• Build logs, Tutorials and Hacks

    Saturday, September 3, 2011

    The Poorman's Robotics: Introduction

    I am doing a repeat of a a series I published on my site a few years back. This series most of the topics of DIY robots and related topics. Feedback is encouraged because I need to know what everyone wants to read. :)



    Introduction


    The poorman's robotics kit is the basic modules approach for a hoybist or student to start with robotics projects. In India resources like Multilayer PCBs, high-end micrcontrollers etc are not available everywhere. Lego Mindstorms does provide robotics materials but in India, instruments like CROs and microcontrollers are not very common.


    So what is the purpose of this documents?


    The answer is that when a student or interested individual goes to buy things for experimentation, he will know exactly what they are getting into and what are the basic components needed. I am not yet commercially selling such kits to individuals, but different versions of this kit are available to students that undergo training by us. I am not promising support to anyone, but the email ID of my friends and myself are given in the contacts section so you may email us doubts and questions and we will try our best to help you out.


    I was involved briefly in some training projects in Pune, India. The students did a great jobm but while they were leaving, I could not help but think that some activities become restricted due to lack of resources like programmers. Since I have been experimenting with electronics for the past 15 years(since my 3rd grade in 1993) I have tried to add some cost effective solutions to robotics design and some of my own ideas on how to hack-up toys etc to get the electronics and mechanical parts needed. Where to find all that is in your hands now.



    The Building Blocks


    I wont start with table-top kits and all that because I assume you have worked with them at your colleges.


    Q. Why do we have table-top kits since they are not the hardware that are going to be used in actual robots?


    A. It is correct that the standard 'kits' are not going to be used in practical projects. These are not exactly developement tools, but rather learning tools. Imagine that you have to make a simple robot. After you freeze your specifications, you assemble your hardware and then write your software. When you put them together and they dont work where is the problem? Since both hardware and software are untested, how do you know where to start debugging? If however, you have a standard kit that you are sure works, then you can test the software and if the same working workware does not work on your hardware, you know where the fault is.


    For any basic practical robotics experiment there are some fundamental modules necessary. These being:




    • Processor or Controller or Control Logic: This is the brain of your robot and has the algorithm on it. It is responsible for controlling the activities of the robot like reading from sensors, decision making and controlling the actuators etc.

    • The Power Supply: Other than the obvious, the power supply is expected to produced all required voltage levels and regulated/unregulated outputs that may be mutually isolated.

    • Sensors: The eyes of the robot- For any real-time task, the robot need inputs that may be regarding objects, temperature, voltage levels and even position. Advanced robots include electronic compases and gyros and accelerometers etc.

    • The Chassis: If your robot is needed to move around, it needs wheels. If it is an arm robot, then it needs the physical arm joints etc. A physical structure that will include the wheels, grippers, motors, gears etc.

    • Drivers: The Processor or Controller or Control Logic usually cannot supply enough to directly run motors etc. So transistors or FETS etc are used to drive them.

    • Programmer: To download the algorithm to microcontroller, or ROM or CPLD or FPGA.

    • Diagnostic Tools: Simple circuit that can be very useful

    • Communications: Sometime there is a need to connect to a robot.


    I have made this kit in terms of modules. The modules can be connected to each other in different ways for different robots. I will be covering these in this series.

    No comments:

    Post a Comment