Negative torque upshift control

摘要

A vehicle includes a prime mover, input clutch, transmission, and controller. The transmission, which is selectively connected to the output shaft via the input clutch, has multiple friction clutches, including respective offgoing and oncoming clutches for a negative torque upshift. The controller includes a torque request module, offgoing clutch module, and oncoming clutch module. The torque request module limits input torque into the transmission during the negative torque upshift. The offgoing control module determines actual offgoing clutch torque capacity of the offgoing clutch, calculates an actual offgoing clutch pressure using the actual offgoing clutch torque capacity, and controls the offgoing clutch through the shift using the actual offgoing clutch pressure. The oncoming control module controls the oncoming clutch through multiple stages of control of the oncoming clutch, including a fill, staging, ramp, and quick-lock stage. Closed-loop pressure correction is provided via PID logic through the inertia and torque shift phases.

主权项

1. A vehicle comprising:
a prime mover having an output shaft; an input clutch; a transmission that is selectively connected to the output shaft via the input clutch, and that has a plurality of friction clutches, at least one of which acts as a respective offgoing clutch and another at least one of which acts as an oncoming clutch during a negative torque upshift of the transmission, wherein the negative torque upshift is a commanded upshift of the transmission occurring when an input torque generated via the output shaft is negative; and a controller in communication with the prime mover, the transmission, and the input clutch, wherein the controller is operable to control the negative torque upshift, and wherein the controller includes:
a torque request module programmed to limit a rate of the input torque into the transmission during the negative torque upshift;an offgoing control module programmed to determine an actual offgoing clutch torque capacity of the offgoing clutch, to calculate an actual offgoing clutch pressure using the actual offgoing clutch torque capacity, and to control the offgoing clutch through the negative torque upshift using the actual offgoing clutch pressure; andan oncoming control module programmed to control the oncoming clutch through multiple stages of control of the oncoming clutch, including each of a fill, staging, ramp, and quick-lock stage of the control.