scholarly journals State movement for controlling trains operating under the virtual coupling system

2021 ◽  
pp. 095440972110437
Author(s):  
Naphat Ketphat ◽  
Anthony Whiteing ◽  
Ronghui Liu
Keyword(s):  
High Capacity ◽  
Operation Time ◽  
Separation Distance ◽  
Safe Distance ◽  
Signaling Systems ◽  
Time Period ◽  
Coupling System ◽  
Virtual Coupling ◽  
Braking Distance ◽  
Minimum Safe Distance

Train Virtual Coupling System (VCS) has been proposed as a new signalling system for controlling trains by building a group of trains as convoys in order to increase line’s capacity. This is achieved because the consecutive trains under the VCS is separated only by a relative braking distance; this is much shorter than the separation distance required in the Fixed Block Signaling (FBS) and Moving Block Signaling systems (MBS). In order to achieve the high capacity obtained from the VCS, the trains in a virtually coupled convoy should keep at a distance as close to the relative braking distance as possible and run at the same speed for maintaining the safe distance between them. In this paper, we propose a distance and velocity difference approach and introduce the multiple state movements for stimulating train’s movement under the VCS. The simulated results show that the capacity can be significantly increased and maximized in which the actual separation distance between trains when they are in convoy state is slightly longer than the minimum safe distance. It could be ensured that the train has proceeded safely in that the actual separation distance is surely longer than the minimum safe distance throughout the operation time period. In addition, we show that the trains can also proceed smoothly, in that a following train catches up with its leading train and joined in the convoy with a stable movement.

On the issue of assessing the errors in the operation of an interactive system for improving road safety outside settlements

2021 ◽  
pp. 36-43
Author(s):  
Keyword(s):  
Road Safety ◽  
Experimental Studies ◽  
Warning System ◽  
Interactive System ◽  
Safe Distance ◽  
The Road ◽  
Braking Distance ◽  
On The Road ◽  
Vehicle Positioning ◽  
Minimum Safe Distance

The article presents the result of the analysis of statistical data of accidents in the Krasnoyarsk Territory on sections of roads outside settlements with their greatest concentration. The main types of vehicle collisions and their accompanying conditions were identified. A mathematical apparatus for determining the minimum safe distance between vehicles located closely in an emergency zone on a section of a road outside settlements is proposed, in which it is necessary to notify the drivers of these vehicles about the danger in conditions of insufficient and/or limited visibility in various road situations, taking into account errors in positioning and determining the speed of the vehicle, the response time of the system, the effective coefficient of adhesion of the tires to the road surface. The results of experimental studies of vehicle positioning and speed errors determined by the driver’s early warning system about hazards on the road and their impact on the operability of the designed system are presented. Keywords: road safety, interactive driver warning system, positioning error, safe distance, rest of track, braking distance

Evolutions in Railway Signaling: A “New Age” of Control?

2009 ◽  
Author(s):  
Cameron Fraser
Keyword(s):  
New Age ◽  
Safe Distance ◽  
Signaling Systems ◽  
Train Control ◽  
Train Routing

The development of railroad signaling systems evolved with the need to provide interlocking between points and signals, and block working to keep trains a safe distance apart. Accordingly, the archetypal behavior of train control is summed up as providing (1) safe and efficient train movement by (2) the management of train routing and separation. This has been rudimentary since the advent of railway signaling and propagated in even the most contemporary of technologies today.

Histopathological differences in bony destruction of malleus and incus following mastoidectomy

2010 ◽  
Vol 124 (11) ◽  
pp. 1162-1166
Author(s):  
T Sasaki ◽  
A Xu ◽  
K Ito ◽  
S-I Ishimoto ◽  
T Yamasoba ◽  
...  
Keyword(s):  
Middle Ear ◽  
Operation Time ◽  
Ear Reconstruction ◽  
Lamellar Bone ◽  
Bone Area ◽  
Bony Destruction ◽  
Time Period ◽  
Middle Ear Reconstruction ◽  
Direct Inspection

AbstractObjectives:Upon direct inspection of surgically removed ossicles from the ears of patients with long-term post-mastoidectomy cavity problems, the extent of malleus destruction often appears greater in patients with a longer duration of cavity problems, whereas the extent of incus destruction does not appear to correlate with the duration of cavity problems. This study aimed to investigate this impression.Materials and methods:As a result of total middle-ear reconstruction, 41 ossicles (21 malleus and 20 incus bones) were obtained from 31 patients with post-mastoidectomy cavity problems. The ossicles were examined histopathologically, and the proportion of lamellar bone area to total bone area (expressed as percentage lamellar bone) was measured. We also calculated the inter-operation time, i.e. the time period between the previous mastoidectomy and the recent total middle-ear reconstruction; this parameter was used as an approximate measure of the duration of the patient's cavity problem. Correlations between percentage lamellar bone and inter-operation time were calculated for the two ossicles.Results:The range of inter-operation times was seven to 65 years. We observed a correlation between percentage lamellar bone and inter-operation time for malleus bones (r = −0.512, p < 0.05), but not for incus bones.Conclusion:These results were in agreement with our pre-study impressions.

scholarly journals Reduction in Lead Time of Automated Gas Fired Kit Fitting Box Using QC Tools and Strategies.

