Skyguide has appointed Olivier Perrin as its new Chief Safety & Security Officer. In this role, Perrin will succeed Klaus Affholderbach from July 1, 2023, who is leaving the company after more than 20 years to take up a new professional challenge. Perrin was simultaneously appointed as a member of Skyguide's Executive Management.

Perrin joined Skyguide in 2000 as a satellite navigation systems engineer and holds a master's degree in geomatics engineering from EPFL and an MBA from Concordia University in Canada. The 48-year-old manager most recently assumed additional responsibility for all military operations and lower airspace operations in 2014. He is also an active private pilot and serves the Swiss Air Force as a colonel. He has also been responsible for the Air Traffic Control Technical Staff as commander since 2017. In his private life, Perrin is married and the father of three young adults.

Source: Skyguide

According to an in-house release from the University Hospital Zurich, the outpatient health center near the airport at the Circle is growing strongly. It has been in operation since fall 2020. Since the beginning of February, the facility has now reached the mark of 1000 patients per day, according to its own information. Under the health center are united 20 specialties for outpatient operations. In addition to consultation hours, the modern infrastructure also offers radiation therapy, dialysis, endoscopy and treatment in the day clinic.

The modern surgical methods and facilities should make it possible to schedule just one day for certain operations. Around 3,600 operations are performed each year in the three operating theaters at USZ Airport. The most common outpatient surgeries include cataract removal and metal removals. According to the USZ, the range of services and capacity utilization have been gradually increased as planned since the opening. In early February 2023, cardiology, nephrology and rheumatology moved additional consultations to the USZ near the airport.

Source: USZ

Since OpenAI made its AI tool "ChatGPT" available to a broad public, users from all over the world have pounced on the now famous chatbot to find out what the interesting tool is already capable of. ChatGPT can virtually conduct dialogues as if a human were sitting on the other end of "the line." The use of the AI application is becoming a bit "mainstream" lately, as users are talking to the chatbot not just for fun. For example, ChatGPT can also help populate web page content or suggest a job application letter as an example.

Example of a typical social engineering attack

Now warns Kaspersky against a scam by cybercriminals who are already creating fake groups on Facebook that look confusingly similar to the official OpenAI account. The fraudulent groups sometimes host official posts with news about the service and advertise a program that poses as a desktop client for ChatGPT. Anyone who clicks on such a fraudulent link is redirected to a fake website that looks and feels like the official ChatGPT site. During the supposed installation of the alleged ChatGPT client, the installation terminates with an error message, during which a Trojan is installed in the background. The Trojan-PSW.Win64.Fobo program targets information about stored accounts from various browsers. This includes, for example, cookies and login information from Facebook, Google and Tiktok accounts.

According to Kaspersky, many cases with the Trojan have already been reported in Africa, Asia, Europe and America. As always, it is advisable to always check the URL as well as the file names of any installation file carefully.

Source: Kaspersky

According to a Study of the European Tissue Symposium (ETS), there would be clear evidence that Europeans have changed their hand hygiene since the outbreak of the Covid 19 pandemic: They wash their hands more frequently throughout the day, opting for paper towels as the most hygienic method of hand drying when out and about.

According to the ETS study, which was carried out in conjunction with a British microbiology institute in Leeds, among others, there was ten times more evidence of contamination by water splashes when jet air dryers were used than when paper towels were used. According to the study, 89 percent of face masks were contaminated with viruses when jet air dryers were used, compared with only 29 percent when paper towels were used.

With both methods, a higher contamination of the face masks with virus aerosols was detected in the first five minutes after hand drying. When jet air dryers were used, the viral load was significantly higher. In the studies using jet air dryers, contamination continued to increase for 15 minutes after hand drying, indicating aerosol formation of small particles suspended in the ambient air for a longer period of time.

