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11	Controlling a Hydraulic System using Reinforcement Learning : Implementation and validation of a DQN-agent on a hydraulic Multi-Chamber cylinder system Berglund, David, Larsson, Niklas January 2021 (has links) One of the largest energy losses in an excavator is the compensation loss. In a hydraulic load sensing system where one pump supplies multiple actuators, these compensation losses are inevitable. To minimize the compensation losses the use of a multi chamber cylinder can be used, which can control the load pressure by activate its chambers in different combinations and in turn minimize the compensation losses. For this proposed architecture, the control of the multi chamber cylinder systems is not trivial. The possible states of the system, due to the number of combinations, makes conventional control, like a rule based strategy, unfeasible. Therefore, is the reinforcement learning a promising approach to find an optimal control. A hydraulic system was modeled and validated against a physical one, as a base for the reinforcement learning to learn in simulation environment. A satisfactory model was achieved, accurately modeled the static behavior of the system but lacks some dynamics. A Deep Q-Network agent was used which successfully managed to select optimal combinations for given loads when implemented in the physical test rig, even though the simulation model was not perfect. Gear selection reinforcement learning machine learning DQN neural network multi chamber cylinder Digital hydraulics hydraulics Matlab Simulink Hopsan hydraulic system validation Other Mechanical Engineering Annan maskinteknik
12	Hardware-in-the-Loop Simulation of Aircraft Actuator Braun, Robert January 2009 (has links) <p>Advanced computer simulations will play a more and more important role in future aircraft development and aeronautic research. Hardware-in-the-loop simulations enable examination of single components without the need of a full-scale model of the system. This project investigates the possibility of conducting hardware-in-the-loop simulations using a hydraulic test rig utilizing modern computer equipment. Controllers and models have been built in Simulink and Hopsan. Most hydraulic and mechanical components used in Hopsan have also been translated from Fortran to C and compiled into shared libraries (.dll). This provides an easy way of importing Hopsan models in LabVIEW, which is used to control the test rig. The results have been compared between Hopsan and LabVIEW, and no major differences in the results could be found. Importing Hopsan components to LabVIEW can potentially enable powerful features not available in Hopsan, such as hardware-in-the-loop simulations, multi-core processing and advanced plotting tools. It does however require fast computer systems to achieve real-time speed. The results of this project can provide interesting starting points in the development of the next generation of Hopsan.</p> Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Rudder Elevator code translation multicore multi-core real-time simulation hydraulics test rig Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Höjdroder Sidoroder kodöversättning multicore multi-core realtid simulering realtidssimulering hydraulik testrig Mechanical engineering Maskinteknik
13	Hardware-in-the-Loop Simulation of Aircraft Actuator Braun, Robert January 2009 (has links) Advanced computer simulations will play a more and more important role in future aircraft development and aeronautic research. Hardware-in-the-loop simulations enable examination of single components without the need of a full-scale model of the system. This project investigates the possibility of conducting hardware-in-the-loop simulations using a hydraulic test rig utilizing modern computer equipment. Controllers and models have been built in Simulink and Hopsan. Most hydraulic and mechanical components used in Hopsan have also been translated from Fortran to C and compiled into shared libraries (.dll). This provides an easy way of importing Hopsan models in LabVIEW, which is used to control the test rig. The results have been compared between Hopsan and LabVIEW, and no major differences in the results could be found. Importing Hopsan components to LabVIEW can potentially enable powerful features not available in Hopsan, such as hardware-in-the-loop simulations, multi-core processing and advanced plotting tools. It does however require fast computer systems to achieve real-time speed. The results of this project can provide interesting starting points in the development of the next generation of Hopsan. Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Rudder Elevator code translation multicore multi-core real-time simulation hydraulics test rig Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Höjdroder Sidoroder kodöversättning multicore multi-core realtid simulering realtidssimulering hydraulik testrig Mechanical engineering Maskinteknik
14	Simulation and Testing of Energy Efficient Hydromechanical Drivlines for Construction Equipment Larsson, Viktor, Larsson, L. Viktor January 2014 (has links) Increased oil prices and environmental issues have increased a need of loweringthe emissions from and the fuel consumption in heavy construction machines. Anatural solution to these issues is a lowered input power through downsizing ofthe engine. This implies a demand on higher transmission efficiency, in order tominimize the intrusion on vehicle performance. More specifically, alternatives tothe conventional torque converter found in heavier applications today, must beinvestigated. One important part of this is the task of controlling the transmissionwithout jeopardising the advantages associated with the torque converter, such asrobustness and controllability.In this thesis, an alternative transmission concept for a backhoe loader is investigated.The studied concept is referred to as a 2-mode Jarchow power-splittransmission, where a mechanical path is added to a hydrostatic transmission inorder to increase transmission efficiency. The concept is evaluated in computerbased simulations as well as in hardware-in-the-loop simulations, where a physicalhydrostatic transmission is exposed for the loads caused by the vehicle duringvarying conditions. The loads are in turn simulated according to developed modelsof the mechanical parts of the vehicle drive line.In total, the investigated concept can be used instead of the torque converterconcept, if the hydrostatic transmission is properly controlled. The results alsoshow that there is a high possibility that the combustion engine in the backhoeloader can be downsized from 64 kW to 55 kW, which would further increase thefuel savings and reduce the emissions. hydraulic power-split hydrostatic PST HST mechatrinics oil volvo backhoe transmission harware-in-the-loop simulation hopsan control PID feed forward HWIL fluid power Hydraulik power-split hydrostat PST HST mekatronik olja volvo backhoe transmission harware-in-the-loop simulering hopsan reglering PID framkoppling HWIL Other Mechanical Engineering Annan maskinteknik

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