Real-Time Traffic Camera-Light Control Systems for Intersections Subject to Accidents: A Petri Net Approach

2013 ◽  
Author(s):  
Liang Qi ◽  
MengChu Zhou ◽  
ZhiJun Ding
Keyword(s):  
Control Systems ◽  
Real Time ◽  
Petri Net ◽  
Light Control ◽  
Real Time Traffic

Remote Simulation to Evaluate Real-Time Traffic Control Strategies

2000 ◽  
Vol 1727 (1) ◽  
pp. 95-100 ◽  
Author(s):  
David E. Lucas ◽  
Pitu B. Mirchandani ◽  
K. Larry Head
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Control Systems ◽  
Real Time ◽  
Traffic Control ◽  
Control Strategies ◽  
Remote Access ◽  
Hardware In The Loop ◽  
Simulation Environment ◽  
Real Time Traffic

Simulation is a valuable tool for evaluating the effects of various changes in a transportation system. This is especially true in the case of real-time traffic-adaptive control systems, which must undergo extensive testing in a laboratory setting before being implemented in a field environment. Various types of simulation environments are available, from software-only to hardware-in-the-loop simulations, each of which has a role to play in the implementation of a traffic control system. The RHODES (real-time hierarchical optimized distributed effective system) real-time traffic-adaptive control system was followed as it progressed from a laboratory project toward actual field implementation. The traditional software-only simulation environment and extensions to a hardware-in-the-loop simulation are presented in describing the migration of RHODES onto the traffic controller hardware itself. In addition, a new enhancement to the standard software-only simulation that allows remote access is described. The enhancement removes the requirement that both the simulation and the traffic control scheme reside locally. This architecture is capable of supporting any traffic simulation package that satisfies specific input-output data requirements. This remote simulation environment was tested with several different types of networks and was found to perform in the same manner as its local counterpart. Remote simulation has all of the advantages of its local counterpart, such as control and flexibility, with the added benefit of distribution. This remote environment could be used in many different ways and by different groups or individuals, including state or local transportation agencies interested in performing their own evaluations of alternative traffic control systems.

A SWITCHED ETHERNET PROTOCOL FOR HARD REAL-TIME EMBEDDED SYSTEM APPLICATIONS

2005 ◽  
Vol 06 (03) ◽  
pp. 345-360 ◽  
Author(s):  
ALIMUJIANG YIMING ◽  
TOSHIO EISAKA
Keyword(s):  
Embedded System ◽  
Control Systems ◽  
Real Time ◽  
Frame Rate ◽  
Dynamic Priority ◽  
Real Time Traffic ◽  
Set Up ◽  
Hard Real Time ◽  
Time Systems ◽  
And Robotics

This paper presents a protocol to support hard real-time traffic of end-to-end communication over non real-time LAN technology. The network is set up with nodes and switches, and real-time communication is handled by software (protocol) added between the Ethernet protocols and the TCP/IP suite. The proposed protocol establishes a virtual circuit based on admission control and manages hard real-time traffic to bypass the TCP/IP stack. This makes considerably reduce the dwell time in the nodes, and increase the achievable data frame rate. After the bypassing, traffic schedule is performed according to dynamic-priority EDF algorithm. The work does not need any modifications in the Ethernet hardware and coexists with TCP/IP suites, and then the LAN with the protocol can be connected to any existing Ethernet networks. It can be adopted in industrial hard real-time applications such as embedded systems, distributed control systems, parallel signal processing and robotics. We have performed some experiments to evaluate the protocol. Compared to some conventional hard real-time network protocols, the proposed one has better real-time performances and meets the requirements of reliability for hard real-time systems.

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