RobotRebels.org

Robot Projects => Walking => Topic started by: Nemesis on January 17, 2019, 09:34:32 AM

Title: Animabot Rev3 - Advanced Hexapod Robot
Post by: Nemesis on January 17, 2019, 09:34:32 AM
(https://anim4bot.files.wordpress.com/2019/06/animabot-render-4.jpg?w=1200&h=&crop=1)

(https://anim4bot.files.wordpress.com/2019/06/animabot-render-7.jpg?w=1200&h=&crop=1)

(http://i.creativecommons.org/l/by-nc-nd/3.0/nl/88x31.png)
Hexapod Robot Animabot is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.



Introduction:
Animabot is an advanced hexapod robot created to be a daily life companion and interact with people and objects. He will be able to talk, play with a ball, recognize you,  take care of the home,  be remote controlled and much more !

The version 1 and 2 have already been done, however I'm not completely satisfied with the current version... The body cut in several part due to print size limitation kind of destroy the overall aesthetic and weaken the body. Then the concept was oriented towards a exploration/security robot and I figured it would be better to design it more like a companion instead !

This will be the third and last version of this robot... I started this project quite some time ago (in 2001) and I think it is time to at least finish one version of it :D
The concept is still the same and most of the exterior design will remain similar to the Rev2. However, the hardware and mechanical will greatly improve !

You will find more explanations and pictures on my blog: https://anim4bot.com/category/animabot-rev3/
And here the Revision 2 : http://www.robotrebels.org/index.php?topic=168.0



Improvements from Rev2:
   • SLA 3D printed body
   • Overall body design improved
   • 4 Layers Single Motherboard for better performance and size reduction
   • All sensors are I2C and on the same bus
   • Improved battery charger
   • Improved Power supply
   • Efficient active cooling
   • Improved communication between STM32 and Rpi
   • 2 axis Head (new feature !)
   • 2x Oled display for the Eyes (new feature !)
   • 2 moving ears (new feature !)
   • Gesture sensor on top the the head for better interactions (new feature !)
   • Docking station capable (new feature !)
   • Flexible Oled display for robot status (new feature !)
   • Hidden Raspberry Pi with moving hood (new feature !)



Components & Characteristics:
   • Energy: Li-Ion 11.1V 7800mAh
   • Power: Custom 140W PSU based on LM25119PSQ
   • Charger: Custom, based on LTC4015
   • Brains: STM32F415VGT6 + Raspberry Pi 3 B+
   • OS: RTOS + Raspian
   • Programming Language: C, Python
   • Communication: 2x Bluetooth + WiFi
   • Vision: 5Mpx Micro Camera
   • Displays:
      - 2x 0.49" OLED for the Eyes
      - 1x 1.81" Flexible OLED for robot status
   • Actuators:
      - Legs: 18x Herkulex DRS-0101
      - Hood: 1x KST DS215MG
      - Head: 2x KST DS215MG
      - Ears: 2x Hitec HS-40
   • Sound: 2x 1W stereo speakers + buzzer
   • Interface:
      - Capacitive touch switch with RGB led
      - Gesture sensor
   • Control: Autonomous and Remote-controlled
   • Sensors:
      - 1x IMU 10-DOF
      - 2x LM75B temperature monitor   
      - 1x IR telemeter(GP2Y0A21)
      - 1x Magnetic switch for charging dock     
   • Target environment: indoor/outdoor
   • Size [LxWxH]: 28cm x 36cm x 16cm
   • Weight: 2,5kg
 


Progress:
   • Mechanical design : 65%
   • Mechanical assembly : 0%
   • Hardware design : 90%
   • Hardware assembly : 0%
   • Firmware on STM32 : 30%
   • Firmware on RasPi : 10%
   • Material & Components : 75%
   • Applications : 0%



Hardware:
As mentioned, now Animabot is only composed of 1 motherboard instead of several which help a lot on 2 points: performance and compactness.
The PCB is divided in 4 main areas:
Front: Power Supplies (7.4V - 5V - 3.3V)
Middle: IMU + Cortex M4 + Interface (Bluetooth, buttons)
Rear: Battery Charger
Edges: Connectors

The Power supply is based on a LM25119 from Texas Instrument and capable of delivering 2x 10A at 7.4V, that's over 140W !!!
Of course, to dissipate all this power you need a proper cooling system... this is why the PCB is equipped with a "wind tunnel" cooling directly the PSU and the Charger ;)
The charger evolved as well and is now capable of Telemetry, I will be able to supervise the input and output energy of the Battery. The charger also takes care of the standard protections (over-charge, battery temperature, under-voltage, etc..) and all the monitoring/configuration is done via I2C !
I also overdimensioned most of the components like the transistors to be sure to be on the safe side.

