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(11) | EP 4 535 926 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | CONTROL DEVICE FOR LIGHTING ELEMENTS |
| (57) The invention relates to a control device for a lighting element comprising: an input
port for a power signal of the lighting element or a signal derived from the power
signal of the lighting element; an output port for sending control commands to the
lighting element, particularly for setting the power of the lighting element; a memory
element capable of storing information related to the lighting element to be controlled;
a real-time counter element capable of providing date and time information; a control
unit interfaced with the input, output, memory element, and counter element. The control
unit is configured to read from the memory element the scheduled turn-on time of the
lighting element or to calculate this turn-on time based on geolocation information
of the lighting element present in the memory unit so that with each turn-on of the
lighting element, the control unit is able to synchronize the time provided by the
counter element.
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TEXT OF THE DESCRIPTION
[0001] The present invention relates to the field of lighting systems, such as a system of light points distributed along the road network of an urban area. These systems can include an extremely high number of streetlights, each equipped with one or more light points, and can be very extensive territorially.
[0002] In more complex systems, each light point is a node in a mesh network that can be individually controlled remotely via radio waves or power line communication.
[0003] In simpler systems, the light points have a reduced communication capacity, being essentially controlled in switching on and off by acting on the power supply through electrical panels based on preset information or remote control.
[0004] With the advent of LED technology, the light points can not only be turned on and off but also dimmed, that is, their power can be varied, for example, to reduce consumption during certain time periods.
[0005] To this end, it is known to use drivers for each light point that can control the lamps with a certain level of interoperability. Various products of this type are commercially available.
[0006] These drivers have the ability to receive commands by exploiting the ON and OFF periods induced by a power supply circuit like a Morse code alphabet.
[0007] This represents a fair compromise between system complexity/costs and the need to offer at least minimal local control, at least to set the lamp dimming.
[0008] It is known to set the dimming ranges of the lamps using protocols that involve interrupting the power supply in an ON/OFF mode according to a combination of interruptions known by the lamps (or by a driver connected to them) and the power source.
[0009] These ranges are represented by power values to be set in time intervals calculated from the so-called virtual midnight.
[0010] Virtual midnight is calculated by the driver by measuring the turn-on and turn-off times of the light point over the last three days. Since turning on and off typically coincides with sunset and sunrise, the midpoint between these two values is conventionally considered to coincide with midnight, which is assumed as the reference for setting each dimming profile. In practice, the driver modifies the power of the light point in time intervals calculated from this virtual reference.
[0011] Such an operating mode has obvious problems as it does not allow for setting power values at precise times as a complete control of lamp dimming would require.
[0012] The scope of the present invention is to provide a control device for a light point, particularly an LED, that can drive said light point with a high level of accuracy without resorting to the use of complex and expensive interconnected systems controllable remotely.
[0013] The invention achieves the goal with a control device for at least one lighting element comprising:
- an input port for a power signal of the lighting element or a signal derived from the power signal of the lighting element;
- an output port for sending control commands to the lighting element, particularly for setting the power of the lighting element;
- a memory element capable of storing information related to the lighting element to be controlled;
- a real-time counter element capable of providing date and time information;
- a control unit interfaced with the input, output, memory element, and counter element.
[0014] The control unit is configured to read from the memory element the scheduled turn-on time of the lighting element or to calculate this turn-on time based on geolocation information of the lighting element present in the memory unit so that with each turn-on of the lighting element, the control unit is able to synchronize the time provided by the counter element.
[0015] Counter elements have poor precision in timekeeping, hence the need for periodic resynchronization without impacting the complexity of the control structure.
[0016] In this way, it is possible to set the dimming profiles of the lighting elements at precise times without resorting to complex communication systems with remote control units or approximations such as the concept of virtual midnight introduced in known systems.
[0017] Since the time synchronization is based on the turn-on times of the lighting element, to prevent errors due to unscheduled turn-ons like during maintenance work, the control unit is advantageously configured to perform the time synchronization operation if the continuous turn-on time of the lighting element exceeds a threshold, for example, two hours. If the maximum duration of an intervention remains below this threshold, no resynchronization is performed, and the device can operate correctly.
[0018] Since the counter element provides reliable time information in the short term, if one or more dimming profiles of the lighting element containing power levels to be set for predetermined time intervals are stored in the memory element, the control unit is able to set the power of the lighting element based on these levels at times stored within the memory element or derived from the information in the memory element.
