*wpw* − *number o f waypoints*.

The first objective function in Equation (6) tries to maximize the search space by visiting various numbers of cells in the map. In a good scenario, robots should avoid explored cells. The waypoints in MOGWO exploration allow saving the direction to the unexplored part of the map. However, there are some constraints for a successful search. For example, the number of waypoints should not be too small and big. In the case when it is small, robots will stay in one point, because they do not have the tasks to drive next waypoints. If it is bigger than the total number of cells in a map, then a robot will drive around one place longer than it is needed.

After the map is explored, the second objective function tries to improve the map accuracy by reducing the probability values of the grid cells. It means once a sensor beam touches a grid cell, the cell is marked as explored. However, the signal strength projected on the cell is not identical. In the robot position, the probability value has the lowest value. In frontier cells, the values are higher according to the power of a signal.

In the subsection below, the MOGWO exploration algorithm is described extensively.
