Autopilot ImplementationSystem Set-up Experiments

This page displays my latest progress with the ArduCopter platform. The ArduCopter is an open-sourced quadrotor system that offers users both manual RC control as well as advanced autonomous flight using GPS waypoints and a ground control station (GCS).The frame is build by 3D Robotics. The kit I bought came with an ArduPilot Mega 2.5 board which can be loaded with the latest ArduCopter autopilot software. This APM 2.5 board comes with a 3-axis gyro, accelerometer and magnetometer, along with a high-performance barometer. Additionally, a MediaTek MT3329 GPS V2.0 is connected to allow the ArduCopter to receive its GPS position and navigate to GPS waypoints. Based on position commands input from the user via a remote control or the GCS, the APM 22.5 computes control commands to the individual motors. Motor control commands are sent to 4 PWM Electronic Speed Controllers. My design currently uses 4 AC2830-358 850Kv motors with 10X47 SFP Style plastic propellers. The entire systems is powered by 1500mAh LiPo batteries which give about 10 minutes of flight time.

3DRobotics Quadrotor Kit Experimental Setup

For manual control, I use a Spectrum DX7s radio transmitter. This transmitter supports 7 channels utilizing DSM2 modulation on the 2.4GHz frequency band. An AR8000 is attached to the ArduCopter to receive the commands and send them to the APM2.5 board.

For a GCS, the open-source APM Mission Planner software is used. This software acts as a GUI that supports functions such as calibrating the APM2.5 sensors, calibrating the radio receiver/transmitter signals, loading the latest ArduCopter firmware, modifying the autopilot flight parameters, creating GPS waypoint missions, and logging and monitoring telemetry. Utilizing the MAVLink software library, messages are sent wirelessly from the APM2.5 board to the GCS utilizing the 3D Robotics 915 Mhz telemetry kit.

Quadrotor Research Ground Control Station

For on-board video, a GoPro Hero 3 Black was used. This small and durable camera is lightweight and compact enough not to hinder the flight performance of the aircraft. IWeighing only 2.6 ounces, it is capable of recording 2.7KP-30 fps video, taking 12MP stills at a 10 photo-per-second rate with built-in WiFi. The WiFi allows a user to live stream video from the camera on a handheld device through a GoPro app as well as change camera modes or settings. Additionally, a 900 Mhz video receiver/transmitter system was purchased along with a lighter and cheaper 1/3 inch CCD Camera. This first person view (FPV) system was used to stream live video from the CCD camera or the GoPro to the GCS. An EasyCap D60 adapter connected the component video from the wireless receiver to the computer’s USB port.

The 3D Robotics system including the quadrotor frame, propellers, motors, ESCs, and APM2.5 board is available in a kit for around $400. Basic assembly is required which takes only a few hours. The Spektrum DX7s transmitter and receiver are available for $300. The 915 MHz telemetry kit costs $70 and the 1500 mAh batteries are $20 each. The FPV system costs $60. Lastly, the GoPro Hero3 Black is $400. The total cost of this system is around $1,200 not counting the costs of a laptop to run the GCS software. Using a cheaper on-board camera will get the total cost of the system well below $1,000.