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 a second 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 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 sensors for the plurality of physical parameters for the at least one operational state;
• storing the acquired sensor data in a memory;
• monitoring values of a subset of said sensors while said system is in operation;
• and
• computing at least one inferential sensor signal corresponding to a physical parameter not among those measured by said subset 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.

A system for monitoring instrumented equipment, comprising:

• a plurality of sensors capable of being monitored from the instrumented equipment;
• an information processor;
• a data acquisition input to said information processor for receiving operational values descriptive of physical parameters of the system from said plurality of sensors;
• a memory operable for being coupled with said signal acquisition input for storing a set of time-correlated sensor data representative of expected operational states, and signals observed during operation of the instrumented equipment;
• said information processor generating at least one output value descriptive of a parameter of the instrumented equipment in addition to signals observed from the instrumented equipment;
• and
• said information processor being operable in response to said signal acquisition input using relationships between the expected operational states and the observed signals from the instrumented equipment to generate additional signals corresponding to one or more process parameters of the equipment from the output value descriptive of the parameter of the instrumented equipment in addition to the signals observed.