THE CDIO INITIATIVE FROM ANAUTOMATIC CONTROL PROJECT COURSE

PERSPECTIVE

M. Enqvist, S. Gunnarsson, M. Norrlöf,E. Wernholt and A. Hansson

Dept. of Electrical Engineering, Linköping University,SE-58183 Linköping, Sweden

Abstract: The CDIO (Conceive Design Implement Operate) Initiative is explained,and some of the results at the Applied Physics and Electrical Engineering programat Linköping University, Sweden, are presented. A project course in AutomaticControl is used as an example. The projects within the course are carried outusing the LIPS (Linköping interactive project steering) model. An example of aproject, the golf playing industrial robot, and the results from this project are alsocovered.

Keywords: Control education, project management, robot programming,mathematical models, group work

1. INTRODUCTION

This paper presents results of a student projectin Automatic Control that was carried out duringthe spring of 2004. The project was one of ap-proximately 25 projects, organized in eleven dif-ferent courses, that were carried out by studentsin the fourth year of the Applied Physics andElectrical Engineering program at Linköping Uni-versity, Sweden. The introduction of the projectcourses is a result of the participation in the CDIOInitiative, which is an international collaborationbetween a number of universities with the aim todevelop further engineering education. The paperis organized as follows. Section 2 gives a shortdescription of the CDIO Initiative, its organiza-tion, and its main goals, and in Section 3 the Ap-plied Physics and Electrical Engineering programis presented briefly. In all the project courses thathave been introduced at Linköping University viathe CDIO Initiative, the project work is carriedout using a common and structured methodol-ogy. This methodology is defined by the projectmodel LIPS, and it is presented in Section 4.

The Automatic Control project course is one ofthe eleven project courses, and it is described insome detail in Section 5. The project that will bepresented in this paper is the development of a golfplaying industrial robot, and this project will bepresented in Section 6. Finally, Section 7 containsthe conclusions.

2. THE CDIO INITIATIVE

The CDIO Initiative started in 2000, and from thebeginning it consisted of three universities fromSweden (Linköping University, Chalmers Univer-sity of Technology, and the Royal Institute ofTechnology) and one university from the USA(Massachusetts Institute of Technology). Duringthe development of the initiative, a number ofuniversities have joined the CDIO Initiative. Alist of the participating universities can be foundon the web site http://www.cdio.org. The aimsof the project are to emphasize the CDIO view ofengineering education and to present a systematicprocedure for developing an engineering program

into a CDIO program. The activities within theCDIO Initiative are based on two documents, theCDIO Syllabus (The CDIO Syllabus 2004) andthe CDIO Standards (The CDIO Standards 2004),respectively. The first document, the CDIO Syl-labus, can be seen as a specification of the desiredknowledge and skills of the students that graduatefrom the engineering education. The Syllabus isorganized in the following four sections:

1. Technical knowledge and reasoning2. Personal and professional skills and attributes3. Interpersonal skills: Teamwork and commu-

nication4. Conceiving, designing, implementing and op-

erating systems in enterprise and societalcontext.

For each section there are subsections specifyingin more detail the desired skills of an engineer.The main goal of the CDIO Initiative is to developmethods and activities that strengthen items 2-4of the Syllabus.

The second document, the CDIO Standards, spec-ifies the desired properties of an engineering pro-gram. The philosophy behind the CDIO Initiativeis formulated in the first standard saying ”Adop-tion of the principle that product and system life-cycle development and deployment - Conceiving,Designing, Implementing and Operating - are thecontext for engineering education”.

3. THE APPLIED PHYSICS ANDELECTRICAL ENGINEERING PROGRAM

The Applied Physics and Electrical Engineeringprogram is one of the largest engineering programsat Linköping University. It admits 180 students(150 in the regular program and 30 in the in-ternational version) each year. The program hasa strong emphasis on mathematics, physics, andelectrical engineering, and it is considered to beone of the most demanding engineering programsin Sweden. The main part of the first three yearsconsists of mandatory courses and the main partof the fourth year is spent on a specializationwithin a selected area. In agreement with theSwedish system the nominal time of studies is4.5 years, corresponding to 180 units, i.e. 40units/year. 160 units are spent on courses and 20units are spent on the Master’s Thesis Project.The course part consists of approximately 115units of mandatory courses (50 units mathemat-ics), 25 units specialization and 20 units electivecourses. Starting from the last semester of yearthree, the students choose one out of twelve spe-cializations.

