Making a 6 Legged Walker-Spider
Date: Monday, January 06 @ 08:13:15 EST
Topic: Ayaklę Robotlar



Photos of the robotic spider which had been built by our visitor Tequilasunrise with the info given in this article. Thanks tequila for your photos and your work well done. Congratulations.



Here are some details of the 6 legged spider robot that we'we worked on recenlty.



This work is primarily based upon a ready made spider robot kit.

The spider uses 3 servos to operate, walk forwards, backwards and spot-turn.


First we've assembled the controller card , cables etc that came out of the box. We were very careful while assembling the card. Well the circuitry didn't work as we expected. The circuit components, all the RS-232 cables were all inclued in the packet. But all were as separate pieces. Even the metal contacts in the RS-232 plugs were in small packet all needing to be soldered properly one by one. Quite tough job for a beginner.

I the kit, there isn't any part that you may be sure whether it works or not. All pieces are subject to cause errors of any kind. Withing these circumstances we found it useless to work on the given circuit. And we opted for developing our own electronics which has simple feeler sensors and even simpler behaviour like our robugs'.

The cirtuitry only consisted of a pic 16F84 microcontroller and necessary side components for its operation. Only 3 pins are used for Pulse Width Modulation outputs to the servos.

The pic's program is written for checking two input sensors (The feelers) and giving out the necessary pwm signals to make the spider walk ahead, backwards or turn according to the feelers' data.

The article continues with the walking details of the spider and the plywood cutting schematic for you to make a similar one.

The mid legs of the spider that move up and down are only used for lifting the sides of the spider. one side at a time for sure. The front and rear legs which are off the ground can then move freely to front or rear according to the direction which the spider moves to. Simultaneously, the front-rear legs on the other side that touch the ground move to the opposite direction and pushes the spider into the moving direction. The legs that complet their movements are change level by the mid legs' opposite movement. The ones on the ground raise up and the ones off the ground lover down to touch the ground. The front-rear legs that are on the other side raise off the ground this time. And this side's front-rear legs do the pushing job. So a cycle is complete and the spider is one step ahead.

The turning process is also accomplished with similar movements- counter movements and looks really nice :) That is a process which must be studied on the model before starting to be programmed.

If you also want to build a similar 6 legged spider out of sheet plywood or plastic, here is my spider's plan. Print this pdf file, enlarge it as you wish considering the strength and dimensions of your servos. Download it from here..



You may find info on mechanics of servos and how to use them in our tutorials. The circuitry of our spider and all assembly code will be included here shortly.





Click to download source code.
Click to download the circuit schematic.



This article comes from Robotik & Elektronik
http://www.endtas.com/robot

The URL for this story is:
http://www.endtas.com/robot/modules.php?name=News&file=article&sid=32