Final Rules, draft 2 (the final
draft)
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ME72: Engineering Design Laboratory
“FIRE and FLY”
Contest Description and Rules
Twenty-third Annual
Engineering Design Competition
1.
Introduction and Overview
The ME 72 Engineering Design Laboratory contest
involves the construction of:
(1)
a projectile or flying device that will rise from a
ground-level launcher, fly over a rope hurdle and then glide or be projected as
far as possible over clear ground. This device must carry a 50 gram payload (likely
to consist of a stack of metal washers). Each team will be provided with at least one such
payload.
(2)
a ground-level launching device that will help propel
the flying/projectile device on its way.
The final contest will take place at
As
described in more detail below, each team will have the potential ability to
control their flying/projectile device during the launching and air-borne
periods via a standard hobbyist remote control system. The control will be effected
by a fixed number of servo motors (2 medium and 2 small hobbyist servo motors),
battery packs, and a radio control receiver provided to each team.
During
each heat of the contest, at least one team member must be initially positioned
within a 3m x 3m box surrounding the launch area. The second team member can be initially
positioned at any location north of the rope hurdle, and between the lateral
contest boundaries. After the launch, both team members may move as may be
needed to monitor and control their device.
However, at no time can a team member, or any other person, have contact
with either the launching or flying components of their system until the
payload has come to rest. Moreover, no
team member, other person, or mechanical device may interfere with the movement or activities
of their human competitors during the setup and launch periods. Once both competing flying/projectile devices
are launched, your device may interfere with your competitor’s flight, as long
as there is no intent to cause structural damage to the competitor’s apparatus.
More
details about each aspect of the contest are given in the following sections.
2.
Energy and Actuation Sources
Every team will be provided with the same energy
sources and actuators, which will consist of
1)
Possible
potential energy used by devices within the launch area.
2)
A “small” battery
pack for the radio-controlled receiver and 4 hobbyist servo-motors (two “small”
and two “medium” sized hobbyist servo-motors).
3)
A large battery pack
and two D.C. servomotors that are compatible with the battery pack. Students will have a choice of two different
motors sizes (one “small” and one “large”).
Neither the large battery pack nor the D.C. servomotors can leave the
launch area from the time when the launching sequence is started until the time
when the payload comes to rest.
4)
Energy stored passively
in elastic members or in compressed materials (e.g., compressed air), as long
as these energy storage components are made from the prescribed contest materials
(see below), and with upper limits on how much energy can be stored in these
materials prior to the launching period.
5)
Note: it IS possible to use a propeller, or any
device that can be construed as a propeller, on the flying/projectile device,
with the constraint that the propeller is power only be stored mechanical
energy. I.e., it can not be powered by
the battery packs.
Each team will be have access to a standard model-airplane
radio-controller with 6 channels of control that can be used to remotely
control the motions of the hobbyist servos and the D.C. servo motors if desired
(through the use of an optional D.C. motor controller board). These radios and
receivers cannot be modified in any way; they must be used in the format as
they are provided to you. Similarly, the
battery packs provided can not be chemically or thermally altered.
3.
Launching the Contest Device
- Prior to each
launch, a contest team will be permitted a maximum set up time of 45
seconds (beginning with the instructors’ start command) to place their
device(s) within their launching zone.
The launching zone will consist of a simple flat slab including
eight ¼-20 tapped holes (see Figure 1).
Contestants may choose to (but are not required to) use these
mounting holes to fasten and stabilize their device during the launching
period.
- Two launching
pads will be available for each heat of the competition. They will be placed 3 meters apart,
symmetrically located about the midline of the competition zone. We are choosing to go with a
head-to-head heat competition format so that transient weather effects,
such as gusts, have minimal impact on contest performance.
- During the 45
second setup period, any of the provided actuators and battery packs can
not be used to store energy in the device.
Energy can be stored in the passive mechanical storage devices
during this period (as part of the set-up process), as long as the amount
of energy does not exceed the guidelines described elsewhere.
