KR20180061958A - Led traffic light having a dimming control function - Google Patents

Abstract

The present invention relates to an LED traffic light having a dimming control function performed by using a phase counter method. The LED traffic light comprises: a rectifying unit for converting an AC driving voltage received from a traffic signal controller into a DC driving voltage; a driving current unit for converting the DC driving voltage into a constant current to provide the constant current to an LED lamp; and a control unit for extracting an illuminance value to control dimming by analyzing a waveform of the AC driving voltage in a dimming control mode, and generating a driving signal to adjust brightness of the LED lamp based on the illuminance value.

Description

{LED TRAFFIC LIGHT HAVING A DIMMING CONTROL FUNCTION}

The present invention relates to an LED traffic light and a method of operation thereof. More particularly, the present invention relates to an LED signal lamp and an operation method thereof that can easily change the illuminance of a traffic light according to a change in installation environment.

Traffic signals are used to ensure safe traffic order on the roads the vehicle is running. The traffic signal light is typically configured to form a single equalizer by combining basic signals such as red (R), yellow (Y), green (G), and arrow The lighting control is performed so as to be suitable for the road environment.

In recent years, power consumption is about one-eighth that of conventional incandescent lamps, and LED (Light Emitting Diode) signals having energy savings of about 80% to 90% at the same luminosity are increasingly used.

When such an LED signal lamp operates in the nighttime, there is a problem of causing unnecessary power loss as well as disturbing driving due to glare. In order to solve such a problem, a conventional LED traffic light has a dimming control function (i.e., a dimming control function) for adjusting the illuminance of a traffic light at night.

However, since a conventional LED signal uses a half-wave signal for dimming control, there is a phenomenon that an extension of the lighting-off time due to a charging / discharging time delay of a capacitor and a flicker- And the like.

On the other hand, according to the standard of LED signal lamps, it is required to use a light amount of 50% to 70% at the time of dimming control, and such a light fluctuation width is set to be variable according to the installation place of LED signal lamps. However, A product that does not have a function is developed. Therefore, there is a need for research on a dimming control method that can satisfy the above-mentioned standard while solving the above-mentioned problems.

The present invention is directed to solving the above-mentioned problems and other problems. Another object of the present invention is to provide an LED signal lamp that performs a dimming control function using a phase counter method and an operation method thereof.

According to an aspect of the present invention, there is provided a rectifier for converting an AC driving voltage received from a traffic signal controller into a DC driving voltage. A driving current unit for converting the DC driving voltage into a constant current and providing the DC lamp voltage as an LED lamp; And a control unit for analyzing a waveform of the AC driving voltage to extract an illuminance value for dimming control and generating a driving signal for adjusting the brightness of the LED lamp based on the illuminance value in the dimming control mode, .

More preferably, the control unit of the LED signal or the like analyzes the waveform of the AC driving voltage to determine whether the lighting mode of the signal lamp is the normal lighting mode or the dimming control mode.

More preferably, the control unit of the LED signal or the like determines that the lighting mode of the signal lamp is the dimming control mode when the waveform of the AC driving voltage has STX (start of text) phase and ETX (end of text) .

More preferably, the control unit of the LED signal light counts the number of AC phases existing between the STX phase and the ETX phase, and extracts the roughness value based on the number of the counted phases.

More preferably, the LED signal lamp includes a power converter for adjusting an amount of a constant current input to the LED lamp based on a first driving signal output from the controller; And a load unit for discharging a part of the stored energy for driving the LED lamp based on the second driving signal outputted from the control unit.

More preferably, the LED signal light further includes a mode selection unit for selecting an operation mode of the LED signal, wherein the operation mode includes a general mode without a dimming function, a dimming mode using ambient light variation, a dimming mode using a half- , And a dimming mode using a phase counter method.

More preferably, the LED signal light further includes a voltage monitoring unit disposed between the rectifying unit and the driving current unit, for monitoring whether a low voltage, an overvoltage, or a loop (LED) disconnection occurs in the DC driving voltage outputted through the rectifying unit .

