Vehicle battery charging control with transmission in neutral

Abstract

This invention relates to a control method for controlling the charging of a battery (BR) of a vehicle (V), the vehicle including a first tractor (MM1) connected to a clutch (EM), the clutch also connected to a second tractor (MM2), the second tractor being electrically connected to the battery (BR) and to the main shaft (AP) of a transmission (BV), the transmission being connected to an axle. The control method includes the steps of, when the transmission (BV) is in neutral and the battery (BR) is in a charging phase, monitoring a deviation between a first rotational speed of the first tractor (MM1) and a second rotational speed of the second tractor (MM2), and controlling a first torque generated by the first tractor (MM1) based on the deviation.

Description

[0001] The present application claims priority from French application 1908319 filed on July 23, 2019, the content of which (words, drawings and claims) is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to a means of transport comprising a first and a second traction machine coupled via a clutch, and more particularly to the control of the charging of a battery coupled with the second traction machine in these means of transport. BACKGROUND

[0003] Some means of transport comprise a drive train comprising a first traction machine, for example a thermal engine or an electric machine or a hydraulic machine, coupled with a clutch, which is also coupled with a second traction machine, which is electric and which is also coupled with a rechargeable battery and with a main shaft of a gearbox, which is coupled with a road wheel. Among such means of transport, the first and second traction machines are part of what is usually called a powertrain (or GMP).

[0004] The term "traction machine" means a machine configured to provide or recover torque, which moves the means of transport either alone or as a complement to another thermal or non-thermal traction machine. A non-thermal traction machine can for example be an electric machine (or electric engine), a hydraulic machine, a pneumatic machine (or air compressor) or a flywheel. A thermal traction machine can for example be a thermal engine.

[0005] When it is wished to charge the battery of one of these means of transport while parked, a neutral charge function is activated, which aims to use the GMP as a generator set which converts the power generated by the first traction machine into charging power for said battery. This situation requires the gearbox to be in neutral position so as to make the means of transport non-movable, then to make the first traction machine run (if it is not already running) and to couple the first and second traction machines via the clutch. Then, the first traction machine is used to generate a charging torque, while the second traction machine stabilizes the optimum rotational speed of the assembly made up of the first and second traction machines by opposing the charging torque generated. This opposing torque thus causes the charging of said battery.

[0006] As known to those skilled in the art, a rotational speed regulation function is usually used for the second traction machine in order to oppose the first traction machine and thus stabilize said optimum rotational speed. As in Figure 1On the graph of figure 1, it can be observed that, in a first portion marked P1, the rotation speed of the first traction engine (curve cl) is linked to the rotation speed of the second traction engine (curve c2) because the clutch is closed (the torque of the clutch is greater than the torque of the first traction engine). It is also observed that the first traction engine provides a positive torque (curve c3) while the second traction engine provides a torque of the same value but with an opposite sign (curve c4) in order to maintain the rotation speed of the main shaft (which here is equal to the second rotation speed) constant and equal to the rotation speed setpoint of the main shaft (curve c5). If an unwanted drop in the torque of the clutch (curve c6) occurs in a second portion marked P2, the first traction engine is no longer held by the clutch and therefore its rotation speed (curve cl) increases greatly, with the risk of damaging this first traction engine. This unwanted drop generally occurs in the case of a clutch slip resulting from a faulty tracking of the setpoint or from a clutch failure causing the clutch to be partially or totally disconnected.

[0007] To avoid damaging the first traction engine as soon as its rotation speed reaches the maximum rotation speed r1max in a third portion marked P3, when this first traction engine is a thermal engine, it is possible to provide for implementing sudden injection cut-offs when the rotation speed of the first traction engine becomes very close to the maximum rotation speed r1max, but these injection cut-offs cause strong noise and strong vibrations (or jolts) in a fourth portion marked P4. As for the second traction engine, its rotation speed (curve c2) stabilizes on the rotation speed setpoint of the main shaft (curve c5) because the rotation speed of the second traction engine is piloted by the rotation speed regulation. This situation can be very worrying and stressful for the driver and the passengers of the vehicle. SUMMARY

[0008] The object of the present invention is therefore to improve this situation.

