NOx emission-control system using a virtual sensor

A method for controlling NOx emissions of an engine that includes a physical NOx sensor that measures actual NOx emission values produced by the engine during operation and a controller including a model that produces predicted values of NOx emissions based on collected values of control parameters corresponding to the engine during the operation, the method comprising:

• collecting actual NOx emission values from the physical NOx sensor and corresponding values for each of the control parameters during operations of the engine;
• applying the collected control parameter values to the model to produce predicted NOx emission values;
• training the model during the operations based on an analysis of the predicted NOx emission values and the actual collected NOx emission values;
• determining whether the physical NOx sensor has failed;
• setting the trained model based on a training that occurred immediately prior to the physical NOx sensor failure;
• and
• controlling NOx emissions exhausted from the engine during subsequent operations based on predicted NOx emission values produced from the trained model in response to collected values associated with each of the control parameters during the subsequent operations.

A method for adjusting the performance of an emission-control system associated with a target engine, wherein the emission-control system includes a controller, the method comprising:

• creating a model reflecting a relationship between NOx emission values produced by at least one test engine and control parameters collected during test operations of the at least one test engine;
• adjusting the model to a first trained state;
• storing the adjusted model in the controller;
• determining characteristics associated with the target engine;
• readjusting the model stored in the controller to a second trained state based on the determined characteristics;
• and
• controlling NOx emissions exhausted from the target engine during operations based on predicted NOx emission values produced by the readjusted model.

A system for controlling NOx emissions of an engine, the system comprising:

• a controller configured to:
• receive measured values of each of a plurality of control parameters during operations of the engine, wherein the control parameters include ambient humidity, manifold pressure, manifold temperature, fuel rate, and engine speed,
• predict NOx emission values of the engine based on values associated with each of the plurality of control parameters, and
• produce control signals as a function of the predicted NOx emission values;
• and
• a system coupled with the controller to receive the control signals and configured to control NOx emissions exhausted from the engine as a function of the control signals.

A system for controlling NOx emissions of an engine, the system comprising:

• a physical NOx sensor that measures actual NOx emission values produced by the engine during operation;
• and
• a controller including software that performs emission control processes, when executed by a processor, the emission control processes including:
• a process for providing predicted values of NOx emissions based on collected values of control parameters corresponding to the engine during the operation;
• a process for collecting actual NOx emission values from the physical NOx sensor and corresponding values for each of the control parameters during the operation of the engine;
• a process for training the process for providing predicted NOx emission values during the operation based on an analysis of the predicted NOx emission values and the actual NOx emission values;
• a process for determining whether the physical NOx sensor has failed;
• and
• a process for controlling NOx emissions exhausted from the engine during subsequent operation based on predicted NOx emission values produced from the trained process for predicting in response to collected values associated with each of the control parameters during the subsequent operation.

An apparatus for controlling NOx emissions from an engine, comprising:

• a controller including:
• a memory including program code configured to predict NOx emission values of the engine based on values associated with each of the plurality of control parameters, wherein the program code represents a neural network that uses the control parameters as inputs and generates the predicted NOx emission values as outputs,
• an interface coupled with the engine and configured to receive measured values of each of a plurality of control parameters during operations of the engine, wherein the control parameters include ambient humidity, manifold pressure, manifold temperature, fuel rate, and engine speed, and
• a processor coupled with the memory and the interface and configured to execute the program code to produce predicted NOx emission values as a function of the received measured values and to produce control signals as a function of the predicted NOx emission values;
• and
• a system coupled with the processor to receive the control signals and configured to control NOx emissions exhausted from the engine as a function of the control signals.

An apparatus for controlling NOx emissions from an engine, comprising:

• an engine;
• an exhaust system coupled with the engine to process emissions produced by the engine during operation;
• a physical NOx sensor coupled with the exhaust system and configured to measure actual NOx emission values produced by the engine during operation;
• and
• a controller coupled with the physical NOx sensor and the engine and configured to:
• collect actual NOx emission values from the physical NOx sensor and corresponding values for each of a plurality of engine control parameters from the engine during operation, wherein the control parameters include ambient humidity, manifold pressure, manifold temperature, fuel rate, and engine speed associated with the engine during operation;
• apply the collected control parameter values to a neural network to produce predicted NOx emission values;
• train the neural network during operation of the engine based on an analysis of the predicted NOx emission values and the actual collected NOx emission values;
• determine whether the physical NOx sensor has failed;
• set the trained neural network based on a training that occurred immediately prior to the physical NOx sensor failure;
• and
• provide control signals to the engine, wherein the control signals control NOx emissions exhausted from the engine during subsequent operations based on predicted NOx emission values produced from the trained neural network in response to collected values associated with each of the control parameters during the subsequent operations.