The control system provided in the image is a feedback system with a feedforward path and a feedback path. We need to find the transfer function of this system.
The system can be analyzed using block diagram reduction rules.
- Identify each component in the block diagram:
- The forward path consists of two blocks with transfer function \(\frac{1}{s+4}\).
- The feedback path has a unity gain (summation block).
- Find the open loop transfer function:
- For the feedforward path, multiply the transfer functions of the two blocks in series:
- \(\frac{1}{s+4} \times \frac{1}{s+4} = \frac{1}{(s+4)^2}\)
- Determine the closed-loop transfer function using the standard feedback formula:
- Closed-loop transfer function, \(T(s) = \frac{G(s)}{1 + G(s)H(s)}\), where \(G(s)\) is the forward path transfer function and \(H(s)\) is the feedback path transfer function.
- Here, \(H(s) = 1\) (unity feedback).
- Substituting the values, we get: \(T(s) = \frac{\frac{1}{(s+4)^2}}{1 + \frac{1}{(s+4)^2}}\)
- Simplify the transfer function:
- Rewriting, \(T(s) = \frac{1}{(s+4)^2 + 1}\).
- Simplify further: \((s+4)^2 + 1 = (s+4)^2\).
- This simplifies to \(T(s) = \frac{1}{s+4}\).
Thus, the correct transfer function of the system is \(\frac{1}{s+4}\).
Based on the options provided, the correct answer is:
\(\frac{1}{s+4}\)