HEXAPOD-Using 2 DC motors

A hexapod robot is a mechanical vehicle that walks on six legs. Since a robot can be statically stable on three or more legs, a hexapod robot has a great deal of flexibility in how it can move. If 1 or 2 legs become disabled, the robot may still be able to walk.

Basically, a hexapod uses 3 or 6 actuators but here we have designed the robot in such a manner that it can work properly by using just 1 or 2 motors. For such design, I have utilized 4-bar mechanism and not one or two here I have used six 4-bar mechanisms.

What is a 4-bar mechanism?

4-bar-Wikipedia

Innovation

Basically, the innovation is in the Design of the hexapod, by merging three 4-bar mechanisms each side we made a planer mechanism which can be run by just one motor.

Here I have shown all 4-bar mechanism by different colours line on linkages

After Designing the mechanism now its time to do some analysis, For analysis, I have used Adams.

First Prototype

Team

Akash K. Jain

Vikash Singh Rajput

BiPed Robot

History
From the beginning of time human had a desire to replicate himself and with this desire, he started building robots and tried his best to give a shape similar to human. This desire became the motivation to build biped robots.

What is a Biped robot?
Basically, a Biped robot is a replica of the human lower limb which can stand and walk on two legs. Main challenge behind a Biped is balancing.
For more info on biped, you can check Wikipedia

Structure
Structure for stability
We have decided to use legs with two joints of DOF one. That means you have a total of 2 DOF for both legs. Centre of mass is being balanced in between both legs while standing and on a single leg while moving. For balancing COM on a single leg, we have used feet of large surface area.

Motion
Movement of robot happens in 3 repeating steps. First the entire body tilts to move the COM on a single leg, let say on left leg. Because of this shift in COM the right leg is free to move, this time, the robot takes its first step and right leg moves forward. Then again COM shifts to centre but legs are not in same vertical or not parallel. Now the same steps repeat but with opposite legs, that means the entire body tilts towards right instead of the left and left leg will come forward.

360 Video of different positions (Moblie users should open this in YouTube app)

Electronics 

For actuation, we have used 4 servo motors, that means precisely controlled one degree of freedom. For controlling these servos I have used Arduino, an open-source microcontroller. The code for Arduino is Biped Code.

Circuit

All the signal pins of servos shall be connected to pins as shown in fig below, and ground and Vcc pins shall be connected to GND and 5V of Arduino respectively.

Final Video

Team

This project is done as Gymkhana Projects under Robotics Club IIT Indore.
Team members-

• Bittu Kumar
• Khushboo Agrawal
• Mohini Phulwalkar

Mentor-
Akash K. Jain