  Monotone systems, also known as order-preserving or cooperative systems, are
prevalent in models of engineering applications such as transportation and
biological networks. In this paper, we investigate the problem of finding a
control strategy for a discrete time monotone system with bounded uncertainties
such that the evolution of the system is guaranteed to be confined to a safe
set in the state space for all times. By exploiting monotonicity, we propose an
approach to this problem which is based on constraint programming. We find
control strategies that are based on repetitions of finite sequences of control
actions. We show that, under assumptions made in the paper, safety control of
monotone systems does not require state measurement. We demonstrate the results
on a signalized urban traffic network, where the safety objective is to keep
the traffic flow free of congestion.
