Control method of electric trailer and electric trailer

Abstract

The present invention relates to the technical field of pure electric commercial vehicles, and specifically discloses a control method for an electric trailer and an electric trailer. The electric trailer control method includes a tractor and a trailer, wherein the tractor's EBS and the trailer's VCU are both communicatively connected to the tractor's VCU, and the tractor's EBS and the trailer's EBS are communicatively connected. The electric trailer control method provided by the present invention utilizes the tractor's EBS, the trailer's VCU, the tractor's VCU, and the trailer's EBS to achieve coordinated control, thereby effectively distributing the total braking torque. This method can fully utilize the electric trailer's braking effect and the electric trailer's endurance, effectively resolving the problem in the prior art of lacking coordinated control of electric trailers under braking conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of pure electric commercial vehicles, and in particular to a control method for an electric trailer and the electric trailer. Background Art

[0002] In recent years, pure electric commercial vehicles have experienced rapid growth. Electric trailers, typically used for medium- and long-distance transport, have higher requirements for battery life. However, current trailers cannot meet these demands due to the cost and weight of power batteries. Electric trailers, however, have their own battery packs and can utilize their electric drive systems for brake energy recovery, significantly improving their battery life. However, limited prior research has focused on the coordinated control of electric trailers in both driving and braking states, hindering their full potential. Summary of the Invention

[0003] The object of the present invention is to provide a control method for an electric trailer and an electric trailer, so as to at least solve the problem in the prior art that the electric trailer lacks coordinated control under braking state.

[0004] On the one hand, the present invention provides a control method for an electric trailer, the control method for an electric trailer comprising: a tractor and a trailer, the tractor EBS and the trailer VCU are both in communication connection with the tractor VCU, the tractor VCU can control the operation of the tractor EBS and the trailer VCU, the tractor EBS and the trailer EBS are in communication connection, the tractor EBS can control the operation of the trailer EBS, if the electric trailer is in a braking state: obtaining the total braking torque required by the electric trailer; the tractor EBS distributes the total braking torque into the tractor braking torque and the trailer braking torque, and transmits the trailer braking torque to the trailer EBS; the tractor EBS distributes the tractor braking torque into the tractor braking torque and the trailer braking torque, and transmits the trailer braking torque to the trailer EBS; the tractor EBS distributes the tractor braking torque into the trailer braking torque The power torque is distributed into the tractor vehicle electric braking torque and the tractor vehicle mechanical braking torque, and the tractor vehicle electric braking torque is transmitted to the tractor vehicle VCU and the tractor vehicle mechanical braking torque is transmitted to the tractor vehicle mechanical brake actuator; the tractor vehicle VCU transmits the tractor vehicle electric braking torque to the first electric drive axle of the tractor vehicle, so as to use the first electric drive axle to brake the electric trailer; the trailer EBS distributes the trailer braking torque into the trailer electric braking torque and the trailer mechanical braking torque, and transmits the trailer electric braking torque to the second electric drive axle of the trailer and the trailer mechanical braking torque to the trailer mechanical brake actuator, so as to use the second electric drive axle to brake the electric trailer.

[0005] As an optional technical solution for the control method of the electric trailer, the control method of the electric trailer also includes:

[0006] The first electric drive axle feeds back the first permissible braking torque to the tractor VCU, and the second electric drive axle feeds back the second permissible braking torque to the tractor VCU through the trailer VCU.

[0007] The tractor VCU transmits the first permissible braking torque and the second permissible braking torque to the tractor EBS;

[0008] If the first permissible braking torque is less than the tractor's electric braking torque and the second permissible braking torque is less than the trailer's braking torque, the tractor's EBS redistributes the total braking torque so that the first permissible braking torque is greater than or equal to the tractor's electric braking torque and the second permissible braking torque is greater than or equal to the trailer's braking torque.

[0009] As an optional technical solution for the control method of electric trailers, the tractor EBS distributes the total braking torque into tractor braking torque and trailer braking torque, including:

[0010] The tractor's EBS distributes the total braking torque into the tractor's braking torque and the trailer's braking torque based on the tire adhesion coefficients of the tractor and trailer.

