Steam Base Station Trackers and AASD Motion Drivers Interference

Hello,

I have just finished building my 3 dof motion rig which is an SFX 100 style system with 4 actuators. The motion is working fine however I am having an extremely difficult time with my VR headset and picking up the tracking towers with the motion rig.

The issue is steam VR shows all 4 lighthouses as visible, however it also states that the headset is looking for lighthouses. I have 4 Index lighthouses at the 4 corners of my gaming room. It will intermittently pick up a tower and the VR tracking will work for a bit, I have even been able to drive a lap or two with only a couple tracking dropouts. However, I had zero tracking issues with the 4 towers prior to motion being added to the rig. I have only been able to do this with my Valve Index, with my Vive Pro 2 the second I switch the motion rig on all 4 towers drop off and will not reappear until the rig is turned off, then they slowly reappear one by one. Then steam VR tells me I need to rerun the room setup for the headset, every single time I turn on the motion rig it does this.

I am using 80ST motors instead of the standard 90ST and 80X80 extrusion. I am using the newer AASD-15A V6.3.1 drivers that are white and a Thanos motion controller. All motor and signal wires are shielded for the motion rig and the controllers are plugged into a Furman EMI/RFI reducing power brick.

Any help or advise would be amazing, at this point it seems like motion and VR are not an option together for me which doesnt seem right since I have seen so much footage of people using the Index and VP2 in motion rigs with what appear to be no issues.

Thank You for any help!

mount the towers so they are on the rig and see if the headset becomes visible

Hi,

I think you may be getting EMI noise interference in your power line, common problem if you are not using line filter on your servos power entry. The EMI can contaminate the rest of the devices connected on same line, or even your whole house electrical circuit if there is no filtering in the main panel. Or could be ground loop issue too.

I'd suggest attaching a line filter, if not comfortable with electrical etc, a safe enclosure can help. Check out some posts on my thread about it:

https://www.xsimulator.net/community/threads/amc-aasd15a-servo-controller.13945/page-20


And this article as well:
https://luisblando.medium.com/how-i-solved-the-emi-problem-in-my-simrig-3ea6c0907609

Thanks
Thanos

Is the shielding screen on the servo power cables earthed at both ends? IE to the servo case and Driver earth point?

@SeatTime and @Thanos I'm thinking you are bang on with the EMI issues. Since the original post I have moved the drivers to a small server cabinet and moved the cabinet into the closet of my gaming room and I have been able to successfully use my Index without tracking issues, however I am still running into issues with the VP2.

With the VP2 and the above described setup I have good tracking when I walk around the rig (rig is located in the center of the room/center of the 4 tracking towers) but tracking drops off once I get in the rig and am in the middle of the 4 motors.

I will be adding a line filter as you have suggested @Thanos and will report back with results.
@SeatTime the power cable for the motors are earthed to each respective servo driver, and the drivers are also each earthed to the power line ground. I will be adding additional grounds from the drivers to the server case. When you say 'both ends' it makes me think I should do some additional grounding on the motor/rig side. The motors I have are the type with the little bit of cable coming out before the connector, the motor cables do not plug directly into the motor housing. Do I need to add some type of grounding from the motor cable directly to the motor?

Thank you guys so much for the help!

Just to clarify, the servo motor power cables are not normally screened as standard, (usually special order) and this screen must be earthed at both the driver and motor end (which is also not standard practice).

I just wanted to update and thank you guys for the advice.

I performed all of the changes outlined in the guide you provided Thanos, adding ferrites to my wires, and adding the EMI line filter to the actuator power loop, as well as utilizing a common ground. I am very happy to report that this has eliminated tracking issues with both my Valve Index and Vive Pro 2! They both function flawlessly now with the tracking precision you would expect from a lighthouse based system.

I have also designed a small box similar to the one you built to house an on-off switch for the actuators, a little volt meter, and the EMI line filter in one nice little package.

I will be uploading the files and parts list for this box to thingiverse soon so that anyone can make one if they like!

Nice looking power box!!

Here is the link to the files for the EMI box incase someone wants to make one, page also contains links to all the subcomponent parts for purchase.

https://www.thingiverse.com/thing:5369155