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Alexander F avatar image
Alexander F asked Alexander F commented

How can i set right travel sequece by crane when navigation is activated?


Hello I need your help.

I have used several cranes in my model to simulate some drones. I have only left the hook visible and replaced by a corresponding shape, see enclosed model. Since the drones are supposed to fly certain items, I have activated the AStar navigation. But the problem is now that the lift, drop and travel does not work as intended. When traveling, the hook (dron) is moved at the ground and not in the air. Only the crane without navigation moves in the right way, but can not avoid objects. But I want the hook travels in the air and still navigates the shortest way around objects. How can I change this?

FlexSim 17.1.4
task executerastarcranescrane movementnavigation
uavmodle.fsm (243.1 KiB)
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5 |100000

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Maybe the A Star module isn't in the current version capable to extrapolate the two dimensional boundary plane into the third dimension.

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Is it possible that someone can test my model in an other version? Maybe it's not a problem of my current version and I have made a mistake in the settings.

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1 Answer

Joerg Vogel avatar image
Joerg Vogel answered Alexander F commented

There isn't a problem with the version. The problem lays inside the standard transport tasksequence. The task sequence contains two tasks of TASKTYPE_TRAVEL which force the taskexecuter travel to the load and then to the unload object. But the Crane moves only in the defined strategy in OFFSET TRAVEL. Those two travel task are obsolete for the transport. You have to delete them or set them inactive by changing the type for example to a TASKTYPE_TAG. I found this answer when I tried to let a transporter do the flight. In The UAV_Crane163 I have changed the travel tasks to the tag tasks in the OnReceiveTaskSequence trigger. Then the UAV behaves as expected.

if(ts.subnodes.length == 5){

7964-uavmodel-jv.fsm (245.2 KiB)
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@ Jörg thank you first for your effort. With your changes to uav_crane163, the crane works in the correct order, but it looks as if your changes had deactivated the a*-navigation. Because the cran moves now no longer around the barriers and moves like uav_crane150 (thatone without navigation). I have also added to uav_crane163 your code above, because after several loading cycles it has occurred, that after the unloading task is no longer lift off. But then on the way back has the a*-navigation worked again. But unfortunately this does not solve my problem.

To your variant with the transporter, the loaded and unloaded tasks works also as it should, but also here the a*-navigation seems to be deactivated. And after the unloading task the forklift should also take off and travel back again.

I also noticed that the travel status differs from the normal cran and the a*-navigation. So I tried something in the tasksequence of the uav_crane164. Now he lifts himself after the load and moves along the a * -navigation, but he does not lift anymore after the unloaded. Unfortunately, I have nowhere found in which order I can set the travel sequence so that the cran / uav moves right. I am also not quite clear according to which logic / sequence the movements are executed when a*-navigation is activated.
Is it somehow possible to set the right travel sequence for the a*-navigation?

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changed-uavmodle.fsm (248.1 KiB)

@Alexander F Have you considered to build a taskexecuter which travels on the ground and shows only the animation of the drone vertically?

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No, I have not, because the crane has the characteristics I would like and I can adjust and change the speeds and height easily. The taskexecuter is by principle the same as the transporter and there it is not so easy to implement the desired movement as I think.

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inserttask(ts,TASKTYPE_PLACEOFFSET, obj. item, obj.unloadstation,0,1,0); 

// Travel in y direction only.

0 percent travel in x, 100% in y, 0 % in z because the vehicle is ground based.

inserttask(ts,TASKTYPE_PLACEOFFSET, obj. item, obj.unloadstation,1,1,0);

// Then travel to destination. It is the travel only in x direction.

100 percent travel in x, plus the already traveled 100% in y and still on the ground.

And then you use an animation to show a drone which lift off and sink to the ground, while the drone is traveling.

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