Research Article

Output Feedback Nonlinear 𝐻 -Tracking Control of a Nonminimum-Phase 2-DOF Underactuated Mechanical System

Figure 6

Time evolution of the determinants of the principal minors of the matrix 𝑃 4 × 4 𝑃 𝑚 1 , 𝑃 𝑚 2 , 𝑃 𝑚 3 , 𝑃 𝑚 4 .
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