摘要:
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.
摘要:
A continuously variable transmission (CVT) for a vehicle includes an input member, an output member and a variator assembly including a first pulley rotatably coupled to the input member and a second pulley rotatably coupled to the output. The first and second pulleys are rotatably coupled by a flexible continuous rotatable device. A control system is provided including an instruction set executable to determine an initial variator speed ratio of the variator assembly and detect an event causing a change in an operational state of the vehicle. The control system determines a compensation strategy to adjust the variator speed ratio in response to the change in the operational state of the vehicle and generates an adjusted variator speed ratio based upon the compensation strategy. The control system transmits the adjusted variator speed ratio to the variator assembly.
摘要:
A method of controlling a clutch-to-clutch power-on upshift of a transmission includes defining a possible engine torque as a latched possible engine torque value. An on-coming clutch torque phase target value is defined as a latched on-coming clutch torque value, and held constant until a final ramp. A commanded engine torque is reduced and maintained to a maximum torque reduction value until a shift completion ratio is achieved. The commanded engine torque is increased until the commanded engine torque is equal to a restore ramp target value. Both the on-coming clutch torque and the commanded engine torque are simultaneously increased at a final ramp rate, such that the increase in the on-coming clutch torque parallels the increase in the commanded engine torque, until an actual engine torque is substantially equal to the possible engine torque, to complete the shift.
摘要:
A vehicle includes an engine, an engine control module (ECM), and a dual clutch transmission (DCT) assembly. The DCT assembly has first and second input clutches, first and second gear sets selectively connected to the engine via the respective first and second input clutches, and a transmission control module (TCM). In executing a launch control method, the TCM receives a launch request, receives an actual engine torque, and determines the inertia and acceleration of the engine. The TCM then calculates a clutch torque for the particular input clutch used for vehicle launch as a function of the actual engine torque and the product of the inertia and the acceleration, compares the calculated clutch torque to the commanded clutch torque, modifies a torque-to-position (TTP) table depending on the comparison result, and transmits a clutch position signal to the designated input clutch to command an apply position extracted from the TTP table.
摘要:
A continuously variable transmission (CVT) for a vehicle includes an input member, an output member and a variator assembly including a first pulley rotatably coupled to the input member and a second pulley rotatably coupled to the output. The first and second pulleys are rotatably coupled by a flexible continuous rotatable device. A control system is provided including an instruction set executable to determine an initial variator speed ratio of the variator assembly and detect an event causing a change in an operational state of the vehicle. The control system determines a compensation strategy to adjust the variator speed ratio in response to the change in the operational state of the vehicle and generates an adjusted variator speed ratio based upon the compensation strategy. The control system transmits the adjusted variator speed ratio to the variator assembly.
摘要:
A method of controlling a clutch-to-clutch power-on upshift of a transmission includes defining a possible engine torque as a latched possible engine torque value. An on-coming clutch torque phase target value is defined as a latched on-coming clutch torque value, and held constant until a final ramp. A commanded engine torque is reduced and maintained to a maximum torque reduction value until a shift completion ratio is achieved. The commanded engine torque is increased until the commanded engine torque is equal to a restore ramp target value. Both the on-coming clutch torque and the commanded engine torque are simultaneously increased at a final ramp rate, such that the increase in the on-coming clutch torque parallels the increase in the commanded engine torque, until an actual engine torque is substantially equal to the possible engine torque, to complete the shift.
摘要:
A method for learning the bite point of a position-controlled clutch in a vehicle having an engine and a transmission includes commanding an engagement of a clutch fork via a controller when the transmission is in park and the engine is idling. The method also includes controlling an apply position of the clutch via the controller, calculating a clutch torque capacity of the clutch, and measuring the apply position via a position sensor. The apply position is recorded as the clutch bite point when the calculated clutch torque capacity equals a calibrated clutch torque capacity. The transmission is then controlled using the recorded clutch bite point. A system includes the transmission, input clutches, and a controller configured to execute the method. A vehicle includes an engine, the transmission, the position-controlled input clutch, and the controller, as well as a clutch position sensor.
摘要:
A vehicle includes an engine, a dry dual-clutch transmission (dDCT) having a pair of input clutches and a gearbox containing oddly- and evenly-numbered gear sets, and a transmission control module (TCM). Application of one of input clutches connects the engine to a corresponding one of the oddly- or evenly-numbered gear sets. The TCM includes feed-forward PID-based control logic, and a torque-to-position (TTP) table for each input clutch. The TCM commands a position of a designated input clutch during a power-on upshift using the feed-forward, PID-based control logic, and selectively adapts the TTP table as a function of an inertia and acceleration value of the engine. The TCM may apply an asymmetrical handoff profile to commanded oncoming and offgoing clutch torques during the torque phase of the upshift. The TCM may also adjust the TTP table as a function of the frequency of use of the input clutches.
摘要:
A vehicle includes an engine, an engine control module (ECM), and a dual clutch transmission (DCT) assembly. The DCT assembly has first and second input clutches, first and second gear sets selectively connected to the engine via the respective first and second input clutches, and a transmission control module (TCM). In executing a launch control method, the TCM receives a launch request, receives an actual engine torque, and determines the inertia and acceleration of the engine. The TCM then calculates a clutch torque for the particular input clutch used for vehicle launch as a function of the actual engine torque and the product of the inertia and the acceleration, compares the calculated clutch torque to the commanded clutch torque, modifies a torque-to-position (TTP) table depending on the comparison result, and transmits a clutch position signal to the designated input clutch to command an apply position extracted from the TTP table.
摘要:
A system and method can control the dry dual clutch transmission (dDCT) of a vehicle. The method includes modifying a recorded torque-to-position (TTP) table based on a calculated clutch torque difference between a calculated clutch torque and a commanded clutch torque. The commanded clutch torque is provided by a transmission control module and is defined as a clutch torque sufficient to move the vehicle without applying the accelerator applier after the brake applier has been released. The calculated clutch torque is a function of the actual engine torque value, the engine inertia, and the engine acceleration.