Relative Stability Analysis Method of Systems Based on Goal Seek

In the design and analysis of the automatic control system, it is difficult to analyze the relative stability of system because of the complexity of calculating the gain and phase-crossover frequencies. The analysis of the influence of open-loop gain on the relative stability of system needs to solve many more complex equations, which is more difficult. This paper explores a method of system stability analysis based on the goal seek method, and studies the operation steps and points for attention in application of this method. The feasibility and convenience of the method are verified by the analysis of a complex third-order control system. The results show that this method can be used to find out the gain-crossover frequency and the phase-crossover frequency easily, meanwhile the phase margin and gain margin can be obtained easily too. The influence of open-loop gain on them can also be analyzed, and the optimum parameters of open-loop gain can be found. This method will provide a basis for the research of multi-process dynamic collaborative optimization manufacturing under the environment of the workshop Internet of Things.