WO2023151467A1

WO2023151467A1 - P-gear control method for vehicle

Info

Publication number: WO2023151467A1
Application number: PCT/CN2023/073536
Authority: WO
Inventors: 马文武; 李迎; 任毛杰
Original assignee: 华为数字能源技术有限公司
Priority date: 2022-02-08
Filing date: 2023-01-28
Publication date: 2023-08-17
Also published as: CN114623231A

Abstract

A P-gear control method for a vehicle, for use in a charging scenario of an electric vehicle. The P-gear control method for a vehicle comprises: before a charging pile is powered off, driving a pawl (71) of a P gear (7) to fall into a ratchet recess (C) on a ratchet wheel (72), and releasing torque so that there is no torsional force between an input end (31) of a speed reducer and a wheel (2).

Description

A method for controlling the P gear of a vehicle

Cross References to Related Applications

This application claims the priority of the Chinese patent application with the application number 202210119267.7 and the application title "A Method for Controlling Vehicle P Gear" submitted to the China Patent Office on February 08, 2022, the entire contents of which are incorporated in this application by reference .

technical field

The present application relates to the technical field of electric vehicles, in particular to a method for controlling a P gear of a vehicle.

Background technique

The electric vehicle is equipped with a power battery, and the power battery provides electric power for the electric vehicle to drive the electric vehicle. At present, electric vehicles are equipped with slow charging and fast charging functions. The convenient and fast fast charging method is more and more favored by consumers.

The fast charging of electric vehicles is a charging method controlled by the charging pile. When the voltage of the charging pile is lower than the voltage of the power battery, a boost charging circuit can be used to meet the fast charging requirements of the low-voltage charging pile for the high-voltage power battery. When the motor windings are connected in parallel and connected in series, the sum of the two-phase currents in this boost charging circuit is equal to the third-phase current. When applied to a synchronous motor, the motor produces torque. During the boost charging process, the torque generated by the electric motor will continue to act on the transmission system between the electric motor and the wheels. When the charging pile is powered off quickly, the charging current drops rapidly, and the torque generated by the motor quickly drops to zero, which causes the mechanical structure in the transmission system to bounce back, causing NVH (noise, vbration, harshness, noise, vibration and harshness , referred to as NVH) problem.

Contents of the invention

This application provides a vehicle P gear control method, which can reduce or eliminate the power generated when the charging pile is powered off by controlling the P (park) gear to make the pawl fall into the ratchet groove before the charging pile is powered off. There was a rattling sound.

The present application provides a vehicle P gear control method, which can be applied to an electric vehicle charging method in which charging piles are quickly powered off. Before the charging pile is powered off, the vehicle P gear control method specifically includes: driving the P gear pawl to fall into the ratchet groove on the ratchet wheel, and making there be no torsional force between the reducer input end and the wheel. The vehicle controller controls the P gear so that the pawl of the P gear falls into the ratchet groove, and releases the torque between the input end of the reducer and the wheels, so that there is no torsional force between the input end of the reducer and the wheels. During boost charging, the torque generated by the motor can continue to act on the mechanical transmission structure between the motor power output shaft and the wheels. Since there is no torsional force between the input end of the reducer and the wheel, when the charging pile is powered off quickly, the torque generated by the motor acts between the pawl and the ratchet, so that the toothing caused by the entire mechanical transmission structure occurs at the ratchet when the power is turned off. Within the gap between the claw and the ratchet groove. With less clearance between the pawl and ratchet groove, rattle noise is reduced and NVH issues are reduced or even eliminated.

In the above vehicle P gear control method, driving the P gear pawl into the ratchet groove on the ratchet wheel can lock the P gear first, and then adjust the ratchet wheel, which can specifically include:

Issue the P gear lock command to lock the P gear;

Drive the ratchet to rotate so that the pawl falls into any one of the ratchet grooves.

The ratchet groove is arranged on the peripheral surface of the ratchet wheel, and when the ratchet wheel rotates, the ratchet groove rotates accordingly, thereby changing the position of the ratchet relative to the ratchet groove. When the ratchet is rotated until a certain ratchet groove corresponds to the ratchet pawl, the ratchet pawl can fall into the ratchet groove to realize the cooperation between the ratchet pawl and the ratchet groove.

In the above vehicle P gear control method, the pawl that drives the P gear falls into the ratchet groove on the ratchet wheel. The ratchet wheel can be adjusted first, and then the P gear wheel can be locked. The motor drive is connected to the ratchet wheel; therefore, the rotation of the driving ratchet wheel can be specifically controlled by torque control. The motor spins.

In a possible implementation manner, driving the ratchet to rotate may include:

The motor is controlled to rotate until the motor generates a target torque; the target torque is the torque required by the motor to drive the ratchet to rotate the first stroke, and the first stroke is the sum of the width of the ratchet and the width of the pawl.

In another possible implementation manner, driving the ratchet to rotate may also include:

drive the motor to rotate;

Obtain the position information of the pawl relative to the ratchet;

When the ratchet falls into the ratchet groove, the control motor stops rotating.

In the above vehicle P gear control method, the pawl that drives the P gear falls into the ratchet groove on the ratchet wheel, the ratchet wheel can be adjusted first, and then the P gear gear can be locked. Specifically, it can include:

Drive the ratchet to rotate so that the pawl corresponds to any position of the ratchet groove;

Issue the P gear lock command to lock the P gear.

The ratchet groove is arranged on the peripheral surface of the ratchet wheel, and when the ratchet wheel rotates, the ratchet groove rotates accordingly, thereby changing the position of the ratchet relative to the ratchet groove. When the ratchet is rotated until a certain ratchet groove corresponds to the position of the ratchet, the P gear is locked, and the ratchet can directly fall into the ratchet groove to realize the cooperation between the ratchet and the ratchet groove.

Wherein, the motor drive is connected to the ratchet; therefore, the rotation of the ratchet can be driven by a position control method to control the rotation of the motor. Driving the ratchet to rotate may then include:

Obtain the position information of the pawl relative to the ratchet;

According to the position information, the motor is controlled to rotate until the pawl corresponds to any position of the ratchet groove.

