As you see many product and open source using RC servo to build small robot arm. This question might simple but I think it important to someone that want to build robot arm and decide which type of actuator to use.
1. How RC Servo control position? what type of control used (P,PI,PID)?
As engineer student I learn to control DC motor and learn how it interact with dynamics system like robot arm (manipulator) It take many knowledge about this system and parameter that we try to control to cancel non linear term or at least make it stable. But how RC servo work to control its position? I've try to build robot arm myself (parallelizer type ,15 CM Arm, 3 x MG995) it look stable (not osculate and still actuated) How that possible to design position control that work in wide range parameter?
2. From that type of control, Is that suitable for robot arm or should I use another one?
As you see in many project. it seem to work with manual control. some project make its remember command and repeat it (show some repeatability). after playing around I see that RC servo cannot compensate steady state error (may be it don't have I term) and it can't read its position it quit dangerous when it start and do rapid move. In my application I want to control robot by calculate inverse kinematic. after working on it for many days, it seem pretty hard to to tune or calibrate it.