Abstract: Vehicle apparatus adjusts a vehicle powertrain of the vehicle in response to a speed setpoint. An optimizer selects a control policy to periodically generate speed adjustments for applying to the speed setpoint to operate at increased efficiency. The control policy is based on a value function providing an optimized solution for a cost model and a transition probability model. The transition probability model corresponds to a driving state defined according to a plurality of dimensions including a time-of-day dimension and a geographic region dimension. The transition probability model and the control policy have inputs based on road grade and speed. The optimizer collects road grade data during routine driving of the vehicle to construct a observed transition probability model and uses divergence between the observed transition probability model and a set of predetermined transition probability models to identify a control policy for use during the routine driving.

Abstract: A vehicle having a drivetrain is controlled based on a difference between a torque transmitted by the drivetrain when the vehicle has constant non-zero speed and the torque transmitted by the drivetrain when the vehicle is accelerating. The drivetrain torque may be measured by a drivetrain torque sensor. The effective vehicle mass is computed from the torque difference. The computed mass of the vehicle is used to adjust the activation of a collision warning system or a collision avoidance system. A method of operating a vehicle where the activation of a collision avoidance system is adjusted based on a difference between a torque transmitted by a drivetrain when the vehicle has constant non-zero speed and the torque transmitted by the drivetrain when the vehicle is accelerating is disclosed. The torque difference is used to compute a vehicle mass that is used to adjust a collision warning distance.

Abstract: Designs to package a magneto-elastic torque sensor in an automotive transmission for volume production applications are provided. One transmission includes an output shaft and a magnetic torque sensor. The output shaft has a magnetized region. The sensor, for detecting torque of the output shaft, is mounted on friction reduction members such as bushings supporting the output shaft. In another transmission, the sensor is alternatively mounted to a transmission case.

Abstract: A method for controlling pressure applied to a displaceable piston in a cylinder, piston displacement actuating a control element of an automatic transmission during a gearshift, includes determining whether piston displacement exceeds a free length of an isolation spring located between the piston and a friction plate of the control element; calculating the pressure using A the cross-sectional area of the piston; K a coefficient of a return spring extending between the piston and a reference position in the cylinder; x the piston displacement; F0 a pre-load of the return spring; xfree the free length of the isolation spring; and Kis a coefficient of the isolation spring; and applying the calculated pressure to the piston.

Abstract: A method for controlling cylinder pressure producing piston displacement for actuating a control element of an automatic transmission during a gearshift, includes (a) applying boost pressure to the to the control valve controlling the piston, provided one of the following conditions is present a boost phase is unexpired, cylinder pressure is less than a desired pressure, and piston displacement exceeds a desired displacement; (b) applying stroke pressure to the cylinder provided piston displacement away from control element plates occurs; and (c) increasing stroke pressure provided piston displacement away from clutch plates has not occurred.

Abstract: A method for an automatic transmission includes measuring torque of a component of the transmission using a torque sensor in communication with the component. The torque of the component is estimated from information other than the measured torque. The measured torque is rejected from being used in a control operation of the transmission if the difference between the measured torque and the estimated torque is greater than a selected threshold.

Abstract: A method for controlling pressure applied to a displaceable piston in a cylinder, piston displacement actuating a control element of an automatic transmission during a gearshift, includes determining whether piston displacement exceeds a free length of an isolation spring located between the piston and a friction plate of the control element; calculating the pressure using A the cross-sectional area of the piston; K a coefficient of a return spring extending between the piston and a reference position in the cylinder; x the piston displacement; F0 a pre-load of the return spring; xfree the free length of the isolation spring; and Kis a coefficient of the isolation spring; and applying the calculated pressure to the piston.

Abstract: A downshift control method during a coasting drive condition includes computing changes in output torque and input speed from initial output torque and initial input speed; reducing offgoing element pressure, provided a change in input speed exceeds a reference input speed change; using closed loop control based on output torque and a change in measured output torque to adjust oncoming element pressure such that output torque remains between predetermined maximum and minimum torques; and fully engaging the oncoming element.

Abstract: The following description relates to systems and methods for adjusting vehicle response parameters in response to indications of vehicle operator preferences. In one example approach, a method comprises, during a cruise control mode of operation, adjusting a vehicle response parameter from a default set-point based on an indication of vehicle operator preference.

Abstract: A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.

