Elegant avoiding of obstacle

Young Joon Kimhttp://www.helloapps.com

MSRDS First Beginner Course – STEP5

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Topics

• Preparing basic environment

• Detecting distance by using laser distance sensor

• Stopping robot driving

• Avoiding obstacles

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Preparing basic environment

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Preparing basic environment

• Add a “Data” activity and “SPL Engine”

• Type “Script/BasicEnv4.txt” in the “Data” activity

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Preparing basic environment

• Execution result

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Detecting distance

by using laser distance sensor

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• Laser distance sensor

– Detect distance against target

– Notify distance with millimeter unit

– Max distance is 8000 millimeter

• SPL Engine provides notification data for laser sensor

– LRFNotify

• EntityName

• SensorData

– DistanceMeasurements

Detecting distance by using laser sensor

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• Add “SPL Sensors” service by dragging

Detecting distance by using laser sensor

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Detecting distance by using laser sensor

• Add “Calculate” activity

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Detecting distance by using laser sensor

• Connect the notification point of “SPL Sensors” to the input

point of “Calculate” activity

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Detecting distance by using laser sensor

• Select “LRFNotify” item from the left list

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Detecting distance by using laser sensor

• Type ““Distance is “ +” in the Calculate

• Select “SensorData” from the list

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Detecting distance by using laser sensor

• Add “.”

• Select “DistanceMeasurements” item from the list

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Detecting distance by using laser sensor

• Add “[180]”

– “Distance is “ + SensorData.DistanceMeasurements[180]

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Laser Sensor Data

• DistanceMeasurements

– Array of 361 distances

For 180 angles,Detect distances by 0.5 degrees

0th index360th

180th

Millimeter unit, max distance is 8m(8000 millimeter)

90th270th

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Laser Sensor Data

• Distance for the front direction

– SensorData.DistanceMeasurements[180]

• Distance for the right 45 degrees direction

– SensorData.DistanceMeasurements[90]

• Distance for the left 45 degrees direction

– SensorData.DistanceMeasurements[270]

• Distance for the right direction

– SensorData.DistanceMeasurements[0]

• Distance for the left direction

– SensorData.DistanceMeasurements[360]

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Detecting distance by using laser sensor

• Add “HelloApps Console” service

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Detecting distance by using laser sensor

• Connect the output point of “Calculate” activity to the input

point of “Console” service

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Detecting distance by using laser sensor

• Select “WriteLine” item from the right list

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Detecting distance by using laser sensor

• Select “value” item from the left list

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Detecting distance by using laser sensor

• Save and run diagram

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Detecting distance by using laser sensor

• Execution results

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Stopping robot driving

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Stopping robot driving

• If the distance from obstacle is below 1m(1000millimeter),

make a robot stop

– If (SensorData.DistanceMeasurements[180] < 1000)

• myrobot.Stop()

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Stopping robot driving

• Remove “Calculate” activity and “Console” service

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• Add a “If” activity

Stopping robot driving

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• Connect the notification point of “SPL Sensors” to the input

point of “If” activity

Stopping robot driving

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Stopping robot driving

• Select “LRFNotify” item from the list

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Stopping robot driving

• Click textbox in the “If” activity

• Select “SensorData” item from the list

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Stopping robot driving

• Type “.”

• Select “DistanceMeasurements” item from the list

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Stopping robot driving

• Type “[180] < 1000”

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• Add “Stop driving” diagram

Stopping robot driving

Add diagram

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• Connect the output point of “If” condition to the input point

of “Data” activity

Stopping robot driving

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Stopping robot driving

• Save and run diagram

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Stopping robot driving

• Execution result

Stop

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Avoiding obstacles

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• Modify “Stop driving” diagram into “Turn 90 degrees”

– Turn(90, 0.2)

Avoiding obstacles

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• Add “Go forwards” diagram and connect them

– Go(0.2)

Avoiding obstacles

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Avoiding obstacles

• Save and run diagram

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Avoiding obstacles

• Execution result