Long distance flight

[Yuri Pederi]

Kevin, Evan, we are in prep for the long distance flight. The UAV will travel from point A to point B around 120km. Point A is located 165m AMSL, point B is located 220m AMSL.

Do we need to take extra considerations for automatic landing at point B? We will bring the UAV to Point B landing zone and perform automatic take-offs and landings to make sure it can land safely when we send it from point A. The UAV will fly at 300m AGL altitude.

I would appreciate any guidance.

Regards,
Yuri

[08tcshfrpa8u5]

Hi Yuri,

The minimum target altitude (m) under ‘Operational limits’ section of the ‘Flight’ tab in the .vrs file should be set lower than 220 m. Since the point B is at a higher altitude than point A, you can add an altitude offset in the landing circuit command in the .fly file. The circuit command parameters are explained in the ‘MicroPilot Autopilot Installation and Operation’ Manual under Chapter 11-Commands. In your case, the altitude offset parameter in the circuit command will be set to 55 m. Let me know if you have any questions.

Sincerely, 

Diksha Randev

MicroPilot Support

[Yuri Pederi]

logs.rar

Hello Diksha,

Thank you for your reply.

We performed the flight with CircuitASL command at point B. During the landing at right hand circuit we had a weird behavior. The UAV didn't hold well the downwind leg and before the base leg instead of the right turn it went left and started descending. We had to take over manually and land.

Could you please check the log file for me and let me know what went wrong? We had similar landing pattern yesterday at our home airfield. 

Regards,

Yuri 

[08tcshfrpa8u5]

Hi Yuri,

Thank you for providing the details. I am looking into the datalogs and will get back to you with the analysis soon. Thanks for your patience.

Regards,

Diksha

[08tcshfrpa8u5]

Hi Yuri,

To begin with, there are a number of errors in your .vrs file flagged by the .vrs checker. We would recommend that you should fix those failures. Some of our observations from your datalogs are provided below:

It looks like your AGL broke sometime around 1981, then went back to normal at 3050, then broke pretty much for good at 3436. So you didn't have an AGL for the landing and you switched to PIC at 4158s, and landed manually.

We observed the difference between current yaw and GPS heading right before the takeover indicating that you were trying to land in some pretty hard side wind. Or it could be poorly calibrated compass that caused that discrepancy. 

We also noticed that you were maxing out the roll all the way from 4124 to 4156, all the while the UAV was going straight. The circuit was supposed to be at 130 degrees, that means the down wind leg should have been at 310. However, the heading during that stretch of max roll was mostly above that number. In order to reduce the heading (ie. turn left), the UAV should have to roll left. However, the UAV was rolled all the way to the right the whole time. This was a strange behavior. An explanation for that could be that if it wasn't lined up with the downwind leg, and was trying really hard to move closer to it, and when it turned left is when it finally lined up with it, so it turned left to line up with the line. Since the circuit was in a thread, it's hard to see where it lined up, and where the UAV was supposed to be.

In addition, the noisy body Pitch, Roll and Yaw dot values and the Z acceleration is indicating a vibration problem. 

Regards,

Diksha