Hybrid electric drive and control method therefor

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and providing a multi-speed transmission with a forward and reverse mode and having a low speed in which vehicle speed is below 10 mph and a high-speed range and wherein the fuel cut-off occurs when the vehicle transmission is in the forward drive mode and in the low speed range.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• and controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation, wherein the fuel cut-off is initiated by gas pedal release and brake pedal application when the vehicle speed is greater than a predetermined value and is initiated by the brake when the vehicle speed is less than said predetermined value.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and providing a multi-speed transmission;
• monitoring the gear setting and above a predetermined higher gear setting and above a critical speed V determining release of the gas pedal;
• and initiating a engine fuel-off sequence in response to such gas pedal release, wherein the method further includes providing a timer and delaying the beginning of the fuel cutoff sequence by the timer following gas pedal release.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and providing a multi-speed transmission;
• monitoring the gear setting and above a predetermined higher gear setting and above a critical speed V determining release of the gas pedal;
• and providing a multi-cylinder gas engine with a fuel cut-off at each cylinder and providing the fuel cutoff sequence by cutting fuel feed to one cylinder at a time to provide a smooth deceleration feel.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and detecting a high speed and determining if the fuel is shut off (by either release of gas pedal or application of brake);
• coasting the vehicle with neither gas or brake pedal application to a drop-to-neutral velocity;
• and operating the torque converter locking clutch to back drive the engine until some low engine RPM at which compression pulses of the engine become objectionable;
• providing a multi-speed transmission operative in a low speed range and maintain coasting by freewheel at the drop-to-neutral velocity;
• and providing fuel and spark delivery to the engine just before the drop-to-neutral velocity so as to not stall the engine.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and setting a hybrid-active vehicle speed that must be exceeded to enable any fuel cut-off by brake or gas pedal operation;
• and further providing a speed hysteresis in the hybrid-active speed having a hybrid-active speed for acceleration Va, and having another for deceleration Vd and wherein the quantification of acceleration/deceleration determined by whether the driver has applied the gas pedal just before the fuel-off command.

A fuel management control method for a hybrid electric vehicle drive having an internal combustion engine and an electric motor arranged in parallel such that both can propel the vehicle;

• the system including an electric motor driven fuel pump and a programmable microprocessor the method comprising:
• providing a belt drive connection between the electric motor and the engine;
• providing a torque converter with an impeller turbine connection through a forward drive free wheeling and reverse drive locking one-way clutch connection in the vehicle drive;
• controlling the electric motor to charge batteries during vehicle deceleration/coasting operation and during regular cruising if the battery state of charge is low and cutting off fuel flow to the engine in response to either gas pedal or brake operation while the torque converter is operative thereby to synchronize overdrive of the vehicle during coasting with the engine speed to prevent the internal combustion engine from stalling upon fuel flow cut-off during such coasting operation;
• and determining if the engine temperature is above a prescribed threshold and controlling the electric motor such that the engine does not have to be re-cranked when an ignition key is turned to run (but not all the way to crank) and a PRNDL lever is shifted into drive (D) and the brake pedal is released, the electric motor operating creep the vehicle forward and start the engine as fuel flow commences.

A method for controlling a hybrid vehicle drive comprising an internal combustion engine and an electric motor generator connected to the crankshaft of the internal combustion engine by a direct drive belt and wherein the electric motor is utilized to charge batteries during vehicle deceleration/coasting operation comprising the steps of:

• monitoring vehicle speed to determine one of a brake start speed range;
• a hysteresis speed range and a regenerative braking speed range;
• initiating a combination of fuel flow to the engine and start of the engine with the electric motor when the speed of the vehicle is at or below the brake start speed range and below the maximum speed of the hysteresis speed range;
• providing a brake pedal and a brake switch responsive to brake pedal pressure for producing an input signal;
• and operating the vehicle in a deceleration and engine stall mode wherein the fuel supply to the engine is cutoff if the brake pedal is initially depressed when the speed of the vehicle is above a maximum hysteresis speed.

A method for controlling a hybrid vehicle drive comprising an internal combustion engine and an electric motor generator connected to the crankshaft of the internal combustion engine by a direct drive belt and wherein the electric motor is utilized to charge batteries during vehicle deceleration/coasting operation and during regular cruising if battery charge is low comprising the steps of:

• monitoring vehicle speed;
• providing a brake pedal and a brake switch responsive to brake pedal pressure for producing an input signal;
• determining fuel gas pedal operation;
• if gas pedal depressed maintain fuel flow to the internal combustion engine under the control of the gas pedal;
• if the vehicle is stopped with fuel off releasing brake to produce a brake position signal and operating said electric motor in accordance with the brake position signal to electrically turn the internal combustion engine to increase the vehicle speed to a predetermined creep speed;
• and
• providing fuel and spark to the internal combustion engine when the engine speed and vehicle speed reach predetermined values.