bipedal

17 Articles

Hackaday Prize Entry: Two Leg Robot

October 20, 2017 by 12 Comments

If you’re working on your own bipedal robot, you don’t have to start from the ground up anymore. [Ted Huntington]’s Two Leg Robot project aims to be an Open Source platform that’ll give any future humanoid-robot builders a leg up.

While we’ve seen quite a few small two-legged walkers, making a pair of legs for something human-sized is a totally different endeavor. [Ted]’s legs are chock-full of sensors, and there’s a lot of software that processes all of the data. That’s full kinematics and sensor info going back and forth from 3D model to hardware. Very cool. And to top it all off, “Two Leg” uses affordable motors and gearing. This is a full-sized bipedal robot platform that you might someday be to afford!

Will walking robots really change the world? Maybe. Will easily available designs for an affordable bipedal platform give hackers of the future a good base to stand on? We hope so! And that’s why this is a great entry for the Hackaday Prize.

The HackadayPrize2017 is Sponsored by:

Biped Bob Walks And Dances

June 14, 2017 by 5 Comments

If you have a few servo motors, an Arduino, and a Bluetooth module, you could make Biped Bob as a weekend project. [B. Aswinth Raj] used a 3D printer, but he also points out that you could have the parts printed by a service or just cut them out of cardboard. They aren’t that complex.

Each of Bob’s legs has two servo motors: one for the hip and one for the ankle. Of course, the real work is in the software, and the post breaks it down piece-by-piece. In addition to the Arduino code, there’s an Android app written using Processing. You can build it yourself, or download the APK. The robot connects to the phone via BlueTooth and provides a simple user interface to do a few different walking gaits and dances. You can see a few videos of Biped Bob in action, below.

This wouldn’t be a bad starter project for a young person or anyone getting started with robotics, especially if you have a 3D printer. However, it is fairly limited since there are no sensors. Then again, that could be version two, if you were feeling adventurous.

We have mixed feelings about the BlueTooth control. BlueTooth modules are cheap and readily available, but so are ESP8266s. It probably would not be very difficult to put Bob on WiFi and let him serve his own control page to any web browser.

If Bob meets Jimmy, he may find himself envious. However, Jimmy would be a little more challenging to build. We’ve actually seen quite a few walking ‘bots over the years. Continue reading “Biped Bob Walks And Dances” →

“Look Ma, No Gyros!”: A Self-Balancing Mechanical Velociraptor

May 7, 2017 by 22 Comments

You’ve got to walk before you can run, right? Perhaps not, if this bipedal dino-like running robot is any indication.

Officially dubbed a “Planar Elliptical Runner,” the bot is a test platform for bipedal locomotion from the Institute for Human and Machine Cognition. Taking inspiration from the gait of an ostrich — we think it looks more like a T. rex or velociraptor, but same difference — [Jerry Pratt]’s team at IHMC have built something pretty remarkable. Contrary to all the bipedal and quadrupedal robots we’ve seen, like Boston Dynamics’ Big Dog and PETMAN, which all fairly bristle with sensors and actuators, the PER is very stripped down.

A single motor runs the entire drive chain using linkages that will look familiar to anyone who has taken an elliptical trainer apart, and there’s not a computer or sensor on board. The PER keeps its balance by what the team calls “reactive resilience”: torsion springs between the drive sprocket and cranks automatically modulate the power to both the landing leg and the swing leg to confer stability during a run. The video below shows this well if you single-frame it starting at 2:03; note the variable angles of the crank arms as the robot works through its stride.

The treadmill tests are constrained by a couple of plastic sheets, but the next version will run free. It’s not clear yet how directional control will be achieved, not is it obvious how the PER will be able to stop running and keep its balance. But it’s an interesting advance in locomotion and we look forward to seeing what IHMC’s next trick will be.

