Transmission shifter having automatic adjustment of control parameters
AssigneeEaton Corporation
InventorsStephen A. Edelen, Ong Chiau-Chieh
Life of this patent
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Abstract
A position-feedback-control servomechanism for shifting the transmission of a vehicle has a control algorithm that adjusts the loop gains in a proportional-integral-differential controller to compensate for manufacturing variations in the apparatus as well as for temperature changes and wear. The resulting control system moves the shifting servomechanism into the selected positions accurately and as quickly as possible without permitting excessive overshooting or resonance.
Claims17
A method for shifting a change-gear transmission having a servomechanism for moving a mechanical shifting member along a predetermined path in response to shifting commands (140), a sensor (48) for sensing the position of said shifting member and providing a position signal accordingly, and a feedback control loop (136) having a gain and receiving said position signal from said sensor and driving said shifting member to a commanded destination position, comprising the steps of:
- measuring the elapsed time (184) for said shifting member to traverse said path to reach a predetermined point thereon;
- comparing said elapsed time with a stored time value;
- changing said gain (65, 75, 148, 156) of said feedback control loop if said elapsed time to reach said predetermined point is greater than said stored time value.
A transmission control system for shifting a change-gear transmission by means of a servomechanism in response to a shifting command, said servomechanism having various system parameters including at least a proportional channel gain and a differential channel gain, comprising:
- means for measuring the elapsed shifting time of the transmission control system in performing a shift;
- means for comparing said elapsed shifting time with a predetermined stored reference time to determine an error time;
- means for changing at least said proportional channel gain and differential channel gain in accordance with said error time prior to a subsequently occurring shift.
Dependencies are inferred from the claim text.