Electric vehicle energy-saving cruise control method, system and storage medium

Abstract

The present invention discloses an energy-saving cruise control method, system and storage medium for electric vehicles, the method comprising: obtaining the current running speed of the vehicle, calculating the first acceleration of the vehicle according to the current running speed, and obtaining the second acceleration of the vehicle according to the whole vehicle acceleration sensor; using the first acceleration and the second acceleration to calculate the road slope and filter to obtain a stable slope value; comparing the current vehicle speed with the reference speed, and adjusting the whole vehicle gear and the optimal driving torque in combination with the road slope; when the vehicle is in a preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear; taking the highest total transmission efficiency as the objective function, obtaining the optimal model with the lowest total power consumption, taking the optimal total power consumption as the objective function, and calculating the optimal operating condition point within the cruise allowable speed range. The present invention can reduce the running energy consumption of the whole vehicle and ensure the comfort of the driver.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle control, and more specifically, to an electric vehicle energy-saving cruise control method, system and storage medium. Background Art

[0002] The energy consumption of electric vehicles is one of the main concerns of commercial vehicle owners and large fleets. How to reduce the energy loss during the acceleration, constant speed and deceleration of the vehicle will greatly reduce the energy consumption of electric vehicles. Therefore, energy-saving cruise has important engineering value and economic significance.

[0003] Existing technology can use high-precision GPS to automatically identify road conditions and calculate the optimal speed and torque to achieve offline optimization of the optimal gear for different working conditions and achieve optimal energy utilization.

[0004] 1) Its focus is on the field of internal combustion engines, but not electric vehicles;

[0005] 2) Energy recovery is not considered during deceleration and downhill conditions;

[0006] 3) High-precision map GPS is required to obtain slope information, and the system coupling cost is high; Summary of the invention

[0007] In order to overcome the problems in the prior art of obtaining road slope information in energy-saving cruise of electric vehicles, that is, obtaining slope information through high-precision map GPS, high system coupling cost, and failure to combine slope information and vehicle status for cruise control, the present invention provides an energy-saving cruise control method, system and storage medium for electric vehicles.

[0008] The primary purpose of the present invention is to solve the above technical problems. The technical solution of the present invention is as follows:

[0009] A first aspect of the present invention provides an electric vehicle energy-saving cruise control method, comprising the following steps:

[0010] Obtain the current running speed of the vehicle, calculate the first acceleration of the vehicle according to the current running speed, and obtain the second acceleration of the vehicle according to the vehicle acceleration sensor;

[0011] Calculating a road slope using the first acceleration and the second acceleration, and filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope value;

[0012] Compare the current vehicle speed with the reference vehicle speed, and adjust the vehicle gear and optimal driving torque according to the comparison result and the road slope, wherein the reference vehicle speed is a preset cruising speed;

[0013] When the vehicle is in the preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position;

[0014] Taking the highest total transmission efficiency as the objective function, an optimization model with the lowest total power consumption is obtained. Taking the optimal total power consumption as the objective function, the optimal operating point within the cruise allowable speed range is calculated. The optimal operating point includes the optimal gear, requested torque and optimal operating speed.

[0015] Furthermore, the first acceleration and the second acceleration are used to calculate the road slope, and the calculation formula is:

[0016]

[0017]

[0018] Among them, θ represents the road slope, a represents the first acceleration, and a sensor represents the second acceleration, g represents the acceleration due to gravity, Δt represents the time difference, V veh(t+1) represents the vehicle speed at time t+1, V veh(t) represents the vehicle speed at time t.

[0019] Further, filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope signal value specifically includes:

[0020] When the calculated difference between the road slope at the current moment and the road slope at the previous moment is less than the preset value, the road slope value at the previous moment remains unchanged;

[0021] When the calculated difference between the road slope at the current moment and the road slope at the previous moment is greater than the preset value and less than N times the preset value, where N is a positive integer, the road slope value at the previous moment plus the preset value is taken as the road slope at the current moment;

[0022] When the calculated difference between the road slope at the current moment and the road slope at the previous moment is greater than N times the preset value, the calculated road slope value is used as the road slope at the current moment.

[0023] Furthermore, the road slope is filtered according to a preset anti-shake filtering algorithm and then subjected to high-frequency filtering to obtain a stable slope value.

