Optimization method for optimizing the hot engine speed of an automatic transmission vehicle during a transfer

Abstract

The invention relates to an optimization method for optimizing the thermal engine speed (30) of an automatic gearbox (32) type vehicle during a transfer, for implementing an optimization device (1) in communication with an engine control module (2) and a clutch control module (5), said method comprising a step in which real-time engine speed information (RMTH) is provided by the engine control module (2) to the optimization device (1), another step in which the real-time engine speed information (RMTH) is compared by the optimization device (1) with engine speed setpoint information (CRM), and yet another step in which, in the event of a mismatch between real-time engine speed (RMTH) information and engine speed setpoint (CRM) information, the optimization device (1) transmits a fade factor (FG) to the clutch control module (5) for fading the clutch torque gradient to limit the clutch torque gradient.

Description

Technical Field

[0001] This invention claims priority to French Application No. 2000152, filed on January 9, 2020, the contents of which (text, drawings and claims) are incorporated herein by reference.

[0002] The present invention relates to a method for optimizing the hot engine speed of an automatic transmission vehicle during a pick-up and drop-off, and to a vehicle implementing such a method. Background Technology

[0003] Hybrid vehicles of the PHEV (Plugin Hybrid Electric Vehicle) type typically include a heat engine, an electric motor, a clutch, a gearbox for engaging the clutch to the wheels via one or more gear ratios, the clutch being able to engage by sliding between the heat engine and the gearbox, the electric motor being connected to a network and coupled to the gearbox, and a main storage device of the battery type.

[0004] The use of the clutch enables decoupling between the thermal engine and the wheels.

[0005] The clutch is capable of transmitting the engine's torque by sliding between the rotational speed of the hot engine and the rotational speed of the motor connected to the wheels: in practice, the hot engine is only available when the rotational speed exceeds a minimum speed (referred to as idle speed).

[0006] During engine engagement (e.g., for hybrid vehicles, during start-up or start-up and then engagement of an enroulant engine), the engine speed needs to be controlled in response to various constraints: the engine speed must be prevented from dropping to avoid engine stalling, the spindle must be able to deliver sufficient torque to the driver, and the engine's acoustic and vibration levels must be optimized by keeping the engine at a specific speed.

[0007] However, in these engine engagement scenarios and with reference to the fundamental equations of dynamics, the given engine speed is the result of the torque provided by the hot engine and the torque intercepted by the clutch and provided to the wheels.

[0008] Therefore, a trade-off must be struck between the torque of the hot engine and the torque of the clutch.

[0009] Some existing solutions aim to manage engine engagement using the clutch to implement the torque demanded by the driver. Other solutions aim to regulate the engine speed to maintain the engine's optimal speed, ensuring compliance with multiple prestations, while simultaneously providing the necessary torque to the wheels via the clutch.

[0010] A control device is known from document FR3054189 for controlling the torque provided by the drive motor of a parallel hybrid vehicle with a manual transmission, in terms of the clutch: the technical solution provided in that document determines the limiting (limiting) torque of the drive motor based on the position of the clutch pedal. This device cannot prevent excessive torque from being transmitted to the hot engine and is only applicable to powertrains with a manual transmission and a clutch pedal. Summary of the Invention

[0011] The present invention provides an alternative operating solution that avoids acoustic and vibration inconveniences and is able to comply with the driver's wishes.

[0012] Therefore, the present invention relates to an optimization method for optimizing the hot engine speed of an automatic transmission vehicle during engagement, the vehicle further comprising a clutch system and a transmission, the transmission including an electric motor for ensuring control of transmission motion to the wheels of the vehicle, the engagement of the hot engine being ensured by slippage of the clutch between the rotating hot engine and the main shaft connected to the wheels, the method being implemented by an optimization device communicating with an engine control module and a clutch control module.

[0013] The method according to the present invention includes the steps of providing real-time engine speed information to the optimization device by the engine control module, another step in which the real-time engine speed information is compared by the optimization device with engine speed setpoint information, and yet another step in which, in the case of a mismatch between the real-time engine speed information and the engine speed setpoint information, the optimization device transmits a decay factor to the clutch control module, the decay factor being used to decay the clutch torque gradient to limit the clutch torque gradient.

