| Industrial Robot |
Article Index for Industrial |
Website Links For Industrial |
Information AboutIndustrial Robot |
| CATEGORIES ABOUT INDUSTRIAL ROBOT | |
| industry | |
| manufacturing | |
| production and manufacturing | |
| robots | |
|
).]] Typical applications of robots include Welding , painting, Ironing , assembly, Pick and place, Packaging and Palletizing , product inspection, and testing, all accomplished with high endurance, speed, and precision. ROBOT TYPES, FEATURES The most commonly used robot configurations are Articulated Robot s (the first and most common), SCARA Robot s and Gantry Robot s (aka Cartesian Coordinate robots, or x-y-z robots). In the context of general robotics, most types of robots would fall into the category of Robot Arm s (inherent in the use of the word ''manipulator'' in the above-mentioned ISO standard). Robots exhibit varying degrees of Autonomy :
HISTORY OF INDUSTRIAL ROBOTICS George Devol applied for the first robotics patents in 1954 (granted in 1961). The first company to produce a robot was Unimation , founded by George Devol and Joseph F. Engelberger in 1956 , and was based on Devol's original patents. Unimation robots were also called ''programmable transfer machines'' since their main use at first was to transfer objects from one point to another, less than a dozen feet or so apart. They used Hydraulic Actuator s and were programmed in '' Joint Coordinate s'', i.e. the angles of the various joints were stored during a teaching phase and replayed in operation. They were accurate to within 1/10,000 of an inch. Unimation later licensed their technology to Kawasaki Heavy Insudtries and Guest-Nettlefolds, manufacturing Unimates in Japan and England respectively. For some time Unimation's only competitor was Cincinnati Milacron Inc. of Ohio . This changed radically in the late 1970s when several big Japanese conglomerates began producing similar industrial robots. In 1969 Victor Scheinman at Stanford University invented the Stanford Arm , an all-electric, 6-axis Articulated Robot designed to permit an Arm Solution . This allowed it to accurately follow arbitrary paths in space and widened the potential use of the robot to more sophisticated applications such as assembly and Arc Welding . Scheinman then designed a second arm for the MIT AI Lab, called the "MIT arm." Scheinman, after receiveing a fellowship from Unimation to develop his designs, sold those designs to Unimation who further developed them with support from General Motors and later marketed it as the Programmable Universal Machine For Assembly (PUMA). In 1973 KUKA Robotics built its first robot, known as FAMULUS, this is the first articulated robot to have six electromechanically driven Axes . Interest in robotics in the late 1970s and many companies entered the field, including large firms like General Electric , and General Motors (which formed Joint Venture FANUC Robotics with FANUC LTD of Japan). US Start-up s included Automatix and Adept Technology , Inc. At the height of the robot boom in 1984 , Unimation was acquired by Westinghouse Electric Corporation for 107 million US dollars. Westinghouse sold Unimation to Stäubli Faverges SCA of France in 1988 . Stäubli was still making articulated robots for general industrial and Clean Room applications as of 2004 and even bought the robotic division of Bosch in late 2004. Eventually the myopic vision of American industry was superseded by the financial resources and strong domestic market enjoyed by the Japanese manufacturers. Only a few non-Japanese companies managed to survive in this market, including Adept Technology , Stäubli-Unimation, the Swedish - Swiss company ABB (ASEA Brown-Boveri), the Austria n manufacturer igm Robotersysteme AG and the German company KUKA Robotics . TECHNICAL DESCRIPTION Defining parameters
Robot programming and interfaces ]] See Also: Robotics suite The setup or Programming of motions and sequences for an industrial robot is typically taught by linking the robot controller to a Laptop , desktop Computer or (internal or Internet) network. ''Software:'' The computer is installed with corresponding Interface Software . The use of a computer greatly simplifies the programming process. Specialized Robot Software is run either in the robot controller or in the computer or both depending on the system design. ''Teach Pendant:'' Robots can also be taught via Teach Pendant , a handheld control and programming unit. The common feature of such units are the ability to manually send the robot to a desired position, or inch or jog to adjust a position. They also have a means to change the speed since a low speed is usually required for careful positioning. They also have a large emergency stop button. Typically once the robot has been programmed there is no more use for the teach pendant. ''Lead-by-the-nose'' is a technique offered by most robot manufacturers but is of dubious value. While user holds the