Define
This project aims to create a solar seed planter; this entails a solar powered robot capable of drilling a hole large enough for a seed to be planted, plant a seed, hydrate the seed, and do this while being capable of moving around on all types of terrain.
Empathy - Inspiration
The UN Sustainable Development Goals (UN SDG) are a set of 17 goals set by the UN to be accomplished by the year 2030. These goals aim to move us towards a more sustainable and happier future for humanity.
The Aloha+ Challenges are a set of challenges in Hawaii meant to help inspire and create a more sustainable future for both Hawaii and the greater world. These goals are based around the UN SDGs, a set of 17 goals set for every UN member state. There are 6 major goals featured in the Aloha+ Challenge, each with their own subgoals and progress trackers. These major goals are the following:
Clean Energy Transformation
Local Food Production & Consumption
Natural Resource Management
Solid Waste Reduction
Smart Sustainable Communities
Green Workforce and Education
This Aloha+ goal targets to create a more diversified, sustainable, and innovative workforce and educational system by 2030. More specifically, we're targeting the 5th subgoal of Green Workforce and Education: Innovation and Entrepreneurship.
Our project is an innovative approach towards the agricultural scene. Granted, it is a proof of concept workpiece, but it still creates a new and innovative concept of automated solar powered planting for the agricultural industry.
This Aloha+ goal targets the Hawaiian energy industry and aims to increase renewable energy usage to upwards of 70% of Hawaiian energy consumption by 2030.
Our project takes advantage of clean energy by using solar power to fuel most of its activities.
Ideate - Sketches
$100 Budget
Access to robotics equipment in shop
Must have drill module
Must have seed insertion module
Must have irrigation module
Must use solar energy
4 Yellowjackets (Installed in Chassis)
1 New Yellowjacket (For Drill)
1 Tetrix TorqueNADO
Tetrix Gear Hubs
120 Tooth Tetrix Gear
40 Tooth Tetrix Gear
Tetrix C-Channels
GoBilda C-Channels
FTC Control Hub
FTC Expansion Hub
FTC Driver Station
Solar Panel
Charge Converter
Auger (Hardened Steel)
Tracks
Track Wheels
Belts
Belt Pulleys
Zip Ties
Anderson Converted 12v Pump
Plastic Tubing
PLA Parts
Tetrix Rack and Pinion Kit
36mm bore 2-side 2-post Clamping Mounts
7mm Hex Shaft 2-post Bearing/6mm D-Shaft 2-post Bearing
GoBilda Servos
Servo Programmer
Servo Gears
Servo Mounts
Anderson Converter Kit
6mm Non-Flanged Ball Bearings
Screws
Nuts
GoBilda Outlaw Chassis (Materials Included Above)
Makergear 3D printer
Universal Laser Cutter
Angle Grinder
Adobe Illustrator
OnShape
These basic ideation sketches create a general idea for what our modules and subsystems will look like, as well as full assembly of the prototype.
Design - CAD
During this process of Computer-Aided-Design (CAD) we turned our original ideation sketches into more solid, defined ideas and computer files. Some of the work here was desiging our own custom parts, especially for the irrigation and seed planter modules. The remaining portion of the work was mostly modeling assemblies with existing CAD files (.STEP) imported from the source of the imported parts.
GoBilda Files
Pitsco Files
Spur Gear Generator
Fastened Mates
Revolute Mates
Slider Mates
Planar Mates
Gear Relations
Rack and Pinion Relations
We used a variety of CAD imports for this project, mostly from the robotics company GoBilda; we used one of their prebuilt chassis for this project, one from the attempt at this project from last year. The GoBilda Outlaw Chassis is the chassis that we used for this project, with two tank treads on each side of the chassis, each powered by 2 motors (4 motors total).
Part Studios (Iteration 1)
Assemblies (Iteration 1)
Unfortunately, our computers were not able to fully render a full assembly for this project. The files we used were too large, and we used the full GoBilda Outlaw CAD file.
At the start of this process, we had no idea how to program this robot. Both of us preferred fabrication and construction over programming the electronic component of the robot. However, as every robot does, this robot needed programming.
