Method and system for controlling vehicle speed during turn using road previews

Abstract

Methods and systems for providing driving assistance in a vehicle. In one embodiment, a method includes determining, by a processor, curvature data associated with a road ahead of a vehicle; determining, by the processor, speed data based on the curvature data, steering data of the vehicle, and set speed data associated with a semi-autonomous control system of the vehicle; and generating, by the processor, a control command to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data.

Description

[0001] TECHNICAL FIELD The present invention relates generally to systems, methods, and apparatus for providing speed control by an autonomous or semi-autonomous driving system based on a road preview. Background Art

[0002] Some semi-autonomous driving features, such as adaptive cruise control, allow the speed of the vehicle to be controlled based on a set control speed to follow an intended path or intended lane. In some instances, such as on a curved road, when the vehicle is performing a turning maneuver, the semi-autonomous driving feature does not adjust the set control speed and requires the driver to intervene and assist in the operation of the vehicle. Optimal vehicle turning requires that the vehicle slow down when entering the turning maneuver and accelerate at and after the apex of the turning maneuver.

[0003] Therefore, it is desirable to provide improved speed control strategies, methods and systems for improving semi-autonomous control of the vehicle without driver assistance during such turning maneuvers.In addition, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the invention

[0004] A vehicle having a method and system for providing driving assistance is disclosed herein. In one embodiment, a method includes: determining, by a processor, curvature data associated with a road ahead of a vehicle; determining, by the processor, speed data based on the curvature data, steering data of the vehicle, and set speed data associated with a semi-autonomous control system of the vehicle; and generating, by the processor, a control command to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data.

[0005] In various embodiments, determining curvature data is based on image data received from an image sensor of the vehicle.

[0006] In various embodiments, determining the curvature data is based on at least one of map data and location data received from a global positioning system sensor.

[0007] In various embodiments, determining the curvature data includes determining a radius of a curve in a road in front of the vehicle, wherein determining the speed data is based on the radius.

[0008] In various embodiments, the method includes determining a target lateral acceleration based on a radius of a curve in a road in front of the vehicle and a vehicle speed, and wherein determining the speed data is based on the target lateral acceleration.

[0009] In various embodiments, the steering data includes a steering angle and a steering rate.

[0010] In various embodiments, the method includes basing the speed data on the target lateral acceleration when the steering angle is greater than a threshold and the speed data is set above a threshold.

[0011] In various embodiments, the method includes basing the speed data on the updated target lateral acceleration when the steering angle remains greater than a threshold and the set speed data remains above a threshold.

[0012] In various embodiments, the method includes the speed data being based on the acceleration profile and the set speed data when the steering angle is less than a threshold and the steering rate has changed opposite to an initial steering rate and the radius of a curve in a road ahead of the vehicle is increasing.

[0013] In various embodiments, determining speed data is based on weather conditions associated with a road ahead of the vehicle.

[0014] In various embodiments, determining the speed data is based on at least one of a tire pressure and a fuel level associated with the vehicle.

[0015] In another embodiment, a system includes: a controller including a non-transitory computer-readable medium and configured to, by a processor: determine curvature data associated with a road ahead of a vehicle; determine speed data based on the curvature data, steering data of the vehicle, and set speed data associated with a semi-autonomous control system of the vehicle; and generate a control command to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data.

[0016] In various embodiments, the controller is configured to determine curvature data based on image data received from an image sensor of the vehicle.

[0017] In various embodiments, wherein the controller is configured to determine the curvature data based on at least one of map data and position data received from a global positioning system sensor.

[0018] In various embodiments, the controller is configured to determine the curvature data by determining a radius of a curve in the road ahead of the vehicle, and to determine the speed data based on the radius.

[0019] In various embodiments, the controller is configured to determine a target lateral acceleration based on a radius of a curve in a road ahead of the vehicle and a vehicle speed, and to determine the speed data based on the target lateral acceleration.

[0020] In various embodiments, the steering data includes a steering angle and a steering rate.

[0021] In various embodiments, the controller is configured to: determine the speed data based on the target lateral acceleration when the steering angle is greater than a threshold and the set speed data is above a threshold; determine the speed data based on an updated target lateral acceleration when the steering angle remains greater than a threshold and the set speed data remains above the threshold; and determine the speed data based on the acceleration profile and the set speed data when the steering angle is less than a threshold and the steering rate has changed to be opposite to the initial steering rate and the radius of the curve in the road ahead of the vehicle is increasing.

[0022] In various embodiments, the controller is configured to determine the speed data based on at least one of weather conditions associated with a road ahead of the vehicle, tire pressure of the vehicle, and a fuel level of the vehicle.

[0023] In another embodiment, a vehicle includes: a sensor system configured to sense an environment of the vehicle; a semi-autonomous control system; and a controller for implementing a driver assistance system, the controller being configured to: determine, by a processor, curvature data associated with a road ahead of the vehicle based on sensor data from the sensor system; determine, by the processor, speed data based on the curvature data, steering data of the vehicle, and set speed data associated with the semi-autonomous control system; and generate, by the processor, a control command to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments will be described below with reference to the following drawings, wherein like numerals represent like elements, and wherein:

[0025] Figure 1 is a block diagram illustrating a vehicle having a speed control system according to various embodiments;

[0026] Figure 2 is an illustration of an area associated with a road having curvature according to various embodiments; and

[0027] Figure 3 is a data flow diagram illustrating features of a speed control system for a vehicle according to various embodiments; and

[0028] Figure 4 is a process flow diagram depicting an example process for speed control according to various embodiments. DETAILED DESCRIPTION

[0029] The following detailed description is merely exemplary in nature and is not intended to limit application and use. In addition, there is no intention to be bound by any express or implied theory presented in the aforementioned technical field, background technology, invention content or the following detailed description. As used herein, the term "module" refers to any hardware, software, firmware, electronic control component, processing logic and / or processor device, alone or in any combination, including but not limited to: application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), electronic circuits, processors (shared, dedicated or groups) and memories that execute one or more software or firmware programs, combinational logic circuits and / or other suitable components that provide the described functions.

[0030] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by any number of hardware, software, and / or firmware components configured to perform a specified function. For example, embodiments of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which may perform various functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any number of systems, and the systems described herein are merely exemplary embodiments of the present disclosure.

[0031] For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, machine learning models, radar, lidar, image analysis, and other functional aspects of the system (and the various operating components of the system) may not be described in detail herein. In addition, the connecting lines shown in the various figures included herein are intended to represent example functional relationships and / or physical couplings between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in the embodiments of the present disclosure.

[0032] refer to Figure 1 According to various embodiments, a speed control system, generally shown at 100, is associated with a vehicle 10. Generally, the speed control system 100 controls the longitudinal speed of the vehicle based on information obtained from a preview of a road ahead. In various embodiments, the preview of the road is based on map information, sensor image preview information, steering angle information, and vehicle speed.

[0033] like Figure 1 As depicted in FIG. 1 , the vehicle 10 generally includes a chassis 12, a body 14, front wheels 16, and rear wheels 18. The body 14 is disposed on the chassis 12 and substantially surrounds the components of the vehicle 10. The body 14 and the chassis 12 may together form a frame. The wheels 16-18 are each rotationally coupled to the chassis 12 near a respective corner of the body 14.

[0034] In various embodiments, the vehicle 10 is an autonomous or semi-autonomous vehicle, and the speed control system 100 is incorporated into the autonomous or semi-autonomous vehicle 10. For example, the vehicle 10 is a vehicle that is automatically controlled in some manner (i.e., with the aid of cruise control) to transport passengers or cargo from one location to another. In the illustrated embodiment, the vehicle 10 is depicted as a passenger car, but it should be understood that any other means of transportation may also be used, including motorcycles, trucks, sport utility vehicles (SUVs), recreational vehicles (RVs), marine vessels, aircraft, etc.

