CN115158315A

CN115158315A - New energy automobile mountain road cruise control method

Info

Publication number: CN115158315A
Application number: CN202210980768.4A
Authority: CN
Inventors: 张建明; 卢峥; 辛登岭; 曹利军; 魏宏; 李天兵
Original assignee: SAIC Volkswagen Automotive Co Ltd
Current assignee: SAIC Volkswagen Automotive Co Ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-10-11

Abstract

The invention provides a new energy automobile mountain cruise control method, which comprises the following steps: entering the mode under the condition of meeting the starting condition of mountain cruise control; controlling the vehicle speed according to the slope condition, wherein the control method comprises the steps of outputting the torque before releasing the accelerator under the working condition of an upslope, and obtaining the target vehicle speed under different torques according to the vehicle speed difference and the slope difference; under the downhill working condition, the target vehicle speed is obtained under the condition that feedback torque or hydraulic braking force is selected according to the electric quantity of the battery; when the mountain cruise control exit condition occurs, the mode is immediately exited. The invention is convenient and quick to enter and exit the MCC mode, and the control method adaptively adjusts and controls the driving torque and the energy recovery torque, so that the vehicle can keep a proper stable speed to run when going up a slope and going down a slope, thereby saving energy and reducing emission; the user does not need to control the accelerator or brake most of the time, the driving experience is safe and comfortable, and the driving fatigue is reduced.

Description

New energy automobile mountain road cruise control method

Technical Field

The invention relates to the field of new energy automobile cruise control, in particular to a new energy automobile mountain cruise control method in a mountain road scene.

Background

Under the condition of good road conditions such as an expressway, a driver sets a fixed vehicle speed, the vehicle keeps the set vehicle speed under the condition that no target vehicle speed exists in the front, and under the condition that the vehicle is blocked in the front, the vehicle can be actively braked and reduced by auxiliary sensors such as a radar or a camera and the like to drive along with the front vehicle, so that the fatigue of the driver can be relieved, and the energy can be saved.

However, under the complex road conditions of mountains and roads with a plurality of uphill slopes and downhill slopes and a plurality of curves, the vehicle speed variation range is very large, and the proper fixed target vehicle speed is difficult to set; when the vehicle is in a curve, the lost vehicle of the target vehicle can quickly accelerate to a set target vehicle speed, when the vehicle is in a curve, a driver has to use more brakes to reduce the vehicle speed to a proper curve-passing speed, when the vehicle is in a mountain road, the vehicle is easy to accelerate and decelerate suddenly, and the electric quantity consumption of the electric vehicle greatly exceeds the expectation; frequent braking enables the adaptive cruise function to be frequently withdrawn, and the adaptive cruise control function needs to be manually set through the deflector rod when being activated again. Adaptive cruise control is almost useless in mountain road conditions.

On the other hand, for new energy automobiles, energy can be saved by the energy recovery function when mountains and slopes go down, but the energy recovery function of the existing electric vehicle is mostly only two gears: strong energy recuperation shelves and weak energy recuperation shelves, the energy recuperation value difference of these two kinds of gears is great, often can not be fine adaptation mountain road downhill path driving demand: when the vehicle runs on the downhill with a slightly larger slope, the vehicle speed is faster and faster, and the driver is required to step on the brake to control the vehicle speed, so that the thermal load of hydraulic friction braking is increased. When the vehicle runs on a downhill mountain for a long time, the energy consumption is not economical, and the driving is tired and the driving comfort is not good.

Disclosure of Invention

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure.

Aiming at the pain point in the aspects of the current adaptive cruise function and energy recovery, the mountain cruise control MCC system and the method provided by the invention have the advantages that a driver can release an accelerator pedal at any time when ascending, the torque is dynamically adjusted by a power system in a self-adaptive mode to keep the driver in expected vehicle speed running, the driver can release a brake pedal at any time when descending, and the feedback torque is dynamically adjusted by an ESC energy recovery system in a self-adaptive mode to keep the driver in expected vehicle speed running under most conditions.

