Acumen

PhD and Research Programmer Openings at Rice and Texas A&M

2011-12-15T22:26:00.000-08:00

New announcements have just been posted for four PhD positions and one research programer positions funded by a new NSF project lead by Professor Taha. The positions are hosted by Rice and Texas A&M Universities, but participants will spend significant periods of time at Halmstad University. Please forward these announcements to strong candidates. Note that the two deadlines are as early as January 6th.

Research Programmer in Computer Science at Rice

2011-12-15T22:07:00.000-08:00

Major technical challenges get in the way of developing novel cyber-physical systems (CPS). Overcoming these challenges can significantly accelerate the design process. A new NSF CPS project on Robot Design is building foundations and tools to achieve this goal for novel robotics applications. The project focuses on issues relating to modeling hybrid (continuous/discrete) systems and model validation. The project, which is a close collaboration between Computer Science and Mechanical Engineering at Rice University, Mechanical Engineering at Texas A&M, and Halmstad University in Sweden, will develop and validate foundations, methods, and tools for the modeling and simulation of hybrid and cyber-physical systems.

The project has an opening a research programmer with Professor Taha at Rice University. The successful candidates will work closely a team of four professors and four PhD students working on various aspects of this project, contributing and coordinating the development of the Acumen modeling language for the purposes of this project.

Applicants for this position must have strong skills and interest in programming language design and theory; functional programming; and test-driven development. Excellent communication and collaboration skills are required as the student will be expected to work as part of a large, international research team investigating modeling languages. Priority will be given to applicants who already hold a doctoral degree in Computer Science or Mechanical Engineering, but applicants with suitable skills and interests who hold a doctorate in Mathematics, Physics, or Electrical Engineering are also encouraged to apply. Desirable experience includes working interval and enclosure methods, exact real arithmetic, domain theory, operational semantics, formal verification, differential equations, hybrid/impulsive differential equations, and mechanical hardware design and control, especially in the context of robotics. Desirable skills include facility with Scala, Java, Haskell, OCaml, ML, Scheme, Mathematica, Maple, OpenGL, Matlab, Simulink, the Open Dynamics Engine (ODE), or other modeling and simulation tools.

The position is for one year, renewable to two years, and is subject to the availability of funding. The successful applicant will spend part of their time in Halmstad, Sweden (50%) as part of the collaboration and must be ready to start the position by May or June 2012.

The deadline for applications is January 15th, 2012. Application for this position should be sent directly to Professor Taha by email. The title of the email should be (without quotes) "Application for Robot Design Research Programmer Position". The application should consist of one, self-contained PDF attachment. The application should include 1) a brief cover letter including motivation for the application, 2) a CV, and 3) a list of names of references. It is also suggested that the application include online pointers to previous publications or software produced by the applicant.

Doctoral (PhD) student in mechanical engineering at Texas A&M

2011-12-15T21:59:00.000-08:00

Major technical challenges get in the way of developing novel cyber-physical systems (CPS). Overcoming these challenges can significantly accelerate the design process. A new NSF CPS project on Robot Design is building foundations and tools to achieve this goal for novel robotics applications. The project focuses on issues relating to modeling hybrid (continuous/discrete) systems and model validation. The project, which is a close collaboration between Computer Science and Mechanical Engineering at Rice University, Mechanical Engineering at Texas A&M, and Halmstad University in Sweden, will develop and validate foundations, methods, and tools for the modeling and simulation of hybrid and cyber-physical systems.

The project has an opening for a Mechanical Engineering doctoral (PhD) student with Professor Ames at the University of Texas A&M. The student's dissertation will focus modeling and simulation of lower-limb robots and will involve the evaluation and development of new technologies for modeling and simulation of such systems. The successful candidate will work closely with Computer Scientists developing new computational tools to support modeling and simulation.

Applicants for must have strong skills and interest in mechanics, control theory, rigid body dynamics, and robotics. Excellent communication and collaboration skills are required as the student will be expected to work as part of a large, international research team investigating modeling languages. Priority will be given to applicants with a masters in Mechanical or Electrical Engineering, but students with suitable skills and interests who hold a masters in Mathematics, Physics, or Computer Science are also encouraged to apply. Desirable experience includes working differential equations, hybrid/impulsive differential equations, or with mechanical hardware design and control, especially in the context of robotics and upper limb rehabilitation robots. Desirable skills include facility with Mathematica, Maple, Matlab, Simulink, the Open Dynamics Engine (ODE), or other modeling and
simulation tools.

Selected students are will spend part of their time in Halmstad, Sweden (25%) as part of the collaboration and must be ready to start the position by May or June 2012.

The deadline for applications is March 1st. Application for these positions is done through the on-line application form. Your application (and in particular your Research Statement) must make it clear that your are applying for a PhD position with Professor Ames on the Robot Design project.

Two Doctoral (PhD) students in Computer Science at Rice University

2011-12-15T21:52:00.000-08:00

Major technical challenges get in the way of developing novel cyber-physical systems (CPS). Overcoming these challenges can significantly accelerate the design process. A new NSF
CPS project on Robot Design is building foundations and tools to achieve this goal for novel robotics applications. The project focuses on issues relating to modeling hybrid (continuous/discrete) systems and model validation. The project, which is a close collaboration between Computer Science and Mechanical Engineering at Rice University, Mechanical Engineering at Texas A&M, and Halmstad University in Sweden, will develop and validate foundations, methods, and tools for the modeling and simulation of hybrid and cyber-physical systems.

The project has an opening for two Computer Science doctoral (PhD) student with Professor Taha at Rice University. Each student's dissertation work will have distinct technical focus. One will focus on developing the meta-theory for relating user-level descriptions of mechanical systems, mathematical equations describing the behavior of such systems, and the simulation codes needed to solve these equations. The other will focus on developing methods for the simulation of hybrid systems, including zero-crossing and Zeno behavior. The succesful candidates will work closely with Mechanical engineerings who are working on modeling and simulation of new experimental robots. The engineers will use and evaluate the results of the work of the PhD students.

Applicants for this position must have strong skills and interest in programming language design and theory; functional programming; and test-driven development. Excellent communication and collaboration skills are required as the student will be expected to work as part of a large, international research team investigating modeling languages. Priority will be given to applicants with a masters in Computer Science or Electrical Engineering, but students with suitable skills and interests who hold a masters in Mathematics, Physics, or Mechanical Engineering are also encouraged to apply. Desirable experience includes working with interval and enclosure methods, exact real arithmetic, domain theory, operational semantics, formal verification, differential equations, hybrid/impulsive differential equations, and mechanical hardware design and control, especially in the context of robotics. Desirable skills include facility with Scala, Java, Haskell, OCaml, ML, Scheme, Mathematica, Maple, OpenGL, Matlab, Simulink, the Open Dynamics Engine (ODE), or other modeling and simulation tools.

Selected students are will spend part of their time in Halmstad, Sweden (50%) as part of the collaboration and must be ready to start the position by May or June 2012.

The deadline for applications is ~~January 6th, 2012~~ January 16th, 2012 (Rice Computer Science extended the deadline). Application for these positions is done through the on-line application form. Your application (and in particular your Research Statement) must make it clear that your are applying for a PhD position with Professor Taha on the Robot Design project.

Doctoral (PhD) student in mechanical engineering at Rice University

2011-10-15T05:03:00.000-07:00

Major technical challenges impede the effectiveness of modeling and simulation of novel robot designs. The NSF CPS project on Robot Design develops foundations and tools for overcoming these challenges. The project focuses on issues relating to improving hybrid modeling formalisms demonstrating the physical validity of models developed in this formalism. The project is a close collaboration between Computer Science and Mechanical Engineering at Rice University, Mechanical Engineering at Texas A&M, and Halmstad University in Sweden, will develop and validate foundations, methods, and tools for the modeling and simulation of cyber-physical systems (CPS).

The project has an opening for doctoral (PhD) student with the MAHI lab at Rice University. The student will contribute to the project by using a new modeling language to model and validate the MAHI lab's upper-extremity exoskeleton robot (the RiceWrist).

Applicants must strong skills in dynamic systems and controls, including modeling, simulation, and hardware implementation. Excellent communication and collaboration skills are required as the student will be expected to work closely with software team building the modeling language. Priority will be given to applicants with a masters in Mechanical or Electrical Engineering. Desirable experience includes mechanical hardware design and control experience, especially in the context of robotics and upper limb rehabilitation robots. Desirable skills include Mathematica, Maple, Matlab, Simulink, other modeling and simulation tools.