[0009] To this end, the invention notably provides a control method for a vehicle comprising a first traction engine, said first traction engine being coupled with a clutch, said clutch also being coupled with a second traction engine, said second traction engine being electric and also being coupled with a rechargeable battery and with a main shaft of a gearbox, said gearbox being coupled with a vehicle axle.

[0010] The control method is characterized in that it comprises a step in which, when the gearbox is in a neutral position and the battery is in a charging phase, a deviation between a first rotation speed of the first traction engine and a second rotation speed of the second traction engine is monitored and a first torque generated by the first traction engine is controlled as a function of said deviation.

[0011] This control of the first torque makes it possible to stop the high rotation speed of the first traction engine and therefore any risk of damage to this first traction engine.

[0012] The control method according to the application can comprise other features, which can be adopted individually or in combination, in particular:

[0013] - in the first embodiment, in said step, the first torque generated by the first traction machine can be reduced as a function of the said difference between the first rotational speed and the second rotational speed;

[0014] - in said step, a first limit torque can be determined for the first traction machine as a function of stored data establishing a correspondence between a difference between the first rotational speed and the second rotational speed and a first limit torque;

[0015] - in a variant, in said step, the first traction machine can be provided to generate a selected first limit torque when the said difference between the first rotational speed and the second rotational speed becomes greater than a threshold value;

[0016] - the first limit torque provided can be predefined or else selected as a function of the said difference;

[0017] - in said step, a threshold value can be used, the threshold value being selected as a function of the second rotational speed or as a function of a set value for the rotational speed of the main shaft;

[0018] - in the second embodiment, in said step, the first rotational speed of the first traction machine can be reduced as a function of the said difference between the first rotational speed and the second rotational speed.

[0019] The application also provides a computer program product comprising a set of instructions adapted, when executed by a processing means, to implement a control method of the type described above to control the charging of a battery of a means of transport comprising a first traction machine coupled with a clutch also coupled with a second traction machine, the second traction machine being electric and also coupled with the battery and with a main shaft of a gearbox coupled with a vehicle axle.

[0020] The application also provides a control device able to control the charging of a battery of a means of transport comprising a first traction machine coupled with a clutch also coupled with a second traction machine, the second traction machine being electric and also coupled with the battery and with a main shaft of a gearbox coupled with a vehicle axle.

[0021] The control device is characterized in that it comprises at least one processor and at least one memory configured for performing operations when the gearbox is in the neutral position and the battery is in the charging phase, said operations comprising monitoring the deviation between the first rotational speed of the first traction machine and the second rotational speed of the second traction machine, and controlling the first torque generated by the first traction machine as a function of said deviation.

[0022] The application also provides a means of transport, optionally of the motorized type and comprising, on the one hand, a first traction machine coupled with a clutch, said clutch also being coupled with a second traction machine, said second traction machine being electric and also being coupled with a rechargeable battery and with a main shaft of a gearbox, said gearbox being coupled with an axle, and comprising, on the other hand, a control device of the type described above.

[0023] For example, the first traction machine can be a thermal engine or an electric machine supplied with electric energy by the battery. BRIEF DESCRIPTION OF DRAWINGS

[0024] Other characteristics and advantages of the application will become apparent on reading the following detailed description and on examining the attached drawings, among which:

[0025] - Figure 1 A first example of time variation curves of the first rotational speed of the first traction machine and of the second rotational speed of the second traction machine of a means of transport of the prior art during a battery charging phase comprising a second torque drop of the clutch is schematically shown in a first graph (upper part), and a second example of time variation curves of the first and third torques of the first and second traction machines of this means of transport during this same charging phase is schematically shown in a second graph (lower part),

[0026] - Figure 2 A means of transport comprising a hybrid drive chain and a monitoring calculator equipped with a control device according to the application is schematically and functionally shown,

[0027] - Figure 3 An example of an algorithm implementing a control method according to the application is schematically shown,

