# Indor positioning using UWB

**URL:** <https://discuss.px4.io/t/indor-positioning-using-uwb/8350>\
**Category:** Pixhawk\
**Created:** [November 2, 2018, 11:21am UTC](https://discuss.px4.io/t/indor-positioning-using-uwb/8350 "2018-11-02T11:21:38Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![hdiethelm](https://discuss.px4.io/letter_avatar_proxy/v4/letter/h/b5a626/32.png) [@hdiethelm](https://discuss.px4.io/u/hdiethelm)\
**Post date:** [November 2, 2018, 11:21am UTC](https://discuss.px4.io/t/indor-positioning-using-uwb/8350/1 "2018-11-02T11:21:38Z")

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Hello,

I’d like to build an indoor drone using UWB. At the moment I have a Pozyx but might be later I’ll build an own implementation. However, this system delivers just the position. Speed is not available and attitudes are probably estimated by the gravity vector or an EKF but I think the Pixhawk can do this equally well.

What are the options using Pixhawk?  
I’ve found so far:  
VISION\_POSITION\_ESTIMATE -\> ORB vehicle\_vision\_position / vehicle\_vision\_attitude  
vehicle\_vision\_position is used in EKF2 / LPE / INAV  
vehicle\_vision\_attitude is used in EKF2

ATT\_POS\_MOCAP -\> ORB att\_pos\_mocap  
att\_pos\_mocap is used in LPE / INAV

VICON\_POSITION\_ESTIMATE -\> Not used in PX4

Parameters:  
ATT\_EXT\_HDG\_M -\> INAV  
LPE\_VIS\_XY -\> LPE  
LPE\_VIS\_Z -\> LPE  
LPE\_FUSION -\> LPE  
EKF2\_AID\_MASK -\> EKF2  
SYS\_MC\_EST\_GROUP -\> Select LPE / INAV / EKF2

As I understand, the local coordinate X should be aligned with north? Is there a way of running this system without compass? I think an EKF should be able to filter out the yaw deviation if the drone is moving.

Does someone have tested these options?

Whats the best filter? LPE / INAV or EKF2 for this setup?

Whats the best way of sending the position? VISION\_POSITION\_ESTIMATE or ATT\_POS\_MOCAP?

As it seams, EKF2 uses also the attitude from the vision data. How is this used?  
MASK\_ROTATE\_EV seams to rotate the VISION frame to the navigation frame by vehicle\_vision\_attitude.  
MASK\_USE\_EVYAW seams to use YAW from the vision message instead of YAW from the compass.

Thanks!