The student wil spend part of their time in Halmstad, Sweden (25%) as part of the collaboration.

Students can apply to enter the program either in January 2012 (deadline November 1, 2011) or August 2012 (deadline February 1, 2012). Applicants desiring Fall 2012 start will be encouraged to begin research in May/June 2012. Application for this position is done through the on-line application form.

Patent Trolls

2011-08-07T06:59:00.000-07:00

Over the years I have been hearing more and more negative stories about patents. Today I came across a podcast that suggests this problem has reached alarming levels.

Three research positions relating to Acumen

2011-07-01T07:14:00.000-07:00

Applications are currently being accepted for the following three research positions:

PhD on Visualizing Cyber-physical Systems

2011-07-01T01:35:00.000-07:00

Position Reference Number: “IDE 6/11”

We are developing a novel modeling and simulation language called Acumen. The goal is to create a language that can significantly accelerate innovation in the design and production of cyber-physical systems. We are seeking a doctoral student interested in developing and investigating the use of Acumen as a basis for a virtual reality environment. The research leader and supervisor will be Professors Walid Taha and Veronica Gaspes.

The goal of this doctoral position is to develop and investigate extensions of the Acumen run-time with support for visual modeling, simulation, and visualization.
This involves developing graphical entry of physical models, real-time 3D rendering, and support for interaction during the execution of simulations, developing a large and diverse suite of benchmark models and visualization, and developing techniques to formally specify and verify such a platform. Ultimately, these technologies are expected to significantly advance the utility of Acumen for modeling and experimentation with novel cyber physical designs.

Qualifications:

The position is intended for someone that will have a Masters degree by the start of their doctoral studies. Desirable skills include expertise in functional programming, modeling and simulation, virtual reality, game design and implementation, and Scala.

Compensation and Term:

After taxes, the salary is currently the rough equivalent of US $35K/year. The appointment start with a one year appointment renewable up to four years. If a student carries out part-time (20%) teaching duties or other departmental work, it may be extended for an additional year.

Application Procedure and Deadlines:

The application should comprise a single PDF file consisting of:

1) a cover letter stating the purpose of the application and a brief statement of why you believe that your goals are well-matched with the goals of this position,

2) a CV that includes at least

A list of previous degrees, dates, and institution
Transcripts for higher-education studies until most recent available
Optionally, results from standardized tests such as GRE or TOEFEL may be included
A list of publications and a description of previous research and other work experience
Links to online copies of the most important publications
A statement of purpose
Contact information for at least three references

The application should be sent as one PDF file attached to an email addressed to: registrator@hh.se. The subject line of the email should be “Application to IDE 6/11”. Application must be received by 2011-08-31 to receive full consideration. The expected starting date is 2011-10-15, or as soon as possible after this date. For more information, contact Professors Walid Taha or Veronica Gaspes, Dean Magnus Larsson or Inger Wieslander (SACO union representative). All can be reached through the switchboard +46 35 16 71 00 or by email: firstname.lastname@hh.se.

Post-doc on Parallel Hybrid Simulation

2011-07-01T01:25:00.000-07:00

Position Reference Number: “IDE 10/11”

We are developing a novel modeling and simulation language called Acumen. The goal is to create a language that can significantly accelerate innovation in the design and production of cyber-physical systems. We are seeking a post-doctoral researcher interested in demonstrating the effectiveness of the language design in enabling parallel execution of simulation codes. The research leader and supervisor will be Professors Walid Taha and Veronica Gaspes.

The goal of this post-doctoral position is to develop and investigate several different back-ends for an Acumen compiler. This includes developing core-Acumen back ends that generate Habanero, LiME, X10, Cilk, and Timber code; developing hybrid (continuous/discrete) systems benchmarks to evaluate the language design on these platforms; and carrying out a series of systematic performance evaluation of the languages and of these target platforms. Both traditional and non-traditional hardware architectures may be investigated under the project. Ultimately, this work should yield clear insights about the aspects of Acumen design that are most effective at enabling the parallel execution of hybrid system simulations, possibly suggesting ways in which they can be improved.

