Patent Publication Number: US-11662247-B2

Title: Vehicle wheel assembly having improved monitoring capabilities for various vehicle conditions and monitoring device for accomplishing such monitoring

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 16/814,011, filed Mar. 10, 2020, the disclosures of which are incorporated herein by reference in entirety, which is continuation of U.S. Ser. No. 15/759,559, filed Mar. 13, 2018, now U.S. Pat. No. 10,598,541, issued Mar. 24, 2020, the disclosures of which are incorporated herein by reference in entirety, which claims priority to International Patent Application No. PCT/US16/051606, filed Sep. 14, 2016, the disclosures of which are incorporated herein by reference in entirety, which claims priority to U.S. Provisional Application Ser. No. 62/218,097, filed Sep. 14, 2015, the disclosures of which are incorporated herein by reference in entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to vehicle wheel assemblies and in particular to a vehicle wheel having improved monitoring capabilities for various vehicle conditions and monitoring device for accomplishing such monitoring. 
     Full size trucks in addition to heavy duty trucks are subject to weight restrictions when driving along certain traveled roads. Loads in the vehicle may be detected by weight sensors integrated on the truck itself. Such weight sensors, if incorporated on the truck, may be integrated to a fixed frame of the vehicle between the chassis of the vehicle and the bed of the vehicle. These respective load sensors are dedicated to the only sensing the weight in the bed of the truck. Such sensors do not provide other data for other vehicle conditions nor are such sensors designed for sensing other conditions or positioned for sensing other conditions such, weight distribution, temperature, as tire pressure camber of the wheel. Such load conditions as well as other sensed operating conditions can affect how a vehicle system operatively reacts. While the information relating to different operating conditions is useful in controlling vehicle operations, many of the sensed conditions of the vehicle requires a dedicated sensor which is costly and adds packaging complexity. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a vehicle wheel having improved monitoring capabilities for various vehicle conditions and monitoring device for accomplishing such monitoring. 
     According to an embodiment, a feature of the invention is to add functionality to existing wheels by adding a monitoring device or system, including one or more components and associated sensors, to the vehicle wheel. The monitoring device will have the capability to monitor various vehicle conditions, such as for example including but not limited to, wheel clamp load, wheel load, axle load, weight distribution, ambient temperature, wheel temperature, and tire air pressure. 
     The information obtained by the sensor can be used to by various systems including, but not limited to, TCS, ABS, EBD, AAR, CMBS, AWD, CTIS, tire wear, and damage control reporting. Such systems can utilize this information for countering instability control issues or making adjustments to maintain stability. In addition, such information can be provided to the driver for driver awareness such as overload or uneven loading, unsafe wheel attachment, low tire pressure, or potential rollover. 
     Furthermore, a feature of the monitoring device is that the device preferably generates sufficient electricity to power itself via one of several technologies that turn kinetic energy into electrical energy. Such energy can be used to drive the electrical components of the sensor directly or can be used as a power source to charge rechargeable power cells. 
     An embodiment contemplates a monitoring device that includes a housing adhered to a drop well of a wheel inside of a vehicle tire. The housing rotates with the wheel. An electronic circuit is disposed within the housing. The electrical circuit includes a load sensing device disposed within the housing. The load sensing device senses forces exerted on the wheel. A transceiver is coupled to the electrical circuit. The transceiver communicates load data sensed by the load sensing device to components exterior of the wheel. 
     An embodiment contemplates a monitoring system including a housing adhered to a drop well of a wheel inside of a vehicle tire. The housing rotates with the wheel. An electronic circuit is disposed within the housing. The electrical circuit includes a load sensing device disposed within the housing. The load sensing device senses forces exerted on the wheel. A transceiver is coupled to the electrical circuit. The transceiver communicates load data sensed by the load sensing device to components exterior of the wheel. At least one controller controls a vehicle operation. The at least one controller receives the load data and adjusts a vehicle operation in response to the load data. 
     Other advantages of this invention will become apparent to those skilled in the art from the following detailed description of the invention and preferred embodiments, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a view of a portion of a vehicle wheel having an improved monitoring device configured to be operatively installed thereon in accordance with this invention. 
