Archive for March, 2014


Summary

As lectures start again and the official thesis weeks come to an end this is our last blogpost. What follows is a short summary.

We tried to acquaint some sensorapplications and their usefulness to society. We saw sensors will become ubiquitous. More and more sensors and their applications are integrating into our lives and our society. In the future many more applications will be developed. Sensors are changing the way we live, how we behave and can deliver us many advantages. However we should also be carefull because of security threads and privacy issues. Furthermore a correct regulation should be provided. There still is much work to do.

I hope you found our blog (or at least some parts of it) interesting. I’d like to thank everyone who read the blog and especially those people who contributed with their usefull comments.

See you!

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Car2Car communication

To make the life of car drivers easier, car brands such as Honda, GM, Audi, BMW, Daimler and Volvo joined the car2car communication consortium. What is the idea behind this, establishing a wireless communication system that allows vehicles of any brand or model to communicate with each other. They hope that this network will reduce the number of accidents, improve the traffic flow and make driving easier. The movie above gives an idea of how it would improve the current driving dangers. The consortium hopes that the system will be ready to use by 2016.

 

 

 

Volvo-Testing-Cloud-Based-Car2Car-Communication-1

Volvo is already testing this cloud-based car2car communication to prevent accidents because of slippery roads, in collaboration with the Swedish Transport Administration and the Norwegian Public Roads Administration. This pilot project momentarily has 50 test cars on the road and next winter the fleet will grow even more. The project uses the mobile network, when a test car detects a slippery spot on the road, the information is send to the Volvo Cars’ database using the mobile phone network. This information is then send to other vehicles in the neighborhood, or ones that are approachingthe slippery patch in the road. Not only can it alert drivers but it can also pass this information on to the road administrator to prevent slippery roads better and execute better road maintenance when the winter ends.

 

 

 

Volvo-driver-sensors-1 Volvo-driver-sensors

Volvo doesn’t only sense external dangers, they also implemented the use of sensors to monitor the movements of the driver itself. A camera is mounted in the dashboard, to monitor the driver’s head position and calculate the direction he is looking in. The system can adjust the direction of the headlights to follow the direction the driver is looking in. It also detects if the driver is  sleepy or tired by looking at his eyes, the support systems can sharpen the attention of the driver.

Volvo immediately said that the cloud data is uploaded anonymously so it doesn’t store who makes a fault. They also state that the monitoring system doesn’t save any pictures, this to avoid any privacy issues.

 

 

Do you think that these systems could save lives?
Or do you think they instill a false sense of safety that at the end of the line causes even more accidents because the drivers depend too much on those safety system?

 

Social sensing

The above video from the Digital Enterprise Research Institute (DERI) explains the principle of social sensing. But the definition social sensing isn’t limited to gathering data with mobile phones only.  Mining and aggregating user inputs and content over multiple social networking sites is also a form of social sensing.

Social sensing can be a powerfull tool for journalists and news centers. For example the Hudson Bay plane crash had been tweeted for minutes after the crash including pictures. It took more than a quarter before showing up on regular news channels. tweet_hudsonhudson_plane_crash

The Social Sensor project funded by the EU is aiming to use this kind of information. The original statement is written below.

SocialSensor will develop a new framework for enabling real-time multimedia indexing and search in the Social Web.

Furthermore social sensing is  used to provide more accurate and up-to-data media experiences. The recommandations provided by Spotify are provided using a form of social sensing.  They look for trending toppics, combined with your user data to serve you the music you’ll most likely approve. This kind of technology is influencing our day to day living in my opinion. In the future it’s possible we will all have our own advisor based on social sensing and big data algorithm’s to provide us insight in possible choices and trying to influence us to make the best choice.. according to the opinion of the designers.SocialSensorBannerSmallFINAL

 

Sensing temperature

Like I said already a few times is that we use ultrasound for our thesis, I also mentioned that the speed of sound is reliable of temperature and humidity.

So let’s have a closer look at how we measure temperature with sensors, I found this interesting comparison between temperature sensors so I’ll summarize it for you guys.

There are two types of sensors to measure temperature, the contact and the noncontact ones.

 

 

Here are the most common contact temperature sensor types:

A thermocouple uses two metals to create a voltage that is dependent of the temperature difference between the ambient and junction temperature. This is already a big advantage because it doesn’t need extra power and it’s also very cheap. They are robust but decay over time and can measure a big range going up to 3,000°C and as low as –250°C. Thermocouples are often used in ground vibration tests.

Thermistors (NTC and PTC) work somewhat like an LDR (light dependent resistor), so it’s a resistor which his resistance value is dependent of its temperature. These are often used as inrush current limiters, temperature sensors, self-resetting overcurrent protectors, and self-regulating heating elements. So like you see they are mostly used for simple temperature measurements.

Resistance temperature detectors (RTD) are also resistors (thin-film or wire-wound) with a resistance value which is dependent of its temperature. They are very accurate, robust and stable because it’s made of platinum, which is not affected by corrosion or oxidation. Thin-film RTD elements have a thin layer of platinum for its resistor and are used for Health & Usage Monitoring Systems.

 

 

The noncontact types are represented by the infrared temperature probes.

So every object that has a temperature above absolute zero emits Infrared radiation which is linked to its surface temperature. So by using an infrared sensor you can measure it, but you still need some electronics afterwards to process the data into something which is readable for the user.ScreenHunter_4

A problem with the use of infrared probes is that the object you want to measure needs to be bigger than the measurement spot like you see here:

measurement spot

One of the big advantages is that they can be used from a big distance and they can measure high temperatures because they don’t contact. Also measuring moving objects is an option.