According to another aspect of the present invention, there is provided a traffic light scheduler for scheduling a flashing operation of an LED signal light; A driving voltage unit for generating an AC driving voltage for driving the LED signal lamp; And a controller for controlling the driving voltage unit such that an AC driving voltage having different waveforms is generated according to the lighting mode of the LED signal.

More preferably, the driving voltage section of the traffic signal controller includes a start of text (STX) phase indicating the start of the dimming control mode, an AC phase indicating the illuminance value of the LED signal light, and an end of the dimming control mode And generates an AC drive voltage having an ETX (end of text) phase that instructs it.

Effects of the LED signal lamp and the operation method thereof according to the embodiments of the present invention will be described as follows.

According to at least one of the embodiments of the present invention, by performing the dimming control function using the phase counter method, it is possible to satisfy the requirements of the standard of the LED signal or the like, and to easily change the illuminance of the traffic light according to the change of the installation environment .

According to at least one of the embodiments of the present invention, by performing the dimming control function using the phase counter method, voltage fluctuation can be minimized, dimming control can be freely expressed, and noise .

However, effects that can be achieved by the LED signal lamp and the operation method thereof according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are described in the following description It will be understood by those of ordinary skill in the art.

Brief Description of the Drawings Fig. 1 is an overall configuration diagram of a traffic control system according to an embodiment of the present invention; Fig.
2 is a block diagram illustrating a configuration of a traffic signal controller according to an exemplary embodiment of the present invention;
3 is a diagram illustrating an AC driving voltage output according to a lighting mode of an LED signal lamp in a traffic signal controller;
4 is a block diagram illustrating a configuration of an LED signal lamp according to an embodiment of the present invention;
5 is a detailed circuit diagram of an LED signal lamp according to an embodiment of the present invention.
6 is a flowchart referred to explain the operation of an LED traffic light according to an embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. That is, the term 'part' used in the present invention means a hardware component such as software, FPGA or ASIC, and 'part' performs certain roles. However, 'minus' is not limited to software or hardware. The " part " may be configured to reside on an addressable storage medium and may be configured to play back one or more processors. Thus, by way of example, and by no means, the terms " component " or " component " means any combination of components, such as software components, object- oriented software components, class components and task components, Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and parts may be combined into a smaller number of components and parts or further separated into additional components and parts.

In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

The present invention proposes an LED signal lamp that performs a dimming control function using a phase counter method and an operation method thereof.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

1 is an overall configuration diagram of a traffic control system according to an embodiment of the present invention.

1, a traffic control system 100 according to an exemplary embodiment of the present invention includes a traffic signal light 110, a traffic light 120, a traffic light signal 130, and a traffic signal controller 140 .

The walking signal lamps 110 may be installed on both sides of the crosswalk 130 with respect to the road, and may include various types of signal lamps as well as a general streetlight structure including red light, green light, and the like.

The gait signal lamp 110 alternately operates red light, green light, and the like at a predetermined time period under the control of the traffic signal controller 140 provided in the vicinity of the crosswalk 130. In this case, the green light or the like of the gait signal lamp 110 indicates a walk permission signal of the pedestrian, and the red light indicates a walk inhibition signal of the walker. In addition, the pedestrian signal lamp 110 may display the remaining time with respect to the allowable walking time in the form of a number or a bar when the green lamp lights up.

The vehicle signal lamp 120 is installed on the road in a direction opposite to the vehicle running direction so as to enter the front sight of the driver and is configured to indicate the proceeding, stopping, and detouring of the traveling vehicle by flashing red, green, .

The vehicle signal lamp 120 alternately operates a green arrow lamp such as a red light lamp, a green light lamp, a yellow light lamp and the like in a predetermined time period under the control of the traffic signal controller 140 provided in the vicinity of the crosswalk 130.

The walking signal lamp 110 and the vehicle signal lamp 120 may use an LED element as a light source and may include an apparatus (or circuit) for performing a dimming control function. Hereinafter, for the convenience of explanation, the walking signal lamp 110 and the vehicle signal lamp 120 are collectively referred to as a 'traffic signal lamp' or an 'LED signal lamp'.

