WO2017167765A1

WO2017167765A1 - Method of detecting use of tuning kit

Info

Publication number: WO2017167765A1
Application number: PCT/EP2017/057339
Authority: WO
Inventors: Gustave MUGABO; Eric L P MICHEL; Anthony MALLERET
Original assignee: Delphi International Operations Luxembourg S.À R.L.
Priority date: 2016-03-29
Filing date: 2017-03-28
Publication date: 2017-10-05
Also published as: GB2548831A; GB201605170D0

Abstract

A method of detecting unauthorized tuning of an engine system comprising; a) providing a model of the engine system, said model proving one or more signals representing engine parameters; and performing a monitoring cycle comprising: b) measuring at least one parameter from an actual sensor or demand signal; c) comparing the values from a) and b) d) indicating unauthorised tuning if the values differ by more than a threshold

Description

Method of Detecting use of Tuning Kit Field of the Invention

This disclosure relates to a method of detecting the use of a tuning kit and unauthorized tuning of a vehicle engine. Background

In an internal combustion engine, torque is produced by burning the fuel inside the combustion chamber. The more fuel that is supplied and is efficiently burned, the more torque is produced.

Typically an Engine Control Unit is calibrated to achieve specified engine torque in respect with several constraints such as: mechanical limit, acceptable emission level, driveability, and such like. Unauthorised tuning of an engine to provide enhanced performance generally involves increasing engine torque to increase performance than initially calibrated. Torque is increased by delivering much more fuel and much more fresh air to the engine.

There are two methods for engine tuning. In a software method, tuners reprogram the Engine Control Unit and modify calibration in the Engine Control Unit memory. In a hardware method, tuning can be provided by installing an external electronic kit (power up kit) which modifies one or several electrical signals (Engine Control Unit) input signals or (Engine Control Unit) output signals. Figure 1 shows the effects of engine tuning on power and torque at varying engine speed. Line 1 shows the initial calibrated torque and line 2 the torque after tuning. Line 3 shows the initial calibrated power and line 4 the power after tuning. As mentioned tuning the engine can have many consequences such as component damage, engine damage, and such like. Such damage can include turbocharger damage; tuning can damage the turbocharger when maximum compressor ratio is exceeded. Tuning also can damage the engine when maximum cylinder pressure is exceeded Therefore, any strategy which can allow to detect engine tuning is welcome for two reasons: Engine protection: a tuning detection strategy can activate special safe actions to reduce the engine torque/power in order to minimize the risk of engine damage. Good indicator of damage root cause : in case of damage because of tuning activity, the tuning detection strategy can provide indicators to prove that the car owner was responsible of the damage.

It is an object of the invention to provide a method to detect the external electronic tuning kit which is the most popular tuning method.

Statement of the Invention

In one aspect of the invention is provided a method of detecting unauthorized tuning of an engine system comprising;

a) providing a model of the engine system, said model proving one or more signals representing engine parameters; and performing a monitoring cycle comprising: b) measuring at least one parameter from an actual sensor or demand signal; c) comparing the values from a) and b)

d) indicating unauthorized tuning if the values differ by more than a threshold.

The method may include repeating the monitoring cycle step b) and c) at one of more later time points, and for each time point determining a difference between said values, and indicating unauthorised tuning if the difference between values at successive time-points values increases or decreases by more than a threshold.

For each parameter, the values may be averaged over a time period and in step c) the averages are compared.

The parameters may be one or more of any of the following; fuel pressure, air mass flow and air fuel ratio.

In step b) the parameter may be the turbocharger position demanded by closed loop boost pressure controller and the corresponding model signal is that which provides expected turbocharger position demand in the open loop. In step b) the parameter may be the High Pressure Valve current applied by closed loop controller and the corresponding model signal is that which provides expected current in the open loop. The parameter may be the engine brake torque estimation based on crank teeth acceleration and the corresponding model signal is the desired engine brake torque.

The threshold may be variable or adaptive.

The method may involve increasing the threshold value if the increase in absolute differences with respect to successive monitoring cycles is less than a predetermined amount.

The threshold could be a ratio.

Brief Description of Drawings

The invention will now be described by way of example and with reference to the following figures of which:

Figure 1 shows the effects of engine tuning on power and torque at varying engine speed;

Figure 2 shows an illustration of electronic tuning kit installation;

Figure 3 gives an illustration of rail pressure sensor modification by a tuning kit;

Figures 4a, 4b, 4c, 5 and 6 show examples of instantaneous large deviation between measured signals and the expected values from models for fuel pressure, air mass flow and air fuel ratio respectively subsequent to tuning;

Figure 7 shows an illustration of tuning kit detection methodology; and, Figure 8 shows a timeline of the monitoring process according to one general example.