[0014] As such, the method according to the invention is able to provide higher thermal engine torque, attributed to a higher thermal engine speed, in accordance with the driver's wishes. The method also solves acoustic and vibration inconveniences because the thermal engine speed follows its own optimal speed setting.

[0015] Furthermore, the method prevents the hot engine from stalling by keeping its rotational speed away from its idle speed.

[0016] Finally, due to the good bonne incidence between the rotational speed of the spindle and the rotational speed of the heat engine, the method limits the risk of collisions and vibrations when the clutch engages.

[0017] The method conforming to the present invention may also include the following features:

[0018] The engine speed setpoint information is calculated by the engine control module based on the engine torque setpoint, which is determined by the position information of the accelerator pedal actuated by the driver.

[0019] - The attenuation factor used to attenuate the clutch torque gradient is based on the hot engine load factor, which is calculated as a function of the implemented torque of the hot engine and the maximum torque, and based on the speed deviation gradient between the real-time hot engine speed and the hot engine speed setpoint.

[0020] The present invention also relates to a component for optimizing the rotational speed of a hot engine in a vehicle during a docking, the vehicle further comprising a clutch system and an automatic transmission, the automatic transmission including a motor for ensuring control of transmission motion to the wheels of the vehicle, the docking of the hot engine being ensured by slippage of the clutch between the rotating hot engine and a main shaft coupled to the wheels, the component being used to ensure the implementation of the above method.

[0021] According to the present invention, the component includes an optimization device, an engine control module, and a clutch control module. The engine control module is configured to provide real-time engine speed information to the optimization device. The optimization device is adapted to compare the real-time engine speed information with hot engine speed setpoint information and to transmit a decay factor to the clutch control module. The decay factor is used to decay the clutch torque gradient to limit the clutch torque gradient in the event of a mismatch between the real-time engine speed information and the engine speed setpoint.

[0022] The component may also include the following features:

[0023] The engine control module calculates the engine speed setpoint information based on the engine torque setpoint, which is determined by the position information of the accelerator pedal actuated by the driver.

[0024] The optimization device is based on a thermal engine load factor, which is a function of the implemented torque of the thermal engine and the maximum torque, and calculates the attenuation factor for attenuating the clutch torque gradient based on the speed deviation gradient between the real-time thermal engine speed and the thermal engine speed setpoint.

[0025] Finally, the present invention relates to a vehicle equipped with a device conforming to the present invention and as described above. Attached Figure Description

[0026] Other objects, features, and advantages of the invention will become more apparent upon reading the following non-limiting description and with reference to the accompanying drawings, in which:

[0027] - Figure 1 A simplified block diagram illustrates a particular embodiment of the apparatus for establishing engine speed setpoints according to the present invention.

[0028] - Figure 2 Another block diagram illustrates the different modules implemented in a method conforming to the present invention.

[0029] - Figure 3 The rotational speed curves of the main shaft and the engine during the start-up phase are shown as a function of time in the prior art, and the curves of the set value of (mechanical torque) and the mechanical torque during the start-up phase are also shown as a function of time in the prior art.

[0030] - Figure 4 The curves of the spindle speed and engine speed in the context of implementing the method according to the present invention are shown as functions of time, and the driver setpoint curve, clutch torque curve and hot engine torque curve, engine load factor curve, clutch torque gradient decay curve and speed deviation gradient curve are also shown as functions of time in the context of implementing the method according to the present invention. Detailed Implementation

[0031] like Figure 1 As shown, the present invention includes an optimization device 1, which works in conjunction with the engine control module 2 and the clutch control module 5.

[0032] The function of the engine control module 2 is to control the operation of the powertrain 3, that is, to control the hot engine, clutch 31 and automatic transmission 32.

[0033] The engine control module 2 transmits the torque setpoint CCM to the hot engine 30 of the powertrain 3 of the vehicle.

[0034] The gearbox 32 is mechanically coupled to the clutch 31 via its own main shaft AP and to the vehicle wheels 4 via its own output shaft tree AS.

[0035] Clutch 31 ensures the controlled sliding transmission of mechanical torque from the thermal engine 30 to the main shaft AP of the transmission 32. The transmission 32 is coupled to the hybrid rotary motor 320 at its own main shaft AP position, and the transmission includes gear mechanisms 321 that authorize multiple gear ratios.

