Five machine design challenges and how motion controls help

Commercial challenges for machine designers are being address by the motion control industry. See how these five advances can help with motion control designs.

By Jason Crawford, Thomson Industries Inc. October 2, 2018

Motion control system designers are under pressure to differentiate offerings in an increasingly commoditized marketplace in a wide range of applications, such as benchtop laboratory automation, plant-floor material handling, and heavy-duty construction vehicles. Many original equipment manufacturers (OEMs) ask control component vendors for help, seeking more functionality in less space, faster time to delivery for prototypes and products, and more control and flexibility over price points with seamless integration and operation.

The motion control industry has evolved to deliver new capabilities to add value. Motion control innovations are making a difference by responding to the following five commercial challenges.

1. Smaller products

Small system designers want to go even smaller so systems are more compact, easier to carry, and store. Many customers want to move analytical or monitoring instruments closer to the point of use to make things more convenient for health professionals and patients. Such machines are examples where manufacturing technologies enable miniature linear motion components to be produced to meet those needs.

Factory systems designers want to help customers better use limited floor space or present a cleaner, more open workspace. Makers of larger equipment, such as agricultural combines, also may want more efficient use of space to incorporate technology that improves operating efficiency or safety or offer other benefits that provide market differentiation.

To meet smaller space requirements, manufacturing technology improvements have allowed for smaller products to be produced more efficiently, enabling design engineers to incorporate more functionality into smaller form factors. Miniature ball screws, motorized linear actuators, motorized lead screws, and linear bearings are increasingly being chosen for use in smaller-scale applications. Electromechanical actuators also have become more capable of replacing the pumps, compressors, delivery systems, and other space-consuming technology essential for hydraulic and pneumatic actuation.

Embedding electronics into smart linear actuators and other motion control products makes a more space-friendly product by supporting network communications, position monitoring, and other functionalities that previously required external devices. Internal electronics also eliminate complex wiring, to avoid bulky, unsightly clusters. These latest actuators connect to power sources and communications networks with just a few wires. 

2. Faster prototyping

As competitive pressures mount, demand for faster delivery of more personalized equipment heightens. Effective prototyping is important to many solutions because designers typically must try various component options before settling on the one that best suits the application. Advanced modeling technology, such as 3-D metal-based printers and simulation software, give designers more flexibility and greater speed. Enhanced modeling capability also puts the motion control components on the critical path. In the past, designers may have waited six to eight weeks for a component. Now, they may need it in days.

This need for speed is driving changes at the component manufacturing level. Some manufacturers reengineered processes to offer next-day turnaround on one-off items for prototyping use. Some are increasing component inventory most often needed for prototyping initiatives. Distribution channels help by increasing inventory stock of components commonly used in prototyping. 

3. Holistic component selection, integration

A critical aspect to increasing time to market is selecting the right components and integrating them optimally for maximum accuracy, precision, straightness, noise level, and other performance characteristics. The challenge is motion control optimization is complex. Although many system designers have the expertise necessary to select motion control products, many are closer to retirement than college. Replacing them will not be easy. Part of the reason is because there are limited schools that train motion control engineers. Recruits are typically from electrical or mechanical engineering disciplines. Motion control expertise must be nurtured on the job.

Less experienced design engineers might know what kind of speed or straightness they need but may not be familiar with the capability of motion control components to meet design requirements. Someone designing a patient table, for example, may know the decibel level they must achieve for compliance with industry standards or regulations but may not know how a ball screw would affect the noise level or even the "quality" of noise. The electrical engineer may come at it from the electrical perspective, and the mechanical engineer may take a more physical perspective, but neither may have enough experience to appreciate subtle component interactions. To compensate, designers may over-design, specifying more capability than may be required and then try to optimize on the bench. Design changes at that point can unnecessarily increase time to market and production costs.

The increasing importance of holistic system design, combined with the shortage of motion control experts, is a good reason to involve motion control vendors early in the process. They have more experience with impact of integration in multiple applications and, if consulted up front, can save significant time and money.

For engineers who prefer to go it on their own, some vendors offer online configuration tools, some of which can reduce optimal product selection for applications from hours to minutes. Design engineers can use software to help with selection of linear actuators, ball/lead screws, and gearheads. 

4. Component cost vs. lifecycle cost

Although machine designers want to have the highest quality components for systems, they don’t necessarily want parts that will outlive the machine. Putting a motion control component designed to last 20 years into a system that may be obsolete in five years does not make good business or engineering sense.

As the component market matures, designers who take the time to shop can find a product that suits application and budgetary needs, but using proper judgment in such cases requires a greater understanding of motion control systems, not less.

A designer driven only by economics is more likely to under-design rather than over-design. Although testing will determine if the design will meet the required specifications in the near term, they typically cannot test for the full life of all components and will implement a shortened test procedure. This will not always provide enough data to differentiate a higher quality motion control component from a lower cost/inferior designed product, which no one discovers until they encounter problems down the road.

For many applications, total cost of ownership can be a deciding factor. An equipment manufacturer that sells many products to the rental market, for example, may have more appreciation of the long-term value of total cost of ownership. If purchase price were the sole factor, they might opt for a pneumatic or hydraulic actuator over an intelligent electromechanical component. But when other factors such as reliability, uptime, footprint, and maintenance are figured in, the electromechanical option has much greater benefit. 

5. Adding product value

Probably the greatest commercial challenge OEMs face is one they share with the component manufacturer: understanding what the market will buy and how to differentiate in delivering it. Connected products that share data in the cloud are a promising opportunity for strategic differentiation.

For example, one major medical device manufacturer put the Industrial Internet of Things (IIoT) at the center of its business strategy. The system records data on machine performance, the status of its components, and system errors detected. In conventional systems, using this data required a trained technician to tap into the machine, read the log files, and manually schedule maintenance repair-based on parts that need to be ordered. With connected machines, those log files are securely uploaded for analysis and planning from just about any location.

The motion control industry is going down this avenue as well, gearing up to help companies integrate motion technology into their connected solutions. Toward this end, motion control vendors have added, and are continuously improving, the onboard intelligence of components, giving them the computational capability and communications necessary to participate in connected strategies.

Whether it is connected systems or something else, the motion control industry is supporting support OEM innovation with the right motion control performance at the right price.

Jason Crawford, Thomson Industries Inc.; Edited by Mark T. Hoske, content manager, Control Engineering, CFE Media, mhoske@cfemedia.com.

KEYWORDS: Motion control, machine design

Machine designs improve with motion control innovations.

Smaller space, more control, flexibility Software helps with sizing and selection.

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