Libelium World:

Publish in: Articles

Measuring the inertial forces in two of the most savage roller coasters of the world with wireless sensors

Measuring the inertial forces in two of the most savage roller coasters of the world with wireless sensors

September 13th, 2012 - Alberto Bielsa

PortAventura is one of the biggest theme parks in Europe and it offers two of the most impressive roller coasters of the world such as Dragon Khan and Shambhala. Have you ever asked how many 'g' are you suffering when you ride a roller coaster? Libelium wanted to use this hard scenario in order to test the accelerometer included in our sensor platform Waspmote, as one of the important applications which our clients perform is related to the location and motion sensing of mobile vehicles such as cars, trains and even airplanes. In this case we wanted to measure the inertial force a person suffers when riding a roller coaster.

 

 

 

 

Technology

 

Waspmote is a wireless sensor node with one of the lowest power consumption within the market (0,7uA). It is capable of measuring from over 50 different sensors (from gases to agriculture sensors) and transmitting the data over different wireless protocols such as ZigBee, GPRS/3G, WiFi or RFID/NFC.

Fig. 1.- Waspmote

 

Moreover, Waspmote integrates a powerful and accurate accelerometer to measure inertial forces up to +-8g. Combining the features of the accelerometer with SD card's, Waspmote is able to register acceleration on 3 axis (X, Y, Z) with output data rates up to 1kHz.

 

Real test

 

One sunny summer day was chosen to make the test at PortAventura. We placed a Waspmote inside a protection box and programmed it to measure the acceleration on 3 axis, storing the output in the SD card. At the end of each roller coaster test Waspmote sent the data to our Smartphone using the Wifi module, one of the wireless interfaces available for Waspmote among other such as 3G/GPRS, Bluetooth and ZigBee.

 

Fig. 2.- Waspmote in Port Aventura

 

PortAventura has a lot of different attractions though we selected its 2 most savage roller coasters: Dragon Khan and Shambhala. Do you want to see the results of our tests? Keep reading below!

 

Fig. 3.- Dragon Khan and Shambhala roller coasters

 

Dragon Khan
The Dragon Khan ride of PortAventura consists of an impressive downhill drop of more than 45m and 8 inversions, defying the bravest on a journey of 110km/h. During its 1:45 journey, a person suffers inertial forces over 4g as you can see in the graphic below.

 

Fig. 4.- Inertial force at Dragon Khan

 

Just to explain a little about the results, let's divide them in 3 groups:

  • Flat zone at the beginning: sensor is going up during the first climb. It is moving at constant speed so summing all axis gives around 1g. 
  • Acceleration around 0g: when the roller coaster is falling, we are experiencing a free fall sensation so this is why the sensor registers around 0g.
  • Pikes on different axis: after each fall our body slows down and changes of direction, so we are experiencing different acceleration on different axis, registering pikes over 4g on axis Z.

 

As you can see, during the journey at Dragon Khan, we are experiencing some 'weightlessness' moments (0g acceleration) as well as some pikes above 4g, what means a hard journey for our body!

 

Shambhala
Shambhala has a run over 1650 meters, being the highest roller coaster in Europe (76m), having the longest fall in Europe (78m) and being the fastest within its type in Europe (134Km/h).

There are 5 camel-backs (elevations during the course), the lowest of which has a height equivalent to a 7-store building. On each of these camel-backs you experience the effect known as air time, losing contact with the seat.

 

Fig. 5.- Inertial force at Shambhala

 

Just to explain a little about the results, let's divide them in 3 groups:

  • Flat zone at the beginning: sensor is going up during the first climb. It is moving at constant speed so summing all axis gives around 1g. 
  • Acceleration around 0g: when the roller coaster is falling, we are experiencing a free fall sensation so this is why the sensor registers around 0g.
  • Pikes on different axis: after each fall our body slows down and changes of direction, so we are experiencing different acceleration on different axis, registering pikes up to 5g on axis Z.

 

As you can see, during the journey at Shambhala, we are experiencing some 'weightlessness' moments (0g acceleration) as well as some pikes up to 4g, what means a rough ride for our body!

 

Conclusion

 

Waspmote has proved to be the perfect platform to measure inertial forces in moving objects and vehicles. In fact, it can be used to study the behaviour of all kind of transportation mediums such as terrestrial vehicles, trains, ships or even planes.

 

Moreover, GPS module may be used to register real-time location since these data can be sent using different radios such as 3G/GPRS anywhere and anytime. Furthermore, the use of some sensors (Waspmote platform has already integrated over 50 different sensors) allows to monitor real-time state of transportation mediums in logistics (refrigerated trucks, ships, containers, etc.).

 

If you are interested in Waspmote, we will be glad to help you to design your system. You can request for a quotation of Waspmote here.

 

 

Quick Publish: