WO2018103591A1

WO2018103591A1 - Ambient brightness-based led adjustment method and system

Info

Publication number: WO2018103591A1
Application number: PCT/CN2017/114164
Authority: WO
Inventors: 毛秋翔; 钟国基
Original assignee: 赤多尼科两合股份有限公司; 毛秋翔
Priority date: 2016-12-06
Filing date: 2017-12-01
Publication date: 2018-06-14
Also published as: CN108156690B; CN108156690A

Abstract

An ambient brightness-based LED adjustment method and system. The method comprises: a brightness sensor (74) acquires ambient brightness information to generate an ambient brightness signal and transmits the same to a PWM signal generator (73); the PWM signal generator receives the ambient brightness signal to determine a light adjustment level; the PWM signal generator generates, according to the light adjustment level, a voltage variation signal in a LED driving circuit (75) and corresponding to the light adjustment level; and an LED driver (71) acquires, via the driving circuit, the voltage variation signal, determines according to the acquired voltage variation signal the light adjustment level, and adjusts an output power to achieve light adjustment. The embodiment is utilized to transmit, by using a voltage variation signal in the LED driving circuit, light adjustment information, resolving issues of apparatus costs, installation costs, and electromagnetic compatibility resulting from installation of an additional light adjustment signal transmission circuit in the prior art.

Description

LED dimming method and system based on ambient brightness

Technical field

The present invention relates to the field of LED driving technologies, and in particular, to an LED dimming method and system based on ambient brightness.

Background technique

Due to the advantages of energy saving and environmental protection, LED has been widely used as a new generation of lighting sources. The LED dimming device enables the LED lighting system to sense the brightness of the external environment for dimming, saving energy while providing a smarter and more comfortable lighting environment.

In the existing LED lighting system according to the ambient brightness dimming control scheme, after detecting the ambient brightness, the photosensitive device transmits the ambient brightness signal to the MCU (Micro Controller Unit) module, and the MCU module converts the ambient brightness signal into a tone. The optical signal transmits the dimming signal to the LED driver, and the LED driver adjusts the output power according to the received dimming signal to achieve the dimming purpose.

The disadvantage of this solution is that since the photosensitive device is usually installed together with the lighting fixture to sense the ambient brightness, and the light source driver is installed outside the lamp, the ambient brightness signal is transmitted and converted into a dimming signal, and an additional dimming signal needs to be added. Transmission line and MCU processor. Especially in the field of outdoor lighting, when the distance between the light source driver and the LED lamp and the photosensitive device is long, a long light-sensing signal and a dimming signal transmission line are required, and the cost of adding the line is high, and the electromagnetic compatibility problem is caused. Distortion of the dimming signal.

Summary of the invention

The object of the present invention is to provide a new environment brightness-based LED dimming method and system, which can replace the prior art technical solution of transmitting a dimming signal by adding a dimming signal line, so as to reduce the frequency of the dimming line. Cost, while avoiding the issue of electromagnetic compatibility caused by the addition of dimming lines.

To achieve the above objective, the present invention provides an ambient brightness based LED dimming method, comprising the following steps:

The brightness sensor collects ambient brightness information, generates an ambient brightness signal, and transmits the ambient brightness signal to a PWM (Pulse Width Modulation) signal generator;

The PWM signal generator receives the ambient brightness signal to determine the dimming level;

The PWM signal generator generates a voltage change signal corresponding to the dimming level according to the dimming level;

The LED driver collects the above voltage change signal through the LED driving circuit;

The LED driver determines the dimming level according to the voltage change signal obtained by the acquisition, and adjusts the output power to achieve the dimming purpose.

As an alternative, the PWM signal generator generates a voltage change signal corresponding to the dimming level on the LED driving line according to the dimming level: using a MOSFET or a triode to perform at least one of the LED lamps The power-off operation is performed to generate a voltage change signal corresponding to the dimming level.

As an alternative, the power-off operation is: turning on and off the at least one lamp bead during a sampling period in which the LED driver acquires the voltage change signal, and converting the voltage change signal into a high-low level signal. Digital signal. The digitized signal represents the dimming level.

