US 2015/0032342 A1 · ASYNCHRONOUS-TO-SYNCHRONOUS CLUTCH TORQUE EXCHANGE IN A HYBRID ELECTRIC VEHICLE

Abstract

A vehicle includes torque sources, a transmission, and a controller programmed to execute a method. In executing the associated method, the controller determines whether continuous output torque is required through a torque exchange. When continuous output torque is required, the controller synchronizes and fills the oncoming clutch, estimates capacity of the oncoming clutch, and expands a short-term torque capacity of the oncoming clutch during the torque exchange, doing so in response to a control objective having a threshold priority. Onset of the torque exchange delays until the short-term torque capacity is sufficient for receiving all torque load from the offgoing clutch without affecting output torque. The controller asynchronously controls the offgoing clutch and synchronously controls the oncoming clutch through the torque exchange, and loads the synchronous oncoming clutch via an expanding set of long-control torque capacity limits as a function of a simultaneously exhausting of the offgoing clutch load.

Claims17

Dependent claims

A hybrid electric vehicle comprising:

a plurality of torque sources;
a transmission having:
a gear set;
and
a plurality of clutches including an offgoing clutch and an oncoming clutch;
and
a controller in communication with the transmission and the torque sources, wherein the controller is configured to:
determine whether continuous output torque is required through a duration of a torque exchange commanded via a requested shift;
and
when the continuous output torque is required:
synchronize and fill the oncoming clutch;
estimate a hydraulic capacity of the oncoming clutch;
temporarily expand a short-term torque capacity of the oncoming clutch during the duration of the torque exchange in response to a control objective having a threshold priority;
delay onset of the torque exchange until the short-term torque capacity of the oncoming clutch is sufficient for receiving all torque load from the offgoing clutch without affecting the continuous output torque;
asynchronously control the offgoing clutch through the duration of the torque exchange;
synchronously control the oncoming clutch through the duration of the torque exchange;
and
load the synchronous oncoming clutch via an expanding set of long-control torque capacity limits as a function of a simultaneously exhausting the offgoing clutch load.

15 more elements

A transmission assembly for a hybrid electric vehicle having a plurality of torque sources, the transmission comprising:

a gear set;
a plurality of clutches, including an oncoming and an offgoing clutch, wherein the offgoing clutch has a torque load at the onset of a requested torque exchange having a duration;
and
a controller configured to selectively connect and disconnect some of the plurality of torque sources to the gear set via respective engagement and disengagement of the plurality of clutches, wherein the controller is configured to determine when continuous output torque is required through a requested torque exchange, and in response to the required continuous output torque, to:
synchronize and fill the oncoming clutch;
estimate a hydraulic torque capacity of the oncoming clutch;
apply, in response to a control objective having a threshold control priority, a set of short-term torque capacity limits which temporarily expand a torque capacity of the oncoming clutch during the torque exchange;
delay the onset of the torque exchange until the estimated torque capacity of the oncoming clutch is capable of receiving all offgoing clutch load from the offgoing clutch without affecting the continuous output torque;
asynchronously control the offgoing clutch through the duration of the torque exchange;
synchronously control the oncoming clutch through the duration of the torque exchange;
and
load the synchronous oncoming clutch via expanding long-control torque capacity limits as a function of a simultaneously exhausting the offgoing clutch load.

9 more elements

A method for control of a hybrid electric vehicle having a plurality of torque sources, a gear set, a plurality of clutches, including an oncoming and an offgoing clutch, and a controller, the method comprising:

determining when continuous output torque is required through a requested torque exchange having a duration;
and
when the continuous output torque is required:
synchronizing and filling the oncoming clutch;
estimating a hydraulic torque capacity of the oncoming clutch;
applying, in response to a control objective having a threshold control priority, a set of short-term torque capacity limits which temporarily expand a torque capacity of the oncoming clutch during the duration of the torque exchange;
delaying the onset of the torque exchange until the estimated torque capacity of the oncoming clutch is capable of receiving all of the torque load from the offgoing clutch without affecting the output torque;
asynchronously controlling the offgoing clutch through the duration of the torque exchange;
synchronously controlling the oncoming clutch through the duration of the torque exchange;
and
loading the synchronous oncoming clutch via expanding long-control torque capacity limits as a function of a simultaneously exhausting the offgoing clutch load prior to or when the estimated torque capacity of the offgoing clutch reaches zero.

8 more elements

Dependencies are inferred from the claim text.

Asynchronous-to-synchronous clutch torque exchange in a hybrid electric vehicle

Life of this patent

Asynchronous-to-synchronous clutch torque exchange in a hybrid electric vehicle

Life of this patent

Abstract

Claims17