How to quantify the severity of multiple shock events
How to quantify the severity of multiple shock events
(OP)
Hello all. Here's my situation:
I've got a customer who manufactures seats for big rigs. The drivers of these rigs occasionally will see large shock events (~2-3 g's). The customer wants to install a system of accelerometers that continously records accelerometer readings from the seat. The goal is to come up with a system that will inform the driver when he's had too much input for the day. It can't be just a simple "count the number of events greater than 1.5 g's" since multiple events of say .75 g's quickly add up to more cumulative damage than a few 1.5 g events. Would it be possible to take a PSD of the time history data perhaps? Maybe update this every few minutes or so? (I understand the DRI and Se from OSHA codes but I don't think I can apply them for a limit switch...) If anyone has ever done anything like this or could help me out with the fundamentals I would be very grateful. Thanks.
I've got a customer who manufactures seats for big rigs. The drivers of these rigs occasionally will see large shock events (~2-3 g's). The customer wants to install a system of accelerometers that continously records accelerometer readings from the seat. The goal is to come up with a system that will inform the driver when he's had too much input for the day. It can't be just a simple "count the number of events greater than 1.5 g's" since multiple events of say .75 g's quickly add up to more cumulative damage than a few 1.5 g events. Would it be possible to take a PSD of the time history data perhaps? Maybe update this every few minutes or so? (I understand the DRI and Se from OSHA codes but I don't think I can apply them for a limit switch...) If anyone has ever done anything like this or could help me out with the fundamentals I would be very grateful. Thanks.





RE: How to quantify the severity of multiple shock events
Good luck
Regards
Dave
RE: How to quantify the severity of multiple shock events
So I guess that energy imparted to the driver is the way to go. I'm just not sure as to how to keep track of the total energy that the driver sees.
As far as the monitoring system, cost does not seem to be an issue. They have the seats instrumented, but now need to figure out the programs to create for the data recorders/processors to keep track of the input seen by the driver.
RE: How to quantify the severity of multiple shock events
However, if you are concerned with a specific mechanism (eg back injuries) you may have trouble finding an appropriate filter.
Make sure that you understand the interaction with the transfer function of the seat itself, ideally you should be measuring the acceleration of the seat pad itself, not the seat rail.
Occupational Health and Safety should have ths covered for mines and farmers.
Cheers
Greg Locock
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