TITRUS-III was developed by the Tokyo Institute of Technology (Hirose + Yondea Lab) and is a bipedal walking robot in the form of a miniature dinosaur.
While at the surface, it may seem to be a generic toy robot that can move about, that is far from the case. The mechanisms at hand here are phenomenal and which I will later get into
For now, here is a clip of the robot:
The Leg Mechanism
Each leg is controlled by just 2 servo-motors forming a parallelogram-like leg. By controlling each servo individually and moving them to the desired angle, we can move the foot of the leg to any position we want. So long as it is in bounds.
Now having the motor that controls the knee of the leg-mounted in the body can be very advantageous as it means the robot can still continue operating even if the knee gets damaged.
The only issue with having this sort of leg configuration is the inverse kinematics gets quite tricky. In robotics, we use inverse kinematics to figure out what angle each motor should be to move the arm or leg to the desired position in 2D/3D space. In this case, it is 2D space since the legs cannot tilt which might be a slight concern.
researchers at the Disney Research Lab have made a leg mechanism that can tilt as well and looks somewhat similar to TITRUS-III leg design however It does require more motors for the legs.
Here is their design in operation:
For each leg, it now requires 4 motors rather than 2. It can almost be described as 2 parallelogram legs merged together as one controls tilt and the other general walking movement. However inverse kinematics for this robot is a lot harder since we are dealing with 3D space and the mechanisms are quite intricate.
The tail is what I find the most fascinating about the robot and how this design can be implemented across a huge variety of different robots.
You see the tail is controlled by just 2 servo motors and is configured so that the tail is attached to the ball socket at the body.
This allows the tail to move up and down and side to sidegiving it fantastic versatility.
Now for a bipedal robot, this is much needed as they have a tendency to shift their center of gravity too far to the left or the right when walking. Which would cause it to fall over.
Now by having a tail that has a mass (the battery) at the end of it; It can stabilize its position while walking and not fall down.
Of course for humanoid robots, having a tail would be quite amusing, you could have a weight that moved very precise distances very quickly to stabilize.
The tail mechanism can even be used in robot snakes or quadruped robots that need to climb over tall terrain or fit into tight spaces with lots of turns.
So overall I think TITRUS-III is a brilliant robot that uses some well-thought-out mechanisms. These mechanisms not only make the robot more robust but can diminish costs as well.
So that’s all for today. If you’re interested in robotics, electronics or philosophy, be sure to follow me and stay tuned.