This article has for purpose to explain to you how works the FT-300S and how the calibration is done.
Knowledge
How does the FT-300S work?
Our force sensor, FT-300S, measures mechanical deformation using electric capacitor electrical capacitance.
In this image, you can see the inside of the FT300-S. The plate with the "start" like shape deforms when a force is applied to the force sensor. Then the distance between the plate and the PCB varies. The distance variation changes the electric capacitance which is measured by the PCB electronics.
This is a solution to measure mechanical deformation through capacitance.
The force is calculated from the measured deformation.
To make it short:
- Force sensor calculate force and torque from mechanical disformation
- FT-300S measure deformation through a capacitance measurement system.
How does the calibration work?
The calibration routine saves the information permanently in the sensor so it will be taken into account during the next start-up. Calibration, therefore, makes it possible to:
- Estimate the mass and position of the center of mass (sensor + tool), then compensate automatically
- Cancel the effect of the forces due to the screwing of the sensor
- Save this information in the permanent memory of the sensor
The "Zero sensor" allows you to add an additional and temporary offset which normally compensates for the drift of the signal and must be used in the robot program just before the task which needs the sensor data (ex: find surface, insert, etc.).