Elevator Controller - Inside...
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Elevator Controller BRANDON AHO AND JINBO ZHU
Transcript of Elevator Controller - Inside...
Elevator Controller BRANDON AHO AND JINBO ZHU
What are we modeling?
What are our simplifications?
Small model with robotics components
No special operation such as special buttons, weight compensation,
vibrations in the system, safety measures, precise elevation etc.
2 floors
No doors
This is a demonstration of the controller’s basic operation – not a
simulation of an actual elevator.
What are we using to model it?
HCS12 Microcontroller on SSMI Board
Breadboard
Resistors x4
Indicator Switches x2
User Switches x2
DC Stepper Motor
DC Stepper Motor Controller
Actobotics Equipment
What are we using to model it?
HCS12 Microcontroller
Breadboard
Resistors x4
User Switches x2
DC Stepper Motor Controller
What are we using to model it?
DC Stepper Motor
Indicator Switch x2
(microswitch)
Actobotics equipment
(C channel, sprockets,
chain, various fasteners, shaft)
2 objects of equal
mass to simulate
elevator and
counterweight
What are we using to model it?
• Normally open contact.
• Normally closed contact.
• Common pin is connected to
HCS12 input pin.
• Grounded via resistor.
• A complete depression of the
lever arm is suggested to
ensure a signal is sent.
How does it all work together?
The microcontroller controls the elevator just how you would expect
it to.
Press a button, no other user buttons will function again until the
elevator reaches its destination.
Controller knows if a floor has been reached through input from one
of two indicator microswitches.
How does it all work together?
Rough Timing Diagram
pseudocode
How the hardware works
Stepper motor has four wires & poles: A, A’, B, B’
Stepper motor controller handles the clockwise/ counter clockwise
rotation of the stepper motor
Pulse the “step” pin to rotate the motor one position. This advances the
DC stepper motor pins in the correct fashion – it is hard-coded onto the
motor controller
Direction pin can be logic 1 or 0.
Motor receives +9V from the AC to DC power source
What special functions of the
HCS12 are we implementing?
Real-Time Interrupt System Output Compare
Sends a pulse from the HCS12 to the motor controller at varying
intervals, giving us an acceleration profile similar to what one would
expect from a real world elevator.
Loops and logic structures to handle our four states: stationary at top, stationary at bottom, moving up, and moving down.
As one might expect, the user buttons will not do anything until the
previous button’s corresponding floor has been reached.
The microswitches only cause a state change when the elevator is
already in motion.
Our conclusions
The HCS12 in conjunction with DC stepper motor & controller work
for this small application.
Not enough pins for a full-scale building with potentially more than a
hundred floors.
No accounting for weight changes in the elevator, this factor is
removed by using a stepper motor.
Not as advanced as other elevator controllers which are built with
other features which can control the lighting, doors, sounds, music,
entertainment/news/weather/directory consoles, and even video
communications/ surveillance of modern elevator systems.
Your questions