In order to reduce energy consumption, the motor can be controlled to rotate to drop the ratchet into the ratchet groove closest to the ratchet.

Wherein, the rotation of the motor can be a stepwise rotation, so that the ratchet can be rotated in a progressive adjustment manner. In addition, the step amplitude of the forward rotation of the motor and the step amplitude of the reverse rotation of the motor can also be set to be consistent, which is beneficial to the control of the motor.

In a possible implementation manner, the above vehicle P gear control method further includes:

Before the pawl of the P gear falls into the ratchet groove on the ratchet wheel, an electronic parking lock command is issued to lock the wheels;

After the pawl of the P gear is driven into the ratchet groove on the ratchet wheel, an electronic parking unlock command is issued to unlock the wheels.

Based on this method, after the above-mentioned electronic parking unlock command is issued to unlock the wheels, it may also include:

Send an electronic parking lock command to lock the wheels again.

In another possible implementation, after the P gear control method of the above-mentioned vehicle is driven to fall into the ratchet groove on the ratchet wheel, the method further includes:

Issue an electronic parking lock command to lock the wheels.

Description of drawings

Figure 1a and Figure 1b are schematic structural diagrams of a boost charging circuit in the prior art;

Fig. 1c is a schematic diagram of a power transmission structure of an electric vehicle provided by the embodiment of the present application;

Fig. 2 is a schematic structural diagram of a transmission connection between a reducer and a P gear provided in the embodiment of the present application;

Fig. 3 is a schematic diagram of the implementation process of a vehicle P gear control method provided by the embodiment of the present application;

Fig. 4 is a structural schematic diagram of a pawl falling into a ratchet groove in a vehicle P gear control method provided by an embodiment of the present application;

Fig. 5 is a structural schematic diagram of a vehicle P gear control method provided by an embodiment of the present application, in which the pawl does not fall into the ratchet groove;

6 is a schematic diagram of the implementation process of driving the ratchet to rotate in a vehicle P gear control method provided by the embodiment of the present application;

7a to 7c are structural schematic diagrams of driving the pawl into the ratchet groove in a vehicle P gear control method provided by the embodiment of the present application;

Fig. 8 is a schematic diagram of the implementation process of driving the ratchet to rotate in a vehicle P gear control method provided by the embodiment of the present application;

Fig. 9 is a schematic diagram of the implementation process of controlling the rotation of the motor in the position control mode in a vehicle P gear control method provided by the embodiment of the present application;

Fig. 10 is a structural schematic diagram of driving the pawl into the ratchet groove in a vehicle P gear control method provided by the embodiment of the present application;

Fig. 11a is a schematic flow chart of a vehicle P gear control method provided by an embodiment of the present application;

Fig. 11b is a schematic diagram of the implementation process of a vehicle P gear control method provided by the embodiment of the present application;

Fig. 12a is a schematic flowchart of a vehicle P gear control method provided by an embodiment of the present application;

Fig. 12b is a schematic diagram of the implementation process of a vehicle P gear control method provided by the embodiment of the present application;

Fig. 13a is a schematic flowchart of a vehicle P gear control method provided by an embodiment of the present application;

Fig. 13b is a schematic diagram of the implementation process of a vehicle P gear control method provided by the embodiment of the present application.

Detailed ways

At present, electric vehicles have two charging methods: fast charging and slow charging. The slow charging source module is also called an on board charger (OBC), which is generally placed on an electric vehicle. The power of the slow charging source module is generally within 10kW, the mains 220V AC voltage is used as the input, and the output current of tens of amperes is used for slow charging of the power battery. The charging time is generally within 10 hours. The fast charging source module is placed in the charging pile, and outputs a large current DC to quickly charge the power battery, which has obvious advantages of high efficiency. Among them, the charging pile has two output specifications: 200-500V or 200-750V and above. When the voltage platform 750V of the electric vehicle power battery is higher than the output voltage of the charging pile, fast charging cannot be performed. For this reason, for example, the voltage of the power battery is 500-750V, and a 200-500V charging pile cannot be used for fast charging outdoors.

For this reason, a boost charging circuit as shown in Figure 1a and Figure 1b can be used to realize fast charging of a low-voltage charging pile as a high-voltage power battery. As shown in FIG. 1a, the boost charging circuit includes an inverter 300 located between a DC power source 100 (equivalent to a charging pile) and a power battery 200, and the power battery 200 is connected in parallel with a capacitor C. The inverter 300 includes a motor E and six diodes (respectively exemplified as a first diode T1, a second diode T2, a third diode T3, a fourth diode T4, a fifth diode T5, sixth diode T6). The first diode T1 and the second diode T2 form the first bridge arm, the third diode T3 and the fourth diode T4 form the second bridge arm, the fifth diode T5 and the sixth diode T6 forms the third bridge arm. The midpoint Q1 of the first bridge arm, the midpoint Q2 of the second bridge arm, and the midpoint Q3 of the third bridge arm are respectively connected to the three-phase circuit of the motor E. Wherein, the positive pole of the DC power supply 100 is connected to the positive pole of the power battery 200 , the midpoint Q1 of the first bridge arm is connected to the negative pole of the power battery 200 , and the midpoint Q2 of the second bridge arm is connected to the negative pole of the DC power supply 100 . Of course, as shown in Figure 1b, the negative pole of the DC power supply 100 is connected to the negative pole of the power battery 200, the midpoint Q1 of the first bridge arm is connected to the positive pole of the power battery 200, and the midpoint Q2 of the second bridge arm is connected to the positive pole of the power battery 200. The positive pole of the power supply 100. Therefore, the sum of the two-phase circuit currents of the motor E corresponding to the midpoint Q1 of the first bridge arm and the midpoint Q3 of the third bridge arm is equal to the other phase circuit current of the motor E corresponding to the midpoint Q2 of the second bridge arm current. Since this boost charging circuit does not need to use an inductor, it has good heat dissipation performance. The boost charging circuit can be applied to an asynchronous motor or a synchronous motor. When applied to a synchronous motor, the motor generates torque, and the torque generated by the motor is different at different angles. The motor output shaft of the electric vehicle is connected to the wheels through a series of mechanical transmission structures. During the charging process of the electric vehicle, the boost charging circuit makes the motor generate torque, and the torque of the motor will continue to act on the above-mentioned mechanical transmission structure. When the charging junction If the torque of the motor is reduced to zero quickly, the above-mentioned mechanical transmission structure may kick back and make obvious noise. The key to solving this problem is how to release the torsional torque between the wheel end and the motor output shaft at the end of charging.

