Week 4Week 4

Team ECHOTeam ECHO

““Megatron”Megatron”

Main()Main()

Megatron orient itself facing east, Megatron orient itself facing east, activation of all systemsactivation of all systems

Start sweep:Start sweep: Wall following using proximity sensor, light Wall following using proximity sensor, light

sensors on the lookout for unloading area sensors on the lookout for unloading area (cst. period of dark floor on both sensors) (cst. period of dark floor on both sensors) & helping with path correction & helping with path correction

Question: Can we have a color sample Question: Can we have a color sample of stacking area for sensor of stacking area for sensor calibrating?calibrating?

Search patternSearch pattern

Picking up boxes and avoiding Picking up boxes and avoiding obstacles while searching.obstacles while searching.

Robot width:10”Robot width:10” Search distance:2’3”Search distance:2’3”

Search patternSearch pattern

Advantages: Advantages:

dead simpledead simple easy to implementeasy to implement independent of unknown variables independent of unknown variables

(grid size & stacking location)(grid size & stacking location)

Stacking areaStacking area

When we get there, disable When we get there, disable orientation correction & wall orientation correction & wall following (in_stacking_area=true). following (in_stacking_area=true). mark the start of stacking area and mark the start of stacking area and (if box count= 3), drop stack. After (if box count= 3), drop stack. After dropping stack, back up, avoid it & dropping stack, back up, avoid it & mark locationmark location

Also mark location of far edge of Also mark location of far edge of unloading zone.unloading zone.

subsequent stackingsubsequent stacking

Consistent approach: slow, but failsafe and easy Consistent approach: slow, but failsafe and easy to implementto implement

Lookout for stack location from US and odometer Lookout for stack location from US and odometer from edge of stacking area (which ever one from edge of stacking area (which ever one comes first to avoid crashing in a stack)comes first to avoid crashing in a stack)

LUS used to correct distance from wallLUS used to correct distance from wall No turning in stacking area!!No turning in stacking area!!

subsequent stackingsubsequent stacking

Advantages: Advantages: dead simpledead simple easy to implementeasy to implement independent of unknown variables (grid size & stacking independent of unknown variables (grid size & stacking

location)location) Allows for good protection of stacks from dumb robotAllows for good protection of stacks from dumb robot

Dowside: Might be a bit slow (sacrificing speed for security)Dowside: Might be a bit slow (sacrificing speed for security)

Resume SearchResume Search

If we had reached 3 boxes before If we had reached 3 boxes before reaching areareaching area• record location of where 3rd box was record location of where 3rd box was

picked up picked up • go backgo back• resume search from there.resume search from there.

SYSTEMSSYSTEMS

BADS (Box acquisition and BADS (Box acquisition and dropping system)dropping system)

While loop always on the lookout for boxes While loop always on the lookout for boxes except in stacking area and when shaft is except in stacking area and when shaft is full (!in_stacking_area && !Full)full (!in_stacking_area && !Full)

Counts: as soon as sensor=true, count++Counts: as soon as sensor=true, count++ when boxes = 3; full = true -> goTo when boxes = 3; full = true -> goTo

stacking areastacking area Trigger switch on the back of the forks Trigger switch on the back of the forks

(BADS = true) => activates lift and pauses (BADS = true) => activates lift and pauses motionmotion

NAS (Navigation system) NAS (Navigation system)

Corrects heading when crossing Corrects heading when crossing perpendicular linesperpendicular lines

While loop Turned off when picking While loop Turned off when picking up boxes and avoiding obstacles up boxes and avoiding obstacles

while (!BADS !BOR)while (!BADS !BOR)

BOReS (Box and Obstacles BOReS (Box and Obstacles Recognition System) Recognition System)

HUS looks out for obstacles in front. Dead angle is covered by HUS looks out for obstacles in front. Dead angle is covered by proximity sensorproximity sensor

If obstacle is detected in front, avoids it by going around & If obstacle is detected in front, avoids it by going around & checking to make sure it passed before resuming normal pathchecking to make sure it passed before resuming normal path

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BOReS (Box and Obstacles BOReS (Box and Obstacles Recognition System)Recognition System)

If LUS detects < 75cm, rotate 90o ccw to look If LUS detects < 75cm, rotate 90o ccw to look with HUSwith HUS• If obstacle || box < 10cm to wall; {move forward 15cm If obstacle || box < 10cm to wall; {move forward 15cm

once and retry}once and retry}• If boxIf box

locate exact locationlocate exact location BOR = true;BOR = true; Record current number of onboard boxes (old number)Record current number of onboard boxes (old number) Orient To box angleOrient To box angle Go To box distance +15cm as per LUS readingGo To box distance +15cm as per LUS reading Since the first thing BADS does is count++Since the first thing BADS does is count++

• wait(1000)wait(1000)• if count !> old count {jiggle and move forward some more}if count !> old count {jiggle and move forward some more}

Return to search location & resume searchReturn to search location & resume search

BOReS Main disadvantage BOReS Main disadvantage will not see boxes behind obstacles will not see boxes behind obstacles

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Time budgetTime budget

Used/Allocation (W4)= 76/66Used/Allocation (W4)= 76/66 Used/Allocation (YTD) = 214/264Used/Allocation (YTD) = 214/264

6

5

20

20

5

10

66

6

1

26

28

5

10

76

0 10 20 30 40 50 60 70 80

Meeting

Structure

Navigation

Recognition

Paper work

I2C

Total

Used

Allocated