- At the end of
the 45 second setup period, the total contest entry system must be
statically stable, prior to launch activation. Moreover, at the end of this 45 second
placement period, each contest entry must fit within an imaginary
rectangular box that is 80cm x 80cm at the base, and 2m in height.
- Each system
must have a launching mechanism that can be simply activated by the press
of a switch, or an analogous device.
A switch will be provided in the contest material list. Prior to
activation of the launching switch, the launcher and all flying components
must be static and must be contained within the imaginary box described
above. Note that some teams may
choose to build a multi-stage flying device. All stages must fit within the imaginary
box at the end of the setup period.
Additionally, some of you may choose to craft different types of
flying devices which will work better or worse in different flying
conditions. This is permitted as
long as ALL devices do not contain more than the prescribed amount of
material, and ALL of the devices fit inside the launching box by the end
of the 45 second setup period.
- The launch
sequence may take up to 15 seconds.
Starting from the instant at which the launch switch is depressed
or activated, the contestants (or any other person) may have no further physical
contact with their device, except for purposes of dismantling their device
and removing it from the launch area.
However, internal mechanisms within the launching system may carry
out pre-designed tasks, and remote control of the launching system and
flying/projectile component(s) via the radio controller system and servo
motors is allowed during the launching period. Additionally, the battery packs and
motors can be used to store additional energy into either the launching or
flying mechanisms, as long as the energy storage process is completed by
the end of the 15 second launching interval.
- The
flying/projectile components of each contest entry must be clearly
designated. By the end of the 15
second period, the flying/projectile components must separate from the
launching apparatus. If no portion
of the design system has left the imaginary box by the end of the 15
second period, then that contest entry will be assigned a zero travel
distance, and a loss in that particular heat of the competition. Additionally, if the flying/projectile
device has not separated from the launching mechanism by the end of the 15
second launching period, a loss will be assigned in that heat of the
competition. That is, it is not
possible for the launching device to “crawl” out of the launch zone and
continue to supply energy to the launching device outside of the launch
zone for more than the 15 second launching interval.
- No external electrical,
chemical, or other mechanical connection can be
made to the launching/flying/projectile system during the setup or
launching phases. I.e., additional
sources of energy besides those in the approved contest material list can
be connected to your device during the setup or launching period. The
switch may only be connected to the battery packs, servo motors, and
controllers provided to each team.
- After
launching, the launching subsystem (and all of its parts which are clearly
not part of the flying/projectile component) must come to rest (before the
touch down of your flying/projectile device) within a circle of radius 130cm
whose center is the center of the imaginary box described above.
- After the end
of the launching period, flying, and touch down periods, all parts of the
system must be removed from the launching zone within 45 seconds.
Figure 1: Geometry
of the launching plate (not drawn to scale).
Each hole will be tapped to receive ¼ -20 threaded bolts.
4.
Landing
As described above, the goal is to have the
flying/projectile device reach the farthest possible southerly
configuration. Once the payload first
touches the ground, the payload will be allotted a 5 second settling
period. That is, the payload can
continue to roll, bounce, etc. for a period of up to 5 seconds. The total payload distance will be judged by
the payload location at the end of this 5 second period, or when the payload
comes to rest (in the opinion of one or more of the contest judges)—whichever
comes first.
During the 5 second settling period, the
flying/projectile system can not deploy or use external wheels, legs, or tracks
to further the movement of the payload.
5.
Summary of Key Contest Time Intervals
To summarize, the key time intervals in the contest
are:
- Setup Period. There is a 45 second
period to set up your entry in the launch zone. During this interval you can add passive
mechanical energy to your device up to the prescribed limits, and ensuring
that you only use allowed amounts of approved contest materials. Your
device(s) must reach a static equilibrium state by the end of the set-up
period. You may choose to launch
before the end of the 45 second period.
But, at the end of the 45 second period, a team must initiate the
launch sequence, or be assigned a loss for that heat.
- Launch Period. At the beginning of
the 15 second launch period, a team must activate their launch sequence via
an electrical switch or simple mechanism.