For the scene of charging end, the charging end of electric vehicles can be divided into two types: battery management system (battery management system, BMS) control or charging pile control. Battery management system control generally means that the owner sets different state of charge (state of charge, SOC) thresholds (generally 70%-100%) on the man-machine interface in the electric vehicle; when the battery management system judges that the charging has reached the set After a certain state of charge threshold, the battery management system can send the current demand to the motor controller to gradually reduce the charging current. In this way, the torsional torque between the wheel and the motor can be gradually released. The charging end scene controlled by the charging pile is usually that the charging module inside the charging pile stops outputting. When the controller at the vehicle end (such as the battery management module) does not know that the charging is about to end, the charging pile has already stopped the charging module output; usually in milliseconds Within the stage time, the charging current drops to zero, and the motor torque is positively correlated with the charging current, causing the motor torque to quickly drop to zero, and the mechanical transmission structure between the wheel and the motor output shaft produces rebound gearing, causing serious NVH problems. What needs to be said is that in the charging method controlled by the charging pile, the end of charging at least includes the car owner controlling the end of charging through the mobile phone software, the end of charging controlled by the man-machine operation interface of the charging pile, and the emergency power off of the charging pile in case of failure. Regardless of the power-off method, because the torque of the motor disappears instantaneously due to the rapid power-off, there is a possibility of serious NVH problems between the transmission structures of electric vehicles.

Based on the NVH problem caused by the charging and powering off of the charging pile, the embodiment of the present application provides a vehicle P gear control method to solve the above problem. In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings.

The terms used in the following examples are for the purpose of describing particular examples only, and are not intended to limit the application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also Expressions such as "one or more" are included unless the context clearly dictates otherwise.

Reference to "one embodiment" or "some embodiments" or the like in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean "one or more but not all embodiments" unless specifically stated otherwise. The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless specifically stated otherwise.

As shown in Figure 1c, the motor 1 of an electric vehicle is connected to the wheel 2 through a reducer 3, a differential 4, a drive half shaft 5, and other transmission components 6, and the reducer 3, a differential 4, a drive half shaft 5 and other The transmission assembly 6 is equivalent to a mechanical transmission structure for power transmission between the motor 1 and the wheels 2 . Among them, the speed reducer 3 and the differential 4 are connected through gear meshing transmission, the differential 4 is connected with the half shaft spline 51 of the driving half shaft 5 through meshing transmission, and the driving half shaft 5 and the drive transmission assembly 6 are connected through the meshing transmission. The transmission spline 61 is in transmission connection. The reducer input end 31 may also be provided with structures such as a transmission, a clutch, and a transmission shaft between the motor 1 and the reducer 3 , which are not shown here.

Combined with the boost charging circuit shown in Figure 1a or Figure 1b, when the electric vehicle adopts the charging method controlled by the charging pile, the three-phase synchronous motor 1 will generate torque, which can continuously act on the reducer input end of the reducer 3 31 and the gear between the differential 4, the half shaft spline 51 of the driving half shaft 5, and the transmission spline 61 in other transmission components 6. When the charging is finished, the torque generated by the motor 1 decreases sharply to zero, and the transmission connection structure between the reducer 3, the differential 4, the driving half shaft 5 and other transmission components 6 may rebound due to tooth punching, resulting in serious NVH question.

Taking the connection structure between the reducer 3 and the P gear 7 shown in Figure 2 as an example, a vehicle provided by the embodiment of the present application The P gear control method can release the torque between the reducer input end 31 and the wheel 2 before the charging pile is powered off, thereby reducing or even eliminating the NVH problem generated during boost charging. Referring to FIG. 2 , the P gear 7 of the electric vehicle includes a pawl 71 and a ratchet wheel 72 , the ratchet wheel 72 has a ratchet groove C for matching the ratchet groove 71 , and a ratchet D is between any two adjacent ratchet grooves C. The ratchet 72 can be driven to rotate by the motor 1 . The speed reducer 3 has a speed reducer input end 31 , a speed reducer output end 32 and a transmission gear 33 drivingly connected between the speed reducer input end 31 and the speed reducer output end 32 . Wherein, the reducer input 31 can be coaxially connected to the power output shaft of the motor 1, and the ratchet 72 can be coaxially connected to the reducer input 31, which is equivalent to the coaxial connection of the ratchet 72 to the power output shaft of the motor 1, so that the motor 1 The rotation drives the reducer input end 31 and the ratchet 72 to rotate (at this moment, the motor 1, the reducer input end 31 and the ratchet 72 can share the power output shaft of the motor 1). Certainly, the ratchet 72 can also be arranged on the output end 32 of the reducer, and the motor 1 sequentially drives the input end 31 of the reducer, the transmission gear 33 and the output end 32 of the reducer to rotate, and then drives the ratchet 72 to rotate. It should be understood that the structure of the speed reducer 3 may also have other implementation manners, and FIG. 2 is only an example. The ratchet 72 can also be arranged on other transmission structures, as long as the motor 1 can drive the ratchet 72 to rotate. As shown in Figure 3, the vehicle P gear control method provided by the embodiment of the present application is applied before the charging pile is powered off, including:

Step S10 : Make the pawl 71 of the P gear 7 fall into the ratchet groove C on the ratchet wheel 72 , and make there be no torsion force between the reducer input end 31 and the wheel 2 .

