Method and system for estimating trailer hitch values

Abstract

Methods and systems are provided for a vehicle that pulls a trailer. In one embodiment, a method includes receiving, by a processor, sensor data from one or more sensors of a vehicle; estimating, by the processor, a steering torque value based on the sensor data; estimating, by the processor, a steering angle value based on the sensor data; determining, by the processor, a trailer hitch value based on the steering torque value and the steering angle value; and generating, by a processor, a control signal to control the vehicle based on the trailer hitch value.

Description

[0001] TECHNICAL FIELD The present invention relates generally to vehicles and, more particularly, to methods and systems for determining a tow body tongue value when a tow body is coupled to the vehicle and controlling the vehicle based on the determined value. Background Art

[0002] The trailer body hitch load is a measure of the load applied by the hitch onto the towing hitch of the vehicle. The hitch body hitch load affects lateral vehicle dynamics. When the hitch body hitch load is outside the nominal range, suboptimal lateral performance of the vehicle may be experienced. Most vehicles are not equipped with sensors to directly sense the hitch body hitch load. Adding additional sensors to directly sense the hitch body hitch load increases the cost and complexity of the vehicle.

[0003] In addition to the trailer body tongue load, a leveling system may be installed between the vehicle and the trailer body to apply a leveling torque on the hitch so that the vehicle does not experience a pitching effect due to the heavy load of the trailer body. The effect of the leveling system on the vehicle is called front axle load restoration. The trailer body tongue load and front axle load restoration affect vehicle dynamics in different ways and must be configured together to ensure proper vehicle handling.

[0004] Therefore, it is desirable to provide a method and system for determining a tow body trailer load and front axle load recovery associated with the trailer trailer load without adding any additional sensors. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. Summary of the invention

[0005] A method and system for a vehicle towing a towed body is provided. In one embodiment, the method includes: receiving, by a processor, sensor data from one or more sensors of a vehicle; estimating, by the processor, a steering torque value based on the sensor data; estimating, by the processor, a steering angle value based on the sensor data; determining, by the processor, a towed body hitch value based on the steering torque value and the steering angle value; and generating, by the processor, a control signal to control the vehicle based on the towed body hitch value.

[0006] In various embodiments, the tow body trailer value is a trailer trailer load value.

[0007] In various embodiments, the trailer tongue value is a front axle load recovery value associated with a leveling system.

[0008] In various embodiments, the trailer tongue value is a leveling system present value indicating whether a leveling system is present.

[0009] In various embodiments, the trailer tongue value is determined based on a linear model that combines the steering torque value and the steering angle value.

[0010] In various embodiments, the steering torque value includes a steering stiffness coefficient.

[0011] In various embodiments, the method includes determining a steering stiffness coefficient based on the lateral acceleration from the sensor data and the applied steering torque.

[0012] In various implementations, the steering angle value includes an understeer factor.

[0013] In various embodiments, the understeer coefficient is determined based on applied steering angle, yaw rate, and lateral acceleration from sensor data.

[0014] In various embodiments, automated features of a vehicle are controlled based on the tow vehicle hitch value.

[0015] In various embodiments, the method includes generating display data based on the tow body tongue value.

[0016] In another embodiment, a system includes: a non-transitory computer readable medium configured to store one or more models that relate a tow body hitch value to a steering torque value and a steering angle value; and a computer system onboard a vehicle. The computer system is configured to, by a processor: receive sensor data from one or more sensors of the vehicle; estimate a steering torque value based on the sensor data; estimate a steering angle value based on the sensor data; determine a tow body hitch value based on the one or more models and the steering torque value and the steering angle value; and generate a control signal based on the tow body hitch value to control the vehicle.

[0017] In various embodiments, the tow body trailer value is a trailer trailer load value.

[0018] In various embodiments, the tow body tongue value is at least one of a front axle load recovery value associated with a leveling system and a leveling system presence value indicating whether a leveling system is present.

