Capacitive monitoring of vehicle hitches

Method and apparatus are disclosed for capacitive monitoring of vehicle hitches. An example vehicle includes a hitch that includes a body, a hitch ball, and a sleeve that electrically insulates the hitch ball from the body. The example vehicle also includes a hitch module including a capacitive switch electrically coupled to the hitch ball. The hitch module is to wirelessly emit an alert that a trailer has decoupled from the hitch responsive to the capacitive switch detecting, via the hitch ball, a predetermined increase in capacitance.

TECHNICAL FIELD

The present disclosure generally relates to vehicle hitches and, more specifically, to capacitive monitoring of vehicle hitches.

BACKGROUND

Generally, vehicles include storage areas (e.g., trunks, truck beds, etc.) to store objects. In some instances, a driver and/or a passenger of the vehicle may have an object that is unable to fit within the storage area of the vehicle. In such instances, a trailer may be utilized to store and transport the object. Typically, a trailer is connected to a hitch that is located toward a rear side of the vehicle to enable the vehicle to tow the trailer and object(s) stored within the trailer.

SUMMARY

Example embodiments are shown for capacitive monitoring of vehicle hitches. An example disclosed vehicle includes a hitch that includes a body, a hitch ball, and a sleeve that electrically insulates the hitch ball from the body. The example disclosed vehicle also includes a hitch module including a capacitive switch electrically coupled to the hitch ball. The hitch module is to wirelessly emit an alert that a trailer has decoupled from the hitch responsive to the capacitive switch detecting, via the hitch ball, a predetermined increase in capacitance

An example disclosed method includes monitoring, via a capacitive switch of a hitch module, a capacitance around a hitch ball of a hitch. The hitch ball is electrically insulated via a sleeve. The example disclosed method also includes detecting whether there is a predetermined increase in capacitance around the hitch ball and wirelessly emitting, via the hitch module, an alert that a trailer has decoupled from the hitch responsive to the capacitive switch detecting, via the hitch ball, a predetermined increase in capacitance.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Generally, vehicles include storage areas (e.g., trunks, truck beds, etc.) to store objects. In some instances, a driver and/or a passenger of the vehicle may have an object that is unable to fit within the storage area of the vehicle. In such instances, a trailer may be utilized to store and transport the object. Typically, a trailer is connected to a hitch that is located toward a rear side of the vehicle to enable the vehicle to tow the trailer and object(s) stored within the trailer. Some vehicles and trailers include sensors for detecting when a trailer is coupled or decoupled from a vehicle.

Further, vehicles typically include a liftgate that enables user(s) to access a trunk and/or other cargo area of the vehicle. As used herein, a “liftgate” refers to a door or panel at a rear of a vehicle that opens upwardly to provide access to a trunk and/or another cargo area or compartment of the vehicle. In some examples, the liftgate includes a hatch that is coupled to a body of the vehicle (e.g., a sports-utility vehicle (SUV), a minivan, a hatchback. etc.) via a hinge located along an upper edge of a cargo area or compartment. In other examples, the liftgate includes a trunk lid that is coupled to a body of the vehicle (e.g., a sedan, a compact car, etc.) via a hinge along an outer edge of a trunk.

Recently, some vehicles include hands-free liftgate systems that enable a user to initiate opening and/or closing of a liftgate without use of his or her hands. As used herein, a “hands-free liftgate system” refers to a vehicle system that enables a user to initiate opening and/or closing of a liftgate without use of his or her hands. Some example hands-free liftgate systems include proximity sensor(s) located near the liftgate of the vehicle and cause the liftgate to actuate upon the proximity sensor(s) detecting that a vehicle operator is located near the liftgate.

In some instances, the detection area of the sensors that monitor the connection between the trailer and the vehicle overlap with the detection area of the proximity sensors of the hands-free liftgate system of the vehicle. As a result, the sensors for the trailer connection may potentially detect that the trailer is being coupled to or decoupled from the vehicle when a user is attempting to open or close the liftgate via the hands-free liftgate system, or the proximity sensors of the hands-free liftgate system may potentially open or close the liftgate when a user is attempting to couple or decouple the trailer and the vehicle.

