scholarly journals COLLISION AVOIDANCE OF FLYING LOCUSTS: STEERING TORQUES AND BEHAVIOUR

1993 ◽  
Vol 183 (1) ◽  
pp. 35-60 ◽  
Author(s):  
R. M. Robertson ◽  
A. G. Johnson
Keyword(s):  
Wind Tunnel ◽  
Avoidance Response ◽  
Collision Avoidance ◽  
Flight Path ◽  
Field Of View ◽  
Strain Gauges ◽  
Time To Collision ◽  
Leaf Springs ◽  
Forward Translation ◽  
The Right

1. Obstacles approaching in the flight path trigger postural and wing kinematic adjustments in tethered flying locusts. We sought to confirm that these behaviours were steering behaviours by measuring the changes in the flight forces associated with their execution. We also investigated the coordination of these behaviours in the execution of collision avoidance manoeuvres and the effect of speed or size of the obstacle on the timing and magnitude of the response. 2. Locusts were tethered and suspended in a wind tunnel from orthogonally arranged leaf springs mounted with strain gauges. Lift and yaw torque could be monitored unambiguously. We also monitored a forward translation force which combined pitch and thrust. During flight, the locusts were videotaped from behind while targets of different sizes (5 cmx5 cm, 7 cmx7 cm, 9 cmx9cm, 11 cmx11 cm) were transported towards the head at different speeds (1, 2, 3 or 4 m s-1). 3. Angular asymmetry of the forewings during the downstroke with the right forewing high, and abdomen and hindleg movement to the left, were temporally associated with an increase in yaw torque to the left. With the left forewing high, abdomen and hindleg movement to the right were temporally associated with a decrease in yaw torque to the left. Obstacle avoidance behaviours could be associated with either an increase or a decrease in the pitch/thrust component. 4. Leg, abdomen and wingbeat alterations in response to the approach of an obstacle were independent but tightly coordinated. Slower approaches increased the magnitude of the responses. However, the size of the obstacle had no effect on the magnitude of the response. Slower and larger targets generated earlier reactions (i.e. locusts reacted when the targets were further from the head). 5. We conclude that the behaviours we have described were steering behaviours which would have directed the animal around an obstacle in its flight path, and that there were at least two strategies for collision avoidance associated with slowing or speeding flight. Leg, abdomen and wingbeat alterations formed a coherent avoidance response, the magnitude of which was dependent upon the time available for it to develop. We further conclude that the manoeuvre was not initiated at a constant time to collision and we propose that the avoidance strategy was to initiate the manoeuvre when the targets subtended more than 10 s in the insect's field of view.

scholarly journals WING MOVEMENTS ASSOCIATED WITH COLLISIONAVOIDANCE MANOEUVRES DURING FLIGHT IN THE LOCUST LOCUSTA MIGRATORIA

1992 ◽  
Vol 163 (1) ◽  
pp. 231-258 ◽  
Author(s):  
R. MELDRUM ROBERTSON ◽  
DAVID N. REYE
Keyword(s):  
Wind Tunnel ◽  
Collision Avoidance ◽  
High Speed ◽  
Locusta Migratoria ◽  
Video Camera ◽  
Flight Path ◽  
The Body ◽  
Force Vector ◽  
High Speed Cinematography ◽  
The Asymmetry

1. Flying locusts will try to avoid colliding with objects directly in their flight path. This study investigated the wing movements and behaviour patterns associated with collision avoidance. 2. Tethered locusts were flown in a wind tunnel. Targets were transported at different speeds either directly towards the head of the animal or to one side of the midline but parallel to it. Changes in the form of the wingbeat for each of the wings were monitored using either a video camera or a high-speed ciné camera. 3. Animals attempted to avoid an impending collision by making movements interpreted here as (a) increasing lift to fly over the object, (b) gliding and extending the forelegs to land on the object, and (c) steering to one side of the object. Steering was monitored by observation of abdominal movements. 4. Steering to one side of an approaching target was reliably associated with an earlier and more pronounced pronation of the wings on the inside of the turn. Also, in the middle of the downstroke, the forewings were markedly asymmetrical. On the outside of the turn, the forewing was more elevated and separate from the hindwing. On the inside of the turn, the forewing was more depressed and often came down in conjunction with, or in advance of, the hindwing on that side. 5. The forewing asymmetry correlated with the position of the target such that most attempted turns were in the direction that would take the animal around the closest edge. High-speed cinematography showed that the asymmetry was caused both by changes in the timing of the two wings and by changes in the angular ranges of the wingbeats. 6. We propose that these changes in the form and timing of the wingbeats are likely to have swung the flight force vector around the long axis of the body to produce a banked turn around the closest edge of the object.