As an alternative, the power-off operation is: turning on and off the at least one lamp ball at a fixed frequency and a signal width within one sampling period of the LED driver collecting the voltage change signal, converting the voltage change signal into A digitized signal consisting of high and low level signals. The digitized signal represents the dimming level.

As an alternative, converting the voltage change signal into a digitized signal composed of high and low level signals includes: defining a high level as a digital signal 1 and a low level as a digital signal 0; or, a low level is a digital signal 0 The high level is the digital signal 1, and the on-off operation of the fixed frequency and the signal width is converted into a set of binary digital codes, and a start bit, a stop bit, and a check code are added to the binary digital code to obtain a digitized signal.

As an alternative, the on-off operation is: performing on-off operation of at least one lamp bead at a certain frequency within a sampling period of the LED driver acquiring the voltage change signal to generate a voltage change signal of a certain frequency. This frequency represents the dimming level.

As an alternative, the power-off operation is: during a sampling period in which the LED driver acquires the voltage change signal, the at least one lamp be turned on and off with a certain duty ratio to generate a voltage with a certain duty ratio. Change signal. The dimming level is represented by the duty ratio.

As an alternative, the power-off operation is: performing a certain number of on-off operations on at least one of the lamp beads during a sampling period in which the LED driver acquires the voltage change signal, and generating a certain number of voltage changes. The dimming level is represented by the number of voltage changes described above.

As an alternative, the power-off operation is: performing a single-time power-on or power-off operation for at least one lamp bead for a certain period of time during a sampling period in which the LED driver collects the voltage change signal, and generating a voltage change for a certain period of time. The dimming level is indicated by the duration of the voltage change.

The invention provides an ambient brightness-based LED dimming system, which comprises an LED driver, an LED lamp, a PWM signal generator and a brightness sensor. The LED driver supplies working voltage and current to the LED lamp through a driving line, and the brightness sensor collects ambient brightness information. Generating an ambient luminance signal and transmitting it to the PWM signal generator, which is characterized by:

The PWM signal generator further includes a brightness signal receiving module, a brightness signal analyzing module and a voltage change generating module. The brightness signal receiving module is configured to receive an ambient brightness signal emitted by the brightness sensor; the brightness analyzing module is configured to analyze the ambient brightness signal to determine the dimming level. The voltage change generation module is configured to control the PWM signal generator to generate a voltage change signal corresponding to the dimming level on the LED driving circuit;

The LED driver further includes a voltage change signal acquisition module, a voltage change signal analysis module, and an output power adjustment module. The voltage change signal acquisition module is configured to collect a voltage change signal on the LED drive line; and the voltage change signal analysis module is configured to analyze the voltage change signal. Determining the dimming level; the output power adjusting module is configured to control the LED driving output power to realize the dimming operation of the dimming level.

As an alternative, the PWM signal generator performs on-off operation of at least one of the LED lamps through a MOSFET or a triode to generate a voltage change signal on the LED drive line.

As an alternative, the power-off operation includes: turning on and off the at least one lamp bead at a fixed frequency and a signal width within one sampling period of the LED driver acquiring the voltage change signal.

As an alternative, the power-off operation includes: turning on and off the at least one lamp bead at a certain frequency within one sampling period of the LED driver acquiring the voltage change signal.

As an alternative, the power-off operation includes: turning on and off the at least one lamp bead at a certain duty cycle during one sampling period of the LED driver acquiring the voltage change signal.

As an alternative, the power-off operation includes: performing a certain number of on-off operations on the at least one lamp bead during one sampling period of the LED driver acquiring the voltage change signal.

As an alternative, the power-off operation includes: performing a single power-on or power-off operation of the at least one lamp bead for a certain period of time during one sampling period in which the LED driver acquires the voltage change signal.

The invention has the advantages that the ambient brightness-based LED dimming method and system provide a basic device based on a common LED driving control circuit, and at least one of the LED lamps is used by using a PWM signal generator. Through the power-off operation, causing the voltage change signal on the LED drive line, carrying different levels of dimming requirements through the diversity of voltage changes, the LED driver passes the detection Analyze the voltage change on the LED drive line, adjust the output power, and achieve this level of dimming.

