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Introducing the drogue

A project log for Robot drogue

A towed vehicle for aiding camera framing

lion-mclionheadlion mclionhead 09/02/2025 at 08:310 Comments

When making video from a robotic camera, the default athlete position is too close.

Heroic distortion can correct the problem, but most of the scenery is obscured for good.  The athlete needs a marker to stay far enough away.

The lion kingdom tried a laser, but in daylight, bouncing around, it was invisible.  A towed wheel vehicle was the leading contender.  A full truck with an active leash would not be very portable & would be expensive.

This was a deceptively hard problem.  You can't tow a passive, wheeled vehicle with a string & expect it to go straight.  It'll always oscillate & flip over.  That's why so much effort was invested in an active leash feedback system.  https://hackaday.io/project/188284-smart-leash

A castered front wheel could go reasonably straight, but not recover from flips.

Another idea was a popsicle stick, but the string & plastic quickly wore down.  It didn't track straight.  It definitely needed wheels to get the string high enough & reduce wear. 

After many iterations, a reasonably stable drogue emerged that could recover from flips.  A 1.3m string was a decent length.  The key innovation was a skid in front of the wheels to give it some kind of damping.  A skid behind the wheels was unstable.  The skid has limited life, but it's better than nothing.  

Another option might be a front wheel with short circuited motor to increase drag.  Then the only wear would be sideways.

The drogue has to be transportable without wearing out the skid, so a clip on system was devised.

The mane problem is it's invisible in the dark.  It really needs some kind of lighting, but night movies are the rarest.

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