Inferential signal generator for instrumented equipment and processes

A control apparatus for a system selected from a process or machine, comprising:

• at least one actuator signal line connected to said system for conducting a control signal to said system;
• at least one sensor signal line connected to said system for conducting a signal from at least one sensor on said system indicative of a physical parameter of said system;
• a memory for storing a set of time-correlated sensor data representative of expected operational states of said system;
• and
• a processor disposed to receive the signal from the at least one sensor signal line, for generating a control signal provided to said actuator signal line, by comparing the similarity of the signal from said sensor signal line to the set of sensor data in said memory to generate at least one computed value descriptive of an physical parameter of said system, on the basis of which said control signal is generated.

A method for generating at least one inferential sensor signal for a system selected from a machine or process, comprising the steps of:

• instrumenting said system with a first set of sensors and a second set of sensors to measure a plurality of physical parameters of said system;
• operating said system in at least one operational state;
• acquiring sensor data from said first set of sensors and said second set of sensors for the plurality of physical parameters for the at least one operational state to provide an inferential measure of an uninstrumented physical parameter not among paramaters measured with respect to said second set of sensors;
• storing the acquired sensor data from said first set of sensors and said second set of sensors in a memory;
• monitoring values of said first set of sensors while said system is in operation;
• and
• computing at least one inferential sensor signal from said second set of sensor signals corresponding to a physical parameter not among those measured by said first set of sensors, by linearly combining the stored sensor data according to a measure of similarity of the monitored sensor values to the stored sensor data.

A computer for generating virtual sensor signals describing a physical system, comprising:

• a memory for storing a plurality of reference state vectors, each state vector having as elements sensor values descriptive of a physical state of said system;
• a first computing module disposed to receive a current state vector describing said physical system, having as elements sensor values corresponding to a subset of sensors in each of said reference state vectors, for comparing the current state vector to each said reference state vector to determine a measure of similarity therebetween;
• and
• a second computing module disposed to receive the measures of similarity between the current state vector and each said reference state vector, and generate from a combination of said reference state vectors as weighted by the measures of similarity, a virtual signal vector having as elements estimates of those sensor values corresponding to sensors in said reference state vectors remaining out of said subset of sensors.