CN115476837A

CN115476837A - Vehicle speed control method and system and vehicle

Info

Publication number: CN115476837A
Application number: CN202211144082.8A
Authority: CN
Inventors: 伍庆龙
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2022-12-16
Also published as: WO2024060837A1

Abstract

The invention discloses a vehicle speed control method, a vehicle speed control system and a vehicle. The method comprises the following steps: according to the current vehicle speed auxiliary mode, a vehicle speed auxiliary mode signal is sent to an engine control system and a motor controller, the engine control system controls output engine output torque, and the motor controller controls output motor output torque so as to control a vehicle to run at a speed meeting a speed limit condition; acquiring a torque required by a driver under the condition that the detected operation amount of an accelerator pedal is greater than or equal to a preset operation amount threshold value; acquiring an external characteristic torque of the engine; and determining the output torque of the engine and the output torque of the motor according to the torque required by the driver and the external characteristic torque of the engine, and controlling the engine control system to output the output torque of the engine and the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle. The invention improves the fault tolerance and the safety of vehicle speed control.

Description

Vehicle speed control method and system and vehicle

Technical Field

The invention relates to the technical field of vehicle control, in particular to a vehicle speed control method, a vehicle speed control system and a vehicle.

Background

Along with the increasingly wide automobile application field, the automobile application convenience is also more and more emphasized, and the hybrid electric vehicle can design different control strategies due to the particularity of a power system of the hybrid electric vehicle, so that the hybrid electric vehicle is widely concerned.

At present, a hybrid electric vehicle can be driven automatically, and the control mode of the vehicle speed mainly depends on the parameters set by the vehicle. However, depending on the parameters set by the vehicle itself, the driver's demand is not sufficiently considered, and the control of the vehicle speed has problems of low fault tolerance and low safety.

Disclosure of Invention

The invention provides a vehicle speed control method, a vehicle speed control system and a vehicle, which improve the fault tolerance and safety of vehicle speed control.

According to an aspect of the present invention, there is provided a vehicle speed control method including:

according to the current vehicle speed auxiliary mode, a vehicle speed auxiliary mode signal is sent to an engine control system and a motor controller, the engine control system controls output engine output torque, and the motor controller controls output motor output torque so as to control a vehicle to run at a speed meeting a speed limit condition;

acquiring the torque required by the driver under the condition that the detected operation amount of the accelerator pedal is greater than or equal to a preset operation amount threshold value;

acquiring an external characteristic torque of the engine;

and determining the output torque of the engine and the output torque of the motor according to the torque required by the driver and the external characteristic torque of the engine, and controlling the engine control system to output the output torque of the engine and the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle.

According to another aspect of the present invention, there is provided a vehicle speed control system including:

the vehicle controller is used for sending a vehicle speed auxiliary mode signal to the engine control system and the motor controller according to a current vehicle speed auxiliary mode, the engine control system controls the output torque of the engine, and the motor controller controls the output torque of the motor so as to control the vehicle to run at the speed meeting the speed limit condition;

acquiring an external characteristic torque of the engine;

According to another aspect of the present invention, there is provided a hybrid vehicle including:

at least one processor; and

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the engine control system and the motor controller are connected with the processor;

an engine connected to an engine control system;

a motor connected to the motor controller;

the memory stores a computer program executable by the at least one processor, the computer program being executable by the at least one processor to enable the at least one processor to perform the vehicle speed control method of any of the embodiments of the invention.

According to the technical scheme of the embodiment of the invention, a vehicle speed auxiliary mode signal is sent to an engine control system and a motor controller according to a current vehicle speed auxiliary mode, the engine control system controls the output engine output torque, and the motor controller controls the output motor output torque so as to control a vehicle to run at a speed meeting a speed limit condition; acquiring the torque required by the driver under the condition that the detected operation amount of the accelerator pedal is greater than or equal to a preset operation amount threshold value; acquiring an external characteristic torque of the engine; the method comprises the steps of determining engine output torque and motor output torque according to torque required by a driver and external characteristic torque of an engine, controlling an engine control system to output the engine output torque and controlling a motor controller to output the motor output torque so as to adjust the running speed of the vehicle, solving the problems of low fault tolerance and low safety in vehicle speed control, and improving the fault tolerance and the safety of vehicle speed control.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of a method for controlling vehicle speed according to one embodiment of the present invention;

FIG. 2 is a flowchart of a vehicle speed control method according to a second embodiment of the present invention;

fig. 3 is a schematic diagram illustrating a navigation module determining a speed limit value and a distance between road segments according to a second embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a camera module determining a speed limit and a distance between road segments according to a second embodiment of the present invention;

fig. 5 is a schematic diagram illustrating a camera module determining a speed limit and a distance between road segments according to a second embodiment of the present invention;

FIG. 6 is a flowchart of a method for controlling vehicle speed according to a third embodiment of the present invention;

FIG. 7 is a diagram showing a relationship between torque and rotational speed when the driver's required torque is equal to or less than the external characteristics of the engine according to the third embodiment of the present invention;

FIG. 8 is a graph showing the relationship between torque and rotational speed when the driver demand torque is larger than the external characteristics of the engine according to the third embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a hybrid electric vehicle powertrain according to a fourth embodiment of the present invention;

FIG. 10 is a schematic diagram of a vehicle speed control system according to a fourth embodiment of the present invention;

FIG. 11 is a network topology diagram of a vehicle speed control system according to a fourth embodiment of the present invention;

fig. 12 is a schematic structural diagram of a hybrid vehicle in which the embodiment of the invention is implemented.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example one

Fig. 1 is a flowchart of a vehicle speed control method according to an embodiment of the present invention. The embodiment is applicable to the condition of controlling the speed of the new energy hybrid electric vehicle, and the method can be executed by a speed control device, the speed control device can be realized in a hardware and/or software mode, and the speed control device can be configured in electronic equipment, in particular in a vehicle-mounted terminal. As shown in fig. 1, the method includes:

and S110, sending a vehicle speed auxiliary mode signal to an engine control system and a motor controller according to the current vehicle speed auxiliary mode, wherein the engine control system controls the output torque of the engine, and the motor controller controls the output torque of the motor so as to control the vehicle to run at a speed meeting a speed limit condition.

