ROBOTIC TIGER P

Agenda Project Goals Legacy Projects Air Muscle Info Customer Needs Specs Functional Decomposition System Flow Chart Tiger Jump Dynamics Jump Logic Morphological Chart Concept Selection (Pugh) Tentative Parts List Kinetics Testing Theoretical Muscle Force Calculations 3D Modeling Feasibility Risk Assessment Schedule

Project Goals  The project goal is to create a robot that mimics a jumping tiger both dynamically and to a lesser extent, aesthetically  The jumping force is to be provided by air muscles

Legacy Projects  P08023/ Artificial Limb I/II  P Artificial Limb III  P Process Development for Air Muscles  P Biomimetic Crab  P12029 – Biomimetic Robo Ant

Air Muscles  Rubber tube inside of a braided mesh sleeve  Pressurized tube inflates causing the mesh to contract in length  Closely mimics biological muscles

Air Muscle Contraction 28% contraction at 49psi under 29lb load

Air Muscle Fill Speed.18s to reach 28% contraction Source:

Customer Needs Customer Need Importance (1 = high)Description CN11 Can jump forward a distance equal to at least the length of its body (only 1 jump required per tank fill) CN21Use air muscles to provide jumping force CN31Lands safely without damage CN42 Is ready to jump again after landing, without user adjustment of robot body or legs CN52Self-contained (on board power sources) CN62 Portable (small enough for one person to carry) CN72 Reasonable battery life; battery charging takes hours CN83Resemble a tiger CN93Controls do not yield a noticeable delay

Specifications SpecSourceMetric Unit of Measure Marginal Value Ideal Value Preferred Direction S1CN1Horizontal Jump DistanceFeet 1*body length 1.5*body lengthUp S2CN1,2Uses Air Muscles Binary Yes S3CN3Sliding Distance After LandingInches 3 2Down S4CN4,5Self-Contained Binary Yes S5CN3,6Overall WeightLbs5025 Down S6CN3,5,6Overall LengthFeet42Down S7CN3,5,6Overall HeightFeet21Down S8CN3,5,6Overall WidthFeet1 Down S9CN8Resemble a Tiger Percent80 100Up S10CN2Regulated Air Pressurepsi<60 Down S12CN9 Total Response Time to Jump Commands Down S13CN2,9Solenoid Response Timems5025Down S14CN2,9Muscle Fill Times Down S15CN2,7Battery Life # of Jumps50100Up S16CN2,8Four Actuated LegsBinary Yes S17CN4,5 Tank can be removed in 5 min, without toolsBinary Yes S18CN1,2,3,4 Allowable error in leg measurement/adjustmentDegrees31Down

Functional Decomposition

System Connections Battery/Tether Power Runs Compressor Air Energy from compressor is stored in tanks Pressure energy is converted into motion Air Muscles and Cables Moves hind legs for jumping action Leg Mechanism function simultaneously for Jumping motion Control system Designed for system (Lab View) Sends a Output through Wireless transmitter Output Changes the state of the Solenoid Valves Tiger Jumps Forward

Tiger Locomotion Using the average cat as a model, the muscular and skeletal systems were observed to get a basic idea of what muscles are involved in a feline jump with special attention given to the front and hind legs

Tiger Locomotion  Jumping force will come from the hind legs and lower back  Front legs will be used as shock absorbers for landing as well as getting the robot in position for each jump 1st 2nd 3rd Bracing for Impact

Air Muscle Layout Concept 1 Concept 3 Concept 2

Leg Design Overhang for cable attachment

Jump Logic Power On Reset Muscle Positions to normal Wait for Go Input Command Return Go? No Contract muscle Group 1 Yes Contract muscle Group 2 Wait for landing Sensor input Hold Release Muscles No Yes

Morphological Chart

Concept Generation ComponentCheapBaselineLight WeightSturdyGroup Opinion Air Supply single tank carbon fiber tankmultiple tankssingle tank Electrical source NiMH 2000 mAH lithium ion NiMH 2000 mAH Controller push button w/ delay tethered control push button w/ delay Transport no handles handlesno handle Base plateframe and plateframeframe and plate Base Material plasticsaluminumcarbon fibersteel plastics plate, aluminum tube Leg Material plasticsaluminumcomposit tubingsteelaluminum Joint Material plasticsaluminumplasticssteelplastics Housing Cover nonefiber glassnonecarbon fiberrapid prototyping

Pugh Chart ABCDE CheapBaselineLight WeightSturdyGroup Opinion Selection CriteriaWeightRating Weighted Score Rating Weighted Score Rating Weighted Score Rating Weighted Score Rating Weighted Score cost+/-313 DATUM technical risk+/ portability+/ land safely without damage +/ air capacity+/ reuses available parts yes/no weight+/ Total Score Rank24351

Tentative Parts List  Legacy parts used to reduce cost  Clippard Pneumatic parts Material/ItemNameQTYDescription/Part Number Air TankPaintball HPA Tank13000psi compressed air 48 cubic inches RegulatorRegulator for Paintball Tank1High pressure air regulator Solenoids 24V solenoids Manifolds Air Muscles Air Hose Used to connect muscles to manifold Air Fittings Tank to manifold connections Batteries24V 2000 mAhr NiMH Battery1Existing battery pack from previous projects ChargerTenergy Smart Charger V1Existing charger from previous projects ArduinoArduino Mega 25601Mouser 782-A Wiring Various electronic connections and wires

