GRAD VALLEY STATE UIVERSITY Padnos College of Engineering and Computing School of Engineering Project Proposal EGR 345 Semester Project Target Acquisition and Firing System Team # 4: Brad Peirson Chris Knowlton Justin Clark Ken Rocker Steve Michel Instructor: Dr. Hugh Jack October 17, 20052Executive Summary The following documentation is a proposal to build a fully functioning automated target acquisition and firing system. The purpose of this project is to develop a system capable of competing in the Fall 2005 EGR 345 semester competition. The design will be optimized to meet the constraints of the competition, which will be outlined later in the proposal. The system will be capable of firing up to 30 practice golf balls at randomly selected targets at a distance of 1.83m (6ft). This will be accomplished through the integration of a pneumatically operated turret and firing system, which will be linked through a microcontroller. The system will operate from live signals, which are sent from the randomly active targets. The turret design will consist of two ball bearing turntables used to mount two spring return air cylinders. Two cylinders and four mechanical hard stops will provide the system with four firing positions, one for each target. The firing system will utilize a breach and blot design found in many firearm applications, along with an external air supply. This project has an estimated budget of $140.3Table of Contents Executive Summary………………………………………………………………………. Table of Contents…………………………………………………………………………. 1.0 Design 1.1 Concept…………….……………………….…………….………………. 1.2 Calculations………………………………….……………………………. 1.3 Controls…………………………………….……...……………………… 1.3.1 Flow Chart…………………….………………………………….. 1.3.2 Wiring Diagram………………..…………………………………. 2.0 Inventory 3.0 Appendices 3.1 Appendix A: Prints……………………………………………………… 3.1.1 Assembly Drawing BOM………………………………………… 3.1.2 Barrel Mount………………………….………………………….. 3.1.3 Firing Base…………………………………………………………. 3.1.4 Bolt Cylinder………………………………………………………. 3.1.5 Barrel………………………………………………………………. 3.1.6 Barrel Cylinder Mount……………………………………………... 3.1.7 Base………………………………………………………………… 3.1.8 Base Cylinder……………………………………………………... 3.1.9 Hard Stop………………………………………………………….. 3.1.10 Nozzle Mount……………………………………………………… 3.1.11 Pivot………………………………………………………………... 3.1.12 Targeting Base……………………………………………………. 3.1.13 Turntable…………………………………………………………... 3.2 Appendix B: Calculations 3.2.1 Turret Position…………………………………………………….. 3.2.2 Drag Coefficient…………………………………………………… 3.2.3 Air Cylinder Stroke………………………………………………… 3.2.4 Trajectory of Wiffle Ball…………………………………………... 3.2.5 State Equations for Rotation 3.3 Appendix C: Control Program…………………………….………………. 3.4 Appendix D: Purchased Components……………………………………..4 1.0 Design 1.1 Concept The proposed design is based off of two major concepts, the firing mechanism and the turret. Figure 1 is a schematic diagram of the mechanics behind turning the cannon. Figure 1: Turntable Setup5 The turning system will consist of a set of two turntables. An air cylinder will turn the top turntable to which the barrel is attached. The fixed end of this air cylinder will be attached to the lower turntable. When the lower turntable turns the barrel will be turn as will the top air cylinder. Both air cylinders will be hard stopped at pre-determined points. This setup allows for four unique firing positions with only two linear air cylinders. Figure 2 demonstrates the firing mechanism. Figure 2: Air Nozzle/Sliding Bolt Mechanism A third air ram will be attached to the barrel itself to operate the sliding bolt. The top portion of the mechanism will separate the ball in the barrel from the rest of the balls in the magazine. This will prevent any undesired effects from having balls stacked directly on top of one another. When a ball is loaded it will rest against the air nozzle. Once the barrel has rotated into firing position a solenoid operated air valve will open to fire the ball. The bolt will then open and allow another ball to be fired. 1.2 Calculations There are several calculations required to design a functioning cannon. All calculations and applicable diagrams are included in Appendix B. The first is the calculation to determine the angle of rotation of the barrel to hit the center of each of the6target blocks. It was determined that the angle between the centers of the two middle targets is 0.154 radians (8.797°). Because of the design of the two air cylinder system the angle required to hit the outer two targets is not the angle between them but the angle between them minus the angle between the inner two targets. The angle was determined to be 0.15 radians (8.596°). The next set of calculations shows the calculation of the drag coefficient. The calculations were carried out assuming that drag is determined by the surface area (4πr2) of the waffle ball and not the silhouette area (πr2). This being the case the drag coefficient of a waffle ball is, on average, 0.052. This is a unit-less quantity. Once the drag coefficient was determined
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