Control method and system

Abstract

The invention discloses a control method and system, a main controller generates a synchronization field based on an expected bit rate, the main controller generates a data segment based on a first expected rotating speed, the main controller generates an LIN frame based on the synchronization field and the data segment, and the LIN frame comprises the synchronization field and the data segment; the sub-controller receives the LIN frame, and obtains a synchronization field and a data field based on the LIN frame; the sub-controller determines an actual bit rate based on the synchronization field; the sub-controller determines a deviation coefficient based on the actual bit rate and the expected bit rate, wherein the deviation coefficient is used for indicating the deviation of the actual bit rate relative to the expected bit rate; and the sub-controller determines a second expected rotating speed based on the data segment, corrects the second expected rotating speed based on the deviation coefficient to obtain a third expected rotating speed, and controls the electric pump based on the third expected rotating speed. The control precision of the electric pump can be improved.

Description

Technical Field

[0001] This application relates to the field of control technology, and particularly to a control method and system. Background Art

[0002] The control system of an electric pump includes a main controller and multiple electric pumps. The main controller uniformly issues control instructions to the multiple electric pumps. After receiving the control instructions, the electric pumps usually determine the rotation speed of the electric pumps according to the sub-controllers (Microcontroller, MCU) configured in themselves. The clock deviation of the main controller is less than 0.5%, and the clock deviation of the sub-controllers is generally within ±2%, and even the clock deviation reaches 4%. Therefore, there is a deviation between the clock of the main controller and the clock of the sub-controllers. Due to this deviation, there is also a deviation between the rotation speed expected by the main controller and the actual rotation speed of the electric pump. Therefore, there is a problem that the control accuracy of the system for the electric pump is not high. Summary of the Invention

[0003] This application provides a control method and system, which improves the control accuracy of the system for the electric pump. The technical solutions are as follows.

[0004] This application provides a control method for controlling an electric pump. The method includes a control system. The control system includes a main controller and a sub-controller. The main controller is connected to the sub-controller. The sub-controller is used to control the electric pump. The method further includes:

[0005] The main controller generates a synchronization field based on an expected bit rate, generates a data segment based on a first expected rotation speed, generates a LIN frame based on the synchronization field and the data segment. The LIN frame includes the synchronization field and the data segment;

[0006] The sub-controller receives the LIN frame and obtains the synchronization field and the data segment based on the LIN frame;

[0007] The sub-controller determines an actual bit rate based on the synchronization field;

[0008] The sub-controller determines a deviation coefficient based on the actual bit rate and the expected bit rate. The deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate;

[0009] The sub-controller determines a second expected rotation speed based on the data segment, corrects the second expected rotation speed based on the deviation coefficient to obtain a third expected rotation speed, and controls the electric pump based on the third expected rotation speed.

[0010] The present application also provides a control system, which includes a main controller and a sub - controller. The main controller is connected to the sub - controller, and the sub - controller is used to control an electric pump;

[0011] The main controller is used to generate a synchronization field based on an expected bit rate, generate a data segment based on a first expected rotational speed, and generate a LIN frame based on the synchronization field and the data segment. The LIN frame includes the synchronization field and the data segment;

[0012] The sub - controller is used to receive the LIN frame, obtain the synchronization field and the data segment based on the LIN frame; determine the actual bit rate based on the synchronization field; determine a deviation coefficient based on the actual bit rate and the expected bit rate, where the deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate; determine a second expected rotational speed based on the data segment, correct the second expected rotational speed based on the deviation coefficient to obtain a third expected rotational speed, and control the electric pump based on the third expected rotational speed.

[0013] Thus, the embodiments of the present application have the following beneficial effects:

[0014] In the control method and control system of this embodiment, the main controller generates a synchronization field based on an expected bit rate, the sub - controller determines the actual bit rate based on the synchronization field, then determines a deviation coefficient based on the actual bit rate and the expected bit rate, and corrects the rotational speed of the electric pump through the deviation coefficient, eliminating the interference of the clock deviation between the main controller and the sub - controller on the rotational speed of the electric pump, making the first expected rotational speed of the main controller consistent with the actual operating rotational speed of the electric pump, thereby improving the control accuracy of the system for the electric pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the format of a LIN frame provided by an embodiment of the present application;

[0016] Figure 2 is a schematic diagram of the format of a synchronization field provided by an embodiment of the present application;

[0017] Figure 3 is a flowchart of a control method provided by an embodiment of the present application;

[0018] Figure 4 shows a schematic diagram of the set of bit rates stored in the cache;

[0019] Figure 5 is a schematic structural diagram of a correction device for the rotational speed of an electric pump provided by an embodiment of the present application;

[0020] Figure 6 is a schematic structural diagram of an electric pump provided by an embodiment of the present application. Detailed Implementation Manner

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following will further describe the implementation manners of this application in detail with reference to the accompanying drawings.