[0011] As an optional technical solution for the control method of the electric trailer, obtaining the total braking torque required by the electric trailer includes:

[0012] The total braking torque required by the electric trailer is obtained according to the opening signal of the brake pedal of the electric trailer.

[0013] As an optional technical solution for the control method of the electric trailer, there are two first electric drive axles;

[0014] The tractor VCU distributes the tractor electric braking torque and transmits it to the two first electric drive axles respectively.

[0015] As an optional technical solution for the control method of the electric trailer, the control method of the electric trailer also includes:

[0016] If the electric trailer is in driving state:

[0017] Obtain the total driving torque required by the electric trailer;

[0018] The tractor VCU distributes the total drive torque to the first electric drive axle and the trailer VCU;

[0019] The trailer VCU transmits the total drive torque allocated by the tractor VCU to the second electric drive axle;

[0020] The electric trailer is driven by the first electric drive axle and the second electric drive axle.

[0021] As an optional technical solution for the control method of the electric trailer,

[0022] The first electric drive axle feeds back the first permissible driving torque to the tractor VCU, and the second electric drive axle feeds back the second permissible driving torque to the tractor VCU through the trailer VCU.

[0023] If the first allowable driving torque is less than the driving torque assigned to the first electric drive axle, and the second allowable driving torque is less than the driving torque assigned to the second electric drive axle, the tractor VCU redistributes the total driving torque so that the first allowable driving torque is greater than or equal to the driving torque assigned to the first electric drive axle and the second allowable driving torque is greater than or equal to the driving torque assigned to the second electric drive axle.

[0024] As an optional technical solution for the control method of the electric trailer, obtaining the total driving torque required by the electric trailer includes:

[0025] The total driving torque required by the electric trailer is obtained according to the opening signal of the accelerator pedal of the electric trailer.

[0026] On the other hand, the present invention provides an electric trailer, which applies the control method of the electric trailer in any of the above-mentioned schemes. The electric trailer includes a tractor, a trailer, a tractor control system and a trailer control system. The tractor control system can control the driving and braking of the tractor. The tractor control system and the trailer control system are communicatively connected. The tractor control system controls the driving and braking of the trailer through the trailer control system.

[0027] As an optional technical solution for electric trailers, the tractor control system includes the tractor VCU, the tractor EBS, the first electric drive axle and the tractor's mechanical brake mechanism. The tractor VCU drives the tractor through the first electric drive axle, and the tractor EBS brakes the tractor through the first electric drive axle and the tractor's mechanical brake mechanism; the trailer control system includes the trailer VCU, the trailer EBS, the second electric drive axle and the trailer's mechanical brake mechanism. The trailer VCU drives the trailer through the first electric drive axle, and the trailer EBS brakes the trailer through the first electric drive axle and the tractor's mechanical brake mechanism.

[0028] The beneficial effects of the present invention are:

[0029] The present invention provides a control method for an electric trailer, which includes: a tractor and a trailer, wherein the tractor EBS and the trailer VCU are both communicatively connected to the tractor VCU, and the tractor EBS and the trailer EBS are communicatively connected. When the electric trailer is in a braking state, it first obtains the total braking torque required by the electric trailer, and then distributes the total braking torque into the tractor braking torque and the trailer braking torque through the tractor EBS, and transmits the trailer braking torque to the trailer EBS through the tractor EBS, and then uses the tractor EBS to distribute the tractor braking torque into the tractor electric braking torque and the tractor mechanical braking torque again, and transmits the tractor mechanical braking torque directly to the tractor's mechanical brake actuator for braking through the brake. At the same time, the tractor EBS transmits the tractor electric braking torque to the tractor VCU, and uses the tractor VCU to transmit the tractor electric braking torque to the first electric drive axle, and brakes the electric trailer through the first electric drive axle. Similarly, the trailer EBS can distribute the trailer braking torque into the trailer electric braking torque and the trailer mechanical braking torque, and directly transmit the trailer mechanical braking torque to the trailer's mechanical brake actuator through the trailer EBS, and at the same time transmit the trailer electric braking torque to the second electric drive axle, and use the second electric drive axle to brake the electric trailer. The control method for an electric trailer provided by the present invention performs coordinated control through the tractor EBS, trailer VCU, tractor VCU, and trailer EBS, thereby effectively distributing the total braking torque, which can fully exert the braking effect of the electric trailer and also fully exert the endurance of the electric trailer, effectively solving the problem in the prior art of the lack of coordinated control of the electric trailer under braking state. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of a control method for an electric trailer according to an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of an electric trailer in a braking state according to an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of an electric trailer in a driving state according to an embodiment of the present invention.

[0033] In the picture:

[0034] 1. Tractor; 11. Tractor VCU; 12. Tractor EBS; 13. First electric drive axle; 14. Tractor mechanical brake actuator;

[0035] 2. Trailer; 21. Trailer VCU; 22. Trailer EBS; 23. Second electric drive axle; 24. Trailer mechanical brake actuator;

[0036] 3. Total braking torque;

[0037] 4. Total driving torque. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0040] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0042] like Figures 1 to 3As shown, this embodiment provides a control method for an electric trailer, which includes a tractor 1 and a trailer 2. The tractor EBS (Electronic Brake Systems, short for electronic brake systems) 12 and the trailer VCU (Vehicle Control Unit, short for electronic control systems) 21 are both connected to the tractor VCU 11 in communication, and the tractor EBS 12 is connected to the trailer EBS 22 in communication. When the electric trailer is in a braking state, the total braking torque 3 required by the electric trailer is first obtained, and then the total braking torque 3 is distributed into the tractor braking torque and the trailer braking torque through the tractor EBS 12, and the trailer braking torque is transmitted to the trailer EBS 22 through the tractor EBS 12, and then the tractor EBS 12 is used to distribute the tractor braking torque into the tractor electric braking torque and the tractor mechanical braking torque again, and the tractor mechanical braking torque is directly transmitted to the tractor's mechanical brake actuator 14, wherein the tractor's mechanical brake actuator 14 is a brake, so as to be braked. The tractor EBS 12 transmits the tractor electric braking torque to the tractor VCU 11, which then transmits the tractor electric braking torque to the first electric drive axle 13 via the tractor VCU 11, and brakes the electric trailer via the first electric drive axle 13. Similarly, the trailer EBS 22 can distribute the trailer braking torque into the trailer electric braking torque and the trailer mechanical braking torque, and directly transmit the trailer mechanical braking torque to the trailer's mechanical brake actuator 24 via the trailer EBS 22, while simultaneously transmitting the trailer electric braking torque to the second electric drive axle 23, and braking the electric trailer via the second electric drive axle 23. The control method for an electric trailer provided by the present invention can coordinately control the tractor EBS 12, the trailer VCU 21, the tractor VCU 11, and the trailer EBS 22, thereby effectively distributing the total braking torque 3, fully utilizing the braking effect of the electric trailer, and also fully utilizing the endurance of the electric trailer, effectively solving the problem of the prior art lacking coordinated control of the electric trailer under braking.

[0043] Among them, the tractor VCU11 is the electronic control system of tractor 1, and the tractor EBS12 is the electronic braking system of tractor 1; similarly, the trailer VCU21 is the electronic control system of trailer 2, and the trailer EBS22 is the electronic braking system of trailer 2.

[0044] It should be noted that the tractor 1 of this embodiment has a 6×4 drive configuration and the trailer 2 has a three-axle configuration. The mechanical brake actuator 14 of the tractor and the mechanical brake actuator 24 of the trailer are both brakes on each electric drive axle.

[0045] Specifically, the control method of the electric trailer also includes: the first allowable braking torque can be fed back to the tractor VCU11 through the first electric drive axle 13; similarly, the second electric drive axle 23 can also feed back the second allowable braking torque to the tractor VCU11 through the trailer VCU21; then the first allowable braking torque and the second allowable braking torque are transmitted to the tractor EBS12 through the tractor VCU11; when the first allowable braking torque is less than the electric braking torque of the tractor 1, and the second allowable braking torque is less than the braking torque of the trailer 2, it means that the allocated electric braking torque of the tractor 1 and the allocated braking torque of the trailer 2 are too large, and the first electric drive axle 13 and the second electric drive axle 23 cannot bear the allocated torque. Therefore, the tractor EBS12 needs to redistribute the total braking torque 3 so that the first allowable braking torque is greater than or equal to the electric braking torque of the tractor 1 and the second allowable braking torque is greater than or equal to the braking torque of the trailer 2, thereby satisfying the braking effect through the first electric drive axle 13 and the second electric drive axle 23.