According to the ETS, according to this new research, restaurant and bar owners, as well as purchasing managers responsible for large sports venues and shopping malls, would be well advised to reconsider the hand drying method they offer and offer their customers what the ETS considers a more hygienic option, namely paper towels.

Source: ETS

Due to its exceptional properties, graphene is now added to a wide range of plastics. For example, the carbon-based material improves the conductivity and stability of composites. Empa researchers are currently investigating the health risks of these comparatively new composite materials in several studies. The most recent investigations are looking at the residues of graphene nanoplatelets that can be produced after the composites are incinerated in waste incinerators or in a fire accident.

A realistic lung model in the petri dish

Since the human organism is most likely to come into contact with graphene particles via the respiratory tract, the researchers used the 3D lung model developed at Empa with cell cultures for the toxicity tests. The team led by Peter Wick of Empa's Particles-Biology Interactions laboratory in St. Gallen exposed lung cells to residues from the combustion of composite materials containing graphene nanoplatelets. To estimate as realistically as possible the amount of graphene particles to which people are typically exposed, a team led by Jing Wang of Empa's Advanced Analytical Technologies Laboratory examined and quantified the combustion residues of the graphene composites. Researchers from Empa's Advanced Fibers Laboratory were also involved in the interdisciplinary project.

No acute injury

Using this data, the team exposed the 3D lung model to realistic conditions so that predictions could be made about the acute toxicity of graphene nanoplatelets after combustion. The results showed that although combustion residues of plastic resins without graphene triggered already known reactions indicating a health risk. However, after contact with the graphene nanoplatelet residues, there was no further evidence of acute damage to lung cells, such as inflammatory reactions, oxidative stress or cell death.

In an earlier study, Empa researchers had already been able to show that the health risks of graphene dust produced by abrasion from polymer composites are negligible. The effects of prolonged exposure to graphene nanoparticles will now be investigated in more long-term studies.

Source: Empa

Whether burglary protection, access and exit control, escape route, fire protection, self-locking, intervention function, building physics requirements or resistance - the demands on doors are enormously diverse. Well over 100 laws, standards and directives are related to doors and the surrounding area.

Faultless operation of doors and door systems requires specialist knowledge, experience, and an understanding of how to cover the complex requirements and implement the quality specifications in the projects in the best possible way. A specialist and eight experts will therefore talk about their experience and know-how at a Save AG symposium on March 29, 2023, entitled "Doors and components - multifunctional and safe all round!

To the conference program

Mr. Brügger, how has the intrusion detection system (EMA) changed over the past 30 years from your perspective?

From 1990 to around 2015, very little happened; an EMA remained an isolated solution that performed its task in isolation from other systems. With the new age of Industry 4.0, a great deal has changed. For example, an intrusion alarm system should and must communicate with several other systems today. Secure operation of the EMA system from anywhere in the world is standard using a smartphone or web browser. Even without a management system: So it has to be a cloud solution and operating devices have to be more intuitive, but also more visually appealing. However, the system must still be able to perform its core task "autonomously" on site (without communicating with a cloud or other systems) or to secure and alarm the object.

According to the police crime statistics (PKS), the number of burglaries is declining. Has a classic EMA become superfluous?

It is very pleasing to see that the number of sneak-in thefts is declining. The classic, traditional EMA of past decades will indeed be superfluous in the future. An EMA that communicates with "surrounding systems" and makes and executes decisions with them itself will be needed - we can already see this trend quite clearly today.

Do you have specific examples?

As already mentioned, the core zone to be defined must always remain monitored and be able to alert a system. Both private customers with apartments or houses, institutions such as the military, prisons, museums and critical infrastructures such as energy suppliers, data centers and banks will continue to demand a 100 percent autonomous system in the future. This must function autonomously, regardless of whether the power supply and thus communication to the outside is interrupted or a saboteur attempts to paralyze the system.

How will the interaction with plants develop?

