On Thu, Dec 17, 2015 at 1:59 PM, Ralf Müller
We are exploring accessing the wheel movement information.
Here I could ask which wheel do you mean …
A vehicle wheel. Preferably not one driven by the transmission. So on a rear-wheel drive system, we want the rotation information of the forward wheel. We do not want the tire that may slip when accelerating or decelerating.
We currently install our own wheel pulse transducer that has <1mm resolution. We use that resolution to control high speed lasers that are sampling the road for the calculation of things like texture. I cannot see how one could get such access via this mechanism.
This massively depends on what you need to transmit at which rate.
Each tick of the wheel rotation. I would imagine the resolution here is vehicle dependent. Our wheel pulse transducer provides up to 10000 pulses per wheel rotation. It is a quadrature signal so we also know direction of rotation.
It is not just to know that X number of pulses have occurred. We need to act on each individual one. We currently use a small embedded
computer card (no OS) and our own pulse transducer for this. It can act on individual pulses (controlling various bits of hardware) and relaying summary information as needed. We are exploring what we might accomplish with CANBUS for this.
Using a bit rate of 1 MBit to transmit 32 Bit paylod in CAN frames with 11 bit addresses you can achieve more then 10000 messages per second when you saturate your bus. Don’t know if that is sufficient for your needs …
Not for all of them. For some data synchronization, we use a pulse roughly each millimeter. At 90 km/h that's 25 kHz. Anyway, we have just been exploring what CANBUS offers to see if it is interesting. Maybe wheel pulses are not useful. At least not in some systems. We do have others where we do not need the high resolution. So maybe CANBUS can work there. For other types of things, http://www.opencar.com/ looks interesting. Not sure how one gets their app installed... -- Roger Oberholtzer -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org