6 leg robot

[uaefame]

hes got 6 legs, and probably has two joints per leg, as well as the joint where the leg connects to the body, for a toal of 18 joints. 1 servo at each joint, and you have 18 servos.

now, my question is this. In general computing, its easier to layer things, as you can make each task less complex, and can more efficiently route traffic. This can be seen when making a computer cluster. its easier to fill a switch with nodes, and then connect taht switch to a second switch, that will in turn connect another node filled switch. its slightly slower, but its easier to understand what's happening.

Is the same idea possible from a µC point of view? for example, could he have three servos per µC, and the 6 µCs connected to a master µC? The master would not directly control the servos, but would instead tell the slave µCs what to do, and they would in turn control the motors. This sounds kind of redundant seeing as they make TQFP µCs with 100+ pins, but still, imagine this on a large scale. even at a small scale, you could take a Java-like approach and re-use the code in each of the slave controllers. Then you have the master designate which signal to send to which slave. It cuts down on overall coding, as you can program multiple devices with the same information, and cuts down on troubleshooting as there is less going on so there is less to check through. Can someone tell me if this can be done? I'm really good at thinking like this, but I don't know enough about µCs to know whether or not this mode of thinking is practical.

Oh, and I'm signing up for a digital electronics class, as well as a semiconductor applications class next semester. Hopefully they won't diappoint.

I am interested if that is possible. But don't you think its abit tomuch to have 7 PIC 16F818 around. The less the number The less the complication right or I am wrong?

 

[blueroomelectronics]

An 18f is a better PIC
How long do you have to finish your robot before it's due? What programming language are you familiar with?

 

[uaefame]

The project is due 8Dec2008, I see 18FXXX? which type or any type will work fine.

Expert, I am not expert in anything (I started learning about assembly) but I have a guys who is working with me who is expert in C language does this help.

 

[blueroomelectronics]

Six weeks! You're dreaming. You're still in the design phase and can't even drive a single stepper. How do you plan on building a chassis. Spec the power supply (driving 18 servos will chew through batteries) learn a programming language (getting 18 servos to work at the same time) add sensors? ( assuming you want it to do more than just walk in circles. A six legged multijointed robot is a complex project even for robot builders. I suggest you build something simple while you still have the time.

 

[uaefame]

I already finish the design stage, and I won't be pulling back!

I already have 4 servo motors arrived. I am ordering 14 more It will be here soon.

I am doing all I can. the building of the robot will be finish next week.

While the building is done I will be learn programming (A programmer is working with me but he only know C language) or do the electronics.

Don't worry I will show you the picture as I move on...

So you will be updated!!

Thanks for any kind of help

 

[blueroomelectronics]

Well good luck, you're going to have to work very quickly. Are there no sensors?

 

[Cotowar]

I am interested if that is possible. But don't you think its abit tomuch to have 7 PIC 16F818 around. The less the number The less the complication right or I am wrong?

The less the number, the less complex the physical aspect of the project becomes. The more controllers you have, the simpler the logical aspect of the project.

Basically its a trade off, I recommend you put the complexity in your area of expertise. I'm personally much more adept at programming than actually building a circuit, so I'd probably want a single controller with a billion I/O and a crap ton of memory, but if you can build a circuit easily, and take 5 hours to write a HELLO, WORLD!! application, I recommend you use multiple chips with fewer I/O per unit, and duplicate the code.

That's just me though. do what you want.

Also, blueroom is right, you will have no where near enough time to build this thing and program it. If you are planning on making it move without intelligence (ie, no sensors) you might stand a chance of finishing. Regardless, good luck.

 

[uaefame]

Right now, I am thicking of doing it with sensor if time allows. I will be using LDR and LED for the tracking part. Here is the tracking that the robot should follow.

http://techfest.org/competitions/techtronics/arthrobot/img/2.jpg

BTW, if you know a PIC that can be program using C language and can run 18 servo motor please let me know. I have a programmer working with me on my project, He has 16 Year of experience in C language. Right, Know I am introducing him to Assembly language and He is doing the PWM right now, learning how to rotate a servo using PIC16F818 using PWM mode.

THanks in advance

 

[blueroomelectronics]

Ok here's the track you have to navigate, how large is it? Why do you want a six legged robot?
**broken link removed**
You'll need photo sensors to with any luck follow the dark line down the middle, if you had some serious skillz you might be able to get something running in about six months but doubtful otherwise. I'd switch now to a wheeled design while you still have the time, the bump (is it an inch or a foot?) can probably be climbed over with a triwheel design.
**broken link removed**

 

[uaefame]

It must have 2 or more legs.
It must not rotate like a wheel.

I will upload the mechanical picture soon

BTW, I will try shifting to C language do you know a well C compiler for 16F818.

Thanks in advance

 

[dknguyen]

C18 from Microchip student version from Microchip is a "free" C-compiler (no code optimization after 30 days but who cares about that) that works with their MPLab IDE which is also free.

 

[Maninder]

1. The robot should complete a closed loop obstacle course of 500m consisting of various hurdles within an anticipated time of 20 min using Autonomous Navigation.

2. Maximum robot speed should be 10 kmph and maximum robot speed should be limited by hardware.

3. Robot should carry a max payload of 20 kg.

4. The robot should navigate with the help of GPS waypoints & Land marks.

5. Facility for wireless E-Stop during emergency should be provided.

6. Type of locomotion to be chosen by the students and it should be self powered in all respects.

7. The robot should navigate the terrain while avoiding static positive hard obstacles.

8. Maximum width of the robot should be 1m.

9. Course position & exact obstacle positions will be provided one hour before the event.

10. Width of the lane: maximum is 3m and minimum is 1.2 m.

11. Terrain details:
(a) Sand 3 inches of depth.
(b) Gravel size of 2inches.
(c) Gradient with an up/down maximum slope of 15 Deg.
(d) Staircase climbing up to a maximum of 6 steps up and down (7 inches height x 10 inches tread).
(e) 8 Corrugations with a maximum radius of 8 inches and pitch 16 inches.
(f) Lane following by color detection.

give me some idea how i made this type of robot, also tell me chain system is possible or leg system possible