METHOD FOR REGULATING THE POSITION OF A MOTORIZED THROTTLE OF AN INTERNAL COMBUSTION ENGINE

Abstract

One aspect of the invention relates to a method 100 for regulating the position of a throttle body of an engine, said method 100 comprising, when a position difference between a position of said throttle body and a position setpoint is determined, the steps of: Regulating 103 the position of the throttle body by means of a proportional, integral, derivative type controller, applied to a pulse-width modulation control of an electric motor configured to position said throttle body, each of the terms of the controller being tabulated; Adding 104 a first positive or negative deviation to the proportional term when said determined position difference is respectively positive or negative; Adding 105 a second deviation to the proportional term as a function of a determined vacuum between the air inlet and the air outlet of the throttle body; Adding 106 an alternative parameter to said controller depending on said vacuum;Add 107 an open loop to the regulator, the value of said open loop being selected from a table of differences in throttle position measured relative to a rest position of the throttle. Figure to be published with the abbreviation: Figure 2;

Description

Title of the invention: METHOD FOR REGULATING THE POSITION OF A MOTORIZED THROTTLE OF AN INTERNAL COMBUSTION ENGINE. TECHNICAL FIELD OF THE INVENTION

[0001] The field of the invention is that of regulating the position of a motorized throttle of a vehicle equipped with an internal combustion engine. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] As is known per se, a throttle body comprises a disc-shaped throttle valve, called a butterfly valve, rotatably mounted in a duct passing through the throttle body. The butterfly valve moves within this duct to regulate the supply airflow to an internal combustion engine.

[0003] The throttle plate is usually returned to a rest position, corresponding to a predetermined opening position of the duct, by elastic return means, generally consisting of two opposing springs. The angular position of the throttle plate in the duct is electrically controlled, in opposition to the elastic return means, by an electric motor.

[0004] The precise positioning of such a throttle valve is essential because it regulates the airflow injected into the internal combustion engine, and therefore influences the engine's acceleration and responsiveness. The throttle valve's position must therefore accurately reflect the acceleration desired by the vehicle's driver, the desired acceleration being determined by the position of the throttle grip or pedal. The lighter the vehicle, the more important this precision becomes, particularly for two-wheeled vehicles. Summary of the invention

[0005] One objective of the invention is to provide a solution to increase the positioning accuracy of the throttle according to that desired by the driver.

[0006] To this end, the invention relates, in its broadest sense, to a method for regulating the position of a motorized throttle body of an internal combustion engine of a vehicle, the method comprising the steps, executed by means of controlling the internal combustion engine, consisting of: • Determine a target position for the butterfly valve, • Determine the positional difference between a measured throttle position and the specified position setpoint, • The process is remarkable in that, when a positional deviation is determined, it comprises the following steps: • Regulate the throttle position using a proportional, integral, or derivative type controller applied to a pulse-width modulation control of an electric motor configured to position the throttle. • The value of the proportional term is determined by comparing said positional deviation determined to a table of positional deviations based on values ​​of the proportional term; • The value of the integral term is determined by adding a first value of the integral term determined at a previous calculation recurrence and a second value of the integral term determined by comparing the filtered determined positional deviation to a table of positional deviations as a function of integral term values; • The value of the derivative term is determined by comparing the derivative of said positional deviation determined to a table of derivatives of positional deviations as a function of derivative term values; • Add a first positive deviation to the proportional term when said determined position deviation is positive or add a first negative deviation to the proportional term when said determined position deviation is negative; • Add a second deviation to the proportional term based on a specific depression between the air intake and the air outlet of the throttle body; • Add an alternative parameter to the regulator, said alternative parameter being dependent on said depression determined between the air inlet and the air outlet of the throttle body; • Add an open loop to the regulator, the value of said open loop being selected from a table of differences in throttle position measured relative to a rest position of the throttle.

[0007] Thanks to the method according to the invention, the position of the butterfly is quickly brought back as close as possible to the setpoint reflecting the wish of the vehicle driver.

[0008] In addition to the characteristics mentioned in the preceding paragraph, the process according to the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0009] According to a non-limiting implementation of the invention, the proportional term can be set between -200% and +200%.

[0010] According to a non-limiting implementation of the invention, the derived term can be set between -100% and +100%.

[0011] According to a non-limiting embodiment of the invention, the method comprises a step, executed by the control means, of adding a multiplicative term to the regulator, said multiplicative term being a function of a voltage value of a vehicle battery.

