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Search Area for Lost Aircraft plotted on Planning Software #896

Closed dcwalmsley closed 10 years ago

dcwalmsley commented 10 years ago

I wanted to post this for discussion and possible implementation. I for one can feel the stress and sorrow for a lost copter or airplane. I had a few close calls and after reading Quadzimido's "Joy, Excitement, Flight, Loss, ..." post, I decided to draft up what I think could work in any mission planner once coded.

Ok here goes my thoughts and ideas and by no means does this cover everything but it's a good start. Please feel free to read, digest, and provide inputs as I feel this is a necessary feature in helping pilots locate downed aircrafts.

Is there a way to build into the Mission Planner software a Rescue Line/Triangular Search Area for lost copters/airplanes?

  1. Assumptions a. You have 2-way telemetry activated and recording in Mission Planner (MP). b. You programmed correct battery mAh settings into MP. c. Onboard sensors and IMU is functioning normally.
  2. Line/Triangular Search Area a. Needs to automatically calculate the following
    1. The winds direction and velocity
    2. Last known position
    3. Course of aircraft
    4. Distance traveled based on a. Ground speed at time of loss b. Battery life remaining at time of loss

  3. Other Factors a. Flight Mode. What was the aircraft set to when it flew away? Autopilot or Operator Inputs b. Aircraft Altitude

    Note: Not sure how to address airplanes and glide slope issues, or how search areas could be affected by different flight modes. Best leave this open for discussion with other folks.

  4. Dead-Reckoning.
    a. Normally this is a simple process of calculating position based on a point (Lat-Long), time, course, and speed and plots position as time progresses. This is a simple mathematic equation but all of this isn’t necessarily needed. What's needed is a line/triangular search area that shows minimum and maximum flight range based on last known position and battery life remaining, and ground speed. This established the beginning and end points. The side of the triangle would be based on wind direction and velocity referred to as steering winds.
  5. Glide Slope a. With helicopters the glide slope isn’t really a factor as it will normally just fall out of the sky whereas airplanes glide from its aerodynamic wings for the most part. Airplanes could be pushed or steered to a different heading if there is no onboard guidance controls (ie, lost power).

Here are some thoughts on how to possibly incorporate this idea into the Mission Planner.

         Capacity (Amp-hours) / Discharge rate (Amps) = Run Time (hours)

         Example.  Fully charge battery at 5 Ah (5000 mAh) / 25C = .2 hrs or 12 minutes

Note: This is basic and does not indicate true flight time for numerous reasons such as battery health, battery life remaining, pilot inputs, aircraft weight, onboard power demands, winds, etc.

Using this as a means to measure voltage, I recommend sampling battery voltage every 15 seconds so as to not over task the processor time. Take current voltage reading and subtract that from maximum and this provides voltage remaining.

                            Example:  2.5 Ah / 25C = .1 hrs or 6 minutes remaining.

  1. Position Calculation a. Plot Position at time Aircraft last reported position. Calculate distance remaining based on last known ground speed x time remaining of battery life.

     Time remaining (decimal) X aircraft speed = Distance

 Example:
                  .1 X 30 mph = 3 miles 
                  .1 X 48.5 kmh = 4.85 kilometers
                  .1 x 26.07 kts = 2.6 nautical miles
  2. Calculate Winds a. Head winds – Subtract aircraft speed from head wind speed. b. Tail winds – Add aircraft speed from tail wind speed. c. Cross winds – not really a major factor for speed of aircraft, therefore recommend null. However, drift angle and distance of search area though will have greater affect in search area.

  3. Steering Winds

      Tool to calculate Wind Components - http://www.aeroplanner.com/calculators/avcalcdrift.cfm?wdd=270&...

    a. Cross winds will affect aircraft normal path of travel.
    Recommend using 90 degree offset (Perpendicular) to normal travel as a worst case scenario and will make calculations far easier to incorporate. 

            Example:Winds from the west (270) at 10 mph, aircraft heading 360, cross winds value -10 degrees heading.

          The Max Drift Navigation Technique - http://www.jenxs.co.uk/Navfiles/Maxdrft.html. This is informative and could be used in calculating drift angles. I’m not fluent with Trigonometry so I will leave this to the 20 pound brains to work through.
  4. Plotting on a Mission Planner Map a. Once the measurements are taken; Position at time signal was lost, Heading of aircraft, Speed of aircraft, Time remaining on battery life, Wind components, a line/triangle will be displayed on map to indicating best possible areas to search for downed aircraft.

example1 example2 example3

rmackay9 commented 10 years ago

Thanks for the detailed thoughts and effort put into this enhancement reqest. I suspect that it's better to discuss this on drones-discuss though before raising it as an enhancement request.

I'm going to close this issue, because I think this request is more of a ground station request which would mean it belongs in the mission planner issues list. https://github.com/diydrones/MissionPlanner

I don't think there's much we can do in the flight control software.

dcwalmsley commented 10 years ago

What do you mean by drones-discuss. ?

Doug W.

On March 12, 2014 11:03:17 PM Randy Mackay notifications@github.com wrote:

Thanks for the detailed thoughts and effort put into this enhancement reqest. I suspect that it's better to discuss this on drones-discuss though before raising it as an enhancement request.

I'm going to close this issue, because I think this request is more of a ground station request which would mean it belongs in the mission planner issues list. https://github.com/diydrones/MissionPlanner

I don't think there's much we can do in the flight control software.

Reply to this email directly or view it on GitHub: https://github.com/diydrones/ardupilot/issues/896#issuecomment-37496056

rmackay9 commented 10 years ago

Doug, There's an email discussion group called drones-discuss@gogglegroups.com. Feel free to post there and it'll go out to all the ArduCopter/ArduPlane dev and a bunch of other people.

dcwalmsley commented 10 years ago

Ok. I will send my thoughts to that address.

Thank you.

Doug W.

On March 13, 2014 10:47:30 AM Randy Mackay notifications@github.com wrote:

Doug, There's an email discussion group called drones-discuss@gogglegroups.com.
Feel free to post there and it'll go out to all the ArduCopter/ArduPlane dev and a bunch of other people.

Reply to this email directly or view it on GitHub: https://github.com/diydrones/ardupilot/issues/896#issuecomment-37541191