Description:TECHNICAL FIELD
The primary objective of this project is to design and build a robotic arm with six degrees of freedom using six servo motors that are connected to an Arduino uno. A mobile device can operate these motors via an MIT application that is connected using a Bluetooth module called the HC-05. Applications of the Arm involve pick and place operations.
BACKGROUND
A robotic arm is a mechanical system designed to mimic the functions of a human arm. It typically consists of a series of rigid segments (links) connected by joints, allowing it to move and manipulate objects in its environment. Robotic arms have a wide range of applications across various industries, including manufacturing, healthcare, automotive, aerospace, and research. Here's some background information on robotic arms:
1. History: The development of robotic arms dates back to the mid-20th century. One of the earliest and most famous examples is the "Unimate," developed by George Devol and Joseph Engelberger in the 1950s. It was the first industrial robot used for assembly line production in General Motors' factory in 1961. Since then, robotic arms have undergone significant advancements in terms of design, functionality, and applications.
2. Components: Robotic arms consist of several key components:
- Links and Joints: These are the segments and connections that enable the arm to move. The joints can be rotary (allowing rotation around an axis) or linear (allowing movement along an axis).
- Actuators: Actuators provide the power to move the joints of the robotic arm. Common types of actuators include electric motors, pneumatic cylinders, and hydraulic cylinders.
- End-Effector: This is the tool or device attached to the end of the robotic arm that interacts with objects in the environment. End-effectors can include grippers, suction cups, welding torches, cameras, or specialized tools for specific tasks.
- Control System: The control system governs the movement and operation of the robotic arm. It can be programmed to perform predefined tasks, controlled remotely by a human operator, or operate autonomously using sensors and feedback mechanisms.
3. Types of Robotic Arms:
- Industrial Robotic Arms: These are used for tasks such as assembly, welding, painting, material handling, and packaging in manufacturing environments.
- Collaborative Robotic Arms (Cobots): Designed to work alongside humans in shared workspaces safely. Cobots are equipped with sensors and safety features to detect and avoid collisions with humans.
- Medical Robotic Arms: Utilized in surgical procedures for precision and minimally invasive operations, such as robotic-assisted surgery.
- Mobile Robotic Arms: Mounted on mobile platforms, these arms can navigate and manipulate objects in dynamic environments, such as warehouses or disaster zones.
- Research and Educational Robotic Arms: Used in academic and research settings for experimentation, prototyping, and teaching robotics principles.
4. Advancements and Challenges: Recent advancements in robotics technology, including improvements in sensors, artificial intelligence, and materials, have led to more capable and versatile robotic arms. Challenges in the field include enhancing dexterity and flexibility, improving human-robot interaction, ensuring safety, and reducing costs to make robotic arms more accessible across various industries.
Overall, robotic arms play a crucial role in increasing efficiency, precision, and automation in numerous tasks, contributing to advancements in manufacturing, healthcare, and other fields.
SUMMARY
It is a fundamental concept in robotics and mechanical systems that refers to the number of independent parameters required to fully describe the position and orientation of a system. In the context of robotic arms, DOF represents the number of independent motions or axes along which the arm can move.Each DOF corresponds to a specific axis of motion, which can be either translational or rotational. Translational DOF allows the robotic arm to move linearly along a specific axis, while rotational DOF enables the arm to rotate around a particular axis..
The total number of DOF in a robotic arm is the sum of its translational and rotational DOF. For example, a robotic arm with three translational DOF (X, Y, Z) and three rotational DOF (Roll, Pitch, Yaw) has a total of six DOF and is referred to as a 6DOF robotic arm.In summary, Degrees of Freedom (DOF) in robotic arms represents the number of independent motions or axes along which the arm can move. It encompasses both translational and rotational motions, and it determines the arm's range of motion, flexibility, and capability to perform tasks in various applications
A mechanical system or robotic arm that has six degrees of freedom (6DOF) may move independently in six separate directions or axes. Three translational degrees of freedom (DOF) and three rotational degrees of freedom are included in these axes.
The robotic arm can move linearly in three dimensions thanks to the translational DOF. Movement is possible along the depth using the Z-axis, vertical movement is possible along the Y-axis, and horizontal movement is possible along the X-axis. The robotic arm may access many locations in a three-dimensional space because of this translational DOF.
These six DOF work together to give a robotic arm extraordinary flexibility and maneuverability. It can make intricate movements and adjustments, including changing positions, tilting and angling the end effector, and rotating along a number of axes. The robotic arm can undertake complex tasks, adapt to different workplaces, and interact with items in a flexible and precise way because of its freedom of movement.
Numerous sectors, including manufacturing, automation, healthcare, research, and exploration, can benefit from the 6 DOF concept. It makes it possible for robotic arms to carry out activities that call for deft manipulation, exact positioning, and flexibility in changing settings.
In summary, the concept of Six Degrees of Freedom (6DOF) refers to the ability of a robotic arm to move independently along six different axes: X, Y, Z for translation, and Roll, Pitch, Yaw for rotation. This freedom of movement enables the robotic arm to achieve versatile and precise motions, making it a valuable tool in various industries and applications.
DESCRIPTION OF THE DRAWING

Figure 1 shows the Block Diagram of the proposed 6 DOF Robotic arm.
Figure 2 shows the Circuit Diagram.
Figure 3 shows the Flowchart of the working of the system.

