DJITelloPy Tello not reporting correct X-Velocity

Tello not reporting correct X-Velocity

Open VaeZarek opened this issue 3 years ago • 9 comments

Hello, my Tello drone does not seem to be reporting a correct velocity in the x direction. My code looks like:

from djitellopy import Tello
from threading import Thread
import time

droneVelocity = 0

def speedometer():
    seconds = 0
    while tello.is_flying == True:
        droneVelocity = tello.get_speed_x()
        print("Velocity of Drone: " + str(droneVelocity))
        print("At " + str(seconds) + " seconds")
        seconds += 1/10
        time.sleep(1/10)

speedCheck = Thread(target=speedometer)
tello = Tello()

tello.connect()
print(tello.get_battery())
tello.takeoff()
speedCheck.start()
tello.move_forward(100)
tello.move_back(100)
tello.land()

From this, the drone moves forward 100 centimeters and back 100 centimeters. These both take 2 seconds, so the drone x velocity should be 50 cm/s, but the max it is reporting is around 7 cm/s. This makes sense in decimeters but that is a weird unit of measurement. Is there something else wrong with my code or that I should try? Thanks.

Jun 22 '21 19:06 VaeZarek

Hey, can you paste the full output of the program? My first guess is the drone tilts itself in the direction it wants to fly and thus the actual speed is divided in a X and Z component. Did you also try printing the other speeds (Y and Z)?

Jun 22 '21 21:06 M4GNV5

I have not tried the other speeds yet, but I will implement them and generate an output. For the code I posted before the output is:

[INFO] tello.py - 107 - Tello instance was initialized. Host: '192.168.10.1'. Port: '8889'.
[INFO] tello.py - 422 - Send command: 'command'
[INFO] tello.py - 446 - Response command: 'ok'
50
[INFO] tello.py - 422 - Send command: 'takeoff'
[INFO] tello.py - 446 - Response takeoff: 'ok'
Velocity of Drone: 0
At 0 seconds
[INFO] tello.py - 422 - Send command: 'forward 100'
Velocity of Drone: 0
At 0.1 seconds
Velocity of Drone: 0
At 0.2 seconds
Velocity of Drone: 0
At 0.30000000000000004 seconds
Velocity of Drone: 0
At 0.4 seconds
Velocity of Drone: -3
At 0.5 seconds
Velocity of Drone: -4
At 0.6 seconds
Velocity of Drone: -5
At 0.7 seconds
Velocity of Drone: -6
At 0.7999999999999999 seconds
Velocity of Drone: -7
At 0.8999999999999999 seconds
Velocity of Drone: -7
At 0.9999999999999999 seconds
Velocity of Drone: -7
At 1.0999999999999999 seconds
Velocity of Drone: -6
At 1.2 seconds
Velocity of Drone: -5
At 1.3 seconds
Velocity of Drone: -4
At 1.4000000000000001 seconds
Velocity of Drone: -3
At 1.5000000000000002 seconds
Velocity of Drone: -3
At 1.6000000000000003 seconds
Velocity of Drone: -3
At 1.7000000000000004 seconds
Velocity of Drone: -3
At 1.8000000000000005 seconds
Velocity of Drone: -2
At 1.9000000000000006 seconds
Velocity of Drone: -2
At 2.0000000000000004 seconds
Velocity of Drone: -2
At 2.1000000000000005 seconds
Velocity of Drone: -2
At 2.2000000000000006 seconds
Velocity of Drone: -2
At 2.3000000000000007 seconds
Velocity of Drone: -1
At 2.400000000000001 seconds
Velocity of Drone: -1
At 2.500000000000001 seconds
Velocity of Drone: 0
At 2.600000000000001 seconds
Velocity of Drone: 0
At 2.700000000000001 seconds
Velocity of Drone: 0
At 2.800000000000001 seconds
[INFO] tello.py - 446 - Response forward 100: 'ok'
[INFO] tello.py - 422 - Send command: 'back 100'
Velocity of Drone: 0
At 2.9000000000000012 seconds
Velocity of Drone: 0
At 3.0000000000000013 seconds
Velocity of Drone: 1
At 3.1000000000000014 seconds
Velocity of Drone: 2
At 3.2000000000000015 seconds
Velocity of Drone: 4
At 3.3000000000000016 seconds
Velocity of Drone: 5
At 3.4000000000000017 seconds
Velocity of Drone: 6
At 3.5000000000000018 seconds
Velocity of Drone: 6
At 3.600000000000002 seconds
Velocity of Drone: 7
At 3.700000000000002 seconds
Velocity of Drone: 7
At 3.800000000000002 seconds
Velocity of Drone: 7
At 3.900000000000002 seconds
Velocity of Drone: 6
At 4.000000000000002 seconds
Velocity of Drone: 5
At 4.100000000000001 seconds
Velocity of Drone: 4
At 4.200000000000001 seconds
Velocity of Drone: 3
At 4.300000000000001 seconds
Velocity of Drone: 3
At 4.4 seconds
Velocity of Drone: 3
At 4.5 seconds
Velocity of Drone: 2
At 4.6 seconds
Velocity of Drone: 2
At 4.699999999999999 seconds
Velocity of Drone: 1
At 4.799999999999999 seconds
Velocity of Drone: 1
At 4.899999999999999 seconds
Velocity of Drone: 0
At 4.999999999999998 seconds
[INFO] tello.py - 446 - Response back 100: 'ok'
Velocity of Drone: 0
[INFO] tello.py - 422 - Send command: 'land'
At 5.099999999999998 seconds
Velocity of Drone: 0
At 5.1999999999999975 seconds
Velocity of Drone: 0
At 5.299999999999997 seconds
Velocity of Drone: 0
At 5.399999999999997 seconds
Velocity of Drone: 0
At 5.4999999999999964 seconds
Velocity of Drone: 0
At 5.599999999999996 seconds
Velocity of Drone: 0
At 5.699999999999996 seconds
Velocity of Drone: 0
At 5.799999999999995 seconds
Velocity of Drone: 0
At 5.899999999999995 seconds
Velocity of Drone: 0
At 5.999999999999995 seconds
Velocity of Drone: 0
At 6.099999999999994 seconds
Velocity of Drone: 0
At 6.199999999999994 seconds
Velocity of Drone: 0
At 6.299999999999994 seconds
Velocity of Drone: 0
At 6.399999999999993 seconds
Velocity of Drone: 0
At 6.499999999999993 seconds
Velocity of Drone: 0
At 6.5999999999999925 seconds
Velocity of Drone: 0
At 6.699999999999992 seconds
Velocity of Drone: 0
At 6.799999999999992 seconds
Velocity of Drone: 0
At 6.8999999999999915 seconds
Velocity of Drone: 0
At 6.999999999999991 seconds
Velocity of Drone: 0
At 7.099999999999991 seconds
Velocity of Drone: 0
At 7.19999999999999 seconds
Velocity of Drone: 0
At 7.29999999999999 seconds
Velocity of Drone: 0
At 7.39999999999999 seconds
Velocity of Drone: 0
At 7.499999999999989 seconds
[INFO] tello.py - 446 - Response land: 'ok'
>>> 

---------- FINISHED ----------
exit code: 2 status: 0

And implementing the velocity in all 3 directions with this code:

from djitellopy import Tello
from threading import Thread
import time

droneVelocityX = 0
droneVelocityY = 0
droneVelocityZ = 0

def speedometer():
    seconds = 0
    while tello.is_flying == True:
        droneVelocityX = tello.get_speed_x()
        droneVelocityY = tello.get_speed_y()
        droneVelocityZ = tello.get_speed_z()
        print("X Velocity of Drone: " + str(droneVelocityX))
        print("Y Velocity of Drone: " + str(droneVelocityY))
        print("Z Velocity of Drone: " + str(droneVelocityZ))
        print("At " + str(seconds) + " seconds")
        seconds += 0.1
        time.sleep(1/10)

speedCheck = Thread(target=speedometer)
tello = Tello()

tello.connect()
print(tello.get_battery())
tello.takeoff()
speedCheck.start()
tello.move_forward(100)
tello.move_back(100)
tello.land()

I get this output:

[INFO] tello.py - 107 - Tello instance was initialized. Host: '192.168.10.1'. Port: '8889'.
[INFO] tello.py - 422 - Send command: 'command'
[INFO] tello.py - 446 - Response command: 'ok'
33
[INFO] tello.py - 422 - Send command: 'takeoff'
[INFO] tello.py - 446 - Response takeoff: 'ok'
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0 seconds
[INFO] tello.py - 422 - Send command: 'forward 100'
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.1 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.2 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.30000000000000004 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.4 seconds
X Velocity of Drone: -3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.5 seconds
X Velocity of Drone: -4
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.6 seconds
X Velocity of Drone: -5
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.7 seconds
X Velocity of Drone: -6
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.7999999999999999 seconds
X Velocity of Drone: -7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.8999999999999999 seconds
X Velocity of Drone: -7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 0.9999999999999999 seconds
X Velocity of Drone: -7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.0999999999999999 seconds
X Velocity of Drone: -7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.2 seconds
X Velocity of Drone: -6
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.3 seconds
X Velocity of Drone: -5
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.4000000000000001 seconds
X Velocity of Drone: -4
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.5000000000000002 seconds
X Velocity of Drone: -3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.6000000000000003 seconds
X Velocity of Drone: -3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.7000000000000004 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.8000000000000005 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 1.9000000000000006 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.0000000000000004 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.1000000000000005 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.2000000000000006 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.3000000000000007 seconds
X Velocity of Drone: -2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.400000000000001 seconds
X Velocity of Drone: -1
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.500000000000001 seconds
[INFO] tello.py - 446 - Response forward 100: 'ok'
[INFO] tello.py - 422 - Send command: 'back 100'
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.600000000000001 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.700000000000001 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.800000000000001 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 2.9000000000000012 seconds
X Velocity of Drone: 1
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.0000000000000013 seconds
X Velocity of Drone: 3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.1000000000000014 seconds
X Velocity of Drone: 4
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.2000000000000015 seconds
X Velocity of Drone: 5
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.3000000000000016 seconds
X Velocity of Drone: 6
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.4000000000000017 seconds
X Velocity of Drone: 7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.5000000000000018 seconds
X Velocity of Drone: 7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.600000000000002 seconds
X Velocity of Drone: 8
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.700000000000002 seconds
X Velocity of Drone: 7
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.800000000000002 seconds
X Velocity of Drone: 5
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 3.900000000000002 seconds
X Velocity of Drone: 4
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.000000000000002 seconds
X Velocity of Drone: 3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.100000000000001 seconds
X Velocity of Drone: 3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.200000000000001 seconds
X Velocity of Drone: 3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.300000000000001 seconds
X Velocity of Drone: 3
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.4 seconds
X Velocity of Drone: 2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.5 seconds
X Velocity of Drone: 2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.6 seconds
X Velocity of Drone: 2
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.699999999999999 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.799999999999999 seconds
[INFO] tello.py - 446 - Response back 100: 'ok'
[INFO] tello.py - 422 - Send command: 'land'
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.899999999999999 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 4.999999999999998 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 5.099999999999998 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 5.1999999999999975 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 5.299999999999997 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 5.399999999999997 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: 0
At 5.4999999999999964 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -1
At 5.599999999999996 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -1
At 5.699999999999996 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -1
At 5.799999999999995 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -3
At 5.899999999999995 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 5.999999999999995 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.099999999999994 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -5
At 6.199999999999994 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -5
At 6.299999999999994 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -5
At 6.399999999999993 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.499999999999993 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.5999999999999925 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.699999999999992 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.799999999999992 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.8999999999999915 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -4
At 6.999999999999991 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -3
At 7.099999999999991 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -3
At 7.19999999999999 seconds
X Velocity of Drone: 0
Y Velocity of Drone: 0
Z Velocity of Drone: -2
At 7.29999999999999 seconds
[INFO] tello.py - 446 - Response land: 'ok'