Background of the Invention

Figure 2 shows an illustration of electronic tuning kit installation. Input signals from sensors 5 are forwarded to an ECU 6, which processes signals and decides on output parameters sent to actuators 7 e.g. in conjunction with look up tables. So for example typically a fuel rail will supply high pressure fuel to fuel injectors and this fuel pressure is controlled according to torque demands by an ECU 5. Feedback is provided by a pressure rail sensor. A tuning kit can modify (see block 7) the electrical sensor signals e.g. of rail pressure sensor feedback signal, sent to the ECU. In this way e.g. a rail pressure controller increases itself the pressure in the rail which will result in much more fuel delivered. In turbocharged systems, a tuning kit can modify the electrical signal of boost pressure sensor so that the boost pressure controller increases the intake manifold pressure resulting in much more fresh air available in combustion chamber to allow much more fuel burning. The tuning kit can modify the electrical injectors command signal (output from the ECU) (see block 8) in order to increase the injectors open duration which will lead to much more fuel delivered. So various inputs can be "tuned" including rail pressure, air-mass flow, boost pressure and such like. In essence the figures show that ECU input signals and output signals can be tampered with or amended using a tuning kit or by unauthorised tuning

Figure 3 gives an illustration of rail pressure sensor modification by a tuning kit. Line 9 represents the normal relationship between pressure and voltage fed back. Then other lines 10 represent increasing levels of manipulation of reducing the actual voltage seen by the ECU. For a given rail pressure (e.g. 1700 bar), the tuning kit can reduce the voltage (pressure sensor feedback voltage) and the Engine Control Unit will read 2600mV instead of 3500mV (actual sensor feedback). Therefore, after linearization, the Engine Control Unit will see that rail pressure is only 1300 bar (while it is already 1700 bar). As a consequence, the rail pressure controller will automatically increase the pressure in the rail leading to much higher effective pressure in the rail. For the same injectors open duration, higher rail pressure will result in over-fuelling (tuning). Tuning can perform the same operating principle or boost pressure sensor.

Detailed Description of the Invention Most of electronic tuning kit available in the market combine fuel system tuning and air path tuning so that much more fuel can be delivered and much more air can be available to burn the extra fuel. When the electronic tuning kit is installed, it creates a large instantaneous deviation of several measurable signals. According to one example the method comprises providing an engine model, and comparing one or more measured signals with the corresponding model signals (the model provide the expected values). Deviation is determined and used to determine whether there has been tampering of the engine or a tuning kit installed is visible by comparing the difference in the measured and modelled signals e.g. with a threshold.

Generally, deviations created by tuning kit are much larger and quicker than normal system drift (aging effects). Thus in preferred examples the method comprises detecting instantaneous and/or large deviation of one or more or several measured signals. In a preferred methods the results of a plurality all individual detection to confirm tuning kit installation.

In a basic example, the method comprises providing an engine model, monitoring particular signals where a large deviation would occur from expected values after tuning installation.

In examples, with respect to the methodology, Air Mass Flow from AMF sensor is compared to a model which provides expected mass flow. Alternatively or additionally, Air Fuel Ratio from WRAF sensor is compared to a model which provides expected Air Fuel Ratio. Alternatively or additionally turbocharger position demanded by closed loop boost pressure controller is compared to a model which provides expected turbocharger position demand (open loop). Alternatively or additionally the High Pressure Valve current applied by closed loop controller is compared to a model which provides expected current (open loop). Alternatively or additionally the engine brake torque estimation based on crank teeth acceleration is compared to desired engine brake torque (driver brake torque demand). In further examples the step of checking the amplitude of fuel correction factor from WRAF closed loop control is performed. In other examples the presence of an injector solenoid voltage glitch is determined and compared with a reference or threshold value, or the closing delay computed and compared with a reference or threshold or valve speed determined and compared with a threshold value or reference.

For all or any of the above mentioned signals, the method may identify the conditions where the tuning kit creates much larger deviation and enable the comparison between measured signal and corresponding model. Such signals may be high torque demand, high rail pressure demand, high boost pressure demand as such like. For all above mentioned signals , under enabling conditions identified above, in one step a reference deviation is memorized .The reference deviation may be updated if the deviation is small (aging effects, model accuracy). Under enabling conditions identified above, compare the reference deviation and new deviation. For each individual monitoring, memorize a flag when instantaneous large deviation is detected one or several times.

Figures 4a, 4b, 4c, 5 and 6 show examples of instantaneous large deviation between measured signals and the expected values from models for fuel pressure, air mass flow and air fuel ratio respectively subsequent to tuning.

Figures 4a, 4b, 4c shows deviations with respect to relative error between High pressure Valve (HPV) open loop current (which is the expected current from a model) and HPV closed loop current. The values in the figures may be calculated following way

_{T r} , HPV closed loop current— HPV open loop current Actual value— Expected value

Value = =

HPV open loop current Expected value

Plot 41 is the memorized reference deviation (it can be updated under specific conditions) and plot 42 is new deviation calculated at each monitoring cycle

In figure 5 the model signal is shown as 52. The actual signal is shown as 51 and reflects the model single until the tuning kit is switched on at time Tl . After this a large discrepancy occurs. In figures 6 the model signal is shown as 62. The actual signal is shown as 61 and reflects the model single until the tuning kit is switched on at time Tl . After this a large discrepancy occurs.

