Development of a Power Hardware-in-the-Loop Test Rig for Gas Hydraulic Suspension in Heavy Duty Vehicles

Abstract: In this thesis a Power-Hardware-in-the-Loop (PHiL) test rig is developed forhydro-pneumatic suspension by utilizing the physical suspension unit together with asimulated vehicle model in MATLAB Simulink. Power-Hardware-in-the-Loop is the termfor combining simulation models with power-transmitting hardware components inreal-time. This is useful when a system contains some parts that are complex and somethat are simpler to model. The simple parts of the system can be modelled andsimulated in conjunction with more complex parts consisting of physical objects. Thereason for keeping the items to be tested as physical components is their complexity andunknown characteristics that can be difficult to estimate. By utilizing PHiL, vehiclecomponents can be tested and developed without the need for the actual vehicle, whilekeeping the characteristics that the physical vehicle would bring. The process included development of a real-time enabled vehicle model, evaluation ofcontrol strategies as well as selection of hardware used for a small scale test rig. The project resulted in a functional small scale single wheel test rig. Validationexperiments confirmed that the rig produced results close to expectations. Thecommunication between the the test rig and the simulated model was accurate andshowed the potential for a full scale test rig. It can be concluded that a PHiL test rigcan be a suitable option to full vehicle testing. The vehicle model is fully customisable,so that the suspension units can be tested in various configurations of vehicles.