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Automatic transmission shifting performance evaluation

  • US 10,641,683 B2
  • Filed: 04/02/2018
  • Issued: 05/05/2020
  • Est. Priority Date: 04/02/2018
  • Status: Active Grant
First Claim
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1. A method, performed by a test control system, of evaluating shift performance of an automatic transmission system having gears, and a torque converter, the method comprising:

  • driving the automatic transmission with an input motor at an input speed while applying a rotational load by a pair of output motors;

    applying a command to a solenoid to change fluid pressure and detecting a time when the solenoid command is sent to the solenoid;

    shifting between a pair of the gears;

    measuring transmission output torque and obtaining torque values;

    determining a threshold value for a torque converter rotation speed;

    determining a threshold value for the transmission output torque;

    determining a lag time between a threshold for a turbine speed and the detected time for the solenoid;

    determining an engage time based on the torque threshold value and the turbine speed threshold; and

    judging the performance of the pair of gears based on the lag time, engage time and a peak of the transmission output torque.

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