Hi,
When designing a controller, my understanding is that to look for stability, you have to consider the gain and phase margins. However, i have a design that has both positive gain and phase margins (>10 dB and > 60 degrees) yet the step response to the system is still unstable. What other tests can do i to test the stability?
i have also heard of the root locus plot, but i think usually looks at the gain parameter and its effects on the poles and zeroes. Can this be unstable even with the above conditions? (+ GM, +PM)
TIA
When designing a controller, my understanding is that to look for stability, you have to consider the gain and phase margins. However, i have a design that has both positive gain and phase margins (>10 dB and > 60 degrees) yet the step response to the system is still unstable. What other tests can do i to test the stability?
i have also heard of the root locus plot, but i think usually looks at the gain parameter and its effects on the poles and zeroes. Can this be unstable even with the above conditions? (+ GM, +PM)
TIA