WO2014078907A1

WO2014078907A1 - Intelligent lamp fitting

Info

Publication number: WO2014078907A1
Application number: PCT/AU2013/001356
Authority: WO
Inventors: Christopher Scott Trewin; Michael Joseph MANION
Original assignee: 300K Enterprises Pty Ltd
Priority date: 2012-11-26
Filing date: 2013-11-25
Publication date: 2014-05-30

Abstract

The present invention provides a lamp fitting and a method of remotely monitoring a lamp fitting. The lamp fitting has a lens through which light is transmittable. The fitting has at least one sensor able to detect dirt/contamination on the lens and/or damage to the lens and optionally has other sensors that are able to detect other internal and external conditions relevant to maintenance considerations and report these to a maintenance controller. The invention also relates to methods of providing a distributed SCADA network using the lamp fitting.

Description

Intelligent Lamp Fitting

Technical Field

[0001] The present invention relates to lamp fittings, particularly industrial lamp fittings, and emergency lighting and includes outdoor lamp fittings.

Background

[0002] Lamp fittings are commonly mounted at height and are inaccessible. Lamp fittings may also be heavy or unwieldy, particularly industrial lamp fittings. Due to conditions present of various industrial sites maintenance of lamps often presents difficulties. Specialised lifting equipment may be required to gain access to the lamp and maintenance by personnel is often conducted on an elevated web platform, scissor lift, scaffold or other apparatus. These apparatus present their own difficulties and may be expensive due to hourly hire rates applicable to such equipment. In addition maintenance of a lamp fitting may interfere with traffic or other operations being conducted in the vicinity of the lamp fitting. For example the area around a person working at height has to be barricaded for safety. This may result in disruption to traffic and personnel. Further, on some sites lamp fittings may be spread over a large area not readily accessible by maintenance personnel.

[0003] Problems encountered while maintaining emergency lighting are similar to those involved with normal lighting, however emergency and shower lighting is much more strictly controlled as it is generally considered and treated as a statutory piece of equipment. This makes it even more important for emergency lights to be functioning correctly and to be repaired quickly. Further, various buildings on a site may have emergency lighting also not readily accessible by

maintenance personnel.

[0004] At the moment maintenance of lamp fittings is conducted in most industrial or commercial settings on a scheduled basis, whether or not an individual lamp fitting needs to be repaired or replaced.

[0005] There are a number of issued patents which describe proposals for self-diagnostic or intelligent control systems for equipment. For example US patent No. 6, 252, 505 in the name of Northrop Grumman Corp discloses an on-site environmental monitoring systems for temperature or humidity whereas US patent number 6, 534,942 in the name PS Automation GmbH fur

Gesellschaft Antriebstechnik discloses an intelligent control and adjustment device which uses sensors to regulate processes involving flowable substances. US patent number 6, 973, 396 in the name of General Electric Co relates to a method for developing a unified quality assessment and automatic fault diagnostic for turbine machine systems.

[0006] Further US patent number 6, 788, 000 in the name of E-Lite technologies Inc discloses a distributed energy lighting system with self-diagnostic capabilities. US patent number 6, 392, 349 in the name of Crenshaw discloses a remote control test apparatus emergency lighting which is achieved by an infrared transmitter capable of transmitting a coded signal for interrogation of an emergency ballast control via a cable.

[0007] There are also a number of patent applications relating to various systems for example US patent application 2009/0222223 in the name of Walters et al relates to a street light monitoring system which reports malfunctions wirelessly including detection of failed lamps.

[0008] US patent application 2013/0131882 in the name of Orion Energy Systems Inc discloses lighting fixtures which sense conditions and report to a central controller.

[0009] US patent application 2012/0086561 in the name of General Electric Company discloses an outdoor lighting system which is able to wirelessly communicate with utility meters (gas, water, electric) in a mesh network.

[0010] European patent application 2131630 in the name of Tecnologie e Servizi Innovativi T.S.I. S.r.l. discloses a smart LED street lamp which can sense noise, carbon monoxide, ozone, fine dust, and traffic conditions and internal parameters such as current, temperature and

luminescence. These conditions are reported wirelessly to a central controller.

[001 1] China patent application 202035190 discloses an intelligent LED power supply for streetlamps using ZigBee technology which are able to acquire data such as temperature and humidity from the environment. Other similar systems are disclosed in China patent applications 102802315, 202841646, 102437868, 102595701 , 102740558, 102905434, 103068128,

202353864 and 202818741.

[0012] US patent application 2013/0093357 in the name of Energy Intelligence Corporation discloses an LED intelligent illumination control device which operates via a ZigBee interface mainly for domestic lighting. The invention includes ability to sense and report on individual LED performance within the lighting array. This is achieved by current analysis.

[0013] Other intelligent lighting systems include US patent applications 2013/0200807, US 2013/0103201 and US 2012/0217882.