[0036] Engine control module 2 exchanges information with the optimization device conforming to the present invention, including accelerator pedal information PA and engine speed setpoint CRM. During engine engagement (e.g., starting or starting and then engaging), engine control module 2 adjusts different operating parameters of the hot engine 30 to obtain an engine speed subordinate to (serving) the engine speed setpoint CRM.

[0037] like Figure 1 As can be seen and according to the present invention, the optimization device 1 receives real-time engine speed information RMTH from the engine control module 2. This information is compared by the optimization device 1 with engine speed setpoint information CRM to transmit a decay factor FG, used to attenuate the clutch torque gradient, to the clutch control module.

[0038] The attenuation factor FG used to attenuate the clutch torque gradient results in the transmission of a clutch torque setpoint CCE that limits the clutch torque gradient.

[0039] Figure 2 The invention is also schematically illustrated: when the driver presses the accelerator pedal 6 of the vehicle, he conveys his intention to accelerate. The accelerator pedal information PA is processed to transmit the engine torque setpoint CCM to the engine control module 2 and the clutch torque setpoint CCE to the clutch control module 5.

[0040] The engine control module 2 communicates the hot engine speed setpoint (CRM) to the optimization device.

[0041] The optimization device 1 then considers the real-time engine speed RMTH, the implemented engine torque CMT, and the maximum engine torque CMTmax to optionally generate a decay factor for attenuating the clutch torque gradient FG.

[0042] The clutch control module 5 controls the limitation of the clutch torque CEM according to the attenuation factor FG.

[0043] Now refer to Figure 3 The curves illustrate the initial use of existing technologies.

[0044] In the aforementioned start-up use case and at the clutch torque setting value ( Figure 3 At the bottom, during the increase of curve CCE, the clutch may intercept more torque than required due to an implementation error (manufacturing error): this error (error) is schematically shown by the curve CER (implemented clutch torque) with a dashed line. Figure 4 superior.

[0045] In this scenario, despite reaching its maximum torque, the engine speed RMTH will decline towards the main shaft speed RAP (the curves are indicated by the reference numerals RMTH and RAP in the figure). Figure 3 (Shown at the top).

[0046] exist Figure 3 At the bottom; the curve representing the torque of the hot engine carries the reference numeral CMT and the curve representing the maximum torque of the hot engine carries the reference numeral CMTmax.

[0047] As for the curve bearing the reference numeral CCEcor, it corresponds to the curve of the corrected clutch torque setting value, which has been corrected by existing technology.

[0048] If the clutch torque is not further corrected, several undesirable effects should be noted:

[0049] Since the maximum torque of the hot engine depends directly on its own rotational speed, it cannot provide sufficient hot engine torque to meet the driver's wishes.

[0050] This situation generates some acoustic vibrations and vibrations because the engine speed does not follow its optimal speed setting.

[0051] Since the rotational speed of the hot engine is close to its own idle speed, the timing of the hot engine is definitely reduced but not zero.

[0052] Due to the mavaise incidence between the rotational speed of the main shaft and the rotational speed of the heat engine, during the clutch engagement (see in...), Figure 3 The attached chart with the symbol D) indicates a risk of collision or oscillation.

[0053] Figure 4 Some curves are shown, which illustrate the effect of implementing the invention (as in...) Figure 3 The same usage scenario as shown above.

[0054] The purpose of this invention is to calculate the torque gradient limit of the clutch based on the load of the thermal engine and the evolution of the thermal engine's rotational speed.

[0055] The apparatus according to the present invention calculates the heat engine load factor based on the torque CMT implemented by the heat engine and based on the maximum torque CMTmax of the heat engine (see in...). Figure 4 (The curve at the bottom carries the attached diagram label FCM).

[0056] The device also calculates the speed deviation gradient between the engine speed and a set value for the engine speed (in Figure 4 The curve at the bottom is GER.

[0057] Based on the states of these two dependencies (FCM and GER), the device derives a clutch torque gradient attenuation factor, which is applied to the clutch torque setpoint: this attenuation factor... Figure 4 (Bottom) is shown by curve FA.

