SYSTEM AND METHOD FOR CHANGING LANES ON CURVY ROADS

Abstract

The present disclosure provides a system (100) and a method (400) for changing lanes on curved roads. The system (100) comprises a control unit (110) configured to determine the curvature of the curved road, determine the lateral acceleration required to change lanes on the curved road, and compare the required lateral acceleration with the lateral steering limit of a vehicle (102). The control unit (110) can then either perform the lane change if the required lateral acceleration is less than the lateral steering limit, or prevent the lane change if the required lateral acceleration is greater than the lateral steering limit.

Description

TECHNICAL FIELDThe present disclosure relates to the field of vehicle initiated lane change. In particular, the present disclosure provides a system and method for changing lanes on curved roads.BACKGROUNDDuring operation, ego vehicles may change lanes for various reasons, such as during passing operations to avoid obstacles, navigate through a predetermined path, or pass another vehicle. Changing lanes in turns, however, may be a difficult and potentially dangerous task, particularly when the vehicle is driving at high speed (e.g., 90 km / h). Moreover, the angle at which the vehicle can be turned is limited by the physical conditions of the vehicle, making some lane changes impossible, dangerous or very unpleasant to the occupants. The occupant's experience is impaired if the lane change is initiated but is aborted due to the strong road curvature. Previous solutions do not provide a way to detect such situations and to handle them so that they are safe for the occupants of the vehicle as well as for other road users in the environment.WO 2023194801A1 describes a system that determines and executes a navigation action based on characteristics of the environment of a host vehicle or a steering limit of the host vehicle. The navigation actions are determined so that their execution does not exceed a maximum permissible lateral acceleration. However, the cited document contains no information regarding the calculation and execution of lane changes when driving on curved roads.Therefore, there is a need for a system and method for changing lanes on curved roads.OBJECT OF THE PRESENT DISCLOSUREA general object of the present disclosure is to provide a system and method for lane change on curved roads.An object of the present disclosure is to determine the lateral acceleration required to perform lane change on curved roads based on at least one of curvature of the curved roads or linear speed of the vehicle.Another object of the present disclosure is to avoid lane change failures due to the strong road curvature that ego vehicles cannot cope with at current speeds.SUMMARYAspects of the present disclosure relate to the field of vehicle initiated lane change. In particular, the present disclosure provides a system and method for changing lanes on curved roads.One aspect of the present disclosure relates to a system for changing lanes on curved roads. The system includes a controller configured to determine a curvature of a curved road, determine a lateral acceleration required to change a lane on the curved road, and compare the required lateral acceleration to a lateral steering limit of a vehicle. The controller is then configured to either perform the lane change when the required lateral acceleration is less than the lateral steering limit or prevent the lane change when the required lateral acceleration is greater than the lateral steering limit.In some embodiments, the required lateral acceleration may be determined based on at least one of the curvature of the curved road and a linear velocity of the vehicle.In some embodiments, the curvature may be determined based on sensor data or map data associated with the curved road.In some embodiments, the curvature for a road portion of the curved road may be determined for a lane change duration.A further aspect of a method for changing the lane on curved roads consists in determining the curvature of a curved road with the aid of a control unit, determining a transverse acceleration required for changing a lane on the curved road and comparing the required transverse acceleration with a transverse steering limit of a vehicle. The method then comprises carrying out the lane change if the required lateral acceleration is less than the lateral steering limit, or preventing the lane change if the required lateral acceleration is greater than the lateral steering limit.Various objects, features, aspects and advantages of the subject matter of the invention will become more apparent from the following detailed description of preferred embodiments, taken in conjunction with the accompanying drawing figures, in which like numerals represent like components.BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings serve to further understand the present disclosure and form part of this description. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. FIG. 1 shows an example vehicle having a system for changing lanes on curved roads according to embodiments of the present disclosure. FIG. 2 shows an example block diagram of the controller according to embodiments of the present disclosure. FIGS. 3A and 3B show examples of curved roads having different curvatures according to embodiments of the present disclosure. FIG. 4 is a flowchart of an example of a method for changing lanes on curved roads according to embodiments of the present disclosure. FIG. 5 illustrates an example computer system in or with which embodiments of the system according to embodiments of the present disclosure may be implemented.DETAILED DESCRIPTIONThe following is a detailed description of the embodiments of the disclosure illustrated in the accompanying drawings. The embodiments are so detailed as to clearly convey the disclosure. It is not intended, however, to limit the predictable variations of embodiments with the particularity provided; rather, all modifications, equivalents and alternatives falling within the scope of the present disclosure as defined by the appended claims are intended to be covered.The embodiments discussed herein relate to the field of vehicle initiated lane change. In particular, the present disclosure provides a system and method for changing lanes on curved roads.One aspect of the present disclosure relates to a system and method for changing lanes on curved roads. The system includes a controller that implements the method. The controller is configured to determine a curvature of the curved roads, determine a lateral acceleration required for a lane change on the curved roads, and compare the required lateral acceleration to a lateral steering limit of the vehicle. The control device can then either carry out the lane change if the required lateral acceleration is less than the lateral steering limit or prevent the lane change if the required lateral acceleration is greater than the lateral steering limit.Various embodiments of the present disclosure will be discussed in more detail with reference to FIGS. 1-5. 1-5.Referring to FIG. 1, a system 100 for changing lanes on curved roads may be implemented in a vehicle 102. The vehicle 102 may include, but is not limited to, cars, vans, trucks, buses, trains, highwayways, aircraft, and the like. In some embodiments, the vehicle 102 may be an ego vehicle, i.e., a vehicle capable of detecting its environment. In some embodiments, the vehicle 102 may be a self-driving vehicle configured to perform autonomous actions to navigate the vehicle 102. The vehicle 102 may include one or more wheels 104- 1, 104- 2, 104- 3, 104- 4 (collectively referred to as wheels 104). The vehicle 102 may use steering 106 or a controller 110 to steer the wheels 104 and turn the vehicle 102. The vehicle 102 may also include one or more sensors 108, such as cameras, proximity sensors, light detection and ranging (LIDAR), global positioning system (GPS), speed sensors, steering angle sensors, terrain sensors, and the like. The sensor 108 may allow the ego vehicle 102 to sense its environment and make autonomous decisions to initiate and make lane changes.In some embodiments, the controller 110 may be configured to autonomously control the vehicle 102. The controller 110 may be implemented as an electronic control unit (ECU) or a vehicle controller (VCU). The controller 110 may receive sensor data from the sensors 108 or use map data stored therein to navigate the vehicle 102 through roads. The controller 110 may take control of and steering of the wheels 104, among other navigation decisions. The controller 110 may steer the wheels 104 to change lanes, move the vehicle 102 along curved roads, and the like, but is not limited to, moving the vehicle 102 to a destination specified by occupants of the vehicle 102. The controller 110 may generate a path and drive the vehicle 102 to the destination via the path. The controller 110 may also receive sensor data to control the vehicle 102 and avoid collisions / accidents with obstacles, other vehicles, or pedestrians.In some embodiments, the steering 106 may be mechanically connected to the wheels 104. In some examples, the steering 106 may be, but is not limited to, knuckle steering, knuckle steering, rack and pinion steering, and the like. In other embodiments, the steering 106 may be connected to the controller 110. In such embodiments, the steering 106 may send electronic signals to the controller 110 to indicate the angle to which the wheels 104 are to be steered. The controller 110 may cause the wheels 104 to move to the indicated angle using a series of actuators. The steering 106 may be used when the occupant assumes manual control of the vehicle 102. In further embodiments, the controller 110 may be configured to autonomously steer the vehicle 102, e.g., based on sensor data received from the sensors 108. In some embodiments, controller 110 may be connected to steering 106 via an engine. The controller 110 may actuate the engine and cause the steering 106 to steer the wheels 104 based on