CN118082519A - Method for controlling a vehicle, vehicle control system, vehicle and computer program product - Google Patents

Abstract

The invention discloses a method for controlling a vehicle, comprising at least the following steps: acquiring a road surface adhesion coefficient during a braking operation before a vehicle is stopped as an initial road surface adhesion coefficient, wherein the vehicle is brought to a stop due at least in part to the braking operation; and controlling a subsequent start operation of the vehicle at least with the initial road adhesion coefficient introduced. The invention further relates to a corresponding vehicle control system, to a corresponding computer program product, in particular a computer-readable program carrier, and to a corresponding vehicle, in particular a new energy vehicle. According to one or more exemplary embodiments of the present invention, it is possible to make a vehicle start on a road surface having a low adhesion coefficient, such as an ice surface or a snow surface, smooth and comfortable, and to improve acceleration performance of the vehicle on an ice separation road or a hill separation road.

Description

Method for controlling a vehicle, vehicle control system, vehicle and computer program product

Technical Field

The invention relates to a method for controlling a vehicle, a corresponding vehicle control system, a corresponding computer program product and a corresponding vehicle.

Background

With the development and technical progress of society, vehicles slowly go into ordinary families and become important transportation means in people's life.

During driving, vehicles encounter various road surfaces, and particularly, when driving on a road surface with a low adhesion coefficient, the vehicles are prevented from slipping due to improper control. Slip not only affects the running safety of the vehicle, but also seriously affects the subjective driving feeling of the driver.

For this purpose, current vehicles are generally equipped with corresponding safety systems, some of which have become mandatory systems for vehicles according to legal requirements. For example, the body electronic stability system ESC is an inheritance and further extension of the antilock braking and traction control functions.

Generally, a vehicle body electronic stability system also includes an electronic brake distribution force system, an antilock brake system, a tracking control system, a vehicle dynamic control system, and the like. These systems ensure driving safety well.

However, when the vehicle starts on a road surface with a low road adhesion coefficient, particularly at full throttle, a serious slip phenomenon still occurs.

In particular, in recent years, new energy vehicles have been rapidly developed, and one of the advantages of the new energy vehicles is that the starting speed is high, and thus, the torque loading slope is high. However, this aggravates the phenomenon of starting and slipping of the vehicle on a road surface with a low attachment coefficient, and gives a very uncomfortable subjective driving feeling to the driver.

Accordingly, there is a continuing need for improvement in this regard.

Disclosure of Invention

The present invention aims to overcome one of the above-mentioned disadvantages of the prior art and/or other disadvantages of the prior art which may not be mentioned herein. To this end, the invention provides an improved method for controlling a vehicle, a corresponding vehicle control system, a corresponding computer program product and a corresponding vehicle.

According to a first aspect of the present invention, there is provided a method for controlling a vehicle, the method comprising at least the steps of: acquiring a road surface adhesion coefficient during a braking operation before a vehicle is stopped as an initial road surface adhesion coefficient, wherein the vehicle is brought to a stop due at least in part to the braking operation; and controlling a subsequent start operation of the vehicle at least with the initial road adhesion coefficient introduced.

According to a second aspect of the present invention there is provided a vehicle control system comprising one or more controllers configured to be able to perform a method according to any of the above-described exemplary embodiments.

According to a third aspect of the present invention, there is provided a computer program product, in particular a computer readable program carrier, comprising or storing computer program instructions which, when executed by a processor, at least assist in carrying out a method according to any of the above-described exemplary embodiments.

According to a fourth aspect of the present invention, a vehicle, in particular a new energy vehicle, is provided, comprising a vehicle control system according to any of the above-described exemplary embodiments or a computer program product according to any of the above-described exemplary embodiments.

According to one or more exemplary embodiments of the present invention, it is possible to make a vehicle start on a road surface having a low adhesion coefficient, such as an ice surface or a snow surface, smooth and comfortable, and to improve acceleration performance of the vehicle on an ice separation road or a hill separation road.

