Filtered speed

Q&A forumCategory: QuestionsFiltered speed
Case Mx100 asked 3 weeks ago

Hi,
I have a problem with a leg control that needs a stable speed. The speed transmitted by the Ardusimple module continuously ranges between 0.1-0.5 km / h, however the tractor remains at a stable speed, same engine speed, same travel speed.
Is there a way to filter the speed that the f9p transmits so that it remains stable?
Thanks in advance

Ardusimple Staff replied 3 weeks ago

Hi Case, in standalone mode, velocity accuracy is in the range of 0.2-0.3 km/h. This means:
– When vehicle is stopped, error is huge.
– At high speed, error is very small.
This is why at low speeds usually people say that GPS speed is not realiable. The only way to improve this is use better antenna or do better installation.

In RTK mode, speed error is much lower and you should not see this problem so much.

Finally, there’s a configuration called “low speed filter” in u-blox receiver, which artificially filters speed at low speeds, might do the job for you.

2 Answers
Case Mx100 answered 3 weeks ago

Hi, thank you for your answer.
The speed variation that I am commenting on occurs in RTK mode, the installation is with a Survey Ardusimple antenna and without any extension to the module.
The speed variation occurs at about 6 km / h from the vehicle and the speed on the screen varies between 5.8 km / h and 6.3 km / h.
I will try to change the antenna cable in addition to activating the low speed filter

Case Mx100 replied 3 weeks ago

Can I try pedestrian mode?

Ardusimple Staff replied 3 weeks ago

Make sure signals are good and that you are in permanent FIXED mode. If the system is mounted on a vehicle, “automotive” might be the best option.

Case Mx100 answered 3 weeks ago

What kind of low speed filter do you recommend?  3.1.7.3.1 Speed (3D) low-pass filter ,  3.1.7.3.2 Course over ground low-pass filter ,  3.1.7.3.3 Low-speed course over ground filter

Ardusimple Staff replied 3 weeks ago

Unfortunately we don’t have experience with this parameter… sorry.