Gm Global Technolgoy Operations, Inc.

Greg J Perantoni

Ronald F Lochocki, Jr

Paul G Otanez

Bret M Olson

Xuefeng Tim Tao

Christopher Jay Weingartz

Matthew Pruski

Bryan J Williams

Scott D Biggs

Brian James Pellerito

Jeryl McIver

Brian W Hanselman

Mary M Whitley

Nathan A Schmidt

Leo P Dion

Stuart W Parker

Systems and methods are provided for controlling a transmission associated with a vehicle. The method includes receiving a neutral range selection for the transmission, and receiving a temperature and a pressure of a lubricant associated with the transmission. The method includes receiving a speed of an input shaft associated with the transmission, and determining, by a processor, based on the temperature and the speed of the input shaft, a pressure threshold value for the lubricant. The method includes outputting, by the processor, one or more control signals to command the transmission to a one clutch neutral state in which one clutch of a plurality of clutches associated with the transmission is engaged based on a comparison of the pressure threshold value to the pressure of the lubricant.

Methods and systems for controlling transmission in neutral

A clutch-to-clutch transmission monitoring system for an automobile vehicle includes a control software generating a control signal. A monitor is in communication with the control software. A pre-compute monitor is in communication with the control software. The pre-compute monitor also receives the input data and outputs an operating threshold signal to the control software. The operating threshold signal defines allowed operating bounds for at least one component in communication with the monitor. A post-compute monitor is in communication with both the control software and the pre-compute monitor. The post-compute monitor receives both the control signal and the operating threshold signal. The post-compute monitor compares the control signal to the operating threshold signal to identify if the control signal violates the allowed operating bounds defined by the pre-compute monitor.

Method and apparatus for safe gear ratio selection and control for a clutch-to-clutch transmission

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 pressure sensor rationality diagnostic for a dual clutch transmission includes a series of sensor tests. One such test includes charging an oil accumulator to a maximum pressure and storing the maximum pressure value. After performing a discharge pressure event and measuring the pressure value, the difference between the max pressure value and the discharge pressure value is calculated to determine if the difference is less than a predetermined threshold. If the difference is less than the predetermined threshold then at least one remedial action is performed which may include a driver alert or default charging mode. Additionally, similar sensor tests are performed to determine if faults exists and, if true, at least one remedial action is performed.

Pressure sensor rationality diagnostic for a dual clutch transmission

A transmission control system of a vehicle includes an estimated acceleration module and a pressure control module. The estimated acceleration module determines an estimated longitudinal acceleration of the vehicle based on a force at axles of the vehicle corresponding to engine torque, a braking force imposed by mechanical brakes of the vehicle, an aerodynamic drag force of the vehicle, and a road load force imposed on the vehicle by contact between tires of the vehicle and a road surface. The pressure control module, when a measured longitudinal acceleration of the vehicle is negative and the estimated longitudinal acceleration is greater than the measured longitudinal acceleration of the vehicle, adjusts transmission fluid pressure applied to one or more clutches of the transmission and shifts the transmission to neutral.

Vehicle deceleration control systems and methods

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Milford, MI, United States of America

Greg J Perantoni