Examples methods and apparatus disclosed herein include a system for detecting when a trailer is connected to a hitch of a vehicle that is spaced apart from a hands-free liftgate system of the vehicle to prevent the hitch monitoring system from overlapping with the hands-free liftgate system. The hitch includes a hitch body and a hitch ball coupled to the hitch body. A capacitive switch is electrically coupled to the hitch ball, which is electrically isolated from the hitch body via an insulation layer positioned between the hitch ball and the hitch body. In some examples, the hitch ball and the hitch body are positioned so that an electric field of the hitch ball utilized by the capacitive switch for detection of object(s) is emitted upward to prevent the hitch monitoring system from interfering with a hands-free liftgate system of the vehicle. A hitch module includes the capacitive switch and a short-range communication module (e.g., a BLE module) that is configured to wireless communicate with a communication module of the vehicle (e.g., a first communication module) and a mobile device of a vehicle operator. When the capacitive switch detects a first predetermined change in capacitance, the hitch module sends a signal via short-range wireless communication to the vehicle and/or the mobile device of the vehicle operator to warn the vehicle operator that the trailer has been decoupled from the hitch. In some examples, another communication module of the vehicle (e.g., a second communication module) sends a signal via cellular communication to the mobile device of the vehicle operator upon detecting that the vehicle operator is beyond a communication range of the short-range communication module of the hitch module.

Turning to the figures,FIG. 1illustrates an example vehicle100in accordance with the teachings here. In the illustrated example, a trailer102is coupled to the vehicle100via a hitch104of the vehicle100. The vehicle100may be a standard gasoline powered vehicle, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, and/or any other mobility implement type of vehicle. The vehicle100includes parts related to mobility, such as a powertrain with an engine, a transmission, a suspension, a driveshaft, and/or wheels, etc. The vehicle100may be non-autonomous, semi-autonomous (e.g., some routine motive functions controlled by the vehicle100), or autonomous (e.g., motive functions are controlled by the vehicle100without direct driver input). In the illustrated example, the vehicle100includes the hitch104, exterior lights106, a horn108, a communication module110, and another communication module112.

The hitch104(e.g., a tow hitch, a tow bar, a trailer hitch, etc.) of the illustrated example is located towards the rear of the vehicle100. For example, the hitch104is coupled to and/or extends from a chassis of the vehicle100. The hitch104is configured to receive a trailer connector of the trailer102(e.g., a trailer coupler306ofFIG. 3) to couple the trailer102to the vehicle100. That is, the vehicle100is able to tow the trailer102when the trailer102is coupled to the vehicle100via the hitch104.

The exterior lights106of the vehicle100include one or more lights (e.g., headlights, taillights, etc.) of the vehicle100that emit light from an exterior of the vehicle100. Further, the horn108is a sound-making device that emits audio signal(s) directed to a surrounding area of the vehicle100. Oftentimes, an operator (e.g., a driver) of the vehicle100utilizes the horn108to provide an alert that the vehicle100is approaching and/or to call attention to a hazard. Additionally or alternatively, the vehicle100includes other sound-making device(s) that emit audio signal(s) directed to the surrounding area of the vehicle100.

The communication module110of the illustrated example includes wired or wireless network interfaces to enable communication with external networks. The communication module110also includes hardware (e.g., processors, memory, storage, antenna, etc.) and software to control the wired or wireless network interfaces. In the illustrated example, the communication module110includes one or more communication controllers for cellular networks (e.g., Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Code Division Multiple Access (CDMA)) and/or other standards-based networks (e.g., WiMAX (IEEE 802.16m); Near Field Communication (NFC), local area wireless network (including IEEE 802.11 a/b/g/n/ac or others), Wireless Gigabit (IEEE 802.11ad), etc.). In some examples, the communication module110includes a wired or wireless interface (e.g., an auxiliary port, a Universal Serial Bus (USB) port, a Bluetooth® wireless node, etc.) to communicatively couple with a mobile device (e.g., a smart phone, a wearable, a smart watch, a tablet, etc.). In such examples, the vehicle100may communicated with the external network via the coupled mobile device. The external network(s) may be a public network, such as the Internet; a private network, such as an intranet; or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to, TCP/IP-based networking protocols.

The communication module112of the illustrated example includes wired or wireless network interfaces to enable communication with external networks. The communication module110also includes hardware (e.g., processors, memory, storage, antenna, etc.) and software to control the wired or wireless network interfaces. In the illustrated example, the communication module112includes one or more communication controllers for wireless personal area network(s) (e.g., including area networks based on the IEEE 802.15 standard) and/or wireless local area network(s) (e.g., Wi-Fi networks and/or other area networks based on the IEEE 802.11 standard). For example, the communication module112is a short-range wireless module that includes the hardware and firmware to establish a connection with a mobile device and/or another short-range wireless module (e.g., a short-range communication module820ofFIG. 8) that is located nearby. In some examples, the short-range wireless module implements the Bluetooth® and/or Bluetooth Low Energy (BLE) protocols. The Bluetooth® and BLE protocols are set forth in Volume 6 of the Bluetooth® Specification 4.0 (and subsequent revisions) maintained by the Bluetooth® Special Interest Group.