Qualifications:

The position is intended for someone with a recent PhD degree and that has experience with parallel computing as well as writing interpreters and/or compilers for small languages.

Desirable skills include expertise or an interest in learning: typed and higher-order functional programming, programming language semantics, the design and implementation of novel languages, modeling and simulation, program generation, performance analysis, and parallel computing, and programming Scala and Java.

Compensation and Term:

Salary is negotiable. After taxes, the salary is typically the rough equivalent of US $40K/year. The employment is time-limited to 18 months.

Application Procedure and Deadlines:

The application should comprise a single PDF file consisting of:

1) a cover letter stating the purpose of the application and a brief statement of why you believe that your goals are well-matched with the goals of this position,

2) a CV that includes at least

A list of previous degrees, dates, and institution
A list of publications and a description of previous research and other work experience
Links to online copies of the most important publications
A statement of purpose
Contact information for at least three references

The application should be sent as one PDF file attached to an email addressed to: registrator@hh.se. The subject line of the email should be “Application to IDE 10/11”. Application must be received by 2011-08-31 to receive full consideration.

The expected starting date is 2011-10-15, or as soon as possible after this date. For more information, contact Professors Walid Taha or Veronica Gaspes, Dean Magnus Larsson or Inger Wieslander (SACO union representative). All can be reached through the switchboard +46 35 16 71 00 or by email: firstname.lastname@hh.se.

Post-doc in Modeling Electric Motorcycles

2011-06-30T22:57:00.000-07:00

Position Reference Number: “IDE 18/11”.

We are developing a novel modeling and simulation language called Acumen. The goal is to create a language that can significantly accelerate innovation in the design and production of cyber-physical systems. We are seeking a post-doctoral researcher interested in demonstrating the effectiveness of the language in achieving this goal in the context of smart grid and smart vehicle applications. The research leader and supervisor will be Professors Walid Taha and Veronica Gaspes.The goal of this post-doctoral position is to develop a series of increasingly more refined holistic cyber-physical models of smart motorcycles. The models will include components such as mechanics, motors, sensors, batteries, and embedded controllers. The post-doc can expect to receive assistance from experts in these various sub-fields. The project will include demonstrating the fidelity of these models with respect to physical prototypes. The post-doc will be involved in using the model to assess current research technologies, as well as incorporating resulting models in courses being taught at both Halmstad and Portland State Universities. Part of the work will be carried out at Portland State University with Professor Dan Hammarstrom and his group.

Qualifications:

The position is intended for someone with a recent PhD degree and that has experience in modeling and simulation or the design of electrical vehicles.

Desirable skills include expertise or an interest in learning: modeling and designing a wide range of physical systems, developing embedded systems, design and analysis of mechanical and electrical systems, control theory, computer simulation, and computer graphics and visualization.

Compensation and Term:

Salary is negotiable. After taxes, the salary is currently the rough equivalent of US $40K/year. The employment is time-limited to 12 months.

Application Procedure and Deadlines:

The application should comprise a single PDF file consisting of:

1) a cover letter stating the purpose of the application and a brief statement of why you believe that your goals are well-matched with the goals of this position,

2) a CV that includes at least

A list of previous degrees, dates, and institution
A list of publications and a description of previous research and other work experience
Links to online copies of the most important publications
A statement of purpose
Contact information for at least three references

The application should be sent as one PDF file attached to an email addressed to: registrator@hh.se. The subject line of the email should be “Application to IDE 18/11”. Application must be received by 2011-08-31 to receive full consideration. The expected starting date is 2011-10-15, or as soon as possible after this date. For more information, contact Professors Walid Taha or Veronica Gaspes, Dean Magnus Larsson or Inger Wieslander (SACO union representative). All can be reached through the switchboard +46 35 16 71 00 or by email: firstname.lastname@hh.se.

Acumen Core Language

2011-04-07T05:51:00.000-07:00

The following paper will be presented at ICCPS next Tuesday in Chicago in the WIP session:

Terminal Velocity of a Ping Pong Ball

2011-03-16T05:59:00.000-07:00

In a recent lab using Acumen the question of what is the terminal velocity of a ping pong ball came up. Using a back of the envelope calculation, we estimated it and used that to compute a drag coefficient. It turned out that we had come in within 20% of a number published in a research paper!

