Braking control method for new energy commercial vehicle

Abstract

The invention discloses a braking control method for a new energy commercial vehicle, and relates to the technical field of new energy vehicle braking. Determining an electric braking parameter and a mechanical braking parameter according to the target deceleration of the vehicle; determining an electric braking torque and a mechanical braking torque according to the electric braking parameter and the mechanical braking parameter; controlling the vehicle to brake according to the electric brake torque and the mechanical brake torque; wherein the step of determining the electric braking parameters and the mechanical braking parameters according to the target deceleration of the vehicle comprises the steps that when the target deceleration of the vehicle is smaller than a first preset deceleration, the electric braking parameters are calculated according to a first regression curve equation about the target deceleration of the vehicle; and when the target deceleration of the vehicle is greater than a second preset deceleration, calculating the mechanical braking parameter according to a second regression curve equation about the target deceleration of the vehicle. And the problem that the sudden change of the braking force is large under the unstable critical working condition of the vehicle due to gradual braking is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle braking, and in particular to a braking control method for a new energy commercial vehicle. Background Art

[0002] The commonly used braking system for commercial vehicles is a mechanical braking system that uses hydraulic or pneumatic media for transmission. With the continuous development of new energy vehicle models, in order to make full use of the stored energy of the vehicle, pedal travel controllers and deceleration sensors are added to make control more comfortable and energy regeneration more efficient.

[0003] Because traditional braking systems use solidified steering angle signals, there is a certain degree of asynchronous difference in linkage with the regenerative braking system. The regenerative braking will be weakened to a certain extent and also has a strong mutation problem, the energy regeneration utilization rate and driving comfort will be low; there is a lack of a wider range of interaction between braking intensity regenerative braking and mechanical braking; there is a lack of self-adjustment performance of energy recovery intensity under different load conditions, and it is unable to adapt to environmental changes in a wider spectrum. Summary of the invention

[0004] The present application provides a braking control method for a new energy commercial vehicle to at least solve at least one technical problem existing in the related art.

[0005] An embodiment of the present application provides a braking control method for a new energy commercial vehicle, including: obtaining a vehicle target deceleration; determining an electric braking parameter and a mechanical braking parameter according to the vehicle target deceleration; determining an electric braking torque and a mechanical braking torque according to the electric braking parameter and the mechanical braking parameter; controlling the vehicle to brake according to the electric braking torque and the mechanical braking torque; wherein, determining the electric braking parameter and the mechanical braking parameter according to the vehicle target deceleration includes: when the vehicle target deceleration is less than a first preset deceleration, calculating the electric braking parameter according to a first regression curve equation regarding the vehicle target deceleration; when the vehicle target deceleration is greater than a second preset deceleration, calculating the mechanical braking parameter according to a second regression curve equation regarding the vehicle target deceleration.

[0006] As an optional implementation, the method further includes: setting the vehicle target deceleration to a, setting the electric brake parameter to y1, and the first regression curve equation includes: Where k1 is a constant.

[0007] As an optional implementation, the value range of the first preset deceleration includes 3.5m / s2-5m / s2; the value range of k1 includes 1.1-1.6, and the value range of the vehicle target deceleration a includes: 0-5.

[0008] As an optional implementation, determining the electric braking parameter and the mechanical braking parameter based on the vehicle target deceleration also includes: if the vehicle target deceleration is greater than a first preset deceleration, making the electric braking parameter equal to a preset electric braking parameter; the preset electric braking parameter is a fixed value.

[0009] As an optional implementation, determining the electric braking parameter and the mechanical braking parameter based on the vehicle target deceleration also includes: if the vehicle target deceleration is less than the second preset deceleration, making the mechanical braking parameter equal to a preset mechanical braking parameter; the preset mechanical braking parameter is a fixed value.

[0010] As an optional implementation, the method further includes: setting the vehicle target deceleration to a, setting the mechanical brake parameter to y2, and the second regression curve equation includes: Where k2 is a constant.

