Methods and systems are provided for reducing lean air-fuel ratio excursions due to degradation of a port injector while fueling an engine via each of port and direct injection. During a PFDI mode of engine operation, responsive to an indication of port injector degradation, such as due to circuit or injector power issues, intake airflow is limited by reducing the opening of an intake throttle. Air flow is limited to be based only on the direct injected fuel fraction, and independent of the commanded port injected fuel fraction.

A friction loss management system for an engine, comprises a combustion engine comprising a crankshaft and a plurality of cylinders, a reciprocating piston assembly connected to the crankshaft, a fuel injector, an intake valve, and an exhaust valve. A control unit comprises at least one set of control algorithms configured to receive engine power demand data, and determine a number of cylinders of the plurality of cylinders for deactivation based on the received engine power demand data and further based on sensed or stored friction values for the plurality of cylinders. Determining the number of cylinders of for deactivation minimizes friction between the plurality of cylinders and their respective reciprocating piston assembly by selecting a cylinder combination of active cylinders and deactivated cylinders with the lowest total friction while meeting engine power demand. All cylinders can be deactivated for purposes of coasting or controlling speed during platooning.

Methods, systems, and devices related to a method of controlling an autonomous vehicle, in particular, an autonomous diesel-engine truck are disclosed. In one example aspect, the method includes determining an available engine brake torque generation mechanism for reducing a current speed of the autonomous vehicle to a lower speed and selecting a brake mode corresponding to the engine brake torque availability. In case a rate of speed reduction is equal to or smaller than a threshold, the brake mode includes only an engine brake in which engine exhaust valve opening is adjusted for reducing the current speed. The threshold determined in part based on the available engine brake torque, gear position of the transmission, and the online estimated vehicle longitudinal dynamic model. In case the rate of speed reduction is greater than the threshold, the brake mode incudes a combination of the engine brake and the foundation brake.

Cross-port air flow that improves engine fuel economy and reduces pumping losses during part-throttle operation can be implemented in various types of internal combustion engine systems using ports that interconnect the intake ports of different cylinders, thus allowing different cylinders to share combustion air. Cross-port air flow is commenced during part-throttle engine operation to disrupt the primary combustion air flow from each throttle to its associated cylinder, which reduces charge density and engine power. The engine compensates for the reduced power by incrementally opening the throttles, thus increasing the primary combustion air flow, reducing pumping losses and improving fuel economy.

Methods and systems are provided for mitigating issues related to sluggish engine performance. In one example, a method comprises, responsive to an indication of degradation of one or more cylinders in the engine, reducing carbon buildup associated with the one or more cylinders via injecting a diesel exhaust fluid into an intake manifold of the engine while the engine is combusting air and fuel. In this way, a water content of the diesel exhaust fluid may be vaporized in the one or more engine cylinders, which may effectively reduce the carbon buildup.

A method to determine reference actuator positions for a gasoline engine, includes entering a base torque request, a known spark advance, a known CAM position and a known exhaust gas recirculation (EGR) valve position into an inverse torque model to generate a first iteration desired air per cylinder (APC) value. The first iteration desired APC value is passed through a deadband filter to produce a filtered first iteration desired APC signal. A Predicted As Cal (PAC) spark advance is calculated for the filtered first iteration desired APC value. The PAC spark advance and the base torque request are modified, and data from a first lookup table is entered to generate a second iteration desired APC value.

An apparatus includes an engine friction module in operative communication with an engine and structured to interpret engine operation data indicative of an engine friction amount, and a stop/start module structured to compare the engine operation data with predetermined protective criteria that includes an engine friction threshold and to turn off the engine for at least a portion of time based on the engine friction threshold exceeding the engine friction amount.

The present disclosure includes a system for improving the perceived ease of operation in a work vehicle with an internal combustion engine. According to an aspect of the present disclosure, the system comprises a torque converter coupled at one end to the internal combustion engine and is coupled to a transmission at an opposite end via at least a transmission input shaft. The system also comprises at least two governors coupled to the internal combustion engine, wherein the governors are configured to adjust an operating parameter of the internal combustion engine. In addition, the system comprises a vehicle control unit communicatively coupled to the governors wherein the vehicle control unit is configured to receive a first and a second speed signal. This vehicle control unit commands the engine control unit to enable to at least one of the governors when a ratio of the first speed signal to the second speed signal exceeds a first predetermined threshold.

A engine control device includes an variable exhaust valve mechanism 72 which varies an opening and closing timing of an exhaust valve 22, and a PCM 10 which controls the variable exhaust valve mechanism 72 such that the opening and closing timing of the exhaust valve 22 is varied, wherein the variable exhaust valve mechanism 72 is configured such that a lift amount of the exhaust valve 22 becomes smaller as a retarded degree of the valve opening timing increases, and the PCM 10 is configured to set a maximum retarded valve opening timing in an exhaust stroke based on the lift amount at an exhaust top dead center, and to control the variable exhaust valve mechanism 72 so as to open the exhaust valve 22 in advance of the maximum retarded valve opening timing.

A system comprises a powertrain including an engine configured to output torque to a driveline, and an electronic control system operatively coupled with the powertrain. The electronic control system is configured to determine an engine torque value, and control a component of the driveline in response to the engine torque value. The engine torque value may account for an effect of air-fuel ratio (AFR) on engine torque. The engine torque value may account for an effect of charge transport delay on engine torque.