vehicle and method for controlling a speed thereof
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- HYUNDAI MOTOR CO LTD
- Filing Date
- 2018-05-22
- Publication Date
- 2026-07-30
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Background of the invention Field of invention The present invention relates to a vehicle and a method for controlling its speed, and in particular relates to a vehicle and a method for controlling its speed during autonomous parking operation. Description of the related technology In a vehicle equipped with a fluid torque converter automatic transmission, engine torque is transmitted via a hydraulic fluid. Accordingly, first-gear engagement is possible even when the vehicle is stopped or traveling at extremely low speeds (0 to 4 km / h), ensuring a stable engine start and sufficient torque for efficient vehicle speed control during autonomous parking operation. In contrast, in a vehicle equipped with a dual-clutch transmission (DCT), one clutch half (e.g., one of the two clutches) can remain engaged at extremely low speeds due to clutch control using direct friction. Consequently, the frictional heat generated by the clutch can build up rapidly, and engine starts can be unstable if the clutch is fully engaged when the vehicle is stopped or traveling at low speed. The above information disclosed in this “Background of the Invention” section is intended only to improve the understanding of the general background of the invention and should not be regarded as an admission or any indication that this information belongs to the prior art as already known to the person skilled in the art. Furthermore, JP 2009-179208A discloses a vehicle comprising: a dual-clutch transmission that sets the vehicle's speed based on clutch torque; a brake that causes the vehicle to decelerate to reduce its speed; and a control device that sets a target speed for the vehicle and controls the dual-clutch transmission and the brake so that the vehicle's speed is maintained at the set target speed. Other vehicles and vehicle control devices and methods are known from US 2002 / 0132702A1 and US 2016 / 0297445A1. Explanation of the invention The task is to provide a vehicle for reducing heat generated by a dual clutch and a method for controlling its speed. The technical problems to be solved by the present invention are not limited to the aforementioned problems, and further technical problems not mentioned herein will be clearly understood by those skilled in the art to which the present invention belongs from the following description. The present invention provides a vehicle (e.g., a motor vehicle, such as a passenger car) according to claim 1, comprising: a dual-clutch transmission which sets the vehicle's speed based on a clutch torque; a brake which causes the vehicle to slow down (e.g., decelerate) in order to reduce the vehicle's speed; and a control unit which sets a target speed (e.g., desired speed) for the vehicle and controls the dual-clutch transmission and the brake so that the vehicle's speed is allowed to follow the set target speed (e.g., so that the vehicle's speed follows the set target speed). According to the invention, the target speed is defined as a speed that is lower than the vehicle's creeping speed.According to the invention, the control device is configured to control the dual-clutch transmission so that the clutch torque is increased when the vehicle's driving speed is lower than the target speed, and the control device controls the dual-clutch transmission so that the clutch torque is reduced when the vehicle's driving speed is higher than or equal to the target speed. In numerous aspects of the present invention, the brake can adjust a brake pressure, thus causing the vehicle to slow down. In numerous aspects of the present invention, the control device can be configured to control the brake such that the brake pressure is reduced by a first level (e.g., a first brake pressure value) when the vehicle's speed is lower than the target speed, and the control device can control the brake such that the brake pressure is increased by a second level (e.g., a second brake pressure value) when the vehicle's speed is higher than or equal to the target speed. In numerous aspects of the present invention, the control device can be configured to control the brake such that the brake pressure is reduced by a third level (e.g., a third brake pressure value), which is lower than the first level, when the vehicle's speed is lower than the target speed while the vehicle is on a downward-sloping section (e.g., a descending, traversed section). In numerous aspects of the present invention, the control device can be configured to control the dual-clutch transmission so that a first additional torque is generated when the vehicle is on an upwardly inclined section (e.g., an uphill, driven section). In numerous aspects of the present invention, the control device can be configured to control the brake such that the brake pressure is reduced until the clutch torque increases (e.g., is raised) to reach the first additional torque or more when the vehicle is on the upward-inclined section, and the control device can control the brake such that the brake pressure is released when the clutch torque is greater than or equal to the first additional torque. In numerous aspects of the present invention, the control device can be configured to control the dual-clutch transmission so that the clutch torque is reduced, and the control device can control the brake so that the brake pressure is increased when the target speed of the vehicle is set to zero. In numerous aspects of the present invention, the control device can be configured to control the dual-clutch transmission so that a second additional torque is generated when the vehicle's speed decreases in a section (e.g., a road section, for example, when driving onto a speed bump / brake) in which the clutch torque is greater than or equal to a predetermined value. Furthermore, the present invention provides a method for controlling the speed of a vehicle (e.g., a motor vehicle, such as a passenger car) according to claim 9, comprising: setting (e.g., specifying) a target speed of the vehicle, and controlling a dual-clutch transmission and a brake such that the vehicle's driving speed is permitted to follow the target speed (e.g., so that the vehicle's driving speed follows the target speed), based on the set target speed. According to the invention, the target speed is defined as a speed that is lower than the vehicle's creeping speed.According to the invention, the control of the dual-clutch transmission and the brake comprises: controlling the dual-clutch transmission so that the clutch torque is increased when the vehicle's driving speed is lower than the target speed, and controlling the dual-clutch transmission so that the clutch torque is decreased when the vehicle's driving speed is higher than or equal to the target speed. In numerous aspects of the present invention, the brake can adjust a brake pressure, thus causing the vehicle to slow down. In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can further comprise: controlling the brake so that the brake pressure is reduced by a first level (e.g., a first brake pressure value) when the vehicle's driving speed is lower than the target speed, and controlling the brake so that the brake pressure is increased by a second level (e.g., a second brake pressure value) when the vehicle's driving speed is higher than or equal to the target speed. In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can further comprise: controlling the brake such that the brake pressure is reduced by a third level (e.g., a third brake pressure value), which is lower than the first level, when the vehicle's speed is lower than the target speed while the vehicle is on a downward-sloping section (e.g., a descending, traversed section). In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can include: controlling the dual-clutch transmission so that a first additional torque is generated when the vehicle is on an upwardly inclined section (e.g., an uphill, driven section). In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can further comprise: controlling the brake so that the brake pressure is reduced until the clutch torque increases (e.g., is raised) to reach the first additional torque or more when the vehicle is on the upward-sloping section, and controlling the brake so that the brake pressure is released when the clutch torque is greater than or equal to the first additional torque. In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can include: controlling the dual-clutch transmission so that the clutch torque is reduced, and controlling the brake so that the brake pressure is increased when the target speed of the vehicle is set to zero. In numerous aspects of the present invention, the control of the dual-clutch transmission and the brake can include: controlling the dual-clutch transmission so that a second additional torque is generated when the vehicle's speed decreases in a section (e.g., a road section, for example, when driving onto a speed bump / brake) in which the clutch torque is greater than or equal to a predetermined value. A vehicle and a method for controlling its speed according to various aspects of the present invention can reduce the heat generated by a dual clutch. A vehicle and a method for controlling its speed according to various aspects of the present invention can cooperatively control a dual-clutch transmission and a brake, thereby enabling efficient speed control during autonomous parking operation. A vehicle and a method for controlling its speed according to various aspects of the present invention can improve the marketability and usability of a vehicle which has an autonomous parking function. The methods and devices of the present invention have further features and advantages, which will become clear from the accompanying drawings included herein and the following detailed description, which together serve to explain certain principles of the present invention, or which are detailed therein. Brief description of the drawings Fig. 1 shows a vehicle according to an exemplary embodiment of the present invention. Fig. 2 shows a graph to illustrate a process of controlling the speed of the vehicle when the vehicle is on a flat section, according to an exemplary embodiment of the present invention. Fig. 3 shows a graph to illustrate a process of controlling the speed of the vehicle when the vehicle is on an upwardly inclined section, according to an exemplary embodiment of the present invention. Fig. 4 shows a graph to illustrate a process of controlling the speed of the vehicle when the vehicle is on a downwardly inclined section, according to an exemplary embodiment of the present invention.Figure 5 is a flowchart illustrating a vehicle speed control method according to an exemplary embodiment of the present invention. Figure 6 represents a vehicle according to a further exemplary embodiment of the present invention. Figure 7 is a flowchart illustrating a vehicle speed control method according to a further exemplary embodiment of the present invention. Figure 8 is a diagram illustrating the vehicle speed control method according to the further embodiment of the present invention. Figure 9 is a block diagram of a data processing system for executing a vehicle speed control method according to an exemplary embodiment of the present invention. It should be understood that the attached drawings are not necessarily to scale and represent a somewhat simplified depiction of various properties in order to illustrate the basic principles of the invention. The specific design features of the present invention, including, for example, specific dimensions, orientations, positions, and shapes as disclosed herein, are (at least) partially determined by the respective intended application and usage environment. In the figures, identical reference numerals refer to identical or equivalent components of the present invention. Detailed description Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. Although the invention is described in connection with the exemplary embodiments, it is clear that the present description is not intended to limit the invention to these exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments but also various alternatives, modifications, variations, and other embodiments that may be included within the scope of the invention as defined by the attached claims. Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. The same reference numerals are used throughout the drawings to identify the same or equivalent elements. Furthermore, a detailed description of well-known features or functions may be omitted to avoid unnecessarily obscuring the essence of the present invention. In describing elements of the present invention, terms such as "first", "second", "A", "B", "(a)", "(b)", and the like may be used herein. Such terms are used solely to distinguish one element from another and do not limit the subject matter, sequence, precedence, or number of such elements. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by a person skilled in the art in the field to which this invention / disclosure belongs.Terms such as those found in a generally used dictionary should be interpreted as having meanings equal to the context-dependent meanings in the relevant technical field and should not be interpreted as having ideal or overly formal meanings unless it is clearly defined in the present application that they have such meanings. Fig. 1 shows a vehicle according to an exemplary embodiment of the present invention. Fig. 2 shows a graph illustrating a process of controlling the vehicle's speed when the vehicle is on a flat section, according to an exemplary embodiment of the present invention. Fig. 3 shows a graph illustrating a process of controlling the vehicle's speed when the vehicle is on an upward-sloping section, according to an exemplary embodiment of the present invention. Fig. 4 shows a graph illustrating a process of controlling the vehicle's speed when the vehicle is on a downward-sloping section, according to an exemplary embodiment of the present invention. With reference to Fig. 1, a vehicle (e.g. a motor vehicle, e.g. a passenger car) 100 according to an exemplary embodiment of the present invention can have a dual clutch transmission 110, a brake 120, a control unit 130, a parking space search device 140, a parking path generator 150 and a position detection device 160. The dual-clutch transmission 110 can include a dual clutch 111 and transmissions (e.g., transmission sets) 112. The dual-clutch transmission 110 can engage or disengage an engine (e.g., an internal combustion engine, a hybrid engine, an electric motor) and vehicle wheels depending on whether the dual clutch is engaged or disengaged (e.g., engaged or disengaged). For example, when the dual clutch 111 is engaged, the engine's drive force can be transmitted directly to the wheels via the transmissions 112, and the drive force cannot be transmitted to the wheels when the dual clutch 111 is disengaged. The dual-clutch transmission 110 can adjust the vehicle's speed based on clutch torque. The dual-clutch transmission 110 can control the clutch torque in response to input from the control unit 130 to adjust the engine's drive power transmitted to the vehicle's wheels 100. For example, the dual-clutch transmission 110 can control the clutch torque to allow the vehicle's speed to follow a target speed set by the control unit 130. The brake 120 can cause the vehicle to slow down (e.g., decelerate, brake) to reduce its speed. For example, the brake 120 can adjust the brake pressure to cause the vehicle to slow down. The control unit 130 can control the operation (e.g., driving mode) of the vehicle 100 and can control the overall operation of components within the vehicle 100. For example, the control unit 130 can control the autonomous parking operation (e.g., operation during an autonomous parking maneuver) of the vehicle 100. The control unit 130 can control the autonomous parking operation of the vehicle 100 when a command to start the autonomous parking operation is received from a user. The control unit 130 can control the autonomous parking operation of the vehicle 100 using the parking path information generated by the parking path generator 150 based on the parking space information acquired by the parking space search device 140 and the current position of the vehicle 100, which is determined by the position detection device 160. The control unit 130 can set a target speed for the vehicle 100 during autonomous parking operation. The control unit 130 can control the dual-clutch transmission 110 and the brakes 120 to allow the vehicle 100 to maintain the set target speed during autonomous parking operation. The target speed can be defined as a speed lower than the vehicle 100's creep driving speed. Based on the instantaneous position of the vehicle 100 detected by the position detection device 160, the control unit 130 can determine whether the vehicle 100 is on a flat section (e.g., a substantially level section traveled by the vehicle), a downward-sloping section (e.g., a descending section traveled by the vehicle), or an upward-sloping section (e.g., an ascending section traveled by the vehicle), and can control the dual-clutch transmission 110 and the brake 120 in response to the determined section. Alternatively, the control unit 130 can determine whether the vehicle 100 is on a flat section, an upward-sloping section, or a downward-sloping section using detection