         FIG.  2    is a perspective view of a portion of the monitoring sensor illustrated in  FIG.  1    showing internal components of the associated monitoring device. 
         FIG.  3    is a perspective view of a housing cover for the monitoring sensor. 
         FIG.  4    is a perspective top view of a clamp load spacing device. 
         FIG.  5    is a perspective view of bottom surface of a clamp load spacing device. 
         FIG.  6    is a perspective view of a wheel incorporating a clamp load sensor. 
         FIG.  7    is a system diagram of the monitoring system within the vehicle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, there is illustrated in  FIG.  1    embodiment of a monitoring device, indicated generally at  10 , which is configured to be operatively installed on a vehicle wheel  12  in accordance with the present invention. The vehicle wheel  12  may be of any type of construction and/or configuration. In addition, the monitoring device  10  may be installed on any desired location on the vehicle wheel  12 , preferably as illustrated as being located in a drop well  13  of an outer side surface  14  of the wheel  12  by suitable techniques including, but not limited to, adhesives, fasteners, or the like. The outer side surface  14  is defined herein as the side of the wheel that is exposed to the inside of the tire for enclosing a chamber to maintain tire pressure. The drop well  13  is defined herein as an axial portion of outer side surface  14  circumferentially formed around the wheel  12  that is adjacent to a rim leg  15  and a bead hump  16 . The monitoring device  10 , when mounted on the drop well  13  of the outer side surface  14  of the wheel, would be disposed internal within a chamber of a pressurized tire shielded from the external environmental elements. 
       FIG.  2    illustrates the monitoring device  10  (i.e., less a cover) that includes various components for sensing various conditions including, but not limited to, wheel load, wheel clamp load, axle load, weight distribution, camber, impact loads, ambient temperature, wheel temperature, and tire air pressure. A chassis body  18  includes a lower portion of a housing for encasing the various components of the monitoring device  10 . A top enclosure or cover  20 , as shown in  FIG.  3   , attaches to the chassis body  18  for sealing the components therein. 
     Referring again to  FIG.  2   , the chassis body  18  and the cover  20  are made of a material that can withstand high temperatures and adverse chemicals that can potentially damage electrical components therein. For example, since the monitoring device  10  resides within the tire, sulfuric acid may be emitted from the rubber compound of the tire during operation of the vehicle and deteriorate the electrical components therein if not properly encased. The material used to form the chassis body  18  and the cover  20  may include, but is not limited to, plastic, nylon, or composites. 
     The components mounted within the monitoring device  10  include, but are not limited to, a plurality of piezo elements  22 , a plurality of excitation masses  24 , and a printed circuit board (PCB)  26 , and a strain gauge  28 . 
     The plurality of piezo elements  22  are used for energy harvesting. It should be understood that while discs are illustrated herein, the piezo elements can be other shapes and configurations including, but not limited to, piezo films. The plurality of piezo elements  22  reacts to pressure, acceleration, strain, temperature, and other forces that generate vibrations on the piezo elements. The vibrations are converted to an electrical charge. Piezoelectric materials that comprise the disc possess crystalline structures. Positive and negative charges of each piezo element  22  do not overlap and therefore yield dipole moments. When the crystalline structure is subjected to mechanical vibrations or motion, a mechanical force or strain is applied to the piezoelectric materials which leads to distortion of the dipoles, thereby creating an electrical charge. The electrical energy can be harvested by storing the energy in power cells, capacitance devices, or may be supplied directly to devices of the monitoring device  10 . Other types of energy harvesting that may be utilized include, but are not limited to, a microgenerator and solar energy. 
     As shown in  FIG.  2   , a plurality of piezo elements  22  includes discs of different sizes.  FIG.  2    illustrates a first piezo element and associated excitation mass  30 , a second piezo element and associated excitation mass  32 , a third piezo element and associated excitation mass  34 , and a fourth piezo element and associated excitation mass  36  that are disposed at various locations around the monitoring sensor  10 . It should be understood that the number of associated piezo elements may be more or less than what is shown, and may be located at different locations that what is shown. Frequency limits of piezo elements are typically determined by resonances as set forth by the size and/or shape of the piezo element. Therefore, multiple piezo elements of different sizes are utilized to capture a large bandwidth of the different frequencies that may excite the piezo elements. 
