Animals like dogs, cats, raccoons, rhinoceroses, and many more get around on four legs. To help imitate this natural phenomenon, maker “Technovation” decided to create a low-cost quadruped robot using 12 servo motors and variety of 3D-printed and laser-cut parts.
Each leg features two servos that move inline with the body, as well as one arranged with its rotation axis at 90 degrees. This enables it to walk forward, scoot side-to-side, and perform a variety of twisting motions.
The robot is powered by an Arduino Uno, along with a sensor shield for easy motor connections. Inverse kinematics can be used to properly calculate servo moves, which is integrated into the device’s control sketch.
Daniel Hingston wanted to build a four-legged walking robot for several years, and with current coronavirus restrictions he finally got his chance. His 3D-printed robodog, dubbed “GoodBoy,” is reminiscent of a miniature version of Boston Dynamics’ Spot, which helped inspired the project.
It’s extremely clean, with wiring integrated into the legs mid-print. Two micro servos per leg move it in a forward direction, controlled by an Arduino Uno.
Obstacle avoidance is provided by a pair of ultrasonic sensor “eyes,” allowing it to stop when something is in its path. An LDR sensor is also implemented, which when covered by its human minder commands it to present its paw for shaking.
Be sure to check out a short demo of GoodBoy below!
To accomplish this, the round quadruped utilizes one servo to deploy each leg via a parallelogram linkage system and another to move it forwards and backwards. A clever single-servo assembly is also implemented on the bottom to fill gaps left by the legs.
The device is controlled by an Arduino Nano, along with a 16-channel servo driver board. Obstacle avoidance is handled via an ultrasonic sensor, which sticks out of the top half of the sphere and rotates side to side using yet another servo.
It’s an impressive mechanical build, especially considering its diminutive size of 130mm (5.12in) in diameter.