[0014] While these proposals may offer some advantages in allowing various pieces of equipment to sense particular conditions, there is still a need for more targeted information regarding the maintenance status of lamps or their components. [0015] The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art.

Disclosure of the Invention

[0016] In one aspect the invention provides a self monitoring lamp fitting having a lens through which light is transmittable said fitting able to sense conditions internal and/or external to itself and able to report the conditions to a maintenance controller, which enables the maintenance controller to decide whether inspection, maintenance or replacement of the fitting or another appliance is needed, said fitting comprising: at least one sensor for gathering data about internal and/or external conditions operatively linked to a reporting means, wherein said reporting means is able to transmit said data, or information derived from said data to said maintenance controller to enable said decision to be made; characterized in that the at least one sensor is able to sense light reflected by at least part of the lens providing information about transparency of the lens.

[0017] The term "self-monitoring" refers to a self aware or intelligent lamp fitting which can perform regular surveillance on itself, an adjacent appliance or surrounding environment. This includes, for example the lamp conducting surveillance on a pump or other piece of equipment and being able to report on abnormal vibrations and the like.

[0018] The term "lamp fitting" refers to an appliance which contains a lamp or lamps capable of producing light for illumination purposes such as an incandescent, fluorescent, light emitting diode (LED) or other type of lamp and includes emergency lighting. The term may also include control equipment such as the ballast, the reflector and other such components which make up the fitting.

[0019] The term "lens" refers to that part of the lamp from which light emanates or is directed and includes a diffuser.

[0020] The term "able to sense conditions internal and/or external to itself" means that the lamp fitting has the ability to sense one or more conditions in or around itself. These conditions may be conditions generated inside the lamp such as light output from the lamps or by a light emitter or temperature, battery status, particularly for emergency lighting, or other parameters or conditions generated outside of the lamp fitting such as external temperature, ambient light levels, the state of adjacent appliances or the like.

[0021] The term "able to report the conditions" means that the lamp is able to send a message or signal. [0022] The term "maintenance controller" refers to a person and/or a computer program responsible for directing maintenance on the lamp fitting or adjacent appliances including scheduling of maintenance.

[0023] The term "another appliance" refers to appliances such as instrumentation, electrical motors, pumps, process control / instrumentation devices, flow control valves, modems, electricity meters, smart meters, submeters and status indicators i.e. proximity switches, pressure switches, flow indicators, valves, pH meters and the like.

[0024] The term "sensor" refers to a mechanism or means for sensing a condition and may include means for processing the data into a suitable output to be sent to the reporting means. The term includes a light sensor and associated elements, one or more temperature sensors (for determining internal or external temperatures), battery charge levels, a vibration sensor (such as an accelerometer for detecting wind loads and wind gusts, impact loads such as hail or heavy rain drops) and a humidity sensor or the like.

[0025] The term "for gathering data" refers to the detection and/or collection of data such as light levels, including reflected light levels, temperature levels, battery power levels, vibration levels and moisture levels or the like.

[0026] The term "operatively linked" means that the sensor and reporting means are linked or connected by a linking means which enables the data or information to be sent from the sensor to the reporting means. The linkage means may include other elements such as a digital interface and a central processing unit (CPU) or a microprocessor.

[0027] The term "a reporting means" refers to communication via wireless or cabled means. Communication via wireless refers to a radio transceiver and associated elements in the appliance which allow communication between the appliance and the maintenance controller. This includes radio frequency technology such as ZigBee and WiFi. A cabled means includes a dedicated communications cable and a power supply cable. In the case of a power supply cable, reporting may be achieved by a combined power and/or signal overlay such as a high frequency control signal.

[0028] The term "or information derived from said data" includes information and/or messages derived from the data. For example a message about the condition of the lamp where certain threshold levels have been reached (such as a certain amount of reflection from the lens indicating dirt or damage, whether lamp vibration is above safe levels or whether a specified number of LED in the array have failed and/or the position of the failed LED) may be sent to the maintenance controller. This can reduce the amount of traffic on a network as the lamp fitting makes a decision about its status based on its programme and then reports the status.

[0029] The term "light reflected by at least part of the lens" includes visible and non-visible light produced by a light generating means adjacent the lens inside the fitting.

[0030] The term "transparency" of the lens includes reference to the ability of the lens to allow light to travel through it unaltered as seen by an external observer. Scratches, cracks or other damage to the lens will alter the ability of the lens to allow light to travel through it. The term transparency also includes apparent transparency of the lens where dirt or other contamination impedes the ability of the lens to allow light to travel through the lens thus making the lens appear less transparent.

[0031] Preferably the lamp fitting includes a light generating means which directs light onto an inside surface of the lens. Preferably the at least one sensor is a photodetector. More preferably the light generating means produces monochromatic light and the photodetector comprises photodiodes. Alternatively, more preferably the light generating means is an infrared emitter and the photodetector is an infrared sensor.

[0032] Preferably the other sensors sense light output for illumination purposes to determine whether the lamp or its components have failed or are underperforming. More preferably the lamp fitting comprises LED. Even more the preferably other sensors comprise a photodetector, each photodetector paired with an LED thereby enabling detection of which individual LED has failed. Alternatively, preferably the other sensors comprise a charge coupled device and/or linear photodiode array which generates an image of the light output enabling identification of individual LED and assessment of whether that individual LED has failed or is underperforming.

[0033] Preferably the reporting means is a wireless reporting means.

[0034] Preferably the lamp fitting comprises other sensors which sense temperature inside and/or outside the lamp, vibration in the fitting, impact on the fitting or humidity inside or outside the fitting.

[0035] Preferably the lamp fitting is able to sense conditions external to itself wherein the conditions relate to another appliance. More preferably the other appliance comprises

instrumentation, an electrical motor, a pump, a process control/instrumentation device, a flow control valve, modem, electricity meter, smart meter, a proximity switch, a pressure switch, flow indicator, valve, pH meter and the like. [0036] In another aspect the invention provides a self monitoring lamp fitting having a lens through which light is transmittable wherein said fitting is able to monitor conditions which affect the fitting including transparency of the lens, said fitting comprising at least one sensor able to sense light reflected by at least a part of the lens and optionally having other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a reporting means, wherein said reporting means is able to transmit data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

[0037] The term "conditions which affect the lamp" refers to transparency/opacity of the lens (where the dirt, dust, snow or other material has built up on the lens), light generated by the lamp, internal or external temperature, humidity, vibration and the like. These are all conditions which affect the proper functioning, or are likely to affect the proper functioning of the lamp.

[0038] In another aspect the invention provides a method of remotely monitoring a lamp fitting having a lens through which light is transmittable said monitoring being for conditions which affect the fitting including transparency of the lens, said method comprising providing: a lamp fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally providing other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a reporting means, wherein said reporting means is able to transmit data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

[0039] Preferably the light reflected by the lens in the lamp fitting is produced by a light generating means adjacent the lens and the at least one sensor comprises a photodetector.

[0040] Preferably the other sensor in the lamp fitting senses light output for illumination purposes to determine whether the lamp fitting or its components have failed or are underperforming.

[0041] Even more preferably the lamp fitting provided in the method comprises LED.

[0042] Still more preferably the lamp fitting used in the method comprises a wireless reporting means.

[0043] In yet another aspect the invention provides method of reducing maintenance inspections of a lamp fitting having a lens through which light is transmittable by providing a lamp fitting which is self reporting of conditions which affect the lamp including transparency of the lens, to a maintenance controller said method comprising providing: a lamp fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally providing other sensors for gathering data about internal and/or external conditions relevant to maintenance said sensors operatively linked to a reporting means, wherein said reporting means is able to transmit said data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

[0044] The term "internal and/or external conditions relevant to maintenance" refers to such conditions which indicate that maintenance or replacement of the lamp is indicated. For example parameters such as opacity of the lens, light generated by the lamp, internal or external temperature, humidity, vibration and the like are conditions relevant to maintenance of the fitting.

[0045] Preferably the light reflected by the lens in the lamp fitting is produced by a light generating means adjacent the lens and the at least one sensor comprises a photodetector.

[0046] Preferably the other sensor in the lamp fitting senses light output for illumination purposes to determine whether the lamp fitting or its components have failed or are underperforming.

[0047] Even more preferably the lamp fitting provided in the method comprises LED.

[0048] Still more preferably the lamp fitting used in the method comprises a wireless reporting means.

[0049] In another aspect the invention provides a method of providing a distributed supervision control and data acquisition network for monitoring or controlling lamp fittings and other appliances remotely comprising providing: a plurality of the lamp fittings mounted on power poles or other structures in a location, each lamp fitting having a lens through which light is transmittable and an ability to report conditions which affect the lamp including transparency of the lens said fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a wireless reporting means, wherein said reporting means is able to transmit said data, or information derived from said data to a maintenance controller where each fitting is able to receive signals from and transmit signals to other lamp fittings or other appliances within range and receive signals from and transmit signals to a maintenance controller allowing remote monitoring or control of the lamp fittings and/or other appliances associated with the network.

[0050] Preferably the lamp fitting is able to sense conditions external to itself wherein the conditions relate to another appliance.

[0051] Preferably the other appliance comprises instrumentation, an electrical motor, a pump, a process control/instrumentation device, a flow control valve, modem, electricity meter, smart meter, a proximity switch, a pressure switch, flow indicator, valve, pH meter and the like. [0052] The invention also extends to provision of a system for detecting cloud cover information in real time or close to real time and using the information to predict likely effects on photovoltaic power generation capacity in an area having photovoltaic panels which produce electricity from light generated by the sun which electricity is fed into an electricity grid operated by a controller, said system comprising providing the lamp fittings of the invention mounted in a position exposed at least some of the time to the sun in the area or an adjacent area, each lamp fitting comprising a light sensor able to detect ambient light levels indicative of cloud cover said sensor operatively linked to a reporting means able to report said light levels indicative of cloud cover to said controller, allowing said controller to determine likely effects on photovoltaic output in that area and/or adjacent areas.

