Integrated System Build & Test with Customer Demo
Table of Contents
Team Vision for System Level Demo with CustomerDuring this phase our team aimed to arrive at a fully functional vibration test rig. Additionally we hoped to make strides in completing our final paper and poster. We have begun work on both the poster and paper and feel we are on track to have these completed by their respective deadlines. Our team ran into unexpected challenges which have slowed our progress on the physical test rig but we are confident we will be able to provide an excellent final product.
Test Results Summary
Pnuematics IntegrationFor this design review we wanted to incorporate the LabVIEW device, the accelerometer, and the assembly of the whole system. The current state of our system has us on the verge of all three of these subsystems. However, the DAQ device and the accelerometer are still having LabVIEW difficulties.
LabVIEWThe advantages of using this over the current function generator is that it allows us to perform a dynamic test to run the system at differing frequencies. The current device generates a sine wave with a peak to peak of 10V. The USB6008 DAQ controller will be switching us to a square wave with a peak to peak of 5V, this is a concern for the higher frequency responses but this is all we are able to achieve with the current DAQ device and is the way to control our system for a dynamic test. Using LabVIEW, we can also create a single VI to control the system as we can both generate the signal and read the data from the accelerometer together. LabVIEW is currently set up on Tim’s laptop and is how we plan to run the system for imagine RIT.
myDAQOur current USB6008 DAQ device was borrowed from Dr. Kempski and will need to be returned to him at the end of the project. The integration of our system with the DAQ is still in the debugging stage and we have been experiencing frequent setbacks at every turn. From connectivity issues to incompatibilities as well as code issues, we have seen a lot of frustration in this subsystem. We are still working to establish functionality from the device and will continue to do so until fully operational.
AccelerometerAfter working to establish functionality with the Arduino, we moved forward to LabVIEW integration using the LINX MakerHub. Using this application with LabVIEW lets us bring in the acquisition data directly from the accelerometer to the LabVIEW program where we can process and analyze it easier. We have successfully connected to the device and have readings from a different accelerometer but are still having difficulties connecting to our own. This is another system where we have not had good luck and we have seen many setbacks in the process. Currently, we are able to read and zero the accelerometer but are having difficulty changing the acceleration range from ±2 to ±16. When we do have the accelerometer fully operational, the first step will be to verify its functionality with the Packaging Science vibration table. Once it is proven accurate, we can begin analyzing our own system to ensure the correct output.
As of yesterday the base plate was machined and is ready for testing with our system, but the p-pod is not ready for full integration with the system. Testing this section has been simply testing with the piston secured to the baseplate with an improvised baseplate. The testing has shown that with weight on the system there is still a response at 100hz from the system.
The specific parts that still need to be machined with respective time to complete.
- 3x interior rails. 12 hours total, at 4 hours a piece. We have the stock for this.
- Interior plate to replicate spring displacement. 2-7 hours depending on which method is chosen.
- Sides, top, and bottom. Still have not received water jet parts from a submission last week. 1-2 hours to drill clearance holes.
- Rework of parts out of tolerance or just adjustment. 6 hours?
Brings total to 21-27 hours of additional machining to have fully complete.
It can form a "P Pod" but the tolerance stack up which I was concerned about before proved to be a major issue.
Also, the mills in the machine shop are not perfectly straight which cause anywhere from a .005-.010" thickness difference of an 8" rail. The holes were then not drilled in a perfectly straight line due to this. Despite best efforts of calibrating the clamp, this issue still arose.
Through a slight design change, the top frame of 80/20 rail may not be necessary. The P Pod is now secured by screws in 4 locations into the base plate. This should prove more than adequate for holding it, and each screw in the p pod sides will be tightened on with Allen wrenches. Instead have one placed to prevent rotation. A design change is in process to mitigate this issue.
Outputs & Destination
Final PaperOur final paper is outlined and is currently 40% complete. A high level outline can seen below:
Abstract: Here we will give a brief overview of the customer and goal of the project.
Nomenclature: This section will allow us to denote any specialized naming conventions or definitions for our project
Background: In this section we will discuss the need for the project, our main goals, and the bench marking of current systems.
Methodology and Process: In this section we will discuss the development of customer needs, engineering requirements, and initial risks
Design and Development: This section will be broken down into subsections for each subsystem. Within these subsections we will discuss some of our options, the research and testing we did, and ultimately why we made the design choices we did.
Conclusions and recommendations: In this section we will discuss the successes and shortcomings of our project as well as attempt to outline a clear path for any future teams to work off of.
References and Acknowledgements: This will be two separate sections in which we pay homage to the knowledge we have referenced and the large assortment of supporters we've had during this journey.
User GuideOur User Guide, which will be handed off to SPEX upon completion of MSDII, is currently 70% complete.
This guide is split into four sections, 'General Information', 'System Summary', a 'Getting Started' section, and 'Using the Test Rig'.
The General Information section outlines a high-level system overview of our project, some of our major engineering requirements and the purpose of the test rig for CubeSats. There is also a subsection for acronyms and abbreviations related to our project and MSD.
The System Summary section provides a schematic of our test rig, including a list of all of its parts. It also provides a few illustrations related to how our system is integrated and has a description of each subsystem in detail.
The Getting Started section of the guide illustrated how our system is configured to run its tests. There are also subsections for setting up our LabVIEW program and installing the accelerometer.
Section four provides everything the user will need to know in order to use the rig properly for successful testing.
Imagine RIT PosterOur poster is currently 85% complete.
Our poster will include a picture of our final vibration test rig when it's complete. We've included our project overview, our customer requirements and engineering requirements.
There are also several pictures and key highlights of the different testing we've performed as well as highlights of our more complicated systems (i.e pneumatics).
Risk and Problem Tracking
Bill of MaterialsWe are still within budget. A few additional purchase have been made since last design review. We do not foresee going over budget.
Plans for next phaseIn order to meet the following goals for the end of the year we will need to accomplish to associated tasks:
Minimum action test rig
-Machine the final Ppod rails
-Drill holes in water jet parts
-Assemble frame structure to hold Ppod
Minimum test rig with code controls
-Work out any kinks in connections between code, lab view, and driver
-Add capability to control valve for amplitude control
Test rig with controls, feedback, and validation
-Get the accelorometer to communicate with code
Senior Design Requirements
-Complete Essay-Finish Poster
Materials for delivery and hand off to SPEX
-Write user guide, include like assembly photos
-In depth notes describing decisions made. Provide as much knowledge to future teams as possible.