SYSTEM FOR DETECTING TRAILER LOAD-CONNECTED SUSPENSION SWIPPING AND ROLLING AWAY

Abstract

A trailer load-induced suspension sway and roll-away detection system (TLSR) in a vehicle includes a trailer attached to the vehicle via a trailer hitch. Sensors detect a load on the vehicle's suspension. A TLSR application monitors the vehicle's state information, determines that the initialization conditions have been met, and monitors the vertical loads on the vehicle's front and rear axles via the sensors. The TLSR application determines the rear axle vertical load and generates at least one of the following: an overload warning, a sway warning, and a roll-away warning.Upon generating at least one of the overload warning, sway warning, and roll-away warning, the TLSR application notifies a vehicle operator that a vertical load exerted by the trailer has exceeded a positive load threshold, a calibratable minimum negative load threshold, and / or a calibratable negative rear axle load threshold, unless and until none of the thresholds have been exceeded.

Description

INITIATIONThe present invention relates to trailers and more specifically to the detection and mitigation of rocking and rolling away of vehicles to which trailers are attached. In particular, the invention relates to a system for detecting trailer load-induced suspension sway and roll-away according to the preamble of claim 1 and claim 6, respectively, as is known in the art substantially from EP 3 865 324 A1. Further prior art is evident from the publications U.S. Pat. No. 2024 / 0 132 054 A1 and DE 10 2019 113 995 A1.Towed trailers are prone to sway caused by various different factors including horizontal crosswinds, road discontinuities, trailer misloading, or other effects. The rocking may cause a vehicle / trailer system to become unstable, which may potentially generate scenarios of swerving.Conventional trailer sway reduction systems utilize the electronic stability control system of a towing vehicle, but such systems do not monitor or generate tension on a tow hitch. In addition, because the conventional systems use yaw rate sensors and the like to detect yaw vibrations of the vehicle occurring in a specific frequency band that would coincide with the swinging of the trailer, such systems do not know in advance that a trailer is coupled, relying on the detection of vibrations to verify that the swinging of the trailer occurs.Accordingly, while conventional trailer sway reduction systems serve their intended purpose, there is a need for a new and improved trailer load suspension sway and roll-away detection and prevention system and method that maintain or reduce overall system complexity, improve system redundancy and robustness, reduce potential for use of improperly loaded trailers, reduce potential for human operating errors, and maintain or reduce system complexity while utilizing pre-existing hardware.SUMMARYAccording to the invention, a system for detecting suspension rocking and rolling away caused by trailer loading is presented, which is distinguished by the features of claim 1 or those of claim 6.According to another aspect of the present invention, the one or more sensors include: wheel speed sensors, brake sensors, throttle position sensors, accelerator position sensors, powertrain system sensors, transmission sensors, engine control sensors, inertial measurement units (IMUs), a global positioning system (GPS), and sensors that can directly and / or indirectly measure a vertical or normal load on force and / or a vertical displacement or ride height of a front axle and a rear axle of the vehicle. The sensors may directly and / or indirectly measure a vertical or normal load and / or a vertical displacement or ride height of a front axle and a rear axle of the vehicle include:Suspension load detection sensors and / or suspension displacement sensors and / or semi-active damping suspension (SADS) and / or air suspension sensors and / or continuous damping control ride height (CDC) sensors.According to another aspect of the present invention, the first control logic further includes: control logic that monitors vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, trailer connectivity, and trailer loading mode.According to another aspect of the present invention, the second control logic further includes: control logic that determines that a trailer is coupled to the vehicle at the tow hitch; and control logic that determines that a transmission of the vehicle is in a park state. The second control logic further determines that the brakes of the vehicle are not currently being applied, and upon determining that: no trailer is being coupled and / or the transmission is not in a park state and / or the brakes are currently being applied, continues to monitor vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, and trailer connectivity. Upon determining that: a trailer is hitched, the transmission is in a park state, and the brakes are not applied, the second control logic further generates an output signal indicating that the predetermined initialization conditions have been met.According to another aspect of the present invention, the fourth control logic further includes: control logic that, upon determining that a positive rear vertical axle load is applied by the trailer via the tow hitch, compares the positive rear vertical axle load to a calibrateable positive load threshold. Upon determining that the positive rear vertical axle load is equal to or greater than the calibrateable positive load threshold, the fourth control logic generates a message to the vehicle operator that includes an overload warning.Further described is a method for detecting trailer load-related suspension sway and roll-away (TLSR) detection method in a vehicle. The method includes: directly or indirectly detecting a load applied by a trailer to the suspension of the vehicle with one or more sensors. The trailer is movably attached to the vehicle via a trailer coupling. The method further includes executing, by a processor of a controller of the vehicle, program code portions stored in a memory of a controller, the controller further including input / output (I / O) ports in communication with the one or more sensors, the program code portions including a TLSR application. The TLSR application includes control logic for: monitoring information about the static and dynamic state of the vehicle and determining that predetermined initialization conditions have been met. Upon determining that the initialization conditions have been met, the TLSR application monitors, via the one or more sensors, the vertical loads on each of the front and rear axles of the vehicle. The TLSR application determines a vertical rear axle load and generates at least one of an overload warning, a swing warning, and a roll-away warning. Upon generating at least one of the overload alert, the swing alert, and the roll-away alert, the TLSR application notifies an operator of the vehicle that a vertical load applied by the trailer to the tow hitch has exceeded one or more of a positive load threshold, a calibrateable minimum negative load threshold, and a calibrateable negative rear axle load threshold. The messages to the operator of the vehicle continue unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable rear axle negative load threshold have been exceeded.According to another aspect of the present invention, the method further includes directly or indirectly detecting a load applied by the trailer to the suspension of the vehicle with one or more of: wheel speed sensors, brake sensors, throttle position sensors, accelerator position sensors, powertrain system sensors, transmission sensors, engine control sensors, inertial measurement units (IMUs), a global positioning system (GPS), and sensors capable of directly and / or indirectly measuring a vertical or normal force load and / or a vertical displacement or ride height of a front axle and a rear axle of the vehicle. The sensors, which may directly and / or indirectly measure a vertical or normal load and / or a vertical displacement or ride height of a front axle and a rear axle of the vehicle, include: suspension load detection sensors and / or suspension displacement sensors and / or a semi-active damping suspension (SACS) and / or air suspension sensors and / or continuous damping control ride height (CDC) sensors.According to another aspect of the present invention, the method further includes monitoring vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, trailer connectivity, and trailer loading mode.According to another aspect of the present invention, the method further includes: determining that a trailer is coupled to the vehicle at the tow hitch; determining that a transmission of the vehicle is in a park state; and determining that the brakes of the vehicle are not currently being applied. Upon determining that: no trailer is coupled and / or the transmission is not in a park state and / or the brakes are currently applied, the method continues to monitor vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, and trailer connectivity. Upon determining that: a trailer is hitched, the transmission is in a park state, and the brakes are not applied, the method generates an output indicating that the predetermined initialization conditions have been met.In accordance with another aspect of the present invention, upon determining that a positive rear vertical axle load is being applied by the trailer via the tow hitch, the method compares the positive rear vertical axle load to a calibrateable positive load threshold; wherein upon determining that the positive rear vertical axle load is equal to or greater than the calibrateable positive load threshold, the method generates a message to the operator of the vehicle that includes an overload warning.In accordance with another aspect of the present invention, upon determining that a zero rear vertical axle load or a negative rear vertical axle load is applied by the trailer via the tow hitch, the method compares the zero rear vertical axle load or the negative rear vertical axle load to a calibrateable minimum negative load threshold. The calibrateable minimum negative load threshold further includes a calibrateable range of rear axle negative loads that extends from about a zero or neutral load to about a 25% negative load on the rear axle. Upon determining that the rear axle negative vertical load does not exceed the calibrateable minimum negative load threshold, the method generates a message to the vehicle operator that includes a swing warning.In accordance with another aspect of the present invention, upon determining that a negative rear vertical axle load is being applied by the trailer via the tow hitch, the method compares the negative rear vertical axle load to the calibrateable rear negative axle load threshold. Upon determining that the negative vertical rear axle load is equal to or exceeds the calibrateable negative rear axle load threshold or upon detecting roll of the front axle, the method generates a message to the vehicle operator that includes a roll-away warning. The calibrateable rear axle negative load threshold further includes: a range of values extending from about 50% to 100% negative load on the rear axle. A 100% negative load on the rear axle indicates that the rear axle is fully unloaded and that the rear wheels mounted on the rear axle no longer provide frictional contact with the ground under the vehicle.According to another aspect of the present invention, the method further includes generating audio visual and / or haptic feedback messages to the operator of the vehicle via: a human machine interface (HMI) including touch panels disposed on or integrated with various components of an exterior surface of the vehicle or an interior cabin of the vehicle, and / or lights and / or a horn of the vehicle mounted on the exterior surface of the vehicle. The method further includes generating messages via wireless communication capable devices including: mobile computing devices, laptop computers, tablet computers, and cellular phones. The messages provide audio visual indication that a load on the trailer corresponds to or exceeds one or more of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable rear axle load negative threshold unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable rear axle load negative threshold have been met or exceeded.According to another aspect of the present invention, the method further includes automatically applying the vehicle brakes during a roll-away warning, thereby preventing the vehicle and trailer from rolling even though the trailer exerts a negative rear axle load that is equal to or exceeds the calibrateable negative rear axle load threshold.According to another aspect of the present invention, the method further includes a method for detecting trailer load-related suspension sway and roll-off (TLSR) detection method in a vehicle, including: directly or indirectly detecting a load applied by a trailer to the suspension of the vehicle with one or more sensors including: wheel speed sensors, brake sensors, throttle position sensors, accelerator position sensors, powertrain system sensors, transmission sensors, engine control sensors, inertial measurement units (IMUs), a global positioning system (GPS), and sensors capable of directly and / or indirectly measuring a vertical or normal load of force and / or a vertical displacement or ride height of a front axle and a rear axle of the vehicle, These include: suspension load detection sensors and / or suspension displacement sensors and / or semi-active damping suspension (SADS) and / or air suspension sensors and / or continuous damping control ride height (CDC) sensors.The trailer is movably attached to the vehicle via a trailer coupling. The method further comprises executing, by a processor of a controller of the vehicle, program code portions stored in a memory of the controller, the controller further including input / output (I / O) ports in communication with the one or more sensors, the program code portions including a TLSR application. The TLSR application includes control logic for: monitoring vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, trailer connectivity, and trailer loading mode. The TLSR application further determines that predetermined initialization conditions have been met, including: determining that a trailer is coupled to the vehicle at the tow hitch, determining that a transmission of the vehicle is in a park state, and determining that the brakes of the vehicle are not currently being applied. Upon determining that: no trailer is coupled and / or the transmission is not in a park state and / or the brakes are currently applied, the TLSR application and method continue to monitor vehicle wheel speed, transmission state or position, brake actuation state, suspension system load, and trailer connectivity. Upon determining that: a trailer is hitched, the transmission is in a park state, and the brakes are not applied, the TLSR application and method generate an output indicating that the predetermined initialization conditions have been met, and monitor the vertical loads on each of the front and rear axles of the vehicle via the one or more sensors. The TLSR application and method determine a vertical rear axle load and generate at least one of an overload warning, a swing warning, and a roll away warning. Upon determining that a positive rear vertical axle load is being applied by the trailer via the tow hitch, the TLSR application and method compare the positive rear vertical axle load to a calibrateable positive load threshold. Upon determining that the positive rear vertical axle load is equal to or greater than the calibrateable positive load threshold, the TLSR application and method generate a message to an operator of the vehicle that includes an overload alert. Upon determining that a zero vertical rear axle load or a negative vertical rear axle load is being applied by the trailer via the tow hitch, the TLSR application and method compare the zero vertical rear axle load or the negative vertical rear axle load to a calibrateable minimum negative load threshold. The calibrateable minimum negative load threshold further includes: a calibrateable range of rear axle negative loads extending from about a zero or neutral load to about a 25% negative load on the rear axle. Upon determining that the rear axle negative vertical load does not exceed the calibrateable minimum negative load threshold, the TLSR application and method generate a message to the vehicle operator that includes a swing warning. Upon determining that a negative rear vertical axle load is being applied by the trailer via the tow hitch, the TLSR application and method compare the negative rear vertical axle load to the calibrateable negative rear axle load threshold. Upon determining that the negative vertical rear axle load is equal to or exceeds the calibrateable negative rear axle load threshold, or upon detecting roll of the front axle, the TLSR application and method generate a message to the operator of the vehicle that includes a roll-away warning. The calibrateable negative rear axle load threshold further includes: a range of values extending from about 50% to 100% negative load on the rear axle, wherein 100% negative load on the rear axle indicates that the rear axle is fully unloaded and that the rear wheels attached to the rear axle no longer provide frictional contact with the ground under the vehicle. Upon generating at least one of the overload alert, the swing alert, and the roll-away alert, the TLSR application and method provide the overload alert, the swing alert, and the roll-away alert to operators of the vehicle via audio-visual and / or haptic feedback messages to the operator of the vehicle via: a human-machine interface (HMI) including touch-sensitive panels disposed on or integrated with various components of an exterior surface of the vehicle or an interior cabin of the vehicle, and / or lights and / or a horn of the vehicle mounted on the exterior surface of the vehicle. The TLSR application and method generate messages via wireless communication capable devices including: mobile computing devices, laptop computers, tablet computers, and cellular phones. The messages provide audio visual indication that a load on the trailer corresponds to or exceeds one or more of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable rear axle load negative threshold unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable rear axle load negative threshold have been met or exceeded. The TLSR application and method automatically apply the vehicle brakes during a roll-away alert, thereby preventing the vehicle and trailer from rolling even though the trailer exerts a negative rear axle load that is equal to or exceeds the calibrateable negative rear axle load threshold.Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are provided for purposes of illustration only.BRIEF DESCRIPTION OF THE DRAWINGSThe drawings described herein are for illustrative purposes only; it shows: FIG. 1 is a schematic diagram of a system for detecting and preventing trailer load-induced suspension sway and roll-away according to an exemplary embodiment; FIG. 2 is a flow chart illustrating a method for detecting and preventing trailer load-induced suspension sway and roll-away according to an example embodiment; FIG. 3A is a graphical representation of trailer load and displacement of the front suspension of the trailer load-related suspension swing and roll-away detection and prevention system of FIG. 1, according to an exemplary embodiment; and FIG. 3B is a graphical representation of trailer load and rear suspension displacement of the trailer load-related suspension swing and roll-away detection and prevention system of FIG. 1, according to an example embodiment.DETAILED DESCRIPTIONThe following description is merely exemplary.Referring now to FIG. 1, a system 10 for detecting and preventing trailer load-induced suspension sway and roll-away is schematically illustrated.The system 10 includes a vehicle 12 connected to a trailer 14 via a tow hitch 16. The vehicle 12 is illustrated as passenger cars, but it should be appreciated that the vehicle 12 may be any type of vehicle including: passenger cars, trucks, sport utility vehicles (SUVs), vans, recreational vehicles, semi-trucks, semi-trucks, delivery vehicles including vehicles used in warehouses, tri-wheels, motor-wheels, aircraft, amphibious vehicles, or any other such vehicle 12 that both makes contact with the ground and may be connected to a trailer 14. Similarly, the trailer 14 is shown as a box trailer, however, it should be appreciated that the trailer 14 may be any type of trailer 14, including: closed trailers, dump trailers, truck trailers, utility trailers, Conestoga trailers, car trailers, multi-vehicle trailers, low-load trailers, cold trailers, boat trailers, landscape trailers, car transport trailers, swannnel trailers, and the like. The tow hitch 16 is shown as a ball mount receiver hitch, however, it will be appreciated that the tow hitch 16 may be any of a wide variety of tow couplings 16, such as receiver couplings, 5 tes-wheel tow couplings, swan neck couplings, weight distribution couplings, pin couplings, or the like.The system 10 further includes one or more sensors 18 integrated with the vehicle 12 and / or the trailer 14. The sensors 18 detect static and dynamic information about the vehicle 12 and the trailer 14, and may include: electromagnetic (EM) sensors 18A, such as cameras, infrared cameras, video cameras, light detection and ranging (LiDAR) sensors, radio detection and ranging (RADAR) sensors, sound navigation and ranging (SONAR) sensors, and the like. The EM sensors 18A, such as those described above, may be used to determine a proximity of the vehicle 12 and / or trailer 14 to each other and / or to objects in the surrounding environment of the vehicle 12 and / or trailer 14. The sensors 18 may further include sensors 18 that may directly and / or indirectly measure static and dynamic conditions of the vehicle 12 and the trailer 14, including: inertial measurement units (IMUs), suspension sensors 18B, and control units such as a semi-active damping suspension (SACS), air suspension sensors, continuous damping control (CDC) ride height sensors, a global positioning system (GPS), sensors 18C of speeds of the wheels 20 and / or the brakes 21 that may measure speeds of one or more wheels 20 of the vehicle 12, throttle sensors, accelerator pedal position sensors, steering position sensors that may measure steering system position, steering rate, and steering speed, tire pressure monitoring systems, aerodynamic element position sensors, and the like. According to several examples, the suspension sensors 18B and the controllers, such as semi-active damping suspension (SADS), air suspension sensors, continuous damping control ride height (CDC) ride height sensors, and the like, define the axle load detection devices of the vehicle 12 that can monitor a vertical or normal load on the suspension of the vehicle 12. More specifically, the suspension sensors 18B and the control units such as the semi-active suspension suspension (SADS), the air suspension sensors, the CDC ride height sensors, and the like of the exemplary embodiments may directly and / or indirectly measure a vertical or normal load load and / or a vertical displacement or ride height of a front axle 19A and a rear axle 19B of the vehicle 12.The IMUs can measure motion, acceleration, and the like in multiple degrees of freedom. According to a specific example, the IMUs may measure position, motion, acceleration, etc., in at least three degrees of freedom. Likewise, the SACS sensors may be IMUs that can measure in three or more degrees of freedom. According to some examples, the SADS may be suspension hub accelerometers or the like. Accordingly, the state information of the vehicle 12 may include any of a wide variety of data including: speed data of the wheels 20, SADS, GPS, and IMU data including location, acceleration, location, and the like. The sensors 18 may further include the sensors of the powertrain system 22 of the vehicle 12, the sensors 26 of the transmission 24, the control sensors 30 of the engine 28, and the like.The system 10 further includes one or more controllers 32 in communication with the various sensors 18 of the vehicle 12 and / or trailer 14, which process information received therefrom and generate output signals used to control or alter the performance of the vehicle 12 and / or trailer 14. The controllers 32 are integrated into the vehicle 12. More specifically, the controllers 32 are non-generalized electronic control devices having a preprogrammed digital computer or processor 34, a non-transitory computer readable medium or memory 36 used to store data such as control logic, software applications, instructions, computer code, data look-up tables, etc., and input / output (I / O) ports 38. A "non-transitory" computer readable storage 36 excludes wired, wireless, optical, or other communication links that carry transitory electrical or other signals. A non-transitory computer readable storage 36 includes media where data may be permanently stored and media where data may be stored and later overwritten, such as a rewritable optical disk or an erasable storage device. The computer code includes any type of program code, including source code, object code, and executable code. The processor 34 is configured to execute the code or instructions. The vehicle 12 may include additional controllers 32, such as a dedicated Wi-Fi controller, an engine control module, a transmission control module, a body control module, an infotainment control module, or the like. The I / O ports 38 may be configured to communicate via wired communications, wirelessly via IEEE 802.11x Wi-Fi protocols, or the like.The controller 32 further includes one or more applications 40. an application 40 is a software program configured to execute a specific function or set of functions. The application 40 may include one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or portions thereof, configured for implementation in suitable computer readable program code. The applications 40 may be stored within the memory 36 or in an additional or separate memory 36. Examples of the applications 40 include audio or video streaming services, games, browsers, social media, etc. In other examples, the applications 40 are used to manage body control system functions, suspension control system functions, transmission and / or engine control system functions, or the like, in an example vehicle 12.In FIG. 2 and still in FIG. 1, the system 10 uses one or more applications 40, specifically a trailer 14, suspension swing and roll-away (TLSR) application 42 detection, stored in the memory 36 to manage and coordinate the state of the vehicle 12 and the trailer 14 while the trailer 14 is being loaded while being hitched to the vehicle 12 via the tow hitch 16. The TLSR application 42 is depicted in FIG. 2 in the form of a flowchart as a method 100 that represents multiple subroutines that perform different, but contiguous, functions that cause the trailer 14 to be properly loaded so that rocking of the trailer 14 and rolling away of the vehicle 12 are effectively and efficiently prevented.More specifically, the TLSR application 42 begins at block 102. At block 104, the method 100 executes a first subroutine or control logic of the TLSR application 42 that determines whether the vehicle 12 is equipped with a load detection device for the axles 19A, 19B of the vehicle 12. The axle load detection device 19A, 19B may include any of a wide variety of sensors 18. Upon determining at block 104 that the vehicle 12 does not include the required load detection device for the axles 19A, 19B of the vehicle 12 or that any other initialization condition is not met, the method 100 returns to block 102 where it restarts. However, if at block 104, the TLSR application 42 determines that the vehicle 12 is equipped with the axle load detection device 19A, 19B, the method 100 proceeds to block 106. At block 106, the TLSR application 42 and method 100 use the onboard sensors 18 of the vehicle 12 to monitor information about the static and dynamic state of the vehicle, including: the speed of the wheel 20 of the vehicle 12, a current state of the transmission 24, a current state of operation of the brake 21, a suspension system load, a state of a hitched trailer 14, and a loading mode of the trailer 14, if such a mode is available in the vehicle 12.The method 100 then proceeds to block 108 where the TLSR application 42 determines whether a trailer 14 is coupled to the vehicle 12 via the tow hitch 16, whether the transmission 24 is in the "PARK" state, and whether the brakes 21 of the vehicle 12 are currently applied. More specifically, the system 10 and method 100 may determine whether a trailer 14 is coupled to the vehicle 12 via the presence or absence of an electrical connection between the vehicle 12 and the trailer 14, via a camera, radar, LiDAR, or other electromagnetic data indicating the presence of a trailer 14 attached to the trailer hitch 16 of the vehicle, and / or via mechanical, hydraulic, or other such connections between the vehicle 12 and the trailer 14. Upon determining that: currently no trailer 14 is coupled to the vehicle 12 and / or the transmission 24 is currently not in "PARK" and / or the brakes 21 are currently applied, the method 100 and the TLSR application 42 continue monitoring via the sensors 18 of the vehicle 21 until such time as all of these threshold conditions are met. That is, until all sensors 18 report that a trailer 14 is coupled to the vehicle 12 via the tow hitch 16, the transmission 24 is in a "PARK" state, and the brakes 21 of the vehicle 12 are not currently being applied, the TLSR application 42 and method 100 remain in blocks 106 and 108. According to some examples, the sensors 18 may detect that a trailer 14 is coupled to the vehicle 12 via software, electrical connectivity or electrical resistance, changes in suspension load levels, or the like. According to additional examples, the system 10 may be notified by a direct or indirect input received via a human-machine interface (HMI) 44 via which an operator of the vehicle 12 confirms the presence and attachment of a trailer 14 to the vehicle 12 at the tow hitch 16. The HMI 44 may take various different forms. According to some examples, the HMI 44 is an infotainment screen and / or instrument cluster and / or other such display disposed on the vehicle 12 and / or integrated with the vehicle 12. According to additional examples, the HMI 44 may include one or more buttons, haptic feedback devices, touch-sensitive panels, or the like, disposed on or integrated with various components of an exterior surface of the vehicle 12 or an interior cabin of the vehicle 12. According to still further examples, the HMI 44 may include a mobile computing device, such as a laptop computer, a tablet computer, a cellular telephone, or other such wireless communication capable device that may be accessed by the vehicle 12 operator. Once the threshold conditions have been met at block 108, the method 100 and the TLSR application 42 proceed to block 110 where the TLSR application 42 monitors the suspension to determine a relative load of the front / rear axles 19A, 19B.Using the data from block 110, the TLSR application 42 and method 100 determine whether the suspension system detects whether a load of the rear axle 19B is reduced or negative with respect to the load of the front axle 19A at block 112. In several aspects, it should be appreciated that the weight of a vehicle 12 may be described as a "dead weight" distributed across the front and rear axles 19A, 19B in a typical vehicle 12. Accordingly, when a trailer 14 is attached to the hitch 16, a load of the rear axle 19B is frequently changed from the dead weight of the vehicle 12.Upon determining that the load of the rear axle 19B is positive, i.e., that a vertical load on the rear axle 19B indicates that the current load of the rear axle 19B is greater than the expected deadweight or load of the rear axle 19B, the TLSR application 42 and method 100 proceed to block 114. At block 114, the TLSR application 42 and method 100 determine whether the positive vertical load currently being applied to the rear axle 19B is equal to or exceeds a predetermined calibrateable positive threshold. According to some examples, the predetermined calibrateable positive threshold defines each vertical load on the rear axle 19B that is greater than a load capacity of the tow hitch 16, a suspension load capacity of the vehicle as defined by material quality, engineering standards, or the like. Upon determining in block 114 that the positive vertical load is greater than or equal to the predetermined calibrateable positive threshold, the TLSR application 42 and method 100 proceed to block 116. In block 116, the TLSR application 42 and method 100 generate a message to the vehicle 12 operator. specifically, the TLSR application 42 and method 100 provide the message to the vehicle 12 operator in any of various different ways via one or more of the HMI 44 and via one or more audio visual alerts projected from the exterior 46 of the vehicle 12. According to some examples, the message is provided via one or more lights, and more specifically via rear stop lights, emergency lights, turn signal lights, hazard lights, backup lights, load indicator lights, headlights, fog lights, and / or high level stop lights of the vehicle 12. Additional messages may be provided via audible alerts such as turning on a horn system of the vehicle 12, speakers in the passenger compartment, and / or external speakers of the vehicle 12, or the like. According to an example example, the message is displayed via lamps or lights 48 at a rear of the vehicle 12 at positions visible to an operator of the vehicle 12 and / or trailer 14 while the trailer 14 is being loaded. Additionally, the message may be sent directly or indirectly to the HMI 44 via a cloud server 52. The messages are then presented via audio visual prompts on the HMI 44, which may include a cellular phone of the vehicle 12 operator, such that the vehicle 12 operator may effectively and accurately adjust the load position of the trailer 14 while performing live monitoring of the load position of the trailer 14 as reported by the vehicle 12 sensors 18 and the TLSR application 42. The message generated at block 116 may include various information including both warnings of a trailer hitch 16 overload or the like and an indication that a cargo load on or within the trailer 14 requires adjustment to reduce the current load of the trailer hitch 16. From block 116, the method 100 and the TLSR application 42 return to blocks 102 and / or 104, where the system 10 continues monitoring the vehicle 12 via the sensors 18. However, if, at block 114, a positive load of the tow hitch 16 does not exceed the predetermined calibrateable positive threshold, the method 100 and the TLSR application 42 directly return to blocks 102 and / or 104, with the system 10 continuing to monitor the vehicle 12 via the sensors 18.Again, at block 112, if a trailer 14 is hitched to the hitch 16 of an example vehicle 12 and the trailer 14 is loaded such that the "support load" (the vertical load on the hitch 16) is negative, then the trailer 14 effectively reduces a vertical load or normal force acting on the rear axle 19B from a first level to a second level that is less than the first level. When such changes in the dead weight of the vehicle 12 cause the rear axle 19B of the vehicle 12 to be loaded with less than a predetermined unloaded dead weight, the vehicle 12 has an increased potential for the trailer 14 to swing or roll away to occur. Accordingly, in block 112, the method 100 and the TLSR application 42 proceed to block 118 when it is determined that the load of the rear axle 19B is negative.If a calibrateable minimum negative load threshold load is detected on the rear axle 19B at block 118, the TLSR application 42 and method 100 generate a notification to the operator of the vehicle 12 of a potential swing condition. In several aspects, the calibrateable minimum negative load threshold load defines a zero, neutral, or small amount of the negative support load. According to some examples, the calibrateable minimum negative load threshold is a range of negative support loads or the loads of the rear axle 19B that extends from about a zero or neutral load to about a 25% negative load on the rear axle 19B. The message may include a "SWING ALERT" provided to the operator of the vehicle 12 in any of various different ways via one or more of the HMI 44 and via one or more audio visual alerts projected from the exterior 46 of the vehicle 12. According to some examples, the message is provided about one or more lights and more specifically rear stop lights, emergency lights, turn signal lights, hazard lights, backup lights, load indicator lights, headlights, fog lights, and / or high level stop lights of the vehicle 12. Additional messages may be provided via audible alerts such as turning on a horn system of the vehicle 12, speakers in the passenger compartment, and / or external speakers of the vehicle 12, or the like. According to an example example, the message is displayed via lamps or lights 48 at the rear of the vehicle 12 at positions visible to an operator of the vehicle 12 and / or trailer 14 while the trailer 14 is being loaded. Additionally, the message may be sent directly or indirectly to the HMI 44 via a cloud server 52. The messages are then presented via audio-visual prompts on the HMI 44, which may include a cellular phone of the vehicle 12 operator, such that the vehicle 12 operator may effectively and accurately adjust a load position of the trailer 14 while performing the live monitoring of the load position of the trailer 14 as reported by the vehicle 12 sensors 18 and the TLSR application 42. Once again at block 112, the operator of the vehicle 12 has properly adjusted the position of a load on the trailer 14 to cause the trailer 14 to apply a positive load to the hitch 16 and the rear axle 19B, the potential sway or roll messages automatically end.Next, the TLSR application 42 and method determine whether a magnitude of the negative support load has exceeded a calibrateable negative rear axle load threshold and / or whether roll of the front axle 19A is detected at block 120. It will be appreciated that the powertrain systems 22 of vehicles 12 equipped with a tow hitch 16 often propel the rear axle 19B of the vehicles, and even in front wheel drive vehicles (i.e., front axle 19A drive), all-wheel or four-wheel drive vehicles (i.e., front and rear axle 19A, 19B drive), this position of the transmission 24 often only prevents rotation of the front and / or rear axles 19A, 19B. If a negative support load or negative load of the tow hitch 16 is sufficiently great, then the load of the rear axle 19B of the vehicle 12 may be reduced such that the wheels 20 rotatably mounted to the rear axle 19B may lift completely off a surface or floor 50 under the vehicle 12 or be under-loaded such that the wheels 50 no longer provide sufficient frictional contact with the floor 50 to prevent sway or roll-away conditions. In the circumstances where the negative load of the tow hitch 16 meets or exceeds a calibrateable negative rear axle load threshold or rolling of the front axle 19A is detected, the method 100 and the TLSR 42 proceed to block 122 where a "ROLL AWAY WARNING" is provided to the operator of the vehicle 12. That is, when a sufficiently large magnitude of the negative load of the tow hitch 16 is detected, the system 10 notifies the operator of the vehicle 12 that roll-away is possible.The "ROLL AWAY WARNING" is provided to the operator of the vehicle 12 in any of various different ways as described above with respect to the "SWING WARNING.". That is, the "ROLL AWAY ALERT" is provided to the operator of the vehicle 12 via one or more of the HMI 44 and via one or more audio visual alerts projected from the exterior 46 of the vehicle 12. According to some examples, the message is provided about one or more lights and more specifically rear stop lights, emergency lights, turn signal lights, hazard lights, backup lights, load indicator lights, headlights, fog lights, and / or high level stop lights of the vehicle 12. Additional messages may be provided via audible alerts such as turning on a horn system of the vehicle 12, speakers in the passenger compartment, and / or external speakers of the vehicle 12, or the like. According to an example example, the message is displayed via lamps or lights 48 at the rear of the vehicle 12 at positions visible to an operator of the vehicle 12 and / or trailer 14 while the trailer 14 is being loaded. Additionally, the message may be sent directly or indirectly via a cloud server 52 to the HMI 44, which then presents the message to the vehicle 12 operator, thereby allowing the vehicle 12 operator to effectively and accurately adjust the load position of the trailer 14 while performing live monitoring of the load position of the trailer 14 as reported by the vehicle 12 sensors 18 and the TLSR application 42.Additionally, at block 122, the system 10 engages an emergency braking system that releases and actuates the brakes 21 of the vehicle 12 via the TLSR application 42 and the method 100, and according to examples where the trailer 14 is equipped with the brakes 21, the TLSR application 42 also actuates the brakes 21 of the trailer 14. As previously described, once the vehicle 12 operator has properly adjusted the position of a load on the trailer 14 to cause the trailer 14 to exert a positive load on the hitch 16 and the rear axle 19B, the "ROLL-AWAY WARNING" messages automatically end, and the TLSR application 42 and method 100 proceed back to block 102 to be executed again. That is, in several aspects, the "ROLL AWAY WARNING" message may be more severe than the "SWING WARNING" including, but not limited to, activating a horn of the vehicle 12, flashing lights of the vehicle 12, and the like. Additionally, upon detection of a potential roll-away condition, the system 10 weakens the roll-away by applying the brakes 21. Further, in vehicles 12 equipped with a balance control of the brake 21, the application of the brake 21 may be biased toward the front axle 19A of the vehicle 12.The calibrateable negative rear axle load threshold may vary significantly from application to application. However, it should be appreciated that the calibrateable negative rear axle load threshold for triggering a "SWING WARNING" may be described as: conditions under which a trailer 14 is hitched to the hitch 16 of the vehicle 12 and it is measured that a dead weight or load of the rear axle 19B is less than an unloaded and normal dead weight or load of the rear axle 19B when no trailer 14 is hitched; wherein the "ROLL-AWAY WARNING" may be described as: conditions under which a trailer 14 is attached to the hitch 16 of the vehicle 12 and it is measured that a dead weight or load of the rear axle 19B is less than fifty percent (50%) of an unloaded and normal dead weight or load of the rear axle 19B when no trailer 14 is attached to the hitch 16.In Figs. 3A and 3B and further with respect to Figs. 1 and 2, the load estimates of the front and rear axles 19A, 19B are shown in the form of a line graph. More specifically, FIG. 3A illustrates a measured load on the front axle 19A of a vehicle 12 to which a trailer 14 is attached via a tow hitch 16. The graph depicts gross weight (GW) estimates along the X axis and percent along the Y axis. The load 200 of the trailer 14 is shown as a first line graph, against which the displacement 202 of the front suspension is shown in a second line graph. A "normal" load 204 is shown to extend from about 0% to about 80%, above which the trailer load 200 is shown in an overloaded condition 206. The ranges between about 40% and about 80% represent both an optimal load 208 of the trailer 14 and the front suspension, and the conditions of the light or light load trailer 14 and the light or light load front suspension 210.In contrast, FIG. 3B illustrates a measured load on the rear axle 19B of a vehicle 12 to which a trailer 14 is attached via a tow hitch 16. The graph depicts gross weight (GW) estimates along the X axis and percent along the Y axis. Both FIGS. 3A and 3B illustrate the same sequence of situations differing only in that FIG. 3A is directed to changes in the load of the front axle 19A and the displacement of the rear suspension, while FIG. 3B is directed to changes in the load of the rear axle 19B and the displacement of the rear suspension. In FIG. 3B, the load 300 of the trailer 14 is shown as a first line graph, against which the displacement 202 of the rear suspension is shown in a second line graph. A "normal" load 304 is shown to extend from about 25% to about 75% above which the trailer load 300 is shown in an overloaded state 306. The ranges between about 25% and about 80% represent both an optimal load 308 of the trailer 14 and the rear suspension, and the conditions of the low or slightly unloaded trailer 14 and the low or slightly unloaded rear suspension 310. Below about 25%, Figure 3B illustrates a situation where the rear axle 19B is fully and fully unloaded and the rear axle 19B begins to lift from the floor 50 or lifted from the floor 50.A system 10 and method 100 for detecting and preventing loading of the trailer 14, suspension sway, and roll-away of the present invention provide several advantages. These include the ability to provide immediate, consistent, and accurate feedback to operators of the vehicle 12 about how a vehicle / trailer system 12, 14 is currently loaded and whether adjustments to the load position or amount of the trailer 14 are required to ensure that the vehicle 12 does not enter a swing or roll-away condition. Moreover, the system 10 and method 100 of the present invention maintain or reduce the complexity of the overall system 10, improving the redundancy and robustness of the system 10, reducing the potential for use of improperly loaded trailers 14, reducing the potential for human operating errors, and effectively and efficiently utilizing pre-existing hardware. Moreover, the system 10 and method 100 of the present invention may be adapted or installed as an assembly in vehicles 12 equipped with suitable types of suspension load sensors and the like.

