Purpose of this Presentation Drivetrain Selection o Types of drivetrains o Types of wheels o...

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Transcript of Purpose of this Presentation Drivetrain Selection o Types of drivetrains o Types of wheels o...

  • Slide 1
  • Slide 2
  • Purpose of this Presentation Drivetrain Selection o Types of drivetrains o Types of wheels o Drivetrain mechanics o Best drivetrain for your team o Maintenance
  • Slide 3
  • Ideal Drivetrain Gets your robot where it needs to be, when it needs to be there Is robust and reliable Can push/pull objects and other robots Meets your strategy goals Fits with the game Can be built with your resources Rarely needs maintenance Can be fixed quickly
  • Slide 4
  • Basics Know your resources Decide after kickoff: Speed, power, shifting, mobility Use the most powerful motors on drivetrain Dont drive of your robot WEIGH IT DOWN! Break it early Give software team TIME to work Give drivers TIME to drive
  • Slide 5
  • Wheel Types: Traction Standard wheels with varying amounts of traction, stength and weight AndyMark KOP VEX Pro AndyMark Plaction AndyMark Pneumatic
  • Slide 6
  • Wheel Type: Holomonic Special Wheels that allow the robot to achieve Holomonic motion Mecanum Omni Crab Module
  • Slide 7
  • Caster, Omni, Slide Driven Wheel + Easy to design + Easy to build + Light weight + Inexpensive + Agile - Not much power - Will not do well on ramps - Easily turned Motor(s) Drivetrain Types: 2 Wheel Drive
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  • Chain or belt Driven Wheels + Easy to design + Easy to build + Inexpensive + Powerful + Sturdy and stable - Not agile - Turning is difficult Motor(s) Driven Wheels Drivetrain Types: 4 Wheel Drive 2 Gearboxes
  • Slide 9
  • Drive Wheels + Easy to design + Easy to build + Powerful + Sturdy and stable + Many options: Mecanum, traction - Heavy - Costly Motor(s) Drive Wheels Motor(s) Drivetrain Types: 4 Wheel Drive 4 Gearboxes
  • Slide 10
  • Gearbox + Easy to design + Easy to build + Powerful + Stable + Agile* - Heavy ** - Expensive ** ** - depending on wheel type *2 ways to be agile 1.Lower contact point on center wheel 2.Omni wheels on front or back or both This is very common in FRC + simple + easy + fast and powerful + agile Drivetrain Types: 6 Wheel Drive 2 Gearboxes Check out 1114s Kitbot on Steroids Simbotics.org Resources Kitbot en esteroides
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  • Gearbox + Powerful + VERY Stable - NOT AGILE - HEAVY - Inefficient - EXPENSIVE - Hard to maintain For turning, lower the contact point on center of track wheel Sole benefit: Ability to go over things Will NOT push more than a well- controlled 6wd Drivetrain Types: Tank Treads 2 Gearboxes
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  • Tank vs. Holomonic Tank Drive 2 Degrees of Freedom Rotation Forward-back Motion Holomonic Drive 3 Degrees of Freedom Rotation Forward-back Motion Side-side Motion
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  • 4 wheel drive or 3 wheel drive + Immediate Turning + Simple Control 4 wheel independent - No brake - Minimal pushing power - Jittery ride, unless w/ dualies - Incline difficulty Drivetrain Type: Killough
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  • + Simple mechanisms + Immediate turn + Simple control 4 wheel independent - Minimal brake - Minimal pushing power - Should have a suspension - Difficulty on inclines Drivetrain Type: Mecanum
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  • http://www.youtube.com/watch?v=xgTJcm9EVnE Team 1346 Mechanum Drive
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  • > Each wheel rotates to steer + High-traction wheels + No friction losses in wheel-floor interface + Ability to push or hold position + Simple wheels - Complex system to control and program - Mechanical and control issues - Difficult to drive - Wheel turning delay Drivetrain Type: Crab/Swerve
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  • 368s Crab Drive in 2010 http://www.youtube.com/watch?v=q9uck-wRa_8
  • Slide 18
  • Game dependent Determined by wheel size and gear ratios Controllable top speed: 15 ft/sec Average 1-speed rate: 9 ft/sec Good pushing speed: 4-5 ft/sec Drivetrain Top Speeds
  • Slide 19
  • Center of Gravity (CG) o Robot mass is represented at one point o Mobility increases when Cg is low and centered o High parts = light weight o Low parts = heavy (within reason) Which is more Stable?
  • Slide 20
  • Gearboxes/Transmissions Gear ratio determines top speed and motor load Single Speed and Shifting options CIMple Box shipped in 2011 KOP 1 or 2 CIMs per gearbox 2011 4 CIMs allowed Must be greased to reduce friction
  • Slide 21
  • Belts + Dont Stretch + Can reach far - Need to buy in custom sizes
  • Slide 22
  • Chain Selection #25 + Lightweight + Easy to install + Smaller - Easy to derail - "Steches" over time #35 + Allows for slop + Minimal "stretching" + Heavy duty applications - More weight
  • Slide 23
  • Working with Chains Tensioning o Critical to keep robot from throwing chains o Must be accessible and easily adjustable o Does not need to be used on ALL chains but should be on drive systems
  • Slide 24
  • Look at other Designs! Competitions chiefdelphi.com Team websites YouTube thebluealliance.com
  • Slide 25
  • Presented by: Paul Hines John Hines Drive Types + Wheel Pictures www.AndyMark.com (FRC Supplier) Swerve Drive Revolution Custom Frame www.team221.com (FRC Supplier) Check out 1114s Kitbot on Steroids Simbotics.org Resources Kitbot en esteroides