Methods
In this project, we mainly use two methods....
THREE APPROACHES
Rotary Encoder Method
The principle of operation of a rotary encoder is shown in this picture (ref: Masaeli, Mohammad. (2012). Robot Mechanisms And Mechanical Devices Illustrated - McGraw Hill.)
Light is emitted by a LED and sent through tiny slits of the coding wheel. That creates a pattern that is read by a photodetector. The information is then translated into an angle.
Rotation of each of the gimbal’s axes is measured with a separate sensor.
Each encoder is coupled with a board capable of the wireless transmission of data.
Laser Snail Method
By using a laser distance meter we will be able to measure the distance to the “snail”. Knowing the shape of the snail, we will be able to map the distance to a rotation angle.
Once the angle has been measured we will send back the data through wifi.
We decided to use an Archimedean spiral as the shape of the “Laser Snail” which is not the usual spiral of choice for the regular snails :)
Multi-Camera Image Process
This approach consists of using three cameras recording from outside to each rotating colored frames of gimbal. The motion description of gimbal (including: Angle, Angular velocity) should be given synchronously through image detection and image process technique.
We split each frame of the gimbal by color splitting, then do the corners detection and get details about corners’ coordinates by OpenCV functions. Through calculation about the coordinates, we will get motion details.