Combining the structure of the pawl 71 and the ratchet 72 of the P gear 7 illustrated in FIG. 4 . The pawl 71 is fixed to the casing of the power assembly, that is, the structure of the pawl 71 is relatively fixed. The ratchet 72 is coaxially connected with the reducer input end 31 of the reducer 3 . Fixing the ratchet 72 can not only lock the input end 31 of the speed reducer, but also interrupt the power transmitted to the wheels 2, that is, the P gear 7 can be engaged to realize parking. A plurality of ratchet grooves C are provided in the circumferential direction of the ratchet wheel 72 . There are ratchets D between any two ratchet grooves C, and the plurality of ratchet grooves C are arranged in a circular array. The ratchet 71 can cooperate with the ratchet groove C, specifically, the ratchet 71 can fall into the ratchet groove C (the state shown in FIG. 4 ). When the ratchet 71 falls into the ratchet groove C, the ratchet 72 can be fixed to realize parking.

The vehicle controller or the motor controller reasonably controls the P gear 7, finally locks the P gear 7, and makes the ratchet 71 fall into any ratchet groove C. And the torque between the reducer input end 31 and the wheel 2 is released, so that there is no torsional force between the reducer input end 31 and the wheel 2 .

Combining the structure of the ratchet 72 and the pawl 71 shown in FIG. 4 , it can be seen that the number of ratchet grooves C on the ratchet wheel 72 is limited (6 ratchet grooves C are illustrated in FIG. 4 ). After the P gear 7 is locked, the pawl 71 may fall into the ratchet groove C, or fall on the ratchet D between two adjacent ratchet grooves C (as shown in FIG. 5 ). Driving the pawl 71 of the P gear 7 into the ratchet groove C of the ratchet wheel 72 can limit the ratchet phenomenon generated when the power is turned off within the gap between the ratchet 71 and the ratchet groove C.

After the pawl 71 of the P gear 7 is driven into the ratchet groove C of the ratchet wheel 72, so that there is no torque between the reducer input end 31 and the wheel 2, the torque generated by the motor 1 during the boost charging process will act on the pawl 71 and the wheel 2. Between the ratchet grooves C and other mechanical transmission structures between the reducer input end 31 and the wheel 2 there is almost no torsional torque, that is, there is no torsional force between the reducer input end 31 and the wheel 2 . When the power is turned off quickly, only the tooth rebound phenomenon may occur between the ratchet 71 and the ratchet groove C. However, the gap between the ratchet 71 and the ratchet groove C is much smaller than the gap between other transmission structures (for example, the gap between the splines). Therefore, even if the teeth rebound between the ratchet 71 and the ratchet groove C, the The tooth beating phenomenon also occurs in the gap range between the pawl 71 and the ratchet groove C, and the tooth beating sound is relatively small. In addition, it should be understood that the above step S10 may also be completed before the boost charging of the electric vehicle, so as to facilitate the boost charging operation of the electric vehicle.

Therefore, the vehicle P gear control method can release the torque between the reducer input end 31 and the wheel 2 before the charging pile is powered off, so that there is no torsional force between the reducer input end 31 and the wheel 2 . When the electric vehicle is powered off (especially quickly powered off) after the boost charging is completed, the toothing phenomenon between the mechanical structures occurs between the pawl 71 and the ratchet groove C. Within the clearance range, the rattling sound is attenuated, which can reduce or even eliminate NVH problems.

In some embodiments, based on the above vehicle P gear control method, as shown in FIG. 6 , step S10 driving the pawl 71 of the P gear 7 to completely fall into the ratchet groove C may specifically include:

Step S111: Issue a P gear lock command to lock P gear 7;

Step S112: Drive the ratchet wheel 72 to rotate, so that the ratchet 71 falls into any ratchet groove C.

After the P gear 7 is locked, if the pawl 71 does not fall into the ratchet groove C as shown in Figure 7a, the ratchet 71 falls into two adjacent ratchet grooves C (for example, the first ratchet groove C1 and the second ratchet groove C On the ratchet D between the two ratchet grooves C2). It is necessary to control the ratchet 71 to fall into the ratchet groove C. The P gear lock command is issued by the vehicle controller, and the pawl 71 of the P gear 7 is driven to fall into the ratchet groove C of the ratchet 72, which is realized by the vehicle controller controlling other structures, as long as the pawl 71 can be dropped into The ratchet groove C gets final product. Specifically, the position of the ratchet 71 relative to the ratchet 72 can be changed by controlling the rotation of the ratchet 72 . When the ratchet wheel 72 rotates, the ratchet groove C on the ratchet wheel 72 rotates accordingly, and the relative position between the ratchet groove C and the ratchet pawl 71 will change. When a ratchet groove C adjacent to the ratchet 71 moves to the ratchet groove C corresponding to the ratchet 71, the ratchet 71 can fall into the ratchet groove C, thereby, the ratchet 71 can fully cooperate with the ratchet groove C , to achieve parking.

Wherein, as shown in FIG. 2 , since the ratchet 72 is coaxially connected to the input end 31 of the reducer, and the input end 31 of the reducer is in transmission connection with the motor 1 , the ratchet 72 can be driven to rotate by driving the motor 1 to rotate.

As can be seen in Figure 7a, when the ratchet 71 falls on the ratchet D between the two ratchet grooves C, there will be two ratchet grooves C on both sides of the ratchet 71 (here, the first ratchet groove C1 and the second ratchet groove C2). Set the forward rotation direction and reverse rotation direction of the ratchet wheel 72 as shown in Figure 7a. The first ratchet groove C1 is equivalent to being located on the side of the ratchet 71 along the forward rotation direction of the ratchet wheel 72, and the second ratchet groove C2 is equivalent to being located along the side of the ratchet 71. The ratchet 72 is one side in the reverse direction of rotation. Theoretically, when the ratchet wheel 72 rotates forward, the pawl 71 will fall into the second ratchet groove C2; when the ratchet wheel 72 rotates reversely, the ratchet 71 will fall into the first ratchet groove C1. That is to say, no matter whether the ratchet wheel 72 rotates forward or reversely, the ratchet 71 can fall into the ratchet groove C (the first ratchet groove C1 or the second ratchet groove C2 ).

