Yaskawa SMC–4000 - Manual (Page 27)

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SMC–4000 User Manual
2 Theory of Operation
Overview
The following discussion covers the operation of motion control systems. A typical motion control
system consists of the elements shown in the following illustration:
Elements of Servo Systems
The operation of such a system can be divided into three levels, as shown in the following illustration
Levels of Control Functions . The levels are:
1. Closing the Loop
2. Motion Profiling
3. Motion Programming
The first level, the closing of the loop, assures that the motor follows the commanded position. Closing
the position loop using a sensor does this. The operation at the basic level of closing the loop involves the
subjects of modeling, analysis, and design. These subjects will be covered in the following discussions.
The motion profiling is the generation of the desired position function. This function, R(t), describes
where the motor should be at every sampling period. Note that the profiling and the closing of the loop
are independent functions. The profiling function determines where the motor should be and the closing
of the loop forces the motor to follow the commanded position
The highest level of control is the motion program. This can be stored in the host computer or in the
controller. This program describes the tasks in terms of the motors that need to be controlled, the
distances and the speed.
COMPUTER CONTROLLER DRIVER
MOTOR ENCODER