The clearly designated flying/projectile device must leave the
launch area and must separate from the launching system by the end of this
15 second period, or a loss will be assigned to the team.
- Flight Period. There is no limitation on the
duration of the flight period.
During this period, your flying/projectile component may interfere
non-destructively with your competitor’s device. You can also interact with your device
via the provided radio-control system.
However, you can not have any physical contact with your device
during this period.
- Landing/Settling Period. Once your flying/projectile device
first touches the ground (within the boundaries of the contest zone),
there will be a 5 second settling period.
Subject to the limitations described above, your payload can roll, tumble, etc. for up to 5 additional seconds. Your
travel distance will be determined by the payload location at the end of
this period. If you contest device
leaves the contest zone (e.g., by flying outside of the boundaries), then
your travel distance will be determine by the point at which the payload
first exits the contest boundaries.
6.
Evaluation
An overall winner will be determined in a
double elimination tournament. This is just like a single elimination
tournament, except a team must lose twice (instead of once) to be eliminated
from the competition. The double elimination format is chosen so as to
eliminate, as much as is humanly possible, the effects of transient weather
conditions (e.g., gusts), on overall contest performance. Your device must be robust enough to survive
repeated launches and landings. Basic
mechanical repairs to your device are allowed between competition heats. However, it is not possible to substitute
“spare” devices for the original device between contest rounds.
Pairing
of teams to compete will be chosen randomly at the start of each round of the
tournament. The team selected first in the random draw will go first in every
contest round. In each contest pairing, the team whose payload comes to rest
furthest south, according to the rules described above, will be declared the
winner of that heat. Again, recall that a flying/projectile device that lands
outside of the proscribed boundaries will have its southerly progress marked at
the point where the device first crosses the boundary. Each boundary will be staffed
by a line judge who will determine this point of exit. In all cases (particularly those requiring
judgment) the judges will decide the winner.
7.
Individual Work
While you will be working in teams of two, it
is expected that each individual will design and fabricate a significant
portion of each functional device. It is acknowledged that interaction between
teams in the class is highly beneficial. To that end, any conversations,
calculations, analyses, ideas and tests may be shared among the teams, but the
device design and fabrication must be an individual team effort. Note that this
collaboration policy does not extend to replicating others’ ideas. Occasionally
two teams will arrive independently at very similar solutions. Sometimes one team will see a great idea in another
team’s device, and finding no superior alternative, will want to incorporate
it. This duplication is permissible, however, not encouraged. In the past, some competitors have maintained
a high level of secrecy around their device, and blindly copying an idea or
strategy may be risky. In many respects,
you should treat this design project as similar to an ordinary homework set. It is permissible to collaborate with your
classmates and seek the advice of the instructor, TA’s, M.E. Shop staff, other
class participants, and other students.
However, the final product must be your own work. At the end of the
term, for grading purposes, you should indicate, where possible, the boundary
of the functional devices that you designed and fabricated, and in particular
to distinguish it from the parts of the device that your teammate designed and
fabricated. Furthermore, it is vital to document both your own work and the
contributions of others to your ideas by detailing the process of ideation,
design, and fabrication in your design notebook. If you are concerned about the acceptable
limits to collaboration, discuss the situation with the instructor(s). Do your own work, and as always, it is best
if you use your own ideas and concepts.
8. Additional Clarifications of the
Contest Rules
8.1.
Safety:
(a) Any device which is judged to have the
potential to cause injury to any participant or spectator will be disqualified.
(b) It is mandatory that safety glasses be worn
at all times while competing and testing. This requirement will be relaxed
during the final tournament. It is, of
course, also mandatory that safety glasses be worn at all times while in the
M.E. Shop.
8.2.
Energy Sources:
The energy used by each contestant’s device is
limited to the following:
(a) Electrical power
supplied by a “small” and a “large” battery pack that is provided to each
design team. Students will have access to an ample number of battery chargers
throughout the course and during the contest.
