Abstract:
A street lighting fixture and street lamp used in street lighting containing an accelerometer that is used to detect and characterize acceleration events on a street lighting fixture. The accelerometer readings may be combined with GPS technology to determine a relocation of the street lighting fixture.

Description:
BACKGROUND 
       [0001]    Area and street lighting is one of the most important elements of a city&#39;s infrastructure. For such extensive lighting installations it is desirable to know the locations of individual luminaires for maintenance and other purposes involving planning and billing. 
         [0002]    In many instances, maintenance and installation crews installing luminaires record the luminaire locations by their GPS coordinates. The GPS coordinates are often provided by GPS receivers carried by the installation crews as part of a crew&#39;s personal data assistant. 
         [0003]    It occasionally happens that luminaires are moved and their new location coordinates are not recorded. This introduces bookkeeping errors and adds to the overhead of maintaining the city&#39;s lighting infrastructure. It may also result in incorrectly locating and therefore misinterpreting data provided by non-illumination functions that are associated with, and physically proximate to, the luminaire. 
         [0004]    A need therefore exists for a luminaire associate that will also provide the luminaire&#39;s true position and the location of associated functions regardless of a relocation of the luminaire and its associate. 
     
    
     
       BRIEF DESCRIPTION OF ILLUSTRATIONS 
         [0005]      FIG. 1  illustrates a lamp, luminaire associate, and a post. 
           [0006]      FIG. 2  illustrates the luminaire associate sending a GPS message. 
           [0007]      FIG. 3  illustrates a luminaire associate connected to an electric meter. 
           [0008]      FIG. 4  illustrates severe wind battering the post supporting the luminaire associate. 
           [0009]      FIG. 5  illustrates a vehicle impacting the post supporting the luminaire associate. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    A luminaire installed in an area or street lighting system typically comprises a lamp, a luminaire associate that supplies power to the lamp at appropriate times and may perform other functions, and a post supporting the lamp and luminaire associate. 
         [0011]      FIG. 1  illustrates the luminaire  100  comprising the lamp  110 , the luminaire associate  120 , and the supporting post  130 . A GPS receiver is incorporated into the luminaire associate  120  and provides the true location of the luminaire associate  120  even if the luminaire associate  120  is relocated without recordation in the lighting utility&#39;s property database. An accelerometer is also incorporated into the luminaire associate. By this combination of the GPS receiver and the accelerometer, the luminaire associate  120  may also report accurate luminaire location and accelerations imparted to the post  130  on which the luminaire associate  120  is mounted. 
         [0012]    An acceleration event is declared and reported if (1) the magnitude of the measured acceleration exceeds a prescribed threshold or (2) the spectrum of the measured acceleration has one or more spectral components that exceed one or more prescribed thresholds or (3) in the case of a multiple axis accelerometer, the previous case (1) or (2) wherein the case applies to a particular accelerometer axis. 
         [0013]    The technical advantages to incorporating the combination of a GPS receiver and accelerometer into the luminaire associate  120  are manifold. Not only can the luminaire be accurately located following its relocation, any accelerometer data will be associated with the luminaire&#39;s accurate geographical location. The accelerometer data can be used for very many purposes including, but not limited to: (1) monitoring wind speeds or detection of winds exceeding certain limits and (2) detection of a vehicle impacting the luminaire support pole and (3) estimating traffic loading on adjacent streets through analysis of coupled vibration and (4) earthquake alerting and (5) tornado tracking. 
         [0014]    Not illustrated but optionally included in the luminaire associate  120  is a communication device that allows the luminaire associate to communicate with at least one of the lighting utility&#39;s data centers, vehicles, maintenance worker crew, and data centers belonging to other infrastructures such as an electric power utility. Also not illustrated but optionally included in the luminaire associate  120  is a data recorder that records compressed or uncompressed accelerometer data and the time associated with the compressed or uncompressed accelerometer data. Such recorded data may be of value to the lighting utility for such actions as warranty claims, insurance actions, and maintenance and replacement or upgrade scheduling. 
         [0015]      FIG. 2  illustrates the luminaire associate  120  sending a GPS message. The message may comprise three spatial location coordinates, ie x,y,z and time, t, and is denoted by GPS:(x,y,z,t). The GPS generated message may be sent to one or more of the lighting utility&#39;s data centers  220 . The GPS generated message may be sent to a vehicle  230 . The GPS generated message may also be sent to a maintenance worker crew  240 . 
         [0016]    Another embodiment is illustrated in  FIG. 3 . A utility meter, such as an electric meter  310 , communicates its readings to the luminaire associate  120  by an electrical conductor  320  or by another communications means, not illustrated, such as an RF communications link, an optical communications link, or a sonic-based communication link. The meter&#39;s readings are recorded by the luminaire associate  120  or forwarded to an infrastructure&#39;s data center. 
         [0017]      FIG. 4  illustrates the scenario  400  wherein the luminaire is subjected to extreme weather conditions such as an intense windstorm or a tornado. The accelerometer and GPS data may be used to report or store weather conditions within the city and such data may be communicated to one or more infrastructure data centers and to public safety officials. The data may also be of use for assessing damage to the lighting infrastructure and for processing insurance claims. 
         [0018]      FIG. 5  illustrates the scenario  500  wherein a vehicle  510  or other massive moving object impacts the post  130 . The impact will cause shock data to be noted and recorded or transmitted by the luminaire associate  120 . The shock data may be accompanied by GPS produced data respecting time or position. Such data may be useful for summoning emergency response services and also useful for characterizing the magnitude and time of the incident for insurance and law enforcement personnel.