Control system and control method for hybrid vehicle

A control system for a hybrid vehicle including an internal combustion engine, an electric motor capable of generating electric power, a storage battery capable of supplying and receiving electric power to and from the electric motor, a first transmission mechanism that is capable of receiving motive power from an engine output shaft of the engine and the electric motor by a first input shaft, and transmitting the motive power to drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a second transmission mechanism that is capable of receiving motive power from the engine output shaft by a second input shaft, and transmitting the motive power to the drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a first clutch that is capable of engaging between the engine output shaft and the first transmission mechanism, and a second clutch that is capable of engaging between the engine output shaft and the second transmission mechanism, the control system comprising:

• first memory means for memorizing a first total fuel consumption which is a total fuel consumption of the hybrid vehicle in an ENG travel mode in which only the engine is used as a motive power source;
• and
• second memory means for memorizing a second total fuel consumption which is a total fuel consumption of the hybrid vehicle in a charge travel mode in which the engine is operated in a vicinity of an optimum fuel economy line and regeneration is performed by the electric motor using a surplus amount of torque of the engine with respect to a required driving force,
• wherein the second total fuel consumption is set according to a predetermined assumed power usage effectiveness which is a predicted value of driving efficiency of the hybrid vehicle to be exhibited when the hybrid vehicle is caused to travel by supplying electric power which has been charged into the storage battery during the charge travel mode, afterwards to the electric motor, and
• wherein a travel mode in which a smaller total fuel consumption can be obtained is selected from the ENG travel mode and the charge travel mode, based on a result of comparison between the first total fuel consumption and the second total fuel consumption.

A control system for a hybrid vehicle including an internal combustion engine, an electric motor capable of generating electric power, a storage battery capable of supplying and receiving electric power to and from the electric motor, a first transmission mechanism that is capable of receiving motive power from an engine output shaft of the engine and the electric motor by a first input shaft, and transmitting the motive power to the drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a second transmission mechanism that is capable of receiving motive power from the engine output shaft by a second input shaft, and transmitting the motive power to drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a first clutch that is capable of engaging between the engine output shaft and the first transmission mechanism, and a second clutch that is capable of engaging between the engine output shaft and the second transmission mechanism, the control system comprising:

• travel mode-executing means capable of selecting an ENG travel mode in which the hybrid vehicle is caused to travel using the engine as a motive power source, and an EV travel mode in which the hybrid vehicle is caused to travel using the electric motor as a motive power source, for a travel mode of the hybrid vehicle;
• engine consumption degree parameter-calculating means for calculating an engine consumption degree parameter indicative of a degree of consumption of fuel to be consumed by the engine when the ENG travel mode is executed, according to a traveling state of the hybrid vehicle;
• and
• EV consumption degree parameter-calculating means for calculating an EV consumption degree parameter indicative of a degree of consumption of fuel corresponding to a degree of consumption of electric power of the storage battery to be used for conversion to motive power by the electric motor when the EV travel mode is executed, according to the traveling state of the hybrid vehicle,
• wherein said travel mode-executing means selects, as the travel mode, the ENG travel mode when the degree of consumption of fuel represented by the engine consumption degree parameter is smaller than the degree of consumption of fuel represented by the EV consumption degree parameter, and the EV travel mode when the degree of consumption of fuel represented by the EV consumption degree parameter is smaller than the degree of consumption of fuel represented by the engine consumption degree parameter.

A control system for a hybrid vehicle including an internal combustion engine and an electric motor capable of generating electric power, as motive power sources, a storage battery capable of supplying and receiving electric power to and from the electric motor, and a transmission mechanism that transmits motive power of the engine and the electric motor to drive wheels while changing a speed of the motive power of the engine and the electric motor, and includes a plurality of speed positions, the control system comprising:

• consumption degree parameter-calculating means for calculating, in association with each speed position, a consumption degree parameter which represents a degree of consumption of fuel to be consumed, when a difference between torque to be generated by the engine when the engine is operated in a given one of the speed positions such that the degree of consumption of fuel is minimized, and a required torque demanded by the hybrid vehicle, is absorbed/supplemented by regenerative operation/powering operation by the electric motor, by using one of a past charge amount, which is a charge amount on which charging efficiency of the storage battery up to a current time is reflected, and a predicted efficiency, which is an efficiency predicted to be exhibited when it is predicted that an amount of electric power charged in the storage battery is to be used;
• and
• travel mode-executing means for selecting and executing a travel mode corresponding to a smallest value of a degree of consumption of fuel indicated by the consumption degree parameter which is calculated in association with each speed position, according to the required torque and a vehicle speed of the hybrid vehicle.

A control system for a hybrid vehicle including an internal combustion engine, an electric motor capable of generating electric power, a storage battery capable of supplying and receiving electric power to and from the electric motor, a first transmission mechanism that is capable of receiving motive power from an engine output shaft of the engine and the electric motor to by a first input shaft, and transmitting the motive power to drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a second transmission mechanism that is capable of receiving motive power from the engine output shaft by a second input shaft, and transmitting the motive power to the drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a first clutch that is capable of engaging between the engine output shaft and the first transmission mechanism, and a second clutch that is capable of engaging between the engine output shaft and the second transmission mechanism, the control system comprising:

• consumption degree parameter-calculating means for calculating, in association with each speed position of the first transmission mechanism and the second transmission mechanism, a consumption degree parameter which represents a degree of consumption of fuel to be consumed, when a difference between torque to be generated by the engine when the engine is operated in a given one of the speed positions of the first transmission mechanism and the second transmission mechanism such that the degree of consumption of fuel is minimized, and a required torque required by the hybrid vehicle, is absorbed/supplemented by regenerative operation/powering operation by the electric motor, by using one of a past charge amount, which is a charge amount on which charging efficiency of the storage battery up to a current time is reflected, and a predicted efficiency, which is an efficiency predicted to be exhibited when it is predicted that an amount of electric power charged in the storage battery is to be used;
• and
• travel mode-executing means for selecting and executing a travel mode corresponding to a smallest value of a degree of consumption of fuel indicated by the consumption degree parameter which is calculated in association with each speed position, according to the required torque and a vehicle speed of the hybrid vehicle.