[0012] According to a non-limiting embodiment of the invention, the method comprises the steps, executed by the control means, consisting of: • Estimate the oscillation frequency of the butterfly; • If the estimated oscillation frequency is characteristic of a high-frequency oscillation, decrease the first positive deviation or the first negative deviation added to the proportional term; • If said estimated oscillation frequency is characteristic of a low frequency oscillation, increase said first positive deviation or said first negative deviation added to said proportional term.

[0013] According to a non-limiting implementation of the invention, the estimated oscillation frequency is characteristic of a high-frequency oscillation when a high-frequency cumulative variable is greater than a high-frequency threshold, said high-frequency cumulative variable being determined when the absolute value of the position deviation is greater than a first threshold and when the absolute value of the gradient of the position deviation is greater than a second threshold.

[0014] According to a non-limiting implementation of the invention, the estimated oscillation frequency is characteristic of a low-frequency oscillation when the absolute value of a low-frequency cumulative variable is greater than a low-frequency threshold, said low-frequency cumulative variable being determined by adding position deviations.

[0015] According to a non-limiting implementation of the invention, the value of the alternative parameter is between +10% and +20% of the value of the regulator.

[0016] According to a non-limiting implementation of the invention, the value of this alternative parameter is updated periodically, with a period of between 1 and 5 milliseconds.

[0017] A non-limiting embodiment of the invention relates to a vehicle, for example of the two-wheel type, comprising an internal combustion engine having a throttle body equipped with a motorized throttle, the vehicle further comprising an electric motor configured to position the throttle, the vehicle being notable in that it comprises control means configured to execute the steps of the process according to any one of the preceding embodiments.

[0018] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures.

[0019] [Fig.1] illustrates, schematically, a two-wheeled vehicle according to the invention.

[0020] [Fig.2] illustrates, schematically, a process according to a non-limiting implementation of the invention.

[0021] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0022] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0023] Fig. 1 illustrates a two-wheeled vehicle 1 equipped with an internal combustion engine 2 comprising a single cylinder 3.

[0024] A throttle body 4 is associated with this cylinder 3. This throttle body 4 includes a motorized butterfly valve 5 configured to regulate the quantity of air injected into the cylinder 3. The butterfly valve 5 is controlled by an electric motor 6.

[0025] The electric motor 6 is controlled by control means 7 of the internal combustion engine 2 by means of pulse-width modulation control, also known as PWM. The electric motor 6 is configured to position the throttle 5 according to a position setpoint. This position setpoint corresponds in particular to the position of the throttle grip. It also depends on other parameters such as mechanical friction of the internal combustion engine 2.

[0026] According to this embodiment, the control means 7 are configured to regulate the position of the throttle 5 by means of a proportional-integral-derivative type controller, each term of said controller being tabulated. More particularly, each term of the controller is determined by means of a table of position deviations between a measured position of the throttle 5 and a setpoint position of this throttle 5. The proportional-integral-derivative type controller is applied to the pulse-width modulation control of the electric motor 6. More particularly, these control means 7 are configured to perform the steps of the method 100 according to the invention illustrated in [Fig. 2].

[0027] Fig. 2 illustrates a method 100 for regulating the position of the motorized throttle 5 of the internal combustion engine 2 of the vehicle 1.

[0028] The process 100 includes a step, executed by the control means 7, consisting of determining 101 a position setpoint for the butterfly 5.

[0029] The position setpoint depends in particular on a measured position of the throttle handle. This position can be measured by means of a position sensor. The position setpoint may also depend on other parameters, such as the altitude at which the vehicle 1 is traveling or on specific mechanical friction.

[0030] The method 100 then includes a step, performed by the control means 7, consisting of determining 102 a position difference between a measured position of the throttle 5 and the setpoint position. The position of the throttle 5 can be measured by a position sensor (not shown).

[0031] When a position difference between the position of the throttle 5 and the position setpoint is determined, the method 100 includes a step of regulating 103 the position of the throttle 5 by means of a proportional, integral, derivative type controller, applied to a pulse width modulation control of the electric motor 6 configured to position the throttle 5.

[0032] The value of the proportional term is determined by comparing the determined position deviation to a table of position deviations based on the values ​​of the proportional term. Thus, by comparing the determined position deviation to the position deviations entered in the table of position deviations based on the values ​​of the proportional term, the control means 7 determine a value to be assigned to the proportional term of the proportional, integral, or derivative type controller.

[0033] The value of the integral term is determined, via the control means 7, by adding a first value of the integral term determined during a previous calculation recurrence and a second value of the integral term determined by comparing the filtered position error to a table of position errors based on integral term values. Thus, the control means 7 determine, by means of the table, a value to be assigned to the integral term of the controller.