The technical solution for transmitting the dimming command through the voltage change signal described above solves the problem of equipment cost and installation cost caused by the need to additionally add a dimming signal transmission line in the prior art, and avoids adding the above-mentioned dimming signal transmission line to Electromagnetic compatibility issues caused by the entire lighting circuit system. The dimming scheme provided by the invention is convenient and feasible, and can select different conversion modes between the voltage change signal and the dimming level according to the specific dimming level requirement of the LED lighting system, and the dimming accuracy is high.

DRAWINGS

1 is a schematic flow chart of an LED dimming method based on ambient brightness according to an embodiment of the present invention;

2 is a schematic diagram of a voltage change waveform signal according to an embodiment of the present invention;

3 is a schematic diagram of a voltage change waveform signal according to an embodiment of the present invention;

4 is a schematic diagram of a voltage change waveform signal according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a voltage change waveform signal according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic diagram of a voltage change waveform signal according to an embodiment of the present invention; FIG.

FIG. 7 is a schematic diagram of an LED dimming system based on ambient brightness according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the drawings in conjunction with the specific embodiments.

The LED dimming method based on ambient brightness provided by the present invention, as shown in FIG. 1 , comprises the following steps:

Step 101: The brightness sensor collects ambient brightness information, generates an ambient brightness signal, and transmits the ambient brightness signal to the PWM signal generator.

Step 102: The PWM signal generator receives an ambient brightness signal to determine a dimming level.

Step 103: The PWM signal generator generates a voltage change signal corresponding to the dimming level according to the dimming level;

Step 104, the LED driver collects the voltage change signal through the LED driving circuit;

Step 105: The LED driver determines the dimming level according to the voltage change signal obtained by the acquisition, and adjusts the output power to achieve the dimming purpose.

The dimming method provided by the invention solves the problem of equipment cost and installation cost caused by the need of additionally adding a dimming signal transmission line in the prior art, and avoids adding the above dimming signal transmission. The electromagnetic compatibility problems that the circuit brings to the entire lighting circuit system.

Optionally, the PWM signal generator generates a voltage change signal corresponding to the dimming level on the LED driving line according to the dimming level: using a MOSFET or a triode to turn on and off at least one of the LED lamps Operation, generating a voltage change signal corresponding to the dimming level. The on/off operation of at least one of the LED lamps in the LED device is a key step in generating a voltage change signal in the technical solution of the present invention. Of course, in addition to the MOSFET and the triode disclosed in the embodiment, other commonly used in the field The controllable switching device can also achieve the same technical effect. In addition, it should be noted that the substantial meaning of the on-off operation of at least one of the LED lamps in the LED lamp means that the voltage waveform on the LED driving circuit is changed, in practice. In the application scheme, turning on and off a plurality of lamp beads or one or more LED lamps can also generate a voltage waveform change, and the voltage variation difference is larger, so that the number of switched light sources can be performed according to requirements in actual use cases. Design and selection.

Optionally, the power-off operation is: turning on and off the at least one lamp bead during a sampling period in which the LED driver acquires the voltage change signal, and converting the voltage change signal into a digitized signal composed of a high-low level signal. The dimming level is represented by a digitized signal.

Optionally, the power-off operation is: turning on and off the at least one lamp ball at a fixed frequency and a signal width in one sampling period of the LED driver collecting the voltage change signal, converting the voltage change signal into a high-low level A digitized signal composed of signals. The dimming level is represented by a digitized signal.

Further, converting the voltage change signal into a digitized signal composed of high and low level signals includes: defining a high level as a digital signal 1 and a low level as a digital signal 0; or, a low level is a digital signal 0, a high level For the digital signal 1, the above-mentioned fixed frequency and signal width on-off operation is converted into a set of binary digital codes, and a start bit, a stop bit, and a check code are added to the binary digital code to obtain a digitized signal.

