Abstract: A method for controlling a manual transmission includes using a controller to determine a desired torque transmitted through an input clutch for the desired gear after a shift lever is moved to a desired gear position and while a clutch pedal is being released for engaging the clutch; inferring torque in the vehicle drive assembly; using inferred torque to determine clutch torque; and using the controller to automatically adjust a clutch actuator such that a difference between the desired torque and the inferred torque is reduced.

Abstract: A transmission clutch control method includes defining a transfer function relating clutch torque to a control signal under transmission operating conditions; determining a target clutch torque for current operating conditions; determining the target control signal from the transfer function to produce target torque at the clutch; correcting clutch torque on the basis of a difference between the target clutch torque and the actual torque at the clutch by adjusting the control signal; calculating actual clutch torque with reference to transmission input torque and transmission output torque; computing a clutch torque error as a difference between calculated clutch torque and the target clutch torque; and repetitively adjusting the transfer function on the basis of the clutch torque error.

Abstract: A method of downshifting an automotive transmission. An on-coming transmission element is stroked while pressure for an off-going element is reduced. Pressure for the stroked on-coming element is increased to be sufficient to carry torque. Pressure for the off-going element is reduced below a torque transmitting amount once the stroked on-coming element has a sufficient torque carrying capacity. Torque capacities for the elements are determined from transmission output torque and acceleration and transmission input torque and acceleration. Feed forward or feedback terms for off-going and on-coming element torque capacities may be calculated using the transmission output torque, transmission input acceleration, and transmission input torque.

Abstract: A method for controlling a manual transmission includes using a controller to determine a desired torque transmitted through an input clutch for the desired gear after a shift lever is moved to a desired gear position and while a clutch pedal is being released for engaging the clutch; inferring torque in the vehicle drive assembly; using inferred torque to determine clutch torque; and using the controller to automatically adjust a clutch actuator such that a difference between the desired torque and the inferred torque is reduced.

Abstract: A method for controlling a manual transmission includes using a controller to determine a desired torque transmitted through an input clutch and a desired clutch slip for the desired gear after a shift lever is moved to a desired gear position and while a clutch pedal is being released for engaging the clutch; measuring torque in the vehicle drive assembly; using measured torque to determine actual clutch torque transmitted through the clutch; and reducing torque error using the controller to adjust a clutch actuator such that a difference between the desired torque and the actual torque is reduced. Slip error may also be reduced by adjusting the clutch actuator to reduce the difference between the desired slip and measured slip.

Abstract: A method of downshifting an automotive transmission. An on-coming transmission element is stroked while pressure for an off-going element is reduced. Pressure for the stroked on-coming element is increased to be sufficient to carry torque. Pressure for the off-going element is reduced below a torque transmitting amount once the stroked on-coming element has a sufficient torque carrying capacity. Torque capacities for the elements are determined from transmission output torque and acceleration and transmission input torque and acceleration. Feed forward or feedback terms for off-going and on-coming element torque capacities may be calculated using the transmission output torque, transmission input acceleration, and transmission input torque.

Abstract: A method for controlling a manual transmission includes using a controller to determine a desired torque transmitted through an input clutch and a desired clutch slip for the desired gear after a shift lever is moved to a desired gear position and while a clutch pedal is being released for engaging the clutch; measuring torque in the vehicle drive assembly; using measured torque to determine actual clutch torque transmitted through the clutch; and reducing torque error using the controller to adjust a clutch actuator such that a difference between the desired torque and the actual torque is reduced. Slip error may also be reduced by adjusting the clutch actuator to reduce the difference between the desired slip and measured slip.

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 transmission clutch control method includes defining a transfer function relating clutch torque to a control signal under transmission operating conditions; determining a target clutch torque for current operating conditions; determining the target control signal from the transfer function to produce target torque at the clutch; correcting clutch torque on the basis of a difference between the target clutch torque and the actual torque at the clutch by adjusting the control signal; calculating actual clutch torque with reference to transmission input torque and transmission output torque; computing a clutch torque error as a difference between calculated clutch torque and the target clutch torque; and repetitively adjusting the transfer function on the basis of the clutch torque error.

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 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 valve-actuator includes a chamber, a spool that opens and closes connections between ports in the chamber, an actuator including a housing containing a piezoelectric stack having a bore, and a spring contacting the spool through the bore and forcing the stack toward the chamber, the stack expanding and contracting in response to a voltage, the spool moving in the chamber in response to said expansion and contraction.

Abstract: A valve-actuator includes a chamber, a spool that opens and closes connections between ports in the chamber, an actuator including a housing containing a piezoelectric stack having a bore, and a spring contacting the spool through the bore and forcing the stack toward the chamber, the stack expanding and contracting in response to a voltage, the spool moving in the chamber in response to said expansion and contraction.

Abstract: A valve-actuator for a hydraulic valve includes a valve chamber, ports spaced mutually and opening into the chamber, a spool axially located in the chamber for opening and closing hydraulic connections between at least two of the ports as the spool moves axially in the chamber. An actuator includes a housing having mutually spaced surfaces, and a piezoelectric element located in the housing between the surfaces, the element expanding and contracting in response to an electric signal applied to the element. A temperature compensation and motion damping circuit comprising feedback resistors and a thermistor. The spool moves axially in the chamber in response to expansion and contraction of the element.

Abstract: An actuator system includes a piezoelectric pump; an accumulator including a cylinder, a piston located in the cylinder, a port located at a first side of the piston and hydraulically connected to the pump outlet and a switching circuit, a relief port hydraulically connected to the reservoir and located at a second side of the piston, and a spring biasing the piston toward the port; and a hydraulically actuated servo including a front port hydraulically connected to the switching circuit, a back port hydraulically connected to the reservoir, and the servo causing the friction element alternately to engage and to disengage in response to a magnitude of hydraulic pressure in the servo.

Abstract: A valve-actuator for a hydraulic valve includes a valve chamber, ports spaced mutually and opening into the chamber, a spool axially located in the chamber for opening and closing hydraulic connections between at least two of the ports as the spool moves axially in the chamber. An actuator includes a housing having mutually spaced surfaces, and a piezoelectric element located in the housing between the surfaces, the element expanding and contracting in response to an electric signal applied to the element. A temperature compensation and motion damping circuit comprising feedback resistors and a thermistor. The spool moves axially in the chamber in response to expansion and contraction of the element.

Abstract: An actuator system includes a piezoelectric pump; an accumulator including a cylinder, a piston located in the cylinder, a port located at a first side of the piston and hydraulically connected to the pump outlet and a switching circuit, a relief port hydraulically connected to the reservoir and located at a second side of the piston, and a spring biasing the piston toward the port; and a hydraulically actuated servo including a front port hydraulically connected to the switching circuit, a back port hydraulically connected to the reservoir, and the servo causing the friction element alternately to engage and to disengage in response to a magnitude of hydraulic pressure in the servo.