[paulg78]

I recently bought a 2022 Nissan Leaf S. It's the basic model but supposedly has automatic emergency braking so I wanted to test it. I let my car roll down a hill toward a stack of boxes at about 15 mph with e-pedal disabled. It blasted right thru the boxes with no braking. Is this a valid test? Does it mean automatic emergency braking is not working?

 

[VStar650CL]

Not valid. Put tinfoil over the box. Radar only detects metal easily, although a strong signal can also detect stuff containing lots of water (like human tissue). Cardboard will give absolutely no bounce.

 

[remanaz]

I have seen others try using boxes to test emergency braking with similar results to your test. Being that sonar works by sending a signal out and then looking for it to bounce back and then using the time it took to return to estimate the distance to said object, I can see what Vstar is saying. My 22 Rogue seems good at detecting humans. It warned me yesterday that my neighbor was about to walk behind it. I already knew this but it let me see how far away it works with a human. I have not tested this moving forward though I would hope it would behave exactly the same.

Please do try the tin foil suggestion and report back. It makes sense that it should work.

 

[VStar650CL]

I have seen others try using boxes to test emergency braking with similar results to your test. Being that sonar works by sending a signal out and then looking for it to bounce back and then using the time it took to return to estimate the distance to said object, I can see what Vstar is saying. My 22 Rogue seems good at detecting humans. It warned me yesterday that my neighbor was about to walk behind it. I already knew this but it let me see how far away it works with a human. I have not tested this moving forward though I would hope it would behave exactly the same.

Please do try the tin foil suggestion and report back. It makes sense that it should work.

The forward AEB doesn't actually use sonar, only radar (and I think some integration with the cameras on some models). The RAB that saved your neighbor is exactly the opposite, it's all sonar plus the rear and side cams. Sonar gives coarser measurements, but at high power is much better at detecting stuff like cardboard. RAB should work with a simple box for a target, AEB won't.