The idea to make a DBW controller has been with me for quite some time now, and this is the second iteration of the DBW controller. The first DBW controller was made by me for my bachelor's thesis (2015), and that controller was in my car for quite some time. Current DBW controller addresses the problems found in the first one, and has more powerful hardware.
The reasoning behind this project was to finally make possible full engine control with automatic downshift blips and all sorts of torque management and engine protection schemes found in top dollar systems. The MS3 controller is probably the most cost effective solution for really good engine control, but it has the limitation of no DBW control. That is what we want to change. As I saw that the MS3 1.5 firmware had the added DBW controls, this project was taken out from hibernation.
Specs
Dual DBW throttlebody capability on one controller. Both dbw throttles can be controlled independently. Also the pid / frequency settings are independent on each channel. Maximum frequency is 20kHz, so you won't be hearing that high pitched whine from the throttlebody.
Maximum current for each DBW channel is 10Amps, so it can control most of the dbw throttlebodies. The dual throttlebody capability gives the possibility to run dual plenum intakemanifolds on V engines, like the Holley sniper manifold. And you don’t have to setup a complicated throttle linkage that is prone to failure if done incorrectly. If you do not need both throttlebodies to control the actual intake, you can use the other channel as a dbw blowoff valve or a supercharger bypass valve. We can program the system to do almost anything with software updates.
Controller has 2 modes of operation, Standalone and the 11bit ms dbw can messaging. This can be set independently for both throttlebodies. When selected to operate via MS can messaging, complete control of the throttlebody is given to the megasquirt. Only exception is the user settable safety table that can be setup to reject out of bounds requests. This table is Maximum allowed opening as the Y-axis and throttle pedal position as the X axis.
Safety
Safety has been handled by using dual microcontrollers on the controller. Both "tps" signals (main / secondary) from the pedal and throttlebodies are constantly monitored by both CPU's independently, and in the case of malfuntion or sensor missmatch the throttles are closed / powered off.
Both CPU's have independent ability to shut down the throttles in case of malfuntion. Both CPU's also process the information independetly. This arrangement makes the hardware completely fault tolerant if one of the CPU's have a critical error/harwarefault.
As the main CPU is a ARM Cortex 32bit core, we wanted to use a more proven/rugged CPU as the secondary. So we chose the 8Bit AVR as the secondary microcontroller. The AVR is a old but proven cpu architecture, and the electrical specifications of the mature microcontrollers are generally more robust than the newer parts.
Tuning the controller
My favourite part on this controller is that it can be tuned via Tunerstudio. Big thanks to Efi Analytics for making it possible. Tunerstudio is a powerful tuning software with exceptionally good logging capabilities. You probably knew all this but anyways... The idea is that you can tune/setup this DBW controller via the MS can passthrough. However this is still a work in progress because of a small issue regarding the communication endianness on the can passthrough, but the issue is being worked on.
The controller can also be configured via USB. USB is also the preferred connection method if you are tuning the PID controller. USB connection provides the fastest logging speed of the controllers parameters, and you really want the fastest possible speed in communication when tuning the PID controller. I will try to make a video on how to tune the PID controller for a throttlebody so that you can see yourself how hard/easy it is.
Our plan is to get the most popular throttlebodies and provide the calibrations/PID settings for them so that most users don’t have to deal with the pid tuning.
As you will see on the following short video, the controller is capable of excellent performance on controlling the throttle blade position. On the video you will see a Tunerstudio live log trace that has on the upper trace the "target" and "actual" positions off the throttlebody. You can see that most of the time the traces are identical, and on rapid movements when the mechanical mass of the throttlebody can't keep up you can see small differences on the traces.
See the video here:
https://youtu.be/Cf0ir3W05cg
I am thinking of setting up a kickstarer/alternative to fund the first manufacturing batch if there is interest. As these controllers are actually quite expensive to make in small quantity, it would be ideal to make a bach of 100 or more to keep the unit cost reasonable. If we could get 100 pieces manufactured, the retail pricing should be in the 300-400usd range depending on how good of a deal we can get with the manufacturing side of things.
Looking forward on hearing your thoughts!
Edit:
Order here: http://www.dbwx2.com/
Thanks very much Petski3...! I have always adored and admire the Fins as I used to worked in Scandinavia particularly in Norge...! they are awesome people...!