Ev bus failure

[Cujet]

Let's be honest here.

One could take 2ea Model 3's and put a bus body on top. Prob change the final drive ratio for Bus tires and speeds. It would be 100% reliable. Furthermore, if the batteries were not mega charged 3x per day like some Uber drivers do, but instead slow charged at night, would last 300,000 miles.

 

[PandaBear]

China Bangers take note.

When there's a will there's a way. BYD buses do have some teething problems and a few did caught on fire in the past but you got to admit, they are in a "move fast and break things early" phase. There could be a concern the entire nation get oil blockade if both Russia and US don't like them and all they are left with is nuke and coal.

I've seen VanHool EV double deckers around everyday on the freeway, I guess they are reasonably reliable?

 

[PandaBear]

SCM is the main brain and controller for the whole enchilada. I have no idea as to why it is so expensive.

Lockheed Martin's CEO once said firmware is the most expensive thing in the universe is my guess, or they build everything in ONE module and it takes a lot of work to build one. If it is fried I would expect a replacement to only cost repair money instead of a completely new unit.

I've seen low volume electronics to cost $35k each but if it is not expected normal wear and tear, B2B customers can usually negotiate with the manufacturers to get the cost down to reasonable amount.

 

[PandaBear]

My 2 cents; political agenda commentary/rebuttals and overall 'ecological wisdom' assessments aside.

There's nothing wrong with developing electric vehicles. It's that posturing and selling are involved. Engineers and designers should be improving things along the way. Steady development and improvements will displace foolish, backwards looking arguments.

As mentioned above, it's not the "go parts" of these machines but the silly, ancillary stuff which fail. It stinks that various control systems (one company's SCM) or super touch screens have to be individualized for each manufacturer. Having to make essentially experimental vehicles appear to be finished examples of industrial design is wasteful.

And a third cent, if I may. Any company which buys expensive, newly designed machinery with a 90 day warranty is stupid, stupid, stupid.

90 days warranty sound like an R&D unit you force them to build but they don't really want to build it. Some more honest vendors would either tell you NO WARRANTY up front and charge a non-recurring-engineering fee to custom design for you.

Still can't figure out what they did there and why they need a different non traction unit than a normal school bus. This is actually the reason why a lot of company don't go with Tesla's unifying approach because you want to reduce risk and use as many proven designs as possible so things don't break.

 

[Chris142]

Correct. This is because some things don't work well when scaled up. Did anybody ever wonder why insects mostly remained so small compared to other earthly creatures? It is mostly because their method of breathing is from spriacles in their thoraxes and abdomens which can't be made larger and functional through evolution.

This is fiction just like EV buses and trucks.


View attachment 192864
Last Movie Outpost

OT: tarantula wàs filmed in my town.

 

[y_p_w]

Lockheed Martin's CEO once said firmware is the most expensive thing in the universe is my guess, or they build everything in ONE module and it takes a lot of work to build one. If it is fried I would expect a replacement to only cost repair money instead of a completely new unit.

I've seen low volume electronics to cost $35k each but if it is not expected normal wear and tear, B2B customers can usually negotiate with the manufacturers to get the cost down to reasonable amount.

A lot of modern automotive electronics use FPGAs. I suppose that makes it possible to remap the logic rather than replace entire boards. And that could make a lot of sense in buses where they might only be making in the thousands rather than millions.

 

[Opelman]

90 days warranty sound like an R&D unit you force them to build but they don't really want to build it. Some more honest vendors would either tell you NO WARRANTY up front and charge a non-recurring-engineering fee to custom design for you.

Still can't figure out what they did there and why they need a different non traction unit than a normal school bus. This is actually the reason why a lot of company don't go with Tesla's unifying approach because you want to reduce risk and use as many proven designs as possible so things don't break.

I don't get it either. Blue Bird/Cummins should have this figured out. The school district chose from what was qualifying for state grant money. They still had to pony up a good chunk of change fore these out of pocket for these units.

 

[PandaBear]

A lot of modern automotive electronics use FPGAs. I suppose that makes it possible to remap the logic rather than replace entire boards. And that could make a lot of sense in buses where they might only be making in the thousands rather than millions.