Based on the scheme of driving the ratchet wheel 72 to rotate after the P gear 7 is locked, the rotation of the motor 1 can be controlled in a torque control manner. Specifically, the rotation of the motor 1 can be controlled by setting the maximum rotational torque of the motor 1 , and the ratchet 71 must fall into the ratchet groove C when the motor 1 is set to rotate forward or reverse to reach a certain target torque.

Therefore, the above-mentioned driving the rotation of the ratchet 72 specifically includes: controlling the rotation of the motor 1 until the motor 1 generates a target torque. Wherein, the target torque is the torque required by the motor 1 to drive the ratchet 72 to rotate the first stroke, and the first stroke is the sum of the width of the ratchet D on the ratchet 72 and the width of the ratchet 71 . Here, the width of the ratchet D and the width of the pawl 71 are referenced to the circumferential direction of the ratchet 72 .

As shown in Fig. 7a, along the circumferential direction of the ratchet 72, set the width of the ratchet D to be L1, and the width of the pawl 71 to be L2, and rotate the ratchet 72 so that the ratchet 71 passes through the width of the ratchet D plus the pawl The width of 71 is the first stroke. The ratchet 72 rotates around its own axis, and the ratchet 72 rotates at most the first stroke, and the ratchet 71 must fall into the ratchet groove C. The motor 1 can be driven to rotate the ratchet 72 so that the torque required by the motor 1 when the ratchet 71 goes through the first stroke is the target torque. After the ratchet 71 falls into the ratchet groove C, if the motor 1 has not generated the target torque, the motor 1 will continue to rotate until the target torque is generated, and there is a torque effect between the ratchet 71 and the ratchet groove C. The torque generated by the rotation of the motor 1 to drive the input end 31 of the reducer to drive the ratchet 72 to rotate the central angle β is set as the target torque, and the absolute value of the target torque is the target torque value. Since the motor 1 may rotate forward or reversely, the motor 1 is rotated forward to generate the torque with the target torque value as the first target torque, and the motor 1 is reversed to generate the torque with the target torque value as the second target torque .

Based on this control method, controlling the motor 1 to rotate until the motor 1 generates the target torque can be divided into at least the following situations:

Case 1: Control the motor 1 to rotate forward until the motor 1 generates the first target torque; that is, if the motor 1 rotates forward to generate the first target torque, the pawl 71 must fall into the ratchet groove C. Set the forward rotation of motor 1 to the stepping type, and the process of motor 1 forward rotation to generate the first target torque can be divided into multiple times, and the torque generated by motor 1 forward rotation each time can be +1N·m, +3N·m ,

+5N·m...+20N·m. Wherein, +20N·m is the first target torque. It should be understood that the torque generated during the forward rotation of the motor 1 is cumulative, that is, the first forward rotation generates +1N·m, and the second forward rotation generates +3N·m based on the previously generated torque +1N·m Superposition, that is, after the motor 1 rotates forward twice, a total torque of +4N·m is generated.

Situation 2: The motor 1 is controlled to reverse until the motor 1 generates the second target torque; that is, if the motor 1 reverses to generate the second target torque, the ratchet 71 must fall into the ratchet groove C. Set the reverse rotation of motor 1 to step type, the process of motor 1 reverse rotation to generate the second target torque can be divided into multiple times, and the torque generated by motor 1 forward rotation each time can be -1N·m, -2N·m ,

-4N·m...-20N·m. Wherein, -20N·m is the first target torque. It should be understood that the torque generated during the reverse rotation of the motor 1 is cumulative, that is, the first reverse generates -1N·m, and the second reverse generates -2N·m is the torque generated earlier

Superimposed on -1N·m, that is, after the motor 1 reverses twice, a total torque of +3N·m is generated.

Case 3: Control the motor 1 to rotate forward and reverse alternately until the motor 1 generates the first target torque or the second target torque. That is, the motor 1 rotates forward and reverses once alternately, and the torque generated by the rotation of the motor 1 is sequentially shown as +1N m, -1N m, +3N m, -3N m, +5N m... to the motor 1 Generate any one of the target torques (the first target torque or the second target torque). It should be understood that when the rotation direction of the motor 1 is changed, the torque generated by the previous rotation is released first, and then the rotation of the motor 1 is controlled to generate the next rotation torque. For example, when the motor 1 rotates forward to generate +1N·m torque, before controlling the motor 1 to reverse to generate -1N·m torque, first control the motor 1 to reverse to release the above +1N·m torque.

Situation 4: The motor 1 is controlled to rotate forward and reverse irregularly, until the motor 1 generates the first target torque or the second target torque. That is, the motor 1 is controlled to rotate forward for n times and reversely for m times, and the order of forward rotation and reverse rotation is not limited. Wherein, n is an integer greater than or equal to 1, and m is also an integer greater than or equal to 1. For example, control motor 1 to rotate forward twice, and the torque generated by motor 1 forward rotation is sequentially shown as +1N·m, +3N·m; after releasing the torque generated by forward rotation, control motor 1 to rotate reversely once, and motor 1 reversely The example of the torque generated by one rotation is -1N m; after releasing the torque generated by the reverse rotation, control the motor 1 to rotate forward once, and the torque generated by the reverse rotation of the motor 1 is +5N m; after releasing the torque generated by the forward rotation, continue Controlling the reverse rotation of the motor 1...By irregularly controlling the forward rotation or reverse rotation of the motor 1, the motor 1 generates the first target torque or the second target torque.

In a possible implementation manner, the forward and reverse step amplitudes of the motor 1 are set to be consistent. The forward rotation of the motor 1 to generate the first target torque can be divided into multiple gradual changes, which can be specifically exemplified as +1N·m, +3N·m, +5N·m...+20N·m. The reverse rotation of the electric motor 1 to generate the second target torque can be divided into multiple gradual changes, which can be specifically illustrated as -1N·m, -3N·m, -5N·m...-20N·m.

