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Teddy’s Status Report for 3/1

Over the last two weeks, I worked on constructing the gantry as well as the frame that holds it. I was able to construct the 4xidraw part of the gantry since all of our parts had finished arriving. I was then able to print, assemble, and attach the z-axis to the gantry. Currently, the parts required for the z-axis movement are assembled, but the end-effector is not attached, since we are still waiting for the vacuum pump and the relays to arrive. There is an issue in that the z-axis can’t extend very far away from the gantry, as the weight causes the rods to sag. In order to remedy this, I’m planning on attaching a bar horizontally onto the part where the z-axis attaches to the rest of the gantry, which will rest on two other bars so that the front does not sag. A picture of the current gantry is shown below.

I am a little behind schedule, partly due to delays in the shipping of the gantry parts as well as the end-effector parts. I plan to fix the sagging issue on the gantry next week, as well as hopefully get the electronics and the code for the 4xidraw working.

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Team Status Report for 2/22

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

Currently, the most significant risk to the success of the project is the end-effector design. It has to be able to adapt to a wide range of surfaces, and there is a decent change that our current design might not be enough to achieve that. We recently decided that we would be adding a vacuum pump to the end-effector in order to create a better suction for items that are porous, have irregular surfaces, and/or heavy. If this doesn’t work, we will pivot to a claw-like end effector.

Another risk to our design is our current depth estimator. Right now, we plan to use a stereo camera in order to obtain the height of the objects so that the end-effector knows how far down it should travel. If there are problems with the resolution or the reliability of the depth reading that we get from this camera, it would prevent the gantry from moving to the correct location. The current contingency plan is to add a pressure sensor onto the end-effector if the readings end up being too coarse or unreliable.

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

We’ve added a vacuum pump to the end effector, as from some initial testing the suction cup end effector is not of adequate consistency when it comes to picking up some basic trash items. This does not incur any costs, except to our budget.

Provide an updated schedule if changes have occurred. 

No schedule changes have been made.

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Teddy’s Status Report for 2/22

The bulk of the time this week was spent designing parts for the z-axis movement/end effector as well as working on making a functioning conveyor belt. I’ve created CAD models for the rack and pinion movement, and have started assembly of the parts. I received multiple parts that had been ordered, including the suction-cup attachment for the end effector, and after some testing, decided that it would be necessary to actively pull a vacuum instead of having just passive suction. After some research, I was able to find a way to pull a vacuum (with minimal noise so it doesn’t interfere with other demos) and have ordered the parts for the vacuum attachment. I’m currently working on designing the 3d printed parts that will attach the vacuum and the end effector to the rack and pinion system. Additionally, I was able to construct a frame for the conveyor belt out of 3d printed parts and aluminum (image of frame is shown below). Currently working on designing a basic belt that will be the surface that the trash will rest on.

I am currently a little behind schedule, as the switch to an actively-pulled vacuum requires additional design work. I’m planning on finalizing the design of the z-axis/end effector and working on the Arduino code for the gantry xy movement for the over the next week.

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Teddy’s Status Report for 2/15

This week, I started the design of the z-axis movement and the vacuum end effector. I did a bit of research on methods of vertical linear motion, and settled on a rack-and-pinion based system driven by a stepper motor. I’ve started to create and assemble the CAD files which will be printed out when the design is fully fleshed out. The relevant parts for the end-effector have also been ordered, and added to the BOM in a new section. I spent a few hours working with the stereo camera, and discovered that it has its own python wrapper which should hopefully integrate well into our other code.

Additionally, I printed out all of the 3d printable parts for the 4xidraw gantry for the xy movement. 

Currently, I am a little bit behind schedule, as I expected the parts we ordered to come in earlier so I could start designing around them.

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Teddy’s Status Report for 2/8

Most of the week was spend finding parts to purchase for the xy part of the robot gantry. Tried to keep costs low while not sacrificing too much in quality where it counts (e.g., spent more on the rods for guiding the movement of the end effector in the xy plane, since they needed to hold up to tighter tolerances).  Also had to do some small design changes to the 4xidraw design since our gantry will be significantly larger.  Additionally did some research on an adequate vacuum end-effector and possible ways that the gantry could have motion in the z-axis.

Link to the BOM for the xy part of the gantry is here: https://docs.google.com/spreadsheets/d/1N34-p-gZ5hg3E984jC0rKGtYfBRqveXMVGyWjgI6nZA/edit?usp=sharing

Plan for next week is to start designing the z-axis movement and the end effector, as well as to start 3D printing parts.

Currently everything is on schedule.