Gear shifting method of two-gear transmission of electric vehicle and related equipment

Abstract

The invention discloses a gear shifting method of a two-gear transmission of an electric automobile and related equipment, and relates to the technical field of automobile automatic transmission control, the method comprises the steps that the control quantity and the state quantity of gear shifting control are obtained, the control quantity comprises the driving motor torque, the clutch torque and the brake torque, and the state quantity comprises the driving motor torque and the clutch torque; the state quantity comprises a gear ring angular velocity and a planet carrier angular velocity of the planet row system; establishing a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation comprises a kinetic equation and a state space equation; and gear shifting control indexes and constraint conditions of gear shifting control are established, and optimal gear shifting control is conducted on the mathematical relation equation according to the gear shifting control indexes and the constraint conditions.

Description

Technical Field

[0001] The present application relates to the technical field of automobile automatic transmission control, and in particular to a shifting method and related equipment for a two-speed transmission of an electric vehicle. Background Art

[0002] At present, in order to improve power and economy, new energy vehicles such as hybrid or four-wheel drive widely choose to be equipped with transmissions, especially two-speed transmissions, which are increasingly favored by vehicle manufacturers due to their low cost, small size and easy layout.

[0003] However, compared with traditional fuel vehicles, hybrid or four-wheel drive vehicles are characterized by having multiple power sources. When shifting gears, they often choose to shift gears without power input, that is, when shifting gears, the torque transmission on the shift drive shaft is cut off, and the torque demand is transferred to other power sources for assistance. After the shift is completed, the torque demand is restored. The advantage is that the shift requirement is low and there will be no torque interruption caused by the shift. However, the accompanying disadvantage is that on the one hand, it limits the power of the whole vehicle. The power source must have enough power reserve to supplement the shift interruption torque. On the other hand, it limits the scope of application of the gearbox in new energy vehicles, that is, it can only be applied to vehicles with multiple power sources, and does not use vehicles with a single power source, such as front-wheel drive or rear-wheel drive electric vehicles. At present, there is no appropriate method to solve the above problems. Therefore, it is necessary to propose a shifting method for a two-speed transmission of an electric vehicle to at least solve some of the above problems. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In a first aspect, an embodiment of the present application provides a shifting method for a two-speed transmission of an electric vehicle, the method comprising:

[0006] Acquire control quantities and state quantities of shift control, wherein the control quantities include drive motor torque, clutch torque and brake torque, and the state quantities include ring gear angular velocity and planet carrier angular velocity of the planetary gear system;

[0007] Establishing a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation;

[0008] A shift control index and a constraint condition of the shift control are established, and an optimal shift control is performed on the mathematical relationship equation according to the shift control index and the constraint condition.

[0009] In one embodiment of the present invention, the ring gear angular velocity is expressed as:

[0010] ω r =ω m ;

[0011] Among them, ω r is the ring gear speed, ω m is the driving motor speed.

[0012] In one embodiment of the present invention, the planet carrier angular velocity is expressed as:

[0013]

[0014] Among them, ω c is the rotation speed of the planet carrier, R W is the wheel rolling radius, k is the main reduction ratio, η is the unit speed coefficient, and v is the speed.

[0015] In one embodiment of the present invention, the kinetic equation is expressed as:

[0016]

[0017] Among them, i m is the main reducer speed ratio, T road is the road resistance torque, r r , r s are the planetary gear ring and sun gear pitch circle radii, T M is the driving motor torque in the control quantity, T CL is the clutch torque in the control quantity, T BR is the brake torque in the control quantity, To control the amount, is the state quantity.

[0018] In one embodiment of the present invention, the state space equation is expressed as:

[0019]

[0020] Among them, g is the input matrix and u(t) is the input signal.

[0021] In one embodiment of the present invention, the shift control index is expressed as:

[0022]

[0023] Among them, N is the prediction step length, λ1, λ2, λ3 are all indicator weights, Cb is the shift shock, Ch is the shift heat generation and Ce is the motor efficiency, F(x N ,u N ) is the indicator when the gear shift is completed.

[0024] In one embodiment of the present invention, the constraint condition is expressed as:

[0025]

[0026] Among them, B is the speed of each component of the transmission, M max is the maximum speed limit, T N is the time when the gear shift ends, T set is the time when the gear shift starts, M t is the maximum required time.

[0027] In a second aspect, the present application proposes a shifting system for a two-speed transmission of an electric vehicle, the system comprising: a data acquisition module, an equation building module and a shifting control module;

[0028] The data acquisition module is configured to: acquire control quantities and state quantities of the shift control, wherein the control quantities include the drive motor torque, the clutch torque and the brake torque, and the state quantities include the ring gear angular velocity and the planet carrier angular velocity of the planetary gear system;

[0029] The equation establishment module is configured to: establish a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation;

[0030] The shift control module is configured to establish a shift control index and a constraint condition for the shift control, and perform optimal shift control on the mathematical relationship equation according to the shift control index and the constraint condition.

[0031] In a third aspect, an electronic device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is used to implement the steps of a shifting method for a two-speed transmission of an electric vehicle as described in any one of the first aspects above when executing the computer program stored in the memory.

[0032] In a fourth aspect, the present application further proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a shifting method for a two-speed transmission of an electric vehicle according to any one of the first aspects.

[0033] In summary, a shifting method for a two-speed transmission of an electric vehicle according to an embodiment of the present application includes: obtaining a control quantity and a state quantity of a shifting control, wherein the control quantity includes a driving motor torque, a clutch torque and a brake torque, and the state quantity includes a ring gear angular velocity and a planetary carrier angular velocity of a planetary gear system; establishing a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation; establishing a shifting control index and a constraint condition for the shifting control, and performing an optimal shifting control on the mathematical relationship equation according to the shifting control index and the constraint condition. By establishing a shifting control index and a constraint condition for the shifting control, and performing an optimal shifting control on the mathematical relationship equation according to the shifting control index and the constraint condition. The electric vehicle single-drive non-powered shifting is realized, and no other power unit is required to supplement torque when shifting, which reduces the shifting constraints, and shifting is performed through optimal control, which greatly provides shifting comfort.

[0034] The shifting method of the two-speed transmission of an electric vehicle proposed in this application, and other advantages, objectives and features of this application will be partially reflected through the following description, and will also be partially understood by technical personnel in this field through research and practice of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present specification. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1 A schematic diagram of a process flow of a shifting method for a two-speed transmission of an electric vehicle provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a shift control system for a two-speed transmission of an electric vehicle provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the structure of a shift control electronic device for a two-speed transmission of an electric vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to better understand the technical solutions provided by the embodiments of this specification, the technical solutions of the embodiments of this specification are described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0040] In this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. The term "more than two" includes two or more than two situations.

[0041] See also Figure 1 , which is a schematic flow diagram of a shifting method of a two-speed transmission of an electric vehicle provided in an embodiment of the present application, and may specifically include:

[0042] S110, acquiring a control quantity and a state quantity of a gear shift control, wherein the control quantity includes a drive motor torque, a clutch torque, and a brake torque, and the state quantity includes an angular velocity of a ring gear and an angular velocity of a planetary carrier of a planetary gear system;

[0043] Exemplarily, the control quantity and state quantity of the gear shift control are obtained, wherein the control quantity includes the drive motor torque, clutch torque and brake torque. The drive motor torque refers to the magnitude of the torsional force that the drive motor can output. During the gear shifting process, the torque output of the drive motor will affect the power transmission and acceleration of the vehicle, etc. The clutch torque refers to the magnitude of the torque transmitted by the clutch during the engagement or disengagement process. The function of the clutch is to connect or disconnect different transmission components, and its torque control is crucial to the smoothness and reliability of the gear shift. Brake torque refers to the braking torque applied by the brake to the transmission system or wheels. When shifting gears, the brake may be used to control the vehicle speed or adjust the speed of the transmission system to achieve smooth gear shifting.

[0044] The state quantity includes the ring gear angular velocity and the planet carrier angular velocity of the planetary gear system. Planetary gear is a common transmission mechanism, and the ring gear is a part of the planetary gear. The ring gear angular velocity reflects the rotation speed of the component, which is of great significance for understanding the working state of the transmission system and judging the timing of gear shifting. The planet carrier is also a component of the planetary gear, and its angular velocity can also reflect the operating state of the transmission system, and together with the ring gear angular velocity, it can help determine the transmission ratio and power distribution of the planetary gear, thereby providing a basis for gear shifting control.

[0045] S120, establishing a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation;

[0046] Exemplarily, a mathematical relationship equation is established based on the control quantity and the state quantity. The purpose of establishing the mathematical relationship equation is to describe the relationship between the control quantity and the state quantity in the system, so as to better understand and control the system. Among them, the mathematical relationship equation includes the dynamic equation and the state space equation. The dynamic equation mainly describes the relationship between the force and motion of the system. The state space equation generally includes the state equation and the output equation. The state equation describes the change law of the state variable over time, that is, the relationship between the derivative of the state variable and the state variable and the control variable; the output equation describes the relationship between the output of the system and the state variable and the control variable. By establishing the state space equation, the dynamic performance of the system can be more comprehensively analyzed and controlled, providing a theoretical basis for the design of the shift control strategy.