The vehicle100of the illustrated example also includes one or more proximity sensors114of the a hands-free liftgate system. For example, the hands-free liftgate system enables an operator of the vehicle100to open a liftgate (e.g., a liftgate204ofFIG. 2) without utilizing his or her hands. The proximity sensors114are to detect when the operator of the vehicle100is nearby, for example, by measuring a change in capacitance that is caused by the presence of the operator near the proximity sensors114. In the illustrated example, the proximity sensors114are positioned toward a rear of the vehicle100to monitor an activation area (e.g., an activation area202ofFIG. 2) of the liftgate. For example, when one or more of the proximity sensors114detects that the operator of the vehicle100has extended his or her leg into the activation area, the hands-free liftgate system opens and/or closes the liftgate of the vehicle100.

As illustrated inFIG. 1, the vehicle100also includes a camera116that is positioned toward the rear of the vehicle100near the proximity sensors114and the hitch104. In some examples, the camera116capture image(s) and/or video of the activation area of the hands-free liftgate system to verify that an operator of the vehicle100has extended his or her leg into the activation area. Additionally or alternatively, the camera116captures image(s) and/or video of the hitch104for monitoring the hitch104and/or the connection between the vehicle100and the trailer102.

Further, the vehicle100of the illustrated example includes a monitoring system118and an alert controller120. For example, the monitoring system118monitors and/or emits alerts a status of the hitch104. For example, the monitoring system118is to determine whether the trailer102is coupled to the hitch104, whether a person is near (e.g., touching) the hitch104, etc. Further, the monitoring system118subsequently is to provide an alert that the trailer102has been coupled to the hitch104, the trailer102has been decoupled from the hitch104, a person is near the hitch104, etc. The alert controller120of the illustrated example monitors, via the communication module112(e.g., a first communication module), whether a key fob or phone-as-a-key of an operator of the vehicle100is nearby and/or a mobile device of the operator is able to receive an alert emitted by the monitoring system118via a wireless personal area network. As used herein, a “key fob” refers to an electronic device that wirelessly communicates with a vehicle to unlock door(s), open door(s) and/or activate an engine of a vehicle. As used herein, a “phone-as-a-key” refers to a mobile device (e.g., a smart phone, a wearable, a smart watch, a tablet, etc.) that includes hardware and/or software to function as a key fob.

Further, the alert controller120relays, via the communication module110(e.g., a second communication module), an alert to the mobile device of the operator via a cellular network if the mobile device of the operator is unable to directly receive the alert from the monitoring system118via the wireless personal area network. Additionally or alternatively, the alert controller120emits an alarm (e.g., via the exterior lights106, the horn108, etc.) if the key fob or phone-as-a-key of the operator is not near the vehicle100.

FIG. 2illustrates the hitch104and a hands-free liftgate system of the vehicle100. As illustrated inFIG. 2, an activation area202of the hands-free liftgate system is below a liftgate204that is near the hitch104of the vehicle100. The activation area202is defined, at least in part, by the proximity sensors114. In the illustrated example, the proximity sensors114of the vehicle100are oriented downward toward a ground surface such that the activation area202is located below the hitch104toward and/or along the ground surface. The activation area202is utilized by a user of the vehicle100to cause the liftgate204to actuate. For example, the user extends his or her leg (e.g., a foot) into the activation area202to cause the hands-free liftgate system to open and/or close the liftgate204.

FIG. 3further illustrates the hitch104of the vehicle100when the trailer102is coupled to the vehicle100via the hitch104. As illustrated inFIG. 3, the hitch104includes a hitch body302and a receiver tube304. The receiver tube304is coupled to a portion of a body (e.g., a chassis) of the vehicle100. The hitch body302is inserted into and received by the receiver tube304to couple the hitch body302to the body of the vehicle100.

As illustrated inFIG. 3, a trailer coupler306of the trailer102couples to the hitch104of the vehicle100to couple the trailer102to the vehicle100. In the illustrated example, the trailer coupler306includes a receiver308that is to receive a hitch ball (e.g., a hitch ball406ofFIG. 4) of the hitch104and a latch310that is to secure a connection between the receiver308and the hitch ball to couple the trailer coupler306to the hitch104.

FIG. 4illustrates the monitoring system118of the hitch104. As illustrated inFIG. 4, the hitch body302includes a post402that protrudes away from the vehicle100when the hitch body302is coupled to the vehicle100. For example, the hitch body302is formed of, for example, a strong metallic material that enables the hitch body302to retain its shape while the trailer102is being towed by the vehicle100via the hitch104. Further, the hitch body302defines an aperture404at the distal end of the hitch body302.

