Powertrain and method for controlling a driveline retarder

• Main Authors: MC CAFFERTY BRADLEY L, RUSHING MARK A, SHULTZ JEFFREY E, CONN RANDALL S
• Format: Patent
• Language: English
• Published: 15.07.2008
• Subjects: ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; CALCULATING; COMPUTING; CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; PERFORMING OPERATIONS; PHYSICS; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OFVEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; TRANSPORTING; VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES; VEHICLES IN GENERAL

A method of controlling a driveline retarder of a powertrain including a transmission having a rotatable input shaft connected to an engine and an output shaft connected to the driveline retarder is provided. The method includes determining a set speed value and comparing the set speed value plus a customer modifiable constant value to a current rotational speed value of the output shaft. A driveline retarder cruise modulation torque request value is then calculated when the current rotational speed value of the output shaft is greater than or equal to the set speed value plus the customer modifiable constant value. The driveline retarder is controlled as a function of the driveline retarder cruise modulation torque request value. A powertrain configured to implement the aforementioned method is also disclosed.