     To generate vibrations within each piezo element  22 , excitation masses  24  are disposed with a center of each piezo element  22 . Each of the excitation masses  24  is associated with a respective piezo element. Each excitation mass  24  includes a cylindrical portion  35  supported by a stem portion  37 . 
     Each cylindrical portion  35  is positioned a predetermined height above each piezo element  22 . Each stem portion  37  extends through a center of each piezo element  22 . An enlarged side view of the piezo element and excitation mass is shown in  FIG.  2   . It is shown that the stem portion  37  associated with the excitation mass/piezo element  32  are monolithic such that the stem portion  37  and excitation mass  32  are formed as a single component. The stem portion  37  associated with excitation mass/piezo element  32  is tapered. The stem portion  37  tapers as it is mounts within the center of the associated piezo element. This allows for movement of the excitation mass as the wheel rotates which induces vibrations in the associated piezo element. In contrast, stem portion  37  associated with the excitation mass/piezo element  30  is a cylindrical-shaped stem portion. The length and diameter of the cylindrical-shaped stem portion is constructed to allow movement of the excitation mass for inducing vibrations in the associated piezo element. It should be understood that each of the respective excitation masses of the monitoring sensor  10  can use the taper stem portion for all excitation masses, or can use the cylindrical-shaped stem portion for all excitation masses, or can use a combination of both tapered and cylindrical-shaped stem portions. It should also be understood that other shapes and configurations can be used. 
     As the vehicle wheel rotates along a road of travel, each cylindrical portion  35  of each excitation mass  24  sways in various directions. The stem portion  37  which is coupled to the excitation mass  24  and extends through the center of the piezo element  22  acts on the piezo element  22  thereby generating a force on the piezo element  22 . The piezo elements  22  sense the force applied along a neutral axis which generates charge in a respective direction that is perpendicular to the line of force. The sensed excitation is converted to an electrical charge which is harvested by the power components of the PCB  24 . 
     The cover  20  includes walls  39  that align with the plurality of excitation masses  24  when the cover  20  is coupled to the chassis body  18 . Each of the walls  39  are shaped similar to a shape of the excitation masses. For example, the excitation masses  24  as shown in  FIG.  2    are cylindrical-shaped; therefore, the walls  39  associated with each excitation mass are cylindrical shaped. Each wall  39  is circumferentially larger than a circumference of its associated excitation mass. The function of the walls  39  in the cover  20  is to restrict the excitation masses from displacing too far and damaging the piezo element. As a result, the excitation mass is limited to a predetermined distance that excitation mass is allowed to be displaced. 
     The PCB  26  includes a power conditioning PCB  40  and a processing PCB  42 . The power conditioning PCB  40  and the processing PCB  42  may be a single integrated PCB or may be two or more separate PCBs coupled by a communication medium  44  (e.g., ribbon cable) as illustrated. Two or more separate PCBs may be utilized due to a potential curvature of the chassis body  18 . Since the wheel itself is arcuate shaped, it is preferable that the sensor follow the contour of the mounting surface of the drop well on which it is mounted. If the monitoring sensor  10  is flat and the chassis body  18  is arcuate-shaped, the chassis body  18  may have issues seating within a designated seating location of the chassis body  18 . Therefore, by utilizing two separate PCBs  40  and  42  that are each smaller than half the length of the chassis body  18 , each PCB board may be properly seated within the chassis body  44  despite the chassis body  18  being partially arcuate shaped. If two or more PCBs are utilized, the communication cable  44  is used to communicably couple the PCBs. Alternatively, it should be understood that design alternatives may be made to the chassis body  18  to accommodate a single PCB board that contain the component for both the power conditioning and processing. 
     The power conditioning PCB  40  controls the energy generation and management of the monitoring device  10 . The powering conditioning PCB  40  includes power cells  46 , AC/DC converters  48 , a DC/DC converter  50 , and a power manager  52 . 
     The power cells  46  include an energy storage device including, but is not limited to, battery cells. Such battery cells may include lithium-ion battery which exhibits long life longevity. In addition, other types of batteries including rechargeable batteries may be utilized. Preferably, the power cells are rechargeable and are recharged by the energy harvesting of the piezo elements  22 . 
