Rising environment consciousness and the need for automation have been creating demand for the drives and encoders category in India.
by madhukar joshi
In the field of industrial mechanics, drives and encoders play an important role. A drive is used for movement and encoders are used for sensing and controlling the movement to carry certain operations in specified time to optimise productivity. Precise control over movement while maintaining highest quality and safety standards are the key functions in this context.
Often a combination of hardware and software, encoders are used to sense and control the motion. Their output is either analogue or digital signals. The purpose of encoders is to perform trouble free for long durations without losing accuracy and signal strength.
Response from digital encoder could be a series of pulses just for sensing motion or a complex digital output for sensing, motion, the direction of motion and also position. Encoders can be used for sensing rotary motion, linear motion, the direction of motion, speed and also current. Incremental encoders sense and indicate only position change/ motion and are used to measure the rate of motion and control. e.g. Wheel bearings with magnetic encoder, tachometers. Absolute encoders not only indicate position change/motion but also the direction of motion and current position.
They even retain position information if power is disconnected. Absolute encoders are used in applications where current position is to be indicated for further usage and position information should also be retailed even in case of any power outage or shut down of machine/equipment. Their usage areas include MRI scan machines in the medical industry, in production machines for executing different operations in sequence.
Encoders can be classified into four categories:
• Mechanics, with or without integral bearing, with or without external shaft coupling
• Accuracy: Typical ranges start from 10 arc seconds and go lower as per the application
• Line Counts
• Output signal absolute or incremental Sinusoidal, TTL or EnDat absolute
Encoders are used in machine tool industry, elevators, conveying solutions, energy sector, food processing industry, packaging industry, medical equipments, servomotors, aerospace application, semiconductor industry, textile industry, printing machines and various other applications where repetitive operations are to be performed in sequence in production process, also other applications where precise control on motion is needed for desired output.
The drives category overview
As mentioned above, in the manufacturing sector, a drive is used for movement. In certain applications, this helps in reducing the power consumption by modulating power input according to requirement. Drives play a vital role in machine and factory automation. Especially, with the increasing complexity of machines motions tasks become increasingly multifaceted. It is important for machine builders to have synchronisation among various families of drives namely servos, steppers, long stator linear motors and VFDs. All these have different performances and fit different needs of the machine. However, when we look at the machine as a unit, it becomes extremely important to synchronise them to gain maximum productivity and efficiency.
Drives market has been evolving for many years. Previously, drives used digital and analogue inputs signals from the controller for desired movements. Later these were upgraded to Fieldbus networks working on serial communications. A couple of years back the drive systems moved to Industrial Ethernet networks, out of which Ethernet POWERLINK stood out for machine builders thanking its open source nature, real-time deterministic capabilities, standardisation, high performance for executing complex applications and its vendor-independent nature.
Given their diverse range and applications, drives and encoders is a difficult category to estimate the market size. While no third-party research data is easily available, some indicative market estimates can be found. Estimating the total variable frequency drives market in India to be Rs 2,500 crore, PL Muthusekkar, MD, Nord Drivesystems, says, “Construction and infrastructure projects, automation, and compliance are key factors leading to a huge demand for drives and encoders segments.”
The automation trend up-close
Two court verdicts came in November this year that may potentially reshape the business processes followed by construction companies in India. The Madras High Court directed the Tamil Nadu government to stop sand mining within six months, placing a periodic ban upon the quarrying of granites and other minerals. Similarly, in a landmark verdict, the Supreme Court placed a ban on sand mining pertaining to a case in Rajasthan. In both these cases, maintaining the ecological balance appears to be the guiding principle that led to such rulings. With these verdicts, natural resources will not be available in their present form for construction, forcing construction companies to look for alternatives. Explaining the impact of these verdicts on drives and encoders business, Muthusekkar of Nord Drivesystems cites the example of sand as a commonly used construction material. “Since sand will not be available for use, companies will have to crush stones to make that sand. This will push up the demand for equipment such as stone crushers. Moreover, the need for speedy availability of raw material will ensure that manufacturers must improve their internal operations through automation, thus further benefiting the drives and encoders category.”
The need for automation by manufacturers across sectors has been the key demand driver for drives and encoders categories. Any manufacturing unit deploys automation for various needs at various levels. The motivation of factories for automation is focused on gathering data and analysing it for improving the overall equipment effectiveness (OEE), monitoring energy and conditions of the machines. A 24/7 connectivity to the lines is a demand from various factories. Mid and large manufacturing plants can be seen integrating more and more drive/encoders in their manufacturing set-ups for better utilisation of their assets, better control over the quality of end products, lowering the cost of production, and minimise errors.
Shreepal Ranjan Negi, head, Schaeffler Technology Centre, informs, “Drives and encoders operate across a diverse segment, in a range of operating conditions – from the extremely sterile environment such as medical and food processing to harsh conditions such as material handling and elevators. The application and operating conditions continue to be key drivers for the type of drives/encoders. Automation is a key driver for the industry and we see extensive use of integrated systems for intelligent controls and optimisation.”