Kinetics  MATLAB simulation will yield required forces from air muscles  Simulation consists of two portions  Take off  Free flight

A quick rough test rig was set up (see video bellow) In order to see how muscles behave under loading (deflections, Inflation speeds, max force to failure) and also get a rough idea of what kind of forces and deflections we can get out of an air muscle, Much more testing to come Blue air muscle specs: Roughly.5” deflection 32 lbs till Failure (fitting pulled out) Preliminary Testing

Test Muscle Data Tested Air Muscle Dimensions\Information Tube and Mesh ConstructedTubeMesh Muscle Identity Uncompressed Length Compressed Length Dia. at Rest Max Dia.ODID Material Type ThicknessRest Dia. Contracted Dia. Orange Mesh Silicone RWB Mesh Silicone Red Mesh Silicone Tan Mesh Silicone Blue Mesh Rubber Theoretical Calculations Calculations Muscle Identity Weave Angle (degrees) Weave Angle (radians) Pressure (psi) Dia. at Rest εF Orange Mesh RWB Mesh Red Mesh Tan Mesh Blue Mesh

Theoretical Air Muscle Calcs Source:

Theoretical Air Muscle Calcs

3D Modeling Rendering 2: Legs and tiger design in a ready to jump position. Rendering 3: Concept in a fully extended position, just after jump initiation.

3D Modeling Rendering 1: Shows the right side view of the 3D modeled concept leg design.

Design Sensitivity Diagram: Shows dimensions used in design sensitivity analysis of leg joints. D R F

Design Sensitivity

Feasibility  Battery Life (continuous use, 2000mAh 24V NiMH)  L=battery life, I=current per solenoid  Force  Simplified linear actuator model  165lbs of force for 20lb robot to jump 1.6ft

Risk Assessment RiskEffectCause Chance of Occurri ng Severity Importan ce Action to Mitigate Long Lead Time Unable to complete robot construction due to lack of certain ordered parts. Natural for some unique parts. Poor group planning 3412 Make sure to plan on ordering specialized parts promptly. Include shipping times in planning. Mismanaged Budget Could result in changes in development. Poor group planning and limited funds. 248 Exercise budget management properly. Mismanagement of Time Unable to complete some aspects of project. Poor group planning. Lack of time management. 236 Plan out all aspects of development and testing properly for allotted time. Poor Documentation Dissatisfied customer. Follow up projects would be hindered Poor documentation throughout design and testing process. 248 Continually update logs and keep track of data. Make back-ups of data. Group Dysfunction Divergent design ideas. Poor communication and decision protocol. 122 Build a decisions making system. Inadequate Muscle Displacement Lack of or sub-par jumping ability. 339 Research muscle capabilities before application. Inadequate Muscle Force Lack of or sub-par jumping ability. 339 Research muscle capabilities before application. Inadequate Air Lack of or sub-par jumping ability. 339 Test air supply options vigorously. Malfunction of Air Muscle Cables Binding or stretching of cables. Improper transmission of muscle force. Improper cable material selection. Poor design/placement of cable paths. 224 Carefully design cable pathways and be aware of binding possibility during testing. Air Muscle Contraction Timing Uneven firing of leg muscles. Poor jump coordination Improper circuitry. Poor design of calculations Properly test the programming of muscle firing.

Risk Assessment RiskEffectCause Chance of Occurring SeverityImportanceAction to Mitigate On Board Power Supply Failure of electronics to operate. Not enough power supplied from on board Test power supply. Dynamics Design Proper jump motion is not achieved. Poor leg design 5420 Take care when in design phase. Dimension Related Muscle Interference Muscles cannot expand fully causing less than full utilization of muscle potential Poor layout planning. Inadequate attention paid to design around muscles. 236 Take care when in design phase. Account for muscle expansion. Air Muscle Performance Failure Muscle tears or expands in an unexpected manner leading to poor dynamics and function Poor construction protocol. Non-uniform construction quality of muscles Take great care when constructing each air muscle to ensure quality and uniformity. Electrical Communication Failure Failure of all solenoids to release air to muscles. Extreme movement of this robot could loosen wires. Landing may also cause strong enough impulses to disconnect electrical circuits. 212 Make sure electrical connections are secure. Material FailureMaterial yielding leading to failed operation. Poor material selection/design. 326 Consider strains and stresses induced in structures when designing tiger.

Schedule MSD1Week 1Week 2Week 3Week 4Week 5Week 6Week 7Week 8Week 9Week 10 SuMTWRFS MTWRFS MTWRFS MTWRFS MTWRFS MTWRFS MTWRFS MTWRFS MTWRFS MTWRFS Meet With Guide Learn Edge Code of Ethics Customer Needs Specs Benchmarking Functional Decomp System Flow Chart Risk Assesment Morph/Pough Chart Leg Concepts Tiger Leg Modeling Jump Logic System Design Prep System Design Review Muscle Data Collection Peer Review Create Test Plans Prototyping CAD Models Bill of Materials Arduino Code Project Manag. Review