In order to solve the technical problem, the invention provides a new energy automobile mountain cruise control method, which is characterized by comprising the following steps:

step one, entering the mode under the condition of meeting the starting condition of mountain cruise control;

step two, controlling the vehicle speed according to the gradient condition, wherein the step comprises the steps of outputting the torque before releasing the accelerator under the working condition of an upslope, and obtaining the target vehicle speed under different torques according to the vehicle speed difference and the gradient difference; under the downhill working condition, the target vehicle speed is obtained under the condition that feedback torque or hydraulic braking force is selected according to the electric quantity of the battery;

and step three, when the mountain cruise control exit condition occurs, immediately exiting the mode.

Preferably, the invention further provides a new energy automobile mountain cruise control method, which is characterized in that the second step further comprises the following steps of:

step two a1, taking the output torque at the moment of releasing the accelerator as an initial value;

step two b1, acquiring the current vehicle speed and the longitudinal acceleration in real time, and acquiring a vehicle speed difference value and a gradient difference value between the current vehicle speed and the initial gradient and the target vehicle speed and the initial gradient:

when the current vehicle speed is lower than the target vehicle speed, increasing the output torque, and when the current vehicle speed is higher than the target vehicle speed, reducing the output torque;

when the gradient difference value is a positive value, increasing the output torque, and when the gradient difference value is a negative value, reducing the output torque;

step two c1, further judging when the current vehicle speed is close to the target vehicle speed:

ΔV/V0<±5％

if the condition is met, returning to the step two b1 after the output torque of the previous cycle is maintained;

and if the condition is not met, the power system model returns to the step two b1 after calculating the output torque according to the speed difference value and the gradient difference value.

Preferably, the invention further provides a new energy automobile mountain cruise control method, which is characterized in that under the working condition of a downhill slope, the second step further comprises the following steps:

step two a2, when the electric quantity of the battery is not fully charged, feedback torque is output according to the current longitudinal acceleration;

step two b2, acquiring the current vehicle speed and the longitudinal acceleration in real time, obtaining a vehicle speed difference value and a gradient difference value between the target vehicle speed and the initial gradient, increasing feedback torque when the gradient difference value is a negative value, and reducing the feedback torque when the gradient difference value is a positive value;

step two c2, further judging under the condition that the current vehicle speed is close to the target vehicle speed:

ΔV/V0<±5％

if the condition is met, returning to the step b2 after the feedback torque of the previous cycle is maintained;

if the condition is not met, the step two b2 is returned after the feedback torque is calculated according to the speed difference value and the gradient difference value.

Preferably, the invention further provides a mountain cruise control method for the new energy automobile, which is characterized in that under a downhill working condition, the second step further comprises:

step two a3, when the battery is fully charged, outputting a hydraulic braking force according to the current longitudinal acceleration;

step two b3, acquiring the current vehicle speed and the longitudinal acceleration in real time to obtain a real-time speed difference value and a real-time gradient difference value, increasing hydraulic braking force when the real-time gradient difference value is a negative value, and reducing the hydraulic braking force when the real-time gradient difference value is a positive value;

step two c3, further judging under the condition that the current vehicle speed is close to the target vehicle speed:

ΔV/V0<±5％

if the condition is met, after the last cycle of hydraulic braking force is maintained, the step b3 is carried out;

and if the condition is not met, calculating the hydraulic braking force according to the real-time speed difference value and the real-time gradient difference value, and then switching to the second step b3.

Preferably, the invention further provides a mountain cruise control method for the new energy automobile, which is characterized in that the starting conditions of the mountain cruise control in the first step comprise that:

and pressing a function trigger button, wherein the current vehicle speed is in a trigger speed range and a gear is in a D gear.

Preferably, the invention further provides a mountain cruise control method for the new energy automobile, which is characterized in that the step one and the step two further comprise:

and judging to enter the mountain road cruise control starting condition by taking the accelerator brake switching time interval of more than or equal to 0.5 second, if the condition is not met, keeping the manual driving state, and if the condition is met, prompting to enter the mountain road cruise control mode.

