Driving power control apparatus for four wheel drive vehicle
First Claim
1. A driving power control apparatus for a four wheel drive vehicle having first left and right drive wheel units and second left and right drive wheel units, comprising:
- a first motor;
a first power transmission mechanism transmitting a motive power generated by the first motor to the first left and right drive wheel units, the first left and right drive wheel units being coupled to a first drive shaft;
two second motors, a first one of the second motors being coupled to the second left drive wheel unit, and a second one of the second motors being coupled to the right drive wheel unit, and being drivable independently from each other, and exhibiting a maximum efficiency in a different output range than the first motor;
a second power transmission mechanism transmitting motive powers generated by the two second motors to the second left and right drive wheel units, respectively;
a first drive circuit receiving electric power from a power supply to control driving of the first motor;
two second drive circuits receiving electric power from the power supply to control driving of the two second motors, respectively;
a driving power allocation determination unit that determines an allocation of an output, between the first motor and the two second motors of a driving power, that the first and second motors as a whole are required to output; and
a driving control unit that controls the first and second drive circuits to cause the first motor and the two second motors to output their respective, allocated driving powers, wherein;
at least one of the first and second power transmission mechanisms includes a speed reducer that transmits the motive power generated by an associated motor of the first motor and the two second motors to an associated drive wheel unit of the drive wheel units such that the speed reducer reduces a rotational speed of the motive power; and
the driving power allocation determination unit includes;
a storage device for previously converting a characteristic of efficiency of each of the first motor and the two second motors with respect to each of the first motor'"'"'s and the two second motors'"'"' torque and each of the first motor'"'"'s and the two second motors'"'"' rotational speed into a characteristic of efficiency of each of the first and second motors with respect to each of the first motor'"'"'s and the two second motors'"'"' torque and vehicular speed, and storing the characteristic of efficiency thus converted; and
a first allocation determination device for determining the allocation of the output between the first motor and the two second motors, as based on a drive torque and a vehicular speed that the first motor and the two second motors as a whole are required to output, and based on the characteristic of efficiency, as stored, of each of the first motor and the two second motors with respect to its torque and vehicular speed, to allow the first motor and the two second motors to output torques that satisfy in total the drive torque that the first motor and the two second motors as a whole are required to output, and also to allow a total efficiency of the first motor and the two second motors to be greater than or equal to a predetermined threshold value.
1 Assignment
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Accused Products
Abstract
Front left and right wheel units are driven by an engine and a motor generator. Rear left and right wheel units are independently driven by in-wheel motor type motor generators. The motor generator and the motor generator are configured to have different rated outputs, respectively, and be subjected to different speed reduction ratios, respectively, between the motor generators and their respectively associated drive wheel units, and thus have characteristics, respectively, in efficiency with respect to torque and vehicular speed, that exhibit high efficiency in mutually different output ranges, respectively. When a mileage oriented mode is selected as a traveling mode, an ECU determines how a drive torque should be allocated between the motor generators, as based on the motors'"'"' required drive torque and vehicular speed and on each motor generator'"'"'s characteristic in efficiency, to maximize the motor generators'"'"' total efficiency.
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Citations
11 Claims
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1. A driving power control apparatus for a four wheel drive vehicle having first left and right drive wheel units and second left and right drive wheel units, comprising:
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a first motor; a first power transmission mechanism transmitting a motive power generated by the first motor to the first left and right drive wheel units, the first left and right drive wheel units being coupled to a first drive shaft; two second motors, a first one of the second motors being coupled to the second left drive wheel unit, and a second one of the second motors being coupled to the right drive wheel unit, and being drivable independently from each other, and exhibiting a maximum efficiency in a different output range than the first motor; a second power transmission mechanism transmitting motive powers generated by the two second motors to the second left and right drive wheel units, respectively; a first drive circuit receiving electric power from a power supply to control driving of the first motor; two second drive circuits receiving electric power from the power supply to control driving of the two second motors, respectively; a driving power allocation determination unit that determines an allocation of an output, between the first motor and the two second motors of a driving power, that the first and second motors as a whole are required to output; and a driving control unit that controls the first and second drive circuits to cause the first motor and the two second motors to output their respective, allocated driving powers, wherein; at least one of the first and second power transmission mechanisms includes a speed reducer that transmits the motive power generated by an associated motor of the first motor and the two second motors to an associated drive wheel unit of the drive wheel units such that the speed reducer reduces a rotational speed of the motive power; and the driving power allocation determination unit includes; a storage device for previously converting a characteristic of efficiency of each of the first motor and the two second motors with respect to each of the first motor'"'"'s and the two second motors'"'"' torque and each of the first motor'"'"'s and the two second motors'"'"' rotational speed into a characteristic of efficiency of each of the first and second motors with respect to each of the first motor'"'"'s and the two second motors'"'"' torque and vehicular speed, and storing the characteristic of efficiency thus converted; and a first allocation determination device for determining the allocation of the output between the first motor and the two second motors, as based on a drive torque and a vehicular speed that the first motor and the two second motors as a whole are required to output, and based on the characteristic of efficiency, as stored, of each of the first motor and the two second motors with respect to its torque and vehicular speed, to allow the first motor and the two second motors to output torques that satisfy in total the drive torque that the first motor and the two second motors as a whole are required to output, and also to allow a total efficiency of the first motor and the two second motors to be greater than or equal to a predetermined threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification