To make the robot arm (with raspberry pi 4) do what I need to do, I will use off the shelf parts whenever possible. All parts will be mounted to a metal plate.
The base of the arm 2 DoF Pan Tilt Digital Servo Kit
- uses 2 pwm servos for 2 dof
- attached a 20kg dual output servo to give it 3 Dof
- attached the end effector from yahboom robot arm to the 20kg servo to achieve 4 dof.
- using raspberry pi 4 for computing and to control servos
- pwm 16 servo hat from adafruit
- geekpi ice tower cooling fan
- rpi4 case
- I am using digital pwm servos, not serial servos. Digital servos are easier for me to control and have more precise movement.
- 55kg servo
Vision - Oak-D pro camera(manual focus) from Luxonis
- detection model can run on camera, inference results will be sent to nano
- will use yolov5 custom model to identify leaves and direct scissors to trim leaves
- yolov5 for locating and picking branches from bin
- created custom bracket in blender to mount camera to robot
- custom bracket 3d printed on Xometry.com
- Aluminum Alloy, Servo Controlled - connects to servo
- cheap aluminum 2 inch gripper
- I attached scissors to end effector and upgraded servo on bottom of end effector
- started with this robot arm kit
- from yahboom, however I could not update jetson nano, nor use the serial servos it came with. Also, the brackets for the arm only fit the servos from yahboom
- standard trimming scissors, cheap and effective, widely used.
- The shape of the handle makes it easy to attach to the end effector
**** As of August 2023 - no longer using the parts below ****
- started with a jetson nano, it was difficult to do anything with the jetson nano. the expansion board it was attached to had no documentation that I could find, so I switched to a raspberry pi 4 with 8 gb ram and pwm servo hat to drive the servos.
- I used win32disk imager to write the custom jetson image provided by yahboom for the robot arm
- running operations on the jetson nano is much faster using an external ssd via usb3 rather than a micro usb drive.
- run gparted in the terminal to see partitions and expand the file system partion to use the entire 500 gb SSD, in my case it was /dev/sda1
- boot from usb jetsonhacks.com
- create backups of critical files before attempting, loss of data may occur when trying to remount file system
- I upgraded to Ice tower cooling fan