[0011] As an optional implementation, the value range of the vehicle target deceleration a includes: 0.2-8; k2 is determined according to the first preset deceleration; or, the value range of k2 includes 10-16.

[0012] As an optional implementation, determining the electric braking torque and the mechanical braking torque based on the electric braking parameters and the mechanical braking parameters includes: determining the electric braking proportional coefficient and the mechanical braking proportional coefficient based on the electric braking parameters and the mechanical braking parameters; determining the electric braking torque and the mechanical braking torque based on the electric braking proportional coefficient and the mechanical braking proportional coefficient.

[0013] As an optional implementation, determining the electric braking proportional coefficient and the mechanical braking proportional coefficient based on the electric braking parameter and the mechanical braking parameter includes: setting the electric braking proportional coefficient to k3, setting the electric braking parameter to y1, setting the mechanical braking proportional coefficient to k4, mechanical braking parameter y2, k3=y1 / (y1+y2), k4=1-k1.

[0014] As an optional implementation, the method further includes: obtaining a locking state of the vehicle; if the vehicle is in a locked state, controlling the electric braking torque to be 0.

[0015] In an embodiment of the present application, a braking control method for a new energy commercial vehicle is provided, including: obtaining a target deceleration of the vehicle; determining electric braking parameters and mechanical braking parameters according to the target deceleration of the vehicle; determining an electric braking proportional coefficient and a mechanical braking proportional coefficient according to the electric braking parameters and the mechanical braking parameters; determining an electric braking torque and a mechanical braking torque according to the electric braking proportional coefficient and the mechanical braking proportional coefficient; and controlling the vehicle to brake according to the electric braking torque and the mechanical braking torque. A regression curve equation is used to control the theoretical distribution relationship between braking energy recovery and mechanical braking of new energy vehicle models, eliminating the problem of large sudden changes in braking force under critical conditions of vehicle instability caused by progressive braking. At the same time, the range of vehicle deceleration interaction of the two superimposed braking forces under conventional braking conditions is expanded. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 It is a flow chart of a braking control method for a new energy commercial vehicle provided according to an embodiment of the present application.

[0019] Figure 2 It is a schematic diagram of a distribution curve of electric braking parameters provided according to an embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of a distribution curve of mechanical brake parameters provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] like Figure 1-3 As shown, the embodiment of the present application provides a braking control method for a new energy commercial vehicle, comprising:

[0024] S1 obtains the target deceleration of the vehicle;

[0025] S2 determines the electric brake parameter and the mechanical brake parameter according to the target deceleration of the vehicle; when the target deceleration of the vehicle is less than the first preset deceleration, the electric brake parameter is calculated according to the first regression curve equation about the target deceleration of the vehicle; when the target deceleration of the vehicle is greater than the second preset deceleration, the mechanical brake parameter is calculated according to the second regression curve equation about the target deceleration of the vehicle

[0026] S3 determines the electric braking torque and the mechanical braking torque according to the electric braking parameter and the mechanical braking parameter;

[0027] S4 controls the vehicle to brake according to the electric braking torque and the mechanical braking torque.

[0028] Add electric brake parameters and mechanical brake parameters, determine the calculation of different brake parameters in advance according to the different decelerations of the vehicle, and then determine the mechanical brake parameters and electric brake parameters according to the target deceleration during the vehicle driving process, and calculate the electric brake proportional coefficient and mechanical brake proportional coefficient according to the mechanical brake parameters and electric brake parameters. Use the regression curve equation to control the theoretical distribution relationship between the braking energy recovery and mechanical braking of new energy vehicles, and eliminate the problem of large sudden changes in braking force under critical conditions of vehicle instability caused by progressive braking. At the same time, expand the range of vehicle deceleration interaction of the two superimposed braking forces under conventional braking conditions.

[0029] The deceleration can be acquired by providing a deceleration sensor.

