Hybrid Vehicle Drive Control System and Method for Providing Motor Torque Boost Compensating for Engine Delay and Torque Exceeding Maximum Engine Torque

A method of controlling a vehicle drive system that includes an engine control unit for an engine having a maximum torque output value and a torque increase delay response function that spans a predetermined time period, a torque motor control unit for an electric motor, and a transmission that selectively receives torque from one or both of the engine and the motor, the method comprising:

• initiating a torque request signal requesting a torque boost with an accelerator control member;
• generating a motor torque boost signal requesting an increase in torque from the electric motor if the torque request signal exceeds at least one of the maximum torque output or the torque increase delay response function;
• and
• limiting the motor torque boost signal initially to a maximum motor torque value available to meet the torque level of the torque request signal for a first period of time that is based upon the predetermined time period.

A vehicle drive control system comprising:

• an engine;
• an electric motor that generates a motor speed signal;
• a transmission that selectively receives torque from one or both of the engine and the electric motor, and wherein the transmission has a fluid power system that receives torque from the electric motor and that requires a minimum line pressure;
• the vehicle drive control system being configured to receive the motor speed signal from the motor that is compared to a minimum motor speed value to maintain the minimum line pressure for the transmission.