Does vps over-ride command inputs from the transmitter? [Uncontrolled Drift] [Crash Story Inside]

[inspireflyer172]

I was unfortunate enough to have my first crash with an inspire 2 yesterday. It is boxed up and ready to be sent back to DJI for a replacement via the refresh express program. However, now I am starting to wonder if I should have gone through the warranty process instead. While flying an indoor shoot the aircraft began to drift towards me without any input from the controller. I was flying in P-GPS with zero satellites throughout the entirety of the flight, so it was just relying on the vps sensors for position hold. As the Inspire continued to drift towards me I attempted to counter the movement with a control input in the opposite direction. This had no affect on the drift, so in a last ditch to effort to prevent damage to the property I attempted a hand catch. While grabbing the inspire, I simultaneously brought the throttle to zero. With the Inspire in hand I could still feel it trying to drift in the same direction, while also ramping up the motors a significant amount. (I was still holding the throttle stick all the way down with my left hand). Without having any success shutting down during the hand catch, I foolishly tried to manually power down with the button on top of the aircraft. My hand came into contact with the prop and broke it in half, and the vibrations of half a prop spinning at such a high speed tore the aircraft apart. It eventually powered down on its own. In hindsight, it was extremely foolish to try and hand catch an aircraft not responding to my controls, and I really should initiated a csc and let it drop to the ground. With that being said, I am left wondering what caused the the Inspire to drift in the first place. Did the vps become confused in some way? I had already been flying in that same room for about five minutes without issue. (strong signal with the aircraft and no magnetic interference) Can anyone here help interpret the dat files to see what may have gone wrong? I'm not quite sure how to read them or attach them to this post, but I would really like some insight as to what happened.

 

[MrTVR]

Wow, if you still have all of your fingers intact you have had a lucky escape!

In my experience the VPS acts just like GPS in that it will attempt to hold position in the absence of any stick input. It will not override your stick input.

I have however experienced situations where the I2 will drift when a large object within the VPS field of view starts moving on a plain background. For instance, on one job, I was taking a top down shot of a fork lift truck operating inside a warehouse. No GPS, just VPS. At times, when the fork lift moved, the I2 would follow its movement as it was the only thing the VPS could lock onto on the otherwise plain grey warehouse floor.

Maybe you had a similar problem?

 

[inspireflyer172]

Wow, if you still have all of your fingers intact you have had a lucky escape!

In my experience the VPS acts just like GPS in that it will attempt to hold position in the absence of any stick input. It will not override your stick input.

I have however experienced situations where the I2 will drift when a large object within the VPS field of view starts moving on a plain background. For instance, on one job, I was taking a top down shot of a fork lift truck operating inside a warehouse. No GPS, just VPS. At times, when the fork lift moved, the I2 would follow its movement as it was the only thing the VPS could lock onto on the otherwise plain grey warehouse floor.

Maybe you had a similar problem?

Thanks for the reply MrTVR. I was definitely lucky it wasn’t any worse than it was. When picking up broken propeller pieces after the crash I found one of them lodged into a sound barrier 5 feet from where I was standing. I was actually filming in a big auditorium when the crash happened, no moving objects in the room. I will say that the lighting in the room was pretty dim, but it still should should have responded to my control inputs when it began to drift. I’m thinking more and more that this was an equipment malfunction with the aircraft itself. The fact that it wouldn’t respond to my controls is very concerning.

 

[The Editor]

I was unfortunate enough to have my first crash with an inspire 2 yesterday. It is boxed up and ready to be sent back to DJI for a replacement via the refresh express program. However, now I am starting to wonder if I should have gone through the warranty process instead. While flying an indoor shoot the aircraft began to drift towards me without any input from the controller. I was flying in P-GPS with zero satellites throughout the entirety of the flight, so it was just relying on the vps sensors for position hold. As the Inspire continued to drift towards me I attempted to counter the movement with a control input in the opposite direction. This had no affect on the drift, so in a last ditch to effort to prevent damage to the property I attempted a hand catch. While grabbing the inspire, I simultaneously brought the throttle to zero. With the Inspire in hand I could still feel it trying to drift in the same direction, while also ramping up the motors a significant amount. (I was still holding the throttle stick all the way down with my left hand). Without having any success shutting down during the hand catch, I foolishly tried to manually power down with the button on top of the aircraft. My hand came into contact with the prop and broke it in half, and the vibrations of half a prop spinning at such a high speed tore the aircraft apart. It eventually powered down on its own. In hindsight, it was extremely foolish to try and hand catch an aircraft not responding to my controls, and I really should initiated a csc and let it drop to the ground. With that being said, I am left wondering what caused the the Inspire to drift in the first place. Did the vps become confused in some way? I had already been flying in that same room for about five minutes without issue. (strong signal with the aircraft and no magnetic interference) Can anyone here help interpret the dat files to see what may have gone wrong? I'm not quite sure how to read them or attach them to this post, but I would really like some insight as to what happened.

