On the new ECU and sensors...

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.

Post Tue Feb 05, 2008 6:18 pm

I was reading about the 100+ sensors that are on the cars these days, and the 1Km of wire that hooks them to the new ECU. I immediately wondered why the teams havent built a Bluetooth solution to eliminate the wire, and thus the weight. The Bluetooth 1.2 sensors could run off a watch battery, be electromagnetically shielded with a small external antenna, and literally bond with the host ECU.

Does anyone have any info on this type of system? Or any comments from experience? I know that most people would immediately frown upon anything wireless, but some of the new BT standards and security are really very reliable.

Thoughts?

Chris

PS I forgot to mention that with a standard ECU, does it not use a set of standard sensors? Could a manufacturer make a set, and sell them to all teams?
Conceptual
 
Joined: 15 Nov 2007

Post Wed Feb 06, 2008 6:58 am

Conceptual wrote:I was reading about the 100+ sensors that are on the cars these days, and the 1Km of wire that hooks them to the new ECU. I immediately wondered why the teams havent built a Bluetooth solution to eliminate the wire, and thus the weight. The Bluetooth 1.2 sensors could run off a watch battery, be electromagnetically shielded with a small external antenna, and literally bond with the host ECU.

Does anyone have any info on this type of system? Or any comments from experience? I know that most people would immediately frown upon anything wireless, but some of the new BT standards and security are really very reliable.

Thoughts?

Chris

PS I forgot to mention that with a standard ECU, does it not use a set of standard sensors? Could a manufacturer make a set, and sell them to all teams?


It"ll be for sure more expensive, different MAC addresses for each sensor with different key codes (wow lol).

I believe also bluetooth has a slight delay in transmission.

Since it's a controlled component I doubt any manufacturer could make a set and sell them to teams. They'd have to consult with FIA first, then go from there.
bizadfar
 
Joined: 3 Jan 2007

Post Wed Feb 06, 2008 7:31 am

Wireless is always more interference-prone than wired.
Paranoia about sensor-data being hijacked by other teams.
Greater software complexity.
Greater package size and complexity.

It's certainly a cool idea, and perhaps usable for stuff in appendages such as a front wing+nose cone or so. For pretty much all other cases, I think the wired downside of cable management is easily compensated by it's stability, security and simplicity.
Saribro
 
Joined: 27 Jul 2006

Post Wed Feb 06, 2008 2:15 pm

There is a nice study on the subject I read a year ago: Feasibility of In-car Wireless Sensor Networks: A Statistical Evaluation, by Tsai et al. for GM. I quote:

"... the communication channel between the base station and a sensor placed under the engine compartment is the worst in terms of stability, average fade duration, and fade proportion..."

Conclusion: you can get 98% packet transfer (that's a so-so number) and 500 ms (half a second) of delay, which rules out wireless control devices for the moment, because of the time lag, and limits the system to sensors.

Besides, there is a problem called "temporal correlation". If you have a random delay of 0.5 seconds AND there are some sensors that "work in parallel", like for example, the volume of air in the intake and the position of the throttle, you do not know if the measures from one of the sensors are "in step" with the other, or if the flow of air you measured was taken 0.5 seconds before you measured the throttle position. So, right now it's not a practical system for this kind of sensors.

On the other hand, please notice, dear Conceptual, that these sensors are not simple replacements for current ones: there are places in a car where you cannot put a wired sensor. If, for example, you wish to put a sensor on top of a piston, you have to use a wireless one.

Another example: the US Air Force is working on what they call MEMS, which are miniaturized sensors that are being tested to sense the temperature at turbine bearings. The sensors are located inside the rotating bearing, ruling out a wired sensor or, at least, providing evident advantages if you use a wireless one.

Micro Electro-Mechanical System: it has ears and arms (the mechanical part) etched in silicon
Image

The little sensors are fed electricity through an induction coil that picks a radio signal and convert it into electricity (more or less in the same way the supermarket "thief alarms" work). You have to energize them somehow: if you have to use a wire to provide electricity for the sensor to work, what's the point of the communication wireless channel? Advanced wireless micro-sensors to prevent jet, spacecraft and car engine failures

I would say that the "concept" here is to substitute a direct system (like yourself watching something) by an indirect, relayed system with a noticeable delay (like yourself watching something through a network of people that reports back to you).

It seems a logical conclusion that you will "delegate" for a more efficient system: why do you have to report a sensor signal to a central computer and receive the control signal back?

It seems more logical to put ALL the intelligence in the sensor, so there is no need to report to the ECU. This is the XXIth century, for heavens sake. Are we using "mainframes" on purpose? I conclude that the whole concept of ECU is "wrong", or at least that it will be improved very quickly. I'd call it PECU, or personal ECU, ;) and it has occurred to me as I wrote this post, so probably it's just another one of my discardable ideas.

