June 8, 2022
How Humotech’s partnership with MathWorks and Speedgoat is driving Caplex development
At Humotech, our mission is both as ambitious as it is broad: to transform the development and use of wearable machines. And for the record, we’re not wavering on that. The company was founded on initial research that showed the game-changing capabilities of robotic emulation technology to the field of wearable devices – and the notion that we could bring this technology to market and make it accessible to anyone who wants to use it.
It was a risk worth taking. Caplex, Humotech’s proprietary robotic emulator platform, is making gains in the research and development of exoskeletons, prosthetics, and beyond. It’s being used by researchers across fields; in rehabilitation and injury prevention, prosthetic prescription, and commercial exoskeleton development, for example. (Check out our new Research Library for a full list of publications!)
But going in, we knew that Caplex’s success would hinge on its software components. The Control System is the brain and interface of the emulator, allowing experimenters to regulate the force and motion applied to the device worn by the user (an exoskeleton or prosthesis, for example), and thus, to ‘test-drive’ a variety of different wearable devices without switching out physical devices or even changing stride.
Not only does the software need to be high-performance and capable of meeting customers’ diverse research needs, but it also has to provide a seamless user experience; it has to be affordable; and it has to deliver continual value, capable of being leveraged over and over again for ongoing development.
That’s a tall order.
As a programming language, the MATLAB and Simulink platform developed by MathWorks had been around for a long time when we first started developing Caplex, but we didn’t know of an example of it being used before as a robotics application for real-time control of a machine. We figured we’d give it a go. The software ended up being a natural fit and today is part of the DNA of both our Full-Size and Portable Caplex systems.
The high degree of built-in functionality is a big part of what makes MATLAB/Simulink such a good option for the system. We know Caplex users may not be hardcore software engineers or interested in the time-consuming process of creating code from scratch. But the software lets Caplex users get a head start on anything they want to develop. It also allows researchers to customize the code to create and test entirely new devices, such as the PRO-003 multi-axial prosthetic foot emulator.
Speedgoat made the cut early on as well, as we searched for a real-time target machine to enable remote manipulation, especially one that would integrate easily with MATLAB/Simulink software. Luckily, MathWorks was collaborating on development with Speedgoat at the same time we were developing Caplex. Also having never been applied to what we were trying to do, we took a leap of faith and built out Caplex with Speedgoat. Since then, it’s been our go-to target machine. In fact, Humotech was the one of the first to apply Speedgoat for rapid prototyping of real-time control systems for robotics, using the functionality for control, I/O, and signal processing.
Both of these tools met all of the requirements we were looking for: they were high-performing, user-friendly; scalable and customizable; and also, affordable. As a small startup with limited resources, the MathWorks startup program enabled us to get going with the tools.
However, the real test came as we turned our attention to scaling down Caplex into a portable system.
Small System, Big Challenges
A long time in the works, a portable version was the next big hurdle in Caplex development. A smaller battery-powered system that could be worn as a backpack by the user would open up a whole new range of experimentation (even being able to test outdoors off of a treadmill). It would extend the Caplex platform to explore the kinds of real-world devices that would benefit end users.
We wanted the portable system to do everything the full-size system was capable of but without making things too complicated or expensive for our customers. However, the portable system would use much smaller hardware components – essentially, completely different hardware from our standard system. We were faced with adapting the code so that it worked for both systems – no small feat. That included big tasks like swapping out data sheets for a smaller motor and also developing a new software interface for the Speedgoat unit, since the portable system would use a much smaller Speedgoat model.
The built-in capabilities of MathWorks software made doing something like this possible. We leveraged the MathWorks variant subsystem feature to design a control system able to accommodate a smaller motor and overall package. Using the feature, we isolated the software components that change from the components that don’t between the standard and new portable system, and packaged those parts in variant subsystems. The result? Users can flip control standard to control portable with a switch and easily change code in MATLAB.
In the end, we debuted the Portable Caplex System (BCK-001) running the exact same software as the Full-Size Caplex System. That would have been much more difficult without the variant subsystem feature. We also added new options for on-the-fly operation, including different host PCs, optimized display and signal processing, and a new I/O card.
MATLAB/Simulink and Speedgoat components for the Portable Caplex System:
- MATLAB/Simulink R2020a
- Speedgoat Real Time Target Machine
- Speedgoat I/O 10397 module
Pushing the Limits Together
It’s not just the tools themselves that enable companies like us to push the limits of application. MathWorks and Speedgoat’s knowledgeable and responsive support teams – as well as their extensive documentation – have helped source solutions for both Caplex customers and Humotech as we expand our platform.
The way we see it, it’s this kind of partnership that is driving change in the field of wearable devices. Mathworks and Speedgoat are enabling Humotech to build the wearable robotics platform of the future, and Humotech is helping to expand the range of applications for Mathworks and Speedgoat technologies.
Looking ahead, we’ll continue to improve upon our Control System and introduce new programming techniques to enhance performance, such as object oriented programming structure to speed up customizing code. We’ll also explore new MATLAB versions and packages in order to offer affordable options and make Caplex accessible to wider audiences.
Check out our official customer story on the MathWorks website!
(Cover image courtesy of DoD Center for the Intrepid)