[0028] - Figure 4 A first example of time variation curves of the first rotational speed of the first traction machine and of the second rotational speed of the second traction machine of a means of transport equipped with a control device according to the application during a battery charging phase comprising a second torque drop of the clutch is schematically shown in a first graph (upper part), and a second example of time variation curves of the first and third torques of the first and second traction machines of this means of transport during this same charging phase is schematically shown in a second graph (lower part), and

[0029] - Figure 5 An embodiment of the control device according to the invention is illustrated schematically and functionally. Detailed Implementation

[0030] The present invention is particularly intended to provide a control method and an associated control device DC, the control method and the control device being designed to control the charging of a battery BR of a vehicle V, the vehicle including a first tractor MM1 connected to a clutch EM, the clutch also connected to a second tractor MM2, the second tractor being electrically connected to the battery BR and to the main shaft AP of a transmission BV, the transmission being connected to an axle T1.

[0031] In the following text, as a non-limiting example, the means of transport V is considered to be motorized. This means of transport is, for example, a car, such as... Figure 2 The above is not a limiting illustration. However, the invention is not limited to this type of transport vehicle. The invention actually relates to any type of transport vehicle including a drivetrain comprising at least a first traction unit, which is thermally or non-thermally powered and coupled to a clutch, the clutch also being coupled to a second traction unit, which is electrically powered and also coupled to the main shaft of a gearbox, the gearbox being coupled to an axle. Therefore, the invention relates not only to land transport vehicles, but also to ships and aircraft.

[0032] Note that the term "traction machine" refers to a machine configured to provide or recover torque, either alone or as a supplement to another thermal or non-thermal traction machine, to move a transport vehicle. A non-thermal traction machine can be, for example, an electric motor (or electric engine), a hydraulic press, a pneumatic motor (or air compressor), or a flywheel. A thermal traction machine can be, for example, a thermal engine.

[0033] Figure 2 The above schematically illustrates a transport vehicle V, which includes a drive train, a monitoring calculator CS adapted to monitor (or manage) the operation of the drive train, and a control device DC according to the invention.

[0034] The drivetrain here specifically includes a first traction machine MM1, an engine shaft AM, a clutch EM, a second electric traction machine MM2, a gearbox BV, a rechargeable battery BR, and a drive shaft AT.

[0035] In the following text, by way of non-limiting example, the first traction unit MM1 is considered to be thermal. This first traction unit is, for example, a thermal engine. However, the invention is not limited to this type of first traction unit. In practice, the first traction unit MM1 can be thermal or non-thermal (especially electrical).

[0036] The first traction unit MM1 (here, a heat engine) includes a crankshaft (not shown) which is fixedly connected to the engine shaft AM to drive the engine shaft AM to rotate. Furthermore, the first traction unit MM1 is designed to provide a first torque to at least the first axle T1 (here, a wheel axle) via a clutch EM, a second traction unit MM2, and a gearbox BV.

[0037] For example, the first axle T1 is located at the front of the vehicle V, and is preferably connected to the drive shaft AT via a differential (here, the front differential) D1 as shown in the figure. However, in a variant, the first axle T1 may be located at the rear of the vehicle V.

[0038] The clutch EM is responsible for connecting / disconnecting the engine shaft AM (connected to the first tractor MM1) with / from the second tractor MM2 under the command of the monitoring computer CS, so as to transmit a second torque based on the first torque generated by the first tractor MM1. The clutch EM can be of any type, as long as it can take at least the following states: a first state (engaged, or disengaged, or closed), wherein the clutch ensures maximum engagement between the first tractor MM1 and the second tractor MM2; a second state (disengaged, or disconnected, or released), wherein the clutch completely disconnects the first tractor MM1 from the second tractor MM2; and a slipping third state.

[0039] The second (electric) traction unit MM2 is connected to the battery BR to be powered or to power the battery BR. The second traction unit is also connected to the output of the clutch EM to receive a second torque, and to the main shaft AP of the gearbox BV to provide it with a third torque.

