Abstract: A technique for controlling air-fuel ratio in an internal combustion engine consuming more than one fuel type includes determining a target air-fuel ratio as a function of engine operating conditions; determining an actual air-fuel ratio from the engine operating conditions; determining a first fuel quantity of a first fuel to introduce into a combustion chamber as a function of the engine operating conditions; determining a second fuel quantity of a second fuel such that the actual air-fuel ratio equals the target air-fuel ratio to within a predetermined range of tolerance when the first fuel quantity and the second fuel quantity are introduced into the combustion chamber, the second fuel quantity being determined as a function of the engine operating conditions, the target air-fuel ratio, the actual air-fuel ratio and the first fuel quantity; and introducing the first fuel quantity and the second fuel quantity into the combustion chamber.

Abstract: A vehicle power generation system may include an alternator and an energy conversion device that supply electrical power to an electrical system of a vehicle. A regulator may control the alternator based on a voltage level of the electrical system. A control module may control the energy conversion device based on an operation indicator of the alternator such that the control module adjusts a field coil current of the energy conversion device based on operation indicator of the alternator.

Abstract: A waste heat recovery system may include a pump, first and second heat exchangers, an expander, and a valve. The first heat exchanger receives working fluid from the pump. The expander receives working fluid from the first heat exchanger and includes an output shaft that is powered by the flow of working fluid through the expander. The second heat exchanger may include a first fluid path and a second fluid path that is shorter than the first fluid path. The valve controls fluid flow through the first and second fluid paths. A sensor may measure a parameter of the working fluid that indicates whether the working fluid is in a gaseous state, a liquid state or a mixture of gas and liquid. A control module in communication with the sensor may control a position of the valve based on a value of the parameter measured by the sensor.

Abstract: A technique for controlling air-fuel ratio in an internal combustion engine consuming more than one fuel type includes determining a target air-fuel ratio as a function of engine operating conditions; determining an actual air-fuel ratio from the engine operating conditions; determining a first fuel quantity of a first fuel to introduce into a combustion chamber as a function of the engine operating conditions; determining a second fuel quantity of a second fuel such that the actual air-fuel ratio equals the target air-fuel ratio to within a predetermined range of tolerance when the first fuel quantity and the second fuel quantity are introduced into the combustion chamber, the second fuel quantity being determined as a function of the engine operating conditions, the target air-fuel ratio, the actual air-fuel ratio and the first fuel quantity; and introducing the first fuel quantity and the second fuel quantity into the combustion chamber.

Abstract: A method is provided for maintaining the speed of a spark-ignited internal combustion engine operating at a desired idle speed to compensate for engine speed variations caused by torque disturbances, utilizing an actual idle speed and the desired idle speed expressed as an RPM error ratio. A desired operating torque ratio is determined based on the torque available, a torque ratio reserve created by retarding spark from the maximum spark advance value and a torque ratio correction which reflects the torque disturbance. A desired final spark advance value is obtained from the desired operating torque ratio utilizing a nonlinear relationship between spark advance and torque ratio. The spark advance is modified to the desired final spark advance value so as to vary the torque supplied by the engine in order to maintain the desired idle speed.