Turn in place on manual mode with two motors

Posted by jean-luc on January 30, 2015 at 1:27pm

Hi all,

I just equiped one medium inflatable boat (3 meters lenght) with pixhawk and APM2.7.

The boat have two electrics motors and a capacity to turn in place with the RC (vtail mixage) connecting directly on the motors controller. if trottle stick at zero, steering stick completly right or left, one motor go fast forward and the other motor go fast backward.

Now, with the pixhawk module, when i want to turn in manual mode (trottle stick at zero, steering stick completly right or left), one motor go slowly forward and one motor go slowly backward.

If i move the trottle stick for more speed, the backward motor stop and only the forward motor go fast, not good for a real turn in place!

Is there one parameter for change that? i can't found.

Other think, in my advanced setting, i don't found the setting for serial port 4 and 5 configuration. Only the setting for the1, 2 and 3 serial port, it is normal on 2.47 apmrover firmware?

Thanks and regards.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

  • jean-luc February 2, 2015 at 9:43am
    Thomas,

    I have a Pixhawk, not an APM.
    And all my sticks are at 1500 on middle position.

    Regards,
    • jean-luc February 4, 2015 at 1:09pm

      Thanks a lot Thomas, yes it's the latest version V2.47.

      So i try to go on sea tomorow for the first test with the autopilot. (depending of the weather...)

      Another question:  the loiter or stabilize mode was effective or not on the apmrover? do you think we can use these mode like a DP (dynamic positioning) mode on real vessel?

      Regards,

  • This reply was deleted.
    • jean-luc January 30, 2015 at 11:55pm

      Thomas,
      I make a serial cable to connect a second C-NAV GPS to the common serial plug 4&5 on pixhawk (i just use the port 4 RX/TX and GND) and when i want configure the setting for this port, i don't find this port in my firmware :/

      For the RC controls (DC16 jeti), i use the trottle stick for trottle and aileron stick for Roll, connect these RC output on the channel 1 and 3 of the PPM encoder module. Just cheat a little to connect the ppm module channel 3 on the RC output receiver channel 2.
      When i make the calibration, the roll and trottle bar are moving perfectly to 930 / 1990 and around 1500 for middle position.

      So, this monday i check again to find where is this serial 4 parameter.

      Have a good week-end.

    • jean-luc February 2, 2015 at 8:58am

      Hi Thomas,

      I make a test with all joysticks and assignements possible, the result is alway the same:

      -if i place the trottle on middle position (neutral) and i turn the steering at full right or left the differential motors speed in only at 20% of capacity.

      -if i move the trottle full speed in same time with the steering full right or left, only one motor go full speed, the other motor stop or go very slowly in same direction.

      Normaly, without pixhawks module, if i place the trottle on middle position (neutral) and i turn the steering at full right or left the differential motors speed is at full capacity.

      So, i confirm my other problem, i don't have any serial port 4 and 5 parameters in my full parameters list. (see my list attached)

      Thanks a lot if you have another idea.

      regards,

      serial.JPG

      https://storage.ning.com/topology/rest/1.0/file/get/3702776626?profile=original
    • Developer
      Grant Morphett > jean-luc February 5, 2015 at 7:04pm

      Can you please post your logs.  tlog and flashlog's (.bin).  I'll have a look through them once posted.

      Thanks, Grant

    • jean-luc > Grant Morphett February 25, 2015 at 8:45am

      Hi Grant,

      Sorry for the response delay.

      I make the first test on water and after somes settings modifications, the boat comming to navigate fine.

      During the test i have a "bad compas healt" msg comming with a permanent lag, but i thinks the problem is comming from my ESC powering pinout.

      Now, i'm using the opto-isolated pinout of the ESC and powering the pixhawk only with his power module and USB port and it seems working good on these conditions.

      3702877136?profile=original3702877041?profile=original

      For my steering problem, please find attached the files requiered.

      Best regards

      Jean-luc

      2015-02-18 10-29-32.tlog

      2015-02-18 10-40-34.bin

    • jean-luc > jean-luc January 31, 2015 at 12:15am

      Other think, i use the pixhawk output ch1 and 3 for left and right motor.

      So on the apmrover sticker providing with the pixhawk, output channel assignement was completly different, why?

      regards,

  • This reply was deleted.
    • jean-luc January 30, 2015 at 3:11pm

      Hi Thomas,

      Sure, i 'm not using the mixage for the configuration with pixhawk module and i use the ardurover APM with the setting skid Steering out enable.

      the differential steering works, but the pb is just that the motor go slowly when i turn the steering stick on maximum, same pb of this reply

      "

      Reply by Sebastian Schürmann on September 10, 2014 at 5:21am

      I have setup my transmitter to put out  ca. 1100 to 1900us on all channels. I tried to set it to its default values of 990 to 2010, but that did not change anything. It goes full speed forward and backward, but pivot is only half throttle. This is also the case with full forward and full left/right stick. One side goes full speed, but the other only goes to about half speed instead of stopping.

      As it is now, it does not equal independent dual stick control of both sides."

      Regards,

  • Developer
    Grant Morphett January 30, 2015 at 1:39pm

    I think you want the skid steering setup.  Search for skid on these pages

    http://rover.ardupilot.com/wiki/setup/

    http://rover.ardupilot.com/wiki/parameter-meanings-and-tuning/

    This discussion also has some good information

    http://diydrones.com/group/ardurover-user-group/forum/topics/tank-r...

    Thanks, Grant

    • jean-luc > Grant Morphett January 30, 2015 at 2:40pm

      Thanks Grant for your reply.

      Yes, good information on the discussion but apparently, there is no simple way to resolve this problem.

This reply was deleted.