The crosswalk 130 is a fixed area on the road shared by the vehicle and the pedestrian according to the Road Traffic Act. The crosswalk 130 operates in accordance with a constant signaling system to facilitate the use of opportunities between the vehicle and the pedestrian. At least one crosswalk 130 may be provided depending on the type of road, and the width and length of the crosswalk 130 may be set differently depending on the situation of each road.

Traffic Signal Controller (140) is installed at intersections and crosswalks, and collects and analyzes occupation time to manage optimal traffic lights.

The traffic signal controller 140 is electrically connected to the vehicle signal lamp 120 and the walking signal lamp 110 to provide a driving voltage to the vehicle signal lamp 120 and the walking signal lamp 110, 120, and the gait signal lamp 110, as shown in FIG. At this time, the traffic signal controller 140 may be integrally formed with the vehicle signal lamp 120 or the walking signal lamp 110, or may be installed on the vehicle separately from the traffic lights 110 and 120.

2 is a block diagram illustrating a configuration of a traffic signal controller according to an embodiment of the present invention.

2, the traffic signal controller 200 may include a traffic light scheduler 210, a driving voltage unit 220, a communication unit 230, and a control unit 240. The components shown in FIG. 2 are not essential for implementing a traffic signal controller, so that the traffic signal controller described herein may have more or fewer components than the components listed above.

The traffic light scheduler 210 can perform a function of scheduling the flashing operation regarding the green light, the red light, etc. of the gait signal. Also, the traffic light scheduler 210 can perform a function of scheduling the flashing operation regarding the green arrow indicator such as the red light, the green light, the yellow light, etc. of the vehicle traffic light.

The traffic light scheduler 210 may perform a function of scheduling a light control operation of a traffic light according to a time zone. For example, it is possible to schedule 100% illumination at the traffic lights in the first time zone, and 50% to 70% illumination at the traffic lights in the second time zone.

The driving voltage unit 210 performs an on / off switching operation according to a phase required for an AC voltage for driving an LED signal and outputs the switching signal to an LED signal. At this time, the AC voltage may be 220V, but it is not limited thereto.

That is, the driving voltage unit 210 can generate and output an AC voltage having different waveforms (i.e., phases) according to the lighting mode of the LED signal or the like (i.e., the normal lighting mode and the dimming control mode).

3 (a), the driving voltage unit 210 can generate an AC voltage having a phase of a complete sinusoidal waveform in the normal lighting mode.

3 (b) and 3 (c), the driving voltage unit 210 outputs a start of text (STX) phase, an AC phase, and an end of text (ETX) phase in the dimming control mode Can be generated.

In one embodiment, as shown in FIG. 3 (b), the STX phase is a phase signal indicative of the start of the dimming control mode and includes (+) half wave phase, (+) half wave phase, -) < / RTI > half-wave phase may be a sequentially input phase signal and is not limited thereto.

The ETX phase is a phase signal indicating the end of the dimming control mode, and may be a phase signal in which (-) half wave phase, (-) half wave phase, (+) half wave phase, Do not. In the method according to the present embodiment, the STX command and the ETX command are differently set and controlled.

3 (c), the STX phase is a phase signal indicating the start of the dimming control mode, and includes (+) half wave phase, (+) half wave phase, (-) half wave phase , And (-) half-wave phases may be input sequentially, but the present invention is not limited thereto.

The ETX phase is a phase signal indicating the end of the dimming control mode and may be a phase signal in which (+) half wave phase, (+) half wave phase, (-) half wave phase, Do not. The method according to the present embodiment is a method of controlling the STX command and the ETX command by setting them to be equal to each other.

The AC phase existing between the STX phase and the ETX phase is a phase signal indicating the illumination value of the dimming control. For example, as shown in the figure, if the number of AC phases is 70, the illumination value of the dimming control becomes 70%. Through the phase counter method, the driving voltage unit 210 can generate an AC voltage indicating the illuminance value of the signal lamp in the dimming control mode. Also, by appropriately changing the number of AC phases according to the change of the installation environment, the illuminance of the traffic light can be easily changed and the ripple due to the phase truncation can be optimized.

