Using visible light communication to improve indoor positioning accuracy

GPS is the most widely used positioning technology in the world, but it is ineffective or inaccurate in indoor spaces. This is because radio frequency (RF) signals transmitted from satellites are blocked by indoor obstacles such as walls or ceilings of buildings. This shortcoming of GPS has led the industry to adopt other techniques for indoor location tracking, with varying degrees of success. IPS typically consists of two distinct elements – beacons and tags, where beacons are placed at different points in the building, and tags are carried by individuals or placed on objects that are being tracked by location. Some technologies used for location tracking include:

Using visible light communication to improve indoor positioning accuracy

Inertial Measurement Units: These units use multiple sensors such as accelerometers, magnetometers, and gyroscopes to provide information about the relative movement of the tags. An advantage of this technique is that it does not require the use of beacons, but the overall accuracy is poor (a few meters) because position errors accumulate rapidly over time.

Ultrasonics: They use sound as a communication medium, operate on time-of-flight (the time it takes for sound to travel from a beacon to a tag, and vice versa), and can resolve position to less than 1 meter, but suffer from interference from solid objects. This means that measurements are not always reliable.

Other RF technologies: The widespread availability of Bluetooth and Wi-Fi makes them well suited for use with IPS, but the main difficulty is that these signals behave very differently in the presence of obstacles and people walking around (due to reflections and multipath propagation). Ultra-Wideband (UWB) can penetrate materials such as concrete, glass, and wood, making it suitable for in-building applications (where the beacon’s line of sight is often obstructed as the tag moves around), but this technology is not yet widely used, and the power levels of some signal frequencies are limited by regulations on the use of the radio spectrum.

The methods mentioned above have certain limitations in usage and accuracy, meaning they are not ideal for IPS applications, while visible light communication (VLC) is emerging as a very promising solution to the accuracy problem. Visible light is the part of the electromagnetic spectrum (375-780nm) that the human eye can perceive, and VLC uses this bandwidth to wirelessly transmit data while illuminating indoor spaces. In a VLC system, the microcontroller modulates data onto an LED (beacon), which is received by a photodiode in the tag (e.g., a phone’s front-facing camera). Using light as a medium to transmit data requires little extra power than LED lighting requires, and installation costs are low because the lighting is already present in almost all interior spaces. While the modulated data inevitably causes the LEDs to flicker at frequencies that are imperceptible to the human eye, they are easily detected by the receiving device. By embedding a unique identifier in each LED and modulating it onto the LED driver, each light fixture (often called a light source) within a building can transmit a unique code related to its exact location. Using the identifiers received from the three luminaires, a triangulation algorithm can determine the location of the tag with an accuracy of 30 centimeters – an order of magnitude better than the best-performing radio frequency-based positioning systems.

Efficiency and compact size are two major challenges to face when designing VLC systems, and on semi’s NCL31000 advanced light engine addresses both issues by integrating all the functions that such systems require into a compact IC. It features a 97% high-efficiency LED driver, supports PWM dimming, and has an EMI-compliant DC-DC converter for driving other system components such as sensors. It also features an onboard analog-to-digital converter (ADC) that provides accurate and detailed diagnostics for the local MCU with a choice of integrated I2C or SPI bus. The NCL31000’s companion device, the NCL31001, supports multi-channel LED applications, while another IC in the family, the NCP31010, also integrates a Power-over-Ethernet (PoE) driver (still with an LED driver) into a single package, allowing data to be modulated directly to LED lights without the need for a separate Ethernet driver IC, and also allows lighting fixtures to be connected as part of a smart lighting solution. This is especially attractive to smart building designers looking to manage to light as efficiently as possible. By continuously monitoring room occupancy, lighting levels can be dynamically adjusted based on daily usage patterns. Using DC power provided by PoE drivers to power the luminaire eliminates the need for AC cables and AC/DC transformers in the luminaire, where temperature, humidity, air quality, and other smart sensors can be deployed. These ICs meet the requirements of the “yellow dot” luminaire certification program, which allows manufacturers to test and certify that their LED luminaires are interoperable with Philips’ indoor positioning technology, and is open to all luminaire manufacturers.

