Running a Team Robot Design Mobility Controls Competition FIRST Competition Waterloo Regional Pneumatics

●Introduction to Pneumatics ●Pneumatic Components ●Pneumatic Mechanisms ●Resources Running a Team Robot Design Mobility Controls Pneumatics Competition FIRST Robotics Competition Waterloo Regional Ian Mackenzie

● 8 years FIRST experience ● Co-General Manager for Team 1114 in 2004, winning 8 FRC awards ● Lead designer for two revolutionary FIRST drive systems (Hexadrive 2002, SimSwerve 2004) ● Specific Areas of Mentorship – Mechanical Design, Competition Strategy ● 3rd year Systems Design student at the University of Waterloo ● Current member of the Waterloo Regional Planning Committee Running a Team Robot Design Mobility Controls Pneumatics Competition FIRST Robotics Competition Waterloo Regional

Introduction to Pneumatics FIRST Robotics Competition Waterloo Regional Pneumatic Principles

Introduction

solenoid Components

cylinder Mechanisms

hose Resources

reservoir tank FIRST Robotics Competition Waterloo Regional Pneumatic Principles

Introduction

compressor solenoid valve Components

cylinder Mechanisms

hose Resources

reservoir tank FIRST Robotics Competition Waterloo Regional Why Use Pneumatics?

Introduction ● Weight – Much lighter than motors (as long as several used) Components ● Simple Mechanisms – Much easier to mount than motors – Much simpler and more durable than rack and Resources pinion ● More rugged – Cylinders can be stalled indefinitely without damage – Resistant to impacts ● Disadvantage: All the way in or all the way out FIRST Robotics Competition Waterloo Regional Pneumatics Board

Introduction

Components

Mechanisms

Resources Running a Team Robot Design Mobility Controls Pneumatics Competition FIRST Robotics Competition Waterloo Regional

Pneumatic Components FIRST Robotics Competition Waterloo Regional Compressor

Introduction ● Generates pressure of 120 psi Components ● Always run off

Mechanisms relay module, in forward Resources – Do not use to generate a vacuum! FIRST Robotics Competition Waterloo Regional Reservoir(s)

Introduction ● Up to two

● Store at 120 psi Components ● Top up before each match Mechanisms – Slow leaks can decrease pressure between pit and field Resources – Tether robot beside field to top up pneumatics FIRST Robotics Competition Waterloo Regional Regulator

Introduction ● Allows air from reservoirs Components to flow to rest of pneumatic Mechanisms system

● Resources Limits pressure in , cylinders to 60 psi FIRST Robotics Competition Waterloo Regional Pressure Sensor

Introduction ● Detect pressure in pneumatic system Components – Indicate whether system is above or below a set pressure Mechanisms – Can be calibrated

Resources ● Usually two (one set for 115 psi, one set for 105 psi) – Pressure below 105 psi: compressor on – Pressure above 115 psi: compressor off FIRST Robotics Competition Waterloo Regional Solenoids

Introduction

Components electromagnetic coil iron core spring rod Mechanisms

Resources FIRST Robotics Competition Waterloo Regional Single Solenoid Valve

Introduction ● When energized, cylinder goes to one state Components ● When de-energized, cylinder

Mechanisms always returns to rest state – When power is cut at the end Resources of the match, cylinder will return to rest state ● Each valve powered by one relay module (only in forward) FIRST Robotics Competition Waterloo Regional Double Solenoid Valve

Introduction ● One solenoid pulsed to move cylinder one way, other solenoid pulsed to move cylinder Components the other way

● Mechanisms Results unpredictable if both pulsed ● Valve will stay in either state when neither Resources solenoid energized

● Can use one relay for each solenoid or one relay and two diodes FIRST Robotics Competition Waterloo Regional Cylinders

Introduction ● Force = Pressure × Area

– Components 2” diameter piston – Area = 3.14 × 12 = 3.14 in2 Mechanisms – Pressure = 60 psi 2 × Resources – 3.14 in 60 psi = 188 lbs – Force while extending greater than while retracting ● Main decisions: Length and diameter – Diameter based on required force – Larger diameter: more force, but more air FIRST Robotics Competition Waterloo Regional Cylinder Tips

Introduction ● If you need the piston to stay extended or retracted, add a mechanical latch Components ● Be careful to ensure the

Mechanisms piston rod cannot get bent ● Hard to get locknuts/lock Resources washers in large sizes, so nuts on pistons likely to come loose FIRST Robotics Competition Waterloo Regional Flow Controls

Introduction ● Regulate flow of air into and out of a cylinder Components ● Used to control speed of a

Mechanisms pneumatic cylinder ● If used, attach directly to Resources cylinder (only one end needed)

● Seems to regulate air flowing in both directions, but one direction is restricted a little more FIRST Robotics Competition Waterloo Regional Fittings

Introduction ● Put Teflon tape on all threads to ensure a good seal Components – Do not put tape on first two threads, as it may come loose and clog up a valve Mechanisms ● Tubing attached simply by pushing it

Resources into connector – If you have a leak, try cutting off the last couple centimeters of tubing; if it is damaged, it will not seal properly – To detect leaks, put soapy water on suspect connections and watch for bubbling FIRST Robotics Competition Waterloo Regional Exhaust Valve

Introduction ● Use to release pressure (especially Components at the end of a match) Mechanisms ● Useful if you need

Resources to be able to release a grabber after a match is over Running a Team Robot Design Mobility Controls Pneumatics Competition FIRST Robotics Competition Waterloo Regional

Pneumatic Mechanisms FIRST Robotics Competition Waterloo Regional Linear Motion

Introduction ● Much simpler, easier, more durable than rack and pinion Components ● Can maintain constant force

Mechanisms Piston

Resources wires from A B Single relay solenoid P valve regulator

reservoir compressor FIRST Robotics Competition Waterloo Regional Short Rotation

Introduction ● Arm joints

● Grabbers Components

Mechanisms

Resources FIRST Robotics Competition Waterloo Regional Short Rotation

Introduction ● May want to keep joint in position at end of match (whatever position it's in) Components

Piston Mechanisms diodes

Resources wires double from relay A B solenoid valve P

regulator compressor reservoir FIRST Robotics Competition Waterloo Regional Constant Force

Introduction ● Gear shift

● Critical piston Non-critical piston Components

double single solenoid Mechanisms solenoid valve A B A B valve

P P Resources tee fitting regulator A P double B solenoid valve

pressure sensors reservoir compressor Running a Team Robot Design Mobility Controls Pneumatics Competition FIRST Robotics Competition Waterloo Regional

Resources FIRST Robotics Competition Waterloo Regional Resources

Introduction ● www.firstroboticscanada.org – Grippers, Joints galleries in 'Resources' section Components ● www.chiefdelphi.com/forums/papers.php Mechanisms – White papers on many topics

● Resources www.chiefdelphi.com – Very active and helpful FIRST forums FIRST Robotics Competition Waterloo Regional Questions?

Introduction ● Ian Mackenzie ([email protected])

Components

Mechanisms

Resources