Grade crossing gate arm position detection system

A crossing gate mechanism comprising:

• a swingable gate arm;
• a rotatable gate arm shaft fixed to the gate arm so that rotation of the gate arm shaft corresponds with swinging of the gate arm;
• an electronic sensor assembly coupled to the gate arm shaft to sense an angular position of the gate arm shaft and transmit a position signal corresponding thereto,
• said electronic sensor assembly being configured to generate the position signal based on position of the gate arm shaft;
• a calibration assembly,
• said calibration assembly being configured to detect a fixed angular characteristic of the gate arm shaft and transmit a characteristic signal corresponding thereto;
• and
• a controller electrically coupled to the electronic sensor assembly and the calibration assembly,
• said controller being configured to receive the position signal from the electronic sensor assembly and transmit data associated with the angular position of the gate arm shaft,
• said controller being configured to receive the characteristic signal from the calibration assembly and compare the position and characteristic signals.

A crossing gate mechanism comprising:

• a swingable gate arm;
• a rotatable gate arm shaft fixed to the gate arm so that rotation of the gate arm shaft corresponds with swinging of the gate arm;
• an absolute encoder coupled to the gate arm shaft to sense a mechanical angular position of the gate arm shaft;
• and
• a controller electrically coupled to the absolute encoder,
• said controller being configured to transmit data associated with the mechanical angular position of the gate arm shaft.