[0022] The following explains some term concepts related to the embodiments of this application.

[0023] (1) Bit Rate

[0024] The bit rate is also known as the data transfer rate or bit rate. The bit rate refers to the number of bits transmitted per unit time. The bit rate is usually expressed as the number of bits transmitted per second.

[0025] (2) Local Interconnect Network (LIN)

[0026] Figure 1 This is a schematic diagram of the format of a LIN frame (Frame) provided by the embodiments of this application. As Figure 1 shown, the LIN frame includes two parts: a header and a response. The host is used to send the header; the slave is used to receive the header and parse the information contained in the header, and then the slave decides whether to send a response, receive a response, or make no reaction based on the information contained in the header.

[0027] The header includes a synchronization break field, a synchronization field, and a PID (Protected Identifier) segment. The response includes a data segment and a checksum segment. Among them, the value "0" is the dominant level, and the value "1" is the recessive level.

[0028] The synchronization break field includes a synchronization break and a synchronization break field delimiter. The synchronization break is at least 13 bits of dominant level (based on the host node rate). Since all intervals in the frame or when the bus is idle must maintain the recessive level, and other fields in the frame will not emit more than 9 bits of dominant level, the synchronization break can mark the start of a frame. Among them, when the slave receives the synchronization break field, it is based on the node rate of the slave. When 11 consecutive bits of dominant level are detected on the bus, it is considered the start of the frame.

[0029] The synchronization break field delimiter includes at least 1 bit of recessive level.

[0030] The first 6 bits of the protected ID field are used to carry the frame ID, and the last 2 bits of the protected ID field are used to carry parity bits. The 8-bit data composed of the 6-bit frame ID plus 2 parity bits is called the protected ID. The slave responds to the frame header based on the frame ID. If the protected ID is transmitted incorrectly, it will cause the LIN frame to fail to reach the destination correctly. Therefore, parity bits are introduced: P0 = (ID0 ^ ID1 ^ ID2 ^ ID4) & 0x01; P1 = (~(ID1 ^ ID3 ^ ID4 ^ ID5)) & 0x01. It can be seen that the PID will not be all 0 or all 1. Therefore, if the slave receives 0xFF or 0x00, the slave can determine that there is a transmission error.

[0031] The checksum field is used to check the transmitted content. For example, the calculation method of the checksum is that the sender performs binary addition with carry for each byte (subtract 255 whenever the result is greater than 256), and then takes the inverse of the obtained result; the receiver performs binary addition with carry for each received byte, and does not take the inverse of the result. This sum is added to the received checksum. If the result is 0xFF, the checksum is correct.

[0032] (3) Sync Byte Field

[0033] Appendix Figure 2 is a schematic diagram of the format of a sync byte field provided by an embodiment of the present application. Appendix Figure 2 The sync byte field shown is, for example, Figure 1 a specific example of the sync byte field in the LIN frame. The sync byte field includes 1 start bit (Start Bit, dominant), 8 data bits, and 1 stop bit (Stop Bit, recessive). The sync byte field has a standard Universal Asynchronous Receiver Transmitter (UART) data transmission format, as Figure 2 shown. The sync byte field has a format similar to a pulse signal.

[0034] Next, the application scenarios of the embodiments of the present application will be illustrated by examples.

[0035] The embodiments of the present application are applied to a control system. The control system includes a main controller and a sub-controller. The main controller is connected to the sub-controller, and the sub-controller is used to control an electric pump.

[0036] The control system is, for example, a vehicle system. The main controller acts as the host (also called the upper computer). The electric pump acts as the slave (also called the lower computer). Usually, the accuracy of the clock of the main controller is relatively high, while the electric pump usually uses a clock with a lower accuracy such as an on-chip oscillator, resulting in a deviation between the clock of the electric pump and the clock of the main controller, and further causing poor accuracy of the rotation speed of the electric pump.

[0037] Based on this, in some embodiments of the present application, the master controller generates a synchronization field based on an expected bit rate, the slave controller determines an actual bit rate based on the synchronization field, and then determines a deviation coefficient based on the actual bit rate and the expected bit rate. The rotation speed of the electric pump is corrected by the deviation coefficient, eliminating the interference of the clock deviation between the master controller and the slave controller on the rotation speed of the electric pump, making the first expected rotation speed of the master controller consistent with the actual rotation speed of the electric pump, thereby improving the control accuracy of the system for the electric pump.