[0024] Furthermore, the current vehicle speed is compared with the reference vehicle speed, and the vehicle gear position and the optimal driving torque are adjusted according to the comparison result and the road slope, specifically including:

[0025] If the current actual vehicle speed is less than the reference vehicle speed, and the speed difference △V>0, or the road slope is greater than the first threshold value B, and the first threshold value B is greater than zero, then it is defined that the vehicle is currently in the energy-saving driving mode, and the vehicle adaptively adjusts the vehicle gear position and the optimal driving torque according to the road slope and the speed difference;

[0026] If the current actual vehicle speed is greater than the reference vehicle speed, and the speed difference -A<△V<0, A>0, -A represents the lower limit of the speed difference, and the road slope is less than the threshold value B, then the vehicle is currently in the gliding mode, at this time there is no electric braking recovery, and the vehicle uses inertia to travel;

[0027] If the current actual vehicle speed is greater than the reference speed, and the speed difference △V is less than -A, or the road slope is less than -B, the vehicle is defined as being in adaptive energy recovery mode. The vehicle adaptively adjusts the vehicle gear position and optimal recovery torque according to the road slope and speed difference to meet the driver's braking purpose and recover electrical energy.

[0028] Furthermore, when the vehicle is in a preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current vehicle speed difference, slope and gear. Specifically, when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current vehicle speed difference, slope and gear, wherein the speed difference, slope and gear correction coefficients are obtained by querying a preset table.

[0029] Furthermore, the total transmission efficiency is the highest and its expression is as follows:

[0030] ε emax =max[ε mcu *ε moter *ε tcu *ε g ]

[0031] θ min <θ<θ max

[0032] v min <v<v mmax

[0033] ε min <ε<1

[0034] Optimal total power consumption EC min The objective function is expressed as:

[0035] EC min =minF(F f , v, ε emax )

[0036] Where v represents the current vehicle speed; θ represents the current slope; F fTo represent the road resistance, it is obtained by looking up the slope θ and the current vehicle speed v, ε mcu represents the efficiency of the microcontroller MCU, ε moter Motor efficiency, ε tcu Gearbox efficiency, ε q Rear axle efficiency.

[0037] A second aspect of the present invention provides an electric vehicle energy-saving cruise control system, the system comprising: a memory, a processor, the memory comprising an electric vehicle energy-saving cruise control method program, the electric vehicle energy-saving cruise control method program when executed by the processor to implement the following steps:

[0038] Obtain the current running speed of the vehicle, calculate the first acceleration of the vehicle according to the current running speed, and obtain the second acceleration of the vehicle according to the vehicle acceleration sensor;

[0039] Calculating a road slope using the first acceleration and the second acceleration, and filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope value;

[0040] Compare the current vehicle speed with the reference vehicle speed, and adjust the vehicle gear and optimal driving torque according to the comparison result and the road slope, wherein the reference vehicle speed is a preset cruising speed;

[0041] When the vehicle is in the preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position;

[0042] Taking the highest total transmission efficiency as the objective function, an optimization model with the lowest total power consumption is obtained. Taking the optimal total power consumption as the objective function, the optimal operating point within the cruise allowable speed range is calculated. The optimal operating point includes the optimal gear, requested torque and optimal operating speed.

[0043] Furthermore, the first acceleration and the second acceleration are used to calculate the road slope, and the calculation formula is:

[0044]

[0045]

[0046] Among them, θ represents the road slope, a represents the first acceleration, and a sensor represents the second acceleration, g represents the acceleration due to gravity, Δt represents the time difference, V veh(t+1) represents the vehicle speed at time t+1, V veh(t) represents the vehicle speed at time t.

[0047] A third aspect of the present invention provides a storage medium, which includes an electric vehicle energy-saving cruise control method program. When the electric vehicle energy-saving cruise control method program is executed by a processor, the steps of the electric vehicle energy-saving cruise control method are implemented.

[0048] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0049] The present invention obtains the road slope through vehicle running speed and acceleration calculation without relying on high-precision maps and GPS systems. The present invention adjusts the vehicle gear and the optimal driving torque according to the comparison result and the road slope to control the vehicle to run in different modes. The present invention obtains the optimal operating condition point of the vehicle through PID control and sensor efficiency control, thereby controlling the vehicle operation, reducing the operating energy consumption of the vehicle, and ensuring the comfort of the driver. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A flow chart of an energy-saving cruise control method for an electric vehicle provided by an embodiment of the present invention.

[0051] Figure 2 This is a flow chart of an anti-shake filtering processing algorithm provided by an embodiment of the present invention.

