Arduino based quadruped !!! ,Quadruped stands for four legged bot ,which is basically look like a four legged spider ,so let learn us learn how the spider walks and try to replicate it with arduino

## Step 1: Components Required

• 1 X Arduino Mega or Arduino Uno
• 1 X Drilled PCB
• 12 X Servo Motors(9g)
• 1 X HC-SR04 Ultrasonic Sensor
• 4 X RGB LED
• Cardboard

## Step 2: Maintaining CG

center of gravity (CG) is main factor while walking .Center of gravity remains in center of the body to stand balance

,if CG moves out of center on certain limits then balance will be affected and leads to falling down

So let us see about maintaining CG while walking .

if every legs are in 45 degree then the CG will be perfectly main in center ,But if we moved any leg the cg will shift to that side so it lead to falling on that side .

So to avoid this the either end legs are maintained at an angle greater than 45 degree based on the bot size

so the three legs will form a triangle ,were the CG will be inside it and the fourth leg will be free to move and CG

will remains inside a triangle.

## Step 3: Walking Procedure

• This is the starting position, with two legs(C,D) extended out on one side, and the other two legs(A,B) pulled inward.
• The top-right leg(B) lifts up and reaches out, far ahead of the robot.
• All the legs shift backward, moving the body forward.
• The back-left leg(D) lifts and steps forward alongside the body. This position is the mirror image of the starting position.
• The top-left leg(B) lifts and reaches out, far ahead of the robot.
• Again, all the legs shift backward, moving the body forward.
• The back-right leg lifts(B) and steps back into the body, bringing us back to the starting position.

## Step 5: Construction of Body

construct the body according to pdf

## Step 6: Circuit Connection

make your own shield according to your requirement arduino mega has 15 pwm pin ,use 12 of them for servo connections and 3 for RBG led and any two pins for ultrasonic sensor

## Step 7: Intialization of Servo

• Upload the program to arduino mega and start assembling the leg according to picture