In a specific operation, the motor 1 can be controlled to only rotate forward or only reversely, that is, the torque generated by the forward rotation of the motor 1 is for example +1N·m, +3N·m, +5N·m...+20N·m, or The torque generated by the reverse rotation of the motor 1 is sequentially illustrated as -1N·m, -3N·m, -5N·m...-20N·m. It is also possible to control the forward rotation and reverse rotation of the motor 1 alternately. It can be inferred that when the forward rotation and reverse rotation of the motor 1 have the same step amplitude, and the forward rotation and reverse rotation of the motor 1 are alternately performed, the first rotation direction can be determined. The motor 1 finally reaches Is the target torque of the first target torque or the second target torque. For example, if the motor 1 rotates forward first, then the motor 1 finally generates the first target torque; if the motor 1 rotates reversely first, then the motor 1 finally generates the second target torque.

Based on the torque control method to control the rotation of the motor 1 after the P gear 7 is locked, the rotation of the motor 1 can also be controlled according to the position of the pawl 71 relative to the ratchet 72 until the pawl 71 falls into the ratchet groove C. Referring to Fig. 7b, the rotation of the above-mentioned driving ratchet 72 includes:

Step S2121: Drive the motor 1 to rotate; it can be seen from FIG. 7a that the ratchet 71 can fall into the ratchet groove C no matter whether the motor 1 is rotating forward or reverse. Therefore, the driving motor 1 rotates, and the direction of rotation may not be limited.

Step S2122: Obtain position information of the pawl 71 relative to the ratchet wheel. In an electric vehicle, the shape and specifications of the ratchet wheel 72 are determined. Therefore, to which position the ratchet wheel 72 rotates relative to the ratchet 71 and where the ratchet 71 can fall into the ratchet groove C is also relatively determined. The motor 1 can drive the ratchet 72 to rotate, and then the position of the ratchet 72 relative to the pawl 71 can be determined according to the rotation angle of the motor 1 . A rotary transformer is installed on the motor 1, and the vehicle controller or the motor controller can know the rotation angle of the motor 1 according to the rotary transformer, so as to obtain the rotation angle of the ratchet wheel 72, and obtain the position information of the ratchet wheel 71 relative to the ratchet wheel 72, Whether the ratchet 71 falls into the ratchet groove C can be judged according to the position information. Of course, the rotation angle of the motor 1 can also be obtained by other means, such as a position sensor, an angle sensor, and the like.

Step S2123: When the ratchet 71 falls into the ratchet slot C, control the motor 1 to stop rotating.

The vehicle controller or motor controller judges whether the pawl 71 falls into the ratchet groove C according to the position information of the above-mentioned pawl 71 relative to the ratchet wheel 72 . When it is determined that the ratchet 71 has fallen into the ratchet groove C, the motor 1 can stop rotating. Of course, in this method, the motor 1 can also rotate in steps, and the rotation mode is not limited. It can only rotate forward, reverse only, or rotate forward and reverse alternately, which will not be repeated here.

Combining the structure shown in Figure 7c, it should be understood that when the P gear 7 is locked and the pawl 71 falls on the ratchet D, the motor 1 drives the ratchet 72 to rotate until the pawl 71 falls into any one of the ratchet grooves C. The torque is less than or equal to the target torque in the above-mentioned embodiment.

As shown in Figure 7c, the control motor 1 drives the ratchet 72 to rotate until the pawl 71 falls into the first ratchet groove C1, and the second stroke of the ratchet 72 is required to rotate until the ratchet 71 falls into the first ratchet groove C1, and the second stroke is The width L2 of the ratchet 71 and the distance L3 between the ratchet 71 and the first ratchet groove C1 . The control motor 1 drives the ratchet 72 to rotate until the pawl 71 falls into the second ratchet groove C2, and the third stroke of the ratchet 72 is required to rotate until the ratchet 71 falls into the second ratchet groove C1, and the third stroke is the width L2 of the ratchet 71 The distance L4 between the pawl 71 and the second ratchet groove C2.

Possibly, in terms of energy saving and convenient operation, it is more beneficial for the ratchet 71 to fall into the ratchet groove C closest to the ratchet 71 . Therefore, the vehicle controller or the motor controller can judge which ratchet groove C the ratchet 71 is closest to according to the position information of the ratchet 71 relative to the ratchet wheel 72, and then control the motor 1 to drive the ratchet wheel 72 to rotate in the target direction so that the ratchet 71 falls into The closest spine C. Therefore, the distance L3 between the pawl 71 and the first ratchet groove C1 can be compared with the distance L4 between the ratchet 71 and the second ratchet groove C2. When L3 is greater than L4, the second ratchet groove C1 is the closest to the ratchet 71 The ratchet groove C, control the motor 1 to rotate forward to make the ratchet wheel 72 rotate the third stroke, the ratchet 71 can fall into the second ratchet groove C2; when L3 is smaller than L4, the first ratchet groove C1 is the ratchet groove C closest to the ratchet 71 , control the motor 1 to reverse the second stroke, the ratchet 71 can fall into the first ratchet groove C1; when L3 is equal to L4, the distance between the first ratchet groove C1 and the ratchet 71 is equal to the second ratchet groove C2 and the ratchet 71 The distance between them can control the motor 1 to rotate forward for the second stroke so that the pawl 71 can fall into the second ratchet groove C2, and can also control the motor 1 to reverse the second stroke so that the ratchet 71 can fall into the first ratchet groove C1.

In other embodiments, based on the above vehicle P gear control method, as shown in FIG. 8 , step S20 driving the pawl 71 of the P gear 7 into the ratchet groove C may specifically include:

Step S221: drive the ratchet wheel 72 to rotate, so that the ratchet 71 corresponds to any position of the ratchet groove C;

Before the P gear 7 is locked, the position of the ratchet 71 relative to the ratchet wheel 72 is obtained, and it is judged that the ratchet 71 cannot just fall into the ratchet groove C after the P gear 7 is locked. It is necessary to drive the ratchet 72 to rotate before the P gear 7 is locked, so that the ratchet 71 can correspond to any position of the ratchet groove C. The position corresponding here refers to: along the radial direction of the ratchet 72 , the centerline of the ratchet groove C coincides with the centerline of the ratchet 71 .

