IOT Based Multi Terrain Quadruped

Project Title

IOT Based Multi Terrain Quadruped

Project Area of Specialization RoboticsProject Summary

The upcoming world is shifting from manual labor to automated industry. Exploration, surveillance and operations are transferred from human job to machine jobs. The task is to be performed by programmed robots to ensure safety of human lives. Here the problem arises of how to perform the motion when the terrains are not known. The robots are majorly wheeled robots that are controlled by remote in defined region. Therefore, we intend to develop a robot that will replace the moving disability of wheels by footsteps motion to gain access to various field areas. The motion will be performed by specifically designed robot with 4 legs having 3 direction of motion (forward, backward and turning in either direction). The robot will follow the gait pattern of 4 legged animals to perform the walking job. The robot is not only dedicated for step walking, it follows a proper gate movement with variety of sensors installed in it including GPS, Gyroscope, Camera and Ultrasonic sensors to gather data from surroundings, defining the incline or decline angles and globally defined location. The robot will be controlled remotely by IOT control to gain single station operations with live video stream access in 2-D plane with user having control of movement on his cell phone. The kinematics equations define the motion angle. The robot will be capable of walking, balancing the center of gravity with ability of bear certain weather condition and is to be prepared with lowest of cost making it best fit for designated fields.

Project Objectives

Quadruped is basically an animal having four limbs and which can walk using this legs.The goal of this project is to create a low-cost multi-terrain traversing robot prototype for search and rescue operation, connected via Internet of things (IoT) it can be used for Rescue, military jobs, spying, can be used at risk taking jobs e.g. industries to monitor and check the control of machines. Each leg have three Degree of Freedom just like the humanoid leg. The leg consist of three joints first is the hip joint, second knee joint and the last one is ankle joint. By using all the joints at once it can move past a step.

Project Implementation Method

The project begins with 3-D modeling of desired robot body type using solid works. Along with this, there begins the preparations for mathematical modeling of robot to define the stability of robot.

The stability is divided into 2 parts

• Static stability
• Dynamic stability

These 2 calculations are necessary to define the body dimensioning and leg for movement. Once the D-H table is defined describing input voltage for output angle movement the robot body was designed following the calculated values and #-D solid works model. The main focus was made on leg material and motor selection. Finally MG996 Servo motors were selected and metal clamps to fit in for leg formation were combined to give it shape of leg.

The top assemble is double sheet combination of 7mm and 5mm acralic sheet used to put together the motors and complete the assembly parts of robot. One the body was complete first step was to define the stability of legs foe its standing position. As the leg is lifted the centre of gravity of leg shifts which need to be retained. Along with this the walking steps were defined to specify the gait pattern for movement of robot. A 2 dimensional stand for camera placement is placed on head of robot to provide motion to camera for plane surveillance.

In parallel with technical team comes the programming team whose work was to setup the IOT control Using Raspberry pi 3B using its inbuilt module. The first task was to make a local client server and develop a mobile application for this connection. Initially a single line code to drive servo motor was used to start and stop motor. Once this was completed an interface for usage was setup with video stream options for view and control of system. The video is to screamed in real time.

Finally works for making it presentable were done and secondary wheels were setup to make it multi=operational.

Benefits of the Project

Quadruped robots can mimic animal walking gait and they have certain advantages like walking on terrain and extremely rough surfaces. Obstacles can impede the movement of wheeled vehicles, where a quadruped can adapt to avoid obstacles by adjusting its height. All the four legs have three DoF so that it can walk and turn around left and right. The main goal to construct this quadruped is the application in domestic, industrial sector and for surveillance. Taking the example of domestic application, now a day mostly women are working and their children are alone at home, took care by maids and according to many incidents it proves dangerous for their health.so this quadruped can easily look after the home and the kids also. Camera is mounted on the top of robot which is transmitting the live footage and videos bac to the owner, who can easily check the status on their smart phones.

Moreover, standalone robots require a power source to operate them, more the power losses, greater will be the power consume by the quadruped. So, the walking motion makes this problem easy as it only requires less amount of power to walk on rough terrain as compared to wheels motion because it impacts more friction as surface area increases. Going further this robust structure helps to monitor plants in industries where human life is in danger. In petroleum  industries Sulphur is producing from the leftovers of the crude oil, at that area of plant there is a high risk of the emission of Sulphur dioxide, and the workers who are there just to check the parameters (temperature, pressure, level, flow)   are in control, there life are at a great risk. So, the remedy is that quadruped which can take place the position of workers and they there is no need, as the sensors mounted on them will measure the parameters and send them to the Distributed Control System through Internet of Things.