In order to offer customers greater security and an even more cost-effective solution, the systems must be able to communicate with each other. This interaction will not only increasingly take place with access control or video systems, but other systems (such as outdoor protection, audio, light) or detectors will be integrated directly via IP. Look forward, it will be exciting.

What is the biggest challenge today in providing or evaluating an EMA in the digital age?

When you know the customer segment you want to serve, it is important to analyze the customer requirements and the standards the system must meet. Only then you will have an approximate idea regarding the system requirement. Systems for the monitoring of several large objects with the highest security requirements are only available in a handful in the DACH market - so the choice is small. For the customer segments from medium-sized objects with high security requirements to the protection of small single-family houses or apartments, there is a large variety of system providers. If you are not familiar with the market, it is advisable to carry out a detailed deskresearch and then subject your top 3 to top 5 to a utility value analysis and invite the most suitable providers to a meeting to clarify any questions you may have. For example, how easy it is to install, program and maintain the system and what innovations are planned for the next few years.

Do the current and certainly future requirements of the networked, learning building impact the survival of EMA system providers?

As I mentioned, there are currently still very many system providers in the customer segment for small to medium-sized properties; this will change. I assume that one third to one half of the current traditional providers will disappear from the market in the next ten years. Even in the segment for monitoring large properties with the highest security requirements, it must be assumed that not all system providers will be able to provide the expertise and resources to follow these trends.

Why?

Complexity will continue to increase, networked solutions are in demand. Access from anywhere (via mobile and web) has long been a must, as has communication with other systems on site. In the future, parts of the intelligence of an EMA will no longer be on site, but in the providers' cloud. This will exchange data with other cloud services (cloud-2-cloud) and make decisions based on this.

Conclusion: If you offer hybrid solutions, you need specific specialist personnel, and you must be able to find, train, pay and retain them. So pay attention to how the company you are working with is positioned and whether it will be up to the future challenges.

What is the situation in the private customer segment?

Exactly the same. There are two to three EMA system providers with hybrid solutions that are stimulating the market in the private customer segment with innovative, stable, secure and intuitive products and are also achieving success with them. These will be able to hold their own in the future or become even more established.

In addition, this mass market will increasingly see solutions from tech giants and other technology companies that are currently outside the industry but have a functioning cloud infrastructure and already offer solutions for end customers.

It can already be assumed that sooner or later they will offer home security solutions on the market that will meet customer needs and are attractively priced.

How do standards discussions currently affect the realities of an EMA?

These influence the EMA, and the system providers try to influence the standards. As is well known, new standards usually follow new trends immediately. As a trend, for example a technology, is initially used by individual trendsetters, this gradually becomes a customer need, and a standardization process is set in motion. Fortunately, there is also a great deal of movement in this area, which has made standards work and discussion more diverse. The revision of EN 50131 addressed new topics such as remote operation for the first time. This was just the beginning; many more interactions are being worked on so that EMA can be integrated into the life of buildings - in the sense of an autonomous building. The premise of the standards work is that our systems remain secure.

Whether 3D printing has ushered in a new age of production - as predicted - remains to be seen. The big hype seems to be over, but the fact is that additive manufacturing has arrived in many industries and is beginning to change the working world. The advantages for designers and developers are undisputed. High-precision and geometrically complex structures with filigree details and even integrated functions such as conductor paths can be manufactured from a wide variety of materials.

Additive instead of subtractive

When discussing the risks of "additive manufacturing," it is important to keep in mind that 3D printing is not a single or strictly defined technology. Rather, the term encircles dozens of manufacturing processes, the most important of which fall into one of the following types:

• powder bed based, e.g. selective laser and electron beam melting
• nozzle-based, e.g. laser buildup welding with powder or wire
• Material extrusion, in which, for example, filaments or granules of plastic are heated
• Photopolymerization/stereolithography, in which light-sensitive substances are selectively solidified by exposure to light, e.g. in additive microfabrication

