S-curve profile switching method using fuzzy system for position control of DC motor under uncertain load

In the paper, we consider the motion profile for position control of DC motor. Usually, a motion profile is created only once, before DC motor is driven, by using parameters such as distance to move, maximal jerk, maximal acceleration and maximal velocity. If the uncertain load is exists, the maximal velocity can be reduced and the system may not track the desired velocity and large vibration can be occurred. We propose fuzzy s-curve profile switching method that replaces profile with more suitable profile for precise driving of the system. Immediately after the motor begin to drive, new maximal velocity is predicted based on undershoot of velocity by fuzzy system. The new profile based on the new maximal velocity is created. By applying the new profile to DC motor, as a result, we can achieve the precise position control. S-curve profile is used as a type of profile in this paper.