences the success of collision avoidance. This study therefore contributes by providing experimental analyses on a range of delivery times of warning messages, which has been overlooked in past studies. Using simulator-based techniques, experimental scenarios are specifically designed for accounting the red-light-running events at intersections and drivers are recruited to test on different settings of warning timings. Several measures including brake reaction time, alarm-to-brake-onset time and deceleration are adopted as reflections of drivers’ performances under the collision avoidance process and they are connected to several factors by mixed effect models. According to the results, the collision warning system actually can largely reduce the occurrence of red-light-running collisions, more importantly it reveals the influence of warning timings within the predefined ranges and 4.0 s or 4.5 s may be a proper warning timing for the right-angle collisions accused by red-light-running vehicles in this study. Besides, effects from directional information embedded in warning messages are also investigated in this study. Findings are important to the design of collision warning systems especially in the aspect of warning timings.

Collision avoidance of two general robot manipulators by minimum delay time

Abstract: A simple time delay method for avoiding collisions between two general robot arms is proposed. Links of the robots are approximated by polyhedra and the danger of collision between two robots is expressed by distance functions defined between the robots. The collision map scheme, which can describe collisions between two robots effectively, is adopted. The minimum delay time value needed for collision avoidance is obtained by a simple procedure of following the boundary contour of collision region on collision map. To demonstrate the effectiveness of the proposed time delay method, a computer simulation study is shown where a collision is likely to occur realistically. >

Formation surveillance and collision avoidance

Abstract: A formation collision avoidance system includes a Traffic Alert and Collision Avoidance System (TCAS) having a passive mode and an active mode. The passive mode enables several members of an aircraft formation to fly without actively interrogating using TCAS while only one or few formation members are actively interrogating. Formation members in passive mode maintain awareness of current air and ground traffic conditions using networked surveillance information provided over a communications link between formation members in active mode and formation members in passive mode. The networked surveillance information includes positional and intent information of current air/ground traffic obtained from ADS-B broadcasts and replies to the actively interrogating members of the formation. The communications link utilizes Station Keeping Equipment (SKE) already existing on certain aircraft.

CAR-2-X and Pedestrian Safety

Abstract: Traffic accidents involving pedestrians or cyclists cause thousands of fatalities and serious injuries every year. In this article, we present an innovative approach for a collision avoidance system that seeks to reduce these accidents. We also discuss the different architectural approaches utilizing ad hoc and/or cellular technologies and different processing setups and present a physical analysis of the system time available between detection, warning, and reaction to give an overview of the time constraint.