Presentation on theme: "Presented By: Lynbrook Robotics, Team 846 John Chai, David Liu, Aashish Sreenharan, Michael Wachenschwanz, and Toshi Tochibana Available online at lynbrookrobotics.comlynbrookrobotics.com."— Presentation transcript:
Presented By: Lynbrook Robotics, Team 846 John Chai, David Liu, Aashish Sreenharan, Michael Wachenschwanz, and Toshi Tochibana Available online at lynbrookrobotics.comlynbrookrobotics.com Tech > Resources > “WRRF Presentations”
Michael Wachenschwanz and Toshi Tachibana present…
Pneumatics Can you feel the pressure Pneumatics is the use of pressurized air to achieve mechanical movement. Air tends to move from high pressure to low pressure Important note: There is no such thing as a negative pressure
Compressor Where it all starts The compressor takes air from the surrounding atmosphere and compacts it via pistons. Comes with a release valve attached to it
Pressure Switch Better safe than sorry Safety Mechanism Turns the compressor off at 120 psi and turn it back on at 115 psi
Tank The more the merrier Tanks allows more air in the system. When air is lost, psi drop is mitigated by larger tanks
Plug Valves Done for the day Releases all the compressed air in the system. Must be release manually Be sure to release the stored air when done with the system
Regulator Stay in control Regulators regulate the pressure. Uses air from input to maintain the pressure of the output Usually kept at 60 psi for FIRST competitions
Electric Valves Handling the pressure Single and double solenoid valves are used Controlled by the control board via electricity Double solenoids exposes one port to pressure and the other to the surrounding atmosphere
Actuators Use the force Actuators convert the difference in air pressure to mechanical motion Linear actuators, or cylinders, are the more common actuators. For the competition, they come in 3 bore sizes: ¾, 1 ½, and 2 inches Rotary actuators are also allowed
Notes on Actuators Force = Pressure x Area Area= pi x squared radius radius = diameter (bore) / 2 Retracting force is less than extending force
Flow Rate Valve Control the flow Simply a fitting that widen or narrows the flow path of the air Used to slow the air movement, thus slowing mechanical movement Does not take away from the net force. Must be adjusted manually
Spikes Relays Control direction. Two single pole, double throw relays. Forward = 12V to M+ and M- grounded. Reverse = 12V to M- and M+ grounded. Neutral = M+ and M- grounded, or 12V applied. H-Bridge.
H - Bridge 4 Switches. Combination of switches on to drive motor.
Electronic Speed Controllers Known as: Victors. Use Victor 884's. Control speed and direction. Uses PWM.
Pulse Width Modulation Two Types: Power Delivery Control Signal
Optical Encoders Determining Speed A. Count pulses per interval ○ Example: in 1 second, 256 pulses. Speed = 2 revolutions/second ○ Inaccurate and slow ○ Analogy: On a bicycle Mark the wheel Count passes in a minute
Optical Encoders Determining Speed B. Measure time between pulses ○ Example: time between two pulses = 3.9ms ○ Only requires observing two consecutive pulses
Ultrasonic Sensors Determine distance Send pulse of sound Measure time until echo