Brain Drain

For decades now the US has been the place for the best and brightest from other countries to study.  I sizable chunk decide to stay especially in engineering.  As a result when various companies and the US gov decided they needed more engineers they simply imported them.

God forbid we

1. actually pay and treat engineers like they are professionals
2. give them something to do other than shuffle paper work and dodge management

And yet some people still lamented the lack of native born engineers graduating from our schools.  Some were so blind as to wonder why so few were graduating.

Well it’s time to start paying the bill…

India’s Space Program

A large chunk of our imported engineers come from India.  Often they come here because opportunities are limited in India for people born to the wrong caste.  So the people that can get to the US come over, study engineering, and stay.  But it is harder and harder for them to get jobs in Aerospace since most of the Aerospace companies have chosen to pursue defense work.

Now India has started its own space program while the US program slowly decays.  A number of those Indian engineers that stayed here are asking if there are jobs in their home country working on the space program.

The economy in the US is tanking making jobs harder to come by.  The US space program and surrounding Aerospace industry is less welcoming than it used to be.  And many would like to go home if they can find good job opportunities.

Reverse Brain Drain

The emerging space programs of China and India are a serious threat to the US technological superiority.  It may be years before the programs show a string of years with real funding and enthusiasm at home.  However, once those programs are established a much larger percentage of those foreign born engineers that come here to study will go back home when they are finished.

We will have fewer engineers in the coming years.  Without something inspirational to bring native US kids back into engineering it will only get worse.  I’ve complained about the pay and nature of the business where companies lay off large numbers of people every time their sales hiccup for a quarter but that’s not really the problem.

We can’t keep expecting to drain the brains of India and China

The problem is a lack of inspiration and vision.  As India and China demonstrate space programs that are a point of national pride they will become a more and more appealing career prospect.   As such it will become harder and harder to keep young foreign born engineers from going back to their country of origin.  However, the US lacks any serious goal for aspiring engineers to tackle.

There are inspirations out there, just no one with vision AND money

I’m a fan of space exploration and I think serious exploration – not just toy cars on Mars – would inspire.  But so would serious nano-tech, artificial intelligence, robotics (like Honda’s Asimo), alternative energy, and several other fields.

Instead we have risk averse companies who have reduced their R&D to incremental improvement shops.  The gov is just as risk averse and every satellite/R&D program is just 1 baby step better than the last.  In Aerospace the holy grail is propulsion.  In propulsion we’ve barely invented the wheel let alone an automobile.  Until the X-Prize was won almost no company spent any money on even incrementally better propulsion.  Even today the total dollar amount is a pittance.

If we want to continue to lead the world in technology (and by extension the world economy) then we need to get serious.  We need to choose 1 or 2 major project that can change everything – like alternative energy, Sci-Fi style propulsion, etc.  We need to get serious about real basic scientific research and serious engineering R&D.  You don’t make great leaps forward with risk averse baby steps.

Thankfully there’s at least DARPA, if only we could get about 1000 more of those going…

Here’s the article that inspired this rant:

Source Article

Sensor Fusion

As discussed in the previous blog entry, sensor fusion is used to create one good sensor from at least 2 sensors that are not good enough to meet specifications.  This can be done simply but when real sensors are involved it can also become a bit of a black art requiring a lot of skill and experience.

Simple Sensor Fusion Example

The wiki has an example showing the details of simple sensor fusion.  The simple example has a low frequency sensor with a bandwidth of 20 Hz.  It also included a high frequency sensor with a lower bandwidth of 1 Hz and an upper of 1 kHz.  The sensors are blended using a second order low pass and high pass filter.  Both filters have a bandwidth of 15 Hz.

I hope to eventually create another example with better filters.  I also hope to create another sensor fusion example for sensors with non-ideal transfer functions.

Sensor Fusion or Sensor Blending

Sensors are what provides feedback to a closed loop system.  Sometime you can’t get the sensor characteristics you need.  This happens a lot in the aerospace industry.