information obtained from various sensors on the vehicle 100. For example, if the vehicle 100 is positioned on a flat section, the control unit 130 can control the dual-clutch transmission 110 and the brake 120 with reference to Fig. 2 to allow the vehicle 100 to follow a target speed. Fig. 2(a) shows that a command to start an autonomous parking operation is received from a user over a time interval from t1 to t8. In Fig. 2(b), the solid line shows the target speed of vehicle 100, and the dashed line shows a change in the vehicle's speed. Fig. 2(c) shows a change in the brake pressure of brake 120, Fig. 2(d) shows a change in the clutch torque, and Fig. 2(e) shows a change in the clutch temperature. During an initial time interval from t0 to t1, the vehicle 100 is controlled so that it remains in a stopped state. During this first interval, the clutch torque can be controlled to be essentially near zero (e.g., held at essentially zero (e.g., by means of control)), and the brake pressure can be controlled to an initial level (e.g., held at an initial brake pressure value (e.g., by means of control)). During a second time interval from t1 to t2, the control unit 130 can set the target speed and control the dual-clutch transmission 110 and the brakes 120 to allow the vehicle 100 to maintain the target speed in response to the user's command to start the autonomous parking operation. The control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased when the vehicle's driving speed 100 is lower than the target speed, and it can control the dual-clutch transmission 110 so that the clutch torque is decreased when the vehicle's driving speed 100 is higher than or equal to the target speed. For example, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased and also control the brake 120 so that the brake pressure is reduced by the first level. Over a third time interval from t2 to t3, the control unit 130 can control the brake 120 so that the brake pressure is released. For example, releasing the brake pressure can refer to reducing the brake pressure to zero. The control unit 130 can further control the dual-clutch transmission 110 so that the clutch torque is increased, and can then control the dual-clutch transmission 110 so that the clutch torque is decreased if the difference between the vehicle's driving speed 100 and the target speed is less than a threshold value. Over a fourth time interval from t3 to t4, the vehicle's speed 100 can exceed the target speed. Over a fifth time interval from t4 to t5, the control unit 130 can control the brake 120, increasing the brake pressure by a second level (e.g., a second brake pressure value). This second level can be defined as a value lower than the first level, but it is not limited to this. Accordingly, the vehicle's speed 100 can decrease over a sixth time interval from t5 to t6. Over a seventh time interval from t6 to t7, the vehicle's speed can decrease again below the target speed. In this case, the control unit 130 can control the dual-clutch transmission 110 to increase the clutch torque, and can then control the dual-clutch transmission 110 to decrease the clutch torque if the difference between the vehicle's speed 100 and the target speed is less than the threshold value. Over an eighth time interval from t7 to t8, the vehicle's speed 100 can be the same as, or substantially the same as, the target speed. Over a ninth time interval from t8 to t9, the control unit 130, in the case where the target speed is set to zero (e.g., in the case where the vehicle 100 is fully parked and stopped), can control the dual-clutch transmission 110 to reduce the clutch torque and control the brake 120 to increase the brake pressure. To reduce the vehicle's speed 100, the control unit 130 can, for example, control the brake 120 so that the brake pressure is increased by the first level and control the dual-clutch transmission 110 so that the clutch torque is released (i.e., the clutch torque is set to zero). Furthermore, the control unit 130 can release the clutch torque when the vehicle 100 stops (i.e.,(when the vehicle's speed is reduced from 100 to zero). Releasing the clutch torque can, for example, refer to controlling the clutch torque to zero. As described above, the control unit 130 can control the dual-clutch transmission 110 and the brake 120 to allow the vehicle 100 to maintain the target speed, while controlling the clutch torque within a predetermined range, thus preventing significant temperature changes due to friction within the engine. A detailed description of this is given below. Referring to Fig. 3, when the vehicle 100 is on an upward-sloping section, the control unit 130 can control the dual-clutch transmission 110 and the brake 120 so that the vehicle 100's speed is maintained at a target speed. For example, the control unit 130 can control the dual-clutch transmission 110 so that a first additional torque is generated when the vehicle 100 is on an upward-sloping section. The aim is to control the vehicle 100's speed so that it maintains the target speed, given that a greater clutch torque is required to maintain the same target speed when the vehicle 100 is on an upward-sloping section than when the vehicle 100 is on a flat section. Fig. 3(a) shows that a command to start an autonomous parking operation is received from a user over a time interval from t1 to t8. In Fig. 3(b), the solid line shows the target speed of vehicle 100, and the dashed line shows a change in the vehicle's speed. Fig. 3(c) shows a change in the brake pressure of brake 120, Fig. 3(d) shows a change in the clutch torque, and Fig. 3(e) shows a change in the clutch temperature. During an initial time interval from t0 to t1, the vehicle 100 is controlled so that it remains in a stopped state. During this first interval, the clutch torque can be controlled to be essentially near zero (e.g., held at essentially