However, design teams may choose to purchase additional battery packs if
so desired in order to ensure maximum charge during the contest. But no more than one small and one large
battery pack may be used at any one time in the system design and deployment.
Additionally, batteries will be provided during the testing and contest period
for the hand-held radio control modules. The battery packs may not be modified
in any way at any time (mechanically, chemically, thermally, electrically,
etc.); they must be stored and operated at ambient temperature. Used radio
control module batteries must be recycled when depleted of electrical energy. A
container for this purpose will be available in the M.E. Shop.
(b) There will be limits
on the amount of mechanical energy that can be stored in your devices prior to
the initiation of the launch sequence. This energy may be obtained by deforming
any element or elements in the prescribed material list, or by compressing air
or other contest materials.. The limit of this type of
energy that can be stored in the launcher prior to the start of the launch
sequence will be 20.0 joules (approximately the amount of energy stored by
deforming six (6) medium sized rubber bands).
The limit on the passive energy that can be stored in the flying device prior
to the start of the launch sequence will be 10.0 joules (approximately the
amount of energy stored by deforming three (3) medium sized rubber bands). Testing
and analysis that demonstrates conclusively that these limits have been met
must be included in your design notebook, and approval of your analysis must be
indicated by the signature of the instructor.
During the 15 second launch period, you may use potential energy or
energy from the large battery pack to store additional energy in the launcher
or flyer/projectile.
8.3.
Contest Materials:
Each contestant’s device(s) must be constructed
entirely from materials supplied in the contest materials list (which can be
found in a separate document on the course website). No other materials (either from the M.E. Shop, or elsewhere) can be used or substituted, with exceptions
described immediately below. In addition
to the standard material list each contestant may also use:
(a) A maximum of 113.4
grams [4.0 ounces] (dry cured mass) of RTV silicone casting compound. This
casting compound is supplied in bulk. See the Staff in the M.E. Shop if you
wish to cast one or more parts out of silicone. The intended purpose of this
casting compound is for sealing, however, it may be used for molding
components.
(b) A maximum of 3 meters
[118.1 inches] of 2.38 mm [3/32 inch] diameter “Orange-Go” belt material may be
used. The M.E. Shop staff can show you how to join the ends of a segment of
this material into a continuous belt. The intended purpose of the “Orange-Go”
is for power transmission as a belt, however, it may find
other (non-decorative) purposes.
(c) Glues and epoxies that
are used only for bonding. Additionally,
a total of 2 ounces of glue or epoxy may be used (in combination with other
materials on the approved contest material list) to create a composite material,
with glue as the matrix.
(d) Paint or Shellac may be
used to insulate strands of wire, if desired.
Similarly, up to one meter of black electrical tape may also be used for
purposes of electrical insulation. Such
tape may not be used for structural purposes.
(e) Light machine oil,
mineral oil, or vegetable oil (depending on the competitor’s preference) can be
used SPARINGLY to lubricate moving parts.
(f) Non-functional
decorations (such as decals and paint) can be used, and are encouraged.
Each contestant’s final device(s) must be able
to have been fabricated from the materials or parts contained in the parts
list, with the exceptions described above.
During the construction and testing of your devices, you may use more
total materials than are prescribed on the approved material list, but the
final device9s) can not use any more material than is specified by this list. Some of you may choose to build different
types of flying/projectile components so that you can select a flyer optimized
for the weather conditions on contest day.
This is permitted. However, the
total ensemble of your devices must be built within the limitations of the
prescribed contest materials.
Replacement supplies and materials are
available on a limited basis. If you damage something, or cut it up and then
want to do something different with it, see the M.E. Shop staff or one of the
TA’s. We will do our best to supply replacements, but we cannot guarantee
unlimited supplies of all materials. We also cannot guarantee that replacements
will be identical to the original. You may want to check availability of
replacements prior to conducting a risky experiment with a rare part. In particular, each team will only be
supplied with only one set of hobbyist motors and radio control system. If these devices are damaged, it is up to the
students to replace them. Sources for
these items can be found in the resources
section of the class web site.