Indoor positioning systems have the potential to bring many benefits to managers of smart buildings, allowing them to greatly improve the user experience, safety and security of visitors to shopping malls, event venues, airports, and hospitals. GPS is not suitable for use in indoor environments, therefore, many different techniques have been tried in the industry to provide indoor tracking with varying degrees of success in providing the accuracy of location tracking. VLC overcomes the limitations and deficiencies of other technologies and can be implemented by using LED driver ICs such as NCL31000 in the design stage of LED lighting fixtures, so that the designed IPS can be used to track indoor objects and personnel positions with an accuracy of up to 30 cm.

Keelung City School Classroom Lamps Replacement LED Lamps

The Education Department of Keelung City Government said today that last year and this year, 16 million were allocated, and more than 20,000 lamps in the city’s schools were fully upgraded to LED lamps, and T5, T8, and T9 fluorescent lamps were replaced, and the problem of insufficient classroom lighting was improved. It is hoped that the rate of poor eyesight of students can be reduced, and electricity bills can also be saved.

Keelung City School Classroom Lamps Replacement LED Lamps

According to the Ministry of Education, statistics show that Taiwan has the highest proportion of myopic population in the world, with 9 out of 10 people being shortsighted, and nearly one million schoolchildren with myopia, which has become a major health problem for Taiwanese. Because the eye muscles are still developing in elementary and middle school students, the earlier they get myopia, the higher the degree of stereotypes in adulthood. Poor lighting is one of the important factors causing myopia, so we started to improve campus lighting.

The base city government has allocated 16 million yuan each in last year and this year, with a total of 32 million yuan in the two years, and fully updated 24,394 lamps in the city’s schools to LED lamps, and replaced T5, T8, T9 fluorescent lamps, and achieved classroom illumination. National illuminance standard of 500lux and blackboard illumination of 750lux.

According to the Department of Education, the information provided by the Energy Bureau of the Ministry of Economic Affairs shows that 0.554 kilograms of carbon dioxide will be produced per kilowatt-hour of electricity. According to the number of replacement groups in the city, the original use of traditional lamps of 30W for 8 hours a day, the school electricity cost is calculated at 3.52 yuan per kilowatt-hour. The school uses about 2,108,160 kWh per year, the electricity bill is about 7,420,000 yuan, and the carbon emission is about 1,167,920kgCO2. After changing to LED lamps, the city’s schools can save about 3.71 million yuan in electricity bills each year, and reduce carbon emissions by about 583,960kgCO2, each by about 50%.

Director of Education Lin Zhuli said that the lamps and lanterns purchased in the past two years are all in line with CNS regulations, and have the product certificate of luminous efficiency and energy-saving mark recognized by TAF. In addition to avoiding glare and improving illuminance by replacing the lamps in the classroom, it is also easier to maintain and replace the lamps in the school.

Buildings in Pingjiang New Town in Gusu District are replaced with LED lights of various colors

In the underground garage, the lights are on when cars come, and the lights are off when they are leaving; road light poles, the sun rises to store energy, and the sunset is self-illuminating. In Pingjiang New Town, Gusu District, many buildings have been replaced with various energy-saving lamps, including LED lamps with low power consumption and high brightness; lamps that can sense the flow of people and automatically turn off; and lamps that automatically store electricity with solar energy. These buildings greatly save electricity and cost by replacing energy-saving lamps.

