Chapter 3: Industrial robot
A robot system that is used in production is referred to as an industrial robot. Automation, programmability, and the ability to move in three or more axes are distinguishing characteristics of industrial robots.
Robots are used for a wide variety of applications, including welding, painting, assembly, disassembly, pick and place for printed circuit boards, packing and labeling, palletizing, product inspection, and testing; all of these tasks need a high level of endurance, speed, and accuracy. They are able to provide assistance with material handling.
According to estimates provided by the International Federation of Robotics, there will be around 1.64 million industrial robots in use throughout the globe in the year 2020. (IFR). These days, people make use of a certain kind of technology known as robots. Robots have found their way into a variety of fields, including agriculture, manufacturing, medical, technology, and even travel.
Industrial robots may be broken down into six distinct categories.
Robots with articulating joints Their articulated arms are capable of a broad range of motion because to their articulations, which have several degrees of freedom.
Cartesian robots feature three prismatic joints for moving the tool, and three rotational joints for orienting it in space. Together, these six joints make up the robot's tetrad.
A robot of this kind has to have six axes in order to be able to move and position the effector organ in all directions (or degrees of freedom). In a setting with just two dimensions, it is sufficient to have three axes: two for determining displacement, and one for determining orientation.
The robots that use cylindrical coordinates
Robots operating in a spherical coordinate system can only have rotational joints.
At the effector of the SCARA system, rotating shafts are arranged in a vertical orientation.
SCARA robots are used for tasks that call for precise lateral motions to be performed. They work well in situations requiring assembly.
Delta robots They are made up of parallel connections that are all linked to the same base. Delta robots are very helpful for jobs that need direct control as well as those that require high levels of maneuverability (such as quick pick-and-place tasks). Delta robots take use of four bar or parallelogram linkage systems.
In addition, industrial robots may either have a serial architecture or a parallel one.
Serial architectures, more often known as Serial manipulators are the most popular kind of industrial robot. Their construction consists of a series of links that are joined by motor-actuated joints and stretch from a base to an end-effector. The SCARA system and the Stanford manipulators are two examples that are characteristic of this group.
In contrast to a serial manipulator, a parallel manipulator is constructed such that each chain is often rather short and straightforward, and as a result, it may be stiff and resistant to undesired movement. The errors that occur in the placement of one chain are averaged out in combination with the errors that occur in the positioning of the other chains, rather than being accumulated. In a parallel robot, each actuator must still move within its own degree of freedom, just as they do in a serial robot; however, the off-axis flexibility of a joint is also constrained by the effect of the other chains. This is in contrast to a serial robot, which only has one degree of freedom per actuator. In contrast to a serial chain, which gradually loses its rigidity as more components are added, the closed-loop rigidity of a parallel manipulator contributes to the overall rigidity of the device as a whole compared to its individual components.
An item may be moved with up to six different degrees of freedom using a complete parallel manipulator (DoF), defined by three translational coordinates (three T's) and three rotational coordinates (three R's) for complete 3T3R mobility.
However, Whenever a manipulation job calls for less than 6 degrees of freedom, the use of manipulators with a reduced level of motion, with less than 6 degrees of freedom, may provide benefits in terms of a more straightforward architectural design, easier control, more rapid movement and at a lesser cost.
Take, for instance:
The three-degrees-of-freedom Delta robot, which has a reduced three-dimensional mobility, has shown to be particularly useful for applications requiring quick pick-and-place translational placement.
The workspace of lower mobility manipulators may be decomposed into `motion' and `constraint' subspaces.
Take, for instance:
The motion subspace of the three degrees of freedom (DoF) Delta robot is made up of three position coordinates, while the constraint subspace is made up of three orientation coordinates.
The motion subspace of lower mobility manipulators may be further decomposed into independent (desired) and dependent (concomitant) subspaces: consisting of `concomitant' or `parasitic' motion which is undesired motion of the manipulator.
When designing effective lower mobility manipulators, it is imperative that the incapacitating effects of simultaneous motion be reduced or removed altogether.
Take, for instance:
Because the end effector of the Delta robot does not spin, this machine does not have any parasitic motion.
There is a spectrum of degrees of autonomy present in robots. Some robots may be programmed to carry out the same activities over and over again (known as repetitive actions) with little to no variation and a high level of precision. These activities are regulated by programmed routines that describe the direction, acceleration, velocity, and deceleration of a sequence of coordinated movements. The distance between each motion in the series is also specified.
Other robots have a much greater degree of adaptability in terms of the orientation of the object on which they are operating or even the task that needs to be performed on the object itself, which the robot may even need to identify. These other robots are much more likely to be used in a variety of settings. For instance, machine vision sub-systems that operate as the robot's visual sensors and are coupled to either sophisticated computers or controllers are often included in robots so that they can provide more accurate guidance. The level of artificial intelligence, or at least anything that can pass for it, in today's sophisticated industrial robots is becoming an increasingly crucial aspect.
"Bill" Griffith P. Taylor finished the first known industrial robot in 1937, and it was published in Meccano Magazine in March 1938. This robot was the first to correspond to the ISO definition of an industrial robot. The Meccano pieces were used almost exclusively in the construction of the crane-like contraption, which was driven by a single electric motor. It was able to move along any of the five axes, including grabbing and rotating while grabbing. It was possible to automate the movement of the crane's control levers by employing punched paper tape to provide energy to solenoids, which allowed for automation to be accomplished. The robot was able to stack blocks of wood in a variety of pre-programmed configurations. On a piece of graph paper, the intended movements were initially drawn with the needed amount of motor rotations. After that, the information was copied onto the paper tape, which was likewise driven by the single motor that was contained inside the robot. In 1997, Chris Shute constructed an exact copy of the robot from scratch.
In 1954, George Devol submitted an application for the first robotics patents (granted in 1961). Unimation, which was established in 1956 by Devol and Joseph F. Engelberger, is recognized as the first business to mass-produce a robot. Unimation robots were also known as programmed transfer machines at one point in time. This was due to the fact that their primary function at the time was to move things from one location to another that were little more than a few dozen feet away. They were programmed in joint coordinates and utilised hydraulic actuators. This meant that the angles of the different joints were saved during a training period and then replayed when the robot was in operation. They were precise to within 1/10,000 of an inch at the most (note: although accuracy is not an appropriate measure for robots, usually evaluated in terms of repeatability - see later). Later on, Unimation licensed its technology to Kawasaki Heavy Industries and GKN, which respectively manufactured Unimates in Japan and England. Ohio-based Cincinnati Milacron Inc. was Unimation's one and only rival for a while. When this started to alter in the late 1970s, numerous large Japanese companies began creating industrial robots that were quite similar to those already existing.
In 1969, Victor Scheinman of Stanford University came up with the idea for what would become known as the Stanford arm. It was an electric, articulated robot with six axes that was meant to allow for an arm solution. Because of this, it was able to properly follow arbitrary trajectories in space, which expanded the robot's potential uses to include more complex tasks like welding and assembling. After that, Scheinman created a second arm for the MIT AI Lab that he referred to as the "MIT arm." After receiving a fellowship from Unimation to develop his designs, Scheinman sold those designs to Unimation, which then further developed them with support from General Motors and later marketed it as the Programmable Universal Machine for Assembly. Scheinman also received a fellowship from Unimation to develop his designs (PUMA).
Both ABB Robotics and KUKA...