scholarly journals A Probabilistic Model for Real-Time Semantic Prediction of Human Motion Intentions from RGBD-Data

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4141
Author(s):  
Wouter Houtman ◽  
Gosse Bijlenga ◽  
Elena Torta ◽  
René van de Molengraft
Keyword(s):  
Real Time ◽  
Collision Avoidance ◽  
Probabilistic Model ◽  
Real Life ◽  
Human Motion ◽  
Model Based ◽  
Multiple Hypotheses ◽  
Navigation Algorithms ◽  
The Right ◽  
Motion Behavior

For robots to execute their navigation tasks both fast and safely in the presence of humans, it is necessary to make predictions about the route those humans intend to follow. Within this work, a model-based method is proposed that relates human motion behavior perceived from RGBD input to the constraints imposed by the environment by considering typical human routing alternatives. Multiple hypotheses about routing options of a human towards local semantic goal locations are created and validated, including explicit collision avoidance routes. It is demonstrated, with real-time, real-life experiments, that a coarse discretization based on the semantics of the environment suffices to make a proper distinction between a person going, for example, to the left or the right on an intersection. As such, a scalable and explainable solution is presented, which is suitable for incorporation within navigation algorithms.

scholarly journals Successful Resection of a Giant Pulmonary Colloid Adenocarcinoma via Median Sternotomy

2020 ◽  
Vol 13 (3) ◽  
pp. 1097-1102
Author(s):  
Daisuke Nakamura ◽  
Ryoichi Kondo ◽  
Akiko Makiuchi ◽  
Hiroko Itagaki
Keyword(s):  
Superior Vena Cava ◽  
Lung Tumor ◽  
Mediastinal Lymph Node ◽  
Superior Vena ◽  
Median Sternotomy ◽  
Vena Cava ◽  
Cystic Mass ◽  
Field Of View ◽  
Surgical Field ◽  
The Right

We report on a giant pulmonary colloid adenocarcinoma successfully resected using a median sternotomy approach. A 69-year-old woman visited our hospital owing to a giant mass detected on chest radiography. A giant cystic mass measuring 115 × 90 mm was detected in the right upper lung using computed tomography. We suspected mucinous adenocarcinoma and performed right upper lobectomy and mediastinal lymph node dissection with median sternotomy. The surgical field of view for the tumor and superior vena cava was satisfactory, and compression but not invasion of the superior vena cava and chest wall by the tumor was observed. The tumor was pathologically diagnosed as a colloid adenocarcinoma of stage IIIA with pT4N0M0. The postoperative course was uneventful, with no signs of recurrence at one and a half years after operation. Thus, this case demonstrates that for giant lung tumor surgery, median sternotomy is useful and safe for improving the surgical field of view.

Bi-level Flight Path Planning of UAV Formations with Collision Avoidance

2018 ◽  
Vol 93 (1-2) ◽  
pp. 193-211 ◽  
Author(s):  
Egidio D’Amato ◽  
Massimiliano Mattei ◽  
Immacolata Notaro
Keyword(s):  
Path Planning ◽  
Collision Avoidance ◽  
Flight Path ◽  
Level Flight

Collision Avoidance Response Stereotypes in Pilots and Nonpilots

1978 ◽  
Vol 20 (5) ◽  
pp. 529-536 ◽  
Author(s):  
Dennis B. Beringer
Keyword(s):  
Avoidance Response ◽  
Collision Avoidance ◽  
Response Bias ◽  
Response Selection ◽  
The Other ◽  
Left Turn ◽  
Optimal Response ◽  
Avoidance Responses

