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The open loop transfer function of a unity feedback control is given by:

G(s)= 3s²+3s+1​ / s³(s⁴+3s³+3s²+s+1)
Check for system stability by determining the number of poles in each half of the complex plane.

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Final answer:

The stability of the control system can be determined by finding the poles of the open loop transfer function and assessing their location in the complex plane. The system is stable only if all poles are in the left half of the complex plane.

Step-by-step explanation:

The student asks about checking the stability of a control system with a given open loop transfer function G(s)= 3s²+3s+1 / s³(s⁴+3s³+3s²+s+1). Stability in control systems, particularly in the context of the complex plane, is often determined using the location of the system poles. In essence, for a system to be stable, all poles must be in the left half of the complex plane.

To determine the location of the poles of the transfer function, we need to find the roots of the denominator polynomial s³(s⁴+3s³+3s²+s+1). This polynomial is factored already as the product of and a quartic polynomial, indicating there are three poles at the origin (s=0), and additional poles that are the roots of the quartic polynomial s⁴+3s³+3s²+s+1. The number and location of these additional poles would need to be determined, potentially using numerical methods as analytical solutions for quartic equations can be quite complex.

If any poles are found to be in the right half of the complex plane, the system would be unstable. If all poles are on the left half or on the imaginary axis (excluding the origin), the system would be marginally stable, and if all poles are in the left half of the complex plane, it is stable.

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