Servers by jDrones

Both Throttle and steering affects on skid_steer_in parameter set

(Rahul Sharma) #1

I usually see there are two parameters-
skid_steer_out and skid_steer_in. I am using rover3.2.0 with BBBlue and i can see only one skid_steer_in parameter. Is skid_steer_out not implemented now?
Also if i set skid_steer_in to 1 then if i move throttle stick then steering values are also changed similarly with the steering stick. I am not able to understand the mapping.
Can anyone suggest?

(Sebastian Schürmann) #2

I just setup a rover with 3.2.0 and the skidsteer_out parameter is there. If you have a normal rc transmitter, you will have to set skidsteer_in 0 and skidsteer_out 1.

(Rahul Sharma) #3

Thanks for the reply.
That’s strange to me as i couldn’t find that parameter.

Can you just verify my steps for building from the link(

  1. cd ardupilot
    2)git checkout ArduPlane-beta
    3)git submodule update --init --recursive
    4)./waf configure --board=blue

Am i missing something for correct version?

(Sebastian Schürmann) #4

I am sorry, my fault. It seems I accidentally started an older version of Ardurover on my Navio2. You are indeed right,skidsteer out is gone.

(Sebastian Schürmann) #5

With 3.2 you setup skid steering with the new servoX_function parameters. Set the channels were the motors are connected to 73 and 74.

(Rahul Sharma) #6

Oh yes.
I did that.
That was working fine when i have skid_steer 0 also the output of steer and throttle values are smooth.
But on skid_steer 1, both values seems depending on each other. Both values changes even if i move one stick.
That’s what i wanted to know.

(Sebastian Schürmann) #7

Skidsteer_in is for a controller where both left and right stick are spring loaded. So the left stick forward and back, controls the left track/wheels and the right stick controls the right track/wheels.

(Rahul Sharma) #8

Ok that’s great.
It cleared my doubt.
Can you also tell me that for waypoint navigation is it necessary to have skid_steer_in 1?
I am having a bit problem for waypoint navigation.
As soon i shift to Auto mode with some waypoints, it just starts rolling and an unexpected motion.

(Sebastian Schürmann) #9

Skidsteer_in has nothing to do with Auto modes. It is just there to tell Ardurover what input signals to expect.
Auto mode should not be affected by this setting.

(Rahul Sharma) #10

Also can i use the same spring loaded stick for both operations?
Such as if i swipe the RC input channel 3<->2, then it must work for throttling in up-down motion of stick(that controls the right track/wheel) and steering in left-right motion of same stick(that controls the left track/wheel).
Is it ok?

(Sebastian Schürmann) #11

You can use whatever stick combination you prefer. Of course some possible combinations are not very practical/intuitive. I use the right stick of my transmitter (mode 2) only. Pitch for forward/back and what would be aileron/roll to steer left and right.

(Rahul Sharma) #12

That means may be some other issues are there as because i did the same and both the readings (steering and throttle) values are changing with the stick motion in either of the axis.

(Sebastian Schürmann) #13

You should be more clear if you are talking about RC_IN or RC_OUT. If RC_IN is changing on both channels with only one input axis moving, there might be some kind of mixer active in your tx.
If both RC_OUT channels are changing with only one input axis, then this is exactly how it should be.
This is the way skid steer output works.

(Rahul Sharma) #14

Thanks for the clarification.
I was checking the throttle_scaled and steering_scaled values in AP_MotorUGV.cpp file in APMrover2 folder for that.

(Rahul Sharma) #15

Can you tell me if you are able to see MAV_FRAME_LOCAL_NED parameter in your parameter list?
I am using GPS denied system and not able to use that

(Sebastian Schürmann) #16

I think, that parameter is only used by PX4 flightstack, not Ardupilot.

(Rahul Sharma) #17

Thanks for the reply.