“Besides black art, there is only automation and mechanization.”

Federico Garcia Lorca

The Gantry Automation Project Overview

The Objectives

Our Approach

How it was programed

The Logic Codes

The Final Result

Rhys Porter , Joseph Eric Roy, Anthony Moody

The Objectives

To Solve a Puzzle Using Automation

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

The Objectives

To Solve a Puzzle Using Automation

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

The Objectives

To Solve a Puzzle Using Automation

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

The Objectives

The Puzzle Solved State

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

Our Approach

Understand the task, then

Define the sequences

How it’s going to be done

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

Stack all the disks together

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

Measure the disks

Till the puzzle is solved

H0 H1 H2 H3 H4

V0

V1

V4

V2V3

Green

Amber

Red

“Controlling complexity is the essence of computer programming”

(Brian Kernigham)

S1 : Dormant

LightsS100-199

S2 : Starting

LightsS200-299

S3 : Recover

ActionsS300-349

LightsS350-399

S4 : E-Stopped

LightsS400-499

S5 : Running

StackingS1000-

1499

SortingS1500-

1999

LightsS350-399

Hierarchical State Machine Design

Resource AllocationName Main State Sub-States State Memory Other Memory Timers

Primary – S0-9 M0.0-3.7 M4.0-9.7 T0-9

Powerup S0 – – – –

Dormant S1 S100-199 M10.0-13.7 M14.0-19.7 T10-19

Starting S2 S200-299 M20.0-23.7 M24.0-29.7 T20-29

Recover S3 S300-349 M30.0-33.7 M34.0-34.7 T30-34

Recover+Run Lights S3 S350-399 M35.0-38.7 M39.0-39.7 T35-39

E-Stop S4 S400-499 M40.0-43.7 M44.0-49.7 T40-49

Running: Stacking S5 S1000-1499 M100.0-103.7 M104.0-149.7 T100-149

Running: Sorting S5 S1500-S1999 M150.0-M153.7 M140.0-199.7 T150-199

Recover+Run Lights S5 S350-399 M35.0-38.7 M39.0-39.7 T35-39

Interaction of Main States

Interaction of Main States (Simplified)

Benefits of a Hierarchical State Machine

• Minimises code duplication• Eg “Go Home” memory bit to return to HO,VO

• Easy to follow debugging• Ability to see states the PLC is in at any point

• Any sub-state bugs are contained• Use of function calls and sub-state re-initialisation and clean up

• Mutated sub-state behaviour based on “Flag” memory bits set• Eg Different Lighting behaviours or stacking columns

“If you don’t trust them, then program them”

Machines

(Joseph Eric Roy)

Gantry Simulation

Physical Constraints • Speed• Simulation• Suction

• Time• Over extension

• Switch location• S7-300 PLC• TIA portal software

Stacking State

Recovery State