A control system for a hybrid vehicle including an internal combustion engine and an electric motor capable of generating electric power, as motive power sources, a storage battery capable of supplying and receiving electric power to and from the electric motor, and a transmission mechanism that transmits motive power of the engine and the electric motor to drive wheels while changing a speed of the motive power of the engine and the electric motor, the control system comprising:

• charge travel mode-executing means for executing a charge travel mode in which driving of the drive wheels by the motive power of the engine and charging of the storage battery by the electric motor are simultaneously executed, as a travel mode of the hybrid vehicle;
• engine driving energy-calculating means for calculating engine driving energy which is energy transmitted from the engine to the drive wheels, using engine efficiency and driving efficiency of the transmission mechanism;
• charging energy-calculating means for calculating charging energy which is electric energy to be charged when charging of the storage battery by electric power conversion of the motive power of the engine by the electric motor is executed, using the engine efficiency, charging efficiency of the transmission mechanism, charging/discharging efficiency of the electric motor, and predicted efficiency, which is an efficiency to be exhibited when it is predicted that electric power in the storage battery is to be used;
• and
• charge consumption degree parameter-calculating means for calculating a charge consumption degree parameter indicative of a degree of consumption of fuel to be consumed by the engine when the charge travel mode is executed, using the engine driving energy and the charging energy,
• wherein said charge travel mode-executing means executes the charge travel mode such that a smallest value of the degree of consumption of fuel indicated by the charge consumption degree parameter can be obtained.

A method of controlling a hybrid vehicle including an internal combustion engine, an electric motor capable of generating electric power, a storage battery capable of supplying and receiving electric power to and from the electric motor, a first transmission mechanism that is capable of receiving motive power from an engine output shaft of the engine and the electric motor by a first input shaft, and transmitting the motive power to drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a second transmission mechanism that is capable of receiving motive power from the engine output shaft by a second input shaft, and transmitting the motive power to the drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a first clutch that is capable of engaging between the engine output shaft and the first transmission mechanism, and a second clutch that is capable of engaging between the engine output shaft and the second transmission mechanism, the method comprising:

• setting a first total fuel consumption which is a total fuel consumption of the hybrid vehicle in an ENG travel mode in which only the engine is used as a motive power source;
• setting a second total fuel consumption which is a total fuel consumption of the hybrid vehicle in a charge travel mode in which the engine is operated in a vicinity of an optimum fuel economy line and regeneration is performed by the electric motor using a surplus amount of torque of the engine with respect to the required driving force, according to a predetermined assumed power usage effectiveness which is a predicted value of driving efficiency of the hybrid vehicle to be exhibited when the hybrid vehicle is caused to travel by supplying electric power which has been charged into the storage battery during the charge travel mode, afterwards to the electric motor;
• and
• selecting a travel mode in which a smaller total fuel consumption can be obtained from the ENG travel mode and the charge travel mode, based on a result of comparison between the first total fuel consumption and the second total fuel consumption.

A method of controlling a hybrid vehicle including an internal combustion engine, an electric motor capable of generating electric power, a storage battery capable of supplying and receiving electric power to and from the electric motor, a first transmission mechanism that is capable of receiving motive power from an engine output shaft of the engine and the electric motor by a first input shaft, and transmitting the motive power to the drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a second transmission mechanism that is capable of receiving motive power from the engine output shaft by a second input shaft, and transmitting the motive power to drive wheels in a state in which a speed of the motive power is changed in one of a plurality of speed positions, a first clutch that is capable of engaging between the engine output shaft and the first transmission mechanism, and a second clutch that is capable of engaging between the engine output shaft and the second transmission mechanism, the method comprising:

• calculating, in association with each speed position of the first transmission mechanism and the second transmission mechanism, a consumption degree parameter which represents a degree of consumption of fuel to be consumed, when a difference between torque to be generated by the engine when the engine is operated in a given one of the speed positions of the first transmission mechanism and the second transmission mechanism such that the degree of consumption of fuel is minimized, and a required torque required by the hybrid vehicle, is absorbed/supplemented by regenerative operation/powering operation by the electric motor, by using one of a past charge amount, which is a charge amount on which charging efficiency of the storage battery up to a current time is reflected, and a predicted efficiency, which is an efficiency predicted to be exhibited when it is predicted that an amount of electric power charged in the storage battery is to be used;
• selecting and executing a travel mode corresponding to a smallest value of a degree of consumption of fuel indicated by the consumption degree parameter which is calculated in association with each speed position, according to the required torque and a vehicle speed of the hybrid vehicle;
• and
• calculating the predicted efficiency, using charging/discharging efficiency of the storage battery, driving efficiency of the electric motor, and driving efficiency of the transmission mechanisms.