Ground Station Setup For Converged IoT Platform

Antenna Cluster Planning

The mission scenario sketch example with Blender 3-D modeling is in the picture on the right. The small matchbox at the lower left corner is the base station. And, based on the mission scenario, the RF-control/FPV antennas are arranged to prevent internal interference and obstructions.

RF Transmitter Setup

The alternative micro sized transmitter module wiring pictured here.

The alternative Frsky R9M module can be set to output 500mW using alternative Taranis QX7's transmitter's regular power pins without external power source, as shown in this video,

This flight sequence rehearses the mission plan, diving from 330 feet east, 440 feet north, ground distance 550 feet, air distance 1000 feet, relative to ground station. 3 flips above the landing patch area. Level traversal between 330 feet east, 440 feet north, and 330 feet straight east.

Video Receiver Setup

In-Car Battery Charging

Fight batteries should be warmed/cooled with car vent before charging in cold/hot temperatures. When the car engine is offline, the car battery voltage has a slight drop, so the flight battery charger needs to be set to output 1A maximum, to prevent low voltage cut-off during charging.

FPV Feed Flight Path Tracking

The raw FPV DVR recorded mp4 of the tail-spin crash with fishbowl optical illusion is saved at googledrive https://drive.google.com/file/d/1IchzErZsqhmW0qukS_ZLuJz3CpO4A27t .

When viewed in Android MX Player or the FPV headset, the last 3 frames used to track down the wreckage is not available frame-by-frame. A laptop or Chromebook with Avidemux.AppImage is needed to step in the last 3 frames. 

Blade 180 - Oxy 210 Rotor Characteristics

Product source is ebay seller amain. Item "OXY2-081 OXY Heli Plastic Main Blade 210mm (Orange) (2)"

The airfoil profile is (NASA predecessor)NACA0015. The symmetrical airfoil is generally known to have the center of pressure CP at quarter blade width from the leading edge during cruise flight when the attack angle is smaller than 2-3 degrees in the research paper. As shown in the picture below, the CP point is at 17.5mm/4 = 4.375mm from the leading edge but the bolting is at 4.3mm, so, when the attack angle is very small, it has perpetual pitch suppression. The research measurement also shows that the airfoil has perpetual up-pitching torque at a cruise attack angle of 6 degrees because of the "center of pressure moving forward of the quarter chord". 

When the mechanical margin of error is added between the actuator servos and the actual blade position, the blade angle shifts as the following timeline.


This means that a large slop gap can result in an unstable craft. And in the above example depiction, the slop should be improved from 3.2 degrees to 3 degrees to escape the perpetual pitch suppression slump. And to avoid over-correction, the slop needs to be smaller than 2.1 degrees.