Buildings in Pingjiang New Town in Gusu District are replaced with LED lights of various colors

Located on Pinglong Road, Pingjiang New Town, Suzhou City Life Plaza is a large-scale comprehensive office building integrating administration, business, office, catering, and shopping. Its underground parking garage is a multi-story duplex with more than 2,000 parking spaces. The property side of Suzhou City Life Plaza told reporters that dozens of government departments have settled in the Suzhou Administrative Service Center located in the office building, with 561 approvals, management, and service items, with an average of thousands of cases per day. “These clerks have the characteristics of relatively concentrated parking, and the traffic flow during lunch breaks and get off work hours is relatively small, so there is no need to set up permanent lights.” In October last year, in order to save electricity, Suzhou City Life Plaza changed about 1,400 permanent lights in the underground garage to induction lights. The lights will turn on when car arrives, and the light will automatically turn off when car leaves, which can save thousands of kilowatt-hours of electricity every month.” the property manager said.

In the Guofa Building, energy-saving lamps and lanterns have also been transformed. In May of this year, the B2-B3 parking lots of Guofa Building were all changed to LED energy-saving lamps, and the lighting effect was very good. “Compared with traditional lamps, LED lamps have higher lighting brightness, but the energy consumption is only 1/7 of the original, saving thousands of kilowatts of electricity every month. ”

In addition to the underground garage, some street lights in Pingjiang New City have also undergone energy-saving renovations. In Sushang Building, the street lights in the community were replaced with solar lamp heads. The reporter saw that all the street lights around this office building have a solar panel, which can store electricity during the day and continue to release it at night. About 10 hours of continuous lighting, each light pole uses about 220 kWh of electricity a year, and the property bought 17 solar street lights to replace the lamp heads on 17 light poles. The annual electricity consumption is about 3,740 kWh. “The person in charge of Sushang Building said.

Can UV-LED lights effectively kill the coronavirus?

Disinfection of contaminants remains an important public health measure to reduce the spread of various infectious diseases, especially during the COVID-19 pandemic. In addition, researchers are also actively developing more efficient disinfection techniques, especially for high-traffic public places.

Can UV-LED lights effectively kill the coronavirus?

Ultraviolet (UV) light has previously been identified as a useful method of disinfection and has been shown to be effective in inactivating a wide variety of microorganisms. The advent of UV light-emitting diodes offers the advantage of ease of disinfection, as germicidal UV light can be provided using the same lighting units that provide standard white light to illuminate a room.

Scientists at the University of Toronto’s Scarborough campus have demonstrated the effectiveness and feasibility of UV light-emitting diodes as a means of purification by inactivating two different virus models: human coronavirus 229E and human immunodeficiency virus (HIV). Alternate between white light and germicidal ultraviolet (UV) light. With inexpensive retrofits, they can also be used in many standard lighting fixtures, bringing a “unique appeal” to public spaces, said Christina Guzzo, senior author of the study.

“We are at a critical juncture where we need to use every possible stop to get us out of this pandemic,” said Guzzo, an associate professor in the school’s Department of Biological Sciences. “Every mitigation strategy that can be easily implemented should be used.”

UV lamps kill viruses through radiation. Along with doctoral students Arvin T. Persaud and Jonathan Burnie, Guzzo first tested the lamp on bacterial spores known for their resistance to this radiation, known as Bacillus pumilus spores.

“If you can kill these spores, then you can reasonably say that you should be able to kill most other viruses that you regularly encounter in the environment,” Guzzo said.

Within 20 seconds of UV exposure, spore growth decreased by 99 percent.

The researchers then created droplets containing the coronavirus or HIV to simulate the typical way people encounter the virus in public, such as from coughing and sneezing. The droplets were then exposed to UV light and placed in a culture to see if any virus remained active. After just 30 seconds of exposure, the virus’s ability to infect was reduced by 93 percent.

When testing different concentrations of the virus, they found that samples with more viral particles were more resistant to UV light. But even with such a high viral load (which Guzzo called a “worst-case scenario”), infectivity dropped by 88%.

Although not included in the study, Guzzo and her students also compared UV light to two heavy-duty disinfectants used in the lab study. They found that the lights had a similar effect in their ability to inactivate the virus.

LED luminaires with new installations are the main growth factor

According to a report by market research agency MarketsandMarkets, by 2023, the global outdoor LED lighting market value will reach US$21.95 billion, and will grow at a compound annual growth rate of 13.7% during the forecast period from 2017 to 2023.


