Mechatronics on Campus

Systems Engineering is not Mechatronics

What is the role of a systems engineer?

A systems engineer ensures a company’s product is going to function within cost, specification, while satisfying the user, making the trade off decisions between features, solving problems without an obvious source, and of course much more. An exemplary systems engineer has significant education and experience, leadership, good communication skills and common sense. A few things I’d like to touch on, include what a systems engineer does, how a systems engineer gains required skills, personal characteristics of a systems engineer, and finally touch on a personal experience related to systems engineering.

What is systems engineering?

I define systems engineering as the process of using engineering knowledge to design or improve a system from conceptualization and design through use and disposal. This may include outside influences, interfacing specialized interconnected components, safety, sustainability, and more. Also, a systems engineer will balance other engineers’ requirements and desires for their subsystem. The systems engineer must do this with an utmost advocacy for the entire system’s stability and functionality. This means a systems engineer must make decisions ideal for the system as a whole. This zoomed out perspective on a system, as opposed to a strict domain-centric view is much more difficult to obtain than mechanical system experience or even mechatronic experience.

How do you gain the insight to become a superb systems engineer?

Majoring in systems engineering is a great start, but more importantly a larger variety of in-depth engineering courses is a great foundation to start a systems engineering career. However expansive an educational foundation a systems engineer has, previous experience designing or fixing systems is the key to becoming a great systems engineer. This experience is ideally obtained in a company because politics, finances, schedules and lives affected by the decisions of a systems engineer. It is more difficult to see all the influences on a system in academia, where profits and many other factors are likely not the main focus.

Systems engineers must possess common sense. The natural or acquired feeling of instinctually knowing when something is wrong is very helpful. This sense for systems engineering is obtained by experience: trial and error of solving many problems in various situations. Knowing where to look for a problem and finding the problematic subsystem is a valuable skill for a systems engineer. The systems engineer does not necessarily need know how to fix the problem, but must be able to isolate the problem for a specialist to solve. Common sense is important in the entire engineering profession, but no place greater than a discipline where so many things need to be considered and balanced. Also, communication is very important aspect of the systems engineering perspective.

What is different about a systems engineer?

Systems engineering forms a bridge between different engineering disciplines, but a systems engineer often functions as a guide for other engineers and plays a part in the overall design process. This may sound like a systems engineer is a type of manager and this is both true and false. A systems engineer does not manage people, but instead mediates people to manage the system and be the system advocate.

As with every engineer, systems engineers should communicate clearly, concisely and often. However, because systems engineers often have the added task of working with different groups of people and systems engineers also require information from other professionals, it is important that systems engineers handle themselves well, and are particularly effective in their communication and requests of others. Systems engineers heavily rely on the documentation of others, which immediately introduces the need for two-way communication for clarifications. This is why a systems engineer must be adept at communication and ‘speak the language’ of other engineering domains.

One of the major differences between many fields of engineering and systems engineering is the demand for a greater number of personal attributes in systems engineering. Systems engineers have to have leadership abilities to work with other engineers to e.g., solve a problem or make a compromise that’s best for the system. This also implies that a systems engineer must be socially adept, working with many different groups of professionals.

A personal experience…

A personal systems engineering experience is from my past summer working in the Institute of Control Systems at the Kaiserslautern Technical University, located in Kaiserslautern, Germany. The research group has a robotic arm used for developing control algorithms, but their electrical current measurement of each motor in the robotic arm was so noisy it provided very little usable data. Since this problem was inhibiting many control algorithms from working properly, I made this my priority and went through each subsystem and component to ensure everything was functioning properly. More than ten electrical components and hundreds lines of code formed the current measurement subsystem. However, in order to diagnose the problem, I had to learn how to use the rest of the system, including half a dozen subsystems such as intersystem-communication, position sensing, multiple digital signal processors, motors and hardware. Almost any part of the current measurement subsystem could be the root of the problem, or even a different subsystem. After meticulously testing each component, I found it was a complex combination of problems crossing subsystems included coding errors, lack of memory protection, and a poorly chosen resistor value. These problems were could likely be contributed to a lack of internal documentation of the system, as well as inaccurate and poor documentation from the hardware vender. More to come on this.

Although I do not have substantial systems experience, I was able to solve a complex problem that multiple PhD students and masters students hadn’t yet solved. However, this may not be as remarkable as it seems. The researchers are very focused on control algorithms and likely had not used many electrical skills since early college, which may seem as long ago as algebra to the general public. As a completely new person working on the project, I took a top-down approach to learning about the system and solving the problem. The researchers knew much more about the intricacies of certain subsystems than I do, but I was able to solve a problem that crossed subsystems. This is likely because I was not as focused on any particular subsystem and could have a better ‘zoomed-out’ perspective.

Although my personal experiences do not reach very far into the field of systems engineering, I have had much electromechanical (mechatronic) experience interfacing hardware and software components of electrical and mechanical systems. This falls very short of managing external influences in large systems engineering problems, such as logistic support, capabilities of operating personnel, politics, staffing, operational environment, etc. In any case, I think that engineering experience is excellent preparation for becoming a systems engineer. The aggregate of varied engineering experiences amounts to the ability to work within different domains of engineering – an important aspect of systems engineering.