When any one sensor cannot provide the necessary feedack then it is time for sensor fusion or sensor blending.  The simplest form of sensor fusion is a matter of two or more sensors which are filtered so that their strengths (good responsivity and low noise) are used while their weaknesses are filtered out.

Often times sensor fusion is nothing more than simple second order low pass or high pass filters with their outputs added together.  This simple fusion allows for two sensors to provide the desired output.

Simple Example of Sensor Fusion

The most simple sensor fusion that I’ve come across is the combination of two angular rate gyroscopes.  The low frequency gyro was good out to a frequency of approximately 20 Hz.  The high frequency gyro was good between 1 and 1000 Hz.  Unfortunately this system was sensitive to frequencies around 5 Hz.

Normally the blending frequency of the sensor fusion would have happened between 1 Hz and 20 Hz based on an analysis of each sensor’s noise and responsivity.  This example system was sensitive to frequencies around 5 Hz which meant that we needed to avoid frequencies between 0.5 Hz and 50 Hz.

The main weakness of the high frequency sensor was phase loss below 1 Hz.  So we designed a filter to extend the low end of the high frequency sensor down to 0.5 Hz.  More difficult to implement than to conceptualize but it takes some practice to do it correctly.

Ideal Sensor vs. Real Sensor

The ideal sensor is typically modeled with a second order system that has a natural frequency equal to the spec bandwidth and a damping of 0.707 or 1.  I default to 0.707.  This leads to a nice flat, unity response for the sensor below the bandwidth.  Real sensors are non-unity below the bandwidth – i.e. the magnitude has some ripple to it.  Sensor ripple around the blending frequency can be very problematic and must be assessed based on the system needs.

Introduction to Sensor Fusion on the Wiki

Here is an article on the wiki on Sensor Fusion.  It is currently a small, simple article that I hope to expand and encourage anyone interested in Sensor Fusion to help me expand.

Maybe I’m wrong but here are a few suggestions for making cars better.

Stirling vs. Alternators

In modern automotives the alternator uses energy off the engine to generate electricity to power the radio, A/C, etc.  The alternator sucks horsepower off the engine in order to create this electricity.

What about the Stirling engine?

The Stirling engine is a piston engine driven by an external heat source.  Internal combustion engines have a lot of waste heat that can be captured.  The radiator and exhaust are 2 obvious examples.  Current Stirling designs have reported efficienies of 18%.  Alternators are most likely 90% or more but they require power directly from the engine.

Stirlings have a lower efficiency but convert otherwise wasted energy.  Alternators are robust and realiable.  Stirlings are unproven but can be designed to be small.  Several, possibly more than a dozen, can be placed at convenient places around the engine.  Designed properly they could be swappable such that if one Stirling fails it can be replaced easily and without loss of electricity generation.

Airplane Nozzles vs. Electronic temperature control

The most recent trend in air conditioning and heating in luxury cars is to provide electronic control for each side of the car and in some cases it seems like control is provided for each passenger.  On airplanes each passenger has their own control through a simple nozzle.

So why do we need electronic control that can fail when a simple nozzle would suffice?

Layoffs suck…

I work in the Aerospace industry.  It used to be a 7 year cycle of ups and downs.  Thankfully the 7 year cycle doesn’t appear to be sync’ed in time between the different Aerospace companies.  Unfortunately the 7 year cycle appears to be more like 3 or 4 years now.

During the down side of the Aerospace business cycle layoffs happen (also read s**t happens).  Over this last year my company has been in a constant state of trickling layoffs.  My employer has stated that people with the correct skill set will be kept.  The reality appears to be that dumb luck defines who stays and who goes.

A state of constant layoffs drives morale into the basement.  As a result most people who can find a satisfactory replacement job have done so.  That isn’t to say the rest of us are unemployable by another company but many are looking for a job in just the right place with the right salary and several other factors.  There’s no need to take just any job so long as you still have your current job.

