✔️Week 16: Applications & Implications
What will it do?
My Project LEO is an omni-directional indoor robotics platform that I'm making as a testbed for my robotics skills. Everything will be controlled by an onboard Raspberry Pi computer, which will allow for the addition of processing intensive features. A touch screen on the front will allow for easy interaction with the Pi. It will have 4 meccanum wheels to allow for omni-directional movement and each leg will be on a suspension arm. Each suspension arm will also have the ability to be actuated up and down to change the pose of the main body and a side-goal of this project is to create a robot that can move in a way to give it character and personify it.
Who has done what beforehand?
The idea for the suspension system for this robot was largely inspired by this James Bruton project. There have also been plenty of omnidirectional robots in fabacademy, Mufeed Mohamed made this awesome scissor lift bot that utilises mecanum wheels, and Jefferson Sandoval has made this one with omni-wheels
What will you Design?
There are a few systems and sub-systems to design.
The Body:
- A central chassis to mount everything to.
- A platform to mount the electronics onto.
- A top cover to house everything and mount the touch screen
Suspension Arms
- Mechanical part of the arms
- Spring part of the arms
- Actutation Mechanism
Wheel hubs
- Motor mounting
- Mecanum wheel mounting
- System of transfering motor torque to wheels
Code based - Board to board communication - Motor control system
What Materials and Components, Where will they come from, how much will they cost?
I've compiled a table of everything for this project that will be used. Note that the USD approximation was made at a rate of 1 AUD = 1.5 USD.
| Item | Price (AUD) | Quantity | Total (AUD) | Total (USD Aprox.) | Link / Location |
|---|---|---|---|---|---|
| Pico W | 9.9 | 2 | 19.8 | 13.2 | Core Electronics |
| Pi 4 2GB | 73.8 | 1 | 73.8 | 49.2 | Core Electronics |
| 7 inch Touch Screen | 65.99 | 1 | 65.99 | 43.99 | Amazon |
| USB Power Bank | 10 | 1 | 10 | 6.66 | Amazon |
| 20kg Servo (4 pack) | 45 | 2 | 90 | 60 | Amazon |
| Copper Clad | 3.1 | 2 | 6.2 | 4.13 | Core Electronics |
| 2x7A DC Motor Driver | 34.95 | 2 | 69.9 | 46.6 | Core Electronics |
| DC Motor w/Encoder | 48.25 | 4 | 193 | 128.66 | Core Electronics |
| Jumper Wires | 3.95 | 4 | 15.8 | 10.53 | Core Electronics |
| Silicone Wire (16AWG) | 7.54 | 2 | 15.08 | 10.05 | Core Electronics |
| XT60 Connectors | 2.6 | 3 | 7.8 | 5.2 | Core Electronics |
| 12v Lipo | 58.99 | 1 | 58.99 | 39.32 | Amazon |
| 7.4 Lipo | 30.59 | 1 | 30.59 | 20.39 | Amazon |
| Meccanum Wheel Kit | 36.55 | 1 | 36.55 | 24.36 | Core Electronics |
| Mounting Hubs (2 pack) | 16.6 | 2 | 33.2 | 22.13 | Core Electronics |
| 2020 Extrusion (600 mm) | 10.35 | 2 | 20.7 | 13.8 | Core Electronics |
| 130mm M6 Bolt and Nuts | 15.62 | 1 | 15.62 | 10.41 | Bunnings |
| PETG Filament (1kg) | 26.95 | 3 | 80.85 | 53.9 | 3DFillies |
| 6mm Dowel | 4.4 | 1 | 4.4 | 2.93 | Bunnings |
| 10mm M4 Bolts and Nuts | 1.86 | 5 | 9.3 | 6.2 | Bunnings |
| 25mm M4 Bolts and Nuts | 2.12 | 4 | 8.48 | 5.65 | Bunnings |
| 3mm Acrylic Sheet | 20 | 1 | 20 | 13.33 | Bulk Acrylics |
| Totals: | 886.05 | 590.7 |
What Parts and Systems will be MAde, and what processes will be used?
The Body:
- A 3D printed frame held together with 2020 extrusion
- Milled and soldered breakout and connector boards for the Picos
- A laser cut top cover that will also mount the screen
Suspension Arms
- 3d printed suspensions
- A 3d printed actuation mechanism.
Wheel hubs
- A 3d printed housing to hold all the wheel parts together
- Modify the mecanum wheels with 3d prints
- A 3d printed and laser cut motor mounting system
- 3d printed gearing
3D prints will be modelled in Onshape, and laser cut pieces will be modelled with onshapes 2d capabilities or illustrator.
What Questions Need to be Answered
There are some questions left to answer for this project:
- How many features can be added before the due date? e.g. Lidar, mapping, etc.
- How much force is needed to actuate the arms?
- Is the changing size of the wheel base going to effect the meccanum wheel dynamics?
How will it be evaluated?
Outside of being evaulated by Fab Acdemy's project requirements, I will evaluate the success of this based on:
- How resonsive it is when driving around.
- How well the legs are actuated.
- How tidy the inner electronics are.
- How much character and personality can it give off.
- How easy is to assemble/ dissasemble and actually use.