Brief Description of the Drawings

[0053] The invention will now be described with reference to the following non limiting illustrative drawings.

[0054] Figure 1 is a sectional side view of a lamp fitting according to one embodiment of the invention.

[0055] Figure 2 is a sectional side view of a lamp fitting according to another embodiment of the invention.

[0056] Figure 3 is a schematic of the imaging sensors and LED according to one embodiment of the invention.

[0057] Figure 4 is a schematic of sensors which detect the opacity/transparency of the lens of one embodiment of the lamp fitting.

[0058] Figure 5a is a schematic of sensor which detects the opacity/transparency of the lens of the other embodiment of the lamp fitting.

[0059] Figure 5b is a circuit diagram of the sensor of Figure 5a.

[0060] Figure 6 is a schematic of the LED array and detectors of individual failed LED.

[0061] Figure 7 is a circuit diagram of the LED string of Figure 6.

[0062] Figure 8 is a schematic of the interface between image sensors and wireless reporting means. [0063] Figure 9 is a schematic representation of monochromatic backscatter pattern visible to a sensor on a clean lamp lens.

[0064] Figure 10 is a schematic representation of monochromatic backscatter pattern visible to a sensor on a dirty lamp lens.

[0065] Figure 11 is a schematic showing the relationship between an image sensor light intensity pattern and the voltage output for each pixel.

Modes of Carrying out the Invention

[0066] Figure 1 shows the lamp fitting 10 of invention with lamp holder member 14 at one end for connection to a power source. Lamp fitting 10 may comprise an integral lamp holder member such as lamp holder member 14 which operates as part of a coupling. Alternatively lamp fitting 10 may be coupled to a mount which is directly wired in to the mains. In the figures shown lamp holder member 14 is the same as that disclosed in PCT/AU2009/001 121 known as the Connex™ connector made by 300K Enterprises Pty Ltd. The lamp fitting /coupling combination may also be that disclosed in international patent application PCT/AU2010/001513 known as the HazEx™ connector.

[0067] Opposite lamp holder member 14, lamp fitting 10 comprises a substantially oblong shaped body 20 with curved back cover 25 on one side and substantially flat lens 30 and curved heat sink 40 on the other side. Adjacent lens 30 inside body 20 is main PCB 45, LED array 50, sharp monochromatic light source 80 and backscatter image sensor 90. Led array 50 has approximately 30 individual LED's (50a) to provide light output. Imaging sensors 60 and ambient light sensor 65 are present in small structural void 70 located between lamp holder member 14 and LED array 50.

[0068] Lamp fitting 10 can sense dirt on lens 30 via use of sharp monochromatic light source 80 which is used for illuminating inside surface 30a of lens 30. Imaging sensor 90 is a backscatter image detector and detects contamination on the lens. It comprises a linear array (128 or more) of photodiodes (pixels) each with a charge amplifier and internal pixel data-hold circuitry (explained in more detail below). Image sensor 90 is mounted above the front lens cover (Figure 4) and looks directly down over the point where the incident light ray 5 hits the back of the lens surface (inside surface 30a). As illustrated in Figure 4 when incident light 5 from the monochromatic light source 80 illuminates any lens contaminant or debris material 7 (e.g. dirt/dust/snow etc.) on outside 30b of lens 30 it produces a diffuse reflection (backscatter) pattern 9. As contaminant material 7 increases on outside 30b of lens 30 the backscatter pattern 9 will be changed significantly as more of the monochromatic incident light 5 is reflected back to imaging sensor 90. This change is used to flag an issue with opacity or lack of transparency of lens 30 (or at least flag that inspection is warranted). When the external surface (30b) of the lens is clean then a small amount of backscattered light will be seen by imaging sensor 90 (see Figure 9). A linear slice of this image is captured by the 128 photodiode array (each photodiode is a pixel) and converted to a sequential series of voltages proportional to each pixels photocurrent. The digitised pixel voltages give the micro-processor an "ideal" or "reference" image (series of voltage levels) that is stored internally by the microprocessor.

[0069] As the amount of dirt accumulates on the outside of the lens, the amount of backscattered light increases causing the shape of the backscattered light visible to the image sensor to change (see Figure 10). By making a comparison between the "ideal" or "reference" image and another temporally later image a numerical comparison can be made by the micro-processor to determine if there has been a significant change in the backscattered light. If a large change is determined then this is taken to indicate a large amount of dirt has accumulated on the outside of the lens. The micro-processor can then report this information back to a maintenance controller via a wireless reporting means in the form of a Zigbee radio transceiver which is mounted on main PCB 45 (not shown).