[0046] For example: If the maximum torque allocated to one of the electric drive axles exceeds its own capacity, the electric drive axle will not respond. The tractor VCU11 and trailer VCU21 will redistribute the torque allocated to other electric drive axles and appropriately increase it within a safe range. If the torque cannot be increased, the total braking torque will be reduced by 3.

[0047] In this embodiment, the tractor EBS 12 distributes the total braking torque 3 into the braking torque of the tractor 1 and the braking torque of the trailer 2. The distribution is based on the ability to avoid idling of the tires of the tractor 1 and the trailer 2 according to the adhesion coefficients of the tires of the tractor 1 and the trailer 2. Subsequently, the total braking torque 3 is distributed by the tractor EBS 12 into the braking torque of the tractor 1 and the braking torque of the trailer 2.

[0048] To obtain the total braking torque 3 required by the electric trailer, the electric trailer control method of the present invention further includes: obtaining the total braking torque 3 required by the electric trailer based on an opening signal of the electric trailer's brake pedal, that is, the depth to which the driver depresses the brake pedal. Due to different road conditions and driving habits, the depth to which the driver depresses the brake pedal varies, and thus the total braking torque 3 required by the electric trailer also varies.

[0049] In this embodiment, there are two first electric drive axles 13 , which are respectively distributed on the middle axle and the rear axle of the tractor 1 ;

[0050] With such an arrangement, the tractor VCU 11 can once again distribute the electric braking torque of the tractor 1 and transmit it to the two first electric drive axles 13 respectively, and utilize the two first electric drive axles 13 for braking, thereby improving the braking effect.

[0051] Since the structure of the tractor in this embodiment is 6×4, the two first electric drive axles 13 can be respectively distributed on the middle axle and the rear axle of the tractor 1 , and the second electric drive axle 23 is the middle axle of the trailer 2 .

[0052] The control method of the electric trailer provided by the present invention also includes: when the electric trailer is in a driving state: first, the total driving torque 4 required by the electric trailer is obtained; then, the total driving torque 4 is sent to the tractor VCU11, and the tractor VCU11 considers driving stability and economic effects, and distributes the total driving torque 4 to the first electric drive axle 13 and the trailer VCU21; then, the total driving torque 4 distributed by the tractor VCU11 is transmitted to the second electric drive axle 23 through the trailer VCU21; finally, the electric trailer is driven by the first electric drive axle 13 and the second electric drive axle 23. The above method can distribute the total driving torque 4 to the first electric drive axle 13 and the trailer VCU21 through the tractor VCU11, thereby realizing coordinated control between the tractor 1 and the trailer 2, and then effectively distribute the total driving torque 4, so that the endurance level of the electric trailer can be fully utilized.

[0053] Among them, in order to further optimize the coordinated control between the tractor 1 and the trailer 2, the first electric drive axle 13 feeds back the first permissible driving torque to the tractor VCU 11, and the second electric drive axle 23 feeds back the second permissible driving torque to the tractor VCU 11 through the trailer VCU 21. If the first permissible driving torque is less than the driving torque allocated to the first electric drive axle 13, and the second permissible driving torque is less than the driving torque allocated to the second electric drive axle 23, then the maximum torques of the first electric drive axle 13 and the second electric drive axle 23 cannot meet the allocated driving torque. Therefore, the tractor VCU 11 needs to redistribute the total driving torque 4 to ensure that the first permissible driving torque is greater than or equal to the driving torque allocated to the first electric drive axle 13 and the second permissible driving torque is greater than or equal to the driving torque allocated to the second electric drive axle 23. This arrangement can maximize the driving effect of the first electric drive axle 13 and the second electric drive axle 23.

