Is there any industry that is likely to earn a profit during the economic downturn? The answer is automation. As corporate majors try to increase productivity, one way they are likely to achieve this is through automation.

Flexibility and efficiency are going to be the differentiators in order to quickly develop and manufacture an increasing number of products to meet the rapidly changing demands of the market. Moreover, with growing competition, “timing and speed are going to be vital for survival and success of the future organisation. No organisation in today’s age can survive without agility and responsiveness to changing environments. Systemic efficiencies can only be brought in and improved through automation. With companies becoming more and more complex and dispersed, there is need for efficient manpower,” says Sumit Paul, general manager-industrial, Rockwell Automation India.

Is it an accelerator?

While employees of many global companies are bombarded by inflation and job worries, the employees in the automation industry of India by and large continue to enjoy rising salaries and strong demands for their services. Automation plays an increasingly important role in the global economy and in daily experience. Engineers strive to combine automated devices with mathematical and organisational tools to create complex systems for a rapidly expanding range of applications and human activities.

India’s manufacturing sector, which is spurring the country’s gross domestic product (GDP) growth, is undergoing a major transformation. It is scaling up and beginning to seek global competitiveness through the wider application of automation and IT (information technology). This trend is contributing to the robust growth of the automation industry.

“Automation is a well-established technology, both in the manufacturing sector and infrastructure. India’s hope of emerging as an economic superpower depends a lot on how we groom our engineers to leverage this technology. By transferring global quality learning processes, we can convert a much larger percentage of the emerging manpower into more enriching careers,” said Anup Wadhwa, director, Automation Industry Association.

According to Wadhwa, only 25 per cent of the 600,000 available engineering graduates are ready to be deployed in this industry and efforts to increase the figure need to be made. The automation industry is growing 6-8 per cent globally, whereas in countries like India and China, it is growing at more than 30 per cent.

The five-year forecast shows healthy trends and the industry will be requiring more technical graduates— both from polytechnics and engineering colleges—to join the industry. The industry employs almost 50,000 professionals today. “This demand will be at least double in the next three years. Science and engineering graduates having an aptitude for machine control will find space for a fulfilling professional career here,” adds Wadhwa.

Money matters

Speaking of salary prospects, a fresh engineering passout may start at Rs 300,000-Rs 400,000 per annum. However, the scene is not so encouraging for diploma holders as their starting salary usually ranges from Rs 150,000 to Rs 200,000 per annum.

You could start at a junior level as part of a major project and grow to become a project leader in 10-12 years’ time frame. In most cases, salaries are proportional to the cost of the projects. Even in this time of economic downturn, the automation industry is offering a salary in the range of Rs 500,000 to Rs 1 million per annum for professionals with five to seven years of experience.

Notably, the salary is on the higher side for design section. And if you grab an international opportunity, the minimum salary may be in the range of Rs 2 million per annum within just about five years.

Groom for automation

Now that you have received enough boosters about the opportunities to be grabbed in the automation field, it’s time to explore the power circuit. The automation field is specifically suitable for engineering professionals with multidisciplinary as well as project management interests, such as project engineering. Exciting and technically satisfying careers can be pursued in the field of technical marketing, design engineering, project management, integration and servicing. And if you consider technology, I must say, wherever there is a need for process control to increase productivity, there is automation. It may be a human gene analysis laboratory or a locomotive workshop.

The main metric is grip on control. And as a professional you are expected to acquire the knowledge and skills needed to design practical control loop as per that metric. If you can achieve these, instrumentation and maintenance related solutions will be automatically on your fingertips. To make maximum use of the situation, you need to have expertise to survive in the global-quality working environment of automation.

Since the automation industry comprises fairly large and mature companies with highly technical processes, this reflects on the manpower needs as well. The skill requirements are vast and there is room for professionals for product design and development, sales, project engineering, product management, marketing and sales. Professionals who have a superior understanding of electronics, instrumentation, electrical, mechanical and robotics engineering are required among others.

Automation is a very technical field and therefore domain expertise and knowledge of processes is very important. Because of the technology-driven nature of this field, professionals must at all times keep themselves abreast of the latest improvements and technological upgradations that are taking place, instead of narrowly focusing on their departmental concerns.

In additional to technical skills, recruiters are looking for such competencies as interpersonal skills and drive for end results down the ranks. Don’t get nervous. You are not expected to know everything but your learn-ability levels should be high as a lot of training would essentially take place on the job.

Next, let me share some basics of automation beyond programmable logic control (PLC) and SCADA.

How to control the control loop?