[0070] Lamp 10 can also identify failure of individual LEDs 50a within array 50. Imaging sensors 60 are setup to detect light emanating from LEDs 50a (they actually 'look down between each row' of LED's through aperture 72 as can be seen in Fig 3). Each of the imaging sensors 60 is comprised of a linear array of photodiodes (pixels) with a charge amplifier and internal pixel data- hold circuitry. The light rays 3 impinging on imaging sensor 60 generate photocurrent which is integrated by the charge amplifier associated with that pixel. The amount of charge accumulated at each pixel during the integration period of the charge amplifier is directly proportional to the light intensity and integration time. The accumulated charge from each of the pixels in the linear array is stored on separate sampling capacitors that are sequentially connected (clocked) to a charge coupled output amplifier that generates a buffered analog output voltage for each pixel (see Figure 8). The buffered analog output voltage for each pixel is then sequentially digitised by a microprocessor with an analog-to-digital converter to give a digital representation of the impinging light intensity for each pixel. The digitised pixel voltages give the micro-processor a quantitative spacial amplitude representation of the light pattern falling across the linear photodiode pixels (see Figure 11). If any of the individual LED elements 50a have failed a dark spot will be produced on the linear photodiode array (imaging sensor 60) corresponding to that LED's location and consequently a low output voltage will be produced by those photodiodes in the dark spot. The microprocessor can detect the low voltage from the pixels and determine by threshold analysis whether at a certain LED location LED 50a has failed. The micro-processor can then report this information back to the maintenance controller via the Zigbee radio transceiver. [0071] Local or remote calculation can then establish the subsequent consequence of LED element 50a failures on total light output and lamp 10 can automatically/remotely be adjusted (drive remaining LED elements with more power) to compensate for lost LED elements 50a to meet a prescribed LUX requirement for a particular illuminated area or a decision made by maintenance control to replace the lamp fitting.

[0072] Identification of which individual LED have failed can be important particularly in relation to occupational health and safety considerations. For example when the LED which light up the periphery of the lamp's footprint fail, this could lead to an unacceptable decrease in lighting. In contrast failure of LED near the centre of the array may not give rise to a maintenance

requirement.

[0073] Lamp 10 may also comprise the means for measuring vibration, temperature and humidity using off-the-shelf components that may also be located within structural void 70.

[0074] Temperature sensing ability may be provided in different locations within lamp 10. Such as a temperature sensor in the internal battery pack. This sensor is used by the battery charger to ensure that the batteries are not over-charged or charged when at elevated temperature detrimental to the battery chemistry. Further a temperature sensor may be present on the internal LED array. The temperature of the LED array is measured to ensure that the LED safe operating temperature is not exceeded as this directly effects the LED lifetime. In addition a temperature sensor for measuring external air temperature may be provided. This sensor is located in housing 70 which is exposed to ambient air temperature. If the ambient temperature exceeds

recommended levels then this may have warranty implications for the lamp.

[0075] All temperature readings are accessible and made available to the maintenance controller remotely so that decisions about lamp operation can be more effectively managed.

[0076] In certain situations monitoring external temperature is important. Excessive external temperatures impact on the longevity of a lamp fitting and could be detrimental to the integrity of the fitting. Further monitoring external humidity may also be important as this can indicate rainfall which may affect the cleanliness of the fitting. In addition humidity sensors are able to generate data which may be used to indicate the likelihood of fog/frost and other moisture laden weather events or the likelihood of snow which may impact on the performance of the lighting.

[0077] In an alternative embodiment lamp 110 is provided where reference numerals are similarly designated. For example 50 denotes the LED array in the first embodiment and 150 designates the same part in the second embodiment. [0078] Lamp 110 detects dirt, contamination or damage 107 on lens 130 by using a sensor 195.

[0079] Sensor 195 comprises emitter 195a, infrared detector 195b and an ambient light sensor (not shown). The sensor may be VCNL 4010 made by Vishay Semiconductors or similar.

Alternatively these three functionalities may be provided by separate devices.

[0080] Sensor 195 detects objects by illuminating them with a modulated infrared light from a infrared emitter 195a and then measuring the amount of reflected infrared light with an integrated pin diode photodetector (infrared detector) 195b. Sensor 195 is mounted on LED array 150 above front lens 130 looking down on internal surface 130a. Similar to the earlier embodiment, because lens 130 is transmissive of infrared light from emitter 195a most of the impingement light 105 from emitter 195a will pass straight through. The majority of any reflected incident (infrared) light 108 will be as a result of contaminant material on exterior surface 130b which reflects light back to the photodetector component 195b of sensor 195. In addition if lens 130 is damaged or significantly scratched the amount of reflected infrared light will increase. A high level of dirt or damage to lens 130 results in greater reflection of infrared light adjacent in the area by sensor 195. An increase in infrared reflection indicates the clarity (or capacity to transmit light) of lens 130 is compromised and this is used to determine whether the lamp 110 needs to be inspected for maintenance or replacement.

