Throttle response no longer proportional?

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APailthorp
Posts: 2
Joined: Tue Nov 19, 2013 5:08 am

Throttle response no longer proportional?

Post by APailthorp »

My tuning post hasn't gotten any response, and now I've had a set back. I've been trying out different PID values, but now for some reason the throttle response has gone basically so from armed idle, I get near full throttle. As soon as I try to apply even a little power, the quad takes off like a scalded cat and I have to chop the throttle or risk destruction.

Bypassing the Multiwii confirms that the radio and ESCs are working correctly, and using the EZ-GUI config software to see radio inputs shows that the radio is connected to the Multiwii correctly as before (didn't change it anyhow).

I guess I'm getting ready to completely reflash the Multiwii software, which will get me 2.3 at least (presently 2.2) but I'm stumped as to how everything could seem to be working as before (functional, if not PID tuned) and then all of a sudden this throttle response issue. ESC to FC calibration? It's been a while since I flashed the original 2.2 code, so that will an exercise. Any hints as to what may have happened greatly appreciated.

Alexinparis
Posts: 1630
Joined: Wed Jan 19, 2011 9:07 pm

Re: Throttle response no longer proportional?

Post by Alexinparis »

you could try to reduce the LPF of your gyro in config.h
#define ITG3200_LPF_42HZ
or #define MPU6050_LPF_42HZ
depending on the one you have

subaru4wd
Posts: 316
Joined: Sat Dec 08, 2012 2:16 am

Re: Throttle response no longer proportional?

Post by subaru4wd »

Typically the line in config.h that controls the "idle" speed of the motors can be found here:

Code: Select all

/****************************    Motor minthrottle    *******************************/
  /* Set the minimum throttle command sent to the ESC (Electronic Speed Controller)
     This is the minimum value that allow motors to run at a idle speed  */
  //#define MINTHROTTLE 1300 // for Turnigy Plush ESCs 10A
  //#define MINTHROTTLE 1120 // for Super Simple ESCs 10A
  //#define MINTHROTTLE 1220
  //#define MINTHROTTLE 1150
  #define MINTHROTTLE 1180 // for RCTimer ESCs 30A

SEE: http://www.multiwii.com/wiki/?title=Con ... m_throttle

Even though the comment says to use 1300 for Turnigy Plush, this will be too high. Try something closer to 1000 and your motors will not spool up so quick off-idle.

This can only be controlled in the config.h file, and not through the GUI. So Im not sure how messing with PID's would have changed this. But since you are planning on updating to v2.3 anyhow, pay close attention to this line in config.h It should take care of your problem.

And as far as the poor flight performance in your other thread.... drop the P gain for LEVEL down from 9.0 to 7.0 and try again.

odem
Posts: 14
Joined: Wed Sep 11, 2013 2:07 pm

Re: Throttle response no longer proportional?

Post by odem »

Change the MINTHROTTLE until the props start to spin when armed, then scale back if you don't want this behaviour.

What does the GUI show? Have you played with the EXPO settings?

sully16
Posts: 2
Joined: Mon Dec 09, 2013 5:08 am

Re: Throttle response no longer proportional?

Post by sully16 »

Hi check page one Multiwii Pro 2.2 - Motors dont move until 1500+ this could be the problem

MikeF74
Posts: 16
Joined: Fri Dec 13, 2013 5:38 pm

Re: Throttle response no longer proportional?

Post by MikeF74 »

APailthorp,

I am having a similar issue. Did any of these suggestions work for you?

odem
Posts: 14
Joined: Wed Sep 11, 2013 2:07 pm

Re: Throttle response no longer proportional?

Post by odem »

MikeF74 wrote:APailthorp,

I am having a similar issue. Did any of these suggestions work for you?


Have you calibrated the ESC's?

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