Control system and control method for maximum speed limit of pure electric bus

Abstract

The invention provides a control system and a control method for the maximum speed limit of a pure electric bus, relates to the technical field of vehicle control, and aims to solve the problems that the speed limit of an existing pure electric bus is generally changed by flashing a speed limit device program on site, the service cost is too high, and the speed limit process is large in speed fluctuation even if instrument adjustment is adopted. Therefore, the working difficulty of the driver is increased, and the comfort of the passenger car is influenced. The system comprises an instrument and a speed limiting device, the speed limiting device comprises a vehicle control unit, the maximum limit vehicle speed value is changed through an instrument interface, the instrument sends the maximum limit vehicle speed value to the vehicle control unit through a CAN bus, the vehicle control unit responds to a maximum limit vehicle speed request sent by the instrument according to a judgment strategy, and the actual maximum limit vehicle speed is obtained. According to the invention, the service cost is reduced, the pure electric bus is enabled to adapt to different operation highest speed limit environments, and meanwhile, stable operation of the pure electric bus in different operation environments is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle control, and in particular relates to a control system and a control method for a maximum speed limit of a pure electric 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 vigorous development of new energy vehicles, pure electric buses, as a new energy vehicle, have the advantages of energy saving, environmental protection, low noise, etc., and are gradually applied to urban transportation. Since pure electric buses have been put into use for a short time, they face many technical challenges.

[0004] Since pure electric buses need to operate in different operating environments, the requirements for the maximum speed limit are different. When encountering different working scenarios and different road environments, different maximum speed limits need to be selected to meet the needs of the vehicle. At present, the speed limit device of pure electric buses is generally the vehicle controller, and the maximum speed limit is changed by flashing the speed limit device program. For example, pure electric buses exported overseas change the speed limit by flashing on site, which is relatively high in economic and time costs. At the same time, program changes take time, which increases service costs.

[0005] In addition, although there is a method of adjusting the maximum speed limit through an instrument, such as patent CN 118617995A vehicle speed limit setting method, system, computer equipment, storage medium and vehicle, a maximum speed limit value is obtained, but the response strategy of the vehicle controller is not considered. The vehicle speed fluctuates greatly during the speed limit process and it is difficult to maintain it within an accurate range, which increases the difficulty of the driver's work and affects the comfort of the bus. At the same time, each adjustment directly replaces the previous maximum speed limit. When running to the previous working scene again, it is necessary to make judgments and adjustments again, which increases the time cost. The method of adjusting the maximum speed limit cannot meet the stable operation of pure electric buses in different operating environments. Summary of the invention

[0006] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a control system and control method for the maximum speed limit of a pure electric bus. The maximum speed limit is adjusted by an instrument, and the adjusted maximum speed limit is sent to the vehicle controller; the vehicle controller parses the maximum speed limit message, and according to the response strategy, sends the adjusted maximum speed limit to the instrument, and the instrument parses the maximum speed limit responded by the vehicle controller for display and storage, so that the pure electric bus can be kept within an accurate range during the speed limit process, reducing service costs, reducing the difficulty of the driver's work, and improving the stability and comfort of bus operation.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0008] In a first aspect, a control system for a maximum speed limit of a pure electric bus is disclosed, comprising:

[0009] Instruments and speed limiting devices;

[0010] The speed limiting device includes a vehicle controller;

[0011] The instrument receives the set maximum speed limit and sends a maximum speed limit request to the vehicle controller;

[0012] The vehicle controller obtains an actual maximum vehicle speed limit response based on a judgment strategy for the maximum vehicle speed limit request;

[0013] Among them, the judgment strategy of the vehicle controller is:

[0014] The vehicle controller sets a fixed value of the upper limit of the maximum speed limit and a fixed value of the lower limit of the maximum speed limit, and the vehicle controller responds to a limited speed that does not exceed the upper limit of the maximum speed limit and the lower limit of the maximum speed limit;

[0015] When the requested maximum speed limit after the instrument adjustment is less than the fixed value of the lower limit of the maximum speed limit, the fixed value of the lower limit of the maximum speed limit is used as the maximum speed limit; if not, the requested maximum speed limit after the instrument adjustment is compared with the fixed value of the upper limit of the maximum speed limit;

[0016] When the requested maximum speed limit after the instrument is adjusted is greater than the fixed upper limit of the maximum speed limit, the fixed upper limit of the maximum speed limit will be used as the actual maximum speed limit. If not, the maximum speed limit after the instrument is adjusted will be used as the actual maximum speed limit.

[0017] As a further technical solution, the instrument includes a processor and a dashboard interface;

[0018] The instrument panel interface is used to adjust the maximum speed limit value and display the maximum speed limit;

[0019] The processor is used to send the adjusted maximum speed limit request message to the vehicle controller, and at the same time, receive the actual maximum speed limit response sent by the vehicle controller and store the actual maximum speed limit.

[0020] As a further technical solution, the instrument and the vehicle controller communicate via a CAN bus.

[0021] As a further technical solution, the instrument panel interface is provided with a maximum speed limit sub-interface. In the maximum speed limit sub-interface of the instrument, the value of the instrument panel interface is adjusted by pressing the + / - button. The minimum adjustment value is 1km / h. Press the '+' key to increase 1km / h, and press the '-' key to decrease 1km / h. At the same time, the adjusted value is displayed in the interface. After the adjustment is completed, press the confirm button.

[0022] In a second aspect, a pure electric bus is disclosed, including a control system for limiting the maximum speed of the pure electric bus, an accelerator pedal, a motor controller and a motor;

[0023] The control system receives the voltage signal sent by the accelerator pedal, analyzes the current accelerator pedal opening percentage, reads the CAN message sent by the motor controller, analyzes the current motor speed value, calculates the current driving torque based on the current motor speed value and the accelerator pedal opening percentage, and controls the vehicle's maximum speed limit by limiting the driving torque.

[0024] In a third aspect, a method for controlling the maximum speed limit of a pure electric bus is disclosed, comprising:

[0025] Obtain the start gear signal, and read the memory value stored after the start gear power is turned off as the current maximum vehicle speed limit;

[0026] Adjust the current maximum speed limit and send the adjusted maximum speed limit to the vehicle controller in the form of a request message;

[0027] The vehicle controller responds to the received maximum speed limit request based on the judgment strategy, obtains the actual maximum speed limit, and sends it to the instrument for display and storage.

[0028] As a further technical solution, it also includes: when the vehicle controller executes the speed limit operation, the current vehicle speed is obtained. When the current vehicle speed reaches the maximum speed limit, the driving power is the lowest and the current vehicle speed no longer increases. When the current driving power is the maximum driving power, the speed limit is completed.

[0029] As a further technical solution, the judgment strategy of the vehicle controller is that the vehicle controller sets a fixed value of the upper limit of the maximum speed limit and a fixed value of the lower limit of the maximum speed limit, and the vehicle speed limit responded by the vehicle controller does not exceed the upper limit of the maximum speed limit and the lower limit of the maximum speed limit;

[0030] When the requested maximum speed limit after the instrument adjustment is less than the fixed value of the lower limit of the maximum speed limit, the fixed value of the lower limit of the maximum speed limit is used as the maximum speed limit; if not, the requested maximum speed limit after the instrument adjustment is compared with the fixed value of the upper limit of the maximum speed limit;

[0031] When the requested maximum speed limit after the instrument is adjusted is greater than the fixed upper limit of the maximum speed limit, the fixed upper limit of the maximum speed limit will be used as the actual maximum speed limit. If not, the maximum speed limit after the instrument is adjusted will be used as the actual maximum speed limit.

[0032] As a further technical solution, adjust the current maximum speed limit, specifically: in the instrument maximum speed limit sub-interface, adjust the value of the instrument panel interface by pressing the + / - button, and the minimum adjustment value is 1km / h. Press the '+' key to increase 1km / h, press the '-' key to decrease 1km / h. At the same time, the adjusted value is displayed in the interface. Press the confirm button after the adjustment is completed.