I feel that the steps to become a systems engineer may be more expensive, vague and time consuming than other engineering degrees, but the problem solving and responsibility of keeping a system functional are exciting, difficult and critical. Not anyone can become a superb systems engineer, but various professionals such as mechanical engineers, chemical engineers and even entrepreneurs extend themselves to solve demanding problems in impressive and complex systems.

Share your opinion.

Now that you’ve read my opinion of systems engineering, what do you think? Be sure to post below, and I’ll respond to any questions you may have.

Mechatronics Improves and Speeds Up fMRI Scans

The inside of an MRI cavity is precisious real estate, why would you want to share this potentially closterphobic space with a robot?

In a recent release of the IEEE/ASME Transactions on Mechatronics, one article particularly caught my attention. Functional MRI scans (fMRI) are a type of brain activity scan where an image of brain activity, based on blood flow, is captured every couple seconds. The patient is often told to do a specific task, but these tasks are limited within this space. This single degree of freedom robot, more similar to an actuator, can provide resistance, measure a patient’s force, or guide a patient’s hand in a certain way. This all happens while inside of a machine where a single hair pin could be deadly. A typical fMRI machine produces a magnetic field of 3 Tesla and sometimes as high as 6 Tesla. The earth’s magnetic field is on average 0.00004 Tesla, or 75,000 times weaker than a fMRI magnet.

Shown above, the entire actuator must be made of materials that do not interfere with the magnetic field of the fMRI machine, must be guaranteed to work properly while inside the machine and must not make the 55cm to 70cm aperature of the MRI any more cramped than necessary. The senors, actuators, and device structure are simple to implement out of traditional parts, but these must not cause interference with the magnetic field. This rules out all electronic sensors and ferromagnetic transmission wires, as the metal would be dangerous in the magnetic field, but also an electronic sensor would be innacurate in such a strong magnetic field. The paper compares the options between hydrodynamic and pneumatic actuators.

These actuators use fluid lines instead of electrical lines to ‘transmit’ force to an electronic sensor at a large distance from the MRI machine. The best part of a fluid line is how it is actually a wonderful physical analog of electrical system: voltage as pressure, and current as volume flow rate. This simply means that if the tubing does not expand, and the fluid is not compressible (water is not very compressible), that a hydrolic line, esentially a polymer pipe, is perfect for this application. The fluid and the pipe are magnetically inert, ‘power’ in the form of water pressure can be created at a distance from the MRI unit and sent to the actuator. The end effector, or handle the patient moves (pictured previously), is relatively easy to create out of MRI safe and non-interferring materials.

This system is a very simple mechanical and electrical system, but it is a vast improvement over an operator telling the patient to move their fingers. Now there is a quantifiable measurement of force linked with the brain activity. I find simple solutions that are novel, realiable, and useful are some of the best mechatronic applications. In order to see these solutions, often you have to have experience looking from all angles at a problem. Engineers who are educated at the union of different fields who will make progress to solve some of our most complex problems.

Original article at IEEE (IEEE membership and subscription required)

A Mechatronic and Medical Marvel: Heavy Ions Curing Cancer at GSI

The Gesellschaft für Schwerionenforschung mbH (GSI), or Association for Heavy Ion Research, is a research facility where scientific researchers work with heavy ions for a wide range of experiments to explore the structure of matter. GSI is a particle accelerator facility where ions are accelerated up to 90% the speed of light.

Of the accomplishments at GSI, atoms of atomic number 107 through 112 were discovered at GSI: Bohrium, Hassium, Meitnerium, Darmstadtium, Roentgenium and Ununbium. Another major accomplishment is the use of heavy ions to treat cancer.

In the United States, ionic cancer treatment is primarily done by bombarding protons at a patient’s tumor. The heavy ion accelerator, as the name suggests, accelerates muclei of heavier elements, and for cancer treatment, carbon. These carbon nuclei are particularly adept at destroying tissue, yet are able to destroy tissue at a point. The diagram below shows the higher energy released from carbon ions.

When carbon atoms penetrate the patient’s skull, they pass through the brain tissue, but when they reach a specified depth, they radiate the tissue. This means that the bone, tissue, and everything between the environment and the patient’s tumor, is virtually untouched, but the tumor is destroyed. This specialized radiation beam is created in the huge GSI complex.

Although the carbon nuclei treatment has obvious advantages, including damaging less good tissue and destroying tumors more effectively than using a proton beam, the technique is not used in the US. A problem is that creating a heavy ion beam is more diffucult than creating a proton beam and the only current place for treatment is at GSI, near Darmstadt, Germany. Patients often bike to their daily painless radiation treatment that lasts normally a bit less than a month.

Currently a smaller heavy ion beam still capable of penetrating any depth within a human body is being built in Frankfurt, Germany as a sole medical facility. Other centers are planned through-out Europe to precision treat cancerous tumors.

European funding for public facilities and research project has been surging in recent years. This is particularly evident in higher education, where Germany has funded a total 1.9 billion Euros known as the “excellence initiative” where young scientists and PhD students receive one million Euros each at certain Universities.

The above photos (click to enlarge) from left to right: (1) The control room at GSI oversees the UNILAC linear accelerator and synchrotron. (2) The yellow section is the acceleration phase of the synchrotron where millions of volts accelerate ions. (3) The red section is the steering phase where the ions are precisely turned using very strong magnetic fields produced by the huge wire coils. (4) A research sensor array for detecting scattered ions and atoms.