Abstract
Team Members
•  NATCAR is a 1/10 scale autonomous vehicle competition, which
requires the vehicle to navigate an unknown course while maintaining
a high speed.
Prairie Barger – EE – Archivist, Funding Manager
•  The course itself will be marked with wire carrying a 100mA 75
kHz signal and reflective white tape which will be sensed using
magnetic field sensors and optical sensors.
•  The sensors will be incorporated into a control system which must
be integrated into the vehicle to control both velocity and steering
position simultaneously.
Software Specifications
•  Each time the main loop starts an analog value will be read from the
magnetic sensors and sent to the Analog to Digital Converter (ADC).
•  Meanwhile the optical sensors will be read as digital inputs. Once
the ADC is finished the location data can be used in the vehicle
control system.
•  The vehicle control system will interpret the location data to
determine whether the car is on a straight or curve to select a state.
•  The state will determine the appropriate velocity and control system
to use. Each will be some variant of a lead-lag or PID controller.
•  Separating the states allows the control system to be optimized for
the current scenario.
Matt Carr – EE – Hardware Manager
Stephan King – EE – Team Leader, Software Manager
Software Block
Diagram
Competition Requirements
•  Car must use custom DC-DC converter and motor driver
•  Wheels less than 4.25" diameter and 2.5" width
•  Wheel base must have: length ≤ 14 inches width ≤ 14 inches
•  Car must have height ≤ 9 inches
•  Car must have rigid flag to trigger timer and double as an emergency
stop
Engineering Requirements
•  Measure displacement from the track to within ½”
•  System must have zero steady state error.
•  System must have a setting time of less than 2 seconds.
•  System must Measure speed of car
•  The motor should be a DC brushed motor capable of outputting 50W
•  The battery should hold at least 2700mAh of charge, capable of
outputting 7A, and cost less than $30
Hardware Block
Diagram
Hardware Specifications
•  A single battery supplies power to a DC-DC convertor which will step
the voltage to the proper level that the PIC, sensors, and actuators of
the car need.
•  The sensors of the car will pass a signal to the PIC telling the
position of the car in reference to the track.
•  The PIC then outputs a Pulse Width Modulated (PWM) signal to the
steering servo which will steer the car in a desired direction.
•  The PIC also outputs a PWM signal to the H-Bridge motor driver that
can drive the motor in forward or backward motion based on the signal
it receives.
• 2010-2011 Senior Design Capstone Project • Dr. Hartley & Dr. Tran, Faculty Advisor • Gregory A. Lewis, Senior Design Coordinator • Department of Electrical and Computer Engineering • College of Engineering • University of Akron •