[0038] In addition, it is possible to improve the control accuracy of the circuit architecture where the host and the electric pump are located without changing the hardware, that is, without increasing the hardware cost and reducing the deviation of the hardware.

[0039] There can be only one electric pump in the control system, or multiple electric pumps can be used. In some embodiments, the number of electric pumps in the control system is greater than or equal to three. In the case where there are multiple electric pumps in the vehicle system, the master controller and each electric pump respectively execute the Figure 3 method shown to correct the rotation speed of each electric pump. When the rotation speeds of the electric pumps are corrected, the rotation speeds of several electric pumps reach basic consistency, thereby reducing the rotation speed inconsistency caused by clock deviation.

[0040] The method flow of the embodiments of the present application will be exemplified below.

[0041] The Figure 3 is a flowchart of a control method provided by an embodiment of the present application. The method shown Figure 3 includes the following steps.

[0042] Step S310, the master controller generates a synchronization field based on an expected bit rate, the master controller generates a data segment based on a first expected rotation speed, and the master controller generates a LIN frame based on the synchronization field and the data segment. The LIN frame includes a synchronization field and a data segment. The master controller sends the LIN frame to the slave controller.

[0043] When the master controller successfully establishes a LIN communication connection with the electric pump, the master controller can send a LIN frame to the electric pump through the LIN communication connection so that the electric pump can identify the bit rate of the master controller through the synchronization field included in the LIN frame. The electric pump is, for example, a water pump or an oil pump.

[0044] Step S320, the slave controller receives the LIN frame and obtains the synchronization field and the data segment based on the LIN frame.

[0045] Step S330, the slave controller determines the actual bit rate based on the synchronization field.

[0046] In some embodiments, the sub - controller determines a set of bit rates based on a synchronization field, and the set of bit rates includes at least two bit rates; the sub - controller filters the set of bit rates to obtain the actual bit rate. For example, the sub - controller receives LIN frames from the master controller multiple times in a row to obtain a plurality of LIN frames; the sub - controller determines the bit rate of the master controller based on the synchronization field in each of the plurality of LIN frames respectively to obtain the set of bit rates.

[0047] In some embodiments, the sub - controller intercepts the synchronization field to obtain a data segment; the sub - controller counts the data segment to obtain the number of transmitted bits, and the sub - controller times the data segment to obtain the transmission time; the sub - controller determines the bit rate based on the number of transmitted bits and the transmission time. Exemplarily, the sub - controller determines the falling - edge moment of the start bit in the synchronization field and the falling - edge moment of the 7th bit in the synchronization field. The sub - controller determines the bit rate based on the falling - edge moment of the start bit in the synchronization field, the falling - edge moment of the 7th bit in the synchronization field, and the number of bits between the start bit and the 7th bit. The bit rate is positively correlated with the number of transmitted bits and negatively correlated with the transmission time.

[0048] The bit rate refers to the time taken to transmit 1 bit. Exemplarily, the sub - controller determines the bit rate An of the master controller based on the following formula 1.

[0049] Bit rate An=(Falling - edge moment of the 7th bit - Falling - edge moment of the start bit) / 8; Formula 1

[0050] Wherein, the falling edge is the judgment flag of the synchronization segment. The function of the start bit is to coordinate synchronization. When the receiving device detects this logical low level of the start bit, the receiving device starts to prepare for the subsequent data - bit signals. The stop bit is used to mark the completion of the transmission of a piece of data.

[0051] For example, please refer to the appendix Figure 4 , the appendix Figure 4 shows a schematic diagram of the set of bit rates saved in the cache. In the appendix Figure 4 , the capital letter A represents the bit rate. The A1, A2... A8 shown in the appendix Figure 4 are equivalent to the bit rates determined continuously 8 times. A1 is the bit rate determined for the first time, A2 is the bit rate determined for the second time, and so on. A8 is the bit rate determined for the eighth time.

[0052] In some embodiments, the sub - controller filters the set of bit rates to obtain the actual bit rate, including: the sub - controller sorts the set of bit rates in ascending order to obtain a bit - rate sequence, and the bit - rate sequence includes the 1st bit rate, the 2nd bit rate,... the nth bit rate; the sub - controller truncates the bit - rate sequence to obtain a truncated sequence; the sub - controller takes the mean of the truncated sequence as the actual bit rate.