We used OnBot Java (a web-based programming platform) to program our robot. We created a tele-op mode (driver operated), and an autonomous mode. However, it should be noted that the autonomous mode is not reliable as there are no sensors on the robot and there was a lack of odometry installed. This makes it so if external factors (such as wind or physical movement) interferes with the robot's movement or activities at all, it will need to
Part Studios (Iteration 2)
Here is the final version of the seed planter module that we used on our robot. This was the second iteration, with the main changes being the servo mounting platform and changes in different gear types (switching to herringbone, then switching back to normal non-angled).
While our rack and pinion system did not receive any significant updates, we realized that our current auger system would not function properly, as we used a 3D printed auger. We had to change this to using a hardened steel auger that Mr. Kinnear found in the shop, and used an angle grinder to shorten it. From this, we had to create a connector piece to connect the motor to the auger using a series of set screws.
The idea behind our irrigation module did not change, however there were a multitude of various major changes that did occur from a design standpoint. First of all, we realized that the pump has to be placed in the water to function properly, and will not work while out of the water. Secondly, for our placing of pump inside the water required us to create multiple holes out of the top, for easy refilling of the tank, as well as threading the wires of the pump out of the tank. Since we removed the pump from the external segment of the box, it was evident that we removed the external mount.
Our solar panel mount went through multiple iterations. Caused by the downage of the waterjet, we were not able to produce our first design out of solid aluminum, making it a weak wooden prototype instead. Secondly, if we did produce a prototype out of aluminum, it would have elevated our center of mass too high relative to the width of the robot chassis, making it unstable, especially for an all terrain robot.
For this reason, we improvised and used a series of Tetrix C-Channels to create a mount. These were connected by a series of flat aluminum pieces to the main chassis.
A main focus of this project is the usage of solar energy into creating a more sustainable future. Plugging a solar panel into either a battery or directly into the controller electronics would be a non-viable option, as the battery would be quickly overloaded, and the controlling electronics would quickly burst into flames (or something like that). For this reason, we needed to integrate a solar charge controller as a medium, as it would control the
Prototyping
Our original attempt at prototyping a water dispenser involved mounting our water pump on the side of the water tank, hooked up via tube to the inside of the tank; this did not work, as the pump was not strong enough to draw a consistent amount of water through the plastic tubing. Instead, we added two extra holes out of the top of the water container, and inserted the pump in a manner where it sits directly in the water supply. The water is then piped out via a plastic tube, where it is hooked up to a bottom dispenser platform.
The seed dispenser prototype was quite similar to the design from last year's version of this project; it used a power source (last year used a motor, we used a servo) for the turning of gears. One of these gears was placed underneath the seed container with holes placed periodically throughout the gear; this was rotated in a controled and precise manner by the servo (through a system of gears) which allowed us to control seed dispensing. The output dispenser was connected to an output funnel by plastic tube, allowing us to precisely place the seed (avoiding interference of other potential obstacles like wind). The gears were the only major itteration between different designs.
The prototyping of the auger had two major versions. The first version was a custom designed 3D printable auger. This auger was then directly connected to the motor via a set-screw. Evidently, this was not strong enough to push through dirt and other Earth substances effectively. The second prototype involved taking a hardened steel auger, cutting it in half with an angle grinder, and then adjusting a new tip for the shorter auger. This auger then had a press-fit mount created for it, to be attached to the motor via a 3D printed part (PLA-CF from Bambu Labs). The press fit mount also had two set-screw mounts for the auger and the motor connection points.
The auger and the attached motor were then mounted to the inside of a GoBilda C-Channel by 2-side-2-post motor mounts.
The prototyping of the rack and pinion system was the most straightforward part of this project. This portion of the project used Tetrix rack and pinions for lateral movement. This was geared up to a 4:1 gear ratio (4x the torque application from the motor) to a Tetrix TorqueNado. The auger C-Channel mount was mounted along the rack section of the system. The pinion gear was mounted inside a Tetrix C-Channel, which was directly mounted to the chassis.
