Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.

Abstract: An exhaust system and method for optimizing the efficiency of an internal combustion engine from which spent gas emerges. Spent gas is fed to an exhaust housing that accommodates a venturi. Part of the spent gas travels through the venturi and part travels outside the venturi. Across the mouth of the venturi sits a directing valve plate that can be moved, thereby opening or closing the path through the venturi. Some of the spent gas is reflected rearwardly from the venturi and thus reenters the cylinder. Upon doing so, the reflected spent gas occupies some of the space above the piston, lowers combustion pressure and reduces the velocity and pressure of the gas flow emerging therefrom.

Abstract: A method of changing an active cylinder count of an engine may include determining a vehicle vibration limit and a vehicle vibration level. The cylinder count may be modified (increased or decreased) based upon the vehicle vibration limit and the vehicle vibration level. The vehicle vibration limit may be based upon a vehicle speed, and a coolant temperature of the engine. The vehicle vibration level may be based upon at least one of a desired torque of the engine and a number of active cylinders of the engine. According to other features, the vehicle vibration level may be based upon a measured vibration level of a vehicle component.

Abstract: A driveline clunk control system for a vehicle having an engine that drives a driveline through a transmission includes a transmission output shaft speed (TOSS) sensor that generates a TOSS signal and a first module that receives the TOSS signal and that determines a secondary parameter (?TOSS) based on the TOSS signal. A second module detects onset of a clunk condition based on the ?TOSS and a third module regulates operation of the vehicle to inhibit the clunk condition when the onset of the clunk condition is detected.

Abstract: A method of changing an active cylinder count of an engine may include determining a vehicle vibration limit and a vehicle vibration level. The cylinder count may be modified (increased or decreased) based upon the vehicle vibration limit and the vehicle vibration level. The vehicle vibration limit may be based upon a vehicle speed, and a coolant temperature of the engine. The vehicle vibration level may be based upon at least one of a desired torque of the engine and a number of active cylinders of the engine. According to other features, the vehicle vibration level may be based upon a measured vibration level of a vehicle component.

Abstract: A control system for controlling a valve in a fuel system of engine including an engine airflow sensor that senses a mass engine airflow (Mengair), a barometric pressure sensor that senses a barometric pressure (Pbaro), and an ambient temperature sensor that senses an ambient temperature (Tamb). An actuator determination module determines an effective area (Aeff) of the valve based on at least one of the Mengair, the Pbaro, and the Tamb. A duty cycle (DC) calculation module that determines a first duty cycle (DC) of the valve based on the Aeff.

Abstract: A control system for controlling a valve in a fuel system of engine including an engine airflow sensor that senses a mass engine airflow (Mengair), a barometric pressure sensor that senses a barometric pressure (Pbaro), and an ambient temperature sensor that senses an ambient temperature (Tamb). An actuator determination module determines an effective area (Aeff) of the valve based on at least one of the Mengair, the Pbaro, and the Tamb. A duty cycle (DC) calculation module that determines a first duty cycle (DC) of the valve based on the Aeff.

Abstract: A fuel savings informational system is provided for implementation on an alternative fuel vehicle the operation of which may be characterized by a first plurality of fixed parameters and a second plurality of variable parameters. The system compares the fuel consumption of the alternative fuel vehicle to that of a virtual comparison vehicle characterized by a third plurality of fixed parameters, and comprises a plurality of sensors for monitoring the second plurality and a processor coupled thereto. The processor is configured to recall the first and third pluralities, capture data corresponding to the second plurality, and determine the fuel consumption of the alternative fuel vehicle from the second plurality. The processor is further configured to estimate the fuel consumption of the comparison vehicle from the first, second, and third pluralities, and compare the fuel consumption of the alternative fuel vehicle to the estimated fuel consumption of the comparison vehicle.

Abstract: An engine control system is disclosed for reducing the hydrocarbon content in the exhaust gas of a crankcase scavenged, two-stroke engine in the operating range near idle, with light operator induced engine loading. As operator demand for engine output power is increased, the system increases the fuel per cylinder supplied to the engine while restricting the supplied mass of air per cylinder to a value less than that flowing at unloaded engine idle.

Abstract: A method is described for controlling the injection of fuel in a direct injected, multi-cylinder internal combustion engine, to smooth transients in engine output torque associated with a deceleration fuel cut-off mode of engine operation. This is accomplished by detecting engine operating conditions that call for the initiation of a transition associated with the decelaration fuel cut-off engine operating mode. In response to the detected operating conditions, a transitional period is initiated, during which the injection of fuel into a varying portion of engine cylinders is then interrupted. When the transitional period is associated with entry into the deceleration fuel cut-off mode, the injection of fuel to a progressively increasing number of cylinders is interrupted. When the transitional period is associated with recovery from the deceleration fuel cut-off mode, the injection of fuel to a progressively decreasing number of engine cylinders is interrupted.