[0047] S130, establishing a shift control index and a constraint condition for the shift control, and performing optimal shift control on the mathematical relationship equation according to the shift control index and the constraint condition.

[0048] Exemplarily, the shift control index and constraint conditions of the shift control are established, and the mathematical relationship equation describing the shift process is optimized according to the shift control index and constraint conditions to achieve optimal shift control and improve the performance and driving experience of the vehicle. The optimal shift can be achieved by adjusting the output torque of the drive motor, controlling the engagement and disengagement of the clutch, and adjusting the braking torque of the brake. In the process of implementing the optimal control, it is necessary to monitor the state quantity (gear ring angular velocity and planet carrier angular velocity) in real time to ensure that the system operates within a safe range, and to adjust and optimize according to the actual situation.

[0049] In summary, the shifting method of the electric vehicle two-speed transmission proposed in the embodiment of the present application establishes the shifting control index and constraint conditions of the shifting control, and performs optimal shifting control on the mathematical relationship equation according to the shifting control index and constraint conditions. The electric vehicle single-drive non-powered shifting is realized, and no other power unit is required to supplement the torque during the shifting, which reduces the shifting constraints. The shifting is performed through optimal control, which greatly improves the comfort of the shifting.

[0050] In some examples, the ring gear angular velocity is expressed as:

[0051] ω r =ω m (1);

[0052] Among them, ω r is the ring gear speed, ω m is the driving motor speed.

[0053] Exemplarily, the present invention realizes non-power interruption by controlling the drive motor, clutch and brake, so the control quantity of the shift control includes the drive motor torque, clutch torque and brake torque, and the state quantity is the ring gear angular velocity and the planet carrier angular velocity of the planetary gear system. Since the ring gear is directly connected to the drive motor, the ring gear angular velocity is as shown in formula (1). Where, ω r is the ring gear speed in rpm, ω m is the speed of the driving motor in rpm.

[0054] In some examples, the planet carrier angular velocity is expressed as:

[0055]

[0056] Among them, ω c is the rotation speed of the planet carrier, R W is the wheel rolling radius, k is the main reduction ratio, η is the unit speed coefficient, and v is the speed.

[0057] For example, the planet carrier is adjacent to the vehicle at a certain speed ratio, and the angular velocity of the planet carrier can be calculated according to the vehicle speed. The angular velocity of the planet carrier is shown in formula (2), where ω c is the rotation speed of the planet carrier in rpm, R W is the wheel rolling radius in meters (m), k is the main reduction ratio, and η is the unit speed coefficient, whose value is approximately 2.65.

[0058] In some examples, the kinetic equation is expressed as:

[0059]

[0060] Among them, i m is the main reducer speed ratio, T road is the road resistance torque, r r , r s are the planetary gear ring and sun gear pitch circle radii, T M is the driving motor torque in the control quantity, T CL is the clutch torque in the control quantity, T BR is the brake torque in the control quantity, To control the amount, is the state quantity.

[0061] For example, T M , T CL and T BR represents the driving motor torque, clutch torque and brake torque in the control quantity. Then the control quantity and state quantity The dynamic equation of is shown in formula (3).

[0062]

[0063] Among them, i m is the main reducer speed ratio, T road is the road resistance torque, r r , r s are the planetary gear ring and sun gear pitch circle radii, J m , J r , J s , J c , J p They are the rotational inertia of the motor output shaft, gear ring, sun gear, planet carrier, and planet gear respectively. n is the number of planet gears, m is p is the mass of a single planetary gear, and the relationship between the force and motion of the system is described by the dynamic equation.

[0064] In some examples, the state space equation is expressed as:

[0065]

[0066] Among them, g is the input matrix and u(t) is the input signal.

[0067] Exemplarily, the state space equation is shown in equation (8), where the state quantity is shown in equation (9) and the control quantity is shown in equation (10).

[0068] x=[ω r ω c ] T (9);

[0069] Among them, ω r is the ring gear speed, ω c is the rotation speed of the planet carrier.

