I've been inside one automated greenhouse that produces potted herbs. there is a machine which fills the pots with compost and adds seeds thats relatively simple. The pots go onto a tray that sits on two tubular rails and they get automatically watered. there is a robot which works beween the rails which lifts up the tray and moves it forward. Essentially pots with seeds at one end and ready to sell herbs at the other . with the robots doing the heavy lifting no need for walkways between the rows so maximizes the use of the space. It tends to be uncomfortably warm and humid in there. I think it was a dutch company that owned the factory which was in south lincolnshire this was around the late 90's. I think the loading and unloading at each end was manual.
A crisp or chip factory has pretty good automation. A trailer loaded with potato's has a small conveyor in the bottom of it. This is plugged in at one end of the line the potatos drop into a flume which is full of water which pumps them through a pipe up to a 3 stage peeler. It is essentially 3 sets of rollers with a coarse medium and fine grit this removes the skins.
Onto the grader halver big potato's get cut in half and then onto an elevator. it carries the potatoes up to the cutters, it has a sensor monitoring the weight and adjusts the feed speed and the overall production rate,
This feeds the cutters these are like a cauldron which spins, potatoes drop in there and the potatoes get sliced with razor blades set in the side. These blades need changing on a regular basis (human needed). There were 3 of them so 1 would get changed while the other 2 keep working.
Next step is a bath which removes starch which is harvested. Then the chips hits the fryer, this is a bus size fryer the chips are kept submerged under the oil and a PID maintains the temperature adjusting the burners that heat the oil. There is like a chain conveyor which keeps them moving along the fryer.
Coming out the oil they go on to a fast moving conveyor, at the end of which there is a small conveyor which the chips jump over. Here there is a camera system which is looking for burnt chips. If it spots any it directs air jets to blast them into the small conveyor, the rest passing through to a bucket elevator. the ones that get diverted onto the cross feed conveyor go through the camera system again because the first pass will take out some good chips as well as burnt ones.
The bucket elevator feeds a storevayor which can hold up to about 10 tons of chips, sensors show were there is space for more chips and the belt feeds out to a system of vibrating stainless steel conveyors which feed the flavor stations.
When the flavor station needs more product they call for more product and a side ways vibration is used to divert to the flavor station. the storevayor gives some flexibility to the system and feeds back to the earlier stages.
flavor stations are fairly simple there is some thing like a galvanized dustbin ,which the chips feed into, on its side which rotates and a screw feed which feeds the flavoring through a small pipe the rotation of the drum mixes the flavor with the chips.
This feeds a check head weigher the chips land on a central cone and around that are little hoppers which weigh the product. each will have some random quantity of product and will release a combination that meets the minimum weight requirement e.g 12g and 13g to make a 25g packet.
The packet is actually a sheet of film which is wrapped into a bag and sealed when the chips start falling there is no bag and its formed as they are falling. the top of one bag when it is sealed makes the bottom of the next. these then hit another small conveyor with a section that weighs the bags any that are out of tolerance get rejected.
The packing in boxes can be manual but there is a robot system which takes a flat box opens it and then a lifter picks up 8 packets it has a sucker for each packet if it doesnt sense a packet it rejects the 7 and has another go it puts 8 in a layer repeats till it has 48 packets and closes and seals the carton which gets stacked onto a pallet. these get shrink wrapped ready for distribution.
Pretty much just 2 people work on the cooker side on the flavor stations there are more operators they load flavors clean down the machines there are either a couple of people mostly packing or a robot doing the job. That robots pretty expensive but it works 24 hours a day.
It is way harder to automate the farms though. Take a potato harvester it does a fairly good job of picking up potatoes but it also picks up mud and rocks there is usually a team of around 4 people riding on the back pulling off mud and rocks to avoid carrying half the field back to the sheds then the crates filled on the field go on to a grader which sizes the potatos and again there is a team of people removing more mud and rocks. you can't automate that.
Even easier crops to harvest automatically can have problems sometimes weeds grow. Very hard for a machine to identify a nettle from a lettuce someones got to pick that out. As my old mam used to say the cheapest robot is the human being.