Abstract: A method is described for increasing engine braking, when a crankcase scavenged two-stroke engine is operated in a deceleration fuel cut-off mode. In response to the detection of operating conditions indicating engine operation in the deceleration fuel cut-off mode, the quantity of air inducted into the engine is decreased, for a predetermined period of time. After this period of time elapses, the quantity of air inducted into the engine is then increased. This is preferably accomplished by regulating the degree of opening of a throttle valve disposed within the engine air intake system. The initial closing of the throttle valve restricts air flow through the engine for a predetermined time, to maintain efficient catalyst operating temperatures in the engine exhaust system. During extended operation in the deceleration fuel cut-off mode, the throttle valve is opened, after the lapse of the predetermined time, to increase the quantity of air inducted by the engine.

Abstract: The mass of air available for combustion within a cylinder of a crankcase scavenged two-stroke engine is obtained by estimating the mass of air trapped within a crankcase chamber, prior to its transfer to the associated cylinder combustion chamber. The estimate for air mass is derived from the product of pressure of the air in the crankcase chamber and the crankcase chamber volume at a selected engine cycle position during that portion of the engine cycle when the air is trapped and undergoes compression within the crankcase chamber divided by a factor containing the trapped air temperature at the selected engine cycle position.

Abstract: A two-stroke cycle spark ignition cylinder fuel injection engine is provided with an exhaust emission control system that separately treats hot blowdown gases and uses the hot treated gases to warm the scavenging gases for further treatment. Various exhaust gas separation concepts are described for use in separating the blowdown and scavenging portions of the exhaust gas discharged from the cylinder exhaust ports.

Abstract: Combinations of split and valved exhaust ports are provided in a ported two cycle engine with divided emission control system to provide better control of the division of exhaust gas flow to the two converters.

Abstract: A method and apparatus are described for determining the mass of air available for combustion within a cylinder of a crankcase scavenged two-cycle engine, without the use of a mass-air flow sensor. This is achieved by estimating the mass of air under compression within a crankcase chamber, prior to its transfer to a cylinder combustion chamber. The estimate for air mass is based upon the integration of crankcase pressure over the interval of decreasing crankcase volume, while air within the crankcase is under compression. The volume of the air within the crankcase chamber is derived as a function of engine cycle position, with crankcase air temperature being derived as a function of intake air temperature. Air pressure during compression is monitored with a crankcase pressure sensor. The estimate for air mass is corrected to account for air leakage and incomplete transfer of the air between the crankcase and combustion chambers.

Abstract: An engine control system is disclosed for reducing the hydrocarbon content in exhaust gas from a crankcase scavenged, two-stroke engine in the operating range near idle, with light operator induced engine loading. As operator demand for engine output power is increased, the control system increases the fuel per cylinder delivered to the engine, while restricting the supplied mass of air per cylinder to a value less than or equal to that flowing at unloaded engine idle.

Abstract: A method and means are described for determining the mass of air available for combustion within a cylinder of a crankcase scavenged two-cycle engine, without the use of a mass-air flow sensor. This is achieved by estimating the mass of air under compression within a crancase chamber, prior to its transfer to the cylinder combustion chamber. The estimate for air mass is based upon the integration of crankcase pressure over the interval of decreasing crankcase volume, while air within the crankcase is under compression. The volume of the air within the crankcase chamber is derived as a function of engine cycle position, with crankcase air temperature being derived as a function of intake air temperature. Air pressure during compression is monitored with a crankcase pressure sensor. The estimate for air mass is corrected to account for air leakage and incomplete transfer of the air between the crankcase and combustion chambers.

Abstract: A pneumatic direct cylinder fuel injection system for an internal combustion engine includes a pneumatic injector for each cylinder so as to supply a pressurized air/fuel charge to an associate stratified charge chamber forming a part of the associate combustion chamber preferably during the compression stroke of the associate piston, the quantity of fuel being supplied by an electromagnetic fuel injector. The pressurized air for the system can be supplied by an electrical or engine driven air pump or preferably the engine itself can be used as an air compressor with each cylinder having an air source control valve operatively associated therewith to control the flow of pressurized air during the compression stroke of the piston in its associate cylinder.

Abstract: A mass air flow meter for an internal combustion engine is described in which the mass air flow into the engine is determined by the measured throttle angular position, the sensed pressure above the throttle and a stored schedule of values dependent upon the ratio of the pressure below the throttle to the pressure above the throttle.

Abstract: A mechanical, throttle body injection apparatus has an air valve positioned metering rod controlling fuel flow from a constant pressure fuel source through one side of a pressure regulator valve to a nozzle for continuous fuel injection into the throttle bore of the throttle valve controlling induction flow therethrough. Excess fuel, not metered by the metering rod, applies a control pressure to the other side of the pressure regulator valve and is returned to a fuel reservoir via a drain passage, flow through which is controlled by a pulse width modulated solenoid valve. The apparatus includes means for fuel enrichment at cold start and during engine warm-up.