Patent ID: 8942901
Filing Date: 2015-01-27
Classification: F16H,Y10T

Abstract:
1. A method of controlling a dual clutch and a plurality of synchronizers in a transmission, the method comprising: selecting an actuator from a plurality of actuators that actuates a synchronizer of one of the plurality of synchronizers or engages a clutch from one of a first and a second clutch of the dual clutch in order to achieve a desired speed ratio in the transmission; actuating the selected clutch of the dual clutch with a pressurized hydraulic fluid; commanding a first synchronizer control solenoid to provide a first supply of hydraulic fluid to a first input of a first mode valve, wherein the first synchronizer control solenoid is in downstream fluid communication with a source of pressurized hydraulic fluid; commanding a second synchronizer control solenoid to provide a second supply of hydraulic fluid to a second input of the first mode valve, wherein the second synchronizer control solenoid is in downstream fluid communication with the source of pressurized hydraulic fluid; actuating the first mode valve to one of a first position and a second position to direct the first and second supplies of hydraulic fluid to one of a second mode valve and a third mode valve, wherein actuating the first mode valve in the first position directs the first supply of hydraulic fluid from the first input of the first mode valve to a first output of the first mode valve and directs the second supply of hydraulic fluid from the second input of the first mode valve to a third output of the first mode valve, and wherein actuating the first mode valve in the second position directs the first supply of hydraulic fluid from the first input of the first mode valve to a second output of the first mode valve and directs the second supply of hydraulic fluid from the second input of the first mode valve to a fourth output of the first mode valve, and wherein the first output of the first mode valve is in fluid communication with a first input of the second mode valve, the second output of the first mode valve is in fluid communication with a first input of the third mode valve, the third output of the first mode valve is in fluid communication with a second input of the second mode valve, and the fourth output of the first mode valve is in fluid communication with a second input of the third mode valve; and actuating at least one of the first, second, and third mode valves to direct the first and second supplies of hydraulic fluid to the selected actuator to control the position of the actuator, wherein actuating at least one of the first, second, and third mode valves directs the first supply of hydraulic fluid from the first input of the respective mode valve to a first side of the piston of the selected actuator and directs the second supply of hydraulic fluid from the second input of the respective mode valve to the second side of the piston of the selected actuator; determining a target clutch torque to be provided by the selected clutch, determining a target clutch position of the selected clutch that will provide the target clutch torque using a clutch torque to clutch actuator position relationship, selecting a first pressure of a hydraulic fluid to be provided by a pressure control solenoid from the higher of a pressure required to enable a required amount of flow through the flow control solenoid to actuate the clutch, a pressure required to hold the target clutch torque on the clutch, and a pressure required to shift a mode valve, commanding the pressure control solenoid to provide a third supply of hydraulic fluid at the selected first pressure to establish an upstream side of a pressure potential across a flow control solenoid that is downstream of the pressure control solenoid, sensing a position of the clutch actuator, estimating a second pressure of a fourth supply of hydraulic fluid at the clutch actuator using a predetermined clutch actuator position to clutch pressure relationship, calculating a pressure potential across the flow control solenoid by subtracting the second pressure from the first pressure, wherein the pressure potential across the flow control solenoid creates a relationship between a control signal and a flow rate from the flow control solenoid, determining a flow rate of the third supply of hydraulic fluid to be provided by the flow control solenoid that will position the clutch actuator to the target clutch position, determining a control signal to be sent to the flow control solenoid to provide the flow rate of the third supply of hydraulic fluid, and communicating the control signal to the flow control solenoid to move the clutch actuator to the target clutch position to provide the target clutch torque.