One of the main results of the participation inthe CDIO Initiative is that a sequence of project

courses has been introduced into the program.One aim of these courses is to cover items 2-4in the CDIO Syllabus, which means emphasizingpersonal skills, interpersonal skills and the CDIOview of engineering. The sequence consists of anIntroductory Course in year one, an Electronicsproject course in year three and a set of projectcourses in the fourth year, related to the special-izations of the program. A further objective ofintroducing the project courses is to give the stu-dents training in project work using industry likemethods. For that purpose, a project managementmodel, LIPS (Svensson and Krysander 2004), hasbeen developed. This project model is based onindustrial project models, but it has been adaptedfor educational purposes.

The third stage in the sequence of project coursesconsists of a set of eleven courses with connectionsto the specializations in the program:

• Applied mathematics, project course• Design and manufacturing of sensor chips• Computational physics• Mixed signal processing systems• System design• VLSI design project• Image and graphics, project course• Automatic control, project course• Systems engineering, project course• Biomedical engineering, project course• Embedded systems simulation and verifica-

tion

The courses are given by five different depart-ments, and they vary between five and six unitsin size. All courses are given during the springsemester of year four. For the development ofthese courses, the board of the program formu-lated a set of specifications to be satisfied by thecourses:

• Minimum of four students in each projectgroup.

• At least four units spent on the project part.• The project should be carried out using the

project model LIPS.

The set of courses was given for the first time2004. Around 210 students participated in thecourses, and approximately 125 students belongedto the Applied Physics and Electrical Engineeringprogram. 60 students were non-Swedish speakingand came from some of the international master’sprograms that are offered at Linköping University.The remaining group of students belonged to someof the other engineering programs.

4. THE LIPS PROJECT MODEL

The LIPS project model has been designed atLinköping University to support the CDIO con-

cept and to introduce a professional project man-agement approach into the academic environment.

LIPS is similar to modern industrial project mod-els but adapted for usage in education or insmall industrial projects. The model introducesthe phases, definitions and tollgates necessary forrunning a project in an efficient way. The threesteps of the model describe the project prepara-tion and planning phase, the project executionphase and the project delivery and evaluationphase. The model also includes descriptions ofactivities, roles and communication flows in aproject.

The different project documents are described andexemplified by electronic templates. Examples ofdocuments are requirement specification, projectplan, time plan, status report, meeting minutes,and project reflection document.

The use of milestones and tollgates is introduced.At defined tollgates the students are required todeliver documents etc. to get approval for enteringthe next phase in the project.

The model is scalable, and it can advantageouslybe used in a track of project courses with varyingcomplexity. The model has been successfully usedin more than 150 projects, and the experiencesare very positive. As an example, the well-definedsteps in the model automatically introduce con-tinuous assessment. It also triggers processes thatreveal if a project is delayed or if a member in agroup does not contribute.

5. AUTOMATIC CONTROL PROJECTCOURSE

5.1 Overall description

The automatic control project course is a 200hours course where groups of at least six stu-dents do projects according to the LIPS projectmodel (described in Section 4). Quoting the offi-cial course plan of the course, the aim is:

“The project should be conducted according toindustrial standards and it should develop thestudents competence in the following areas: - Howto analyze engineering problems - Research ofknowledge - Application of knowledge obtainedfrom previous courses - To find creative solutions- When applicable, the project work should consistof modeling, design, implementation and testingof a control system.”

In the course 2004 there were six projects:

(1) Autonomous robot control (Dept. of EE)(2) Golf playing industrial robot (Dept. of EE)(3) Control of a missile (Saab Bofors Dynamics)(4) Control of a fighter aircraft (MathCore)

(5) Target estimation for a UAV platform (SwedishDefense Research Agency)

(6) Occupant Spatial Sensing (Autoliv)

As can be seen from this list, two projects werecarried out at the department, and four werecarried out together with companies. In Section6, the second project is going to be described insome detail.

5.2 Course organization

The course starts with a presentation of the avail-able projects. The students then choose a projecttask they would like to carry out. Based on thestudents’ choices, the examiner of the course as-signs students to the different projects.

For each project there is a customer, sponsor,project manager, and a supervisor. For the indus-trial projects the customer is a person at the com-pany, and for the internal project the customeris a faculty member from the department. Thesponsor is a graduate student, and the task of thesponsor is to be the link between the customer andthe project group. The role of the supervisor, whoin most cases is a graduate student, is to supportthe group with technical issues. The project man-ager is one of the students in the project group.The sponsor together with the customer approvesthe original requirement specification. The endproduct is later evaluated against the requirementspecification. If there are requirements that thegroup cannot meet, those requirements have tobe negotiated with the sponsor and the customer.Formal meetings between the sponsor and theproject group have to take place at tollgate two(TG2) and TG5 according to the LIPS projectmodel. At the tollgate, the sponsor reviews theprogress of the project and decides if the projectis allowed to move into the next phase. Minutesfrom the two meetings are used by the examineras inputs for the final assessment of the students.

Within the groups, each student gets his/her ownarea of responsibility. In addition to the projectmanager task, the areas of responsibilities aredocuments, quality, testing, customer relations,and design. The project manager should reportweekly to the sponsor how the project develops.

6. THE GOLF PLAYING ROBOT

In this section, the results of the project “Thegolf playing robot” will be presented. In Section6.1, the hardware platform that was given to thestudents is presented, and the aim of the project isalso explained. In Sections 6.2 to 6.5 the technicaldetails of the project and the achieved results arediscussed.

6.1 Project platform

The students were given a hardware platform thatthey should use in the project. This platform isshown in Figure 1 and consists of a standardindustrial robot, the ABB IRB1400 robot (ABB1997a), a golf course built by the department, atool with a golf putter and a vacuum device topick up the ball.

The robot is programmed in the programminglanguage RAPID 2.0 (ABB 1997b), and it is con-nected to the local area network in the laboratory.The project group was given a short course inrobotics, programming RAPID, and safely usingthe robot.

Fig. 1. The ABB IRB1400 robot and the golfcourse.

The goal of the project, as it was formulated to thestudents when the course started, was to create agolf playing robot that could be used to explaincontrol and robotics to a wide range of people inboth a pedagogical and an entertaining way. Theresulting product should be interactive and havean easy-to-use graphical user interface (GUI).

6.2 Graphical user-interface

The graphical user interface (GUI) was imple-mented in Matlab using the Guide tool (MathWorks2002). The software is divided into three modeswhich the user can reach from the system mainwindow, shown in Figure 2. The three modes are,“competition mode”, “demonstration mode”, and“play mode”, and the GUI for the last two areshown in Figure 3 and Figure 4. In competitionmode, it is possible for one or more players tocompete against the robot in a game of six shots.In demonstration mode, the user can give an anglethat the robot should hit the ball at. Using amodel, to be described in Section 6.3, the software

computes the velocity that gives the highest prob-ability for a hole-in-one. In Figure 3 the angle 9◦ isshown together with the probability 0.95 for hole-in-one and the predicted ball path. In play mode,the user can choose angle and speed manually.

Fig. 2. Main menu screen shot.

Fig. 3. Demonstration mode. The user gives anangle and the software computes the speedthat gives the highest probability for a hole-in-one shot and shows the predicted ballpath.

6.3 Model

The model consists of a geometrical model of thegolf course, a physical model of the dynamics ofthe ball, and a statistical model which is updatedevery time the robot hits the ball.

6.3.1. Geometrical model of the course The ge-ometrical model of the golf course was found byusing the robot to measure a large number ofpoints on the course surface. The model is madeout of three segments, two planes and a cubic-spline surface connecting the two planes. In Fig-ure 5 the model is shown and the three differentsegments are indicated with numbers.

Fig. 4. Play mode. The vertical line on the courseshows the angle which the robot will hitthe ball at. The user can choose angle andvelocity for the robot by pushing the differentbuttons in the interface.

0

0.5

1

1.5

2

2.5

00.20.40.6

0.81−0.1

0

0.1

0.2

0.3

0.4

0.5

x [m]

y [m]

z [m

]

1

2

3

Fig. 5. The geometrical course model.

6.3.2. Model of the ball and the ball trajectoryThe model of the ball is based upon fundamentalphysical laws (Alonso and Finn 1980), but therotational dynamics of the ball are not consid-ered. The approximative equations describing thedynamics therefore become

ẍ = − 1m

(µNFN sign(ẋ)+µvẋ+FN sin(θ) cos(φ)

),

and

ÿ = − 1m

(µNFN sign(ẏ) + µv ẏ + FN cos(θ) sin(φ)

),

where µN and µv are coefficients of friction whichare proportional to the normal force FN andthe velocity, respectively. Furthermore θ and φare Euler angles representing the orientation ofthe course plane in the position of the ball. Thevariable θ corresponds to rotation around the y-axis, while φ corresponds to rotation around thex-axis. The normal force is computed as

FN = mg cos(θ) cos(φ),

where m is the mass of the ball. The initialposition is known since the robot itself puts theball on the course and the initial velocity isfound as a constant times the programmed hitvelocity. To take into account the ball bouncingon the walls of the course and going into the hole,

events have been used in the simulation, leadingto a hybrid system. The standard Matlab ode45solver, which also supports events, has been usedto calculate the trajectory of the ball.

6.3.3. Statistical model The statistical modelwas created in a three step procedure. In step 1, allangles and velocities in a range −35◦ to 35◦ and3200 to 4500 mm/s were tested by the robot. Inthe setup described in Section 6.1, the only inputto the identification process is the value zero, if theball has missed the hole, or the value one if theball has gone into the hole. An exhaustive searchalgorithm was employed and all combinations ofangles and velocities, in steps of 1◦ and 20 mm/swere tested. In a future project, a camera will alsobe used as input. This will make the search processmuch more rapid since the ball trajectory will beavailable to the identification process.

