Method for position regulation of an electric throttle valve 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, comprising the following steps when a position deviation between the position of the throttle valve and a position set value is determined: regulating (103) the position of the throttle valve by means of a proportional-integral-derivative controller applied to a pulse width modulation control of an electric motor configured to position the throttle valve, the terms of the controller being tabulated; adding (104) a first positive or negative deviation to the proportional term when the determined position deviation is respectively positive or negative; adding (105) a second deviation to the proportional term, the second deviation being a function of a determined pressure drop between an inlet and an outlet of a throttle body assembly; adding (106) a first oscillation value to the output value of the controller, the first oscillation value being dependent on the pressure drop; adding (107) a second value to the output value of the controller, the second value being selected from a table of differences between the measured position of the throttle valve and a rest position of the throttle valve.

Description

Technical Field

[0001] The present invention pertains to the field of electric throttle position adjustment for vehicles equipped with internal combustion engines. Background Technology

[0002] As is well known, the throttle body assembly includes a disc-shaped throttling component called the throttle valve, which is rotatably mounted in a passage that runs through the throttle body assembly. The throttle valve moves within this passage to regulate the airflow supplied to the internal combustion engine.

[0003] The throttle valve is typically pulled back to a resting position by a spring-loaded return mechanism, which corresponds to a predetermined opening position in the throttle passage. This spring-loaded return mechanism usually consists of two counteracting springs. The angular position of the throttle valve in the passage is electrically controlled by an electric motor to counteract the spring-loaded return mechanism.

[0004] The positioning accuracy of this throttle valve is crucial because it regulates the airflow injected into the internal combustion engine, thus affecting the engine's acceleration and responsiveness. Therefore, the throttle valve position must precisely reflect the acceleration desired by the driver, as indicated by the position of the accelerator lever or pedal. This precision is even more important for lighter vehicles, especially two-wheeled vehicles. Summary of the Invention

[0005] One object of the present invention is to provide a solution to improve the positioning accuracy of the throttle valve according to the position desired by the driver.

[0006] Therefore, in its broadest sense, the present invention relates to a method for adjusting the position of an electric throttle valve of a throttle body assembly of an internal combustion engine in a vehicle, the method comprising the following steps performed by a control device of the internal combustion engine: - Determine the throttle position setting. - Determine the positional deviation between the measured position of the throttle valve and the position setting value. The method is characterized in that, when the positional deviation is determined, the method includes the following steps: The throttle position is adjusted via a proportional-integral-derivative controller, which is applied to pulse-width modulation control of the electric motor used for throttle positioning. - The value of the proportional term is determined by comparing the determined position deviation with a position deviation table, which is a function of the proportional term value; - The value of the integral term is determined by adding the first value of the integral term determined in the previous calculation loop to the second value of the integral term determined by comparing the filtered determined position deviation with a position deviation table, which is a function of the integral term value; - The value of the differential term is determined by comparing the derivative of the determined position deviation with a table of position deviation derivatives, which is a function of the value of the differential term; - When the determined positional deviation is positive, add the first positive deviation to the proportional term, or when the determined positional deviation is negative, add the first negative deviation to the proportional term; - Add a second bias to the proportional term, which is a function of the negative pressure determined between the intake and exhaust ports of the throttle body assembly; - Add a first oscillation value to the output value of the controller, the first oscillation value forming a signal that alternates between negative and positive values, the first oscillation value depending on the negative pressure determined between the intake and exhaust ports of the throttle body assembly; - Add a second value to the controller's output value, the second value being selected from a table of differences between the measured position of the throttle valve and its stationary position.

[0007] By means of the method according to the invention, the position of the throttle valve is quickly brought back to the position setting value that is closest to the vehicle driver's intention.

[0008] In addition to the features just mentioned in the preceding paragraph, the method according to the invention may also have one or more of the following additional features, which may be considered individually or in all technically possible combinations.

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

[0010] According to a non-limiting embodiment of the present invention, the differential term may be set between -100% and +100%.

[0011] According to a non-limiting embodiment of the invention, the method includes a step performed by a control device, namely multiplying the output value of the controller by a third value, the third value being a function of the voltage value of the vehicle's battery.

[0012] According to a non-limiting embodiment of the present invention, the method includes the following steps performed by a control device: - Estimate the oscillation frequency of the throttle valve; -If the estimated oscillation frequency characterizes high-frequency oscillation, then reduce the first positive deviation or the first negative deviation added to the scaling term; If the estimated oscillation frequency characterizes low-frequency oscillation, then increase the first positive deviation or the first negative deviation added to the proportional term.

