1/5th scale rover

Hi all,

I started building a rover based on a 1/5th scale truck. Since most rovers discussed here are 1/8 or 1/10 trucks/crawlers I am wondering if you can provide any thoughts, ideas or recommendations about bigger rovers?

The rover is a 4WD truck with the motor placed in the middle. I’ll place the Pixhawk in the front and already moved the ESC (originally sitting in front of the motor) behind the motor to reduce interference. I am planning to use the power module for powering the Pixhawk.

I have two specific questions:

Where to place the power module? I.e., should I use a longer DF13 cable from the back of the rover to connect to the Pixhawk in the front or should I use a longer power cable and pace the power module closer to the Pixhawk? The wheelbase is 57cm.
Can the high torque 6V steering servo be powered from the Pixhawk or should I use the output of the ESC as a direct input to the servo (does this work at all?) and then only connect the signal and the ground to the Pixhawk (for both the ESC and the servo)?

Thanks a lot in advance!
Thorsten

@Thomas,

thanks! Yes I will! I had a look at different logs but I could not find anything obvious. So I will prepare a video along with a log file.

The main problem I have is that the behavior of the rover is not consistent: Sometimes it is running fine as it should and sometimes it stutters and doesn't want to start at all when Auto Mode is engaged. When playing around with CAM_TRIGG_DIST and the Start/Stop Switch it sometimes it proceeds normally, sometimes stutters or proceeds with a wheely.

Stuttering also occurs in manual mode. What parameters might influence this behavior (I am using EKF)?

The 4S battery should be fine but maybe I should use 6!?

Thanks in advance and kind regards,

Thorsten

Replies

T3

Thorsten June 13, 2014 at 6:12am

Hi all,

this is a screenshot of the first successful auto missions:

There seems to be a GPS glitch at the end of a mission and I am also still fighting some shutdowns which occur mostly at very low speeds. I will post some logs the next days.

Kind regards,

Thorsten
- T3
  
  Thorsten June 17, 2014 at 12:31pm
  
  @Thomas,
  
  thanks! Yes I will! I had a look at different logs but I could not find anything obvious. So I will prepare a video along with a log file.
  
  The main problem I have is that the behavior of the rover is not consistent: Sometimes it is running fine as it should and sometimes it stutters and doesn't want to start at all when Auto Mode is engaged. When playing around with CAM_TRIGG_DIST and the Start/Stop Switch it sometimes it proceeds normally, sometimes stutters or proceeds with a wheely.
  
  Stuttering also occurs in manual mode. What parameters might influence this behavior (I am using EKF)?
  
  The 4S battery should be fine but maybe I should use 6!?
  
  Thanks in advance and kind regards,
  
  Thorsten
- T3
  
  Thorsten June 17, 2014 at 2:20pm
  
  @Thomas,
  
  Yes, indeed I am having some "problems" with the ESC calibration. I tried to calibrate it several times but the behavior is different to what is described in the (copter) wiki. What is missing is the "two additional beeps to indicate that the maximum throttle has been captured." I just tried it again for several times.
  
  However, after pulling the transmitter’s throttle stick down to its minimum position the ESCs emits some melody (the wiki says long tone) - I assume that this is indicating that the minimum throttle has been captured!?
  
  You are right: I played with Cruise_Throttle and ended up at 50%. For now I let it drive at low Cruise_Speeds of 2-3m/s.
  
  I'll make some tests tomorrow...
  
  Thanks and kind regards,
  
  Thorsten
T3

Thorsten June 12, 2014 at 2:36am

Hi all,

I finally installed my new telemetry and two sonars following Thomas' guide. The CLI Sonartest looked perfect. However, I am not sure if my LV‑MaxSonar‑EZ1 will work for this purpose. Anyway, I am ready for tuning...

Regards,

Thorsten
T3

Thorsten June 10, 2014 at 11:54pm

Hi all,

attached some more pictures. Telemetry, however, is still missing...

Regards,

Thorsten
- T3
  
  Thorsten June 12, 2014 at 2:29am
  
  @Thomas,
  
  good point! I will put some roll cage on it at some point (when I decided what I really want to do with it :-) ). So far even with speeds higher than I am planning for Auto missions it was rock-solid. It is pretty heavy...
  
  Kind regards,
  
  Thorsten
- T3
  
  Thorsten June 12, 2014 at 2:38am
  
  Thanks!
AKRCGUY June 9, 2014 at 10:59am

Saw these at AUVSI this year. They were priced at like $5000.00 for the car itself not including the gimbal or video Tx.
This reply was deleted.
- T3
  
  Thorsten June 9, 2014 at 7:26am
  
  @BTE, yes good to see another 1/5 scale build (I have a HPI 5SC). Today, I installed the firmware and did some initial calibrations. I will also update with more pics soon.
  
  No idea about breaking so far. The ESC seems to be capable of braking. But not sure if this is supported by the firmware.
- T3
  
  Thorsten June 9, 2014 at 2:30pm
  
  @Thomas, perfect! I already installed the latest beta available in Mission Planner.
  
  I hope to start some first tests tomorrow. But currently I have a first problem: although the status report in Mission Planner shows output to ch1 and ch2 the rover does not drive and steer. I only had little time today so I will have a closer look tomorrow. Maybe I have to adjust the RCMAP settings.
  
  Thanks and best regards,
  
  Thorsten

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This reply was deleted.

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