robot end effector another person enters a command which de-energizes the robot and it goes limp. The user then moves the robot by hand to the required positions or along a required path while the software logs these positions into memory. The program can later run the robot to these positions or along the taught path. This technique was popular for tasks such as paint spraying. ''Others'' In addition, machine operators often use Human Machine Interface devices, typically Touch Screen units, which serve as the operator control panel. The operator can switch from program to program, make adjustments within a program and also operate a host of Peripheral Device s that may be integrated within the same robotic system. These include End Effector s, feeders that supply components to the robot, conveyors, emergency stop controls, machine vision systems, safety interlock systems, Bar Code printers and an almost infinite array of other industrial devices which are accessed and controlled via the operator control panel. The teach pendant or PC is usually disconnected after programming and the robot then runs on the program that has been installed in its Controller . However a computer is often used to 'supervise' the robot and any peripherals. A robot and a collection of machines or peripherals is referred to as a cell. A typical cell might contain a parts feeder, a molding machine and a robot. The various machines are 'integrated' and controlled by a single computer or PLC . End Effectors The most essential robot peripheral is the End Effector without which the robot can not do anything. Obvious examples are grippers which are devices that can Grasp an object, usually electromechanical or Pneumatic . Another common means of picking up an object is by Vacuum . End effectors are frequently highly complex, made to match the handled product and often capable of picking up an array of the products at one time. Movement and singularities Most articulated robots perform by storing a series of positions in memory, and moving to them at various times in their programming. For example, a robot which is moving items from one place to another might have a simple program like this (commonly called a 'pick and place' program): ''Define points P1–P5:'' # Safely above workpiece (defined as P1) # 10 cm Above Bin A (defined as P2) # At position to take part from bin A (defined as P3) # 10 cm Above bin B (defined as P4) # At position to take part from bin B. (defined as p5) ''Define program:'' # Move to P1 # Move to P2 # Move to P3 # Close gripper # Move to P4 # Move to P5 # Open gripper # Move to P1 and finish For a given robot the only parameters necessary to locate the end effector (gripper, welding torch, etc.) of the robot completely are the angles of each of the joints or displacements of the linear axes (or combinations of the two for robot formats such as SCARA). However there are many different ways to define the points. The most common and most convenient way of defining a point is to specify a Cartesian Coordinate for it, i.e. the position of the 'end effector' in mm in the X, Y and Z directions. In addition the angles of the end effector in pitch, roll and yaw and the length of the tool must also be specified, depending on the types of joints a particular robot may have. For a Jointed Arm these coordinates must be converted to joint angles by the robot controller and such conversions are known as Cartesian Transformations which may need to be performed iteratively or recursively for a multiple axis robot. The mathematics of the relationship between joint angles and actual spatial coordinates is called kinematics. See Robot Control Positioning by Cartesian coordinates may be done by entering the coordinates into the system or by using a teach pendant which moves the robot in X-Y-Z directions. It is much easier for a human operator to visualize motions up/down, left right etc. than to move each joint one at a time. When the desired position is reached it is then defined in some way peculiar to the Robot Software in use, e.g. P1 - P5 above. RECENT AND FUTURE DEVELOPMENTS See Also: Future of robotics . This doesn't allow the robotic cell to easily handle different parts, in different orientations. Hand in hand with increasing off-line programmed applications, Robot Calibration is becoming more and more important in order to guarantee a good positioning accuracy. Other developments include downsizing industrial arms for consumer applications (micro-robotic arms), manufacture of Domestic Robot s and using industrial arms in combination with more intelligent Automated Guided Vehicle s (AGVs) to make the Automation Chain more flexible between pick-up and drop-off. Prices of robots will vary with the features, but are usually from 12,000 USD for an Entry Level model, and as much as 100,000 or more for a Heavy-duty , long reach robot. ROBOT MANUFACTURERS
NOTES SEE ALSO REFERENCES
EXTERNAL LINKS
|
|
|