zero (e.g., by means of control)), and the brake pressure can be controlled to an initial level (e.g., held at an initial brake pressure value (e.g., by means of control)). During a second time interval from t1 to t2, the control unit 130 can set the target speed and control the dual-clutch transmission 110 and the brakes 120 to allow the vehicle 100 to maintain the target speed in response to the user's command to start the autonomous parking operation. The control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased when the vehicle's driving speed 100 is lower than the target speed, and it can control the dual-clutch transmission 110 so that the clutch torque is decreased when the vehicle's driving speed 100 is higher than or equal to the target speed. For example, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased and also control the brake 120 so that the brake pressure is reduced by the first level. Over a third time interval from t2 to t3, the control unit 130 can control the brake 120 so that the brake pressure is released (e.g., completely released) when the clutch torque becomes greater than or equal to the first additional torque. Here, the first additional torque can refer to a torque amount to compensate for a reduction in the vehicle's speed due to the gradient or road incline. The control unit 130 can also control the dual-clutch transmission 110 so that the clutch torque is increased, and then it can control the dual-clutch transmission 110 so that the clutch torque is decreased if the difference between the vehicle's speed 100 and the target speed is less than a threshold value. Over a fourth time interval from t3 to t4, the vehicle's speed 100 can exceed the target speed. Over a fifth time interval from t4 to t5, the control unit 130 can control the brake 120, increasing the brake pressure by a second level. Accordingly, the vehicle's speed 100 can decrease over a sixth time interval from t5 to t6. Over a seventh time interval from t6 to t7, the vehicle's speed can decrease again below the target speed. In this case, the control unit 130 can control the dual-clutch transmission 110 to increase the clutch torque, and can then control the dual-clutch transmission 110 to decrease the clutch torque if the difference between the vehicle's speed 100 and the target speed is less than the threshold value. Over an eighth time interval from t7 to t8, the vehicle's speed 100 can be the same as, or substantially the same as, the target speed. Over a ninth time interval from t8 to t9, the control unit 130, in the case where the target speed is set to zero (e.g., in the case where the vehicle 100 is fully parked and stopped), can control the dual-clutch transmission 110 to reduce the clutch torque and control the brake 120 to increase the brake pressure. To reduce the vehicle's speed 100, the control unit 130 can, for example, control the brake 120 so that the brake pressure is increased by the first level and control the dual-clutch transmission 110 so that the clutch torque is released (i.e., the clutch torque is set to zero). Furthermore, the control unit 130 can release the clutch torque when the vehicle 100 stops (i.e.,(when the vehicle's speed is reduced from 100 to zero). Referring to Fig. 4, when the vehicle 100 is on a downward-sloping section (e.g., a sloping section traversed by the vehicle), the control unit 130 can control the dual-clutch transmission 110 and the brake 120 so that the vehicle 100's speed is allowed to maintain a target speed. For example, if the vehicle 100's speed is lower than the target speed while on the downward-sloping section, the control unit 130 can control the brake 120 so that the brake pressure is reduced by a third level (e.g., a third brake pressure value), which is lower than the first level.The goal is to control the vehicle's speed so that it follows the target speed, given that when the vehicle is on a downhill slope, greater braking pressure is required to reduce the same amount of speed than when the vehicle is on a flat slope. This means that the braking pressure when the vehicle is on the downhill slope can be controlled so that it is greater by an offset value than the braking pressure when the vehicle is on the flat slope. Fig. 4(a) shows that a command to start an autonomous parking operation is received from a user over a time interval from t1 to t8. In Fig. 4(b), the solid line shows the target speed of vehicle 100, and the dashed line shows a change in the vehicle's speed. Fig. 4(c) shows a change in the brake pressure of brake 120, Fig. 4(d) shows a change in the clutch torque, and Fig. 4(e) shows a change in the clutch temperature. During an initial time interval from t0 to t1, the vehicle 100 is controlled so that it remains in a stopped state. During this first interval, the clutch torque can be controlled to be essentially near zero (e.g., held at essentially zero (e.g., by means of control)), and the brake pressure can be controlled to an initial level (e.g., held at an initial brake pressure value (e.g., by means of control)). During a second time interval from t1 to t2, the control unit 130 can set the target speed and control the dual-clutch transmission 110 and the brakes 120 to allow the vehicle 100 to maintain the target speed in response to the user's command to start the autonomous parking operation. The control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased when the vehicle's speed 100 is lower than the target speed, and it can control the dual-clutch transmission 110 so that the clutch torque is decreased when the vehicle's speed 100 is higher than or equal to the target speed. For example, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased and control the brake 120 so that the brake pressure is reduced by the third level (e.g., a third brake pressure value). The third level can be lower than the first level and higher than the second level. However, the third level is not limited to this and can be defined differently depending on the specific (vehicle) design. Over a third time interval from t2 to t3, the control unit 130 can control the brake 120, thus releasing the brake pressure. The control unit 130 can also control the dual-clutch transmission 110, increasing the clutch torque, and then decrease the clutch torque if the difference between the vehicle's driving speed 100 and the target speed is less than a threshold value. Over a fourth time interval from t3 to t4, the vehicle's speed (100) can exceed the target speed. Over a fifth time interval from t4 to t5, the control unit (130) can control the brake (120), increasing the brake pressure by the second level. Accordingly, the vehicle's speed (100) can decrease over a sixth time interval from t5 to t6. Over a seventh time interval from t6 to t7, the vehicle's speed can decrease again to below the target speed. In this case, the control unit (130) can control the dual-clutch transmission (110) to increase the clutch torque and can then control the dual-clutch transmission (110) to decrease the clutch torque if the difference between the vehicle's speed (100) and the target speed is less than the threshold value. Over an eighth time interval from t7 to t8, the vehicle's speed 100 can be the same as, or substantially the same as, the target speed. Over a ninth time interval from t8 to t9, the control unit 130, in the case where the target speed is set to zero (e.g., in the case where the vehicle 100 is fully parked and stopped), can control the dual-clutch transmission 110 to reduce the clutch torque and control the brake 120 to increase the brake pressure. To reduce the vehicle's speed 100, the control unit 130 can, for example, control the brake 120 so that the brake pressure is increased by the third level and control the dual-clutch transmission 110 so that the clutch torque is released (i.e., the clutch torque is set to zero). Furthermore, the control unit 130 can release the clutch torque when the vehicle 100 stops (i.e.,(when the vehicle's speed is reduced from 100 to zero). Referring again to Fig. 1, the control unit 130 can control the dual-clutch transmission 110 so that a second additional torque is generated when the vehicle speed 100 decreases in a section where the clutch torque of the dual clutch 111 is greater than or equal to a predetermined value (e.g., in the case where the vehicle speed 100 is reduced by a braking bump (e.g., road speed bump)). The parking space search device 140 can search for a parking space for the vehicle 100 (e.g., a free or empty parking space suitable for the vehicle). For example, the parking space search device 140 can search for a parking space using detection information obtained from a radar sensor, a LiDAR sensor, or the like. The parking path generator 150 can generate a movement path (e.g. a movement trajectory) for parking the vehicle 100 in a parking space, taking into account the position of the vehicle 100 and the position of a found parking space. The position detection device 160 can detect the current position of the vehicle 100. For example, the position detection device 160 can determine the current position of the vehicle 100 using a Global Positioning System (GPS) sensor. Since the vehicle 100 is performing autonomous parking without driver intervention, the dual-clutch transmission 110 can control the clutch torque so that the vehicle 100's speed follows a creep speed. However, a target speed set for the autonomous parking operation of the vehicle 100 may be lower than the creep speed, and the vehicle 100's speed can be controlled by the brake 120 so that it follows the target speed. At this time, it is common for the dual-clutch transmission 110 to continuously increase the clutch torque, regardless of the brake 120 being applied, to allow the vehicle 100's speed to follow the creep speed, and frictional heat may be generated between the dual-clutch transmission 111 and the engine as a result.However, the control unit 130 of the vehicle 100 according to an exemplary embodiment of the present invention can control the dual-clutch transmission 110 and the brake 120 to allow the vehicle 100's driving speed to follow the target speed, thereby reducing the heat generated by the dual clutch 111. Consequently, the durability (in particular component lifetime) of the vehicle can be improved, and the marketability and usability of the vehicle 100 with the autonomous parking function can be enhanced. Fig. 5 is a flowchart illustrating a vehicle speed control method according to an exemplary embodiment of the present invention. With reference to Fig. 5, a vehicle speed control method according to an exemplary embodiment of the present invention may comprise: a step of setting a target speed of a vehicle (step S110), a step of controlling a clutch torque and a brake pressure (step S120), a step of determining whether the vehicle has reached a target position (step S130), a step of controlling a stop of the vehicle when the vehicle has reached the target position (step S140), a step of determining whether the vehicle has come to a complete stop (step S150), and a step of releasing the clutch torque when the vehicle is completely stopped (step S160). Step S120 may include: a step of controlling the clutch torque (step S121), a step of determining whether a required torque is being generated (step S122), a step of releasing the brake pressure when the required torque is being generated (step S123), a step of controlling a vehicle speed (step S124), a step of determining whether the vehicle speed exceeds a target vehicle speed (step S125), a step of controlling the brake pressure when the vehicle speed exceeds the target vehicle speed (step S126), and a step of determining whether the vehicle's speed is within a predetermined range with respect to the target speed (step S127). Steps S110 to S160 are described in more detail below with reference to Fig. 1, Fig. 2, Fig. 3 to Fig. 4. In step S110, the control unit 130 can set (e.g., define) a target speed for the vehicle 100. In step S121, the control unit 130 can control the dual clutch transmission 110 in such a way that the clutch torque is increased. In step S122, the control unit 130 can determine whether a clutch torque (e.g., a first additional torque) is generated, which is required to control the driving speed of the vehicle 100 so that it follows the target speed (see the second time interval of Fig. 3). In step S123, the control unit 130 can control the brake 120 so that the brake pressure is released when it is determined that the required clutch torque is being generated. In step S124, the control unit 130 can control a vehicle speed by controlling the dual clutch transmission 110 while the brake pressure is released. In step S125, the control unit 130 can determine whether the vehicle speed 100 exceeds the target vehicle speed. In step S126, the control unit 130 can control the brake 120 so that the brake pressure is increased when it is determined that the vehicle speed 100 exceeds the target vehicle speed. In step S127, the control unit 130 can determine whether the vehicle speed 100 is within a predetermined range with respect to the target vehicle speed (e.g., within a predetermined range around the target vehicle speed). The control unit 130 can then control the dual-clutch transmission 110 to maintain or reduce the clutch torque if it is determined that the vehicle speed 100 is within the predetermined range with respect to the target vehicle speed. In step S130, the control unit 130 can determine whether the vehicle 100 is in a target position. For example, the target position could be a parking space found for the vehicle 100. In step S140, the control unit 130 can increase the brake pressure if it is determined that the vehicle 100 is in the target position. In step S150, the control unit 130 can determine whether the vehicle 100 is / will be stopped. In step S160, the control unit 130 can control the dual clutch transmission 110 so that the clutch torque is released when it is determined that the vehicle 100 has stopped. Fig. 6 shows a vehicle according to a further exemplary embodiment of the present invention. With reference to Fig. 6, the vehicle 100 according to a further exemplary embodiment of the present invention differs from the vehicle 100 shown in Fig. 1 in that the former may additionally have a temperature management device 170. The temperature management device 170 can manage the temperature of the dual-clutch transmission 110. For example, if the dual-clutch transmission 110 is a wet type (e.g., a type with a wet clutch), it can be cooled by a coolant when its temperature is higher than or equal to a threshold temperature. Alternatively, if the dual-clutch transmission 110 is a dry type (e.g., a type with a dry clutch), the temperature management device 170 can inform the control unit 130 that vehicle speed control for autonomous parking operation is not possible, thus preventing wear and tear on the dual clutch 111. Fig. 7 is a flowchart illustrating a vehicle speed control method according to a further exemplary embodiment of the present invention. Fig. 8 is a diagram explaining the vehicle speed control method according to a further embodiment of the present invention. Fig. 8(a) shows that a command to start autonomous parking is received from a user over a time interval from t1 to t8. In Fig. 8(b), the solid line shows the target speed of vehicle 100, and the dashed line shows a change in the vehicle's speed. Fig. 8(c) shows a change in the brake pressure of brake 120, Fig. 8(d) shows a change in the clutch torque, and Fig. 8(e) shows a change in the clutch temperature. For an initial time interval from t0 to t1, vehicle 100 is controlled so that it remains in a stopped state. Accordingly, over the first time interval, the clutch torque can be controlled to be essentially close to zero (e.g., kept at essentially zero (e.g., by means of control)) and the brake pressure can be controlled to a first level (e.g., kept at a first brake pressure value (e.g., by means of control)). Referring to Fig. 7 and Fig. 8, in step S210 the control unit 130 can set the target speed of the vehicle 100. In step S220, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased. Over a second time interval from t1 to t2 in Fig. 8, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased, and control the brake 120 so that the brake pressure is reduced by the first level. In step S230, the control unit 130 can determine whether a clutch torque is generated that is required to control the vehicle's speed 100 so that it follows the target speed. For example, the control unit can determine over the second time interval from t1 to t2 whether a clutch torque is generated that is required to control the vehicle's speed 100 so that it follows the target speed. In step S240, the control unit 130 can control the brake 120 so that the brake pressure is released when it is determined that the required clutch torque is being generated. Over a third time interval from t2 to t3 in Fig. 8, the control unit 130 can control the brake 120 so that the brake pressure is released. In step S250, the control unit 130 can control a vehicle speed by controlling the dual clutch transmission 110 while the brake pressure is released. In step S260, the control unit 130 can determine whether the vehicle's speed is decreasing. For example, over the third time interval from t2 to t3 in Fig. 8, the vehicle's speed may decrease while the clutch torque is greater than or equal to a predetermined value. Such a case might occur, for example, when the vehicle 100 enters an upwardly inclined section of a speed bump, and the vehicle 100 may require additional clutch torque to