22.3 : 框图简化

The control system's transfer function is derived by reducing its block diagram to one block. Shifting a branch point or a comparator within the diagram simplifies this process.

A branch point that needs to be relocated is identified. The new location is determined, and the branch point is relocated without affecting the system's overall function.

The mathematical relationships before and after the relocation are compared, and if the signals remain unchanged, the operation has been successful.

Moving a comparator is the second operation. The new position is determined, and the comparator is moved from its original location.

The mathematical relationships are compared before and after the move to verify that the system's output remains unaltered.

Consider the block diagram of a system. The first move is shifting a branch point to the left side of a specific block.

Following this, multiple blocks are combined, reducing the diagram's complexity. The final stage is the removal of several feedback loops, leading to a simplified representation with one block.

This reduction enables the calculation of the transfer function.