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Control apparatus and method for automatic transmission

  • US 7,006,907 B2
  • Filed: 03/23/2005
  • Issued: 02/28/2006
  • Est. Priority Date: 03/31/2004
  • Status: Active Grant
First Claim
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1. A control apparatus for an automatic transmission, the automatic transmission comprising:

  • a plurality of frictional clutching elements having a hydraulically operated piston and a frictional clutching member clutched when pressed by means of the piston; and

    a shift map determining a target shift stage on the basis of a drive point determined according to at least a throttle opening angle and a vehicle speed or parameter values corresponding to the throttle opening angle and the vehicle speed and the automatic transmission achieving a plurality of shift stages by a combination of a clutching or release of the plurality of frictional clutching elements, the control apparatus comprising;

    a piston revolution speed detecting section that detects a revolution speed of the piston of one of the frictional clutching elements clutched during a gear shift to a predetermined target shift stage;

    an ordinary gear shifting piston revolution speed calculating section that calculates the piston revolution speed at the same shift kind and at the same throttle opening angle or at a parameter value corresponding to the throttle opening angle when the automatic transmission carries out the gear shift to the predetermined target gear shift at the drive point different from during an ordinary gear shift during which the gear shift based on the shift map is carried out;

    an initial hydraulic setting section that sets an initial hydraulic by which the piston strokes in a direction in which the clutched frictional clutching element presses;

    an initial hydraulic reference value calculating section that calculates an initial hydraulic reference value which provides a reference value of the initial hydraulic from the shift kind and the throttle opening angle or from the parameter value corresponding to the throttle opening angle; and

    a correction quantity calculating section that calculates a correction quantity for the reference value of the initial hydraulic on the basis of squares of the revolution speed of the piston calculated by the ordinary gear shifting piston revolution speed calculating section and of the revolution of the piston detected by the piston revolution speed detecting section, the initial hydraulic setting section setting the initial hydraulic reference value to the initial hydraulic during the ordinary gear shift and correcting the initial hydraulic reference value by the correction quantity to set the corrected initial hydraulic reference value to the initial hydraulic when the gear shift to the predetermined target gear shift stage is carried out at the drive point different from during the ordinary gear shift.

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