shooting targets at varying unknown distances can be a challenge even for experienced shooters....
TRANSCRIPT
Shooting targets at varying unknown distances can be a challenge even for experienced shooters. Judging bullet drop can be a difficult task, and manual adjustments in the field are cumbersome. This process can be simplified by using existing technology and formulas. The auto-adjusting scope will make the proper adjustments so the shooter doesn’t have to, thus saving time and improving accuracy.
General Background:
Currently rangefinders can be used to approximate distances to targets and shooters can manually readjust their sights or hold their sights over the target. However, formulating an exact bullet drop in the field is an awkward process, which is why most people choose to guess bullet drop, but this method is unreliable. A device mounted to a gun that would compensate for different shooting distances would provide the user with a considerable shooting advantage.
Technical Problems:
Component interfacing: rangefinder sensor, microcontroller, LCD, shooting scope, keypad, and servo
Calculating bullet drop: using distance to target, predefined formula, and pre-entered information
Adjusting target scope: according to drop calculations
Design Objectives:
Design a simple user interface that will allow entry of bullet information
Design flexible formulas that can be used for multiple calibers
Make the scope adjustment system automatic
Target shooting at a variety of distances
Testing will be done with .22 caliber rifles
Acceptable results will be a pattern of five inches in diameter
Testing will be done on the bullet drop formula
The microprocessor will be tested by comparing hand calculations with the correctness of programming
The laser rangefinder will be tested at a number of distances and also tested to see the types of objects it picks up
The end result of the product will be a portable device, to be mounted to a gun that will automatically adjust the sights of a scope to compensate for bullet drop.
Operating Environment:Temperature: –20° F and 110° F
Humidity: 0% – 90%
Shock: Bullet discharge
Assumptions:Bullet drop can be accurately calculated
Assume bullets from the same lot hold close tolerances
Intended users:Hunters
Target shooters
Military
Limitations:Effective shooting distance: 400 – 600 yards
Servo and microcontroller must fit on riflescope
Personnel Effort Estimate
Jenny Custer 186 hours
Danielle Frey 189 hours
Eric Halbur 200 hours
Brad Retterath 192 hours
Total estimated effort 767 hours
Functional Requirements:
Allow data input
Allow pointing of the sensor at a target
Calculate bullet drop for a given distance
Auto Adjust scope’s vertical adjustment
Design Constraints:
Time
Budget
Space: Must be small enough to attach to gun
Caliber: Prototype, .22 caliber rifles only
Measurable Milestones:
Finding a suitable formula to calculate bullet drop
Finding a servo with enough torque to turn the vertical adjustment on a standard riflescope
Acquiring a laser rangefinder sensor with serial interface
Designing a user interface that will allow for user input
Designing mounting hardware to mount the servo to the scope
Total: $1,400
$40 $110$50
$1,000
$40 $60 $100
Microcontroller Miscellaneous Servo/Motor
Sensor Mounting Hardware LCD & Keypad
Scope
Hardware Interface
Serial Interface
Serial & Bit Level Interface
Bit Level Interface
RangeFinder Sensor
Microcontroller
User Interface
Servo
Rifle Scope
Estimated bullet drop on .223 caliber rifle. Scope sites always on a target on X-axis at zero.
Client Faculty Advisor Technical Advisor Team Members
Senior Design Project Dec02-08
Project will be broken down for simplicity
Bullet Drop Table
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Yards to Target
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Eric Halbur Dr. Randall Geiger LTC Marvin Meek Jenny Custer Electrical [email protected] [email protected] [email protected] Danielle Frey Computer Engineering135 Oriole St 351 Durham 132 Armory Eric Halbur Computer EngineeringAmes, IA 50010 Ames, IA 50011 Ames, IA 50011 Brad Retterath Electrical Engineering