Method and apparatus to control a continuously variable transmission
AssigneeGM Global Technology Operations LLC
InventorArtin Farahani
Life of this patent
Estimating the term…
Abstract
A powertrain system including a continuously variable transmission (CVT) is described. A method for controlling the CVT includes determining, employing a first controller, a first desired speed ratio in response to an output torque request. The first desired speed ratio is evaluated to determine if it is valid and achievable. A second controller is employed to determine a second desired speed ratio, and a final desired speed ratio is determined based upon the first and second desired speed ratios. The final desired speed ratio is evaluated, and the CVT is controlled based upon the final desired speed ratio.
Claims15
A method for controlling a continuously variable transmission (CVT) of a powertrain system, the method comprising:
- determining, employing a first controller, a first desired speed ratio in response to an output torque request;
- determining whether the first desired speed ratio is valid and achievable;
- determining, employing a second controller, a second desired speed ratio;
- determining a final desired speed ratio based upon the first and second desired speed ratios;
- evaluating the final desired speed ratio;
- and
- controlling the CVT based upon the final desired speed ratio.
A method for controlling a continuously variable transmission (CVT) of a powertrain system in response to a driver command, the method comprising:
- determining, employing a supervisory control system, a first desired speed ratio in response to the driver command;
- determining whether the first desired speed ratio is valid and achievable;
- determining, employing a transmission controller, a second desired speed ratio;
- determining a final desired speed ratio based upon the first and second desired speed ratios;
- and
- controlling the CVT based upon the final desired speed ratio.
A powertrain system, comprising:
- a continuously variable transmission, including:
- a variator including a first pulley and a second pulley, the first and second pulleys rotatably coupled by a flexible continuous rotatable device, wherein the first pulley rotatably couples to an input member and the second pulley rotatably couples to an output member,
- the first pulley including a moveable sheave that translates along a first axis relative to a stationary sheave in response to urging of a first actuator, and the second pulley including a moveable sheave that translates along a second axis relative to a stationary sheave in response to urging of a second actuator;
- a transmission controller operatively connected to the first and second actuators and in communication with a first sensor configured to monitor a first speed associated with the first pulley and a second sensor configured to monitor a second speed associated with the second pulley;
- a supervisory control system operatively connected to the powertrain system and in communication with the transmission controller;
- the supervisory control system and the transmission controller operative to:
- determine, employing an executable instruction set in the supervisory control system, a first desired speed ratio in response to an output torque request and determine whether the first desired speed ratio is valid and achievable,
- determine, employing an executable instruction set in the transmission controller, a second desired speed ratio,
- determine, employing an executable instruction set in the supervisory control system, a final desired speed ratio based upon the first and second desired speed ratios, and
- control, employing an executable instruction set in the transmission controller, the CVT based upon the final desired speed ratio.
Dependencies are inferred from the claim text.