Continue reading ““Look Ma, No Gyros!”: A Self-Balancing Mechanical Velociraptor” →

Gyroman Walks With Just One Motor

May 8, 2016 by 11 Comments

For some reason, we seem to really want our robots to walk on two legs like we do. And this despite how much the robots themselves want to be made out of motors, which match up so naturally with wheels. The result is a proliferation of inventive walking mechanisms. Here’s another.

Gyroman is a 3D printed gyroscope with legs. The gyroscope is geared down to lift one leg and then the other. First-semester physics, that we still find a little bit magical, makes the gyro precess and the robot turns a bit. Time these just right and it walks. See the video below for a demo. (Admittedly, Gyroman looks like he’s had a bit too much to drink as he winds down.)

Continue reading “Gyroman Walks With Just One Motor” →

Walk Your Pet Robot

June 18, 2015 by 20 Comments

Anyone who’s ever tried to build a bipedal robot will quickly start pulling their own hair out. There are usually a lot of servos involved, and controlling them all in a cohesive way is frustrating to say the least. [Mark] had this problem while trying to get his robot to dance, and to solve it he built a control system for a simple bipedal robot that helps solve this problem.

[Mark]’s robot has six servo motors per leg, for a total of 12 degrees of freedom. Commands are sent to the robot with an RC radio, and the control board that he built, called the Smart Servo Controller, receives the signals and controls the servos appropriately. There are 14 outputs for servos, operating at 12 bits and 50 Hz each, as well as 8 input channels. The servo controller can be programmed on a computer with user-selectable curves for various behaviors for each of the servos on the project. This eliminates the need to write cumbersome programs for simple robot movements, and it looks like it does a pretty good job!

Full disclosure: [Mark] currently has this project up on Kickstarter, but it is a unique take on complex robot control that could help out in a lot of different ways. Since you don’t need to code anything, it could lower the entry barrier for this type of project, possibly opening it up to kids or school projects. Beyond that, even veterans of these types of projects could benefit by not having to do as much brute-force work to get their creations up and moving around!

Continue reading “Walk Your Pet Robot” →

Move Aside Boston Dynamics, ATRIAS Is Coming!

May 6, 2015 by 35 Comments

ATRIAS has just taken its first steps outside on grass, marking an impressive achievement for this university robotics project.

Built by Oregon State University, ATRIAS is a bipedal robot whose name in jest stands for “Assume The Robot Is A Sphere”. It’s an old physics joke really, which describes how any complex scientific model can be reduced to its simplest form in order perform calculations — but sometimes (always) makes its application in reality a challenge…

We’re sure you all remember BD’s Big Dog and its impressive ability to throw freaking cinder blocks — but remember, it has four legs and a tail — or is it a trunk — an arm? ATRIAS on the other hand is a true threat to humanity and our unique ability to walk around on two legs. And the mechanism they made for it is pretty damn clever.

Continue reading “Move Aside Boston Dynamics, ATRIAS Is Coming!” →

Project Sentinel — A Bipedal Walking Robot

July 6, 2014 by 30 Comments

Bipedal-Walking-Sentinel-Project-500x375

[Ye Guan] has always been fascinated by walking robots — so he decided to build his own. It’s called Project Sentinel, and he’s loosely based the design off of the Sentinel Walker from Warhammer 40K, and the two-legged AT-AT walker from Star Wars.

Both of these robots are based off of a bird’s walking style. Scientifically this is called the digitgrade walking style, which means they stand and walk on their digits (toes) — this typically allows them to move more quickly and quietly than most other animals.

[Ye] has managed to achieve this for his project using 8 servo motors, balancing the center of mass directly above the feet. Think about it like a reverse pendulum, which is supported by the servos torque and balanced by a gyroscope. He plans to have it fully autonomous with sensor feedback.

It’s not done yet, but he’s already released all the CAD files and a nice build log for anyone to attempt it themselves — we’re excited to see the final product. Just take a look at it walking in place after the break!

Continue reading “Project Sentinel — A Bipedal Walking Robot” →