Contestants are responsible for providing their
own glues and epoxies. Some glues and epoxies will be available in the M.E.
Shop, but to ensure an un-interrupted supply, go to a (hardware) store, and buy
your own.
The approved contest materials may be
mechanically modified in any way (disassembled, cut, machined, turned, ground,
etc.). However, they may not be altered chemically (except locally by glues,
for bonding, or paint for decoration or insulation purposes).
Soldering and brazing are permitted, though not
particularly encourage. Welding is not permitted.
8.4.
Contest Device:
(a)
Size:
i. Prior to the start of the tournament, each
team must demonstrate to the course instructors that, in its immediate pre-launch
configuration, all the devices will fit into an imaginary 80 x 80 x 200 cm box.
A measuring device will be available in
the M.E. Shop to check this constraint.
ii. At the start of the
each contest (t=0), each team’s combined devices must be positioned within the proscribed
launch area as described above.
iii. At the end of the flying
period, as described above, all parts of the launching system must come to rest
within a circle of 130 cm radius, centered on the launch pad.
(b)
Mass: Each team’s total design
must not weigh more than 7.5 kg, including the mass of the supplied actuators
and battery packs (but not including the hand-held radio control module or the
payload).
(c)
Finalized Design. After each device’s
initial flight during the final contest, no major design changes or
construction will be allowed (it will not be possible to substitute an
alternative flying/projectile or launching device, even though such
alternatives satisfy the
limitations on contest materials, size, and mass). Crashes of the
flying devices are inevitable and repairs to these devices using materials from
the approved materials list will be permitted provided that, in the judges’
opinion, they involve no major design changes to the initial device. However, changes
to flight parameters such as angles of incidence or rebalancing of the flying
device will not only be permitted but are encouraged. Any such minor corrections to the device must
respect the rules on size, mass, and materials described elsewhere.
(d)
Interaction with the device. Other than radio control through the
servomotors and the radio transmitter, and through the activation of the
launching switch or device, no manipulation of, or interaction with, a device
will be allowed while it is competing (i.e., after the start of the launching
period, and up to the end of the 5 second payload settling time).
(f)
Team Number. Each team will be assigned a 2-digit integer
number to identify their team and their contest device(s). Each major component of each team’s design
must carry an identifying team number.
Note that Number 00 is reserved for the contest placebo. While not
required, teams are also encouraged to choose a team name.
8.5. Device Deployment Rules:
(a) The contest arena includes all air-space
above the ground, and within the lateral contest boundaries (as described in
more detail below).
(b) Each device must be designed to functionally
interact with nothing other than the launch area, the
air, the ground, and the remote control system.
Bouncing off buildings and other exotic strategies that deploy the
buildings, trees, or other infrastructure in the vicinity of the contest are not
allowed.
(c) At the start, before the launch switch is
activated, all portions of each team’s devices must rest entirely within that
team’s start volume, as defined by the imaginary 80 cm x 80 cm x 200 cm box described
above.
(d) You may not interfere in any way with the
conduct of any opponent’s device during the set-up and launch period. However, you are allowed to interfere with an
opponent’s device once your device and the opponent’s flying/projectile devices
are both in the air. You may not interact
with, modify, or intentionally block the radio control signals from the
opposing teams’ transmitter. Each team’s
transmitter/receiver pair will have a different frequency to minimize
interference effects.
(e) Intentional damage to any receiver/control
module will result in disqualification. It is your responsibility to avoid
damage to the receiver/control module during the design, fabrication, testing,
and contest phases. Competitors should make efforts in the design and
fabrication of their devices to avoid placement of the receiver/control module
in a vulnerable position.
8.6.
Contest Arena:
(a) The final contest will take place in the Court of
Man. The launchers can be placed at any location within a defined launch area,
which will be close to the front of Beckman Auditorium. The rope hurdle will be
strung between the Beckman Behavioral Biology building and Baxter Hall. It will
not be horizontal but will sag such that its minimum elevation of 5 meters will
occur near the mid-point between the two buildings. The rope hurdle will be placed 30 meters
south from the launch area. The rope
will be oriented in as nearly an east-west direction as is possible.
