Shift Feel Testing
SwRI Project: |
03-4141 |
Client: |
Industrial Confidential |
Project Brief
As drivers demand higher standards for vehicle performance, shift harshness is no longer acceptable. Southwest Research Institute (SwRI) has conducted considerable vehicle shift feel testing
and evaluation with specially trained evaluators. The evaluators quantify
the rate of change of acceleration (jerk) of the vehicle.
To eliminate the subjective nature of these measurements, SwRI has developed test methods to evaluate shift feel characteristics outside the vehicle. The entire powertrain is installed on a dynamometer test stand, and the engine and transmission or transaxle are
physically separated so an in-line torque transducer can be interspersed between them. All electrical sensors and controllers are installed.
Downstream of the transmission and transaxle is an eddy current dynamometer to simulate parasitic losses and aerodynamic drag. Connected to the output are inertia wheels that simulate a vehicle weight and rolling radius.
Output torque is obtained with high-speed data acquisition equipment at 100 Hz. The resulting torque curve versus time is digitally differentiated to determine the rate of change of torque with respect to time.
For more information about drivetrain engineering capabilities and past
project briefs at SwRI or how you can contract with SwRI, please contact
Douglas Fussner at
dfussner@swri.org or (210) 522-3972.
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