Drawings

The principles, features and advantages of the present invention may be better understood by describing the present invention in more detail with reference to the drawings. The drawings include:

fig. 1 shows a flowchart of a method for controlling a vehicle according to an exemplary embodiment of the present invention.

Fig. 2 shows a flowchart of a method for controlling a vehicle according to a more specific exemplary embodiment of the present invention.

Fig. 3 schematically shows a vehicle according to an exemplary embodiment of the invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous technical effects to be solved by the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and a plurality of exemplary embodiments. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Fig. 1 shows a flowchart of a method for controlling a vehicle according to an exemplary embodiment of the present invention.

As shown in fig. 1, the method at least comprises the following steps: step S1, obtaining a road surface adhesion coefficient during a braking operation before a vehicle is stopped as an initial road surface adhesion coefficient, wherein the vehicle is stopped at least partially due to the braking operation; step S2 of controlling a subsequent start operation of the vehicle at least with the initial road surface adhesion coefficient introduced. The initial road-attachment coefficient may be stored in a memory and then recalled or actively transmitted to the corresponding control device during the start of the vehicle.

It can be seen that the control of the vehicle start phase takes into account the road surface adhesion coefficient obtained in the final vehicle braking and stopping phase, since the road surface on which the vehicle is finally stopped is most likely the road surface on which the vehicle is started, and therefore they generally have at least similar road surface adhesion coefficients. Therefore, the road surface adhesion coefficient is directly introduced as an initial value of the road surface adhesion coefficient controlled in the starting stage when the vehicle starts, and temporary calculation (the temporary calculation means that the vehicle may slip) is not needed, so that the current road surface characteristic can be predicted in advance, and the possibility is provided for the early intervention control in the starting stage.

It is understood that "braking operation" herein includes braking operation by the driver depressing the brake pedal and/or braking operation by the coasting energy recovery control system of the vehicle.

If a plurality of road surface attachment coefficients are obtained in the braking stage and each of the road surface attachment coefficients is reliable, it is preferable to select the road surface attachment coefficient obtained last as the initial road surface attachment coefficient because this is closer to, and thus more truly reflects, the road surface characteristics when the vehicle is stopped.

A particularly representative application scenario for such a control method is: when a new energy vehicle, such as an electric vehicle starts on a full accelerator on ice or snow, the response time of a Vehicle Control Unit (VCU) is slow (a feedback signal is needed), the torque loading slope of a motor is too fast, the torque is not timely reduced, the rotating speed of a driving wheel is too high, the slip quantity is serious, and uncomfortable subjective driving feeling is brought to a driver. By early intervention and timely changing of the torque loading characteristics, the vehicle can be smoother and more comfortable when starting on ice or snow. Those skilled in the art will appreciate that the acceleration performance of the vehicle on an icy road or a hill-off road may also be improved.

According to an exemplary embodiment of the present invention, only the road surface adhesion coefficient acquired under the predetermined acquisition condition is taken as the initial road surface adhesion coefficient. This is because it is ensured that the subsequent control operation is also reliable only if the obtained road surface adhesion coefficient is truly reliable.

It will be appreciated by those skilled in the art that the road adhesion coefficient may be calculated or obtained in the event of a slip condition of the vehicle, i.e. when at least one wheel is in a slipping condition. To this end, according to an exemplary embodiment of the present invention, the predetermined acquisition condition includes at least one wheel of the vehicle being in a slip state. The occurrence of slip during braking and stopping often means that the slip phenomenon also occurs at a high probability in the starting stage.

For safety reasons, vehicles are generally suppressed by appropriate control measures for undesired wheel slip. In this case, the vehicle is generally equipped with a corresponding control device. The control means may be activated when a specific slip condition occurs to cope with the slip condition. To this end, according to an exemplary embodiment of the present invention, the predetermined acquisition condition includes: a first control device for controlling the vehicle based at least on the slip of at least one wheel is activated.