Step S222: Issue a P gear lock command to lock P gear 7.

After step S221 is completed, the pawl 71 of the P gear 7 has already corresponded to a certain ratchet groove C position, therefore, when the P gear 7 is locked, the ratchet 71 can smoothly fall into the ratchet groove C corresponding to the ratchet 71 . This control method, in the locked P file At 7 o'clock, the ratchet 71 falls into the ratchet groove C naturally.

Based on the scheme of driving the ratchet wheel 72 to rotate before the P gear 7 is locked, the rotation of the motor 1 can be controlled in a position control manner, that is, the rotation of the motor 1 can be controlled by setting the maximum rotation angle of the motor 1 . The motor 1 is set to rotate forward or reverse to reach a certain rotation angle, and the pawl 71 corresponds to a position of a ratchet groove C. Specifically, as shown in FIG. 9 , driving the rotation of the ratchet 72 may specifically include:

Step S2211: Obtain the position information of the ratchet 71 relative to the ratchet 72 .

As shown in Figure 10, when the ratchet 71 does not fall into the ratchet groove C, the ratchet 71 falls into the ratchet between two adjacent ratchet grooves C (for example, the first ratchet groove C1 and the second ratchet groove C2). on tooth D. Along the rotation direction of the ratchet wheel 72 , there are two ratchet grooves C (here, a first ratchet groove C1 and a second ratchet groove C2 ) on both sides of the ratchet pawl 71 . Specifically, the first ratchet slot C1 is located on one side of the ratchet 71 along the direction of forward rotation of the ratchet wheel 72 , and the second ratchet slot C2 is located on one side of the ratchet 71 along the direction of reverse rotation of the ratchet wheel 72 . Theoretically, when the ratchet wheel 72 rotates forward, the pawl 71 will fall into the second ratchet groove C2; when the ratchet wheel 72 rotates reversely, the ratchet 71 will fall into the first ratchet groove C1. A rotary transformer is installed on the motor 1 , the rotation angle of the motor 1 can be obtained according to the parameters of the rotary transformer, and the position of the ratchet 72 relative to the pawl 71 can be determined according to the rotation angle of the motor 1 . The vehicle controller or the motor controller can obtain the rotation angle of the ratchet wheel 72 according to the rotation angle of the motor 1, and also obtain the position information of the ratchet wheel 71 relative to the ratchet wheel 72, specifically including the distance between the first ratchet groove C1 and the ratchet wheel 71 And the distance between the second ratchet groove and the ratchet 71 is C2.

Step S2212: Control the motor 1 to rotate according to the position information until the position of the pawl 71 corresponds to any one of the ratchet grooves C.

The ratchet 71 is located between the first ratchet groove C1 and the second ratchet groove C2. As shown in FIG. The included angle relative to the center of the ratchet 72 is α1, the included angle between the pawl 71 and the first ratchet groove C1 relative to the center of the ratchet 72 is α2, and the included angle between the ratchet 71 and the second ratchet groove C2 relative to the center of the ratchet 72 is α3. It is set that the motor 1 reversely drives the ratchet 72 to rotate α1+α2, and the pawl 71 falls into the first ratchet groove C1; the motor 1 rotates forward to drive the ratchet 72 to rotate α1+α3, and the ratchet 71 falls into the second ratchet groove C1. α1+α3 corresponds to the first set angle of the forward rotation of the motor 1, and α1+α2 corresponds to the second set angle of the reverse rotation of the motor 1. Certainly, the rotation of the motor 1 in step S2212 may also adopt a stepping method.

Possibly, in terms of energy saving and convenient operation, it is more beneficial for the ratchet 71 to fall into the ratchet groove C closest to the ratchet 71 . Therefore, the angle α1 and the angle α2 can be compared. When α1 is greater than α2, the first ratchet groove C1 is the closest ratchet groove C to the ratchet 71, and the motor 1 is controlled to reverse the second set angle, and the ratchet 71 can be Fall into the first ratchet groove C1; when α1 is less than α2, the second ratchet groove C2 is the ratchet groove C closest to the pawl 71, and the motor 1 is controlled to rotate forward at the first set angle, and the ratchet 71 can fall into the second ratchet groove C2; when α1 is equal to α2, the distance between the first ratchet groove C1 and the ratchet 71 is equal to the distance between the second ratchet groove C2 and the ratchet 71, and the motor 1 can be controlled to rotate the first set angle to make the ratchet 71 It can fall into the second ratchet groove C2, or control the motor 1 to reverse the second set angle so that the ratchet 71 can fall into the first ratchet groove C1, and the first set angle is the same as the second set angle.

On the basis of the above-mentioned embodiments, the vehicle P gear control method provided in the embodiments of the present application may also have multiple specific implementation methods, including but not limited to the following specific implementation methods.

method one

As shown in Figure 11a, a step-up charging process, taking the control method of the P gear of the vehicle before the boost charging is completed as an example, before the pawl 71 driving the P gear 7 falls into the ratchet groove C, the wheel 2 is locked, And after the ratchet 71 falls into the ratchet groove C, the wheel 2 is unlocked, and the torque between the reducer input end 31 and the wheel 2 is released.

Based on the step-up charging process shown in FIG. 11a, as shown in FIG. 11b, the vehicle P gear control method provided by the embodiment of the present application includes:

Step S011: Issue an electronic parking lock command to lock the wheels 2 .

Specifically, the vehicle controller or the motor controller sends the electronic parking lock command to the electronic parking system, and the electronic parking system locks the wheels 2 .

Step S012 : Drive the pawl 71 of the P gear 7 into the ratchet groove C on the ratchet wheel 72 .

If the pawl 71 just falls in the ratchet groove C after the P gear 7 is locked, there is no need to adjust the pawl 71 and the ratchet wheel 72, and this step can be kept still or omitted. If the ratchet 71 cannot fall into the ratchet groove C, the ratchet 71 and the ratchet wheel 72 need to be adjusted so that the ratchet 71 falls into the ratchet groove C finally. This step S012 is equivalent to step S10 in FIG. 3 in which the pawl 71 of the drive P gear 7 falls into the ratchet groove C on the ratchet wheel 72 .

