JeremyW wrote:In the google doc we have a few "is this speed/volts/torque?" for a few of the high priority (10ms) messages. I thought of two little tricks to find some of the inverter messages: while in reverse at say a few MPH, throw the car into drive. With the parking brake on, put the car into drive and put a little throttle on to make the motor push against the brakes. From those two tests (in a secluded area with nobody around!) I found the following on the EV CAN bus:
Message 1D4 bytes 2-3 2's complement is in fact commanded torque. Units are unknown but I've confirmed the value is positive while the car was still going backwards but "accelerating" forward (after I put it into drive from reverse while moving).
Message 1DA bytes 4-5 2's complement is motor RPM. Units are again unknown but this one should be easy to figure out since we know wheel speed from other values as well as the reduction gear ratio. Probably 0.5 rpm/bit.
Message 1DA byte 8 with the mux identifier as byte 7 shows the individual phase currents for the motor, including neutral. Byte 7 00-02 are the 3 phases and 03 is the sum or neutral. Even at 10ms per message there is significant undersampling.
Anyway I have about 90% confidence on these values. I encourage anyone with a bit of space around to try the above tricks and see what's what. If you have a 2011 or 2012 with the electronic parking brake note that if you hammer on it too much, it'll automatically disengage!
Interesting idea but I am not convinced it really provides insight. Both commanded torque and motor amps will be positive if imparting
positive torque - regardless of the motor rotation direction. This occurs when accelerating forward (top right scenario) or decelerating reverse (bottom right) which is the mode you entered when you threw it into D from R. Similarly, during forward regen (top left), 1D4:23 goes negative when regen braking although you are still rotating the same direction. So I don't think we can make any conclusion on whether it is commanded torque or actual current or torque.
Also, how did you conclude that 1D4:45 is motor rpm vs. motor Volts (Volts is directly proportional to motor speed)?