Reglering av variabel traktorpump

• Main Author: Söderberg, Johan
• Format: Others
• Language: Swedish
• Published: Linköpings universitet, Fluida och mekatroniska system 2014
• Subjects: Mobila hydraulsystem; Lastkännade hydraulsystem; Elektroniskt lastkännande hydraulsystem
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108201

This project is a master thesis at Linköping University with focus on hydraulic  systems. Particularly in mobile hydraulics and electronic control of the load sensing signal on a variable tractor pump. The project has been conducted at Väderstad-Verken AB, Sweden’s biggest manufacturer of soil preparation and seeding equipment for agricultural use. Väderstad is also a well know competitor on the global market and continuously expanding their territory. This approach of controlling the load sensing signal, when using a variable tractor pump, is new to Väderstad. Therefore there hasn’t been any research done previous to this project. The reason for trying this way of controlling the load sensing signal is in order to construct a hydraulic system completely inde-pendent of the pump on the tractor. And thereby allowing Väderstad’s imple-ments a more efficient and stable use of the variable hydraulic tractor pump. The theoretical results indicate a possibly more stable system when using the electronic control, due to a higher leak flow out of the system volume, generated as a result of the control flow through the electronic control unit. The results from the computerized simulations show that it is possible to create a working load sensing controller when applying required control theory. The practical tests that have been carried out demonstrate how the system seems to be independent of the pump. Although, no practical test results are documented or available with traditional load sensing technique used in the same application, which prevents a compari-son of traditional load sensing versus electronic load sensing. Making it difficult to draw conclusions weather the hypothesis is valid or not. The greatest difficulties with electronic control of the load sensing signal are related to the software and control theory. Future work involves trying a new digital methodology on the electronic controller, and thereby enhancing the resolution of the control loop when at the same time reducing recovery time after an external disturbance.