SYSTEM AND METHOD FOR MONITORING SENSOR LINEARITY AS PART OF A PRODUCTION PROCESS

摘要

Methods and systems for automated monitoring of sensors associated with a tool used in a manufacturing process are described. Sensor health may be evaluated based on the sensor's actual responses to set point changes. Rather than interrupt operation of the tool to determine whether one or more sensors are behaving in a predictable manner over an applicable range of operating conditions, pairs of set point values and sensor responses may be collected during the manufacturing process and stored in a time-indexed manner. A virtual model may be created for each sensor using selected ones of the indexed pairs and represented as points in an orthogonal coordinate system to identify a predictable operating region corresponding to the operating range. If a sensor response to a set point change, reflected in a stored, time indexed pair, is non-linear or offset relative to the predictable operating region, an alarm may be generated.

主权项

1. A computer-implemented method for automated monitoring of behavior of at least one sensor having a predictable operating behavior expected over a range of operating conditions applicable to a manufacturing process, wherein the at least one sensor is associated with a tool operated during the manufacturing process and provides data sensitive to at least one of a tool state or a process state change, the method comprising:
while operating the tool during the manufacturing process,
collecting at each of a plurality of points in time, a respective set point associated with a target tool state or a target process state; andcollecting from the at least one sensor, at each of the plurality of points in time, a corresponding actual measurement value read back from the at least one sensor; storing the collected set points and actual measurements together with an indication of an applicable time of actual measurement collection to create time indexed pairs of set points and actual measurements corresponding to operation of the tool; and evaluating health of the sensor based on actual measured response of the at least one sensor to set point changes represented by the indexed pairs.