DESCRIPTION OF THE WORKING OF THE INVENTION ALONG WITH DRAWINGS/BLOCK DIAGRAMS
The primary objective of this project is to design and build a robotic arm with six degrees of freedom using six servo motors to perform pick and place operations. Figure 1 shows the block diagram of the 6 DOF Robotic arm.
It uses an Arduino Uno R3 as the microcontroller, which is configured to carry out particular duties. The output is delivered to the six motors that execute different tasks for the robotic arm as indicated by the arrows pointing in their direction. Wireless connection is accomplished via an HC-05 Bluetooth module. The wireless connection between the Bluetooth module and the mobile device is indicated by the dotted line.
The device consists of an Arduino Uno R3 100, it has a microcontroller chip and has input and output pins allowing it to interact with the external environment. We use this board to connect the necessary motors and the Bluetooth module along with the power supply.
The entire arm is controlled by the Smartphone 101, in which the MIT App Inventor app is downloaded. We used the MIT App to represent the six motors, identified by sliders with names such as grip, wrist pitch, wrist roll, elbow, shoulder, and waist. Each slider regulates how each motor moves.
The HC-05 bluetooth module 102 creates a wireless connection between the robotic arm and a computer or mobile device. The HC-05 module operates according to the fundamentals of serial communication. This gadget transmits over a range of approximately 10 meters using a frequency spectrum of roughly 2.45GHz. This device can either send or receive data from an external source in its default mode of operation, which is the master-slave mode.
The robotic arm's joints are moved by the six motors. Every motor is wired to a motor driver, which also supplies power and control signals to the motors.
WAIST MG996R 103 represents the base of the robot. It swings the entire arm around its 360° rotational range.
SHOULDER MG996R 104 signifies the shoulder, similar to that of a human arm.
ELBOW MG996R 105 is the elbow, which is a revolute/rotatory joint that rotates everything connected beyond it.
WRIST ROLL SG90 106 is constructed to work as a forearm which is also a revolute joint.
WRIST PITCH SG90 107 signifies the wrist and performs two motions; bend and rotation.
GRIPPER SG90 108 is an additional rotational axis that facilitates rotation of the wrist independently, irrespective of the forearm.
Figure 2 shows the circuit diagram of the device. It consists of an Arduino Uno R3 200, HC-05 Bluetooth module 201, 5V External Power supply 202, and the 6 motors namely, WAIST MG996R 203, SHOULDER MG996R 204, ELBOW MG996R 205, WRIST ROLL SG90 206, WRIST PITCH SG90 207, GRIPPER SG90 208 . Below is the pin configuration for the same.

SENSORS
Pin Configuration
WAIST MG996R
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 5 of Arduino
SHOULDER MG996R
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 6 of Arduino
ELBOW MG996R
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 7 of Arduino
WRIST ROLL SG90
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 8 of Arduino
WRIST PITCH SG90
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 9 of Arduino
GRIPPER SG90
VCC--- >5v of Arduino
GND---- >GND of Arduino
PWM---- > Pin 10 of Arduino
HC-05 Bluetooth module
VCC--- >5v of Arduino
GND---- >GND of Arduino
Tx---- > Pin 3 of Arduino
Rx---- > Pin 4 of Arduino
5V External Power Supply
Positive (+) ---- > 5v of Arduino
Negative (-) ---- >GND of Arduino

Figure 3 shows the flowchart of the working of the device. The arm stays in its initial position when the program is first launched. As we adjust the angle using our mobile device, the resultant command is sent to the Bluetooth module, which then passes it on to the Arduino, whose instruction causes the motor to move. As shown in the diagram, it first determines whether the command received is for the wrist angle. If it is, Arduino is used to drive the motor movement. If it is not, it determines which angle to execute.At the end of the procedure, if no further commands are given, it returns to its original position; otherwise, another process is initiated.
, Claims:We Claim:

A 6 DOF Robotic Arm Manipulator system, comprising

A robotic arm with six degrees of freedom using six servo motors that are connected to an Arduino uno. A mobile device which can operate these motors via an MIT application that is connected using a Bluetooth module called the HC-05. Applications of the Arm involve pick and place operations with 90% accuracy and 60% lesser power used compared to other traditional robotic arms.
The arm has been made using simple and cost-effective components, starting from an Arduino Uno which has excellent peripherals and can support the functionality of 6 motors to work simultaneously.
A combination of 6 servo motors have been used, 3 MG996R servo motors for joints 1,2, and 3, and SG90 micro-servo motors for joints 4,5, and 6 to facilitate the 6 DOF movements. The Bluetooth module HC-05 is small, compact, and has a good range. The interface on the mobile app is fairly simple which has sliders for each motor at each joint and carries out the commands smoothly.
The Arduino Uno R3 is the main brain behind this 6 DOF robotic arm system. It interfaces the motors with the bluetooth module which provides wireless connectivity to control the motors. We used Arduino IDE to write our code which contains the instructions as well as the interfacing with the HC-05.
To achieve 6 degrees of freedom we use 6 servo motors in our robotic arm. The MG996R servo motor is used at the waist, shoulder and elbow joints. It is done so because the first 3 joints hold a lot of weight and should therefore have motors that have high torque.
The SG90 micro-servo motor is used at wrist roll, wrist pitch and the gripper, because these joints incorporate the gripper part of the arm, which is much smaller when compared to the rest of the arm and can therefore accommodate a smaller motor with a lower torque.
The HC-05 Bluetooth module which can either send or receive data from an external source in its default mode of operation, which is the master-slave mode. The module comprises six pins, labeled as following:enable, Vcc, ground, Tx (transmitting), Rx (receiving), and state.
The 5V external power source supplies the voltage and current required to operate the motors and other parts
We have developed the GUI using MIT App Inventor. We have included controls for each joint of the arm, starting with gripper, wrist pitch, wrist roll, elbow, shoulder, waist, and speed control. There is also an option provided that can save a consecutive set of commands/steps given to the arm and be run multiple times.