Wherein the current vehicle speed assist mode may be a mode in which the current assist controls the vehicle speed. Optionally, the current vehicle speed assist mode may include: an automatic vehicle speed assist mode, a manual vehicle speed assist mode, and the like. The function activation conditions and the exit conditions for different current vehicle speed assist modes are different. The function activation condition is the starting condition of the current vehicle speed control mode; the exit condition may be an exit condition of the current vehicle speed control mode. For example, when the current vehicle speed control mode is set to the automatic vehicle speed auxiliary mode, the function activating condition should satisfy all of the following conditions: (1) each controller of the vehicle has been turned on; (2) The states of the camera module and the navigation module are non-fault states; (3) The camera module, the navigation module and the gateway node have no loss fault; and (4) selecting an automatic vehicle speed assisting mode by the driver. The exit condition includes at least one of: (1) A limp home fault of the generator control system or a power down fault of the motor controller due to the fault; (2) The camera module, the navigation module and the gateway node lose faults; (3) starting a cruise system and starting a cruise function; and (4) the driver selects the non-automatic vehicle speed auxiliary mode. Setting a current vehicle speed control mode as a manual vehicle speed auxiliary mode, (1) starting each controller of the vehicle; (2) The camera module, the navigation module and the gateway node have no loss fault; and (3) selecting a manual vehicle speed auxiliary mode by a driver. The exit condition includes at least one of: (1) A limp home fault of the generator control system or a power down fault of the motor controller due to the fault; (2) The camera module, the navigation module and the gateway node lose faults; (3) starting a cruise system and starting a cruise function; and (4) the driver selects the non-manual vehicle speed auxiliary mode.

An Engine Management System (EMS) may be a System that controls output torque of an Engine. A Motor Control Unit (MCU) may be a system that controls an output torque of the Motor.

The vehicle speed assist mode signal may be a vehicle speed control signal corresponding to the current vehicle speed assist mode. Optionally, the vehicle speed assist mode signal may include: current vehicle speed assist mode, output torque of the engine and the motor in the current vehicle speed assist mode, and the like. The output torque of the engine may be a torque of a drive shaft of the engine-controlled vehicle. The output torque of the motor may be torque of a drive shaft of the vehicle controlled by the motor.

The speed limit condition may be a condition of limiting the speed. Optionally, the speed limit condition may include: road speed limit conditions, vehicle self speed limit conditions and the like.

Specifically, the vehicle control unit may send a vehicle speed assist mode signal to the engine control system and the motor controller according to the current vehicle speed assist mode, the engine control system and the motor controller receive the vehicle speed assist mode signal including information of output torques of the engine and the motor in the current vehicle speed assist mode, the engine control system controls the output torque of the engine, the motor controller controls the output torque of the motor, and the output torques of the engine and the motor control tires through the driving shaft to control the vehicle to run at a speed satisfying the speed limit condition.

And S120, acquiring the required torque of the driver when the operation amount of the accelerator pedal is detected to be larger than or equal to the preset operation amount threshold value.

The operation amount may be an opening degree value of an accelerator pedal. Illustratively, the operation amount may be 20%, 40%, 60%, 80%, or the like. The preset operation amount threshold may be an upper limit value of an opening degree of an accelerator pedal set in advance. An exemplary preset operation amount threshold may be 80%. The preset operation amount threshold value may be set and adjusted according to an empirical value of a technician. The driver required torque can be torque comprehensively calculated by the vehicle controller based on vehicle parameters such as gear shifting operation of the driver, an accelerator pedal, a brake pedal and vehicle speed. For example, the voltage value of the sensor may be set according to the operation amount of the accelerator pedal, and the vehicle control unit may determine the corresponding driver required torque according to different voltage values.

Specifically, the vehicle control unit may detect an operation amount of an accelerator pedal, and may calculate and acquire a torque required by the driver according to the operation amount of the accelerator pedal when the detected operation amount of the accelerator pedal is greater than or equal to a preset operation amount threshold value.

And S130, acquiring the external characteristic torque of the engine.

The engine external characteristic torque may be a torque on an engine external characteristic curve.

Specifically, the vehicle control unit can acquire the external characteristic torque of the engine.

And S140, determining the output torque of the engine and the output torque of the motor according to the torque required by the driver and the external characteristic torque of the engine, controlling the engine control system to output the output torque of the engine and controlling the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle.

Specifically, the driver required torque and the engine external characteristic torque may be compared, and if the driver required torque is less than or equal to the engine external characteristic torque, the driver required torque is used as the engine output torque, and the engine control system is controlled to output the engine output torque; and if the driver required torque is larger than the external characteristic torque of the engine, determining a difference value between the driver required torque and the external characteristic torque of the engine to be used as the output torque of the motor, using the external characteristic torque of the engine as the output torque of the engine, controlling the engine control system to output the output torque of the engine and controlling the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle.

In an optional embodiment of the present invention, after controlling the engine to output the engine output torque and controlling the motor to output the motor output torque, the method further comprises:

and under the condition that the detected operation amount of the accelerator pedal is smaller than the preset operation amount threshold value and the current vehicle speed of the vehicle is smaller than the speed limit value corresponding to the current vehicle speed auxiliary mode, controlling the vehicle to run at the speed meeting the speed limit condition according to the current vehicle speed auxiliary mode.

Specifically, the vehicle controller may control the vehicle to run at a speed satisfying the speed limit condition according to the current vehicle speed auxiliary mode and the speed limit condition when detecting that the operation amount of the accelerator pedal is smaller than the preset operation amount threshold and the current vehicle speed is smaller than the speed limit value corresponding to the current vehicle speed auxiliary mode.

According to the scheme, under the condition that the operation amount of the accelerator pedal is smaller than the preset operation amount threshold value and the current vehicle speed meets the speed limit, the vehicle controller controls the vehicle to continuously run at the speed meeting the speed limit condition in the current vehicle speed auxiliary mode, so that the vehicle is guaranteed to run according to the current auxiliary mode without intervention of driver requirements, the condition that the driver steps on the accelerator pedal by mistake is avoided, and the comprehensiveness of vehicle speed control is improved.