The growth of the outdoor LED lighting market can be attributed to the increasing demand for outdoor visibility, the need to ensure the safety of drivers and passersby, and the modernization of infrastructure. In addition, factors such as low energy consumption and high cost-effectiveness of LEDs have also contributed to the growth of the global outdoor LED lighting market.

From 2017 to 2023, LED luminaires with new installation methods will be a major factor driving the growth of the outdoor LED luminaires market.

Outdoor LED lighting fixtures with new installation methods have the advantages of long service life and energy saving, so they are very popular among consumers. Despite the high cost of outdoor LED lighting technology, installation and maintenance costs are relatively low.

Luminaires ranging from 50 watts to 150 watts will help boost the growth of the LED lighting market during the forecast period. The reason for such market growth can be attributed to the increasing adoption of LED outdoor lighting, which is energy-efficient and low-maintenance, outdoors around the world. Such LED outdoor lighting fixtures are mainly used on highways and roads.

During the forecast period, the outdoor LED lighting market in the Asia-Pacific region will witness a high CAGR. The growth of the market in this region can be attributed to the modern infrastructure development and optimization of cities. Countries and regions like Australia, Taiwan, Singapore, and Vietnam are experiencing huge economic growth and urbanization, which has greatly increased the demand for outdoor LED lighting systems in these countries.

Audi LED headlights are at the forefront of the times

With the advent of LED technology, Audi launched its first all-LED headlight in 2008. The light-emitting diode technology not only greatly improves the efficiency, projection range, and lighting function of the headlight, but also gives the light a higher degree of freedom in modeling design. With the technological evolution of the times, Audi launched Matrix LED headlights, Laser headlights, and OLED taillight technology in 2013, which have been widely used in Audi models so far.

Audi LED headlights are at the forefront of the times

2020 Digital Matrix LED digital matrix headlights are used in Audi e-Tron models for the first time. Audi’s engineering team not only has more advanced lighting technology in Audi lighting but also a dynamic projection lighting display when returning home/leaving home, making the lighting exclusive to the new generation of customers experiencing a link; taillights are also going digital. Digital OLED taillight technology uses curvilinear characteristics and three-dimensional light group structure to further communicate with the outside world. The light sources of the Digital OLED light group will all light up to warn people and vehicles behind to pay attention, bringing a safer driving experience. At present, this function has been installed on the Audi Q5 and Audi A8 models.

With the evolution of digital lighting, lighting is not only lighting for Audi, but also a medium of communication to achieve driving safety. Through exclusive lighting interaction, each car model is given a unique lighting shape and a personalized driving experience. Looking forward to the future, the Audi R&D team will continue to create more lighting functions, and gradually perform them in the Audi sphere series of concept cars, such as lighting canvas, light and shadow welcome red carpet, and then to Car-to-X communication and other future feasibility. With digital lighting technology integrated into design aesthetics, driving safety, and external road communication, Audi continues to create innovative mobile experiences.

Sustainable LED lighting could improve city safety

Safety is the number one concern for most people, but about 60 percent feel unsafe walking at night in their community. Investing in lighting that is both environmentally friendly and crime deterrent is a win for any community.

Sustainable LED lighting could improve city safety

Overall, sustainable lighting is a better choice and the community will see the difference after the change.

Brighter than regular LED lights, LED lights can increase productivity and keep people awake, making them a great choice for everything from home offices to dark street corners. Bright lights mean better street lighting, making people feel safer walking home.

With brighter lights, people don’t have to worry about crime. The brightness of the LED lights can help victims identify attackers to deter crime or allow security cameras to capture the facial features of potential criminals. LED lights are also a great way to prevent corruption in your community and make a place safer.

Humans respond to light, and more people are active during the day than at night, but bright city streets can feel like there’s the activity or someone is in the area. With more people around, few criminals would consider attacking.

Even if a community doesn’t want to keep those street lights on all night, they can still reap the safety benefits of switching to LED lights.

