Autopilot

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ROVER3D
Posts: 128
Joined: Nov 9th, 2012, 7:45 pm
Location: Wuppertal, Germany

Autopilot

Post by ROVER3D »

Hey,

one of the last steps of the ROV-CONTROL Software development is the auto-pilot.

here are two ways you can control a ROV:
  • The first way is to control motors directly by pushing the joystick to one direction (dive). The autopilot is only used for "hold" depth/postion.
    For example: If you turn left, the ROV will turn left until you set the joystick back.

    The second way is to only set changes of position or depth by the joystick. By pushing the Joystick the value of this axis will change (depth) and the auto-pilot fully controls all motors itself to set the new entered depth.
    For example: If you turn (the joystick) left, you only change the value of the (compass)direction, and the autopilot will turn the rov until the direction is reached
.

Iam very interested in how you want to control your ROV (in future)?
rossrov
Posts: 383
Joined: Feb 28th, 2013, 5:01 pm
Location: Australia

Re: Autopilot

Post by rossrov »

Hi ROVER3D. Heading-hold and depth-hold are what I want to implement in what I'm building at the moment. The thruster configuration is similar to yours, so the ROV will be able to automatically maintain heading and still move around without doing too much mixing of the controls.
RangeRov
Posts: 1
Joined: Dec 17th, 2013, 1:22 pm

Re: Autopilot

Post by RangeRov »

When will it be available to purchase ? , I put my project on hold waiting for your design . Nice work and design. Thanks
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ROVER3D
Posts: 128
Joined: Nov 9th, 2012, 7:45 pm
Location: Wuppertal, Germany

Re: Autopilot

Post by ROVER3D »

Hi ROVER3D. Heading-hold and depth-hold are what I want to implement in what I'm building at the moment.
Hi rossrov, how you control autoheading and depth? Push a button and the rov hold his depth? How you change this (automatic headed) depth?

@RangeROV
Shop is online: http://www.rov-control.com/shop/en
NCUWI
Posts: 58
Joined: Nov 25th, 2011, 3:27 am

Re: Autopilot

Post by NCUWI »

@ROVER3D - "Heading Hold" usually holds a compass course while you manually push the joystick forward to control the speed. So if you set the compass heading to "180 degrees", for example, and push the joystick forward, the ROV will hold course 180 regardless of whether the ROV is traveling at 3 knots or 0. "Depth Hold" works in a similar fashion: It automatically keeps the ROV at a specified depth (usually based on water pressure) regardless if the ROV is traveling fast or stopped.

The problem I've encountered with some control systems is that they do not properly compensate for speed changes. They often work perfectly while the ROV is stopped, but zig-zag erratically when the ROV is traveling at maximum speed.
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ROVER3D
Posts: 128
Joined: Nov 9th, 2012, 7:45 pm
Location: Wuppertal, Germany

Re: Autopilot

Post by ROVER3D »

Hi, thx for your answer, but i mean it different.

if you drive a course 180° with auto heading and now move/turn right (your joystick which turn the rov), how the will the auto heading react?
  • 1. deactivate itself an need to activate again (set new course)?
  • 2. will turn back the rov automatic to last course set (180°)?
  • 3. wait until a new there is no change at the compass-value anymore and take that value as new course?
The ROV-CONTROL autopilot will control the rov like a plane. If active, you only change the value(180°) (by moving your configured joystick-axis) to set new course and the autopilot controls the turn automatic by holding depth/position, like:
  • 4. you only change the course/depth/position (value) by your joystick and the autopilot controls the rov to the new set course/depth/position.
Also there is no need to push the joystick 10% forward all the time. You only push it to change the auto-speed value. Set to 10% and now you can take off your hands - the autopilot holds this speed until you change it.

My question was: Do you think this is a nice feature for relaxed roving or do you want to control it manually...maybe with simple autoheading/depth while no joystick-input?
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ROVER3D
Posts: 128
Joined: Nov 9th, 2012, 7:45 pm
Location: Wuppertal, Germany

Re: Autopilot

Post by ROVER3D »

The problem I've encountered with some control systems is that they do not properly compensate for speed changes. They often work perfectly while the ROV is stopped, but zig-zag erratically when the ROV is traveling at maximum speed.
i guess you mean control systems for quadcopters or else which needs a high sampling-rate to compensate (fast) movements. the rov needs a different configuration of the PIDs. 8-)
rossrov
Posts: 383
Joined: Feb 28th, 2013, 5:01 pm
Location: Australia

Re: Autopilot

Post by rossrov »

ROVER3D, how the heading and depth hold depends on the user interface. For hardware user controls, yes, a button can be held or toggled on/off to lock to the present actual heading. The joystick can then move the ROV sideways instead of turning it. The depth variable can be incremented or decremented by using the joystick (or the normal manual dive/surface control), to pre-select the depth while holding in a button. The button is released and the ROV descends or ascends to that depth. That's the basic concept. In the case of the ROV that you have posted pictures of, I understand that you also like to be able to aim the ROV up or down, as you have a fixed, not tilting camera, and also to be able to speed-dive. The same concept as the heading-hold could be used here, just using an inclinometer (optionally assisted with a gyro) instead of the compass.
Last edited by rossrov on Jul 26th, 2015, 6:03 pm, edited 1 time in total.
NCUWI
Posts: 58
Joined: Nov 25th, 2011, 3:27 am

Re: Autopilot

Post by NCUWI »

ROVER3D wrote:
The problem I've encountered with some control systems is that they do not properly compensate for speed changes. They often work perfectly while the ROV is stopped, but zig-zag erratically when the ROV is traveling at maximum speed.
i guess you mean control systems for quadcopters or else which needs a high sampling-rate to compensate (fast) movements. the rov needs a different configuration of the PIDs. 8-)
I don't know about quad-copters, never flown one. But have flown many ROVs and ships. ;) Yes, I have experienced this zig-zagging issue with ROVs at their maximum thruster and no, it's not something I would want to happen in my build. ;)
NCUWI
Posts: 58
Joined: Nov 25th, 2011, 3:27 am

Re: Autopilot

Post by NCUWI »

ROVER3D wrote:Hi, thx for your answer, but i mean it different.

if you drive a course 180° with auto heading and now move/turn right (your joystick which turn the rov), how the will the auto heading react?
  • 1. deactivate itself an need to activate again (set new course)?
  • 2. will turn back the rov automatic to last course set (180°)?
  • 3. wait until a new there is no change at the compass-value anymore and take that value as new course?
The ROV-CONTROL autopilot will control the rov like a plane. If active, you only change the value(180°) (by moving your configured joystick-axis) to set new course and the autopilot controls the turn automatic by holding depth/position, like:
  • 4. you only change the course/depth/position (value) by your joystick and the autopilot controls the rov to the new set course/depth/position.
Also there is no need to push the joystick 10% forward all the time. You only push it to change the auto-speed value. Set to 10% and now you can take off your hands - the autopilot holds this speed until you change it.

My question was: Do you think this is a nice feature for relaxed roving or do you want to control it manually...maybe with simple autoheading/depth while no joystick-input?
I think giving the operator control so he/she can choose which combination they want is the best option. I would like to be able to selectively turn on/off any combination of auto head, auto speed and auto depth. ideally I would like to have an on/off switch for each and a visual indicator on screen to let me know what the settings are.

How to set / adjust the heading for autohead while flying varies from ROV to ROV. I prefer option #2 of those you listed, ideally selected with a button on the joystick. That way I can toggle autohead on or off at will while flying or trying to hold position.
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