Morale after over a year of constant layoffs

The morale in any company after over a year in a state of constant layoffs is always terrible.  There is no other way to describe it.  After a year, every employee

1. has lost faith in their upper management to fix the situation. 
2. is sick of waiting for things to get better on their own. 
3. is sick of the revolving door of hirings, firings, adn reorganizations at the top. 
4. has had their hopes for a promotion in the near future quashed.
5. has gotten no raise or a crummy raise.
6. has watched a lot of friends leave or get the pink slip.
7. feels unappreciated.
8. is ready to move on. 

So who’s left?

 After a year of layoffs, who’s left?  You can probably answer that for yourself but it boils down to the people with no ambition and the people looking for another job.  The people looking won’t just stop looking when things get better.

Do layoffs payoff?

Layoffs happen.  After a couple of years of good profits most companies have some deadwood.  Short targeted layoffs are probably worth doing every so often.  Long, drawn out layoffs just drive everyone to look for alternative employment.

In engineering, there is a “coming up speed” time that every new employee goes through.  New employees have to learn the ins and outs of the company’s processes.  New employees have to learn the people involved.  New employees have to learn the already developed tools and the tools that still need development.  Replacing an engineer is not cheap but the true cost doesn’t appear to be recognized by the guys at the top.

Control System Modeling: Purpose

I’m going to use model and simulation as synonyms in this post.

The purpose of modeling in any discipline, including control systems, is to answer a question; often a very specific question is answered.  There are several reasons for why any given model only answers a small set of questions.  Budget and Schedule.

Modeling Complexity

Budget and schedule force engineers to model only those aspects deemed necessary to answer the question posed.

Modeling the universe in detail – even the very localized universe around a small object – takes a lot of work and time.  Budget and schedule concerns always force engineers to start with first principles and then model progressive deeper levels of details and fidelity.  The deeper layers are only modeled if the desired level of result accuracy requires this extra fidelity.

There are several reasons for keeping a model as simple as possible:

1. Initial time to development goes up with complexity
2. Time required for maintanence goes up with complexity
3. Odds of a mistake go up with complexity
4. Time between simulation start and delivery of results goes up with complexity

My observation is that items #1 through #3 increase roughly exponentially with complexity.  Turn around time (#4) increases but the amount of increase is highly dependent on the slowest part of the model as it exists prior to the increase in fidelity.

Control System Modeling: Pitfalls

Expanded Purpose

Engineers and other professionals who do not create or run simulations on a regular basis often forget about the narrow focus of a good model.  As a result these people often ask for results the model is not designed to produce.  Obviously the engineer being asked for the results needs to consider the request very carefully.  There may be an assumption built into the model which invalidates its use for this expanded purpose.

Juggling Programs

Each day that I work on a model I go through a process of “loading my RAM” or short term memory.  In order to work on the model and produce meaningful results a certain number of details and parameters must be loaded up into short term memory.  I find this process takes no more than 30 minutes and rarely takes more than 45 minutes.

The pitfall is in assuming you can juggle certain types of work.  Last summer I was asked to juggle modeling work and hardware maintanence work.  The hardware work needed me for 30 minutes at a time about 4 or 5 times a day.  As a result the hardware work repeatedly interrupted my efforts on the modeling work.  The interruptions came about every hour and a half.  So I used half of my time in between “loading my RAM”.

After about 2 or 3 weeks of trying to juggle the hardware and the modeling work I realized I was never gonig to get anything done on the model if I didn’t set some limits.  I asked the two programs how they wanted me to handle the problem.  The basic response was just deal with it.  So I decided to tell the hardware guys that 2 days a week they couldn’t bother me, except for emergencies.  No one was happy but it was the best I could do.

