Engine start/stop control for multiple engine ohv based on operating conditions

An off-highway vehicle comprising:

• a plurality of engines;
• a controller for controlling operation of the engines, wherein when a first engine of the plurality of engines is operating and a second engine of the plurality of engines is not operating, said controller initiates operation of the second engine when a set of operating conditions are met, said operating conditions comprising:
• a throttle position of the off-highway vehicle is greater than a predetermined throttle position;
• a speed of the off-highway vehicle is greater than a predetermined speed;
• and
• the first engine is operating at an output level greater than a predetermined output level.

A method of operating an off-highway vehicle having a plurality of engines wherein a first engine and a second engine of the plurality of engines are operating and an operator reduces a throttle position of the off-highway vehicle to a predefined amount, said method comprising:

• operating the second engine at a revolutions per minute corresponding to an idle condition and thereafter controlling the second engine revolutions per minute as a function of the throttle position;
• controlling the first engine revolutions per minute as a function of the throttle position;
• and
• stopping the second engine after a predetermined period of time during which the second engine has been in the idle condition.

An off-highway vehicle comprising:

• a plurality of engines;
• a controller for controlling operation of the engines wherein when a first engine and a second engine of the plurality of engines are operating and an operator reduces a throttle position of the off-highway vehicle to a predefined amount, said controller:
• operates the second engine at a revolutions per minute corresponding to an idle condition and thereafter controls the second engine revolutions per minute as a function of the throttle position;
• controls the first engine revolutions per minute as a function of the throttle position;
• and
• stops the second engine after a predetermined period of time during which the second engine has been in the idle condition.

A method of minimizing fuel consumption of an engine of an off-highway vehicle having an idle state wherein the engine produces no motive force in the idle state and wherein the engine is in said idle state, said method comprising:

• starting the engine in response to at least one of the following start-up conditions:
• a battery voltage less than a predetermined first battery voltage;
• an ambient air temperature less than a predetermined first ambient air temperature;
• a direction input changed from neutral to either forward or reverse;
• a brake cylinder pressure below a predetermined first brake cylinder pressure;
• and
• an engine start input activated by an operator;
• and
• stopping the engine after a predetermined idle period of time in response to at least one of the following shutdown conditions:
• a battery charging current less than a predetermined battery charging current;
• a battery voltage greater than a predetermined second battery voltage;
• an ambient air temperature greater than a predetermined second ambient air temperature;
• a direction input in neutral;
• and
• a brake cylinder pressure above a predetermined second brake cylinder pressure;
• wherein at least one of:
• (1) the predetermined idle period of time begins when all of the shutdown conditions are met and the predetermined idle period of time is restarted if any of the shutdown conditions are violated;
• (2) the predetermined idle period of time begins when all of the engines of the off-highway vehicle have reached a revolutions per minute corresponding to idle and the predetermined idle period of time is only restarted if any of the engines are increased to a revolutions per minute above the revolutions per minute corresponding to idle such that if none of the engines of the off-highway vehicle have been at a revolutions per minute above a revolutions per minute corresponding to idle for the predetermined idle period of time and the shutdown conditions are met at the end of the predetermined idle period of time, the engines are stopped;
• (3) the predetermined idle period time begins when a throttle position of the off-highway vehicle is in a position corresponding to idle and the direction input is in neutral, and the predetermined idle period of time is restarted only if the revolutions per minute of the engine increases above the revolutions per minute corresponding to idle;
• (4) the predetermined idle period of time begins when the throttle position is changed to the position corresponding to idle and the predetermined idle period of time is restarted only if the throttle position is changed to a position other than the position corresponding to idle;
• and
• (5) the predetermined idle period of time begins when a revolutions per minute setting of the engine is set to an idle setting and the engine is stopped when the predetermined idle period of time ends and all of the shutdown conditions are met, wherein the predetermined idle period of time is reset only if the throttle position is changed from the position corresponding to idle to another position.

An off-highway vehicle having an idle state wherein the off-highway vehicle produces no motive force in the idle state and the off-highway vehicle is in said idle state, said vehicle comprising:

• an engine;
• a controller for controlling operation of the engine, said controller monitoring at least one of a battery voltage of the vehicle, an ambient air temperature of the vehicle, a direction input of the vehicle, a brake cylinder pressure of the vehicle, an engine start input of the vehicle, and a battery charging current;
• said controller starting the engine in response to at least one of the following start-up conditions:
• the monitored battery voltage is less than a predetermined first battery voltage;
• the monitored ambient air temperature is less than a predetermined first ambient air temperature;
• the monitored direction input is changed from neutral to either forward or reverse;
• the monitored brake cylinder pressure is below a predetermined first brake cylinder pressure;
• and
• the monitored engine start input is activated by an operator;
• and
• said controller stopping the engine after a predetermined idle period of time in response to at least one of the following shutdown conditions:
• the monitored battery charging current is less than a predetermined battery charging current;
• the monitored battery voltage is greater than a predetermined second battery voltage;
• the monitored ambient air temperature is greater than a predetermined second ambient air temperature;
• the monitored direction input is in neutral;
• and
• the monitored brake cylinder pressure is above a predetermined second brake cylinder pressure;
• wherein at least one of:
• (1) the predetermined idle period of time begins when all of the shutdown conditions are met and the predetermined idle period of time is restarted if any of the shutdown conditions are violated;
• (2) the predetermined idle period of time begins when the engine of the off-highway vehicle has reached a revolutions per minute corresponding to idle and the predetermined idle period of time is only restarted if the engine is increased to a revolutions per minute above a revolutions per minute corresponding to idle such that if the engine of the off-highway vehicle has not been at a revolutions per minute above a revolutions per minute corresponding to idle for the predetermined idle period of time and all of the shutdown conditions are met at the end of the predetermined idle period of time, the engines are stopped;
• (3) the predetermined idle period of time begins when a throttle position of the off-highway vehicle is in a position corresponding to idle and the direction input is in neutral, and the predetermined idle period of time is restarted only if the revolutions per minute of the engine increases above the revolutions per minute corresponding to idle;
• (4) the predetermined idle period of time begins when the throttle position is changed to the position corresponding to idle and the predetermined idle period of time is restarted only if the throttle position is changed to a position other than the position corresponding to idle;
• and
• (5) the predetermined idle period of time begins when a revolutions per minute setting of the engine is set to an idle setting and the engine is stopped when the predetermined idle period of time ends and all of the shutdown conditions are met, and wherein the predetermined idle period of time is reset only if the throttle position is changed from the position corresponding to idle to another position.