[0081] By interfacing sensor 195 with a microprocessor (i.e. the 12C interface - SDA and SCL) it is possible to get a direct measurement (16-bit number) of reflected infrared light seen by the photodetector 195b and make simple threshold calculation to determine lens

contamination/damage levels. Ambient light levels are also able to be measured by VCNL 4010 and can be used to determine onset and cessation of daylight.

[0082] In the embodiment shown sensor 195 is placed in the centre of LED array 150 and measures any reflected light in a small adjacent area on lens 130. The small area is deemed to be representative of the entire lens surface. Alternatively if lamp 1 10 is not mounted parallel to the ground, but angled such that holder 1 14 is closer to the ground, then sensor 195 can be mounted closer to this end of the lamp where dirt it is more likely to accumulate (due to moisture runoff). In addition alternatively one or more sensors may be placed on LED array 150.

[0083] Further lamp 110 provides another way of determining if an individual light element has failed. Each LED 150a has a companion pin diode photodetector 160 in close proximity that faces the LED directly and is strongly illuminated but the intense LED light output when the LED is on. In the event of LED light failure, no light is produced and photodetector 160 is no longer illuminated by the intense light output and consequently the reverse light current produced by detector 160 decreases markedly in a known manner. [0084] The reduction in reverse light current can be detected by a resistor circuit that converts the reverse current to a voltage (see R 4 to R13 in Figure 7). The voltage is then put through a thresholding digital circuit (MCP23016) and converted to a logical zero (lots of light current) or one (little or no light current).

[0085] By interfacing the digital logic with a microprocessor it is possible to read the status of each LED's light output when the LED is supposed to be On' (emitting light) by synchronising the detection system with the PWM (pulse width modulation) control of the light. The PWM control sets the light fitting 110 output intensity. The PWM signal is connected to the DIM (dimming control) in the circuit as shown in Figure 7.

[0086] Because each LED 150a has its own companion photodetector 160 that forms part of a digital logic circuit, the 32-bit microprocessor (not shown) can precisely determine which LED has failed and a decision can be made as to whether the light needs to be replaced.

[0087] Temperatures are measured by temperature sensors 175 at three locations around body 120 of lamp 110 namely main PCB 145, void 170 and LED array 150. They are detailed in Table 1 below:

[0088] A microprocessor on the main PCB 145 is connected to each sensor 175 via a digital communication interface that allows the microprocessor to obtain the temperature in a digital format (digital number) that the sensor is experiencing at that time. The microprocessor can then scale and store this number for later reference and use it to determine if parts of the light fitting are operating beyond their safe operating temperatures and consequently raise an alarm via the wireless network (the ZigBee transceiver mounted on main PCB 145, not shown) or other means (such as flashing LEDs). [0089] Various manufacturers have conducted tests to determine expected lifetime of their LEDs as a function of LED temperature (solder-point temperature) and current drive. By monitoring the LED array temperature (via 175c) a sound estimate on LED life expectancy may be made.

[0090] The vibration that the light fitting is exposed to and the barometric pressure that the light is operating in are measured by two off-the-shelf digital sensors both with I2C digital serial interfaces. Vibration is measured in all three axes (X, Y and Z) by an accelerometer that interfaces to the microprocessor via the I2C digital serial interface. In this case the accelerometer is MMA7455 by Freescale Semiconductor Inc. The accelerometer (not shown) is mounted on a small circuit board in void 170 of lamp 1 10. By communicating with the accelerometer the microprocessor can establish the number of g's the light fitting is experiencing in each of the 3 axes. The digital number(s) communicated back to the microprocessor by the accelerometer gives a scaled numeric representation of the acceleration forces (g's) being experienced by the fitting in all three axes at that time. These numbers can be scaled and recorded by the microprocessor to establish if the light fitting is operating outside normal vibrational limits and whether or not an alarm condition needs to be established.

[0091] Barometric pressure is measured by a barometric pressure sensor that also interfaces to the microprocessor via the I2C digital serial interface. The barometric pressure sensor is

MPL115A2 by Freescale Semiconductor Inc. The barometer (not shown) is mounted on main PCB 145. By communicating with the barometer the microprocessor can establish through calculation the absolute atmospheric pressure being experienced by lamp 1 10. The digital numbers communicated back to the microprocessor by the barometer allow the microprocessor to calculate an absolute measure of the barometric pressure at that time in hPa (hectopascals). The barometric pressure can be stored for historical record purposes and/or used potentially for weather forecasting.

[0092] When deemed necessary for periodic maintenance reasons to test the lamp the maintenance controller can initiate a lamp "self-test" via the wireless reporting means. This self test involves the lamp testing all its sensors (internal and external environmental conditions), battery voltage levels, battery discharge capacity, LED light output (LED failure counts) and lamp lens cleanliness and have the lamp produce a report that is sent back to the maintenance controller via the wireless reporting means outlining the "self-test" results. The maintenance controller then has the data necessary to make a decision on whether maintenance is required or not on the particular lamp. This provides the maintenance controller with an easy/automated method of undertaking lamp maintenance (remotely) with a clear and defined audit trail. [0093] Furthermore, the lamp may makes its own determination that there is a fault that needs to be communicated to the "maintenance controller" and it will generate a fault report and use the wireless reporting means pre-emptively to report a fault to the maintenance controller so that decisions on immediate maintenance/repair/replacement can be made.

[0094] The lamps of the present invention suitably installed at a site or in an area may be used to provide a network for data transmission and control relating to lighting, power metering and control or maintenance of other appliances. Sensors on adjacent appliances within range can transmit data to the lamp fitting network and in this way create an "ecosystem" in an industrial environment where maintenance information about equipment is fed back to a central control as further detailed in example 1 below.

[0095] A faulty lamp at a mine site for example is able to transmit a signal via a series of other lamps back to the maintenance controller. The signal is received on a dash board and a maintenance person dispatched to replace the faulty lamp.

[0096] In the system contemplated a series the lamp fittings of the present invention provides a distributed secure control network which avoids the need for telephone cables to transmit data. In a sense the invention provides for a de facto network. The network has the ability to act as an "intelligent swarm".

[0097] It can be seen from the above that the lamp fitting the invention has many uses in addition to reporting on lamp lens cleanliness such as remote reading of power meters, real time monitoring of power distribution system performance, transponder tracking, reporting faults with lights or other equipment.

[0098] The invention allows for remote control of lighting in large areas such as industrial sites where it may be desirable to save energy. At night or other times the lights may be run at half brightness and only powered up to full brightness when needed. This may be achieved by the lamp fittings being activated by a controller on a key fob or the like carried by a worker. As the worker moves around the site the lights are brought up to full brightness and are dimmed after a predetermined time once the worker has moved away.

Example 1 : use of lamp fitting in wireless mesh network for control and management of equipment.

[0099] The lamp fitting incorporating wireless technology may be used to form a robust wireless mesh network of lights which with the relevant sensing capabilities enables provision of targeted information regarding the status of the lamp fitting thereby reducing maintenance requirements of industrial lamp fittings in accordance with the aims of the invention. [00100] The ability of the fittings to form a self- organising wireless mesh network allows them to report status and control information back to a central control and management centre as well as be operable remotely.

[00101] This mesh network of lamp fittings provides a backbone networking environment that can also allow adjacent monitoring and control devices to connect-in and become part of the lighting network. This ability to provide an environment for devices to connect and live on the light network enables what is effectively an ecosystem of devices that can relay status and control information back to a central control and monitoring location.

[00102] Because of the nature of the mesh networking technology, every lamp fitting and other devices on the network effectively can provide a connection into the network. This allows for many small, low- powered monitoring devices to require only minimum energy to get their data into the network and have it available remotely for active maintenance management and planning.

[00103] In the ecosystem envisaged lamp fittings mounted at suitable intervals throughout a site interspersed the adjacent devices/appliances and a controller providing the appropriate topology. In this 'Ecosystem' of devices the lamp fittings provide the backbone network that transports data back to the controller node. Any data from the lamp fittings or from the adjacent devices such as temperature sensors, vibration sensors, pressure sensors etc will be transported back to the controller node where it will be processed and passed on to the main data acquisition and control system.

[00104] By using the networking capabilities inherent in the lamp fittings it is possible to connect-in a range of adjacent devices than can be cheap and low power. This then, for example, enables plant operators to monitor many more parameters in their facility than they perhaps would have previously because of wiring and connectivity complications. By having a near ubiquitous wireless ecosystem of networked devices, the cost of plant maintenance is reduced significantly because the on-demand maintenance capability drives up and improves scheduling and operational efficiencies.

[00105] The basic wireless technology has the following features:

- low power requirements and robustness

- good signal range and interference immunity

- good security

- ability to mesh and self-heal when a node fails. [00106] The technology for the wireless networking hardware in the lamp fittings is the XBeePro Digimesh from Digi International Inc.

[00107] With a large scale roll-out of light fittings across an industrial plant comes the added benefits of:

- low cost brought about by On-demand' maintenance;

- less down-time and higher productivity;

- self-reporting of problems;

- ubiquitous secure wireless network across the site;

- possibility of cheap 'no-wires' distributed sensor technology across multiple pieces of plant equipment;

- management from any network point;

- low power requirements;

- easy integration to existing SCADA/control systems.

[00108] The present application claims priority from Australian provisional patent applications No. 2012905125 and 2012905127, the specifications of which are hereby incorporated by reference.

[00109] From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.

[001 10] Throughout this specification and the claims that follow, unless the context requires otherwise the words "comprise", "comprises", "comprising" will be understood to mean the inclusion of the stated integer, step or group of integers or steps but not the exclusion of any of other integer, step or group of integers or steps.