The above technical solution based on the fixed frequency and signal width and corresponding to the dimming level by the standard digitization method is a relatively easy solution in the embodiment of the present invention: using a certain number of binary digits, such as 8 bits, the high power The flat is defined as 1, the low level is defined as 0, and the 8-bit binary digits are respectively 00000000-11111111, which represent different dimming levels by such standardized binary numbers. In addition, based on the above binary digits, a start bit, a stop bit, and a check code may be added to represent different dimming level signals according to a signal pattern more suitable for LED dimming system identification. The communication protocol of the scheme is simple, the signal transmission is stable, the switching operation of the MOSFET or the triode is simple and easy, and the influence on the light is also very small, and has high practical application value. As shown in FIG. 2, when the at least one lamp bead is energized, the voltage on the LED drive line is V _on , and when the power is _off , V _off , t represents time, the low level is defined as 0, and the high level is defined as 1, then The set of binary digits is 01010101, and the binary digit can be used to correspond to a dimming level.

Optionally, the power-off operation is: turning on and off the at least one lamp bead at a certain frequency within a sampling period of the LED driver collecting the voltage change signal to generate a voltage change signal of a certain frequency. This frequency represents the dimming level. This on-off operation scheme is based on the switching operating frequency of the MOSFET or the triode to represent different dimming level requirements. Correspondingly, the LED driver detects the frequency of the voltage waveform change, thereby determining the dimming level. As shown in FIG. 3, when the at least one lamp bead is energized, the voltage on the LED driving circuit is V _on , and when the power is _off , V _off , t represents time, and T is an on-off cycle period, and passes different switching frequencies. f(f=1/T) represents a different dimming level.

Optionally, the power-off operation is: performing a power-off operation on at least one of the lamp beads with a certain duty ratio during a sampling period in which the LED driver acquires the voltage change signal, and generating a voltage change signal with a certain duty ratio. The dimming level is represented by the duty ratio. The on-off operation scheme is based on the duty ratio of the switching operation of the MOSFET or the triode to represent different dimming level requirements. Correspondingly, the LED driver detects the duty cycle parameter carried by the voltage waveform to determine the dimming level. . The voltage change waveform diagram shown in FIG. 4 is in the on-off cycle, the power-on duration is T _on , the power-off duration is T _off , and the duty cycle Duty Ratio=T _on /(T _on +T _off ), Different dimming levels are represented by different duty cycle parameters.

Optionally, the power-off operation is: performing a certain number of on-off operations on the at least one lamp bead during a sampling period in which the LED driver acquires the voltage change signal, and generating a certain number of voltage changes. The dimming level is represented by the number of voltage changes described above. The on-off operation scheme is based on the number of times that the MOSFET or the triode is turned on and off for the LED lamp bead to represent different dimming level requirements. Correspondingly, the LED driver detects the number of changes in the voltage waveform to determine the dimming level. . As shown in the voltage change waveform diagram shown in FIG. 5, the voltage on the LED drive line has changed six times in total between V _on and V _off , and the different dimming levels are represented by the number of different changes in voltage.

Optionally, the power-off operation is: performing a single power-on or power-off operation for at least one lamp bead for a certain period of time during a sampling period in which the LED driver collects the voltage change signal, and generating a voltage change for a certain period of time. The dimming level is indicated by the duration of the voltage change. The power-on and power-off operation scheme represents the different dimming level requirements of a single power-on or power-off time of the LED lamp bead by the MOSFET or the triode. Correspondingly, the LED driver detects the time of the single voltage waveform change, thereby determining Dimming level. As shown in the voltage change waveform diagram shown in FIG. 6, in the case where the original voltage on the LED drive line is V _on , the lamp bead is subjected to a single power-off operation T _off for a certain period of time, which is represented by different single-time voltage change durations. Different dimming levels.

The invention provides an LED dimming method based on ambient brightness, which transmits a dimming command through a change of a voltage waveform on an LED driving line. The traditional dimming scheme eliminates the need for additional dimming signal transmission lines and devices. The dimming scheme is convenient and feasible, and the dimming level and voltage waveform control and variation modes are various and optional, and have very significant practical application value.