Schaeffler products integrate multiple supplementary functions, says Negi. “Essential components in that process are sensors, e.g. for position, speed, force, torque or vibration, which in most cases are subject to harsh operating conditions.” Inverse-magnetostrictive sensors, he adds, are used for contactless torque measurements. In the automotive sector, this sensor principle is used in roll stabilisers. In the industrial division, bottom brackets in bicycle or agricultural machines are the typical application fields. Rotary table bearings with angular measuring system (YRTSM) are fitted with magnetoresistive sensors.
Stating that automation is the key trend in this segment, Abhilash Tripathi, MD, Heidenhain, mentions, “With increasing automation in factories and fading of boundaries between software and hardware in the IoT world of interconnected objects, it is imperative that advanced and reliable sensors and encoders will play an important role in making the factories of tomorrow, truly connected.”
Rising importance of energy efficiency
With rising energy costs, manufacturing units have always looked at optimising energy consumption. Variable frequency drives (VFDs) is one of the solutions to optimise energy consumption. Manufacturers deploy these instead of pneumatic and hydraulic solutions at many places to achieve power savings, improve efficiency, and reduce the cost of manufacturing.
Ninad Deshpande, head, marketing, B&R Industrial Automation, illustrates with a plastic industry example, “If we look at injection moulding machines from plastic industry, then most of them changed from hydraulic to all-electric design deploying servos extensively. It not only enables higher efficiency, design flexibility but also higher accuracy and productivity.” VFDs are used by various industries including textile, packaging, plastics and batching plants, he informs.
Mentioning that nearly 30% of all electricity produced in the world is consumed by drives, motors and gearboxes, Muthusekkar of Nord Drivesystems highlights the criticality of power conservation in the manufacturing sector. “If these products become energy efficient, then it will lead to huge energy savings and also be beneficial to the environment,” he says.
“The new compliances with respect to mandatory migration to IE2 products will prove beneficial to the industry by cutting down power costs. Besides driving demand for automation products, the new compliance laws will also help protect the mother earth from depletion of natural resources and ill effects of pollution,” Muthusekkar adds.
Evolution of technology
While drives and encoders are helping companies to automate their processes, there are advancements happening in these categories themselves. Deshpande of B&R shares examples of his company’s products. ACOPOS P3, the latest drive from B&R, for instance, can control three motors with a single cable for power and feedback. “With advancements such as IoT and digitisation, B&R, with its Mapp technology, provides diagnostics and maintenance details right up to a variable level even at the drive level.” As machine builders can diagnose drives via a web browser, it reduces the time for diagnostics and enables machine builders to provide best in class service to their customers, he claims.
Use of simulation
The technology advancements such as virtual commissioning and digital twin, machine builders are able to simulate the system, right down to motors today. Vendors provide simulation environments for all electronic components to ensure accuracy in manufacturing and to improve operational efficiency. With simulation platforms such as MaplSim and Matlab machine builders can start machine development without the need for actual hardware by simulating right down to machine mechanics. This helps them in identifying design or selection flaws well before production, thus, reducing costs and time to market.
Benefits of globalisation
Like many industries, globalisation has helped the encoders category immensely with customers demanding high-quality products that meet global standards. According to Tripathi of Heidenhain, the local manufacturers are benefited by improving their product quality and accuracy by adopting methods and components used by global leaders. Stating that the encoders business in India has been registering a healthy growth during the past decade, he points to a strong growth in this category going forward. Many Indian manufacturers have employed automation to improve their processes and products to such an extent that they have emerged as preferred suppliers to reputed companies worldwide, he informs. Heidenhain’s encoders go into the manufacturing of mother machine tools and automation products. The applications include machine tools, robots, factory automation, elevator gearless motors, cranes, printing presses, metrology, wind turbines and medical machines.
The future scope
The success of automation in manufacturing has led to research in robotics and its commercial adoption. Manufacturing set-ups such as packaging and automotive have started deploying robots extensively. Today, with connected shop floor we are moving in the direction of collaborative robotics. The robots used are powered by servomotors and drives. The stream of openROBOTICS has opened up new dimensions in robotics integration for machinery and production lines. According to Deshpande of B&R, the uniform programming for every component in the line, including robotics, will help machine builders take a holistic approach to operations, diagnostics, and maintenance without compromising on human safety.
At another level, adaptive manufacturing has emerged as a strong trend extending the economies of scale to batch sizes — produce small batches efficiently and benefit from the higher margins of personalised products. This will catalyse a digital transformation of machine builders to include motion control and mechanical design. “Industrial IoT presents new challenges for existing network architectures. The need to pre-process data acquired from machinery makes edge architectures the solution of choice. A holistic approach must also satisfy the demand for real-time communication and provide the necessary data processing functionality,” Deshpande says.
Going forward, industrial IoT, Industry 4.0 and digitalization will become big trends enabling growth in various aspects of automation, he concludes.