[0033] As a further technical solution, the maximum driving power at the current vehicle speed is calculated as follows:

[0034] P_current_max=P_max-K×(V-V1);

[0035] Among them, P_max represents the maximum available power of the drive system, K represents the debugging ratio, V1 is the initial speed of the pure electric bus entering the speed limit adjustment, and V represents the current speed.

[0036] One or more of the above technical solutions have the following beneficial effects:

[0037] The maximum speed limit system in this embodiment adjusts the maximum speed limit through the instrument, and the vehicle controller responds and controls according to the strategy, and implements speed limit and other operations on the pure electric bus through the accelerator pedal. There is no need to flash the speed limit device program on site to achieve the maximum speed limit, which can reduce service costs and enable pure electric buses to adapt to different maximum speed limit operating environments.

[0038] In this embodiment, through the response of the vehicle controller, the pure electric bus can be kept within an accurate range during the speed limit process, which reduces the driver's work difficulty and improves the stability and comfort of the pure electric bus. At the same time, each adjustment is performed on the basis of the previous maximum speed limit and is stored. When running to the previous working scene again, there is no need to re-judge and adjust, which reduces the time cost and meets the stable operation of the pure electric bus in different operating environments.

[0039] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings in the specification, 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.

[0041] Figure 1 This is a principle block diagram of a control system for a maximum speed limit of a pure electric bus according to the first embodiment of the present invention;

[0042] Figure 2 This is a flow chart of a method for controlling the maximum speed limit of a pure electric bus according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0043] 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 meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0044] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0045] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0046] Embodiment 1

[0047] This embodiment discloses a control system for a maximum speed limit of a pure electric bus, including:

[0048] Instruments and speed limiting devices;

[0049] The speed limiting device includes a vehicle controller;

[0050] The instrument receives the set maximum speed limit and sends a maximum speed limit request to the vehicle controller;

[0051] The vehicle controller obtains an actual maximum vehicle speed limit response based on a judgment strategy for the maximum vehicle speed limit request;

[0052] Among them, the judgment strategy of the vehicle controller is:

[0053] The vehicle controller sets a fixed value of the upper limit of the maximum speed limit and a fixed value of the lower limit of the maximum speed limit, and the vehicle controller responds to a limited speed that does not exceed the upper limit of the maximum speed limit and the lower limit of the maximum speed limit;

[0054] When the requested maximum speed limit after the instrument adjustment is less than the fixed value of the lower limit of the maximum speed limit, the fixed value of the lower limit of the maximum speed limit is used as the maximum speed limit; if not, the requested maximum speed limit after the instrument adjustment is compared with the fixed value of the upper limit of the maximum speed limit;

[0055] When the requested maximum speed limit after the instrument is adjusted is greater than the fixed upper limit of the maximum speed limit, the fixed upper limit of the maximum speed limit will be used as the actual maximum speed limit. If not, the maximum speed limit after the instrument is adjusted will be used as the actual maximum speed limit.

[0056] At present, pure electric buses are widely used. Since pure electric buses need to operate in different operating environments, the requirements for maximum speed limits are different. When encountering different working scenarios and different road environments, different maximum speed limits need to be selected to meet vehicle needs. For example, pure electric buses exported overseas need to provide a maximum speed limit control system.

[0057] In this embodiment, the instrument includes a processor and an instrument panel interface;

[0058] The instrument panel interface is used to adjust the maximum speed limit value and display the maximum speed limit;

[0059] The processor is used to send the adjusted maximum speed limit request message to the vehicle controller,

[0060] At the same time, the actual maximum speed limit response sent by the vehicle controller is received, and the actual maximum speed limit is stored.

[0061] In this embodiment, the instrument panel interface is provided with a maximum speed limit sub-interface. In the instrument panel maximum speed limit sub-interface, the stored maximum speed limit is called for adjustment to obtain the adjusted maximum speed limit, and the adjusted maximum speed limit is sent to the vehicle controller in the form of a request message.