Thanks to Slawomir Nowaczyk for pointing us to this paper.

Core Acumen

2011-03-02T08:41:00.000-08:00

A draft paper is now available describing the main features of the proposed core language for Acumen. The language described is supported by the current implementation. (Please see updated version above).

Winner of the Differential Steering challenge Problem

2011-02-01T01:41:00.000-08:00

The winning entry from the submissions to the challenge came from Musab Alhayan. The code that he wrote reduced the total cost function (or "energy") needed during the simulation from 151 in the original problem to 109. His code for the controller can be found as a comment on the original posting about the challenges.

Thanks for everyone who participated in this challenge, and congratulations to Musab for his winning submission!

Differential steering challenge problem

2010-12-07T01:35:00.000-08:00

I posed a challenge problem in today's guest lecture in the Embedded Systems Programming course. The challenge is to efficiently control a simple differential steering robot. The Acumen code below presents both the model of the robot (dsbot), a target object, and a very simple controller. How well the controller performs is measured in the Main object by the total energy (e) at the end of the simulation. My score was 161.3. You are welcome to submit to me the code of an controller that performs better.

The only rule is that you can only send me the code for the controller. In other words, the code for the robot, target, and the main program has to remain the same.

class dsbot () // Differential steering robot
  private x=0; x'=0; y=0; y'=0;
   a=0; a'=0 ; v=0
  end
  x' [=] v * cos(a);
  y' [=] v * sin(a);
end

class target () // A simple target moving in a circle
  private t=0; t'=0; x=0; y=0 end
  t' [=] 1;
  x = 2*sin(t/1.5);
  y = 2*cos(t/1.5);
end

class controller () // A simple controller
  private t =0; t'=0; // local time
  ex = 0; ey = 0; // Error in x and y
  ia = 0; // Input angle
  ov = 0; oap = 0; // Ouput v and a'
  end
  t' [=] 1;
  if t>0.1
  t = 0;
  // Control code goes here
  if (ex*ex + ey*ey) < 1 // Robot is close enough. Slow down
   ov = 1
  else
   ov = 4;
   if ( (ex>0 && cos(ia)<0)
   || (ey>0 && sin(ia)<0))
   || ( (ex<0 && cos(ia)>0)
   ||(ey<0 && sin(ia)>0))
   oap = -10
   else
   oap = 0
   end
  end
else
end
end

class Main(simulator)
  private r = create dsbot ();
   t = create target ();
   c = create controller ();
   d = 0; e = 0; e'= 0; // Measures of success
  end
  // Controller see robot
   c.ex [=] t.x - r.x;
   c.ey [=] t.y - r.y;
   c.ia [=] r.a;
  // Robot listens to controller
   r.a' [=] c.oap;
   r.v [=] c.ov;
  // Error over time
   d [=] sqrt(c.ex*c.ex+c.ey*c.ey);
   e' [=] r.v*r.v + 2*d*d
end

Bouncing ball example in your favorite language

2010-10-26T07:30:00.000-07:00

This is a request for audience participation!

The code below is a minimalist model defining the behavior of a ball subject to gravity, air resistance, and idealized bouncing. I'd like to use this example to collect in one place code written in different hybrid modeling languages. It would be great if you can send me (or add as comment) equivalent code written in your favorite hybrid modeling language, or for that matter any hybrid modeling language that you are familiar with. As much as possible, please follow the same style and avoid making stylistic changes to the extent possible. Please free to provide multiple versions if necessary, and to offer explanation of your stylistic choices as needed.

If you happen to know Verilog-AMS, PSPICE, Modelica, Sol, MapleSim, or Impromptu, I would really appreciate if you can express this model in those languages as well. All other languages are very welcome as well!

