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.