Ati Industrial Automation, Inc.

David Fleissner

Andrew Glusiec

In a Force/Torque sensor employing strain gages, a hardware temperature compensation procedure substantially eliminates thermal drift of a plurality of load-sensing strain gages with changes in temperature, using trimming resistors and a single, unstressed strain gage. The strain gages are connected in a quarter-bridge configuration, in multiple parallel stages. An unstressed strain gage in quarter-bridge configuration is connected in parallel. Trimming resistors are added across one or more of the unstressed and load-sensing strain gages in a compensation procedure that substantially eliminates thermal drift of the load-sensing strain gages over a predefined temperature range.

Quarter-bridge temperature compensation for force/torque sensor

Strain gages on a robotic force/torque sensor are individually temperature compensated prior to resolving the gage outputs to estimate force and torque loads on the sensor. Thermal sensors are mounted proximate each strain gage, and the initial gate and thermal sensor outputs at a known load and temperature are obtained. The force/torque sensor then undergoes warming, and strain gage and thermal sensor outputs are again obtained. These gage and thermal sensor outputs are processed to calculate coefficients to a temperature compensation equation, such as by using a least squares algorithm. Each strain gage output is compensated using the temperature compensation equation, and the temperature-compensated outputs of the strain gages are then combined to resolve temperature-compensated force and torque values.

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Cary, NC, United States of America

David Fleissner