Society of Robots - Robot Forum

General Misc => Misc => Topic started by: rich2subhu2007 on January 19, 2011, 03:04:59 PM

Title: NEED HELP FOR HUMANOID
Post by: rich2subhu2007 on January 19, 2011, 03:04:59 PM
Hi friends...
I am a new member to the forum and was surfing for my humanoid stuff.
I am working with a group of 4 students for the project.
The problems are:
1)Mechanical design,how to get a suitable design?
2)Are the components i have selected proper?
3)Is motor controller required for servos.
Other things will discuss progressively.
Here I'll share the specifications:
Size-        2ft (approx)

Weight-       10 kg

Body material -

Skeleton structure (like plates n rods) made of carbon fibre,PVC
                       and Aluminum Coverings on it.

Motors-
        Nos. of motors- 8

Type of motors- servo motor.

Rating- 20kg-cm,12volt(max),Weight<100gm.

Application- Human bots,robust in construction with metallic gear.
         

Microcontroller kit-
                       Type- Atmel with minimum 56 pins
                       Nos.- 2
                       

Circuits&Controller board-

Arduino board with good design and Quality.
                       Nos.- 2
           
Sensors-

Gyro sensor(1 in no.)
                       G-sensor(7 in nos.)
                       6-axis sensor(7 in nos.)

IC-
        H-Bridge( for 8 motors)


Can any one please help me for the components and is the torque requirement correct?
Title: Re: NEED HELP FOR HUMANOID
Post by: waltr on January 19, 2011, 03:13:01 PM
Quote
3)Is motor controller required for servos.
If you are referring to "hobby servo" then no, they do not need a controller.

Go up to the "Robot Tutorials" above and read about how hobby servos work and how to control them.
Also there is much information on motors, torque calculations and mechanical design.

Next, search through and read the many threads in these forums. Many have the answers to your questions.
Title: Re: NEED HELP FOR HUMANOID
Post by: rich2subhu2007 on January 20, 2011, 02:15:10 PM
Thank you......ill try finding the required informations.......
Title: Re: NEED HELP FOR HUMANOID
Post by: klims on January 20, 2011, 04:12:13 PM
Your going to need some super strong servos to hold a 10kg robot rigid. Most of the small hobby robots you see weighing 1-2kg have servos with holding torque of 10kg/cm or more. Take a look at the hobby robots here (http://www.robotshop.com/world/biped-development-platforms-1.html) for yourself.

For a 10kb bot you will probably want some servos like the high powered dynamixel servos (http://www.robotshop.com/world/specialty-servo-en.html). Its going to get very expensive very quickly.
Title: Re: NEED HELP FOR HUMANOID
Post by: nickc on January 23, 2011, 05:23:42 PM
I think you will need way more than 8 motors. Many hobby humanoids have 25 DOF.  With only 8 you wouldn't be able to shift weight onto one foot to walk and would have to shuffle.  Just a pair of legs like a mech-warrior type usually has 4-6 servos/leg. 
You should also figure out your weight better. 10kg seems unrealistically heavy and would require some very high torque at the joints.
Title: Re: NEED HELP FOR HUMANOID
Post by: smashing robots on January 24, 2011, 10:58:46 AM
What I understand from your topic is that you have a project, so in this case it's a hard work to find the answers for all your questions.
You can start from here: http://www.societyofrobots.com/robot_tutorial.shtml; (http://www.societyofrobots.com/robot_tutorial.shtml;) here you can find great tutorials that can help you to start your project