What is an industrial robot?

The world’s first industrial robot was born in the United States in 1962. American engineer George Charles Devol, Jr. proposed “a robot that can flexibly respond to automation through teaching and playback”. His idea sparked a spark with entrepreneur Joseph Frederick Engelberger, who is known as the “father of robots”, and thus the industrial robot named “Unimate (= a working partner with universal capabilities)” was born.
According to ISO 8373, industrial robots are multi-joint manipulators or multi-degree-of-freedom robots for the industrial field. Industrial robots are mechanical devices that automatically perform work and are machines that rely on their own power and control capabilities to achieve various functions. It can accept human commands or run according to pre-programmed programs. Modern industrial robots can also act according to the principles and guidelines formulated by artificial intelligence technology.
Typical applications of industrial robots include welding, painting, assembly, collection and placement (such as packaging, palletizing and SMT), product inspection and testing, etc.; all work is completed with efficiency, durability, speed and accuracy.
The most commonly used robot configurations are articulated robots, SCARA robots, delta robots, and Cartesian robots (overhead robots or x-y-z robots). Robots exhibit varying degrees of autonomy: some robots are programmed to perform specific actions repeatedly (repetitive actions) faithfully, without variation, and with high accuracy. These actions are determined by programmed routines that specify the direction, acceleration, speed, deceleration, and distance of a series of coordinated actions. Other robots are more flexible, as they may need to identify the location of an object or even the task to be performed on the object. For example, for more precise guidance, robots often include machine vision subsystems as their visual sensors, connected to powerful computers or controllers. Artificial intelligence, or anything that is mistaken for artificial intelligence, is becoming an increasingly important factor in modern industrial robots.
George Devol first proposed the concept of an industrial robot and applied for a patent in 1954. (The patent was granted in 1961). In 1956, Devol and Joseph Engelberger co-founded Unimation, based on Devol’s original patent. In 1959, Unimation’s first industrial robot was born in the United States, ushering in a new era of robot development. Unimation later licensed its technology to Kawasaki Heavy Industries and GKN to produce Unimates industrial robots in Japan and the United Kingdom, respectively. For a period of time, Unimation’s only competitor was Cincinnati Milacron Inc. in Ohio, USA. However, in the late 1970s, this situation changed fundamentally after several large Japanese conglomerates began to produce similar industrial robots. Industrial robots took off quite quickly in Europe, and ABB Robotics and KUKA Robotics brought robots to the market in 1973. In the late 1970s, interest in robotics was growing, and many American companies entered the field, including large companies such as General Electric and General Motors (whose joint venture with Japan’s FANUC Robotics was formed by FANUC). American startups included Automatix and Adept Technology. During the robotics boom in 1984, Unimation was acquired by Westinghouse Electric for $107 million. Westinghouse sold Unimation to Stäubli Faverges SCA in France in 1988, which still makes articulated robots for general industrial and cleanroom applications, and even acquired Bosch’s robotics division in late 2004.

Define Parameters Edit Number of Axes – Two axes are required to get anywhere in a plane; three axes are required to get anywhere in space. To fully control the pointing of the end-arm (i.e., wrist), another three axes (pan, pitch, and roll) are required. Some designs (such as SCARA robots) sacrifice motion for cost, speed, and accuracy. Degrees of Freedom – Usually the same as the number of axes. Working envelope – The area in space that the robot can reach. Kinematics – The actual configuration of the robot’s rigid body elements and joints, which determines all possible robot movements. Types of robot kinematics include articulated, cardanic, parallel, and SCARA. Capacity or load capacity – How much weight the robot can lift. Velocity – How quickly the robot can get its end-arm position into position. This parameter can be defined as angular or linear velocity of each axis, or as a composite velocity, meaning in terms of end-arm velocity. Acceleration – How quickly an axis can accelerate. This is a limiting factor, as the robot may not be able to reach its maximum velocity when performing short moves or complex paths with frequent changes of direction. Accuracy – How close the robot can get to the desired position. Accuracy is measured as how far the robot’s absolute position is from the desired position. Accuracy can be improved by using external sensing devices such as vision systems or infrared. Reproducibility – How well a robot returns to a programmed position. This is different from accuracy. It may be told to go to a certain X-Y-Z position and it only goes to within 1 mm of that position. This is an accuracy problem and can be corrected with calibration. But if that position is taught and stored in the controller memory, and it returns to within 0.1 mm of the taught position each time, then its repeatability is within 0.1 mm. Accuracy and repeatability are very different metrics. Repeatability is usually the most important specification for a robot and is similar to “precision” in measurement – with reference to accuracy and precision. ISO 9283[8] establishes methods for measuring accuracy and repeatability. Typically, the robot is sent to a taught position several times, each time going to four other positions and returning to the taught position, and the error is measured. The repeatability is then quantified as the standard deviation of these samples in three dimensions. A typical robot may of course have position errors that exceed the repeatability, and this may be a programming problem. Furthermore, different parts of the work envelope will have different repeatability, and repeatability will also vary with speed and payload. ISO 9283 specifies that accuracy and repeatability be measured at maximum speed and at maximum payload. However, this produces pessimistic data, as the robot’s accuracy and repeatability will be much better at lighter loads and speeds. Repeatability in industrial processes is also affected by the accuracy of the terminator (such as a gripper) and even by the design of the “fingers” on the gripper that are used to grasp the object. For example, if a robot picks up a screw by its head, the screw may be at a random angle. Subsequent attempts to place the screw into the screw hole are likely to fail. Situations such as these can be improved by “lead-in features”, such as making the entrance of the hole tapered (chamfered). Motion Control – For some applications, such as simple pick and place assembly operations, the robot only needs to go back and forth between a limited number of pre-taught positions. For more complex applications, such as welding and painting (spray painting), the movement must be continuously controlled along a path in space at a specified orientation and speed. Power Source – Some robots use electric motors, others use hydraulic actuators. The former is faster, the latter is more powerful and is useful for applications such as painting where sparks could cause explosions; however, the low-pressure air inside the arm prevents the ingress of flammable vapors and other contaminants. Drive – Some robots connect the motors to the joints through gears; others have the motors connected directly to the joints (direct drive). The use of gears results in measurable “backlash”, which is the free movement of an axis. Smaller robot arms often use high-speed, low-torque DC motors, which usually require higher gear ratios, which have the disadvantage of backlash, and in such cases harmonic gear reducers are often used instead. Compliance – This is a measure of the amount of angle or distance that a force applied to an axis of the robot can move. Because of compliance, the robot will move slightly lower when carrying a maximum payload than when carrying no payload. Compliance also affects the amount of overrun in situations where acceleration needs to be reduced with a high payload.