# US 2017/0130837 A1 · Method and apparatus to control a continuously variable transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0130837 A1 - Document ID: US20170130837A1 - Status: Published application - Kind: A1 - Application number: 14/935,583 - Filed: 2015-11-09 - Published: 2017-05-11 - Earliest claimed: 2015-11-09 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Artin Farahani - Web page: https://patentgrep.com/patent/US20170130837A1 ## CPC - F16H 61/662: with endless flexible members - F16H 9/18: only one flange of each pulley being adjustable - F16H 61/66259: {using electrical or electronical sensing or control means} - F16H 2061/66213: {dependent on driver's choice} - F16H: GEARING ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The method of claim 1, further comprising determining, employing the second controller, the second desired speed ratio when the second controller determines the first desired speed ratio is unachievable, and controlling the CVT based upon the second desired speed ratio. ### Claim 3 (depends on 1) The method of claim 1, further comprising determining, employing the second controller, the second desired speed ratio when the second controller determines the first desired speed ratio is invalid, and controlling the CVT based upon the second desired speed ratio. ### Claim 4 (depends on 1) The method of claim 1, wherein determining the final desired speed ratio based upon the first and second desired speed ratios comprises arbitrating between the first and second desired speed ratios to select a minimum state thereof. ### Claim 5 (depends on 1) The method of claim 1, further comprising: adjusting the final desired speed ratio based upon the evaluation; and controlling the CVT based upon the adjusted final desired speed ratio. ### Claim 6 (depends on 1) The method of claim 1, wherein controlling the CVT based upon the final desired speed ratio comprises controlling, via the second controller, a pressure command to drive an actuator of a moveable sheave of a clamping pulley of the CVT based upon a commanded clamping pressure associated with the final desired speed ratio. ### Claim 7 (depends on 1) The method of claim 1, wherein the first controller is a supervisory control system and the second controller is a CVT controller. ### Claim 8 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. ### Claim 9 (depends on 8) The method of claim 8, further comprising determining, employing the transmission controller, the second desired speed ratio when the second controller determines the first desired speed ratio is unachievable, and controlling the CVT based upon the second desired speed ratio. ### Claim 10 (depends on 8) The method of claim 8, further comprising determining, employing the transmission controller, the second desired speed ratio when the second controller determines the first desired speed ratio is invalid, and controlling the CVT based upon the second desired speed ratio. ### Claim 11 (depends on 8) The method of claim 8, wherein determining the final desired speed ratio based upon the first and second desired speed ratios comprises arbitrating between the first and second desired speed ratios to select a minimum state thereof. ### Claim 12 (depends on 8) The method of claim 8, further comprising: evaluating the final desired speed ratio; adjusting the final desired speed ratio based upon the evaluation; and controlling the CVT based upon the adjusted final desired speed ratio. ### Claim 13 (depends on 8) The method of claim 8, wherein controlling the CVT based upon the final desired speed ratio comprises controlling, via the second controller, a pressure command to drive an actuator of a moveable sheave of a clamping pulley of the CVT based upon a commanded clamping pressure associated with the final desired speed ratio. ### Claim 14 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. ### Claim 15 (depends on 14) The powertrain system of claim 14, further comprising: evaluate, employing an executable instruction set in the transmission controller, the final desired speed ratio, adjust, employing an executable instruction set in the transmission controller, the final desired speed ratio based upon the evaluation, and control, employing an executable instruction set in the transmission controller, the CVT based upon the adjusted final desired speed ratio.