[0040] For example, the battery BR is a low-voltage type (typically, for example, 220V). But the battery can be a medium-voltage or high-voltage type.

[0041] The main shaft AP of the gearbox BV is designed to receive a third torque from the second traction machine MM2.

[0042] The transmission BV also includes at least one countershaft (not shown) designed to receive a third torque via the main shaft AP in order to transmit the third torque to a driveshaft AT connected thereto, which is indirectly connected to the drive wheels (here, the front drive wheels) of the vehicle V via a differential D1.

[0043] like Figure 2As shown in the above non-limiting illustration, note that the drivetrain may also include a starter or AC starter AD, which is connected to and responsible for starting the first tractor MM1. This starting is achieved using electrical energy, which is stored in an auxiliary battery BS, for example, as shown in the non-limiting illustration. The auxiliary battery BS may be configured as a battery of ultra-low voltage type (e.g., 12V, 24V, or 48V) and may also power, for example, an onboard network to which electrical equipment of the vehicle V is connected. Note that the auxiliary battery BS may be connected to the battery BR and the second tractor MM2 via a DC / DC type converter CV, as shown in the non-limiting illustration, so that it can be charged.

[0044] The operation of the first traction machine MM1, the second traction machine MM2, and the clutch EM can be controlled by the monitoring computer CS.

[0045] It should be noted that, in addition to the first traction unit MM1 and the second traction unit MM2, the drivetrain may also include a non-thermal third traction unit. In this case, the non-thermal third traction unit is responsible for providing torque to, for example, the second axle T2 located at the rear of the vehicle V based on the energy stored in the battery BR. The third traction unit thus operates either independently or as a supplement to the first traction unit MM1 and / or the second traction unit MM2, according to commands provided by the monitoring computer CS.

[0046] As described above, the present invention provides a control method designed to control the charging of a battery BR. The control method can be implemented at least in part by a control device DC of a vehicle V, which includes: at least one, for example, a digital signal processor PR (or DSP (“Digital Signal Processor”); and at least one memory MD. Therefore, the control device can be implemented as a combination of circuitry or electrical components or electronic components (or “hardware”) and software modules. The memory MD is a live memory for storing instructions for at least a portion of the control method to be implemented by the processor PR. The processor PR may include integrated (or printed) circuitry, or multiple integrated (or printed) circuits connected via wired or wireless connections. Note that integrated (or printed) circuitry refers to any type of device suitable for performing at least one electrical or electronic operation.

[0047] exist Figure 2 In the non-limiting example shown above, the control device DC is part of the monitoring computer CS. However, this is not mandatory. The control device DC can actually be a device directly or indirectly connected to the monitoring computer CS.

[0048] like Figure 3As shown above in a non-limiting manner, the control method according to the invention includes steps 10-40, which begin with sub-step 10, during which it is determined (e.g. by a monitoring calculator CS or by the driver internally) to perform a charging phase of the battery BR when the transmission BV is in neutral (or dead).

[0049] When the above conditions are met (or exist) and the battery BR is in the charging stage, the (control device DC) begins to monitor the deviation er between the first rotational speed of the first traction machine MM1 and the second rotational speed of the second traction machine MM2 in sub-step 20.

[0050] The monitoring is used to control the first torque in steps 10-40 of the method, the first torque being generated by the first traction machine MM1 according to the deviation er.

[0051] Because of this control over the first torque, high speeds of the first traction machine MM1 can be prevented, and thus any risk of damage to the first traction machine MM1 can be prevented, such as in Figure 4 The example is shown in the graph of rotational speed (upper part) and torque (lower part).

