ELECTRONICS TELECOM STEM Teachers Summit Handout

ELECTRONICS TELECOM Seminar Overview Hour 1 – Learning –Hardware– Software Mechanical ∙ Sensing Electronics ∙ Control Hour 2 – Doing –Build robot –Develop control algorithm –Generate software Hour 3 – Integration –Testing / Optimizing –Feedback – survey Hour 4 – Krisys Race of Champions –Drag Race, Road Race –2011 STEM Teacher Summit Bragging Rights

ELECTRONICS TELECOM Hardware Mechanical –1 Base – 8”x8”x1/4” –2 DC motors with brackets –2 Wheel hubs –2 Rubber wheels – ¾” width x 3” diameter –1 Ball bearing third wheel Power –7.4V Lithium-Ion battery

ELECTRONICS TELECOM Questions Empirical data provide the following information for a 7.4 V battery directly connected to two Krisys Robot motors –Total resistance is 12 ohms –Each motor turns at a rate of 240 Rev/min Determine the following –Diameter of robot wheel: ______________ –Speed of robot in MPH: ______________ –Current draw of robot in mA: ______________ –Capacity of battery needed for 30 minutes of operation: ___________ –Distance robot could travel on fully charged battery: _____________

ELECTRONICS TELECOM Algorithm Three sensors –Left, Middle, Right –Active low output => “0” when signal present –Calibrate to provide different output combinations –Develop control strategy – first pass LMRPositionActionMotor PWM 101On lineStraightL = R

ELECTRONICS TELECOM State Machine Controller NAME ACTION TRANSITION INPUT

ELECTRONICS TELECOM Revised Control Strategy LMRPositionActionMotors PWM Duty Cycle * * PWM Duty Cycles are first pass estimates and should be optimized

ELECTRONICS TELECOM Revised State Machine

ELECTRONICS TELECOM Systematic Testing and Debugging Do you have control of the wheels? Are you receiving correct information from the sensor board? Have the devices been properly interfaced?

ELECTRONICS TELECOM Take Away Are you interested in using Krisys in your class? Provide ten cool ideas to leverage Krisys robot for STEM teaching and outreach Receive a Krisys robot kit –Must assemble both KSB and KMCB PCBs Five kits are available

ELECTRONICS TELECOM Outreach Kit Wiki Build Expand Contribute

ELECTRONICS TELECOM Optimum Algorithm What is this worth to you? If all robots use the same code, what will the results of the race be? Would adding more sensors improve the control process? How would you improve your robot’s racing ability? What factor(s) should be held constant to have an “open” race?