 

 

 

So hope you now know a bit how they measure temperature in the world of electronics. What would you use to measure the temperature at home?

The value of your user data

user_data_value

Try this calculator form the Financial Times to estimate the value of your user data when sold in large chunks of anonymous data. The more details, the higher the value of it. The outcome is extremely low. However if you try to sell your user data as an individual with identifiable records it may become quite valuable.

There are various companies buying user data with real money from individuals, like Handshake.

I took the next description directly from their website:

 Handshake is an app and a website that allows you to negotiate a price for your personal data directly with the companies that want to buy it.

Make sure to check it out. Maybe you want to get some cash for your user data. Please let me know if you sold it and how much you got paid for it. I personally would never sell my data like that and many of you may think alike. But perhaps you do fill in your information from time to time when there is some kind of reward or loyalty program, like a price contest.

Food for thoughts.

Measuring a distance

So in our master thesis, we need to measure a distance between two nodes with ultrasonic waves. So I was wondering, what ways can you measure distance.

 

Should I use a measure tape, an Ultrasonic Distance Meter or a Laser Distance Meter?

 

What is the problem with a measurement tape, it is not very accurate and it doesn’t ease the work of the user. Why do we still use it then, first of all it’s very cheap and easy to handle and use. It has also a lot of shortcomings, like how to measure something when object are in the way. Also it is difficult to measure long distances when you’re by yourself.

File:Tape measure colored.jpeg

So how can we overcome these limitations, let us use a more “intelligent” measuring system. These digital measurement tools use electronics to ease the work of the user, like knowing how to use Pythagoras.

A Laser as well as a Ultrasonic Distance Meter, sends out a burst and waits for the signal to reflect back from the object and then measure the time it took. The only difference is what kind of burst it is, a laser uses a burst of light. Logically an Ultrasonic meter uses an ultrasonic sound burst to measure distance. There are some differences between light and sound, light is more directive and travels in a straight line, at a velocity of 299 792 458 m / s which is dependent of the used wavelength and  medium. While sound travels with a speed of 340.29 m / s and is dependent of humidity, pressure and temperature because it needs a medium to travel through. It propagates less directive, it sends out a cone (like you see on the picture underneath).

beam width

In general are laser distance meters more accurate, this because they use more focused bundles so they have a bigger range and light is less dependent of external factors. But the components to measure this are more expensive because they need to work at higher clock frequency. We use Ultrasound in our thesis, because we only need a range of about 10 meters, which is viable for Ultrasound and find it beneficial that that a transmitter sends out a cone of ultrasound, because then multiple receivers can receive the transmitted burst. It is also less sensitive to the time errors because sound propagates at lower speed, so the time error of the electric signal that needs propagates trough the cable is more negligible.

 

What would you choose to measure distance, the Laser or Ultra Sound? You can read this small paper, because it is a good comparison and my post is also based on it.

What about user data?

Almost everyone know that cookies collect data as you browse the web. This personal data is mainly used for advertising purposes and thus your user data is worth money. How much do you tink your user data is worth? Well if you want to buy anonymous user data sold in large amounts, it’s dirt cheap. Prices are as low as $0.005 per user profile. My next post will discuss the value of your user data.

blog_picture_german_politician

In this post well go into detail on one specific case. The case of a German politician (Spitz, TED talk) who asked his telecom provider the six month of phone data that is stored as obligated by the German law. This information was mapped with freely available information on the internet like his tweets and blogs and cookie information.

Check out this website that provides a detailed look into these 6 months in the life of Spitz. It’s surprising how much detailed information is available. What do you think about user data collection?I think it’s something to reckon and important to be aware of. However it’s also something that’s nearly unavoidable these days and delivers many benefits to our daily lives and economy. A lot of free services are only usable because of our user data we share when using it.

Nature inspired ultrasonic distance measurement

An animal that uses ultrasound is the bat, they use it to hunt at night. A lot of animals hunt in the dark, like cats and have special eyes to see in the dark. But because insects are too small to hunt even with that kind of eyes, the bat uses Ultrasound to locate insects to hunt on.

animal ecolocation
So he uses his ears to see (= echolocation). Not only bats use this method, also dolphins and whales. It’s even possible to do it as a human, Daniel Kish is blind from the age of 13 and has adapted to this, by learning himself echolocation.

human-echolocation-in-action

Not only nature uses echolocation, also submarines and cars use it, like you see on the first picture. Submarines can use sonar to check the depth of the sea or to see other objects in the neighborhood. Because we use ultrasound in our thesis I find it more appropriate to talk about the echolocation in cars.

example of park assist

Now a days every car has park assistance on it,  like you see on this picture there is already a lot of evolution in this sector.

evolution in ultrasound sensors

For the ones that don’t know how it works, the sensor transmits a burst and then he times how long it takes to receive the echo/reflection of the burst. Then he uses this time difference in combination with the velocity of sound to calculate the distance.

Because the sensors are used outdoor, they need to be waterproof. For this reason they opt for enclosed sensors, that can both transmit and receive. These types are normally less sensitive, but more robust.

An important factor, they need to choose in the application is at what frequency to transmit. Transmitting at a high frequency, makes your signal more directive, what is better to prevent interaction with the ground. For the same reason asymmetric types are used, sensors that have a bigger horizontal range than they have vertical.

directivity of higher frequencies

 

 

 

I hope you see that nature inspired this invention, you could see it as an example of biomimicry.

See you next time.