[0052] Figure 3 A flow chart of an energy-saving cruise control strategy provided by an embodiment of the present invention.

[0053] Figure 4 A PID coordinator control flow chart provided for an embodiment of the present invention.

[0054] Figure 5 A flow chart of electric vehicle driving and adaptive recovery control provided by an embodiment of the invention. DETAILED DESCRIPTION

[0055] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0056] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0057] Example 1

[0058] like Figure 1 As shown, the first aspect of the present invention provides an electric vehicle energy-saving cruise control method, comprising the following steps:

[0059] S1: Obtain the current running speed of the vehicle, calculate the first acceleration of the vehicle according to the current running speed, and obtain the second acceleration of the vehicle according to the vehicle acceleration sensor;

[0060] In a specific embodiment, the current running speed of the vehicle is obtained by the vehicle speed sensor, which is denoted as V veh According to the differential equation and low-pass filtering method, the first acceleration of the current vehicle is obtained, which is recorded as a. The acceleration signal is obtained through the vehicle acceleration sensor, and the acceleration signal is low-pass filtered to obtain the current second acceleration of the vehicle, which is recorded as a sensor .

[0061] S2: calculating a road slope using the first acceleration and the second acceleration, and filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope value;

[0062] In a specific embodiment, the road slope is calculated using the following formula:

[0063]

[0064]

[0065] Among them, θ represents the road slope, a represents the first acceleration, and a sensor represents the second acceleration, g represents the acceleration due to gravity, Δt represents the time difference, V veh(t+1) represents the vehicle speed at time t+1, V veh(t) represents the vehicle speed at time t.

[0066] Figure 2 The flowchart of the anti-shake filtering processing algorithm in this embodiment is shown.

[0067] It should be noted that the road slope value obtained by the above calculation is unstable and needs to be processed by anti-shake filtering, such as Figure 2 As shown, the specific steps are:

[0068] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is less than the preset value C, the road slope value at the previous moment remains unchanged;

[0069] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is greater than the preset value C and less than 2 times the preset value C, the road slope θ at the previous moment is last Add the preset value C as the road slope at the current moment;

[0070] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is greater than 2 times the preset value, the calculated road slope θ 0 As the road slope at the current moment.

[0071] It should be noted that, in the present invention, after the calculated road slope is processed by the anti-shake filtering algorithm, the high-frequency noise signal therein needs to be filtered to obtain a stable road slope θ.

[0072] S3: comparing the current vehicle speed with a reference vehicle speed, and adjusting the vehicle gear and the optimal driving torque according to the comparison result and the road slope, wherein the reference vehicle speed is a preset cruising speed;

[0073] like Figure 3 As shown, step S3 specifically includes:

[0074] The driver's requested speed V ref That is, the reference speed, the calculated road slope is θ, and the difference between the actual speed and the requested speed is △V = V ref -V.

[0075] If the current actual vehicle speed is less than the reference vehicle speed, and the speed difference △V>0, or the road slope is greater than the first threshold value B, and the first threshold value B is greater than zero, then it is defined that the vehicle is currently in the energy-saving driving mode, and the vehicle adaptively adjusts the vehicle gear position and the optimal driving torque according to the road slope and the speed difference;

[0076] If the current actual vehicle speed is greater than the reference vehicle speed, and the speed difference -A<△V<0, A>0, -A indicates the lower limit of the speed difference, and the road slope is less than the threshold value B, then the vehicle is defined as being in the gliding mode. At this time, there is no electric braking recovery, and the vehicle inertia is used to travel, which can also prevent the motor torque from switching frequently near 0 torque;

[0077] If the current actual vehicle speed is greater than the reference speed, and the speed difference △V is less than -A, or the road slope is less than -B, the vehicle is defined as being in adaptive energy recovery mode. The vehicle adaptively adjusts the vehicle gear and optimal recovery torque according to the road slope and speed difference to meet the driver's braking purpose and recover electrical energy, thereby improving driving comfort.

[0078] In a specific embodiment, the driver can adjust the vehicle speed by using the combination switch buttons Set+ and Set-, where Set+ increases the vehicle speed and Set- decreases the vehicle speed. When the vehicle runs to different scenes, it enters different control modes respectively.

[0079] S4: When the vehicle is in the preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position;

[0080] In a specific embodiment, Figure 4 As shown in the figure, when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the PID coordinator identifies the current speed difference, slope, gear position, and actual speed, automatically corrects and adjusts the control parameters, and selects the optimal PID control parameters, among which the speed difference, slope, and gear position correction coefficients are obtained by querying the preset table. Through the above coefficient correction, a smooth response of the torque is achieved, the whole vehicle is prevented from shaking, and the driver's comfort is improved.

