Laboratory-Based Automatic Transaxle Calibration, 03-R9635

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Principal Investigator
Joe Steiber

Inclusive Dates:  07/01/06 – 06/30/08

Background - Interest in developing automated calibration of transmissions to reduce product development time has been increasing. Previous SwRI research has successfully demonstrated that in-vehicle autocalibration was feasible. The next step in improving the inconsistencies associated with human-based shift quality assessment while expediting the calibration process is the execution of these tasks in a completely controlled laboratory environment.

Approach - The goal of this research program is to develop and demonstrate a laboratory-based system that can autonomously calibrate an automatic transaxle controller. The approach emphasizes three aspects of calibration: automation of the test cell, objective shift quality assessment, and numerical optimization of calibration parameters. From a host computer, automation commands will be communicated to powertrain actuators and dynamometers that will perform user-defined maneuvers. This computer will then convert lab-sensor data into human-like shift quality metrics that will be utilized by specialized calibration algorithms. These algorithms will determine the best calibration parameters for the given maneuver, download them to the transaxle controller, and issue a command to verify the performance. The process is repeated until calibration is completed.

Accomplishments - SwRI engineers assembled a test cell that incorporated an automatic clutch-to-clutch transaxle in production. Special routines for autocalibration were developed. Preliminary simulation of the process was undertaken and provided promising results. Test results confirmed the underlying approach.

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