How Motion Control Advances are Boosting Machine Productivity
| By: Ray Chalmers, Contributing Editor
Consumer applications are helping move industrial productivity forward
Machine productivity is at the heart of economic growth. This is true not only for equipment-dependent industrial manufacturing companies, but applies to a growing number of non-manufacturing firms as well.
Online shopping, for example, is driving greater focus on having the selected products available, which means high-volume automated package handling if companies such as Amazon, eBay, and other online retailers are to keep their delivery promises. Additive manufacturing (3D printing) is rewriting component design for a growing number of industries while making more of an appearance in homes and schools. The market for collaborative robots – robots working collaboratively with human workers as opposed to in safety-gated cells – is reported to hit $3 billion in global sales as early as 2020.
The impact of these and other related developments are meeting with mixed responses from consumer and business audiences. Consultants Price Waterhouse Coopers (PwC) surveyed consumers and CEOs and reported results at the recent 2017 World Economic Forum in Davos, Switzerland. From more than 5,000 consumers surveyed, 79% think technology such as robotics, automation, and more efficient production tools will cause job losses over the next five years. But the reality is that more than half the CEOs surveyed (52%) plan on hiring more employees in the next 5 years.
Both are correct. The manufacturing plants of our fathers and grandfathers are gone forever, along with the “three Ds” (dirty, dangerous, and dull) nature of the jobs therein. Much is made of bringing back manufacturing jobs, but the context continues to evolve and grow. The technical skills shortage of inspired, engaged, and digitally savvy workers in today’s production is real, and advances in production technology and efficiency will only continue to highlight the need for such workers in the brave new world manufacturing is becoming.
Shop floor machines will increase their level of intelligence to accommodate more predictive planning and more flexible production needs, say a number of machine and component suppliers. The term “smart machine” implies a machine that is better connected, more flexible, more efficient and safe. It can quickly respond to new demands. Based upon a collection of smart, connected components, it maximizes efficiency through intuitive collaboration with its users. A smart machine is also capable of participating in predictive maintenance practices while minimizing its own environmental footprint and total cost of ownership.
On the technology side, both innovation and lower costs are making new generations of equipment accessible to industrial operations. Here are some highlights:
- Ethernet connectivity – Enables integration of machines and networks and improved data access; provides the basis for service-based models and management of security
- Wireless (e.g., RFID) – Allows for rapid, automatic data entry
- Mobile technologies – Allows for safer, more remote operation of equipment
- Increasing CPU power – More throughput enabled at lower cost
- Memory cost decreases – Allows for advanced data management and better decision support
- Digitization – Allows for low-cost development of machine automation simulation programs
New technology applications increase the expectation of machine operators and system users, and also alter training approaches for both new and veteran employees. With internet use commonplace in many people’s lives, the expectation of workers to have access to production information in real-time continues to increase. An interactive web mentality is promoting an expectation that smart machines and distributed control centers collaborate much in the same way that people do on social networks.
A Change in Thinking
New motion control components are driving how machines respond to production advances. “This really requires a change in thinking for machine designers,” says Corey Morton, director of technology solutions, B&R Automation, (Roswell, Georgia USA). “Components are increasingly high-performance, lower cost, easier to install, and safer. The whole game changes.”
Linear transport technology is a good example. Pitchless design means the throughput of one machine section does not need to dictate the overall throughput of the machine. There is no longer any need for collection zones or conveyor belts to speed up and slow down products since each item can be moved through the line independently.
This can also impact factory design. “More motion control technologies can be aligned for better synchronizing of position and function on a production line,” Morton says. For example, individual shuttles can be controlled via CNC channels and be synchronized with other CNC axes. This can significantly shrink a production line’s footprint.
Helping advance ease of integration is modularity. In high-axis-count machines, a substantial portion of control panel space may be consumed by classic panel-mount drives, including the requisite fusing, filtering, and more. In contrast, a decentralized drive platform significantly reduces necessary panel space and expense by distributing the servo drives around the machine. Kollmorgen features a multi-axis servo system that is a decentralized drive platform consisting of a central power supply and robust IP67-rated servo drives placed near the motor.
The patented design AKD-N servo system also enables substantial cable reduction, in which communication is combined in a single 11-mm diameter hybrid cable. On the motor side, there is also only a single cable needed for power, brake control and feedback. Together these can lead to substantial savings in cables.
Technology providers are also saying customers are demanding customized approaches. “Many look to us to integrate motors and encoders into some kind of application-specific mechatronic solution,” says Mark Holcomb, senior staff engineer and motion control specialist at Celera Motion’s Motor Center of Excellence in Loomis, California USA. “This can mean a motor that brings all the required factors including power and duty cycle into a specific geometry. We then characterize, integrate, test, and deliver a solution together with our customer every step of the way.”
For example, one customer required precision rotary axis control in the lowest profile form factor for multiple sequential robot arm joints. Key additional requirements included minimal movement at start-up to report absolute position, and minimal signal cabling to keep the overall arm size as small as possible.
Celera engineered a series of custom-sized PCB-based encoder modules with read-heads, communication interfaces, and what the company calls Micro Motion Absolute™ technology. This employs a standard 40-micron pitch incremental counting track, coupled with a reference track where each index is uniquely spaced. With only a small movement at start-up, multiple index marks are detected, and the measured spacing is compared to a lookup table in firmware to determine absolute position.
One Controller to Rule Them All
Machine design continues to be an exciting world. Aerotech (Pittsburgh, Pennsylvania USA) has introduced galvos, hexapods and piezo mechanical systems into its product portfolio. “Over the last few years, we’ve introduced the ability to control delta robots, hexapods, piezo and galvo axes, which when added to controlling brush, brushless, stepper, voice coils and third-party drives (for VFDs), means one controller can govern all the axes of a machine,” says Joseph Profeta, director of control systems.
This results not only in improved machine throughput and/or accuracy, depending on customer requirements, but easier-to-use machines that decrease design and commissioning time. “Engineers only need to use one tool, meaning less training and quicker expertise. And we’ve developed advanced control algorithms to provide better tracking than conventional control structures,” he adds. “This leads to improved accuracy and/or higher throughput.”
Siemens has updated the software for its high-end motion control system Simotion and, in the new Version 4.5, has equipped it with object-oriented programming (OOP) and communication via OPC UA (Open Platform Communications Unified Architecture). This means mechanical engineers can now implement large software projects much more efficiently than before and can now access Simotion data in a standardized way, across all automation levels – as far as the cloud.
Using object-oriented programming (OOP) according to IEC 61131-3 ED3, complex applications can be broken down into manageable object structures to precisely illustrate the structure of a modular machine, for example. Mechanical engineers can better standardize and reuse software modules and considerably reduce the programming and testing costs and the susceptibility to errors. This allows them to implement large software projects considerably more efficiently than before.
The requirements for increasing machine productivity and efficiency are ongoing. In the increasingly connected workplace of the future, motion control hardware and software applications are evolving as well.