According to the embodiment of the invention, a vehicle speed auxiliary mode signal is sent to an engine control system and a motor controller according to a current vehicle speed auxiliary mode, the engine control system controls the output engine output torque, and the motor controller controls the output motor output torque so as to control a vehicle to run at a speed meeting a speed limit condition; acquiring the torque required by the driver under the condition that the detected operation amount of the accelerator pedal is greater than or equal to a preset operation amount threshold value; acquiring an external characteristic torque of the engine; determining an engine output torque and a motor output torque according to the torque required by a driver and the external characteristic torque of the engine, and controlling an engine control system to output the engine output torque and a motor controller to output the motor output torque so as to adjust the running speed of the vehicle; the torque required by a driver is introduced through the operation amount of an accelerator pedal, and the fault tolerance and the safety of vehicle speed auxiliary control are improved through the intervention of the torque required by the driver.

Example two

Fig. 2 is a flowchart of a vehicle speed control method according to a second embodiment of the present invention, where in this embodiment, based on the above embodiment, the method further refines controlling the vehicle to run at a speed meeting the speed limit condition according to the current vehicle speed auxiliary mode to obtain a speed limit value corresponding to the current vehicle speed auxiliary mode; comparing the current speed of the vehicle with the speed limit value; and controlling the vehicle to run at the speed less than or equal to the speed limit value according to the comparison result of the current vehicle speed and the speed limit value. As shown in fig. 2, the method includes:

and S210, acquiring a speed limit value corresponding to the current vehicle speed auxiliary mode.

The speed limit value can be a speed limit value determined by the current vehicle speed control mode. Optionally, the speed limit value may be set by a user (i.e., a driver) or a technician through a cruise system, or may be obtained by analyzing a module (e.g., a navigation module and a camera module) in the vehicle, which is used for acquiring and analyzing the speed limit information.

Specifically, the vehicle control unit may obtain a current vehicle speed assist mode and obtain a speed limit value corresponding to the current vehicle speed assist mode.

And S220, comparing the current speed of the vehicle with the speed limit value.

Specifically, the current vehicle speed of the vehicle may be compared with the speed limit value corresponding to the current vehicle speed limit mode.

And S230, controlling the vehicle to run at the speed less than or equal to the speed limit value according to the comparison result of the current vehicle speed and the speed limit value.

Specifically, if the comparison result of the current vehicle speed and the speed limit value is that the current vehicle speed is less than or equal to the speed limit value, controlling the vehicle to run at the current vehicle speed; and if the comparison result of the current vehicle speed and the speed limit value is that the current vehicle speed is greater than the speed limit value, controlling the vehicle to run at the speed corresponding to the speed limit value.

And S240, acquiring the required torque of the driver under the condition that the operation amount of the accelerator pedal is detected to be larger than or equal to the preset operation amount threshold value.

And S250, acquiring the external characteristic torque of the engine.

And S260, determining the output torque of the engine and the output torque of the motor according to the torque required by the driver and the external characteristic torque of the engine, controlling the engine control system to output the output torque of the engine and controlling the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle.

In another alternative embodiment of the present invention, the current vehicle speed assist mode includes a manual vehicle speed assist mode; the method for acquiring the speed limit value corresponding to the current vehicle speed auxiliary mode comprises the following substeps:

step a, the cruise system receives a speed limit value input by a user.

Specifically, the Cruise Control (CC) may receive a speed limit value input by a user. Optionally, the user may input the speed limit value through a set signal corresponding to a key of the speed limit value on the vehicle. The set signal may be preset by a driver or a technician.

And b, receiving the speed limit value sent by the cruise system.

Specifically, the vehicle control unit receives a speed limit value sent by the cruise system.

For example, the driver may operate a Set button to Set the speed limit value, and the cruise system will receive a Set signal corresponding to the Set + key or the Set-key. Optionally, the vehicle controller may determine whether a time for the driver to press the Set + key or the Set-key is less than a calibration value (for example, 1 s), and if so, the vehicle controller controls the vehicle speed to increase or decrease at a 1-level rate; if not, the vehicle controller controls the vehicle speed to increase or decrease at a 2-level speed; and after the Set key is Set, the vehicle control unit takes the final speed limit value as the speed limit value of the vehicle speed control system. Wherein, the vehicle speed is increased or decreased into two stages: the 1 st rate and the 2 nd rate can be respectively set to be 5km/h and 10km/h as an example; the regulating range of the speed limit value can also be calibrated, for example, the regulating range is 50-200 km/h.

And under the manual vehicle speed assisting mode, determining whether the output torque of the engine or the output torque of the motor needs to be adjusted to reduce the current vehicle speed according to the current vehicle speed and the speed limit value acquired by the cruise system. The vehicle controller should control the vehicle to reduce the current vehicle speed below the speed limit value within a preset time (for example, within 30 s). The vehicle speed reduction is realized by adjusting the output torque of the engine and the output torque of the motor. When the current speed can not be adjusted to be reduced below the speed limit value within the preset time, the driver needs to be reminded of the current overspeed information and can be informed of the speed reduction of the vehicle by stepping on the brake pedal, and the operation of the driver is prior under the condition.

According to the scheme, under the condition of the manual vehicle speed auxiliary mode, the cruise system is used for receiving the speed limit value input by the user and sending the speed limit value to the vehicle control unit, and the vehicle control unit is used for receiving the speed limit value sent by the cruise system and taking the speed limit value as the speed limit value corresponding to the manual vehicle speed auxiliary mode, so that the speed limit value in the manual vehicle speed auxiliary mode is determined, and the flexibility and the accuracy of vehicle speed control are guaranteed.

In an alternative embodiment of the invention, the current vehicle speed assist mode comprises an automatic vehicle speed assist mode; the method for acquiring the speed limit value corresponding to the current vehicle speed auxiliary mode comprises the following substeps:

and A, acquiring at least one vehicle speed limiting source.

Wherein, the vehicle speed limit source can be the source of the vehicle speed limit information. The vehicle speed limiting source can receive the speed limiting information of the vehicle and analyze and calculate the corresponding speed limiting value. Illustratively, a navigation module and a camera module can be used. The vehicle can obtain the speed limit information from the navigation module and the camera module.

Specifically, the vehicle control unit may obtain at least one vehicle speed limiting source.

And B, screening target vehicle speed limiting sources from the vehicle speed limiting sources.

Wherein the target vehicle speed limit source may be a vehicle speed limit source that actually determines the speed limit information.

