I've been getting asked this question by a lot of people. So I figured Id just make a post.
Its popular and yes you can use angle error and modify the torque values then calculate the inverse of the load tables. I do not suggest it as calculating the inverse for the top inverse row the torque is 0 is impossible.
Heres why:
Its an inverse relationship which is y=1/x.
x being air load and y being indicated torque.
It can also be x=1/y. This is where dividing by that 0 is impossible.
If you look at the inverse relationship Y will go to infinity before x is 0 and x will go to infinity before y goes to 0.
If you look at the inverse relationship indicated torque will go to infinity before air load is 0 and air load will go to infinity before indicated torque goes to 0.
ETC torque/desired torque/ driver demand torque can all go below 0. basically you need to use this as your 1 or the "constant" to establish your base air load and indicated torque.
inverse.png
The way I suggest to do it is start by modifying the load values. I first find my desired/ETC/driver demand torque in the torque tables. The PIDs read nearly the same when things are not way off.
To find our values to replace that 1 and get our desired torque values we can multiple the load and torque of the Y axis of the torque and inverse tables. X*Y=1 As long as your maximum driver demand falls somewhere near the bottom of the tables everything should work out. And because ETC goes below 0 we end up with a load floor for that 0 torque row. All you have to do is setup a Graph with these values in the rows and using PID ETC TQ. Then set the columns to the RPM range in your tables. I suggest making them slightly higher than your red line. Then have the table fill with your air load. Drive around trying to hit every RPM and every load to fill in the table. Filter the graph by MPs so you can apply the load to the correct MP. After applying the new load values you will need to click smooth the entire table a few times to get it smoothed out. You can then take these new values and apply them in to the attached sheet to get the new torque values. The torque values in the top table do nothing(except the top row) in this sheet so it cant be used for the angle error method.
shouldn't take to long for all IPC error to clear up and the car driving much better. .
inverse.xlsx