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Neobotix navigation rotation behavior

I am trying to get the Neobotix LP-655 platform (not omni-directional) to move to a goal in rviz. The global plan seems to go directly to the goal location. I would expect a curved plan, as the platform only can rotate and not move sideways. Furthermore it does not create a new plan if there is something unknown obstacle blocking the path. Instead it just rotates in front of the obstacle!

The platform sometime manage to go to the desired goal, but it shakes a lot, and it often rotate before moving towards the goal and when it is very close to the goal. I have uploaded two videos of this behavior:

http://www.youtube.com/user/VT3AAU2011?feature=mhee

I have tested my odomotry using this guide: http://ros.org/wiki/navigation/Troubleshooting and the scans seems pretty good.

Because I am a new use to the site, I cannot upload my config files, so I am sorry that I have to post them here:

*costmapcommon.yaml

obstacle_range: 12.5

raytrace_range: 30.0

footprint: [[0.50,0.45],[0.50,-0.45],[-0.50,-0.45],[-0.50,0.45]]

inflation_radius: 0.55

observationsources: laserscanner

laserscanner: {sensorframe: /baselink, expectedupdaterate: 0.0, observationpersistence: 0.0, data_type: LaserScan, topic: scan, marking: true, clearing: true}

*costmapglobal.yaml

global_costmap:

global_frame: /map

robotbaseframe: /base_link

update_frequency: 1.0

static_map: true

rolling_window: false

transform_tolerance: 2.5

costscalingfactor: 10.0

unknowncostvalue: 0

publishvoxelmap: false

lethalcostthreshold: 100

map_topic: map

*costmap_local.yaml

local_costmap:

global_frame: /map

robotbaseframe: /base_link

update_frequency: 1.0

publish_frequency: 0.0

static_map: false

rolling_window: true

width: 20.0

height: 20.0

resolution: 0.1

transform_tolerance: 2.5

origin_x: 0.0

origin_y: 0.0

map_type: costmap

trackunknownspace: false

*planner_local.yaml

TrajectoryPlannerROS:

maxvelx: 0.35

minvelx: 0.001

maxrotationalvel: 0.3

mininplacerotationalvel: 0.001

escape_vel: -0.1

acclimth: 0.05

acclimx: 0.05

acclimy: 0.

holonomic_robot: false

pathdistancebias: 0.6

goaldistancebias: 0.8

occdist_scale: 0.01

heading_lookahead: 0.325

heading_scoring: false

headingscoringtimestep: 0.8

sim_time: 3.0

sim_granularity: 0.025

dwa: false

xygoaltolerance: 0.2

yawgoaltolerance: 0.1

latchxygoal_tolerance: true

If I set e.g. the resolution of the map to 0.05, my CPU has not got enough power to calculate the path and it misses its desired loop. Could this be a problem? Or that my update_frequency is set to only 1.0?

I dont know what to do, to get the platform to navigate smoothly to a goal without any shaking or rotating?

/Christian

Asked by mtechAAU on 2012-09-18 04:11:30 UTC

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