摘要:
A control strategy and method for controlling application and release of friction elements in an automatic transmission to effect gear ratio changes as one friction element is release and another friction element is applied during ratio changes. The transmission has an electronic controller and multiple solenoid regulator valves hydraulically coupled directly to pressure-operated friction elements. Powertrain variables are obtained and processed to calculate gear ratio control parameters derived from desired line pressure for a pressure control valve circuit that communicates with the friction elements. The desired gear ratio is determined for each given set of powertrain variables. Upshifts and downshifts are obtained by releasing one friction element in synchronism with an application of the other friction element, whereby a direct friction element to friction element torque transition is achieved with minimal inertia torque disturbances.
摘要:
An automatic transmission ratio shift control system and method for a powertrain having a throttle-controlled engine and multiple-ratio gearing, torque flow paths through the gearing being established and disestablished by pressure-operated friction elements, an electronic controller for establishing torque transitions between the friction elements as ratio changes occur in the multiple-ratio gearing, the engine throttle being controlled by an electronic throttle control that is decoupled from the driver-controlled accelerator pedal, the transmission torque output being controlled by means of a friction element capacity control strategy including a feed-forward torque term determined by changes in commanded torque, the slip duration during a ratio change being controlled by means of closed-loop engine torque control.
摘要:
A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.
摘要:
A method of controlling engine torque in a motor vehicle having an internal combustion engine and multi-ratio transmission when launched from a neutral idle rest condition. At neutral idle, the transmission is controlled such that the input and output members are decoupled. During vehicle launch, two different strategies may be employed to control engine torque. One preferred method is to determine an engine brake torque limit as a function of time. Another preferred method to determine the engine brake torque limit is to estimate the torque capacity of the forward clutch at any given time using a mathematical model and a calibrated offset of turbine torque. Irrespective of the particular method used, the determined engine brake torque limit is compared to the corresponding engine torque amount that is requested by the vehicle operator. As a result, the actual engine torque output is optimized at all times to provide approximately the maximum amount of requested torque without exceeding the capacity of the transmission's forward clutch.
摘要:
A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.
摘要:
A method of controlling engine idle speed in a motor vehicle having an internal combustion engine and multi-ratio transmission when launched from a neutral idle rest condition. At neutral idle, the transmission is controlled such that the input and output members are decoupled. During vehicle launch from neutral idle operation, two different strategies may be employed to control engine idle speed. One preferred method is to determine a feedforward or predicted torque converter load as a function of time. Another preferred method is to determine the feedforward or predicted torque converter load by comparing a maximum engine brake torque and the torque capacity of the forward clutch at any given time. Irrespective of the particular method used, other engine torque loads are added to the feedforward or predicted torque converter load to determine the engine output torque required to control engine idle speed and provide a smooth between transmission operating modes throughout the launch period.
摘要:
A gear ratio shift control and control method controls gear ratio upshifts in a multiple-ratio transmission for an automotive vehicle. Pressure actuated friction elements establish torque flow paths in transmission gearing as they are selectively engaged and released. A net torque reduction at a transmission torque output shaft during an upshift event is reduced by increasing transmission input torque prior to the start of the inertia phase of the upshift event.
摘要:
A speed ratio shaft control for multiple ratio vehicle transmission has controlled release of an off-going transmission clutch and controlled engagement of an on-coming transmission clutch during a speed ratio upshift, at least one clutch being a friction torque establishing clutch. A controller, using shift-timing software strategy, actively manages in real time a clutch torque level for each clutch so that transient torque disturbances in a transmission torque output shaft are mitigated.
摘要:
A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided.
摘要:
A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided.