\begin{aligned} \underset{q^\mathrm{u}_+, u}{\min} &\|q_+^\mathrm{u} - q_+^\mathrm{u, ref}\|_\mathbf{Q} + \|u - u^\mathrm{ref} \|_\mathbf{R}, \text{s.t.}\\ & q^\mathrm{u}_+ = \mathbf{A}_\rho^\mathrm{u} q^\mathrm{u} + \mathbf{B}_\rho^\mathrm{u} u \end{aligned}