Abstract: Methods and systems are provided for estimation of a road roughness index (RRI) and adjusting vehicle operation based on the metric. In one example, a method may include estimating the RRI as a function of a pitch energy and a roll energy of the vehicle travelling on the road. In response to the RRI being higher than a threshold, engine operation such as EGR flow rate may be adjusted.

Abstract: Methods and systems are provided for estimation of a road roughness index (RRI) and adjusting vehicle operation based on the metric. In one example, a method may include estimating the RRI as a function of a pitch energy and a roll energy of the vehicle travelling on the road. In response to the RRI being higher than a threshold, engine operation such as EGR flow rate may be adjusted.

Abstract: Methods and systems are provided for adjusting engine cranking. In one example, a method for an engine cold start may include extending engine cranking at least based on one or more engine cold start conditions, where extending engine cranking may increase an engine oil pressure in a plurality of camshaft phaser cavities of a variable camshaft timing (VCT) phaser. In some examples, the method may further include, after engine cranking, enabling fueling. In this way, fuel efficiency considerations may be balanced with increases to the engine oil pressure such that components of the VCT phaser may be actuated and/or lubricated.

Abstract: A method for controlling a vehicle driveline having a power source and a transmission clutch includes using a difference between two spaced locations in the subject vehicle driveline to determine driveline twist speed due to applied torque, using a product of driveline twist speed and a sampling interval to produce an estimated driveline twist from the sum of incremental changes in driveline twist that are between predetermined upper and lower magnitudes, producing, in response to a demanded wheel torque, a first signal that controls torque transmitted from the power source to the clutch during a lash crossing using the estimated driveline twist and the current driveline torque; and producing a second signal that controls clutch torque capacity such that clutch slip is produced during the lash crossing.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: A method for controlling a driveline having a transmission clutch includes locking the clutch before a driveline lash crossing occurs; maintaining a locked clutch during the lash crossing; after the lash crossing occurs, increasing a clutch capacity at a slower rate than a driveline twist torque rate; and after the lash crossing occurs, producing clutch slip by controlling engine torque and clutch capacity such that engine torque exceeds clutch capacity.

Abstract: A method for operating an engine having a variable cam timing control system, for controlling a camshaft angle in such engine. The method includes deactivating the variable cam timing system and setting the camshaft angle to a predetermined angle for a predetermined duration after failure in a sensor used to control the variable cam timing system and then reactivating the variable cam timing system after such predetermined time. The deactivating continues during the predetermined duration in the presence of a subsequent failure of the sensor during the predetermined duration. The reactivating comprises driving the cam angle to a camshaft angle established by the variable cam timing system in a predetermined manner. The reactivating occurs over a predetermined reactivation time.