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 valve of an engine, said method (100) comprising, when a position difference between a position of said throttle valve and a position setpoint is determined, the steps of: Regulating (103) the position of the throttle valve 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 valve, 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) a first oscillatory value dependent on said vacuum to a value at the output of the controller;Add (107) a second value to the regulator output value, the second value being selected from a table of differences in throttle position measured relative to a throttle rest position. Figure to be published with the abbreviation: Figure 2;

Description

Title of the invention: METHOD FOR REGULATING THE POSITION OF A MOTORIZED THROTTLE VALVE 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 valve of a vehicle equipped with an internal combustion engine. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] In a manner known per se, a throttle body comprises a disc-shaped throttle member, called a butterfly, rotatably mounted in a duct passing through the throttle body. The butterfly moves in this duct to regulate a flow of air supplying an internal combustion engine.

[0003] The butterfly 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 butterfly in the duct is controlled, against the elastic return means, electrically by an electric motor.

[0004] The positioning accuracy of such a throttle is essential because it allows the flow of air injected into the internal combustion engine to be regulated, and therefore influences the acceleration and responsiveness of the internal combustion engine. The position of the throttle must therefore accurately reflect the acceleration desired by the driver of the vehicle, the desired acceleration being materialized by the position taken by the handle or the accelerator pedal. The lighter the vehicle, the more important this accuracy is, particularly for two-wheeled vehicles. Summary of the invention

[0005] An objective of the invention is to propose a solution for increasing the positioning precision of the throttle according to that desired by the driver.

[0006] To this end, the invention thus relates, in its broadest acceptance, to a method for regulating a position of a motorized throttle valve of a throttle body of an internal combustion engine of a vehicle, the method comprising the steps, executed by control means of the internal combustion engine, consisting of: • Determine a throttle position setpoint, • Determine a position difference between a measured throttle position and said position setpoint, • The method being remarkable in that, when a position deviation is determined, it comprises the steps of: • Regulate the position of the throttle valve by means of a proportional, integral, derivative type regulator, applied to a pulse width modulation control of an electric motor configured to position the throttle valve, • The value of the proportional term being determined by comparing said determined position deviation with a table of position deviations based on proportional term values; • The value of the integral term being 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 determined filtered position deviation to a table of position deviations based on integral term values; • The value of the derivative term being determined by comparing the derivative of said determined position deviation with a table of derivatives of position deviations as a function of values ​​of the derivative term; • 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 depending on a determined depression between the air inlet and the air outlet of the throttle body; • Add, to an output value of said regulator, a first oscillatory value forming a signal which alternates between a negative and positive value, said first oscillatory value being dependent on said depression determined between the air inlet and the air outlet of the throttle body, • Add a second value to the regulator output value, said second value being selected from a table of throttle position differences measured relative to a throttle rest position.

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

[0008] In addition to the characteristics which have just been mentioned in the preceding paragraph, the method according to the invention may have one or more complementary characteristics 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 derivative term can be set between -100% and +100%.

[0011] According to a non-limiting implementation of the invention, the method comprises a step, executed by the control means, consisting of multiplying the output value of the regulator by a third value, said third value being a function of a voltage value of a battery of the vehicle.

[0012] According to a non-limiting implementation of the invention, the method comprises the steps, executed by the control means, consisting of: • Estimate the butterfly’s oscillation frequency; • If said estimated oscillation frequency is characteristic of a high frequency oscillation, reduce said first positive deviation or said 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 first oscillatory value is between 10% and 20% of the output value of the regulator.

[0016] According to a non-limiting implementation of the invention, the first oscillatory value is updated periodically, according to a period of between 1 and 5 milliseconds.

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

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

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

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

[0021] The figures are presented for information purposes only and in no way limit the invention.

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

[0023] [Fig.l] 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 comprises a motorized throttle 5 configured to regulate the quantity of air injected into the cylinder 3. The throttle 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 a pulse width modulation control, also known by the acronym MLI. The electric motor 6 is configured to position the throttle 5 in accordance with a position setpoint. This position setpoint corresponds in particular to the position of the accelerator handle. It also depends on other parameters such as mechanical friction of the internal combustion engine 2.

[0026] According to this implementation, the control means 7 are configured to regulate the position of the throttle valve 5 by means of a proportional, integral, derivative type regulator, each term of said regulator being tabulated. More particularly, each term of the regulator is determined by means of a table of position deviations between a measured position of the throttle valve 5 and a position setpoint of this throttle valve 5. The proportional, integral, derivative type regulator is applied to the pulse width modulation control of the electric motor 6. More particularly, these control means 7 are configured to execute 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 valve 5 of the internal combustion engine 2 of the vehicle 1.

[0028] The method 100 comprises a step, executed by the control means 7, consisting of determining 101 a position setpoint for the throttle 5.

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

[0030] The method 100 then comprises a step, executed by the control means 7, consisting of determining 102 a position difference between a measured position of the throttle 5 and the position setpoint. 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 comprises a step consisting of regulating 103 the position of the throttle 5 by means of a proportional, integral, derivative type regulator, 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 with a table of position deviations as a function of proportional term values. Thus, by comparing the determined position deviation with the position deviations entered in the table of position deviations as a function of proportional term values, the control means 7 determine a value to be assigned to the proportional term of the proportional, integral, derivative type regulator.

[0033] The value of the integral term is determined, via the control means 7, 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 position deviation to a table of position deviations depending 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 regulator.

[0034] The determined position deviation is filtered, for example by means of a first-order filter. In addition, the value of the integral term of the deviation table evolves slowly, especially when the position deviation is large. This filtering and this slow evolution make it possible to avoid a drift of the integral term.

[0035] The value of the derivative term is determined by comparing the derivative of the determined position deviation with a table of derivatives of position deviations as a function of derivative term values. This derivative of the determined position deviation is for example formed by the difference between this determined position deviation and the position deviation determined at the previous recurrence 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 regulator.

[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 + or -100% allows the throttle 5 to move very quickly when the position of the throttle 5 is far from the position setpoint.

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

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

[0039] According to this implementation, the method 100 comprises a step, executed by the control means 7, consisting of adding 104 a first positive deviation to the proportional term when a positive position deviation between the throttle position setpoint 5 and the measured throttle position 5 is determined. Conversely, a first negative deviation is added to the proportional term when a negative position deviation between the throttle position setpoint 5 and the measured throttle position 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 implementation, the method 100 comprises a step, executed by the control means 7, consisting of adding 105, to the proportional term, a second difference depending on a determined depression between the air inlet and the air outlet of the throttle body 4.

[0042] Indeed, a pressure difference is present 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, i.e. at the inlet of the cylinder 3. This pressure difference can reach 900 millibars and generate a force on the axis of the throttle body 5 of a few 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 the 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 by means of 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 quickly so that this second deviation can be updated very frequently, for example every 10 ms.

[0045] The method 100 also comprises a step, executed by the control means 7, consisting of adding 106 a first oscillatory value to a value at the output of the regulator, the first oscillatory value being dependent on the depression determined between the air inlet and the air outlet of the throttle body 4.

[0046] This oscillatory value corresponds to a signal which alternates between a negative and positive value, a signal rather of the 'square' type centered on 0. This signal oscillates at a high frequency, for example at a frequency of the order of 1Khz.

[0047] This first oscillatory value applied to the output value of the regulator makes it possible to apply a force capable of countering friction forces of the electric motor 6 controlling the position of the throttle 5. In other words, this first oscillatory value makes it possible to continuously excite the electric motor 6 so that when the motor electric motor 6 is to be set in motion, the frictional forces are already counteracted. It is then simply necessary to set the electric motor 6 in rotation without it being necessary to counteract frictional forces.

[0048] According to a non-limiting implementation, the first oscillatory value is between +10% and +20% of the output value of the regulator, and this first oscillatory value is updated periodically, according to a period between 1 and 5 milliseconds.

[0049] In other words, an oscillatory value is added to the output value of the regulator in order to excite the electric motor 6 to control it to a value just below that which would make it move.

[0050] Furthermore, according to this non-limiting implementation, the method 100 comprises a step, executed by the control means 7, consisting of adding 107 a second value to the output value of the regulator, the second value being selected from a table of differences in measured position of the throttle 5 relative to a rest position of the throttle 5, also known by the English terminology of “limhome” position.

[0051] The addition of this second value makes it possible to anticipate the movement of the butterfly, and therefore to improve the responsiveness of the electric motor 6. This second value is of great interest when the position of the butterfly 5 is close to the rest position and the butterfly 5 passes from one side to the other of the rest position.

[0052] According to a non-limiting implementation, the method 100 comprises a step, executed by the control means 7, consisting of multiplying 108 the output value of the regulator to a third value, the third value being a function of a voltage value of a battery of the vehicle. Indeed, the voltage value taken by the pulse width modulation control of the electric motor 6 is proportional to the voltage of the battery of the vehicle.

[0053] In order to avoid oscillations of the butterfly 5, the method 100 comprises a step, executed by the control means 7, consisting of estimating 109 an oscillation frequency of the butterfly 5.

[0054] If the estimated oscillation frequency is characteristic of a high frequency oscillation, the method 100 comprises a step consisting of decreasing 110 the first positive deviation or the first negative deviation added to the proportional term. By decreasing, we mean approaching zero.

[0055] 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 deviation of position is greater than a first threshold and when the absolute value of the gradient of the position deviation is greater than a second threshold.

[0056] Conversely, if the estimated oscillation frequency is characteristic of a low-frequency oscillation, the method 100 comprises a step consisting of increasing 111 the first positive deviation or the first 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.

[0057] 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.

[0058] Thus, the butterfly 5 is controlled reactively without entering an oscillation zone.

Claims

Claims

1. Method (100) for regulating a position of a motorized throttle (5) of a throttle body (4) of an internal combustion engine (2) of a vehicle (1), said method (100) comprising the steps, executed by control means (7) of said internal combustion engine (2), consisting of: - Determine (101) a position instruction for said throttle (5), - Determine (102) a position difference between a position of said measured throttle (5) and said position setpoint, said method (100) being characterized in that when a position 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 being determined by comparing said determined position deviation with a table of position deviations based on proportional term values; • The value of the integral term being 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 determined filtered position deviation to a table of position deviations based on integral term values; • The value of the derivative term being determined by comparing the derivative of said determined position deviation with a table of derivatives of position deviations as a function of values ​​of the derivative term; • 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 depending on a determined depression between the air inlet and the air outlet of the throttle body (4); • Add (106), to an output value of said regulator, a first oscillatory value forming a signal which alternates between a negative and positive value, said first oscillatory value being dependent on said determined depression between the air inlet and the air outlet of the throttle body (4); • Add (107) a second value to the output value of said regulator, said second value 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 adjusted between -200% and +200%.

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

4. Method (100) according to any one of the preceding claims, characterized in that it comprises a step consisting of multiplying (108) the output value of the regulator to a third value, said third value being a function of a voltage value of a battery of the vehicle (1).

5. Method (100) according to any one of the preceding claims, characterized in that it comprises the steps of: - Estimating (109) an oscillation frequency of the throttle; - 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. Method (100) according to the preceding claim, characterized in that 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.

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 first oscillatory value is between 10% and 20% of the output value of the regulator.

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

10. Vehicle (1) comprising an internal combustion engine (2) comprising a throttle body (4) provided 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 execute the steps of the method (100) according to any one of the preceding claims.