[0052] In fact, it can be observed in the first section labeled P1' that the first rotational speed (curve c1') of the first traction machine MM1 is related to the second rotational speed (curve c2') of the second traction machine MM2 because the clutch EM is engaged (the second torque of the clutch EM (curve c6') is greater than the first torque of the first traction machine MM1 (curve c3')). It is also observed that the first traction machine MM1 provides a positive first torque (curve c3'), while the second traction machine MM2 provides a third torque (curve c4') that is slightly less than the first torque but with the opposite sign, in order to keep the rotational speed of the spindle AP (which here is equal to the third rotational speed) constant and equal to the rotational speed setpoint of the spindle (curve c5'). In the second section labeled P2', an undesirable decrease in the second torque of the clutch (curve c6') is observed, which is automatically detected by the control device DC that monitors the deviation between the first and second rotational speeds. In practice, the first traction machine MM1 is no longer held by the clutch EM, and therefore its first speed (curve c1') is increased, while the second speed (curve c2') of the second traction machine MM2 is decreased (because the second traction machine MM2 applies negative torque at the start of clutch EM disengagement). This results in an increase in the deviation er in the third section marked P3'. The control unit DC thus decides to immediately reduce the first torque (curve c3') generated by the first traction machine MM1 in the fourth section marked P4'. This inevitably causes a gradual decrease in the third torque (curve c4') generated by the second traction machine MM2, but importantly, it avoids the first speed (curve c1') of the first traction machine MM1 becoming too large in the fifth section marked P5' (it can be observed that the first speed is still very far from the maximum speed r1max). For the second traction machine, its second speed (curve c2') is stabilized at the speed setpoint of the spindle AP (curve c5'), because this second speed is controlled by speed regulation.

[0053] It should be noted that when the first tractor MM1 is a thermal engine, the present invention is also able to avoid performing jet cut-off and thus avoid causing noise and vibration (as occurs in prior art transport vehicles).

[0054] At least two embodiments may be considered to implement control of the operation of the first traction machine MM1 according to the deviation er.

[0055] exist Figure 3 In the first embodiment shown above (non-limiting), in steps 10-40 of the method, the control device DC may reduce the first torque generated by the first traction machine MM1 according to the deviation er between the first and second rotational speeds.

[0056] Therefore, in steps 10-40 of the method, when the deviation between the first and second rotational speeds becomes greater than the threshold sr (i.e., er > sr), the control device DC can instruct the first traction machine MM1 to generate the selected first limiting torque. In this case, as... Figure 3 As shown in the non-limiting illustration above, in sub-step 30, the control device DC compares each deviation er with a threshold sr. If the deviation is less than the threshold sr, the control device DC returns to executing sub-step 20. Conversely, if the deviation is greater than the threshold sr, the control device DC executes sub-step 40, wherein the control device determines the selected limiting torque by specifying... Figure 4 The curve c7' in the figure decreases the first torque.

[0057] In the above selection, the specified first limiting torque can be, for example, either pre-limited (and therefore constant, regardless of the value of the deviation er), or selected based on the deviation er.

[0058] Similarly, under the above selection conditions, the threshold sr can be selected based on the second rotational speed or the rotational speed setting value of the spindle AP.

[0059] In the above-selected variant, in steps 10-40 of the method, the control device (DC) can determine a first limiting torque for the first traction machine MM1 based on stored data, which establishes a correspondence between the deviation between the first and second rotational speeds and the first limiting torque. This data (stored in the control device DC) can constitute what is commonly referred to as a mapping by those skilled in the art.

[0060] In a second embodiment (not shown), in steps 10-40 of the method, the control device (DC) can reduce the first rotational speed of the first traction machine MM1 based on the deviation between the first and second rotational speeds. For example, in each calculation stage of the control device DC, a limiting torque value dependent on the deviation er between the first and second rotational speeds can be defined. The limiting torque is parameterized so that it decreases and completely offsets as the rotational speed deviation er increases. This inevitably leads to the stabilization of the rotational speed of the first traction machine MM1. This second embodiment consumes more computational resources and requires a longer time for parameter setting compared to the first embodiment.

[0061] Note that, such as Figure 5As shown in the above non-limiting description, in addition to the live memory MD and processor PR, the control device DC may also include a large-capacity memory MM, which is specifically used to store the values ​​of the first and second speeds and different torque and speed setpoints, as well as intermediate data involved in all these calculations and processes. Furthermore, the control device DC may also include an input interface IE, which is used to receive at least the values ​​of the first and second speeds and different torque and speed setpoints, to optionally use these values ​​in calculations or processes after they have been converted and / or demodulated and / or amplified in a known manner by means of the digital signal processor PR'. Furthermore, the control device DC may also include an output interface IS, which is specifically used to transmit (at least for monitoring the calculator CS) commands, instructions, and messages.