Preferably, the invention further provides a mountain cruise control method for the new energy automobile, which is characterized in that the starting condition of the first step comprises the following steps:

the current vehicle speed meets the triggering speed range of 10kph to 80kph.

Preferably, the invention further provides a mountain cruise control method for the new energy automobile, which is characterized in that in the third step, the exit condition of the mountain cruise control mode comprises:

applying any of a throttle, a brake, an external brake request, an ESP intervention, an ESP controller failure, or a long press of the hill cruise control mode button.

Compared with the prior art, the control method has the advantages that the entering and exiting of the MCC mode are convenient and rapid, the manual setting of a deflector rod is not needed, and the control method adaptively adjusts and controls the driving torque and the energy recovery torque, so that the vehicle can keep a proper and stable speed to run when going up a slope and going down a slope, the electric quantity consumption of a battery can be greatly saved, and the energy conservation and emission reduction are realized; because the user does not need to control the accelerator or brake most of the time, the driving experience is safe and comfortable, and the driving fatigue is reduced; in addition, the fuel vehicle has certain practicability, no energy recovery is available on the traditional fuel vehicle, and the function can be realized only by changing the downhill energy recovery torque control model into a simple hydraulic braking control model.

Drawings

Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Further, although the terms used in the present disclosure are selected from publicly known and used terms, some of the terms mentioned in the specification of the present disclosure may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present disclosure is understood, not simply by the actual terms used but by the meaning of each term lying within.

The above and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the present invention with reference to the accompanying drawings.

FIG. 1 is a flow chart illustrating an MCC mode implementation of the present invention;

FIG. 2 is a flow chart of uphill or downhill vehicle speed control in MCC mode;

FIG. 3 is a graph of energy recovery value versus vehicle deceleration in accordance with the present invention;

fig. 4 is a graphical representation of ESC hydraulic brake pressure versus vehicle deceleration in accordance with the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, and that for a person skilled in the art the application can also be applied to other similar contexts on the basis of these drawings without inventive effort. Unless otherwise apparent from the context, or stated otherwise, like reference numbers in the figures refer to the same structure or operation.

As used in this application and in the claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to include the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be discussed further in subsequent figures.

In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

For ease of description, spatially relative terms such as "over 8230," "upper surface," "above," and the like may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary terms "at 8230; \8230; 'above" may include both orientations "at 8230; \8230;' above 8230; 'at 8230;' below 8230;" above ". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, so that the scope of the present application is not to be construed as being limited. Further, although the terms used in the present application are selected from publicly known and used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Further, it is required that the present application is understood not only by the actual terms used but also by the meaning of each term lying within.

Flow charts are used herein to illustrate operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, various steps may be processed in reverse order or simultaneously. Meanwhile, other operations are added to or removed from these processes.

According to the Mountain Cruise Control (MCC) system and the method, a driver can release an accelerator pedal at any time when ascending, the torque is dynamically adjusted in a self-adaptive manner by a power system to keep the driver to expect the vehicle speed to run, the driver can release a brake pedal at any time when descending, and the feedback torque is dynamically adjusted in a self-adaptive manner by an ESC energy recovery system to keep the driver to expect the vehicle speed to run under most conditions.

Please refer to the MCC pattern flow chart of the present invention as shown in fig. 1.

Step 1, the vehicle-mounted conditions for starting the MCC mode provided by the invention comprise the following three conditions:

condition one, is a function trigger button pressed?

The system of the invention is matched with a function trigger button arranged on a driving console, when entering a mountain road, a driver can press the function button, the MCC mode is in a waiting working state, and if the driver wants to exit the MCC mode, the driver can press the function button for a long time.

Condition two, is the current vehicle speed meet the trigger speed?

The MCC mode can be provided with a function-triggered speed section, due to the characteristics of the motor, the motor gradually quits energy recovery when the motor is below 10kph, so that energy recovery braking cannot be carried out, and for the sake of safe driving on mountain roads, in a preferred embodiment, the speed range of the function-triggered speed section is 10kph to 80kph, so that most of mountain road conditions can be met, and economic energy conservation and safe driving of a new energy automobile on the mountain roads can be met.

Condition three, is the gear meet D gear?

The MCC mode may set a gear determination signal for triggering the precondition.

In the preferred embodiment, the D gear is set as the trigger precondition of the MCC mode, and the downhill energy recovery model is used to adaptively and dynamically output a proper energy recovery value, so that the defects of two different energy recovery gears of the current new energy vehicle are overcome, the original B gear strong sliding energy recovery mode is retained, and unnecessary triggering of the MCC mode by the vehicle at other gears is avoided.

For example, once the MCC mode is in the on function button waiting mode and the vehicle is in the D range and the vehicle speed is between 10kph and 80kph, the MCC mode may be entered as long as the driver releases the brake or throttle for more than 0.5 seconds.

Step 2, in order to avoid frequent switching of accelerator brake of the driver, a time interval is set, and in the preferred embodiment, the time interval of 0.5 second is used as a basis for judging whether the vehicle enters or not;

step 3, if not, the MCC mode is not entered, and the manual driving state is still kept;

and 4, starting the MCC mode by the vehicle under the condition of meeting the condition, and setting an MCC mode working indicator lamp on the instrument so as to prompt the driver that the MCC is in the working mode.

Step 5, respectively controlling the vehicle speed according to the working conditions of the uphill slope or the downhill slope in the MCC mode, and maintaining the target vehicle speed;

step 6, when the MCC exit condition occurs, the function is immediately exited.

The exit conditions include: applying throttle or brake, or external brake request, or ESP intervention, or ESP controller failure, or by long pressing the MCC mode button, the MCC mode can be taken out of service.

The foregoing condition is a relationship of or, triggering exit of MCC upon satisfaction of a condition.

In the main flow given in fig. 1 above, the specific control process step 5 is involved, and a description of further detailed implementation is given with fig. 2:

step 21, an MCC mode is triggered, namely the system enters an MCC mode working mode;

step 22, collecting the vehicle speed V0 and the longitudinal acceleration signal ax0 at the moment by the ESC controller;

specifically, the ESC controller is provided with a wheel speed sensor and can acquire signals of the wheel speed sensor in real time, and the ESC controller can calculate the vehicle speed in real time so as to take the vehicle speed VO when the MCC is intervened at 0.5 second after the accelerator is released or braked as a target vehicle speed.

The longitudinal acceleration sensor is arranged in an ESC controller, can output the value in real time, and the longitudinal acceleration when the MCC is accessed at 0.5 second after the accelerator is released or the brake is recorded as ax0.

In a steady state without applying the brake or the accelerator the value of the longitudinal acceleration corresponds substantially to the value of the grade, for example a longitudinal acceleration of 0.1g corresponds to a longitudinal acceleration of the vehicle on a 10% grade of the vehicle and a longitudinal acceleration of 0.2g corresponds to a longitudinal acceleration of the vehicle on a 20% grade of the vehicle. Under the steady state of not stepping on the brake or the accelerator, when the longitudinal acceleration is a positive value, the vehicle is in an uphill working condition, and when the longitudinal acceleration is a negative value, the vehicle is in a downhill working condition.

Step 23, the system obtains the longitudinal acceleration according to the longitudinal acceleration sensor built in the ESC controller, and can output the value in real time to judge whether the vehicle is an uphill slope or a downhill slope;

specifically, if the longitudinal acceleration satisfies:

ax≥0 (1)

judging the working condition of uphill, and entering step 24;

if the longitudinal acceleration does not satisfy equation (1), but:

ax<0 (2)

judging the working condition of the downhill and turning to the step 25;

step 241, similar to the principle of constant speed cruise control, starting the output torque of the engine to take the torque EM0 at the moment of releasing the accelerator as an initial value,

step 242, the ESC controller collects the vehicle speed V1 and the longitudinal acceleration signal ax1 at the moment in real time;

step 243, calculating the vehicle speed difference value and the gradient difference value in real time:

