Walking Exoskeleton

Exoskeletons are external structures to the human body known as active orthosis, their function is to provide support in body movements, seeking to increase the capabilities of the human body, the main feature of the interaction of this device with a person is the ability to transfer mechanical energy and information signals to the user to recreate the gait cycle, which can be defined as the form of displacement in the bipedal position of the human being in which bipedal and monopodal supports are followed. This project proposes a simple prototype of an exoskeleton that will mimic the gait cycle designed in a CAD software with materials such as MDF cut with a CNC, specifically a Laser cutter, so if you have always been interested in biomechanics and robotics this small prototype is for you. 

For context, it is important to remember that the gait cycle begins when the foot contacts the ground and ends with the next ground contact of the same foot. The two main components of the gait cycle are the stance and balance phases. A leg is in the stance phase when it is in contact with the ground and is in the swing phase when it is not in contact with the ground.

Definitions:

CNC (Computer Numerical Control): Automated control of machining tools (such as laser cutters, drills, lathes, mills, routers, and 3D printers) through a computer.

CAD (Computer-Aided Design): The use of computer technology to design an object.

Laser Cutter: CNC machine that uses a high-power laser beam to melt, burn, or vaporize away materials, leaving an edge with a high-quality surface finish.

MDF (Medium Density Fibreboard): A wood-substitute material.

• Arduino board
• 6 x Servo motor
• 6 servo motor screws
• Breadboard
• Jumper wires
• Watchmaker's screwdriver (M2, for the screws that come with the servo motor)
• A power source (battery or USB cable)
• Any available laser cutter
• Robot structure (can be made of MDF of 3mm or any material of your choice)

• These files contain all the pieces to assemble the exoskeleton.

• Remember to check that the scale of the laser cutter is in millimeters
• The pieces are ready for cutting

• Cut the parts with a laser using an MDF panel of 3 mm thick.

• Once all the pieces have been cut, we number them as follows to assemble them later.

• Take piece 3a and insert the propeller including the servomotor into the borehole at the bottom, taking as a reference the position of the part as in the picture.
• Insert a servomotor between the three boreholes in piece 5a and place the screws to secure the servomotor to the piece.

• Then join pieces 5a and 3a with the help of the screw corresponding to the servo motor.

• Insert the servomotor into piece 4a and insert its two corresponding screws.
• Assemble piece 4a to the top of piece 3a using a propeller corresponding to the servo motor, and using a screw as shown below:

• Insert the servo motor into piece 2a and don't forget to put its screws in place.

• Insert a propeller into the top borehole of part 4a and attach this part to the servo motor of part 2a with the help of the propeller and a screw.

• Insert part 5b into part 6a, as shown in the picture:

• Assemble both parts mentioned in step 9 on the opposite side of piece 5a that had been placed at the beginning.
• Insert part 1 into the thin and long rectangular slot of piece 2a.

• Repeat all steps with piece b and at the end join using the 2b part slot with piece 1.

• Installed ID Arduino on your computer.

Link to download: https://docs.arduino.cc/software/ide-v1

• Connect each servo motor in the Arduino as shown in the picture.

Note: each servo motor must be connected to the corresponding pin of the Arduino.

• To recreate the gait cycle, the motors were programmed at 90º to place them in that position on the exoskeleton. 
• After that, the following code was used for the simulation of the gait cycle: