Dynamic whole system testing of combined renewable heating systems : the current state of the art

Objective: For the evaluation of the energetic performance of combined renewable heating systems that supply space heat and domestic hot water for single family houses, dynamic behaviour, component interactions, and control of the system play a crucial role and should be included in test methods. Methods: New dynamic whole system test methods were developed based on “hardware in the loop” concepts. Three similar approaches are described and their differences are discussed. The methods were applied for testing solar thermal systems in combination with fossil fuel boilers (heating oil and natural gas), biomass boilers, and/or heat pumps. Results: All three methods were able to show the performance of combined heating systems under transient operating conditions. The methods often detected unexpected behaviour of the tested system that cannot be detected based on steady state performance tests that are usually applied to single components. Conclusion: Further work will be needed to harmonize the different test methods in order to reach comparable results between the different laboratories. Practice implications: A harmonized approach for whole system tests may lead to new test standards and improve the accuracy of performance prediction as well as reduce the need for field tests.

The remote control ofmobile robot on theInternet

During last decades, the Internet teleobotics has been growing at an enormous ratedue to the rapid improvement of Internet technology. This paper presents theinternet-based remote control of mobile robot. To face unpredictable Internet delaysand possible connection rupture, a direct continuous control based teleoperationarchitecture with “Speed Limit Module” (SLM) and “Delay Approximator” (DA) isproposed. This direct continuous control architecture guarantees the path error of therobot motion is restricted within the path error tolerance of the application.Experiment results show the feasibility and effectiveness of this direct Internet controlarchitecture in the real Internet environment.

Must teachers be social workers, as well …? : Reflections on the current teacher role in the Swedish upper secondary school and how it affects teacher training

The Swedish upper secondary school has made a transition from a school for the elite to be a school for everybody. When almost every youth nowadays chooses to continue studying, for some of them this is not what they want to do most of all. However, as there in practice is no choice, there come up problems and many upper secondary school teachers experience a growing frustration. We will here discuss some aspects of the following questions: -  How do upper secondary schoolteachers handle their working-conditions in a new situation? - What possible consequences do this have on teacher education?