[0081] S5: Taking the highest total transmission efficiency as the objective function, an optimization model with the lowest total power consumption is obtained. Taking the optimal total power consumption as the objective function, the optimal operating condition point within the cruise allowable vehicle speed range is calculated. The optimal operating condition point includes the optimal gear, requested torque and optimal operating speed.

[0082] In a specific embodiment, when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the maximum total transmission efficiency of MCU-motor-gearbox-rear axle is taken as the objective function ε emax , and obtain the optimal model EC with the lowest power consumption min ;

[0083] The highest total transmission efficiency is the objective function, and its expression is:

[0084] ε emax =max[ε mcu *ε moter *ε tcu *ε q ]

[0085] θ min <θ<θ max

[0086] v min <v<v max

[0087] ε min <ε<1

[0088] Optimal total power consumption EC min The objective function is expressed as:

[0089] EC min =minF(F f , v, ε emax )

[0090] Where v represents the current vehicle speed; θ represents the current slope; F fTo represent the road resistance, it is obtained by looking up the slope θ and the current vehicle speed v, ε mcu represents the efficiency of the microcontroller MCU, ε moter Motor efficiency, ε tcu Gearbox efficiency, ε q Rear axle efficiency.

[0091] In a specific embodiment, Figure 5 The figure shows the control flow chart of electric vehicle driving and adaptive recovery. First, the vehicle speed v, the current road slope θ and the gear position are obtained, and the road resistance F is obtained by looking up the table. f , the total power consumption is optimal EC min The optimal operating condition point is calculated as the objective function, and the optimal operating condition point includes the optimal gear, the requested torque and the optimal operating speed. The vehicle speed v, the current road slope θ and the gear are input into the PID coordinator to obtain the optimal PID control parameters, and the optimal gear, the requested torque, the optimal operating speed and the optimal PID control parameters are input into the VCU controller system of the vehicle to control the vehicle operation.

[0092] A second aspect of the present invention provides an electric vehicle energy-saving cruise control system, the system comprising: a memory, a processor, the memory comprising an electric vehicle energy-saving cruise control method program, the electric vehicle energy-saving cruise control method program when executed by the processor to implement the following steps:

[0093] S1: Obtain the current running speed of the vehicle, calculate the first acceleration of the vehicle according to the current running speed, and obtain the second acceleration of the vehicle according to the vehicle acceleration sensor;

[0094] In a specific embodiment, the current running speed of the vehicle is obtained by the vehicle speed sensor, which is denoted as V veh According to the differential equation and low-pass filtering method, the first acceleration of the current vehicle is obtained, which is recorded as a. The acceleration signal is obtained through the vehicle acceleration sensor, and the acceleration signal is low-pass filtered to obtain the current second acceleration of the vehicle, which is recorded as a sensor .

[0095] S2: calculating a road slope using the first acceleration and the second acceleration, and filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope value;

[0096] In a specific embodiment, the road slope is calculated using the following formula:

[0097]

[0098]

[0099] Among them, θ represents the road slope, a represents the first acceleration, and a sensor represents the second acceleration, g represents the acceleration due to gravity, Δt represents the time difference, V veh(t+1) represents the vehicle speed at time t+1, V veh(t) represents the vehicle speed at time t.

[0100] Figure 2 The flowchart of the anti-shake filtering processing algorithm in this embodiment is shown.

[0101] It should be noted that the road slope value obtained by the above calculation is unstable and needs to be processed by anti-shake filtering, such as Figure 2 As shown, the specific steps are:

[0102] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is less than the preset value C, the road slope value at the previous moment remains unchanged;

[0103] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is greater than the preset value C and less than 2 times the preset value C, the road slope θ at the previous moment is last Add the preset value C as the road slope at the current moment;

[0104] When the calculated road slope θ at the current moment 0 The road slope θ at the previous moment last If the difference △θ is greater than 2 times the preset value, the calculated road slope θ 0 As the road slope at the current moment.

[0105] It should be noted that, in the present invention, after the calculated road slope is processed by the anti-shake filtering algorithm, the high-frequency noise signal therein needs to be filtered to obtain a stable road slope θ.