[0054] It should be noted that driving stability refers to avoiding the dangerous situation of pushing the tractor 1 through the traction pin due to excessive driving torque of the second electric drive axle 23 of the trailer 2; economic effect refers to considering the motor working in the high-efficiency range while taking into account the adhesion systems of each tire to avoid tire idling.

[0055] Furthermore, the total driving torque 4 required by the electric trailer can be obtained based on the opening signal of the accelerator pedal of the electric trailer.

[0056] This embodiment also provides an electric trailer, which utilizes the control method for the electric trailer in the above-mentioned solution. The electric trailer includes a tractor 1, a trailer 2, a tractor control system, and a trailer control system. The tractor control system is capable of controlling the driving and braking of the tractor 1. The tractor control system and the trailer control system are communicatively connected, and the tractor control system controls the driving and braking of the trailer 2 through the trailer control system. The electric trailer provided by the present invention utilizes the tractor control system and the trailer control system to achieve coordinated control, thereby effectively allocating the total braking torque 3 and the total driving torque 4, thereby fully utilizing the braking and driving effects of the electric trailer and also fully maximizing the endurance of the electric trailer, effectively resolving the problem in the prior art of lacking coordinated control of the electric trailer under braking.

[0057] Specifically, the tractor control system includes a tractor VCU 11, a tractor EBS 12, a first electric drive axle 13, and a tractor mechanical brake actuator 14. The tractor VCU 11 drives the tractor 1 via the first electric drive axle 13, and the tractor EBS 12 brakes the tractor 1 via the first electric drive axle 13 and the tractor mechanical brake actuator 14. The trailer control system includes a trailer VCU 21, a trailer EBS 22, a second electric drive axle 23, and a trailer mechanical brake actuator 24. The trailer VCU 21 drives the trailer 2 via the first electric drive axle 13, and the trailer EBS 22 brakes the trailer 2 via the first electric drive axle 13 and the tractor mechanical brake actuator 14. The tractor mechanical brake actuator 14 is a brake installed on the first electric drive axle 13, and the trailer mechanical brake actuator 24 is a brake installed on the second electric drive axle 23.

[0058] The advantages of the electric trailer control method provided by the present invention are as follows: the electric trailer control method clarifies the connection relationship between the tractor control systems and trailer control systems of the pure electric tractor and the electric trailer, as well as the functions and signal transmission paths of the tractor control systems and trailer control systems in the driving and braking states, respectively, providing a basis for formulating specific control strategies.

[0059] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A control method for an electric trailer, the electric trailer comprising a tractor (1) and a trailer (2), wherein the tractor EBS (12) and the trailer VCU (21) are both communicatively connected to the tractor VCU (11), the tractor VCU (11) is capable of controlling the operation of the tractor EBS (12) and the trailer VCU (21), the tractor EBS (12) is communicatively connected to the trailer EBS (22), the tractor EBS (12) is capable of controlling the operation of the trailer EBS (22), and the method is characterized in that: The control method of the electric trailer includes: If the electric trailer is in a braking state: Obtaining the total braking torque required by the electric trailer (3); The tractor EBS (12) distributes the total braking torque (3) into a tractor braking torque and a trailer braking torque, and transmits the trailer braking torque to the trailer EBS (22); The tractor EBS (12) distributes the tractor braking torque into a tractor electric braking torque and a tractor mechanical braking torque, and transmits the tractor electric braking torque to the tractor VCU (11) and transmits the tractor mechanical braking torque to a mechanical brake actuator (14) of the tractor; The tractor VCU (11) transmits the tractor electric braking torque to the first electric drive axle (13) of the tractor (1), so as to brake the electric trailer using the first electric drive axle (13); The trailer EBS (22) distributes the trailer braking torque into a trailer electric braking torque and a trailer mechanical braking torque, and transmits the trailer electric braking torque to the second electric drive axle (23) of the trailer (2) and transmits the trailer mechanical braking torque to the mechanical brake actuator (24) of the trailer, so as to brake the electric trailer using the second electric drive axle (23) and the mechanical brake actuator (24) of the trailer; The control method of the electric trailer further includes: The first electric drive axle (13) feeds back a first permissible braking torque to the tractor VCU (11), and the second electric drive axle (23) feeds back a second permissible braking torque to the tractor VCU (11) via the trailer VCU (21); The tractor vehicle VCU (11) transmits the first permissible braking torque and the second permissible braking torque to the tractor vehicle EBS (12); If the first permissible braking torque is less than the tractor vehicle electric braking torque and the second permissible braking torque is less than the trailer vehicle electric braking torque, the tractor vehicle EBS (12) redistributes the total braking torque (3) so that the first permissible braking torque is greater than or equal to the tractor vehicle electric braking torque and the second permissible braking torque is greater than or equal to the trailer vehicle electric braking torque; The tractor EBS (12) distributes the total braking torque (3) into the tractor braking torque and the trailer braking torque, including: Distributing the total braking torque (3) into the tractor braking torque and the trailer braking torque via the tractor EBS (12) according to the tire adhesion coefficients of the tractor (1) and the trailer (2); Obtaining the total braking torque (3) required by the electric trailer, comprising: Obtaining the total braking torque (3) required by the electric trailer according to the opening signal of the brake pedal of the electric trailer; There are two first electric drive bridges (13); The tractor VCU (11) distributes the tractor electric braking torque and transmits it to the two first electric drive axles (13) respectively.