[0062] Before adjusting the instrument, first determine whether there is an ON gear signal. If not, start the ON gear, then the instrument will call out the last maximum speed limit and make adjustments.

[0063] Instrument adjustment method: Each adjustment will use the last stored maximum speed limit as the current maximum speed limit. The instrument will display the current maximum speed limit in the maximum speed limit sub-interface. Use the + / - button to adjust the value on the instrument panel interface. The minimum adjustment value is 1km / h. Press the '+' button to increase by 1km / h, and press the '-' button to decrease by 1km / h. At the same time, the adjusted value will be displayed in the interface. Press the confirm button after the adjustment is completed.

[0064] like Figure 1 As shown, the instrument and vehicle controller communicate via the CAN bus.

[0065] The adjusted maximum speed limit is sent to the CAN bus in real time in the form of a message and synchronized for display on the instrument interface. The vehicle control unit (VCU) parses the maximum speed limit message to control the maximum speed limit of the vehicle and sends the adjusted maximum speed limit after response to the CAN bus. The instrument parses the maximum speed limit responded by the VCU for display.

[0066] As Figure 1 shown, the VCU obtains the actual maximum speed limit response based on the judgment strategy for the maximum speed limit request.

[0067] The judgment strategy of the VCU is that the VCU sets the fixed value of the maximum speed limit upper bound and the fixed value of the maximum speed limit lower bound, and the limited speed responded by the VCU does not exceed the maximum speed limit upper bound and the maximum speed limit lower bound; when the adjusted maximum speed limit requested by the instrument is less than the fixed value of the maximum speed limit lower bound, the fixed value of the maximum speed limit lower bound is taken as the maximum speed limit, otherwise, the adjusted maximum speed limit requested by the instrument is compared with the fixed value of the maximum speed limit upper bound; when the adjusted maximum speed limit requested by the instrument is greater than the fixed value of the maximum speed limit upper bound, the fixed value of the maximum speed limit upper bound is taken as the actual maximum speed limit, otherwise, the adjusted maximum speed limit of the instrument is taken as the actual maximum speed limit.

[0068] Specifically: Let the maximum speed limit be V_max, and after sending the adjusted maximum speed limit V_set of the instrument to the VCU, it is compared and judged with the fixed value of the maximum speed limit upper bound V_high and the fixed value of the maximum speed limit lower bound V_low set by the VCU.

[0069] First, V_max is compared with the fixed value of the maximum speed limit lower bound V_low for the first time.

[0070] When V_set < V_low, then V_max = V_low, and V_low is the maximum speed limit.

[0071] When V_set ≥ V_low, then V_max = V_set, and V_set is compared with the fixed value of the maximum speed limit upper bound V_high set by the VCU for the second time.

[0072] When V_set > V_high, then V_max = V_high, and V_high is the maximum speed limit.

[0073] When V_set ≤ V_high, then V_max = V_set, and V_set is the maximum speed limit.

[0074] After two judgments and comparisons, the final V_max is obtained, the confirmation key is pressed, and the current maximum speed limit value is updated to V_max.

[0075] Finally, after the vehicle is turned off to the ON position, the instrument will store the current maximum speed limit value V_max. The next time the vehicle is turned on to the ON position, the memory value V_max stored after the vehicle is turned off to the ON position will be read as the maximum speed limit for this operation.

[0076] In this embodiment, after obtaining the maximum vehicle speed limit through the control system, the vehicle controller performs the speed limit operation according to the current maximum speed limit requirement.

[0077] The driver or safety personnel operates the accelerator pedal to send the opening and closing degree of the accelerator pedal to the vehicle controller in the form of a voltage signal. The vehicle controller receives the voltage signal sent by the accelerator pedal and parses the current accelerator pedal opening percentage; the vehicle controller reads the CAN message sent by the motor controller and parses the current motor speed value; the vehicle controller calculates the current driving torque value T1 based on the current motor speed value and the accelerator pedal opening percentage, compares it with the current maximum limit driving torque T_current_max, takes the minimum value to output the final driving torque T2, and limits the maximum vehicle speed in this way.

