Stanford APM:Plane Overview. Trent Lukaczyk April 7, 2014

Transcription

1 Stanford APM:Plane Overview Trent Lukaczyk April 7,

2 The Problem Fly Autonomously Airframe State Algorithm Processing Control Ground Monitoring 2

3 The Components Autopilot Unit Wireless Telemetry Remote Control Radio GPS Radio Compass Magnetometer Airspeed Sensor BaKery Monitor Servos, ESC, Motor 3

4 Autopilot Unit Auto Pilot Module (APM) ArduPilot Mega (APM) 2.6 Based on Arduino 16MHz Atmega2560 processor 16 MB dataflash memory ~ 2hours of logging (download owen) Needs: to point forward to be securely akached accelerometer calibra@on if relocated 4

5 Wireless Telemetry Wireless Telemetry 915 MHz, 100mW Shares a NetID MAVLink Protocol 5

6 Wireless Telemetry USB Micro B DF13 6- Pin DF13 5- Pin USB A 6

7 DF13 Connectors LiC this lip gently with a screwdriver Can shave these hooks off with a knife Pain and a Half to use Easy to break But small, reconfigurable Be careful when disconnec@ng! 7 Can add hot glue at the wire- connector joint. Do not use super glue here.

8 Radio Control Setup RC TransmiKer, 2.4 GHz Binds with Receiver Always carry the bind plug Four axes + mode switch Turn on first, before plane Autopilot Mode Switch 8

9 Radio Control 3pin Servo Wires x5 9

10 Radio Control Setup Autopilot Mode Switch The order of these vary with receiver 10

11 Servo Wires Mixing up signal and ground can fry electronics Look for markings like this - 11

12 GPS + Compass 1.57 GHz GPS radio 5Hz posi@on update Needs clear sight of sky Magnetometer Provides heading es@mate Needs to be clear of high- current electronics Needs: to point forward calibra@on if relocated 12

13 GPS and Compass DF13 6pin GPS DF13 4pin MAG DF13 4pin DF13 5pin 13 Remember to point GPS and APM forward

14 Airspeed Sensor Pitot tube measures difference in and Total pressure, which is related to airspeed. Airspeed is to wind will be higher or lower if you travel against or with the wind 14

15 Airspeed Sensor Silcone Tubing 3pin Servo Wire A1 15

16 Power Module Records current and voltage from bakery Integrate for energy usage, and bakery level Powers APM, Receiver, Radios, and Servos 16

17 Lithium Polymer BaKeries 3.7 Volts per Cell Metrics: N- Cells (2S = 2 Cells = 7.4V) Capacity (C = 1100 mah) Discharge Rate (25C = 27.5A) Charge Rate (2C = 2.2A) Can catch fire or leak during charging Always be present during charging Capacity loss or Bricking if over- discharged i.e. leaving plugged in over night 17

18 LiPo Discharge LiPo s die suddenly around 3.4Volts/Cell Be ready to land around 3.5Volt/Cell Higher Current 18 traxxas.com

19 Speed Controller Rated by Max Current and Max Voltage Direct Current Power in, Three- phase Current out Opto vs BEC BEC can power RC gear, Opto can t 19

20 Brushless Outrunner Motor Outrunner - magnets rotate around stator Rated by kv = no load rpm/v High kv = fast rpm, low torque Low kv = low rpm, high torque Too much power melts windings, burns out motor 20

21 Power Electronics Setup DF13 6- Pin DC Power DC Power 21 3 Phase AC

22 Carbon Folding Props More rigid, more efficient, more expensive (vs props) More dangerous they are spinning knives Spinner cap lets them fold on landing, or if motor braking is on (more efficient glide) 22

23 Servos Drive Motor + Rota@on Sensor + PID Control board in 8- grams Forcing the control arms by hand wrecks gears 23

24 Servo Setup Elevator Rudder 3pin Servo Wires Ailerons Servo Wire Y ThroQle 24

25 The Components Autopilot Unit Wireless Telemetry Remote Control Radio GPS Radio Compass Magnetometer Airspeed Sensor BaKery Monitor Servos, ESC, Motor 25

26 Telemetry Ploqng Two types of logs Telemetry log Dataflash log store at higher log- rates Download from APM over USB Cable Mission Planner can dump matlab data files 26

27 The Problem Fly Autonomously Airframe State Algorithm Processing Control Ground Monitoring 27

28 Resources FliteTest: youtube channel DIY Drones: forum RC groups: forum GrabCAD: community CAD models 3DRoboVcs: Store and Manuals GitHub: Stanford_ArduPlane Code 28