Patent ID: 6267189
Filing Date: 2001-07-31
Classification: B60W

Abstract:
In a vehicle having a power source for producing rotational motion, an apparatus for controlling engagement of a power take-off shaft (PTO) for supplying rotational motion to a piece of equipment other than the vehicle, the apparatus comprising:a clutch including an input shaft coupled to the power source and an output shaft coupled to the PTO, the clutch including a plurality of plates operable to translate through a distance during engagement of the clutch and, upon engagement of the clutch, controllably transmitting torque between the input and output shafts;an input speed sensor for sensing a quantity related to the angular velocity of the input shaft and providing an input speed signal representative thereof;an output shaft speed sensor for sensing angular velocity of the output shaft and providing an output shaft speed signal representative thereof;an electromechanical clutch controller coupled to the clutch for adjusting pressure of a hydraulic fluid applied to the clutch in response to control signals during engagement of the PTO, wherein torque transmitted between the input and output shafts is responsive to the control signals; anda control circuit coupled to the input and the output shaft speed sensors and the clutch controller, the control circuit configured to receive the input and the output shaft speed signals and to provide the control signals in response thereto, and wherein, during engagement of the PTO, the control circuit continuously determines a desired acceleration of the PTO based upon the input speed signal and continuously determines an actual acceleration of the PTO shaft based upon the sensed angular velocity of the output shaft, and the control circuit generates the control signals using the desired and actual accelerations,wherein the control circuit provides control signals to cause the torque transmitted through the clutch to increase at a rate depending upon the difference between the desired and actual accelerations when the actual acceleration is more than a threshold proportion of the desired acceleration, and to cause the torque to increase at a rate independent of the difference when actual acceleration is less than the threshold proportion of the desired acceleration.