Abstract:
A new and improved outdoor lighting control system for an outdoor lighting system network for automatically sensing, conveying, and recording data relevant to the operation of the lighting system network so that both control and maintenance can be performed more efficiently. At each of plural lamp locations in the network, there is a controller module that receives electric power input and that supplies electric power to the remaining lamp locations. Each controller module has a first relay to deliver current to one or more outdoor illumination lamps at the controller module&#39;s location, and a second relay for switching electric power on to a succeeding lamp location. A first current sensor monitors current to the lamps at each lamp location, and a second current sensor monitors current to the remaining locations. The network&#39;s power lines form portions of a bi-directional data link via which data is transmitted from each controller module to a command station, and vice versa.

Description:
This application is a division of Ser. No. 08/804,714, filed Feb. 21, 1997, now U.S. Pat. No. 5,962,991. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to outdoor lighting control systems, and is especially advantageous for street and road lighting systems. 
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Certain individuals and governments consider both ownership and use of motor vehicles as a social concession which is compensated and checked by the levying of duties and various taxes on the vehicles and on products used in conjunction with the motor vehicles, especially fuels. Ownership of motor vehicles is however increasing throughout the world, and this is at least to significant extent attributable to increased prosperity. As a result, there is increased demand for new infra-structure, such as new streets, roads, highways, expressways, parking lots, etc., to accommodate both the increasing number of motor vehicles and the presence of more luxurious vehicles. Existing infra-structure is often outdated and needs maintenance, upgrading, and/or replacement. 
     One important component of both existing and new infra-structure is lighting systems for streets, roads, highways, expressways, parking lots, etc. While lighting systems are primarily intended to be functional, in some traditional areas, such as airports and shopping malls, it is important that they have a decorative character. Decorative character of lighting systems is becoming more important especially where the lighting systems are in the presence of illuminated signage and lighted buildings. Increased cost per unit of land area will be accompanied by an increase in the amount of lighting cost per unit of land area. Infra-structure associated with streets, roads, highways, expressways, parking lots, etc. requires maintenance. Because of extensive daylight usage of these corridors of travel, maintenance is often performed at night. If daylight maintenance is performed, it often interferes with use of streets, roads, highways, expressways, parking lots, etc. Because of increased traffic volumes, higher speeds, etc., one can appreciate that performance of maintenance involves increased risks of accidental, and even fatal, harm to maintenance workers and to occupants of motor vehicles. 
     Therefore, there is an increasing need for lighting installations that are easier and more cost-effective to maintain. This is why sox catenary installations are becoming less popular while the less efficient conventional SON-T installations with 18 meter high light poles placed up to 80 meters apart are increasingly popular. 
     One general objective of the present invention is to provide a new and improved system for automatically sensing, conveying, and recording data relevant to the operation of a lighting system network so that maintenance can be performed more efficiently. 
     Another general objective of the present invention is to provide a new and improved system for automatically controlling the operation of a lighting system network more efficiently. 
     The present invention utilizes known electrical components organized and arranged in a lighting system in a way that has never been done before. 
     One general aspect of the invention relates to an outdoor lighting control system for a string of outdoor illumination lamps disposed at various locations along an outdoor lighting system comprising: for each of plural lamp locations in the string, a controller module comprising input means for receiving electric power input and output means for supplying electric power to the remainder of the string; each of said plural lamp locations further comprising one or more outdoor illumination lamps; each controller module comprising first switching means for switching the electric power input to deliver current to the one or more outdoor illumination lamps at the controller module&#39;s location, and second switching means for switching electric input power from the controller module&#39;s input means to the controller module&#39;s output means in response to receipt of electric power input at the controller module&#39;s input means. 
     The foregoing, and other features, along with various advantages and benefits of the invention, will be seen in the ensuing description which is accompanied by drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view of a typical outdoor lighting system embodying principles of the invention. 
     FIG. 2 is a block diagram of an installation at a lamp pole. 
     FIG. 3 is a more detailed block diagram of FIG.  2 . 
     FIGS. 4 and 5 are still more detailed diagrams. 
     FIG. 6 is a diagram of a central control room. 
     FIG. 7 is a chart showing functions performed by a controller module in a lamp pole and functions performed by a control computer. 
     FIG. 8 is a block diagram of a control for executing functions. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows the general plan of a lighting system installation embodying principles of the present invention. There are a series of light poles  10  (only one pole being shown in FIG.  1 ), each of which has one or more lamps  12  for illuminating a land surface area. These poles are arranged in a string at appropriate distances, and in a given network there can be any number of strings and any number of poles in a string. Power (240/480 volts typically) is delivered to the poles via power lines  14 , usually buried underground cables, and extending in a string from a lighting cabinet  16  that serves one or more strings in a network. 
     A network may have various numbers of such lighting cabinets  16  that are linked with a central control room  18 . Detail of an example of a central control room is shown in FIG.  6 . Control room  18  receives electric power via incoming power lines  20  and delivers that power to the various lighting cabinets  16  via outgoing power lines  22 . In addition, the power lines  14 ,  22  provide a means for bi-direction communication and control between the control room  18  on the one hand and the lighting cabinets  16  and controller modules  27  in each pole  10  on the other hand. Data from the lighting cabinets and controller modules is conveyed to the control room, and commands are conveyed from the control room to the lighting cabinets and controller modules. 
     The control room is adapted for automatic operation to turn various lamp strings and/or individual lamps on and off at various times and to collect data from the lighting cabinets and the lamps served from each cabinet. The illustrated control room has a communication link  24  to the outgoing power lines  22  which includes an IR module and adapter for linking a P.C.  26  with the outgoing power lines while providing electrical isolation between them. 
     FIGS. 1 and 2 shows each pole  10  to comprise a controller module  27  that houses a lamp relay  28  via which electric power is delivered from power lines  14  to the pole&#39;s lamp or lamps. According to certain principles of the invention, a switched power relay  30  and a LON chip  32  are also provided within each controller module  27 . 
     FIG. 3 shows further detail wherein each module  27  further comprises various switches  34  that are operated by service personnel at time of component replacement for inputting to the LON chip  32  signals to indicate replacement of various components, such as the lamp, or lamps,  12 , the ballast, and the capacitor. Controller module  27  further comprises a power supply  36  that converts a small part of the incoming power to suitable voltage for operating other module components, particularly the LON chip  32 . There is also a LON power line interface  38  that interfaces the LON chip with power lines  14 . The lamp relay  28  and the switched power relay  30  are connected with the LON chip  32 . Current flow to the pole&#39;s lamp(s) is monitored by a current sensor  40  which supplies a current measurement signal to an analog-to-digital converter  42 . Lamp voltage is also supplied to the converter. Current leaving the controller module via the switched power relay  30  is monitored by a current sensor  44  that supplies a current measurement signal to converter  42 , and the voltage from switched power relay  30  is supplied as a voltage signal to the converter. 
     The LON chip  32  is a device that provides certain functions at each pole. It turns the pole&#39;s lamp(s) on and off by operating the lamp relay  28  in accordance with commands received by module  27  via the incoming power lines  14 . It turns power to the next pole in the string on and off by operating the switched power relay  30  in accordance with commands received by module  27  via the incoming power lines  14 . 
     The LON chip  32  also provides data back to the control room  18  via the power lines  22  and lighting cabinets  16 . This data includes lamp current, lamp voltage, and signals for indicating that a new ballast, a new capacitor, or new lamps have been installed. Communication between the LON chip  32  and power lines  14  is via interface  38 . 
     At the central control station the usage of each lamp is logged so that a running count of hours on is maintained. Voltages and currents are also logged. Any unusual event that causes an alarm to be given is also logged. FIG. 7 is a chart describing various functions performed by a controller module  27  in a lamp pole  10 , and functions performed by PC  26  at control station  18 . Although the FIG. 6 shows the PC at the control station, the PC may be located elsewhere and connected via suitable means, including for example telemetry and/or modems, with the interface to the power lines  22 . At a lighting cabinet  16 , there may be conventional electrical equipment such as a transformer or transformers that couples the incoming power lines  22  to power lines  14  that serve the various strings of poles, various disconnects, etc. However, in certain installations, generally smaller installations, the equipment shown in control room  18  and the contents of a lighting cabinet may be contained at a single site. 
