How I started using Rero…
Photo from left to right: Tan Eng Tong(CEO of Cytron Technologies Sdn.Bhd), Aw Yong Tuck Weng, Jensen Jazz Cher, Hiew Wei Seng, Jing Wen Keng.
My First Rero Camp
Suggested by my teachers from my secondary school Chong Hwa Independent High School, my friends and I accepted the offer at the age of 16 years old.
Rero Training Camp at Pay Fong High School, image and details of the camp can also be found on this website: https://www.rero.io/news/15/3-day-2-night-technology-workshop-in-melaka
Mimic the Snake
Photo of me and my friends adding extra locomotion features to our snake to increase its traction to the ground.
To understand how a snake slithers, there are a few important concepts to understand:
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There are four ways a snake can move:
a. Serpentine Method, the snakes moves in a sinusoidal way, by pushing itself away from the ground, the snake is able to move forward, this movement highly depends on traction.
b. Corcentina method, although identical to serpentine, the snake behaves like a spring and propels itself forward by pushing the back portion of its body, this snake robot uses this method.
c. Sidewinding method, used under slippery or muddy ground, the snake propels sideways by pushing its head.
d. Rectilinear Method, this is a slow, creeping, straight movement. The snake uses some of the wide scales on its belly to grip the ground while pushing forward with the others.
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Friction plays a great role in the slithering movement of a snake, and we can explain this using Impulsive Force’s equation:
F=(mv-mu)/t
m is mass of the robot,
v is final velocity,
u is initial velocity,
t is time of impulse.
Here’s the trick, if you want your snake robot to move really fast, you would need a strong impulsive force at the back portion of your robot. Hence, your change in velocity must be large( that would mean your snake needs to slither really fast ).
However, if your snake slithers too fast, it might slip because your snake relies on friction force, which is F=uR and is a constant value. If your impulsive force is larger than your friction, slip occurs. (Generally speaking, you have the backward force but you lack the frontward force, so try to strike a balance)
Locomotion
To increase the traction of the robot with the ground, we not only added locked rubber wheels to the back portion to the robot snake, we also added the locomotion of a worm to increase the normal force acting on the robot.
In order to make the snake robot tilt to the left or right, we programmed it to repeat the left or right side cycle until we achieved the desired angle.
Result
Despite us losing the competition in terms of speed( the goal is to design a robot to escape one of the tunnels as soon as possible), we obtained best creativity award in the same competition and was published on the news the next day.
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Image taken from SinChew Daily Melaka link