Target volume based torque phase control during upshift
First Claim
1. A transmission control system for a transmission including a first gear engagement element that receives fluid and engages a first gear in response to pressure from the fluid, comprising:
- an electromagnetic actuator that receives a control signal and that selectively interrupts flow of the fluid to the first gear engagement element based on a duty cycle of said control signal; and
a control module that generates said control signal and that adjusts said duty cycle so that a flow rate of the fluid to the first gear engagement element continuously decreases as the first gear engagement element produces a first torque sufficient to hold the first gear,wherein said flow rate is based on a first estimated volume of the fluid necessary for the first gear engagement element to produce said first torque.
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Accused Products
Abstract
A transmission control system includes a first gear engagement element that receives fluid and engages a first gear. An electromagnetic actuator selectively interrupts fluid flow to the first gear engagement element based on a duty cycle of a control signal. A control module adjusts the duty cycle so that a fluid flow rate continuously decreases as the first gear engagement element produces a first torque sufficient to hold the first gear. The flow rate is based on a first estimated volume of the fluid necessary for the first gear engagement element to produce the first torque. The control module computes a current volume of the fluid when the first gear engagement element produces the first torque. The control module adjusts a value of the first estimated volume for subsequent transmission control when a difference between the current volume and the first estimated volume is greater than a predetermined volume.
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Citations
20 Claims
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1. A transmission control system for a transmission including a first gear engagement element that receives fluid and engages a first gear in response to pressure from the fluid, comprising:
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an electromagnetic actuator that receives a control signal and that selectively interrupts flow of the fluid to the first gear engagement element based on a duty cycle of said control signal; and a control module that generates said control signal and that adjusts said duty cycle so that a flow rate of the fluid to the first gear engagement element continuously decreases as the first gear engagement element produces a first torque sufficient to hold the first gear, wherein said flow rate is based on a first estimated volume of the fluid necessary for the first gear engagement element to produce said first torque. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A transmission control system for a transmission including a first gear engagement element that receives fluid and engages a first gear in response to pressure from the fluid and a second gear engagement element that includes a first volume of the fluid and holds a second gear, comprising:
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an electromagnetic actuator that receives a control signal and that selectively interrupts flow of the fluid to the first gear engagement element based on a duty cycle of said control signal; and a control module that begins to evacuate the first volume of fluid from the second gear engagement element a first predetermined amount of time after said control module initiates a shift, that generates said control signal, and that adjusts said duty cycle so that a flow rate of the fluid to the first gear engagement element continuously decreases as the first gear engagement element produces a first torque sufficient to hold the first gear, wherein the first gear engagement element produces said first torque a second predetermined amount of time after said shift is initiated and wherein said second predetermined amount of time is fixed for all upshifts in the transmission. - View Dependent Claims (11)
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12. A method for operating a transmission control system for a transmission including a first gear engagement element that receives fluid and engages a first gear in response to pressure from the fluid, comprising:
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selectively interrupting flow of the fluid to the first gear engagement element based on a duty cycle of said control signal; and adjusting said duty cycle so that a flow rate of the fluid to the first gear engagement element continuously decreases as the first gear engagement element produces a first torque sufficient to hold the first gear, wherein said flow rate is based on a first estimated volume of the fluid necessary for the first gear engagement element to produce said first torque. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification