Autonomous Cars

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roon
roon
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Re: Autonomous Cars

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Downside would be geometric uniformity. Some standard, or set of standard, battery shapes would be required. Fuel suppliers don't have to deal with this because fuel is a liquid, and conforms to any size or shape of fuel tank. The equivalent would be an oil change shop needing to stock dozens or hundreds of oil filter sizes and shapes. If there was one, or a handful, of standard oil filter sizes, their supply chain, inventory, and purchasing would simplify and enable greater profit. Battery suppliers would face similar limitations unless auto manufacturers would agree to standardize the largest, heaviest, most expensive singular component of the EV.
Last edited by roon on Sat Jul 07, 2018 7:06 pm, edited 1 time in total.

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strad
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Re: Autonomous Cars

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Sorry Henry I thought it was you that asked what I considered "near future". :oops:
It was actually AJI.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

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strad
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Re: Autonomous Cars

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In Australia we used to call petrol stations 'service stations', because the man came out and filled up your car
Used to call them service stations here as well, but that was when they not only filled your tank but wiped the windshield and checked your oil. One of my first jobs and was for many a young lad.
It was also when they did brake jobs, lubrication and oil changes etc.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

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loner
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Re: Autonomous Cars

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according to all this conversations shouldn't an electrical engineer has the top future jobs
all this energy efficiency and energy storage direction...
para bellum.

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Tim.Wright
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Re: Autonomous Cars

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roon wrote:
Sat Jul 07, 2018 6:34 pm
Downside would be geometric uniformity. Some standard, or set of standard, battery shapes would be required. Fuel suppliers don't have to deal with this because fuel is a liquid, and conforms to any size or shape of fuel tank. The equivalent would be an oil change shop needing to stock dozens or hundreds of oil filter sizes and shapes. If there was one, or a handful, of standard oil filter sizes, their supply chain, inventory, and purchasing would simplify and enable greater profit. Battery suppliers would face similar limitations unless auto manufacturers would agree to standardize the largest, heaviest, most expensive singular component of the EV.
Exactly - the unification of the battery across all manufactures isn't a reasonable thing to implement.

By the time you have standardized the mechanical interface, voltage and power specs, battery management systems, cooling fluid type, pressure and flow rate, maintenence plans, charging systems, thermal logic, electrical and electronic interfacing you will end up with a tiny block which fits in any car, costs a fortune, gives 50km of range, overheats when fitted to a sports car and massively compromises the vehicle architecture of any car it's designed around.

The killer though is the costs and logistics for the battery stations. Even a modest battery station would need an inventory of several hundred batteries which will cost millions. The electrical draw to charge them all at one likely cannot be supplied by the electrical infrastructure of any town - so they will either need to be delivered (doulbing or tripling the number of trucks on the road compared to fuel tankers) or they will need an on site generator which again is going to cost millions.

Then, after all that, once they figure out how to charge a battery in a reasonable time no-one will swap batteries anymore...
Not the engineer at Force India

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Big Tea
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Re: Autonomous Cars

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The batteries do not need to be unified, just the fittings. It there are 3 rails at XX/XX/XX with terminal fixtures of a set type at position aaa/aaa/aaa and supply spec is as art abc, the physical size as long as smaller than outline does not matter nor the rating of the batter. You just chose then as you would Shell, Esso, Elf etc.

The powerpack only has to charge the onboard battery pack.
Last edited by Big Tea on Sat Jul 07, 2018 8:07 pm, edited 1 time in total.
We are standing on the shoulders of Giants. So don't kick.

Just_a_fan
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Re: Autonomous Cars

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Like I said, this was in the 1970s and they were expecting "progress to be made" on many of the technical issues.

The book also had stuff in it about Moon bases... :lol:
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

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Tim.Wright
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Re: Autonomous Cars

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Big Tea wrote:
Sat Jul 07, 2018 8:06 pm
The batteries do not need to be unified, just the fittings. It there are 3 rails at XX/XX/XX with terminal fixtures of a set type at position aaa/aaa/aaa and supply spec is as art abc, the physical size as long as smaller than outline does not matter nor the rating of the batter. You just chose then as you would Shell, Esso, Elf etc.

The powerpack only has to charge the onboard battery pack.
Everything needs to be unified. You can't put a 300V battery in a 400V car. You can't put an oil cooled battery in a water cooled car, you can't put a battery that can only charge at 50kW in a car with 100kW of regen braking. If your BMS does not use a unified communication protocol the battery won't be able to communicate with the car to tell you how much energy is left or if it is about to overheat.

Absolutely everything that interfaces with the rest o the car needs to be unified otherwise it simply won't work.

