Theraphosa Salconi, my robot spider 8x4DoF

salco · February 25, 2015, 4:07am

[font=Arial][size=2]Hi everyone,[/size][/font]
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[font=Arial][size=2]I present developments of my integrative project designed for my last year of technique.[/size][/font]
[font=Arial][size=2]I was inspired by the many robots designed by Zenta.[/size][/font]
[font=Arial][size=2]I also wanted to put a more organic touch by taking inspiration from the tarantula Goliath birdeater. The robot is approximately four times larger than the Goliath birdeater.[/size][/font]

[font=Arial][size=2][highlight=#fbfbfb]Mechanics:[/highlight]
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[highlight=#fbfbfb][font=Arial][size=2]24 x HS-645MG [/size][/font][/highlight]
[highlight=#fbfbfb][font=Arial][size=2]8 x 1501MG (more torque)[/size][/font][/highlight]
[font=Arial][size=2][highlight=#fbfbfb]1-4 x 7.4v 5000mAh LiPo[/highlight][/size][/font]
[font=Arial][size=2][highlight=#fbfbfb]1 x SSC32 V2 [/highlight][/size][/font]
[font=Arial][size=2][highlight=#fbfbfb]1 x nucleo-L152RE[/highlight][/size][/font]
[font=Arial][size=2][highlight=#fbfbfb]1 x homemade pcb to regulate all LiPo [/highlight][/size][/font]
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[font=Arial][size=2]My project includes several objectives:
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[font=Arial][size=2]1. Controlled 32 motor (8 legs with 4DOF makes the robot extremely “acrobatic”)[/size][/font]
[font=Arial][size=2][highlight=#fbfbfb]2. [/highlight]Create a robot including less dependence possible. [/size][/font]
[font=Arial][size=2]Example: every side of my robot can be removed or modified without interfere on others.[/size][/font]
[font=Arial][size=2]Another example is the software side, I’ll be able to add new module without having to reprogram everything.[/size][/font]
[font=Arial][size=2]3. For the future presentation, I will use the robot to solve a maze.[/size][/font]
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[font=Arial][size=2]I will add more info soon, but if you have question I will try to answer it as good i can. [/size][/font]

[font=Arial][size=2][highlight=#fbfbfb]Thank you [/highlight][highlight=#fbfbfb]RobotShop for the sponsorship [/highlight][/size][/font][font=Arial][size=2][highlight=#fbfbfb]
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[font=Arial][size=2][highlight=#fbfbfb]ps: [/highlight]Sorry if my English is not the best, my first language is french. If you can’t understand something ask me and I will answer you.[/size][/font]

cbenson · February 25, 2015, 2:17pm

We would love to see images of the project, but they do not seem to be displaying correctly. Can you upload them as attachments?

salco · February 26, 2015, 10:35pm

I made two little video :

Crab walk :

Lift test:

ps: I link 2 new picture

cbenson · February 27, 2015, 2:56pm

That is indeed a crab! Hope you do a quick cutout to add some claws

salco · February 27, 2015, 3:38pm

In fact the ultimate goal is to make a tarantula like the Goliath birdeater.
The crab is only a temporary phase.

salco · May 7, 2015, 6:45pm

Almost done, only 2 weeks before the presentation, sorry if I don’t post all my progression.
I will post a video in 1 week to show you my spider walking and the controller.

salco · May 31, 2015, 2:27am

Hi, I just finish to edit the video of my expo. Big thanks to RobotShop to have sponsored the project.

I will detail all the parts really soon but if you want you can check in the video i’ve add some info.

And again if you have any question you can ask me !

cbenson · June 1, 2015, 1:00pm

You indicate it can work for 3 hours and by adding 3 batteries you can get even more time. Would that 3 hours be lifting its own weight?

salco · June 1, 2015, 2:48pm

The robot can move and be lifting its own weight or more weight for 3 hours with only 1 batterie Lipo 2S(7,4V). So if i add 3 more batteries it would be 3h*4=12, this calcule is an approximation because the additional batteries add more weight but not too much.

cbenson · June 1, 2015, 3:18pm

That’s surprising since most of the Lynxmotion hexapod robots can only stand / walk for around 15-20 minutes using a 6V, 2800mAh NiMh battery. The current consumption for the RC servos would be around the same, regardless of the battery, so a battery which could last 3 hours would need to be around 25Ah. Can you measure the current consumption from the battery when the robot is standing and supporting its own weight?

salco · June 1, 2015, 3:29pm

Yes I know an hexapod cant be use really too long and it’s why one of my first objective was to boost this autonomy for one hours or more. I dont measure on the final assembly but on bench test it can use 5A constant for moving and carrying only itself, it consume 10-15A constant if I made move with 10 lb additional.

cbenson · June 1, 2015, 4:15pm

If it consumes 5A continuously while standing, a 5Ah battery would last 1 hour, so you would need a 15Ah battery to last 3 hours. What battery are you using?

salco · June 1, 2015, 5:40pm

Yes I know it’s supposed to be only 1 hour but like i said I don’t do the test on the final version. I have modified the code and if the robot is immobile it consume really not to much,
I found a servo motor able to lock itself when i dont give a direction to go :HD-1501MG. the name of my battery is zippy compact
link here:http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=21369

I agree with you, the autonomy can be less than 3 hours but it’s more than 1, for the exposition I presented for 7 hours long and with a full battery, I have been able to use for at least 1 hour.

The robot build like now is made to be improved, if the transfer of weight is better i think it is possible to boost the autonomy.

cbenson · June 1, 2015, 6:13pm

Appreciated!