So in general, when the tuning kit is OFF, the measured signal is close to the model. As soon as the tuning kit is ON, there is large deviation between measured signals and the models. Such instantaneous large deviation is indicator of tuning kit installation. When the large instantaneous deviation is observed on one more or several signals, the combination allows to confirm tuning kit installation.

Figure 7 shows an illustration of tuning kit detection methodology. In examples deviations between actual parameters (from sensors) are compared with reference values provided by a model. For various sensors, certain operation or other condition may be required before these steps are performed. One or more of these are input into a co- ordinator which may flag up tuning if the deviation or instantaneous deviation is greater than a threshold. In refined examples as shown in the figure 7 in steps S 1 a normal reference deviation for a particular parameter is stored. This references an acceptable deviation which may occur due to e.g. aging effects. This step may in refined examples require certain conditions. In step S2 the reference deviation may be updated (again preferably under certain conditions) to compensate for slow insipid changes such as aging. In step S3 any new deviation is compared. In step S4 a flag is set if the difference between the reference deviation and a deviation between the actual and model signal is above a threshold. The flag may be set when this condition occurs in one or more of any of the sensor signals used in the method and /or if the deviation(s) occur more than a set/or variable number of times - again preferably under certain (e.g. running conditions) . The flags are then used e.g. combined to determine in step S5 whether tuning has occurred. So e.g. all the memorized flags (e.g. over a period of time or vehicle mileage) are to see if they are significant. It may be decided that one flag is significant to alert to unauthorized tuning.

Figure 8 shows a timeline of the monitoring process according to one general example. The top plot shows a number of successive monitoring cycles. The figure illustrates basic example and shows on the top plot a series of monitoring cycle. In each cycle the monitoring consists of comparing a new deviation (that is the deviation between the value of the salient parameters from cycle N-l to cycle N) to a reference deviation.

During each cycle the deviation for one (or more) parameters is computed. This is the difference between the actual and model signal. This computation may be implemented under specific enabling conditions. The deviation is compared with a reference (threshold) deviation. If this deviation is above the threshold deviation tuning is detected. Preferably the reference deviation is variable and is updated. In preferred examples where there is slow deviation (due to e.g. aging effect, model accuracy and not due to tuning kit use), so in other words a small deviation between the successive monitoring cycles the reference deviation is updated. Thus an aging sensor which progressively drifts from ideal characteristics will not flag up unauthorized tuning (kit). An adaptive threshold provides this feature. For example if the deviation between the deviations (between model and actual parameters) of successive monitoring cycles is less than a "deviation deviation threshold", then the reference threshold may be updated to be the deviation between the actual/sensor value and model value in the last monitoring period, i.e. the latest deviation. In this way, if because of an ageing sensor, the deviation between model and actual values slowly creeps up, the reference (threshold) deviation is increased. In other words one can look at deviations between successive deviations. If kit is installed, new monitoring cycle will detect higher deviation (compared to memorized reference deviation).

Claims

1. A method of detecting unauthorized tuning of an engine system comprising; a) providing a model of the engine system, said model proving one or more signals representing engine parameters; and performing a monitoring cycle comprising: b) measuring at least one corresponding parameter from an actual sensor or demand signal;

c) comparing the values from a) and b)

d) indicating unauthorised tuning if the values from step c) differ by more than a threshold.

wherein in step a) at least one of said parameters is the engine brake torque estimation and the corresponding parameter in step b) is the desired or demand engine brake torque.

2. A method as claimed in claim 1 wherein in step a) said model provides the parameters of engine brake torque estimation based on crank teeth acceleration.

3. A method as claimed in claims 1 or 2 including repeating the monitoring cycle step b) and c) at one of more later time points, and for each time point determining a difference between said values, and indicating unauthorised tuning if the difference between values at successive time-points values increases or decreases by more than a threshold.

4. A method as claimed in claims 1 to 3 where for each parameter, the values are averaged over a time period and in step c) the averages are compared.

5. A method as claimed in any preceding claim wherein the parameters are one or more of any of the following; fuel pressure, air mass flow and air fuel ratio.

6. A method as claimed in claims 1 to 4 where in step a) one of said signals is the parameter of expected turbocharger position demand in the open loop, and the corresponding parameter in step b) is the turbocharger position demanded by closed loop boost pressure controller.

7. A method as claimed in claim 1 to 3 where in step a) one of said signals is the parameter of expected High Pressure Valve current in the open loop and the corresponding parameter in step b) is the High Pressure Valve current applied by closed loop controller..

8. A method as claimed in any preceding claim where said threshold is variable or adaptive.

9. A method as claimed in claim 9 including increasing the threshold value if the increase in absolute differences with respect to successive monitoring cycles is less than a predetermined amount.