3. NCAP protocols and injury channel requirements

Consumer rating programmes do not test a dummy; they test a vehicle and then interrogate the dummy as a measurement instrument. The Q-Series child dummy (Q0, Q1, Q1.5, Q3, Q6, Q10) exists to make that interrogation defensible: each channel is defined by a sensor location, a filtering and timing convention, and a limit that is compared against a specific test configuration. Before any channel assessment can be judged, the engineer must know which protocol governs the test, which seating position and restraint configuration apply, and which channel set that protocol actually scores. This section maps the three programme families most often encountered in Q-Series work — Euro NCAP, C-NCAP, and the wider set of consumer and regulatory programmes — onto their test configurations and channel-specific pass/fail logic.

Programme landscape and what each one scores

Euro NCAP and C-NCAP are the two programmes that most directly drive Q-Series channel work, but they differ in emphasis. Euro NCAP's child occupant protection assessment combines frontal offset, side barrier, and — in recent protocols — far-side and more demanding frontal configurations, with a strong weighting on CRS (child restraint system) installation and vehicle-based assessment alongside dummy readings. C-NCAP applies its own frontal 100% overlap rigid barrier and 40% overlap offset deformable barrier tests plus a side impact, and scores child protection through dummy channels in the rear seats. Other programmes — JNCAP, KNCAP, Latin NCAP, ASEAN NCAP, and the UN R-regulation family (R44, R129) — use overlapping but not identical channel sets and limits, so a channel that passes under one protocol is not automatically compliant under another.

The practical consequence is that a channel assessment is only meaningful when bound to a protocol version. Euro NCAP limits have been revised across protocol years, and C-NCAP has moved through successive management rules. Always record the protocol name and version in the assessment record; a bare "HIC15 = 640" without the governing document is not a result.

Test configurations that generate the channels

Each configuration produces a distinct loading regime, and therefore a distinct set of channels that matter. In the frontal offset test, the child dummy in the rear outboard position experiences forward excursion restrained by the CRS harness and the vehicle belt; the dominant channels are head resultant acceleration (for HIC), neck tension and flexion moment, and chest resultant acceleration. In side impact, the dummy is loaded laterally through the CRS shell and door trim; head resultant acceleration, head excursion, and chest deflection or acceleration dominate, and neck lateral bending becomes relevant. Far-side configurations add lateral head excursion and neck lateral tension as the dummy is thrown across the cabin.

Seating position and CRS orientation change the channel set further. A rearward-facing Q1.5 or Q3 in the rear outboard seat is assessed primarily on head and neck channels because the shell distributes chest load; a forward-facing Q6 or Q10 adds chest and, in some protocols, abdomen channels. The assessment must therefore state the dummy variant, the CRS category and orientation, the seating row and position, and the anchor configuration (ISOFIX plus top tether, belt-routed, or support leg) before any limit is applied.

Channel-specific pass/fail criteria in practice

The comparison stage is where protocol differences bite. Euro NCAP and C-NCAP both use HIC15 for head injury, but the limit values and the capping behaviour differ, and both programmes apply a 3 ms clip to head and chest resultant acceleration. Neck criteria are expressed as tension force and bending moment, with separate limits for flexion and extension and, in side and far-side configurations, for lateral bending. Chest criteria combine resultant acceleration with deflection where the dummy variant provides a deflection sensor. The Q-Series family is designed so that these channels are physically measurable at the stated locations, but the engineer must confirm that the specific dummy variant carries the sensor required by the protocol — a Q3 without a chest deflection option cannot satisfy a protocol that scores deflection.

Two conventions cause most assessment errors. First, filtering: channels are filtered to a defined class (commonly CFC 600 or CFC 1000 for accelerations, with SAE J211 channel classes for moments and forces), and applying the wrong filter shifts HIC and 3 ms values enough to flip a marginal result. Second, time window: HIC is computed over the 15 ms window that maximises the value, and the 3 ms clip is the maximum resultant sustained for 3 ms; both must be computed on the correctly filtered and correctly oriented signal. Orientation matters because resultant acceleration is invariant to sign, but neck moments and forces are not — the sign convention (for example, tension positive along the neck axis) must be fixed before comparison.

Worked assessment example

Consider a forward-facing Q6 installed with ISOFIX and top tether in the rear outboard seat, assessed under a frontal offset configuration. The relevant channels are head HIC15, head resultant 3 ms, neck tension and flexion moment, chest resultant 3 ms, and chest deflection. Suppose the filtered signals yield HIC15 = 610, head 3 ms = 72 g, neck tension = 1.85 kN, neck flexion moment = 48 N·m, chest 3 ms = 47 g, and chest deflection = 34 mm. These are illustrative values, not measured results. The engineer compares each against the governing protocol's limit for that channel and configuration, records the margin, and marks pass or fail per channel. A single channel exceeding its limit fails the channel; the programme then applies its own scoring or capping rule to translate channel outcomes into a child protection score.

The reproducibility test is simple: hand the assessment record to a second engineer and ask whether they can reconstruct every channel value and every pass/fail decision without asking a question. If the protocol version, dummy variant, CRS installation, filter class, and analysis window are all present, they can. If any is missing, the assessment is an anecdote, not a result.

Cross-programme comparison and its limits

Because Euro NCAP, C-NCAP, and other programmes share channel definitions but not limits or configurations, a channel value can be compared across programmes only at the level of the physical measurement, not the pass/fail outcome. A head HIC15 of 610 is the same physical quantity under any protocol; whether it passes depends entirely on the limit and configuration that govern the test. Engineers supporting multiple markets should therefore maintain a channel matrix that maps each programme and configuration to its scored channels and limits, and populate it from the current published protocol documents rather than from memory or from an older assessment file.

The Q-Series dummy's value in this landscape is that it makes the channel definitions consistent across programmes: the same sensor location and the same physical quantity are used, so the measurement is portable even when the limit is not. The assessment discipline is to keep the measurement and the judgement separate — measure once, correctly, and then apply the governing protocol's criteria explicitly and traceably.