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Lahari’s Status Report for 10/2/21

This week I helped with the slides for next week’s presentation and the pretests we conducted over the weekend. I created a block diagram using a third-party software and redid our Ghant chart in response to the feedback we received during proposals. I set out to be as specific as possible at this stage of the project, given that we have developed our device design more according to the specs of some of our parts. Over the weekend we integrated the directional antenna with the ESP32 board. We then took several measurements in the grassy area outside Hamerschlag Hall, to check the RSSI measurements.

We were unsatisfied with the direction finding algorithm we proposed earlier. The previous idea was to move in the direction of greatest RSSI by maximum value. After I researched the RSSI quantity further it is actually feasible to get the exact angle of the direction then vectorize that quantity among the three propellers we will have. This will add more precision to the programming portion of this project, with very little added computational complexity. These and other more descriptive tasks were determined this week, like the need for a digital filter. We plan to do more pretests in the coming week when our parachutes arrive.

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Team Status Report for 10/2/21

This week we prepared our design presentation and continued to order parts. Our design presentation consists of much of the introductory information from the proposal, with a few updates. For example, we updated the schedule to be more detailed because we had a better idea of our tasks. We created a block diagram based on the parts we ordered and our integration plan. 

We researched and ordered more parts earlier this week including a 4-pack of motors, 16-pack of propellers, 4 ESC controllers, bullet connectors, and a 2-pack of parachutes. This makes up a bulk of materials, not including a housing unit to put them inside of. We received the Wi-Fi board and after some delay, we finally received the antenna we ordered last week. We ran some pretests on the antenna and board and determined the directional antenna was usable for direction finding. A problem we saw with the RSSI data we collected was considerable noise. We plan to use a filter to remove it, so we will research RSSI filter design in the coming week.

Because of the delay on the antenna and a few other parts we are still waiting on, we have adjusted the schedule. Our pretest phase will continue into the week of design presentations. We hope to verify some important metrics during this time, namely, drop speed with the parachute and thrust of the propellers.

An updated schedule and CAD model is attached.

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Vikram’s Status Report For 9/25/2021

This week, after the proposal presentation I focused on two major fronts; starting the design phase of our project and reviewing and coming up with answers to feedback we got from the presentation. On the design front, I helped the team find options for off-the-shelf components for our antennae perception system, as well as motors for propulsion. These motors ranged from brushed DC motors without speed control to brushless DC motors that need designated speed controllers, like those used on drones. Picking the right propulsion will depend on thrust values, weight, and power draw. Correctly spec’ing the motors will be very important for ensuring our ability to maneuver during “flight”. This involves putting together spreadsheets with those requirements spelt out, especially with regards to weight, as that impacts our drop time. Thrust will be hard to measure as well, without being able to empirically determine how much is needed. Right now I am on schedule, hoping to start pre-tests with antennae and perhaps motors in the coming week. Hopefully be the end of next week we will have preliminary results on the ALFA directional antennae we ordered, and if they will work for our direction-finding system.

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Team Status Report for 9/25/21

This week we researched directional antennas and accompanying boards. We were looking for antennas that were small enough that could fit on our device and strong enough directionality for our purposes. We looked at EE forums to find one that would suit our use case. We then searched for these products on Amazon. We considered multiple approaches on how to get the RSSI. One idea was multiplexing between antennas, but this might result in higher latency. We arrived on individual ESP32 based boards, one per antenna, these act like Arduinos so we can get RSSI from existing libraries.

With the single computational unit, RSSI retrieval of the several directional antennas will happen sequentially. So a risk that we have discussed at this stage is latency when computing RSSI. Our risk mitigation plan for this issue is to implement a multithreading system or  reduce the number of antennas.

No design changes or schedule changes so far.  We are on track, contingent on the materials we ordered working for our project.

 

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Lahari’s Status Report for 9/25/21

This past week, our proposal presentation occurred on Wednesday, so I spent the first half of the week practicing. Mainly I familiarized myself with the slides and focused on explaining our visuals and calculations in an organized manner. Our group received feedback regarding the slides yesterday via Slack. Overall, some helpful questions were brought up both in the comments and in the Q/A portion of the presentation. For example, whether we were considering other steering systems and the tradeoffs associated with them. In turn, I am researching other methods of steering like compressed air, and how they would affect the device’s weight and robustness (against weather and other confounding variables).

After the proposal presentation we ordered some parts to try out. Namely, we ordered one directional antenna and a chip to control the signal reception on the antenna. We expect to be able to compute RSSI and find out the range of our directional antenna. Hopefully, these items will meet the needs of our perception task.

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Team Status Report for 9/18/2021

As of today, we finalized our proposal for the presentation next week. This involved several kinematic models which we created earlier in the semester to better quantify our requirements.

One of the most significant risks we predict for our project is its ability to perceive the target and activate propulsion with minimal latency. We anticipate that the system will need some time for movement in between perception tasks (receiving and processing a signal from the target). The device may not move fast enough if the perception tasks are to close in time. We will manage this risk as we write the software for these perception tasks. This pause will be something to take into account when programming the device. We will also make sure directional antenna signal processing will require a small compute time. Our contingency plan would be to switch our perception method to computer vision, to detect visual markers on the ground.

No design changes or schedule changes have occurred yet.

Below is a drawing of our preliminary design:

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Daniel’s Status Report for 9/18/2021

 

This week,  I sat with my team and helped brainstorm and do the necessary calculations to figure out certain requirements of our project, such as lateral drop distance as well as landing accuracy. These are crucial to estimate how we expect our device to behave, and what design considerations are relevant to make it behave in the way we want. I also personally worked on the proposal slides for the upcoming presentation this week. I had to distill all the information we came up with during our calculations and group discussions into an easily understandable format for the viewers. This involved summarizing our project problem statement and solution in such a way that the audience understands why our device exists. Additionally, calculations had to be summarized and combined alongside diagrams to properly explain how the project works, why the requirements we chose make sense, and why we expect it to work (by explaining the kinematic calculations we worked on this past week).

 

As of right now, I believe we are on schedule as we have finalized the project idea, as well as core requirements. As for next steps, we are going to begin the design phase of the project. We will begin experimenting with water bottles attached to parachutes, as well as antennas to figure out certain design elements of our final device, such as which type of motors are appropriate as well as antenna setup.

 

 

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Lahari’s Status Report for 9/18/2021

This week we have been preparing the proposal presentation for the upcoming week. In order to quantify the requirements of our project,  we have been researching current technology related to our topic and modelling the kinematics of our device in action. Personally, I have been editing the proposal slides and typing up the equations we used in LaTeX for readability. I also looked around for potential drop sites around campus in person and on Google Maps.

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Vikram’s Status Report for 9/18/2021

This week, I worked on the proposal presentation with my team. I focused on some of the numerical aspects of calculating our requirements, as well as some of the updated drawings for the proposal. The calculations are important because they have to support our quantitative requirements, and the drawings because they can convey a lot more information about the physical footprint of our project than a description.
So far, I think we are on schedule. The next phase, design, will be important for us, especially for testing some subsystems so we know that they are viable avenues for implementing on our system.
In the next week, I hope to have a more clear idea on the individual parts we are looking for, in order to get a close estimate for the weight and function of our device.