In step 2, the process continued by returning toareas in the angle velocity space where the robothas managed to hit the hole. Since there areuncertainties in the initial position of the ball,the probability for most combinations of angleand velocity to actually get hole-in-one is lessthan one. The results from step 2 is a matrix ofprobabilities for hole-in-one for each combinationof angle and velocity.

The last step, step 3, is a continuous process thatallows to update the probabilities based upon theresult (zero or one) from a hit. In this way therobot has a learning capability which makes itpossible to adjust for slowly varying parameters.If a parameter is changed rapidly, for example theball is replaced with a new ball, the process shouldstart from step 1 again since the statistical modelin this case is no longer valid.

2000 2500 3000 3500 4000 4500 5000 5500

−30

−20

−10

0

10

20

30

Velocity [mm/s]

Ang

le [d

eg]

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

A

B

C

D

Fig. 6. Probability for hole-in-one for differentangles and different hit velocities.

In Figure 6 the result of the statistical model afterthe project had finished is shown. A number ofinteresting features can be observed. In the region

A, the ball goes directly into the hole (as shown inFigure 3). Region B contains cases where the ballbounces on the left wall before going into the hole.In region C there are some samples where the ballbounces on the back wall before entering the hole.Finally, region D contains the cases where the ballbounces on the right wall before reaching the hole.

6.4 Robot program

The robot program communicates with Matlabusing a simple file interface. The Matlab programsends information such as action (collect ballor hit ball), speed (hit speed in mm/s), angle(hit angle in degrees), and personality (on oroff). The personality flag is used to make thedemonstration a bit more interesting, with thisoption the robot shows emotions if the hit is asuccess or a failure and it also warms up beforehitting the ball. After hitting or collecting the ball,the robot program sends score (missed or hit thehole) back to the Matlab program.

In the robot program, the golf course is defined asa work-object with an associated coordinate sys-tem. All the coordinates for, for example, pickingup and hitting the ball are given in the work-object coordinate system. If the golf course ismoved with respect to the robot, it is thereforeonly the work-object coordinate system that hasto be calibrated in order to run the program. Thehit procedure is done by moving the robot alonga circular path. More work should be done in theoptimization of the club path to maximize theavailable speed.

6.5 Future developments

In next year’s project, the technical platformgiven to the students will be developed further.There will be an extension to the golf coursewhere the ball will drop if it goes into the hole.This is illustrated in Figure 7. In this way, thegame can continue for more than one shot. Thenew course also makes it necessary to have acamera to find the ball on the new platform. Thecamera can also be used in the modeling andidentification step and will make it possible forthe robot system to see if the course has beenmoved. The calibration process could at leastin principle be done using the camera system.The model of the ball dynamics could be furtherdeveloped. Although it is quite difficult it wouldbe interesting to take the rotational dynamics ofthe ball into account. The step when the club hitsthe ball should be more thoroughly studied, andthe ball bouncing on the walls is not covered verywell by the current model.

New platform

Fig. 7. Course design for the spring 2005 course.

7. CONCLUSIONS

The CDIO initiative has been described and astudent project in Automatic Control has beenpresented. The task of the project has been todevelop a control program and a user interface fora golf playing industrial robot. The project hasbeen carried out using the project model LIPS inorder to mimic the way an industrial project iscarried out.

ACKNOWLEDGMENT

The CDIO Initiative has been sponsored by TheKnut and Alice Wallenberg Foundation. TheABB IRB1400 robot has been available via theCenter of Excellence, ISIS, sponsored by VIN-NOVA. Finally, the authors wish to thank thestudents in the Automatic Control project courseand especially the students in the golf playingrobot project, Lars Stenlind, Elin Eklund, MikaelaWaller, Alexander Nordström, Magnus Norden-borg, Hanna Sjöstedt, and Staffan Ohlsson, forproviding the material on which the technicalproject description is based.

REFERENCES

ABB (1997a). Product Manual IRB1400. M97Aed.

ABB (1997b). RAPID Reference Manual. Robot-Ware 2.0 ed.

Alonso, M. and E.J. Finn (1980). Fundamen-tal university physics: Volume One, Mechan-ics and Thermodynamics. 2nd ed.. Adison-Wesley. Reading, Massachusets.

MathWorks (2002). Using MATLAB Graphics,Version 6. MathWorks. 3 Apple Hill Drive,Natick, MA 01760-2098, USA.

Svensson, T. and C. Krysander (2004). The LIPSproject model. Ver 1.0. Linköping University,Sweden.

The CDIO Standards (2004). www.cdio.org.The CDIO Syllabus (2004). www.cdio.org.