Ultrasonic Sensors Controlled Motors

Without knowing what any of the components are it's impossible to say much. What motors, what relay, what are the things that look like transistors/MOSFETs and how connected, what diodes, what power source and why aren't the grounds connected?

Your text says 100cm, code says 20. Dividing an integer by 58.2 may not give the results you expect.

Steve