scholarly journals Observation and assessment of crossing situations between pleasure craft and a small passenger ferry

2020 ◽  
Vol 19 (3) ◽  
pp. 337-355
Author(s):  
Kjell Ivar Øvergård ◽  
Marius Stian Tannum ◽  
Per Haavardtun
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Control Strategies ◽  
High Density ◽  
The Other ◽  
Right Of Way ◽  
The Right ◽  
Passenger Ferry

Abstract A study of navigational situations involving a small passenger ferry ‘Ole III’ was conducted based on participatory observations in the Husøysund strait in Tønsberg municipality, Norway. The aims were to document the extent to which crossing situations are solved according to navigational rules and practice, and to investigate the number of incidents which could pose a risk for Ole III and its passengers. Because of the high density of private pleasure craft, we expected a rather large number of non-compliance with navigational rules. Observations supported this assumption, and based on the total of 3152 crossings with Ole III where other vessels where present, a total of 279 (8.9%) incidents were considered to involve non-compliance with navigational rules and practice. A total of 165 incidents were caused by the other vessels failing to give way even though it had Ole III on its starboard side. This indicates that, at least in Norway, we may routinely expect pleasure craft to deviate from navigational rules for crossing situations. A number of incidents could partly be explained by a mismatch in understandings of which vessel had the right-of-way. Also, incident risk was higher when Ole III used active control strategies to handle crossing situations (e.g. keeping course and speed) as compared with passive control strategies. A taxonomy of situations based upon intentions is presented together with suggestions for control strategies for small passenger vessels that operate in waters with many pleasure craft.

Validation and Implementation of Control Strategies for Liquid Composite Molding Processes

Materials ◽  
2003 ◽  
Author(s):  
Mathieu Devillard ◽  
Kuang-Ting Hsiao ◽  
Suresh G. Advani
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Control Strategies ◽  
Process Models ◽  
Injection System ◽  
Composite Part ◽  
Rtm Process ◽  
Flow Disturbances ◽  
Filling Time ◽  
Optimization Search

The manufacturing of polymeric composites ranges from using a rudimentary hand lay-up to the use of automated processes such as Liquid Composite Modeling (LCM) developed over the past decades in order to increase the yield of manufactured composite parts. In these processes, fiber preforms are placed in a closed mold and resin is infused into the mold to saturate the preform. After the resin cures, the mold is opened and the net shape composite part is demolded. However, by introducing more complexity into the part, one also introduces higher probability of flow disturbances, such as race tracking along preform edges, into the molding system. This can lead to incomplete saturation of fiber performs resulting in flaws such as dry spots in the composite part. The strength and existence of race-tracking is a function of the fabric type, perform manufacturing method, and its placement in the mold. It can vary from one part to the next in the same production run, and therefore it is not repeatable. In this work, after illustrating experimentally the unpredictability of variation of race-tracking and its influence on the flow, two approaches have been investigated and validated to address this issue associated with the variation of inherent disturbances in LCM processes. An active control strategy method using process models and simulations along with sensing and control to address flow disturbances during the impregnation stage of the process was shown to be reliable and effective for Resin Transfer Molding (RTM) process. In an attempt to improve the automation of RTM process, a modular RTM workstation including all hardware and software necessary to implement active control strategies for various part geometries and a novel injection system was designed and tested. In addition, a passive control method for Vaccum Assisted RTM (VARTM) aimed at optimizing the placement of distribution media for a given set-up in order to reduce dry spot formation and filling time was developed and validated experimentally. The optimization method employs numerical flow simulations and global optimization search techniques (Genetic algorithm) to generate the design for strategic flow control system.

