Carhop™ – V2V Communication

Triggered Directional Vehicle to Vehicle Signaling

by Intervening Vehicle Signal Relay

‘A rear-signaling system that communicates moderate to hard lead-vehicle decelerations can potentially decrease the incidence of rear-end near-crashes and incidents.’ NHTSA Report

The Problem

The vehicular signal relay is designed to be incorporated into vehicles in order to decrease the possibility of accidents in congested traffic. A common traffic scenario involves a leading vehicle (#1), a first trailing vehicle (#2), and a second trailing vehicle (#3). The leading vehicle (#1) applies the brakes and the brake lights are activated. The first trailing vehicle (#2) has line of sight to the brake lights and hopefully applies the brakes. Second trailing vehicle (#3) has line of sight access to the brakes of that first trailing vehicle (#2). In turn, second trailing vehicle then applies its brakes. This exposes the underlying problem where reaction time is lost because the driver of second trailing vehicle (#3) doesn’t know that the driver of leading vehicle (#1) and isn’t alerted upon brake application.

The Solution

The vehicular signal relay provides directed V2V communications and addresses the problem in a manner where dedicated short range communication (DSRC), undercarriage radar, and GPS position data is impractical. The vehicular signal relay includes a front receiver and rear transmitter, both of which are attached to each vehicle. Simultaneous with brake application, the rear transmitter of the lead vehicle (#1) emits an overlay wave having a one lane width to avoid inter-lane noise. In the optimum version, the rear transmitter of the trailing vehicle (#2) relays the brake application status of the lead vehicle (#1) to the second trailing vehicle (#3), where a dash indicator or heads up display indicator alerts the driver (or control system of an autonomous vehicle). This improves reaction time, decreases stressful driving, and decreases wear and tear on the vehicles.

Extended Video Overview of the Directional V2V System

IEEE Smart Cities Presentation (PDF)