Important Questions and Answers: Robot Drive Systems and End Effectors

1. Define end effectors.

 End effector is a device that is attached to the end of the wrist arm to perform specific task. It is also called as gripper.

2.  Give some examples of Robot End Effector.

Gripper

Tools

Welding equipments

End of arm Tooling (EOAT)

3.  Difference between internal grippers and external grippers.

In internal grippers, the finger pads are mounted on the inside of the fingers. This mounting allows the pads to fit into the inside diameter of the part it must lift. The pads are pressed against the inside wall of the part.

An external gripper is designed so that the finger pads press against the outside of the component. The exterior surface of the grips had closed fingers.

4.  Types of Mechanical Grippers.

Linkage actuation gripper

Gear and rack actuation gripper

Cam actuated gripper

Screw actuated gripper

5.  List any two limitations of magnetic grippers

Residual magnetism

Side slippage

More than one sheet will be lifted by the magnet from a stack

6.  List any four important factors to be considered in the selection and design of grippers.

The gripper must have the ability to reach the surface of a work part.

The change in work part size must be accounted for providing accurate positioning.

During machining operations, there will be a change in the work part size. As a result, the gripper must be designed to hold a work part even when the size is varied.

The gripper must not create any sort of distort and scratch in the fragile work parts.

7.  Give some examples of tool as robot End effector.

Spot Welding Tools

Arc welding Torch

Spray painting nozzle

Water jet cutting tool

8.  Name some feedback devices used in robotics.

Potentiometer

Resolver

Encoder

9. Types of encoders?

(a) Linear encoder

(b) Rotary encoder

(i) Absolute encoder

(ii) Incremental encoder

10. Types of Drive systems used in Robots.

Electric motors like: Servomotors, Stepper motors

Hydraulic actuators

Pneumatic actuators

11. Characteristics of actuating systems.

Weight

Power-to-weight ratio

Operating Pressure

Stiffness Vs. Compliance

12. List any two unique features of a stepper motor.

Moves in known angle of rotation.

Position feedback is not necessary.

Rotation of the shaft by rotation of the magnetic field.

13. What is a RCC device? For what purpose is it used in a robot?

In robotics, a Remote Center Compliance, Remote Center of Compliance or RCC is a mechanical device that facilitates automated assembly by preventing peg-like objects from jamming when they are inserted into a hole with tight clearance. In a naive design without an RCC, a robot might pick up a peg with its gripper, center the peg over the hole and then push the peg along the axis of the hole.