Plato seems to avoid invisible obstacles

• Is the room still in the same configuration than when the mapping was done ?

It is possible that the layout of your restaurant may have changed between the first time you mapped the room and recent use of Plato. If that is the case, you will need to map the room again to take into account the changes made to the layout. 

• Was the room in its final configuration during mapping ?

If during mapping you haven't removed all temporary obstacles, objects that were not meant to be in their place in the final layout, or if people were moving around the front of the robot during the mapping, it is possible that the robot has detected and saved an obstacle in that spot. 

You will need to map the room again in its final layout to solve the issue. 

• Was there direct light on the robot sensors during mapping ?

Direct light on the sensors can also be detected as an obstacle by the robot. Make sure that during the mapping no direct light goes onto the sensors.