Positioning an object with respect to a target location

A method for positioning an object, the method comprising the steps of:

• providing an optical grid having a first set of optical elements and a second set of optical elements, the first set of optical elements being optically distinguishable from the second set of optical elements;
• moving an optical sensor in a forward direction at a constant speed with respect to the optical grid, wherein transitions are encountered when the optical sensor senses a border between one of the first set of optical elements and one of the second set of optical elements;
• beginning a clock cycle counter when a target location is reached;
• stopping the clock cycle counter when a first transition beyond the target location is encountered to obtain a first clock cycle count;
• continuously moving the optical sensor in the forward direction at the constant speed until at least a second transition beyond the target location is encountered;
• reversing the direction of movement of the optical sensor and moving the optical sensor in a reverse direction and at the constant speed;
• resetting and beginning the clock cycle counter a second time when the first transition beyond the target location is encountered in the reverse direction;
• and
• stopping the movement of the optical sensor when the clock cycle counter reaches the first clock cycle count.