OK. Were Making Some Progress...
So. Now; for the painfully obvious but trivially technical and somewhat predictable legal parts.
Sans any Olympic bits etc. Here's how I worked it out from first principles. This after watching various random attempts from the first few sets of local Lexus franchise's sales guys showing me how they thought it worked by basically floundering around without much of a clue and failing time after time:-
Given other product feature decisions and public announcements already made by Lexus it would seem sensible to assume that this particular safety interlock sytem. As with much else similar from this class of modern vehicle is motivated by a corporate desire to avoid any legal pursuit from a user having suffered harm or worse either by their own or by their appointed representatives errors or omissions i.e. always follow the money first...
Thus for entirely pragmatic reasons. The immediate foregoing suggests that the the step back part is likely the most crucial aspect, primarily because (all) the rear (ultrasonic) sensor(s) is(are) likely resolving, at the very least, one pair of entirely separate phenomena, i.e. pair part one: an Event, E1 and part two: an Elementary user position mapping, E2. These, and probably some others, seemingly evaluated strictly in one order:-
Simplified Input Condition List:-
E1 - Has there been a tailgate lift open request from the rear underbody sensor i.e. an air kick?
E2 - Is the users elementary position safe? i.e. located clear beyond the horizontal extent of the vertically swept arc from the tailgate's lower edge?
Compacted Truth Table:- Minimalised Output Action List:-
If E1 = YES AND E2 = YES; then actuate the tailgate opening.
If E1 = YES AND E2 = NO; then ignore the E1 request and bleat?
If E1 = YES AND E2 = NOT SURE; then do nothing to aviod user injury.
If E1 = NO AND E2 = NO OR YES; then do nothing until E1 changes.
As the above generally holds true in practice, then the step back part is far more necessary to successful operation than the kick part
i.e. kick at it all day but for reasons now made plain. Until you step away then nothing much should or will happen. Save perhaps for very occasionally causing random, temporary and unrepeatable confusion of the sensor and software suite with potenialy hazardous results.
No surprises then that, for even more obviously apparent reasons, when returning the tailgate to its closed position. Similar fundamentals, but with a critically enhanced input event set and management matrix providing a well matched expansion of the closed loop output control functions likely applies even moreso i.e. closing the tailgate is, at a deeper level of analysis, even more fraught than opening. But if this extra complexity for closing has to be in place then why not make good use of it on the opening cycle?
Any useful recountings from other owners,
i.e. what works best on your UX?
All relevant experience welcome...