The communication unit 230 may perform a function of providing a communication interface for supporting wired / wireless communication with a road traffic system installed in a police agency or a local autonomous entity. The communication unit 230 may receive the traffic control signal from the road traffic system and may transmit the traffic information collected through the traffic signal controller 200 to the road traffic system.

The control unit 240 controls an operation related to an application program stored in a memory (not shown) and an overall operation of the traffic signal controller 200 in general. In addition, the control unit 240 may control at least one of the above-described components in order to implement various embodiments described below on the traffic signal controller 200 according to the present invention.

FIG. 4 is a block diagram illustrating a configuration of an LED signal lamp according to an embodiment of the present invention, and FIG. 5 is a detailed circuit diagram of the LED signal lamp of FIG.

4 and 5, the LED signal lamp 200 includes a filter unit 410, a rectifying unit 415, a voltage monitoring unit 420, a driving current unit 430, a voltage divider 435, a mode selecting unit 440 A control unit 445, a power converter 450, a first rod unit 455, a second rod unit 460, and an LED lamp 465. The components shown in FIG. 4 are not essential for implementing the LED signal light 400, so that the LED signal light described in this specification can have more or fewer components than those listed above.

The filter unit 410 performs a function of removing a noise component of an AC driving voltage input from the traffic signal controller 200 and a function of removing noise generated in the LED signal lamp 400 do.

The rectifying unit 415 rectifies the AC driving voltage from which noise components have been removed to generate a DC driving voltage, and outputs the DC driving voltage to the voltage monitoring unit 420.

The rectification unit 415 can use a voltage doubling rectification scheme which can obtain a rectification output close to the AC drive voltage by using a rectifier and a capacitor. The reason for using this double voltage rectification method is that when the LED lamp 465 is turned off due to disconnection, the line voltage due to no load increases greatly, and when there is a constant load, the voltage decreases due to the impedance, It is easy to recognize the state.

The voltage monitoring unit 420 monitors whether a low voltage, an overvoltage, or a loop disconnection occurs in the DC driving voltage output from the rectifying unit 415, and when the low voltage, the overvoltage or the loop disconnection is detected, The operation of the power converter 450 is stopped and the LED lamp 465 is turned off to prevent malfunction or damage of the LEDs 465 and 465.

The driving current unit 430 converts the DC driving voltage output from the rectifying unit 415 into a constant current and outputs the converted constant current to the LED lamp 465.

The voltage divider 435 divides the AC driving voltage output from the filter unit 410 to lower the voltage. The reason for providing the voltage divider 435 is to lower the AC driving voltage output from the filter unit 410 to a voltage that can be recognized by the controller 445.

An integrating circuit may be added to the circuit of the voltage divider 435 to remove the high-frequency noise of the AC driving voltage, and a zener diode may be added to prevent the overvoltage from being applied to the controller 445.

The mode selection unit 440 performs a function of selecting an operation mode of the LED signal lamp 400 according to an operation command of an administrator or an operator. The operation mode of the LED signal lamp 400 can be classified into a normal mode having no dimming function and a dimming mode having a dimming function.

The dimming mode may be classified into a first dimming mode using ambient light variation, a second dimming mode using a radio wave signal and a half-wave signal, and a third dimming mode using a phase counter method. Since the first dimming mode or the second dimming mode itself is a known technique, a detailed description thereof will be omitted.

Accordingly, the mode selection unit 440 may include at least two of the four operation modes, and may select one of the operation modes according to an operation command of the administrator or the operator.

The mode selection unit 440 may provide the control unit 445 with information on the operation mode of the LED signal lamp 400 selected by an administrator or an operator. Meanwhile, in another embodiment, the mode selection unit 440 may be configured to provide the traffic signal controller 200 with information on the operation mode of the LED signal lamp 400.