Claims

The claims defining the invention are as follows:

1. A self monitoring lamp fitting having a lens through which light is transmittable said fitting able to sense conditions internal and/or external to itself and able to report the conditions to a maintenance controller, which enables the maintenance controller to decide whether inspection, maintenance or replacement of the fitting or another appliance is needed, said fitting comprising: at least one sensor for gathering data about internal and/or external conditions operatively linked to a reporting means, wherein said reporting means is able to transmit said data, or information derived from said data to said maintenance controller to enable said decision to be made; characterized in that the at least one sensor is able to sense light reflected by at least part of the lens providing information about transparency of the lens.

2. The lamp of claim 1 wherein the light reflected by at least part of the lens is produced by a light generating means adjacent the lens and wherein the at least one sensor comprises a photodetector.

3. The lamp of claim 2 wherein the light generating means produces monochromatic light and the photodetector comprises photodiodes.

4. The lamp fitting of claim 2 wherein the light generating means is an infrared emitter and wherein the photodetector is an infrared sensor.

5. The lamp fitting of claim 1 wherein the other sensor senses light output for illumination purposes to determine whether the lamp fitting or its components have failed or are underperforming.

6. The lamp fitting of any one of the previous claims comprising LED.

7. The lamp fitting of claim 6 wherein the other sensors comprise a photodetector paired with each LED and enable detection of which individual LED has failed.

8. The lamp fitting of claim 6 wherein the other sensors comprise a charge coupled device and/or linear photodiode array which generates an image of the light output enabling identification of individual LED and assessment of whether that individual LED has failed or is underperforming.

9. The lamp fitting of claim 1 wherein the other sensors comprise a temperature sensor inside the fitting and an ambient temperature sensor for sensing temperature outside the fitting enabling inside and outside temperatures to be compared to make a determination whether components of the fitting are underperforming.

10. The lamp fitting of claim 1 wherein the other sensors sense light generated by the fitting for illumination purposes, temperature inside and/or outside the fitting, vibration in the fitting or humidity inside or outside the fitting.

11. A method of remotely monitoring a lamp fitting having a lens through which light is

transmittable said monitoring being for conditions which affect the fitting including transparency of the lens, said method comprising providing: a lamp fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally providing other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a reporting means, wherein said reporting means is able to transmit said data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

12. A method of reducing maintenance inspections of a lamp fitting having a lens through which light is transmittable by providing a lamp fitting which is self reporting of conditions which affect the lamp including transparency of the lens, to a maintenance controller said method comprising providing: a lamp fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally providing other sensors for gathering data about internal and/or external conditions relevant to maintenance said sensors operatively linked to a reporting means, wherein said reporting means is able to transmit said data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

13. The method of claim 11 or claim 12 wherein the light reflected by the lens in the lamp fitting is produced by a light generating means adjacent the lens and wherein the at least one sensor comprises a photodetector.

14. The method of claim 11 or claim 12 wherein the other sensor in the lamp fitting senses light output for illumination purposes to determine whether the fitting or its components have failed or are underperforming.

15. The method of claim 11 or claim 12 the lamp fitting comprises LED.

16. The lamp fitting or method of any one of the previous claims wherein the reporting means is a wireless reporting means.

17. In another aspect the invention provides a method of providing a distributed supervision control and data acquisition network for monitoring or controlling lamp fittings and appliances remotely comprising providing: a plurality of the lamp fittings mounted on power poles or other structures in a location, each lamp fitting having a lens through which light is transmittable and an ability to report conditions which affect the lamp including transparency of the lens, said fitting having at least one sensor able to sense light reflected by at least part of the lens and optionally other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a wireless reporting means, wherein said reporting means is able to transmit said data, or information derived from said data to a maintenance controller where each fitting is able to receive signals from and transmit signals to other lamp fittings or other appliances within range and receive signals from and transmit signals to a maintenance controller allowing remote monitoring or control of the lamp fittings and/or other appliances associated with the network.

18. The lamp fitting of claim 1 or the method of claim 17 wherein the lamp fitting is able to sense conditions external to itself wherein the conditions relate to another appliance.

19. The lamp fitting or method of claim 18 wherein the other appliance comprises instrumentation, an electrical motor, a pump, a process control/instrumentation device, a flow control valve, modem, electricity meter, smart meter, a proximity switch, a pressure switch, flow indicator, valve, pH meter and the like.

20. A self monitoring lamp fitting having a lens through which light is transmittable wherein said fitting is able to monitor conditions which affect the fitting including transparency of the lens, said fitting comprising at least one sensor able to sense light reflected by at least a part of the lens and optionally having other sensors for gathering data about internal and/or external conditions said sensors being operatively linked to a reporting means, wherein said reporting means is able to transmit data regarding transparency of the lens and optionally other conditions, or information derived from said data to a maintenance controller.

21. The lamp fitting or method of any one of the previous claims substantially as hereinbefore described with reference to the drawings.