topic Re: How to make truck face rack when loading/unloading? in FlexSim Forum

How to make truck face rack when loading/unloading?

patrickABAWF — Fri, 20 Jan 2023 15:54:39 GMT

[ FlexSim 23.0.2 ]

Hello, I'm trying to find the best way to force the trucks to face the racks when they are loading/unloading. This model and its video will be for marketing purpooses so it needs to be more realistic.

Option 1: In this picture, I'm using Astar and it doesn't work. I tried doing a "On Unload Time" set rotation to 0 but it doesn't work because AStar seems to override that.

Option 2: I might be able to make it work with Network Nodes but I'm hoping for a more elegant solution.

Option 3: I'm thinking I could program the task sequence with process flow Travel, Rotate, Unload, etc. but before I start I want to make sure it's the only option.

Suggestions ?

Thanks a lot,

Re: How to make truck face rack when loading/unloading?

joerg_vogel_HsH — Fri, 20 Jan 2023 16:16:02 GMT

I had worked with an network path on a plane object. I moved the plane in front of a rack cell and connected dynamically the transporter to the network node. This was without an AStar network and long ago, when we worked only with rack objects.

Re: How to make truck face rack when loading/unloading?

jason_lightfoot_adsk — Fri, 20 Jan 2023 16:19:20 GMT

Tell the TE to do the pick or place travel offset in the x direction first and then the Y and Z. If that isn't quite good enough then tell it to travel to a position relative to the slot first - say 3 metres in front - giving it enough space to rotate around when approaching the rack.

Re: How to make truck face rack when loading/unloading?

patrickABAWF — Fri, 20 Jan 2023 16:29:46 GMT

I've never done that. Where do I tell the TE to do the offset in the X first and then YZ?

Re: How to make truck face rack when loading/unloading?

jason_lightfoot_adsk — Fri, 20 Jan 2023 17:07:46 GMT

If you're using process flow use a custom task activity and choose either pick offset or place offset for the task type. Here it's telling the TE to do ALL of the X movement - by using 1 (100%):

To get it to then move the Y and Z you should set ALL the fields to 1 (otherwise, if you make X zero, it will undo the X travel it has already done):

These task types are described in the manual here and can be used in regular, code/script generated task sequences.

Re: How to make truck face rack when loading/unloading?

jason_lightfoot_adsk — Fri, 20 Jan 2023 17:28:05 GMT

There's an example here where the main topic is refining the fork movement

Re: How to make truck face rack when loading/unloading?

patrickABAWF — Tue, 24 Jan 2023 14:17:09 GMT

I have not been able to make it work with Custom Task Activity.

But I made it work with Kinematics in Process Flow.

So instead of Travel --> Unload

I do Travel --> Kinematics (rotate, move in) --> Unload --> Kinematics (move out, rotate).

The result is great. See attached gif.

Re: How to make truck face rack when loading/unloading?

jason_lightfoot_adsk — Tue, 24 Jan 2023 16:03:22 GMT

That looks good - glad you got something working.

Re: How to make truck face rack when loading/unloading?

MatildeM_ — Wed, 25 Jan 2023 10:26:30 GMT

Hi! I have the same problem as you. Can you please share the model? Or can you give me more info on how to use the Kinematics command? Thanks!

Re: How to make truck face rack when loading/unloading?

joerg_vogel_HsH — Wed, 25 Jan 2023 10:42:12 GMT

https://docs.flexsim.com/en/23.0/Reference/DeveloperAdvancedUser/Kinematics/Kinematics.html

The datanode is a Parameter, that can be a label node.
You can also open a tree view of an object of model tree. Enhance object to see attributes > and mark a sub tree node, hit return of your keyboard to create a new node. Mark right of this new node the empty space to get an editable field. Write a name and then you have created a datanode that you can find in your attributes of an object.

Re: How to make truck face rack when loading/unloading?

patrickABAWF — Wed, 25 Jan 2023 13:29:05 GMT

I can't share the model but here is the Process Flow that does everything.

Basically, after the Assign slot logic, I calculate the xy destination of the slot and I determine a "offsetside" which is -1 or 1 depending if I'm going to the left or the right of the rack.

Then, when I get to the destination, I calc the rotation angle (token.drz) required to be facing the rack and I Apply Kinematics for this angle:

They I Apply Kinematics to move the truck 7 feet forward.

After that, I unload the item (Unload Time + Move Object) and then, redo the kinematics in reverse (reverse 7 feet and rotate angle).

Or course, this only works if all the aisles are in the same Y axis but you get the idea.

Re: How to make truck face rack when loading/unloading?

patrickABAWF — Wed, 25 Jan 2023 13:34:29 GMT

I want to add the the truck movement is controlled by AStart and there are hidden barriers under the racks (the grey rectangles in this photo):

And, in case, you're wondering, the truck forks don't move up and down. It's just a TaskExecuter for which I changed the whole 3D shape. If I have time left later in the project, I will make the forks movable.

Re: How to make truck face rack when loading/unloading?

jason_lightfoot_adsk — Wed, 25 Jan 2023 13:34:30 GMT

You can also do this using travel tasks instead of kinematics (except rotation on the spot)

Plus if you use the pick and place offset tasks you have control over the fork height.