Abstract: A vehicle powertrain includes a transmission and a clutch. The slip of the clutch is adjusted to a target where a magnitude of a sensed parameter of a shaft of the transmission corresponds to a desired noise, vibration, and harshness (NVH) level in the powertrain. The sensed parameter of the transmission shaft may be one of acceleration, speed, and torque of the transmission shaft. The transmission shaft may be one of the input shaft and output shaft of the transmission.

Abstract: A non-synchronous automatic transmission up-shift control utilizes input torque measurements. The input torque is measured during an up-shift having preparatory, torque, and inertia phases. Target input torque profiles for the torque and inertia phases are determined based on the input torque during the preparatory phase. During the torque phase, an engine torque is controlled to cause the input torque to achieve the target profile for the torque phase. During the inertia phase, the on-coming clutch is controlled to cause the input torque to achieve the target profile for the inertia phase.

Abstract: A synchronous automatic transmission up-shift control utilizes input torque measurements. The input torque is measured during an up-shift having preparatory, torque, and inertia phases. Target input torque profiles for the torque and inertia phases are determined based on the input torque during the preparatory phase. During the torque phase, an engine torque is controlled to cause the input torque to achieve the target profile for the torque phase. During the inertia phase, an on-coming clutch is controlled to cause the input torque to achieve the target profile for the inertia phase.

Abstract: A method for detecting backlash and adjusting driveline variables, includes measuring torque transmitted between components across a torsional discontinuity, measuring driveline twist across the discontinuity, using a ratio of driveline twist divided by torque and an inverse of driveline stiffness to determine whether the driveline is entering, exiting or in a backlash zone, and using measured driveline twist and torque at the backlash zone to adjust reference values of driveline twist and torque.

Abstract: A multiple ratio transmission having an input shaft, an output shaft and oncoming clutch and off-going clutch for effecting ratio upshifts is provided. The transmission also includes a transmission controller configured for controlling shifts. During the torque phase of a ratio upshift, the controller increases input torque. Next, the controller estimates an oncoming clutch target torque. The controller controls a torque input to ensure the off-going clutch remains locked. The controller measures an actual transmission value for a torque transmitting element of the transmission and corrects the oncoming clutch target torque using the actual transmission value whereby an increasing torque for the oncoming friction element is achieved with minimal torque transients along the output shaft during the upshift.

Abstract: A closed loop shift control apparatus and method based on estimated torque in friction elements controls a torque transfer phase when shifting from a low gear configuration to a high gear configuration for an automatic transmission system. When pressure actuated friction elements are selectively engaged and released to establish torque flow paths in the transmission, estimates of torsional load exerted on the off-going friction element are used to predict the optimal off-going friction element release timing for achieving a consistent shift feel. The estimated torque is preferably calculated by using estimated torque signals generated as a function of speed measurements represented either the engine speed and turbine output speed or transmission output speed and wheel speed under dynamically changing conditions.

Abstract: A method for enacting DFSO in a motor vehicle having an engine and a transmission. The method includes, during a condition of normal engine-braking efficiency, disabling the DFSO below a higher gear of the transmission. During a condition of reduced engine-braking efficiency, by contrast, the DFSO is disabled below a lower gear of the transmission.

Abstract: A method of controlling a line pressure in a transmission is provided. Line pressure in a transmission is set to a pressure value including a first term that is proportional to an input torque value. The first term has a coefficient of proportionality that is increased in response to a signal indicating clutch slippage. The input torque value is a measured input torque value in a steady-state condition. The input torque value may be a maximum of the measured input torque value and a driver demand torque value in a transient condition.

Abstract: A transmission and control method are disclosed which ensure proper stroke pressure and minimize torque transients during a shift event. The transmission includes a clutch having a torque capacity based on a fluid pressure, a torque sensor adapted to measure a torque value that varies in relationship to the torque capacity, and a controller. The method includes varying the fluid pressure around a predetermined value, measuring a resulting torque difference with the torque sensor, and adjusting a clutch control parameter if the resulting torque difference is less than a threshold value.

Abstract: A system and method for controlling a vehicle powertrain includes a controller that is operative to automatically control at least one powertrain function other than engine torque based on a measured torque and a predetermined torque range. The predetermined torque range is based on a first engine torque estimate. The measured torque is related to actual engine torque, and can be measured directly at the engine crankshaft, or in another location in the powertrain and then transferred to the engine space.