An ambient brightness-based LED dimming system provided by an embodiment of the present invention, as shown in FIG. 7, includes an LED driver 71, an LED lamp 72, a PWM signal generator 73, and a brightness sensor 74. The LED drive is driven by the drive line 75 as an LED. The luminaire provides working voltage and current, and the brightness sensor collects ambient brightness information, generates an ambient brightness signal, and transmits it to the PWM signal generator;

The PWM signal generator further includes a brightness signal receiving module 731, a brightness signal analyzing module 732, and a voltage change generating module 733. The brightness signal receiving module is configured to receive an ambient brightness signal sent by the brightness sensor; the brightness analyzing module is configured to analyze the ambient brightness signal, and determine a dimming level; the voltage change generating module is configured to control the PWM signal generator to generate a voltage change signal corresponding to the dimming level on the LED driving circuit;

The LED driver further includes a voltage change signal acquisition module 711, a voltage change signal analysis module 712, and an output power adjustment module 713. The voltage change signal acquisition module is configured to collect a voltage change signal on the LED drive line; and the voltage change signal analysis module is used to analyze the voltage. The dimming level is determined by changing the signal; the output power adjusting module is configured to control the output power of the LED driver to implement the dimming operation of the dimming level.

Optionally, the PWM signal generator turns on and off the at least one of the LED lamps through the MOSFET or the triode to generate a voltage change signal on the LED driving circuit.

Optionally, the power-off operation includes: turning on and off the at least one lamp ball at a fixed frequency and a signal width within one sampling period of the LED driver acquiring the voltage change signal.

Optionally, the power-off operation includes: turning on and off the at least one lamp bead at a certain frequency within one sampling period of the LED driver acquiring the voltage change signal.

Optionally, the power-off operation includes: turning on and off the at least one lamp bead at a certain duty cycle during one sampling period of the LED driver acquiring the voltage change signal.

Optionally, the power-off operation includes: performing a certain number of on-off operations on the at least one lamp bead during one sampling period of the LED driver acquiring the voltage change signal.

Optionally, the power-off operation includes: performing a single power-on or power-off operation for the at least one lamp bead for a certain period of time during a sampling period in which the LED driver acquires the voltage change signal.

Finally, the LED brightness adjustment method and system based on ambient brightness provided by the embodiment of the present invention, by using a PWM signal generator, receiving and parsing ambient brightness information collected and transmitted by the brightness sensor to determine a dimming level. After that, at least one of the LED lamps is turned on and off to generate a voltage change waveform corresponding to the dimming level, and the LED driver detects the waveform and adjusts the output power to achieve the dimming level of the dimming level, thereby solving the problem. In the prior art, the problem of equipment cost and installation cost caused by the additional dimming signal transmission line is required, and the electromagnetic compatibility problem caused by adding the above dimming signal transmission line to the entire lighting circuit system is avoided. The dimming scheme provided by the invention is convenient and feasible, and can select different conversion modes between the voltage change signal and the dimming level according to the specific dimming level requirement of the LED lighting system, and the dimming accuracy is high.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. It should be understood by those skilled in the art that the technical solutions described in the foregoing embodiments may be modified, or some or even all of the technical features may be equivalently replaced, and these modifications or replacements may be performed without any creative work. The essence of the corresponding technical solutions is not departed from the scope of the technical solutions of the present invention.

Claims

An LED dimming method based on ambient brightness, characterized in that it comprises the following steps:

The brightness sensor collects ambient brightness information, generates an ambient brightness signal, and transmits the ambient brightness signal to a PWM (Pulse Width Modulation) signal generator;

The PWM signal generator receives the ambient brightness signal to determine a dimming level;

The PWM signal generator generates a voltage change signal corresponding to the dimming level according to the dimming level;

The LED driver collects the voltage change signal through an LED driving circuit;