Keep in mind that automation is the use of control systems (such as numerical control, programmable logic control and other industrial control systems), along with other applications of information technology (such as computer-aided design and computer-aided manufacturing), to control industrial machinery and processes, thereby reducing the need for human intervention.

A simple process control loop consists of three elements: a measurement system, a controller and a final control element. With regards to industrialisation, automation is a step beyond mechanisation. While mechanisation provided human operators with machinery to assist them in the physical requirements of their work, automation greatly reduces the human sensory and mental requirements. It refers to a wide range of hardware and software products and protocols used to communicate between standard computer platforms (PC, Macintosh or workstation) and devices used in industrial automation applications such as controllers.

Before the advent of computers, controllers were usually single-loop proportional-integral-derivative (PID) controllers. These were used to execute PID control functions. These days, the controllers can do a lot more, however, 80 to 90 per cent of the controllers used in India are still PID controllers. Digital controllers do not have mechanical moving parts. Instead, these use processors to calculate the output based on the measured values. Since they do not have moving parts, they are not susceptible to wear and tear with time. However, digital controllers are not continuous.

Understand the controllers from both the theoretical and practical point of view. Forget the analogue versus digital controversy. Both types of controllers have their respective pros and cons. Analogue controllers are based on mechanical parts that cause changes to the process via the final control element. Again, like final control elements, these moving parts are subjected to wear and tear over time and that causes the response of the process to be somewhat different with time. But analogue controllers control continuously.

The next thing you need to know is the measurement system. In the context of process control, controller decisions are based on measurements of process parameters. With the advent of computers, it is now possible to do inferential measurements, which means telling the value of a parameter without actually measuring it physically. It should, however, be remembered that inferential measurement algorithms are also based on physical measurements. Therefore, rather than rendering measurements redundant, they have made measurements all the more important.

Final control elements can refer to three things: control valves, variable-speed drives and dampers. In process plants, more often than not, the final control element is the control valve.

The automation industry is growing 6-8 per cent globally, whereas in countries like india and China, it is growing at more than 30 per cent
The issues relating to final control elements are most relevant to control valves, although these are applicable to a large extent to dampers and in some cases variable-speed drives as well. So try to get a clear idea about the instrumentation part of the control valve.

How to standardise the control?

For starters, learn to use OPC—‘OLE (object linking and embedding technology) for process control.’ It is a series of standards’ specifications. The first standard—originally called the OPC specification and now the Data Access specification—resulted from the collaboration of a number of leading worldwide automation suppliers working in cooperation with Microsoft. Originally based on Microsoft’s OLE COM (component object model) and DCOM (distributed component object model) technologies, the specification defined a standard set of objects, interfaces and methods for use in process control and manufacturing automation applications to facilitate interoperability.

Try to realise the practical utilities of the standardisations—the user’s project cycle is shorter using standardised software components and their cost is lower. These benefits are real and tangible. Because the OPC standards are based, in turn, upon computer industry standards, technical reliability is assured.

The original specification standardised the acquisition of process data. It was quickly realised that communicating other types of data could benefit from standardisation. So standards for alarms and events, historical data and batch data were launched.

Additionally, you need to know the current and emerging OPC specifications and their applicability. The original OPC Data Access used to move real-time data from PLCs, distributed control systems and other control devices to human machine interface and other display clients. The Data Access 3 specification is now a Release Candidate. It leverages earlier versions while improving the browsing capabilities and incorporating XML-DA Schema.

OPC Alarms & Events provides alarm and event notifications on demand (in contrast to the continuous data flow of Data Access). These include process alarms, operator actions, informational messages and tracking/ auditing messages.

OPC Batch specification carries the OPC philosophy to the specialised needs of batch processes. It provides interfaces for the exchange of equipment capabilities (corresponding to the S88.01 physical model) and current operating conditions.

Client-to-server and server-toserver communication across Ethernet fieldbus networks is facilitated by OPC Data exchange. It provides multi-vendor interoperability. It also adds remote configuration, diagnostic and monitoring/management services.

OPC Historical Data Access provides access to data already stored. From a simple serial data logging system to a complex SCADA system, historical archives can be retrieved in a uniform manner.

Moreover, all standardisations ensure secured mode of operation—OPC Security specifies how to control client access to servers in order to protect this sensitive information and to guard against unauthorised modification of process parameters. All these commands allow the users to identify, send and monitor control commands which execute on a device.

How to communicate for better control?

Although computers, PLCs and remote terminal units communicate with each other digitally, most end devices (valves, pressure transducers, switches, etc) still use analogue signals. For example, an analogue value of 4 mA might correspond to a pressure of no flow, while a value of 20 mA might correspond to a 1000GPM flow value. With discrete devices, the presence of a signal might represent a ‘closed’ or ‘alarm’ condition, while the absence of a signal might represent ‘open’ or ‘normal.’

