What it is

Project voodoo is a motion control system designed for RC planes. The idea was to explore an alternative method to control RC planes, and design the whole system around it.


Here are the four components of the project -

What it does

How it started

I have always liked building gliders and planes. For this project we wanted to explore and build a different type of controller to fly them.

A video by MIT on control system of F-22 served as trigger and inspiration point for the project

Key takeaways from the video translated in final design

• The fixed force sensitive control stick of the plane
• Software stabilization in the plane

System diagram

1. Designing the controller

Controller design started with explorations with Lego blocks. Our goal was to get an idea for dimensions and explore various grips. After selecting some of the ideas we user tested them and choose one.

Development and explorations

CAD and 3D printing

I always get fascinated by smooth surface on back of my Ipad mini 2. On later exploration I learn about surface continuities and G1,G2,G3 curves. Here is my attempt to make a smooth form which melts into your hands.

Final protoype

The final prototype is processed 3D printed part. The process of sanding, primer and paint was used for final finishing.

2. Designing the Alpha module

This is a module which will record the gyroscopic data and the altitude. It contains an Inertial measurement unit and a barometer. its intended use is to record the flight data of an RC airplane.

The initial design was to make it just as a data recording device but it slowly transformed to having all the necessary IO for a flight controller.

From CAD to 3D printed model

Data collection

Data plays an important role in today's world. We wanted our module to collect data so that it can be further used to improve flight. There is also a dedicated SD card slot in the module for the same.

3. LED display system

A small display on the controller was needed to find the orientation of the plane. But flying already is one the most pressure situation you can be in so we wanted to create a display system which is

Intuitive and easy to read

In harsh outdoor conditions like sunlight, night time, fog etc. A display which can be read while moving the controller, in a glance, something based on natural instincts.

Solution

We created a display system inspired from bubble in the water level. Using and moving a water level is something which we know naturally. A 3X3 grid was chosen for the final display.

Here is visualization of how it will look on the controller -

Orientation vs Display chart

Prototyping

We started the initial prototyping on wokwi.com. Our goal was to create a circuit with 9 LED's and pair them with Arduino and MPU6050. We soon realised that using traditional leds was too much of hassle in terms of wiring and coding.

So we choose NeoPixles for this project which made our wiring and code more efficient.

Circuit diagram, traditional LEDs vs NeoPixels

Trigger module

When you are already moving the controller in three axis, another movement for controlling throttle through trigger can be hard.

To tackle this problem, we created fixed, force sensor trigger inspired from fixed control stick of F-22 Raptor.

Exploded view

Failsafe switch

One of the questions when we thought about motion control was what will happen when we drop the controller by mistake. This led to realization of the need for a failsafe mechanism.

We installed a switch between trigger and force sensor. This button is needs to be pressed to control the plane. This switch also acts as reset of the controller's zero position because after long flights the zero position usually drift away

This project was done in collaboration with Ankit Kumar.

I'd like to hear what you thought about the project. Email: aksavio@gmail.com