[0078] Embodiment 2

[0079] This embodiment provides a pure electric bus, including a control system for a maximum speed limit of a pure electric bus, an accelerator pedal, a motor controller and a motor;

[0080] The control system receives the voltage signal sent by the accelerator pedal, analyzes the current accelerator pedal opening percentage, reads the CAN message sent by the motor controller, analyzes the current motor speed value, calculates the current driving torque based on the current motor speed value and the accelerator pedal opening percentage, and controls the vehicle's maximum speed limit by limiting the driving torque.

[0081] The control system for the maximum speed limit of a pure electric bus in this embodiment is the same as the control system for the maximum speed limit of a pure electric bus in the first embodiment.

[0082] Embodiment 3

[0083] The purpose of this embodiment is to provide a method for controlling the maximum speed limit of a pure electric bus, including:

[0084] S1, obtaining the start gear signal, and reading the memory value stored after the start gear power is turned off as the current maximum speed limit;

[0085] S2, adjusting the current maximum speed limit, and sending the adjusted maximum speed limit to the vehicle controller in the form of a request message;

[0086] S3. The vehicle controller responds to the received request for the maximum speed limit according to the judgment strategy, obtains the maximum speed limit, and sends it to the instrument for display and storage.

[0087] like Figure 2 As shown, in step S1, a start gear signal is obtained, and the last stored memory value is read as the current maximum vehicle speed limit.

[0088] First, determine whether there is an ON gear signal. If not, activate the ON gear. Then the instrument reads and displays the last maximum speed limit as the current maximum speed limit.

[0089] like Figure 2 As shown, in step S2, the current maximum speed limit is adjusted, and the adjusted maximum speed limit is sent to the vehicle controller in the form of a request message.

[0090] S201. Adjust the current maximum vehicle speed limit.

[0091] Each adjustment will use the last maximum speed limit as the current maximum speed limit. The instrument will display the current maximum speed limit in the maximum speed limit sub-interface. The value on the instrument panel interface can be adjusted by pressing the + / - button. The minimum adjustment value is 1km / h. Press the '+' button once to increase by 1km / h, and press the '-' button once to decrease by 1km / h. At the same time, the adjusted value will be displayed in the interface. After the adjustment, press the confirm button and the adjusted maximum speed limit V_set will be displayed on the instrument.

[0092] S202, sending the adjusted maximum speed limit to the vehicle controller in the form of a request message. The maximum speed limit V_set adjusted by the instrument is sent to the CAN bus in real time in the form of a request message, and is synchronously sent to the vehicle controller through the CAN bus.

[0093] like Figure 2 As shown, in step S3, the vehicle controller responds to the received request for the maximum speed limit after adjustment by the instrument according to the judgment strategy, obtains the maximum speed limit, and sends it to the instrument for display and storage.

[0094] S301. The vehicle controller responds to the received request for the maximum vehicle speed limit after adjustment by the instrument according to the judgment strategy, and obtains the maximum vehicle speed limit.

[0095] Specifically, set the maximum speed limit as V_max. After sending the adjusted maximum speed limit V_set of the instrument to the vehicle controller, it is compared with the fixed upper limit value V_high and the fixed lower limit value V_low of the maximum speed limit set by the vehicle controller.

[0096] First, make the first comparison between V_max and the fixed lower limit value V_low of the maximum speed limit.

[0097] When V_set < V_low, then V_max = V_low, and V_low is the maximum speed limit.

[0098] When V_set ≥ V_low, then V_max = V_set, and make the second comparison between V_set and the fixed upper limit value V_high of the maximum speed limit set by the vehicle controller.

[0099] When V_set > V_high, then V_max = V_high, and V_high is the maximum speed limit.

[0100] When V_set ≤ V_high, then V_max = V_set, and V_set is the maximum speed limit.

[0101] After two judgment and comparison operations, obtain the final V_max, press the confirmation key, and update the current maximum speed limit value to V_max.

[0102] S302: Send the maximum speed limit to the instrument for display and storage.