The hitch104of the illustrated example also includes a hitch ball406that is received by the receiver308of the trailer coupler306to couple the trailer102to the vehicle100. In the illustrated example, a protrusion408is integrally formed with and extends from the hitch ball406. The hitch ball406(as well as the protrusion408) is formed, for example, of a metallic material. For example, the metallic material of the hitch ball406is electrically conductive that facilitates capacitive measurements and has a strength that enables the hitch ball406to tow the trailer102.

To couple the hitch ball406to the hitch body302, the protrusion408is inserted into and at least partially extends into the aperture404defined by the hitch body302. As illustrated inFIG. 4, a sleeve410is positioned within the aperture404between the protrusion408of the hitch ball406and the hitch body302to electrically insulate the hitch ball406from the hitch body302. For example, the sleeve410is securely positioned within the aperture404via a washer. Further, a nut412couples to the end of the protrusion408to securely couple the hitch ball406to the hitch body302of the hitch104.

As illustrated inFIG. 4, the monitoring system118includes an electrical connector414that is positioned within and electrically coupled to the hitch ball406. Further, a hitch module416is coupled to the post402of the hitch body302and is covered by a protective covering418(e.g., an overmold) to protect the hitch module416from being removed from the hitch104and/or damaged by foreign object(s). As illustrated inFIG. 4, the electrical connector414receives wiring420that is electrically coupled to the hitch module416to electrically couple the hitch ball406to a capacitive switch (e.g., a capacitive switch822ofFIG. 8) of the hitch module416.

In the illustrated example, the hitch module416provides a small charge to the hitch ball406, which is formed of conductive material, to enable the hitch ball406to emit an electric field422and form a capacitive sensor. When a grounded object (e.g., the receiver308of the trailer coupler306, a person) is positioned within the electric field422, the capacitive switch that is electrically coupled to the hitch ball406measures an increase in capacitance detected via the hitch ball406. Likewise, when a grounded object (e.g., the receiver308of the trailer coupler306, a person) is removed from the electric field, the capacitive switch measures a decrease in capacitance detected via the hitch ball406. Some changes in capacitance correspond to objects being coupled to or removed from the hitch ball406. For example, when the trailer coupler306of the trailer102is being coupled to the hitch ball406, the capacitive switch measures a first predetermined decrease in capacitance detected via the hitch ball406. When the trailer coupler306of the trailer102is being decoupled and/or removed from the hitch ball406, the capacitive switch measures a predetermined increase in capacitance detected via the hitch ball406. Further, when a portion of a person (e.g., a foot, a finger, etc.) is positioned near the hitch ball406within the electric field422, the capacitive switch measures a second predetermined decrease in capacitance detected via the hitch ball406.

As illustrated inFIG. 4, the hitch ball406is positioned above the hitch body302of the hitch104such that electric field422is emitted upward from the hitch ball406but not downward from the hitch ball406. For example, the hitch body302, which is formed of conductive material, is grounded to prevent electric field422from being emitted from the hitch ball406beyond the hitch body302. That is, the hitch body302is positioned between the hitch ball406and the ground surface to enable the hitch ball406and the capacitive switch to monitor a change in capacitance of an area around the hitch ball406above the hitch body302and to prevent the hitch ball406and the capacitive switch from monitoring a change in capacitance of an area below the hitch body302of the hitch104. For example, the hitch ball406is positioned above the hitch body302and the proximity sensors114of the hands-free liftgate system to enable the hitch ball406and the capacitive switch of the monitoring system118to monitor a first area above the hitch body302and the proximity sensors114of the hands-free liftgate system to monitor a second area (e.g., the activation area202) below the hitch body302. In other words, the hitch ball406is positioned relative to the hitch body302and the proximity sensors114to separate the area monitored by the monitoring system118of the hitch104and the area monitored by the hands-free liftgate system of the liftgate204.

FIG. 5illustrates the monitoring system118of the hitch104when the trailer coupler306of the trailer102is coupled to the hitch ball406of the hitch104. As illustrated inFIG. 5, when the trailer coupler306is coupled to the hitch ball406, the receiver308and/or other portions of the trailer coupler306are positioned within the electric field422that is emitted from the hitch ball406. Further, when the trailer coupler306is positioned in the electric field422, the capacitive switch of the hitch module416that is electrically coupled to the hitch ball406detects a first predetermined decrease in capacitance via the hitch ball406. For example, the first predetermined decrease in capacitance corresponds to the material of the trailer coupler306and/or a proximity of the trailer coupler306to the hitch ball406when coupled to the hitch ball406. In turn, the hitch module416determines that the trailer102has been coupled to the hitch104in response to the hitch ball406and the capacitive switch detecting the first predetermined decrease in capacitance.

