OUTPUT TORQUE CONTROL METHOD

摘要

Readings of multiple sensors are utilized to estimate transmission output, which is used as a feedback signal to control the torque capacity of a transmission clutch. Some sensor readings, such as transmission output speed, are used to compute an input vector. Then, a current state vector is computed as a linear function of the previous state vector and the input vector. One of the values in the state vector is shaft twist, which is proportional to transmission output torque. Various other sensor readings, including wheel speed, are used to correct for noise. Wheel speed signals are received with a delay. To accommodate this delay, the state vector is expanded to include estimates of wheel speed at various past points in time. An accelerometer reading is used at very low speeds at which the wheel speed sensor and transmission output speed sensor are unreliable.

主权项

1. A controller comprising:
communication channels for receiving data from a plurality of sensors and for sending a command to adjust a torque capacity of a transmission clutch; and a processor programmed to repeatedly:
compute an input vector comprising a plurality of input values based on the data from the sensors,compute a current step state vector comprising a plurality of state values as a function of the input vector and a previous step state vector, the plurality of state values including a first state value that varies in proportion to transmission output torque, andadjust the torque capacity of the clutch based on the first state value to deliver a target transmission output torque.