Diagnostic method for a torque control of an electrically variable transmission
A condition of impaired speed and torque control of a parallel electrically variable transmission due to factors beyond nominal modeling and estimation errors is diagnosed under low speed operation. The transmission includes at least one electric machine and a motor torque controller for regulating the transmission input speed and output torque. The motor torque controller includes an open-loop control path based on predetermined torques and accelerations and a closed loop control path based on input speed error. The presence of a larger than expected closed-loop correction magnitude, combined with low output speed and one or more other conditions is used to diagnose a condition of potential torque error, in which case the transmission control is altered to prevent unwanted operation.
General Motors Corporation
B B F Y B B F B B
B60W B60W F16H Y02T B60W B60K F16H B60K B60K
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Gregory A. Todd M. Tung-Ming Anthony H. Xuefeng T.
Hubbard Steinmetz Hsieh Heap Tao