Abuse Mode Torque Limiting Control Method For A Ball-Type Continuously Variable Transmission

Abstract

Provided herein is a control system for a multiple-mode continuously variable transmission having a ball planetary variator operably coupled to multiple-mode gearing. The control system has a transmission control module configured to receive a plurality of electronic input signals, and to determine a mode of operation from a plurality of control ranges based at least in part on the plurality of electronic input signals. The control system includes an engine torque limit sub-module adapted to command an engine torque limit based at least in part on the operating conditions of the continuously variable transmission.

What is claimed is: 
     
         1 . A computer-implemented method for controlling engine torque in a vehicle, wherein the vehicle comprises an engine coupled to an infinitely variable transmission (IVT) having a ball-planetary variator (CVP), a plurality of sensors, and a computer-implemented system comprising
 a digital processing device comprising an operating system configured to perform executable instructions and a memory device, and   a computer program including the instructions executable by the digital processing device, wherein the computer program comprises a software module; the method comprising: controlling engine torque by one or more of the plurality of sensors sensing vehicle parameters comprising: an accelerator pedal position, a CVP input speed, a CVP output speed, a current engine torque;   the software module determining a first engine torque limit based on a speed ratio droop of the CVP, wherein the speed ratio droop is based on the CVP input speed and the CVP output speed;   the software module determining a second engine torque limit based on the CVP input speed;   the software module determining a third engine torque limit based on the accelerator pedal position;   the software module determining a minimum value among the first engine torque limit, the second engine torque limit, and the third engine torque limit; and   the software module commanded an engine torque based on the minimum value.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising the software module for determining a temperature derate parameter based on an oil temperature. 
     
     
         3 . The computer-implemented method of  claim 2 , further comprising the software module applying the derate parameter to the minimum value.