ΔV＝V1-V0 (3)

Δax＝ax1-ax0 (4)

wherein V1 is the current vehicle speed, V0 is the target vehicle speed, Δ V is the vehicle speed difference, and Δ ax is the gradient difference;

for equation (3), when the vehicle speed difference Δ V is a negative value, i.e., the vehicle speed V1 is lower than the target vehicle speed V0, the output torque EM1 is increased;

when the vehicle speed difference value delta V is a positive value, namely the vehicle speed V1 is higher than the target vehicle speed V0, reducing the output torque EM1;

similarly, an increase or decrease in the ramp value is also reflected in a change in the vehicle speed.

For formula (4), under the condition of ascending, the gradient difference value Δ ax is a positive value, which indicates that the ramp is steep, and the output torque EM1 needs to be increased, and the gradient difference value Δ ax is a negative value, which indicates that the ramp is slow, and the output torque EM1 needs to be decreased.

Step 244, by means of off feedback control, the vehicle speed V1 will approach the target vehicle speed V0 value more and more, depending on whether:

ΔV/V0<±5％ (5)

respectively outputting torque;

step 245, if the formula (5) is satisfied, returning to the step 242 after the torque output EM1 of the previous cycle is maintained;

step 246, if formula (5) is not satisfied, the powertrain model calculates an output torque (EM 1) based on the speed difference and the gradient difference and returns to step 242;

the steps 241 to 246 are combined into a step 24, and the purpose is to continuously and adaptively adjust the torque and realize the uphill cruise control function.

Step 25, when determining the downhill driving condition of the vehicle by ax <0 in step 23, first determine whether the battery is fully charged?

Step 261, if the battery is not fully charged, the downhill speed is controlled by using downhill energy recovery braking, specifically, the ESC controller outputs feedback torque RBM0 according to longitudinal acceleration ax0;

step 262, collecting a vehicle speed V1 and a longitudinal acceleration signal ax1 by the ESC controller in real time;

step 263, calculating the vehicle speed difference and the gradient difference in real time as follows:

ΔV＝V1-V0 (6)

Δax＝ax1-ax0 (7)

step 264, according to whether:

ΔV/V0<±5％ (8)

respectively outputting energy feedback torques;

step 265, if the formula (8) is satisfied, maintaining the feedback torque RBM1 of the previous cycle, and returning to step 262;

step 266, if equation (8) is not satisfied, the ESC controller calculates the feedback torque RBM1 based on the speed difference and the grade difference, and returns to step 262;

the steps 261 to 266 are combined into the step 26, and the purpose is to continuously and adaptively adjust the energy recovery size, so as to realize the downhill energy recovery cruise control function.

Step 271, when it is determined in step 25 that the battery is fully charged, the ESC controller outputs a hydraulic braking force BP0 according to ax0;

step 272, the ESC controller collects the vehicle speed V1 and the longitudinal acceleration signal ax1 in real time;

step 273, calculating the vehicle speed difference value and the gradient difference value in real time as follows:

ΔV＝V1-V0 (9)

Δax＝ax1-ax0 (10)

step 274, depending on whether:

ΔV/V0<±5％ (11)

respectively outputting hydraulic braking force;

step 275, when the formula (11) is satisfied, maintaining the hydraulic braking force BP1 of the previous cycle, and proceeding to step 272;

in step 276, when equation (11) is not satisfied, the ESC controller calculates hydraulic braking force BP1 based on the speed difference and the slope difference, and proceeds to step 272.

The steps 271 to 276 are combined into a step 27, and the purpose is to continuously and adaptively adjust the hydraulic braking power so as to realize the downhill cruise control function.

The vehicle deceleration value corresponding to the ESC controller sending out the energy recovery value on the horizontal path is substantially a linear relationship as shown in fig. 3.

