Keeping trip record for fun & early problem detection

I have been keeping records of daily trips for fun and also hoping to catch problems early on such as the dreaded inverter coolant pump failure. I figure I will use PriusChat as the "time stamp". Here are the data that I have gathered so far:

Trip miles and gallons used (via ScanGauge): almost all trips are for commuting.


Starting and ending SOC (%) and average speed (MPH): I have been avoiding the interstate highway in the last couple of months to get more relaxed driving as well as higher MPG.

2012 update:

With PriiDash I can add the min and max SOC for each trip to the record. You should be able to see easily the one occasion when I force charged the HV battery until it could not take any more (limited by ECU).

Engine coolant and inverter case temperature: The yellow and pink lines indicate various levels of overheating. It looks like full grill block is not a good idea even in the middle of winter. I did find that the max temperature is registered not while the engine is running. Usually the coolant temperature is lower when the engine is running, and will creep up after the engine is stopped (thus the water pump is stopped). So the actual operating temperature is at least a few degrees cooler than the recorded max. The inverter case temperature is read with an oven thermometer glued to the inverter case.

2012 update:

Shifting to all local commute made the need to adjust the grill blocking less frequent. I ended up leaving the bottom grill mostly covered year round and adjust the top slits slightly according to the season.

With PriiDash I can monitor inverter, converter, HV battery and MG temperatures. Together with the oven thermometer measurement, they are plotted against the outside air temperature and give us a good idea of expected range of temperatures:

Of course it may still vary depending on whether it is local road or highway trip.


Fuel economy (MPG): A sudden change in MPG could be indication of brake drag or 12V battery dying.

2012 update:

When I participated in a hypermiling rally last year I reset the MFD MPG for the first time. A short time after that I started to reset it at the end of every trip. So it has changed from lift time cumulative MPG to per trip MPG. More recently I started experimenting with two OBD-USB devices running in parallel under PriiDash. So ScanGauge II has been retired since. Prior to that I found ScanGauge II does not match the per trip MFD MPG number as well as PriiDash does.
MPG vs. T:

The lower grouping is mostly highway and the upper one mostly local roads. For my commute 90 MPG seems to be the ceiling (for a single trip under the best conditions).

12V Battery Voltage tests:

2012 update:

With the PriiDash project I started to log the lowest IG-ON 12V value for each trip and as I improve the sampling rate the logged lowest value trends lower (more chance of catching the V drop when pressing the brake to go to READY mode) - at least that's my wishful thinking of the reason for the drooping IG-ON 12V value. We will see.

 

PriiDash(TM) - Re: Keeping trip record for fun & early problem detection

I got tired of the shortcomings of ScanGauge: no inverter and MG temperatures for gen 2, too few parameters shown at once, lack of analog or "on/off lights" display for quick glance, slow update speed, no color... etc. So I have been slowly looking for another solution, not only for trip record keeping, but also for hypermiling. I almost decided to buy the expensive Autoenginuity but then I found from the manufacturer that it can not be set up to talk to more than one ECUs in the same session. This pushed me over the edge to start piecing together a solution myself.

Thanks to help from many people, yesterday I started road testing my own DIY gen 2 Prius CAN OBD DigiDash PriiDash(TM):

It shows many more parameters simultaneously, including all the inverter and MG temperatures. Each gauge will light up in different colors if there is something that worth grabbing one's attention - for example in the photo above the coolant T gauge light up bright red when it exceeds 190F. Another example is the HV amp (current ): it shows gray within +/-8A (gliding), yellow above +8A (discharging: EV or power assist), cyan below -8A (charging: braking etc.). Each gauge also shows in small font the min and max values.

I did a quick video of pulse and glide this morning. It should be easy for you to tell when the pulse started and when it ended and the next glide started:
[ame="http://s911.photobucket.com/albums/ac318/2009Prius/CAN%20OBD%20DigiDash/?action=view&current=CANOBDDigiDash20101130.mp4"]CAN OBD DigiDash :: CANOBDDigiDash20101130.mp4 video by 2009Prius - Photobucket[/ame]
And I thought I did not too bad keeping the pulse near IGN 14 that's supposed to be the most efficient.