Specifically, the vehicle speed limit sources may be prioritized among the at least one vehicle speed limit source, and when a function of a vehicle speed limit source ranked in the front is turned on, the vehicle speed limit source ranked in the front may be selected as the target vehicle speed limit source. For example, if the vehicle speed limiting source is a camera module, a navigation module and other modules, the priority may be set as: camera modules, navigation modules, and other modules. When the functions of the camera module are started, the camera module is selected as a target vehicle speed limiting source no matter whether the functions of the navigation module and other modules are started or not; when the functions of the camera module are not started and the functions of the navigation module are started, the navigation module is selected as a target vehicle speed limiting source no matter whether the functions of other modules are started or not; and when the functions of the camera module and the navigation module are not started and the functions of other modules are started, taking the other modules as target vehicle speed limiting sources.

And step C, acquiring a speed limit value provided by the target vehicle speed limiting source, and determining the speed limit value as the speed limit value corresponding to the current vehicle speed auxiliary mode.

Specifically, the target vehicle speed limiting source may receive speed limiting information of the vehicle, and obtain a corresponding speed limiting value through analysis and calculation. The vehicle control unit obtains a speed limit value provided by a target vehicle speed limiting source, and determines the speed limit value as a speed limit value corresponding to the current vehicle speed auxiliary mode.

In the automatic speed auxiliary mode, the vehicle collects the speed limit information of the current road through a speed limiting source (such as a camera module and a navigation module) and controls the current speed of the vehicle to be within a speed limit value. Optionally, the vehicle control unit may obtain the speed limit information according to the real-time position of the vehicle or route planning through the navigation module. Meanwhile, the speed limit information is obtained by acquiring the speed limit signboard in consideration of a vehicle speed limit (e.g., a speed limit signboard) in which the real-time position of the vehicle is known. When the navigation module detects that the vehicle enters a new speed area or the camera module detects a new speed limit signboard, the speed limit signboard is detected and fed back to the vehicle controller, and warning for a driver is achieved.

According to the scheme, at least one vehicle speed limiting source is screened and determined as the target vehicle speed limiting source, and the speed limiting value corresponding to the current vehicle speed auxiliary driving mode is determined according to the target vehicle speed limiting source, so that screening of a plurality of vehicle speed limiting sources is realized, the accuracy of determining the speed limiting value is ensured, and the accuracy of vehicle speed control is further ensured.

In an alternative embodiment of the present invention, the vehicle speed limit source includes: the system comprises a navigation module and a camera module; screening a target vehicle speed limit source from among the vehicle speed limit sources, including:

and step I, detecting the distance between the vehicle and the speed limit signboard by the camera module.

The camera module can be a module for shooting the speed-limiting signboard and detecting the distance between the vehicle and the signboard. The speed limit signboard can be a warning board of a speed limit sign on a road. Optionally, the speed limit signboard may include information such as a speed limit value of a road.

Specifically, the camera module shoots the speed-limiting signboard, and the distance between the vehicle and the speed-limiting signboard is detected according to an image of the speed-limiting signboard or a distance measuring device of the vehicle and the like.

And II, receiving the distance by the vehicle control unit, and screening a target vehicle speed limiting source from the vehicle speed limiting sources according to the distance.

Specifically, the vehicle control unit receives the distance sent by the camera module, and according to the distance between the vehicle and the speed-limiting signboard, if the distance between the vehicle and the speed-limiting signboard is less than or equal to a preset distance, the camera module is used as a target vehicle speed limiting source; and if the distance between the vehicle and the speed-limiting signboard is greater than the preset distance or the camera module does not detect the speed-limiting signboard, taking the navigation module as a target vehicle speed limiting source.

Fig. 3 is a schematic diagram of the navigation module determining the speed limit and the distance between road segments according to the second embodiment of the present invention. As shown in fig. 3, the navigation module needs to send two speed limit values and a distance to the vehicle controller, which specifically includes: the speed limit value of the current road section, the speed limit value of the next road section and the distance between the road sections. And the current road section speed limit value is the speed limit value allowed by the current road section judged by the navigation module. The speed limit target of the next road section is the speed limit value allowed by the next road section judged by the navigation module. Optionally, the speed limit value of the current road section and the speed limit value of the next road section may be determined according to map data in the navigation module. The distance between the road sections is the distance between the vehicle and the limit of the speed limit value of the next road section.

Fig. 4 and fig. 5 are schematic diagrams of determining a speed limit value and a distance between road segments by using a camera module according to a second embodiment of the present invention. As shown in fig. 4 and 5, the camera module needs to send a speed limit value and a distance to the vehicle control unit, and specifically includes: the speed limit value of the speed limit signboard detected by the camera and the distance between the vehicle and the speed limit signboard. When the distance is a negative value, the distance that the vehicle approaches the speed limit sign is represented, and the vehicle speed corresponding to the speed limit value of the speed limit sign shot by the camera needs to be executed to control the current vehicle speed; when the distance is positive, the vehicle is far away from the speed limit sign. Optionally, when the distance is within the preset distance, the speed limit value may be a speed limit value corresponding to the speed limit signboard; when the distance is beyond the preset distance, the speed limit value can be the speed limit value determined by the navigation system.

In the automatic vehicle speed assisting mode, optionally, whether the output torque of the engine or the output torque of the motor needs to be adjusted to reduce the current vehicle speed can be determined according to the current vehicle speed and the speed limit value of the vehicle speed limiting source serving as the camera module. And determining whether the output torque of the engine or the output torque of the motor needs to be adjusted to reduce the current vehicle speed according to the current vehicle speed and the speed limit value of the navigation module serving as a vehicle speed limiting source. The vehicle speed reduction is realized by adjusting the output torque of the engine and the output torque of the motor. When the current speed can not be adjusted to be reduced below the speed limit value within the preset time, the driver needs to be reminded of the current overspeed information and can be informed of the speed reduction of the vehicle by stepping on the brake pedal, and the operation of the driver is prior under the condition.

According to the scheme, the speed limiting source is embodied into the navigation module and the camera module, the map data in the navigation module and the camera module are utilized to collect the speed limiting signboard, the speed limiting information is obtained, the target speed limiting source is screened in the navigation module and the camera module, the flexibility of selecting the target speed limiting source is achieved, and the accuracy of obtaining the speed limiting value is guaranteed.

