Calibrating a Rotary Torque Sensor Using the Teensy and ADS1256
From Matt Bilsky
As part of my snake-like robot project I have been developing a lot of gear boxes that are the smallest, strongest gear boxes on the planet. These are designed to take input torques in the milliNewton-meter (mNm) range and multiply them by upwards of 1000x to get Newton-meter (Nm) scale outputs.
Measuring mNm torque is extremely difficult because the values are so small. I have used resultant torque dynamometers (more details will follow in a later post) but they struggled to accurately measure the small torque values.
To solve this, I purchased a rotary torque sensor from Alibaba that directly measures the torque being transmitted.
This video and tutorial discusses how to calibrate a rotary torque sensor for small-scale measurements using a flywheel system. The output of the sensor is read using a Teensy microcontroller and the ADS1256 Analog to Digital Converter (ADC).
I also discuss the accuracy of the sensor and demonstrate how it is determined by analyzing the noise in data collected.
Amazon affiliate links (same price for you, small kickback for me):
The Arduino/Teensy code is available on GitHub here: https://github.com/mbilsky/teensy_ads1256_quadrature
Follow the guide and tutorial in my video on setting up a Teensy and the ADS1256.
More details about the Teensy Quadrature Encoder Library are available here: PJRC Forum
I plan on releasing a video on how to work with Quadrature encoders and the Teensy at a later time. To use the encoder library you will need to add the files to an appropriate folder in the Arduino libraries folder.
The Excel worksheet I used to calculate the moment of inertia of the flywheel is available here: Rotary Torque Calibration Excel Worksheet