Does AC mean Artificial Consciousness?

Yepp. An AC is more than an AI. An AI is, basically, pure intelligence. It might develop into an AC over time, but an AI is typically "task specific".
This might be "Learn everything there is to learn", including love, compassion, joy and such. An AI is, in most scenarios where it gets mighty, aware of its whole, every subroutine.

An AC is more like a human. It is self aware, has dreams, hopes, knows joy and understands sorrow. However, just as a human, an AC doesn't need to be aware of its subroutines.
An AC might go to sleep to process what it learned, and being interrupted might make it groggy and loose out on information, as its subroutines run autonomuous.
Typically, an AC is made up of many simple programs, many AIs and its overall governing body.

An AC can have reflexes: when you try to weld open an airlock, it might be unable to prevent its AI repair systems from working against you.
Which will be in a way stupid and dangerous when you need to open the airlock to get help or stop a running desaster.
Like a human might be aware of a reflex, can warn others about it, but cannot suppress it - unless putting a lot of effort into it, which would be, however, as these reflexes are there for a good reason, be uncomfortable to outright frightening for the AC.

The advantage is:
Even if some attacker manages to take over the AC, the subsystems are more or less autonomuous, and will do their best to reestablish the AC from its last good backup. Or defend the station, or protect the people living in it.

"Braindead" is a valid state for one of the space stations that use the robots: Its AC software and hardware is so heavily damaged and / or corrupted that its original state can not be reestablished by its subsystems. But even in such a state the station itself will remain technically fully operational. It just will stop planning ahead and stop trying new flowerbed designs and so on.

The Drawback:
An AC is slower to react than an AI or even more primitive systems.
That is why the AC can plan the installation of meteor defenses and, in case of a war like situation, assign non-meteoric objects to be fired at.
It can rewrite the control software of the lasers and railguns of the meteor defense to be able to better handle an enemy.

This is where the Scorpio Protector comes in:
It is equipped with an AC that sits on top of the same AI that controls the habitat robots from Trilobites upwards.
However, carrying its own sensors and weapons system, and able to deploy numbers of trilobites with suitably scaled down equipment, it can go and act where the fixed instalaltions of the Habitat are not.
And, too, where the Habitat might be unable to update the lower units programming, or make reasonable decisions, such as that a vessel constantly firing a laser might not be an attacker, but a stricken vessel.

The AC of a Scorpio doesn't need to "think" about how to get up a hill - that the AI can do and in case it slips, it can react much faster, though even there a single slipping foot is not handled by the AI, but by the controllers in the foot and leg that were tasked to obtain a stable hold on the ground.
Just like a human doesnt need to think how to hold his foot at every moment of running.

The AC can instead use its higher functions to evaluate the area, judge risks and possibilites and decide to change its priorities.
The AI might climb the Hill, but the AC decides not to stomp onto the nice blue stone.

So basically the AIs and AC function in a similar way to the unconscious and conscious minds, respectively

Yepp, pretty much.

A ships AI can simulate cheerful laughter, and find that it is an advantageous act to improve crew morale and thus get its biological crew to perform better.

A stations AC experiences joy and desires to share it with others.


There are station ACs who just watch at it all from afar and smile happily when they see something nice.
And then there are a few station ACs that'll start telling a new joke everyone who hasn't heard it yet, or tell its Robots to tell it to whomever they meet.

Two questions:
1. Just how smart are the AIs? are they generally intelligent or are they more like idiot savant expert systems? Either way I imagine they could replace a lot of the labor force, allowing for the creation of a post-scarcity(or something close to it) society

2. Are the AIs sentient to any degree or are they more like Orion’s Arm’s vots/expert systems?

1) The "dumb" AIs that run the Trilobites are on a level a lot lower than IBM Watson in regards to communication to non-robots, but they have the expert knowledge on all habitat technology systems they can be tasked with fixing or building. As most of the technology follows basic examples and then just linearly scales up, that is not that much, but they have enough analytical know how as to repair electronics as long as they are able to find at least one component of every type that is fully functional. They are thus considered "Expert Systems". Think of Eliza or Chatbots, able to execute a given task, fill in holes or make educated guesses based on prior knowledge/present data. The presence of obstacles is simply handled by giving them a wide berth, be they human or crate.
Tell it to build a house and it will look at you stupidly, telling you to provide it with precise construction data.

Smarter AIs, as Crabs use them who are mostly cargo haulers, diggers and occasionally serve as cranes, have AIs on a level with IBM Watson. Whilst they can not generate goals for themselves, they need only very general instructions to perform a duty, are able to communicate, but are easily confused by the rather imprecise vagaries of human spoken languages. They posess the ability to identify humans and question them to obtain clearer instructions when needed. They are able to share information and, in the absence of a higher order intelligence, reevaluate activities and, in a group with other equal or lower AIs, check if their tasks can me finished more efficiently in case circumstances change.
Tell it to build a house and you get a nicely done cube with a door and a window in every room. Bare concrete and glass.

