Chapter D Problem Sheet 4 (Lectures 8–9)

  • 1. Consider the first order scalar differential equation \(\dot {x}(t)+6x(t)=2u(t)\). Find a control \(u\) such that for a given \(r\in \mR \) we have \(\lim _{t\to \infty }x(t)=r\) no matter what \(x(0)\) is.

  • 2. Consider the first order scalar differential equation \(\dot {x}(t)=x(t)+u(t)\). Find a control \(u\) such that for a given \(r\in \mR \) we have \(\lim _{t\to \infty }x(t)=r\) no matter what \(x(0)\) is.

  • 3. Consider the first order scalar differential equation \(\dot {x}(t)+x(t)=w(t)+u(t)\). Find a control \(u\) such that \(\lim _{t\to \infty }x(t)=r\) no matter what \(x(0)\) is when \(w(t)=r\), where \(r\in \mR \).

  • 4. Consider the second order scalar differential equation

    \[ \ddot {q}+2\zeta \dot {q}+q=u, \]

    where \(\zeta >0\). Find a control \(u\) such that for a given \(r\in \mR \) we have \(\lim _{t\to \infty }q(t)=r\) no matter what the initial conditions are.