Abstract:
A wheel bolt torque monitoring system for a vehicle includes a torque sensor disposed at each bolt that is used to mount a wheel at a wheel mount of a vehicle. A transmitting device is disposed at the wheel mount of the vehicle, and the transmitting device receives data from the torque sensors at the wheel mounted at the wheel mount. The transmitting device transmits data to a control unit, which processes data received from the transmitting device to determine when a torque at a bolt is below a threshold torque level. Responsive to the control unit determining that a torque at a bolt is below the threshold torque level, the control unit generates an alert.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the filing benefits of U.S. provisional application Ser. No. 62/347,836, filed Jun. 9, 2016, which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a vehicle tire monitoring system. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known to monitor air pressure of the tires of the vehicle and to alert the driver when pressure in one or more tires falls below a threshold level. Examples of tire pressure monitoring systems are described in U.S. Pat. Nos. 6,445,287 and 6,294,989, which are hereby incorporated herein by reference herein in their entireties. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides a wheel bolt torque monitoring system that monitors the torque on the lug nuts or bolts that hold the wheels at the corner assemblies of a vehicle. When the system determines that one or more of the fasteners is getting loose, an alert is generated to alert the driver or occupant or service entity of a potentially hazardous condition. 
         [0005]    These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a plan view of a vehicle with a torque monitoring system in accordance with the present invention; 
           [0007]      FIG. 2  is a perspective view of a known torque sensor that senses torque at the head of a bolt; 
           [0008]      FIG. 3  is a sectional view of a wheel attached to a drum via bolts that are electrically connected to a transmitting device at the drum that communicates torque data to a processing unit in accordance with the present invention; 
           [0009]      FIG. 4  is a plan view of a vehicle with a torque monitoring system in accordance with an optional configuration of the present invention, shown with a smart phone  21  attached to or connected to or in communication with the processing and control unit (PU)  16  that is wirelessly connected with the sending electronic devices  14 ; and 
           [0010]      FIG. 5  is a chart of a tire bolt torque monitored by the system of the present invention, showing that torque loosening quotients may increase over time and, as indicated, the system may output four (or more or less) alerts or warnings with increasing severity of bolt torque loss over time, with the system generating the warnings via displaying text alerts such as shown in  FIG. 5  and/or via audible alerts. 
       
    
    
     LEGEND 
       [0000]    
       
         
           
               10  Vehicle 
               12  Torque Monitoring System 
               14  Sending Electronics Device (ED) 
               16  Central Receiving, Processing and Control Unit (PU) 
               18  Display Device 
               20  Interior Rearview Mirror Assembly 
               21  Non-Vehicle Inherent Aftermarket Unit or Smart Phone 
               22  Tire&#39;s Rim 
               24  Wheel Bolt 
               26  Electrical Interface 
               28  Drum 
               30  Receiving and Processing Unit (PU) 
           
         
       