In an alternative embodiment of the invention, the current vehicle speed assist mode comprises an automatic vehicle speed assist mode; the vehicle speed control method further includes:

and controlling the vehicle to keep running at the current speed under the condition that the available speed limiting source is detected to be incapable of acquiring the speed limiting value.

The situation that the vehicle speed limiting source cannot acquire the speed limit value may include, but is not limited to, at least one of the following: (1) the navigation module has normal functions but is not started; (2) The navigation module enters an environment with poor signals (such as a tunnel) and cannot acquire speed limit information; (3) The camera module cannot identify the speed-limiting signboard due to environmental reasons; (4) No speed limit signboard or vehicle has passed the speed limit signboard in the current environment.

Specifically, the vehicle controller controls the vehicle to keep the current vehicle speed running when the vehicle controller detects that the vehicle speed limiting source functions normally (i.e., no fault occurs) but cannot acquire the speed limit value.

Illustratively, if the vehicle speed limiting source is the navigation module and the camera module, whether the functions of the navigation module and the camera module are normal or not is detected, and whether a fault exists or not is detected. And if the navigation module and the camera module are not in fault but cannot acquire the speed limit value, the vehicle controller controls the vehicle to keep the current vehicle speed. As shown in table 1 below, a determination of the target vehicle speed limit source is provided when the vehicle speed limit source is a navigation module and a camera module.

TABLE 1 determination of target vehicle speed Source of restrictions

Camera module	Navigation module	Speed limit value	Vehicle speed limiting source
				Is not defined	Activation	Navigation module speed limit value	Navigation module
Activation	Is not defined	Camera module speed limit	Camera module
				Activation	Activation	Camera module speed limit	Camera module
Fault of	Activation	Navigation module speed limit value	Navigation module
				Activation	Fault of	Camera module speed limit	Camera module
Fault of	Is not defined	Is not defined	Is not defined
				Is not defined	Fault of	Is not defined	Is not defined
Fault of	Fault of	Fault of	Fault of
				Is not defined	Is not defined	Is not defined	Is not defined

The activation of the vehicle speed limiting source is the normal opening of the function of the vehicle speed limiting source; the vehicle speed limiting source is not defined as the vehicle speed limiting source which has normal function but can not obtain the speed limit value; the failure of the vehicle speed limit source is a vehicle speed limit source failure. Illustratively, when the camera module is activated, and the navigation module is activated, undefined or failed, the vehicle speed limiting source is the camera module, and the speed limit value is the camera module speed limit value. When the camera module is in fault or undefined and the navigation module is activated, the speed limiting source is the navigation module and the speed limiting value is the navigation module speed limiting value. When the camera module or the navigation module is undefined, the vehicle speed limit source is displayed as undefined, and the vehicle continues to run along the current vehicle speed. When the camera module or the navigation module is in fault, the vehicle speed limiting source displays that the vehicle speed limiting source is in fault, the speed limiting value is in fault, and the vehicle cannot start the automatic vehicle speed auxiliary mode.

According to the scheme, the vehicle is controlled to keep running at the current speed under the condition that the available speed limiting source cannot acquire the speed limiting value, so that the normal running of the vehicle is ensured under the condition that the speed limiting source cannot acquire the speed limiting value, and the safety of vehicle speed control is improved.

According to the technical scheme of the embodiment of the invention, the speed limit value of the vehicle is determined by utilizing the current vehicle speed auxiliary mode, the current vehicle speed and the speed limit value are compared, and the vehicle is controlled to run at the speed less than or equal to the speed limit value according to the comparison result, so that the condition of overspeed is avoided in the running process of the vehicle, the safety of vehicle speed control is improved, and the running safety of the vehicle is further ensured.

EXAMPLE III

Fig. 6 is a flowchart of a vehicle speed control method according to a third embodiment of the present invention. On the basis of the embodiment, the method further refines the engine output torque and the motor output torque determined according to the driver required torque and the engine external characteristic torque into a difference value between the engine external characteristic torque and the engine loss torque, and determines the maximum external characteristic torque of the engine; comparing the driver required torque with the engine external characteristic torque; selecting an engine output torque from the driver required torque and the maximum external characteristic torque of the engine according to a comparison result of the driver required torque and the external characteristic torque of the engine; calculating a difference value between the driver required torque and the net engine torque, and determining the output torque of the first motor; calculating a difference value between the driver required torque and the maximum external characteristic torque of the engine, and determining the output torque of the second motor; the motor output torque is selected from the first motor output torque and the second motor output torque according to a result of comparison between the driver required torque and the engine-outside characteristic torque. As shown in fig. 6, the method includes:

and S310, sending a vehicle speed auxiliary mode signal to an engine control system and a motor controller according to the current vehicle speed auxiliary mode, wherein the engine control system controls the output engine output torque, and the motor controller controls the output motor output torque so as to control the vehicle to run at the speed meeting the speed limit condition.

And S320, acquiring the required torque of the driver under the condition that the operation amount of the accelerator pedal is detected to be larger than or equal to the preset operation amount threshold value.

And S330, acquiring the external characteristic torque of the engine.

And S340, calculating a difference value between the external characteristic torque of the engine and the lost torque of the engine, and determining the maximum external characteristic torque of the engine.

The engine loss torque may be a loss torque of a process of engine torque conduction, among others. Alternatively, the lost torque of the engine may include: heat loss torque, drive loss torque, and the like.

The engine maximum external characteristic torque may be a maximum external characteristic torque that the engine can achieve.

Specifically, the vehicle control unit may calculate a difference between the engine external characteristic torque and the engine loss torque, and determine the difference as a maximum external characteristic torque of the engine.

And S350, comparing the driver demand torque with the engine external characteristic torque.

Specifically, the vehicle control unit may calculate a difference between the external characteristic torque of the engine and the engine loss torque, and determine the maximum external characteristic torque of the engine from the difference.

And S360, selecting the engine output torque from the driver required torque and the maximum external characteristic torque of the engine according to the comparison result of the driver required torque and the external characteristic torque of the engine.

