Drive Kinematics: Skid Steer & Mecanum (ROS Twist included)

by on June 22, 2016

drive kinematics

Hi all I am often in need of the basic kinematic motion equations for skid steer vehicles. I have also recently been working with mecanum wheeled vehicles. The skid steer equations are fairly simple and easy to find, however I will include it in different versions and include a ROS approach. The mecanum wheel equations […]

Design Thinking for Robotics and Life

by on June 13, 2016

design_thinking_steps

Hi all Recently I went to a seminar about design thinking. Design thinking is an approach to solving a problem from any domain. During the seminar people used design thinking to analyze how to automate password recovery, lead a finance team, build an activities team, and others. I used this as an exercise to look […]

Book Review: Peer Reviews in Software by Karl Wiegers

by on May 31, 2016

peer review in software

I have been part of many software teams where we desired to do code reviews. In most of those cases the code reviews did not take place, or were pointless and a waste of time. So the question is; how do you effectively conduct peer reviews in order to improve the quality of your systems. […]

Antenna Separation: How Close Can You Go?

by on May 16, 2016

antenna on car

Hi When building a new robot the mechanical engineers always ask me how close can the different antennas be to each other. It is not uncommon to try squeezing 5+ antennas on a single robot (GPS, GPS2 for heading, RTK, joystick, e-stop, communications, etc..). So what is the proper response? The real answer is that […]

Adaptive RRT – ARRT (with code)

by on March 28, 2016

Adaptive RRT

Hi all Back in 2010 I was taking an AI class where we learned about Rapidly Exploring Random Trees for motion planning. For my final project I developed an adaptive version of the RRT that I named ARRT. I decided to post it here to share with others. The post below is based from the […]

Book Review: Mastering ROS for Robotics Programming by Lentin Joseph

by on March 17, 2016

mastering ROS for robotics programming

Mastering ROS for Robotics Programming is a good book that will help you learn ROS and take advantage of some of the powerful nodes (programs) that are out there. The book covers both a 7 DOF robot arm and a differential drive robot throughout the different chapters. That should really help you out no matter […]

USB device configuration: Alternative to udev

by on December 16, 2015

USB Port

Hi all Every time I need to add multiple USB devices to a computer I get nervous and dread the architecture. The problem is when a computer boots it automatically brings up USB devices in whatever order it sees fit (think crazy race conditions). So if you have a motor controller, a camera, and a […]

Robotics for Kids (and Adults) – Getting Started and How to Progress

by on December 9, 2015

SIK_Shadow_Chasis Sparkfun

I get many questions from people about how I think kids and adults should get started in robotics, how they should progress, and what they should buy, to learn about robotics. Here is my quick response: I think level 1 is for people older than 12-13. Level 2 is for people older than 15, and […]

Fuse Locations, Protection, Shunt Regulation, & Motors

by on July 31, 2015

shunt regulator

Hi all I wanted to write a quick post today about where to place fuses and how to protect your robot. When you design a system it is often tempting to place a fuse on every component. This idea is fine for most batteries, sensors, and computers. However this can really cause destruction when you […]

Book Review: Practical Field Robotics by Robert Sturges

by on July 7, 2015

practical field robotics

Practical Field Robotics: A Systems Approach by Robert H. Sturges, Jr. from Virginia Tech is an interesting book about how to design a field robot from a high level systems approach, and how to build a robotic lawnmower. This book has 2 primary sections. The first part of the book looks at 3 different example […]

Convert Linux into an Embedded System

by on June 4, 2015

pc104 computer

Hi all Running Linux on your embedded system can be great for giving you a stable base, lots of tools, and you can often solve problems with a quick google search. I define embedded as any custom-built computer system, not only tiny devices. In many cases you can develop on the computer itself for ease […]

Robots taking our jobs, Are you prepared?

by on May 21, 2015

Kambeitz

Hi all Continuing on with posts from the recent RoboUniverse show in New York, I want to talk about Robots, Jobs, and Education. On the last day one of the primary talks was from Dennis Kambeitz at EZ-Robot. The topic was Preparing our workforce for a robotic world. I am going to try to hit […]

RoboUniverse New York 2015 – Initial Reaction

by on May 13, 2015

robo universe sponsors

Hi all I attended the last day (5/13/2015) of the RoboUniverse conference and exhibit in New York City. It was a good experience and I got to hear some interesting talks. I am usually deeply involved in the technical aspects of robotics, so it was interesting hearing about some of the other aspects. This was […]

Book Review: Implementation of Robot Systems by Mike Wilson

by on April 24, 2015

implementation robotic systems

Hi all Today I am reviewing Implementation of Robot Systems by Mike Wilson. This is a book about how to integrate robots into the manufacturing process. In this book Mike Wilson takes you through the process of deploying and developing your robotic systems since “All successful projects require a methodical approach to project planning.” By […]

