KR20190003096A - Vehicle having electric motor and method of controlling coasting torque for the same - Google Patents

Abstract

The present invention relates to a vehicle having an electric motor and a method of controlling coasting torque therefor and, more specifically, relates to a method of changing coasting torque in response to a driving situation and a vehicle to perform the same. According to an embodiment of the present invention, a method of controlling coasting torque in a vehicle having an electric motor comprises the following steps of: starting coasting driving; calculating a level correction value through at least one of traffic information, climbing information, and vehicle-to-vehicle distance information; determining a coasting level based on the level correction value; and controlling torque of the electric motor in accordance with the determined coasting level.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle equipped with an electric motor, and a method of controlling a costing torque for the vehicle.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle having an electric motor and a method of controlling a costing torque for the vehicle, and more particularly, to a method of changing a costing torque in response to a driving situation and a vehicle for carrying out the same.

The driving of the vehicle means driving continuously by the driving force without outputting driving force, and generally means driving in a state in which the accelerator pedal (APS) and the brake pedal (BPS) are not operated.

The torque applied to the drive shaft when such running of the vehicle is performed can be referred to as a torque or a coasting torque. In a conventional internal combustion engine vehicle, the idle torque of the engine is transmitted to the drive shaft by the torque converter and the transmission even when the APS and BPS are not stepped on. This is also called a creep torque.

While the vehicle is running, the creep torque is transmitted to the drive shaft by the engine. On the other hand, the running load according to the vehicle speed acts in the opposite direction of the creep torque, and the sum of the two constitutes the torque. This will be described with reference to FIG.

FIG. 1 shows an example of a relationship between a running torque and a vehicle speed when a driving force is applied in a general vehicle.

Referring to FIG. 1, when the vehicle speed is low, the vehicle runs forward due to the creep torque because the running load is low. However, when the vehicle speed increases and the running load increases, the running load becomes larger than the creep torque, And the vehicle speed is reduced.

On the other hand, as the interest in the environment has increased recently, many developments have been made for hybrid electric vehicles (HEVs) and electric vehicles (EVs) that use electric motors as driving sources.

In a vehicle equipped with such an electric motor, since there is no engine or the engine is not always on, creep torque by the engine does not occur. However, in order to realize the characteristics of a general internal combustion engine, it is common that a control for generating a creep torque is performed by driving the motor. Therefore, unlike the internal combustion engine vehicle in which the torque is determined according to the engine characteristics, the torque of the torque can be variably controlled.

However, even if the torque is controlled, it is difficult to determine the most suitable torque for the current running situation in a vehicle equipped with an electric motor. This will be described with reference to FIG.

Fig. 2 is a diagram for explaining a problem of setting a costing torque.

In Fig. 2, the horizontal axis represents time and the vertical axis represents vehicle speed. Referring to FIG. 2, when the hybrid vehicle is APS off when the vehicle speed is 115 km, when the running torque is applied irrespective of the driving situation, and when the lower or higher costing torque is applied, the advantages and disadvantages As follows.

When the costing torque is applied so that the deceleration rate is high, the regenerative braking amount increases and the kinetic energy decreases. In this case, the kinetic energy can be recovered to increase the amount of power stored in the battery, but the vehicle speed can be rapidly reduced, resulting in unnecessary re-acceleration. Therefore, it is effective only when deceleration relative to the current vehicle speed occurs, for example, when the current vehicle speed is equal to or higher than a limited vehicle speed (for example, 80 km / h).

Conversely, if the running torque is set to a low deceleration rate, the kinetic energy is kept to a maximum and the necessity of re-acceleration is low. However, when a large braking force is required for deceleration, the hydraulic braking intervenes to reduce the regenerative braking efficiency. Accordingly, it is effective to maintain the current vehicle speed, for example, when the current vehicle speed is less than a limited vehicle speed (for example, 110 km).

As described above with reference to FIG. 2, there is a problem that the efficiency depending on the size of the costing torque varies depending on the driving situation.

The present invention is intended to provide a method for setting a costing torque more efficiently in a vehicle and a vehicle for carrying out the same.

Particularly, the present invention is to provide a method capable of changing the costing torque in response to a running situation, and a vehicle for carrying out the method.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to an aspect of the present invention, there is provided a method of controlling a running torque in a vehicle having an electric motor, the method comprising: starting a running of a course; Calculating a level correction value through at least one of traffic information, backlight information, and inter-vehicle distance information; Determining a costing level based on the level correction value; And controlling the torque of the electric motor according to the determined level of the costing.