Step 26 is illustrated below for a certain vehicle type:

for example, when the vehicle has a downward component force of about 0.1g on a 10% downhill, the initial energy feedback torque value RBM0 may be set to 600Nm by looking up a map of "energy recovery value and vehicle deceleration" in order to maintain the target vehicle speed for downward travel, corresponding to step 261.

In steps 262 to 263, the esc controller collects the vehicle speed and longitudinal acceleration values in real time, calculates the vehicle speed difference in real time according to the formula (6), and decreases the feedback torque to RBM1 when Δ V is negative, i.e., the vehicle speed V1 is lower than the target vehicle speed V0, and increases the feedback torque to RBM1 when Δ V is positive, i.e., the vehicle speed V1 is higher than the target vehicle speed V0.

Similarly, the increase or decrease of the ramp value is finally reflected in the change of the vehicle speed, the gradient difference value Δ ax is calculated according to the formula (7), and since ax1 and ax0 are negative values when going downhill, Δ ax is negative, which means that the ramp becomes steep, and the feedback torque needs to be increased to be RBM1. When Δ ax is positive, it indicates that the ramp is decreasing, and the feedback torque needs to be decreased to RBM1. Through continuous feedback control, the vehicle speed V1 is closer to the target vehicle speed V0 value.

Entering step 264 to judge according to the formula (8), if the formula is satisfied, according to step 265, maintaining the feedback torque output RBM1 of the previous cycle; if the determination is not met, the ESC system model calculates a feedback torque RBM1 based on the speed differential and the grade differential, according to step 266.

Fig. 4 illustrates the relationship of vehicle deceleration to ESC controller hydraulic braking force on a level road, substantially in a linear relationship, again with a vehicle model illustrating step 27.

When the vehicle is running on a 10% downhill slope, the vehicle has a downward component of about 0.1g, and the vehicle is running downward in order to maintain the target vehicle speed, the ESC hydraulic braking force initial value BP0 may be compared to a map of 9bar by looking up "ESC hydraulic braking pressure vehicle deceleration" according to step 271.

And (4) collecting the vehicle speed and the longitudinal acceleration value in real time by the ESC controller according to the steps 272-273, calculating the vehicle speed difference value delta V in real time according to a formula (9), and when the delta V is a negative value, namely the vehicle speed V1 is lower than the target vehicle speed V0, reducing the hydraulic braking force to be BP1, and when the delta V is a positive value, namely the vehicle speed V1 is higher than the target vehicle speed V0, increasing the hydraulic braking force to be BP1. Similarly, an increase or decrease in the ramp value is also reflected in a change in the vehicle speed; the gradient difference value delta ax is calculated according to the formula (10), and since ax1 and ax0 are negative values when the slope is descending, the delta ax is negative value, which shows that the slope is steep, and the hydraulic braking force needs to be increased to be BP1.Δ ax is a positive value, which indicates that the gradient is gentle, and the hydraulic braking force needs to be reduced to BP1. Through continuous feedback control, the vehicle speed V1 is closer to the target vehicle speed V0 value,

step 274, determining whether equation (11) is satisfied, if so, maintaining the hydraulic braking force BP1 of the previous cycle according to step 275, and if not, calculating the hydraulic braking force BP1 according to the speed difference and the gradient difference by the esc controller according to step 276.

In summary, in order to realize stable target vehicle speed control, the MCC control of the present invention needs to adjust the driving torque or energy recovery value or hydraulic braking force in real time under different gradients according to vehicle conditions, including vehicle weight, motor characteristics, transmission ratio, running energy loss, etc., and compare the driving torque or energy recovery value or hydraulic braking force with the target vehicle speed to realize feedback control. The values of the regulated control variables EM1, RBM1 and BP1 in fig. 2 need to be matched with appropriate variable values according to the actual vehicle conditions to achieve fast convergence of feedback control.