That too. I think a lot of industrial equipments today are using FPGA for risk reason as well. You can't be sure you won't make a mistake so other than the obvious external facing I/O just make them programmable.

 

[y_p_w]

That too. I think a lot of industrial equipments today are using FPGA for risk reason as well. You can't be sure you won't make a mistake so other than the obvious external facing I/O just make them programmable.

Even big car companies are using FPGAs, although I'm not sure how they might handle something like in-situ remapping. I suppose they could run lots of tests and then reprogram the memory file over the air.

ASICs and SoCs are very expensive, so a lot of them are generic where they can be configured or at least where the firmware can be updated. A lot of my career has been spent on the configurability of ASICs.

My first job offer was with a company that made a high-margin product in small numbers. FPGAs were around (I had some undergrad classes where we programmed FPGAs in a lab) but not terribly high performance. I asked about what the silicon target was, and it was traditional mask-programmable gate arrays. I believe they had an advantage in terms of performance and power consumption compared to FPGAs.

 

[UncleDave]

A lot of modern automotive electronics use FPGAs. I suppose that makes it possible to remap the logic rather than replace entire boards. And that could make a lot of sense in buses where they might only be making in the thousands rather than millions.

Our company is 80% FPGA based and compared to platform C++, writing and programming in Verilog is magnitudes harder but def has its upsides- the big one as you mention being watts used for X result. Not to mention the appliance nature of said device.

Hiring is difficult. For every 100 C++ guys you may find one Verilog guy.

Still 80K sounds like a joke for a board thats already been created and loaded.

We engineer manufacture and sell FIPS level 4 security watermarking & decryption boards for digital cinema for around 10K, and I can pretty much guarantee that bus controller isnt built to that spec.

 

[PandaBear]

Our company is 80% FPGA based and compared to platform C++, writing and programming in Verilog is magnitudes harder but def has its upsides- the big one as you mention being watts used for X result. Not to mention the appliance nature of said device.

Hiring is difficult. For every 100 C++ guys you may find one Verilog guy.

Still 80K sounds like a joke for a board thats already been created and loaded.

We engineer manufacture and sell FIPS level 4 security watermarking & decryption boards for digital cinema for around 10K, and I can pretty much guarantee that bus controller isnt built to that spec.

Agree. 80k is definitely not just material and manufacturing. If something at this cost fail they need to repair instead of building a whole new unit.

I wonder what kind of work they justify that cost. If they have to redesign something custom that's another matter. They shouldn't be charging to fix their broken stuff at this cost.

 

[y_p_w]

Our company is 80% FPGA based and compared to platform C++, writing and programming in Verilog is magnitudes harder but def has its upsides- the big one as you mention being watts used for X result. Not to mention the appliance nature of said device.

Hiring is difficult. For every 100 C++ guys you may find one Verilog guy.

Still 80K sounds like a joke for a board thats already been created and loaded.

We engineer manufacture and sell FIPS level 4 security watermarking & decryption boards for digital cinema for around 10K, and I can pretty much guarantee that bus controller isnt built to that spec.

I'm a Verilog guy but I can't program worth anything. I have a feel for the parallelism inherent in RTL code, but I have problems with pointers. And in my work I've come across a lot of people like me.

However, these days there's probably twice the number of verification engineers than there are design engineers, since the complexity means that the verification efforts increase exponentially. Even with FPGAs, the tradition was to "burn and churn" where they just tried it out in the lab and remapped if it didn't work, but that doesn't necessarily find the source of defects that verification does.

I was actually trying to get into FPGA for some time, but without professional experience most don't seem to give a chance. It takes either giving a chance on an ASIC/SoC engineer or where someone manages to get that experience in parallel.

 

[Opelman]

Agree. 80k is definitely not just material and manufacturing. If something at this cost fail they need to repair instead of building a whole new unit.

I wonder what kind of work they justify that cost. If they have to redesign something custom that's another matter. They shouldn't be charging to fix their broken stuff at this cost.

Probably a lot more than a software brain involved here. I'm thinking that the high amperage controller is involved also. More details as I get them. On one hand I am glad not to have to fix this thing, on the other hand, learning about it is an interesting intellectual challenge.