Angular position indicator for cranes

An angular position indicator for a crane boom, comprising:

• a base adapted for mounting to a crane boom that is to have its angular position measured;
• a pendulum pivotally mounted to the base and hanging freely in a vertical orientation by force of gravity;
• an array of sensors for determining the angular positioning of the pendulum, the array of sensors including optical emitters and optical detectors fixed to the base and an optical encoder mounted to the pendulum, such that the optical emitters and optical detectors are angularly displaced in relation to the optical encoder mounted on the pendulum should any movement of the structure occur, the optical encoder having a series of optical apertures that are illuminated by the optical emitters and which, by such illumination generate unique identifiable light patterns detectable by the optical detectors, the illumination of the optical detectors being a function of optical coupling through optical channels formed by the optical emitters, the optical apertures and the optical detectors, the optical coupling depending upon the position of the optical apertures in the optical channels, for any position of the optical encoder some of the optical channels being fully open, some being fully blocked and at least one being partially open;
• a first set of processing electronics including a transmitter, the first set of processing electronics receiving data from the array of sensors regarding the optical apertures that are fully illuminated, the optical apertures that are not illuminated, and assigning a fractional value to the degree of illumination of the at least one optical aperture that is partially illuminated to enhance resolution of angular measurement, and calculating mean angular displacement in order to compensate for oscillatory motion caused by vibration, shock and angular acceleration;
• a second set of processing electronics including a human readable display, the second set of processing electronics remote from the first set of processing electronics, the first set of processing electronics transmitting a signal with a unique identification code which is received by the second set of processing electronics, the second set of processing electronics displaying angular positioning of the crane boom on the human readable display.

An angular position indicator for a crane boom, comprising:

• a base adapted for mounting to a crane boom that is to have its angular position measured;
• a pendulum pivotally mounted to the base and hanging freely in a vertical orientation by force of gravity;
• an array of sensors for determining the angular positioning of the pendulum, including optical emitters and optical detectors fixed to the base and an optical encoder mounted to the pendulum, such that the optical emitters and optical detectors are angularly displaced in relation to the optical encoder mounted on the pendulum should any movement of the structure occur, the optical encoder having a series of optical apertures that are illuminated by the optical emitters and which, by such illumination generate unique identifiable light patterns detectable by the optical detectors, the illumination of the optical detectors being a function of optical coupling through optical channels formed by the optical emitters, the optical apertures and the optical detectors, the optical coupling depending upon the position of the optical apertures in the optical channels, for any position of the optical encoder some of the optical channels being fully open, some being fully blocked and at least one being partially open;
• and
• processing electronics receiving data from the array of sensors regarding the optical apertures that are fully illuminated, the optical apertures that are not illuminated, and assigning a fractional value to the degree of illumination of the at least one optical aperture that is partially illuminated to enhance resolution of angular measurement.