I have worked a lot with the EV3 kits to really begin my understanding of robotics. Here in this page, you will see a few of my favorite Lego EV3 robots that I have done in the past.
Komodo: The Walking Robot
The goal of this project was to change rotational motion into locomotion without the use of wheels. To do this, we first spent a minutes researching examples of non-rotational locomotion. Our initial design was very unstable and would constantly fall over due to being top heavy. So, we made improvements to the design by lowering the center of gravity both through motor orientation, placement and shortening the lengths of the legs. By keeping the EV3 and motors in line, we could have the center of mass as close to the ground as possible. The orientation of the motors is also key because it allowed us to use beams that are longer than the shortest beams in the kit, thus giving us a little bit more travel of the legs to move the robot forwards or backwards. Once the motors were connected, it was all about making the design as stable as possible. We added beams so the construction would not fall apart, added gears and tracks to increase stability while walking, and finally added the rubber feet to give Komodo the traction needed to move.
Optimus: The Control Truck
The goal for this project, was to create a two motor truck/cab that would have a trailer attached at a joint with a gyro sensor attached to the top of the joint and a second gyro sensor mounted on on to the actual cab. The code that we developed would drive the trailer in reverse and maintain a constant control of the system. This first challenge had to be done with only the gyro sensor attached to the joint. The second challenge required the truck/cab to maintain a circular path in reverse. For this portion of the project, the second gyroscope would come in to play.
2-D Robotic Arm: Inverse Kinematics
One of the most fun challenges was we were assigned to actually assemble the robotic arm composed of two arm links and two joints, one connecting the first arm to the base and the other connecting one arm to the other. The final component is an end effector that actually holds a marker.
We were able to track the position of the end effector and effectively make the arm follow track the position it had previously been to. This function is shown in the following video: