Robots are constantly using energy and, therefore, occasionally have to visit a fuel station, which is located outside of the plate's center. Consensus among robots is achieved prior to every move, with robots that have high levels of fuel acting as a counterbalance to those moving toward the fuel station. Collision avoidance is also implemented by consensus. The application demonstrates tolerance of the robots' and controllers' crash, omission, and computation faults.
Control is subject to soft real-time constraints.
Calculations of the controllers' and robots' moves are executed with a frequency of 4 Hz. The application of composite objects in a scenario with more stringent timing requirements is given in Section 3.2 . Another applet implements the robots' control algorithm in Java and interacts with the real-time simulation's native controllers during consensus rounds. Figure 3-2 shows the communication structure of the complete application. Due to the periodic operation of the soft real-time system, it is sufficient to read status information once per period.