Automated Bridge Scour Inspection FSU/FAMU College of Engineering Team 7 Detailed Design Review and Test Plan 2/8/2011

-Vertical DC motor -Motor Controller -2 SLA Batteries  -MicroController -Sonar -NiMH Battery -Tilt Servo -Circular DC Motor   Vertical Guide Rail Circular Rail 

Vertical Motion Drive Design Updates: Revised gearhead selection Previously a 28:1 Ratio Now a 26:1 Ratio Trade-off: Availability vs. Over-specification Comparable Performance: Slightly slower ascent Moderately higher percentage of motor output ability

Vertical Motion Drive Design Updates: Revised encoder selection Previously using Magneto-Resistant (MR) Now using Optical Trade-off: Availability vs. Cost Comparable Performance: 500 CPR vs. 512 CPR

Vertical Motion Drive Mechanical Test Plan: Part One: Confirm rated no-load output velocity Measure angular velocity with tachymeter Part Two: Prior to full integration, simulated mass lift Confirm loaded output torque ability Protect components prior to integrated test

Circular Motion Drive Design Updates: Unchanged Motor/Encoder/Gearhead Revised drive-surface interaction Previously: Geared drive-surface on guiderail Now: High-friction contact drive Trade-off: Manufacturability vs. Precision

Circular Motion Drive Mechanical Test Plan: Part One: Confirm rated no-load output velocity Measure angular velocity with tachymeter Part Two: Prior to full integration, full-speed revolution Confirm loaded output torque and velocity Protect components prior to integrated test

SONAR Tilt Servo Drive Design Updates: Unchanged Servo Motor selection Low risk of failure under load Focus on adequate positioning

SONAR Tilt Servo Drive Mechanical Test Plan: Prior to SONAR integration Simulate moment arm to represent transducer Demonstrate loaded angular range of motion Confirm inspection range capability

Vertical Motion Updates Material Aluminum vs Stainless Rollers Drivers Idlers Bearings Size Constraint

Bearings and Rollers

Circumferential Motion Updates Material Design Driver Idlers Expectations

Circular Guide Rail Changes Size and Shape Material Connection Manufacturing Ideas Simplify

Testing Vertical and Circumferential Motion Degrees of Freedom Waterproofing Step by Step

Electrical Design Updated Plan- Use two Battery sources Higher-Power →Motor Controller,DC motors Lower-Power →Microcontroller,servo, sonar

Higher-Power Design Battery →Sealed Lead Acid Battery (SLA) - Most likely will be 12 Volt, 3 Ahr SLAs - Will need 2 of these to make 24V in series Fuse and Switch on positive battery wire to motor controller

High-Power Design Why use Volt 3Ahr Battery? The Vert. DC motor → 24V ~3A continous Running for < 3 minutes for a final test run. The Circular motor → 12V ~300mA cont. Running for < 10 minutes for a final test run.

# of Test Runs Amps Drawn by Vert. motorAmps drawn by circ. motorTotal Ahr 1<3 min... 3/60 * 3A=.15Ahr<10min...10/60 *0.3A=.05 Ahr Estimate Current Draw per Test

Lower-Power Design Battery → NiMH MicroController needs 5V ~500mA..Max 2A Voltage regulator to get constant 5V May need heat sink Power to servo and sonar sensor as well Battery size depends on final servo, sonar choice. Neither should be current demanding components

The Beaglejuice $ mAh battery 5V output 1.5A current delivery powers a BeagleBoard for at least 6.5 hrs on/off switch Possible option for battery source, mounts below the microcontroller, space saver

Microcontroller Version: XmVersion: rev. C4 1 GHz ARM Cortex A8 600MHz ARM Cortex A8 512MB LPDDR256MB LPDDR 4 USB1 USB RS-232 Serial & I2C

Expansion Board Zippy2 I2C 1.8v to 5v 2 nd RS-232 port 2 nd SD slot Ethernet

Programming – Autonomous Movement Motor Controller & Motors Coding Sabertooth: In simplified Serial Mode RS-232 port Using single 8byte commands to control speed & direction of motors Each motor 7bits of Resolution Motor1: Motor2:

Programming – Autonomous Movement Encoders & Servo Coding I2C interface Encoders: Counting the leading & falling edge to determine distances Servo: PWM (Pulse Width Modulation)

Testing Autonomous Movement Program Program Simulations: I/O Signals MCU & Oscilloscope: PWM - Pulse Widths approx.: 1ms to 2ms - Period: 10ms to 2ms MCU & Signal Generator: Simulate encoder input (Square Waves)

SONAR – Control Test Humminbird HDR 650 Transducer/Display combo 2ft. – 600ft. Verify data accuracy from other transducers ~ 1.2in. Resolution 200kHz Strictly handheld; will not be connected to MCU

SONAR Transducer Furuno USA 235 kHz 7 degrees 0.04m – 100m NMEA 0183 – ASCII serial communications Sentence structure: DDBT, DDPT

NMEA 0183 Sentence Structure 8 bits 4800bps Checksum = hexadecimal; XOR of all char between $ and *

Microcontroller1$ Motor Control Unit1$ V DC Motor/encoder1$40.00 SONAR3$200.00$ SLA Battery 12V 3.2Ahr2$12.00$ V DC Motor/encoder1$ Beagle Juice (Battery)1$88.00 Mounting Materials$ Circular Ring1$ High-Friction Rollers3$1.20$3.60 Ball Bearings4$12.00$48.00 Shaft1$5.00 Square Vertical Rail1$10.00 Servo1$20.00 Wires, fuses. i.eN/A $5.00 Software Licenses$ Test Supplies$ Soldering Kit1$15.00 Robot casing and fittings $50.00 Total Cost= $