What all 3D printing processes have in common is that software cuts the object designed on the computer into layers and outputs it as a digital data model to the printer, which assembles the three-dimensional component layer by layer. Since the objects are created by application rather than - as in milling, drilling, routing, sawing, planing, etc. - by removal, this process is referred to as additive manufacturing, in contrast to the conventional (mostly subtractive) processes. Initially, the greatest opportunities were seen in the automotive, aerospace and medical technology sectors, but now more and more areas of application are being added. Dental crowns or hip implants, designer jewelry or spare parts that are no longer available, artificial coral reefs or pedestrian bridges, components for space rockets or for submarines, the spectrum of 3D-printed components is immense. At the same time, the build envelopes of printers are getting larger, printing speeds are increasing, and printing processes are becoming more versatile as new starting materials are used. As a result, 3D printing is no longer limited to models and prototypes, but is evolving toward small-scale production and beyond.

Hazards depending on material and printing process

At first glance, additive manufacturing production systems appear elegant and clean. Compared to classic processes, such as metalworking, a 3D printer is quiet, there is no oil dripping and no cooling lubricants splashing. But a deeper look at safety and health issues reveals material-specific as well as technology-specific hazards. 3D printers primarily use plastics, resins and metals. In addition, many other materials are printed, from ceramics and carbon fibers to concrete, marzipan and even living cells. The materials are usually in the form of powders or filaments, and more rarely as pastes, films or pellets. When it comes to "powder", every health protector will sit up and take notice; moreover, quite a few of the starting substances are considered hazardous materials. Other hazards are based on the printing technology. Depending on the process, there are radiation sources (laser, UV) or hot nozzles, and pollutants are also emitted. Thus, there is no one hazard in 3D printing, but one must look closely at each case, which materials are processed in which printer type and in which way.

Apply proven protection measures to 3D printing

The good news is that the health risks relevant to additive manufacturing are not completely new and proven protective measures are available. In many cases, these have already been implemented by the printer manufacturer. For many 3D printer models, enclosure is now standard, as is the fact that the printing process takes place in an inert atmosphere, i.e. under inert gas. For powder handling, there are the glove boxes known from laboratories, which allow working without powder contact, and other technical solutions. Nevertheless, any company planning to purchase a 3D printer would be well advised to consider the necessary safety precautions for the protection of employees at an early stage and in advance, e.g.:

• Which installation conditions of the printer have to be observed, which requirements apply e.g. for temperature, humidity, air exchange rate etc.?
• Can the printer be located in a separate room or separate from workstations that are in constant use?
• Is the floor in the designated printer room easy to clean?
• Do we need access control to the 3D printer workstation?
• Which solid, liquid and gaseous hazardous substances will be used, which will be created and will we protect people and the environment?
• Is shielding from the laser or UV radiation used guaranteed?
• How can we carry out all process steps, including cleaning, maintenance, filter changes, etc., without risk?
• Which steps in powder handling, such as filling, preparation, sieving, mixing, recycling of residual powder, etc., can or must we inertize?
• What protective equipment do employees handling powder need, such as gloves, eye protection, filter masks, possibly also disposable protective suits and blower-assisted respirators?
• How do we prevent the carry-over of powders into other work areas, e.g. by floor mats, changing rooms, self-closing intermediate doors, etc.?
• Do we need Ex-proof industrial vacuum cleaners with wet separators?
• Do we need special fire extinguishers for metal fires?
• If there is a risk of liquid splashes, can an eye shower be installed in the work area?
• Where and how do we want to store powder, where could an F90 safety cabinet be located, for example?
• Have we clarified how cleaning agents contaminated with powder, filter condensates, liquids from wet separators, etc. are disposed of properly?