But keep in mind, in the future, the 4-20mA standard will be replaced with a digital, two-way, multidrop commu-nication—FieldBus. You need to know the reason behind that. In two-way communications, a value can not only be read from the end device but also be written to the device. For example, the calibration constants associated with a particular sensor can now be stored directly in the device itself and changed as needed. The multi-drop capability of a FieldBus results in the most immediate cost savings for users.

With analogue devices, a separate cable needs to be run between the end device and the control system because only a single analogue signal can be represented on the circuit. Modern distributed systems partially solve this problem by locating remote multiplexing devices out in the field. The ultimate solution, however, is to be able to connect a reasonable number of sensors all located in the same area to the same cable. Although this will not happen overnight, you should be prepared to accept this tectonic shift in technology.

Know advanced processcontrol

To get an edge over your competitors, it is always advisable to learn advanced process control with respect to the underlying theory, implementation studies, the benefits that its applications will bring and projections of future trends.

Initially, advanced process control meant any algorithm or strategy that deviated from the classical three-term PID controller. The advent of computers offered more convenient alternatives—feed forward control, multivariable control and optimal process control. Indeed, the proliferation of so-called advanced control methodologies can only be attributed to the advances made in the electronics industry, especially in the development of low-cost digital computational devices (circa 1970). Nowadays, advanced control is synonymous with the implementation of computer-based technologies.

Also, try to understand the impact of advanced process control on product yield, energy consumption, product quality, process safety, environmental emissions, etc. Usually, cost savings ranging from 2 to 6 per cent of the operating cost are observed with the implementation of advanced controls. These benefits are clearly significant and achieved by increasing process efficiency, hence allowing plants to be operated closer to their designed capacity.

You should regard advanced control as more than just the use of a multiprocessor computers or stateof-the-art software environments. Neither does it refer to the singular use of sophisticated control algorithms. It describes a practice, which draws upon elements from many disciplines ranging from control engineering, signal processing, statistics, decision theory and artificial intelligence to hardware and software engineering.

The algorithms of control

Remember that control systems run according to the logical flow of the operating program. Knowledge of different controlling algorithms is always nice to have. Realise the actual logic behind the control systems. For example, statistical process control is a method for achieving quality control in manufacturing processes. It is a set of methods using statistical tools such as mean, variance and others, to detect whether the process observed is under control.

Model predictive control (MPC) is widely adopted in the process industry as an effective means to deal with large, multivariable constrained control problems. The main idea of MPC is to choose the control action by repeatedly solving online an optimal control problem. This aims at minimising a performance criterion over a future horizon, possibly subject to constraints on the manipulated inputs and outputs, where the future behaviour is computed according to a model of the plant.

PID-type controllers do not perform well when applied to systems with significant time-delay. Perhaps the best known technique for controlling systems with large time-delays is the Smith Predictor. It overcomes the debilitating problems of delayed feedback by using predicted future states of the output for control.

Currently, some commercial controllers have Smith Predictors as programmable blocks. There are, however, many other model-based control strategies that have dead-time compensation properties. These are useful for predictive constrained control. Predictive controllers can also be embedded within an adaptive framework.

Most processes require monitoring of more than one variable. Controller-loop interaction exists in such a way that the action of one controller affects other loops in a multiloop system. Depending upon the inter-relationship of the process variables, tuning each loop for maximum performance may result in system instability when operating in a closed-loop mode. Loops that have single-input single-output (SISO) controllers may therefore not be suitable for these types of applications. These types of controllers are not designed to handle the effects of loop interactions. Try to understand how a model-based controller can be modified to accommodate multivariable systems.

Dynamic matrix control is also a popular model-based control algorithm. The process model is stored in a matrix of step or impulse response coefficients. This model is used in parallel with the online process in order to predict future output values based on the past inputs and current measurements.

The final bend

It is possible that your awareness about most of the aforementioned terms is from a notional perspective only. Don’t worry. Utilise your industrial training or final-year project to your advantage. You can get a holistic overview of ‘chip to ship’ of a control loop only after completing a project.

Nearly all of Indian institutes are woefully lagging in terms of providing students with such opportunities. If you feel that you lag behind due to lack of practical exposure, a strategically chosen course may be the solution. I emphasise the word ‘strategically’ because that is what decides whether you will get the job passport or your money will go down the drain. So before choosing a course, judge the reputation of the institute, the certification system, the industry accreditation and also the course curriculum.

The author is a research analyst cum journalist at EFY


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