[0019] In various embodiments, the computer system is configured to determine the trailer tongue value based on a linear model that combines the steering torque value and the steering angle value.

[0020] In various embodiments, the steering torque value includes a steering stiffness coefficient.

[0021] In various embodiments, the computer system is further configured to determine a steering stiffness coefficient based on the lateral acceleration from the sensor data and the applied steering torque.

[0022] In various implementations, the steering angle value includes an understeer factor.

[0023] In various embodiments, the computer system is further configured to determine an understeer coefficient based on the applied steering angle, yaw rate, and lateral acceleration from the sensor data.

[0024] In another embodiment, a vehicle includes: a hitch configured to couple to a tow body having a tow body trailer; and a computer system configured to, by a processor: receive sensor data from one or more sensors of the vehicle; estimate a steering torque value based on the sensor data; estimate a steering angle value based on the sensor data; determine a tow body trailer value based on the steering torque value and the steering angle value; and generate a control signal based on the tow body trailer value to control the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will hereinafter be described in conjunction with the following drawings, wherein like reference numerals refer to like elements, and wherein:

[0026] Figure 1 is a functional block diagram of a vehicle including a tow vehicle hitch value estimation system according to various embodiments;

[0027] Figure 2 is an example of a method according to various embodiments Figure 1 A data flow diagram of components of a vehicle tow vehicle hitch value estimation system; and

[0028] Figure 3 is an example of a method according to an exemplary embodiment. Figure 1 and Figure 2 A flow chart of a process performed by a tow vehicle hitch value estimation system for determining a hitch load value. 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), 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 specified functions. 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., that may implement 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, 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 connections between the 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] Reference Figure 1 According to various embodiments, a tow body trailer value estimation system, generally shown at 100, is associated with a vehicle 10. Generally speaking, the tow body trailer value determination system 100 estimates trailer body trailer values, such as trailer body trailer load and front axle load recovery, based on steering characteristics estimated while the vehicle 10 is towing the tow body 12. The trailer body trailer value determination system 100 estimates these values ​​in a passive manner that does not require any specific driver action of the vehicle 10. The estimated trailer values ​​are then used for observation / display, sensing, and / or other control areas of the vehicle 10, such as automatic control, to coordinate appropriate vehicle maneuvers.

[0033] like Figure 1 As shown, the vehicle 10 includes an automobile configured to tow a trailer body 12. In some embodiments, the vehicle 10 can be any of many different types of automobiles, such as, for example, a sedan, a van, a truck (not shown), or a sports utility vehicle (SUV), and can be a two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), a four-wheel drive (4WD) or an all-wheel drive (AWD), and / or various other types of vehicles. In some embodiments, the vehicle 10 can also include other types of mobile platforms and is not limited to automobiles. In various embodiments, the trailer body 12 can be any type of towable application having one or more wheels and is not limited to any one embodiment.

[0034] The vehicle 10 is configured to be coupled to and connected to a tow body 12 via a connection device 11, and is configured to tow the tow body 12. In various embodiments, the connection device 11 includes a hitch mechanism including a ball coupled to a tow bar of the tow body 12. When coupled to the vehicle 10, the tow bar applies a load to the hitch mechanism and thus to the vehicle 10. This load is referred to herein as the tow body tow bar load. In various embodiments, a leveling system including a leveling bar can be installed between the hitch of the vehicle 10 and the tow bar of the tow body 12. When installed, the leveling system applies a leveling torque on the hitch mechanism in an effort to level the vehicle 10. The leveling torque is referred to herein as front axle load recovery. In various embodiments, the connection device 11 also includes a wiring harness configured to transmit power and / or communication signals to and from components of the tow body 12.

[0035] like Figure 1 As depicted, the exemplary vehicle 10 generally includes a chassis 13, a body 14, front wheels 16, rear wheels 18, and a suspension system 19. The body 14 is disposed on the chassis 13 and substantially surrounds the components of the vehicle 10. The body 14 and the chassis 13 may together form a frame. The wheels 16-18 are each rotatably coupled to the chassis 13 by the suspension system 19 and the axle 17 near the respective corners of the body 14.

[0036] The vehicle 10 also 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 display system 35. 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 transfer 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 motors), and / or other suitable braking systems. The steering system 24 affects the position of the vehicle wheels 16-18. Although drawn as including a steering wheel for illustrative purposes, in some embodiments contemplated within the scope of the present disclosure, the steering system 24 may not include a steering wheel.

[0037] The sensor system 28 includes one or more sensing devices 40a-40n that sense observable conditions of the external and / or internal environment of the vehicle and / or components of the vehicle itself. The sensing devices 40a-40n may include, but are not limited to, radar, lidar, global positioning system, optical camera, thermal camera, ultrasonic sensor, inertial measurement unit, pressure sensor, position sensor, displacement sensor, speed sensor and / or other sensors.

[0038] 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 also 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).

[0039] The data storage device 32 stores data used to control the vehicle 10. In various embodiments, the data storage device 32 stores defined values ​​used to control the vehicle 10. As can be appreciated, the data storage device 32 can 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, a communication bus 45, 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 among 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 permanent 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 the following many known memory devices: PROM (programmable read-only memory), EPROM (electrical PROM), EEPROM (electrically erasable PROM), flash memory, or any other electrical, magnetic, optical or combined memory device capable of storing data (some of which represent executable instructions used by the controller 34 when controlling the vehicle 10). The bus 45 is used to transmit programs, data, status and other information or signals between various components of the vehicle and / or trailer. The bus 45 can be any suitable physical or logical means of connecting computer systems and components. This includes but is not limited to direct hard-wired connections, optical fiber, infrared and wireless bus technologies.

[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 the instructions are 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 media and collaborate to process sensor signals, execute logic, calculations, methods and / or algorithms, and generate control signals that automatically control features of the vehicle 10.

[0042] In various embodiments, one or more instructions of controller 34 are embodied in tow body trailer value determination system 100 and, when executed by processor 44, receive data from sensor system 28 and process the received data to determine trailer body trailer values, such as trailer body trailer load and front axle load restoration (FALR). For example, the instructions process the sensor data to determine steering characteristics, such as steering torque applied to achieve lateral acceleration and steering angle applied to follow a curve. The instructions determine the trailer body trailer value by correlating the steering characteristics with the trailer body trailer load value and the front axle load restoration value based on one or more linear models combining the characteristics. The instructions control vehicle 10 based on the estimated trailer body trailer value.

[0043] As can be appreciated, the controller 34 may be different in other ways. Figure 1 . For example, the controller 34 may be connected to or may otherwise utilize one or more remote computer systems and / or other control systems, such as as part of one or more of the above-described vehicle devices and systems. It should be understood that although the exemplary embodiment is described in the context of a fully functional computer system, those skilled in the art will recognize that the mechanisms of the present disclosure can be distributed as a program product, and one or more types of non-transitory computer-readable signal-bearing media are used to store the program and its instructions and implement its distribution, such as a non-transitory computer-readable medium that carries the program and contains computer instructions stored therein for causing a computer processor (such as, processor 44) to execute and implement the program. Such a program product may take a variety of forms, and the present disclosure applies equally regardless of the specific type of computer-readable signal-bearing medium used for distribution. Examples of signal-bearing media include: recordable media, such as floppy disks, hard drives, memory cards, and optical disks; and transmission media, such as digital and analog communication links. It should be understood that cloud-based storage and / or other technologies may also be utilized in certain embodiments. Similarly, it should be understood that the computer system of the controller 34 may also be different from other systems in other ways. Figure 1 In the embodiments depicted in FIG. 1 , a computer system such as controller 34 may be coupled to or may otherwise utilize one or more remote computer systems and / or other control systems.

[0044] Reference Figure 2 And continue to refer to Figure 1 , a data flow diagram illustrating the various embodiments Figure 1As can be appreciated, various embodiments of the trailer body hitch value determination 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 trailer body hitch value determination system 100 may be received from the sensor system 28, from other control modules (not shown) associated with the vehicle 10 and / or the hitch body 12, and / or by Figure 1 The tow vehicle trailer load determination system 100 may be configured to determine / model the tow vehicle trailer load value by other submodules (not shown) within the controller 34. In various embodiments, the tow vehicle trailer load determination system 100 includes a steering characteristic determination module 202, a trailer load determination module 204, a front axle load recovery determination module 206, and one or more model databases 208, 210. The model databases 208, 210 store one or more models for determining the trailer trailer load value as will be discussed in more detail below.

[0045] In various embodiments, the steering characteristic determination module 202 receives as input sensor data 212. The sensor data 212 may include, for example, inertial measurement unit (IMU) data, wheel speed sensor (WSS) data, electric steering (EPS) data, and / or side angle slip (SAS) data. The steering characteristic determination module 202 estimates a steering value 213 associated with the characteristics of the steering system (such as the torque applied to achieve lateral acceleration and the steering angle applied to follow a curve), and generates steering torque data 214 and steering angle data 216 based thereon.

[0046] In various embodiments, the steering characteristic determination module 202 determines the steering torque value as a steering stiffness value based on the lateral acceleration derived from the sensor data 212 and the applied steering torque (e.g., the total torque is equal to the driver torque plus the motor torque) and using a linear relationship. In various embodiments, the steering characteristic determination module 202 determines the steering angle value based on the applied steering angle, the measured yaw rate, and the lateral acceleration derived from the sensor data 212 and using a linear relationship. As can be appreciated, other sensor data and / or other models may be used to determine the steering value 213 because the present disclosure is not limited to this example.

[0047] In various embodiments, the trailer load determination module 204 receives as input the steering torque data 214 and the steering angle data 216. The trailer load determination module 204 determines the trailer body trailer load based on the received data 214 and 216 and generates the trailer body trailer load data 220. In various embodiments, the trailer load determination module 204 determines the trailer body trailer load based on a linear model defined by the trailer load model data 218, which combines the steering torque data 214 and the steering angle data 216 and is retrieved from the model database 208. For example, the trailer load determination module 204 determines the trailer body trailer load using the following relationship:

[0048] TL=a0+a1K us +a2K s ,

[0049] Where TL represents the load of the trailer frame, K us represents the understeer coefficient, K s represents the steering stiffness coefficient, and a0, a1, and a2 represent linear model parameters that can be implemented as constant calibration.

[0050] In various embodiments, the front axle load recovery determination module 206 receives the steering torque data 214 and the steering angle data 216 as inputs. The front axle load recovery determination module 206 determines the front axle load recovery based on the received data 214 and 216 and generates the front axle load recovery data 223. In various embodiments, the front axle load recovery determination module 206 determines the front axle load recovery based on a linear model defined by the front axle load recovery model data 222, which combines the steering torque data 214 and the steering angle data 216 and is retrieved from the model database 210. For example, the front axle load recovery determination module 206 determines the front axle load recovery using the following relationship:

[0051] FALR=b0+b1K us +b2K s ,

[0052] Where FALR represents the front axle load recovery, K us represents the understeer coefficient, K s represents the steering stiffness coefficient, while b0, b1, b2 represent linear model parameters that can be implemented as constant calibration.

[0053] In various embodiments, the front axle load recovery determination module 206 determines whether a leveling system is present based on the determined value of the front axle load recovery. For example, when the FALR value is equal to or substantially equal to a zero value, the front axle load recovery determination module 206 determines that a leveling system is not present and generates the leveling system present data 226 based on this to indicate this condition. When the FALR value is not equal to or substantially not equal to zero, the front axle load recovery determination module 206 determines that a leveling system is present and generates the leveling system present data 226 based on this to indicate this condition.

[0054] In various embodiments, the tow body hitch load data 220, the front axle load recovery data 224, and the leveling system presence data 226 are then used by the control system or other vehicle systems in automatic control of the vehicle 10, and / or displayed as tow body data. For example, the tow body hitch values ​​may be provided as load values ​​in Newtons, as a percentage load of a maximum load, or as a graphic or display representation of load values ​​and / or percentages.

[0055] Now refer to Figure 3 And continue to refer to Figure 1 to Figure 2 , the flowchart provides a method 300 for determining a trailer body hitch value and controlling the vehicle 10 based thereon according to an exemplary embodiment. As can be appreciated from the present disclosure, the order of operations within the method 300 is not limited to the following. Figure 3 , but may be performed in one or more altered orders when applicable and in accordance with the present disclosure. In various embodiments, the method 300 may be scheduled to run based on one or more predetermined events, and / or may run continuously during operation of the vehicle 10.

[0056] In one example, the method 300 may begin at 302. Sensor data is received at 304 and pre-processed at 306. For example, the sensor data may be quality assessed and / or synchronized as discussed above. Thereafter, steering characteristics are estimated based on the pre-processed sensor data at 308 and 310. For example, a steering torque value, such as a steering stiffness coefficient, is estimated based on the applied steering torque and lateral acceleration at 308; and a steering angle value, such as an understeering coefficient, is estimated based on the steering angle, yaw rate, and lateral acceleration at 310.

[0057] At 312, a traction frame load value is determined from the linear model combined with the estimated steering characteristics. At 314, a FALR value is determined from the linear model combined with the estimated steering characteristics and the FALR value is evaluated at 316. As can be appreciated, at 312 and 314, one or more filtering methods may be applied to the estimated values ​​to remove any measurement uncertainty. When the FALR value is equal to 0, leveling system presence data is generated at 318 indicating that no leveling system is present. When the FALR value is not equal to 0, leveling system presence data is generated at 320 indicating that a leveling system is present.

[0058] Thereafter, at 322 , vehicle 10 is controlled in some manner (eg, by displaying information, providing sensory information, and / or controlling other actuators) based on the trailer hitch load value and / or the FALR value. Method 300 may end at 324 .

[0059] 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 those skilled in the art to implement the exemplary embodiment or multiple exemplary embodiments. 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 towing a vehicle with a trailer, comprising: receiving, by a processor, sensor data from one or more sensors of the vehicle; estimating, by the processor, a steering torque value based on the sensor data; estimating, by the processor, a steering angle value based on the sensor data; determining, by the processor, a towing body hitch value based on the steering torque value and the steering angle value; as well as A control signal is generated by the processor based on the tow vehicle hitch value to control the vehicle.

2. The method according to claim 1, wherein: The trailer body traction frame value is a trailer body traction frame load value.

3. The method according to claim 1, wherein: The trailer tongue value is a front axle load recovery value associated with the leveling system.

4. The method according to claim 1, wherein: The towed body tongue value is a leveling system presence value indicating whether a leveling system exists.

5. The method according to claim 1, wherein: The tow vehicle tongue value is determined based on a linear model that combines the steering torque value and the steering angle value.

6. The method according to claim 1, wherein: The steering torque value includes a steering stiffness coefficient.

7. The method according to claim 6, further comprising: The steering stiffness coefficient is determined based on the lateral acceleration from the sensor data and the applied steering torque.

8. The method according to claim 1, wherein: The steering angle value includes an understeer coefficient.

9. The method according to claim 8, further comprising: The understeer coefficient is determined based on the applied steering angle, yaw rate, and lateral acceleration from the sensor data.

10. A system for a vehicle for towing a trailer, comprising: a non-transitory computer readable medium configured to store one or more models that relate to tow vehicle tongue values ​​to steering torque values ​​and steering angle values; and A computer system, the computer system being carried on the vehicle and configured to: receiving sensor data from one or more sensors of the vehicle; estimating a steering torque value based on the sensor data; estimating a steering angle value based on the sensor data; determining a tow vehicle tongue value based on the one or more models and the steering torque value and the steering angle value; as well as A control signal is generated based on the towed body hitch value to control the vehicle.

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