The RoboGames Shooting Gallery competition is a challenging competition in design and
implementation of an autonomous robot that is able to shoot targets without human assistance.
For this project, a robot to meet all the requirements of the competition will be designed and built
within the time constraints of the project. This will be accomplished by utilizing optical sensors for
targeting and a software piece that will interpret the optical images and determine how to position
a firing mechanism to knock down the targets.
The hardware of the Autonomous Shooting Gallery Robot will be powered
by 120 V AC from a standard wall outlet. This will be attached to the main
system power supply that will distribute power to all subsystems. A poweron switch will allow enabling and disabling of the power supply. A personal
computer (PC), using its own source of power through an AC adapter, will
be connected to a camera by Universal Serial Bus (USB) and connected to
the microcontroller communicating by RS-232. Software running on the PC
will capture images from the camera. A laser emitter mounted to the firing
mechanism will show the current aiming position and will be used for
feedback within the software. The captured images will then be processed
by the software. The software will communicate to the microprocessor,
which will then output signals for motor movement and to determine when
to trigger. Two stepper motors will receive their own set of signals to
control movement. These signals will be used for firing mechanism control,
where sufficient current will be supplied to the stepper motors and the
firing mechanism by using transistors to sink current. There will be a light
indicating whether the firing mechanism can be actively powered at that
moment in time. A firing mechanism power removal switch will disable the
ability to power the firing mechanism.
Key features:
•  Targeting system is autonomous
•  Targeting system is easy to use
•  Targeting system is able to detect and prioritize white targets and ignore black targets
•  Targeting system is easily and quickly calibrated
•  Targeting system will ensure the targets are accurately and effectively removed from sight
•  Robot has safety features to allow it to be quickly disabled
•  The firing mechanism utilizes safe projectiles
•  Robot has a power indicator to clearly indicate it is powered
•  The total project is lightweight
Marketing
Requirements
Engineering Requirements
Justification
1, 5
Must have a LED which will indicate the system has power and
a switch which will remove power from the gun
This is a safety precaution for any individual
who is around the robot.
6, 7
Must be able to recognize and prioritize targets using a camera
and an image recognition algorithm
The competition requires the use of only
hardware and software to shoot targets
8
Must require no human interaction after starting operations
9
Must weigh no more than 100 lbs.
The competition requires a completely
autonomous device
The lighter it is the easier it is to transport
4
Must fire a plastic Airsoft pellet
The gun must fire a non-lethal projectile
2
Must be able to accurately aim given that the targets are 10’
away in a 5’x 5’ enclosure
Must be able to aim at targets which range from ½” diameter to
3” diameter in size
Must be powered by 120V AC wall outlet
These are the requirements for the targets in
the competition
These are the target sizes as dictated by the
competition
It is a competition requirement that the power
for the device will not be flammable or solar.
Must be able to determine the airsoft gun is aiming
directly at a white target and automatically make
adjustments accordingly.
The system needs to self-correcting in
case the original movement calculation
was incorrect.
2
3
2, 6, 8
1.  The system should have a clearly visible light indicating it is on.
2.  The system should have a targeting mechanism that can position a firing mechanism to aim with a certain accuracy
within the bounds of a specific dimension.
3.  The system should have a power system that distributes power between subsystems.
4.  The system should fire a safe projectile.
5.  The system should be equipped with a safety override switch to prevent undesired operation.
6.  The system should be able to quickly recognize white targets and avoid hitting black targets.
7.  The system should be able to prioritize targets based on the distance the gun will need to travel to shoot the target
8.  The system should be automatic and operate without assistance from the operators.
9.  The system should be as light as possible.
The inputs satisfy the requirement for the system to operate and allow the software
the ability to locate and prioritize targets. This can all be done very quickly in software on a
personal computer.
Beginning with the Image Enhancement and Processing block, the software will take
the optical image from the optical sensor and process it in a variety of ways to gather the
necessary information from the image. It will first start out by enhancing and filtering the
image to make the further processing more efficient and reliable. Once this is complete, the
software will be able to use color filters, shape filters, and other necessary filters to locate
and identify both targets and the firing mechanism target coordinate. A framework currently
being researched to ease this processing is the AForge.NET framework for the C#
programming language.
The Target Identification the target layout is sent, at which point the target
identification will assign identifiers to each target for future tracking. The targets will each
track their location, approximate size, and whether or not it is still on the board. These targets
will then be sent (as software objects) into the next block.
In the next block, the targets will be prioritized and iterated through. For prioritization,
an algorithm will be determined for use to allow the firing mechanism the least amount of
movement to hit all the targets. This logic will determine the current target of interest and
send the necessary location data into the Firing Mechanism Motion Control block.
The Firing Mechanism Motion Control block will communicate with the hardware
(microcontroller), provided that it is powered and able to handle commands, in order to get
the firing mechanism to line up with the target. Another input into this block is the firing
mechanism target coordinate, which will be a location that is detected in the image. This firing
mechanism target coordinate will not be used constantly for the location of the firing
mechanism; it will only be used for the final step before determining if the firing mechanism is
ready to fire (if it is indeed on the target).
Once the software determines that firing mechanism is in the proper location, it will
pass the control onto the firing control, which will communicate with the hardware
(microcontroller) to allow the firing mechanism to fire at the target. As long as the target has
successfully been removed (after a limited number of attempts) the control can then be
returned to the target prioritization and processing block to move onto the next target.
In addition to these systems, a manual control system will be implemented in
software. This will allow the firing mechanism to be controlled manually in order to ease
calibration and as well to ease the software development process to determine how the firing
mechanism has to move.
• 2010-2011 Senior Design Capstone Project • George Giakos, Faculty Advisor • Gregory A. Lewis, Senior Design Coordinator • Department of Electrical and Computer Engineering • College of Engineering • University of Akron •