Society of Robots - Robot Forum

General Misc => Misc => Topic started by: colebags007 on January 21, 2014, 11:54:41 AM

Title: Final Year Biped
Post by: colebags007 on January 21, 2014, 11:54:41 AM
Hi I am new here.

I am in collage and for my final year project I am designing a Bi-Pedal robot. I am having trouble on deciding on which control system to use. It will be a open loop design more than likely using stepper motors(x6). The options I have for controlling it are Labview or a PLC. I am not sure if i will get a card for Labview yet but information will be extremely helpful.

I would like to know what hardware I will need to connect everything and how to go about it.
Detail and simplicity are key here as my knowledge of electronics and programming are very limited.

Information on both systems would be appreciated.
Title: Re: Final Year Biped
Post by: jwatte on January 21, 2014, 04:03:48 PM
Typically, this is done with microcontrollers that are programmed specifically for the control in question. This is because PLCs will be too slow and Labview will be to complex and not allow autonomous movement.

Also, using stepper motors without sensors (open loop) for joints is unlikely to be robust.

You may want to study various successful bipedal robots that already exist for some hints. Two examples I can think of are the Bioloid Premium (about $1k,) and the Darwin-OP (about $10k.) Both use closed-loop joint control with high-performance servomotors, and a microcontroller to drive the servos.
Title: Re: Final Year Biped
Post by: colebags007 on January 22, 2014, 11:03:23 AM
I will have to look into what equipment is available to me for the project. W would be an example of a micro-controller used for this applicatio? Could it be constructed easily or would it be complex?   

As for the open loop design I am not concerned about being robust at the moment as I just want to have something completed and moving and in the future the robot can be improved on.

Thank you for the information you have given it is very helpful.
Title: Re: Final Year Biped
Post by: jwatte on January 22, 2014, 11:28:54 AM
Example microcontrollers may include:
- Arduino Uno (lowest capability)
- Teensy3.1++
- OpenCM9.04
- Raspberry Pi

These cost $20 - $40 and are programmable in C/C++. Some of them come with libraries to control some kinds of servo motors. For example, OpenCM9.04 plus AX-12 or MX-28 servos. Others will require drivers for each motor -- especially for steppers. Each driver will require step and direction signals, and you need one driver per motor, and two output signals from your controller per motor -- this will quickly run you out of pins on your controller!
Title: Re: Final Year Biped
Post by: colebags007 on January 22, 2014, 12:11:50 PM
Thanks for all of your help this has helped me so much.