Introduction
The term ‘robot’ is known to have been derived from a Czeck word ‘robota’ which means a ‘slave labourer’ or ‘forced labourer’. Robot is an automated machine capable of being programmed o carry any humanistic characteristics in respect of its movements. It can be programmed to perform a same or different sequence of motions any number of times. According to Robotic Industries Association (RIA), an industrial robote is a programmable, multifunctional manipulator designed to move material, parts, tools, or special devices through variable programmed motions for the performance of a variety of tasks.
Robotics is a science which enables to design and manufacture robots. These robots may be for real life applications in automated manufacturing processes or non-manufacturing activities. The robotics is a multi-disciplinary science covering computer technology, control engineering, sensing, technique to recognize shapes, machine design, kinematics and dynamics of machinery, manufacturing processes, etc. The three popular rules of robotics are as follows:
1. A robot may not injure human being, or through inaction, allow one to come to harm.
2. A robot must obey the orders given to it by human beings except where such orders would conflict with the first law.
3. A robot must protect its own existence as long as such protection does not conflict with the first or second law.
Main Parts of a Robot
The main parts of a robot are shown in Fig. They are as follows:
1. Base may be fixed or mobile,
2. Manipulator arm is provided with a number of degrees of freedom of movement.
3. Gripper or end effecter holds a piece of tool.
4. Drives also called actuators move the manipulator arm and the end effector to the required position in space.
5. Controller delivers commands to the actuator with the help of hardware and software support.
6. Sensors perform two main functions:
(i) act as feedback devices to direct further actions of the manipulator arm and the end effector and (ii) interact with the robot’s working environment.
So that the manipulator arm of the robot possesses the same versatility as the human arm, the robot is made to possess six basic motions or degrees of freedom. The manipulator am of the robot is considered to have two main parts, the body and the wrist. Both the body and the wrist consist of three links each. The body enables the end effector to reach the required location in the work area, whereas the wrist orients the end points of the manipulator.
Six basic motions or degrees of freedom are as follows.
(i) Vertical motion.
The manipulator arm can be moved up and down vertically using. shoulder swivel or by sliding it in a vertical slide.
(ii) Radial motion,
i.e. in and out movements of the manipulator arm are provided by elbow extension by extending it or drawing back.
(iii) Rotational motion is provided by arm sweep.
(iv) Pitch motion or wrist bend enables up and down movement of the wrist and involves rotational movement as well.
(v) Roll motion or wrist swivel enables rotation of the wrist.
(vi) Yaw or wrist yaw facilitates rightward or leftward swivelling movements of the wrist.
See More: Transfer Machining:(Parts and Types)
See More: Mechanization and Automation
See More: Types of Gears:
