Algorithm for detecting activation of a push button

摘要

The invention relates to an algorithm for detecting activation of a tactile pressure sensor having a mechanic structure that includes the steps of: (a) measuring periodically an input quantity (V0; f0) of the sensor, when it is not pressed, the period being set according to sensor dynamic requirements; (b) computing a current idle quantity (Vidle; fidle) depending on the input quantity (V0; f0) measured at step a); (c) computing an activation threshold (ΔVP; ΔfP) based on a quantity characterization of the sensor mechanic structure and depending on the idle quantity (Vidle; fidle) defined at step b); (d) comparing the sensor input quantity (V0; f0) with the last defined idle quantity (Vidle; fidle) increased by the activation threshold (ΔVP; ΔfP) computed in step c) in order to determine whether the sensor is pressed or not.

主权项

1. A system for detecting activation of a tactile pressure sensor, said system comprising:
a tactile pressure sensor operable to exhibit a resistance that corresponds to a force applied to the sensor; a microprocessor equipped with an analog to digital converter suitable to measure an input quantity indicative of the resistance of the sensor, said microprocessor configured to execute the steps of a) measuring periodically an input quantity of the sensor, when it is not pressed, a period for measuring periodically being set according to sensor dynamic requirements; b) computing a current idle quantity depending on the input quantity measured at step a); c) computing an activation threshold based on a quantity characterization of the sensor mechanic structure and the current idle quantity defined at step b), and a non-activation threshold to determine when the sensor is released after having been pressed, said non-activation threshold being strictly lower than the activation threshold; d) comparing the sensor input quantity with a summation of a last defined idle quantity and the activation threshold computed in step c) in order to determine whether the sensor is pressed or not.