You're right, automation throws a wrench in the works of the self-correcting dynamics of my usury-free market system, by completely devaluing labor; and the only way to prevent that is to make sure that everybody ends up owning a piece of the automated means of production, preferably before complete automation occurs. I think basically every possible scenario will eventually end up with everyone who is still alive living for free off the labor of robots: the questions are, firstly, who of those alive when full automation is finally achieved will live through the transition to enjoy it; and secondly, who among them will own the automatons and thus control the world when it's all through. I can see four general possible scenarios:
A) The owning class secures their power with things like robotic security and such to the point that they no longer need the working class at all, all the workers get laid off, starve and go homeless, try futilely to riot but can't overthrow the owning class's secure position, and eventually die off entirely. The remaining owning class and their descendants live in a blissful labor-free utopia for all of time afterward, and the death of the working class is remembered as a tragedy of history that none of the survivors are personally responsible for.
B) The owning class secures their position of power, the working class becomes entirely unnecessary, but out of some little shred of humanity (or possible uncertainty in the security of their position), the owning class keep the working class around, but now wielding absolute power over them as the owners have absolutely no need for the non-owners and the non-owners are absolutely dependent on the owners for their "charity".
C) The revolution comes before the owning class can totally secure their position and the working class are able to overthrow the owning class, either violently or somehow through nonviolent political means. Some traditional form of state socialism is enacted to redistribute wealth, and everyone now lives on the welfare of the state and its robot armies, which in turn (its leadership that is) wields absolute power over the people as it has no need for them per se and they are entirely dependent upon it.
D) The revolution comes soon enough to succeed by whatever means it does, and a more distributivist, libertarian-socialist solution is enacted: divisions between owners and non-owners are dissolved, everyone personally and privately owning some of the automatons, without eradicating all personal liberty in the process.
I think B and C are probably the more likely options, but A is still a frightening possibility, and it depresses me that nobody even seems to consider the possibility of genuine solutions in category D. The best-case plausible scenario is likely to be B or C eventually transitioning into D.
For a B-to-D transition, once automation is so complete that it literally costs the owners nothing (but control) to give it away, even a small trickle of genuine social charity could distribute ownership of automatons to the dependent (no longer working) classes over time, finally giving them independence. Successive generations raised in such a post-scarcity society might see less and less reason not to give their poor automaton-less friends some automatons of their own, and those given automatons could in turn use them to rescue others in the same boat at themselves, accelerating the process.
For a C-to-D transition, the electorate could simply vote to devolve ownership of the automatons from the central control of the government to the people individually. I think pragmatically, aiming for a C outcome at first with an eye to eventually transitioning to D is probably the best strategy we can hope for: a straight D solution is too unlikely to gain traction until it's too late, and a C outcome is the easiest to transition to the ideal D solution afterward. It concerns me how similar to the "dictatorship of the proletariate" that strategy is though: for the interim we have a people's government in absolute control of everything, to keep it out of control of a malevolent few, with the intention that it will devolve that control to the many individually afterwards... but what if it doesn't?
In any case, on a very long scale I think the outlook for people born in the distant future looks good. The big concern is how much it will hurt some of us alive today (and our children, etc) on the way there.