Ramez M. Daoud

Ethernet-Based Car Control Network

The use of networks for communication between electronic control units has increased in car industry over the last two decades. Several types of networks were developed for this purpose. In this study, Ethernet at gigabit speed is tested as a network for such system. The use of Ethernet helps integrating real-time control functions and non-real-time entertainment functions. Two main scenarios were simulated using OPNET. The fist one simulates pure control networks on board of a moving vehicle. The second scenario is the same as the first one with an added video load to simulate on-board entertainment. Both simulations were successful, as the end-to-end delays were below the maximum round-trip delays required by the system

Gigabit Ethernet for redundant networked control systems

In this paper, the use of fast and Gigabit Ethernet in advanced networked control systems is studied. Redundant control node scenario is the key factor for minimum down-time. Ethernet 802.3 protocol is tested without modification in frame format. Gigabit Ethernet succeeded to absorb the control traffic of several working machines while fast Ethernet could not.

WiFi implementation of Wireless Networked Control Systems

This paper studies a Wireless Networked Control System which utilizes the IEEE 802.11b protocol without modifications to communicate between sensors and actuators in a production line environment. OPNET simulations are used to measure the end-to-end delay from sensor to controller and then from controller to actuator. It is observed that the measured delays, including all types of data processing, encapsulation, decapsulation and propagation, meet real-time control network requirements while guaranteeing correct packet reception. The system is then subjected to noise and several worst-case scenarios are analyzed. Simulations indicate that the system is still able to meet the required end-to-end delays. All results are based on a 95% confidence analysis.

Effect of node distributions on lifetime of Wireless Sensor Networks

Wireless Sensor Networks has recently become an attractive research topic due to the rapidly growing field of applications. This paper focuses on prolonging network lifetime by investigating different node deployments including both geometric and uniform. Geometric distributions resulted in a 35.6% increase in lifetime as opposed to random distributions. Furthermore, different sink locations were examined. The optimum sink location introduced a considerable lifetime elongation compared to the previously used location.

Fault-tolerant networked control systems under varying load

In this paper, a simulation study is made to test the fault tolerant ability of networked machines. This ability is introduced by reallocating loads in case of controller failure. Also, the increase in machine speed for higher production, is considered. The maximum speed of operation of individual machines and fault tolerant production-lines, is studied. All machine networks of this study are built on-top-of switched Gigabit Ethernet in star topology.

Fault tolerant two-level pyramid networked control systems

In this paper, a pyramid control hierarchy is proposed. It is based on the presence of a supervisor controller on top of separate controller nodes. A simulation study is conducted to test the functionality of the system. The proposed model is an enhancement of machine modeled in form of networked control systems (NCS). Two models are tested: one supervisor/two sub-controllers, one supervisor/three sub-controllers. All possible combinations of supervisor-controller intercommunication are tested. Also, all supervisor/controller inter-changeability possibilities are taken into consideration. Results are illustrated and discussed. Recommendations are drawn out. All machine models of this study are built using switched gigabit Ethernet in star topology

The Use of Ethernet for Single On-board Train Network

The use of Ethernet protocol for railway vehicle on-board networks is considered. It is shown that a single Ethernet network can carry real-time control data, thus replacing existing train control networks. In addition, this network can also carry entertainment data for passengers as well as data coming from mobile wireless devices carried on-board. OPNET simulations are used to estimate the maximum allowable entertainment traffic that can be carried by the network while satisfying the real-time constraints of the control traffic.

On the effect of interference on Wi-Fi-based Wireless Networked Control Systems

This study investigates a Wi-Fi-based Wireless Networked Control System. This system is first modified in order to enhance resistance to interference. Then, it is subjected to different types of interference. The system consists of a workcell containing 30 sensors, 30 actuators and 1 controller. All forms of interference modeled focus on the operating frequency band used by the control nodes. All simulations are conducted on OPNET Network Modeler and system performance is measured in terms of packet end-to-end delay and correct packet transmission/reception. All results are subjected to a 95% confidence analysis. The results show that intentional jamming is more damaging than medium congestion, which in turn is more damaging than network congestion.

Workcell concatenation using wifi-based Wireless Networked Control Systems

Wireless Networked Control Systems is a growing field in the world of industrial automation. This paper studies a workcell employing Wireless Networked Control Systems based on the 802.11 protocol without modifications. With the increased complexity of automated production and assembly lines, there is a need to accommodate for the concatenation of several simultaneously operating cells. The possibility of concatenating several cells is studied, with a focus on correct packet transmission, acceptable packet end-to-end delays, minimal interference from neighboring cells while subject to alien noise in the vicinity of the 2.4GHz range. The study is based on OPNET simulations, with all results subjected to a 95% confidence analysis.

Wireless Vehicle Communication for Traffic Control in Urban Areas

This paper introduces the idea of using the stigmergic approach to solve traffic problems in congested urban areas and focuses on the communications aspect of the problem. V2I and I2V are based on IEEE 802.11 standard. The urban area is equipped with access points that are wired to a central node. The number of packets lost is investigated at different vehicle speeds as well as different I2V broadcast rates. The best broadcast rate is found in order to reduce the packets lost irrespective of vehicle speed