Under the condition of complex driving road conditions on mountain roads, the gradient changes at any time, various sharp curves are formed, the vehicle speed is suddenly changed and suddenly changed, and the adjustment is required continuously, which is different from the adaptive cruise function of the ACC, and the MCC provided by the invention has the following advantages:

firstly, the target speed can be dynamically adjusted at any time by entering the MCC working condition after releasing the accelerator or braking for 0.5 second, and can be suitable for the complex mountain road condition at any time; unlike the ACC function, a fixed target vehicle speed needs to be set in advance.

Secondly, the MCC mode is convenient and quick to enter and exit, and a driving lever is not required to be manually set;

thirdly, the driving torque and the energy recovery torque are adaptively adjusted and controlled, so that the vehicle can keep a proper stable speed to run when going uphill and downhill, the electric quantity consumption of a battery can be greatly saved, and energy conservation and emission reduction are realized;

fourthly, the accelerator or the brake does not need to be controlled most of the time, the driving experience is safe and comfortable, and the driving fatigue is reduced;

fifthly, the heat load of long downhill hydraulic friction braking is reduced, the risk of heat fading is reduced, and the driving safety is improved;

sixthly, only software development and matching are needed without additional sensors and hardware equipment, so that the development cost is saved;

seventh, the MCC mode is strong in expansibility, the system also has certain practicability for the traditional fuel vehicle, energy recovery is not available on the traditional fuel vehicle, and the function can be realized only by changing the downhill energy recovery torque control model into a simple hydraulic braking control model.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. The processor may be one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital signal processing devices (DAPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, or a combination thereof. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media. For example, computer-readable media can include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, magnetic tape \8230;), optical disks (e.g., compact disk CD, digital versatile disk DVD \8230;), smart cards, and flash memory devices (e.g., card, stick, key drive \8230;).

The computer readable medium may comprise a propagated data signal with the computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, and the like, or any suitable combination. A computer-readable medium may be any computer-readable medium that can be coupled to an instruction execution system, apparatus, or device for communicating, propagating, or transmitting a program for use by or in connection with an instruction execution system, apparatus, or device. Program code on a computer readable medium may be propagated over any suitable medium, including radio, electrical cable, fiber optic cable, radio frequency signals, or the like, or any combination of the preceding.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, though not expressly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

Although the present application has been described with reference to the present specific embodiments, it will be recognized by those skilled in the art that the foregoing embodiments are merely illustrative of the present application and that various changes and substitutions of equivalents may be made without departing from the spirit of the application, and therefore, it is intended that all changes and modifications to the above-described embodiments that come within the spirit of the application fall within the scope of the claims of the application.

Claims

1. A new energy automobile mountain road cruise control method is characterized by comprising the following steps:

2. The mountain cruise control method for the new energy automobile according to claim 1, wherein the second step further comprises the following steps under an uphill condition:

ΔV/V0<±5％

3. The mountain cruise control method for the new energy automobile according to claim 2, characterized in that under a downhill condition, the second step further comprises:

step two c2, further judging when the current vehicle speed is close to the target vehicle speed:

ΔV/V0<±5％

4. The mountain cruise control method for the new energy automobile according to claim 3, wherein under a downhill condition, the second step further comprises:

step two c3, further judging when the current vehicle speed is close to the target vehicle speed:

ΔV/V0<±5％

if the condition is met, after the hydraulic braking force of the previous cycle is maintained, the step two b3 is carried out;

5. The mountain cruise control method of the new energy automobile according to claim 4, wherein the mountain cruise control starting condition in the first step comprises that:

6. The mountain cruise control method for the new energy automobile according to claim 5, further comprising the following steps between the first step and the second step:

and taking the accelerator brake switching time interval of more than or equal to 0.5 second as a judgment to enter the mountain cruise control starting condition, if the condition is not met, keeping the manual driving state, and if the condition is met, prompting to enter the mountain cruise control mode.

7. The mountain cruise control method for the new energy automobile according to claim 6, wherein the starting condition of the first step comprises:

the current vehicle speed meets the triggering speed range of 10kph to 80kph.

8. The mountain cruise control method for the new energy automobile according to claim 6, wherein in step three, the exit condition of the mountain cruise control mode comprises: