Articles and whitepapers

The Hydra Project - Middleware for Easy Networking of Home Automation Systems (4/1/2010)

By Markus Eisenhauer, Fraunhofer Institute for Applied Information Technology

As the refrigerator said to the hi-fi...

Networked sensors and devices have huge potential but how do you ensure that widely different devices can talk to each other? The answer is to link them seamlessly through a common 'middleware'. Immediate applications are in home automation, healthcare and agriculture.

In these energy-conscious times, the old idea of home automation is being revived to give the householder finer control over the many devices in the home. Most proposals envisage devices (embedded systems), such as heating, lighting and ventilation systems, being able to communicate with each other in a wireless network.

How can different devices, using different technologies and made by different manufacturers at different times, communicate with each other? One way would be to insist that all devices conform to some agreed standard, but that would be complex and time-consuming to negotiate and would not apply to existing devices. It could also stifle innovation by putting constraints on future technologies not yet imagined.

An alternative approach has been adopted by the EU-funded Hydra project. Hydra aims to reduce these complexities by developing a service-oriented middleware. Its aim is to help manufacturers, software developers and systems integrators to build devices that can be networked easily and flexibly via web services, to create cost-effective, high-performance solutions.

The Hydra logo.

The Internet of things

With Hydra, all manner of devices such as electricity meters, TV sets, refrigerators, hi-fi systems and heating and lighting systems, can be networked without having to know what goes on inside them. We have some prototypes and demonstration systems running, where we have used an ordinary Playstation 3 as a home control centre. The middleware provides access to all sensors and embedded devices, so a software developer does not have to think about what types of sensor are in the house.

If you want to get a temperature value, you can simply address the middleware with a semantic such as 'I want to get the temperature from this room', and Hydra will resolve it and provide access to the corresponding sensors.

In principle, any Hydra device can connect to any other, bringing the goal of the 'Internet of things' a step nearer. A device development kit allows the middleware to be integrated into future devices as well as existing devices provided they have certain computing power. Manufacturers could even put Hydra-enabled sensors within products such as washing machines so that problems could be diagnosed remotely, without a site visit.

The HYDRA middleware is deployable on both new and existing networks of distributed wireless and wired devices, which operate with limited resources in terms of computing power, energy and memory usage.

Healthcare at home and other applications

Home automation is only one example of what Hydra can do. Another major application is expected to be in healthcare, especially the monitoring of patients in their own homes. The consortium partners in Hydra have set up a demo using networked sensors that measure body weight, blood pressure, blood sugar and oxygen saturation. A muscle sensor provides a warning of an epileptic fit.

Different kinds of technologies such as ZigBee, Bluetooth and others are all covered by the network manager within Hydra, and then just to show that we can also use off-the-shelf devices, we have used a Wii balance board as a weight scale, and have connected it to our Playstation 3. The Playstation 3 games console can be found in many homes, but it can easily run the Hydra middleware while providing complete privacy for the patient's data. While not a fully-fledged telemedicine system, it has all the necessary ingredients of such a system and is currently running with diverse and heterogeneous hardware.

Hydra software architecture layers.

Agriculture can also benefit from Hydra. In one trial, pigs were fitted with RFID tags so that their movements around their enclosure could be tracked. Each pig could be located in the shed or outside, and this could be used to control the heating and ventilation system. If the shed became too crowded, the temperature rises and then the heating system responds to that.

In another trial, wireless ZigBee sensors measured soil humidity in the field, to help farmers decide the best time to sow their crops.

Future developments

The Hydra automated home demonstrator was runner up in the best demonstrator award at the ICT Mobile Summit in Stockholm in June 2008. And the project was voted one of the top ten best projects at the ICT2008 fair in Lyon.

For projects who want to take Hydra as their basic technology and build upon it, we are developing the core components as open source, and they will be published on Source Forge. The partners are also discussing whether to market a commercial version of Hydra with more features.

Conclusion

Hydra brings closer a world of ambient intelligence, or ubiquitous computing, where artificial intelligence becomes part of our everyday surroundings. It is an enabler of the vision that Mark Weiser, the founder of ubiquitous computing, had of the 'disappearing computer'. Hydra is an enabling technology that could make this dream come true.

Dr Markus Eisenhauer is the Hydra project coordinator at the Fraunhofer Institute for Applied Information Technology (FIT). Based in Sankt Augustin, Germany, FIT works to enhance human abilities through flexible, context-adaptive information and cooperation systems. Hydra has received funding from the ICT strand of the EU's Sixth Framework Programme for research.

www.hydramiddleware.eu