Fusion Hybrid Powertrain Technical Analysis with Torque Pro & a ScanGauge

[hybridbear]

I've been analyzing more data over lunch and I found another instance similar to the one mentioned above. This time the Gen RPM went from being around 3000 down to 700 RPM while still putting the same amps back into the HVB. When the Gen RPM dropped, the temps dropped. Both these instances happened when accelerating up to freeway speeds. The change in behavior happened when exceeding 42 MPH in the instance mentioned above and when exceeding 51 MPH in this instance. My theory is that the temps dropped because the Gen RPM dropped and the Gen RPM dropped because the car began sending more ICE torque directly to the wheels instead of generating electricity that was then consumed by the traction motor.

[hybridbear]

Reviewing data from another trip seems to confirm this. One stretch where the ICE came on driving at 50+ MPH caused a minimal increase in Gen Invtr Temp and the Gen RPM was 1200-1400 RPM with 30-38 amps flowing into the HVB. This indicates that in this instance the ICE was sending torque directly to the wheels and was not sending all its torque to the generator to make electricity for the traction motor to use to drive the wheels.

[acdii]

If the cooling system is always circulating, then how is the temp regulated?

[hybridbear]

I made some comments earlier about the typical range of SOC used. Now that I have trip data I can expand those comments.

 

Useable SOC has a minimum value of 13% to 18%. This translates to an absolute SOC minimum of 36.2% to 38.2%.

 

Useable SOC has a maximum value of 48% to 65%. This translates to an absolute SOC maximum 49.6% to 55.9%.

 

The median maximum value in the approx. 20 trips that I analyzed is 53% useable SOC or 51.5% absolute SOC. The median minimum value is 16% useable SOC or 37.2% absolute SOC.

 

The shortest trip I reviewed today was 6.3 miles and the longest was just over 20 miles. All but one were between 6.3 & 12.8 miles.

 

This shows how carefully the battery is managed to protect its longevity. The maximum range of 36.2-55.9% absolute SOC means that we're only using 0.2758 kWh of the 1.4 kWh battery in the FFH in normal driving.

[tr7driver]

I would assume the two cooling systems are completely separate, with one regulating the ice temp (and the climate control) and the other regulating the generator? Can your read temps from both systems?

[hybridbear]

If the cooling system is always circulating, then how is the temp regulated?

Increasing or decreasing the speed of the coolant through the system perhaps. That's how the Prius does it. One of the Torque parameters I can track on the Prius is the hybrid water pump RPM. The lowest water pump RPM is 3250. When temps increase the water pump RPM will increase. I've seen it as high as 5000 RPM in the Prius.

[hybridbear]

I would assume the two cooling systems are completely separate, with one regulating the ice temp (and the climate control) and the other regulating the generator? Can your read temps from both systems?

In the Prius I can, in the FFH I cannot. That's why I use the temps from the Motor Inverter and Generator Inverter to track those temps. In the Prius the temp of the coolant is always much lower than the temps of any of the components. The Generator Inverter and Motor Inverter are the hottest points of all the temp sensors I can track in the Prius, that's why I'm comfortable using their data for the FFH as the hottest points in the hybrid system.

[corncobs]

@HB very nice stuff you are finding / writing here.

 

Now imagine that the computer got messed up during the initial "break in" or other reasons and the usable SOC (operating point) isn't were it should be for some of the underperforming cars out there.

This could explain why the 100% SOC hard reset has helped in most cases to improve FE resetting all mapping tables and making the system aware of its real capabilities.

Edited March 18, 2014 by corncobs

[acdii]

@HB very nice stuff you are finding / writing here.

 

Now imagine that the computer got messed up during the initial "break in" or other reasons and the usable SOC (operating point) isn't were it should for some of the underperforming cars out there.

This could explain why the 100% SOC reset has helped in most cases to improve FE resetting all mapping tables and making the system aware of its real capabilities.

Good point. If the set base values are off from the beginning, it can cascade as time goes on. If the computer determines a full charge is only 40%, and discharge is only 30%, then you only have 10% efficiency of the battery. It does figure into the BD, because I rarely ever saw a charge above 60% while driving, while this one I can get a near full charge.

[ptek]

 

Is there a way to read the position of the active grill shutters? Are they being commanded open when you hit that 140F? It would be interesting to see just when they are open at all, my guess is their main reason to open would be to provide air to the A/C condenser more than anything else.

