Patent ID: 8849538

Claim:
A torque distribution apparatus that distributes input instructed torque to motors connected to drive wheels, the torque distribution apparatus comprising: a determining unit that determines whether to perform any one among power running control and regenerative braking with respect to the drive wheels; an instructed torque acquiring unit that acquires the instructed torque input; an efficiency map acquiring unit that based on a determination result of the determining unit, acquires a motor efficiency map that corresponds to the motors; a vehicular speed detecting unit that detects vehicular speed of a vehicle on which the motors are equipped; a drive wheel rotational speed detecting unit that detects drive wheel rotational speed of the drive wheels; a slip rate calculating unit that based on the vehicular speed and the drive wheel rotational speed, calculates slip rate at the drive wheels; a calculating unit that based on the slip rate, creates an efficiency variation expression that indicates efficiency values on a performance curve that indicates relations between the drive wheel rotational speed and torque, and calculates from the efficiency variation expression on the performance curve, a torque that optimizes efficiency; a distributing unit that among combinations of torque distribution for the motors and when a determination result by the determining unit is for the power running control, calculates torque distribution values for the motors, respectively, such that overall efficiency η total=Σ((Tn/T)×η d n×ηλn) (where, T: the instructed torque, Tn: torque distribution value of each motor, η d n: drive system efficiency of each of the motors, ηλn: propulsion system efficiency of the drive wheels) is maximized, and when the determination result by the determining unit is for the regenerative braking, calculates the torque distribution values for the motors, respectively such that the overall efficiency η total=Σ((Tn/T)×η b n×η r n) (where, T: the instructed torque, Tn: the torque distribution values of the motors, η r n: regeneration efficiency of the motors, and η b n: the propulsion system efficiency of the motors) is maximized, the torque distribution values being calculated based on the slip rate, the instructed torque and the torque that optimizes efficiency; and a control unit that controls torque distribution to the motors, based on the calculated the torque distribution values.