[0106] S3: comparing the current vehicle speed with a reference vehicle speed, and adjusting the vehicle gear and the optimal driving torque according to the comparison result and the road slope, wherein the reference vehicle speed is a preset cruising speed;

[0107] like Figure 3 As shown, step S3 specifically includes:

[0108] The driver's requested speed V ref That is, the reference speed, the calculated road slope is θ, and the difference between the actual speed and the requested speed is △V = V ref -V.

[0109] If the current actual vehicle speed is less than the reference vehicle speed, and the speed difference △V>0, or the road slope is greater than the first threshold value B, and the first threshold value B is greater than zero, then it is defined that the vehicle is currently in the energy-saving driving mode, and the vehicle adaptively adjusts the vehicle gear position and the optimal driving torque according to the road slope and the speed difference;

[0110] If the current actual vehicle speed is greater than the reference vehicle speed, and the speed difference -A<△V<0, A>0, -A indicates the lower limit of the speed difference, and the road slope is less than the threshold value B, then the vehicle is defined as being in the gliding mode. At this time, there is no electric braking recovery, and the vehicle inertia is used to travel, which can also prevent the motor torque from switching frequently near 0 torque;

[0111] If the current actual vehicle speed is greater than the reference speed, and the speed difference △V is less than -A, or the road slope is less than -B, the vehicle is defined as being in adaptive energy recovery mode. The vehicle adaptively adjusts the vehicle gear and optimal recovery torque according to the road slope and speed difference to meet the driver's braking purpose and recover electrical energy, thereby improving driving comfort.

[0112] In a specific embodiment, the driver can adjust the vehicle speed by using the combination switch buttons Set+ and Set-, where Set+ increases the vehicle speed and Set- decreases the vehicle speed. When the vehicle runs to different scenes, it enters different control modes respectively.

[0113] S4: When the vehicle is in the preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position;

[0114] In a specific embodiment, Figure 4 As shown in the figure, when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the PID coordinator identifies the current speed difference, slope, gear position, and actual speed, automatically corrects and adjusts the control parameters, and selects the optimal PID control parameters, among which the speed difference, slope, and gear position correction coefficients are obtained by querying the preset table. Through the above coefficient correction, a smooth response of the torque is achieved, the whole vehicle is prevented from shaking, and the driver's comfort is improved.

[0115] S5: Taking the highest total transmission efficiency as the objective function, an optimization model with the lowest total power consumption is obtained. Taking the optimal total power consumption as the objective function, the optimal operating condition point within the cruise allowable vehicle speed range is calculated. The optimal operating condition point includes the optimal gear, requested torque and optimal operating speed.

[0116] In a specific embodiment, when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the maximum total transmission efficiency of MCU-motor-gearbox-rear axle is taken as the objective function ε emax , and obtain the optimal model EC with the lowest power consumption min ;

[0117] The highest total transmission efficiency is the objective function, and its expression is:

[0118] ε emax =max[ε mcu *ε moter *ε tcu *ε q ]

[0119] θ min <θ<θ max

[0120] v min <v<v mmax

[0121] ε min <ε<1

[0122] Optimal total power consumption EC min The objective function is expressed as:

[0123] EC min =minF(F f , v, ε emax )

[0124] Where v represents the current vehicle speed; θ represents the current slope; F f To represent the road resistance, it is obtained by looking up the slope θ and the current vehicle speed v, ε mcu represents the efficiency of the microcontroller MCU, ε moter Motor efficiency, ε tcu Gearbox efficiency, ε q Rear axle efficiency.

[0125] In a specific embodiment, Figure 5 The figure shows the control flow chart of electric vehicle driving and adaptive recovery. First, the vehicle speed v, the current road slope θ and the gear position are obtained, and the road resistance F is obtained by looking up the table. f , the total power consumption is optimal EC min As the objective function, the optimal operating condition point is calculated, and the optimal operating condition point includes the optimal gear, the requested torque and the optimal operating speed. The vehicle speed v, the current road slope θ and the gear are input into the PID coordinator to obtain the optimal PID control parameters, and the optimal gear, the requested torque, the optimal operating speed and the optimal PID control parameters are input into the VCU controller system of the vehicle to control the vehicle operation.

[0126] A third aspect of the present invention provides a storage medium, which includes an electric vehicle energy-saving cruise control method program. When the electric vehicle energy-saving cruise control method program is executed by a processor, the steps of the electric vehicle energy-saving cruise control method are implemented.

