JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV ROBOTICS Previous Question Paper (March - 2021 - R16)

Industrial robots are categorized based on their payload and speed capabilities, which vary significantly depending on the application, such as material handling, welding, or assembly.

Load Carrying Capacity: Industrial robots are typically classified into three ranges: light-duty (up to 10 kg), medium-duty (10 kg to 100 kg), and heavy-duty (above 100 kg). Specialized heavy-lift robots can handle payloads exceeding 1,000 kg for automotive chassis assembly or aerospace manufacturing. The payload capacity is strictly dependent on the robot's reach; as the arm extends, the maximum allowable payload decreases due to torque limitations on the joints.

Speed Capabilities: Speed is measured in terms of joint velocity (degrees per second) and tool center point (TCP) linear velocity (meters per second). Modern high-speed robots can achieve linear speeds of 2 to 10 m/s. High-speed delta robots, used in pick-and-place operations, can perform over 200 cycles per minute. Speed is often constrained by the robot's inertia, the required acceleration/deceleration profiles, and the precision required at the end of the motion path.

An end effector, or robotic hand, is the device attached to the robot's wrist that interacts directly with the environment. Its design is critical to the robot's overall functionality.

Capabilities: End effectors provide the versatility needed for specific tasks. They include mechanical grippers (parallel or angular) for grasping, vacuum cups for handling flat or non-porous surfaces, magnetic grippers for ferrous materials, and specialized process tools such as welding torches, spray guns, or grinding spindles. They can be equipped with sensors to provide tactile feedback, force control, or vision, allowing the robot to adapt to variations in object position or orientation.

Limitations: The primary limitation is task specificity; an end effector designed for one task often cannot perform another without a tool changer. They are also limited by the robot's payload capacity, as the weight of the end effector reduces the net load the robot can carry. Furthermore, complex end effectors increase the risk of mechanical failure, require sophisticated control integration, and may limit the robot's reach or dexterity due to their physical size and the need for pneumatic or electrical cabling.