[0058] Apply the following logic:

[0059] If the engine is heavily loaded and if the engine speed is far from its set value, the clutch torque gradient is reduced.

[0060] The consequence of this is that the torque increase implemented by the clutch is stopped (see in...). Figure 4 The clutch torque setpoint curve CCE at the middle and the corrected clutch torque setpoint curve CCEcor) are used to limit the excessive transmission of clutch torque to the hot engine (see the curve with implemented clutch torque CER).

[0061] This results in a halt to the decrease in the rotational speed of the heat engine during the said docking (see point A) and a maintained docking mass (observed in the curve of the spindle rotational speed at...). Figure 4 (The top is basically straight).

[0062] As can be understood from the foregoing, the present invention can optimize the speed of the hot engine by limiting the gradient of the clutch torque.

Claims

1. An optimization method for optimizing the hot engine (30) speed of a vehicle with an automatic transmission (32) during a shuttle trip, the vehicle further comprising: The system includes a clutch system (31) and a gearbox (32), the gearbox comprising an electric motor (320) that ensures the transmission of motion to the wheels (4) of the vehicle. The engagement of the hot engine (30) is ensured by the slippage of a clutch between the rotating hot engine (30) and a main shaft (AP) connected to the wheels (4). This method is implemented by an optimization device (1) that communicates with an engine control module (2) and a clutch control module (5). The method includes: - Step, wherein the real-time thermal engine speed (RMTH) information is provided by the engine control module (2) to the optimization device (1). - In another step, the real-time thermal engine speed (RMTH) information is compared by the optimization device (1) with the thermal engine speed setpoint (CRM) information. - And another step, wherein, in the event of a mismatch between the real-time hot engine speed (RMTH) information and the hot engine speed setpoint (CRM) information, the optimization device (1) transmits a decay factor (FG) to the clutch control module (5), the decay factor being used to decay the clutch torque gradient to limit the clutch torque gradient. The attenuation factor (FG) used to attenuate the clutch torque gradient is based on the hot engine load factor (FCM) and calculated based on the speed deviation gradient between the real-time hot engine speed (RMTH) and the hot engine speed setpoint (CRM), the hot engine load factor being a function of the implemented torque (CMT) of the hot engine and the maximum torque (CMTmax).

2. The optimization method according to claim 1, characterized in that, The hot engine speed setpoint (CRM) information is calculated by the engine control module (2) based on the engine torque setpoint (CCM), which is identified by the position information (PA) of the accelerator pedal (6) actuated by the driver.

3. An assembly for optimizing the rotational speed of a hot engine (30) in a vehicle during a docking, the vehicle further comprising a clutch system (31) and an automatic transmission including a motor (320) to ensure control of transmission motion to the wheels (4) of the vehicle, the docking of the hot engine (30) being ensured by slippage of a clutch between the rotating hot engine (30) and a spindle (AP) coupled to the wheels (4), the assembly being for ensuring implementation of the method according to any one of claims 1 to 2 and characterized in that it comprises an optimization device (1), an engine control module (2) and a clutch control module (5), the engine control module (2) being configured to provide real-time hot engine speed (RMTH) information to the optimization device (1), the optimization device (1) being adapted to optimize the real-time hot engine speed (RMTH) information. The engine speed (RMTH) information is compared with the hot engine speed setpoint (CRM) information, and is adapted to transmit a decay factor (FG) to the clutch control module (5). The decay factor is used to decay the clutch torque gradient to limit the clutch torque gradient in the event of a mismatch between the real-time hot engine speed (RMTH) information and the hot engine speed setpoint (CRM). The optimization device (1) calculates the decay factor (FG) for decaying the clutch torque gradient based on the hot engine load factor (FCM) and the speed deviation gradient between the real-time hot engine speed (RMTH) and the hot engine speed setpoint (CRM). The hot engine load factor is a function of the implemented torque (CMT) of the hot engine and the maximum torque (CMTmax).

4. The component according to claim 3, characterized in that, The engine control module (2) calculates the hot engine speed setpoint (CRM) information based on the engine torque setpoint (CCM), which is identified by the position information (PA) of the accelerator pedal (6) actuated by the driver.

5. A vehicle equipped with components conforming to claim 3 or 4.

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