 

 

Not that anyone has found. That's an interesting theory on the temp dropping. I will have to look more closely at the data to see if coolant temp and intake temp are also affected at that same moment to indicate that the shutters are opening.

 

I'm just getting started with my new ELM327 (just got it to connect tonight), so I'm still learning and may be off base here.

 

I'm currently using FORScan with my WinXP laptop. FORScan has parameters for Grille Shutter A Position - Commanded and Grille Shutter A Position - Inferred. These are in the OBDII module. Doesn't Torque have these?

Edited March 19, 2014 by ptek

[tr7driver]

Can you write to memory module with any of these tools? LIke change the parameters for grill shutter position or change the level that causes the shutters to close?

[acdii]

That is a slippery slope to try that.

[hybridbear]

 

I'm just getting started with my new ELM327 (just got it to connect tonight), so I'm still learning and may be off base here.

 

I'm currently using FORScan with my WinXP laptop. FORScan has parameters for Grille Shutter A Position - Commanded and Grille Shutter A Position - Inferred. These are in the OBDII module. Doesn't Torque have these?

It's likely. Torque can read any parameter if you can give it the data to allow it to find the data. What data can you see in FORScan about those data points?

[ptek]

It's likely. Torque can read any parameter if you can give it the data to allow it to find the data. What data can you see in FORScan about those data points?

 

I think the commanded and inferred grill shutter positions would be the only interesting ones. Here is a copy/paste of the FORScan output that I logged the other night with the car parked & ICE not running.

 

AAT 48 °F Ambient Air Temperature

GRILL_A_CMD 15.29 % Grill Shutter A Position - Commanded

GRILL_A_INF 31.37 % Grill Shutter A Position - Inferred

EC_BYPASS_VLV Off Engine Coolant Bypass Valve Control Output

RPM 0 rev/min Engine Revolutions Per Minute

VSS 0.0 mph Vehicle Speed

RUNTM 0 min Engine Run Time

OIL_REMAINING 85.00 % Engine Oil Life Remaining

 

The attached pic shows the available shutter parameters.

 

Note that the PCM module has a few hundred parameters available (some probably aren't very interesting). The BECM (Battery Energy Control Module) has 62. Unfortunately, it doesn't look like FORScan will let you pick and choose parameters between modules. You can only look at data from one module at a time.

[hybridbear]

I don't understand what the percentages mean for the grille shutters or why they're different...

 

I think the commanded and inferred grill shutter positions would be the only interesting ones. Here is a copy/paste of the FORScan output that I logged the other night with the car parked & ICE not running.

GRILL_A_CMD 15.29 % Grill Shutter A Position - Commanded
GRILL_A_INF 31.37 % Grill Shutter A Position - Inferred

[Waldo]

The grill shutters have 16 different positions, so % commanded is simply the % open based on those 16 positions. The Inferred must be based on the feedback from the grill shutter motor, it should represent the actual opening. It should be pretty close to the commanded I would think, but it would depend on how long it had been since the commanded changed. The main purpose of the inferred is to relay back to the computer if the shutters are stuck for some reason.

[larryh]

 

I think you can create a chart very similar to a BSFC chart using the OBD II data from the FFH, but it will take a lot of work. I am not expert on internal combustion engines, but from what I have read, the OBD II Absolute Load data, which measures volumetric efficiency (air flow into the engine), is linearly correlated with brake torque. So using this, Engine RPM, and fuel consumption rate OBD II data, you could synthesize a chart very similar to a BSCF chart. Unfortunately, the different measurements are not synchronized. They are read at different times up to a second or more apart. A lot can change in one second. So it will take a lot of work to make the necessary corrections for this issue and you won't get a complete map since the engine will not operate in all regions during normal operation. You can see a plot of Absolute Load vs. Engine RPM for a 30 mile drive on highways for my FFE here: "http://www.fordfusionenergiforum.com/topic/1880-obd-ii-data-for-ice/?p=12267".

I previously mentioned that it might be possible to create an Engine Map from the OBD II data recorded by Torque. I attempted to do that for my Fusion Energi here:

 

"http://www.fordfusionenergiforum.com/topic/1880-obd-ii-data-for-ice/?p=12414"

 

Since during normal operation the ICE only operates in a limited range of RPMs and Loads, I can only get a rough picture of what the actual map looks like.

