LEGO Biped Project

[rlowerr_1]

LEGO Biped Project

I have built a LEGO swerve drive, a Shift-On-The-Fly LEGO gearbox, and a LEGO hexapod… But now it is time to move on the bigger and better things. Thanks to Tytus Gerrrish’s suggestion in this thread I am now working on my most difficult challenge to date. Unlike my previous projects where I just show you all the final project I thought I would post updates as I work. I am not doing this so much for you guys but more for me. I want to see what people are thinking as I work on it, and possibly get some group opinions/suggestions along the way.



LEGO Biped Theory of Operation

The type of biped I am attempting to build is a COG (Center of Gravity)-shifting type. This means that the weight of the robot will be shifted over one foot of the robot, allowing the other leg to be lifted and swung forward to take a step.

Walking

As stated above to walk the robot will put the weight of itself over one foot allowing the other to be swung forward (or backwards). It will then lower its foot and repeat the same operation with its other foot.

Turning

In order for the robot to make a right of left turn it will use the same operation it used for walking forwards and backwards with one slight difference. After one foot has completed a full step, the second foot will only complete a half (or less) step. Because of this one side of the robot will be traveling farter then the other side, causing it to turn.



Prototype Pictures

So far I have only completed a prototype of one foot assembly.

The first picture is of the foot in its normal upright standing position. As you can see the foot is just a large square shape. This may or may not change depending on any balance needs later on.

In the center you see a LEGO gear motor with an 8 tooth gear on its output shaft. It is meshed with a 40 tooth gear that is attached to the foot assembly. This allows the leg to tilt as shown in this picture. This is what will be used to shift the weight onto one foot.

On the top of the leg you see a large turntable. This is what will be used to swing the legs. The gearing at the top meshes with the gear on the inside of the turntable, allowing it to be powered by a motor. This I idea was borrowed from another builder who uses a “powered turntable” to drive a wheel on one of his creations.

That is all for now. Any comments/suggestions/complaints are welcome!