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

[0014] According to a non-limiting embodiment of the present invention, when the absolute value of the low-frequency cumulative variable is greater than the low-frequency threshold, the estimated oscillation frequency characterizes the low-frequency oscillation, and the low-frequency cumulative variable is determined by summing the position deviation.

[0015] According to a non-limiting embodiment of the present invention, the first oscillation value is between 10% and 20% of the controller output value.

[0016] According to a non-limiting embodiment of the present invention, the first oscillation value is periodically updated, with a period between 1 millisecond and 5 milliseconds.

[0017] One non-limiting embodiment of the present invention relates to a vehicle, such as a two-wheeled vehicle, comprising an internal combustion engine including a throttle body assembly with an electric throttle valve, the vehicle further comprising an electric motor configured to position the throttle valve, the vehicle being characterized in that it includes a control device configured to perform steps of the method according to any of the foregoing embodiments.

[0018] A better understanding of the invention and its various applications will be gained by reading the following description and examining it in conjunction with the accompanying drawings. Attached Figure Description

[0019] [Figure 1] A vehicle of the two-wheeled type according to the present invention is shown schematically.

[0020] [Figure 2] A method according to a non-limiting embodiment of the present invention is illustrated schematically.

[0021] These accompanying drawings are given in an illustrative manner only and are in no way intended to limit the scope of the invention.

[0022] Unless otherwise stated, the same element appearing in different figures has a unique figure reference numeral. Detailed Implementation

[0023] Figure 1 shows a two-wheeled vehicle type 1 equipped with an internal combustion engine 2 including a single cylinder 3.

[0024] Cylinder 3 is associated with throttle body assembly 4. Throttle body assembly 4 includes an electric throttle valve 5 configured to regulate the amount of air injected into cylinder 3. Throttle valve 5 is driven by electric motor 6.

[0025] The electric motor 6 is driven by the control unit 7 of the internal combustion engine 2 via pulse width modulation (PWM) control, also known as MLI. The electric motor 6 is configured to position the throttle valve 5 according to a position setpoint. This position setpoint specifically corresponds to the position of the accelerator lever. It also depends on other parameters, such as the mechanical friction of the internal combustion engine 2.

[0026] According to this embodiment, the control device 7 is configured to adjust the position of the throttle valve 5 via a proportional-integral-derivative (PID) controller, each item of which is listed. More specifically, each item of the controller is determined by means of a position deviation table between the measured position of the throttle valve 5 and the position setpoint of the throttle valve 5. The PLD controller is applied to the pulse width modulation control of the electric motor 6. More specifically, these control devices 7 are configured to perform the steps of the method 100 according to the invention shown in FIG. 2.

[0027] Figure 2 illustrates a method 100 for adjusting the position of the electric throttle valve 5 of the internal combustion engine 2 of a vehicle 1.

[0028] The method 100 includes a step performed by the control device 7, namely determining the position setting value of the throttle valve 5.

[0029] This position setting depends in particular on the measured position of the throttle lever. This position can be measured using a position sensor. The position setting may also depend on other parameters, such as the altitude at which the vehicle is traveling, or on established mechanical friction.

[0030] Next, the method 100 includes a step performed by the control device 7, namely, determining the position deviation between the measured position of the throttle valve 5 and the position set value. The position of the throttle valve 5 can be measured by a position sensor (not shown).

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

[0032] The value of the proportional term is determined by comparing the determined position deviation with a position deviation table. Therefore, by comparing the determined position deviation with the position deviation recorded in the position deviation table, the control device 7 determines a value for the proportional term assigned to the proportional-integral-derivative controller.

[0033] The value of the integral term is determined by control device 7 as follows: the first value of the integral term determined in the previous calculation cycle is added to the second value of the integral term determined by comparing the filtered determined position deviation with a position deviation table. Therefore, control device 7 determines a value of the integral term assigned to the controller by means of this table.

[0034] The determined positional deviation is filtered, for example, using a first-order filter. Furthermore, the integral term in the deviation table changes slowly, especially when the positional deviation is large. This filtering and slow change prevent integral term drift.

[0035] The value of the differential term is determined by comparing the derivative of the determined position deviation with a table of position deviation derivatives. The derivative of the determined position deviation is, for example, the difference between the determined position deviation and the position deviation determined in the previous calculation cycle. Therefore, the control device 7 uses this table to determine a value for the differential term assigned to the controller.