Research on Semi-Active Control of Large-Scale Aqueduct

2011 ◽  
Vol 194-196 ◽  
pp. 1997-2000
Author(s):  
Liang Huang ◽  
Bo Wang ◽  
Jian Guo Xu
Keyword(s):  
Active Control ◽  
Seismic Design ◽  
Theoretical Basis ◽  
Large Scale ◽  
Passive Control ◽  
Control Strategies ◽  
Active Method ◽  
Reference Base ◽  
Active Devices ◽  
Magneto Rheological

The magneto rheological damper (MRD) is employed to control the seismic response of large-scale aqueduct. The active control, semi-active control and passive control strategies are systematically compared, The results indicated that the magneto rheological dampers are effective in reducing the aqueduct response, the mitigation rate of semi-active control approaches with the active method The results from the present study may serve as a reference base for seismic design of large-scale aqueducts, and provide theoretical basis of aqueduct using semi-active devices.

scholarly journals On nonlinear dynamics of a parametrically excited pendulum using both active control and passive rotational (MR) damper

2017 ◽  
Vol 24 (9) ◽  
pp. 1587-1599 ◽  
Author(s):  
AM Tusset ◽  
FC Janzen ◽  
V Piccirillo ◽  
RT Rocha ◽  
JM Balthazar ◽  
...  
Keyword(s):  
Active Control ◽  
Chaotic Behavior ◽  
Control Strategies ◽  
Mr Damper ◽  
The Other ◽  
Parametric Uncertainties ◽  
Nonlinear Saturation ◽  
Saturation Control ◽  
Parametrically Excited ◽  
Pendulum Oscillation

This paper presents two control strategies for a parametrically excited pendulum with chaotic behavior. One of them considers active control obtained by nonlinear saturation control (NSC) and the other a passive rotational magnetorheological (MR) damper. Firstly, the active control problem was formulated in order to design the external torque for the pendulum, considering the NSC. Numerical simulations were carried out in order to show the effectiveness of this method for the active control of the pendulum oscillation. The ability of the control of the proposed NSC in suppression of the chaotic behavior, considering the proposed parameters, was tested by a sensitivity analysis to parametric uncertainties. In the case of the passive rotational MR damper, firstly the influence of the introduction of the MR in a pendulum was performed considering the 0-1 test. Different electric currents are applied to suppress the chaotic behavior of the system. The numerical results showed that the simple introduction of a passive rotational MR damper without electric current did not change the chaotic behavior of the system. However, it is possible to keep the pendulum oscillating with periodic behavior using the rotational MR damper with energizing discontinuity.

Exceptions to Mutual Trust: Children's Use of Second-Order Beliefs in Responsibility Attribution

1987 ◽  
Vol 10 (2) ◽  
pp. 207-223 ◽  
Author(s):  
Nicola Yuill ◽  
Josef Perner
Keyword(s):  
Second Order ◽  
The Other ◽  
Cooperative Interaction ◽  
Road User ◽  
Mutual Trust ◽  
Responsibility Attribution ◽  
Right Of Way ◽  
The Difference ◽  
The Right ◽  
Almost All

Children of 6 to 9 years and adults judged a story protagonist's degree of blame for a traffic accident. All stories depicted a collision between a protagonist, who had the right of way, and another road user. Stories differed, however, in protagonist's second-order belief about the other road-user's knowledge. For instance, in one story, the protagonist mistakenly thought that the other had noticed her coming and that she could therefore rely on him abiding by the priority rule (principle of mutual trust) and grant her the right of way. This story contrasted with one where the protagonist knew that the other had not seen her and so was not justified in claiming priority. Most 7 and 8-year-old children understood the difference in second-order belief and about half of them were also able to make the correct responsibility attribution that the mistaken protagonist, thinking the other character knew, was less to blame for the accident than the one who knew about the other's ignorance. By 9 years, almost all children understood second-order beliefs and three-quarters were also able to make the correct responsibility attribution. The application of second-order beliefs to the principle of mutual trust is discussed in relation to communication failures and cooperative interaction.

