JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV ACTUATORS AND ROBOT SYSTEMS Previous Question Paper (December - 2020 - R16)

Coordinate systems in robotics define the spatial relationship between the robot's links and the environment. They are primarily classified into the following types:

• Cartesian Coordinate System: Uses three linear axes (X, Y, Z) at right angles to each other. The robot moves in a rectangular workspace, providing high precision and simple control, commonly used in gantry robots.
• Cylindrical Coordinate System: Consists of one rotary axis and two linear axes. The workspace is a cylinder. The robot rotates about a vertical axis and extends/retracts radially and vertically.
• Spherical (Polar) Coordinate System: Utilizes two rotary joints and one linear joint. The workspace is a partial sphere. It allows for a large reach but is more complex to control due to the varying moment of inertia.
• Articulated (Jointed-Arm) Coordinate System: Mimics the human arm, consisting of a series of rotary joints (usually three or more). It offers the most flexibility and reach, capable of maneuvering around obstacles, making it ideal for complex assembly tasks.
• SCARA (Selective Compliance Assembly Robot Arm): Features two parallel rotary joints providing compliance in a horizontal plane and a third linear joint for vertical movement. It is highly efficient for high-speed, precise vertical insertion tasks.

Robotic applications are tailored to the mechanical configuration of the system:

• Pick and Place Robots: These are designed for high-speed, repetitive material handling tasks. They excel at moving objects from one location to another, such as transferring components from a conveyor belt to a tray or packaging station. They prioritize cycle time and repeatability.
• Gantry Robots: Also known as Cartesian robots, these are mounted on overhead rails. They are used for large-scale applications where the robot must cover a wide area, such as palletizing heavy loads, large-format 3D printing, or moving automotive parts across a factory floor. Their rigid frame supports heavy payloads with high positional accuracy.
• Arm Type Robots (Articulated): These robots offer high degrees of freedom, allowing them to reach into confined spaces or approach workpieces from various angles. They are widely used in complex applications like arc welding, spray painting, and intricate assembly, where the ability to orient the tool (end-effector) in 3D space is critical.