simulation of bodies' flexibility, vehicle dynamics and hydraulic ...
Transcript of simulation of bodies' flexibility, vehicle dynamics and hydraulic ...
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
Fluid Power Innovation & Research Conference
Minneapolis, MN | October 10 - 12, 2016
STUDY OF AN ARTICULATED BOOM LIFT BY CO-SIMULATION OF BODIES’ FLEXIBILITY, VEHICLE DYNAMICS AND HYDRAULIC ACTUATION
Céline Cabana, Technical Account ManagerFD-GROUPS America, Inc.
www.fd-groups-america.com
Study by A. CHAIGNE, Haulotte GroupAnd G. JAUSSAUD, FLUIDESIGN Group
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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
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Study performed in cooperation
withHaulotte 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.
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NEW DESIGN -New Kinematics
Substantial risks:
Longer and higher-reaching boom
Backward stability of the machine
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Modeling StrategiesHydraulic 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
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Model Imagine.Lab Amesim
• Model « High Part »
– Unalterable Solids: (mass, inertia, CoG, Kinematic connections)
– Connections with contact forces
– Actuator 3D– Hydraulic actuation– Hydraulic circuit (feed)– Super components
CAD
Import from STEP files
Kinematics
3D Joints
Actuation
3D jacks, Hydraulic jacks
Solving
Robust, accurate
Post-processing
1D / 3D
Power
hydraulic systemand components
• Complete Model
– Parts
– Chassis
– Contact wheel/ground
– Behaviors on the road
– Oscillating axle
– Hydraulic transmission circuit
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Model Imagine.Lab Amesim -OUTPUTS
• Model « High Part »
Verification of the kinematic and dynamic of Boom Lift
- Compensation- Speed and
accelerations in the bucket
=> Validation of the hydraulic control
CAD
Import from STEP files
Kinematics
3D Joints
Actuation
3D jacks, Hydraulic jacks
Solving
Robust, accurate
Post-processing
1D / 3D
Power
hydraulic systemand components
• Complete Model
=> Verification of the vehicle stability (without tipping)
=> Validation of the transmission
=> Validation of the compensation by the oscillating axle
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Model Virtual.Lab Motion
Simple model:
– Simplified representation
– Perfect kinematics links
– Mass & Inertia from CAO
– Dynamic results
CAD
Create in VLOr import
Kinematics
JointsConstraints
Initial conditions
Dynamics
Forces (Gravity,Stiffness, Damping,
loads, ..)
Flexiblebodies
Craig-Bampton or test deformation
modes
Solving
Fast, Robust,Accurate
Post-processing
2D / 3D
Advanced model:
– Parts distortion
– Mode reduction (Craig Bampton)
– Recovery of the Ansys data
– Ansys solver control
– Contact wheels/ground
– Fit in connections
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Co-Simulation• Linkage between mechanical and hydraulic models• Validation that models in each of the tool are linked
Control Input
Control Output
Vir
tua
l.La
b M
oti
on
AM
ES
im
Control Nodes
Model AMESim mechanical + hydraulic : long calculation time due to the frequency difference between physicsModel paired AMESim+VLAB Motion : reduction in calculation time
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Co-Simulation
Virtual.Lab Motion• Kinematics• Angle sensor• Link wheels/ground• Flexibility parts
Profile % opening/angle sensor
Spool stroke PVG
Counterbalance Valve
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Boom Lifting ProfileCriteria:
– Normal: Vertical speed close to 0.4m/s
– Felt: Bucket speed felt to be as constant aspossible
– Safety: Low Speed in the final approach
Mechanical curve
Hydraulic curve
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PumpingDescription:
Risk not anticipated & not seen in the Imagine.Lab Amesim model
– At the end of the lifting, when the pistontouches the cap end, pressure is at itsmaximum
– The balancing valve « retains » this pressure
– In the descent movement, this pressure isreleased and destabilizes the system
– The phenomena is magnified during thedescent
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
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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