Re: Control Technology
Posted by:
Chuck Hays (IP Logged)
Date: August 24, 2004 07:56PM
<HTML>Andy writes:
> Hi Garry and Caleb
I'm neither Garry nor Caleb, nor do I play either of them on TV, but hello in any event. :)
> I think everone has a technology they are content with. I am wondering if >we can catagorize them.
> 1. Manual
>
> 2. Mechanical.
>
> 3. Electric
>
> 4. Electronic
>
> 5. Computer
Categorisation is one thing, prioritisation quite another. To take your categories in order, I would say that manual-level controls should be limited to things like turning on the ignition key, or checking various gauges or sight glasses before starting up -- as it has been pointed out, any manual operation takes a lot of attention away from driving, particularly so while one is still learning a new vehicle's operative quirks. Bad enough with a new internal explosive car, much worse with a completely different technology.
Mechanical controls can be grossly simple, to control large processes or critical links -- such as a positive shutoff for a fuel feed or water tank. In some cases where mechanical controls are able to be both robust and simple, they may very well be the most effective. Boiler pressure popoffs, flyweight governors, things like that which require only mechanical power input to work and do not depend on an electrical system. Mechanical controls can be manually operated or they can cross over the other category line and be electrically or vacuum or pressure operated. I would argue that you should have "Electromechanical" as a category, since many of the controls I can think of would be of that sort.
Electronic controls certainly have their place in a modern automobile. I'll discuss them more in a moment, but I would like to address computer controls first. I have ridden high-performance motorcycles which literally require a computer network to operate. One race bike I piloted had five computers -- four to control various parts of the machine and one to act as the network server. The bike could be monitored in its most intimate details while underway, and the tuner could even make changes and upload them to the server on the bike via a radio link as changing race conditions necessitated. As to electronics, I appreciate the reliablility of blackbox componentry, even on my hotrod bobber. I ran the same ignition with zero maintenance from 1989 to 2004, then upgraded to a newer ignition module with performance advance curves and a higher rev limiter. It was cheaper than the old module, mechanically more robust, and it just plugged right in. Zip-zap-shabam -- race-tune in a box.
Electronics are not de facto bad. However, I would say that for any application in a steam vehicle for which you have the choice from among the categories above, the priority tree might look something like this:
1. Can this process be controlled manually in a simple fashion that will not require much of the driver's attention while underway? If so, make it a manual control.
2. If not, can this process be controlled by a relatively simple electromechanical device, preferably one available off the shelf or simple to modify, make and maintain? If so, make the control electromechanical.
3. If not, can this be controlled by a simple electronic blackbox, available off the shelf or easily reconfigured to work in this application? If so, control electronically. Granted, electronic blackboxes do not allow user fiddling. However, a complicated electromechanical process can often be more accurately controlled by a black box. The main question then becomes having sufficient spares available to prevent downtime.
4. If the process cannot be controlled electronically, I would tend to argue that the process needs to be rethought rather than go to computer control from there. That said, having the ability to tune engine parameters at 5-revolution step intervals can be useful for setting up a vehicle for optimal performance. Just as I tend to believe that manual controls are far too crude and require too much of the operator's attention at present-day road speeds, I also tend to believe that very, very few people would care to bother with such an intensive level of micromanagement of their motor vehicle as would be represented by a fully-accessible computer control system. Even setting up a computer controlled fuel-injection program for a Harley takes a lot of time and presents the average tinkerer with an incredible number of ways to screw it up.</HTML>