[0053] In some embodiments, the sub - controller sets to zero the first original bit rate and the nth original bit rate in the bit rate sequence, and uses the bit rate sequence with the first original bit rate and the nth original bit rate set to zero as the truncated sequence.

[0054] In some embodiments, the sub - controller determines the maximum bit rate and the minimum bit rate in the bit rate set; the sub - controller filters out the maximum bit rate and the minimum bit rate from the bit rate set; the sub - controller determines the average value of the filtered multiple bit rates as the actual bit rate. Average filtering is equivalent to the process of truncating and finding the mean. The maximum bit rate and the minimum bit rate are filtered out before determining the average value. Considering that the maximum bit rate and the minimum bit rate are points with a relatively high probability of error, filtering out the maximum bit rate and the minimum bit rate can reduce the influence of the maximum bit rate and the minimum bit rate on the overall average value, making the final actual bit rate more accurate.

[0055] Exemplarily, the sub - controller compares the 8 bit rates stored in the bit rate set, obtains the maximum bit rate Amax among the 8 bit rates and the minimum bit rate Amin among the 8 bit rates, and the sub - controller obtains the actual bit rate through Formula 2.

[0056] Rate A=(A1 + A2+A3 + A4+A5 + A6+A7 + A8 - Amin - Amax) / 6; Formula 2

[0057] The deviation coefficient is used to indicate the deviation between the bit rate of the main controller and the bit rate of the electric pump.

[0058] Step S340, the sub - controller determines the deviation coefficient based on the actual bit rate and the expected bit rate, and the deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate.

[0059] In some embodiments, the deviation coefficient includes a proportionality coefficient. The sub - controller divides the actual bit rate by the expected bit rate to obtain the proportionality coefficient. For example, the proportionality coefficient is determined by the following Formula 3.

[0060] Proportionality coefficient C = actual bit rate A / expected bit rate B; Formula 3

[0061] The proportionality coefficient is used to indicate the relative difference in bit rates between the electric pump and the main controller. The proportionality coefficient can be used to evaluate the clock deviation of the message under the LIN communication protocol.

[0062] In some other embodiments, the sub - controller determines the difference between the actual bit rate and the expected bit rate as the deviation coefficient.

[0063] Step S350: The sub-controller determines a second expected rotational speed based on the data segment, and the sub-controller corrects the second expected rotational speed based on a deviation coefficient to obtain a third expected rotational speed.

[0064] Step S360: The sub-controller controls the electric pump based on the third expected rotational speed.

[0065] For example, in the case where the deviation coefficient is the ratio between the actual bit rate and the expected bit rate, the sub-controller determines the product of the second expected rotational speed and the deviation coefficient to obtain the third expected rotational speed. Also, for example, in the case where the deviation coefficient is the difference between the actual bit rate and the expected bit rate, the sub-controller determines the sum of the second expected rotational speed and the deviation coefficient to obtain the third expected rotational speed.

[0066] Exemplarily, when the sub-controller receives the second expected rotational speed Speed_A, the sub-controller corrects the second expected rotational speed Speed_A according to Formula 4 to obtain the third expected rotational speed Speed_B. The sub-controller controls the operation of the electric pump at the rotational speed of the third expected rotational speed Speed_B.

[0067] The third expected rotational speed Speed_B = the second expected rotational speed Speed_A * proportionality coefficient C; Formula 4

[0068] In some embodiments, the sub-controller compares the ratio of the actual bit rate and the expected bit rate with a threshold range to obtain a comparison result; in response to the comparison result indicating that the ratio of the actual bit rate and the expected bit rate does not exceed the threshold, the sub-controller uses the ratio of the actual bit rate and the expected bit rate as the deviation coefficient.

[0069] In other embodiments, in response to the comparison result indicating that the ratio of the actual bit rate and the expected bit rate exceeds the threshold, the sub-controller does not use the ratio of the actual bit rate and the expected bit rate as the deviation coefficient and determines that the LIN frame is in an abnormal state.

[0070] For example, the deviation coefficient is the proportionality coefficient C, and the threshold range is ±4%. The sub-controller compares the proportionality coefficient C with the threshold range of ±4%. If the proportionality coefficient C is greater than the range of ±4%, the sub-controller determines that there is an abnormality in the LIN frame and does not need to execute using the ratio of the actual bit rate and the expected bit rate as the deviation coefficient. If the proportionality coefficient C is within the range of ±4%, the sub-controller uses the ratio of the actual bit rate and the expected bit rate as the deviation coefficient.

[0071] In the method provided in this embodiment, in the scenario of LIN communication between the slave controller and the master controller in the control system, the slave controller obtains the bit rate of the master controller based on the synchronization field of the LIN frame from the master controller, and the slave controller corrects the rotational speed of the slave controller by referring to the bit rate of the master controller. Therefore, without the need to replace the existing MCU or add an additional crystal oscillator, the accuracy of the rotational speed of the slave controller can be improved, and the additional cost expenditure caused by replacing the hardware to increase the rotational speed of the slave controller can be reduced.

[0072] In addition, since each slave controller corrects its rotational speed through the master controller, the inconsistency in performance caused by the chip differences of each slave controller is also avoided.

[0073] Figure 5 FIG. 7 is a schematic structural diagram of a correction device 500 for the rotational speed of an electric pump provided by an embodiment of the present application, which is provided in a slave controller in a control system. The device 500 includes:

[0074] A receiving unit 510, configured to receive the LIN frame, and obtain the synchronization field and the data segment based on the LIN frame;

[0075] A determining unit 520, configured to determine the actual bit rate based on the synchronization field; determine a deviation coefficient based on the actual bit rate and the expected bit rate, where the deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate, and determine a second expected rotational speed based on the data segment;

[0076] A correcting unit 530, configured to correct the second expected rotational speed based on the deviation coefficient to obtain a third expected rotational speed, and the slave controller controls the electric pump based on the third expected rotational speed.

[0077] In some embodiments, the determining unit 520 is configured to determine a set of bit rates based on the synchronization field, where the set of bit rates includes at least two bit rates; filter the set of bit rates to obtain the actual bit rate.

[0078] In some embodiments, the determining unit 520 is configured to sort the set of bit rates in ascending order to obtain a bit rate sequence, where the bit rate sequence includes a first bit rate, a second bit rate,... an nth bit rate; truncate the bit rate sequence to obtain a truncated sequence; and use the mean value of the truncated sequence as the actual bit rate.

[0079] In some embodiments, the determining unit 520 is configured to set the first original bit rate and the nth original bit rate in the bit rate sequence to zero, and use the bit rate sequence with the first original bit rate and the nth original bit rate set to zero as the truncated sequence.

[0080] In some embodiments, a determining unit 520 is configured to intercept the synchronization field to obtain a data segment; count the data segment to obtain the number of transmitted bits, and the sub - controller times the data segment to obtain the transmission time; determine the bit rate based on the number of transmitted bits and the transmission time.

[0081] In some embodiments, a determining unit 520 is configured to compare the ratio of the actual bit rate to the expected bit rate with a threshold range to obtain a comparison result; in response to the comparison result indicating that the ratio of the actual bit rate to the expected bit rate does not exceed the threshold, use the ratio of the actual bit rate to the expected bit rate as the deviation coefficient.

[0082] In some embodiments, a determining unit 520 is configured to, in response to the comparison result indicating that the ratio of the actual bit rate to the expected bit rate exceeds the threshold, not use the ratio of the actual bit rate to the expected bit rate as the deviation coefficient and determine that the LIN frame is in an abnormal state.

[0083] Figure 6 FIG. 11 is a schematic structural diagram of an electric pump 600 provided by an embodiment of the present application. The electric pump 600 includes an MCU 610, the MCU 610 is coupled to a memory 620, and at least one computer program instruction is stored in the memory 620. The at least one computer program instruction is loaded and executed by the MCU 610 to control the rotation speed of the electric pump.

[0084] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

[0085] A referring to B means that A is the same as B or A is a simple deformation of B.

[0086] In the description of the embodiments of the present application, terms such as "first" and "second" in the specification and claims are used to distinguish different objects, rather than to describe a specific order of the objects, nor can they be understood as indicating or implying relative importance. For example, the first bit rate and the second bit rate are used to distinguish different bit rates, rather than to describe a specific order of the bit rates, nor can it be understood that the first bit rate is more important than the second bit rate.

[0087] In the embodiments of the present application, unless otherwise specified, the meaning of "at least one" is one or more, and the meaning of "a plurality" is two or more. For example, a plurality of bit rates means two or more bit rates.

[0088] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are 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. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (such as coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)).

