Automation transforms the plant, and is transformed in return

By Jack Smith, Managing Editor -- Plant Engineering, 6/15/2007

Not only has automation changed the way we manufacture goods, it has also changed the way we view the manufacturing process.

In 1947, Yardeny Laboratories introduced the pulsing drive, which controlled the speed, direction and position of electric motors. Material was moved using overhead trolleys, belt conveyors and chain conveyors. Today, guided vehicles transport materials without human drivers. Robots connected via industrial networks assemble automobiles and transfer subassemblies between stations.

In the past, cars were produced in batches, running the same model and the same color, hoping consumers wanted the models and colors they made. Today, auto makers manufacture cars to order – in batches of one.

Automation also transformed electronic product manufacturing. Radios and TVs were once wired by hand; they're now assembled by pick-and-place machines.

In 1947, switchgear, motor control centers and plant electrical systems were monitored by operators reading analog meters. Today, switchgear, MCCs and plant electrical distribution systems monitor themselves, protecting motors and equipment with electronic overload relays. Sophisticated metering, software and power monitoring equipment enable plant managers to maximize production time, maintain worker safety and provide the best possible power quality at the lowest possible cost.

Perhaps the biggest plant floor changes automation has made in the past 60 years are in automation itself. Numerical control of machining equipment, the distributed control system and the PLC were innovations that changed the course of manufacturing.

Early refineries were making the transition from batch stills to continuous process operations. Operators made process decisions based on observing product volume, color and temperature through sight glasses or feeling the pipes. They could react to obvious change, but had limited ability to actually control the process.

By the mid-1950s, chemical plants and refineries used pneumatic instruments to control their processes from central control rooms. Armed with clipboards, operators roamed plants, recording data read from gauges and thermometers, and made judgments from process observations.

Electronic instrumentation began to replace pneumatics in the late 1950s. Using mini-computers to control refineries and chemical plants began in the early 1960s – a significant milestone.

DCSs began to appear around 1975. Today, process control extends beyond PID and closed loop control to include model-based control, real-time optimization, real time performance management tools and alarm management.

The American automotive industry drove the need for technology that led to the development of the PLC. Relays and timers performed control, sequencing and safety interlocking for making cars. Bedford Associates developed the first PLC: Modicon, which stood for modular digital controller.

PLCs replaced thousands of relays, cam timers and drum sequencers that controlled machines. Software revision replaced re-wiring of hard-wired control panels when production requirements changed.

A programmable automation controller combines the features and capabilities of a PC-based control system with that of a typical PLC. PACs are used for process control, data acquisition, remote equipment monitoring, machine vision and motion control. Today, PACs can transfer data from the machines they control to other machines and components in networked systems, or to application software and databases.

Automation made today's productivity and efficiency possible. The ability to extract information from manufacturing processes helps plants improve their bottom lines. Tomorrow's challenges will be how best to apply what we have learned and to apply it to new challenges.