The community can take advantage of the brightness of LED lights by incorporating smart controls. Smart controls can flash streetlights when someone nearby needs help, which is great for first responders and first responders who may be searching in the dark.

Overall, smart devices can improve energy efficiency in buildings and outdoors.

New Beihuan River Expressway Replacement LED Lamps

To implement energy saving and carbon reduction, the New Taipei Maintenance Office will handle the LED lighting replacement project on the New Taipei Huanhe Expressway and the Sanchong to Banqiao section for five days on March 1st, 4th, 5th, 7th, and 8th, from 0:00 a.m. to 6:00 a.m. every day, some of the ramps will be closed in turn. The Maintenance Department pointed out yesterday (28th) that the replacement of street lamps will make the nighttime lighting brighter and ensure the safety of passers-by. Please cooperate with diversions when passing by.

New Beihuan River Expressway Replacement LED Lamps

The new Beihuan Express LED lighting replacement project is carried out in five stages. The closed road sections and diversion routes in each stage are as follows: In the first stage, the Sanchonghuanhe Road to Banqiao ramp and the Banqiao Huanhe West Road to Banqiao ramp will be closed on March 1. Bridge and Dahan Bridge pass. In the second stage, on March 4, Banqiao Huanhe West Road will be closed to Sanchong, and Banqiao to Sanchong will be closed. Vehicles should be diverted to Dahan Bridge and re-bridge. In the third stage, on March 5th, the Xinbeihuan Express Ramp on Xinzhuang Huanhan Road will be closed. Vehicles heading towards Banqiao should be diverted to Dahan Bridge. Vehicles heading towards Sanchong may be diverted to re-bridge or pass through Dahan Bridge to Banqiao Huanhe West Road Ramp and go to Xinbei Ring Road Hurry up; at the same time, the ramp from Sanchong Chongjin Street to Banqiao Shangqiao is also closed. For vehicles, please take Sanchong Huanhe Road to the Chenggong Road ramp. In the fourth stage, the Xingzhuang Huanhan Road ramp will be closed on March 7. Vehicles from Banqiao to Xinzhuang can be diverted to Dahan Bridge, and vehicles from Sanzhong to Xinzhuang should be diverted to the new bridge; at the same time, the Xinbei Ring Express to Sanzhong will be closed. Get off the ramp on Fud South Road. Vehicles please turn around and pass through the ramp on Sanzhong Longmen Road.

Shenzhen releases certification standards for MiniLED indoor commercial displays and other certification standards for the whole country

On July 20, the Shenzhen Municipal Market Supervision and Administration Bureau organized and held the Shenzhen Standard Quality Forum of “Deep Standard and High Quality”. At the meeting, the second batch of intelligent display terminal product catalogs was released simultaneously, and the pilot application for Shenzhen standard certification was opened to the whole country. The second batch of intelligent display terminal products that can be declared this time include a Mini LED indoor commercial display, handwriting and painting equipment, and a laser digital movie projector.

Shenzhen releases certification standards for MiniLED indoor commercial displays and other certification standards for the whole country

Among them, “Shenzhen Standard Advancement Evaluation Rules: Mini LED Indoor Commercial Screen” was proposed by Shenzhen Lighting and Display Engineering Industry Association to Shenzhen Standard Advancement Evaluation Organization. With the strong support of leading LED display companies such as Sen, Huaxing, Lehman, etc., they conducted in-depth discussions with experts on the key indicators of the detailed rules. The determining key indicators include brightness uniformity, color coordinate deviation, color gamut, coincidence, gray level, refresh frequency, horizontal brightness viewing angle, vertical brightness viewing angle, energy consumption requirements, ink color consistency/surface color difference, flatness, pixel center distance relative deviation, horizontal cross-border dislocation, vertical cross-border dislocation, and other requirements.

