Why do people walk in a circle when they are blindfolded and intend to walk in a straight line? Why does someone with eyes tied follow a circular path if left to walk in a huge yard(kilometers), that occurs even if he thinks that he is walking in a straight line?

In my opinion once you drawn a well enough curve your balance shift towards inner side of circle and you fullfill to spiralate inwards. But what shifts the balance inward?
It has nothing to do with perception.

It's simply because there are infinitely many ways to go in circles, while only one way to go straight. Even a slightest bias towards one side will produce a circle. When other cues are given to correct the bias, one is able to track straight lines.

Even robots (or toy cars) that are designed to go straight lines will go in circles without sensory feedback!