2. The control method of the electric trailer according to claim 1, characterized in that: The control method of the electric trailer further includes: If the electric trailer is in driving state: Obtaining the total driving torque required by the electric trailer (4); The tractor VCU (11) distributes the total driving torque (4) to the first electric drive axle (13) and the trailer VCU (21); The trailer VCU (21) transmits the total driving torque (4) distributed by the tractor VCU (11) to the second electric drive axle (23); The electric trailer is driven by utilizing the first electric drive bridge (13) and the second electric drive bridge (23).

3. The control method of the electric trailer according to claim 2, characterized in that: The first electric drive axle (13) feeds back a first permissible driving torque to the tractor VCU (11), and the second electric drive axle (23) feeds back a second permissible driving torque to the tractor VCU (11) via the trailer VCU (21); If the first permissible driving torque is less than the driving torque allocated to the first electric drive axle (13), and the second permissible driving torque is less than the driving torque allocated to the second electric drive axle (23), the tractor VCU (11) redistributes the total driving torque (4) so ​​that the first permissible driving torque is greater than or equal to the driving torque allocated to the first electric drive axle (13) and the second permissible driving torque is greater than or equal to the driving torque allocated to the second electric drive axle (23).

4. The control method of the electric trailer according to claim 2, characterized in that: Obtaining the total driving torque (4) required by the electric trailer, comprising: The total driving torque (4) required by the electric trailer is obtained according to the opening signal of the accelerator pedal of the electric trailer.

5. An electric trailer, characterized in that: The control method of an electric trailer according to any one of claims 1 to 4 is applied, wherein the electric trailer comprises a tractor (1), a trailer (2), a tractor control system and a trailer control system, wherein the tractor control system is capable of controlling the driving and braking of the tractor (1), the tractor control system and the trailer control system are communicatively connected, and the tractor control system controls the driving and braking of the trailer (2) through the trailer control system.

6. The electric trailer according to claim 5, characterized in that: The tractor control system includes a tractor VCU (11), a tractor EBS (12), a first electric drive axle (13), and a mechanical brake mechanism (14) of the tractor, wherein the tractor VCU (11) drives the tractor (1) through the first electric drive axle (13), and the tractor EBS (12) brakes the tractor (1) through the first electric drive axle (13) and the mechanical brake mechanism (14) of the tractor; and the trailer control system includes a trailer VCU (21), a trailer EBS (22), a second electric drive axle (23), and a mechanical brake mechanism (24) of the trailer, wherein the trailer VCU (21) drives the trailer (2) through the first electric drive axle (13), and the trailer EBS (22) brakes the trailer (2) through the first electric drive axle (13) and the mechanical brake mechanism (14) of the tractor.

Images