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IMA Manual Control
IMA Manual Control has been a very desirable function for modders and tweakers with IMA cars ever since they came onto the market 20 years ago.
AFAIK it has only been successfully implemented in two Honda IMA models, the G1 Insight 1999-2006 and the HCH1 Civic Hybrid 2003-2005.
Both of these cars were pre CAN bus and had simpler electronics and were basically easier to hack.
In the G1 Insights case there were a lot of seperate computer modules joined using standard analog pwm type control signals.
In the HCH1 Civic a 10,400 bps serial data stream was used to convey assist control information from the ECM in the front to the MCM in the back.
The CAN cars from the HCH2 Civic 2006 onwards have proven to be a much tougher nut to crack.
The IMA CAN data stream between the ECM in the front and PCM in the back runs at 500,000 bps (500k).
A very fast and constant stream of data is passing back and forth/around the modules.
To gain control over the IMA we have to identify the relevant control packets in the IMA CAN datastream, intercept the packets we want,
modify, block, replace them as appropriate in real time, whilst allowing all the other packets and information through in both directions unmolested.
It's hard!
Why do it?
Honda's IMA control algorithm is very good but it isn't perfect, and it's a one size fits all middle of the road average driver solution.
Designed for simple operation and reliable results. It takes no heed of driving conditions, terrain or weather and cannot read the road ahead and plan accordingly.
Modders, tweakers, tuners, hypermilers really don't want tying into a stodgy setup, but with the IMA we have been pretty stuck.
Tuners for instance might want all or nothing assist and regen for maximum acceleration and deceleration during tracks days/racing etc.
The standard setup will only allow that for a very short time before the ECM cuts back to much lower power levels.
Hypermilers might want just a little dob of assist to get over a rise or to disable assist for a section of road due to unfavourable terrain.
In those mpg competitions every ml of petrol counts and parasitic regen can be a killer.
With manual control we can peg the assist or regen at maximum until the battery dies, the motor melts, or we can turn it all off completely.
The motor melting or the battery dying has not happened yet in any IMA modified car I know about even at 30kw+.
Honda engineered it all very well and the hardware (electronics and motor) can take a lot of abuse/tweaking as you have already seen from my CR-Z lithium mods.
So how will we do it?
I did look at this a bit some years ago and do have some IMACAN data gathered.
I wasn't so good with CAN then, but now it might be more doable with some extra effort.
Now though I/we need to gather a lot more data and analyse it to work out what packets and ID's are doing what.
It's important not to bite off too much and go for the whole thing straight away.
It's a big project that will take some time and effort.
Manual IMA control can mean different things and require different levels of complexity...
1) Complete control of the entire system, and the ability to command assist or regen at will, overriding whatever the car wants or was doing without error or complaint.
This will be the toughest and most difficult to accomplish. There may well be numerous critical interdependencies in the CAN data that need to be explored and resolved.
2) Increasing or decreasing car commanded assist or regen power levels.
Potentially much simpler and easier. We only need to identify the critical assist/regen level CAN packets and modify them.
So I will look at option 2 first..
I might need a willing Lithium CRZ owner who will let us gather some data from his car's IMACAN bus.
Anyone in the UK near Hull with one and few days/hours to spare after lockdown ends?
So the basic plan is gather some data, identify the relevant assist/regen level controls packets,
and modify the OEM ones or replace them with our own hacked packets.
I'll add to this thread as work progresses.
Help, ideas and feedback welcomed as usual.
Now I need to work on my man in the middle CAN gadget...........
IMA Manual Control has been a very desirable function for modders and tweakers with IMA cars ever since they came onto the market 20 years ago.
AFAIK it has only been successfully implemented in two Honda IMA models, the G1 Insight 1999-2006 and the HCH1 Civic Hybrid 2003-2005.
Both of these cars were pre CAN bus and had simpler electronics and were basically easier to hack.
In the G1 Insights case there were a lot of seperate computer modules joined using standard analog pwm type control signals.
In the HCH1 Civic a 10,400 bps serial data stream was used to convey assist control information from the ECM in the front to the MCM in the back.
The CAN cars from the HCH2 Civic 2006 onwards have proven to be a much tougher nut to crack.
The IMA CAN data stream between the ECM in the front and PCM in the back runs at 500,000 bps (500k).
A very fast and constant stream of data is passing back and forth/around the modules.
To gain control over the IMA we have to identify the relevant control packets in the IMA CAN datastream, intercept the packets we want,
modify, block, replace them as appropriate in real time, whilst allowing all the other packets and information through in both directions unmolested.
It's hard!
Why do it?
Honda's IMA control algorithm is very good but it isn't perfect, and it's a one size fits all middle of the road average driver solution.
Designed for simple operation and reliable results. It takes no heed of driving conditions, terrain or weather and cannot read the road ahead and plan accordingly.
Modders, tweakers, tuners, hypermilers really don't want tying into a stodgy setup, but with the IMA we have been pretty stuck.
Tuners for instance might want all or nothing assist and regen for maximum acceleration and deceleration during tracks days/racing etc.
The standard setup will only allow that for a very short time before the ECM cuts back to much lower power levels.
Hypermilers might want just a little dob of assist to get over a rise or to disable assist for a section of road due to unfavourable terrain.
In those mpg competitions every ml of petrol counts and parasitic regen can be a killer.
With manual control we can peg the assist or regen at maximum until the battery dies, the motor melts, or we can turn it all off completely.
The motor melting or the battery dying has not happened yet in any IMA modified car I know about even at 30kw+.
Honda engineered it all very well and the hardware (electronics and motor) can take a lot of abuse/tweaking as you have already seen from my CR-Z lithium mods.
So how will we do it?
I did look at this a bit some years ago and do have some IMACAN data gathered.
I wasn't so good with CAN then, but now it might be more doable with some extra effort.
Now though I/we need to gather a lot more data and analyse it to work out what packets and ID's are doing what.
It's important not to bite off too much and go for the whole thing straight away.
It's a big project that will take some time and effort.
Manual IMA control can mean different things and require different levels of complexity...
1) Complete control of the entire system, and the ability to command assist or regen at will, overriding whatever the car wants or was doing without error or complaint.
This will be the toughest and most difficult to accomplish. There may well be numerous critical interdependencies in the CAN data that need to be explored and resolved.
2) Increasing or decreasing car commanded assist or regen power levels.
Potentially much simpler and easier. We only need to identify the critical assist/regen level CAN packets and modify them.
So I will look at option 2 first..
I might need a willing Lithium CRZ owner who will let us gather some data from his car's IMACAN bus.
Anyone in the UK near Hull with one and few days/hours to spare after lockdown ends?
So the basic plan is gather some data, identify the relevant assist/regen level controls packets,
and modify the OEM ones or replace them with our own hacked packets.
I'll add to this thread as work progresses.
Help, ideas and feedback welcomed as usual.
Now I need to work on my man in the middle CAN gadget...........