[0103] Send the maximum speed limit V_max to the instrument. After the vehicle is turned off to the ON position, the instrument stores the current maximum speed limit value V_max. When the vehicle is turned on to the ON position next time, read the memory value V_max stored after turning off the vehicle to the ON position last time as the maximum speed limit for this operation.

[0104] In this embodiment, after obtaining the maximum speed limit through the control system, the vehicle controller performs the speed limit operation according to the current maximum speed limit requirement.

[0105] The driver or safety personnel operates the accelerator pedal to send the opening and closing degree of the accelerator pedal to the vehicle controller in the form of a voltage signal. The vehicle controller receives the voltage signal sent by the accelerator pedal and parses the current accelerator pedal opening percentage; the vehicle controller reads the CAN message sent by the motor controller and parses the current motor speed value; the vehicle controller calculates the current driving torque value T1 based on the current motor speed value and the accelerator pedal opening percentage, compares it with the current maximum limit driving torque T_current_max, takes the minimum value to output the final driving torque T2, and limits the maximum vehicle speed in this way.

[0106] The maximum limiting driving torque T_current_max is calculated as follows:

[0107] T_current_max=9550×P_current_max / n_current(1)

[0108] Among them, n_current represents the current motor speed value, and P_current_max represents the power of the drive system.

[0109] When T1>T_current_max, then T2=T_current_max.

[0110] When T1≤T_current_max, T2=T1.

[0111] When the current speed of the pure electric bus reaches V1, it enters the speed limit stage. As the speed gradually increases, the power P_current_max of the drive system is gradually limited. When the maximum speed limit V_max is reached, the vehicle's drive power is already limited to a lower level and the vehicle no longer accelerates.

[0112] Speed ​​regulation ratio, the formula is:

[0113] K=P_max / ΔV (2)

[0114] V1=V max -ΔV

[0115] Among them, △V can be calibrated according to the vehicle status, usually 7, 8, 9, 10; V1 is the initial speed of the pure electric bus entering the speed limit adjustment, and P_max is the maximum driving power of the vehicle.

[0116] According to formula (2), the maximum driving power at the current vehicle speed is calculated as follows:

[0117] P_current_max=P_max-K×(V-V1) (3)

[0118] Among them, P_max represents the maximum available power of the drive system, K represents the debugging ratio, V1 is the initial speed of the pure electric bus entering the speed limit adjustment, and V represents the current speed.

[0119] After the above steps, the speed limit is achieved by reaching the maximum driving power value.

[0120] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0121] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A control system for a pure electric bus with a maximum speed limit, characterized in that: include: Instruments and speed limiting devices; The speed limiting device includes a vehicle controller; The instrument receives the set maximum speed limit and sends a maximum speed limit request to the vehicle controller; The vehicle controller obtains an actual maximum vehicle speed limit response to the maximum vehicle speed limit request according to a judgment strategy; Among them, the judgment strategy of the vehicle controller is: The vehicle controller sets a fixed value of the upper limit of the maximum speed limit and a fixed value of the lower limit of the maximum speed limit, and the vehicle controller responds to a limited speed that does not exceed the upper limit of the maximum speed limit and the lower limit of the maximum speed limit; When the requested maximum speed limit after the instrument adjustment is less than the fixed value of the lower limit of the maximum speed limit, the fixed value of the lower limit of the maximum speed limit is used as the maximum speed limit; if not, the requested maximum speed limit after the instrument adjustment is compared with the fixed value of the upper limit of the maximum speed limit; When the requested maximum speed limit after the instrument is adjusted is greater than the fixed upper limit of the maximum speed limit, the fixed upper limit of the maximum speed limit will be used as the actual maximum speed limit. If not, the maximum speed limit after the instrument is adjusted will be used as the actual maximum speed limit.

2. A control system for a maximum speed limit of a pure electric bus as claimed in claim 1, characterized in that: The instrument includes a processor and a dashboard interface; The instrument panel interface is used to adjust the maximum speed limit value and display the maximum speed limit; The processor is used to send the adjusted maximum speed limit request message to the vehicle controller, and at the same time, receive the actual maximum speed limit response sent by the vehicle controller and store the actual maximum speed limit.

