Cart-A-Long

Michael BigosJaret Doiron-LaRue

Richard MuiEric Wu

 

Comprehensive Design Review

Advisor: Professor Pishro-Nik

Overview• Review of Cart-A-Long• System Overview• IR Detection System• IR Sensor Data• Triangulation Data• Parts List• Demo Goals• Questions

Cart-A-Long

• Fully Autonomous Cart o Trails a user around while maintaining a distance of 4

feet• IR bracelet

• Worn by user around the ankle to inform robot of user's whereabouts

• 8 IR LEDs at 45 degrees

• powered with CR2032 batteries

System Requirements

• Bracelet should not hinder usero small, lightweight, low power 

• Battery life of robot shall be at least 2 hours• Robot should be able to carry some load• Robot shall stay within 4 feet of user• Robot should operate if user is within 8 feet• Restrictions

o User will not travel more than 3mpho Environment 

System Block Diagram

Base Construction

• Strong tensile and impact strength

• 16” width to maximize triangulation accuracy

• 5” wheels for optimal speed and torque

• 3 wheel design for easy pivoting

• Custom made aluminum motor mount brackets– Special thanks to Steve McKinley

• Modified aluminum wheels hubs

User Tracking Approach• Use geometry to triangulate position of the LEDs

o Two sweeping stepper motors with IR detectors  mounted on top

o Arduino knows stepper positions and IR readings

IR Triangulation

IR Sensor Data

IR Sensor Data

Triangulation Data

Triangulation Data

Triangulation Data

Triangulation Data

DC Motors

• Operate at about 3.3 mph (no load)

• Operate at about 2.9 mph (under load of base)

• Speed is based on pwm from arduino

• Also on input voltage

Finalized Parts List• Sharp GP1UM261XK0F IR detector• Vishay TSAL5300 940nm IR emitter• STMicroelectronics L6207N motor driver• Mercury Stepper Motor• Modern Device BBB Arduino board• PK27 Geared Motor

PCB Board Design

Schematic of the board created in Eagle 

Version 1.0 board

Things to be done• Work out method for precise robot control• Finalize PCB layout and find manufacturer• Write code for robot tracking behavior• Determine the real world specifications of robot• Create IR bracelet• Calibration method for stepper motors

FPR & Demo Day Goals  Demo Day• Fully-functional robot

o Movement algorithm• Error Checking • PCB board created

 

Questions?