Method for controlling centrifugal clutch engagement using engine torque requests

• US 20060135317A1
• Filed: 12/16/2004
• Published: 06/22/2006
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Jacobs, Craig S.
• Granted Patent: US 7,480,555 B2
• Time in Patent Office: Days
• US Class Current: 477/180
• CPC Class Codes: F16D 2500/10412 Transmission line of a vehicle
• CPC Class Codes: F16D 2500/10481 Automatic clutch, e.g. centrifugal masses
• CPC Class Codes: F16D 2500/3065 Torque of the engine
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/3165 Using the moment of inertia of a component as input for the control
• CPC Class Codes: F16D 2500/50239 Soft clutch engagement
• CPC Class Codes: F16D 2500/7027 Engine speed
• CPC Class Codes: F16D 2500/70288 Clutch pedal position
• CPC Class Codes: F16D 2500/7061 Feed-back
• CPC Class Codes: F16D 2500/70631 Feed-forward
• CPC Class Codes: F16D 2500/70668 Signal filtering
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure

Abstract

A method for controlling a centrifugal clutch in a heavy-duty vehicle powertrain uses an engine torque request for a controller including a vehicle engine controller. A clutch controller develops an engine speed request based upon driver input. The engine speed request is converted to the engine torque request to effect smooth vehicle launch engagement of the clutch.

Claims

1. A method for controlling engagement of a centrifugal master clutch in a vehicle powertrain having a throttle-controlled internal combustion engine, a multiple-ratio transmission and a master clutch controller for controlling clutch engagement during launch and acceleration as torque from the engine is delivered to a torque input member of the transmission, and an engine controller responding to operating variables that are determined in successive control loops, the engine having a driver operated vehicle acceleration pedal, the method comprising:

calculating an engine speed request;

converting the engine speed request to an engine torque request; and

developing an engine control command that is responsive to changes in engine torque request whereby launch of the vehicle is characterized by controlled and timed clutch engagement that effects engagement smoothness.

2. The method set forth in claim 1 wherein the step of calculating an engine speed request comprises determining a time sampled engine speed during each control loop of the master clutch controller by determining a difference in engine speed during a current control loop of the master clutch controller and engine speed during a preceding control loop of the master clutch controller;

comparing the difference in engine speed to an engine speed rate change parameter; and

adding the lesser of the rate change limit parameter and the engine speed difference to the engine speed during the preceding control loop.

3. The method set forth in claim 2 wherein the step of converting the engine speed request to an engine torque request comprises establishing a target acceleration speed forward value by converting the engine speed request using a precalculated acceleration gain factor;

integrating the target acceleration speed forward value to obtain a target engine speed;

comparing target engine speed to actual engine speed to determine a speed error;

converting speed error to speed error feedback torque;

converting the target acceleration value to an inertia feed-forward torque; and

combining speed error feed-forward torque, inertia feed-forward torque and engine friction feed-forward torque, to effect the torque request.

4. The method set forth in claim 3 wherein the friction feed-forward torque is determined by multiplying target engine speed by an engine friction coefficient.

5. The method set forth in claim 4 wherein the inertia feed-forward torque is determined by multiplying target feed-forward acceleration by a calibrated engine inertia parameter indicative of mass of rotary elements of the engine.

6. The method set forth in claim 3 wherein the step of establishing a target acceleration feed-forward value comprises using a pre-calibrated gain factor and includes the step of filtering the product of the desired engine speed and the acceleration gain factor to establish an acceleration saturation limit for the target acceleration.

7. The method set forth in claim 4 wherein the step of establishing a target acceleration feed-forward value comprises using a pre-calibrated gain factor and includes the step of filtering the product of the desired engine speed and the acceleration gain factor to establish an acceleration saturation limit for the target acceleration.

8. The method set forth in claim 5 wherein the step of establishing a target acceleration feed-forward value comprises using a pre-calibrated gain factor and includes the step of filtering the product of the desired engine speed and the acceleration gain factor to establish an acceleration saturation limit for the target acceleration.