Gm Global Technolgoy Operations, Inc.

Other

Christopher Jay Weingartz

Steven Patrick Moorman

Bret M Olson

Philip C Lundberg

Xuefeng Tim Tao

John R Czoykowski

Chinar S Ghike

Matthew D Whitton

Craig J Hawkins

David H Vu

Glenn W Hoefflin

Matthew Kempeinen

Andreas Gustavsson

Paul G Otanez

James D Hendrickson

Ronald F Lochocki, Jr

John E Marano

Jeryl McIver

Cole Reinhold

Michael Livshiz

Mark A Schang

Robert L Williams

Mateusz M Nowak

Bharath Pattipati

Colin Hultengren

Greg J Perantoni

James L Abington

Bret J Keller

Mikael M Johansson

Pratap Atchutha Naick

Minh Q Truong

Tomas Carlsson

Artin Farahani

James M Gessner

Mark A Yacoub

Stuart W Parker

Mary M Whitley

Michael T Sarzynski

Nathan A Schmidt

Ludvig Franzen

A hydraulic system may include an electrohydraulic control valve disposed in fluid communication between a source of pressured fluid and a hydraulic actuator. The hydraulic system may be controlled to correct for offset errors between a target actuator pressure and a current actuator pressure output from the control valve, without amplifying pressure oscillations in the fluid between the control valve and the hydraulic actuator.

Method for controlling a hydraulic system

A propulsion system, control system, and method use model predictive control systems to generate a plurality of sets of possible command values and determine a cost for each set of possible command values. The set of possible command values that has the lowest cost is determined and defined as a selected set of command values. In some circumstances, the MPC-determined command value may be replaced by another transmission ratio command based on override inputs. Minimum and maximum transmission ratios are determined based on the override inputs, and a constrained (or arbitrated) transmission ratio is determined therefrom. The constrained or arbitrated transmission ratio is used to determine whether to apply an MPC-determined transmission ratio or a transmission ratio based on the arbitrated transmission ratio to determine an ultimate commanded transmission ratio. Pressure(s) are commanded to a transmission pulley assembly, which is configured to implement the ultimate commanded transmission ratio.

Shift management in model predictive based propulsion system control

A vehicle propulsion system includes a prime mover having a prime mover output shaft, a continuously variable transmission having a variator input shaft coupled to the prime mover output shaft and having a variator output shaft, a driver torque request module in communication with a driver input and for outputting a driver torque request, an engine backbone in communication with the prime mover, and a transmission backbone in communication with the continuously variable transmission and the engine backbone in the vehicle propulsion system. The transmission backbone includes a positive torque request module that generates a positive torque request, and a positive torque request monitor that limits a torque request from the transmission backbone to the engine backbone to a maximum of a predetermined threshold.

Control system for a continuously variable transmission in a vehicle propulsion system

An apparatus for ratio control of a continuously variable transmission includes a driver commanded ratio unit outputting a signal defining a commanded ratio. A clamp control portion is in communication with the driver commanded ratio unit. The clamp control portion includes: a ratio limits and override ring selecting a ratio matching the commanded ratio from an executable functions having stored ratio code data; a screening monitor continuously receiving output from the executable functions and using an input from a vehicle speed signal to compute minimum and maximum ratio limits for the ratio selected by the ratio limits and override ring; and a ratio control execution ring in communication with the screening monitor. The ratio control execution ring calculates a range of pressures allowed for operation of both primary and secondary pulleys of the continuously variable transmission.

Method and apparatus for ratio control for a continuously variable transmission

A powertrain system including an internal combustion engine rotatably coupled to a continuously variable transmission (CVT) is described. A method for controlling the CVT includes determining minimum and maximum CVT input speeds in response to an accelerator pedal position, and monitoring vehicle speed and a CVT input speed. A target CVT input acceleration rate is determined based upon the vehicle speed, and a desired speed ratio is determined that is responsive to the target CVT input acceleration rate. The CVT is controlled based upon the desired speed ratio.

Method and apparatus to control a continuously variable transmission

A continuously variable transmission, a control system, and a method is provided for synchronizing a clutch application state change and a continuous upshift in a motor vehicle propulsion system having a continuously variable transmission (CVT). The control system and method are configured to determine whether a continuous upshift of the CVT is impending. The continuous upshift is defined as a pulley ratio change exceeding a predetermined threshold for a predetermined pulley ratio change period. If a continuous upshift is impending, the control system and method are configured to alter a clutch engagement state after a predetermined delay period to synchronize the change in clutch engagement state with an engine speed change.

