The main objective of this project was to design
and create a robot capable of delivering a beverage to a
specific location, when needed. To achieve this goal, two teams
were combined and worked together into building an acquiring and
delivering robot as well as a dispensing and replenishing
station.
Part 1
Acquiring and Delivering
François-Xavier Bonneville, Pierre-Alexandre Poirier, Martin
Villeneuve, Mechanical Engineering, University of Ottawa
Objective
Our main objective was to build a
robot that would automatically deliver beverages to the user,
with minimal intervention from the latter. In order to do so,
we opted for a vehicle design. In order for the robot to
accurately venture from the base station (built by team B10) to
the user (at a couch, for example), we decided to make a line
following robot; therefore, the user could set a line of
electrical tape as they wished to control the robot’s path. We
also wanted to eliminate the need for programming in an attempt
to make the project purely electronic, where the actuators are
directly driven by signals picked up by the sensors. We also
wanted to solder our circuit into a single, compact circuit to
increase reliability.
Related Work
We performed extensive research early
in the design stage to find was to eliminate the use of a
microcontroller (like an ATMEGA chip, for example) in our
circuit, thus avoiding unnecessary programming. We came across
the following website and used the displayed circuit as a basic
starting point for ours:
However, significant changes were
made as shown on our circuit diagram.
Circuit Design and Component List
Please refer to the power point
presentation for the circuit diagram of our project, as well as
a list of components used during our project. Before building
our project, we used Multisim to simulate a few sections of our
circuit: the sensors and the digital part (logic gates with
4066). Both worked and behaved as expected, giving us the
go-ahead to start building.
Testing
Project testing was quite simple.
After having success using Multisim, we constructed our circuit
on multiple breadboards until we reached satisfactory behavior.
All changes made during this phase were updated on revision 1.1
of our circuit. Next we transferred our circuit little by
little to a copper circuit board and soldered it all together,
always testing for proper functionality as we worked. This
eased troubleshooting since problems would always be caused by
something we changed since the last successful test. Final
testing took place calibrating the potentiometers and
integrating our project with team B10s.
Part 2
Dispensing and Replenishing
Jonathan
Armstrong, Justine Dagenais and Antoine Schryer,
Mechanical Engineering, University of Ottawa
Objectiv
To load the robot with a
beverage, we needed to build an automated dispensing station.
That station had be able to sense the need for a new beverage
before dispensing it. Our goal was to build a weight-sensing
coaster that would be designed to trigger that station when the
beverage was empty.
Circuit design and component list
The coaster consists of a force-varying resistor
that determines when the beverage is empty. It is connected to
two comparators to make sure that no beverage is dispensed if
there is no bottle on the coaster. Once the beverage is empty,
the current goes through a delay circuit preventing any signal
to be sent by simple weight fluctuations caused by the
consumer. The weight-sensor is connected to a radio device that
gets activated when the criteria listed above are met. This
device generates a radio frequency that will be received by the
dispensing station.
Once the radio device, mounted on the dispensing
station, receives the signal from the coaster, it triggers the
motor allowing a beverage to be loaded onto the robot. The
dispensing mechanism consists of a motor with a gearbox
connected to a lever. This lever is attached to a “camshaft”
which allows only one beverage to be dispensed when the motor is
turned on. Once the robot reaches its destination and a new
beverage is put on the coaster, the motor will turn off letting
the “camshaft” return in its original position with the help of
a spring. The next beverage is then ready to be dispensed.
For additional information on
the components and to view the circuit design, please refer to
the power point presentation.
Conclusion
As a whole, we are very proud of our
project, since we were able to build something functional and
useful from only very basic components, without using
programming or pre-manufactured PCBs, for example. We learned
many interesting things about electronics this semester and this
project was a good way to tie it all together.