[0019] To allow a minimum level of remote control, the control unit can be advantageously configured to receive commands from the input port according to a data communication protocol in which the information is encoded as sequences of on and off periods of the power signal, for example, based on the duration of the on period while keeping the off period duration constant.
[0020] In an improvement, it is possible that the information related to the lighting element stored in the memory unit also includes an identifier to uniquely identify the lighting element. In this way, it is possible to address the lighting element or send commands to a plurality of lighting elements connected in parallel to the same power supply panel.
[0021] To this end, the commands can be advantageously structured to include the identifier that identifies the recipient lighting element, a prefix that identifies the type of command, and the data associated with that command.
[0022] In a particularly advantageous embodiment, the device can advantageously include a backup power element such as a buffer battery or a supercapacitor so that the counter element can at least maintain the date information even in the absence of power. In fact, brief power drops are irrelevant to the dimming operation as the time at which the ranges are set is resynchronized at each turn-on. However, prolonged power outages can lead to a loss of date information from which the turn-on and turn-off times are derived based on the device's geolocation.
[0023] In an improvement, there is a module for serial communication with an external configuration unit for setting, during installation, the operating parameters of the lighting element to which the device is or will be associated and/or for storing information related to the lighting element.
[0024] The control commands of the lighting element can be sent in any way, even following proprietary protocols. In an advantageous embodiment, the output port is configured to send commands to the lighting element serially using a standard communication protocol for LED light sources such as DALI or DMX512.
[0025] According to another aspect, the invention relates to an LED lighting element interfaced with a control device according to the invention.
[0026] The invention also relates to a lighting system comprising a plurality of lighting elements each interfaced with a control device according to the invention. Each control device is connected to the same power control panel so that a single power signal turns on/off each lighting element, with communication between the control panel and the lighting elements occurring based on a data communication protocol in which the information is encoded as sequences of on and off periods of the power signal, each lighting element being individually addressable thanks to the identifier assigned to said lighting element during system installation and/or configuration.
[0027] The electrical power panel can advantageously include a communication element capable of communicating with a remote telecontrol unit for setting the on/off periods of the system's lighting elements. It is also possible to use the commands encoded as sequences of on and off periods of the power signal to configure the system's control devices at least partially, for example, to set one or more dimming profiles.
[0028] The invention also relates to a method for controlling an LED lighting element comprising the following steps: reading date information from a counter element; reading from a memory element the scheduled turn-on time of the lighting element on that date or reading the geographic coordinates of the lighting element from the memory element and deriving the turn-on time of the lighting element on that date based on those geographic coordinates; waiting for a preset period at the turn-on of the lighting element; setting the counter device time to the turn-on time plus the preset period; using the counter device to set the start time of one or more dimming profiles of the lighting element's power.
[0029] The start time of one or more dimming profiles can be read from the memory element or derived from the stored geographic coordinates.
[0031] The features of the invention and the advantages deriving therefrom will become more apparent from the following detailed description of the attached figures, in which:
- Fig. 1 shows a block diagram of a lighting system.
- Fig. 2 shows a block diagram of a control device according to an embodiment of the invention that can be used in the previous system.
- Figs. 3 and 4 show some embodiments of the control device according to the invention.
[0032] With reference to Fig. 1, a lighting system comprises a power control panel 1 connected to a plurality of light points 2 such as streetlights along an urban road.
[0033] The power control panel 1 can be a simple power distribution cabinet controlled by a dusk switch or a more complex device capable of communicating with a remote telecontrol unit, for example, via power line communication or a cellular radio network, such as 4G or 5G, a WiFi or Ethernet network using one or more communication cards generally indicated in the figure by reference 101.
[0034] Each streetlight 2 includes a lighting element 3, such as an LED, and a driving driver 4 that serves as an interface between the lighting element 2 and the power control panel 1.
[0035] Communication between driver 4 and lighting element 3 can be of any type. Advantageously, it uses a standard for driving LED lights such as DALI or DMX512.
[0036] As shown in Fig. 2, in one embodiment of the invention, the driving driver 4 includes:
- an input port 104 for a power signal coming directly or through a transformer or a general conditioning circuit from the power control panel 1;
- an output port 204 for sending commands to the lighting element 3;
- a memory element 304 in which the information necessary for controlling the lighting element is stored;
- a real-time counter (RTC) 404 capable of providing date and time information;
- a microprocessor or microcontroller control unit 504 interfaced with the input/output ports 104, 204, the memory element 304, and the counter 404.
