P15571- SUNTRACKER Harrison Sprague Jason Yeh Kaung Myat Thu - PowerPoint PPT Presentation

P15571- SUNTRACKER Harrison Sprague Jason Yeh Kaung Myat Thu Jacob Halstead Craig Bishop Patrick Chiu Tyler Nicholson

Agenda ● Project Overview ● Key Customer Needs and Derived Eng. Requirements ● Final Design Concept ● Product Development Process ● Results: Major Issues and Findings ● Current State of Project ● Objective Project Evaluation

Project Overview ● Design and implement a complete system for a satellite receiver dish to automatically track the Sun for the purpose of gathering RF data. ● Customer: Martin Pepe with the Astronomy Section of the Rochester Academy of Science.

Key Customer Needs and Engineering Metrics Customer Met/ Engineering Requirement Final Design Performance Requirement unmet Satellite Focuses Azimuth range: 70 - 220 degrees from North Azimuth range: 7 - 353 degrees from North Met on Sun’s Position Altitude range: 15- 72 degrees from horizon Altitude range: 10- 74 degrees from horizon Software Compatible with RadioEyes and Windows 7 Compatible with RadioEyes, future Interface applications that use ASCOM, and Met Windows 7 Water Proof IP54 and IP67 ratings IP54 and IP67 ratings on all motors, Met Construction connectors, enclosures, etc. Preset/Home Software Interface supports programmed Custom positions can be set through Met Positions positions RadioEyes and RadioEyes Tasks

Key Customer Needs and Engineering Metrics Customer Engineering Met/ Final Design Performance Requirement Requirement unmet Positional Accuracy Program controlled (default 0.5° accuracy) Motors ± 2° Met capable of 0.01° accuracy (non-tracking). Limit Azimuth Prevent over-rotation Limit switches with diodes prevent over-rotation. Met Limit Altitude Prevent over- Internal and external limit switches prevent over- Met extension/retraction extension/retraction. System Resists Backlash <1° backlash ~0° backlash from worm-type gearing Met LA provides sufficient force >300 lbf The LA is rated for 400 lbf max; and original Met calculations overestimated C.O.G. location. Slewing Drive provides >150 ft lb rotation >1000 ft lb rotation sufficient torques >1000 ft lb overturning ~2000 ft lb overturning Met >200 lb axial load >2000lb axial load

Key Customer Needs and Engineering Metrics Customer Engineering Met/ Final Design Performance Requirement Requirement unmet Protect DAQ Cannot be tested; backup power supply has not been Runs on backup power Unmet (1) for 2 minutes ordered. Collect Data Cannot be tested; new antenna is not installed yet. Movement of dish does Unmet (2) not affect collected data Budget of $500 Bill of Materials cannot Received approval for increased budget of total $1900 Partial exceed customer budget Allow Optional Manual Allow user to change Software User Interface is provided but joystick is Partial Control RA/Dec/Alt/Az never attempted. (1) - Customer will purchase backup power supply that the team has recommended and this task will be accomplished. (2) - Testing on effect of motor noise on the receiver has been performed in the lab without using shielded cable during MSD 1. The test has no indication of noise present in the collected data.

Original Dish Status Original 7’ Satellite Dish Declination Bracket Linear Actuator

Final Design (Installed in Ionia) Original 7’ Satellite Dish Antenna U-Bracket LA Limit Switch Slewing Drive Slewing drive Motor Skirt covering: Pipe flange adapter plate Linear Actuator limit switches LA Mounting Arms

Product Development Process

Results: Major Issues and Findings Problem Description Solution Shear pin Rework components to Original Shear pins only support 230 lb in strength (1) accommodate next shear pin size. double shear. Shear pin External limit switch implemented to Larger shear pin breaks at 1000 lbf (calculated strength (2) stop full retraction. Pin now serves break at 440 lb, rated for 600 lbf) as “catastrophic loading” protection. Shims have been added and the Pipe was measured to be 3” in diameter on 3 Pipe Sizing pipe-flange will be pinned to the post separate trips. Upon installation the pipe is 2.9”. to prevent rotation.

Results: Major Issues and Findings Problem Description Solution Communication Limited report speed of fast Software communication protocol has minimal Flow/Congestion communication. flow/congestion control resulting in long Control processing delay Reference Limit Unknown Reference Limit Switch Signal cannot be reset Switch Reset by Arduino after capturing the event of limit switch being pressed. Noise filter designed with D flip-flop Noise in signal lines from slewing drive affected Position Errors improve all hall signal lines. positional feedback (fixed)

Current State of Project ● Completed: ○ Rigid, weatherproof mechanical system ○ Control drivers for calibration and operation ○ Communication with Radio-Eyes for tracking ○ Utilizes ASCOM protocol ○ <0.5° motor precision ● Unmet Functionality ○ Safe position for high wind speed ○ Systematic shutdown during power outage ● Unmet extra functionality ○ ASCOM interface functionality ■ Sidereal Tracking, move axis, pulse guide, sync ○ Manual control with joystick (“Nice-to-have” feature)

Objective Project Evaluations ● Design Strength ○ Degree of rotation is ample, allowing customer to track other objects. ○ The system can withstand the heavy load (overturning moment). ○ Waterproof connectors, sealant and rust-preventative paint improve environmental protection. ○ Increased motor precision is achieved by filtering hall signals and by using shielded cables. ○ Limit switches and diodes prevent damage to the dish and wires. ○ User interface for manual and auto-calibration allows the user to make changes conveniently and prevent human-error without the need to modify the code in several places.

Objective Project Evaluations ● Future Work / Design Weakness Software ○ ASCOM ■ Sidereal Tracking/ Move Axis/ Pulse Guide / Sync functionality ○ Congestion/Flow control for communication protocol ○ Systematic shutdown and housekeeping ○ TeamViewer Electrical ○ Wiring harness design for Usability (I/O Box for current-limiting diodes) ○ Position feedbacks for daily auto-calibration ○ A single custom board for all electrical designs (Plug-in shield for Arduino)

Objective Project Evaluations ● Future Work / Design Weakness (cont’d) Electrical ○ Pick a different microcontroller with more interrupts ○ Manual Joystick Control ○ Add or access to local weather station ○ Backup Power Supply ○ Self-Diagnostic Test Plan/Program Mechanical ○ Replace Shear Pins with one larger pin ○ The hardware required for installation should be standardized ○ The pipe flange should be a closer fit and not require shims