[0089] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method for controlling an electric pump, characterized in that, The method includes a control system, the control system includes a main controller and a sub - controller, the main controller is connected to the sub - controller, and the sub - controller is used to control an electric pump. The method further includes: The main controller generates a synchronization field based on an expected bit rate, the main controller generates a data segment based on a first expected rotational speed, the main controller generates a LIN frame based on the synchronization field and the data segment, and the LIN frame includes the synchronization field and the data segment; The sub - controller receives the LIN frame and obtains the synchronization field and the data segment based on the LIN frame; The sub - controller determines an actual bit rate based on the synchronization field; The sub - controller determines a deviation coefficient based on the actual bit rate and the expected bit rate, and the deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate; The sub - controller determines a second expected rotational speed based on the data segment, the sub - controller corrects the second expected rotational speed based on the deviation coefficient to obtain a third expected rotational speed, and the sub - controller controls the electric pump based on the third expected rotational speed.

2. The method according to claim 1, characterized in that, The sub - controller determines an actual bit rate based on the synchronization field, including: The sub - controller determines a set of bit rates based on the synchronization field, and the set of bit rates includes at least two bit rates; The sub - controller filters the set of bit rates to obtain the actual bit rate.

3. The method according to claim 2, characterized in that, The sub - controller filters the set of bit rates to obtain the actual bit rate, including: The sub - controller sorts the set of bit rates in ascending order to obtain a bit rate sequence, and the bit rate sequence includes the 1st bit rate, the 2nd bit rate, … the nth bit rate; The sub - controller truncates the bit rate sequence to obtain a truncated sequence; The sub - controller takes the mean of the truncated sequence as the actual bit rate.

4. The method according to claim 3, characterized in that The sub - controller truncates the bit rate sequence to obtain a truncated sequence, including: The sub - controller sets the 1st original bit rate and the nth original bit rate in the bit rate sequence to zero, and takes the bit rate sequence with the 1st original bit rate and the nth original bit rate set to zero as the truncated sequence.

5. The method according to any one of claims 2 to 4, characterized in that The sub - controller determines a set of bit rates based on the synchronization field, and the set of bit rates includes at least two bit rates, including: The sub - controller intercepts the synchronization field to obtain a data fragment; The sub - controller counts the data fragment to obtain the number of transmitted bits, and the sub - controller measures the time of the data fragment to obtain the transmission time; The sub - controller determines the bit rate based on the number of transmitted bits and the transmission time.

6. The method according to claim 1, wherein The sub - controller obtains a deviation coefficient based on the actual bit rate and the expected bit rate, including: The sub - controller compares the ratio of the actual bit rate to the expected bit rate with a threshold range to obtain a comparison result; In response to the comparison result indicating that the ratio of the actual bit rate to the expected bit rate does not exceed the threshold, the sub - controller takes the ratio of the actual bit rate to the expected bit rate as the deviation coefficient.

7. The method according to claim 6, wherein After the sub - controller compares the ratio of the actual bit rate and the expected bit rate with a threshold range and obtains a comparison result, the method further includes: In response to the comparison result indicating that the ratio of the actual bit rate and the expected bit rate exceeds the threshold, the sub - controller does not use the ratio of the actual bit rate and the expected bit rate as the deviation coefficient and determines that the LIN frame is in an abnormal state.

8. A control system, characterized in that, The control system includes a main controller and a sub - controller. The main controller is connected to the sub - controller, and the sub - controller is used to control an electric pump; The main controller is used to generate a synchronization field based on an expected bit rate, generate a data segment based on a first expected rotational speed, and generate a LIN frame based on the synchronization field and the data segment. The LIN frame includes the synchronization field and the data segment; The sub - controller is used to receive the LIN frame, obtain the synchronization field and the data segment based on the LIN frame; determine the actual bit rate based on the synchronization field; Determine a deviation coefficient based on the actual bit rate and the expected bit rate. The deviation coefficient is used to indicate the deviation of the actual bit rate relative to the expected bit rate; determine a second expected rotational speed based on the data segment, correct the second expected rotational speed based on the deviation coefficient to obtain a third expected rotational speed, and control the electric pump based on the third expected rotational speed.

9. The system according to claim 8, wherein The sub - controller is used to determine a set of bit rates based on the synchronization field. The set of bit rates includes at least two bit rates; filter the set of bit rates to obtain the actual bit rate.

10. The system according to claim 9, wherein, The sub - controller is used to sort the set of bit rates in ascending order to obtain a bit rate sequence. The bit rate sequence includes a first bit rate, a second bit rate, …, an nth bit rate; truncate the bit rate sequence to obtain a truncated sequence; use the mean of the truncated sequence as the actual bit rate.

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