Links are considered to be the rigid components of the robot. The purpose of the joint is to provide controlled relative movement between the input link and the output link. Links are considered to be the rigid components of the robot. The purpose of the joint is to provide controlled relative movement between the input link and the output link.
Roll . This d.o.f can be accomplished by a T-type joint to rotate the object about the arm axis Pitch . This involves the up-and-down rotation of the object, typically done by means of a type R joint Yaw . This involves right-to-left rotation of the object, also accomplished typically using an R-type joint
These are the devices that perform the actual task. End effectors are often designed for a particular task, but can also be made as all-purpose hands to do many types of tasks.
Torque - exists when a part is picked up at a place other than its center of gravity. Center of gravity - the point where its mass seems to be concentrated or the point where the part is balanced. Coefficient of friction - measures how efficiently the gripper holds the part. If the part and the grippers surface are both rough, the coefficient of friction may be greater than 1. For most gripping tasks, coefficient of friction is less then 1.
The first complex sensors used by robots used feedback information to ascertain the present conditions or position. This sense is known as haptic perception and is equivalent to the human sense of kinesthesia. Governor is a mechanical device that uses adjustable spinning weights to control the rotational speed of devices such as generators and motors. Some hydraulic cylinders are equipped with lead screws that can detect the position of the cylinder shaft by counting the revolutions of the screw as the shaft is extended or retracted. For rotational joints, a shaft-encoder can be used to detect very fine rotational movement. The expensive direct-readout encoders or absolute-readout encoders can give the degrees of rotation from 0.000 degrees to 359.999 degrees.
One of the earliest sensors for robots was a microswitch or pressure sensor that could detect when the robot had something in its gripper. A photoelectric device can also be used to detect something in a gripper.
For example, hydraulic pressure may have to reach some minimum level before hydraulic actuators are allowed to move.
Single-point detection can tell if a part is present or not. Simple edge detection can be use to determine how far an object is placed into a gripper. A multiple-point shape detector is a matrix of touch sensors that can determine the shape of one surface of an object. The term type of surface refers to such characteristics as hardness and smoothness or roughness.
Artificial Intelligence and Robotics ROBOTICS BE – CIS
“a robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or specialized devices through variable programmed motions, for the performance of a variety of tasks”.