Method and apparatus for sensing gate position

A security gate operating mechanism, comprising:

• driving means operatively connected to the security gate for moving the security gate from a first position to a second position, responsive to operation of the driving means;
• position detection means, associated with the operating mechanism, for determining a first distance of the driving means from a first reference point and a second distance of the driving means from a second reference point, and determining the position of the security gate based upon the relation between the first distance and the second distance;
• and
• wherein the position detector means is a wave transmitter/receiver, and the first distance is measured by reflecting waves from a moving target moving as does the driving means and the second distance is measured by reflecting waves from a fixed target fixed in relationship to the wave transmitter/receiver.

A method of operating a security gate, comprising:

• driving the security gate between a first position to a second position, utilizing a driving mechanism;
• detecting with a position detector the position of the driving mechanism at a first distance from a first reference point and simultaneously at a second distance from a second reference point, and determining the position of the security gate based upon the relation between the first distance and the second distance;
• and
• wherein the position detector is a wave transmitter/receiver, and the first distance is measured by reflecting waves from a moving target moving as does the driving mechanism and the second distance is measured by reflecting waves from a fixed target fixed in relationship to the wave transmitter/receiver.