The control unit 445 analyzes the waveform of the AC driving voltage output from the voltage divider 435 to determine whether the lighting mode of the LED signal lamp 400 is the normal lighting mode or the dimming control mode. If the lighting mode of the LED signal lamp 400 is the dimming control mode, the controller 445 extracts an illuminance value (or a brightness value) for dimming control based on the analyzed waveform of the AC driving voltage .

For example, the controller 445 analyzes the waveform of the AC drive voltage as follows. First, the controller 445 may detect only the peak voltage of the AC driving voltage, take an average, and recognize the half value as an intermediate value. Then, the control unit 445 recognizes the above-mentioned intermediate value as an upper waveform, recognizes the lower waveform as a lower waveform below the intermediate value, and identifies the STX command and the ETX command with the thus-recognized data.

The control unit 445 counts the number of AC phases existing between the STX command and the ETX command in the same manner as the above-described method, and calculates an illuminance value for dimming control based on the counted number of phases Can be extracted.

The control unit 445 may generate a first PWM (Pulse Width Modulation) signal for changing the brightness of the LED lamp 465 and output it to the power converter 450 in the dimming control mode. At the same time, the control unit 445 may generate a second PWM signal for changing the brightness of the LED lamp 465 and output the generated second PWM signal to the second load unit 460.

In addition, the control unit 445 controls the overall operation of the LED signal lamp 400. For example, the control unit 445 may control the mode selection unit 440 to perform an operation mode selected by the LED signal lamp 400.

The power converter 450 converts the power of the first PWM signal output from the controller 445 and outputs the amount of the constant current input to the LED lamp 465 based on the first PWM signal having the converted power As shown in FIG. In addition, the power converter 450 may function to isolate the control unit 445 and the LED lamp 465 from each other.

The first load unit 455 operates in a red state or the like, and is made up of predetermined resistance elements to perform a function of maintaining a specific load value. According to the current standard of LED signal lamps, it is prescribed that in case of red light, it should consume 5 Watt or more of power. Therefore, the controller 445 can increase the power consumption of red light by applying a current to the first load unit 455 during the red light operation.

The second load unit 460 discharges a part of the stored energy for driving the LED lamp 465 based on the second PWM signal output from the control unit 445 in the dimming control mode. That is, the control unit 445 may reduce the brightness of the LED lamp 465 by flowing a part of the current input to the LED lamp 465 to the second load unit 460 in the dimming control mode.

The LED lamp 465 emits light based on the remaining amount obtained by subtracting the constant current flowing from the constant current output from the driving current unit 430 to the second load unit 460. For example, in the normal lighting mode, since the amount of the constant current flowing to the second load portion 460 is 0, the LED lamp 465 emits light with a luminance of 100% using all the constant currents outputted from the driving current portion 430 can do. Since the amount of the constant current flowing to the second load 460 exists in the dimming control mode, the LED lamp 465 generates a constant current flowing from the constant current output from the driving current unit 430 to the second load 460 The light can be emitted with an illuminance of 50% to 70%.

6 is a flowchart referred to explain the operation of the LED signal lamp according to an embodiment of the present invention.

Referring to FIG. 6, the LED signal lamp 400 may receive the AC drive voltage from the traffic signal controller 200 (S610). At this time, the AC driving voltage may have different waveforms depending on the lighting mode of the LED signal lamp 400 (i.e., the normal lighting mode and the dimming control mode), as shown in FIG.

The LED signal lamp 400 may analyze the waveform of the AC drive voltage by subtracting the AC drive voltage from the AC drive voltage when the AC drive voltage is received (S620 and S630). In addition, the LED signal lamp 400 can rectify the AC drive voltage to the DC drive voltage and convert the rectified DC drive voltage to the LED drive current (i.e., constant current) upon receiving the AC drive voltage.

The LED signal lamp 400 can confirm whether the own lighting mode is the normal lighting mode or the dimming control mode based on the waveform analysis result of the AC driving voltage (S640).

