DYNAMIC CAMERA STABILIZATION SYSTEM

Reegan Worobec & David SloanIn collaboration with UAARG

WHAT IS IT?

WHAT IS IT? An additional system intended to

enhance the image processing capabilities of UAARGs UAV

A dynamic stability controller that updates its position in real time based on aircraft pitch and roll

Has the potential to track ground targets given their GPS coordinates

WHAT DOES IT DO? Stabilizes a camera platform relative to

ground independent of aircraft pitch and rollGathers sensor data from an onboard GPS

and IMU (Inertial Measurement Unit) and stabilizes a camera platform by means of a pair of servo motors

OUR GOAL Develop a system utilizing an FPGA Keep platform stabilized

Read GPS data, send positional instructions to servo motors to adjust platform

GPS point trackingSet camera angle at fixed location as

opposed to relative ground plane

ACTION!

HOW DOES IT DO THIS? The IMU takes measurements at a rate of 50Hz and

calculates required servo positions This information is then forwarded to the PWM

controller to update the servo motor positions It constantly polls for these updates, sending speed

calibration data from the GPS to the IMU, and adjusts camera angle

HOW DOES IT DO THIS? (con’t) Essential Matrix math

Normalize input vectors (frame orientation, and gimble orientation)

Project onto the frame servo’s rotational plane Calculate first servo rotation Transform frame orientation with new servo

position Project onto the second servo’s rotational plane Calculate second servo rotation and update servo

positions GPS parsing*

Reads in NMEA sentences and parses for relevant information

*Function completed in a desktop environment but not implemented in demo project

THE FPGA The initial design utilized an

FPGA as a reconfigurable microcontrollerCommunicates with Inertial Measurement

Unit (IMU), GPS, Flight Computer, and two servo motors

Sends information to servos via PWM controllers

SYSTEM VIEW (WITH FPGA)

UART SERIAL

UART SERIAL

UART SERIALGPS STREAM

FLIGHTCOMPUTER

USB TO SERIAL MicroBlaze

PWMCONTROLLER

SERVO ROLL

IMU

SERVO PITCH

OPTO-ISOLATOR

OPTO-ISOLATOR

Interrupt Controller

FPGA

SERVO CONTROLLER

INTERRUPT CONTROLLER

OUT <= IN1 or IN2 or IN3 or IN4

GPS INVOLVEMENT GPS information is fed through a UART

connection as a continuous stream We have parsing routines written to extract vital

information we need for the microcontrollerFix (Latitude/Longitude) converted to radiansAltitude [m]Speed [m/s]Speed bearing (direction of travel)

NMEA sentence:$GPGGA,123519,4807.038,N,01131.000,E,1,08,

0.9,545.4,M,46.9,M,,*47

OBSTACLES Difficult development environment to

interface our componentsUnfamiliar environment to create custom

hardware Numerous operating issues with some of

our componentsTwo IMU chips became unusable

○ one DOA, and a second spontaneously shortedFPGA breakout board came with pins un-

soldered

SYSTEM VIEW (WITH PROPELLER)

PROPELLER CHIP

GPS STREAM

FLIGHTCOMPUTER

USB TO SERIAL

SERVO ROLL

IMU

SERVO PITCH

OPTO-ISOLATOR

OPTO-ISOLATOR

SOFTWARE FLOW DIAGRAMMAIN

IMU HANDLER (CORE 1)

FLIGHT COMMUNICATOR (CORE 6)

UART (CORE 2)

GPS_HANDLER (CORE 6)

SERVO_API (CORE 0)

MATH_lib (CORE 0)

IMU BACKUP HANDLER (CORE 1)

SERVO Y

OPTO-ISOLATORS

ACC/GYRO

ADC

IMU

SERVO CONTROL (CORE 5)

FPU (CORE 3|4)

SPI_ADC (CORE 2)

UART (CORE 7) GPS SERVO X

FLIGHT COMPUTER

slow UART(CORE 6)

or

QUESTIONS?