Georgia Institute of Technology Marquette University Milwaukee School of Engineering North Carolina A&T State University Purdue University University of California, Merced University of Illinois, Urbana-Champaign University of Minnesota Vanderbilt University STUDY OF AN ARTICULATED BOOM LIFT BY CO- SIMULATION OF BODIES FLEXIBILITY, VEHICLE DYNAMICS AND HYDRAULIC ACTUATION Céline Cabana, Technical Account Manager FD-GROUPS America, Inc. www.fd-groups-america.com Study by A. CHAIGNE, Haulotte Group And G. JAUSSAUD, FLUIDESIGN Group Fluid Power Innovation & Research Conference Minneapolis, MN October 10-12, 2016
Introduction Imagine.Lab Amesim study performed on hydraulic systems Observed gap between virtual model and actual machine Need for Co-Simulation in order to create a more reliable model
Study performed in cooperation with Haulotte Group is one of the world leader in lifting technology. They design and manufacture a large range of products from aerial work platforms to articulated boom lifts. FLUIDESIGN Group offers multi-domain 1D & 3D simulation services. We also designs and manufactures custom hydraulic components in small and medium series.
NEW DESIGN -New Kinematics Substantial risks: Longer and higher-reaching boom Backward stability of the machine
Modeling Strategies Hydraulic model Imagine.Lab Amesim Objectives: Confirm sizing of hydraulic components Validate component choice Verify hydraulic and mechanical stability Content: Kinematics Hydraulic schematics Hydraulic components Controls Contact wheels/ground Mechanical model Virtual.Lab Motion Objectives: Analyze kinematics Confirm dynamic stability Define movement control Calculate stresses in the connections Content: Kinematics Rigid and deformable bodies Fit in the connections Ground contact
Model Imagine.Lab Amesim CAD Import from STEP files Kinematics 3D Joints Actuation 3D jacks, Hydraulic jacks Power hydraulic system and components Solving Robust, accurate Postprocessing 1D / 3D Model «High Part» Unalterable Solids: (mass, inertia, CoG, Kinematic connections) Connections with contact forces Actuator 3D Hydraulic actuation Hydraulic circuit (feed) Super components Complete Model Parts Chassis Contact wheel/ground Behaviors on the road Oscillating axle Hydraulic transmission circuit
Model Imagine.Lab Amesim -OUTPUTS CAD Import from STEP files Kinematics 3D Joints Actuation 3D jacks, Hydraulic jacks Power hydraulic system and components Solving Robust, accurate Postprocessing 1D / 3D Model «High Part» Verification of the kinematic and dynamic of Boom Lift - Compensation - Speed and accelerations in the bucket => Validation of the hydraulic control Complete Model => Verification of the vehicle stability (without tipping) => Validation of the transmission => Validation of the compensation by the oscillating axle
Model Virtual.Lab Motion CAD Create in VL Or import Kinematics Joints Constraints Initial conditions Dynamics Forces (Gravity, Stiffness, Damping, loads,..) Flexible bodies Craig-Bampton or test deformation modes Solving Fast, Robust, Accurate Postprocessing 2D / 3D Simple model: Simplified representation Perfect kinematics links Mass & Inertia from CAO Dynamic results Advanced model: Parts distortion Mode reduction (Craig Bampton) Recovery of the Ansys data Ansys solver control Contact wheels/ground Fit in connections
Virtual.Lab Motion Co-Simulation Linkage between mechanical and hydraulic models Validation that models in each of the tool are linked Model AMESim mechanical + hydraulic : long calculation time due to the frequency difference between physics Model paired AMESim+VLAB Motion : reduction in calculation time Control Input Control Nodes AMESim Control Output
Co-Simulation Counterbalance Valve Virtual.Lab Motion Kinematics Angle sensor Link wheels/ground Flexibility parts Profile % opening/angle sensor Spool stroke PVG
Boom Lifting Profile Criteria: Normal: Vertical speed close to 0.4m/s Felt: Bucket speed felt to be as constant as possible Safety: Low Speed in the final approach Mechanical curve Hydraulic curve
Pumping Description: Risk not anticipated & not seen in the Imagine.Lab Amesim model At the end of the lifting, when the piston touches the cap end, pressure is at its maximum The balancing valve «retains» this pressure In the descent movement, this pressure is released and destabilizes the system The phenomena is magnified during the descent Evaluation of different solutions: Increasing cylinder Modification ratio counterbalance valves Throttle of return Descent controlled in pressure Depressurization Two possible solutions retained Spools control before the release of the prototype First trials consistent with model
Conclusions Results Enhance system safety Time saving in fine-tuning Time reduction in development Guarantee in the reliability of the system Help to make decisions Powerful engine for on-going innovation Perspectives Systematize modeling Components library Integration to the development process Integration of the controllers (SiL / HiL) in the co-simulation process => Creation of a virtual prototype