Moved to Inspire 2 section.

VPS can be easily fooled/confused as mentioned above. Even sunlight or changing shadow patterns can cause issues as well as moving objects.
Here is a demo of what I mean, although a Phantom the principle is the same.

 

[inspireflyer172]

Moved to Inspire 2 section.

VPS can be easily fooled/confused as mentioned above. Even sunlight or changing shadow patterns can cause issues as well as moving objects.
Here is a demo of what I mean, although a Phantom the principle is the same.

Thanks for moving the post, I thought I had it in the right section! Interesting video, definitely something to keep in mind. I am still left wondering why the inspire wasn’t responding to my control inputs though.

 

[MrTVR]

My guess is that DJI might be able to tell if it was equipment malfunction when they analyse the crash logs.

 

[jkerrins]

I have wrestled with VPS before. Had and additional gimble mounted to my I2. Thought it was not in direct line of bottom sensor. Launched and went to about 40 feet and released the sticks. The craft started slowly going up and up and up. Like a birthday balloon that was released. Would not respond to any stick movement. Tried return to home, Atti, multiple other steps. Then went in and shut off the downward facing sensor....Which is in a separate spot from other sensor settings. As soon as I turned off the bottom sensor, I regained control.
Landed and changed my shorts after that one

 

[BudWalker]

I was unfortunate enough to have my first crash with an inspire 2 yesterday. It is boxed up and ready to be sent back to DJI for a replacement via the refresh express program. However, now I am starting to wonder if I should have gone through the warranty process instead. While flying an indoor shoot the aircraft began to drift towards me without any input from the controller. I was flying in P-GPS with zero satellites throughout the entirety of the flight, so it was just relying on the vps sensors for position hold. As the Inspire continued to drift towards me I attempted to counter the movement with a control input in the opposite direction. This had no affect on the drift, so in a last ditch to effort to prevent damage to the property I attempted a hand catch. While grabbing the inspire, I simultaneously brought the throttle to zero. With the Inspire in hand I could still feel it trying to drift in the same direction, while also ramping up the motors a significant amount. (I was still holding the throttle stick all the way down with my left hand). Without having any success shutting down during the hand catch, I foolishly tried to manually power down with the button on top of the aircraft. My hand came into contact with the prop and broke it in half, and the vibrations of half a prop spinning at such a high speed tore the aircraft apart. It eventually powered down on its own. In hindsight, it was extremely foolish to try and hand catch an aircraft not responding to my controls, and I really should initiated a csc and let it drop to the ground. With that being said, I am left wondering what caused the the Inspire to drift in the first place. Did the vps become confused in some way? I had already been flying in that same room for about five minutes without issue. (strong signal with the aircraft and no magnetic interference) Can anyone here help interpret the dat files to see what may have gone wrong? I'm not quite sure how to read them or attach them to this post, but I would really like some insight as to what happened.

You might want to take look at

Inspire 2 crash [Help reading .dat log]

I had my first incident with the inspire while filming inside a building on sunday. While I was getting ready to record my next video, the aircraft began to drift towards my direction without any input from the controller. To try and counteract the drift I did an aileron input in the opposite...

forum.dji.com

 

[jkerrins]

I had control to go up and side to side, but decent would not respond

 

[mmarian]

I had control to go up and side to side, but decent would not respond

There are a few switches in GO4 relating to landing and landing gear. Near ground warning, Self addaptive landing gear. Switch them all off and you should be fine.