Torque distribution apparatus, torque distribution method, torque distribution value generation method, and program

Abstract

A torque distribution apparatus acquires instructed torque input and a motor efficiency map; detects vehicular speed and drive wheel rotational speed; calculates based on the speeds, a relational expression of a slip rate at drive wheels and a friction coefficient; creates based on the relational expression, a performance curve expression that indicates torque-drive wheel rotational speed relations, superimposes the performance curve expression on the motor efficiency map, creates an efficiency variation expression that indicates for each vehicular speed, the torque and efficiency values of the motor efficiency map, and calculates torque that optimizes efficiency, from the efficiency variation expression; calculates within a range of the slip rate being 0 to 0.2 and based on the instructed torque and torque optimizing efficiency, a torque distribution value for each of the motors such that total efficiency ηtotal=Σ((Tn/T)×ηdn×ηλn) is maximized; and controls based on the calculated torque distribution values, torque distribution among motors.