[0034] The determined positional deviation is filtered, for example, by means of a first-order filter. Furthermore, the value of the integral term in the deviation table evolves slowly, particularly when the positional deviation is large. This filtering and slow evolution prevent drift in the integral term.

[0035] The value of the derivative term is determined by comparing the derivative of the determined position error to a table of derivatives of position errors based on derivative term values. This derivative of the determined position error is, for example, formed by the difference between this determined position error and the position error determined in the previous iteration of the calculation. Thus, the control means 7 determine, by means of the table, a value to be assigned to the derivative term of the controller.

[0036] According to this non-limiting implementation, the proportional term can be set between -200% and +200% and the derivative term can be set between -100% and +100%. Exceeding the + or -100% range allows the throttle 5 to move very quickly when its position deviates from the setpoint.

[0037] The integral term has a low value which makes it possible to compensate for a deviation when the position of the butterfly 5 approaches the position setpoint.

[0038] In other words, when the position of the butterfly 5 is far from the position setpoint, the proportional and derivative terms will rapidly modify the position of the butterfly 5, then when the position of the butterfly 5 is close to the position setpoint, the integral term will act on the position of the butterfly 5 so as to precisely reach the position setpoint.

[0039] According to this embodiment, the method 100 includes a step, performed by the control means 7, consisting of adding 104 a first positive deviation to the proportional term when a positive position deviation between the setpoint position of the throttle 5 and the measured position of the throttle 5 is determined. Conversely, a first negative deviation is added to the proportional term when a negative position deviation between the setpoint position of the throttle 5 and the measured position of the throttle 5 is determined.

[0040] This first added gap makes it possible to compensate for dry friction generated by mechanical parts of the throttle body 4 and / or the internal combustion engine 2.

[0041] According to this embodiment, the method 100 includes a step, executed by the control means 7, consisting of adding 105, to the proportional term, a second deviation based on a determined depression between the air inlet and the air outlet of the throttle body 4.

[0042] Indeed, a pressure difference exists on either side of the throttle body 4. Atmospheric pressure is present at the inlet of the throttle body 4, and a lower pressure is present at the outlet of the throttle body 4, that is, at the inlet of cylinder 3. This pressure difference can reach 900 millibars and generate a force on the throttle shaft 5 of several tens of daN. This phenomenon generates additional friction. To compensate for this friction due to a pressure difference, a second deviation is added to the proportional term.

[0043] To determine this pressure difference, the control means 7 can subtract atmospheric pressure from a pressure measured at the outlet of the throttle body 4 by a pressure sensor.

[0044] The second deviation can be determined using a table providing second deviations as a function of pressure differences. The pressure measured at the outlet of the throttle body 4 can vary very rapidly so that this second deviation can be updated very frequently, for example every 10 ms.

[0045] The method 100 also includes a step, performed by the control means 7, of adding 106 an alternative parameter to the regulator, the alternative parameter being dependent on the vacuum determined between the air inlet and the air outlet of the throttle body. The value of the alternative parameter is applied to the throttle 5 alternately in a positive and a negative direction of movement of the throttle 5.

[0046] According to a non-limiting implementation, the value of the alternative parameter is between +10% and +20% of the value of the regulator, and this value of the alternative parameter is updated periodically, according to a period of between 1 and 5 milliseconds.

[0047] In other words, an alternative parameter is added to the regulator in order to excite the electric motor 6 to control it at a value just below that which would make it move.

[0048] Furthermore, according to this non-limiting embodiment, the method 100 includes a step, performed by the control means 7, of adding 107 an open loop to the regulator, the value of the open loop being selected from a table of measured position differences of the throttle 5 relative to a rest position of the throttle 5, also known by the English terminology as the "limphome" position. This open loop is of particular interest when the position of the throttle 5 is close to the rest position and the throttle 5 moves from one side of the rest position to the other.

[0049] According to a non-limiting embodiment, the method 100 includes a step, executed by the control means 7, consisting of adding 108 a multiplicative term to the regulator, the multiplicative term being a function of a voltage value of a vehicle battery. Indeed, the voltage value taken by the pulse-width modulation control of the electric motor 6 is proportional to the voltage of the vehicle battery.

[0050] In order to avoid oscillations of the butterfly 5, the method 100 includes a step, executed by the control means 7, consisting of estimating 109 an oscillation frequency of the butterfly 5.

[0051] If the estimated oscillation frequency is characteristic of a high-frequency oscillation, the method 100 includes a step of reducing 110 the first positive deviation or the first negative deviation added to the proportional term. By reducing, we mean approaching zero.

