EVALUATION IN DISTURBANCE FORCE COMPENSATION VIA
STATE OBSERVER AND CONTROLLER DESIGN
This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering (Hons)
by
PHOO YOONG HAU B051410106 940223-10-5433
FACULTY OF MANUFACTURING ENGINEERING
Disahkan oleh:
_____________________________ _____________________________ Cop Rasmi:
Alamat Tetap:
NO. 37 LALUAN TRONOH 11, DESA TRONOH,
31750 TRONOH,
PERAK DARUL RIDZUAN.
Tarikh: 6/6/2018 Tarikh: 6/6/2018
*Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai SULIT atau TERHAD.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
Tajuk: EVALUATION IN DISTURBANCE FORCE COMPENSATION VIA STATE OBSERVER AND CONTROLLER DESIGN
Sesi Pengajian: 2017/2018 Semester 2
Saya PHOO YOONG HAU(940223-10-5433)
mengaku membenarkan Laporan Projek Sarjana Muda (PSM) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan
untuk tujuan pengajian sahaja dengan izin penulis.
3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan pertukaran antara institusi pengajian tinggi.
4. *Sila tandakan (√)
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysiasebagaimana yang termaktub dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/ badan di mana penyelidikan dijalankan)
SULIT
TERHAD
DECLARATION
I hereby, declared this report entitled “Evaluation in disturbance force compensation via state observer and controller design” is the results of my own research except as cited in reference.
Signature : ………
Author’s Name : PHOO YOONG HAU
APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of Universiti Teknikal Malaysia Melaka as a partial fulfilment of the requirements for the degree of Bachelor of
Manufacturing Engineering (Hons.).
The members of the supervisory committee are as follow:
………
i
ABSTRAK
Keperluan asas ketepatan tinggi dan alat mesin yang tepat yang mesti dipenuhi ialah ia dapat
memperoleh output yang diingini dengan input yang diberikan. Walau bagaimanapun, selalu
ada gangguan yang tidak dijangka berlaku semasa proses pemesinan seperti getaran, geseran
dan daya pemotongan yang akan memberi kesan besar kepada ketepatan dan ketepatan
pengeluaran pemesinan. Oleh itu, gaya gangguan seperti ini mesti dikompensasi atau
dielakkan untuk meningkatkan ketepatan dan ketepatan. Daya gangguan biasanya sukar
untuk dianggarkan dan sensor fizikal mempunyai pelbagai kelemahan seperti kos yang tinggi
dan mengurangkan kebolehpercayaan. Pemerhatian negara boleh digunakan untuk
menggantikan sensor untuk menganggarkan daya gangguan. Matlamat projek ini adalah
untuk menganggarkan dan mengimbangi daya gangguan dalam proses penggilingan
simulasi melalui pemerhati negara dan reka bentuk pengawal. Pemerhati itu direka
berdasarkan kaedah Pritschow (2004) yang membina semula kekuatan gangguan yang
berlaku di antara benda kerja dan alat semasa proses pemotongan menggunakan pecutan
relatif. Pengawal kedudukan dan pemerhati negara direka bentuk dalam persekitaran
MATLAB / SIMULINK. Sistem kawalan dijangka dapat memberi pampasan dengan
berkesan daya gangguan input yang dimasukkan dalam bentuk isyarat sinus tunggal dan
isyarat multi-sine. Persembahan pengawal diukur berdasarkan kesalahan pengesanan
maksimum. Berdasarkan hasil pengesahan, pengamat pasukan telah terbukti dapat
mengimbangi gangguan masukan gelombang sinus tunggal dan gangguan masukan
gelombang sinus. Oleh kerana kesilapan pengesanan maksimum di antara anggaran isyarat
dan gangguan input gelombang sinus tunggal atau gangguan masukan gelombang sinus yang
masing-masing mengurangkan 25.00% dan 38.18% apabila isyarat yang diperkirakan dari
ii
ABSTRACT
iii
DEDICATION
For
My beloved father, PHOO SAI ONN
My beloved mother, CHONG MEI MEI
iv
ACKNOWLEDGEMENT
Completing this final year project report is a large task and requires support from numerous people, and those people deserve thanks. First, I would like to convey my deepest gratitude to my respected supervisor, Associate Prof. Dr. Zamberi Bin Jamaludin. It is a great honour and pleasure to be able completing this final year project under his supervision, who willing to spend his precious time for giving me ideas in and providing intellectual opinions throughout the learning process. Your kind advice, time, attention and dedication towards realizing this project are greatly appreciated and indebted.