Further, in a vehicle for controlling a costing torque according to an embodiment of the present invention, at least one sensor controller for sensing information for determining whether or not a running of a running course is to be started and calculating a costing level correction value; Acquiring the information sensed by the at least one sensor controller and detecting the start of the running of the course, calculates a level correction value through at least one of traffic information, backing plate information and inter-vehicle distance information, A hybrid controller for determining a costing level to determine the torque of the electric motor according to the determined costing level; And a motor controller for controlling the electric motor in accordance with the torque command of the hybrid controller.

The vehicle related to at least one embodiment of the present invention configured as described above can be set to a more effective costing torque.

In particular, according to the present invention, since the most efficient costing torque can be set according to the driving conditions such as traffic information, climbing information, and radar information, energy consumption due to unnecessary re-acceleration can be prevented and the amount of regenerative braking .

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

FIG. 1 shows an example of a relationship between a running torque and a vehicle speed when a driving force is applied in a general vehicle.
Fig. 2 is a diagram for explaining a problem of setting a costing torque.
3 is a diagram for explaining the concept of a plurality of costing levels according to an embodiment of the present invention.
FIG. 4 is a view for explaining a concept of a torque determination process according to a correction of a casting level according to an embodiment of the present invention, and FIG. 5 shows an example of a flowchart for reconstructing the process of FIG.
FIG. 6 shows an example of a traffic information-based level correction logic according to an embodiment of the present invention, and FIG. 7 shows an example of a concrete form in which level correction is performed according to a difference between an anticipated vehicle speed and a current vehicle speed.
8 is a block diagram showing an example of a control system of a hybrid vehicle to which embodiments of the present invention can be applied.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as " comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. In addition, parts denoted by the same reference numerals throughout the specification denote the same components.

In one embodiment of the present invention, in order to determine an efficient costing torque, a costing level that is most effective for a current driving situation among a plurality of levels is determined by determining a driving state in a vehicle having an electric motor, It is proposed that the costing torque be controlled along a costing line corresponding to the costing level.

3 is a diagram for explaining the concept of a plurality of costing levels according to an embodiment of the present invention.

Referring to FIG. 3, the relationship between the vehicle speed shown in FIG. 1 and the total torque applied to the axle is shown for each of five different casting tones. Here, a high level of the casting means that an inverse torque greater than a reference level (i.e., level 0) acts above a predetermined speed, while a high level of the casting level indicates that an inverse torque lower than a reference level . Therefore, if the running speed is higher than the target driving speed in the current driving situation and the costing level is lowered as the vehicle speed is lower than the target driving speed, the running of the driving force closer to the target speed becomes possible.

The determination of the running condition for setting the costing level will be described with reference to Figs. 4 and 5. Fig.

FIG. 4 is a view for explaining a concept of a torque determination process according to a correction of a casting level according to an embodiment of the present invention, and FIG. 5 shows an example of a flowchart for reconstructing the process of FIG.

Referring to FIG. 4, traffic information, climbing information, and radar information may be considered as a correction factor of a costing level. The level adjustment value calculated on the basis of each information is applied to the default level (i.e., " 0 ") to determine the costing level. The costing torque can be determined so as to follow a predetermined costing line corresponding to the determined costing level, and in the case where there is a variation in the vehicle speed beyond the level limit for minimizing the sense of sheen due to a change in the costing torque, It can be changed again. The range of the costing level for the vehicle speed will be described later in detail with reference to FIG.

Referring to FIG. 5, the level correction process (S520A, S520B, and S520C) may be performed as the driving of the subject is started (S510). Each level correction process can be performed as follows.

First, the traffic information-based level correction (S520A) will be described. In order for the traffic information-based level correction to be performed, the expected vehicle speed and the average vehicle speed must first be obtained. The average vehicle speed may mean the current vehicle speed, or may mean an average vehicle speed during a certain time interval from the present to the past, and the vehicle speed information for this may be obtained through the vehicle speed sensor. In addition, the estimated vehicle speed may mean a target driving speed calculated based on information such as a limited vehicle speed, a congestion degree, a driver's propensity, a type of a road (an inner city, an expressway, etc.). Information for calculating the expected vehicle speed can be obtained from an AVN (Audio / Video / Navigation) system, but is not limited thereto.

When the expected vehicle speed and the average vehicle speed are obtained, the following correction level can be determined according to the difference between the values.

