Position and Orientation of the Objects - Reference Frames and Transformation of Frames in Robotics

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Industrial Robots result in increased levels of automation in industrial processes. Robot use started in repetitive, simple tasks, and now they are also being used also in precision works. This transition happened because of the sophisticated synthesis of robots and inclusion of electronics and computer control. An industrial robot is designed such that it can be programmed to be used in different applications.

The mechanics of the industrial robots and manipulators is not a new field of engineering in itself. It is actually a combination of different branches of engineering. The mechanics, static and dynamic analysis and design, comes from mechanical engineering, and the analysis of motion and path planning of the manipulators is done with the help of mathematical tools.

The Position and Orientation of Objects

For the design and analysis of the manipulators, the basic thing to keep track of and to plan is the position as well as the orientation of objects. The objects for which we are concerned are the components of the manipulators, like their links, joints, and tools, and also the objects in the space around the manipulator as well as all the objects with which the manipulator interacts.

For the effective design of the manipulator, the position and orientation of the objects concerned need to be represented suitably such that it can be mathematically processed to make the manipulator move in the desired manner.

Attaching Frame to the Object

To define the position and orientation of the object and to keep track of its movement a coordinate frame is rigidly attached to the object. The motion of the object, that is, the change in position and orientation of the object is now given by the frame attached to the object.

Reference Coordinate Frame

A Reference Coordinate Frame is defined with respect to which the position and orientations of all the other frames attached to the objects are described.

Transformation of Frames

We can define any frame as the reference frame. For convenience we keep changing the reference frames. So the position and orientation of the frames attached to the objects need to be transformed from one reference frame to the other. There are mathematical methods for the transformation of the frames.

The article series on Position and Orientation of manipulators dealing with the methods for describing position and orientation of the objects related to the manipulators and different techniques for transformation of the position and orientation for different reference frames will soon follow up under Robotics topic in the Bright Hub Mechanical Engineering Channel.

This post is part of the series: Mechanics of Robotic Manipulators

Robotics is perhaps the outcome of the desire to synthesize such machines which can perform tasks like humans do and even beyond, that is, performing task which humans cannot do, and that too in a way even better than what humans do. This series introduces you to Mechanics of Robotic Manipulators.

  1. Position and Orientation of the Objects in Robotic Automation
  2. The Kinematics of Manipulators – Forward and Inverse
  3. Kinematics of Manipulators: Velocity Analysis
  4. Dynamics of Manipulators