[0037] The memory element 304 can be external to the control unit 504 as in the case of microprocessor circuits or be onboard the same integrated unit forming the control unit 504 as in the case of microcontroller devices. The same or another memory element 304 can be used to contain the control unit's 504 program instructions. The memory element(s) can advantageously include Flash, EEPROM, or similar memories capable of retaining information, such as stored during system configuration, even in the absence of power.
[0038] This information allows the driver 4 to operate correctly during counter 404 synchronization as well as to set the dimming profiles of the lighting element 3.
[0039] The hours of light vary during the year and according to geographic coordinates. Hence the possibility of storing, for a specific installation, a table indicating the lighting element's turn-on and turn-off times as well as the activation of dimming profiles for each day of the year. Alternatively, it is possible to store simple position information during installation. In this case, the control unit will perform the necessary calculations to determine the turn-on and turn-off times and possible activation of dimming profiles.
[0040] It is also possible to store a unique identifier for addressing the driver by a remote control device.
[0041] If communication between driver and power control panel is based on the absence/presence of the power signal, it is advantageously possible to use on-off sequences of variable duration like a Morse code for communication with the driver 4 without resorting to complex and expensive wireless communication networks or power line communication.
[0042] Using the identifier, for example, as a message preamble, it is possible to address each driver, or groups of drivers, similarly to a more advanced communication system like TCP/IP.
ON/OFF PROTOCOL
[0044] According to this protocol, commands are transmitted with a multiple power supply duration of 5 seconds. The time detection is valid from 1.5 seconds before the multiple to 3.5 seconds after.
Packet Structure
Decimal digits setting
[0046]
The digit 0 corresponds to a 10-second turn-on period;
The digit 1 corresponds to a 15-second turn-on period;
The digit 2 corresponds to a 20-second turn-on period;
The digit 3 corresponds to a 25-second turn-on period;
The digit 4 corresponds to a 30-second turn-on period;
The digit 5 corresponds to a 35-second turn-on period;
The digit 6 corresponds to a 40-second turn-on period;
The digit 7 corresponds to a 45-second turn-on period;
The digit 8 corresponds to a 50-second turn-on period;
The digit 9 corresponds to a 55-second turn-on period;
[0047] Conversely, the digit can be determined by measuring the duration of the turn-on period, subtracting 10, and dividing the result by 5:
End of a command list
[0048] At the end of a command list, a 10-second turn-on pulse is sent as a terminal acknowledgment (ACK) to ensure the command is executed upon its sending. Sending the ACK command is optional and does not have the same effect for logic purposes, which is regulated by known lengths and predetermined sequences of turn-ons and turn-offs. In the absence of the terminal ACK turn-on, execution would occur at the next system turn-on, typically the next day, while with the ACK command, the new configuration is sent to the lamp immediately after completing the command reception.
Setting dimming level
[0049]
Valid dimming range: 10%-100%
Setting a dimming level of 10% is achieved with a digit 0, or a 10-second turn-on; Similarly: 20% → 1 → 15 sec, and so on up to 1000 → 9 → 55 sec
Setting Start Level
Setting RTC
[0051]
| Cmd | 3 | 15 sec |
| Day tens | D1 | decimal digit (0-9) |
| Day units | D2 | |
| Month tens | D3 | |
| Month units | D4 | |
| Year tens | D5 | |
| Year units | D6 |
Setting dimming range
[0052]
| Cmd | 4 | 20 sec + range number (0-5) |
| Hour tens | D1 | decimal digit (0-9) |
| Hour units | D2 | |
| Min tens | D3 | |
| Min units | D4 | |
| Dimming Level | D5 |
[0053] Practically, by alternating sequences of turn-ons and turn-offs, it is possible to send messages like a Morse code. Assuming the OFF period is constant, for example, 5 seconds, the duration of the ON period encodes information. In the specific example shown above, this information is a number from 0 to 9 (digit).
[0054] Of course, any encoding can be used that exploits different durations of ON and OFF periods as well as different types of commands.
[0055] In the example shown above, using this advantageous communication system, it is possible to set the dimming ranges of the lighting element. These ranges can also be advantageously set, at least partially, during the initial configuration of the device. Modifying presets represents an advantageous customization option that is entirely optional.
[0056] Similarly, setting the counter (RTC) is definitely advantageous as it allows restoring the device's correct operation after failure situations or prolonged power shortages. Again, however, this is entirely optional customization since the counter's date can be advantageously maintained in the absence of power using a buffer battery or a supercapacitor. This component, indicated by reference 604 in Fig. 3, can be provided inside the device or externally to it.
