- Products & Systems
ALIO Industries has spent 2019 working with numerous customers from across industry that are exploiting the ability to innovate through the use of true nanometer-level motion control solutions.
2019 has been a pivotal year for established nanometer-level motion control solution provider ALIO Industries. Throughout the year, news and coverage of ALIO’s Hybrid Hexapod® has reached every corner of industry globally, and the momentum that has been gained has been exciting as ALIO has helped existing and new customers reach new levels of precision in motion control.
Bill Hennessey says, “In many ways, the ultra-precise end of the motion control market is quite a confusing place to be, as the handful of extremely precise motion control suppliers tend to use non-consistent and often illusory ways of describing the levels of precision that they can attain. ALIO has always worked in the area of nanometer-level motion control, and as such has a unique perspective on what really works when looking for this level of precision. Because of this, during 2019, and with the Hybrid Hexapod® very much front and center, we have focussed on educating the customer base to navigate alternative solutions, and give them the tools to interrogate solutions providers in such a way that they can secure a motion control technology suited to their specific applications.”
In the area of hexapods, this has required ALIO Industries to identify where the usefulness of conventional hexapods expires, as it is here that the Hybrid Hexapod® finds its unique niche.
Hexapods are motion control technologies that operate with 6 degrees of freedom (DOF), and the standard hexapods that abound on the market today satisfactorily service applications where micron motion tolerances are required, but as the demand for nanometer requirements expands, standard hexapods struggle somewhat.
This is because there are performance limitations inherent in all “conventional” hexapod designs. They operate within 3-dimensional space, and have errors in all 6 DOF. However, hexapod motion systems have typically only been characterized by performance data of a single degree of freedom. This practice leaves error sources unaccounted for in several degrees of freedom, especially in the areas of flatness and straightness, which are critical precision needs at the nanometer-level. The hexapod’s best flatness and straightness of travel is still no more precise than in the order of magnitude of tens of microns per axis.
Because hexapods have six independently controlled links joined together moving a common platform, the motion error of the platform will be a function of the errors of ALL links and joints. Hexapods are known to have optimum accuracy and repeatability when performing Z-axis moves, because all links perform the same motion at the same relative link angle. However, when any other X, Y, pitch, yaw or roll motion is commanded, accuracy and geometric path performance of the hexapod degrades substantially because all links are performing different motions. In the case of legacy hexapods built with non-precision joints and motion controllers that are not capable of forward and inverse kinematics equations, the source of error is even more pronounced.
Furthermore, it is generally accepted that hexapods have relatively good stiffness compared to serial stacked multi-axis systems. However, it is often only the hexapod’s “Z” (vertical) stiffness that is considered. Geometric design stiffness has a critical impact on and hexapod’s platform repeatability and rigidity. A lack of design stiffness relates directly to a weak XY plane stiffness with the conventional hexapod working platform. Moreover, this inherent design flaw of the conventional hexapod negatively affects XY axis performance, especially with thermal bonding or machining applications that require more force to be performed accurately within the XY plane.
The Hybrid Hexapod® was developed by ALIO to address the critical weaknesses of conventional legacy hexapod designs, as well as the weaknesses of stacked serial stages, and to achieve nanometer -level accuracy, repeatability, and high-integrity flatness and straightness during motion. It utilizes a tripod parallel kinematics structure to deliver Z plane and tip/tilt motion, integrated with a monolithic serial kinematic structure for XY motion. A rotary stage integrated into the top of the tripod (or underneath it depending on application needs) provides 360-degree continuous yaw rotation. In this hybrid design, individual axes can be customized to provide travel ranges from millimeters to over one meter, while maintaining nanometer-levels of precision.
Hennessey continues, “Engineers working at the cutting edge of what is possible must be stimulated to ask more as they see that this technology reaches places others cannot, has the potential to promote innovations, and can optimise efficiency and cost-effectiveness in manufacture. The Hybrid Hexapod® is orders of magnitude more precise than traditional hexapods, being 100 x stiffer, 30 x faster, and with 10x the usable work envelope of industry standard options.”
ALIO is always eager to discuss how the Hybrid Hexapod® can be used to benefit customer applications, and the company will work to customize specific solutions for particular customer applications.
As the demand for more and more exacting motion control increases across numerous industry sectors, it is vital that before investing, customers are informed enough to make sure that they select the right solution for their specific application.
The motion control sector is characterized by an array of vendors in many ways saying the same things, sometimes in subtly different ways. But statements of competence often flatter to deceive, a bald statement about accuracy, for example, obscuring enormous differences between the capabilities of vendors in terms of repeatability, and motion control solutions being fit for purpose.
Starting with the premise that if a good motion control solution is expensive, how much more expensive is a bad one (with all this implies in terms of time delays and costs of re-investment in a suitable motion control solution) in this piece, we attempt to arm manufacturers with the questions that they need to ask their short-listed motion control technology providers to ensure that the motion control solution option chosen is right first time and up to the job.
Questions need to be asked that delve into motion control vendors’ capabilities and their values.
