초록 ▼

A hybrid vehicle propulsion system is disclosed comprising an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherei

A hybrid vehicle propulsion system is disclosed comprising an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherein the engine is configured to supply an engine output; a motor configured to selectively supply or absorb a secondary output; an energy storage device configured to selectively store at least a portion of the engine output and selectively supply energy to the vehicle; and a control system configured to control at least the engine, the motor, and the energy storage device, wherein the control system is configured to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the energy storage device.

대표청구항 ▼

What is claimed is: 1. A hybrid vehicle propulsion system, comprising: an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition

What is claimed is: 1. A hybrid vehicle propulsion system, comprising: an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherein the engine is configured to supply an engine output, the engine further comprising a lean NOx trap configured to store NOx produced by the engine; a motor configured to selectively supply or absorb a secondary output; an energy storage device configured to selectively store at least a portion of the engine output and selectively supply energy to the vehicle; and a control system configured to control at least the engine, the motor, and the energy storage device, wherein the control system is configured to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the energy storage device, and to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the lean NOx trap. 2. The system of claim 1, wherein said condition of the energy storage device includes an amount of energy stored by the energy storage device. 3. The system of claim 1, wherein said condition of the energy storage device is a battery state of charge. 4. The system of claim 2, wherein the control system is configured to operate said at least one cylinder in the spark ignition mode when a low amount of energy is stored by the energy storage device and wherein the control system is configured to operate said at least one cylinder in the compression ignition mode when a larger amount of energy is stored by the energy storage device. 5. A hybrid vehicle propulsion system, comprising: an engine having at least one combustion cylinder configured to operate in a first and a second combustion mode, wherein the first combustion mode is a spark ignition mode and the second combustion mode is a compression ignition mode, wherein the engine is configured to supply an engine output, the engine further comprising a lean NOx trap configured to store NOx produced by the engine; an energy conversion device configured to selectively supply or absorb a secondary output; an electrical energy storage device configured to selectively store at least a portion of the engine output and selectively supply energy to the vehicle; and a control system configured to control at least the engine, the conversion device, and the energy storage device, wherein the control system is configured to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the energy storage device, said condition of the electrical energy storage device including an amount of electrical energy stored by the energy storage device, the control system further configured to operate said at least one cylinder in the spark ignition mode when a lower amount of energy is stored by the energy storage device and wherein the control system is configured to operate said at least one cylinder in the compression ignition mode when a larger amount of energy is stored by the energy storage device, and to selectively operate said at least one combustion cylinder in one of the spark ignition mode and the compression ignition mode based on a condition of the lean NOx trap. 6. A method of operating an engine having at least one combustion cylinder configured to produce at least a first portion of a vehicle wheel output, wherein the engine is configured to selectively operate said at least one combustion cylinder in one of a compression ignition mode and a spark ignition mode, the engine coupled in a hybrid propulsion system including a battery, the engine including a lean NOx trap in an exhaust of the engine, the method comprising: performing the compression ignition lean mode in said at least one combustion cylinder during a first condition; performing a transition in said at least one combustion cylinder from the compression ignition mode to the spark ignition mode during a second condition and in response to a battery state of charge and based on whether purging of the NOx trap is required due to capacity of the NOx trap; and performing the spark ignition mode in said at least one combustion cylinder during a third condition. 7. The method of claim 6, wherein the third condition includes a higher engine output torque than said first condition. 8. The method of claim 6, wherein the first condition is when the vehicle wheel output is less than when in the third condition. 9. The method of claim 6, wherein the third condition includes a different gear ratio than said first condition. 10. The method of claim 6, wherein the hybrid propulsion system further includes at least a traction motor, the method further comprising producing at least a portion of the vehicle wheel output via the motor. 11. The method of claim 10 further comprising operating the traction motor to produce at least said portion of the vehicle wheel output during said first condition; and operating the motor to absorb at least some of the vehicle wheel output produced by the engine during said third condition. 12. The method of claim 10 further comprising first determining whether the NOx trap capacity is sufficient and second determining whether sufficient stored energy is available in the battery, where the transition is performed in response to the first and second determinations. 13. The method of claim 10 further comprising performing a second transition in said at least one combustion cylinder from the spark ignition mode to the compression ignition mode, where before the second transition and while still operating in the spark ignition mode, purging the lean NOx trap and increasing battery state of charge.