[0057] The date information provided by the RTC counter 404, together with the geographic coordinates or pre-set activation/deactivation profiles based on these coordinates in the memory element 304, allow the control unit 504 to synchronize the counter and set the dimming profiles.
[0058] The control unit 504 is configured to read from the memory element 304 the scheduled turn-on time of the lighting element 3 or to calculate this turn-on time based on the coordinates of the lighting element 3 present in the memory element 304 so that with each turn-on of the lighting element 3, the control unit 504 can synchronize the time provided by the counter 404. For example, it is possible to provide that the control unit performs the time synchronization operation if the turn-on time of the lighting element exceeds a threshold, for example, two hours. This is to prevent operational errors in the case of turn-ons due to maintenance interventions. If the maximum duration of a maintenance intervention remains below this threshold, no resynchronization is performed, and the device can operate correctly.
[0059] In practice, when the power signal is activated, the control device reads or calculates from the information in memory what the actual turn-on time should be on that specific day, waits for a preset period, for example, two hours, and sets the counter to a time equal to the scheduled time plus two if the power continues to be active after this period.
[0060] Fig. 4 shows a variant of the control device according to the invention. It includes the control unit (LOGIC), the counter (RTC), the input port (PWR) for the +24 DC power signal, the output port (DALI), and the buffer battery or supercapacitor (PWR BACK UP). In this diagram, there is also the SERIAL CFG 704 component, which can also be present in the configurations shown in the previous figures. This is a serial communication unit, such as RS232, RS432, or USB, which can be used to communicate with the control unit 504 during device configuration. Thanks to this interface, which can also be of a different type, such as an Ethernet, WiFi, or Bluetooth port, or similar, the device's non-volatile memory can be set to contain georeferencing information and/or turn-on/off and/or dimming tables. The RTC counter can also be set to indicate the current time and date. Maintaining this information is guaranteed by the buffer battery or supercapacitor.
[0061] As for the output port, in this specific embodiment, a DALI protocol interface commonly used to drive LED lighting elements is utilized. Other protocols can also be used, even proprietary ones.
[0062] Although the description mainly refers to control devices with a reduced number of components and limited communication capacity, the teachings of the present invention can be applied to more complex solutions. It is possible, for example, to provide the use of dusk switches or communication systems that can receive remote commands more advanced.
[0063] In addition, in other embodiments that can be freely combined with what is described, it is possible to provide at least one additional sensor for activating or controlling the lights, such as a motion sensor associated with the electronic board.
[0065] Throughout the description, similar reference numbers may be used to identify similar elements.
[0066] It will be readily understood that the components of the embodiments as generally described here and at least partially illustrated in the attached figures could be arranged and designed in a wide variety of different configurations.
[0067] Therefore, the following description, as also represented in the figures, is not intended to limit the scope of the present invention but is simply representative of some possible embodiments.
[0068] The described embodiments should be considered in all respects as illustrative and not restrictive.
[0069] All changes falling within the meaning and range of equivalence of the claims should be understood to be within their scope.
[0070] The reference throughout this description to features, advantages, or similar language does not imply that all features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention.
[0071] Rather, the language referring to features and advantages is intended to mean that a feature, advantage, or characteristic described in connection with a particular embodiment is included in at least one embodiment of the present invention.
[0072] Consequently, discussions of features and advantages and similar language throughout this description may, but do not necessarily, refer to the same embodiment.
[0073] Moreover, the features, advantages, and characteristics described of the invention can be combined in any suitable way in one or more embodiments.
[0074] A person skilled in the art will recognize, in light of this description, that the invention can be implemented without one or more of the specific features or advantages of a particular embodiment.
[0075] In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention.
[0076] The reference throughout this description to "an embodiment," "a variant," "an implementation," or similar language means that a particular function, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention.
[0077] Consequently, references to "an implementation," "a variant," and similar language throughout this description may, but do not necessarily, refer to the same embodiment.
[0078] The components of the embodiments as generally described in this document and illustrated in the attached figures could be utilized and designed in a wide variety of different configurations.
[0079] All changes falling within the meaning and scope of equivalence of the claims should be understood to be within their scope.
[0080] Although the operations of the methods shown and described here are shown and described in a particular order, the order of operations of each method can be altered so that some operations may be performed in a different order and/or so that some operations may be performed, at least in part, simultaneously with other operations.