     The data collection and control capabilities of the inventive control system provide many possibilities for implementation in any installation. Once important purpose is to monitor for abnormal conditions, such as lamp, ballast, and capacitor failure (either actual or impending) at each individual pole. Another purpose is to schedule preventive maintenance. Another purpose is to monitor for line faults. The invention provides for communication between the control center and each individual pole. Each individual pole is uniquely identified and so the control center can communicate with the module  27  of each individual pole to ascertain its operating status and to collect information from the pole. If there is a failure or irregularity in a pole, the failure or irregularity is detected at the pole by the various sensing inputs to the LON chip  32 , either directly from a sensor, such as a current sensor, or via interface  38 . These are in turn communicated back via the power lines (and through any intervening lighting cabinet) to the control room. Personnel may or may not be in attendance at the control room. In event of emergency where no one is present, an alarm signal may be transmitted to a person&#39;s personal beeper to alert the person. 
     The communication of data and commands via the power lines themselves avoids the need for additional separate lines. The data and commands are transmitted digitally on the power lines at voltages and frequencies that can be correctly transmitted and received without interference between these signals and the power line voltage and current. 
     It is to be noted that power cannot be transmitted from one pole to a subsequent pole in a string unless switched power relay  30  in the one pole is actuated closed by the LON chip  32  in the one pole. The LON chip is programmed to prevent relay  30  actuation unless conditions at the one pole are within specification for proper operation. If there is a fault between the one pole and a subsequent pole, it can be detected because the relay  30  of the one pole will be actuated closed, but there will be no communication with the subsequent pole. This capability quickly provides the location of a fault so that service personnel can go directly to the location. 
     FIGS. 5 and 6 shows progressively greater detail of the circuitry of module  27 . FIG. 6 shows the lamp, the capacitor, and the ballast connected in circuit with module  27 . FIG. 5 shows the four individual switches connected to the LON chip  32  each of which is actuated when the corresponding component (lamp, ballast, capacitor) is replaced by a new one. This information is communicated to the control room to,begin logging new data for the new part or parts. 
     The LON chip  32  and interface  38  are conventional commercially available components. The LON chip and the PC are programmed by conventional programming procedures to perform the various functions that have been disclosed herein. A suitable LON chip is an Echelon Neuron Chip. The interface is also available from Echelon. 
     The flow chart shown in FIG. 8 comprises the following steps for the controller. First, a power on step command  100  applies power to the first controller module  27 . The delivery of power to that module serves to initialize it via its LON chip  32 , as represented by step  102 . Step  102  shows that the LON chip is placed in an initialized state that causes no power to be delivered to the lamp(s) of its pole or to the next module  27  in the string of modules. The LON chip then returns a “controller stable” signal to P.C.  26 , represented by step  104 , to indicate that the first controller module is ready to receive a “lamp on” command from the P.C. 
     Step  106  designates the “lamp on” command being given by the P.C. and received by the first controller module  27 . That module responds to that command by its LON chip  32  commanding its lamp relay  28  to turn on the lamp(s) of its pole, as represented by step  108 . When the lamp(s) are turned on, the lamp circuit will, if it is operating properly, execute a short electrical transient until the current and voltage stabilize. When steady state operation is detected, an appropriate signal or signals are returned from the LON chip  32  to the P.C. so that operating times for the lamp(s), ballast, and capacitor begin to be logged. Steady state operation can be detected by monitoring relevant current and/or voltage, or by waiting a sufficient amount of time for them to have stabilized if the circuit is operating properly. Step  108  shows that the current to the lamp(s) is measured after the transient period, and a signal representing that current is returned to the P.C. At the P.C. that signal is compared against proper current for that pole, and if the measured current is within the proper range, the operating times for the lamp(s), ballast, and capacitor begin to be logged. If the signal indicates an out-of-range current, a possible fault condition is logged for investigation and possible corrective action. These series of steps associated with the turning on the lamp(s) of the first pole occur quickly, and they further include a step of the LON chip  32  operating the switched power relay  30  to enable voltage to be transmitted to the next pole in the string, and communication to be established with the P.C. 