Claims

A system (10) for detecting trailer load-related suspension sway and roll-off, the system (10) comprising: a vehicle (12); a trailer (14) movably attached to the vehicle (12) via a trailer hitch (16); one or more sensors (18), wherein the one or more sensors (18) directly or indirectly detect a load on the suspension of the vehicle (12); a controller (18) having a processor (34), a memory (36), and input / output (I / O) ports, the I / O ports being in communication with the one or more sensors (18), the processor (34) executing program code portions stored in the memory (36), the program code portions including a TLSR application (42) comprising: first control logic for monitoring the static and dynamic state information of the vehicle (12); second control logic for determining that predetermined initialization conditions have been met; third control logic that, upon determining that the initialization conditions have been met, monitors the vertical loads on each of the front and rear axles (19A, 19B) of the vehicle (12) via the one or more sensors (18); fourth control logic that determines a rear axle vertical load and generates at least one of: an overload warning, a swing warning, and a roll-away warning; and fifth control logic that, when generating at least one of the overload warning, the swing warning, and the roll-away warning, informs an operator of the vehicle (12) that a vertical load applied by the trailer (14) to the trailer hitch (16) has exceeded a positive load threshold and / or a calibrateable minimum negative load threshold and / or a calibrateable negative rear axle load threshold, wherein the messages to the operator of the vehicle (12) are continued unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable negative rear axle load threshold has been exceeded; wherein the fourth control logic further comprises: control logic that, upon determining that a rear vertical axle load of zero or a rear negative vertical axle load is being applied by the trailer (14) via the trailer hitch (16), compares the rear vertical axle load of zero or the rear negative vertical axle load with a calibrateable minimum negative load threshold; and upon determining that the rear negative vertical axle load does not exceed the calibrateable minimum negative load threshold, generates a message to the operator of the vehicle (12) that includes a swing warning; characterized in that (i) the calibrateable minimum negative load threshold further comprises a calibrateable range of rear negative axle loads that extends from about a zero or neutral load to about a 25% negative load on the rear axle (19B); and / or (ii) the fourth control logic further comprising: control logic that, upon determining that a negative rear vertical axle load is being applied by the trailer (14) via the tow hitch (16), compares the negative rear vertical axle load to the calibrateable negative rear axle load threshold; In determining that the negative vertical rear axle load is equal to or exceeds the calibrateable negative rear axle load threshold, or in detecting roll of the front axle (19A), generating a message to the operator of the vehicle (12) including a roll-away warning, the calibrateable negative rear axle load threshold further comprising: a range of values extending from about 50% to 100% negative load on the rear axle (19B), wherein 100% negative load on the rear axle (19B) indicates that the rear axle (19B) is fully unloaded and that the rear wheels attached to the rear axle (19B) are no longer providing frictional contact with the ground beneath the vehicle (12)The system (10) of claim 1, wherein the one or more sensors (18) include: wheel speed sensors, brake sensors, throttle position sensors, accelerator position sensors, powertrain system sensors, transmission sensors, engine control sensors, inertial measurement units (IMUs), a global positioning system (GPS), and sensors capable of directly and / or indirectly measuring a vertical or normal force load and / or a vertical displacement or ride height of a front axle (19A) and a rear axle (19B) of the vehicle (12), including: suspension load detection sensors and / or suspension displacement sensors and / or a semi-active damping suspension (SADS) and / or air suspension sensors and / or continuous damping control ride height sensors (CDC ride height sensors).The system (10) of claim 2, wherein the first control logic further comprises: control logic that monitors vehicle wheel speed, transmission state or position, brake actuation status, suspension system load, trailer connectivity, and trailer load mode.The system (10) of claim 3, wherein the second control logic further comprises: control logic that determines that a trailer (14) is coupled to the vehicle (12) at the tow hitch (16); control logic that determines that a transmission (24) of the vehicle (12) is in a park state; control logic that determines that the brakes of the vehicle (12) are not currently being applied; and that, upon determining that: no trailer (14) is coupled and / or the transmission (24) is not in a park state and / or the brakes are currently being applied, continues monitoring vehicle wheel speed, transmission state or transmission position, brake application state, suspension system load, and trailer connection; Which, upon determining that: a trailer (14) is hitched, the transmission (24) is in a park state and the brakes are not applied, generates an output indicating that the predetermined initialization conditions have been met.The system (10) of claim 1, wherein the fourth control logic further comprises: control logic that, upon determining that a positive rear vertical axle load is being applied by the trailer (14) via the tow hitch (16), compares the positive rear vertical axle load to a calibrateable positive load threshold; and upon determining that the positive rear vertical axle load meets or exceeds the calibrateable positive load threshold, generates a message to the operator of the vehicle (12) that includes an overload warning.A system (10) for detecting trailer load-related suspension sway and roll-off, the system (10) comprising: a vehicle (12); a trailer (14) movably attached to the vehicle (12) via a trailer hitch (16); one or more sensors (18), wherein the one or more sensors (18) directly or indirectly detect a load on the suspension of the vehicle (12); a controller (18) having a processor (34), a memory (36), and input / output (I / O) ports, the I / O ports being in communication with the one or more sensors (18), the processor (34) executing program code portions stored in the memory (36), the program code portions including a TLSR application (42) comprising: first control logic for monitoring the static and dynamic state information of the vehicle (12); second control logic for determining that predetermined initialization conditions have been met; third control logic that, upon determining that the initialization conditions have been met, monitors the vertical loads on each of the front and rear axles (19A, 19B) of the vehicle (12) via the one or more sensors (18); fourth control logic that determines a rear axle vertical load and generates at least one of: an overload warning, a swing warning, and a roll-away warning; and fifth control logic that, when generating at least one of the overload warning, the swing warning, and the roll-away warning, informs an operator of the vehicle (12) that a vertical load applied by the trailer (14) to the trailer hitch (16) has exceeded a positive load threshold and / or a calibrateable minimum negative load threshold and / or a calibrateable negative rear axle load threshold, wherein the messages to the operator of the vehicle (12) are continued unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable negative rear axle load threshold has been exceeded; wherein the fifth control logic further comprises: control logic that generates audio visual and / or haptic feedback messages to the operator of the vehicle (12) via: a human machine interface (HMI) including touch sensitive panels disposed on or integrated with various components of an exterior surface of the vehicle (12) or an interior cabin of the vehicle (12), and / or lights and / or a horn of the vehicle (12) mounted on the exterior surface of the vehicle (12); a control logic that generates messages via wireless communication capable devices including: mobile computing devices, laptop computers, tablet computers, and cellular phones, the messages providing audio visual indications that a load on the trailer (14) is equal to or exceeds one or more of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable negative rear axle load threshold unless and until none of the positive load threshold, the calibrateable minimum negative load threshold, and the calibrateable negative rear axle load threshold have been met or exceeded; characterized in that the fifth control logic further comprises control logic that automatically actuates the vehicle brakes during a roll-away warning, thereby preventing the vehicle (12) and the trailer (14) from rolling even though the trailer (14) exerts a negative rear axle load that is equal to or exceeds the calibrateable negative rear axle load threshold.

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