By "PECU" I mean that in the end, I imagine, you will have "personal" computers in each component that, by themselves, sense what's happening and take the appropriate action (like yourself having employees that take decissions independently to watch the "something" I mentioned). They can even store in themselves or directly transmit the info for FIA revision, and the wireless system will be limited to carry "general" control signals. Let a hundred ECUs flourish! :)
Ciro
Ciro Pabón
 
Joined: 10 May 2005

Post Wed Feb 06, 2008 6:25 pm

There is already a wireless sensor system in place in Formula One cars. There are four sensors mounted on each wheeel to transmit tire pressures to the car, which relays it to the team.
Beer is cheaper than therapy.
DaveKillens
 
Joined: 20 Jan 2005

Post Wed Feb 06, 2008 7:21 pm

I understand the complexity may go up, but realistically, the reciever could be hardware based, and plug directly into the SECU feeding it "relayed" data. I understand that article that talks about wireless interference and placing the sensors under the motor makes it unstable. My thinking tho is that in an ad-hoc manner, you would virtually eliminate any dead spots, and with the BT 1.2 stuff that I have had the opportunity to play with personally, I think that the latency is VERY sub 500ms. Motorolla has a set of BT headphones that I used to sell, and they were spectacular. The display in my store was directly plugged into a splitter that sent the Sirius radio into the BT sender and a home theater amp, and guess what? They started and stayed perfectly in synch. I used to wear them for hours to demo them for customers, and even after 3-4 hours, there was no problem.

I think that I would like to see the writers of that article go back and test some of the new BT technology, and update their findings!

http://portal.acm.org/citation.cfm?id=1147760

GOOD READ!

Chris
Conceptual
 
Joined: 15 Nov 2007

Post Thu Feb 07, 2008 2:11 pm

I think the idea is very good and may be factible with some special development, but only with some sensors placed in some "easy" signal places.
1km of cable must weight something, if you could only save 500m this would be something.
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio

"I have no idols. I admire work, dedication and competence." -Ayrton Senna
Belatti
 
Joined: 10 Jul 2007
Location: Argentina

Post Thu Feb 07, 2008 7:42 pm

Thank you Belatti!

The development is already being done, and they are called "Motes".

500m of cable would have so save some weight, so who knows!

Chris
Conceptual
 
Joined: 15 Nov 2007

Post Mon Feb 11, 2008 5:07 pm

Conceptual, Motes or MEMS as previously described are something totally different. What Motes aim to acheive is a clustered sensing of the environment. Like the wikipedia article states, an example application would be in and around a hospital. These motes in numerous quantities would be scattered across and would relay temperature, humidity etc params using their clustered architecture.

What is required here though is a real time relay of feedback from most of the sensors. If you look at the ECU diagram provided by the FIA you can see that the steering,etc is connected via CANx2 signifying the need of very-fast-nanosecond-instant responses from such inputs which not yet possible over a wireless medium. So yes, as Belatti said the solution could be a compromise between wired and wireless. I dont know how much complexity that would add but would surely be implementable.
Image
rghai6
 
Joined: 29 Nov 2007
Location: Mumbai, India

Post Wed Feb 13, 2008 1:53 am

I think the cluster motes would be exactly the solution. They would literally be applied to almost every surface in a mosaic pattern, and can give realtime feedback to the ECU or the team directly if they amplify the unit. Especially with Blutooth, once the connection is made in the garage, the trasnfer becomes realtime and digital so the link would have zero degradation.

Although, if it suffers from the same thing as the Playstation 3, where it randomly drops signal for 3-5 seconds, there could be some issues!


Chris
Conceptual
 
Joined: 15 Nov 2007

Post Sat Feb 16, 2008 10:17 am

As the rules currently stand, I believe it's illegal to communicate with the car during the race, except for voice transmissions. So any data acquisition system would have to store the data while the car is on the track, and then download it via a hard connection in the pits.

With MHz or GHz data acquisition rates, and dozens of inputs, that's a lot of data to store.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
riff_raff
 
Joined: 24 Dec 2004

Post Wed Mar 05, 2008 4:40 pm

riff_raff wrote:As the rules currently stand, I believe it's illegal to communicate with the car during the race, except for voice transmissions. So any data acquisition system would have to store the data while the car is on the track, and then download it via a hard connection in the pits.

With MHz or GHz data acquisition rates, and dozens of inputs, that's a lot of data to store.

500GB HDD's go for about $80 on pricewatch.com these days.

Chris
Conceptual
 
Joined: 15 Nov 2007


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