move over the speed bump. In step S270, the control unit 130 can request an additional clutch torque (e.g., a second additional torque) from the dual-clutch transmission 110 (CMD torque). For example, at time t3 in Fig. 8, the control unit 130 can request the additional clutch torque (e.g., the second additional torque) from the dual-clutch transmission 110. In step S280, the control unit 130 can control the dual-clutch transmission 110, generating an additional clutch torque. Accordingly, the vehicle speed 100 can increase over a fourth time interval from t3 to t4 in Fig. 8. In step S290, the control unit 130 can determine whether the vehicle's driving speed 100 has increased. In step S300, the control unit 130 can request the dual-clutch transmission 110 to release the additional clutch torque (e.g., the second additional torque) if it is detected that the vehicle speed 100 is increasing. For example, at time t4 in Fig. 8, the control unit 130 can request the dual-clutch transmission 110 to release the additional clutch torque (e.g., the second additional torque) (e.g., to stop applying the additional clutch torque). In step S310, the control unit 130 can determine whether the vehicle's speed exceeds the target speed. In step S320, the control unit 130 can control the brake 120 so that the brake pressure is increased if it is determined that the vehicle speed 100 exceeds the target vehicle speed. For example, over a fifth time interval from t4 to t5, the control unit 130 can control the brake 120 so that the brake pressure is increased by a second level. In step S330, the control unit 130 can determine whether the vehicle's driving speed 100 is lower than the target speed. In step S340, the control unit 30 can control the dual-clutch transmission 110 so that the clutch torque is increased when the vehicle speed 100 is lower than the target speed. For example, over a sixth time interval from t5 to t6 in Fig. 8, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is increased. In step S350, the control unit 130 can release the brake pressure. In step S360, the control unit 130 can determine whether the vehicle 100 is in a target position. For example, the target position could be a parking space found for the vehicle 100. The control unit 130 can increase the brake pressure of the vehicle 100 if it is determined that the vehicle 100 is in the target position. Over a seventh time interval from t6 to t7, the control unit 130 can control the brake 120, thus increasing the brake pressure. In step S370, the control unit 130 can determine whether the vehicle 100 is stopped. In step S380, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is released when it is determined that the vehicle 100 is / will be stopped. Over the seventh time interval from t6 to t7 of Fig. 8, the control unit 130 can control the dual-clutch transmission 110 so that the clutch torque is released (e.g., reduced to zero). Fig. 9 shows a block diagram of a data processing system for executing a vehicle speed control method according to an exemplary embodiment of the present invention. With reference to Fig. 9, the vehicle speed control method described above can also be implemented by a data processing system (e.g., a computer system) according to an exemplary embodiment of the present invention. A data processing system 1000 can comprise at least one processor 1100, one memory 1300, one user interface input device 1400, one user interface output device 1500, one storage device 1600, and one network interface 1700, which are connected by a system bus 1200. The processor 1100 can be a semiconductor device for processing instructions stored in a central processing unit (CPU) or in the memory 1300 and / or the storage device 1600. The memory 1300 and the storage device 1600 can comprise numerous types of volatile or non-volatile storage media. For example, the memory 1300 can include a read-only memory (ROM) 1310 and a random access memory (RAM) 1320. The steps of the method or algorithm described above in connection with the exemplary embodiments encompassed by the present invention can accordingly be implemented directly by means of a hardware module or a software module executed by the processor 1100, or by means of a combination of these. The software module can be located in a storage medium (i.e., the memory 1300 and / or the storage device 1600), such as RAM, flash memory, ROM, EPROM, EEPROM, a register, a hard disk, a removable disk, a CD-ROM, and the like. An exemplary storage medium can be connected to the processor 1100, and the processor 1100 can read information from and write information to the storage medium. In another technique, the storage medium can be integrated with the processor 1110.The processor and the storage medium can be contained within an ASIC. The ASIC can be located in a user terminal. In another technology, the processor and the storage medium can be separate components within the user terminal. Although the present invention has been described with reference to exemplary embodiments and the accompanying drawings, the present invention is not limited thereto, but can be modified and adapted in various ways by those skilled in the art to which the present invention belongs, without deviating from the meaning and scope of the present invention. The preceding description of certain exemplary embodiments of the present invention served the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to precisely the disclosed forms, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were selected and described to illustrate certain principles of the invention and its practical applicability, thereby enabling the person skilled in the art to produce and apply various exemplary embodiments of the present invention, as well as various alternatives and variations thereof. It is intended that the scope of the invention is defined by the accompanying claims.