[0035] As shown, the vehicle 10 generally includes a propulsion system 20, a transmission system 22, a steering system 24, a braking system 26, a sensor system 28, an actuator system 30, at least one data storage device 32, at least one controller 34, and a communication system 36. In various embodiments, the propulsion system 20 may include an internal combustion engine, an electric motor such as a traction motor, and / or a fuel cell propulsion system. The transmission system 22 is configured to transmit power from the propulsion system 20 to the vehicle wheels 16-18 according to a selectable speed ratio. According to various embodiments, the transmission system 22 may include a step-ratio automatic transmission, a continuously variable transmission, or other suitable transmission. The braking system 26 is configured to provide braking torque to the vehicle wheels 16-18. In various embodiments, the braking system 26 may include friction brakes, wire control brakes, regenerative braking systems such as electric motors, and / or other suitable braking systems. The steering system 24 affects the position of the vehicle wheels 16-18 and includes a steering wheel in some instances.

[0036] The sensor system 28 includes one or more sensing devices 40a-40n that sense observable conditions of the external environment and / or the internal environment of the vehicle 10. The sensing devices 40a-40n may include, but are not limited to, radar, lidar, global positioning system, optical camera, thermal camera, ultrasonic sensor, and / or other sensors. The sensor system 28 further includes one or more sensing devices 40a-40n that sense observable conditions of the vehicle 10, such as, but not limited to, speed sensors, pressure sensors, temperature sensors, etc.

[0037] The actuator system 30 includes one or more actuator devices 42a-42n that control one or more vehicle features, such as, but not limited to, the propulsion system 20, the transmission system 22, the steering system 24, and the braking system 26. In various embodiments, the vehicle features may further include interior and / or exterior vehicle features, such as, but not limited to, doors, trunks, and cabin features, such as air, music, lighting, etc. (not numbered).

[0038] The communication system 36 is configured to wirelessly communicate information to and from other entities 48, such as, but not limited to, other vehicles ("V2V" communications), infrastructure ("V2I" communications), remote systems, and / or personal devices (for example, Figure 2 In an exemplary embodiment, the communication system 36 is a wireless communication system configured to communicate via a wireless local area network (WLAN) using the IEEE 802.11 standard or by using cellular data communications. However, additional or alternative communication methods, such as dedicated short-range communication (DSRC) channels, are also considered within the scope of the present disclosure. A DSRC channel refers to a one-way or two-way short-range to medium-range wireless communication channel designed specifically for automotive use and a corresponding set of protocols and standards.

[0039] The data storage device 32 stores data for automatically controlling the vehicle 10. In various embodiments, the data storage device 32 stores a defined map of the navigable environment. In various embodiments, the defined map may be predefined by and obtained from a remote system. For example, a defined map may be assembled by a remote system and transmitted to the vehicle 10 (wirelessly and / or in a wired manner) and stored in the data storage device 32. It will be appreciated that the data storage device 32 may be part of the controller 34, separate from the controller 34, or part of the controller 34 and part of a separate system.

[0040] The controller 34 includes at least one processor 44 and a computer readable storage device or medium 46. The processor 44 can be any custom or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor of several processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, any combination thereof, or any device generally used to execute instructions. For example, the computer readable storage device or medium 46 can include volatile and non-volatile storage in read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is a persistent or non-volatile memory that can be used to store various operating variables when the processor 44 is powered off. The computer readable storage device or medium 46 can be implemented using any of a number of known memory devices, such as PROM (programmable read-only memory), EPROM (electrical PROM), EEPROM (electrically erasable PROM), flash memory, or any other electrical, magnetic, optical, or combination memory device capable of storing data, some of which represent executable instructions used by the controller 34 in controlling the vehicle 10.

[0041] The instructions may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing logical functions. When executed by the processor 44, the instructions receive and process signals from the sensor system 28, execute logic, calculations, methods and / or algorithms for automatically controlling components of the vehicle 10, and generate control signals to the actuator system 30 to automatically control components of the vehicle 10 based on the logic, calculations, methods and / or algorithms. Although Figure 1 Only one controller 34 is shown, but embodiments of the vehicle 10 may include any number of controllers 34 that communicate via any suitable communication medium or combination of communication mediums and collaborate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals to automatically control features of the vehicle 10.

[0042] In various embodiments, as discussed in detail below, one or more instructions of the controller 34 are embodied in the speed control system 100 and, when executed by the processor 44 , process the sensor data and / or other data to determine road preview data, estimate a target lateral acceleration of the vehicle based on the road preview data, and automatically control the vehicle to adjust a cruise control setting or control a braking system to decelerate and / or accelerate the vehicle 10 when navigating a curve on the road based on the target lateral acceleration and steering data from the steering system 24 .

[0043] For example, Figure 2 As shown, when the upcoming road 200 on which the vehicle 10 is traveling includes a curve 202 that requires the vehicle 10 to perform a turning maneuver, the speed of the vehicle 10 in a first zone 210 is controlled based on the predicted lateral acceleration associated with the curve 202. The speed of the vehicle 10 in a second zone 220 is further controlled based on the updated predicted lateral acceleration associated with the curve 202. The speed of the vehicle 10 in a third zone 230 is then further controlled based on the control set speed of the acceleration profile and the semi-autonomous or autonomous driving features. As will be discussed in the exemplary embodiments herein, the zones are defined based on the steering data and the estimated radius of the curve 202.

[0044] In various embodiments, Figure 1 The speed control system 100 may be included in a semi-autonomous driving system that implements semi-autonomous or autonomous driving features, or may interface with a semi-autonomous driving system. Figure 2 More details are shown and reference is made to Figure 1, a data flow diagram illustrates elements of the speed control system 100 according to various embodiments. It will be appreciated that various embodiments of the speed control system 100 according to the present disclosure may include any number of modules embedded within the controller 34, which modules may be combined and / or further divided to similarly implement the systems and methods described herein. In addition, inputs to the speed control system 100 may be received from the sensor system 28, from other control modules (not shown) associated with the vehicle 10, and / or by Figure 1 The speed control system 100 includes a curvature determination module 350, a lateral acceleration determination module 352, a speed control module 356, and a speed profile data storage 358.

[0045] In various embodiments, the speed profile data store 358 stores speed profiles that define the speed and rate for longitudinal control of the vehicle 10 in order to accelerate or decelerate the vehicle 10. In various embodiments, any number of speed profiles may be defined. For example, the speed profile 400 may be defined as a multi-dimensional lookup table based on the radius of the curve and / or the lateral acceleration, steering data, and / or speed adjustment values ​​associated therewith. It will be appreciated that speed profiles may be defined for any number of environmental conditions and / or vehicle conditions that may affect the lateral acceleration of the vehicle 10 along the curve, such as, but not limited to, weather conditions, tire pressure, fuel level, etc.

[0046] In various embodiments, the speed profile provides a speed value as an output for use by a semi-autonomous or autonomous system in controlling the speed of the vehicle 10. The speed value may be defined based on the configuration of the propulsion system, transmission system, and / or braking system 26 of the vehicle 10 and based on the resulting rate of deceleration / acceleration.

[0047] Refer to Figure 2 In various embodiments, the curvature determination module 350 receives as input sensor data 360 and GPS location and / or map data 362. The sensor data 360 may include, for example, image data from a camera sensor or other sensing device configured to generate an image of the environment of the vehicle 10. The curvature determination module 350 processes the sensor data 360 and the GPS location and / or map data 362 to determine a radius of curvature of the road ahead and generates radius data 354 based on the radius.

[0048] In various embodiments, curvature determination module 350 determines curvature based on the type and location of lane markings identified in front of vehicle 10 and / or based on the location of vehicle 10 relative to a road map. It will be appreciated that in various embodiments, other methods of determining the radius of curvature may be implemented.

