An Electric Motor Braking Torque Calculation Method and System for an Intelligent Connected Bus

Abstract

The present invention proposes a method and system for calculating the braking torque of the motor of an intelligent connected bus, which relates to the field of automobile control technology. The method comprises: fuzzy processing of the brake pedal opening obtained after activation of the whole vehicle controller; calculating the braking coefficient and the optimal value of the motor speed according to the brake pedal opening after fuzzy processing; real-time acquisition of the vehicle motor speed to determine the hysteresis state of the braking torque; and calculating the final motor braking torque based on the hysteresis state, the braking coefficient and the optimal value of the motor speed. The present invention fuzzily processes the brake pedal opening value, calculates the optimal value of the motor speed, and adds a motor torque exit hysteresis strategy to calculate the motor braking torque in real time and control the motor of the whole vehicle, thereby avoiding motor jitter problems caused by abnormal brake pedal opening or motor speed during braking, and improving energy saving and comfort of the whole vehicle.

Description

Technical Field

[0001] The present invention belongs to the field of automobile control technology, and in particular relates to a method and system for calculating the braking torque of a motor of an intelligent networked bus. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the intensification of market competition, the energy-saving and comfort features of products have gradually become the direction of research and development of intelligent connected electric bus technology. Energy recovery is one of the important ways to save energy in intelligent connected pure electric buses. How to accurately control the motor braking torque to ensure optimal energy recovery of the entire vehicle while improving the comfort of the vehicle has become one of the key technologies of current intelligent connected vehicles.

[0004] Most of the currently disclosed methods for calculating the braking torque of intelligent connected vehicles calculate the motor braking torque by collecting the brake pedal opening and motor speed. However, the problem is that when the brake pedal opening or motor speed fluctuates, the braking torque will fluctuate, thereby exacerbating motor vibration and affecting the energy consumption and driving comfort of the entire vehicle. Although the control strategy has been improved in the existing braking torque control scheme, there are still problems with low energy saving and comfort. Summary of the Invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a method and system for calculating the motor braking torque of an intelligent connected bus. By fuzzy processing the brake pedal opening value, calculating the optimal value of the motor speed, and adding a motor torque exit hysteresis loop strategy, the motor braking torque is controlled in real time to avoid motor jitter caused by abnormal brake pedal opening or motor speed during braking, thereby improving the energy saving and comfort of the entire vehicle.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] A first aspect of the present invention provides a method for calculating the braking torque of a motor of an intelligent connected bus;

[0008] A method for calculating the braking torque of a motor of an intelligent connected bus, comprising:

[0009] Perform fuzzy processing on the brake pedal opening obtained after the vehicle controller is activated;

[0010] Calculate the optimal values of the braking coefficient and motor speed based on the brake pedal opening after fuzzy processing;

[0011] Collect vehicle motor speed in real time to determine the hysteresis state of braking torque;

[0012] The final motor braking torque is calculated based on the hysteresis state, braking coefficient and optimal motor speed.

[0013] Furthermore, the specific steps of the fuzzy processing are:

[0014] After the vehicle controller is activated, the brake pedal opening is obtained through a hard-wired signal;

[0015] Filtering the brake pedal opening;

[0016] The filtered brake pedal opening is fuzzy processed.

[0017] Furthermore, the calculation method of the braking coefficient is:

[0018] If the brake pedal opening is less than 5%, it is set to empty travel and the braking coefficient is 0;

[0019] If the brake pedal opening is between 5% and 30%, the braking coefficient is calculated based on the proportional relationship;

[0020] If the brake pedal opening is above 30%, the braking coefficient is set to 100%.

[0021] Furthermore, the calculation method of the optimal value of the motor speed is:

[0022] If the brake pedal opening is less than 5%, the vehicle is considered to be in a non-braking state, and the optimal motor speed is the actual motor speed;

[0023] If the brake pedal opening is greater than 5%, the vehicle is considered to be in a braking state, and the optimal value of the motor speed is set based on the real-time comparison result between the motor reference speed and the actual motor speed.

[0024] Furthermore, when the brake pedal opening is greater than 5%, the vehicle enters the braking state. The motor speed immediately before the braking state is set as the motor reference speed. The motor reference speed is compared with the current actual motor speed in real time:

[0025] (1) If the motor reference speed is less than the actual motor speed, the motor reference speed remains unchanged;

[0026] If the motor reference speed is greater than the actual motor speed, the motor reference speed value is updated to the current actual motor speed;

[0027] (2) The optimal value of the motor speed is the motor reference speed.

[0028] Furthermore, the method for determining the hysteresis state is:

[0029] The motor speed is lower than 150 rpm, the hysteresis state flag is 1, and the motor is not allowed to have braking torque;

[0030] When the motor speed is higher than 400 rms, the hysteresis state flag is 0, allowing the motor to have braking torque;

[0031] When the motor speed is higher than 150 rpm and lower than 400 rms, the hysteresis state flag remains at the previous value.

[0032] Furthermore, the final motor braking torque is calculated as follows:

[0033] If the hysteresis state flag is 1, the motor braking torque requested by the vehicle controller is 0;

[0034] If the hysteresis state flag is equal to 0, then the braking coefficient K and the optimal value of the motor speed N rpm And the maximum braking torque allowed by the motor at different motor speeds is obtained.

[0035] A second aspect of the present invention provides a system for calculating the braking torque of a motor of an intelligent connected bus.

[0036] An intelligent network-connected bus motor braking torque calculation system includes a fuzzy processing module, a parameter calculation module, a state judgment module and a torque calculation module:

[0037] The fuzzy processing module is configured to: perform fuzzy processing on the brake pedal opening obtained after the vehicle controller is activated;

[0038] The parameter calculation module is configured to calculate the optimal value of the braking coefficient and the motor speed according to the brake pedal opening after fuzzy processing;

[0039] The state judgment module is configured to: collect the vehicle motor speed in real time and judge the hysteresis state of the braking torque;

[0040] The torque calculation module is configured to calculate a final motor braking torque based on a hysteresis state, a braking coefficient, and an optimal value of the motor speed.

[0041] A third aspect of the present invention provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of a method for calculating the braking torque of a motor of an intelligent connected bus as described in the first aspect of the present invention.

[0042] The fourth aspect of the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and runnable on the processor. When the processor executes the program, it implements the steps in the method for calculating the braking torque of the motor of an intelligent connected bus as described in the first aspect of the present invention.

[0043] One or more of the above technical solutions have the following beneficial effects:

[0044] The present invention provides a method and system for calculating the braking torque of the motor of an intelligent connected bus. The method performs fuzzy processing on the brake pedal opening value, calculates the optimal value of the motor speed, and adds a motor torque exit hysteresis loop strategy to calculate the motor braking torque in real time and control the motor of the entire vehicle. This avoids motor jitter caused by abnormal brake pedal opening or motor speed during braking, improves the energy saving and comfort of the entire vehicle, and reduces vehicle energy consumption.

[0045] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0047] Figure 1 This is a flow chart of the method of the first embodiment.

[0048] Figure 2 This is a system structure diagram of the second embodiment. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0050] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention; unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0051] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0052] Example 1

[0053] This embodiment discloses a method for calculating the braking torque of a motor of an intelligent connected bus;

[0054] like Figure 1 As shown, a method for calculating the braking torque of a motor of an intelligent connected bus includes:

[0055] Step S1: fuzzy processing is performed on the brake pedal opening obtained after the vehicle controller is activated;

[0056] After the vehicle controller is activated, the brake pedal opening P1 is obtained through the hard-wired signal, and then the brake pedal opening is filtered to obtain the brake pedal opening P2. The calculation formula is as follows:

[0057] P2=0.5×P2(n-1)+0.5×P1(n)

[0058] Among them, P2(n-1) is the brake pedal opening calculated at the previous moment, and P1(n) is the brake pedal opening collected at this moment.

[0059] The filtered brake pedal opening P2 is fuzzy processed to become an integer multiple of 5, and the opening values that are not integer multiples of 5 are discarded to avoid motor torque fluctuations caused by frequent changes in the brake pedal opening. The calculation formula is as follows:

[0060]

[0061] Among them, the uint8 function is a rounding function, and P3 is the brake pedal opening after fuzzy processing, which is an integer multiple of 5.

[0062] Step S2: Calculate the optimal values of the braking coefficient and motor speed based on the brake pedal opening after fuzzy processing;

[0063] The vehicle controller calculates the corresponding braking coefficient K based on the fuzzy processed brake pedal opening P3. To avoid excessive sensitivity of the brake pedal opening, which affects the normal driving of the vehicle, the specific calculation is:

[0064] If the brake pedal opening is less than 5%, it is set to empty travel and the braking coefficient K is 0;

[0065] To improve vehicle braking comfort, before the vehicle's air brake is engaged, the braking coefficient is calculated according to a linear proportional relationship. That is, the braking coefficient is obtained according to the proportional relationship when the brake pedal opening is between 5% and 30%.

