초록 ▼

A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, su

A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for low fuel consumption. CVT ratio is controlled as a function of commanded desired system performance (e.g., power or torque) and measured actual system performance, such as CVT torque output, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristics for any load placed on the engine. Appropriate controls prevent anomalous engine and vehicle behavior, and allow for transient start-up from rest. In order to counteract the inherent tendency of the vehicle to accelerate when the accelerator pedal is released, a mechanism is provided for diminishing fuel flow to the engine by an amount proportional to the rate at which the commanded power or torque is reduced.

대표청구항 ▼

A method of controlling the operation of a power delivery system including an engine of an engine-driven vehicle and a continuously variable ratio transmission coupled to said engine for delivering power from said engine to an output shaft, said engine having fuel delivery means for delivering a var

A method of controlling the operation of a power delivery system including an engine of an engine-driven vehicle and a continuously variable ratio transmission coupled to said engine for delivering power from said engine to an output shaft, said engine having fuel delivery means for delivering a variable quantity of fuel thereto, said power delivery system being controlled by command means for commanding a desired system performance, the method comprising the steps of: measuring the actual performance of the power delivery system; controlling the ratio of said transmission as a function of the desired system performance commanded by said command means and said measured actual system performance, the speed of said engine varying as a function of transmission ratio; predetermining a fuel function defining desired fuel requirements for said engine in relation to engine operating speed; measuring the speed of said engine; controlling said fuel delivery means only in accordance with said fuel function so that the fuel delivered to said engine is determined only by the speed thereof; and diminishing fuel flow to said fuel delivery means when the system performance commanded by said command means is reduced.