[0030] In addition, the target deceleration of the vehicle can be determined by the dynamic mass of the vehicle and the travel of the brake pedal. This application does not make further limitations. For example, during the process of starting acceleration, the motor will output the driving torque T, and the deceleration sensor will output the deceleration a0. The average deceleration a within 0.1s after the deceleration starts to change is taken. l , at this time the motor torque is T l , when the average deceleration value increases to a1+0.5, the motor torque at this time is T h , the vehicle dynamic mass M1 at this time = (T h -T l )*i / r / 0.5.

[0031] After the vehicle obtains the target braking deceleration a, the VCU will determine the electric braking torque and mechanical braking torque based on the electric braking parameters and mechanical braking parameters, and distribute the braking torque. The electric braking torque will be distributed to the motor for energy recovery braking, and the mechanical braking torque will be distributed to the front and rear actuator units to drive the front and rear wheel brakes for wheel-side braking.

[0032] like Figure 2 As shown, as an optional implementation, it also includes: setting the vehicle target deceleration to a, setting the electric brake parameter to y1, and the first regression curve equation includes: Where k1 is a constant.

[0033] As an optional implementation, the value range of the first preset deceleration includes 3.5m / s2-5m / s2; the value range of k1 includes 1.1-1.6, and the value range of the vehicle target deceleration a includes: 0-5.

[0034] It should be noted that the value of the first preset deceleration is close to the first value of a greater than 0 corresponding to y1=0 in the first regression curve equation. Preferably, 4.65 m / s can be selected. 2 .

[0035] As an optional implementation, determining the electric braking parameter and the mechanical braking parameter based on the vehicle target deceleration also includes: if the vehicle target deceleration is greater than a first preset deceleration, making the electric braking parameter equal to a preset electric braking parameter; the preset electric braking parameter is a fixed value.

[0036] The preset electric braking parameter may take a value of 0.04, but this application does not limit this. It may be selected according to actual conditions, but its selected value should be small enough to enable the vehicle to achieve the target deceleration through mechanical braking.

[0037] like Figure 3As shown, as an optional implementation, it also includes: setting the vehicle target deceleration to a, setting the mechanical brake parameter to y2, and the second regression curve equation includes: Where k2 is a constant.

[0038] As an optional implementation, the value range of the vehicle target deceleration a includes: 0.2-8; k2 is determined according to the first preset deceleration; or, the value range of k2 includes 10-16.

[0039] It should be noted that the value of the second preset deceleration is close to the value corresponding to y1=0 in the second regression curve equation, that is, 0. Preferably, 0.5 m / s can be selected. 2 .

[0040] As an optional implementation, determining the electric braking parameter and the mechanical braking parameter based on the vehicle target deceleration also includes: if the vehicle target deceleration is less than the second preset deceleration, making the mechanical braking parameter equal to a preset mechanical braking parameter; the preset mechanical braking parameter is a fixed value.

[0041] The preset electric braking parameter may take a value of 0, but this application does not limit this. It may be selected according to actual conditions, but its selected value should be small enough to enable the vehicle to recover as much braking energy as possible.

[0042] As an optional implementation, determining the electric braking torque and the mechanical braking torque based on the electric braking parameters and the mechanical braking parameters includes: determining the electric braking proportional coefficient and the mechanical braking proportional coefficient based on the electric braking parameters and the mechanical braking parameters; determining the electric braking torque and the mechanical braking torque based on the electric braking proportional coefficient and the mechanical braking proportional coefficient.

[0043] As an optional implementation, determining the electric braking proportional coefficient and the mechanical braking proportional coefficient based on the electric braking parameter and the mechanical braking parameter includes: setting the electric braking proportional coefficient to k3, setting the electric braking parameter to y1, setting the mechanical braking proportional coefficient to k4, mechanical braking parameter y2, k3=y1 / (y1+y2), k4=1-k1.

[0044] As an optional implementation, the method further includes: obtaining a locking state of the vehicle; if the vehicle is in a locked state, controlling the electric braking torque to be 0.