3. A control system for a maximum speed limit of a pure electric bus as claimed in claim 1, characterized in that: The instrument communicates with the vehicle controller via the CAN bus.

4. A control system for a maximum speed limit of a pure electric bus as claimed in claim 2, characterized in that: The instrument panel interface is provided with a maximum speed limit sub-interface. In the maximum speed limit sub-interface of the instrument, the value of the instrument panel interface is adjusted by pressing the + / - button. The minimum adjustment value is 1km / h. Press the '+' button to increase 1km / h, and press the '-' button to decrease 1km / h. At the same time, the adjusted value is displayed in the interface. After the adjustment is completed, press the confirmation button.

5. A pure electric bus, characterized in that: It comprises a control system for the maximum speed limit of a pure electric bus as claimed in claim 1, an accelerator pedal, a motor controller and a motor; The control system receives the voltage signal sent by the accelerator pedal, analyzes the current accelerator pedal opening percentage, reads the CAN message sent by the motor controller, analyzes the current motor speed value, calculates the current driving torque based on the current motor speed value and the accelerator pedal opening percentage, and controls the vehicle's maximum speed limit by limiting the driving torque.

6. A method for controlling the maximum speed limit of a pure electric bus, characterized in that: include: Obtain the start gear signal, and read the memory value stored after the start gear power is turned off as the current maximum vehicle speed limit; Adjust the current maximum speed limit and send the adjusted maximum speed limit to the vehicle controller in the form of a request message; The vehicle controller responds to the received maximum speed limit request based on the judgment strategy, obtains the actual maximum speed limit, and sends it to the instrument for display and storage.

7. A method for controlling the maximum speed limit of a pure electric bus as claimed in claim 6, characterized in that: Also includes: When the vehicle controller performs the speed limit operation, it obtains the current vehicle speed. When the current vehicle speed reaches the maximum speed limit, the driving power is the lowest and the current vehicle speed no longer increases. When the current driving power is the maximum driving power, the speed limit is completed.

8. A method for controlling the maximum speed limit of a pure electric bus as claimed in claim 6, characterized in that: The judgment strategy of the vehicle controller is that the vehicle controller sets a fixed value of the upper limit of the maximum speed limit and a fixed value of the lower limit of the maximum speed limit, and the vehicle speed limit responded by the vehicle controller does not exceed the upper limit of the maximum speed limit and the lower limit of the maximum speed limit; When the requested maximum speed limit after the instrument adjustment is less than the fixed value of the lower limit of the maximum speed limit, the fixed value of the lower limit of the maximum speed limit is used as the maximum speed limit; if not, the requested maximum speed limit after the instrument adjustment is compared with the fixed value of the upper limit of the maximum speed limit; When the requested maximum speed limit after the instrument is adjusted is greater than the fixed upper limit of the maximum speed limit, the fixed upper limit of the maximum speed limit will be used as the actual maximum speed limit. If not, the maximum speed limit after the instrument is adjusted will be used as the actual maximum speed limit.

9. A method for controlling the maximum speed limit of a pure electric bus as claimed in claim 6, characterized in that: Adjust the current maximum speed limit. Specifically, in the instrument's maximum speed limit sub-interface, use the + / - buttons to adjust the value on the instrument panel interface. The minimum value is 1km / h. Press the '+' button to increase by 1km / h, and press the '-' button to decrease by 1km / h. The adjusted value is displayed in the interface. Press the confirm button after the adjustment is completed.

10. A method for controlling the maximum speed limit of a pure electric bus as claimed in claim 6, characterized in that: The maximum driving power at the current vehicle speed is calculated as follows: P_current_max=P_max-K×(V-V1); Among them, P_max represents the maximum available power of the drive system, K represents the debugging ratio, V1 is the initial speed of the pure electric bus entering the speed limit adjustment, and V represents the current speed.

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