[0062] It is also noted that the present invention provides a computer program product (or information program) comprising a set of instructions, which, when executed by a circuit (or hardware) type processing unit (e.g., a processor PR), are adapted to implement the control method described above to control the charging of the battery BR of the transport vehicle V.

[0063] It is also noted that one or more sub-steps of the control method can be executed by different components. Therefore, the control method can be implemented using multiple digital signal processors, active memory, mass storage, input interfaces, and output interfaces.

Claims

1. A control method for a transport vehicle (V), the transport vehicle comprising a first tractor (MM1) connected to a clutch (EM), the clutch also connected to a second tractor (MM2), the second tractor being electrically connected and also connected to a rechargeable battery (BR) and a main shaft (AP) of a gearbox (BV), the gearbox being connected to an axle, characterized in that, The control method includes steps (10-40), wherein, when the transmission (BV) is in neutral and the battery (BR) is in the charging phase, the deviation between a first rotational speed of the first traction machine (MM1) and a second rotational speed of the second traction machine (MM2) is monitored, the deviation is compared with a threshold, and a first torque generated by the first traction machine (MM1) is controlled based on the comparison.

2. The control method according to claim 1, characterized in that, In step (10-40), the first torque generated by the first traction machine (MM1) is reduced according to the deviation between the first rotational speed and the second rotational speed.

3. The control method according to claim 2, characterized in that, In step (10-40), a first limiting torque is determined for the first traction machine (MM1) based on stored data, wherein the stored data establishes a correspondence between the deviation between the first speed and the second speed and the first limiting torque.

4. The control method according to claim 2, characterized in that, In step (10-40), when the deviation between the first speed and the second speed becomes greater than the threshold, the first traction machine (MM1) is instructed to generate the selected first limiting torque.

5. The control method according to claim 4, characterized in that, The specified first limiting torque is pre-limited.

6. The control method according to claim 4, characterized in that, The specified first limiting torque is selected based on the deviation.

7. The control method according to claim 1, characterized in that, In step (10-40), the first rotational speed of the first traction machine (MM1) is reduced according to the deviation between the first rotational speed and the second rotational speed.

8. A computer program product comprising a set of instructions, which, when executed by a processing unit, are adapted to implement the control method according to any one of claims 1 to 7 to control the charging of a battery (BR) of a vehicle (V), the vehicle comprising a first tractor (MM1) connected to a clutch (EM), the clutch also connected to a second tractor (MM2), the second tractor being electrically connected to the battery (BR) and to a main shaft (AP) of a gearbox (BV), the gearbox being connected to an axle.

9. A control device (DC) for a transport vehicle (V), the transport vehicle comprising a first traction unit (MM1) connected to a clutch (EM), the clutch also connected to a second traction unit (MM2), the second traction unit being electrically connected and also connected to a rechargeable battery (BR) and a main shaft (AP) of a gearbox (BV), the gearbox being connected to an axle, characterized in that, The control device includes at least one processor (PR) and at least one memory (MD), the at least one processor and the at least one memory being configured to perform operations when the transmission (BV) is in neutral and the battery (BR) is in a charging phase, the operations including monitoring a deviation between a first rotational speed of the first traction machine (MM1) and a second rotational speed of the second traction machine (MM2), comparing the deviation with a threshold, and controlling a first torque generated by the first traction machine (MM1) based on the comparison.

10. A transport vehicle (V) comprising a first tractor (MM1) connected to a clutch (EM), the clutch being further connected to a second tractor (MM2), the second tractor being electrically connected to a rechargeable battery (BR) and a main shaft (AP) connected to a gearbox (BV), the gearbox being connected to an axle, characterized in that, The transport vehicle also includes the control device (DC) according to claim 9.

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