     The delivery of voltage to that next (second) pole in the string is followed by a “turn on next lamp” signal from the P.C. This is represented by the step  110  in FIG.  8 . Upon receipt of that signal, the second pole&#39;s controller module  27  executes the same series of steps as described above for the first pole, although FIG. 8 does not contain blocks specifically repeating these steps. It is however to be understood that when the second pole&#39;s controller module receives its “turn on signal”, it responds to that command by its LON chip  32  commanding its lamp relay  28  to turn on the lamp(s) of its pole. If it is operating properly, the lamp circuit will execute a short electrical transient until the current and voltage stabilize. When steady state operation is detected, an appropriate signal or signals are returned from the LON chip  32  to the P.C. so that operating times for the second pole&#39;s lamp(s), ballast, and capacitor begin to be logged. Steady state operation is detected as described above for the first pole, current to the lamp(s) is measured after the transient period, and a signal representing that current is returned to the P.C. At the P.C. that signal is compared against proper current for that pole, and if the measured current is within the proper range, the operating times for its lamp(s), ballast, and capacitor begin to be logged. If the signal indicates an out-of-range current, a possible fault condition is logged for investigation and possible corrective action. The turning on of the second pole&#39;s lamps is also accompanied by a step of its LON chip  32  operating its switched power relay  30  to enable voltage to be transmitted to the next (third) pole in the string, and communication of the third pole&#39;s controller module  27  to be established with the P.C. 
     Based on the foregoing description, it can be understood that this procedure continues along the entire string until the lamps of the last pole have been turned on. Any lamp circuit that is not operating properly will be logged. Operating times for each pole&#39;s components will be logged. Thus information and history regarding the operation of each pole is contained in the P.C., which may at times pass the information to a central station. Problems with the string of poles can be detected, and a particular pole having a problem can be identified. 
     Steps  112  and  114  show how a problem can be identified. If a potential problem is signaled from any pole, or at any time that it is desired to check one or more of the poles, a “diagnostics” command is issued from the P.C. to a controller module  27 . Upon receipt of that command the commanded controller module  27  sends lamp current, voltage, log times, and next lamp current data back to the P.C. This is a reason why the exemplary current sensors  40  and  44  in each controller module  27  are important. Not only can the current flow into the lamps at each pole be sent to the P.C., but the current flow from a controller module  27  to the rest of the poles in the string can be ascertained. The P.C. is programmed with, or to calculate, what should be the proper currents and voltages at various points in each pole, including the lamp(s), ballast, capacitor, and controller module. Upon receiving data from the poles, each of which is uniquely identified, the P.C. can compare that data with the proper currents and voltages and thereby determine the location and nature of a fault or faults. This will greatly aid service personnel who must go out into the field to correct a problem. 
     The steps  116  and  118  depict a still further function that occurs in each controller module after it has been turned on. As the LON chip  32  operates the switched power relay  30  to deliver voltage to the next pole, it also enables an overcurrent interrupt. If the current flow to the next pole as sensed by sensor  44  is an overcurrent, the LON chip will immediately stop the operation of relay  30  so that power flow from its pole to the rest of the string is promptly terminated. A fault (alarm) signal is sent back to the P.C. to log the fault. 
     The remaining steps  120 ,  122  shown in FIG. 8 simply represent intentionally turning off the string of lamps. The P.C. issues a “lamp off” command, and when it is received the poles are shut down. This can be done in reverse order to “lamps on” so that each preceding pole in a string can supply final data to the P.C., if desired. Log off times are noted by the P.C. so that component “on” time ceases to accumulate. 
     The invention therefore adds important capabilities in monitoring and servicing a string of outdoor lamps. While a presently preferred embodiment has been illustrated and described, it is to be appreciated that principles are applicable to other embodiments that fall within the scope of the following claims.