     The AC-to-DC converter  48  is used as a rectifier to convert energy captured by the piezo elements  22  by harvesting energy vibrations from the piezo elements  22 . As set forth earlier, energy harvesting utilizing the piezo elements  22  generates an electrical charge in the form of an alternating current (AC). The AC electrical charge obtained from the vibrations of the piezo elements  22  are rectified by the AC-to-DC converter  48  for producing a direct current (DC) which can be used to recharge the power cells  46  or possibly directly energize a component within the monitoring device  10 . 
     The DC-to-DC converter  50  is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. The DC-to-DC converter  50  steps up the power level for power consumption by the various devices on the processing PCB  42 . Moreover, the DC-to-DC converter  50  may include an inductive charging system where the vehicle&#39;s main power source may be used to inductively recharge the power cells  46  or directly power respective devices of the monitoring device  10 . 
     The power manager  52  is an integrated circuit such as a solid state device for managing power requirements by controlling the flow and direction of electrical power. The power manager  52  provides electronic power conversion and/or relevant power control functions. The power manager  52  is enabled to harvest energy from the piezo elements  22  when energy is available. The power manager  52  may further provide power controls such as voltage supervision and undervoltage protection as well as energy management, voltage regulation, charging functions, and dynamic voltage scaling with the use of the DC-to-DC converter  50  to allow dynamic voltage scaling. The power manager  52  may further provide energy in the form of pulse-frequency modulation (PFM) and pulse-width modulation (PWM). 
     The communication medium  44  electrically couples the power conditioning PCB  40  and the processing PCB  42  to provide power transfer and data transfer between components on the power conditioning PCB  40  and the processing PCB  42 . 
     The processing PCB  42  includes devices such as a central processing unit (CPU)  54 , amplifiers  56 , accelerometer  58 , temperature sensor  60 , and transceiver  62 . 
     The CPU  54  is an electronic circuit solid state device that carries out program instructions by performing the various functions including, but not limited to, mathematical functions, logical functions, controls and input/output (I/O) operations specified by its instructions in its operation code. The CPU receives sensing data from the various devices, identifies respective conditions based on the sensing data collected by the various devices and outputs control signals accordingly. 
     The amplifiers  56  allow different performance level options to be selected. The amplifiers  56  amplify the differential signals prior to being input to the analog-to-digital converter. 
     The accelerometer  58  measures accelerations of the vehicle and vehicle wheel. Accelerometers are utilized in inertial navigation systems as well as measuring vibration and shock on vehicles (e.g., impact, bumps, and pot holes). The accelerometer  58  may be used to further determine and monitor the camber of the wheels and rotations of the wheels which may assist in determining vehicle acceleration, direction, and speed. In addition to the accelerometer  58 , similar devices such as a gyrometer and magnetometer may be used to monitor the various conditions described herein. Furthermore, an inclinometer may be incorporated on the vehicle to determine the inclination of the vehicle. The inclinometer is mounted preferably on a bottom flat surface of the chassis of the vehicle. The sensed data by the inclinometer is transmitted to the monitoring device  10 . Given the incline data from the inclinometer along with the load data sensed by the monitoring device  10 , the monitoring device can determine a center of gravity of the vehicle which can be utilized for various stability control operations. 
     The temperature sensor  60  is used to measure temperature of the air within the tire which along with the pressure can be used to determine strategies for vehicle handling capabilities. 
     Other devices that may be mounted on the board include a board mounted pressure sensor for sensing a tire pressure. 
     The transceiver  62  is a device that includes a transmitter and a receiver sharing common circuitry within a same chip. The transceiver  62  transmits data processed by the CPU  54  to a receiving unit elsewhere in the vehicle for utilizing the data by one or more controllers for enabling various vehicle applications, which will be discussed in detail later. 
     The strain gauge  28 , sensor film, or similar is seated on a bottom inside surface of the chassis body  18 . The strain gauge  28  is used to monitor impact loads exerted on the wheel under both a dynamic condition and a static condition. Under a dynamic condition, the vehicle is moving and the strain gauge  28  measures load forces exerted on the wheel as the wheel rotates. The measured loads generate a sinusoidal signal. By measuring and recording the peak of the sinusoidal signal, the load can be determined based on the peak value recorded. 
