I just got a MBot and I was trying out the unmaned mode on the android app mBot. When ever it is in avoidence mode (unmaned mode) it avoides things straight infront of it, but if it comes at something from an angle, it runs into it and scrapes along the object or wall. Is there some way to avoid that without changing it into manual mode?
mBot runs into walls (unmaned mode)
Some of that has to do with the way the ultrasonic sensor works. If the mBot turns enough that the ultrasonic sensor is at an angle that puts the “obstacle” out of the reaction range, then it will do the behavior you describe. The short answer is that you can write a program in mBlock to do that sort of thing. I wrote a short eBook that has an exercise in it that does exactly that, but in essence it comes down to turn enough to not have that situation. I chose to back up and turn 90 degrees but in your program you can make your own choices. 
Best regards,
Chuck