There's a load of design work & simulations behind the setup..... <proprietary work>Hadn’t appreciated there were multiple sensors, but that makes sense. Are they opposing, as your image depicts?
Aside from cost implications, would a third sensor, each offset 120º help solve the detection issue? I’m presuming that’s where the problem lies.
5 emitters & 4 receivers - that's 10/8 in total (front/back) & gives a good detection area, cost, result.




