Waqas Ikram's research while affiliated with Imperial College London and other places

Industrial Control Systems (ICS) are evolving with advances in new technology. The addition of wireless sensors and actuators and new control techniques means that engineering practices from communication systems are being integrated into those used for control systems. The two are engineered in very different ways. Neither engineering approach is capable of accounting for the subtle interactions and interdependence that occur when the two are combined. This paper describes our first steps to bridge this gap, and push the boundaries of both computer communication system and control system design. We present The Separator testbed, a Cyber-Physical testbed enabling our search for a suitable way to engineer systems that combine both computer networks and control systems.

The use of wireless sensor networks has enabled the process industry to collect a vast amount of hitherto unknown data by making physical monitoring of the underlying processes and equipment practically and economically possible. Wireless communication has led to new applications in the field of wireless process automation which in the past were subjected to economical, physical and technological barriers. One such application is vibration monitoring targeting condition monitoring of equipment with rotating parts. This paper presents a case study where a wireless vibration system is installed on an operational water pumping station in a metropolitan city. The data presented here has identified a potential problem with the ball-bearing of a particular motor in use. In addition, the wireless communication performance is also examined.

The adoption of wireless technology for industrial wireless instrumentation requires high-quality communication performance. The use of transmission power control (TPC) can help address industrial issues concerning energy consumption, interference, and fading. This paper presents a TPC algorithm designed for industrial applications based on theoretical and empirical studies. It is shown that the proposed algorithm adapts to variations in link quality, and is hardware-independent and practical.

Wireless communication is one of the fastest growing technologies in process automation and now targets main stream applications. One such application is a safety application; it is unique in its own rights, as any problem with safety related equipment, network or system can compromise on-site safety. For the wired networks which serve safety applications, they are designed to ensure QoS. Therefore, controlling delay, jitter, packet loss rate and bandwidth is critical. To achieve the same performance over an envisioned wireless network with shared communication medium, various problems are to be dealt with. In this regard, this paper is an effort towards the design of a SIL compliant solution. Hence, this paper addresses the key constraints of the wireless technology and demonstrates the proof-of-concept through a field trial.

The designers, optimizers and maintenance personnel of a wireless sensor network are frequently challenged by system level energy budget considerations. Minimizing the need for battery replacement is often the design goal while ensuring that a balance is maintained between capability and current consumption in order to address application needs. In this paper, a tool is introduced which can be used to calculate the lifetime of a battery operated wireless node. It allows the user to configure different wireless sensor platforms, select a battery of choice, and specify the application which needs to be executed over the configured hardware. As a result, the tool computes an estimate for the expected lifetime of the wireless sensor node. Furthermore, the tool also provides a detailed overview of the energy consumed by each component during a duty cycle.

Wireless sensor networks are deployed to monitor real-world phenomena, and are seeing growing demand in commerce and industry. These networks can benefit from time synchronized clocks on distributed nodes. The precision of time synchronization depends on error elimination or reliable estimation of errors associated with synchronization message delays. This paper examines an approach to time synchronize motes using onboard radio-controlled clocks. The advantage will be the minimisation of non-deterministic sources of errors in time synchronization amongst receivers. This approach of synchronization using out-of-band and dedicated time source is aimed to achieve network-wide, scalable, topology-independent, fast-convergent and less application-dependent solutions.

The advancements in wireless networking technology, specifically in the short-range wireless networking technology, offer an enormous opportunity for wireless connectivity of field devices both in oil and gas and other chemical processing plants. The prerequisite of a field network includes real-time support for mixed traffic, availability, security, reliability and scalability in a harsh industrial environment. These conditions have to be fulfilled by any wireless network in order to operate. This paper presents a brief overview of the requirements for wireless in process automation, relative standings of existing short-range wireless network technologies based on the outlined criteria, and associated shortcomings. Furthermore, an examination of emerging industrial wireless standards which are designed to address the unique and stringent requirements of the process industry, is presented.