     Under a static condition, the location of the monitoring sensor  10  is determined based on monitoring the rotation of the wheel using the accelerometer. Alternatively, a rotary potentiometer may be mounted on used by mounting the rotary potentiometer on either the wheel itself or inside of the monitoring sensor  10 . In a test stage, the wheel is rotated one degree at a time and predetermined loads are applied to the wheel. At each degree increment, the loads are recorded given the position of the monitoring device  10 . Once in production, the monitoring device&#39;s rotational position is identified via the accelerometer  58 . The CPU  54  maintains a lookup table or similar for correlating the strain gauge measurements at the respective positions. Based on the correlation data, a respective load is determined. 
     It should be understood that load data can be used in various ways. For example, a vehicle may be self monitoring for detecting when the load being carried by the vehicle exceeds a predetermined threshold (e.g., weight restrictions set forth by city, state, or federal regulations). In another example, a determination may be made whether the vehicle is front loaded, back loaded, or overloaded. In addition to warning the driver of such a condition, the suspension may be adaptively modified to compensate for the improper loading. Moreover, a different braking strategy may be applied based on the improper loading. In yet another example, in response to single wheel being improperly loaded, the suspension of the improperly loaded wheel may be adaptively adjusted to correct the improper loading of the single wheel. 
       FIGS.  4  and  5    illustrate a clamp load device used to house a clamp load sensor for determining a clamp load of a wheel. Clamp load occurs when a bolted joint (e.g., the wheel mounting system) tightly clamps two surfaces together. Friction of the two mated surfaces along with a force created from clamping the two surfaces together with bolts allows the surfaces to resist movement. As a result, the amount of friction and clamp load determines a level of resistance of the joint relative to movement. While the clamp load is created by tightening the bolts against the mated surfaces and is normally measured in foot pounds of torque, variations in the clamping of the surfaces caused by rust or lubrication on the threads can affect a clamp load versus a torque relationship. In addition, items disposed between the mated surfaces can reduce the joint&#39;s friction and also alter the relationship between clamp load and the torque. To determine a clamp load, a clamp load spacing device  64  is positioned between the wheel and the wheel hub. The clamp load spacing device  64  is arcuately shaped to align with a hub mounting plate of the wheel. The clamp load spacing device  64  includes apertures  66  (i.e., lug nut holes) that align with the lug nut holes of the wheel. The clamp load spacing device  64  may segregated into a plurality of sections as shown where each section is mounted between the wheel and the wheel hub for evenly spacing the wheel when mounted to the wheel hub. Alternatively, the clamp load spacing device  64  may be a single monolithic component formed in a complete circle. The advantage of utilizing a single monolithic spacing device would be for ease of assembly. Alternatively, utilizing separate spacing devices would reduce the service cost should a clamp load sensor need to be replaced, thereby only removing a section. 
     When the wheel is mounted to a wheel hub, a disk portion of the wheel which lug nut holes of the wheel are disposed is not entirely planar to the wheel hub. Rather, the disk portion is partially flared/conical shaped in a direction toward the wheel hub. As the wheel is mounted on the wheel hub and lug nuts are secured to the lug bolts, the disk portion deforms such that this portion is substantially planar to the wheel hub when the lug nuts are fully secured. As a result, the disk portion enters a loaded state when secured to the wheel hub. In contrast to actually sensing the torque of the lug nuts, a condition is sensed as to whether the disk portion becomes unloaded from its loaded state which indicates that the clamp load is decreasing. To detect a decrease in the clamp load which is indicative of the disk portion transitioning from its loaded state to an unloaded state, a strain or deflection sensor  68  is integrated within the clamp load spacing device  64 .  FIG.  5    illustrates the strain or deflection sensor  68  integrated within the clamp load spacing device  64 . The clamp load spacing device  64  may include a pocket  70  and associated channel  72  in which the sensor  68  and associated wiring is seated. Alternatively, the sensor  68  may be integrally formed as part of the clamp load spacing device  64  using various techniques, such as an over molding technique. 