A two-part study was conducted to investigate the effects of target variables upon pilot and nonpilot collision avoidance responses to simulated approaches which were head-on or nearly so. Part I investigated the effect of bearing and found that nonpilots preferred to turn left in a head-on approach. Although pilots generally turned right under the same conditions, 25% exhibited the nonpilot left-turn response. The nonpilot response bias seemed related to the type of control used for aircraft pilotage. Part II examined the effects of bearing and collision index (a geometric construct representing an index for optimal response selection) upon the responses of 24 pilots. Two subgroups were identified, one apparently attending primarily to bearing while the other attended to aspect. Only one subject appeared to use the optimal collision-index construct for response selection.

scholarly journals A panoramic synthetic vision model for improving collision avoidance in crowd simulation

2015 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Ricardo Bustamante de Queiroz ◽  
Teófilo Dutra ◽  
Creto Vidal ◽  
Joaquim Cavalcante-Neto
Keyword(s):  
Virtual Reality ◽  
Visual Perception ◽  
Collision Avoidance ◽  
Vision System ◽  
Crowd Simulation ◽  
Field Of View ◽  
Panoramic View ◽  
Natural Manner ◽  
Synthetic Vision ◽  
The Common

Crowd Simulation is very important in many virtual reality applications, because it improves the sense of immersion of the users by making the population of agents in the environment to move as real crowds do. Recently, models for simulating crowds, in which each agent is equipped with a synthetic vision system, have shown interesting results regarding the natural manner in which the agents navigate inside the environment thanks to their visual perception. In this article, we propose an upgrade to the agent’s visual system with a panoramic view in order to allow an agent to expand its vision beyond the limit of 180o imposed by the common projection provided by rendering APIs. Also, we analyze different parameters, which are used to define the field of view, to investigate the influence they have on the agent’s behavior. The impacts that those changes may cause on the efficiency of the algorithms are also analysed. A visible change on the agent’s behavior is achieved by using the technique, with a slight loss of performance.

scholarly journals The Obstacle-Avoidance Path Planning for UAV Based on IOCAD

2020 ◽  
Vol 38 (2) ◽  
pp. 238-245
Author(s):  
Qiqian Zhang ◽  
Weiwei Xu ◽  
Honghai Zhang ◽  
Han Li
Keyword(s):  
Path Planning ◽  
Collision Avoidance ◽  
Rough Set Theory ◽  
Grid Method ◽  
Flight Path ◽  
Ray Method ◽  
Detection Model ◽  
Safety Distance ◽  
Planning Algorithm ◽  
Grid Length

To plan the path for UAV flying in the complex, dense and irregular obstacles environment, this paper proposed an obstacle collision-avoidance detection model and designed an UAV path planning algorithm based on irregular obstacles collision-avoidance detection (IOCAD), which includes irregular obstacles pretreatment method. The proposed method uses the grid method to model the environment. Rough set theory and convexity filling are used to pretreat the obstacles, and the ray method is used to select the available points. The intersection detection and the distance detection are held for the obstacle to the flight path. The objective function minimizes the distance from the obstacle to the flight path to get planned paths. The simulation results show that the proposed method can effectively plan the paths with the constraints of the assumed environment and UAV performances. It is shown that the performance of the proposed method is sensitive to the grid length and safety distance. The optimized values for the grid length and safety distance are 0.5 km and 0.4 km respectively.

Behavioral strategies of automated vehicles in critical right of way situations on intersections

2015 ◽  
Vol 63 (3) ◽  
Author(s):  
Alexander Stoff ◽  
Hermann Winner
Keyword(s):  
Collision Avoidance ◽  
Behavioral Strategies ◽  
Automated Vehicles ◽  
Right Of Way ◽  
Road Users ◽  
Safety Function ◽  
Potential Safety ◽  
Avoidance Strategies ◽  
The Right

AbstractThis paper analyzes and evaluates alternative options for action and earliest possible dates for intervention for an automated safety function to avoid or mitigate collisions in priority situations in which the right of way regulations are violated by the crossing road users. Based on a simulation of the collision avoidance strategies, the potential safety benefits could be predicted.

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