How to Obtain the Right of Way: An Experimental Analysis of Behavior at Intersections

1974 ◽  
Vol 39 (3) ◽  
pp. 1263-1274 ◽  
Author(s):  
Jeffrey Z. Rubin ◽  
Bruce D. Steinberg ◽  
John R. Gerrein
Keyword(s):  
Conflicts Of Interest ◽  
Eye Contact ◽  
The Other ◽  
Experimental Analysis Of Behavior ◽  
Male And Female ◽  
Right Of Way ◽  
Course Of Action ◽  
The Right ◽  
Main Effects

Conflicts of interest over who shall assume the right of way at unmarked intersections may be viewed as a subset of a more general class of conflicts whose resolution is shaped by various strategies of deterrence. In order to examine the effects of five variables upon the determination of right of way, a simulated driving situation was developed in the laboratory, involving the presentation of a series of slide photographs of two vehicles, A and B, approaching an unmarked intersection. Male and female Ss were asked to act either as the driver of one of the two vehicles (A) or as the observer of both vehicles; in addition, the size of the second vehicle (B), the sex of its driver, as well as driver B's maintenance or avoidance of eye contact with A were varied. Ss predicted, with greater confidence, that Vehicle B would cross the intersection first (that driver A would be deterred from seizing the right of way) when B was the same size as A, rather than a vehicle either larger or smaller; when driver B was female, rather than male; and when driver B avoided, rather than maintained, eye contact with A. In addition to these three main effects, a number of interactions emerged between the eye contact variable and one or more of the other four. Several of these findings were interpreted as lending support to Schelling's description of the strategic efficacy of “binding oneself” to a course of action.

CONTROL OF WIND-INDUCED RESPONSE OF TRANSMISSION TOWER-LINE SYSTEM BY USING MAGNETORHEOLOGICAL DAMPERS

2009 ◽  
Vol 09 (04) ◽  
pp. 661-685 ◽  
Author(s):  
BO CHEN ◽  
JIN ZHENG ◽  
WEILIAN QU
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Control Strategies ◽  
Wind Loading ◽  
Induced Response ◽  
Strong Wind ◽  
Transmission Tower ◽  
Line System ◽  
Control Approach ◽  
Mr Dampers

Transmission tower-line system is a high-rise structure with low damping and it is therefore prone to strong wind excitation. In this paper, the control of wind-induced response of transmission tower-line system is carried out by using magnetorheological (MR) dampers. The effects of brace stiffness of damper are introduced and a multi-degree-of-freedom (MDOF) model is developed for both in-plane/out-of-plane vibration of transmission tower-line system. Two semi-active control strategies are proposed for the vibration mitigation of tower-line system. The first one is based on fixed increment of controllable damper force whereas the second one is a clipped-optimal strategy based on fuzzy control principle. The optimal parameters of the MDOF model of transmission line are investigated. A real transmission tower-line system constructed in China is taken as an example to examine the feasibility and reliability of the proposed approach. A parametric study is conducted for the effects of brace stiffness of MR damper, wind loading intensity, and parameters of MR fluids on the control performance. The results demonstrate that the incorporation of MR dampers into the transmission tower-line system can substantially suppress the wind-induced responses of transmission tower if the damper parameters are optimally determined. The performance of the two kinds of semi-active control approaches is better than that of a passive control approach.

The Simple Logic of Radar Avoidance Action

1971 ◽  
Vol 24 (2) ◽  
pp. 219-232
Author(s):  
J. V. Inglesby
Keyword(s):  
The Other ◽  
Field Of View ◽  
Basic Principles ◽  
Right Of Way ◽  
Simple Logic ◽  
The Right ◽  
Do So

