Please, keep in mind that, even though you may get it to work very well in your controlled build and test lab, it may experience noisy environment in different place, for example, a school gym where competition is held.
Over the years, people reported various instances of both ultrasonic sensors not working in pretense of loud music or HVAC noise as well as optical sensors confused by solar or unusual interior light.
Examples:
After you get any sensor to work well for you, try adding some sort of noise filtering algorithm as well as start thinking about testing it in different environments and making contingency plans for backup methods of navigation if the primary becomes unusable.