Method for controlling 3-2 shift before stopping of automatic transmission and system thereof
AssigneeHyundai Motor Company
InventorJin Soo Lee
Life of this patent
Estimating the term…
Abstract
A method and system for controlling a 3→2 shift before stopping of an automatic transmission reduces shift shock as a consequence of an operation of a control duty being delayed according to an angular velocity of an engine at a shift start point in the 3→2 shifting process before stopping. The method includes: detecting driving information; determining whether a 3→2 shift condition before stopping is satisfied; determining, when the 3→2 shift condition before stopping is satisfied, whether a shift control condition is satisfied; and controlling the 3→2 shift before stopping when the shift control condition is satisfied.
Claims10
A method for controlling a downshift from a third gear to a second gear before stopping of an automatic transmission, comprising:
- detecting driving information;
- determining whether a downshift from the third gear to the second gear condition before stopping is satisfied;
- determining, when the downshift from the third gear to the second gear condition before stopping is satisfied, whether a shift control condition is satisfied;
- and
- controlling the downshift from the third gear to the second gear before stopping when the shift control condition is satisfied;
- wherein the control of the downshift from the third gear to the second gear before stopping comprises:
- determining a delay time;
- and
- operating a control duty after the delay time has passed since a shift start point;
- wherein the delay time is determined according to an angular velocity of an engine at the shift start point.
A system for controlling a downshift from a third gear to a second gear before stopping of an automatic transmission, comprising:
- an engine speed detector for detecting an angular velocity of an engine;
- a brake switch for detecting operation of a brake pedal;
- a throttle opening detector for detecting a throttle opening;
- an oil temperature detector for detecting oil temperature in the transmission;
- and
- a transmission control unit receiving driving information from each detector and the brake switch,
- wherein the transmission control unit executes a predetermined program comprising instructions for
- detecting the driving information,
- determining whether a downshift from the third gear to the second gear shift condition before stopping is satisfied,
- determining, when the downshift from the third gear to the second gear shift condition before stopping is satisfied, whether a shift control condition is satisfied, and
- controlling the downshift from the third gear to the second gear before stopping when the shift control condition is satisfied;
- wherein the control of the downshift from the third gear to the second gear before stopping comprises:
- determining a delay time;
- and
- operating a control duty after the delay time has passed since a shift start point;
- wherein the delay time is determined according to the angular velocity of the engine at the shift start point.
Dependencies are inferred from the claim text.