How to Build a Robot

So you want to build a robot? This how-to will guide you through the process of putting together the major parts of a robot, moving your idea from a sketch on paper to a working robot.

Difficulty: Challenging

Instructions

Things You'll Need:

• Chassis, power system, drive system, sensors, software, parts catalogs, Internet access, associated tools

1. Decide on a purpose for the robot. The purpose for the robot can be general or very specific, but you have to know what the robot will do. Your other design choices will be centered around this decision.

2. Research what has been done before. This will give you ideas for your robot project. Similar robot designs will show you what difficulties to expect, what you may want to try differently and where the current state of the art is. Robotic competitions, robotics clubs, and electronics magazines are excellent sources to research current robot designs.

3. Design a chassis. All of the robot's myriad parts have to be bolted to something. This is where your chassis comes in. Design the chassis around the function of the robot, the hardware it has to carry, and also plan for future growth, as you may expand on the robot's design in the future. Lightweight and inexpensive materials such as plastic and aluminum are popular in chassis design for smaller robots, and often recycled products are re-purposed for use as a chassis. Larger robots are typically built on custom chassis designed from industrial grade materials.

4. Decide on a power system. Almost all robots are powered by batteries and there are many options to consider. There are quite a few battery types available today and all have benefits and detractors in terms of weight, memory and charge time. Also consider what you plan to do for charging and conditioning your batteries. Will there be an on-board charging system or will the robot have to be docked with an external charger?

5. Choose a drive system. The function of the robot will be the key to designing a drive system. A robot that needs to operate outdoors and negotiate a variety of terrains may be best served by a set of treads. However an indoor line following robot may be better off with a pair of motors driving small rubber wheels.

6. Decide on a micro controller or computer. This decision is largely one of preference in tools. Two micro controllers frequently used are the Basic Stamp and AVR line of chips. The are many choices in programming tools, software, and support for both micro controllers. Also both support a wide variety of peripherals such as sensors, clock sources, motors, GPS device and wireless chip sets.

7. Select sensors. All but the simplest of robots use sensors. What sensors you choose will be based upon the what the robot is trying to accomplish and what it has to do to achieve that goal. Most robots require some form of navigation and this will require sensors, whether that be a simple rotary encoder or a full blown GPS system. Also consider the sensors specific to the robot's primary goal. A line following robot needs photo sensors, and a robot designed to grasp objects needs sensors to determine contact with an object.

8. Program. Now that all of the hardware is collected and assembled, it is time to write the software that will give the robot some form of intelligence. Your robot must be able to take information in from its environment via its sensors and do something based upon the logic of your program. Write your software in small parts, test it and then write the next part. If you write large sections of code and then test them it will be hard to determine where errors are. However if you know that small blocks of code have been verified to work it is easier to troubleshoot a large program.

9. Test your robot. Just as with the software, test your robot as you progress through your project. Aim for small achievements, meet them and continue doing so until the robot is working as you would like it. Robots are very, very complex devices and you will lose less sleep and gain more enjoyment from your build if you take small calculated steps.

10. Collaborate with other robot builders. There are an increasing number of robotics clubs in major cities as well as groups online. Sharing what you have learned with others and asking for help with your robotics projects is highly encouraged.

[Flybyknight]

on 10/29/2009 Great article on how to build a robot. Thanks for going into detail as far as the different required components and options of each. Some pictures of different components would be nice though.