The String Encoder Module
Entry ID #: 1421
Created: Mon, Jan 12, 2015 5:16 PM
Many teams in the Skyrise Competition require an effective method for measuring the displacement of one or more parts of their robot. Specifically, teams are looking for a method for measuring the height of their lift, or each side of their lift. In competition, it is not an uncommon sight for a scissor lift collapse sideways into a slinky, or to see a Linear Lift jam because the two sides did not travel in unison. The String Encoder solves this problem, by allowing teams to consistently measure how far any part of the robot travels. The string on the sensor is attached to any part of the robot. As the string is pulled, it turns the spool and its axle, which is read by the encoder module at the back of the sensor. A Power Spring is used to retract the spring when it is not being pulled. This would be particularly useful on scissor lift robots, because a pair of String Encoders would give an accurate reading of how high each side of the lift has gone. Programmers could use these measurements to make the lift automatically correct itself, thus preventing it from leaning sideways and bending out of shape. Being able to measure height of a complex lift is very valuable, but cannot be accurately done with conventional encoders or potentiometers. The design process of this model used AutoCAD 2014 to design individual parts, and Autodesk Inventor Professional to assemble the pieces together and color them. The encoder module and the mounting pieces were re-used from the Integrated Encoder Module and the 393 Motor Module, respectively, to save money when producing this product. Because it uses the preexisting Integrated Encoder Module, the String Encoder is easily compatible with 12C hardware, and can already be read by RobotC and EasyC. Little to no modification to the Cortex, Firmware, and Programming Utilities is required to allow use of the String Encoder.