Due to the growing complexity of the applications targeted by FPGA-based reconfigurable systems, the control design of such systems is becoming one of the main hurdles faced by designers. In this paper, we propose a semi-distributed control model based on the separation between different control concerns (monitoring, decision-making and reconfiguration) and on formalism-oriented design in order to decrease the design complexity of the control, and facilitate design verification, reuse and scalability. This model is composed of distributed controllers handling each the self-adaptivity of a reconfigurable region of the system, and a coordinator that coordinates their reconfiguration decisions in order to respect global system constraints. Implementations on FPGA showed that our semi-distributed control model is more flexible, reusable and scalable than the centralized one, at the cost of a slight increase in required hardware resources.