humanoid legs

initial concept

Inspired by the breaking of my own ankle. The design process began with sketches and 3D models, exploring different joint configurations and designs to achieve desired functionality.

first leg

The first leg utilized lego robotics motors which were hand hacked to control. I had to decode the quadrature encoder signals in software, and the microcontroller struggled to keep up while also controlling everything.

second leg and rl results

The final design has 5 degrees of freedom per leg, allowing for a wide range of movements and actions. In simulation, the legs can walk and run following user commands. The gait is fully emergent from the reward structure and not pre-programmed.

initial concept

Initial CAD Model of Humanoid Legs

Initial CAD

For the first iteration of the design, I created a CAD model of the legs. The design incorporated lego robotics servos for actuation, which were the only motors I had available at the time. These servos were really tricky to work with as they were not designed to be controlled by an arduino. They had a quadrature encoder that I had to decode in software, and the microcontroller struggled to keep up with the encoder signals while also controlling the motors. You can see in one of the next videos that this leads to a lot of overshooting and control problems in the legs.

Initial CAD Model of Humanoid Legs

Initial CAD

For the first iteration of the design, I created a CAD model of the legs. The design incorporated lego robotics servos for actuation, which were the only motors I had available at the time. These servos were really tricky to work with as they were not designed to be controlled by an arduino. They had a quadrature encoder that I had to decode in software, and the microcontroller struggled to keep up with the encoder signals while also controlling the motors. You can see in one of the next videos that this leads to a lot of overshooting and control problems in the legs.

first leg

Setting Up One Motor

Breadboarding One Motor

As previously alluded, I had to hack together a way to control the motors and read the encoders using an arduino. This involved a lot of trial and error, but eventually I got it figured out. This is a pic of the breadboard I used to test one motor and get it working with the encoder. Feel free to reach out if you want to see exactly how to wire up these motors and read the encoders.

Setting Up One Motor

Breadboarding One Motor

As previously alluded, I had to hack together a way to control the motors and read the encoders using an arduino. This involved a lot of trial and error, but eventually I got it figured out. This is a pic of the breadboard I used to test one motor and get it working with the encoder. Feel free to reach out if you want to see exactly how to wire up these motors and read the encoders.

second/third leg and rl results

Assembled Legs

Assembled Legs

Here is a pic of the assembled legs, both the lego motor version and DS 3218 version.

Assembled Legs

Assembled Legs

Here is a pic of the assembled legs, both the lego motor version and DS 3218 version.

initial concept

Initial CAD Model of Humanoid Legs

Initial CAD

For the first iteration of the design, I created a CAD model of the legs. The design incorporated lego robotics servos for actuation, which were the only motors I had available at the time. These servos were really tricky to work with as they were not designed to be controlled by an arduino. They had a quadrature encoder that I had to decode in software, and the microcontroller struggled to keep up with the encoder signals while also controlling the motors. You can see in one of the next videos that this leads to a lot of overshooting and control problems in the legs.

Initial CAD Model of Humanoid Legs

Initial CAD

For the first iteration of the design, I created a CAD model of the legs. The design incorporated lego robotics servos for actuation, which were the only motors I had available at the time. These servos were really tricky to work with as they were not designed to be controlled by an arduino. They had a quadrature encoder that I had to decode in software, and the microcontroller struggled to keep up with the encoder signals while also controlling the motors. You can see in one of the next videos that this leads to a lot of overshooting and control problems in the legs.

first leg

Setting Up One Motor

Breadboarding One Motor

As previously alluded, I had to hack together a way to control the motors and read the encoders using an arduino. This involved a lot of trial and error, but eventually I got it figured out. This is a pic of the breadboard I used to test one motor and get it working with the encoder. Feel free to reach out if you want to see exactly how to wire up these motors and read the encoders.

Setting Up One Motor

Breadboarding One Motor

As previously alluded, I had to hack together a way to control the motors and read the encoders using an arduino. This involved a lot of trial and error, but eventually I got it figured out. This is a pic of the breadboard I used to test one motor and get it working with the encoder. Feel free to reach out if you want to see exactly how to wire up these motors and read the encoders.

second/third leg and rl results

Assembled Legs

Assembled Legs

Here is a pic of the assembled legs, both the lego motor version and DS 3218 version.

Assembled Legs

Assembled Legs

Here is a pic of the assembled legs, both the lego motor version and DS 3218 version.