Tenacity is back on the road!(carpet), fresh from what turned out to be an almost 3 month(-ish) refit.
A good bit of consulting work came barrelling out of nowhere right after the start of the New Year, so I've spent most of the past couple months taking care of the funding that makes this rover roll. "No bucks, no Buck Rogers" as a man once said.
One thing that kept breaking last fall was the keypad that was part of the chording keypad teleop control. Replacing that meant getting serious about a proper control system, which led to a complete rewiring and internal reconfig, but overall a much more complete rover and much closer to an actual completed first rev platform.
Current config is:
- Raspberry Pi 3 running ROS Kinetic from Ubiquity Robotics ROS Distro.
- Replaced the ArbotixM Dynamixel controller with a USB2D USB-based controller.
- Arduino ATMEGA 2560 with a screwdown shield board to deal w/ all the pins from the 6 motors.
- L298N motor controllers
- Jetson TX1 to run the depth camera, although I'm working on getting that to run on a Pi 4 because of the smaller physical footprint.
- Orbbec AstraPro depth camera
- ROS Kinetic, largely because the peripherals I want to connect to Tenacity just work out-of-the-box and it's still got a year to go on its LTS. I'm admittedly being impatient but really just wanted to get my rover rolling on a software stack and come back to updating it later.
- My own "Hackermann" steering package to handle the corner steering.
- I've managed to be able to keep much of the Arduino motor control code throughout this entire refrob, so the basic L298 inteface code I wrote last summer is still there.
Materials
Most of the NylonX parts have snapped at this point. The suspension for the rocker/bogie assembly have been replaced with metal. The surviving parts are all the shorter or thicker bits like the motor couplers and drive shafts. The last of the steering shafts broke last weekend when Tenacity got rear-ended by a runaway DonkeyCar. This has provided me with an excuse to open a spool of polycarbonate (PC) and print off some replacement parts. We'll see how these fare compared to the nylon. I will do a longer post about the whole 3D-printed structural adventure and all the different materials I've tried at some point in the future.
TBD:
-Get working on vision and navigation now that I have a driveable rover.
-Add power management support via an INA219 so I can get some sort of software visibility into the overall power consumption of the whole system and from there individual components.
-Sonar and maybe some bump sensors "for better hallway vision".
Anyway, that's an off-the-top-of-my head update on what's going on with Tenacity. Post below if you have comments or questions.
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