Pressure
Sensors for the Delft Hyperloop braking system
Sensors for
measuring the pressure in the braking system and constantly recalculating
the braking distance
The goal of the team was to not only break the current Hyperloop
speed record of 467 kilometre per hour, but also to exceed half
the speed of sound. As you can imagine this is a tremendous engineering
challenge. Not only does the new pod needs to accelerate to top
speed but also brake to standstill again, all within the limited
distance of the test tube. This requires the team to constantly
work on the edge of what is technologically possible.
The pod has to be both fast and reliable, if it does not brake
in time a solid steel door will be the harsh reality for the
pod. Therefore, the braking system has to work 100% of the time,
there is zero margin for error in this critical subsystem. The
team has increased the reliability of the braking system by making
it fully redundant, but also by closely monitoring the system.
This is where Althen Sensors & Controls comes into play,
by providing very small, lightweight but still accurate pressure
sensors to be implemented in the braking system. The engineers
at Althen reviewed the needs for a sensor and came with a suggestion
of which they thought would work best. This turned out to be
the EB100 Miniature Pressure Sensor.
Miniature
Pressure Sensor
The EB100 Miniature Pressure Transducer is a very small sensor
which can still achieve a high accuracy. It was easy to incorporate
these sensors into the pneumatic system design of the Hyperloop
because they come with a metric M5 thread. This allowed the team
to easily screw the sensor in a connection piece that was attached
to the actuation system.
The sensors offered real time information about the pressure
within the pneumatic actuation system both during the final run
as well as during various leak tests. The high accuracy of the
sensors allowed the students to detect even the smallest leak
in the system, giving them the opportunity to remake a leaky
connection. Ultimately improving the overall performance of the
system.
Constant
pressure monitoring
The main reason to implement the Pressure sensors in the system
is to use the sensor data during the final run to constantly
monitor the pressure in the system. This way the navigational
algorithm can calculate the braking distance at any moment during
the run and adjust the point to brake accordingly. Therefore,
allowing the team to know the pod's braking distance at any time
during the run. Consequently, they can keep on accelerating for
as long as possible without accidentally hitting the steel door
at the other end of the tube or coming to a premature stop. These
kinds of small ingenious solutions allows the students to push
the limit even further and get the most out of their pod.
In short, the EB100 Miniature Pressure sensors allowed the students
to get the most out of their cutting-edge prototype. This was
achieved by measuring the pressure in the braking system and
constantly recalculating the braking distance using the data
from the pressure sensors. This makes it possible to keep accelerating
for as long as possible, which ultimately leads to reaching higher
speeds.
August 2019