[0036] According to this non-limiting embodiment, the proportional term can be set between -200% and +200%, and the derivative term can be set between -100% and +100%. The fact that it exceeds + or -100% allows the throttle valve 5 to move very quickly when its position deviates from the position setting value.

[0037] The integral term has a small value that allows for compensation of deviations when the throttle 5 position is close to the position setting.

[0038] In other words, when the position of throttle valve 5 is far from the position set value, the proportional and derivative terms will quickly change the position of throttle valve 5. Then, when the position of throttle valve 5 is close to the position set value, the integral term will act on the position of throttle valve 5 to accurately reach the position set value.

[0039] According to this embodiment, the method 100 includes a step performed by the control device 7, namely, when a positive positional deviation is determined between the position setting value of the throttle valve 5 and the measured position of the throttle valve 5, a first positive deviation of 104 is added to the proportional term. Conversely, when a negative positional deviation is determined between the position setting value of the throttle valve 5 and the measured position of the throttle valve 5, a first negative deviation is added to the proportional term.

[0040] The added first deviation can compensate for the dry friction generated by the mechanical components of the throttle body assembly 4 and / or the internal combustion engine 2.

[0041] According to this embodiment, the method 100 includes a step performed by the control device 7, namely, adding a second deviation of 105 to the proportional term, the second deviation being a function of the negative pressure determined between the air intake and air outlet of the throttle body assembly 4.

[0042] In reality, a pressure difference exists across the throttle body assembly 4. Atmospheric pressure exists at the inlet of the throttle body assembly 4, while a lower pressure exists at the outlet of the throttle body assembly 4, i.e., the inlet of cylinder 3. This pressure difference can reach 900 millibars and generates a force of tens of daN on the shaft of the throttle valve 5. This phenomenon generates additional friction. To compensate for this friction caused by the pressure difference, a second bias is added to the proportional term.

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

[0044] The second deviation can be determined using a table that records the second deviation corresponding to the pressure difference. The pressure measured at the outlet 4 of the throttle body assembly can change very rapidly, so this second deviation can be updated very frequently, for example, every 10 ms.

[0045] The method 100 further includes a step performed by the control device 7, namely adding a first oscillation value 106 to the output value of the controller, the first oscillation value depending on the negative pressure determined between the air intake and air outlet of the throttle body assembly 4.

[0046] This oscillation value corresponds to a signal that alternates between negative and positive values, i.e., a more "square wave" type signal centered at 0. This signal oscillates at a high frequency, for example, on the order of 1 kHz.

[0047] The first oscillation value applied to the controller output can apply a force to counteract the friction of the motor 6 driving the throttle valve 5. In other words, the first oscillation value can continuously excite the motor 6 so that when the motor 6 must start moving, the friction has already been counteracted. Thus, it is only necessary to rotate the motor 6 without having to counteract the friction.

[0048] According to one non-limiting embodiment, the first oscillation value is between +10% and +20% of the controller output value, and the first oscillation value is periodically updated with a period between 1 and 5 milliseconds.

[0049] In other words, an oscillation value is added to the controller's output to excite motor 6, thereby controlling the motor at a value just below that which causes it to move.

[0050] Furthermore, according to this non-limiting embodiment, the method 100 includes a step performed by the control device 7, namely adding a second value 107 to the output value of the controller, the second value being selected from a position difference table of the measured position of the throttle 5 relative to the rest position of the throttle 5, the rest position also known as the English term "limphome" position.

[0051] Adding this second value allows for a pre-emptive response to throttle movement, thus improving the responsiveness of the electric motor 6. This second value is particularly significant when the throttle 5 is near a stationary position and when it moves from one side of the stationary position to the other.

[0052] According to one non-limiting embodiment, the method 100 includes a step performed by the control device 7, namely multiplying the controller's output value by a third value, 108, which is a function of the vehicle's battery voltage. In practice, the voltage value used for the pulse-width modulation control of the electric motor 6 is proportional to the vehicle's battery voltage.

[0053] To prevent throttle valve 5 from oscillating, the method 100 includes a step performed by the control device 7, namely estimating the oscillation frequency of throttle valve 5.

[0054] If the estimated oscillation frequency characterizes high-frequency oscillation, then method 100 includes a step of reducing the first positive or first negative deviation added to the proportional term. Reducing means moving closer to zero.

[0055] According to a non-limiting embodiment of the present invention, when the high-frequency cumulative variable is greater than the high-frequency threshold, the estimated oscillation frequency characterizes the high-frequency oscillation, and the high-frequency cumulative variable is determined when the absolute value of the position deviation is greater than the first threshold and the absolute value of the position deviation gradient is greater than the second threshold.

[0056] Conversely, if the estimated oscillation frequency characterizes low-frequency oscillations, then method 100 includes a step of increasing the first positive or first negative deviation added to the proportional term. "Increasing" means moving away from zero. For example, if the first negative deviation is -1, then increasing the first negative deviation would change it to -2.

[0057] According to a non-limiting embodiment of the present invention, when the absolute value of the low-frequency cumulative variable is greater than the low-frequency threshold, the estimated oscillation frequency characterizes the low-frequency oscillation, and the low-frequency cumulative variable is determined by summing the position deviation.

[0058] Therefore, throttle valve 5 is driven in a responsive manner without entering the oscillation region.

Claims

1. A method (100) for adjusting the position of an electric throttle valve (5) of a throttle body assembly (4) of an internal combustion engine (2) of a vehicle (1), the method (100) comprising the following steps performed by a control device (7) of the internal combustion engine (2): - Determine the position setting value of the throttle valve (5) as described in (101). - Determine the positional deviation between the measured position of the throttle valve (5) and the position setting value (102). Its features are, When the positional deviation is determined, the method includes the following steps: The position of the throttle valve (5) is adjusted by a proportional-integral-derivative controller (103), which is applied to the pulse width modulation control of the electric motor (6) used to position the throttle valve (5). o The value of the proportional term is determined by comparing the determined position deviation with a position deviation table, which is a function of the proportional term value; The value of the integral term is determined by adding the first value of the integral term determined in the previous calculation loop to the second value of the integral term determined by comparing the filtered determined position deviation with a position deviation table, which is a function of the integral term value. The value of the differential term is determined by comparing the derivative of the determined position deviation with a table of position deviation derivatives, which is a function of the value of the differential term. -When the determined position deviation is positive, add (104) first positive deviation to the proportional term, or when the determined position deviation is negative, add first negative deviation to the proportional term; - Add (105) a second deviation to the proportional term, the second deviation being a function of the negative pressure determined between the intake and exhaust ports of the throttle body assembly (4); - Add (106) a first oscillation value to the output value of the controller, the first oscillation value forming a signal that alternates between negative and positive values, the first oscillation value depending on the negative pressure determined between the intake and exhaust ports of the throttle body assembly (4); Add (107) a second value to the output value of the controller, the second value being selected from a table of differences between the measured position of the throttle valve (5) and the stationary position of the throttle valve (5).

2. The method (100) according to the preceding claim, Its features are, The ratio can be set between -200% and +200%.

3. The method (100) according to any one of the preceding claims, Its features are, The differential term can be set between -100% and +100%.

4. The method (100) according to any one of the preceding claims, Its features are, The method includes the following steps: Multiply the controller's output value by the third value (108). The third value is a function of the voltage value of the battery of the vehicle (1).

5. The method (100) according to any one of the preceding claims, Its features are, The method includes the following steps: - Estimate the oscillation frequency of the (109) throttle valve; -If the estimated oscillation frequency characterizes high-frequency oscillation, then reduce (110) the first positive deviation or the first negative deviation added to the proportional term; -If the estimated oscillation frequency characterizes low-frequency oscillation, then increase (111) the first positive deviation or the first negative deviation added to the proportional term.

6. The method (100) according to the preceding claim, Its features are, When the high-frequency cumulative variable is greater than the high-frequency threshold, the estimated oscillation frequency characterizes the high-frequency oscillation. The high-frequency cumulative variable is determined when the absolute value of the position deviation is greater than a first threshold and the absolute value of the position deviation gradient is greater than a second threshold.

7. The method (100) according to claim 5, Its features are, When the absolute value of the low-frequency cumulative variable is greater than the low-frequency threshold, the estimated oscillation frequency characterizes the low-frequency oscillation. The low-frequency cumulative variable is determined by summing the position deviations.

8. The method (100) according to any one of the preceding claims, Its features are, The first oscillation value is between 10% and 20% of the controller output value.

9. The method (100) according to the preceding claim, Its features are, The first oscillation value is updated periodically. Its period is between 1 millisecond and 5 milliseconds.

10. A vehicle (1) comprising an internal combustion engine (2), said internal combustion engine including a throttle body assembly (4) equipped with an electric throttle valve (5), The vehicle (1) also includes an electric motor (6) configured to position the throttle valve (5). The vehicle (1) is characterized in that it includes a control device (7) configured to perform the steps of the method (100) according to any of the preceding claims.

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