In addition to the individual assessment of the situation on site - regardless of the printing process - are important sources of information for each user:

• the operating instructions with information on residual risks and protective measures
• name the safety data sheets of the starting materials, the risks and protective measures

The fact that 3D printers - at least for some printing processes - can now be found not only in DIY stores, but even on the rummage tables of discounters, should not tempt one to be lax when it comes to health protection. The following applies to such simple tabletop 3D printers, which are also used by private individuals or in schools: When used as intended and at the temperatures recommended for the respective filaments, the same recommendations apply in principle as for conventional printers indoors. It is important to ventilate regularly and that the exhaust air streams are not directed at the workplace. The hazards associated with 3D printing, such as fine dusts, volatile hazardous substances, gases or hot surfaces, are well known in occupational safety. Therefore, neither technical measures such as ventilation or exhaust systems nor suitable PPE nor rules for handling hazardous substances need to be newly developed. The crucial thing is to identify the risks on site and apply the measures that have been proven elsewhere. This is particularly true for companies that come from the traditional metal processing sector and have previously been exposed to hazards quite different from those posed by fine dusts or VOCs. Here, educating and training employees are crucial elements of successful prevention.

This technical article appeared in the printed edition SAFETY-PLUS 2-2022. Want to read the full article in this issue? Then close right away here a subscription.

Climate change is progressing rapidly. We are already 2 degrees of warming behind us compared to the reference year 1864. If greenhouse gas releases increase unrestricted (RCP 8.5), an additional 3.3 degrees temperature increase over today is expected by mid-century. Even with comprehensive measures to reduce greenhouse gas emissions (RCP 2.6), warming of 2 degrees is assumed.

However, climate change will not only bring about an increase in temperature. The seasonal precipitation development will change significantly. The average precipitation total will decrease in summer, resulting in more dry summers. In winter, on the other hand, it will increase. Heavy precipitation will become more frequent and up to 30 % more intense.

The expected impacts for different emission or warming scenarios are available according to the Swiss climate scenarios CH2018.

Risk analysis

Natural hazards are already classified as one of the three biggest risks for business failures. The need for a systematic consideration of potential natural hazards and changed hazard bases due to climate change is therefore given.

The basis for a future-oriented risk analysis to reduce business failures as a result of a natural event is the currently valid and the expected hazard patterns. Whether your company is affected by natural hazards can be identified through a targeted risk screening in three phases.

1. Impact Analysis
2. Risk analysis
3. Evaluation of measures

The result of the impact analysis shows whether the examined company site is located in the hazard perimeter, which parts of the company site are affected and by which natural hazards the site is affected. The risk analysis by means of an on-site inspection shows the local hazard of the objects. Weak points and intrusion points on buildings can thus be identified. In addition, a damage estimate can be made for property and personal risks in the event of an incident. The risks are identified, checked and evaluated according to defined criteria. In addition, unacceptable risks are prioritized. The evaluation of measures aims to identify cost-effective and effective measures. The three-phase risk screening thus enables efficient identification of risk hotspots.

Unrecognized hazards and unknown vulnerabilities are the basis for unconsciously assumed risks. Such risks must be avoided by periodically reviewing the hazard images to ensure that they are up to date. If there is no official basis for the hazards, local or selective hazard clarifications can close this gap in a targeted manner.

Particularly when evaluating new operating sites, care should be taken to ensure that appropriately detailed bases are available for all relevant hazard types. Otherwise, it is a case of flying blind with regard to the risks posed by natural hazards. Among other things, the maps of natural hazards serve as hazard bases: the nationwide hazard map of surface runoff as well as cantonal hazard and intensity maps for various processes. These maps can be found on the cantonal geoportals.

Identified unacceptable risks can be systematically included in the planning process in the context of new construction and renovation. Can the risk be avoided locally? Is resilient construction the solution? In EU standards (Eurocode 1), actions from earthquakes, wind and snow have been the standard for some time. Regulations for the effects of floods, surface runoff, hail, landslides and the like are missing. This gap could be closed in Switzerland in the meantime. It promotes natural hazard-compatible or resilient construction.