Customer Focus. Ideally your chosen motion control technology vendor should sell solutions to customers not just products. The key is to be able to customize motion control solutions to specific customer applications. When working in the area of nanometer-level motion control, your chosen vendor should have extensive experience working in the nanometer world. The vendor should also have a demonstrable passion about — and absolute focus on — precision. A vendor supplying nanometer-level motion control solutions should be able to prove its credentials and demonstrate that it has provided a significant number of best-in-class, efficient, and cost-effective motion control solutions for an array of different industry applications. Ask your chosen vendor for evidence. All claims made should be able to be substantiated and this will prove whether your short-listed vendor is equipped to operate at the nanometer-level of accuracy or just the micron level.
What is Motion Control? This may seem like an odd question to ask a motion control technology provider, but it does actually get to the heart of the difference between vendors. Most vendors sell off-the-shelf solutions and leave their customers to align them with their specific applications. In a way, this demotes motion control to a necessary evil, a link in a process chain that is expensive and complicated. But when your vendor provides truly cutting edge nanometer-level accurate and repeatable motion control solutions, it elevates motion control from a necessary evil to an enabling technology. If a vendor provides the best-in-class, most accurate, and most repeatable motion control solutions on the market, they will be able to push the boundaries of what customers may see as possible, and will therefore promote the ability to manufacture innovative, bleeding-edge products that stimulate competitiveness. Try and assess your short-listed vendor’s view of motion control. Do they see obstacles and problems, or opportunities and solutions?
Partnership. Your chosen vendor should place an emphasis on being your strategic partner in product development. It is only by doing this that you can be confident about achieving your challenging motion control and manufacturing goals. Key is early stage engagement with you chosen vendor, and a feeling that they want to truly become embedded in the development of your end-use products and allied motion control solutions. Once again, the difference is between a vendor that sells off-the-shelf solutions (which is not that concerned about your product development process), and one that is dedicated to providing you with customized solutions (which will necessarily want to help you navigate the inherently complicated area of nanometer-level motion control solutions optimized to specific applications). You want to feel that if you don’t engage fully with your chosen vendor that you will compromise quality of outcomes, speed of outcomes, and cost of outcomes. Also, check out the warranty that your vendor is willing to extend. This is a sure-fire way of understanding the level or confidence they have in their own solutions.
Vertical Integration. When working in a world where nanometer-levels of accuracy are the norm, it is vital that motion control products are manufactured in one facility. Ask your vendor whether they have design, machining, metrology, manufacturing, and assembly under one roof. The cross collaboration between product development teams is vital to the achievement of reliable and repeatable ultra-precise motion control solutions, and vertical integration is disproportionately important as the demands for accuracy move from micron-level to nanometer-level precision.
Team. Drill into the experience and technical know-how of your short-listed vendor’s team. Especially when your demand is for nanometer-level motion control, you need to make sure that your vendor has a dedicated focus which will translate into innovative and cutting-edge motion control solutions. Much of this is about the culture you will see in a vendor company. Assess whether you detect a “can do” attitude and whether your vendor seems to nurture a collaborative environment. But above all see if you can feel a passion running through your vendor’s team. If the passion is there, honesty and integrity will often follow, and with that will come trust. And it is ultimately trust that you need to bottom out when choosing a vendor. You need to trust that the motion control solution that you buy fits your requirements, and is not just another unit shifted by the vendor to hit a sales target regardless of ultimate customer satisfaction.
Solutions. If your short-listed precision motion control technology provider is really credible, it will be able to show you a series of innovative solutions that redefine the motion control market. Here you should be looking for evidence of next-generation “blue ocean” technologies, not variations of legacy traditional motion control technologies. This is like the difference between vendors selling hexapods and a company like ALIO Industries that sells the Hybrid Hexapod®, which overcomes process limitations in traditional hexapods, and exhibits orders-of-magnitude improvements in precision, path performance, speed, stiffness, and larger work envelope. Nanaometer-level repeatable motion control is achieved by pushing the envelope, not tweaking years-old technologies to squeeze out ever decreasing increases in accuracy. Check out your vendor’s portfolio of products, the customized solutions they have provided, and the level of innovation that is evident in creating new solutions.
Interrogate precision claims. Pinning down motion control vendors over statements of precision is a minefield. Ultimately, claims on nanometer-level precision is meaningless unless this nanometer-level precision is achieved repeatably. Vendors that cannot achieve repeatable nanometer-level motion control often need to resort to at worst false, and at best illusory claims that muddy the waters. Some vendors even go as far as to publish “typical specifications” and “guaranteed specifications”, typical specifications showing what “could” be possible in a motion control solution, which is greater precision that can actually be guaranteed. In other words, they show what they would like to be able to do, and then demonstrate that what they actually can do is much worse. This takes lack of clarity to a whole new level, and is extremely confusing for customers. Again, look for evidence of vendors that are trying to move this conversation along. ALIO Industries, for example, now talks in terms of Point Precision® referencing performance specifications to a point in space at the single digit micron or nanometer level, and is working with NIST to move on from the planar methodology that current motion control standards use. It is vital that you interrogate precision claims diligently before a making motion control technology purchase. It is also critical that ASTM and/or other internationally registered standards are followed by vendors, instead of methods developed to flatter a particular vendor’s products and which provide flattering data calculations which give a false illusion of precision.
In essence the choice of a nanometer-level motion control solutions provider is based on a number of factors, and is a mix of not just technological competencies but also core values and what “makes a company tick”. Investment in an ultra-precise motion control solution is expensive, and customers need to be certain before nominating a motion control vendor that they will have a best-fit solution that is right first time.