Patent ID: 8762014
Filing Date: 2014-06-24
Classification: B60W,F16H

Abstract:
1. A method of providing torque control operation in a transmission having a variable displacement variator having a hydraulic actuator for varying displacement and having an output, the variator further having an internal circuit pressure, the method comprising: a controller engaging the transmission in a neutral state such that the variator output experiences substantially zero torque; with the transmission in the neutral state, commanding a first hydraulic pressure sweep to the hydraulic actuator wherein the first commanded hydraulic pressure sweep encompasses a first predetermined pressure range, and recording a first corresponding sweep of motor speed ratio of the variator during application of the first hydraulic pressure sweep; engaging the transmission into a locked mode wherein the variator output provides a fixed output speed regardless of circuit pressure; with the transmission in the locked mode, commanding a second hydraulic pressure sweep to the hydraulic actuator, wherein the second hydraulic pressure sweep encompasses a second predetermined pressure range, and recording a second corresponding sweep of variator output torque during application of the second hydraulic pressure sweep; and constructing a map relating motor torque, motor speed ratio, and hydraulic pressure to the hydraulic actuator by scaling the first corresponding sweep of motor speed ratios of the variator during application of the first hydraulic pressure sweep and scaling the second corresponding sweep of variator output torque during application of the second hydraulic pressure sweep.