Multidisciplinary development
of a badminton robot
Model Driven Development Days 2013
April 24th, 2013
Overview
+ Introduction
+ Design specification
+ Conceptual design
+ Embodiment and detailed design
+ Conclusions
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Flanders’ Mechatronics Technology Centre
+ FMTC vzw:
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Non-profit organization
Started in 2003 with support of Agoria
In 2011: +4.8 M€ turnover with +35 staff
Membership for companies with R&D in Flanders
+ Our competence: Mechatronics
= integration of electronics and software in
mechanical systems
+ Our business: Application oriented research
projects
+ Our market: Machine building and mechatronic
component industry
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The FMTC activities are grouped in 4 programs.
Model Based
Design
sensors
Smart
Sensors
energydrivetrain(s)
efficient EM
drivetrain(s)
proces
product
Self-optimisation
environment
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Badminton robot: why?
+ Build a non-confidential demonstration platform with high PR
impact
+ Integrate and demonstrate key FMTC developed technologies
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Low latency wireless communication platform
Energy efficient control
Model based design methodologies
Advanced diagnostics
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Challenges
+ Multidisciplinary design problem
 Combination of different physical & software components required to
fulfill requirements
 Design team
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Mechanical designers
Specialists on dynamic analyses
Control specialists
SW specialists
 Integration of activities crucial
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Model-based development
+ Models used for
 Formal representation of
 Requirements
 Design solution
 Link between requirements and
design solution
 SysML
 Behavioural simulations
 Matlab Simulink, Modellica,
FEM, …
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Overview
+ Introduction
+ Design specification
+ Conceptual design
+ Embodiment and detailed design
+ Conclusions
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From informal/uncomplete thoughts…
1. Able to play badminton against a human player in a noncompetition tempo
2. Able to play badminton with standard badminton equipment
3. It covers half badminton field
4. No strings (wires) attached, it can freely move in its half
badminton field
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… to a complete list of formal requirements
+ List of functional and non-functional requirements
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… to a list of technical system specifications
+ Rationale:
 Time budget = 1s (realistic average time per shoot)
 Maximum travel distance = 8m (badminton field in diagonal)
 Robot waits in the middle of the field
 Maximum travel distance in 1s = half the field minus 0.5 m the racket length  3.5m
 Assuming a triangular profile s = 1/4at2  acceleration has to be 14 m/s2 or 1.4g
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Overview
+ Introduction
+ Design specification
+ Conceptual design
+ Embodiment and detailed design
+ Conclusions
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Idea generation
+ Brainstorming by experienced people with mixed background
 Different working principles identified
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Evaluation of conceptual ideas
+ Fulfillment of all technical specifications
 Wireless communication demonstrator
 H-bridge & cabled robot not OK
 Acceleration
 Basic calculations
Friction = NormalForce * µ
NormalForce = Gravity
Gravity = m * g
µ ~ 0.4
Max acceleration = µ * g = 0.4 g
Wheeled robot on normal field
NOT OK
NormalForce = Gravity + Magnetic Force
Wheeled robot on magnetic field
OK
Gravity = 3500N
Magnetic force @ 4 mm distance = 20000N
Magnetic force @ 1 mm distance = 40000N
Max acceleration = 3g (theory, in practice will
be 2.5 in the best case due to inefficiencies)
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Selected concept
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Overview
+ Introduction
+ Design specification
+ Conceptual design
+ Embodiment and detailed design
+ Conclusions
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Embodiment and detailed design
+ Concretize working principle into a system architecture
VISION
CONTROL
SOFTWARE
PHYSICAL DESIGN
MECHANICS
ELECTRICS
MAGNETICS
SAFETY
 Different disciplines involved / working in parallel
 Coordination by system architect
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Embodiment and detailed design
+ Central role for system architect
ELECTRICS
MAGNETICS
VISION
CONTROL
SYSTEM ARCHITECT
MECHANICS
SOFTWARE
SAFETY
 Coordinate activities of different disciplines
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Define system architecture
Assignment of requirements to different sub-systems
Assess effect of design decisions for one sub-systems to another sub-systems
Keep overview of complete design
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Multidisciplinary design
1. Definition of system architecture
Battery
Hitting mechanism
Frame
Wheels
Motors
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Multidisciplinary design
2. Assignment of requirements to different sub-systems
 Traceability of requirements is important
 Assignment by system architect (communication among disciplines)
 Based on experience
Weight
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Multidisciplinary design
2. Assign requirements to different disciplines
 Traceability of requirements is important
 Assignment by system architect (communication among disciplines)
 Based on simplified multidisciplinary analysis
Ffriction
Tmotor 1
M, I
Ffriction
Power motor
Capacity batteries
Control performance
Tmotor 1
Pmotor = motorTmotor motor
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Multidisciplinary design
3. Fulfill requirements by monodisciplinary design
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Detailed model-based analyses
Magnetic simulations
FEM analysis
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Multidisciplinary design
3. Fulfill requirements by monodisciplinary design
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Models from other disciplines used – dynamic model of the plant
used in Simulink
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Multidisciplinary design
3. Fulfill requirements by monodisciplinary design
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Software: automatic code generation from Simulink Model
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Multidisciplinary design
4. Feedback of monodisciplinary analyses to system architect
 Holonomic vs.
+ Simple control
- Requires a minimum of 3 driven omnidirectional wheels with uniform
friction coefficient
 Non-holonomic design
+ Requires only 2 driven wheels
- Complex trajectory generation and control
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Non-holonomic design selected in order to keep total system mass
below the 400 kg limit
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Multidisciplinary design
4. Feedback of monodisciplinary analyses to system architect
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Magnetic simulations
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Used to optimize the magnetic plate design in order to minimize drag
 Less powerful motors were needed
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Multidisciplinary design
+
Iterative process
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Improved interdisciplinary integration
Refinement of design: High abstraction  detailed analysis
Simplified
multidisciplinary
analysis
Motor selection
Detailed CAD
design
Simplified
multibody
simulation and
optimization
Final CAD
design
M, I
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FMTC’s badminton robot v2
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Overview
+ Introduction
+ Design specification
+ Conceptual design
+ Embodiment and detailed design
+ Conclusions
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Conclusions
+ Models have been extensively used in the design of the new
badminton robot
 To support design decisions by individual designers
 To improve communication between designers
 To keep an overview on the overall design by the system architect
+ Future challenges
 Multidisciplinary simulation models (co-simulation)
 Model-based safety design
 Model-based testing
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