Flood

In the case of floods, a locally higher intensity is to be expected in the future due to heavier heavy precipitation. This precipitation in turn causes flooding as surface runoff, which must also be included in the hazard picture. A prime example was last summer 2021, when the federal government declared the highest warning level for the surface water flood situation in some places in Switzerland. Due to late, rapid snowmelt and heavy thunderstorms, various hydrological highs were exceeded since the beginning of the measurement period. Lakes such as Lake Neuchâtel, Lake Lucerne and Lake Thun overflowed their banks. Floods occurred in small and larger rivers. In some cases, the groundwater level rose so high that it flooded building basements. Protection against flooding due to heavy precipitation, streams, rivers, lakes, surface water and groundwater can be ensured by structural and organizational measures. The water can be diverted from the desired perimeter and thus the object can be shielded. By sealing the building envelope (hinged bulkheads, flood protection doors and windows), water can be prevented from entering the building from the outside. By building with an elevated layout, critical infrastructure can be protected up to a certain water level. In addition, wet precautions with an interior finish that is impervious to water can reduce the potential for damage from flooding.

Hail

In connection with more frequent strong thunderstorm cells, hail is increasingly to be expected. About one third of the damage to buildings caused by natural events is due to hail. Besides roofs, facades, windows and blinds are also exposed to hail. A hailstorm can penetrate the facade plaster and damage the underlying thermal insulation system. Plastic skylight domes can become brittle due to solar radiation. An easy target for hail. The previous record for building damage caused by hail in Switzerland was 260 million Swiss francs in 2009, and the projection of hail damage to buildings for 2021 is over 700 million Swiss francs. With regard to the impact of hail, the hail register (similar to the fire protection register, see www.hagelregister.ch) has provided an important basis for planning. It serves the building owner and the facade planner as a planning aid for hail-resistant materials and systems.

Drought

Climatic hazards such as drought, forest and field fires, and heat waves are generally expected to have entirely new dimensions of hazard. So far, such impacts have hardly been included in risk analyses for company locations in Central and Northern Europe, respectively the resulting risk was generally low to negligible. This can no longer be expected for the medium planning future. In particular, the supply of river water in the summer half-year for cooling purposes will hardly be available any more. Water-intensive production facilities will have to look for locations with drought-resistant water supplies.

Conclusion

An operational disruption caused by a natural hazard can last for months. The systematic analysis of current and intensified hazards at the operating site that are to be expected as a result of climate change is therefore an indispensable basis. The risk identification and assessment based on this analysis shows the need for action and is thus an efficient methodology for the targeted use of financial resources for protective measures. In this way, resilient buildings and effective protection concepts can be implemented on a risk basis.

The new sodium-aluminum battery developed by researchers at the Pacific Northwest National Laboratory (PNNL) is not impressive for its performance or other superficially positive properties, but for the raw materials from which it is made. Both metals are abundant on Earth, unlike lithium and cobalt, which are needed for today's most common electricity storage devices. That makes them a price-taker for storing excess electricity from wind and solar power plants.

Solid state electrolyte on board

The anode of the innovative battery consists of aluminum wool and liquid salt, while the cathode is made of metallic sodium. Between them is a solid-state electrolyte that allows sodium ions to pass through, but prevents the two electrodes from coming into contact with each other and causing a short circuit.

"We have shown that this new liquid-salt battery design provides much faster charging and discharging than high-temperature sulfur-sodium batteries. They also operate at a much lower temperature and the energy storage capacity is maintained over many charge and discharge cycles," said PNNL materials scientist Guosheng Li. After 345 cycles, it was still 82.8 percent.

Clean energy megatrend

Imre Gyuk, director of the Office of Electricity, Energy Storage Program of the US Department of Energy, which supported this research, notes, "This battery technology, made with low-cost, domestically available materials, brings us one step closer to our nation's clean energy goals."

