Method for engine control

A method for governing the operation of a vehicle having a multi-cylinder internal combustion engine and an electronic control unit with memory for controlling the engine so as to improve the response time of a vehicle control system thereby improving control of the road speed of the vehicle, the method comprising:

• sensing at least one engine operating parameter to obtain an engine operating signal;
• sensing at least one vehicle operating parameter to obtain an actual road speed signal;
• determining a desired vehicle road speed to obtain a desired road speed signal;
• processing the engine operating signal to obtain a plurality of engine signal components;
• applying a first filter to at least one of the plurality of engine signal components so as to determine a moving average value of the at least one engine operating parameter over a predetermined interval;
• applying a second filter to at least one of the plurality of engine signal components not subjected to the first filter so as to determine an instantaneous value of the at least one engine operating parameter;
• combining the moving average value and the instantaneous value so as to obtain a controlling value;
• determining a system gain factor based on the at least one engine operating parameter;
• comparing the desired road speed signal with the actual road speed signal;
• controlling the vehicle based on the system gain factor, the controlling value, and the comparison so as to reduce the response time of the control system.

A method of controlling road speed of a vehicle including a multi-cylinder internal combustion engine having means for engine braking, an electronic control unit with memory for controlling the engine, a plurality of sensors for sensing vehicle operating parameters, and means for indicating an overspeed condidion, the method comprising:

• determining a desired vehicle road speed to obtain a desired road speed signal;
• sensing at least one vehicle operating parameter to obtain an actual road speed signal;
• sensing the requested fueling level of the engine to obtain a requested fueling level signal;
• evaluating a first comparison of the desired road speed signal to the actual road speed signal;
• comparing the actual road speed signal to a first parameter stored in the memory associated with a nonzero fueling level request and a second parameter stored in the memory associated with a zero fueling level request;
• initiating a variable time interval based upon at least one of the comparisons;
• indicating an overspeed condition and storing at least one of the vehicle parameters in the memory when the variable time interval expires;
• and
• modifying the engine braking based on the first comparison so as to control the road speed of the vehicle.