Specifically, if the result of comparison between the driver required torque and the engine external characteristic torque is that the driver required torque is equal to or less than the engine external characteristic torque, the driver required torque is taken as the engine output torque. And if the comparison result of the driver required torque and the external characteristic torque of the engine shows that the driver required torque is larger than the external characteristic torque of the engine, taking the maximum characteristic torque of the engine as the output torque of the engine.

And S370, calculating the difference value between the driver required torque and the net engine torque, and determining the output torque of the first motor.

Where the net engine torque is the difference between the engine combustion torque and the engine lost torque. Engine combustion torque is the torque that can be generated by engine combustion. The first motor output torque may be an optional value of the motor output torque when the driver required torque is equal to or less than the engine external characteristic torque.

Specifically, the vehicle control unit may calculate a difference between a driver demand torque and a net engine torque, and determine the difference as the first motor output torque.

And S380, calculating a difference value between the driver required torque and the maximum external characteristic torque of the engine, and determining the output torque of the second motor.

The second motor output torque and the first motor output torque may be selectable values of the motor output torque when the driver demand torque is greater than the engine external characteristic torque.

Specifically, the vehicle control unit may calculate a difference between the driver demand torque and the maximum external characteristic torque of the engine, and determine the difference as the second motor output torque.

And S390, selecting the motor output torque from the first motor output torque and the second motor output torque according to the comparison result of the driver required torque and the engine external characteristic torque, and controlling the engine control system to output the engine output torque and controlling the motor controller to output the motor output torque so as to adjust the running speed of the vehicle.

Specifically, if the comparison result between the driver required torque and the engine external characteristic torque is that the driver required torque is equal to or less than the engine external characteristic torque, the first motor output torque is the motor output torque. And if the comparison result of the driver required torque and the engine external characteristic torque shows that the driver required torque is larger than the engine external characteristic torque, taking the second motor output torque as the motor output torque. The vehicle control unit controls the engine control system to output the output torque of the engine, and controls the motor controller to output the output torque of the motor so as to adjust the running speed of the vehicle.

Fig. 7 is a diagram of torque and rotational speed relationships when the driver-requested torque is equal to or less than the engine-external characteristic according to the third embodiment of the present invention. Fig. 8 is a torque-rotation speed relationship diagram when the driver-requested torque is greater than the engine-out characteristic according to the third embodiment of the present invention. As shown in fig. 7 and 8, the triangle indicates a point corresponding to the driver required torque, and the circle indicates a point corresponding to the engine output torque.

As shown in fig. 7, if the driver required torque is less than or equal to the engine external characteristic torque, the maximum engine external characteristic torque is the difference between the engine external characteristic torque and the engine loss torque, and the engine net torque is the difference between the engine combustion torque and the engine loss torque, the vehicle control unit notifies the engine control system through the command, the engine control system controls the engine output torque to be the driver required torque, the vehicle control unit notifies the motor controller through the command, and the motor controller controls the motor output torque to be the difference between the engine combustion torque and the engine loss torque, that is, compensates a part of the torque of the engine through the motor, thereby realizing the rapid acceleration or overtaking control in the automatic vehicle speed assisting mode.

As shown in fig. 8, if the driver demand torque is greater than the engine external characteristic torque and the engine maximum external characteristic torque is a difference between the engine external characteristic torque and the engine loss torque, the vehicle control unit notifies the engine control system through the command, the engine control system controls the engine output torque to be the engine maximum external characteristic torque, the vehicle control unit notifies the motor controller through the command, and the motor controller controls the motor output torque to be a difference between the driver demand torque and the engine maximum external characteristic torque, thereby implementing the rapid acceleration or passing control in the automatic vehicle speed assist mode.

The technical scheme of the embodiment of the invention determines the maximum external characteristic torque of the engine by calculating the difference between the external characteristic torque of the engine and the loss torque of the engine; comparing the driver required torque with the engine external characteristic torque; selecting an engine output torque from the driver required torque and the engine maximum external characteristic torque according to a comparison result of the driver required torque and the engine external characteristic torque; calculating a difference value between the driver required torque and the net engine torque, and determining the output torque of the first motor; calculating a difference value between the driver required torque and the maximum external characteristic torque of the engine, and determining the output torque of the second motor; selecting a motor output torque from the first motor output torque and the second motor output torque according to a comparison result of the driver required torque and the engine external characteristic torque; the process that the engine output torque and the motor output torque can be determined according to different driver required torques is guaranteed, the requirements of a driver are fully considered, the fault tolerance and the safety of vehicle speed control are guaranteed, and the running smoothness and the safety of a vehicle are guaranteed.

Example four

Fig. 9 is a schematic structural diagram of a hybrid electric vehicle power system according to a fourth embodiment of the present invention. As shown in fig. 9, the power system of the hybrid vehicle mainly includes: the device comprises an engine, a motor, a power battery, a direct current converter, a storage battery, a gearbox, a clutch, a driving shaft and the like. One side of the motor is connected with the engine through a clutch, the other side of the motor is connected with the gearbox, and all parts are controlled by controllers of the parts respectively.

Fig. 10 is a schematic structural diagram of a vehicle speed control system according to a fourth embodiment of the present invention. As shown in fig. 9 and 10, the vehicle speed control system includes: a Vehicle Control Unit (VCU), an Engine Control System (EMS), a Motor Control Unit (MCU), a Battery Management System (BMS), a Transmission Control Unit (TCU), a Vehicle Stability Control System (SCS), a Gateway System (GW), a Navigation Module (navi Control Module, NACM), a Camera Module (Front Vehicle Camera Module, FVCM), an Instrument System (Instrument Control, IC), and a Cruise System (CC).

The vehicle speed control system has the function that under the coordination of map data such as a camera module, a navigation module, a speed limit sign and the like, when a driver exceeds a road speed limit value, the vehicle speed control system reminds the driver to decelerate by adopting a notification, warning or forcing mode and the like. The vehicle speed control system is realized by a vehicle controller, and the vehicle speed control system mainly comprises the following modes: an automatic vehicle Speed Assistance (ISA) mode and a Manual vehicle Speed Assistance (MSA) mode.

The camera module sends a camera request state and speed to the vehicle control unit, and identifies the distance between the speed-limiting signboard and the vehicle so as to determine the speed-limiting value of the current vehicle and the distance between the current vehicle and the speed-limiting signboard; the navigation module sends the current vehicle speed auxiliary mode, the navigation request state, the current road section speed limit value and the next road section speed limit value to the vehicle control unit, and identifies the distance between the road sections so as to feed back the current vehicle speed limit value and the distance between the current vehicle speed limit value and the speed limit signboard to the vehicle control unit.

For example, if a driver operates a soft switch key of the vehicle speed control system on a display screen corresponding to the navigation module, a vehicle speed auxiliary mode signal is sent to the vehicle control unit, and the driver operates the soft switch key of the vehicle speed control system to indicate that the vehicle is required to be controlled to run in an automatic vehicle speed auxiliary mode or a manual vehicle speed auxiliary mode. The vehicle control unit sends the vehicle speed control system state, the speed limit value and the vehicle speed limiting source state to the instrument system so as to feed back the current vehicle running state to the vehicle control unit.

The vehicle control unit sends a braking auxiliary request state and a request value to a vehicle stability control system; and the vehicle control unit feeds back the current vehicle speed auxiliary mode state to the camera module, the navigation module and the instrument system.

Under the current vehicle speed auxiliary mode, if the vehicle encounters torque intervention of the vehicle stability control system, such as the situation that the vehicle turns sharply or brakes and the like, the vehicle stability control system performs vehicle stability torque intervention processing related to a chassis, and at the moment, the vehicle control unit responds to a torque intervention request of the vehicle stability control system by giving priority to the vehicle stability control system related torque intervention so as to ensure safe operation of the vehicle under some special working conditions.

Fig. 11 is a network topology diagram of a vehicle speed control system according to a fourth embodiment of the present invention. As shown in fig. 11, the relevant network is as follows: a power domain network (PTCAN) including network nodes of a conventional vehicle-related engine control system, transmission controller, and vehicle stability system; the hybrid area network (hybrid CAN) comprises network nodes of a vehicle control unit, a battery management system and a motor controller which are related to new energy; an entertainment domain network (ENTCAN) includes network nodes of a meter system, a navigation module, and a camera module. Different controller signal interactions across network nodes may be achieved by nodes of the gateway system.

EXAMPLE five

The fifth embodiment of the invention provides a vehicle speed control system. The system comprises:

acquiring a torque required by a driver under the condition that the detected operation amount of an accelerator pedal is greater than or equal to a preset operation amount threshold value;

acquiring an external characteristic torque of the engine;

In an optional embodiment of the present invention, the vehicle controller is specifically configured to:

acquiring a speed limit value corresponding to a current vehicle speed auxiliary mode;

comparing the current speed of the vehicle with the speed limit value;

and controlling the vehicle to run at the speed less than or equal to the speed limit value according to the comparison result of the current vehicle speed and the speed limit value.

In an alternative embodiment of the invention, the current vehicle speed assist mode comprises an automatic vehicle speed assist mode; the whole vehicle controller is specifically used for:

acquiring at least one vehicle speed limiting source;

screening target vehicle speed limiting sources from the vehicle speed limiting sources;

and acquiring a speed limit value provided by a target vehicle speed limiting source, and determining the speed limit value as a speed limit value corresponding to the current vehicle speed auxiliary mode.

In an alternative embodiment of the present invention, the vehicle speed limit source includes: the system comprises a navigation module and a camera module;

the camera module is used for detecting the distance between the vehicle and the speed-limiting signboard;

and the vehicle control unit is used for receiving the distance and screening target vehicle speed limiting sources from the vehicle speed limiting sources according to the distance.

In an alternative embodiment of the invention, the current vehicle speed assist mode comprises an automatic vehicle speed assist mode; the vehicle control unit is specifically still used for:

In an optional embodiment of the present invention, the vehicle control unit is specifically configured to:

determining an engine output torque and a motor output torque according to a driver required torque and an engine external characteristic torque, comprising:

calculating a difference value between the external characteristic torque of the engine and the lost torque of the engine, and determining the maximum external characteristic torque of the engine;

comparing the driver required torque with the engine external characteristic torque;

selecting an engine output torque from the driver required torque and the engine maximum external characteristic torque according to a comparison result of the driver required torque and the engine external characteristic torque;

calculating a difference value between the driver demand torque and the net engine torque, and determining the output torque of the first motor;

calculating a difference value between the driver demand torque and the maximum external characteristic torque of the engine, and determining the output torque of the second motor;

the motor output torque is selected from the first motor output torque and the second motor output torque according to a result of comparison between the driver-requested torque and the engine-external characteristic torque.

In an alternative embodiment of the invention, the current vehicle speed assist mode comprises a manual vehicle speed assist mode;

the cruise system is used for receiving a speed limit value input by a user;

and the vehicle control unit is used for receiving the speed limit value sent by the cruise system.

In an optional embodiment of the present invention, after controlling the engine control system to output the engine output torque and controlling the motor controller to output the motor output torque, the vehicle controller is further configured to:

The vehicle control system provided by the embodiment of the invention can execute the vehicle control method provided by any embodiment of the invention, and has corresponding functional modules and beneficial effects of the execution method.

EXAMPLE five

Fig. 12 shows a schematic structural diagram of a hybrid vehicle 1200 with which an embodiment of the invention may be implemented. The components shown herein, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the inventions described and/or claimed herein.

As shown in fig. 12, a hybrid vehicle 1200 includes at least one processor 1201, and a memory communicatively coupled to the at least one processor 1201, wherein the processor is coupled to an engine control system and a motor controller; an engine connected to an engine control system; a motor connected to the motor controller; such as a Read Only Memory (ROM) 1202, a Random Access Memory (RAM) 1203, etc., where the memory stores computer programs that are executable by at least one processor, the processor 1201 may perform various suitable actions and processes in accordance with the computer programs stored in the Read Only Memory (ROM) 1202 or the computer programs loaded from the storage unit 1208 into the Random Access Memory (RAM) 1203. In the RAM 1203, various programs and data necessary for the operation of the hybrid vehicle 1200 may also be stored. The processor 1201, the ROM 1202, and the RAM 1203 are connected to each other by a bus 1204. An input/output (I/O) interface 1205 is also connected to bus 1204.

