Ruxu Du, Ph.D.
Professor and Director
Institute of Precision Engineering
The Chinese University of Hong Kong
January 2007
1 http://www.ipe.cuhk.edu.hk/

CUHK
• The Chinese University of Hong Kong is celebrating her 43 th anniversary now
2 http://www.ipe.cuhk.edu.hk/

CUHK
• The numbers
– 9,000 undergraduate and 5,000 graduates
– 8 faculties, 62 departments, 820 professors
– HK$4.2 billion (US$600 million) annual budget
– HK$1.0 billion (US$125 million) annual research grants
3 http://www.ipe.cuhk.edu.hk/

DU
• The academic career of Prof. R. Du
– 1989, Ph.D., the University of Michigan
– 1991, Assistant Professor, the University of Windsor
(Windsor, Ontario, Canada)
– 1995, Associate Professor, the University of Windsor
– 1999, Associate Professor, the University of Miami
(Coral Gables, Florida, USA)
– 2001, Professor, the Chinese University of Hong Kong
– 2006, Founding director, Institute of Precision
Engineering, CUHK
– More updated information can be found at our website at www.acae.cuhk.edu.hk/~rdu
4 http://www.ipe.cuhk.edu.hk/

DU
• Research funding:
– Up to date: HK$92,000,000 (US$11,500,000)
– Annual budget in 2005-06: HK$24,000,000
(US$3,000,000)
• Current team members:
– 4 Professors
– 8 Post Doctor Fellows / Visiting Scholars
– 5 Research Associates / Assistants
– 6 Ph.D students
– 6 M.Phil. students
– 10 in our Shenzhen Operation 1
– 16 in our Shenzhen Operation 2
5 http://www.ipe.cuhk.edu.hk/

DU
• Publications:
– International journal publications: 70
– International conference publications: 82
– Book chapters: 7
– Patents: 5
• Services
– Associate Editor, Int. J. of Control and Intelligent
Systems
– Associate Editor, Computer Aided Design and
Applications
– Member of Editorial Board, Int. J. of Power and Energy
Systems
– Chair, 2 nd Asian International Conference on
Mechantronics (2006)
6 http://www.ipe.cuhk.edu.hk/

The team
2002
2007
7 http://www.ipe.cuhk.edu.hk/

Research Directions
• Condition monitoring, fault diagnosis and automatic control
• Design
– Metal forming press design
– Air conditioning system design
– Industrial sewing machine design
– Footwear design
• Manufacturing
– Metal forming
– Metal cutting
– Plastic injection molding
8 http://www.ipe.cuhk.edu.hk/

Technology Inventions
• Condition monitoring and fault diagnosis
– New methods
• 4D holospectrum (1994)
• Snake Skeleton Graph (2002)
• Fuzzy Transition Probability (2004)
• Bio-inspired method (2006)
– Applications
• Machining (1985 ~ 1995)
• Large rotating machinery (1994)
• Metal forming (1999 ~ 2005)
• Plastic injection molding (2003)
• Air conditioning systems (2005)
9 http://www.ipe.cuhk.edu.hk/

Technology Inventions
• Industry sewing machine and sewing process
Modeling and simulation
Needle heating
Needle cutting
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Technology Inventions
• Sheet metal stamping process monitoring and diagnosis
Inverse FEM software
On-line monitoring based on SVM
Diagnosis based on thermo energy distribution
Current project: design optimization
11 http://www.ipe.cuhk.edu.hk/

Technology Inventions
• Design a new controllable mechanical metal forming press
First Prototype Second Prototype
Current projects: build a
300 ton prototype
12 http://www.ipe.cuhk.edu.hk/

Technology Inventions
• Design a solar air conditioner
Refrigerant storage for instant response
Bubble pump powered by solar vacant tube
On-spot cooling
13 http://www.ipe.cuhk.edu.hk/

Technology Inventions
• Other projects
– Virtual label: an expert system for textile label pattern editing and simulation
– Shoe design: design custom-made athletic and causal footwear
– Condition monitoring and control of plastic injection molding process
– Tool condition monitoring in machining
– ……
14 http://www.ipe.cuhk.edu.hk/

New Projects
• Do you know what mechanism is this?
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New Projects
• The watch project
– The sponsors:
• Innovation and Technology Commission, Hong Kong
• Hong Kong Watch Manufacturers Association
• Federation of Hong Kong Watch Trade and Industry
• Federation of Hong Kong Industry, Watch and Clock Council
– The budget: HK$64 million (US$8 million)
– The objective: Develop technologies and capabilities for design and manufacture high quality mechanical watch movements
– The time: started on Jan. 1, 2006 for three years
16 http://www.ipe.cuhk.edu.hk/

New Projects
• The watch project
– Selected R&D projects:
• Dynamic modeling and design optimization
• Virtual library
• Signature analysis
• Micro CNC gear hobbing machine
• Ultra precision wire EDM machine
• Nanospring
• Micro assembly
• Precision stamping
• Six sigma quality management
• …… .
17 http://www.ipe.cuhk.edu.hk/

New Projects
– Dynamic modeling of the Swiss lever mechanism
– The kinematics does not satisfy the Lipschitz condition and hence, can only model by a set of 11 impulsive differential equations
– Solving the equation set reveals the dynamical behavior of the mechanism
Balance Wheel Displacement versus Velocity Escape Wheel Displacement versus Velocity
2500 800
2000
1500
600
400
1000
500
0
200
0
-500
-1000
-1500
-2000
-2500
-150 -100 100 150
-200
-400
-600
-800
-15 -10 -50 0
Displacement (degree)
50 -5 0
Displacement (degree)
5 10
Phase diagram of the balance wheel
15
Phase diagram of the pallet fork
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New Projects
– Virtual library
Daniel Co-axial
English lever
Swiss lever
19 http://www.ipe.cuhk.edu.hk/

New Projects
– Signature analysis
• Use FEM to find the modal frequencies
• Use reassigned spectrogram to diagnose possible errors
20 http://www.ipe.cuhk.edu.hk/

New Projects
• Micro CNC gear hobbing machine
CAD model of the machine
Computer simulation of gear formation
21 http://www.ipe.cuhk.edu.hk/

New Projects
– Ultra precision wire EDM machine
• Minimum wire size: 0.03 mm
• Minimum resolution: 0.1  m
• 3D EDM milling
22 http://www.ipe.cuhk.edu.hk/

Thank you
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