The solar panel was surprisingly the most difficult part of this project. The mount was originally planned to be zip tied to elevated 3D printed mounts. After prototyping, we were advised that this solution would not work, as the back of the solar panel was touching the PLA mounts; this would result in hard impacts potentially shattering the solar panel mount.
Our next prototyping involved laser cutting and (planned) water-jetting of aluminum parts. This had a planned laser cut/water-jet part mounted to the back of the solar panel, attached to the chassis by PLA-CF (Bambu Labs) 3D printed mounting mechanisms. The laser cut prototype worked, but did not have the stability of an aluminum mount. We realized 3 problems with this solution: 1) the aluminum mount was going to be too heavy for our PLA-CF support frame; 2) the weight of the aluminum mount would shift our robot's center of mass upwards significantly; a large problem for a robot moving over rough terrain that lacks a large surface contract profile; 3) the waterjet was broken, making it impossible for us to prototype our parts out of the required aluminum.
Our final prototype was extremely similar to the solar panel mount of the year prior; a series of Tetrix C-Channels bolted together and zip tied to the solar panel, which was then mounted on more Tetrix C-Channels to the robot. This solution was imperfect, an in an ideal world, we would be able to cut a thin aluminum sheet into the desired solar panel mount shape, and we could mill parts for mounting out of some metal alloy. Obviously, this would not address the shifted center of mass, which we would have to widen our chassis base for; however, this solution worked well and was adequate for the purpose of this project.
Test
This is a video showing the testing of the chassis terrain capacities.
This is a video showing the transfer of power to a charge controller, distributing power from a solar panel both to a battery and the control hub running the machine.
This is a video of the auger and rack and pinion being tested. This mechanism is used to create holes in the ground for seeds to be planted in.
This is a video of our water dispenser module pumping water to our dispensing point.
We do not have a video of our seed planter module functioning, as we programmed our
Unfortunately, for the purpose of this project, we intended to make an autonomous program for the robot to function without a human controller; this did not happen because of the difficulties in creating an autonomous program. It should be noted that it would be relatively difficult to create an autonomous program for THIS ROBOT for multiple other reasons listed below:
Lack of Odometry - This robot lacks any odometry - this makes it difficult to track movements of the robot, specifically unintentional movements that come by equipment moving on various terrain.
Terrain - This is part of the problem with odometry. Many of the commercially available odometry systems are designed for FTC - for a flat field with no gaps, changes in vertical height, or any other significant variation in the terrain; therefore, this makes it extremely difficult to install any sort of odometry system.
Lack of Sensors - Without proper sensor equipment (excluding dead motors/odometry), this robot will have an extremely difficult time properly navigating its terrain.
Inexperience in Programming - While I do have significant experience in programming, I am inexperience in both Java and the FTC libraries. Many of my previous coding experiences worked in python and were algorythm based, not physical, tangible manifestations of the code that I had wrote.
It is true that I programmed this robot; however, the code was extremely simple and posted online (some segments) - this would not be the case for creating an autonomous program.
Perhaps a student in the future could continue this project by creating an autonomous program for this robot to run off of properly.
For future potential projects, I would really like to create another iteration of this project. I would customize the chassis, creating a wider and longer base for increased stability and storage space. I would also like to lower the solar panel mount to lower the center of mass to further increase stability. Increasing chassis power would also be a critical improvement to increase carrying capacity in terms of water capacity and seed carrying capacity. I would redesign the chassis to still incorporate a tank tread chassis, but use 8 motors for power and a parallel plate chassis for storage and electronics protection (from debris). I would have to move away from using FTC electronics because of the motor and servo limits, as I would also like to increase the seed planting capabilities. While this new robot would still utilize a rack and pinion system, it would also aim to use far more augers and capable of simultaneously planting and water 5 different seeds (placed in 5 different holes), while still being solar powered.
Integration of electronic sensors and other autonomous capabilities would be another significant improvement. Usage of tread odometry, IR sensors, and video cameras would all be extremely essential components of any autonomously driven robot. For industrial implementation, it would also be necessary for this robot to be GPS guided and work in conjunction with other robots. It should also be able to be refilled via an autonomous refill station.