Multibody parametrized modeling of the feeding of a trunk by a harvester head

Transcription

1 Multibody parametrized of the feeding of a by a harvester head Presented by: Benjamin HATTON (IFMA / Institut Pascal) Jean-Christophe FAUROUX (IFMA / Institut Pascal) May 21, 2014

2 ECOMEF Project ( ) Goal: Eco-design of a mechanized equipment for hardwood harvesting Context ECOMEF Presentation Presentation Partners Partners Objectives Objectives Crooked Head Head 2 FUI (Single Interministerial Fund) funding : a precompetitive aimed at developing industrial products Think up innovative concepts and products for mechanized / robotized hardwood harvesting Current equipments for softwoods are not suitable for hardwoods Lumberjack: a dangerous job with poor job prospects French forest spreads being underexploited R&D Team 2 PhD thesis (innovative design / and simulation) 2,5 FTE of engineers Full-scale global demonstrator Several demonstrators for monofunctional concepts Knowledge base of hundreds of innovative concepts Many patents pending -- Energy Energy wood wood -- Timber Timber

3 Global budget ECOMEF Presentation Presentation Partners Partners Objectives Objectives Crooked Head Head M M Project partners ISI ( leader) FCBA IFMA / Institut Pascal IRSTEA France Bois Régions (Auvergne Promobois, Interbois Périgord) Comptoir des Bois de Brive Lycée Claude Mercier Accredited by ViaMeca and Xylofutur clusters Funders FUI (French state) Auvergne, Aquitaine and Limousin regions 3 Auvergne and Limousin ERDF Clermont Communauté General councils of Allier and Puy de Dôme Brive conurbation

4 IFMA: French Institute for Advanced Mechanics Engineering school founded in student engineers, 51 apprentice engineers 2387 graduates since the school was founded Staff: 115 people including 30 academic ECOMEF Presentation Presentation Partners Partners Objectives Objectives Crooked Head Head 4 researchers 3 poles: structures, machines and industrialization 1 center for technology transfer Very special relationship with the industrial network Institut Pascal UMR 6602 CNRS/UBP/IFMA created in January Sciences of engineering and systems 130 researchers / 27 engineers and technicians / 115 PhD students Team Mechanics, Materials and Structures (MMS) Materials and Structures (MS) Probabilistic Mechanics of Materials and Structures (MPMS) Machines, Mechanisms and Industrial Systems (MMSI) Synthesis of mechanisms and robots Behaviour of complex systems in real conditions Operational Excellence machines and industrial systems

5 Conifers and broadleaved trees Different morphological structures Conifers: rectilinear with small branches adapted to impact delimbing Broadleaved trees: crooked s, bigger and harder branches, hardwood ECOMEF Presentation Presentation Partners Partners Objectives Objectives Using Using softwoodsoftwooddesigned designed machines machines for for hardwoods: hardwoods: Risk Risk of of breakage breakage Crooked Head Head Yield examples Video 5 Softwood: Softwood: Fir Fir Duration: Duration: 11 min min sec sec 99 short-logs short-logs logs logs 3 Processed Processed volume: volume: m m3 Good Good quality quality Hardwood: Hardwood: Beech Beech Duration: Duration: 22 min min sec sec short-logs short-logs 3 Processed Processed volume: volume: m m3 Poor Poor quality quality

6 Scientific objectives Thesis 1: Innovation methodologies Innovation methodologies to increase by 40% the productivity of mechanized harvesting Mechanisms and agile robots Methods of innovation TRIZ / TIPS / Wois Evolutionary morphology for eco-design Thesis 2: Modeling and simulation of the harvesting process Modeling the actual behavior of machines in their environment Stability of the vehicle + tool + tree set Harvesting process optimization Flexible body (tree / vehicle) Wood/Tool Interaction Multibody dynamics ECOMEF Presentation Presentation Partners Partners Objectives Objectives Crooked Head Head 6

7 s

8 The work of Weber & Penn (1995) Recursive model: each child stem inherit its properties from its parent More than 80 parameters defining the general shape, and each level of stem General structure of each stem: tapered extrusion of a section curve along a profile Iterative definition of the profile curve: the position of (N+1)th point is determined from the position of Nth point Circular section of stems: parametrized curve (sinusoidal variation of the radius with the angle of rotation) for the ECOMEF Crooked Initial Initial model model Modified Modified model model ADAMS ADAMS import import Head Head 8 Weber, Weber, J. J. and and Penn, Penn, J. J. Creation Creation and and rendering rendering of of realistic realistic trees. trees. In: In: Proceedings Proceedings of of the the 22nd 22nd annual annual conference conference on on Computer Computer graphics graphics and and interactive interactive techniques. techniques. ACM, ACM, p. p

9 Proposed modifications to generate more crooked trees Regularity of curvature: the profile curve is planar, limited to single curvature (with possible turning point) uniformly distributed along the stem Addition of a second set of curvature angles, in a plane perpendicular to the actual plane of curvature ECOMEF Crooked Initial Initial model model Modified Modified model model ADAMS ADAMS import import Head Head Regularity of stems: succession of segments of equal length Stem irregularity generated by random positioning of Pn+1 with respect to Pn 9

10 Example of generated trees ECOMEF Crooked Initial Initial model model Modified Modified model model ADAMS ADAMS import import Head Head 10 Weber & Penn Model (left) Proposed model (right)