       FIG.  6    illustrates the sensor  68  and overmolded clamp load spacing device  64  disposed on the hub mounting surface of the wheel. The sensor  68  includes a communication channel  76  that extends from the sensor  68  to an inductive charger unit  78  that is adhered to an inside side surface  74  of the wheel (i.e., near the drop well on the brake side of the wheel rim). The sensor  68  is preferably adhered to the inside side surface of the wheel by an adhesive, however, other processes may be used to fix the sensor to the wheel well. The deflection of the disc portion is monitored by the sensor  68  and is communicated to the monitoring device  10  by the inductive charger unit  70  which is disposed on the opposite wall of the drop well. The inductive charger unit  78  is powered by an electromagnetic induction scheme using contactless energy transfer. A primary induction coil located in the monitoring device  10  energizes a secondary induction coil located in the inductive charger unit  78 . The energy received in the secondary induction coil powers the sensor  68 . In addition, the inductive charger unit  78  allows message/data signals to be transmitted in both directions with the assistance of the electromagnetic induction. As a result, clamp load data is transmitted from the sensor  68  via the inductive charge unit  70  to the monitoring device  10 . 
       FIG.  7    illustrates a system diagram for vehicle applications utilizing the data obtained by the monitoring device  10 . The monitoring device  10  is retained on the vehicle wheel  12 . The monitoring device  10  includes the transceiver which communicates wirelessly with a communication unit  80  that is disposed within the vehicle but exterior of the vehicle wheel  12 . 
     The communication unit  80  is coupled to one or more controllers  82  via a communication bus  84 . Preferably, the communication bus  84  is a controller area network (CAN) which is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. Each controller  82  may be part of the vehicle subsystem or may be used to enable a vehicle subsystem for enabling a vehicle operation. Such subsystems may include braking control systems  84 , traction control system  86 , steering control systems  88 , speed control systems  90 , driver awareness systems  92 , and communication systems  94 . Various data such as vehicle load, vehicle clamp load, center of gravity, camber angle, steering angle, tire pressure, temperature) may be used individually or cooperatively to determine which control system should be enabled as well as the control strategy to be applied by one or more systems. Moreover, data from other sensors or controllers of the vehicle may be used in cooperation with data from the monitoring device  10  to determine control strategies and system enablement. 
     Braking control systems  84  may be applied autonomously by dynamically applying braking strategies given the sensed condition. Such control systems may include, but are not limited to, anti-lock braking system (ABS), electronic brake-force distribution (EBD), active anti-roll (AAR) system using braking, collision mitigation braking systems (CMBS). 
     Traction control systems  86  may provide a strategy that distributes power individually to each respective wheel to reduce wheel slip if loading is applied unequally to one or more wheels. 
     Steering control systems  88  may provide a steering strategy that may be used individually or in combination with braking to provide collision avoidance functionality based sensed data associated with the wheels. 
     Speed control systems  90  such as adaptive speed control can be enabled based on loading of the vehicle wheels where it is determined that excessive speeds may result in stability issues bases on the sensed loads. 
     Driver awareness systems  92  may be utilized to provide warnings to a driver of the vehicle concerning conditions such as improper loading or when a decrease in the clamp load is detected. Such warnings to the driver may include visual warnings, audible warnings, and haptic warnings. The device outputting the alert to the driver may be a vehicle based device or may be a non-vehicle based device (e.g., a smart phone, tablet, computer) 
     The communication system  94  may allow communication to and from the vehicle with another vehicle (V2V), another entity (V2X), or a cloud service. Such data communicated to a cloud service may include vehicle impact data that provides details about a road of travel. For example, carrier entities as well as vehicle insurance companies may utilize the impact data for determining a condition of a road. Carrier companies if hauling fragile goods may utilize the data in determining whether the road of travel is adequate for hauling certain types of goods. Insurance companies may provide recommendations to customers as to which road to avoid for preventing damage to a vehicle, such as a potential for bent wheels if pot holes are present. 
     The principle and mode of operation of this invention have been described in its various embodiments. However, it should be noted that this invention may be practiced otherwise than as specifically illustrated and described without departing from its scope.