[0127] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An energy-saving cruise control method for an electric vehicle, characterized in that: The following steps are involved: Obtain the current running speed of the vehicle, calculate the first acceleration of the vehicle according to the current running speed, and obtain the second acceleration of the vehicle according to the vehicle acceleration sensor; Calculating a road slope using the first acceleration and the second acceleration, and filtering the road slope according to a preset anti-shake filtering algorithm to obtain a stable slope value; The road slope is filtered according to a preset anti-shake filtering algorithm to obtain a stable slope signal value, specifically including: When the calculated difference between the road slope at the current moment and the road slope at the previous moment is less than the preset value, the road slope value at the previous moment remains unchanged; When the calculated difference between the road slope at the current moment and the road slope at the previous moment is greater than the preset value and less than N times the preset value, where N is a positive integer, the road slope value at the previous moment plus the preset value is taken as the road slope at the current moment; When the calculated difference between the road slope at the current moment and the road slope at the previous moment is greater than N times the preset value, the calculated road slope value is used as the road slope at the current moment; Compare the current vehicle speed with the reference vehicle speed, and adjust the vehicle gear and optimal driving torque according to the comparison result and the road slope, wherein the reference vehicle speed is a preset cruising speed; Compare the current vehicle speed with the reference speed, and adjust the vehicle gear and optimal drive torque based on the comparison result and the road slope, including: If the current actual vehicle speed is less than the reference vehicle speed, and the speed difference △V>0, or the road slope is greater than the first threshold value B, and the first threshold value B is greater than zero, then it is defined that the vehicle is currently in the energy-saving driving mode, and the vehicle adaptively adjusts the vehicle gear position and the optimal driving torque according to the road slope and the speed difference; If the current actual vehicle speed is greater than the reference vehicle speed, and the speed difference -A<△V<0, A>0, -A represents the lower limit of the speed difference, and the road slope is less than the threshold B, then the vehicle is currently in the gliding mode, at which time there is no electric braking recovery and the vehicle uses inertia to travel; If the current actual vehicle speed is greater than the reference speed, and the speed difference △V<-A, or the road slope is less than -B, the vehicle is defined as being in adaptive energy recovery mode. The vehicle will adaptively adjust the vehicle gear position and the optimal recovery torque according to the road slope and speed difference to meet the driver's braking purpose and recover electrical energy. When the vehicle is in a preset mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position; specifically: when the vehicle is in energy-saving driving mode or adaptive energy recovery mode, the PID coordinator automatically corrects and adjusts the control parameters according to the current speed difference, slope and gear position, and selects the optimal PID control parameters, among which the speed difference, slope and gear position correction coefficients are obtained by querying the preset table; Taking the highest total transmission efficiency as the objective function, an optimization model with the lowest total power consumption is obtained, and taking the optimal total power consumption as the objective function, an optimal operating condition point within the cruise allowable vehicle speed range is calculated, wherein the optimal operating condition point includes an optimal gear position, a requested torque, and an optimal operating vehicle speed; Among them, the highest total transmission efficiency is the objective function and its expression is: Optimal total power consumption EC min The objective function is expressed as: in, v represents the current vehicle speed; θ represents the current slope; F f To represent the road resistance, the slope θ and the current vehicle speed v Look up the table and get, Indicates the efficiency of the microcontroller MCU, Motor efficiency, Transmission efficiency, Rear axle efficiency.

2. The electric vehicle energy-saving cruise control method according to claim 1, characterized in that: The road slope is calculated using the first acceleration and the second acceleration, and the calculation formula is: in, Indicates the road slope. represents the first acceleration, represents the second acceleration, represents the acceleration due to gravity, Time difference, express The speed of the car at the moment, express The speed of the vehicle at the moment.

3. The electric vehicle energy-saving cruise control method according to claim 1, characterized in that: The road slope is filtered according to a preset anti-shake filtering algorithm and then subjected to high-frequency filtering to obtain a stable slope value.

4. An energy-saving cruise control system for an electric vehicle, characterized in that: The system comprises: a memory and a processor, wherein the memory comprises an electric vehicle energy-saving cruise control method program, and when the electric vehicle energy-saving cruise control method program is executed by the processor, the electric vehicle energy-saving cruise control method as claimed in any one of claims 1 to 3 is implemented.

5. A storage medium, characterized in that: The storage medium includes an electric vehicle energy-saving cruise control method program. When the electric vehicle energy-saving cruise control method program is executed by a processor, the steps of an electric vehicle energy-saving cruise control method as claimed in any one of claims 1 to 3 are implemented.

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