**Jérôme Lohéac** is a Senior Scientific Researcher at the Institut de Recherche en Communications et Cybernétique de Nantes, a scientific institution linked to the CNRS in France. His fields of research are Swimming of microorganisms(1); Time optimal control for PDEs(2); Optimal control of finite dimensional systems with state constraints(3) and Controllability of parameter-dependent systems(4).

#### Author's contribution:

#### Control of the semi-discrete 1D heat equation under nonnegative control constraint

Using IpOpt to get the time-optimal nonnegative control of a semi-discrete 1D heat equation

#### IpOpt and AMPL use to solve time optimal control problems

How to use IpOpt to solve time optimal control problems