For a group of mobile robots in free space, we consider aggregation under the assumption that each robot has information about the position and course of the nearest neighbors only (without any additional information, such as the group target). This problem is the first stage of a mission carried out by a group of robots; it can be solved under certain conditions, see below. We propose a swarm control algorithm based on the metric-topological approach under maneuvering constraints. The sizes and configurations of the arenas are chosen, and initial position requirements are specified for robots. The characteristics of robots are selected, and computer simulations are conducted to evaluate the model parameters for the required directional coordination level of swarm motion without clustering and with a safe distance between robots during the entire mission.