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Our lives began in the Oceans and today there is a rising need to support clean ups by individuals, communities and governments. Inspired by all the good people fighting the good fight around us, we built Shelly and hopefully one day, she will become an actual part of clean up missions around the world and people will be able to build their own Shellies whether they live by Rivers, Lakes or the Ocean.
Shelly is a solution built with LEGO MINDSTORMS EV3, Amazon Alexa and works with an Echo Device through the Alexa Gadgets Toolkit over the internet.
The six-legged rover resembles many rovers before its time and has been assembled entirely from the base element and the expansion element of LEGO MINDSTORMS.
We have been playing with Lego from our childhood, but this was our very first time building with the LEGO MINDSTORMS EV3 platform and we encountered numerous challenges along the way, but we never gave up.
1. One of our many initial models had separate motors, one to move forward and backward and another for turning. This created issues in triggering two outputs simultaneously. We then explored different designs till we finally got one right. Currently, two motors at the front manage these movements together.
2. In the initial design, the Gripper was unable to lift the weight of even a simple, crumpled paper cup. So, we added two additional gear wheels in the motor section. A timely solve for the problem.
3. Initial models had issues with turning. So, we created two segments, one for the drive section and another as a trolley section.
4. The tires in the kit didn’t have enough grip to run on diverse surfaces including undulating ones such as sand or carpets. This was also causing issues while turning. So, we distributed weight evenly in the entire model adding more weight in the front motor section. This resolved the issue to a great extent.
5. Turning radius was very large in the earlier attempts. We improvised the model to a 6-wheeled design to strengthen the drive section and the trolley connecting segment. Currently, we have the EVE 3 brick in the drive section for appropriate weight distribution and better grip.
6. One of the earlier models kept moving continuously in a circle while turning. This was rectified using a change in the logic and algorithm in such a way that the rover could make a steering correction after certain degrees of turn.
7. We also attempted one model and creation with 7 wheels, though we expected it to be far more maneuverable, turns out it was quite unstable during turns.
8. Adding both motors at the back was causing the rover to turn incorrectly. We evenly distributed the weight of the motors to rectify this going forward.
9. The first model’s axle was built using thin Lego pieces, this was causing a whole new set of turning problems. We then modified the model to use circular shaft and gears, purposefully made for rotations. Now, our movement results started becoming satisfactory.
1. The EVE 3 LEGO MINDSTORMS arm cannot pick up heavy objects as ours is just a prototype. You can choose to design your production grade product as per the needed specifications.
2. The surface should have some amount of roughness so that the tires can get some traction or grip to move. Perhaps in future versions, we can use tires similar to beach buggy tires or even custom design them through LEGO for specifically this purpose.
3. Cables connected to ports need to be checked from time to time for proper connectivity. Do listen to the click sounds when you insert cables.
4. Server needs to be restarted if you remove or replace the port cables.
5. Do ensure placement of gears is proper as this can affect smooth functioning.
6. Connect via Remote Python Call (RPyC) in order to make communication between two EVE 3 bricks.
7. Ensure Bluetooth Operation between EVE 3 Master and the primary Alexa Device.
The Touch Sensor has been used to make sure the robotic arm returns to its original position.
The Ultrasonic Sensor has been used to detect if the bin is full by looking for obstructions in the field of view and to relay a message back to Shelly, and finally Alexa reads out the message.
Depending on the use case, we can choose to add more sensors to Shelly to add more features and functionalities to her growing library of skills.
Behind the Scenes,Learning and timeless memories made with our Team