The video embedding still does not work. Please click on the title of the video and go to the photobucket site to see the video.

Update: photo showing most recent version: (not sure why sometimes photo does not show)


2012 update: (not sure why sometimes photo does not show)

Added more gauges, especially the PSD power gauge.

 

Yes I will be adding MG1 and MG2 RPM, probably in a lever graph together with the ICE RPM since the three are linked.

Right now this is just a research/hobby and very far from a finished product. When I am done tweaking/debuggingeek I may just make the software part a shareware or even a freeware accepting donations if people like to. For the hardware people can get their own OBD-USB dongle and tablet PC or laptop/monitor combo - it would definitely be too much hassle for me to sell hardware.

Thank you for showing interest!

 

Thanks for reading and glad the info may be helpful.
I don't have gen 3 (2010), only gen 2 (2009). When I said full block I meant both the upper (2 slits) and the lower (5 slits?), and for the lower slits I even cut little pieces of foam to stick into the sides so no air could come through the gaps on the sides (next to where the fog lamps would be if I had them). Hope this helps. Good luck!

 

It's not "my" device, I just bought an off the shelf OBD-USB connector and wrote a program for it. The free software that came with it does read DTCs but I haven't checked if it reads Prius specific ones. When there is a need I will try to add the capability to my program. Just takes time.

 

Yes. I just realized that name has been taken:
ETB Instruments - DigiDash2 - LITE

I will rename my program PriiDash then.

 

Thanks for showing interest but again right now this is only a hobby with limited spare time to work on. In addition the CAN codes are quite different between gen 2 and gen 3 Prius. So please don't put too much hope on getting this particular piece of program to work on your gen 3 anytime soon. But I am sure there are other options that will suit your needs - just keep an eye on new developments on PriusChat. Good luck!

 

Done! I mimicked this nice simulator that shows the linear relationship between the three RPMs and the limiting factors:
http://eahart.com/flash/PSDAnim.swf
Here is the web page:
Toyota Prius - Power Split Device

Here are some "in action" photos. The lever graph is at the lower right corner and rightly named "PSD".

This one is during "pulse", ICE is running and providing drive power.


This one is during "glide", ICE has stopped and MG1 and MG2 are spinning in opposite directions.


When the speed exceeds ~ 40 MPH the ICE starts to free spin to prevent the MG1 from over revving.

Note in all three pictures the three RPMs in the lever graph form a straight line as they should be.

Some more details:
The ICE RPM is read ~ 15 times per second from already available "passive" CAN messages but the MG1 and MG2 RPMs need to be queried and there are many others to be queried so they each are sampled about 0.4 times per second. Also the most recently read values are recorded every second. As such the recorded values may not line up exactly. This graph shows some recorded data. Most of them follow the rule
3.6 ICE = MG1 + 2.6 MG2
but some are affected by the sampling/recording imperfection:

 

Thanks!

I decided to give the temperature gauges a new look. Or is it an "old look"? Anyone old enough to remember what thermometers used to look like?

 

Thank you for sharing your experience! Yes even before starting the project I had considered the potential issue of sensory overload if there is too much color or graphics. So I try to follow a rule that most important data (speed, rpm, IGN, ICE temp etc.) occupy the more prominent gauges, and the lesser ones in less prominent gauges with less vivid color (but will "light up" if something unusual happens such as inverter overheat). For example right now the ICE coolant temp is in the round gauge at the upper left corner, while the inverter, MG, and battery temps are in the new "thermometer gauges". The cat temps are still plain numbers. I do like the graphic analog gauges that seems to give a more direct and faster feedback than the digital numbers - I think our brain is wired to respond much quicker to graphs than numbers.

And yes I also start to feel the pain of having to mount/unmount the tablet PC and think about doing something more permanent after all the development work is done. Though there is some worry that someone will break the glass if the LCD is visible from outside the parked car. Do you have a recommendation of manufacturer or model number for the touch screen? I heard of something like "liliput"(?) but don't know much beyond that.

 

New Year's Edition: added ICE load, MPG (instantaneous and average), ODO, one more engine coolant temp, fuel gauge, travel time, ... etc.: (also see data plotted in this thread)