**5. Performance goal description**

The three performance goals for the H-infinity minimization such as tracking, maximum LG and minimum LG. The limits/range for these goals is expected as represented in **Figures 4**–**6** as:

• Tracking better than 2 sec

*PID Gain Tuning for Robust Control of PMDC Motor for External Disturbance Rejection with… DOI: http://dx.doi.org/10.5772/intechopen.102546*

**Figure 4.** *Performance goal 1: The response for desired tracking.*

**Figure 5.** *Performance goal 2: The desired min-LG.*

**Figure 6.** *Performance goal 3: The desired max-LG.*