This “Shenzhen Standard Advanced Evaluation Rules: Mini LED Indoor Commercial Screen” is suitable for Mini LED chip size less than 200um, the pixel pitch range of 0.3 ~ 1.5mm, working in an indoor environment of 0 ~ 40 ℃, humidity below 85%, an ultra-high-definition display with Mini LED direct display solution. The main contents include but are not limited to main technical indicators determination procedures, main technical indicators, advanced judgment standards, advanced evaluation procedures, etc.

“Shenzhen Standard” of Mini LED

The LED display industry belongs to the ultra-high-definition video display industry cluster in Shenzhen’s “20+8” action plan. The Shenzhen LED industry was once synonymous with LED in China, because it has a complete industrial chain, the largest LED packaging and display production base in China, and the largest industrial cluster of LED listed companies in the country.

At the same time, the “Shenzhen Standard” will be based on the principle of leading domestic and international advanced level or filling domestic and international gaps. On the basis of relevant requirements such as “Test Methods for Light Emitting Diode (LED) Display Screens”, technical indicators of eight dimensions are proposed for product quality (for details, see Appendix 1 at the end of the article):

1. Product innovation can further meet customer needs and open up new markets;

2. In line with the direction of industrial policy guidance;

3. Fill in the domestic (international) gap and improve product quality;

4. Strictly higher than the national industry standards, the quality has improved significantly;

5. Cleaner production, material selection, and eco-friendly production process;

6. Product safety, health and environmental protection, maintain human safety, benefit physical health, and strengthen environmental protection;

7. Consumer experience, meet the actual needs of consumers, and improve user experience;

8. The special requirements of the industry are in line with and higher than the special requirements of the industry where the product is located, driving the quality to improve significantly.

Australia and New Zealand implement mandatory safety certification for LED bulbs and night lights

Recently, the Australian and New Zealand Bureau of Standards released AS/NZS 4417.2:2012 The fourth edition of the revised standard for electrical and electronic products compliance marking standard A4:2017. The revision expanded the list of regulated products, reclassified the security levels of some products, and updated the definitions of some products.

Australia and New Zealand implement mandatory safety certification for LED bulbs and night lights

It is worth noting that this revision adds 6 categories of products such as LED bulbs and night lights to the scope of compulsory certification products. The standard stipulates that from June 1, 2018, products such as LED bulbs and night lights entering the Australian market must first apply for a mandatory safety certificate (ie SAA certification).

The specific content of this revision includes: First, the new Australian Level 3 mandatory control products: In addition to LED bulbs and night lights, electric heating water bags, DC isolators, glue guns and flexible electric blankets (quilts) will also be available in 2018. It will be enforced from June 1; the second is to add New Zealand Level 2 products: balance vehicles, DC/AC electric vehicle (EV) charging piles, cable assemblies, belt control and protection devices, these types of products since June 2017 From the 30th, if it is sold to New Zealand, at least relevant test reports that meet the standards must be provided (you can also apply for a safety certificate). / The three categories of products such as scrubbers and TV receivers have been downgraded from Level 3 products in Australia to Level 2 products, and have been deleted from the New Zealand Level 2 list; the fourth is product definition update: product descriptions such as flexible heating pads, therapy lamps and wall switches Also updated in this revision.

It is reported that SAA Australian International Standards is the only standards certification body in Australia. Whether it is imported or locally assembled electrical products in Australia, before entering the Australian market, they must first pass the certification of the Australian International Standards Company. Due to the mutual recognition agreement between Australia and New Zealand, all products certified by Australia can smoothly enter the New Zealand market for sale. There are two main types of SAA marks, one is formal approval and the other is standard mark. Formal certification is only responsible for samples, while standard marks need to be inspected one by one.

The expansion of the product range of Australia’s compulsory safety certification will greatly increase the production and testing costs of enterprises; once the product quality does not meet the standard requirements, it will be randomly checked and notified by the Australian market, which will cause enterprises to suffer economic losses.

The inspection and quarantine department reminds the relevant lighting manufacturers that export to Australia: pay attention to the revision of the standards for electrical and electronic products in Australia, study and study the new standards, and do a good job in responding to technical trade measures, so as to know what to do.