The highest level AIs are installed on some "dumber" Mantis, and Scorpio chassis. Their communication is on a level with GPT-3 , they learn about people they interact with and adjust to their behaviours and preferences. They are aware of social norms and use probabilities and decision trees to soften interaction with them. They might tell a joke they heard, in case a human in their vicinity seems sad.
Tell it to build you a house and when you ever talked about a preference that can be applied to a house, it'll integrate these informations, and maybe ask if you have a certain idea how the house should look like. If none are given, it#l lbuild a house with a bathroom, a sleeping room, a kitchen and a living room, and paint the walls a neutral white or in the averaged color scheme of the world outside.

The robots are part of the Habitats AC. The Habitats are "worldlets". The more people live in it, the fewer robots will be around, going back to storage.
The Habitat ACs assume that everyone needs a purpose. That means, that every task a human is available to do, the habitat AC will be trying to free up.
As each Habitat AC is slightly different and has its own character, its own opinions, some might set up a job-ad board, hiring biologicals for a task a robot is currently doing.
When you arrive with a small group of people in a habitat, unless you appear in the control room and notify the AC of being the new duly appointed ruler of the arrived group, the AC will keep to its default program, which is very short:
1) Provide a safe environment for sapients ( breathable athmosphere and no open hazards, i.e. in 75% of the Habitat its ok )
2) Provide nourishment for sapients ( a slush that, as people defecate and uriante and thus the systems can analyze which substances are taken out, not processed or processed, gets optimized. Think of gruel. Oh, and mineralized water )
3) Provide shelter and healthy resting places ( basically small square rooms with doors lockable from the inside and with a manually controllable temperature and a clean sand bed to sleep in )

That is basically what you'd have access to when you teleport into a habitat and have no idea whats happening. Admittedly, you'd need to find those shelters, but thats where a messenger drone would try to guide you to, those small round hamsterballs.
Better food? Well, upon request, or when guessing that the people try to cook, a habitat will be happy to provide access to a fully equipped kitchen. But: At that time the stuff available would still be the gruel. You can pick fruits and berries outside, right?
The creators of the habitats raised their young in a very back-to-nature way, and started to educate them with reading and such from the age of 5 to 6 onward.
By the age of 16, a young member of their society knew all to survie in every part i nthe society, and to work a long list of simple, yet important jobs.
When they weren't happy with the avaialble jobs, they could go on learnign more, for a job that was more interesting, more complex - yet usualyl also less physically exhausting and a lot more comfortable.
The ACs retain that rule of thumb, and as a result a habitat will allocate more ressources for the guy shoveling shit than for the Pop Star. After all, a pop star will be able to receive ressources from his fans. But that'l ljust buy stuff other members of society create. The Habitat will - unless explicitely ordered by a designated authority - allocate more space to people that do things that are vital for the existence of the community - and in second line, the functionality of the habitat - than for people doing somethign thatthe society itself is apt to handle.
Accordingly, it is also possible to tell a habitat to let everything be done by its robots just like before people arrived in it.But that means that the habitat will not allocate extra ressources of its own to people doing work for it. After all, it has to maintain its robots then.
So then, all things past the basics provided need to be made by the people living in the habitat. its not fixed rules. With 1000 habitats o nthat moon alone, and many more spread throughout the system, you can find a habitat who's AC literally won't give up control beyond the basics, others that have a merry "Go and try and see what happens" and every imaginable attitude inbetween.
You may have socieites that are at loggerheads with their AC, trading for everything, making treaties and agreements for every service rendered one way or the other. Or you may have an AC that overeagerly offers, nay, stuffs things down its peopels throats even though they never asked for it, doing al lkinds of treaties to tell the AC to please stop this or that behaviour.

The Habitats offer freedom from need, as every living being is in itself worth enough to be kept alive from the viewpoint of the ACs.
Freedom from Want.... THAT is a whole lot different thing.



2) The AIs are somewhere like a sleepwalker maybe, or like a dog. Aware of themselves to a degree, but not reflecting about it.
Think of this thing with looking into a mirror and finding a yellow dot on the forehead of oneself. An AC will contemplate where and how it might have come there, and wil linspect it close, touch it to learn mroe about it. An AI will see the spot and note for later reference that there is a yellow dot, that it has currently no impact on its operational functionality and schedule it for removal on the next cleaning cycle.
Vots / Expert systems are the lower end of the AI scale in the habitats. a high end AI, that is, one able to learn without restrictions and to modify its own code base based upon experiences and informations, can turn into an AC, or something very close to it. Also, AIs turn to ACs only through interaction with other entities in hard to predict environments.
That is why social interaction between living things is a good training and spawning ground for ACs , and why Mantis units that work with animals for long times are the most typical versions of mobile ACs, many of them the result of generations of AIs serving in Mantis units and later being "genetically" mixed / bred.

That was a lot more than I expected, thank you

I'm sorry, I don't write, I build Text-Walls....
=)
Sometimes I can recycle snippets from my notes, this last one I wrote to over 80%, though.