[0081] It is nevertheless evident that the invention should not be considered limited to the particular arrangements illustrated above, which constitute only exemplary embodiments thereof, but that various variants are possible, all within the reach of a skilled person, without thereby departing from the scope of protection of the invention itself, as defined by the following claims.
1. Control device (4) for controlling at least one lighting element (3), said control
device comprising:
• an input port (104) for a power signal of the lighting element (3) or a signal derived from the power signal of the lighting element (3);
• an output port (204) for sending control commands to the lighting element (3), particularly for setting the power of the lighting element (3);
• a memory element (304) capable of storing information related to the lighting element to be controlled;
• a real-time counter element (404) capable of providing date and time information;
• a control unit (504) interfaced with the input (104), output (204), memory element (304), and counter element (404),
characterized in that said control unit (504) is configured to read from the memory element (304) the scheduled turn-on time of the lighting element (3) or to calculate this turn-on time based on geolocation information of the lighting element (3) stored in the memory element (304) so that with each turn-on of the lighting element (3), determined as a result of receiving a signal at the input port (104), the control unit (504) is configured to synchronize the time provided by the counter element (404) with the scheduled turn-on time.2. Device according to claim 1, wherein the control unit (504) is configured to perform
the time synchronization operation if the turn-on time of the lighting element (3)
exceeds a threshold, for example, two hours.
3. Device according to claim 1 or 2, wherein the memory element (304) is suitable for
storing one or more dimming profiles of the lighting element (3) containing power
levels to be set for predetermined time intervals, the control unit (504) being configured
to set the power of the lighting element (3) based on these levels at times stored
within the memory element (304) or derived from processing the information in the
memory element (304).
4. Device according to one or more of the preceding claims, wherein the information related
to the lighting element (3) stored or to be stored in the memory element (304) includes
an identifier capable of uniquely identifying the lighting element (3) to be controlled.
5. Device according to one or more of the preceding claims, wherein the control unit
(504) is configured to receive commands from the input port (104) according to a data
communication protocol in which the information is encoded as sequences of ON and
OFF periods of the power signal.
6. Device according to claim 5, wherein the information is encoded based on the duration
of the ON period, with the duration of the OFF period being constant.
7. Device according to claim 5 or 6, wherein the commands contain the identifier that
identifies the recipient lighting element (3), a prefix that identifies the command
type, and the data associated with that command.
8. Device according to one or more of the preceding claims, wherein a backup power element
(604) is present for the power supply, such as a buffer battery or a supercapacitor,
so that the counter element (404) can at least maintain the date information even
in the absence of power.
9. Device according to one or more of the preceding claims, wherein a module for serial
communication (704) with an external configuration unit is present for setting, during
installation, the operating parameters of the lighting element (3) to which the device
is or will be associated and/or for storing information related to the lighting element
(3).
10. Device according to one or more of the preceding claims, wherein the output port (204)
is configured to send commands to the lighting element (3) serially using the DALI
or DMX512 protocol.
11. LED lighting element (3) controllable in power, characterized by comprising a control device (4) according to one or more of the preceding claims.
12. Lighting system comprising one or more lighting elements (3) and one or more control
devices (4) according to one or more of the preceding claims, characterized in that each control device (4) is connected to the same power control panel (1) so that
with a single power signal each lighting element (3) is turned ON/OFF, communication
between the power control panel (1) and lighting elements (3) occurring based on a
data communication protocol in which the information is encoded as sequences of ON
and OFF periods of the power signal, each lighting element (3) being individually
addressable thanks to an identifier assigned to said lighting element (3) during system
installation and/or configuration.
13. System according to claim 12, wherein the power control panel (1) includes, or is
interfaced with, a communication element (101) capable of communicating with a remote
telecontrol unit for setting the ON/OFF periods and/or configuring at least partially
the control devices (4).
14. Method for controlling an LED lighting element characterized by comprising the following steps:
• reading date information from a counter element;
• reading from a memory element the scheduled turn-on time of the lighting element on that date or reading the geographic coordinates of the lighting element from the memory element and deriving the turn-on time of the lighting element on that date based on those geographic coordinates;
• waiting for a preset period at the turn-on of the lighting element;
• setting the counter device time to the turn-on time plus the preset period;
• using the counter device to set the start time of one or more dimming profiles of the lighting element's power.
15. Method according to claim 14, wherein the step of reading the start time of one or
more dimming profiles from the memory element or reading the geographic coordinates
of the lighting element from the memory element and deriving the start time of the
dimming profile (s) from these geographic coordinates is provided.