Feedback Controlled Computing Systems

2005 - 2009: Embedded ubiquitous computing systems form a highly heterogenous application landscape. In contrast to many wireless sensor network application, we face with totally different processes operating at the same time in the same environment and often on the same hardware node. A developer of ubicomp appliances encounters a very complex interplay between processes, resources and the environment. In particular, limited resources, e.g. computing power, memory, energy, and a highly-dynamic and unpredictable environment, make it hard to handle this complexity during runtime. The use of feedback controllers allow to monitor the computer system online and adjust runtime parameters for achieving a pre-defined behavior. The objectives are to ensure fairness among processes, avoid system overload, coordinate realtime and non-realtime processes, form collaborative communication groups among nodes and and enable the best possible achievement for a demanded battery lifetime. The major achievement is a novel and mathematical formulation of cooperation and collaboration as two process behavorial patterns for periodic, aperiodic, realtime, and distributed processes. As a result, performance and reliability guarantees can be given for the operation of embedded ubiquitous computing systems in unpredictable and highly-dynamic environments.



2004 - 2007: Collaborative Business Items (CoBIs) is an EC funded project which bridges the gap between enterprise systems and networked embedded systems. It researches the integration of sensor networks in business processes. Our approach is execute parts of business process directly within sensor networks. Collaboration among the sensor nodes enables the execution of complex tasks and re-integrates the results in backend systems. The expected results are a service-oriented architecture for sensor nodes, a standardized interface for ERP systems to sensor networks, fine grain modelling and execution of business processes, and re-usable collaboration mechanisms for efficient task execution in sensor networks. The CoBIs consortium comprises industrial partners like BP, SAP, Infineon and Ambient Systems (SME) as well as the universities from Karlsruhe (TecO), Lancaster and Twente. My work is this project is focused on the service-oriented architecture for sensor nodes serving for the integration of sensor networks in ERP systems. This work includes the leadership of the technical workpackage in CoBIs which is responsible for the design and implementation of this integration approach. On linked project website currently achieved results are presented.



2004: The DigiClip system allows the tracking, synchronization and and integrity control of paper-based documents with their electronic counterparts. Particles were integrated in a paper clip and allowed to obtain location information for a document. In conjuction with a document management system, the DigiClip device enabled a physical notifcation of changes of the electronic document. The sensors of the DigiClip device allow further the application of integrity rules on the physical document, such as document integrity on a single page-level, handling constraints and location restrictions. More details are outlined on the project website. DigiClip was a project in cooperation with SAP. I was the responsible leader on TecO site and I implemented lots of functionality as well as complex demo scenarios. The system was presented to the German chancellor on CeBIT 2004, the SAPPHIRE04 fair and got various other press attention. DigiClip was developed further as a packaged sensor network platform based on Particle Computers for the CoBIs project.

Particle Computers


2000 - ongoing: Particle Computer is TecO's enabling platform for various scenarios related to Ubicomp. Particles are tiny wireless nodes where a huge variety of sensors can be attached. Further, the fully programmable microcontroller accompanied by powerful libraries let novices as well as professionals implement applications in the fields of sensor networks, human-computer interaction, supply-chain management and many more. The proprietary communication protocol AwareCon is able to handle highly mobile and highly scalable communiation situations. Although battery-driven, Particle Computer can achieve lifetime of up to several years. My focus in this ongoing project is on system software for Particle Computers and tools for developing Particle applications and sensor data analysis. I designed and supervised various sub-projects including the libparticle, the ParticleAnalyzer, the Particle Location System (PLS), software for XBridge and USBBridge, ParticleBasic, ParticleComponents, Equip4j for Particles, ParticleDB and the Particle file system. Find more details on the project website.



2002 - 2003: The SmartShelf is an RFID reader enabled shelf. The project goal was to research various strategies to understand and influence the customers' decision behavior during the process of buying items in a retail store. The SmartShelf is a technology to reveal customers' interactions with a product item in an unobtrusive way. This opens up a huge potential for applications. These include recommender systems similar to that known form amazon, but situated in real world retail stores, plan-o-gram compliance applications, out-of-stock predictions and theft prevention. Analysis of advertisment campaigns and product bundlings were also a target areas. This project was done in cooperation with SAP.



1999 - 2001: This project was a cooperation with SAP. The goal of the Aware Goods project was to enable quality management for goods like chemical fluids while they are in transit. I wrote the first prototype system where a small data logging device (Datalogger MINIDAN by Esys) measures temperature of the goods. Afterwards these data is transfered in the SAP R3 system which makes the decision about the quality of the delivered goods. AwareGoods prototype was presented on CeBIT 2000.



1998 - 2000: TEA stands for Technology for Enabling Awareness. It was an EC funded project to investigate serveral aspects of context awareness for small, mobile devices. These devices are aware of their environment they are situated in and they can change their behavior accordingly. I implemented a neural network on the Webchip for context recognition.



2000: The Trafficlights project is an ambient display project. The approach: 3 lights bulbs shine with different brightness on 3 posters with pictures of our websites. Passing people can realize in an ambient way the website traffic. On the project website the hardware and software is presented. The trafficlights have been working for years.

Beck IPC (Webchip)


2000 - 2001: The Beck IPC is an embedded web/telnet/ftp server with a multitasking DOS operating system developed by BECK. At TecO we use this platform for various implemenation of our ideas in the ubicomp research area. For instance in the TEA project the Webchip was used. I implemented various libraries for an easy use of the different funtions, so TCP/IP networking, serial communication, cgi-funtions, and the I/O pins.

Onhand PC


2000: The OnhandPC developed by Matsucom is a mini computer in the form of a watch. We used this device as a wearable monitor for reading the state of the MediaCup. On the project page you can find the specific description and an API index with a full text search engine.



I wrote a little prorgram for reading data from a accel sensor developed by Xbow.



Software which was developed to solve problems which are not directly connected to my work, but it seems useful for others. Feel free to use it. Feedback would be appreciated. :-)