[0070] u=[T M T BR T CL T road ] T (10);

[0071] Among them, T M is the driving motor torque in the control quantity, T CL is the clutch torque in the control quantity, T BR is the brake torque in the control quantity, T road is the road resistance torque. The input matrix is:

[0072]

[0073] In the actual vehicle controller, the software program control needs to meet the real-time performance, that is, to complete the calculation and output the control result within the unit cycle, discretize the continuous state space equation, and use the first-order Euler method to obtain x k+1 =x k +Gu k , where G=gdt, dt is the operation period.

[0074] In some examples, the shift control index is expressed as:

[0075]

[0076] Among them, N is the prediction step length, λ1, λ2, λ3 are all indicator weights, Cb is the shift shock, Ch is the shift heat generation, Ce is the motor efficiency, F(x N ,u N ) is the indicator when the gear shift is completed.

[0077] Exemplarily, the shift control index of the present application includes an index during the shift process and an index when the shift is completed. The shift control index is shown in (11), N is the prediction step length, λ1, λ2, and λ3 are all index weights, which can be set according to the relative importance of the three indicators during the shift process. Cb, Ch, and Ce are the shift shock, shift heat generation, and motor efficiency, respectively, which are defined as equations (12), (13), and (14), respectively.

[0078] Cb=(ω c -ω target ) 2 (12);

[0079] Ch=|T CL ·(ω r -ω c )| 2 +|T BR ·ω s | 2 (13);

[0080] Ce=η(T m ,ω m )(14);

[0081] Among them, Ce can be obtained by looking up the drive motor efficiency chart. N ,u N ) is the index when the gear shift is completed, which is related to the target gear position. When the target gear position is 1st gear, the terminal constraint index is shown in formula (15).

[0082]

[0083] When the target gear is 2nd gear, the terminal constraint index is shown in formula (16).

[0084]

[0085] Among them, ω cset It is the transmission output speed at the beginning of the gear shift process. R , p c , p TM , p TBR is the weight of each indicator when the gear shift is completed, and its value is related to its relative importance.

[0086] In some examples, the constraints are expressed as:

[0087]

[0088] Among them, B is the speed of each component of the transmission, M max is the maximum speed limit, T N is the time when the gear shift ends, T set is the time when the gear shift starts, M t is the maximum required time.

[0089] For example, the present invention uses the maximum speed of each transmission component and the longest shifting time during the shifting process as the shifting control constraint conditions. The constraint conditions are shown in formula (17), where B is the speed of each transmission component, M max is the maximum speed limit, that is:

[0090] B=[ω r ω c ω s ] T (18);

[0091] M max =[ω rmax ω cmax ω smax + T (19);

[0092] In summary, the shifting method of the electric vehicle two-speed transmission proposed in the embodiment of the present application includes: obtaining the control quantity and state quantity of the shifting control, the control quantity includes the driving motor torque, the clutch torque and the brake torque, and the state quantity includes the ring gear angular velocity and the planetary carrier angular velocity of the planetary gear system; establishing a mathematical relationship equation according to the control quantity and the state quantity, and the mathematical relationship equation includes a dynamic equation and a state space equation; establishing a shifting control index and constraint conditions for the shifting control, and performing optimal shifting control on the mathematical relationship equation according to the shifting control index and the constraint conditions, by establishing the shifting control index and constraint conditions for the shifting control, and performing optimal shifting control on the mathematical relationship equation according to the shifting control index and the constraint conditions. The electric vehicle single-drive non-powered shifting is realized, and no other power unit is required to supplement the torque when shifting, which reduces the shifting constraints. Shifting is performed through optimal control, which greatly improves the comfort of shifting.

[0093] like Figure 2 As shown, the present application proposes a shifting system for a two-speed transmission of an electric vehicle, the system comprising: a data acquisition module 21, an equation establishment module 22 and a shifting control module 23;

[0094] The data acquisition module 21 is configured to: acquire control quantities and state quantities of the shift control, wherein the control quantities include the drive motor torque, the clutch torque and the brake torque, and the state quantities include the ring gear angular velocity and the planet carrier angular velocity of the planetary gear system;

[0095] The equation establishing module 22 is configured to: establish a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation;

[0096] The shift control module 23 is configured to establish a shift control index and a constraint condition for the shift control, and perform optimal shift control on the mathematical relationship equation according to the shift control index and the constraint condition.

[0097] The effects of the above-mentioned system when applying the above-mentioned method can be found in the description of the above-mentioned method embodiment, which will not be repeated here.

[0098] like Figure 3 As shown, an embodiment of the present application also provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor. When the processor 320 executes the computer program 311, the steps of any one of the above-mentioned methods for shifting the two-speed transmission of the electric vehicle are implemented.