Synchronizing clutch apply state with continuous ratio shift in a continuously variable transmission

A method and system for controlling a ratio of a continuously variable transmission coupling a prime mover to a driven member in a vehicle. The method includes determining a current ratio of the continuously variable transmission, determining a projected ratio from a first ratio path of a predetermined ratio map, calculating a gradient between the current ratio and the projected ratio, determining whether the calculated gradient satisfies a gradient constraint, setting a control ratio to the projected ratio if the calculated gradient satisfies the gradient constraint, setting a control ratio to a modified ratio if the calculated gradient does not satisfy the gradient constraint, the modified ratio being based upon a ratio that satisfies the gradient constraint, and controlling the ratio of the continuously variable transmission to the control ratio.

System and method for ratio control in a vehicle continuously variable transmission

A target ratio module selectively determines a target ratio of transmission input shaft speed to transmission output shaft speed independently of an accelerator pedal position and as a function of a vehicle speed and a driver axle torque request. A first pulley valve control module controls opening of a first valve based on the target ratio. The first valve controls transmission fluid flow to a first pulley actuator. The first pulley actuator is coupled to the transmission input shaft of a continuously variable transmission (CVT) and expands and contracts based on transmission fluid pressure. A second pulley valve control module controls opening of a second valve based on the target ratio. The second valve controls transmission fluid flow to a second pulley actuator. The second pulley actuator is coupled to the transmission output shaft of the CVT and expands and contracts based on transmission fluid pressure.

Transmission ratio control systems and methods

A method and system for controlling movement of an actuator fork of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity includes adjusting the level of fluid pressure applied to an actuator operatively attached to the actuator fork to control the pre-synchronization fork velocity within a predetermined range of a velocity target. The method determines, via a controller, the fork velocity during the pre-synchronization phase of a current synchronization event, compares the determined fork velocity to a velocity target, and adjusts the pressure level of fluid applied to an actuator piston of the actuator to control the velocity of the actuator fork within a predetermined range defined by the velocity target during a subsequent pre-synchronization phase. The velocity target may be defined for a shift type, such as a fast or slow shift, where the shift type is determined by the controller.

Method of controlling a synchronizer actuator fork of a transmission

A vehicle includes an engine, a transmission having a position-controlled clutch with a synchronizer sleeve and a synchronizer fork, an input member with an input speed, and an output member with an output speed, and a controller. The controller is programmed to register a slip-away condition when the input speed falls within a calibrated speed band and the output speed remains below a calibrated threshold speed. In response to the registered slip-away condition, the controller records a diagnostic code indicative of the synchronizer sleeve being disengaged, changes an engaged position of the synchronizer sleeve by a calibrated amount to thereby adapt the engaged position, and commands the clutch to disengage and the fork to move to a neutral position after increasing the engaged position. The controller also moves the synchronizer sleeve toward the adapted engaged position and applies the clutch when the synchronizer sleeve attains the adapted engaged position.

Synchronizer fork position control

A method of controlling movement of an actuator fork and attached synchronizer sleeve of a transmission through a pre-synchronization phase of a synchronization event at a pre-synchronization fork velocity below a breakaway velocity such that a strut is retained to the sleeve by a ball plunger for the duration of the pre-synchronization phase. A method of adjusting one of a pressure signal and a flow signal to an actuator piston to control movement of the actuator fork includes moving the fork from an initial disengaged position through a pre-synchronization phase of a synchronization event by controlling one of a pre-synchronization fluid pressure value and flow value, where the controlled pre-synchronization fluid value is less than a threshold value corresponding to a breakaway force of a ball plunger configured to selectively retain a strut assembly to a synchronizer sleeve operatively attached to the actuator fork.

A method of controlling a transmission includes selecting a target speed of a second shaft, and measuring a second speed of the second shaft and an output speed of an output shaft. The method includes detecting a rolling neutral condition wherein a first and second clutch are uncoupled from a torque generator and a synchronizer is mated to a predicted gear to apply a load in a direction, and one of a first condition wherein the output speed is decreasing and the target speed is less than the second speed and a second condition wherein the output speed is increasing and the target speed is less than the second speed. The method then includes translating the synchronizer away from the predicted gear, coupling and decoupling the second clutch to and from the torque generator, and mating the synchronizer to the predicted gear to again apply the load in the direction.

Method of controlling a transmission

A method of identifying a synchronous position of a synchronizer actuator fork includes sensing a deceleration rate of a first shaft, when a synchronizer is positioned in a neutral position, to define a first rate of deceleration. The synchronizer is moved along the first shaft from the neutral position toward a gear with a synchronizer actuator fork. A deceleration rate of the first shaft is sensed, while the synchronizer actuator fork moves the synchronizer along the first shaft, to identify a change from the first rate of deceleration to a second rate of deceleration. The location, of the synchronizer actuator fork relative to the first shaft, at which the rate of acceleration of the first shaft changes from the first rate of deceleration to the second rate of deceleration, is identified as the synchronous position of the synchronizer actuator fork.

Method of identifying a synchronous position of a synchronizer actuator fork of a dual clutch transmission

A method of controlling a hydraulic control system for a dual clutch transmission includes controlling a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

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Holly, MI, United States of America

Christopher Jay Weingartz