Additionally, when the trailer coupler306is decoupled from the hitch ball406of the hitch104, the receiver308and/or other portions of the trailer coupler306are no longer positioned within the electric field422of the hitch ball406. As the trailer coupler306is removed from the electric field422, the capacitive switch and the hitch ball406of the hitch module416detects a corresponding predetermined increase in capacitance (e.g., that corresponds to the material of the trailer coupler306and/or a proximity of the trailer coupler306to the hitch ball406when coupled to the hitch ball406). In turn, the hitch module416determines that the trailer102has been decoupled from the hitch104in response to the capacitive switch and the hitch ball406detecting the first predetermined decrease in capacitance.

Upon the capacitive switch and the hitch ball406detecting the first predetermined decrease in capacitance, the hitch module416wirelessly emits an alert (e.g., via a short-range communication module820ofFIG. 8) to alert an operator of the vehicle100that the trailer102has been removed from the hitch104. For example, the hitch module416wirelessly emits the alert via a wireless personal area network to the communication module112(e.g., a first communication module) of the vehicle100and/or to a mobile device of the operator of the vehicle100. Upon receipt from the hitch module416, an output device the vehicle100(e.g., a display814ofFIG. 8, speakers816ofFIG. 8) emit the alert and/or the mobile device of the operator emits (e.g., audibly, visually, haptically) emits the alert.

In some instances, the operator may not obtain the alert that is emitted from the output device(s) of the vehicle100if the operator is not located within the vehicle100at the time the alert is presented via the output device(s). Further, in some instances, the operator may not obtain the alert via the mobile device if the mobile device is outside of the range of the wireless personal area network through which the hitch module416emits the alert. To enable the operator to obtain the alert when he or she is located away from the vehicle100, the alert controller120of the vehicle100identifies whether the operator is located away from the vehicle100by determining whether a key fob or a phone-as-a-key of the operator is located within a predetermined distance of the communication module112. For example, the predetermined distance from the communication module112corresponds to the range of the wireless personal area network through which the hitch module416emits the alert. In response to the alert controller120determining that key fob or the phone-as-a-key of the operator is outside of the predetermined distance, the communication module110(e.g., a second communication module) relays the alert to the mobile device of the operator via a cellular network and/or other long-range network). Additionally or alternatively, the vehicle100emits an alarm (e.g., via the exterior lights106and/or the horn108) in response to the hitch module416determining that the trailer102has decoupled from the hitch104and the alert controller120determining that the key fob or the phone-as-a-key of the operator is located outside of the predetermined distance of the communication module112.

FIGS. 6-7illustrate the monitoring system118of the hitch104when a foot602of a user is proximate to the hitch104. As illustrated inFIGS. 6-7, the hitch ball406is positioned relative to the hitch body302and the proximity sensors114to separate the area monitored by the monitoring system118of the hitch104and the area monitored by the hands-free liftgate system of the liftgate204.

InFIG. 6, the foot602of the user is positioned below the hitch body302and within the activation area202of the hands-free activation system to activate opening and/or closing of the liftgate204. Further, the foot602is not positioned within the electric field422that is emitted by the hitch ball406. In turn, the capacitive switch and the hitch ball406do not detect a change in capacitance when the foot602is located below the hitch body302.

InFIG. 7, the foot602of the user is positioned above the hitch body302. Thus, the foot602of the user is not positioned within the activation area202of the hands-free activation system for activating opening and/or closing of the liftgate204. Further, as a result of the foot602being positioned within the electric filed422above the hitch body302and near the hitch ball406, the capacitive switch of the hitch module416detects a change in capacitance via the hitch ball406. For example, the hitch module416determines that the foot602and/or another portion of a person is near (e.g., stepping on with the foot602, touching with a hand, etc.) the hitch ball406responsive to the capacitive switch detecting a second predetermined decrease in capacitance via the hitch ball406. For example, the second predetermined decrease in capacitance that corresponds with a person being near the hitch ball406is different than the first predetermined decrease in capacitance that corresponds with the trailer coupler306coupling to the hitch104. As a result, the hitch module is able to differential between a person and the trailer coupler306via the change in capacitance measured by the capacitive switch via the hitch ball406.

In some examples, a light (e.g., an LED-based light818ofFIG. 8) illuminates an area around the hitch104responsive to the hitch module416detecting that a person is near the hitch ball406. For example, the light is illuminated to facilitate an operator of the vehicle100in viewing who is near the hitch ball406and/or to warn the person near the hitch ball406not to touch the hitch104and/or the trailer102. To cause the vehicle100to illuminate the light, the hitch module416wirelessly sends a signal to the communication module112of the vehicle100.