[0066] To increase the proportion of motor regenerative energy and reduce vehicle energy consumption, the braking coefficient is maximized after the air brake is engaged. That is, when the pedal opening is higher than 30%, the braking coefficient is set to 100%.

[0067] The setting logic of the above braking coefficient K is shown in the formula:

[0068]

[0069] Among them, P3 is the brake pedal opening after fuzzy processing.

[0070] The calculation of the optimal value of the motor speed is that the vehicle controller determines whether the vehicle is in a braking state through the vehicle brake pedal opening value P3, and sets the optimal value of the motor speed according to the braking state. Specifically:

[0071] If the brake pedal opening is less than 5%, the vehicle is considered to be in a non-braking state, and the optimal motor speed value N rpm is the actual motor speed N0;

[0072] If the brake pedal opening is greater than 5%, the vehicle is considered to be in a braking state. At this time, the motor speed just before the braking state is set to the reference speed N. s , when the vehicle is in braking state, the real-time comparison of the reference speed N s The actual motor speed N0 is the same as the current one. If N s Less than N0, then the reference speed N s Remain unchanged, if N s If it is greater than N0, the reference speed N s The value is updated to the current motor speed value; the optimal motor speed value N rpm =N s .

[0073] Step S3: collecting the vehicle motor speed in real time to determine the hysteresis state of the braking torque;

[0074] To prevent the vehicle from reversing due to the motor braking torque still existing when the vehicle's braking motor speed drops to zero, the corresponding motor speed decreases and the braking torque requested by the vehicle also decreases accordingly. The motor speed is set to 150rpm as the braking torque exit threshold; if the motor speed is higher than 150rm, there will be motor braking torque during braking, and if the motor speed is lower than 150rm, the motor braking torque is zero.

[0075] In order to avoid frequent changes in the motor braking torque near the braking torque exit threshold of 150rpm, the braking torque hysteresis state fl ag judgment is added.

[0076] If the motor speed is lower than 150 rpm, the hysteresis state flag is 1, and the motor is not allowed to have braking torque;

[0077] If the motor speed is higher than 400rm, the hysteresis state flag is 0, allowing the motor to have braking torque;

[0078] If the motor speed is higher than 150rpm and lower than 400rm, the hysteresis state flag remains at the value of the previous moment.

[0079] Step S4: Calculate the final motor braking torque based on the hysteresis state, the braking coefficient and the optimal value of the motor speed.

[0080] If the hysteresis state flag is 1, the final motor braking torque T requested by the vehicle controller is 0;

[0081] If the hysteresis state flag is equal to 0, then the braking coefficient K and the optimal value of the motor speed N rpm And the maximum braking torque allowed by the motor at different motor speeds is obtained, specifically:

[0082] First, according to the optimal value N of the motor speed rpm Look up the table to obtain the maximum braking torque T allowed by the motor at the current speed value max , and then multiply it by the braking coefficient K to calculate the final motor braking request torque T. The specific formula is as follows:

[0083]

[0084] Example 2

[0085] This embodiment discloses a system for calculating the braking torque of a motor of an intelligent connected bus;

[0086] like Figure 2 As shown, a motor braking torque calculation system for intelligent connected buses includes a fuzzy processing module, a parameter calculation module, a state judgment module, and a torque calculation module:

[0087] The fuzzy processing module is configured to: perform fuzzy processing on the brake pedal opening obtained after the vehicle controller is activated;

[0088] The parameter calculation module is configured to calculate the optimal value of the braking coefficient and the motor speed according to the brake pedal opening after fuzzy processing;

[0089] The state judgment module is configured to: collect the vehicle motor speed in real time and judge the hysteresis state of the braking torque;

[0090] The torque calculation module is configured to calculate a final motor braking torque based on a hysteresis state, a braking coefficient, and an optimal value of the motor speed.

[0091] Example 3

[0092] The purpose of this embodiment is to provide a computer-readable storage medium.

[0093] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in a method for calculating the braking torque of a motor of an intelligent connected bus as described in Example 1 of the present disclosure.

[0094] Example 4

[0095] The purpose of this embodiment is to provide an electronic device.

[0096] An electronic device includes a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for calculating the braking torque of a motor of an intelligent connected bus as described in Example 1 of the present disclosure are implemented.