I also removed the ATX Raspi from the robot and the Raspberry Pi will be controlled by the CortexM4 directly for powering ON & OFF. To avoid the last noise issue on the speakers, I added a small isolated DC-DC converter for the audio amplifier.
As mentioned, all the sensors are now connected together on the same I2C bus, which should improve and simplify the data acquisition (one function to gather all sensors data). The IR telemeter as well, I use a small I2C ADC converter to do the trick.

Board dimensions [LxWxT]: 177mm x 84mm x 1mm

(https://anim4bot.files.wordpress.com/2019/07/img_20190724_160836.jpg)
Almost all components are soldered and the testing continues... So far everything is working as expected but I have to test the battery charger to avoid frying my expensive battery...


Mecha Design:

Lower Body:
As you can see, the design is very similar, however, the volume increased a little bit but most importantly the body is much stronger ! Internal ribs have been added on each side of the motors, the thickness is now 2.5mm instead of 1.6mm. Some air intakes have also been added to help the PCB cooling.
Below the battery are located the pads for the charging dock (2 copper rings) and the magnetic switch for the base recognition.
On the bottom there are now 4 small anti-slippery pads and the main breaker switch which disconnect the battery form the rest of the robot.
The rear panel is also very similar to the previous version. There are 3 switches (main, Raspberry Pi and Hood) plus the standard charging connector and on the front the IR telemeter of course.

(https://anim4bot.files.wordpress.com/2019/01/animabotrev3_chassis_bottom_1.png?w=1200&h=&crop=1)   (https://anim4bot.files.wordpress.com/2019/01/animabotrev3_chassis_bottom_2.png?w=1200&h=&crop=1)

Upper Body:

(https://anim4bot.files.wordpress.com/2019/04/inside-body2.jpg)   (https://anim4bot.files.wordpress.com/2019/05/top-asm.jpg)

(https://anim4bot.files.wordpress.com/2019/05/top-asm-3.jpg)


Head:
(https://anim4bot.files.wordpress.com/2019/04/head-section1.jpg)   (https://anim4bot.files.wordpress.com/2019/04/head-back.jpg)

(https://anim4bot.files.wordpress.com/2019/04/img_20190426_151259.jpg)



Robot Kit:

After so many weeks of waiting, all Animabot's parts are finally home !! I decided to start with the lower body assembly and going up to the assembly. The legs will wait a bit longer because I have to disassemble the actual one and I didn't find the courage to do it for now... :(
(https://anim4bot.files.wordpress.com/2019/08/img_5028.jpg)   
(https://anim4bot.files.wordpress.com/2019/08/img_5029.jpg)

Lower Body Assembly:

The Lower part of the body is quite easy to assemble, as it comes in 1 piece (as for the Top body and Top Cover) the only elements to mount are the switches, the DC connector, the IR telemeter, the vent grids and the contact disks for the dock (not yet designed).

I started by installing the grids and fixing them by melting some points to bond the grids to the chassis itself (easy, fast and reliable). Then I installed the switches and connectors just by inserting them in place. The copper contact disks are glued in place, nothing fancy here...

I also did a test fit of the motherboard and the servos and everything fits perfectly for now !

(https://anim4bot.files.wordpress.com/2019/08/img_5059.jpg)   
(https://anim4bot.files.wordpress.com/2019/08/img_4985.jpg)

(https://anim4bot.files.wordpress.com/2019/08/img_5064.jpg)   
(https://anim4bot.files.wordpress.com/2019/08/img_5061.jpg)



Title: Re: Animabot Rev3 - Advanced Hexapod Robot
Post by: Smashley on February 05, 2019, 03:41:50 PM
Very excited to see more on this project. I greatly enjoyed watching you progress through the previous version. I only wish I had the time and budget to build one myself.