Beginner, broad project

Hello all, I am new to these forums and have zero experience with Arduino. I am a mech. engineering student and was assigned the task of creating an experiment that utilizes sensors of my choosing, using Arduino for data collection. The final result will be delivering a 5 minute presentation to my class and professors about the experiment, goals and equipment setup.

Here's the experimental question I will answer:

In the case of a roller coaster launched via Linear Synchronous Motor(s) (LSM), at what ride train weight will the motor pull more power than it is rated for and thus not reach its target velocity? The purpose is to determine at what point the motor would need to be upgraded for a more powerful option.

Project details:
This assignment is entirely theoretical, the experiment will not be performed, it is purely a conceptual project to get us familiar with Arduino. Also, we are not required to write any code, only a general guide for how the program would work to relay sensor data using Arduino back to the computer for analysis. That said, I have determined I will need to use a velocimeter (probably laser), accelerometer, scale (to measure weight of water or sand added to ride train for each test), and a power meter. I have searched digikey for a sensor capable of measuring peak power during the launches and haven't had much luck aside from a few standalone units that cost upward of $2000. The LSM for these tests pulls a peak of approx. 6000Amps during the 4 second launch to 45 mph (I am using the Lightning Rod at Dollywood for the experiment). The motor is rated at approx 1500hp. Since this experiment will not be performed, price of needed equipment doesn't matter, but any suggestions for a clamp meter that could work or otherwise would be appreciated. My professor said a standalone digital meter could be used, but would prefer all sensors use Arduino.

My primary question is this: What sensors would you recommend for this, and would it even be possible to do this with only one Arduino Uno board?

Considerations:
The acclerometer and velocimeter would need to be mounted inside the ride train and data sent to pc via wifi, or stored on a jump drive to be recovered after each trial. The power meter would be connected to the LSM which is fixed to the ride track. I'm thinking at least three boards would be needed (one for the accelerometer and velocimeter in the moving ride train, one for the scales, and one for the power meter). I hope I included enough information to get some suggestions, I know this is not a simple experiment, especially for a beginner, but considering that the project is general, and that I don't need to write any working programs to get this running, I thought it would be a fun concept problem, as it is in my area of interest. Thanks in advance for your input!

Regards,
pianoman

A whole new area of study for me, but I see you can ONLY measure the power to the magnets at the primary source because the voltage/current is rapidly switching polarity as the magnets on the ride pass by. Then the current switching begins with the next coil in the track and the last coil under the ride is disabled. There may be as many active coils moving the ride along as there are magnets under the ride. But there will have to be many more coils in the track that are not yet active, or ones that were active previously.

This will make the power reading much simpler and will include the losses in the controllers and the magnetic coils.

Paul

Yes, an excellent observation. I am no expert on Linear Synchronous Motors, but I have done a lot of research regarding their basic functionality for this project. I can't confirm this but I believe the Lightning Rod's current switching is controlled using a dedicated computer that monitors the train position along the launch section. The most difficult part of this project for me, has been devising a way to measure peak power during launch, which is also the most important piece of data for determining the point at which the motor is being over-driven. Using a velocity and acceleration vs time graph, coupled with good peak power readings it would be easy to find the weight at which performance begins to drop off considerably.

Also for any fellow nerds who are interested in LSM's here's an interesting read :smiley: :

Let me write it a different way. The peak power from the three-phase power going to the DC power sources will peak at the same time as the peak power driving the carriage.

Paul

I came across a post from someone who claimed to work on the project that stated they are utilizing a new ultra-capacitor array (rather than a flywheel) tied into the local utility and regenerative eddy current braking to charge the bank and feed the motor. Perhaps a clamp meter placed in-line between the capacitor bank and motor could be used to take this measurement? (My electrical knowledge is limited, as I'm a mechanical)

Make your self a drawing of how many individual magnets you have attached to the under side of the carriage. Then make a drawing of how many individual electro magnets you will need to move the carriage the distance to the top of the first hill.

That is how many coils will need to be energized and switch in polarity to move the carriage along. That is how many devices you will need to monitor for power usage if you monitor the power to each coil.

That is why I say to monitor the primary power to the whole machine.

Paul