A plurality of components in the hybrid vehicle 1200 are connected to the I/O interface 1205, including: an input unit 1206 such as a keyboard, a mouse, or the like; an output unit 1207 such as various types of displays, speakers, and the like; a storage unit 1208 such as a magnetic disk, optical disk, or the like; and a communication unit 1209 such as a network card, modem, wireless communication transceiver, etc. The communication unit 1209 allows the hybrid vehicle 1200 to exchange information/data with other devices via a computer network such as the internet and/or various telecommunication networks.

The processor 1201 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of processor 1201 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various specialized Artificial Intelligence (AI) computing chips, various processors running machine learning model algorithms, a Digital Signal Processor (DSP), and any suitable processor, controller, microcontroller, and the like. The processor 1201 performs the various methods and processes described above, such as a vehicle speed control method.

In some embodiments, the vehicle speed control method may be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 1208. In some embodiments, part or all of the computer program may be loaded and/or installed on the hybrid vehicle 1200 via the ROM 1202 and/or the communication unit 1209. When the computer program is loaded into RAM 1203 and executed by processor 1201, one or more steps of the vehicle speed control method described above may be performed. Alternatively, in other embodiments, the processor 1201 may be configured to perform the vehicle speed control method in any other suitable manner (e.g., by way of firmware).

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuitry, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), system on a chip (SOCs), complex Programmable Logic Devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, receiving data and instructions from, and transmitting data and instructions to, a storage system, at least one input device, and at least one output device.

Computer programs for implementing the methods of the present invention can be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be performed. A computer program can execute entirely on a machine, partly on a machine, as a stand-alone software package partly on a machine and partly on a remote machine or entirely on a remote machine or server.

In the context of the present invention, a computer-readable storage medium may be a tangible medium that can contain, or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. A computer readable storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, the computer readable storage medium may be a machine readable signal medium. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

To provide for interaction with a user, the systems and techniques described herein may be implemented on a hybrid vehicle having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which a user may provide input to the hybrid vehicle. Other kinds of devices may also be used to provide for interaction with a user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), wide Area Networks (WANs), blockchain networks, and the internet.

The computing system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The Server may be a cloud Server, which is also called a cloud computing Server or a cloud host, and is a host product in a cloud computing service system, so as to solve the defects of high management difficulty and weak service expansibility in the conventional physical host and VPS (Virtual Private Server) service.

It should be understood that various forms of the flows shown above, reordering, adding or deleting steps, may be used. For example, the steps described in the present invention may be executed in parallel, sequentially, or in different orders, and are not limited herein as long as the desired results of the technical solution of the present invention can be achieved.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle speed control method characterized by comprising:

according to the current vehicle speed auxiliary mode, a vehicle speed auxiliary mode signal is sent to an engine control system and a motor controller, the engine control system controls output torque of an engine, and the motor controller controls output torque of a motor so as to control the vehicle to run at a speed meeting a speed limit condition;

acquiring an external characteristic torque of the engine;

and determining an engine output torque and a motor output torque according to the driver required torque and the engine external characteristic torque, and controlling an engine control system to output the engine output torque and a motor controller to output the motor output torque so as to adjust the running speed of the vehicle.

2. The method according to claim 1, wherein the controlling the vehicle to travel at a speed satisfying the speed limit condition according to the current vehicle speed assist mode comprises:

comparing the current speed of the vehicle with the speed limit value;

and controlling the vehicle to run at a speed less than or equal to the speed limit value according to the comparison result of the current vehicle speed and the speed limit value.

3. The method of claim 2, wherein the current vehicle speed assist mode comprises an automatic vehicle speed assist mode;

the acquiring of the speed limit value corresponding to the current vehicle speed auxiliary mode includes:

acquiring at least one vehicle speed limiting source;

and acquiring a speed limit value provided by the target vehicle speed limiting source, and determining the speed limit value as a speed limit value corresponding to the current vehicle speed auxiliary mode.

4. The method of claim 3, wherein the vehicle speed limiting source comprises: the system comprises a navigation module and a camera module;

the screening of the target vehicle speed limit source from the vehicle speed limit sources comprises the following steps:

the camera module detects the distance between the vehicle and the speed-limiting signboard;

and the vehicle control unit receives the distance and screens a target vehicle speed limiting source from the vehicle speed limiting sources according to the distance.

5. The method of claim 2, wherein the current vehicle speed assist mode comprises an automatic vehicle speed assist mode;

the method further comprises the following steps:

and controlling the vehicle to keep the current vehicle speed to run under the condition that the available vehicle speed limiting source is detected to be incapable of acquiring the speed limiting value.

6. The method according to claim 1, wherein the determining an engine output torque and a motor output torque based on the driver demand torque and the engine-out characteristic torque includes:

comparing the driver required torque and the engine external characteristic torque;

selecting an engine output torque among the driver required torque and the engine maximum external characteristic torque according to a comparison result of the driver required torque and the engine external characteristic torque;

calculating a difference between the driver demand torque and the net engine torque, determining a first electric machine output torque;

calculating a difference between the driver required torque and the maximum external characteristic torque of the engine, and determining a second motor output torque;

selecting a motor output torque among the first motor output torque and the second motor output torque according to a result of comparison between the driver required torque and the engine-outside characteristic torque.

7. The method of claim 2, wherein the current vehicle speed assist mode comprises a manual vehicle speed assist mode;

the cruise system receives a speed limit value input by a user;

and receiving the speed limit value sent by the cruise system.

8. The method of claim 2, further comprising, after controlling an engine control system to output the engine output torque and controlling a motor controller to output the motor output torque:

and under the condition that the detected operation amount of the accelerator pedal is smaller than the preset operation amount threshold value and the detected current speed of the vehicle is smaller than the speed limit value corresponding to the current speed auxiliary mode, controlling the vehicle to run at the speed meeting the speed limit condition according to the current speed auxiliary mode.

9. A vehicle speed control system, characterized by comprising:

the vehicle controller is used for sending a vehicle speed auxiliary mode signal to the engine control system and the motor controller according to the current vehicle speed auxiliary mode, the engine control system controls the output engine output torque, and the motor controller controls the output motor output torque so as to control the vehicle to run at the speed meeting the speed limit condition;

acquiring an external characteristic torque of the engine;

10. A hybrid vehicle, characterized by comprising:

at least one processor; and

an engine connected to the engine control system;

a motor connected to the motor controller;

the memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the vehicle speed control method of any one of claims 1-8.