[larryh]

I previously mentioned that it might be possible to create an Engine Map from the OBD II data recorded by Torque. I attempted to do that for my Fusion Energi here:

 

"http://www.fordfusionenergiforum.com/topic/1880-obd-ii-data-for-ice/?p=12414"

 

Since during normal operation the ICE only operates in a limited range of RPMs and Loads, I can only get a rough picture of what the actual map looks like.

I updated the Engine Map in the post at: "http://www.fordfusio...or-ice/?p=12414".

I had assumed that Absolute Load was linearly correlated with Torque as I had read in various articles. That turns out not to be the case. I updated the map to correct for this non-linearity.

Edited March 23, 2014 by larryh

[hybridbear]

I have confirmed that my comments in post #1 about the power flow screens are correct. "Charging HV Battery" means that the ICE is sending torque directly to the wheels. It is not 100% yes or no like the Honda Accord Hybrid though. It also does not appear to be a fixed ratio like the Toyota hybrids. I'll see a wide variation in Generator RPMs per amp of current flowing into the HVB when in this mode. This indicates that sometimes not all of the current from the generator is going to the HVB. Some of the current may still go to the traction motor to send torque to the wheels. Typical Generator RPMs when "Charging HV Battery" appears on the power flow screen are less than 2000, sometimes the Gen RPMs will be as low as 400-500 while still sending 30 amps to the HVB. When the screen says "hybrid drive" the Generator RPM is often 4500+. This indicates that "hybrid drive" means that the ICE is sending little or no torque directly to the wheels, but that all the ICE torque is being used to spin the generator to make electricity to charge the HVB and to spin the traction motor.

 

Occasionally you will see "Charging HV Battery" and lower Generator RPMs in city driving, but not often. I don't do much driving between 35 & 55 MPH, most of my driving is city streets at 35 MPH or less or on the freeway at 55-65 MPH. Rarely below 35 MPH will you see "Charging HV Battery", at those speeds it's almost always "Hybrid Drive" and 4500+ RPMs for the Generator. Above 55 MPH you rarely see "Hybrid Drive", it's almost always "Charging HV Battery" and Generator RPMs of 3000 or less, usually 500-1500 for 30 amps of charge to the HVB.

 

I guess I didn't need Ashley to get an answer from Ford engineering about the power flow screens. Thanks to Larryh helping me get setup with Torque and these PIDs which wouldn't work on the ScanGauge I have been able to figure it out myself.

[hybridbear]

It has been brought to my attention that the Usable SOC numbers I have referenced before are nothing more than a calculation of the Absolute SOC that the car records. Usable SOC is not pulling data from a different sensor and thus doesn't add a whole lot of value other than giving some meaning to the Absolute SOC. There is another PID for Displayed SOC. This one is exactly what it sounds like, it is the % of the dash icon that is full. There is a linear relationship between Disp SOC & Abs SOC (and thus also between Disp SOC & Use SOC). However, Disp SOC is only recorded by the car to 1 decimal place. This is not surprising since Disp SOC merely represents the battery icon and high precision isn't required for the icon. It also is only measured in 1/2 percent increments. This limits the calculations that can be done with Disp SOC. Abs SOC (and thus Use SOC) are recorded by the car to 8 decimal places and provide much more accurate data.

 

I hope to have more information forthcoming about these values. I also would like to write my own equation for Use SOC which will be more accurate. The Use SOC that I have been using won't actually range from 0-100% based on what I've now been able to calculate thanks to also having access to Disp SOC and understanding its relationship with Abs SOC.

[hybridbear]

• Displayed SOC appears to be exactly what it says it is...how much of the dash battery icon is full. I previously posted online that a 75% Use SOC has a battery icon that appears to be 8/10 to 9/10 full. When you plug in 75 for the Use SOC into the equation below you get a Disp SOC of 86.8%. Other reference points that I had posted online follow the same pattern which proves that the Disp SOC is a measure of how full the battery icon is.

• Disp SOC = 2.5878(Abs SOC) - 68.183

Abs SOC = 0.3859(Disp SOC) + 26.373

Disp SOC = 0.9934(Use SOC) + 12.283

Use SOC = 1.0031(Disp SOC) - 12.207

The ICE comes on at 5% Usable SOC to charge the HVB, Usable SOC cannot get lower than this. This is 33.01% Abs SOC and 17.25% Disp SOC. 17.25% Disp SOC fits exactly with how full the battery icon appears when this happens.