the sensor data. In still further embodiments, the controller 110 may control the set of actuators to steer the wheels 104 and turn the vehicle 102 based on the sensor data.The vehicle 102 is associated with a lateral steering limit value that indicates the maximum lateral acceleration / lateral steering limit value at which the vehicle 102 is allowed to turn. For the initiation of lane changes by the ego vehicle 102, it may be desirable that the lateral acceleration required to carry out the lane change is less than the maximum lateral acceleration / the limit value for the lateral steering. In some embodiments, the maximum lateral acceleration may be defined by physical limitations of the vehicle 102, e.g., the maximum steering angle of the steering 106. The steering angle may be determined by, but is not limited to, the type of steering 106 used, the speed of the vehicle 102 at the time of steering, the geometry of the vehicle 102, the terrain, and the like. For example, the knuckle steer may allow the vehicle 102 to steer in a range of about 120 degrees (60 degrees in both directions), depending on the geometry of the vehicle 102. In other embodiments, the maximum lateral acceleration (through intentional design decisions in the design of the vehicle 102) may be selected to maximize occupant comfort and / or meet vehicle regulations.Unlike existing ego vehicles that are configured to steer their wheels to either make a lane change or move the vehicle on curved roads (but not both simultaneously), the system 100 enables a safe lane change while driving on curved roads. The system 100 uses the controller 110 to steer the wheels 104 to either perform or prevent a lane change based on at least one of the following factors: lateral steering limit of the vehicle 102, curvature of the road, or linear velocity of the vehicle 102.When the ego vehicle 102 initiates a lane change, the controller 110 may be configured to determine the curvature of the curved roads and the lateral acceleration required to perform the lane change. The curvature may correspond to the inverse of the radius of curvature or turning radius, i.e., the radius of a curve or circle about which the vehicle 102 must turn to move along the curved road. The turning radius may be defined as a function of the wheelbase of the vehicle 102, a steering angle, and the width of the wheels 104. In some embodiments, the curvature may be determined based on sensor data or map data. In embodiments where sensor data is used, the sensors 108 indicative of imaging devices / cameras may capture images of a road segment of the curved road from which the controller 110 identifies the lanes on the road (e.g., by color on the road representing the lanes). The controller 110 may use artificial intelligence (AI) techniques suitable for performing segmentation / classification or other techniques known in the art to identify the lanes from the images. In addition, the controller 110 may determine the curvature of the lanes based on the images, e.g., using AI techniques suitable for determining the curvature of the lanes, or other known techniques. In other embodiments, the curvature of the lanes may be determined based on the current location and the path traveled by the vehicle 102. For example, the vehicle 102 may be preprogrammed to follow a path (e.g., a path between a starting and a destination), and the sensors 108 indicating GPS may indicate the current location of the vehicle 102 on the path. The path and current location may be used by the controller 110 to determine the road segment that the vehicle 102 is going to traverse or the road segment that the vehicle 102 is going to traverse. The road sections may include turns or turns. The controller 110 may then determine the curvature of the turns in the road segment based on the map data using known techniques.The controller 110 may be configured to make such determinations each time a lane change is initiated, regardless of whether the ego vehicle 102 is on curved or straight roads. In some embodiments, controller 110 may determine the curvature of the road segment before performing the lane change. In other embodiments, controller 110 may determine the curvature of the road segment after the duration of the lane change. In other embodiments, the curvature of the road segment may be determined when the lane change is performed or just before before the vehicle 102 enters a curved road.The controller 110 may be configured to determine the lateral acceleration required for changing the driving lane on curved roads. In some embodiments, the required lateral acceleration is determined based on the curved road curvature and / or the linear velocity of the vehicle 102. For example, the controller 110 may first determine a first lateral acceleration required to perform the turning on the curved road without lane change. In some embodiments, the first lateral acceleration may be determined as follows: where α is the acceleration, v is the linear velocity of the vehicle 102, and K is the curvature.The above equation