Car Vibration Load Data Base
Car Vibration Load Data Base
(OP)
Greetings, Can anyone provide a site that contains typical vibration spectra and loads when an auto is driving down the street and/or stationary with engine running? I understand there are a number of factors and variables, but I just need to get a feel for typical numbers.
Thanks
Thanks
RE: Car Vibration Load Data Base
Cheers
Greg Locock
RE: Car Vibration Load Data Base
In answer to your question - the body.
RE: Car Vibration Load Data Base
A quick answer in the meantime is that the vibration in the car is around the 24 hour comfort limit for human body exposure.
Cheers
Greg Locock
RE: Car Vibration Load Data Base
Thanks for your help in this matter.
RE: Car Vibration Load Data Base
I can't help feeling that in this case there is a simpler solution - picking up the speedo drive, so when the car starts to move the instrument shuts down.
Oh, do you want the thing to work when the engine is running but the car is in neutral?
Cheers
Greg Locock
RE: Car Vibration Load Data Base
The instrument will be sitting on the floor, not bolted to it. Since any number of vehicles can be used, integrating it into each car directly adds complexity. All I am looking for is rough order of magnitude numbers (ROM). I plan to go out and make some measurements with prototype board, but the ROM numbers would be helpful in programming the firmware and preliminary circuit design.
Bill
RE: Car Vibration Load Data Base
Cheers
Greg Locock
RE: Car Vibration Load Data Base
a fore-aft accelerometer (or a set of accelerometers) which actuates the standby mode. A single fore-aft acceleration beyond, say 100 mm/sec^2 (0.01 g) would cause this to shutoff. My logic for this is the following--in order to drive the car, there must initially be some non-trivial fore-aft acceleration. When the instrument feels that the car is starting to move, then it will shutoff the device. Don't worry about average 'drive' accelerations, just worry about the initial acceleration that the undergoes when it starts to drive.
Three potential issues which I already see, but which may not be a big deal for you:
1) Is the damage already done once that initial acceleration occurs?
2) This presumes that the fore-aft driving acceleration is sufficiently higher than your machine's general in-use acceleration environment. I presume this to be true based on your discussion, but that is yours to confirm.
3) Your initial statement was that you wanted to detect the fact that the engine is running. You have since stated that the concern is actually the car in motion. This proposed solution focuses on the car in motion. This would not turn off the car for the non-moving engine running situation.
And Greg, throw in your input on my solution. I think it holds water, but if I've overlooked something, I'm quite sure that you'll pick up on it (and I mean that as a sincere compliment).
Brad
RE: Car Vibration Load Data Base
Thank you for the inputs. To answer Brad's questions,
1. No, instrument will not be damaged.
2. I am fairly certain the in-use acceleraton environment is lower than acceleration when driving. I was planning to measure at rest, engine running no movement and car moving since the firmware can be used to look at a relative change in either frequency, amplitude or both instead of a absolute value. This typically provides a lower false alarm rate in other measurement methods I have used in the past.
3. I am interested in a moving vehicle. In reviewing my original request for input, I was looking for any available data either moving OR engine idle without moving just to get started on my feasibility path. I thought someone could point to a site with a tabulation of data on either situation.
I want to thank you both (Greg and Brad) for the inputs you have provided to my questions.
Greg, (or Brad )if you have any other ROM type data and are willing to share it, I would appreciate it.
Cheers
Bill