Software Engineering Principles

by on April 6, 2015

Fix Bad Code

Hi all I have often thought about what the proper software methodology should be for the various robots that I build. My thoughts have evolved over time as I have seen these tool work. I do not have any formal software engineering training, however these are things that I have seen, heard, read, etc.. that […]

RoboUniverse New York – May 11-13, 2015

by on March 30, 2015

Robo Universe

Hi all Click here to see initial reactions after the event! RoboUniverse 2015 is happening May 11-13 in New York. I plan on being there and would love to meet up with others who are there. Please let me know if you plan on attending. I am waiting to see the full exhibitor list as […]

Lubrication: Dry vs Wet – Oil vs Grease

by on March 25, 2015

grease gun

One thing that is often looked is lubrication (lube). Changing your lubrication and selecting the proper type can dramatically modify the performance of your system. This change of lubrication was one of the primary reasons MSL was delayed from launching to Mars. Improper lubrication can cause your mechanical parts to wear out and fail. It […]

TOUGHBOOK: The Super Rugged Laptop Teardown

by on March 20, 2015

TOUGHBOOK

Hi all Today I have a Panasonic Toughbook CF-18 that I will have the opportunity to tear down and see just what makes these computers so rugged. Please keep reading for the details of scan through for some nice pictures (you can click an image for the larger version). The computer weighs 4lb 10.8 oz […]

Developing Trust in Autonomous Robots Seminar from Michael Wagner

by on March 2, 2015

ASTAA reliability method

Hi all I recently had the opportunity to hear a talk from a colleague that I have worked with many times over the last bunch of years. The talk was all about how to build safe and robust systems. This is a critical topic that we often pass-over but needs to be addressed if robots […]

Camera & Lens Selection

by on February 12, 2015

camera specs

Choosing a camera for your robot or machine vision system can be confusing. It is important to determine your requirements and then figure out how to achieve that between the camera and the optics. The first thing that most people talk about is resolution. The classic resolution of a camera is based on pixels; such […]

Transporting your Robot

by on January 29, 2015

highway transportation

Throughout my career I have had to ship different robots to different locations around the world. Here is a little bit about what I have learnt about transportation. The 3 basic ways for a robot to travel are by land, by air, and by sea. Typically by truck (I guess there are also trains, but […]

Controlling Brushless DC motor with no Encoders

by on December 29, 2014

hall detection

This is just a quick post on controlling DC brushless motors with no encoders. This post applies to brushless motors that typically use hall sensors for commutation. This post does not apply to the hall-less ESC (electronic speed control) motors that typically run at very high speeds and are used for things such as quadcopters […]

Incremental Encoder Selection

by on December 19, 2014

quadrature encoder

Hi all Just a quick post on incremental encoders. Incremental encoders are good for speed control and can be used for position control when we have a homing routine to get absolute position, or the system is constrained to less than one rotation. One way an incremental encoder can also be an absolute encoder is […]

Batteries

by on December 8, 2014

battery

Hi all Today I want to talk about batteries. However before I begin there are a few terms I want to clarify. So here we go. Terminology Cell – This is where the chemical reaction takes place which produces electricity. The characteristics of the cell are determined by its chemical formulation and its construction. Battery […]

Robot Motion (Path) Planning Overview

by on December 2, 2014

motion planning example

This post is going to be a summary of the different motion planning (ie. route finding) algorithms that are commonly used. I am not going to detail any of the particular algorithms, but rather give you a launchpad for finding a suitable algorithm for your application. You should remember that often you will mix and […]

Motors: Active, Reactive, and Apparent Power

by on November 10, 2014

power beer analogy

There are a bunch of confusing powers involved when we look at motors, especially with DC brushless motors. When your boss comes and asks you to measure the electrical power that your motor is using, it is often not straight forward. Typically the easiest way to get the current used by a motor is to […]

Grounding & Avoiding Ground Loops

by on November 3, 2014

Ground Loop

Ground loops are often discussed but less often understood (I am far from being an expert in this). I have seen several cases where a robot malfunctioned or a sensor did not work due to bad grounding. For example if you have a a 0-5V signal and also have a “noisy” ground then the signal […]

Copley Motor Controller Review

by on October 22, 2014

Copley controller

Hi all This is a post about the Copley Controls motor controllers. For this review I will be using a ACJ-055-09 (55Vmax and 9Apeak) motor controller (I love when product names mean something useful) with a 3 phase DC brushless motor. This is a good controller for distributed motion control. Copley makes several versions of […]

Drawbar Pull vs Rim Pull

by on October 13, 2014

rim pull

Hi all Many people get confused between what drawbar pull is and what rim pull is. Many people also use the terms interchangeably. Drawbar Pull – Pull available from the vehicle (think pulling from a hitch in the rear of the robot) Rim Pull – Pull available at the rim of each driving wheel (some […]

For Profit Technical Education Experience (ITT-Tech)

by on October 6, 2014

For Profit

There has been a lot of talk recently about for-profit education. Most of it is negative and a lot of it is true, however there are also some good things about for profit education that is often overlooked. This post is about the good, the bad, and the ugly that I have experienced at a […]