shows that a higher steering angle (and a correspondingly higher lateral acceleration) may be required to make a lane change or motion along the curved road when the vehicle 102 is travelling at high speeds. Then, the controller 110 determines a second lateral acceleration required for lane change. Depending on which lane the vehicle 102 is to be moved to, the second lateral acceleration is either added to or subtracted from the first lateral acceleration. The resulting value may be determined as the required lateral acceleration. In some embodiments, the lateral acceleration may also be determined in consideration of the terrain and geometry of the vehicle 102.The controller 110 may be configured to compare the required lateral acceleration to the lateral steering limit of the vehicle 102. The controller 110 may either perform a lane change or prevent the lane change based on the comparison. In some embodiments, the controller 110 may perform the lane change when the required lateral acceleration is less than the lateral steering limit value. The lane change may be performed by turning the wheels 104 to an angle that allows the vehicle 102 to achieve the determined lateral acceleration. If the required lateral acceleration is within the limit value for the lateral steering, the termination of the lane change can be avoided and the driving behavior of the occupants can be improved. In other embodiments, the controller 110 may prevent the lane change when the required lateral acceleration is greater than the lateral steering limit value. In such cases, the control device 110 can only perform cornering, but not the lane change, and thus increase the safety and comfort of the occupants.As shown in FIG. 2, controller 110 may include one or more processors 202, as shown in block diagram 200. The one or more processor(s) 202 may be implemented as one or more microprocessor(s), microcomputers, microcontrollers, digital signal processors, central processing units, logic circuits, and / or any devices that process data based on operating instructions. Among other capabilities, the one or more processor(s) 202 may be configured to fetch and execute computer readable instructions stored in a memory 204 of the controller 110. The memory 204 may store one or more computer readable instructions or routines that may be fetched and executed to create or share the data units via a network service. The memory 204 may be any non-volatile device, for example, volatile memory such as random access memory (RAM), or non-volatile memory such as erasable programmable read-only memory (EPROM), flash memory, and the like.In one embodiment, controller 110 may also include one or more interfaces 206. The interface(s) 206 may include a variety of interfaces, e.g., interfaces for data input and output devices referred to as input / output (I / O) devices, memory devices, and the like. Interface(s) 206 may / may enable communication between controller 110, steering 106, and sensors 108. The interface(s) 206 may also provide a communication path for one or more components of the controller 110. Examples of such components include processing engine(s) 208 and database 218.In one embodiment, the processing machine(s) 208 may be implemented as a combination of hardware and programming (e.g., programmable instructions) to implement one or more functionalities of the processing machine(s) 208. In the examples described herein, such combinations of hardware and programming may be implemented in various ways. For example, the programming for the processing machine(s) 208 may consist of processor-executable instructions stored on a non-transitory machine-readable storage medium, and the hardware for the processing machine(s) 208 may include a processing resource (e.g., a controller) for executing such instructions.In other embodiments, the processing engine(s) 208 may be implemented by electronic circuitry. Database 218 may include data that is either stored or generated as a result of functionalities implemented by one of the components of processing engine(s) 208. In some embodiments, the database 218 may store the map data.In some embodiments, the processing machine(s) 208 may include a curvature determination machine 210, a lateral movement determination machine 212, an actuation machine 214, and other machine(s) 216. The other motor(s) 216 / s may implement functionalities that supplement the applications / functions executed by the controller 110.The determination engine 210 may be configured to determine the curvature of the road section in front of the vehicle 102. The curvature of the curved road (or road section) may be determined using any combination of sensor data or map data.The determination engine 212 may be configured to determine lateral movement of the vehicle 102 using at least one of the curvature of the curved road or the linear velocity of the vehicle 102.The actuation machine 214 may be configured to steer the wheels 104 when the required lateral acceleration is below the lateral steering limit. If the required