Arduino code to solve maze using 3 ultrasonic sensore

i make simulation in protues but dc motors not work

i’m a beginner, so i need help in my code

how to control speed of two dc motor? ,how make robot rotates 180 degree when no way(road is closed)?

i will use (left hand algorithm) to find (dummy) to rescue and return from the shortest way, this algorithm will be good?

the entrance of maze is the same outlet

thanks very much if you help me

see attachment for my code
_2017-07-04_Maze_solving_with_ultrasonic.zip (989 Bytes)