A type of driving controller for a vehicle that makes use of a combination
of a generator and an AC motor to perform stable motor torque control.
Target output electric power that should be output from the generator is
computed on the basis of the motor's necessary electric power, and the
generator is controlled at the operating point where the torque
instruction value computed on the basis of the target output electric
power can be generated at good efficiency. Also, the torque instruction
value of the motor is computed on the basis of present output voltage and
output current of the generator, and the motor is controlled on the basis
of the torque instruction value.