The LED driver determines the dimming level and adjusts the output power according to the voltage change signal obtained by the acquisition.
The dimming method according to claim 1, wherein the PWM signal generator generates a voltage change signal corresponding to the dimming level on the LED driving line according to the dimming level: using a MOSFET ( A metal-Oxide-Semiconductor Field-Effect Transistor, or a triode, performs on-off operation on at least one of the LED lamps to generate the voltage change signal.
The dimming method according to claim 2, wherein the on-off operation is: switching on and off the at least one lamp bead during one sampling period in which the LED driver acquires the voltage change signal Electrically, the voltage change signal is converted to a digitized signal consisting of high and low level signals, the digitized signal representing the dimming level.
The dimming method according to claim 2, wherein the at least one bead is turned on and off at a fixed frequency and a signal width during a sampling period in which the LED driver acquires the voltage change signal Converting the voltage change signal into a digitized signal consisting of high and low level signals, the digitized signal representing the dimming level.
The dimming method according to claim 3 or 4, wherein the converting the voltage change signal into a digitized signal composed of a high-low level signal comprises: a high level is a digital signal 1, and a low level is a digital signal. 0; or, the low level is a digital signal 0, and the high level is a digital signal 1. The on-off operation is converted into a set of binary digital codes to obtain the digitized signal.
The dimming method according to claim 2, wherein the on-off operation is: operating the at least one lamp bead at a certain frequency within one sampling period in which the LED driver acquires the voltage change signal Performing an on-off operation to generate a voltage change signal of a certain frequency, the frequency representing The dimming level.
The dimming method according to claim 2, wherein the on-off operation is: at least one of the sampling periods of the LED driver acquiring the voltage change signal with a certain duty ratio The lamp bead is powered on and off to generate a voltage change signal of a certain duty cycle, the duty cycle representing the dimming level.
The dimming method according to claim 2, wherein the on-off operation is: performing the predetermined number of times of the at least one lamp bead within one sampling period in which the LED driver collects the voltage change signal The on-off operation produces a certain number of voltage changes, the number of times representing the dimming level.
The dimming method according to claim 2, wherein the on-off operation is: performing a certain duration of the at least one lamp bead within one sampling period in which the LED driver acquires the voltage change signal A single power-on or power-off operation produces a voltage change of a certain duration, which represents the dimming level shown.
An ambient brightness-based LED dimming system includes an LED driver, an LED lamp, a PWM signal generator, and a brightness sensor, and the LED driver provides a working voltage and current for the LED lamp through a driving line, the brightness sensor collecting environment Brightness information, generating an ambient luminance signal and transmitting to the PWM signal generator, wherein:

The PWM signal generator further includes a brightness signal receiving module, a brightness signal analyzing module, and a voltage change generating module, wherein the brightness signal receiving module is configured to receive an ambient brightness signal sent by the brightness sensor; and the brightness analyzing module is configured to analyze The ambient brightness signal is used to determine a dimming level; the voltage change generating module is configured to control the PWM signal generator to generate a voltage change signal corresponding to the dimming level on an LED driving line;

The LED driver further includes a voltage change signal acquisition module, a voltage change signal analysis module, and an output power adjustment module, wherein the voltage change signal acquisition module is configured to collect a voltage change signal on the LED drive line; And determining the dimming level by analyzing the voltage change signal; the output power adjusting module is configured to control the LED driving output power to implement the dimming operation of the dimming level.
The dimming system according to claim 10, wherein the PWM signal generator performs an on-off operation on at least one of the LED lamps through a MOSFET or a triode to generate the voltage change signal.
The dimming system according to claim 11, wherein the on-off operation comprises: The at least one lamp bead is powered on and off at a fixed frequency and a signal width during a sampling period in which the LED driver acquires the voltage change signal.
The dimming system according to claim 11, wherein the on-off operation comprises: pairing the at least one lamp bead at a certain frequency within one sampling period in which the LED driver acquires the voltage change signal Perform power-on and power-off operations.
The dimming system according to claim 11, wherein the on-off operation comprises: pairing the at least one with a certain duty ratio during a sampling period in which the LED driver acquires the voltage change signal The lamp bead is powered on and off.
The dimming system according to claim 11, wherein the on-off operation comprises: performing the at least one lamp bead a certain number of times during one sampling period in which the LED driver acquires the voltage change signal On-off operation.
The dimming system according to claim 11, wherein the on-off operation comprises: performing a certain duration of the at least one lamp bead within one sampling period in which the LED driver acquires the voltage change signal Single power-on or power-off operation.