lateral acceleration is greater than the limit value for the lateral steering, the lane change is prevented. If the required lateral acceleration is less than the limit value for the lateral steering, the lane change is carried out. The actuation engine 214 may use the actuators or motors to steer or turn the vehicle 102 at the required lateral acceleration.Referring to FIGS. 3A and 3B, example representations 300A and 300B of curved roads having different curvatures are shown. As shown, chord angle 301A in plot 300A may be less than chord angle 301B in plot 300B. The chord angles 301A, 301B may be formed by the beginning of the curvature 302 and the end of the curvature 304. The beginning 302 and the end 204 may also provide an indication of the road segment on which the lane change is to be performed. The chord angles 301A, 301B and corresponding curved road radius may determine the duration and distance the vehicle 102 must turn to move along the curved road segment. Since the curvature of the curved road section is small in FIG. 3A, the required lateral acceleration may be lower (as compared to FIG. 3B ). In such examples, if the vehicle 102 may turn 60 degrees (i.e., the lateral acceleration limit / the lateral steering limit at a given speed) in both directions and the curvature / curvature radius required for the turn and lane change is less than 60 degrees, the first lateral acceleration and the second lateral acceleration required to move along the curvature and make the lane change may also be below the lateral steering limit. As a result, the vehicle 102 may change to any lane because the required lateral acceleration may be below the limit for lateral steering.At the same time, the curvature in FIG. 3B is higher (compared to the curvature in FIG. 3A ), which requires a higher transverse acceleration. The vehicle 102 may change to one of the inner, middle, or outer lanes having curvatures 306- 1, 306- 2, or 306- 3 while traveling along the curved road segment. The second lateral acceleration (and accordingly the required lateral acceleration) may be different depending on the selected lane. If the vehicle 102 is not changing lanes and is moving in a medium lane, the second lateral acceleration is 0 and the curvature 306- 2 may correspond to the curvature of the curved road segment. When the vehicle 102 changes to an inner lane, the second lateral acceleration is added to the first lateral acceleration because the curvature 306- 3 is greater than the curvature of the curved road section. When the vehicle 102 changes to an outer lane, the second lateral acceleration is subtracted from the first lateral acceleration because the curvature 306- 1 is less than the curvature of the curved road section. When determining the required lateral acceleration using the first and second lateral accelerations for the intended lane change, the controller 110 may perform or prevent the lane change accordingly. The controller 110 performs the lane change when the detected required lateral acceleration is less than the lateral steering limit, and prohibits the lane change when the detected required lateral acceleration is greater than the lateral steering limit.As shown in FIG. 4, a method 400 for changing lanes on curved roads may include a plurality of blocks 402- 410. Method 400 may be implemented by system 100 or its control device 110.At block 402, method 400 includes determining, by a controller, a curvature of the curved roads.In block 404, the controller determines a lateral acceleration required to change lanes on curved roads as part of method 400.At block 406, method 400 includes comparing, by the controller, the required lateral acceleration to a lateral steering limit of a vehicle, e.g., vehicle 102.The method 400 then proceeds to either block 408 where the method 400 includes execution of the controller's lane change when the required lateral acceleration is less than the lateral steering limit, or to block 410 where the method 400 includes the controller's controller's lane change prevention when the required lateral acceleration is greater than the lateral steering limit.The block diagram of FIG. 5 illustrates a computer system 500 that includes an external device 510, a bus 520, a main memory 530, a read only memory 540, a mass storage device 550, a communication port 560, and a processor 570. One skilled in the art will understand that system 500 may include more than one processor 570 and communication ports 560. Processor 570 may include various modules associated with embodiments of the present disclosure. Communication port 560 may be a recommended standard 232 port for use with a modem-based dial-up connection, a 10 / 100 Ethernet port, a gigabit or 10 gigabit port over copper or fiber, a serial port, a parallel port, or other existing or future ports. Port 560 may be selected depending on a network, such as a local area network (LAN), wide area network (WAN), or other network to which system 500 is connected.In one embodiment, memory 530 may be RAM or other dynamic container well known in the art. Read-only memory (ROM) 540 may be any static device, e.g., programmable read-only memory (PROM) for storing static information. Mass storage 560 may be any current or future mass storage solution that may be used to store information and / or instructions. Example mass storage solutions may include, but are not limited to, parallel advanced technology attachment (PATA) or serial advanced technology attachment (SATA) hard disk drives or solid state drives (internal or external, e.g., with universal serial bus (USB) and / or Firewire interfaces), one or more optical disks, redundant array of independent disks (RAID) storage, e.g., an array of hard disks (e.g., SATA arrays).In one embodiment, bus 520 communicatively couples processor(s) 570 to the other memory, memory, and communication blocks. Bus 520 may be, for example, a peripheral component interconnect (PCI) / PCI extended (PCI-X) bus, a small computer system interface (SCSI), a USB bus, or the like, to connect expansion cards, drives, and other subsystems, as well as other buses, such as a front side bus (FSB), that connects processor 570 to computer system 500.In another embodiment, operator and management interfaces, e.g., a display device, keyboard, and cursor control controller, may also be coupled to bus 520 to assist in direct operator interaction with computer system 500. Other operator and management interfaces may be provided via network connections connected via communication port 560. In some embodiments, the external device 510 may be any type of external hard drives, floppy disk drives, compact disc read only memory (CD-ROM), compact disc rewritable (CD-RW), digital video disc read only memory (DVD-ROM). The above-described components are intended to be illustrative of various possibilities. The example computer system 500 described above is not intended to limit the scope of the present disclosure in any way.While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be developed without departing from the basic scope of application. The scope of the present disclosure is defined by the following claims. The present disclosure is not limited to the described embodiments, versions, or examples included to enable a person of ordinary skill in the art to make and use the present disclosure when combined with the information and skills available to the person of ordinary skill in the art.ADVANTAGES OF THE PRESENT DISCLOSUREThe present disclosure provides a system and method for lane changing on curved roads.The present disclosure enables the lateral acceleration required to perform a lane change on curved roads to be determined based on at least one of curvature of the curved roads or linear velocity of the vehicle.The present disclosure avoids lane change failures due to the strong road curvature that ego vehicles cannot cope with at current speeds.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 2023194801A1

[0003]

Claims

A system (100) for changing lanes on curved roads, comprising: a controller (110) configured to: determine a curvature of a curved road; determine a lateral acceleration required to change a lane on the curved road; compare the required lateral acceleration with a lateral steering limit of a vehicle (102); and either perform the lane change when the required lateral acceleration is below the lateral control limit or prevent the lane change when the required lateral acceleration is greater than the lateral steering limit.The system (100) of claim 1, wherein the required lateral acceleration is determined based on at least one of the following: the curvature of the curved road and a linear velocity of the vehicle (102).The system (100) of claim 1, wherein the curvature is determined based on sensor data or map data associated with the curved road.The system (100) of claim 1, wherein the curvature for a road segment of the curved road is determined for a lane change duration.A method (400) of changing lanes on curved roads, comprising: determining, by a controller (110), a curvature of a curved road; determining, by the controller (110), a lateral acceleration required to change a lane on the curved road; comparing, by the controller (110), the required lateral acceleration with a lateral steering limit of a vehicle (102); and either, performing, by the controller (110), the lane change if the required lateral acceleration is less than the lateral steering limit, or prohibiting, by the controller (110), the lane change if the required lateral acceleration is greater than the lateral steering limit.The method (400) of claim 5, wherein the required lateral acceleration is determined based on at least one of the following: the curvature of the curved road and a linear velocity of the vehicle (102).The method (400) of claim 5, wherein the curvature is determined based on sensor data or map data associated with the curved road.The method (400) of claim 5, wherein the curvature for a road segment of the curved road is determined for a lane change duration.

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