[0052] According to a non-limiting implementation of the invention, the estimated oscillation frequency is characteristic of a high-frequency oscillation when a high-frequency cumulative variable is greater than a high-frequency threshold, said high-frequency cumulative variable being determined when the absolute value of the position deviation is greater than a first threshold and when the absolute value of the gradient of the position deviation is greater than a second threshold.

[0053] Conversely, if the estimated oscillation frequency is characteristic of a low-frequency oscillation, the method 100 includes a step consisting of increasing 111 the first positive or negative deviation added to the proportional term. By increasing, we mean moving away from zero. For example, if the first negative deviation is -1, if we increase this first negative deviation it can be -2.

[0054] According to a non-limiting embodiment of the invention, the estimated oscillation frequency is characteristic of a low-frequency oscillation when the absolute value of a low-frequency cumulative variable is greater than a low-frequency threshold, said low-frequency cumulative variable being determined by adding positional deviations.

[0055] Thus, the butterfly 5 is controlled reactively without entering an oscillation zone.

Claims

Demands

1. A method (100) for regulating the position of a motorized throttle valve (5) of a throttle body (4) of an internal combustion engine (2) of a vehicle (1), said method (100) comprising the steps, carried out by control means (7) of said internal combustion engine (2), consisting of: - Determine (101) a position setpoint for said butterfly (5), - Determine (102) a position difference between a measured position of said butterfly (5) and said position setpoint, said method (100) being characterized in that, when a positional deviation is determined, it comprises the steps of: - Regulate (103) the position of the throttle (5) by means of a proportional, integral, derivative type regulator, applied to a pulse width modulation control of an electric motor (6) configured to position said throttle (5), • The value of the proportional term is determined by comparing said positional deviation determined to a table of positional deviations based on values ​​of the proportional term; • The value of the integral term is determined by adding a first value of the integral term determined at a previous calculation recurrence and a second value of the integral term determined by comparing the filtered determined positional deviation to a table of positional deviations as a function of integral term values; • The value of the derivative term is determined by comparing the derivative of said positional deviation determined to a table of derivatives of positional deviations as a function of derivative term values; • Add (104) a first positive deviation to the proportional term when said determined position deviation is positive or add a first negative deviation to the term proportional when said determined position difference is negative; • Add (105) a second difference to the proportional term as a function of a determined depression between the air inlet and the air outlet of the throttle body (4); • Add (106) an alternative parameter to said regulator, said alternative parameter being dependent on said determined depression between the air inlet and the air outlet of the throttle body (4); • Add (107) an open loop to said regulator, the value of said open loop being selected from a table of position differences of the throttle (5) measured relative to a rest position of the throttle (5).

2. Method (100) according to the preceding claim, characterized in that the proportional term can be set between -200% and +200%.

3. Method (100) according to any one of the preceding claims, characterized in that the derived term can be set between -100% and +100%.

4. A method (100) according to any one of the preceding claims, characterized in that it comprises a step of adding (108) a multiplicative term to said regulator, said multiplicative term being a function of a voltage value of a vehicle battery (1).

5. A method (100) according to any one of the preceding claims, characterized in that it comprises the steps of: - Estimating (109) a throttle oscillation frequency; - If said estimated oscillation frequency is characteristic of a high-frequency oscillation, decreasing (110) the first positive deviation or the first negative deviation added to the proportional term; - If said estimated oscillation frequency is characteristic of a low-frequency oscillation, increasing (111) said first positive deviation or said first negative deviation added to said proportional term.

6. A method (100) according to the preceding claim, characterized in that the estimated oscillation frequency is characteristic of a high-frequency oscillation when a high cumulative variable frequency is greater than a high frequency threshold, said high frequency cumulative variable being determined when the absolute value of the position deviation is greater than a first threshold and when the absolute value of the gradient of the position deviation is greater than a second threshold.

7. Method (100) according to claim 5, characterized in that the estimated oscillation frequency is characteristic of a low frequency oscillation when the absolute value of a low frequency cumulative variable is greater than a low frequency threshold, said low frequency cumulative variable being determined by adding position deviations.

8. Method (100) according to any one of the preceding claims, characterized in that the value of the alternative parameter is between +10% and +20% of the value of the regulator.

9. Method (100) according to the preceding claim, characterized in that the value of this alternative parameter is updated periodically, with a period of between 1 and 5 milliseconds.

10. Vehicle (1) comprising an internal combustion engine (2) comprising a throttle body (4) equipped with a motorized throttle (5), said vehicle (1) further comprising an electric motor (6) configured to position said throttle (5), said vehicle (1) being characterized in that it comprises control means (7) configured to carry out the steps of the process (100) according to any one of the preceding claims.

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