[0099] Since the electronic device introduced in this embodiment is a device used to implement a shifting device of a two-speed transmission of an electric vehicle in the embodiment of the present application, based on the method introduced in the embodiment of the present application, technical personnel in this field can understand the specific implementation method of the electronic device of this embodiment and its various variations, so how the electronic device implements the method in the embodiment of the present application is not introduced in detail here. As long as the equipment used by technical personnel in this field to implement the method in the embodiment of the present application is within the scope of protection of this application.

[0100] In the specific implementation process, when the computer program 311 is executed by the processor, it can achieve Figure 1 Any implementation manner in the corresponding embodiments.

[0101] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-readable program code.

[0103] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0104] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0105] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0106] An embodiment of the present application also provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device executes the process of the LDPC decoding method of the solid-state hard disk controller.

[0107] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or a data center that includes one or more available media integration. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)), etc.

[0108] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0109] In the several embodiments provided in the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0110] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0111] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0112] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0113] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

[0114] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0115] Obviously, those skilled in the art can make various changes and modifications to this specification without departing from the spirit and scope of this specification. Thus, if these modifications and variations of this specification fall within the scope of the claims of this specification and their equivalents, this specification is also intended to include these modifications and variations.

Claims

1. A shifting method for a two-speed transmission of an electric vehicle, characterized in that: The method comprises: Acquire control quantities and state quantities of shift control, wherein the control quantities include drive motor torque, clutch torque and brake torque, and the state quantities include ring gear angular velocity and planet carrier angular velocity of the planetary gear system; Establishing a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation; A shift control index and a constraint condition of the shift control are established, and an optimal shift control is performed on the mathematical relationship equation according to the shift control index and the constraint condition.

2. The shifting method of a two-speed transmission of an electric vehicle according to claim 1, characterized in that: The gear ring angular velocity is expressed as: oh r =ω m ; Among them, ω r is the ring gear speed, ω m is the driving motor speed.

3. The shifting method of a two-speed transmission of an electric vehicle according to claim 1, characterized in that: The planet carrier angular velocity is expressed as: Among them, ω c is the rotation speed of the planet carrier, R W is the wheel rolling radius, k is the main reduction ratio, η is the unit speed coefficient, and v is the speed.

4. The shifting method of a two-speed transmission of an electric vehicle according to claim 1, characterized in that: The kinetic equation is expressed as: Among them, i m is the main reducer speed ratio, T road is the road resistance torque, r r , r s are the planetary gear ring and sun gear pitch circle radii, T M is the driving motor torque in the control quantity, T CL is the clutch torque in the control quantity, T BR is the brake torque in the control quantity, To control the amount, is the state quantity.

5. The shifting method of a two-speed transmission of an electric vehicle according to claim 1, characterized in that: The state space equation is expressed as: Among them, g is the input matrix and u(t) is the input signal.

6. The shifting method of a two-speed transmission of an electric vehicle according to claim 2, characterized in that: The shift control index is expressed as: Among them, N is the prediction step length, λ1, λ2, λ3 are all indicator weights, Cb is the shift shock, Ch is the shift heat generation, Ce is the motor efficiency, F(x N ,u N ) is the indicator when the gear shift is completed.

7. The shifting method of a two-speed transmission of an electric vehicle according to claim 3, characterized in that: The constraints are expressed as: Among them, B is the speed of each component of the transmission, M max is the maximum speed limit, T N is the time when the gear shift ends, T set is the time when the gear shift starts, M t is the maximum required time.

8. A shift system for a two-speed transmission of an electric vehicle, characterized in that: The system comprises: a data acquisition module, an equation building module and a shift control module; The data acquisition module is configured to: acquire control quantities and state quantities of the shift control, wherein the control quantities include the drive motor torque, the clutch torque and the brake torque, and the state quantities include the ring gear angular velocity and the planet carrier angular velocity of the planetary gear system; The equation establishment module is configured to: establish a mathematical relationship equation according to the control quantity and the state quantity, wherein the mathematical relationship equation includes a dynamic equation and a state space equation; The shift control module is configured to establish a shift control index and a constraint condition for the shift control, and perform optimal shift control on the mathematical relationship equation according to the shift control index and the constraint condition.

9. An electronic device, comprising: A memory and a processor, wherein the processor is used to implement the steps of a shifting method for a two-speed transmission of an electric vehicle as described in any one of claims 1 to 7 when executing a computer program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a shifting method for a two-speed transmission of an electric vehicle are implemented as described in any one of claims 1 to 7.

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