Control for engine driven compressor

A method of controlling a vehicle pneumatic system, the method comprising the steps of:

• reading air pressure sensor from an air storage facility;
• determining power generation or absorption by a prime mover for an air compressor feeding the air storage facility;
• determining requested power from the prime mover;
• responsive to indication of power absorption by the prime mover loading the air compressor up to an air pressure reading at a global pressure limit;
• responsive to indication of requested power exceeding an immediate prime mover power generation limit and air pressure readings above a global pressure minimum unloading the air compressor;
• responsive to air pressure readings at or below the global pressure minimum loading the air compressor;
• responsive to air pressure readings exceeding the global maximum unloading the air compressor;
• and
• otherwise unloading and loading the air compressor to maintain air pressure in the air storage facility within a normal operating pressure maximum and a normal operating pressure minimum where the normal operating pressure maximums and minimums are respectively less and greater than the global pressure maximums and minimums.

A control system for a vehicle pneumatic system including an air storage facility, an air compressor coupled to supply air to the air storage facility, and an engine to drive the air compressor, the control system comprising:

• an air pressure sensor communicating with the air storage facility;
• means for determining power output and absorption by the engine;
• means for determining requested power from the engine;
• means responsive to indication of power absorption by the engine for loading the air compressor up to an air pressure reading at a global pressure limit;
• means responsive to indication of requested power exceeding an immediate prime mover power generation limit and air pressure readings above a global pressure minimum for unloading the air compressor;
• means responsive to air pressure readings at or below the global pressure minimum for loading the air compressor;
• means responsive to air pressure readings exceeding the global maximum for unloading the air compressor;
• and
• means for unloading and loading the air compressor to maintain air pressure in the air storage facility within a normal operating pressure maximum and a normal operating pressure minimum where the normal operating pressure maximums and minimums are respectively less and greater than the global pressure maximums and minimums in response to engine generation of power within the immediate power limit.