Radio Frequency Process Sensing, Control, and Diagnostics Network

Abstract

A sensing and control system and method is disclosed, which utilizes cavity resonance and waveguide measurements to directly monitor process state variables or detect changes in the state of a system and provide direct in situ feedback control top optimize the process. The same system may be used to monitor a number of different process parameters including the composition, amount, distribution, and physical or chemical properties of a material, or to monitor the state or health of a system or sub-system. The system is broadly applicable to wide range of systems and process including ranging from engines and exhaust systems to production plants.

What is claimed is: 
     
         1 . A radio frequency process control system comprising:
 a plant or machine requiring at least one input and generating at least one output stream;   a module, conduit, or component in the plant or machine forming a resonant cavity for containing radio frequency signals;   a radio frequency probe in the resonant cavity of the module, conduit, or component to transmit and/or receive the radio frequency signals; and   a radio frequency control unit, in communication with the radio frequency probe, to (i) monitor at least a change in the phase of said radio frequency signals transmitted and/or received through the resonant cavity of the module, conduit, or component and (ii) measure more than one parameter selected from the group including amount of a material, type of the material, spatial distribution of the material, physical or chemical properties of the material, environmental conditions, position or level, cavity integrity, or rate of change of the parameter, based on at least a measurement of the change in the phase of said radio frequency signals transmitted and/or received through the resonant cavity of the module, conduit, or component, the radio frequency control unit containing the components for transmitting, detecting, controlling, modulating, and monitoring the radio frequency signals transmitted and/or received by the radio frequency probe.   
     
     
         2 . The system of  claim 1 , wherein said module, conduit, or component is selected from the group including catalyst, substrate, filter, cavity, or housing, or engine. 
     
     
         3 . The system of  claim 1 , wherein said radio frequency control unit determines leakage of a material through said output stream, based on measured material accumulation in said output stream and known emissions of said material from said machine. 
     
     
         4 . The system of  claim 1 , wherein said radio frequency control unit determines an amount, quality or composition of a material in said module, conduit, or component. 
     
     
         5 . The system of  claim 4 , wherein said material is selected from the group consisting of fuel, oil, coolant, air, urea, and EGR gas. 
     
     
         6 . The system of  claim 1 , wherein said module, conduit, or component comprises an engine of the plant or machine, and the radio frequency probe is disposed in a cylinder of said engine, to monitor one or more engine parameters. 
     
     
         7 . The system of  claim 6 , wherein the one or more engine parameters are selected from the group consisting of position of piston, quality of combustion process, emissions processed by said combustion process, quantity of fuel injected, temperature and pressure. 
     
     
         8 . A radio frequency sensing system, comprising;
 a radio frequency probe to transmit and/or receive radio frequency signals within a cavity of a machine, the first radio frequency probe extending in the cavity and the cavity containing the radio frequency signals;   a timing device; and   a radio frequency control unit, in communication with the radio frequency probe and the timing device, to monitor at least a change in the phase and amplitude of the transmitted and/or received radio frequency signals and to measure a change in said determined process parameter based on inputs from said timing device and a measurement of the change in the phase and amplitude of the transmitted and/or received radio frequency signals, and to initiate an action based on said change in said determined process parameter, the radio frequency control unit containing all of the components for transmitting, detecting, controlling, modulating, and monitoring the radio frequency signals transmitted and/or received by the radio frequency probe.   
     
     
         9 . The radio frequency sensing system of  claim 8 , wherein said radio frequency control unit provides diagnostic information to an operator based on said change in said determined process parameter. 
     
     
         10 . The radio frequency sensing system of  claim 9 , wherein said diagnostic information is selected from the group consisting of an indication of a failure of a filter element, an indication of a failure of a catalyst element, an indication of a broken conduit, and an indication of a blockage or obstruction in said machine. 
     
     
         11 . The radio frequency sensing system of  claim 10 , wherein the radio frequency control unit modifies operation of said machine based on said change in said determined process parameter. 
     
     
         12 . The radio frequency sensing system of  claim 11 , wherein said radio frequency control unit modifies fueling, air flow, boost pressure, EGR rates, injection timing, urea or hydrocarbon dosing. 
     
     
         13 . A machine, comprising:
 at least one input and generating at least one output stream;   a radio frequency probe mounted in a cavity within said machine to transmit and/or receive radio frequency signals contained in and propagated through the cavity within said machine, the radio frequency probe being operable at a specified frequency or range of frequencies which may vary depending on the type, location, and measurement application of the radio frequency probe; and   a radio frequency control unit, in communication with the radio frequency probe, to monitor a change in at least the phase of said radio frequency signals transmitted and/or received through the cavity, measure at least one parameter, based on at least a measurement of the change in the phase of said radio frequency signals transmitted and/or received through the cavity, and initiate an action based on said at least one measured parameter.   
     
     
         14 . The machine of  claim 13 , wherein at least a first radio frequency probe monitors said input and at least a second radio frequency probe monitors said output stream. 
     
     
         15 . The machine of  claim 13 , wherein said radio frequency control unit modifies an operation of said machine based on said at least one measured parameter. 
     
     
         16 . The machine of  claim 13 , wherein said radio frequency control unit alters an operator of a fault condition based on said at least one measured parameter. 
     
     
         17 . The machine of  claim 13 , wherein said radio frequency control unit is in communication with a timing device and said radio frequency control units determines a rate of change of said at least one measured parameter.