1) (estimated vehicle speed - average vehicle speed)> 0: Coasting level decreased

2) (estimated vehicle speed - average vehicle speed) <0: Coasting Level increase

3) (Estimated vehicle speed - average vehicle speed) = 0: Coasting level maintenance

Next, the level correction (S520B) based on the steel plate information will be described. The backing plate information can be obtained through a sensor for sensing the angle of the vehicle or navigation information. When the backing plate information is obtained, the following correction value for the costing level can be determined.

1) During coasting: Coasting level decreased

2) Coasting: Increasing Coasting Level

Next, the level correction based on the headway information (S520C) will be described. The headway information can be determined by the relative acceleration with respect to the preceding vehicle and the headway distance. The relative acceleration and the headway distance can be obtained through the radar information of the ADAS system. When the relative acceleration and the inter-vehicle distance information are acquired, a costing level correction value can be determined as follows.

1) (Δ relative acceleration <0) & inter-vehicle distance <A: Coasting Level increase

2) (Δ relative acceleration> 0) & Inter-vehicle distance <A: Coasting level maintenance

Each level correction process may be performed in conjunction with two or more, or only one of them may be performed.

When the level correction value is determined through the level correction process, the final correction level may be determined by applying the level correction value to the default level (S530).

Accordingly, the course running can be performed so that the costing torque corresponding to the determined final costing level is applied (S540).

Hereinafter, a mode in which level correction is performed based on traffic information among the level correction processes will be described in more detail with reference to FIGS. 6 and 7. FIG.

 FIG. 6 shows an example of a traffic information-based level correction logic according to an embodiment of the present invention, and FIG. 7 shows an example of a concrete form in which level correction is performed according to a difference between an anticipated vehicle speed and a current vehicle speed.

Referring to FIG. 6, the predicted vehicle speed is first calculated based on at least one of congestion degree, driver propensity and restricted vehicle speed. The increase / decrease amount of the costing level is determined by the difference between the calculated estimated vehicle speed, the average vehicle speed, and the current vehicle speed.

For example, when the limited vehicle speed of the current running road is the expected vehicle speed, the predicted vehicle speed is kept constant regardless of the flow in time. In this case, the form in which the costing level varies with the vehicle speed is shown in Fig.

Referring to FIG. 7, a level variation line is set in a predetermined vehicle speed section on the basis of the predicted vehicle speed. For example, when the current vehicle speed is between the Lv-1 line and the Lv + 1 line, the level correction value becomes zero. As another example, when the current vehicle speed is higher than the Lv + 1 line and lower than the Lv + 2 line, the level correction value becomes +1. In the speed section having the same level correction value, the same casting torque is applied, and the speed is constantly reduced corresponding to the costing torque.

Accordingly, as shown in FIG. 7, the vehicle speed at the start of the running of the running (that is, the entering point of the costing section) is higher than the Lv + 1 line and lower than the Lv + 2 line, Reverse torque is applied and the vehicle speed reduction rate is high. The level correction value becomes 0 while the current vehicle speed falls between the Lv-1 line and the Lv + 1 line while the vehicle speed decreases, and the vehicle speed reduction rate becomes gentler due to the operation of the reverse torque less than when the vehicle speed is +1. Then, the level correction value becomes -1 while the vehicle speed corresponds to the Lv-1 line and the Lv-2 line, so that the reverse torque becomes smaller than the case where the vehicle speed is 0, so that the vehicle speed reduction rate becomes gentler. At this time, when the accelerator pedal is operated and the re-acceleration is performed, the costing run is terminated and the costing torque control is also ended.

As a result, when the current vehicle speed is higher than the expected vehicle speed, the efficiency can be improved by increasing the regenerative braking amount, and the vehicle speed can be approached to the expected vehicle speed. As the current vehicle speed is lower than the expected vehicle speed, Is controlled.

8 is a block diagram showing an example of a control system of a hybrid vehicle to which embodiments of the present invention can be applied.

Referring to FIG. 8, in the hybrid vehicle to which the embodiments of the present invention may be applied, the internal combustion engine 110 may be controlled by the engine controller 210. The engine controller 210 is also referred to as an engine management system (EMS). Also, the torque of the electric motor 120 can be controlled by a motor control unit (MCU) 220. In addition, the various sensors 130 may be controlled by the sensor controller 230.

Each controller is connected to a controller (hereinafter referred to as a " hybrid controller " or HCU: Hybrid Control Unit) 240 for performing overall control of the power train in the hybrid vehicle as its upper controller, The controller 240 can provide the information necessary for changing the traveling mode, information necessary for torque setting, and the like according to the control signal transmitted therefrom.

For example, the hybrid controller 240 acquires APS / BPS information from the sensor controller 230 to acquire information for determining whether to start the running of the course and calculating the costing level correction value, The torque command can be transmitted to the motor controller 220 so that the vehicle is controlled with the corresponding costing torque.

In particular, the hybrid controller 240 may perform the respective steps of FIG. 5 described above.

The sensor 130 may include at least one of a vehicle speed sensor, an APS, a BPS, a radar, an acceleration sensor, a gyro sensor, and a GPS sensor. Accordingly, the sensor controller 230 may be provided for each sensor, and one sensor controller 230 may control the plurality of sensors. That is, a plurality of sensor controllers 230 may be provided in one vehicle.

8 is based on a hybrid vehicle, it is obvious to those skilled in the art that the remaining components can be similarly applied to an electric vehicle except for the configuration and operation related to the engine 110 and the engine controller 210 .

The present invention described above can be embodied as computer-readable codes on a medium on which a program is recorded. The computer readable medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer readable medium include a hard disk drive (HDD), a solid state disk (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, .

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all conversions within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (19)

A method of controlling a running torque in a vehicle having an electric motor,
The starting of the running of the course;
Calculating a level correction value through at least one of traffic information, backlight information, and inter-vehicle distance information;
Determining a costing level based on the level correction value; And
And controlling the torque of the electric motor according to the determined costing level. The method according to claim 1,
Wherein the determining comprises:
And adding the level correction value to a default costing level. The method according to claim 1,
Wherein the calculating step comprises:
And calculating a level correction value based on the traffic information using a difference value between a predicted vehicle speed and a current vehicle speed. The method of claim 3,
The predicted vehicle speed may be,
Wherein the at least one vehicle is predicted through at least one of a limited vehicle speed, a congestion degree, a driver propensity, and a road type. The method of claim 3,
Wherein the default costing level
Wherein the estimated vehicle speed is set within a predetermined vehicle speed range around the predicted vehicle speed. The method according to claim 1,
Wherein the calculating step comprises:
Decreasing the costing level if it is in the back plate, and increasing the costing level in the steel plate. The method according to claim 1,
Wherein the calculating step comprises:
And calculating a level correction value based on the headway distance information according to the relative acceleration and the headway distance between the vehicle and the preceding vehicle. The method according to claim 1,
The costing level,
Wherein the regenerative braking amount is increased with an increase in the default casting level, and the regenerative braking amount is decreased with decreasing the default casting level. The method according to claim 1,
The costing level,
And a costing line having a different gradient for each level. A computer-readable recording medium on which a program for executing the inertial running time guiding method according to any one of claims 1 to 9 is recorded. In a vehicle for controlling a running torque,
At least one sensor controller for sensing information for determining whether or not a running of the running is to be made and for calculating a costing level correction value;
Acquiring the information sensed by the at least one sensor controller and detecting the start of the running of the course, calculates a level correction value through at least one of traffic information, backing plate information and inter-vehicle distance information, A hybrid controller for determining a costing level to determine the torque of the electric motor according to the determined costing level; And
And a motor controller for controlling the electric motor in accordance with a torque command of the hybrid controller. 12. The method of claim 11,
The hybrid controller includes:
And adding the level correction value to a default costing level to determine the costing level. 12. The method of claim 11,
The hybrid controller includes:
And calculates a level correction value through the traffic information using a difference value between a predicted vehicle speed and a current vehicle speed. 14. The method of claim 13,
The predicted vehicle speed may be,
Wherein the vehicle is predicted through at least one of a limited vehicle speed, a congestion degree, a driver tendency, and a road type. 14. The method of claim 13,
Wherein the default costing level
Wherein the predetermined vehicle speed is set within a predetermined vehicle speed range around the predicted vehicle speed. 12. The method of claim 11,
The hybrid controller includes:
Decreasing the costing level if in the back plate and increasing the costing level in the steel plate. 12. The method of claim 11,
The hybrid controller includes:
And calculates a level correction value based on the headway distance information according to the relative acceleration and the headway distance between the vehicle and the preceding vehicle. 12. The method of claim 11,
The costing level,
Wherein the regenerative braking amount is increased as the basic costing level is raised, and the regenerative braking amount is decreased as the basic costing level is decreased. 12. The method of claim 11,
The costing level,
And an electric motor having a skating line of different slopes for each level.

Images