Robot Anatomy and Configuration with Types

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What is Robot Anatomy and Configuration?

  • ROBOT ANATOMY deals with the study of several joints and links and other aspects of physical construction.
  • It is the study of physical structure of robots.
  • The mechanical structure of robots deals with rigid bodies.
  • The physical construction of the Body, Arm & Wrist of a machine.
  • Relative movement of various components of Body, Arm & Wrist which are provided by series of joints.
Robot Anatomy and Configuration with Types

Physical Configuration:

The Anatomy of Robots deals with the assembling of components of a robot such as wrist, arm, and body. Before jumping into Robot Configurations, there are some of the key ideas about robot anatomy.

Robot Joints:

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The joints in an industrial robot are useful to perform sliding and rotating movements of a component.

End Effectors:

A hand of a robot is the end effector. The grippers and tools are the two important types of end effectors. The grippers are essential to functions like pick and place an object, while using the tools to carry out operations like spray painting, spot welding, etc. on a work piece.

Manipulator:

The manipulators in a robot are developed by the association of links and joints. In the body and arm, manipulator is applied for moving the tools in the work volume. It is also used in the wrist to maintain the tools.

Robotic Configuration:

  • Cartesian Coordinates Configuration
  • Cylindrical Configuration
  • Spherical Configuration
  • Jointed-arm Configuration 
  • Selective Compliance Assembly Robot Arm
  • (SCARA) Configuration

Cartesian Coordinates Configuration:

  • Three perpendicular slides is used to construct x, y and z axes
  • X-axis expresses right and left motions
    Y-axis expresses forward-backward motions
    Z-axis expresses up-down motions
  • Kinematic designation is PPP/LLL
  • Other names are Rectilinear robot or Gantry robot
  • Operates within a rectangular work volume

Advantages:

  • Requires a large volume to operate in
  • Work space is smaller than robot volume
  • Unable to reach areas under objects
  • Must be covered from dust

Disadvantages:

  • It requires a large volume to operate in
  • Work space is smaller than robot volume
  • Unable to reach areas under the objects
  • Must be Covering from dust

Cylindrical Configuration:

  • Vertical column rotates and a slide that can be moved up or down along the column.
  • Arm is attached to the slide which can be moved in and out.
  • Operates within a cylinder work volume
  • Work volume is restricted at the back side
  • The Kinematic designation is RPP

Advantages:

  • It is simple kinematic model
  • It has rigid structure & high lift-carrying capacity
  • Easy to visualize
  • Very powerful when hydraulic drives are used

Disadvantages:

  • It has restricted work space
  • It has lower repeatability and accuracy
  • Requires more sophisticated control

Polar or Spherical Configuration:

  • It is earliest machine configuration
    It is has one linear motion and two rotary motions
  • The first motion is a base rotation
  • The second motion correspond to an elbow rotation
  • The third motion is radial or in-out motion
  • Kinematic designation rating is RRP]
  • Capability to move its arm within a spherical space, is known as ‘Spherical’ robot

Advantages:

  • Covers a large volume
  • It can bend to pick objects up off the floor
  • Has Higher reach ability

Disadvantages:

  • It is complex kinematic model
  • It is difficult to visualize

Articulated or Jointed-arm Configuration:

  • It is similar to human arm.
  • Consists of two straight components like human forearm and upper arm, mounted o a vertical pedestal.
  • It has components are connected by two rotary joints corresponding to the shoulder and elbow.
  • Kinematic designation rating is RRR.
  • The work volume is spherical.

Advantages:

It has maximum flexibility
Covers large space relative to work volume objects up off the floor
It suits electric motors
Higher reach ability

Disadvantages:

  • It has complex kinematic model
  • It is difficult to visualize
  • Structure not that rigid at full reaction

Selective Compliance Assembly Robot Arm(SCARA) Configuration:

  • It is most common in assembly robot.
  • The arm consists of two horizontal revolute joints at the waist and elbow and a final prismatic joint
  • It can reach at any point within horizontal planar defined by two concentric circles
  • Kinematic designation rating is RRP
  • The work volume is cylindrical in nature

Advantages:

  • The floor area is small compare to work area
  • It is compliant

Disadvantages:

  • It is the rectilinear motion that requires complex control of the revolute joints