As an example, the first control device may include an anti-lock braking system (ABS) control module and/or a Drag Torque Control (DTC) module. At present, an anti-lock braking system or a dragging torque control system is mature, and timely and reliable response is made to wheel slip energy. Therefore, the idea of the invention can be built by combining the control device which is already equipped with the vehicle, thereby greatly simplifying the implementation cost and difficulty.

In particular, according to an exemplary embodiment of the present invention, if the first control device is triggered, the road surface adhesion coefficient calculated by a module for calculating road surface adhesion coefficient, for example, a Vehicle Dynamic Control (VDC) module, is used as the initial road surface adhesion coefficient. The vehicle dynamic control module calculates road adhesion coefficient as the control basis during operation. When the anti-lock brake system control module and/or the drag torque control module are triggered, the road adhesion coefficient calculated by the vehicle dynamic control module can be considered to be reliable, and the current road characteristics can be reflected relatively truly.

The acquisition of the road surface adhesion coefficient is described above in connection with an example, but it will be understood by those skilled in the art that the present invention is not limited thereto in practice. In any case, the road surface adhesion coefficient at the parking area may be reliably acquired.

With the road surface adhesion coefficient, the road surface adhesion coefficient can be used for control in a subsequent starting operation of the vehicle.

For example, according to one exemplary embodiment of the present invention, during the start operation, the traction of the vehicle is controlled at least with the initial road adhesion coefficient introduced. By controlling the traction force, the vehicle can be started more safely without dangerous situations, and particularly, the vehicle can be started more smoothly and comfortably. In other words, the vehicle can be started in response to the current road surface condition.

The control of the traction force involves not only the control of the adjustment modes such as the distribution of the traction force, the change of the traction force, etc., but also the intervention of the traction force control. Thus, as an exemplary embodiment of the present invention, the controlling of traction of a vehicle includes: the intervention timing of traction control and/or the regulation mode of traction are/is controlled.

According to an exemplary embodiment of the present invention, the initial road adhesion coefficient is transmitted to a Tracking Control System (TCS) control module of the vehicle, and the tracking control system control module is triggered to generate a torque reduction request signal to be transmitted to the vehicle control unit under a predetermined trigger condition. Specifically, the tracking control system control module may determine whether and when to send a torque reduction request signal to the vehicle control unit after obtaining the initial road adhesion coefficient, and if such request signal is received by the vehicle control unit, may reduce vehicle launch torque, such as torque of the corresponding wheel, by sending control instructions to the powertrain, the power battery system, and the like. For an electric vehicle, the applied torque can be easily controlled by controlling the operating characteristics of the corresponding motor.

Here, it should be noted that the Vehicle Control Unit (VCU) should be understood as a general concept, i.e., generally controlling the vehicle and thus any in-vehicle device that can signal the execution of traction control may be regarded as a vehicle control unit, although the Vehicle Control Unit (VCU) is generally used in the field of new energy vehicles, and an Electronic Control Unit (ECU) is widely used in conventional fuel vehicles.

The predetermined trigger condition is set up to ensure that the intervention is only performed when torque-reducing intervention is indeed necessary during the vehicle launch phase. As one example, the predetermined triggering condition includes detecting that at least one wheel of the vehicle is in a predetermined slip state. This means that a certain degree of slip is indeed occurring during the start phase before the vehicle control unit is requested for torque reducing intervention. For example, the vehicle control unit may be requested to perform a torque reducing intervention upon a slight slip of the wheels of the vehicle. Here, the predetermined slip state may be defined based on empirical or experimental data.

Of course, it is theoretically possible to request the vehicle control unit to perform torque reducing intervention to perform pre-control when the initial road surface adhesion coefficient is received, regardless of whether or not the vehicle is slipping at the present time, so as to prevent any slipping from occurring or to avoid slipping as much as possible. At this time, the predetermined trigger condition is the action itself in which the initial road surface adhesion coefficient is transmitted to the tracking control system control module.

Typically, the tracking control system control module will set a corresponding trigger threshold, and only if the trigger threshold is exceeded will a torque reduction request signal be generated to the vehicle control unit. As described above, to enable pre-control, the trigger threshold of the tracking control system control module may be reduced, allowing the torque reduction request signal to be generated earlier and thus sent earlier to the vehicle control unit for earlier torque reduction intervention by the vehicle control unit.