FIG. 8is a block diagram of electronic components800of the vehicle ofFIG. 1. As illustrated inFIG. 8, the electronic components800include an on-board computing platform802, an infotainment head unit804, the horn108, the exterior lights106, one or more sensors806, the camera116, the communication module110, the communication module112, the hitch module416, and a vehicle data bus808.

The on-board computing platform802includes a microcontroller unit, controller or processor810and memory812. In some examples, the processor810of the on-board computing platform802is structured to include the alert controller120. Alternatively, in some examples, the alert controller120is incorporated into another electronic control unit (ECU) with its own processor810and memory812. The processor810may be any suitable processing device or set of processing devices such as, but not limited to, a microprocessor, a microcontroller-based platform, an integrated circuit, one or more field programmable gate arrays (FPGAs), and/or one or more application-specific integrated circuits (ASICs). The memory812may be volatile memory (e.g., RAM including non-volatile RAM, magnetic RAM, ferroelectric RAM, etc.), non-volatile memory (e.g., disk memory, FLASH memory, EPROMs, EEPROMs, memristor-based non-volatile solid-state memory, etc.), unalterable memory (e.g., EPROMs), read-only memory, and/or high-capacity storage devices (e.g., hard drives, solid state drives, etc). In some examples, the memory812includes multiple kinds of memory, particularly volatile memory and non-volatile memory.

The memory812is computer readable media on which one or more sets of instructions, such as the software for operating the methods of the present disclosure, can be embedded. The instructions may embody one or more of the methods or logic as described herein. For example, the instructions reside completely, or at least partially, within any one or more of the memory812, the computer readable medium, and/or within the processor810during execution of the instructions.

The infotainment head unit804provides an interface between the vehicle100and a user. The infotainment head unit804includes digital and/or analog interfaces (e.g., input devices and output devices) to receive input from and display information for the user(s). The input devices include, for example, a control knob, an instrument panel, a digital camera for image capture and/or visual command recognition, a touch screen, an audio input device (e.g., cabin microphone), buttons, or a touchpad. The output devices may include instrument cluster outputs (e.g., dials, lighting devices), actuators, a display814(e.g., a heads-up display, a center console display such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a flat panel display, a solid state display, etc.), and/or speakers816. In the illustrated example, the infotainment head unit804includes hardware (e.g., a processor or controller, memory, storage, etc.) and software (e.g., an operating system, etc.) for an infotainment system (such as SYNC® and MyFord Touch® by Ford®). Additionally, the infotainment head unit804displays the infotainment system on, for example, the display814.

The sensors806are arranged in and around the vehicle100to monitor properties of the vehicle100and/or an environment in which the vehicle100is located. One or more of the sensors806may be mounted to measure properties around an exterior of the vehicle100. Additionally or alternatively, one or more of the sensors806may be mounted inside a cabin of the vehicle100or in a body of the vehicle100(e.g., an engine compartment, wheel wells, etc.) to measure properties in an interior of the vehicle100. For example, the sensors806include accelerometers, odometers, tachometers, pitch and yaw sensors, wheel speed sensors, microphones, tire pressure sensors, biometric sensors and/or sensors of any other suitable type. In the illustrated example, the sensors806include the proximity sensors114of the hands-free liftgate system.

The camera116of the illustrated example captures image(s) and/or video of a surrounding area of the vehicle100behind and/or to the side of the vehicle100. In some examples, the camera116capture image(s) and/or video of the activation area202of the hands-free liftgate system to facilitate a determination that an operator has extended his or her leg into the activation area202. Additionally or alternatively, the camera116captures image(s) and/or video of the hitch104to monitor the hitch104and/or a connection between the vehicle100and the trailer102. Further, the camera116may capture image(s) and/or video that are presented to occupant(s) of the vehicle100via the display814and/or are utilized to facilitate performance of autonomous and/or semi-autonomous driving maneuvers of the vehicle100. As illustrated inFIG. 8, the camera116includes an LED-based light818and/or other light that illuminates an area that the camera116is capturing via the image(s) and/or video. In some examples, the LED-based light818illuminates an area around the hitch104in response to the hitch module416detecting that a person is near (e.g., touching) the hitch ball406of the hitch104. Additionally or alternatively, the LED-based light818illuminates the area behind the vehicle100when the vehicle100is moving in reverse to hitch to the trailer102and one or more of the proximity sensors113detect that the vehicle100is approaching the trailer coupler306of the trailer102.