If it is determined in step 640 that the own lighting mode is the dimming control mode, the LED signal lamp 400 may determine the illuminance value for the dimming control based on the analyzed waveform of the AC driving voltage in operation S650. The LED signal lamp 400 may generate a first driving signal for dimming control based on the determined illuminance value (S660). At this time, the first driving signal may be a PWM signal.

Meanwhile, if it is determined that the own lighting mode is the normal lighting mode, the LED signal lamp 400 may generate a second driving signal for normal lighting (S670). Likewise, the second drive signal may be a PWM signal.

In the normal lighting mode, the LED signal lamp 400 can drive the LED lamp according to the second driving signal (S680). That is, the LED signal lamp 400 can emit light at an illuminance of 100% by applying all the constant currents to the LED lamp.

The LED signal lamp 400 can drive the LED lamp according to the first driving signal in the dimming control mode. That is, the LED signal lamp 400 can emit light with an illuminance of 50% to 70% by adjusting the amount of the constant current applied to the LED lamp. On the other hand, as an embodiment of the present invention, it will be apparent to those skilled in the art that the dimming control of 50% to 70% or more can be performed with an illuminance of 50% or less or 70% or more.

The LED signal lamp 400 may repeatedly perform the operations of steps 610 to 680 until an operation stop command is received from the traffic signal controller 200. [

As described above, the LED signal lamp according to the embodiment of the present invention performs the dimming control function by the phase counter method, so that the illuminance of the traffic light can be easily changed according to the change of the installation environment.

The present invention described above can be embodied as computer-readable codes on a medium on which a program is recorded. The computer readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer readable medium include a hard disk drive (HDD), a solid state disk (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, , And may also be implemented in the form of a carrier wave (e.g., transmission over the Internet). Also, the computer may include a control unit of the terminal. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

100: Traffic control system 110: Walking traffic light
120: vehicle traffic light 130: pedestrian crossing
140: Traffic signal controller

Claims (8)

A rectifier for converting the AC drive voltage received from the traffic signal controller into a DC drive voltage;
A driving current unit for converting the DC driving voltage into a constant current and providing the DC lamp voltage as an LED lamp; And
And a controller for analyzing a waveform of the AC driving voltage to extract an illuminance value for dimming control and generating a driving signal for adjusting the brightness of the LED lamp based on the illuminance value in the dimming control mode. The method according to claim 1,
The controller analyzes the waveform of the AC driving voltage to determine whether the lighting mode of the traffic light is the normal lighting mode or the dimming control mode. 3. The method of claim 2,
Wherein the control unit determines the lighting mode of the traffic light to be the dimming control mode when the waveform of the AC driving voltage has a start of text (STX) phase and an end of text (ETX) phase. The method of claim 3,
Wherein the control unit counts the number of AC phases existing between the STX phase and the ETX phase and extracts the illumination value based on the number of the counted phases. The method according to claim 1,
A power converter for controlling an amount of a constant current input to the LED lamp based on a first driving signal output from the controller; And
And a load unit for discharging a part of the stored energy for driving the LED lamp based on the second driving signal outputted from the control unit. The method according to claim 1,
Further comprising a mode selection unit for selecting an operation mode of the LED signal,
The operation mode includes at least one of a general mode without a dimming function, a dimming mode using ambient light variation, a dimming mode using a half-wave signal, and a dimming mode using a phase counter method. The method according to claim 1,
And a voltage monitoring unit disposed between the rectifying unit and the driving current unit for monitoring whether a low voltage, an overvoltage or a loop disconnection occurs in the DC driving voltage. A traffic light scheduler for scheduling the flashing operation of the LED traffic lights;
A driving voltage unit for generating an AC driving voltage for driving the LED signal lamp; And
And a controller for controlling the driving voltage unit so that an AC driving voltage having different waveforms is generated according to the lighting mode of the LED signal,
The driving voltage unit includes an STX (start of text) phase indicating the start of the dimming control mode, an AC phase indicating the illuminance value of the LED signal light, and an end of text (ETX) phase indicating the end of the dimming control mode Wherein the AC drive voltage is generated by the drive signal generator.

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