Bode, Nyquist, Root Locus Plots

Bode Plots

The Digital Compensator Design Tool (DCDT) allows you to select the bode plots that are to be displayed (e.g., plant, compensator, etc) as shown in the figure below.


To zoom in on a specific area of the plot, use the left mouse button. Click into the bode plot and drag the mouse, creating a rectangle on the area of interest. To restore the bode plot view, using the left mouse button, click into the bode plot and drag from right-to-left.

Nyquist Plot

The DCDT will compute the nyquist plot for the closed-loop system using the digital compensator selected. This plot can be used to evaluate the overall stability of the system by determining the number of encirclements of the point at (-1,0). Please review the Nyquist stability criterion for more details.


Root Locus Plot

The DCDT will compute the root locus plot of the closed-loop system taking into account the digital compensator selected. This plot can be used to determine how the roots of the system or the close loop poles will change with variations to a free system variable (α). We can further clarify this by defining the compensator gain as K(s)=αK’(s) where the α is the term the DCDT will vary and use to perform the calculations for the plots.

© 2019 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.