Advanced Remote Monitoring and Operated Recon Device. Andrew Lichenstein Kevin Jadunandan Thomas Kehr. Special Thanks. Motivation. Dragon Runner surveillance robot Extremely Durable Fast and lightweight platform ≈$32,000 per unit Objectives: Fraction of the Price(< $2500)
Dragon Runner surveillance robot
Aluminum Frame – 1/8” Aluminum Sheet
Spring Suspension System
Circuit Board and Motor Controller
Truck Bed Liner
Quick Reaction Time
Explosive and Ballistic resistance
IG42 Geared Motor
NiMH Rechargeable Packs
5" x 2" x 2"
10" x 2" x 2"
Military Style Locking Connector
Capacity = 4 AHr
Current Drain of system = 795mA
Estimated battery life ≈ 5 hrs
Battery Capacity= 4.5 AHr
Current Draw= 2300mA x 4 = 9.2 A
Battery Life = 29.3 minutes
Features our group looked for in MCU:
*PIC18F4520 Max Spec’s in ()
XBee vs. XBee Pro vs. Bluetooth Class 1
The Bluetooth was a bit to expensive and the regular XBee distance was a bit to small. This is why we chose the XBee Pro which was a good combination of both data rate and distance. We really only need 300 to 400 ft max for our application.
We originally were looking at the Copernicus GPS Module that was sold on Sparkfun, but after talking with other sources they pointed out to me the Falcom FSA03 unit. Here are the details of the unit:
One of the best features of this chips is that it has a Sarantel helical antenna which lets you orient this GPS any way you would like , so you don’t have to make it point towards the sky.
The TMP35 outputs a voltage based off the current temperature around the sensor. Using the linear equation below, we can get the temperature on our microcontroller and motors.
Temp in °C = [(Vout in mV) - 500] / 10
Using two simple voltage divider circuits to lower the voltage to a max of 5 volts, we check the battery voltage every other second. Knowing our fully charged voltage we can make an assumption on our remaining voltage as the voltage gets lower.
The GPS’s main purpose was to be sending latitude and longitude to our microcontroller so that we could use this data with our iPhone application. The GPS sends NMEA(National Marine Electronics Association) data to our MCU; here is an example of what it looks like:
As you can see the data that is sent is not an easy to read format so our MCU will parse the data needed and send to a variable that will be sent out via XBee.
Geographic Lat & Lon
Originally we were thinking of creating our own motor controller using PNP BJTs but due to the fact we wanted stability and more features we decided to buy the Sabertooth 10A Dual Motor Controllers. One of the key features that we really liked as a group was that it is a regenerative motor driver, so when the robot stops or reverses it recharges the batteries with the wasted energy. It also has over current and thermal protection which means we won’t have to worry about damaging the motor controllers.
3963.0 * arccos[sin(lat1) * sin(lat2) +
cos(lat1) * cos(lat2) * cos(lon2 - lon1)]
Decision – C#
Solution – External LCD Display