In this paper the basic principles of avoidance action are developed. It is shown that a unique set of rules exists which will guarantee the safe passage of converging aircraft; when two are involved, if either, or both simultaneously, act according to these rules, it is impossible to have an accident whatever the situation. (This assumes inerrant assessments on the part of Controllers, and it also assumes that the uncontrolled aircraft continues on course.) The rules are consistent with the Rules of the Air. Past attempts to formulate rules are compared.The action taken by an aircraft in flight to avoid coming dangerously close to some other nearby aircraft we call ‘avoidance action’. This action may be made by the pilot should the other aircraft come within his field of view, or if ground controlled, it will be initiated by the Radar Controller. The pilot works to the Rules of the Air and the Radar Controller works to them whenever it is possible for him to do so. The Rules of the Air do not always help the Radar Controller because, in every case, except for two aircraft approaching each other head-on, one or other has the right-of-way and ‘an aircraft which has the right-of-way shall maintain its course and speed.’ This means that an aircraft which has the right-of-way must not take avoiding action. The object of this paper, therefore, is to attempt to propose a set of avoidance action rules which will assist Radar Controllers in their task.

Motorists' Understanding of Automated Flagger Assistance Devices in Work Zones

2013 ◽  
Vol 2337 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Nada D. Trout ◽  
Melisa D. Finley ◽  
Brooke R. Ullman
Keyword(s):  
The Other ◽  
Vehicular Traffic ◽  
Department Of Transportation ◽  
Work Zones ◽  
Right Of Way ◽  
Texas Department ◽  
The Difference ◽  
The Right ◽  
Do So

Automated flagger assistance devices (AFADs) are designed to be operated remotely by a flagger positioned outside the travel lanes and thus to reduce their exposure to vehicular traffic. There are two types of AFADs: one type uses a remote-controlled stop and slow sign to alternate the right-of-way and the other uses remote-controlled red and yellow lenses to alternate the right-of-way. A gate arm is required only with the latter. Although AFADs may have increased the safety of flaggers, there were concerns that motorists might have misunderstood AFADs and proceeded before it had been safe to do so. As part of a recent Texas Department of Transportation project, Texas A&M Transportation Institute researchers conducted surveys to assess motorists' understanding of both types of AFADs. For the stop–slow AFAD, a newly designed “Wait on Stop–Go on Slow” symbol sign resulted in the highest percentage of participants who understood that they should stop and remain stopped until the AFAD indicated that it was safe to proceed. However, for all of the stop–slow AFAD treatments, a portion of the participants indicated that they would have stopped and then proceeded instead of waiting until the AFAD displayed the slow sign. Thus researchers recommend that a gate arm be required with stop–slow AFADs. For the red–yellow lens AFAD, participants understood the stop phase. However, there was evidence of a lack of understanding of the difference between the proceed and transition phases. Even so, the use of the gate arm appeared to inform motorists when to proceed and when to stop.

A New Larboard Helm Rule for Power-driven Vessels

1980 ◽  
Vol 33 (3) ◽  
pp. 403-407
Author(s):  
Werner Hinsch
Keyword(s):  
Special Interest ◽  
The Other ◽  
Large Vessel ◽  
Sources Of Information ◽  
Right Of Way ◽  
The Right ◽  
Radar Navigation

The steering and sailing rules are changing with the development of available sources of information. This latest development is of special interest, as radar navigation has prompted a return to the principles of the ‘Larboard Helm Rule’ -if the compass bearing of an approaching vessel does not appreciably change, each of the vessels involved shall alter course so as to place herself to the right of the line of compass bearing o t the approaching vessel’.This rule offered simple sailing instructions: each party to an encounter was required to take action. There was no stand-on vessel and no right of way. Our modern steering and sailing rules are based on the right of way of the vessel on the starboard side and this gives rise to difficulties unknown in the days of the larboard helm rule:(i) There are two vessels on collision course, one large and slow-acting, the other small and manoeuvreable; the smaller vessel can easily take avoiding action. As, however, she is approaching from starboard she is the stand-on vessel. The large vessel, though restricted in her ability to manoeuvre is thus obliged to take avoiding action.(ii) The officer on the bridge of the stand-on vessel recognizes risk of collision. The navigator on the bridge of the burdened vessel is distracted from his duty of keeping a proper look-out. Our existing rules require avoiding action on the part of the vessel that has not recognized the risk of collision.

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