I earned my Bachelors of Science in Mechanical Engineering in 1997.  My Master in Electrical Engineering in 2005.  While earning these degrees I attended 4 schools.  I have a couple of observations…

First Observation: Get Rid of Tests and Finals

Tests and finals are part of every level of education.  They don’t belong in Engineering education. 

The main thing a test grades is a student’s ability to accurately complete an arbitrary problem with very limited resources, no collaboration, and too little time to properly check your work.  Which of these skills is important after you leave school?

Some will argue that tests are the only way to assess a student’s individual ability.  I will admit that I don’t have an entirely adequate replacement.  In my mind that doesn’t justify all the downsides that come with testing.

There are few if any real world situations where your ability to solve an arbitrary problem in 15 minutes or less is important let alone critical.  In fact, the really good engineers that I know do their work thoroughly, double check it thoroughly, and for difficult design or analytical problems they seek out another engineer to double check their work or at least their assumptions.

Second Observation: Good designs are the result of collaboration

Few real world systems are designed by a single person.  Complex systems are tackled by large groups of people working in collaboration.  Student engineers need to learn how to work in teams.  More importantly student engineers need to learn how to quickly, succinctly, and clearly present complex questions and results in Word, PowerPoint, and MathCad documents.

Succinct presentations are a critical skill.  Succinct presentations help you, as an engineer, clarify your thoughts and boil down the issue to the key issue.  I can’t count the number of meetings I’ve sat through that should have been 15 minutes but an hour and a half later we’re still talking about some minor detail on the 3rd slide in the presentation.

More to follow…

The USA needs more engineers and scientists to continue to drive our economy and secure our country.  Our military’s dominance is obviously tied to our technology.  We couldn’t possibly match China man for man due to the shear number of Chinese available to fight.  Our economic dominance is also due to technology.  Technology allows us to have higher levels of productivity and innovation allows us to open up enitrely new markets.  But importing foreign engineers isn’t the answer.

A couple of quick definitions…  Foreign born engineer in this context means a person who was born and primarily raised in foreign country.  Native born engineer in this context means person who was primarily raised in the US.

I work in the Aerospace and Defense industry.  The reasons for wanting native born engineers are obvious.  The security risk posed by a native born engineer is generally considered to be less than a foreign born engineer all other things being equal.

I’ve got a BSME and MSEE and I attended 4 universities to get those degrees.  Most engineering programs are comprised of something like 30% foreign born students; my universities included.  Many of those students would go home if they could have the right kind of life style in their home country.  Many of them have begun going home as the economic conditions in China and India improve.  The money they generate with their brains stays in the country they live in.

We should always encourage the best and brightest to come here, live here, make us stronger.  I am also in favor of teaching engineering to any person from any country that has the drive, brains and money to come get that education.  However, most of the foreign engineers I met were no better or worse than the native born engineers. 

The better the economic conditions at home, the more likely a foreign born engineer is to return to their home country.  If they come here for the education and take that education back to their home country then they have primarily made their home country stronger not the USA.  I have no issue with this but I am primarily concerned with the strength of the USA.  As such, we, in the USA, should be focusing on graduating more native born engineers not recruiting foreign engineers.

I welcome anyone from any country to come and get educated in the USA.  I prefer those that get educated here stay here and contribute.  But I also believe that US efforts and money should be focused on getting more natives to graduate rather than on recruiting engineers from outside the USA.

This is a blog for ControlTheoryPro.com. You can thank my wife for the blog, I had intended to create one eventually but she pushed me to do it sooner rather than later.

The plan for this blog is be useful for the controls engineers who visit ControlTheoryPro.com as well as the broader engineering community. I have ideas for blog posts on the defense industry, engineering education, and the “three kinds of stupid” that is ITAR. The State Dept. says it doesn’t interfere with people publishing academic or intellectual works. Nonsense, interference is the goal of the law. Oh well, I’ll save it for the log post.

The blog posting will include a lot more of my personality in them. They are more personal and my sense of sarcasm will show through.