ECE516 Lab09: Moveillance: Motary Veillance (Sensing-on-the-move)

In this lab you will learn the fundamentals of motary sensing.

Moveillance (motational sensing) is sensing in a moving frame-of-reference, e.g. as is typical of motorized frames of references.

Terminology: "Mo" is a common abbreviation for "Motor". Compare also with "Motown" ("Motor Town", i.e. slang for Detroit, also known as "Motor City"), and "Motel" ("Motor Hotel", i.e. a hotel that is designed for motorists by making it easy for each person to park their car right beside the door to their hotel room).

Industrial and commercial importance of moveillance:

There exist well-defined standards for automotive equipment, but there is a need for well-defined standards and certification for automotive sensors and motors, e.g. for efficacy of sensors and motors in industries like autonomous vehicles.

This year (2019), we have secured $200,000 in funds to hire students to work on sensing, meta-sensing, and moveillance for autonomous vehicles (funded by Ford Motor Company of Canada).

Tasks:

For this lab, you have been given a 3-phase electric motor. Connect one or more LEDs to wires coming from the motor. Spin the shaft with your fingers, and observe what happens on the LEDs. Explain your findings:
1/10 marks Bonus marks for additional insight, e.g. connect three or six LEDs in the right way to see all three phases, both positive and negative lobes. Can you easily see how many lobes the motor has? And therefore, can you easily discern how many poles the motor has?

Try connecting your SWIM to the motor. You can use the wiring diagram shown below, if you like, or you can come up with your own approach:

The Beginner-level wiring simply uses two diodes to set the voltages on the comparator ladder network.

The Intermediate-level wiring diagram gives you some additional control, by providing a gain adjustment potentiometer. As you spin the shaft more quickly, the SWIM will bob up-and-down faster, as it displays a higher frequency of AC (Alternating Current). Try using a long wire to connect the motor to your SWIM, and have someone spin the shaft of the motor while you wave the SWIM back-and-forth and photograph the SWIM:
2/10 marks

What do you notice about the waveform. In particular, comment on the amplitude of the waveform as a function of shaft speed (i.e. frequency)?
1/10 marks

As the world turns:

(2nd part of the lab: change in coordinate frame-of-reference)

Three-phase motors work by way of a rotating magnetic field that turns the shaft, by way of permanent magnets affixed to the shaft. In this (2nd) part of the lab you will fixture the shaft to some object in the room, so that the motor can spin the whole room, and therefore, by the fact that the room is connected to the building, and the building to the earth, you will spin the whole building, and the whole earth, and in fact the whole universe. Since you are standing on the earth (or on a floor who's foundation is upon the earth), the motor will also spin you. Since you will be spun with the motor's shaft, you will be in the same coordinate frame-of-reference as the motor's shaft, is if you were an insect standing on the shaft of the motor and spinning with the shaft.

Relativity of the Rotom:

There is no preferred inertial frame-of-reference, so it is equally right to say that the motor's shaft spins the whole universe, as it is to say that the body of the motor (the part that normally stays still) is being spun, and the shaft and rotor of the motor (the part that normally spins) is being held still.

When the motor is used this way (typically for teaching or research purposes), we call it a "rotom" ("motor" spelled backwards).

Create a surface for the rotom (i.e. a planar suface that is an extension of the body of the motor), upon which you can mount LEDs. A suitable plane is one that is automorphic under rotation of the motor's shaft. Mount one or more LEDs on that planar surface and spin it (i.e. allow it to spin the universe and therefore allow it to spin you around it).

Witness, identify, and photograph the lobes of the motor:
1/10 marks

Bonus marks for something really fun and cool and insightful!

How many lobes does the motor have, and thus, also, how many poles does the motor have?
1/10 marks

SWIMotor

Carefully attach your SWIM to the planar surface. Spin your SWIM. To do this, you will likely need to carefully balance a counterweight across from your SWIM. A good thing to use for the counterweight is the battery that powers the SWIM.
1/10 marks for getting your SWIM to spin around nicely and smoothly, even if it isn't working!

1/10 marks for getting your SWIM to spin around nicely and reveal the ___lobe pattern.

Photograph the ___lobe pattern:
2/10 marks

For some examples of "motography", see http://wearcam.org/SWIMotor.htm

Bonus marks: Machine Learning

Connect the motor to an analog-to-digital converter. You can use three instances of the Intermediate-level circuit to convert the motor's balanced delta configuration to something you can read into three single-ended inputs. Devise a machine learning algorithm that estimates the rotational speed of the motor. Your algorithm must distinguish negative versus positive frequencies.

Implement the ACT (Adaptive Chirplet Transform) LEM (Logon Expectation Maximization) neural network. Connect the motor to the neural network. What can be learned about the electric machine?

Connect multiple motors to a common bus. Spin them at various frequencies. Use ACT + LEM to learn patterns and identify what is happening.

Explain how ACT + LEM can be used to monitor powerlines and estimate how many different motors there are in a building, for example. Can you lock in on specific motational electric signals? Can you identify and locate defective motors?

Readings:

Motography contest:

Bonus marks: 3 marks for first prize, 2 marks for 2nd prize, and 1 mark for 3rd prize. Email photos to me, and Cc. to Diego and Adan.

SWIMulator:

You might find the SWIMulator (SWIM simulator) of use: link.