Patent ID: 8479584

Claim:
A temperature compensation method for a force sensor, the method performing temperature compensation on the force sensor by eliminating an effect of an environmental temperature from a sensor output value that indicates an output value by the force sensor in a transient range where an output by the force sensor is unstable or in a steady range where the output is stable, and the method comprising: a preparation step of obtaining a varying pattern of the environmental temperature in the transient range before the force sensor measures an external force, wherein the preparation step includes: a first monitoring-output-value detecting step of causing a monitoring-output-value detecting unit to detect a monitoring output value indicating the environmental temperature at a predetermined sampling cycle; a threshold storing step of causing a monitoring resistance-change calculating unit to calculate a slope of the monitoring output value relative to a sampling time in a rising or falling of the transient range, and to store the slope as a threshold in a memory; and a function storing step of causing the monitoring resistance-change calculating unit to calculate a function representing a change in the monitoring output value in the transient range together with time, and to store the calculated function in the memory in association with the threshold; and a correction step of estimating the varying pattern from the environmental temperature while the force sensor is measuring the external force, and of correcting the sensor output value using a correction value based on the estimated varying pattern, wherein the correction step includes: a sensor-output-value detecting step of causing a sensor-output-value detecting unit to detect the sensor output value in the transient range or in the steady range at the predetermined sampling cycle; a second monitoring-output-value detecting step of causing the monitoring-output-value detecting unit to detect the monitoring output value in the transient range or in the steady range at the predetermined sampling cycle; a slope calculating step of causing the monitoring resistance-change calculating unit to calculate a slope of the monitoring output value relative to the sampling time; a slope comparing step of causing a transient change determining unit to compare the threshold stored in the threshold storing step with the slope calculated in the slope calculating step; and a sensor-output-value correcting step of causing a transient correcting unit to substitute the sampling time into the function associated with the threshold based on a comparison result by the slope comparing step, and to add or subtract an obtained correction value to or from the sensor output value, thereby correcting the sensor output value.