As mentioned above, such early triggering signal intervention is the control of intervention timing for traction control.

In addition, the controlling traction of the vehicle further includes: at least the second control device, which is involved in controlling the wheel slip, is triggered to act and/or the control parameters of the second control device are adjusted. It should be noted here that the second control device may be physically the same device or overlap the first control device, but may also be a different device. The use of the "second control means" is here mainly intended to embody a different control logic or strategy than the "first control means".

For example, according to an exemplary embodiment of the present invention, the control logic or strategy along the route "second control means" may be: a torque loading characteristic request signal is sent to the vehicle control unit based on the initial road adhesion coefficient to request the vehicle control unit to control the torque loading process of the vehicle according to the corresponding torque loading characteristic.

In order to make vehicle launch smoother and more comfortable, the torque loading characteristics may be designed or optimized to smooth the torque loading process. In particular, the torque loading process is smoothed by reducing the torque loading slope.

As one example, the second control device may include a body electronic stability system control module via which a torque loading request signal is sent to a vehicle control unit. At this time, the vehicle body electronic stability system control module may send the torque loading request signal, i.e., the "triggered action," to the vehicle control unit in response to the initial road adhesion coefficient.

At this time, the second control device may even be regarded as including the vehicle control unit because the control parameters of the vehicle control unit are changed.

Further, from a system architecture perspective, the body electronic stability system control module typically includes an ABS control module, a DTC module, a VDC module, a TCS control module, and the like. Thus, there is an overlapping or inclusive relationship between the first control device and the second control device. The use of the above-described "modules" is also mainly directed to the arithmetic unit of the corresponding control system.

Furthermore, it should be noted that a representative application scenario of the method of the present invention is mentioned above as starting a new energy vehicle on ice or snow, but it is obvious that the method of the present invention is not limited thereto. In particular, the vehicle is not limited to the type of vehicle on the one hand, i.e. not to new energy vehicles, but rather also to conventional fuel vehicles, and on the other hand is in principle not limited to a purely start phase, but rather can also be extended appropriately to a subsequent driving phase, in particular when the vehicle is to be driven a distance on the same road surface after starting.

In order to make it easier for a person skilled in the art to understand the present invention, fig. 2 shows a flowchart of a method for controlling a vehicle according to a more specific exemplary embodiment of the present invention.

As shown in fig. 2, in step S11, the driver releases the accelerator pedal. Then, the vehicle is braked (e.g., the driver depresses the brake pedal and/or the coasting energy recovery control system operates to produce a braking action) until stopped at step S12. Subsequently, proceeding to step S13, it is determined whether an Antilock Brake System (ABS) control module and/or a Drag Torque Control (DTC) module is activated. If triggered (Y), proceed to step S14, the road surface adhesion coefficient is obtained as the initial road surface adhesion coefficient for the subsequent start phase. Thereafter, in step S15, the initial road surface adhesion coefficient may be directly transmitted (since the initial road surface adhesion coefficient is already in the vehicle body electronic stability system control module) to the vehicle control unit, requesting the vehicle control unit to perform torque loading at a lower loading slope. In addition, at step S16, the initial road surface adhesion coefficient may also be transmitted to the tracking control system control module, lowering the triggering threshold of the tracking control system control module to trigger the tracking control system control module earlier to send a torque reduction request to the vehicle control unit. If the determination at step S13 is no (N), the process proceeds to step S17, where the tracking control system control module controls the start operation of the vehicle in a conventional manner.

Fig. 3 schematically shows a vehicle according to an exemplary embodiment of the invention. As shown in fig. 3, according to a second aspect of the present invention, there is also provided a vehicle control system 1, the vehicle control system 1 comprising one or more controllers configured to be able to perform the method according to any of the above-described exemplary embodiments. It will be appreciated by those skilled in the art that although the vehicle control system 1 shown in fig. 3 appears to be a single component, this does not necessarily mean that it is a single component, but may be in a distributed configuration.

According to a third aspect of the present invention, there is provided a computer program product, in particular a computer readable program carrier, comprising or storing computer program instructions which, when executed by a processor, at least assist in carrying out a method according to any of the above-described exemplary embodiments.

According to a fourth aspect of the present invention, as shown in fig. 3, a vehicle 10, in particular a new energy vehicle, is provided, the vehicle 10 comprising a vehicle control system 1 according to any of the above-described exemplary embodiments or a computer program product according to any of the above-described exemplary embodiments.

Although specific embodiments of the application have been described in detail herein, they are presented for purposes of illustration only and are not to be construed as limiting the scope of the application. Various substitutions, alterations, and modifications can be made without departing from the spirit and scope of the application.

List of reference numerals:

1 vehicle control system

10 Vehicle

Claims (15)

1. A method for controlling a vehicle, the method comprising at least the steps of:

acquiring a road surface adhesion coefficient during a braking operation before a vehicle is stopped as an initial road surface adhesion coefficient, wherein the vehicle is brought to a stop due at least in part to the braking operation; and

The subsequent start operation of the vehicle is controlled at least with the initial road-surface adhesion coefficient introduced.

2. The method of claim 1, wherein,

Only the road surface adhesion coefficient acquired under the preset acquisition condition is used as the initial road surface adhesion coefficient; and/or

During the start-up operation, the traction of the vehicle is controlled at least with the initial road adhesion coefficient introduced.

3. The method of claim 2, wherein,

The predetermined acquisition condition includes at least one wheel of the vehicle being in a slip state; and/or

The controlling of the traction of the vehicle includes: the intervention timing of traction control and/or the regulation mode of traction are/is controlled.

4. A method according to claim 2 or 3, wherein,

The predetermined acquisition conditions include: a first control device for controlling the vehicle based at least on the slip of at least one wheel is activated.

5. The method of claim 4, wherein,

The first control device comprises an anti-lock braking system control module and/or a dragging torque control module; and/or

If the first control device is triggered, the road surface adhesion coefficient calculated by a module for calculating road surface adhesion coefficient, for example a vehicle dynamics control module, is used as the initial road surface adhesion coefficient.

6. The method of claim 5, wherein,

The initial road surface adhesion coefficient is transmitted to a tracking control system control module of the vehicle, and the tracking control system control module is triggered to generate a torque reduction request signal under a preset triggering condition and transmit the torque reduction request signal to a vehicle control unit.

7. The method of claim 6, wherein,

The predetermined triggering condition includes detecting that at least one wheel of the vehicle is in a predetermined slip state; and/or

And reducing the trigger threshold of the control module of the tracking control system.

8. The method according to any one of claims 2-7, wherein,

The controlling of the traction of the vehicle includes: at least the second control means involved in controlling the wheel slip is triggered and/or the control parameters are adjusted.

9. The method of claim 8, wherein,

And sending a torque loading characteristic request signal to a vehicle control unit based on the initial road adhesion coefficient so as to request the vehicle control unit to control the torque loading process of the vehicle according to the corresponding torque loading characteristic.

10. The method of claim 9, wherein,

The torque loading process is smoothed by the corresponding torque loading characteristics.

11. The method according to claim 9 or 10, wherein,

The torque loading process is smoothed by reducing the torque loading slope.

12. The method according to any one of claims 9-11, wherein,

The second control device comprises a vehicle body electronic stability system control module, and the torque loading request signal is sent to a vehicle control unit through the vehicle body electronic stability system control module.

13. A vehicle control system (1), the vehicle control system (1) comprising one or more controllers configured to be able to perform the method according to any one of claims 1-12.

14. A computer program product, in particular a computer readable program carrier, comprising or storing computer program instructions which, when executed by a processor, at least assist in carrying out the method according to any one of claims 1-12.

15. A vehicle (10), in particular a new energy vehicle, the vehicle (10) comprising a vehicle control system (1) according to claim 13 or a computer program product according to claim 14.