[0049] In various embodiments, the lateral acceleration determination module 352 receives as inputs radius data 364, vehicle speed data 366, and vehicle sensor data 368. The vehicle sensor data 368 may include data from vehicle sensors (e.g., rain sensors, ambient temperature sensors, tire pressure sensors, fuel level sensors, etc.) that indicate environmental conditions or other conditions associated with an upcoming road or vehicle 10. The lateral acceleration determination module 352 determines a lateral acceleration of the vehicle 10 for the predicted radius of the upcoming curvature and given the associated conditions, and generates target lateral acceleration data 370 based on the lateral acceleration.

[0050] For example, the lateral acceleration determination module 352 determines the target lateral acceleration based on the following relationship:

[0051]

[0052] Where r represents the predicted radius of curvature of the upcoming road provided by radius data 364, and v 2 represents the longitudinal velocity (or speed) of the vehicle 10 provided by the vehicle speed data 366. In various embodiments, the determined lateral acceleration can be compensated by applying a compensation value determined based on the vehicle sensor data 368. For example, when the sensor data 368 indicates that rain is sensed, the lateral acceleration is adjusted downward to account for the lower friction coefficient of the road. In another example, when the sensor data 368 indicates that the tire pressure is lower than the recommended value, the lateral acceleration increases due to, for example, vehicle roll. In yet another example, when the sensor data 368 indicates that the fuel level is high, the lateral acceleration increases due to, for example, sloshing that occurs with the addition of fuel.

[0053] The speed control module 356 receives as input the target lateral acceleration data 370, the set control speed data 372, and the steering data 374. In various embodiments, the set control speed data 372 includes a set control speed identified by a semi-autonomous or autonomous control system (i.e., a cruise control feature). In various embodiments, the steering data 374 includes a steering angle and a steering rate of the steering system 24. Based on the inputs, the speed control module 356 generates a speed control command 376 for use by the semi-autonomous control system to adjust the set control speed of the semi-autonomous feature to control the speed of the vehicle 10.

[0054] For example, when the steering angle is greater than a threshold (e.g., three degrees or some other value), and the semi-autonomous control is engaged at a set control speed greater than the threshold ( Figure 2region 210), the speed control module 356 generates a command for use by the semi-autonomous control system to adjust the set control speed so that the target lateral acceleration can be achieved by obtaining speed data 378 from the speed profile data store 358 based on, for example, radius data 364, target lateral acceleration data 370 and / or steering data 374.

[0055] In another example, when the steering angle remains greater than a threshold, and the semi-autonomous control remains engaged at a set control speed greater than a threshold ( Figure 2 region 220), the speed control module 356 generates a command for use by the semi-autonomous control system to adjust the set control speed so that an updated target lateral acceleration can be achieved by obtaining speed data 378 from the speed profile data store 358 based on, for example, radius data 364, target lateral acceleration data 370 and / or steering data 374.

[0056] In another example, once the steering angle is less than a threshold, and the steering rate has changed to the opposite of the initial steering rate, and the radius is increasing ( Figure 2 230 ), the speed control module 356 generates a speed control command 376 for use by the semi-autonomous control system to adjust the set control speed by defined increments or by a defined acceleration profile.

[0057] Reference now Figure 4 And continue to refer to Figure 1-Figure 3 , the flow chart shows that according to the present disclosure, Figure 1-Figure 4 The process 500 is performed by the speed control system 100. It can be understood from the present disclosure that the order of operations in the process 500 is not limited to the following. Figure 4 , but may be performed in one or more altered orders where applicable and in accordance with the present disclosure. In various embodiments, process 500 may be scheduled to run based on one or more predetermined events, and / or may run continuously during operation of vehicle 10.

[0058] In one example, process 500 may begin at 505. At 510, it is determined whether speed control is active, for example by enabling an autonomous or semi-autonomous feature such as cruise control. If speed control is not active at 510, process 500 may continue to monitor when speed control is active at 510, or may end at 630.

[0059] When it is determined at 510 that speed control is active, the curvature of the upcoming road is monitored at 520. For example, as described above, a target lateral acceleration associated with the radius of the upcoming curvature and other vehicle conditions is determined at 530. When the radius is above a threshold at 540 (e.g., the upcoming road is fairly straight), process 500 can end at 630.

[0060] When the radius is below the threshold at 540, the steering angle is optionally monitored and the control speed is set at 550 and 560. For example, when the steering angle is greater than the threshold at 550, and the control speed is set greater than the threshold at 560, a command is generated at 570 to control the longitudinal speed of the vehicle 10 to achieve a calculated target lateral acceleration that is equal to or less than the target lateral acceleration. Otherwise, when the steering angle is less than the threshold at 550, or the control speed is set less than the threshold at 560, the process 500 continues to monitor the steering angle and set the control speed at 550 and 560.

[0061] At 580 , a target lateral acceleration is determined based on the upcoming radius and the steering data. Once the steering angle becomes less than a threshold at 590 , and the steering rate changes to the opposite direction at 600 , the radius is monitored at 610 .

[0062] If it is determined at 610 that the radius is not increasing, then at 580, the process 500 continues to update the target lateral acceleration and control the vehicle 10 based on the target lateral acceleration. Once it is determined at 610 that the radius is increasing, a command is generated at 620 to control the speed of the vehicle 10 to increase to the set control speed by a defined increment or by a speed acceleration profile. Thereafter, the process 500 may end at 630.

[0063] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that there are a large number of variations. It should also be understood that the exemplary embodiment or multiple exemplary embodiments are merely examples and are not intended to limit the scope, applicability or configuration of the present disclosure in any way. On the contrary, the foregoing detailed description will provide a convenient roadmap for implementing the exemplary embodiment or multiple exemplary embodiments for those skilled in the art. It should be understood that various changes may be made to the functions and arrangements of the elements without departing from the scope of the present disclosure as set forth in the attached claims and their legal equivalents.

Claims

1. A method for providing driving assistance in a vehicle, comprising: determining, by a processor, curvature data associated with a road ahead of the vehicle; determining, by the processor, speed data based on the curvature data, steering data of the vehicle, and set speed data associated with a semi-autonomous control system of the vehicle; as well as A control command is generated by the processor to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data.

2. The method according to claim 1, wherein: The determining the curvature data is based on image data received from an image sensor of the vehicle.

3. The method according to claim 1, wherein: The determining the curvature data is based on at least one of map data and location data received from a global positioning system sensor.

4. The method according to claim 1, wherein: The determining the curvature data comprises determining a radius of a curve in the road in front of the vehicle, wherein the determining the speed data is based on the radius.

5. The method of claim 4, further comprising determining a target lateral acceleration based on the radius of the curve in the road ahead of the vehicle and the speed of the vehicle, and wherein, The determining the speed data is based on the target lateral acceleration.

6. The method according to claim 1, wherein: The steering data includes a steering angle and a steering rate. 7 . The method of claim 6 , further comprising basing the speed data on a target lateral acceleration when the steering angle is greater than a threshold and the set speed data is higher than a threshold. 8 . The method of claim 7 , further comprising basing the speed data on an updated target lateral acceleration when the steering angle remains greater than the threshold and the set speed data remains above the threshold.

9. The method of claim 8, further comprising basing the speed data on an acceleration profile and the set speed data when the steering angle is less than the threshold, and the steering rate has changed to be opposite to an initial steering rate, and a radius of a curve in the road ahead of the vehicle is increasing.

10. A system in a vehicle for providing driving assistance, comprising: A controller comprising a non-transitory computer readable medium and configured, by a processor: determining curvature data associated with a road ahead of the vehicle; determining speed data based on the curvature data, steering data of the vehicle, and set speed data associated with a semi-autonomous control system of the vehicle; as well as A control command is generated to the semi-autonomous control system to control the vehicle to a speed other than a set speed of the set speed data based on the speed data.

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