Drake

Legged robot research has been an active area of study since the late nineties. Let’s take a look at how we can generate walking trajectories for bipedal robots, using some of these ideas.

The Objective: Implement a quick and dirty way of generating walking trajectories
Constraints: Do it quickly. Minimize sophistication. Anything goes!

What this post will cover:

1. Overview of the minimal set of ideas required to develop walking algorithms
2. Computation of bipedal joint trajectories for a simple walking gait

What will not be covered:

Let’s take a look at how we can set up a framework for streamlined simulation and hardware control of a manipulator. The robot under consideration is Ufactory’s Lite6 manipulator and the simulation/setup tool used is Drake.

All the code used in this post can be found in my repo. But before we start, some explanations are in order.

Lite6?

The Lite6 is one of the more economical (not to be confused with cheap) manipulators one can buy, especially for personal research where you’re not going to be spending tens of thousands of dollars on some of the more well established robots out there. It’s well built, has surprisingly good specifications for the price point, and comes with an integrated controller. You can get a parallel and vacuum gripper for it, but also comes with hardware interfaces that can support custom grippers. The product is well supported and their API (python and C++) is easy to use. The main pain point is its parallel gripper, which can only open by 1.6 cm. This severely limits the type of objects you can pick/place, but luckily for us, pick and place is only a small part of robotic manipulation!