Can autonomous wireless sensor networks be designed to fulfill the requirements of industrial applications? That is the research question for this synergy research project, ASIS. Researchers are addressing the challenges of making the wireless sensor network technology competitive in relation to wired networks with respect to reliability, predictability, communication performance, and maintainability. Three research issues will be addressed in a coordinated manner to advance the field.

Background

Industrial control systems are often deployed in large, spatially distributed systems that involve sensors, actuators and internal process variables. Traditionally these systems are connected through wires but with the improvements in the capabilities and cost of wireless technologies have allowed multi-hop wireless networks to be used for (open-loop) monitoring of industrial process automation plants. In near future wireless technologies will be used in the industry for closed-loop control applications such as safety, control of motor speed, or maintaining an appropriate level of bitumen in holding tanks. The five key benefits that are driving the usage of wireless control are improved reliability, improved control performance, improved sensing (ability to measure things that was not possible earlier), flexibility and cost reduction.

Using wireless networks fundamentally differs from wired distributed systems in that the dynamics of the network can change the operational points and physical dynamics of the closed-loop system. But wireless networks pose challenges such as guaranteeing reliable and predictable communication. Another challenge is to maintain the given end-to-end delay for different applications and also reducing the communication load over the network. For utilizing wireless distributed control to its maximum some of the intelligence that previously was located in central controllers needs to be implemented in the sensor devices. This is also a major challenge since available sensor nodes already have limited constraints in terms of physical size, energy consumption and computationally capacity.

Research in synergy

In this project researchers are addressing research questions in three different disciples that are related to each other in a coordinated way. As key technology areas the following three have been identified for autonomous sensors:

• Wireless Networks: The research will address predictability for real-time operation, energy-aware communication, improved resiliency to interferences, and secure communication.
• In-Sensor Processing: The research will address energy-efficient hardware architectures and usage of in-sensor computational resources, energy-constrained optimization of the partitioning of intelligence between and in nodes of the wireless network.
• Energy Harvesting: The research will address the characterization of potential ambient energy reservoirs in industrial environments, the prediction of available energy to the wireless system and support to the energy harvesting system design process.

This synergy between this three areas will address the overall research question in different disciples that are related to each other in a coordinated way. This approach will provide a relevant context for the research within the disciplines and increase our ability to formulate relevant research questions that can give an answer to the overall Synergy question in a better way than if they were addressed separately.