Collision Avoidance

In a previous notebook we explored the concept of nullspace, and I mentioned that there are lots of different applications for this. One of them is obstacle avoidance, where you can move the robot in the null space to increase the distance between segments and obstacles in the workspace. This is actually based on my […]

Automatic URDF Generation from Denavit-Hartenberg Parameters

I just finished working on a Python script that can automatically generate a URDF file from a set of DH parameters. I wrote this to provide some level of visualization for my research in manipulator structure optimization. You can find the code here. It can be called from the command line or integrated into other […]

Manipulator Singularity Analysis

Singularity is an important concept when it comes to robotic manipulators, but many robotics professors provide students with definitions that don’t tell the whole story. This notebook dives into the concept of singularity, the mathematical background necessary to understand it, and how to apply these concepts to robotics. Check out the static notebook here. Download […]

Jacobian Nullspace Movement

Those with a background in linear algebra may be familiar with the concept of a nullspace. The idea of a vector in the input space that produces a zero vector in the output space is especially interesting as we consider the Jacobian of a robot manipulator. Nullspace movement can be used to perform collision avoidance […]

From DH Parameters to Inverse Kinematics

This post details how to use the DH parameters of a manipulator to perform inverse kinematics. Most robotics software packages have some functionality that performs this, so consider this notebook a look under the hood at what might be running at a lower level. You can also use this code to get the symbolic Jacobian […]

Introduction to Lagrangian Mechanics

This notebook serves as an introduction to Lagrangian Mechanics, and how they can be used to model and simulate robotic systems. This covers several examples, including a spring-mass system and a pole-cart system. As with the last post, I would appreciate any feedback! Check out the static notebook here. Download the notebook here. I would recommend […]

Basic Inverse Kinematics

I’ve written this as a very basic introduction to inverse kinematics using a planar manipulator. A lot of people seem to prefer direct inverse kinematics, but as a reminder, these don’t work for redundant manipulators! This Jupyter Notebook covers iterative inverse kinematics via jacobian pseudoinversion and discusses it’s effectiveness. Click the link below to see […]