[0097] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for calculating the braking torque of an intelligent connected bus motor, characterized in that: include: Perform fuzzy processing on the brake pedal opening obtained after the vehicle controller is activated; According to the brake pedal opening after fuzzy processing, the braking coefficient and the optimal value of the motor speed are calculated. The calculation method of the optimal value of the motor speed is: If the brake pedal opening is less than 5%, the vehicle is considered to be in a non-braking state, and the optimal motor speed is the actual motor speed; If the brake pedal opening is greater than 5%, the vehicle is considered to be in the braking state. The optimal motor speed value is set based on the real-time comparison between the motor reference speed and the actual motor speed. Specifically, the motor speed immediately before entering the braking state is set as the motor reference speed, and the motor reference speed is compared with the current actual motor speed in real time: (1) If the motor reference speed is less than the actual motor speed, the motor reference speed remains unchanged; If the motor reference speed is greater than the actual motor speed, the motor reference speed value is updated to the current actual motor speed; (2) The optimal value of the motor speed is the motor reference speed; Collect vehicle motor speed in real time to determine the hysteresis state of braking torque; The final motor braking torque is calculated based on the hysteresis state, braking coefficient and optimal motor speed.

2. The method for calculating the braking torque of a motor of an intelligent connected bus according to claim 1, wherein: The specific steps of the fuzzy processing are: After the vehicle controller is activated, the brake pedal opening is obtained through a hard-wired signal; Filtering the brake pedal opening; The filtered brake pedal opening is fuzzy processed.

3. The method for calculating the braking torque of a motor of an intelligent connected bus according to claim 1, wherein: The calculation method of the braking coefficient is: If the brake pedal opening is less than 5%, it is set to empty travel and the braking coefficient is 0; If the brake pedal opening is between 5% and 30%, the braking coefficient is calculated based on the proportional relationship; If the brake pedal opening is above 30%, the braking coefficient is set to 100%.

4. The method for calculating the braking torque of a motor of an intelligent connected bus according to claim 1, wherein: The method for judging the hysteresis state is: The motor speed is lower than 150 rpm, the hysteresis state flag is 1, and the motor is not allowed to have braking torque; When the motor speed is higher than 400 rms, the hysteresis state flag is 0, allowing the motor to have braking torque; When the motor speed is higher than 150 rpm and lower than 400 rms, the hysteresis state flag remains at the previous value.

5. The method for calculating the braking torque of a motor of an intelligent connected bus according to claim 1, wherein: The calculation method of the final motor braking torque is: If the hysteresis state flag is 1, the motor braking torque requested by the vehicle controller is 0; If the hysteresis state flag is equal to 0, then the braking coefficient , optimal motor speed And the maximum braking torque allowed by the motor at different motor speeds is obtained.

6. A system for calculating the motor braking torque of an intelligent connected bus, characterized in that: Including fuzzy processing module, parameter calculation module, state judgment module and torque calculation module: The fuzzy processing module is configured to: perform fuzzy processing on the brake pedal opening obtained after the vehicle controller is activated; The parameter calculation module is configured to calculate the braking coefficient and the optimal value of the motor speed according to the brake pedal opening after fuzzy processing. The calculation method of the optimal value of the motor speed is: If the brake pedal opening is less than 5%, the vehicle is considered to be in a non-braking state, and the optimal motor speed is the actual motor speed; If the brake pedal opening is greater than 5%, the vehicle is considered to be in the braking state. The optimal motor speed value is set based on the real-time comparison between the motor reference speed and the actual motor speed. Specifically, the motor speed immediately before entering the braking state is set as the motor reference speed, and the motor reference speed is compared with the current actual motor speed in real time: (1) If the motor reference speed is less than the actual motor speed, the motor reference speed remains unchanged; If the motor reference speed is greater than the actual motor speed, the motor reference speed value is updated to the current actual motor speed; (2) The optimal value of the motor speed is the motor reference speed; The state judgment module is configured to: collect the vehicle motor speed in real time and judge the hysteresis state of the braking torque; The torque calculation module is configured to calculate a final motor braking torque based on a hysteresis state, a braking coefficient, and an optimal value of the motor speed.

7. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for calculating the braking torque of a motor of an intelligent connected bus as described in any one of claims 1 to 5 are implemented.

8. An electronic device comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps in the method for calculating the braking torque of a motor of an intelligent connected bus as described in any one of claims 1 to 5 are implemented.

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