[0045] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0046] If the integrated units in the above embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in the above computer-readable storage medium. Based on this understanding, the technical solution of the present application, 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, which is stored in a storage medium and includes several instructions for enabling one or more electronic devices (such as personal computers, servers, or network devices) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0047] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0048] In the several embodiments provided in the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, 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 through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0049] 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 provided in this embodiment.

[0050] 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.

[0051] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0052] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A braking control method for a new energy commercial vehicle, characterized in that: include: Get the target deceleration of the vehicle; determining electric braking parameters and mechanical braking parameters according to the target deceleration of the vehicle; Determine the electric braking torque and the mechanical braking torque according to the electric braking parameter and the mechanical braking parameter; Controlling the vehicle to brake according to the electric braking torque and the mechanical braking torque; Wherein, determining the electric braking parameter and the mechanical braking parameter according to the target deceleration of the vehicle comprises: When the vehicle target deceleration is less than a first preset deceleration, calculating the electric brake parameter according to a first regression curve equation related to the vehicle target deceleration; When the vehicle target deceleration is greater than a second preset deceleration, the mechanical brake parameter is calculated according to a second regression curve equation related to the vehicle target deceleration.

2. The braking control method for a new energy commercial vehicle according to claim 1, characterized in that: Also includes: The vehicle target deceleration is set to a, the electric brake parameter is set to y1, and the first regression curve equation includes: Where k1 is a constant.

3. The braking control method for a new energy commercial vehicle according to claim 2, characterized in that: The value range of the first preset deceleration includes 3.5m / s2-5m / s2; The value range of k1 includes 1.1-1.6, and the value range of the vehicle target deceleration a includes: 0-5.

4. The braking control method for a new energy commercial vehicle according to claim 1, characterized in that: The determining of electric brake parameters and mechanical brake parameters according to the target deceleration of the vehicle further comprises: If the target deceleration of the vehicle is greater than a first preset deceleration, making the electric braking parameter equal to a preset electric braking parameter; The preset electric braking parameter is a fixed value.

5. The braking control method for a new energy commercial vehicle according to claim 1, characterized in that: The determining of electric brake parameters and mechanical brake parameters according to the target deceleration of the vehicle further comprises: If the target vehicle deceleration is less than the second preset deceleration, making the mechanical braking parameter equal to a preset mechanical braking parameter; The preset mechanical brake parameter is a fixed value.

6. The braking control method for a new energy commercial vehicle according to claim 5, characterized in that: Also includes: The vehicle target deceleration is set to a, the mechanical brake parameter is set to y2, and the second regression curve equation includes: Where k2 is a constant.

7. The braking control method for a new energy commercial vehicle according to claim 6, characterized in that: The value range of the vehicle target deceleration a includes: 0.2-8; Determine k2 according to the first preset deceleration; Alternatively, the value range of k2 includes 10-16.

8. The braking control method for a new energy commercial vehicle according to claim 1, characterized in that: Determining the electric braking torque and the mechanical braking torque according to the electric braking parameter and the mechanical braking parameter comprises: Determine an electric brake proportional coefficient and a mechanical brake proportional coefficient according to the electric brake parameter and the mechanical brake parameter; The electric braking torque and the mechanical braking torque are determined according to the electric braking proportional coefficient and the mechanical braking proportional coefficient.

9. The braking control method for a new energy commercial vehicle according to claim 8, characterized in that: Determining the electric braking proportional coefficient and the mechanical braking proportional coefficient according to the electric braking parameter and the mechanical braking parameter comprises: The electric brake proportional coefficient is set to k3, the electric brake parameter is set to y1, the mechanical brake proportional coefficient is set to k4, the mechanical brake parameter is y2, k3=y1 / (y1+y2), k4=1-k1.

10. The braking control method for a new energy commercial vehicle according to claim 1, characterized in that: Also includes: Get the vehicle locking status; If the vehicle is in a locked state, the electric braking torque is controlled to be 0.

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