11 Integration of the tree model into ADAMS 1. Creation of parametrized coordinates matrices for both profile and section curves 2. Creation of the curves from the matrices 3. Creation of B-splines geometries ECOMEF 4. Extrusion Crooked 5. Creation of a dialog box to modify the design parameters Initial Initial model model Modified Modified model model ADAMS ADAMS import import Head Head 11 Major limitation: no taper feature for extrusions

12 Creation and import of the 3D model For each stem ( + branches) : 1. Creation of a NURBS profile, section and scale factor curves from the points ECOMEF Crooked 2. Tapered extrusion of the section along the profile 3. Conversion of the resulting surface into a mesh (tessellation) 4. Removal of superimposed vertices Initial Initial model model 5. Selection of the open edges (non-manifold edges) Modified Modified model model 6. Creation of a face from the selected point (closed mesh) ADAMS ADAMS import import Head Head (5) 7. Export to stereolithography.stl file Import into ADAMS, conversion to.shl shell (6)

13 ECOMEF Crooked Initial Initial model model Modified Modified model model ADAMS ADAMS import import Head Head 13

14 Modeling of the harvester head Model tricks and parameters

15 Model parametrization ECOMEF Global kinematic diagram: One upper knives sub-assembly (2+2') One feed rollers sub-assembly, lateral or concentric gripping mechanism (3+3'+4+4') One lower knives sub-assembly (5+5') Crooked Head Head Simulation Simulation setup setup 1 frame - 1' fixed knife 2-2 upper mobile knives 3-3 feed rollers 4-4' roller arms 5-5' lower mobile knives 15 6 retractable chain saw 7 tilt support

16 Parametrization of each sub-assembly ECOMEF Crooked Head Head Simulation Simulation setup setup 16 Upper and lower knives sub-assemblies

17 Parametrization of each sub-assembly ECOMEF Crooked Head Head Simulation Simulation setup setup 17 rollers sub-assembly

18 Measuring fixed knife biting risk What we would like to detect (and to prevent!): -- Fixed Fixed knife knife biting biting -- Stem splitting Stem splitting ECOMEF Crooked Head Head Simulation Simulation setup setup 18 First definition (geometrical parameter α): angle between the direction tangential to the neutral axis of the and the inner edge of the v-shaped fixed knife

19 ADAMS Model Bodies 0 ground 1 frame - 1' fixed knife 2-2 upper mobile knives cylinder rod and tube 3-3 feed rollers 4-4' roller arms cylinder rod and tube 5-5' lower mobile knives cylinder rod and tube 7 tilt support 8 tree Joints X-axis revolute joint : 7/1 cylindrical joint: 20/21, 40/41, 50/51 Y-axis revolute joint: 1/2, 1/2', 1/5, 1/5' Z-axis revolute joint: 0/7, 1/4, 1/4', 3/4, 3 /4' Spherical joint: 20/2', 21/2, 41/4', 40/4, 51/5', 50/5 Actuating forces/torques: feed torques 3/4, 3 /4' gripping forces: 20/21, 40/41, 50/51 Contacts: 8/0, 8/1, 8/1', 8/2, 8/2', 8/3, 8/3, 8/5, 8/5' ECOMEF Crooked Head Head Simulation Simulation setup setup 19

20 Measuring upper knife biting risk ECOMEF Crooked Head Head Simulation Simulation setup setup 20 ADAMS implementation: building a gliding marker along the neutral axis of the Gliding & spinning marker locked to neutral axis of the Revolute joint (neutral axis) to filter the spinning movement Angle measured between Fixed marker & Gliding marker (around X axis)

21 Simulation script (ADAMS Solver commands) ECOMEF Crooked Head Head Simulation Simulation setup setup 21 Concept: some parts can be either locked in displacement or force controlled Initial state: Feed torques deactivated Feed rollers gripping forces activated and corresponding zero-speed motions activated Zero-speed motion on the tilt support Tree attached to ground First simulation step (dynamic): knives gripping Deactivation of remaining zero-speed motions (rollers gripping mechanism, tilt support), deactivation of the fixed joint between the tree and the ground Second simulation step (dynamic): gripping of the rollers Activation of the feed torques Third simulation step (dynamic): tree feeding

22 Model calibration Mass distribution: Parametrized model Impossible to set manually the inertia matrix Definition of an overall mass distribution based on manufacturer data Adaptation of the density of each part to fit the real mass Rotational speed: Force controlled simulation Need to limit the rotational speed of feed rollers Idle simulation to determine idle gradient of speed of the feed rollers Adding torsion dampers on rollers with a coefficient calculated to reach the desired idle speed (manufacturer data) ECOMEF Crooked Head Head Simulation Simulation setup setup 22 Mass Mass distribution distribution of of the the body body

23 Simulation results

24 Feeding video ECOMEF Crooked Head Head 24

25 Biting risk and velocity ECOMEF Crooked Head Head 25

26 Future work Adams model improvement Modelling shortening (variable shape): log cutting mass variation Modifying the biting risk definition: mobile knives can also bite the Introducing flexible bodies Fitting to experimental results Carrying out design studies to improve mechanical architecture Future of ECOMEF An innovative head to improve harvesting efficiency by 40% Disruptive innovation : advanced concepts of head elements Several patents under process ECOMEF Crooked Head Head 26

27 Thank you for your attention Any questions?