In the sixties, the electronics gave us numerically controlled machines (NC) and computer numerically controlled (CNC) machines.
The increase in speed of production process brought about by the application of computer to machinery, presented a problem in that the loading of parts to the machine and their movement from one machine to another consumed disproportionately more time than the production process. Two solutions were found. The â€˜machining Centerâ€™ was developed which combined both rotational movement of the work piece with the three axis movement normally in milling. This permitted a sequence of operations which had hitherto been done on a number of machines to be done on a single machine. The other development was a system of manufacturing cells in which groups of machines, the operations of which normally followed one another, were located together so that parts could be moved by the operator quickly from one machine to another.
The advent of industrial robots in 1970s allowed the manufacturing cells to be automated in a system which â€˜Flexible Manufacturingâ€™. In flexible manufacturing a computer instructs the machines what to make and a robot moves the parts from one machine to another. The power of the central computer allows more than one type of part to be made at once, ensures that machines are used as effectively as possible, and reduces the time taken for raw materials to be converted to finished products.
Originally robots were numerically controlled handling machines for picking and placing parts from one previously defined position to another. With the increase in their capability and the software operating them becoming more complex, they began to be adapted for other purposes such as spraying paint and welding.
Currently they are normally used in combination with other machinery such that messages are passed from the other machines to the robots indicating which operations are to be carried out and from the robot to the other machines, telling them when the job is complete. In this way they form a team with the other production machines, in which the robot may be either moving a part along its planned production path or alternatively executing one of operations on that part. In both of these applications the robot replaces a human being in what is often a monotonous, uncomfortable and occasionally dangerous operation.
The applications for which robots are used today include: car production, die casting, spot welding, arc welding, forging, heat treatment, press transfer, machine tool loading and shell casting.
Once the problem of â€˜touchâ€™ is solved, the robots will have more use in batch assembly. A robot has to recognize the size and shape of a component and the work on this is in progress. Robot â€˜sightâ€™ using TV cameras would be more useful with camera on the â€˜handâ€™ of the robot and the robot that explored the Atlantic after the Kanishka disaster had this arrangement.
Why robots? It is already known that the use of robot in hostile environments such as paint spraying in auto manufacturing is essential considering the health hazards involved. Further robots can also do away with boring jobs involving repetitive actions.
Low budget assembly presents a tremendous challenge to robotics and the technology required to meet the challenge includes giving robots vision and tactile sensing. A mechanical solution for the latter is being worked out whereby strain gauges will be used to allow the robot to feel the shape in order to carry out â€˜bin pickingâ€™â€”picking out components at random from a bin in order to make up or assemble them.
Robotized operations are economical especially where the labor rates are high. New applications for which robots can be advantageous include order picking, packaging, textiles, and medical laboratory handling work.