Jun 22 '21 23:06 VaeZarek

Hello I am getting a similar issue, I reduced the code to a very simple one and the issue is the same,

[INFO] tello.py - 446 - Response takeoff: 'ok' [INFO] tello.py - 455 - Send command (no response expected): 'rc 0 20 0 0' [INFO] tello.py - 422 - Send command: 'land' [WARNING] tello.py - 432 - Aborting command 'land'. Did not receive a response after 7 seconds [INFO] tello.py - 422 - Send command: 'land' [INFO] tello.py - 446 - Response land: 'ok'

There no response to the rc control command. any idea what is the issue?

Jul 10 '21 22:07 AbdullahJirjees

@AbdullahAmer86 I do not think the output you posted is related to this issue. This issue is about the speed reported by the Tello in state packets. Your output looks fine, the rc command does not send a response and is not expected to do though. Even though your land fails it succeeds on the second try, so that looks fine too.

@VaeZarek the incorrect speed is either a problem with your specific Tello or a bug in the Tello firmware. I will do some testing with one of my Tellos. If it shows the same incorrect behaviour there we should contact Ryze support, otherwise your Tello might be broken or something.

Jul 11 '21 10:07 M4GNV5

@M4GNV5 thank you for your comments, but I don't understand the sentence saying (no response expected)?

Jul 11 '21 10:07 AbdullahJirjees

The send_rc_control function uses send_command_without_return. This means the command is simply sent there but the Tello does not send a response back. The rc command is often used when e.g. tracking an object in the received video stream. When you for example want to follow a moving object you continuously calculate the required drone speed and send it e.g. 10 times a second using send_rc_control. It does not matter if one of 10 packets is lost as there are so many which constantly set the desired drone speed, thus there is no response (i.e. no ok or error).

Jul 11 '21 10:07 M4GNV5

@M4GNV5 Thanks a lot for you clear explanation. I am learning using your library and I am quite thankful for all the efforts.

Jul 13 '21 07:07 AbdullahJirjees

@VaeZarek i finally found some time and a Tello to try your code myself. In fact the velocity seems to be between 0 and 10. As i guessed when moving forward the drone tilts and the velocity is split into a larger X and smaller Y direction. For me the maximum speed is

At 1.0999999999999999 seconds
X Velocity of Drone: 7
Y Velocity of Drone: 3
Z Velocity of Drone: 0

Which would add up to a little bit less than 10 in the "forward" direction. With the speed set to 100cm/s i assume the speed is reported in dm/s just as you assumed.

So i assume everything works as intended? At least on my end, your drone does not seem to provide a Y velocity. What firmware are you running?

Nov 13 '21 16:11 M4GNV5

Hello, I don't currently have access to my drones for the time being, so I can't look up what firmware I updated them to. I did the latest update on the Tello Android app as of July 31st, 2021, and it looks like that would be 02.05.01.17

I hope this helps, I will check when I get access to the drones again. Thank You.

Nov 13 '21 17:11 VaeZarek

DJITelloPy DJITelloPy copied to clipboard

Tello not reporting correct X-Velocity

And implementing the velocity in all 3 directions with this code:

I get this output:

DJITelloPy
DJITelloPy copied to clipboard