In the illustrated example, the communication module110is configured to wirelessly communicate via a cellular network and/or other long-range network, and the communication module112is configured to wirelessly communicate via a personal wireless area network and/or other short-range wireless network. As illustrated inFIG. 8, the communication module112wirelessly communicates with a short-range communication module820of the hitch module416.

The short-range communication module820includes wired or wireless network interfaces to enable communication with external networks. The short-range communication module820also includes hardware (e.g., processors, memory, storage, antenna, etc.) and software to control the wired or wireless network interfaces. In the illustrated example, the short-range communication module820includes one or more communication controllers for wireless personal area network(s) (e.g., including area networks based on the IEEE 802.15 standard) and/or wireless local area network(s) (e.g., Wi-Fi networks and/or other area networks based on the IEEE 802.11 standard). For example, the hardware and firmware of the short-range communication module820enable the short-range communication module820to establish a connection with a mobile device and/or another short-range wireless module that is located nearby. In some examples, the short-range communication module820implements the Bluetooth® and/or Bluetooth Low Energy (BLE) protocols.

In the illustrated example, the short-range communication module820coupled to a capacitive switch822of the hitch module416. The capacitive switch822is electrically coupled to the electrical connector414of the hitch ball406to measure, via the hitch ball406, the capacitance around the hitch ball406. The short-range communication module820wirelessly emits the alert to the communication module112of the vehicle100and/or a mobile device of a vehicle operator based upon the capacitive measurements of the capacitive switch822and the hitch ball406.

Further, the vehicle data bus808communicatively couples the exterior lights106, the horn108, the communication module110, the communication module112, the camera116, the on-board computing platform802, the infotainment head unit804, and the sensors806. In some examples, the vehicle data bus808includes one or more data buses. The vehicle data bus808may be implemented in accordance with a controller area network (CAN) bus protocol as defined by International Standards Organization (ISO) 11898-1, a Media Oriented Systems Transport (MOST) bus protocol, a CAN flexible data (CAN-FD) bus protocol (ISO 11898-7) and/a K-line bus protocol (ISO 9141 and ISO 14230-1), and/or an Ethernet™ bus protocol IEEE 802.3 (2002 onwards), etc.

FIG. 9is a flowchart of an example method900to monitor a vehicle hitch via capacitive sensor. The flowchart ofFIG. 9is representative of machine readable instructions that are stored in memory (such as the memory812ofFIG. 8) and include one or more programs which, when executed by a processor (such as the processor810ofFIG. 8), cause the vehicle100to implement the example alert controller120ofFIGS. 1 and 8and/or the example hitch module416ofFIGS. 4-8. While the example program is described with reference to the flowchart illustrated inFIG. 9, many other methods of implementing the example alert controller120and/or the example hitch module416may alternatively be used. For example, the order of execution of the blocks may be rearranged, changed, eliminated, and/or combined to perform the method900. Further, because the method900is disclosed in connection with the components ofFIGS. 1-8, some functions of those components will not be described in detail below.

Initially, at block902, the hitch module416determines whether the capacitive switch822of the hitch module416has detected, via the hitch ball406, a change in capacitance. In response to hitch module416determining that the capacitive switch822has not detected a change in capacitance, the method900remains at block902. Otherwise, in response to hitch module416determining that the capacitive switch822has detected a change in capacitance, the method900proceeds to block904.

At block904, the hitch module416determines a source of the change in capacitance based on the change in capacitance detected via the hitch ball406. That is, the hitch module416detects a magnitude and direction of the change in capacitance detected by the capacitive switch822via the hitch ball406. Subsequently, the hitch module416determines the source of the change in capacitance by comparing the magnitude and direction of the change in capacitance to predetermined increases and/or decreases in capacitance. For example, the hitch module416determines that the source of the change in capacitance is the trailer coupler306of the trailer102being coupled to the hitch104if the change in capacitance measured by the capacitive switch822via the hitch ball406corresponds to a first predetermined decrease in capacitance.

At block906, the hitch module416determines whether the source of the change in capacitance is a person near (e.g., touching) the hitch ball406. For example, the hitch module416determines that the source of the change in capacitance is a person near the hitch104if the change in capacitance measured by the capacitive switch822via the hitch ball406corresponds to a second predetermined decrease in capacitance.