Furthermore, walking legs is always not the solution because every time we don’t know about the surface on which it is walking. So, a transformation mechanism is applied on this robot. Wheels are attached on the ankle joint of each leg so when there is a plane surface or an inclined surface a head a signal sent to the controller raspberry pie will transform the legs into wheels which can move on. This interesting future further increases its application area where it is not only limited to the walking motion.

Besides this, a gyro attached at the top will give stability to the camera when robot is moving on a rough surface. Ultrasonic sensor is also operated with the whole system to give it a little touch of artificial intelligence, it will avoid obstacles on its own and can be protected from damages even if the operator is not controlling it.

In a nutshell, this robust robot can assist in almost every field of today’s world by only modifying it according to your needs.

Technical Details of Final Deliverable

In light of technical specifications, the technicalities are widespread covering the stability of robot to dynamic motion and control feedback by applying internet of things.

The robot is electrically actuated using MG996 servo motors. Each motor has 11kg-cm torque capable of turning and lifting the leg for step movement. Each leg has 3 fitted motors with application depend of usage. The top hip motors are combinational pairs used for turning, this enables proper turning rather than the speed shift turns done by slowing down one movement compared to other. Second motor is vertically mounted on hip to provide unidirectional lift for the step and finally is the foot motor used to control the altitude placement of leg.

The internet of things connection is established using raspberry pi 3B built in wifi module. The wifi is connected to local host server using connected router and program is installed in pi to decode the input data from mobile application. The mobile application is self designed to provide real time video stream and control to end user to drive the robot at remote locations using the hand control.

Further operations to make it work at any random host are under process and are expected to be completed. There is a 2-D camera mount fitted at head of robot that is used to provide the robot a complete view of surrounding and is controlled via the mobile app.

The in fitted sensors include:

• Global Positioning system
• Gyroscope for camera and leg stability
• Camera for real time monitoring
• Ultrasonic sensors for object detection and vehicle stoppage

The leg movement and foot placement follow a specialized gait pattern followed by a complete back end forward and reverse kinematics derivation defining the coordinate’s placement of leg for each leg setup. In quadruped a good mathematical modeling of quadruped is necessary for the stability of the mechanical structure as well as to define the trajectory of motion.

Forward Kinematics:

In the forward kinematic analysis, the joint variables are given to find the location of the body of the robot. Unique in serial type manipulators, but not unique in parallel type manipulators

                               

Inverse Kinematics:

In the inverse kinematic analysis, the location of the body is given to find the joint variables necessary to bring the body to the desired location.

Components of a Robot:

Link length (a):

It is the shortest distance between joints at both ends of link. ai  is distance from zi-1 to zi measured along xi (constant)

Twist angle (? )
It is the angle between two joint axes attached at both ends of the link. ?i is angle from zi-1 to zi measured along xi (constant) (link twist)

               

Joint angle (? )

It is an angle of one link relative to the previous link. ?i is angle from xi-1 to xi measured along zi-1

Joint displacement (d)

It is the displacement of one link relative to the previous link di is distance from xi-1 to xi measured along zi-1 

                                  

Final Deliverable of the Project HW/SW integrated systemCore Industry SecurityOther Industries Manufacturing Core Technology RoboticsOther Technologies Internet of Things (IoT)Sustainable Development Goals Decent Work and Economic Growth, Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	61700
Servo Motor MG-996	Equipment	12	800	9600
Servo Motor Clamps (Metallic)	Equipment	12	450	5400
Acrylic sheet 5mm & 7mm	Equipment	2	1000	2000
Raspberry Pi 3 B+	Equipment	1	6000	6000
Raspberry Pi Camera	Equipment	1	4500	4500
2S Lipo Battery 10000 mAh	Equipment	1	6000	6000
Camera Mount with Servo Motors	Equipment	1	1500	1500
MPU6050 Sensor Module	Equipment	1	500	500
Ultrasonic sensor HC-SR04	Equipment	1	500	500
GPS module Ublox NEO-6M	Equipment	1	1500	1500
Body Design Molding sheet	Equipment	1	15000	15000
Arduino MEGA	Miscellaneous	1	2200	2200
Robot Metal Stand	Miscellaneous	1	1000	1000
Wires,breadboard and Power Supply	Miscellaneous	1	2000	2000
Transportation	Miscellaneous	2	2000	4000