Secondly, I would also like to thank my parents and my siblings whosupporting me all the time without knowing the meaning of tiredness.
Thirdly, I also would like to thank to my friends who helped me a lot in finalizing this project within the limited time frame.
v
TABLE OF CONTENTS
Abstrak i
Abstract ii
Dedication iii
Acknowledgement iv
Table of Contents v
List of Figures x
List of Tables xiv
List of Abbreviations xv
List of Symbols xvi
CHAPTER 1: INTRODUCTION
1.1 Project Background 1
1.2 Problem Statement 3
1.3 Objectives 3
1.4 Scopes 4
vi CHAPTER 2: LITERATURE REVIEW
2.1 Background 6
2.2 Industrial Revolution 7
2.3 Automation and Control System in Manufacturing Process 9
2.3.1 Numerical Control Automation 1 3
2.3.2 Computer Numerical Control 1 4
2.4 CNC Machining 1 4
2.4.1 CNC Milling 1 5
2.4.2 CNC Machining Center 1 6
2.4.2.1 Vertical-Axis CNC Machining Center 1 6
2.4.2.2 Horizontal-Axis CNC Machining Center 1 7
2.5 Issues in CNC Machine tools and CNC Milling 1 8
2.5.1 Structural 1 8
2.5.2 Chattering 1 9
2.5.3 Friction 2 0
2.5.4 Cutting Force 2 1
2.6 Compensation Methods 2 2
2.6.1 Mechanical Design Approach 2 2
2.6.1.1 Machine Structure Design 2 3
2.6.1.2 Spindle Design 2 4
2.6.2 Cutting Process Approach 2 4
2.6.3 Controller Approach 2 5
2.6.3.1 Proportional, Integral, Derivative Controller 2 6
vii
2.6.3.3 H-Infinity Control 3 3
2.6.3.4 Sliding Mode Control 3 4
2.6.3.5 Fuzzy Logic Control 3 5
2.6.3.6 Artificial Neural Network 3 6
2.6.4 Observer Based Approach 3 7
2.6.4.1 State Observer 3 8
2.6.4.2 Inverse-Model-Based Disturbance Observer 3 9
2.6.4.3 Disturbance Force Observer 4 0
2.6.4.4 Pritschow’s Method 4 1
2.6.4.5 Ferraris Sensor 41
2.6.5 Feedforward Control 4 3
2.7 Summary 4 4
CHAPTER 3: METHODOLOGY
3.1 Project Planning and Scheduling 4 6
3.1.1 Progress Flowchart of the Project 4 7
3.1.2 Gantt Chart 4 8
3.2 System Setup 4 9
3.3 Single Axis Slider 5 0
3.4 Software 5 1
3.4.1 MATLAB 5 1
3.4.2 SIMULINK 5 2
3.4.3 Control Desk 5 2
viii
3.6 Motor Constant Identification 5 5
3.7 Cascade Controller Design 5 6
3.8 Force Observer Design 5 8
3.9 Evaluation of the Effectiveness of Controller and Observer 5 9
3.10 Summary 6 0
CHAPTER 4: DESIGN AND ANALYSIS OF CONTROLLER AND OBSERVER
4.1 Design of Cascade P/PI Controller 6 1
4.1.1 Design of PI Controller for Velocity Loop 6 3 4.1.2 Design of P Controller for Position Loop 6 7
4.2 Evaluation of Cascade P/PI Controller 7 0
4.2.1 Evaluation of Cascade P/PI Controller on Tracking Performance 70
4.2.2 Evaluation of Cascade P/PI Controller on Disturbance Rejection 74
4.3 Design of Observer 76
4.4 Analysis of Observer 79
4.4.1 Analysis of Observer with Single Sine Input Disturbance 80
4.4.1.1 Input Disturbance with Constant Frequency 81
4.4.1.2 Input Disturbance with Constant Amplitude 82
4.4.2 Analysis of Observer with Single Sine Input Disturbance 85
and Time Delay Block (Delayed Estimation Signal) 4.4.3 Analysis of Observer with Multi Sine Input Disturbance 86
4.4.4 Analysis of Observer with Multi Sine Input Disturbance 88
and Time Delay Block (Delayed Estimation Signal) 4.5 Evaluation of Observer 89
ix CHAPTER 5: CONCLUSION AND RECOMMENDATIONS FOR FUTURE
WORK
5.1 Conclusion 94
5.2 Recommendation for Future Work 95
REFERENCES APPENDIX A APPENDIX B APPENDIX C APPENDIX D
x
LIST OF FIGURES
2.1 Flowchart of manufacturing process 7
2.2 Working environment before the industrial revolution 8
2.3 Elements of an automated system 1 0
2.4 Closed loop or feedback control system 1 2
2.5 Open loop control system 1 2
2.6 Example of NC code 1 3
2.7 Milling operation 1 6
2.8 Vertical-axis CNC machining center 1 7
2.9 Horizontal-axis CNC machining center 1 7
2.10 Chatter mark left on the workpiece 1 9
2.11 The quadrant glitches that formed during milling machining 2 1
2.12 Cutting force 2 1
2.13 Block diagram for PI controller 2 8
2.14 Block diagram for PD controller 2 9
2.15 Block diagram for PID controller 3 0
2.16 Block diagram for cascade controller 3 2
2.17 Schematic diagram of cascade P/PI controller 3 2
2.18 Block diagram for H-infinity control 3 3
2.19 Block diagram of fuzzy logic control 3 5
xi
2.21 Block diagram of state observer 3 8
2.22 Block diagram of a system with an IBMDO 3 9
2.23 Block diagram of a system with DFO 4 0
2.24 Ferraris sensor 4 1
2.25 Schematic diagram of the Ferraris principle 4 2
2.26 Block diagram of a combination of feedback and feedforward controller 4 4
3.1 Progress flowchart of the project 4 7
3.2 Gantt chart for the FYP 1 and FYP 2 4 8
3.3 Schematic diagram of system setup 4 9
3.4 System setup 5 0
3.5 Single axis slider 5 1
3.6 Flowchart of the system identification 5 3
3.7 Measured FRF of single axis slider 5 4
3.8 Measured FRF and fitted second order model with time delay 5 4
3.9 Block Diagram of open loop system for estimation of force constant 5 5
3.10 P/PI cascade controller 5 7
3.11 Flowchart of designing the P/PI cascade controller 5 8
3.12 Block diagram of the cascade P/PI controller with the observer 59
4.1 General structure of cascade P/PI controller 62
4.2 Schematic diagram of the velocity loop 63
4.3 Bode diagram of the velocity open loop transfer function 65
xii
4.5 Sensitivity function of the velocity loop 66
4.6 Bode diagram of the position open loop transfer function 68
4.7 Nyquist plot of the velocity open loop transfer function 68
4.8 Sensitivity function of the position loop 69
4.9 Control scheme of cascade P/PI controller in SIMULINK 70
4.10 Reference input position with corresponding tracking errors for cascade P/PI 71
controller using reference input frequencies of 0.5 Hz 4.11 Reference input position with corresponding tracking errors for cascade P/PI 72
controller using reference input frequencies of 1.0 Hz 4.12 Closer observation of reference input position and actual output position at 73
tracking frequency of 0.5 Hz at zero position 4.13 Closer observation of reference input position and actual output position at 74
tracking frequency of 0.5 Hz at peak position 4.14 Control scheme of the observer in SIMULINK 78
4.15 Control scheme of cascade controller with observer in SIMULINK 79
4.16 Control scheme of the observer with single sine input disturbance in SIMULINK 80
4.17 Time delay between the 0.3 amplitude, 3 Hz reference disturbance and 82
estimated disturbance signal 4.18 Result of the analysis for 2 Hz, 2.5 Hz, 3.5 Hz and 4 Hz of input disturbance 83
4.19 Control scheme of the observer with single sine wave input disturbance and 85
given time delay in SIMULINK 4.20 Control scheme of observer with multi sine wave input disturbance in 87
SIMULINK 4.21 Control scheme of observer with multi sine wave input disturbance and 88
given time delay in SIMULINK 4.22 Control scheme of observer with single sine wave input disturbance in 90
xiii
4.23 Control scheme of observer with multi sine wave input disturbance in 90
SIMULINK 4.24 Error signal of single sine wave input disturbance without observer 91
4.25 Error signal of single sine wave input disturbance with observer 91
4.26 Error signal of multi sine wave input disturbance without observer 92
xiv
LIST OF TABLES
3.1 Parameter of system model 5 9
4.1 Parameter of PI controller 66
4.2 Parameter of P controller 69
4.3 Tracking performance of cascade P/PI controller 72
4.4 RMSE variations of cascade P/PI controller with and without the 75
presence of input disturbance 4.5 Performances of the observer with different amplitude of 81
single sine wave input disturbance 4.6 Performances of the observer with a difference frequency of 84
single sine wave input disturbance 4.7 Performance of the observer with a different given time delay 86
4.8 Performances of observer with multi sine wave input disturbance 87
4.9 Performances of observer with multi sine wave input disturbance 88
and different given time delay 4.10 Performances of observer with single or multi sine wave input disturbance 91
xv
LIST OF ABBREVIATIONS
ADC - Analog Digital Converter
ANN - Artificial Neural Network
CAD - Computer Aided Design
CAM - Computer Aided Manufacturing
CIM - Computer Integrated Manufacturing