Although the battery is in its early stages and currently only button cell-sized, researchers speculate that an energy density of up to 100 watt-hours per kilogram (Wh/kg) is achievable when it is "fully grown." That of lithium-ion batteries used in commercial electronics and e-vehicles is 170 to 250 Wh/kg. Thus, the new battery is only suitable for stationary operation.

"Our main goal for this technology is to provide a low-cost, daily shift of solar energy to the grid over a ten- to 24-hour period," says PNNL battery technology expert Vince Sprenkle. Most current battery technologies, including lithium-ion batteries, are well suited for short-term energy storage, he said. Meeting power needs for more than 10 hours would require the development of new, low-cost, safe and long-lasting battery designs.

Source: Press text.com

In the future, motorcycle, scooter and e-scooter riders will also be able to protect their legs and hips from injuries caused by accidents. CX Air Dynamics, manufacturer of protective clothing for two-wheelers, now sells pants equipped with an airbag. They are water-repellent and breathable, like normal pants of this type. But inside is a kind of balloon that is inflated by a compressed air cartridge in less than 200 milliseconds when the rider is thrown from his two-wheeler, for example after a collision.

Legs and hip at high risk

The innovation can prevent many injuries, the company says. After all, 63 percent of all injuries to two-wheelers affect the lower extremities. Unlike airbags in cars, which have to be replaced after an accident, the impact cushions in pants are ready for use again when fitted with a new cartridge.

The new pants are equipped with flexible, shock-absorbing protection made of Poron XRD on the knees and hips. This is a foam based on the plastic polyurethane. The airbag extends from the hips to the ankles. At knee level, it is interrupted so that the joint can move. The pants cost 600 francs in the manufacturer's online store.

Sweden with own development

The Swedish company Mo'Cycle wants to stand up to the French. Its airbag pants, which look like jeans, are to be launched on the market shortly. The inflatable protection mechanism here only extends to the knee. This is protected by a pad, as is the shin. However, the company is still looking for backers.

In a crowdfunding campaign, it wants to collect the funds needed to start production. The pants can already be ordered now at a starting price around 410 francs with a deposit of five dollars (4.65 francs). Vests with integrated airbags have been in use for motorcycle racers for many years. They are also offered for private users. With the pants, however, there were design problems that have only now been solved.

Source: Press text.com

The new drone "Crazyflie" from researchers at the Swiss Federal Institute of Technology Lausanne (EPFL) has neither a camera nor LiDAR or radar. Nevertheless, it flies even at night without touching any obstacles. The model is the bat, which has the same capabilities. It emits ultrasonic pulses and uses the reflected signals to detect obstacles in a flash, which it avoids, or prey objects, which it greedily pounces on.

Four microphones and one buzzer

The drone is equipped with a piezoelectric buzzer mounted in the center of the flying object. At the end of the four arms, which are located between the four webs with the drive motors, so-called MEMS microphones are installed, which pick up the reflections of the buzzing sounds that are emitted with short interruptions. From this, the microcontroller on board designs an image of the surroundings so that the drone flies through the three-dimensional course without visual control.

MEMS microphones are miniaturized microphones designed in SMD technology for direct use on electronic circuit boards. They are particularly inexpensive, as are the drone's other components. "We deliberately did without expensive measurement microphones and loudspeakers to keep the drone's costs down. If there is a strong reflector like a wall nearby, the sound is reflected and interacts with the direct sound at each microphone," says EPFL developer Frederike Dümbgen.

Accurate acoustic localization

Depending on the distance and frequency, these two signals weaken or strengthen each other. From this, the microcontroller determines the distance of the obstacle. Since there are several microphones, it is also possible to determine the angle at which the reflector is located in relation to the drone. Dümbgen outlines the future of Crazyflie this way, "We humans rely more on our ears when it is dark and on our eyes when there is loud ambient noise. I believe that truly intelligent robots should have this capability as well."

(Source: Press text.com)