Here's the code:

// Minimalist model for ball with airodynamic
// resistance (2010/10/26, Scottsdale)

class Main (simulator)
private
  a = create BouncingBall()
end
end

class BouncingBall ()
private
  g = -9.8; cr = 0.95; cd = 0.075;
  x = 10; x' = 2; x'' = 0;
end

if x>=0
  if x'<0
   x'' [=] g + cd * (x')^2
  else
   x'' [=] g - cd * (x')^2
  end
else
  x' = - cr * x';
  x = 0
end
end

Updates:

From Andre Platzer:

Here's the bouncing ball as a hybrid program:

(if (x=0) then v := -r*v fi;
({x'=v,v'=g+d*v^2,v<=0,x>=0}
++{x'=v,v'=g-d*v^2,v>=0,x>=0}))*

Here's the bouncing ball as a differential-algebraic program:

(if (x=0) then v := -r*v fi;
{x'=v,((v'=g+d*v^2&v<=0)
   |(v'=g-d*v^2&v>=0)), x>=0})*

Globally Parallel, Locally Sequential. Or, “Preserving Natural Parallelism”

2010-09-20T08:55:00.000-07:00

We have just finished a draft of a short paper describing some preliminary results on the automatically parallelizing version of Acumen. The paper itself can be found here:

Please stay tuned for a release of the parallelizing version of Acumen that was used in these experiments!

Sneak preview of Acumen 10

2010-08-24T06:30:00.000-07:00

Acumen 10 features improvements to the syntax, semantics, expressivity, and user interface. The picture below is a snapshot using an example illustrating two different models of a bouncing ball.

Here's the code example in plain text:

class BouncingSpringBall1 (x,x',x'')
  x'' [=] - 9.8 + (1/x^2)
end

class BouncingSpringBall2 (x,x',x'')
  x'' [=] - 9.8;
  if (x < 0)
   x = -x; x' = -x'
  else
  end
end

class Main (mode, simulation)
  private state = "Init" end
  switch state
   case "Init"
   create BouncingSpringBall1 (2, 0, 0);
   create BouncingSpringBall2 (2, 0, 0);
   state = "Persist"
   case "Persist"
  end
end

New features in Acumen 10 include class declarations, dynamic object creation & deletion and an explicit imperative programming language for describing what happens during discrete mode changes.

Acumen 3D Trailer

2010-08-04T09:08:00.000-07:00

Breaking news!

A preview of what Acumen 3D will look like can be seen in the videos put together by Paul Brauner and is available on YouTube.

What New Acumen Animations Should Look Like :)

2010-05-31T14:44:00.000-07:00

A google search for bouncing balls returned this interesting visualization of an audio, which has some nice ideas that we will try to use (at least for basic demos).

Scratch also has a bouncing ball demo.

And there is a video from some town with a bouncing ball invasion, probably somewhere in California. :)

Draft paper

2010-01-05T07:55:00.000-08:00

We've just finished a draft of a new paper describing the source language of Acumen and how it is compiled. The PDF can be downloaded from the links on the right of the page. Here's the abstract:

"Cyber-physical systems comprise digital components that directly interact with a physical environment. Specifying the behavior desired of such systems requires analytical modeling of physical phenomena. Similarly, testing them requires simulation of continuous systems. While numerous tools support later stages of developing simulation codes, there is still a large gap between analytical modeling and building running simulators. This gap significantly impedes the ability of scientists and engineers to develop novel cyber-physical systems.

We propose bridging this gap by automating the mapping from analytical models to simulation codes. Focusing on mechanical systems as an important class of models of physical systems, we study the form of analytical models that arise in this domain, along with the process by which domain experts map them to executable codes. We show that the key steps needed to automate this mapping are 1) a light-weight analysis to partially direct equations, 2) a binding-time analysis, and 3) an efficient implementation of symbolic differentiation. As such, our work pinpoints and highlights a number of limitations in the state of the art in tool support of simulation, and shows how some of
these limitations can be overcome."

Enjoy!

Release and Tutorial Notes Ready

2009-11-15T01:37:00.001-08:00

The release and tutorial notes for the short course are now ready, and can be downloaded from the links on the right of this page.

Working on First Release

2009-11-10T18:54:00.001-08:00

In preparation for a four-hour tutorial next week, I am working on getting a collection of interesting examples that works correctly in Acumen, and that I can use as a basis for a tutorial. So far, I have been happy to find that a lot of text-book examples of differential equations compile correctly and produce sensible results when simulated. The examples that I have been looking at so far are mostly ODE's. I'd like to do some discrete systems next, and then follow that with hybrid examples.