Step S013: Issue an electronic parking unlock command to unlock the wheels 2 .

When the pawl 71 is driven to fall into the ratchet groove C, some torsional force may be generated between the reducer 3 and the wheel 2 , and this step S013 can release the torsion force from the reducer 3 to the wheel 2 . The vehicle controller issues the electronic parking unlock command to the electronic parking system, and the electronic parking system unlocks the wheels 2 . It should be understood that since the ratchet 72 is coaxially connected to the input end 31 of the reducer, releasing the torsion force from the reducer 3 to the wheel 2 here is equivalent to releasing the torsion force between the input end 31 of the reducer and the wheel 2 .

In the vehicle P gear control method, only the P gear 7 needs to be unlocked after power off.

way two

Taking the vehicle P gear control method as an example before the boost charging, the boost charging process shown in Figure 12a is similar to the boost charging process provided by method 1, the difference is that the vehicle P gear provided by the embodiment of the present application In the control method, after the wheel 2 is unlocked, the wheel 2 is locked again.

Based on the boost charging process shown in FIG. 12a, as shown in FIG. 12b, the vehicle P gear control method provided by the embodiment of the present application includes:

Step S021: Issue an electronic parking lock command to lock the wheels 2 .

Step S022 : Drive the pawl 71 of the P gear 7 into the ratchet groove C on the ratchet wheel 72 .

Step S023: Issue an electronic parking unlock command to unlock the wheels 2 .

Step S024: Issue an electronic parking lock command to lock the wheels 2 again.

The above step S021 is similar to the step S011 in the first mode, the step S022 is similar to the step S012 in the first mode, and the step S023 is similar to the step S013 in the first mode, and will not be explained here.

When step S023 is performed, the wheel 2 may be displaced to a certain extent. Therefore, when the wheel 2 is locked again in step S024, the wheel 2 may have a certain change relative to the original position.

In this step-up charging method, after the power-off is completed, the P gear 7 and the wheel 2 need to be unlocked in sequence.

way three

Taking the control method of the P gear of the vehicle before the boost charging as an example, in a boost charging process as shown in Figure 13a, after the vehicle plug is plugged into the vehicle socket, the pawl 71 driving the P gear 7 falls into the ratchet. Groove C, after the pawl 71 falls into the ratchet groove C, the wheel 2 is locked.

Based on the boost charging process shown in FIG. 13a, as shown in FIG. 13b, the vehicle P gear control method provided by the embodiment of the present application includes:

Step S031 : Drive the pawl 71 of the P gear 7 into the ratchet groove C on the ratchet wheel 72 .

Step S032: Issue an electronic parking lock command to lock the wheels 2 .

The above step S031 is similar to the step S013 in the first mode, and the step S032 is similar to the step S011 in the first mode, and will not be explained here again.

To sum up, the vehicle P gear control method provided by the embodiment of the present application can be applied to the boost charging mode of fast power off. Before the power is turned off, the torque between the reducer input end 31 and the wheels 2 can be released through the coordinated control of the P gear 7 and the electronic parking system. When the charging is completed and the power is turned off quickly or in other emergency situations, the rattling sound caused by the disappearance of torque can be weakened or eliminated, thereby reducing or eliminating the NVH problem caused by the rattling of the mechanical structure.

The above is only the specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the application, and should cover Within the protection scope of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

A vehicle P file control method, characterized in that, before the charging pile is powered off, it includes:

Make the pawl of the P gear fall into the ratchet groove on the ratchet wheel, and make there is no torsional force between the input end of the reducer and the wheel.
The vehicle P gear control method according to claim 1, wherein said driving the P gear pawl to fall into the ratchet groove on the ratchet wheel comprises:

Issue a P gear lock command to lock the P gear;

The ratchet is driven to rotate so that the pawl falls into any one of the ratchet grooves.
According to the vehicle P gear control method according to claim 2, the motor drives the ratchet; wherein, the driving the ratchet to rotate comprises:

controlling the motor to rotate until the motor generates a target torque;

The target torque is the torque required by the motor to drive the ratchet to rotate a first stroke, and the first stroke is the sum of the width of the ratchet and the width of the pawl.
According to the vehicle P gear control method according to claim 2, the motor drive is connected to the ratchet; it is characterized in that the driving the ratchet to rotate comprises:

drive the motor to rotate;

acquiring position information of the pawl relative to the ratchet;

When the ratchet falls into the ratchet groove, the motor is controlled to stop rotating.
The vehicle P gear control method according to claim 1, wherein said driving the P gear pawl to fall into the ratchet groove on the ratchet wheel comprises:

Driving the ratchet to rotate so that the pawl corresponds to any position of the ratchet groove;

Issue a P gear lock command to lock the P gear.
The vehicle P gear control method according to claim 5, wherein the motor is connected to the ratchet through transmission; the driving the ratchet to rotate comprises:

acquiring position information of the pawl relative to the ratchet;

According to the position information, the motor is controlled to rotate until the pawl corresponds to any position of the ratchet groove.
The vehicle P gear control method according to claim 3, 4 or 6, characterized in that the rotation of the motor is a step rotation.
The vehicle P gear control method according to claim 7, characterized in that, the step width of the forward rotation of the motor is consistent with the step width of the reverse rotation of the motor.
The vehicle P gear control method according to any one of claims 1-8, further comprising:

Before the pawl driving the P gear falls into the ratchet groove on the ratchet wheel, an electronic parking lock command is issued to lock the wheel;

After the pawl that drives the P gear falls into the ratchet groove on the ratchet wheel, an electronic parking unlock command is issued to unlock the wheels.
The vehicle P gear control method according to claim 9, characterized in that, after the electronic parking unlock command is issued to unlock the wheels, further comprising:

An electronic parking lock command is issued to lock the wheels again.
The vehicle P gear control method according to any one of claims 1-8, further comprising:

Issue an electronic parking lock command to lock the wheels.