In response to the hitch module416determining that a person near the hitch ball406, the method proceeds to block908. At block908, the short-range communication module820of the hitch module416sends a signal to the communication module112of the vehicle100and/or a mobile device of a vehicle operator that indicates a person is near the hitch ball406. For example, upon receiving the signal from the short-range communication module820of the hitch module416, the display814and/or the speakers816of the vehicle100and/or a display and/or speakers of the mobile device present an alert indicating that a person is near the hitch ball406. At block910, the alert controller120of the vehicle100determines whether the vehicle100is in park (e.g., via a transmission position sensor). In response to the alert controller120determining that the vehicle100is not in park, the method900returns to block902. Otherwise, in response to the alert controller120determining that the vehicle100is in park, the method proceeds to block912at which the alert controller120sends a signal to activate the camera116to cause the LED-based light818to illuminate the area around the hitch104. Additionally or alternatively, the alert controller120sends a signal to another light of the vehicle100to illuminate the area around the hitch104. Further, in some examples, the alert controller120sends a signal to illuminate the area behind the vehicle100via the LED-based light818when the vehicle100is moving in reverse to hitch to the trailer102and one or more of the proximity sensors113detect that the vehicle100is approaching the trailer coupler306of the trailer102.

Otherwise, in response to the hitch module416determining, at block906, that a person is not near the hitch ball406, the method proceeds to block914. At block914, the hitch module416determines whether the source of the change in capacitance is the trailer102being decoupled from the hitch104. For example, the hitch module416determines that the source of the change in capacitance is the trailer coupler306of the trailer102being removed from the hitch104if the change in capacitance measured by the capacitive switch822via the hitch ball406corresponds to a predetermined increase in capacitance. In response to the hitch module416determining that the trailer102is not being decoupled from the hitch104, the method900returns to block902. Otherwise, in response to the hitch module416determining that the trailer102is being decoupled from the hitch104, the method900proceeds to block916at which the short-range communication module820of the hitch module416transmits an alert signal via a wireless personal area network (e.g., Bluetooth® communication, BLE communication, etc.) and/or a wireless local area network (e.g., Wi-Fi communication) to be received by the communication module112of the vehicle100and/or the mobile device of the vehicle operator. The alert signal indicates that the trailer102has been decoupled from the hitch104. For example, upon receiving the alert signal from the hitch module416, the vehicle presents an alert (e.g., via the display814, the speakers816, etc.) to notify the vehicle operator that the trailer102has been decoupled from the hitch104. Additionally or alternatively, upon receiving the alert signal from the hitch module416, the mobile device of the vehicle operator presents an alert (e.g., a visual alert, an audio alert, etc.) to notify the vehicle operator that the trailer102has been decoupled from the hitch104.

At block918, the alert controller120determines whether a key fob of the vehicle operator and/or the mobile device of the vehicle operator that is functioning as a phone-as-a-key is located near the vehicle100(e.g., within a predetermined distance of the communication module112of the vehicle100. If the key fob or phone-as-a-key is within the predetermined distance of the vehicle100, the alert controller120determines that the mobile device of the vehicle operator is capable of receiving the alert signal transmitted by the hitch module416via the wireless personal and/or local area network. If the key fob or phone-as-a-key is located beyond the predetermined distance of the vehicle100, the alert controller120determines that the mobile device of the vehicle operator is unable to receive the alert signal transmitted by the hitch module416. In response to the alert controller120determining that the key fob or phone-as-a-key is within the predetermined distance such that the mobile device of the vehicle operator is able to receive the alert signal, the method900returns to block902. Otherwise, in response to the alert controller120determining that the key fob or phone-as-a-key is not within the predetermined distance of the vehicle100, the method900proceeds to block920at which the alert controller120emits an alarm via the exterior lights106(e.g., for a visual alarm) and/or the horn108(e.g., for an audio alarm) of the vehicle100to warn that the trailer102has been removed from the hitch104of the vehicle100. Further, at block922, the communication module110of the vehicle100sends or relays the alert signal, which the communication module112of the vehicle100received from the hitch module416, to the mobile device of the vehicle operator via cellular communication to alert the vehicle operator that the trailer102has been removed from the hitch104of the vehicle100.

In this application, the use of the disjunctive is intended to include the conjunctive. The use of definite or indefinite articles is not intended to indicate cardinality. In particular, a reference to “the” object or “a” and “an” object is intended to denote also one of a possible plurality of such objects. Further, the conjunction “or” may be used to convey features that are simultaneously present instead of mutually exclusive alternatives. In other words, the conjunction “or” should be understood to include “and/or”. The terms “includes,” “including,” and “include” are inclusive and have the same scope as “comprises,” “comprising,” and “comprise” respectively. Additionally, as used herein, the terms “module” and “unit” refer to hardware with circuitry to provide communication, control and/or monitoring capabilities, often in conjunction with sensors. A “module” and an “unit” may also include firmware that executes on the circuitry.