Build & Test Prep
Table of Contents
Team Vision for Build & Test Prep PhaseDuring this phase our team evaluated our work from MSD I and made the transition to testing and building in MSD II. A general test plan was developed in which potential tests were created to measure the verification of each engineering requirement and customer constraint created in MSD I.
The Mechanical team primary worked on solidifying a tail design and looking into purchasing material to manufacture the tail pieces. The Electrical team finished constructing the gate drive boards and has begun performing validation tests on the board. Some issues involving faulty solenoid switching have been observed and troubleshooting these issues will begin soon.
The entire team is collaborating to prepare for the next major milestone of the functioning tail test. This will involve having the Arduino swimming algorithm drive the solenoids with will be attached to the McKibben muscles and the tail. The swimming algorithm will be tuned in an attempt to maximize the efficiency of the tail motion toward forward propulsion.
SummaryDuring the beginning of the build phase the combined mechanical team set out to build the tail and the body. Purchases were made including: the pump box, the electrical box, the stock for the body, the stock for the tail, and various small parts. In addition to the purchases several other items were 3D printed including: hinges, brackets, and connectors.
The muscles parts had already been purchased as of this phase. A muscle was constructed for testing which follows the following scheme. Mesh which is 1/2 inch minimum diameter (when stretched) is used with a rubber tubing which is 1/2 inch outer diameter and 3/32 wall thickness. The muscle tubing was cut to be slightly longer than the mesh. The connections were made to the fittings at the ends of the materials such that the extra length of tubing would, in naturally trying to elongate, stretch the mesh to its minimum diameter. The goal with this architecture is that the mesh being wrapped tightly around the tubing and having a maximum contractile range in the mesh, the muscle would provide sufficient contraction both in force as well as distance.
The pump box was purchased. It was determined that changes need to be made to the box in order to allow for the pump to comfortably sit in the case. In addition to this ports will need to be created for the hydraulic and power aspects of the pump.
The tail design was completed and the material purchased. The ME team has created the necessary drawing files for the manufacture of the tail pieces. The work order for this has been submitted as of this phase and the parts will be completed for immediate construction.
The base body component was cut from the sheet acrylic purchased early in the semester. The water jet was used to cut this piece.
Test Plan Documentation
In order to characterize the system we are building the team intends to test all subsystems as they are constructed. The uses of this are twofold. Firstly, the information can be used to judge the risks associated with assembling the larger systems. Secondly, the information can be used to assess the performance of the system/subsystem. The team(s) will be testing the integrated systems as well. With the test results of the subsystems in hand it will be possible diagnose problems as higher tier systems are constructed.
Unified Test Plans DocumentThe test plan was used to summarize test results and assess effectiveness of test plans to unambiguously demonstrate satisfaction of the engineering requirements.
This summary combined the requirements of both Robofish teams, P16029 and P16229, into one document. This document outlines the customer requirements, the engineering requirements associated with these, and the test plans for all test worthy engineering requirements. In addition to this subsystems have been assigned to different teams or individuals. From this unified document a more concrete test plan and a more complete holistic picture of the projects second phase will come to be.
Each of the engineering requirements and customer constraints was evaluated and analyzed to formulate a method to test/measure and verify the requirement in the aforementioned.
The individual tests were also arranged in a flow chart which shows approximately which tests, as denoted by the engineering requirement (ER) or constraint (CS), depend on other tests and/or their results.
Testing - Plans
Muscle Testing - ME
The muscle testing rig, constructed by Aniruddha Phatak, in the BAD lab will beused to test the muscle mentioned above in Build Phase/Muscles. The data collected will be analyzed to determined the force produced by the muscles.
Tail Test Plans - EE
On the EE side, the plan includes testing the new PCBs in conjunction with the newly programmed Arduino, and four valves from the old Robofish. We will also combine this test with the pump to ensure water travels through the appropriate valve(s). Lastly, the swimming algorithm pattern will be tested and tuned.
The complete electronic tail control system will be mated with the constructed tail via tube and the McKibben muscles. The algorithm will be tuned to exhibit the best performance on the whole tail. This testing will involve the designed testing rig for the body and tail.
Tail Test Plans - ME
As mentioned above, the finished tail will be paired with drive system for testing. The mechanical system test rig, setup in the tow tank, will be used to test the tail.
Body Test Plans - ME
The body of the fish would be tested in the mechanical test rig as well. The body will be assembled and lowered into the water suspended from the mechanical testing rig. The buoyancy system can be tested at this point. The tail can be attached to the body and the swimming can be tested as well.
Risk and Problem TrackingAs of this phase the Risk Management document was updated. A link to said document current as of this phase can be found here.
As of this phase the BOM document was updated. A link to said document current as of this phase can be found here.
In addition to this, as of this phase, the team began to track problems. As hardware was/will be constructed it is necessary for us to track potential and immediate problems. The problem tracking was combined with the risk management considering the overlap between the two.
Design Review Materials
- Review the test plans
- Review EDGE page
Plans for next phaseFor the next review the team would like to have built a large number of the subsystems and begin testing on said subsystems. The building of the system, for things to remain on schedule, should be completed by the end of the next phase.
The individual assignments for subsystem construction and testing will be upheld throughout.