The "fittings" are the easiest part. Everything else is the roadblock.
Not the engineer at Force India

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Big Tea
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Re: Autonomous Cars

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Tim.Wright wrote:
Sat Jul 07, 2018 8:19 pm
Big Tea wrote:
Sat Jul 07, 2018 8:06 pm
The batteries do not need to be unified, just the fittings. It there are 3 rails at XX/XX/XX with terminal fixtures of a set type at position aaa/aaa/aaa and supply spec is as art abc, the physical size as long as smaller than outline does not matter nor the rating of the batter. You just chose then as you would Shell, Esso, Elf etc.

The powerpack only has to charge the onboard battery pack.
Everything needs to be unified. You can't put a 300V battery in a 400V car. You can't put an oil cooled battery in a water cooled car, you can't put a battery that can only charge at 50kW in a car with 100kW of regen braking. If your BMS does not use a unified communication protocol the battery won't be able to communicate with the car to tell you how much energy is left or if it is about to overheat.

Absolutely everything that interfaces with the rest o the car needs to be unified otherwise it simply won't work.

The "fittings" are the easiest part. Everything else is the roadblock.
Surely as long as the maximum cube dimensions and voltage and position of the terminals is set everything else can be handled by the electronics of the car?

As I said, not to drive the motor, just to recharge the battery. the 'cube' would have to handle its own cooling via an air flow at a specified position, current would be handled by the software and electronics. Things like re-gen are handled bu the on board (fixed) battery

I am not looking at ideal now, just universal. If say Toyota had their own service depots, fine use Toyota, if not, you will not get stranded with a less efficient universal. Much in the way you recharge your phone via usb from many sources including a universal powerpack.
We are standing on the shoulders of Giants. So don't kick.

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Tim.Wright
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Re: Autonomous Cars

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You can't cool batteries with air, they need to be liquid cooled. If you want to just deliver air to the battery at a specified position you then need a heat exchanger, fluid pump and controller inside your cube making the battery portion even smaller.

If you want the battery electronics to manage the current then basically you are moving the battery and charging management systems inside the cube - again making the battery portion even smaller.

You cant let the battery take care of the braking regen because if affects how the car handles. This needs to be done by the vehicle. The vehicle needs a unified communications protocol with the car - otherwise how will you display the charge state on the dashboard?

What about battery power? You can't ask 500hp from a 200hp battery. If you want to try putting multiple battery packs your space and cooling efficiency becomes even more of a disaster because you will have multiple cooling pumps, heat exchangers, battery management systems and charging systems when only one of each would be required.

Lithium batteries are a hell of a lot more complicated than you seem to think. They aren't just a voltage that needs to be bolted to the car somewhere. They have their own software and controllers that need to integrate with the rest of the car to stop it from catching fire.
Not the engineer at Force India

Just_a_fan
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Re: Autonomous Cars

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One could develop an international standard to which all car manufacturers comply. Of course, you're more likely to attain world peace first...
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

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Big Tea
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Re: Autonomous Cars

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Just_a_fan wrote:
Sat Jul 07, 2018 9:39 pm
One could develop an international standard to which all car manufacturers comply. Of course, you're more likely to attain world peace first...
Canbus? :D
We are standing on the shoulders of Giants. So don't kick.

Just_a_fan
Just_a_fan
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Re: Autonomous Cars

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Big Tea wrote:
Sat Jul 07, 2018 9:46 pm
Just_a_fan wrote:
Sat Jul 07, 2018 9:39 pm
One could develop an international standard to which all car manufacturers comply. Of course, you're more likely to attain world peace first...
Canbus? :D
Ok, I'll give you that but I meant in replaceable battery systems which, as has been pointed out, is somewhat more involved than a bit of wiring i.e. CANBUS.
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

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Big Tea
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Re: Autonomous Cars

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Just_a_fan wrote:
Sat Jul 07, 2018 9:52 pm
Big Tea wrote:
Sat Jul 07, 2018 9:46 pm
Just_a_fan wrote:
Sat Jul 07, 2018 9:39 pm
One could develop an international standard to which all car manufacturers comply. Of course, you're more likely to attain world peace first...
Canbus? :D
Ok, I'll give you that but I meant in replaceable battery systems which, as has been pointed out, is somewhat more involved than a bit of wiring i.e. CANBUS.
And I have to reciprocate by admitting it was not negotiated, just the USA said if you want to sell here you use it.
We are standing on the shoulders of Giants. So don't kick.

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strad
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Re: Autonomous Cars

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Isn't this CANBUS what makes it so some guy can hack into my car and take control? :?
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss