DIY Safety Device to help prevent being rear ended

[bigbadbrucie]

Hmmmm, another thread that appears to have gone south!

[TomG]

I like this forum partly because it often gets me thinking about things I had not previously considered. I like the idea of making my spyder more visible to the radar built into many autos today, but not the idea of giving up storage space on my 2016 F3 L.

The following links are to products now available or being developed.

https://www.alliedelec.com/sensor-ac...%20Engineering

https://www.cycleworld.com/story/bik...ar-reflectors/

[Frostbyte]

I worked radar in the USAF and it's not the strength of a single return that matters, it's the cumulative signal return that triggers the AEB. So, I'm wondering if a fixed array system would also work. Here is my idea...Instead of a single large TriHedral, why not a "Sheet" of small ones? Imagine a surface covered with an array of small ones, like the surface of a rectangular reflector? I could knock one out on my mill using a 45 degree chamfer bit in some 1/4" or thicker Aluminum stock, hit it with some polishing compound, and then mount it below the license plate on my RT. My wife's Mitsubishi has the emergency braking system, so I could test it out using her car.

[IdahoMtnSpyder]

I worked radar in the USAF and it's not the strength of a single return that matters, it's the cumulative signal return that triggers the AEB. So, I'm wondering if a fixed array system would also work. Here is my idea...Instead of a single large TriHedral, why not a "Sheet" of small ones? Imagine a surface covered with an array of small ones, like the surface of a rectangular reflector?

That's what I was thinking. It wouldn't even have to be rigid since a tertrahedron will reflect straight back regardless of it's angle. That is to a certain degree likely maybe up to 30 to 45° from perpendicular of the bean hitting it. If I could find such an array about 1/2" to 1" thick a piece of it would fit quite nicely in the rear wall of the trunk below the latch.

I think you do want to as much as possible concentrate the return beam in a tight pattern. That is because the sender/receiver of the car's AEB radar is only about 3/4" to 1" diameter. On my 2016 Maxima there are only two of them in the front.

As someone else commented above there is a significant limitation when it comes to detecting motorcycles. Here's a quote from my 2016 Nissan Maxima Owner's Manual.

(Illustration A) The predictive forward collision warning system does not function when a vehicle ahead is a narrow vehicle, such as a motorcycle.

Now, if the receiver is looking for a wide beam to gauge the existence of an obstacle ahead, regardless of strength, as you're saying, then a single reflector won't help much. So even in spite of a good reflector we may be screwed.

[UtahPete]

Here is a great video from the Goldwing Docs forum administrator. More and more cars on the road have Automatic Emergency Braking (AEB) to avoid having the driver rear end the vehicle in front of him. The problem is motorcycles are not as readily visible to the AEB radar as is a car. WingAdmin shows how to make a simple radar reflector that greatly enhances the return radar beam the car's AEB utilizes.



I haven't figured out yet how the best way would be to put one on an RT but I'll be working on it. If someone comes up with a solution please post it. We need to help keep each other safe out there!

Here's a link to the Goldwing Docs forum posting. https://goldwingdocs.com/forum/viewt...p?f=10&t=63779

That's brilliant - and cheap and easy.

[UtahPete]

I like this forum partly because it often gets me thinking about things I had not previously considered. I like the idea of making my spyder more visible to the radar built into many autos today, but not the idea of giving up storage space on my 2016 F3 L.

The following links are to products now available or being developed.

https://www.alliedelec.com/sensor-ac...%20Engineering

https://www.cycleworld.com/story/bik...ar-reflectors/

Excellent resource. BMW is proposing using several small reflectors spread apart on the bike to present a larger apparent target. The Banner engineering products look pretty good for that purpose, e.g......

https://www.alliedelec.com/product/b...x84a/70167676/

[UtahPete]

I worked radar in the USAF and it's not the strength of a single return that matters, it's the cumulative signal return that triggers the AEB. So, I'm wondering if a fixed array system would also work. Here is my idea...Instead of a single large TriHedral, why not a "Sheet" of small ones? Imagine a surface covered with an array of small ones, like the surface of a rectangular reflector? I could knock one out on my mill using a 45 degree chamfer bit in some 1/4" or thicker Aluminum stock, hit it with some polishing compound, and then mount it below the license plate on my RT. My wife's Mitsubishi has the emergency braking system, so I could test it out using her car.

How about this stuff? https://www.alliedelec.com/product/b...-100/70167267/

[EdMat]

How about this stuff? https://www.alliedelec.com/product/b...-100/70167267/

Don't most targets like this rely on a solid backing sheet and the angles are all clear?

[IdahoMtnSpyder]

How about this stuff? https://www.alliedelec.com/product/b...-100/70167267/

I looked at that last night. What isn't clear right off the bat is whether the reflector is aluminum thick enough to reflect radar. I'll do some more looking later today. If those do reflect radar they just might be the ticket!

[Frostbyte]

The thickness doesn't matter as it is a "First Surface" device. I'm looking at doing one wide and tall enough to cover the surface between the rear tire and "Mud Flap" on my 19 RT. My plan is to mill a fixed array master, pull a silicone mold and then cast one using 5/0 aluminum powder in water thin epoxy. That way the reflective angles will be facing the correct way. (The milled master comes out as a negative of what is needed)...Yes, I do prototyping on the side, and I see this as a fun adventure for an old inventor like me.

[UtahPete]

I looked at that last night. What isn't clear right off the bat is whether the reflector is aluminum thick enough to reflect radar. I'll do some more looking later today. If those do reflect radar they just might be the ticket!

Maybe use the tape version mounted to a sheet of aluminum?

[IdahoMtnSpyder]

Maybe use the tape version mounted to a sheet of aluminum?

That wouldn't work. The aluminum has to be the corner reflector so the beam will bounce off one, two, or all three, surfaces to be directed straight back to the sender. The principle of the reflector is as long all three surfaces can be hit by the incoming beam, regardless of the reflector's three dimension orientation, the beam will reflect from one surface to the next, and probably to the third surface. The sum of the angles of the reflection on all three surfaces is 180°, i.e., the beam folds back on itself and returns along the same line as the sent beam.

[UtahPete]

That wouldn't work. The aluminum has to be the corner reflector so the beam will bounce off one, two, or all three, surfaces to be directed straight back to the sender. The principle of the reflector is as long all three surfaces can be hit by the incoming beam, regardless of the reflector's three dimension orientation, the beam will reflect from one surface to the next, and probably to the third surface. The sum of the angles of the reflection on all three surfaces is 180°, i.e., the beam folds back on itself and returns along the same line as the sent beam.

Okay, that's what I thought. I'm not actually sure how the tape works anyway given the lack of depth to form a prism.

[UtahPete]

The thickness doesn't matter as it is a "First Surface" device. I'm looking at doing one wide and tall enough to cover the surface between the rear tire and "Mud Flap" on my 19 RT. My plan is to mill a fixed array master, pull a silicone mold and then cast one using 5/0 aluminum powder in water thin epoxy. That way the reflective angles will be facing the correct way. (The milled master comes out as a negative of what is needed)...Yes, I do prototyping on the side, and I see this as a fun adventure for an old inventor like me.

I wonder if one could be created using a 3-D printer using some kind of metallic material? I have no experience with these things; just brainstorming.

[IdahoMtnSpyder]

I wonder if one could be created using a 3-D printer using some kind of metallic material? I have no experience with these things; just brainstorming.

The only issue would be if the surfaces would have a smooth mirror finish. It could be printed with the usual material and then aluminum spray painted, if aluminum spray paint is good enough to reflect the radar beam.