Types of Robot Feedback Control
Commanding to do operations in order to check whether the robot is moving as commanded and to correct if there are deviations is called feedback control, and there are a few methods to do this.
The single-axis robots, ROBO Cylinders, SCARA robots, and Cartesian robots of IAI use the semi-closed loop control.
This is a general servo control method, and the actuator movement is detected by the encoder and fed back.
In contrast to this, the open loop control and the full closed loop control have the following characteristics.
This is a general stepper motor method, and is inexpensive since there is no encoder, but cannot make corrections when there are deviations between the operation commands and the movement because it is not a feedback control.
The slider position can be determined accurately because the absolute position of the slider is measured and fed back. (Due to actuator accuracy errors, for semi-closed loop, there will be errors within a set range between the actual actuator position and the position information that is fed back from the encoder.)