A servomotor control device for a robot which can adjust the
characteristics of maximum torque and/or continuous rated output of the
servomotor and a robot with easy maintenance. The robot is commanded to
execute one cycle of taught motion. During the cycle, a maximum torque
required for the servomotor is calculated by a torque command or the
like. When the maximum torque lacks, a field weakening current correction
value is increased for increasing d-phase current and the maximum torque.
Further, lack of continuous rated output may be judged by detected
temperature of the servomotor. When a lack of continuous rated output
occurs, the correction value is decreased to decrease the d-phase current
so as to adjust the characteristic of continuous rated output. Although
the servomotors have the same specification, the characteristic of each
of the servomotors may be optimized corresponding to the axis by
adjusting the field weakening current (or the d-phase current). As the
hardware such as the control devices have the same specification,
manufacture, maintenance and control of the robot may become easier.