The ICE stops charging the HVB when the Use SOC = 60%. This gives us an Abs SOC of 54.22% and a Disp SOC of 71.9%. This is the old "ICE High" mode that was common in freeway driving before the PCM update last summer.

We know that Disp SOC will hit 100%, this gives us the max charge of the HVB, better than Usable SOC could. This puts the max HVB Abs SOC at 64.99%. Usable SOC put the max Abs SOC at 69.57%.

Usable SOC 0%-100% projects an Abs SOC range of 31.2%-69.57%. Use SOC 5%-100% projects an Abs SOC range of 33.12%-69.57%. Disp SOC 17.25%-100% projects an Abs SOC range of 33.01%-64.99%. This proves that the low end of HVB charge is about 33.1% Abs SOC.

Disp SOC is only recorded to one significant digit which severely limits our calculations. Abs SOC (and thus Use SOC) is calculated to 8 decimal places.

Now that we know the true limits of HVB Abs SOC based on the combination of Use SOC & Disp SOC, I would like to rewrite the Usable SOC formula to make it more accurate so that New Use SOC = 0 when Abs SOC = 33% and New Use SOC = 100 when Abs SOC = 65%. This would then allow a more full use of Use SOC and a more accurate formula for the portion of the battery that is used by the hybrid.

 

[hybridbear]

Here's some data about Generator Speed when the ICE is off (this does not apply to the Energi because it has a different final drive ratio):

Here is the equation based on the 3000 or so data points from a couple trips plus another 10,000 or so data points of (0,0) to get the equation to pass through that point or as close as possible since that's the one data point that we actually know is correct:
Gen RPM = -120*MPH

Note that in theory the intercept should be exactly 0 because when speed is 0 the Gen RPM is also 0. But this is very close to 0 and can probably just be ignored as noise. It's very hard to get the measurements exactly in sync which creates noise in the data.

This means that the previous FFH max Gen RPM was: -7440 @ 62 MPH
Now the max Gen RPM is: -10,200 @ 85 MPH

 

Here is the chart:

 

 

It's interesting to see how this compares to the Prius MG1 speed.

According to: Toyota Prius - Power Split Device
At 62 MPH the Prius MG1 would be spinning at -9578 RPM if the ICE were off. At 85 MPH it would be spinning at -13144 RPM if the ICE were off. The FFH Gen RPMs are lower due to the different size/design of Ford's planetary gear set. The Prius MG1 is limited to -6500 RPM.

 

The Generator RPM is variable when the ICE is on. There is not a fixed ratio of Gen RPM to ICE RPM. It all depends how much of the ICE torque is going to the wheels versus going to the generator. The FFH likes to charge the battery with about 30-40 amps of current (8700-11,600 watts @ 290 volts). The Generator RPM can be as low as 30-50 RPM and still put 30-40 amps into the HVB. When this happens, nearly 100% of the electricity from the generator must be flowing to the HVB and almost 0% of it must be going to the traction motor. In city driving the Gen RPM is often 5000-6000 because the ICE is sending almost 0% of its torque to the wheels. In city driving the ICE primarily only spins the generator and then the generator sends some electricity to the battery and some to the traction motor to power the wheels. In typical highway driving there is a split of the ICE torque and the Gen RPM is usually 1000-2500 depending on how the car decides to split the power.

Edited April 3, 2014 by hybridbear

[hybridbear]

I updated the post above in red

[hybridbear]

Thanks to a great suggestion by Larry H I have been able to make the data more accurate!! Changes above have been posted in blue.

Edited April 3, 2014 by hybridbear

[larryh]

For the Energi, the equation is

 

RPMs = -139.65 * mph.

 

The final drive ratio for the FFH is 2.57. For the FFE, it is 2.91. The tire size for the hybridbear's FFH is 18" and for the FFE it is 17". The tire diameters are 26.33 and 25.86 respectively, Thus the generator/motor/ICE must spin (2.91/2.57) * (26.33/25.86) = 1.15 times faster on the Energi than the Hybrid. Given hybridbear's computation, the comparable one for the Energi can be derived as follows:

 

RPMs = -120 * 1.15 * mph = -138 * mph.

 

That's close to the actual measurement. The generator/motor is rotating at 10.4 times the speed of the wheels, and each RPM of the wheels corresponds to 0.0745 mph.

Edited April 6, 2014 by larryh