(b) Boundary lines that are approximately north/south will
be marked on each side of the Court of Man and will extend into the space
between Dabney Hall and the Parsons-Gates building. Note that the boundary
lines may not necessarily be “straight” at all locations. The boundaries are implied to extend vertically
upward from these lines placed on the ground. As stated earlier, the final
resting place that will determine the winner of each contest will be the southerly
location of the payload, provided it comes to rest inside the boundary lines.
If the payload ends up outside one of the boundary lines then the final resting
place will be the location where the payload first crosses the boundary, as
judged by the line judge responsible for that boundary. If the payload exits
the boundaries, and the falls back into the boundaries, the first exit point
will be define the travel distance
Additional points (in the form of a 50 meter distance added to a team’s
flight distance) will be awarded to entries that land in a circle of 2m radius
placed in front of Parson’s Gates.
(c) Prior to the final contest, participants
are encouraged to use the Court of Man for their practice flights. However no
overhead rope, no launch area, and no boundary lines will necessarily be
provided prior to the contest day for such practices.
(d) Any intentional damage to Caltech buildings,
grounds, or other infrastructure, other than that within the launch area, will
result in disqualification.
8.7.
Time:
(a) During the tournament, contestants will be
called up “On-Deck” while the preceding flight is taking place and should be
prepared to begin their set-up period of 45 seconds as soon as the preceding
flight is concluded and the preceding contestants clear the launching zone of
their entry.
(b) Exceeding the 45 second set-up time will
result in a loss in that round for the offending team.
(c) After the end of the set-up time, no action
of a team’s device(s) is permitted prior to the initiation of the launch switch. I.e., during the setup time, it is not
permissible for motors to be working to store energy. Only those movements of the team’s mechanisms
that are needed to place the devices in the launch region, to store passive
mechanical energy (up to the contest limits), and to bring the devices to rest
by the end of the 45 second set-up period are allowed.
(d) During the 15 second launch period, which
must be initiated by an electrical switch or analogously simple mechanism, any
movement of the mechanism (as long as it is unaided by direct human contact) is
allowed. The flying/projectile portion
of the device must leave the launch region and must clearly separate from the
launching system by the end of the 15 seconds launch period. If no portion of the contestant’s device(s)
leaves the launch region, if the flying/projectile device does not separate
from its launcher after 15 seconds, a flight distance of zero meters and a loss
will be assigned to the team for that round of the competition.
(e) A maximum pick-up time of 45 seconds (commencing
from the end of the landing period) will be allowed for removing all of your
device(s) from the arena after a flight.
8.8.
Tournament:
(a) Teams will compete in a double-elimination
tournament to determine the wining team.
(b) Teams will be chosen at random (during the
tournament) to compete against each other in each round.
(c) If,
after any flight in which the flying device fails to fly over the suspended rope,
the payload within the flying device does not end up outside the launch area, that
effort will be counted as a loss irrespective of the performance of the
competitor.
(d) If the flying device of neither team
manages to fly over the suspended rope then the team whose flying device ends
up furthest south will be declared the winner (the rules pertaining to devices
that end up outside the north-south boundaries will be as described previously)
provided the payload of that device ends up outside the launch area.
(e) If only one of the two flying/projectile
devices manages to fly over the suspended rope, then that team will be declared
the winner irrespective of the location of its final resting place.
(f) During a contest, if your team gets a bye,
or your opponent(s) do not show, your team must be prepared to compete against
a placebo device.
9.
Weather
Since
the outdoor contest will be held in March, there is a possibility that rain may
cause disruption of the event. It is likely that we will proceed with the
contest in the event of light or occasional rain showers. Otherwise the event may be moved to the gym
which is available on that afternoon. However, some of the parameters of the
contest may have to be changed to fit within the confines of the gym. Alternatively, the contest may be postponed.