1. Poka Yoke Concepts in Design Automation
Renukaprasad Belgur

2. Inadvertent Mistakes - Poka
Prevention - Yoke

3. Poka Yoke - Fail Safe
POH-kah YOH-keh - means "fail-safing" or "mistake-proofing”
“Poka” – Inadvertent mistake
“Yoke” – Prevention
Concept by Shigeo Shingo (1909 ~ 1990) – World’s leading expert on Mfg Practices – Shingo Prize – Lean Mfg Practices
A methodology to Detect & Prevent causes of Defects
ZQC – (Zero Quality Control)
Most mistakes – committed by workers / errors in the production systems
Feedback control and action system at the error stage
Hi-Tech Gears Limited – Manesar, Haryana

4. Poka Yoke Principles Elimination
Eliminate the possibility of Errors.
Redesign of the Process or Product s –
No need to inspect
Replacement Substitute a more Reliable Process for the existing one. - Use of Robots or Automation
Elimination
Replacement 2 1 3
Mitigation 5
Mitigation
Minimizing the effect of Error. - Protection, Safety Devices
Facilitation
Facilitation
Make work easier to perform such as color coding, combining steps,.. 4
Detection
Detection
Detect error before further processing. Software interlocks which notifies an Operator for wrong inputs.

5. Product s & Services Design Principles - Fundamental
Basic Functionality
Safety
Poka Yoke (Mistake Proofing)
Ergonomic Design
Simplicity
Flexibility
Robustness & Reliabile
Ease of Use
Ease of Maintainability …..
Product s & Services

6. Design Principles - Examples

7. Design Principles – Innovative

8. Road Crossing Solution

9. Poka Yoke Design - Examples

10. Poka Yoke Solutions - Examples

11. Errors@Work – Examples
Circular Saw - Safety

12. Errors@Work – Examples
Missing Parts Forgetting to assemble a part – Screws, Washers, labels, etc.,
Misassembled Parts Misassembly – loose parts, upside down, not aligned – Ex: Brackets (Reverse), seals not aligned, screws (Loose), Labels (Upside Down)
Incorrect Processing Disposing of a part rejected at test to the wrong pile
Incorrect Parts Retrieving and assembling the wrong part from a model mix selection – seals, labels, brackets, cses…

13. Fail Safe Assembly - Turbochargers
Concept of FailSafe – Prevention & Detection Devices
Guided Part Picking
Verification of the picked part
Verification of the Assembly
Interlocking of checking systems
Elimination – Eliminating the chance of error
Facilitation – Guidance Methods to minimise error
Mitigation – Lessen the effect of the error
Flagging – Methods for capturing all defects prior to shipment
Replacement
Elimination
Mitigation 2 1 5
Facilitation
Detection 3 4

14. TurboCharger - Assembly Line

15. Assembly Line - Electrical Switchgear

16. Assembly Line – Yesteryears

17. Engine Assy Line – Workstations

18. Engine Assy – Engraving Station Inspn.

19. Typical Schematic - Engine Assembly Line
110 Work Stations
3000 I/O’s
14 HMI’s
80 Profinet Nodes
80 ASI Nodes
4 Barcode Printer
12 Vision System
5 Servo Systems
11 Nut runner stations
1 Engraving unit

20. Poka-Yoke – RH, LH Axle Bearing Inspn
Upper bearing counting result
PLC OK
Ethernet Network
Light
Camera 1
Camera 2
Not OK
Detecting RH, LH & Counting Lower Brg Balls
Counting Upper Brg Balls

21. RFID – Typical Configuration
Ethernet
S7-300 PLC
Profinet
Profinet
RFID Controller
RF170C
RFID Controller
RF180C
Read/Wright Head
RF310R
Read/Wright Head
RF310R
Data Carrier, 32kB
RF350T
Data Carrier, 2 kB
RF360T

22. Fail Safe Devices – Poka Yoke
Light Guided pick Devices
Presence of Thread Sensors
Presence of Component Sensors
Vision System – Shape, Dimension, Orientation, etc.,
Laser Distance Sensors – Resolution >2microns
Auxiliary equipment interlocks
Software interlocks – Proceed to next station lock
Component Check - Go – No Go Gauges with sensor
Torque Sensors – Nut tightening
Balancing check – Assembly Check
Manual angular alignments – Checking using encoders

23. Laser Sensors Application Areas
Reference & Diff thickness measurements
Distance Measurements
Positioning
Profile measurements
Level Measurements
Material deformity measurements

24. Intelligent Systems – for Assembly

25. Pick Light Sensors

26. Fail Safe – Poka Yoke Approach
100% On-time delivery irrespective of variants
Flexibility in Assembly line
Consistency in Output with high Quality
Best in class Ergonomics (man material movement)
High Safety Standard Compliance
Zero accidents, less fatigue, maxi efficiency
Built in Sequential disciplined work approach - HMI
No missing Parts / Parts pick sensing
Vision check failsafe through Camera
Quick changeover (< 1 min)
Part Identification
Integration of each station – Ethernet
Data Acquisition, transfer, storage & analysis

27.
Presentation material - © Avasarala Technologies Limited