10.29007/h84w ◽  
2018 ◽  
Author(s):  
Abhishek Rana ◽  
Dhaval Vithani ◽  
R. S. Barot ◽  
Amar Patel
Keyword(s):  
Lead Time ◽  
Manufacturing Sector ◽  
Operation Time ◽  
Flow Time ◽  
Mean Flow ◽  
Mean Flow Time ◽  
Time Period ◽  
Work Cycle ◽  
Potential Methods

Recently in a competitive manufacturing sector, lead time is the most important factor in order to compete in the market. This leads every manufacturer to decrease production time and increase quality of the product. Due to improper work cycle delay of a product occurs. The major changes required are operation sequence, flow of material in the workshop, work cycle, etc. In this paper, the authors have delved into the causes of excessive lead time and suggest practical inexpensive strategies for reducing it. Recommendations are based on detailed study of manufacturing facility and processes for a time period of 6 months in the industry. After describing the relationship between lead time, material flow time and variance and reviewing potential methods for reducing lead time by reducing mean flow time of material and operation time of an automated gas fired kit fitting box (hereafter termed as “box”). The aim of this paper is also to demonstrate the use of QC tools and Kaizen in the industry as to tool for improvement in manufacturing sector especially in small to medium scale industries.

scholarly journals Theoretical Analysis of Interaction Energy in Alginate-Capped Gold Nanoparticles Colloidal System

2014 ◽  
Vol 14 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Foliatini Foliatini ◽  
Yoki Yulizar ◽  
Mas Ayu Elita Hafizah
Keyword(s):  
Separation Distance ◽  
Colloidal System ◽  
Electrostatic Repulsion ◽  
Interaction Energies ◽  
Stabilization Mechanism ◽  
Electrostatic Charges ◽  
Time Period ◽  
Alginate Concentration ◽  
Long Time ◽  
Effective Stabilization

Stability of Au/alginate nanocomposite was theoretically evaluated by computing various interactions energy which contributes in the system, including attraction and repulsion interaction. The results revealed that both polymer and electrostatic charges played a significant role in the stabilization, but the steric repulsion comes from polymer chain is a more effective stabilization mechanism than the electrostatic repulsion. Higher pH yielded in stronger electrostatic repulsion but when the alginate thickness is low the resulting nanocomposite was less stable in a long time period. Interaction energies for Au/alginate nanocomposite colloidal system was up to ~60 kT for alginate thickness of 1 nm, at very short particle-particle separation distance (< 1 nm). As the alginate thickness can be controlled by adjusting the alginate concentration, it can be concluded that the high stability of Au/alginate nanocomposite can be achieved by employing an appropriate amount of alginate concentration.

scholarly journals Optimized Control of Virtual Coupling at Junctions: A Cooperative Game-Based Approach

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 207
Author(s):  
Qi Wang ◽  
Ming Chai ◽  
Hongjie Liu ◽  
Tao Tang
Keyword(s):  
Particle Swarm Optimization ◽  
Cooperative Game ◽  
Coupling Efficiency ◽  
Particle Swarm ◽  
Operation Time ◽  
Optimal Operation ◽  
Optimization Approach ◽  
Swarm Optimization ◽  
Reasonable Amount ◽  
Virtual Coupling

Recently, virtual coupling has aroused increasing interest in regard to achieving flexible and on-demand train operations. However, one of the main challenges in increasing the throughput of a train network is to couple trains quickly at junctions. Pre-programmed train operation strategies cause trains to decelerate or stop at junctions. Such strategies can reduce the coupling efficiency or even cause trains to fail to reach coupled status. To fill this critical gap, this paper proposes a cooperative game model to represent train coupling at junctions and adopts the Shapley theorem to solve the formulated game. Due to the discrete and high-dimensional characteristics of the model, the optimal solution method is non-convex and is difficult to solve in a reasonable amount of time. To find optimal operation strategies for large-scale models in a reasonable amount of time, we propose an improved particle swarm optimization algorithm by introducing self-adaptive parameters and a mutation method. This paper compares the strategy for train coupling at junctions generated by the proposed method with two naive strategies and unimproved particle swarm optimization. The results show that the operation time was reduced by using the proposed cooperative game-based optimization approach.

scholarly journals Dynamic safety system for collaboration of operators and industrial robots

2019 ◽  
Vol 9 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Timo Malm ◽  
Timo Salmi ◽  
Ilari Marstio ◽  
Jari Montonen
Keyword(s):  
Separation Distance ◽  
Safety System ◽  
Industrial Robots ◽  
Safe Distance ◽  
Validation Process ◽  
Sensors And Actuators ◽  
Safety Critical ◽  
Stopping Distance ◽  
And Performance ◽  
Continuous Working

AbstractThere is an increasing need to have a safety system, which allows safe collaboration of operators and industrial robots. Industrial robots are powerful and therefore dangerous impacts and crashes need to be prevented by keeping safe distance between moving robot and the operator. Safe distance can be achieved by monitoring the position and speed of the robot and the position of the operator. Separation distance, speeds and performance of the control system, sensors and actuators are regulated by standards, which must be followed. VTT has developed a dynamic safety system, which monitors the speed and separation between persons and the robot in order to keep the stopping distance of the robot small enough to avoid impacts. The dynamic safety system enables safe continuous working beside the robot and automated restarting after a safety-rated monitored stop. An assistance system is applied to switch safety modes of the robot according to separation distance. Configuring and validating the safety system are safety-critical and time-consuming phases of design. Therefore, a configuration tool is required to get a coherent configuration, which support validation process.

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