assignments-excavator

This is an Excavator (picture taken near my house where there is road construction):

I traced over it to give it a simplified shape of the main pieces:

So you can see that its just made up of a few main pieces that rotate relative to each other:

So, in addition to placing the excavator in the world (think about where the treads go) with a position and orientation, there are 4 other angles that can be changed in the excavator. The centers of rotation are shown with the black dots in the picture. The “first” rotation is around the vertical (the body rotates relative to the treads). The other angles are all in the plane of the picture.

Here’s a very simple 3D excavator in the assignment (basically made by tracing the picture above):

Here is it is in a different pose (arm bent differently, rotated around its “spin” axis a little):

The tricky part is to figure out the forward kinematics (where the bucket is, given the parameters). You need to work out all the matrices (there are 5 rotations!). This is the challenging part of the project. But if you want something REALLY challenging, you could try to figure out the inverse kinematics (how to set the parameters to put the bucket in a desired position). We’re not going to talk about how to do that in class.

Page last modified on October 05, 2008, at 03:34 PM