CNC - Computer Numerical Control
DAC - Digital Analog Converter
DFO - Disturbance Observer
DSP - Digital Signal Processing
FRF - Frequency Response Function
IMBDO - Inverse Model Base Disturbance Observer
IoT - Internet of Thing
MCU - Machine Control Unit
NC - Numerical Control
RMSE - Root Mean Square Error
xvi
LIST OF SYMBOLS
° C - Degree Celsius
G(s) - Transfer Function
Y(s) - The table position in micrometer
U(s) - The input voltage in volts
Kf - Motor Constant
Kp - Propotional Gain
Ki - Integral Gain
Vest - Estimated Velocity
x
(t) - Absolute acceleration
d - Disturbance force
M - Constant
F - Frictional force
1
CHAPTER 1
INTRODUCTION
This project is related to the evaluation of disturbance force compensation via state observer and controller design. In this chapter, the background of this project, objectives, problem statements and scope of the project will be discussed. The background of the project discusses the disturbance force presence in CNC machining. One of the current issues that faced by CNC machining is that disturbance force presented will affect the accuracy of the machine tools and the quality of the machined part. The method of reducing the disturbance force present was suggested at the end of this project.
1.1 Project Background
2 As the demand for high precision and quality product are getting increased. The manufacturing technology has undergone a huge development day by day aiming at improving precision, quality, and productivity as well as reducing the production cost. One of the most significant developments in manufacturing technology that meets this requirement is CNC machining.
According to Valentino & Goldenberg (2008), CNC machining was first introduced in the early 1970s, CNC is the automation of machine tools by the method of a computer perform pre-programmed sequences of machine control command. The CNC machining has the advantages of setup time reduction, lead time reduction, contouring of complex shapes, a high degree of accuracy and increase of productivity. There are many different types of CNC machines are used in industry. The majority of them are CNC machining center and CNC lathes.
3 1.2 Problem Statement
The basic requirement of a high accuracy and precision machine tool that must be met is that it is able to obtain a desired output with the given input. However, there is always some unexpected disturbance occur during the machining process such as vibration, friction and cutting force that will greatly affect the accuracy and precision of the machining output.
For most of the case, direct estimation of disturbance force is impractical. Disturbance forces are usually hard to estimate and physical sensors contain various disadvantages such as increasing cost and reduce reliability. A state observer may use to replace sensor to estimate disturbance force. One of the key advantages of state observer over the sensor is that disturbance signal can often be observed accurately without the addition of sensors. Hence, a state observer is recommended and needed to estimate the disturbance force enter the system while a feedback control scheme is needed to reduce the disturbance. This project is using the relative acceleration in designing the observer.
1.3 Objectives
The objectives of this project are:
1. To design a state observer that estimate disturbance forces entering a system.
2. Applied the estimated state in feedback control loop for disturbance force compensation.
4 1.4 Scopes
The scopes of the project are:
1. The state observer is designed based on the idea of Pritschow (2004). 2. The state observer is designed and simulated using Simulink.
3. The controller is designed and simulated using MATLAB / SIMULINK.
4. The disturbance forces in this project are limited to single sine wave and multi sine wave.
1.5 Organization of Report
This report is consists of five chapters. The first chapter covers the introduction of the report. It generally explains the background of the project, problem statement, objective and scope of the project.
