Vehicles and methods for controlling internal combustion engine rotational speeds

A hybrid vehicle comprising:

• one or more processors;
• one or more memory modules communicatively coupled to the one or more processors;
• a mechanical power distribution apparatus comprising a sun gear, a plurality of planetary gears, a carrier, and a ring gear, wherein the plurality of planetary gears mesh with the ring gear and the sun gear, wherein the plurality of planetary gears are mechanically coupled to the carrier;
• an internal combustion engine comprising a crankshaft, wherein the crankshaft is mechanically coupled to the carrier of the mechanical power distribution apparatus;
• a plurality of drive wheels;
• a first motor-generator comprising an output shaft, wherein the output shaft of the first motor-generator is mechanically coupled to the sun gear;
• a second motor-generator comprising an output shaft, wherein the output shaft of the second motor-generator is mechanically coupled to the plurality of drive wheels and is mechanically coupled to the ring gear;
• an electrical energy storage device electrically coupled to the first motor-generator and the second motor-generator such that the electrical energy storage device can provide electrical energy to the first motor-generator and the second motor-generator;
• and
• machine readable instructions stored in the one or more memory modules that cause the hybrid vehicle to perform at least the following when executed by the one or more processors:
• determine a target wheel torque;
• determine a base increase rate of engine rotational speed;
• increase an engine rotational speed of the internal combustion engine by controlling an amount of electrical energy provided from the electrical energy storage device to the first motor-generator based on the base increase rate of engine rotational speed;
• determine an estimated wheel torque;
• determine an updated increase rate of engine rotational speed based on the target wheel torque and the estimated wheel torque;
• and
• increase the engine rotational speed of the internal combustion engine by controlling the amount of electrical energy provided from the electrical energy storage device to the first motor-generator based on the updated increase rate of engine rotational speed.

A method for controlling an engine rotational speed of an internal combustion engine, the method comprising:

• determining a target wheel torque;
• determining a base increase rate of engine rotational speed;
• increasing the engine rotational speed of the internal combustion engine based on the base increase rate of engine rotational speed;
• determining an estimated wheel torque;
• determining an updated increase rate of engine rotational speed based on the target wheel torque and the estimated wheel torque;
• and
• increasing the engine rotational speed of the internal combustion engine based on the updated increase rate of engine rotational speed.