     
       DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    Referring now to the drawings and the illustrative embodiments depicted therein, a vehicle  10  includes a torque monitoring system  12  that includes a plurality of torque sensors (such as a torque sensor at each of at least four bolts at each wheel) and a transmitter or sending device  14  at the wheels of the vehicle ( FIG. 1 ). The sensors monitor the torque at the wheel bolts and the transmitter  14  transmits data or information to a control  16  of the system. Responsive to a determination of a torque falling below a threshold torque level, the control may generate an alert to the driver of the vehicle, such as at a display  18  at a mirror assembly  20  of the vehicle. 
         [0024]    For implementing a vehicle tire bolt (or wheel bolt) monitoring system (similar to tire pressure monitoring system, but for monitoring the tire bolts instead of the tire pressure) for preventing loose bolts or losing bolts (causing loose wheels/tires or losing wheels/tires) the mounting torque of several or all of the bolts of the vehicle&#39;s wheels may be monitored by using torque measuring tire bolts. Different from bolts of ConSenses (from which the PiezoBolts of  FIG. 2  are commercially available for industrial use, which have integrated torque measuring capabilities), the electrical interface  26  of a tire bolt  24  according the present invention may not be at the head but at the screw far end side. The electrical interface may conduct to a counter plug embedded at the end of the thread of the wheel drum  28  (or wheel saddle or corner assembly) that the bolts gets screwed or threaded into. The bolts&#39; electrical interfaces may be conducted to a processing and data sending electronics device (ED)  14  at the wheel drum or corner assembly. 
         [0025]    Each wheel may include a respective data sending electronics device. The data sending electronics devices may send the status of the torque of the bolts of each wheel to a central receiving, processing and control unit (PU)  16  wirelessly (via Bluetooth, WiFi, NTSC, or such standards). The processing unit  16  may be connected to a communication or network bus (such as a CAN bus or the like) of the vehicle or other physical data line or vehicle bus (non-wirelessly). The processing unit may be vehicle inherent (such as already existing in the vehicle for other purposes). Optionally, there may be an extra aftermarket unit or smart phone  21  attached to or connected to or in communication with the vehicle, preferably via the PU  16  as shown in  FIG. 4 , and having the wireless data communication capabilities for receiving the ED&#39;s data signals. Depending on the architecture, the signal processing may take place in the data sending electronics devices or in the processing unit or in a main processing system of the vehicle, preferably the processing is done centralized in the processing unit. The data processing may optionally take place fully on the optional aftermarket device or smart phone or partially on the optional aftermarket device or smart phone and partially on the vehicle inherent processing unit  16 . 
         [0026]    The processing unit may process whether a (one or more) bolt has reached a certain minimal torque when being mounted newly and may monitor whether a bolt is losing torque over a longer period of time or rapidly losing torque when in use. The system may optionally have algorithms to compensate for the torque sensor&#39;s temperature drift or tolerance band to prevent the system from providing false positive warnings to the driver. When the torque diminishes below a certain minimal torque or threshold torque, the system may generate an alarm or message which brings the malfunctioning bolt mounting to the vehicle driver&#39;s or owner&#39;s attention, who then may stop the vehicle to inspect the vehicle&#39;s wheel bolts. For example, for an autonomous vehicle, the system may generate an alert to the vehicle owner or service entity so the vehicle is brought in for service. If the torque is determined to be below an “urgent” low torque, the system may generate an output so the vehicle is autonomously driven to a service station or facility or is pulled over and stopped. 
         [0027]    The system may also monitor the ratio at which one or multiple tire bolts are losing torque. There may be thresholds of torque losing or loosening quotients (torque per hour or torque per mile) in percentage or calculated absolute values which may trigger warning levels of the severity of losing tire bolt torque, such as shown in the example of  FIG. 5 . As shown in  FIG. 5 , the system may prompt to the driver to “Enter a repair shop soon” or to “emergency stop” depending on the determined tire bolt torque status. 
         [0028]    The system thus can provide an alert that one or more bolts are at an improper torque level. Optionally, the system may generate an alert indicating that an under-torqued bolt has been determined, without any further information about the determined bolt location. Optionally, the system may generate an alert indicating that a particular wheel has an under-torqued bolt, or optionally, the system may generate an alert indicating the particular under-torqued bolt at a particular wheel. 
         [0029]    Optionally, the system according the invention may have means to detect whether the electrical interface is still connected to the tire bolt. This may happen by distinguishing the electrical resistance, where an open circuit may lead to a conclusion of a “lost bolt.” When the torque is essentially at zero but the electrical interface  26  (connector) still detects the presence of the bolt, the system according the invention may conclude that the tire is not fully fixed any more but “loose.” The system may prompt the appropriate alerts or warnings to the driver. 
         [0030]    The vehicle owner may be different from the driver. Optionally, the owner may be informed or alerted via a UMTS connection, optionally to his or her smartphone. The message or alarm or alert to the driver may be acoustic or audible, or haptic or visual, such as via a display device  18 . 
         [0031]    Clearly, having a loosening wheel or being unaware before losing a tire is a severe situation. By that the monitoring system may provide alarms or messages when a bolt has initially lost some (a defined amount of) torque but still has sufficient torque to retain the wheel and tire at the vehicle. 
         [0032]    A wheel bolt loses torque mostly due to under or over torqueing the bolt when the wheel and tire are mounted at the vehicle. When under-torqued, the bolt can turn when vibrating, so this may occur when the vehicle is driven. When over-torqued, the bolt&#39;s or wheel drum&#39;s threads can become damaged, stretched or cracked. Then it may appear that the bolt slips one thread under changing load while the vehicle is driven. 
         [0033]    The system of the present invention may employ algorithms to detect the initial torque on each wheel bolt, to filter long time or short time dips of the bolt&#39;s torque and to filter or process diminishing characteristics which may isolate the cause of losing torque, optionally repeatedly (after manually re-torqueing), on the same or several bolts to advise the driver or vehicle owner or vehicle service whether a bolt or drum thread is damaged. Expert details may be stored in an On Board Diagnostics (OBD) interface that is readable by a technician at a vehicle service station. 
         [0034]    As an alternative to the interface solution above, each wheel bolt may have a wireless interface (itself) at its end instead of having a plug, such as a RFID interface, which is advantageous in terms of dirt. Plug connectors may tend to fail due to dirt while a RFID interface can be done as a closed housing, by that being comparably robust against dirt or contamination. The RFID-bolts may transmit to the processing unit directly or its data may be received by the electronics device  14  and forwarded to the processing unit  16  by the electronics device  14 . 
         [0035]    The system may also communicate between components via any suitable wired or wireless communication means. Optionally, the system may communicate with other systems, such as via a vehicle-to-vehicle communication system or a vehicle-to-infrastructure communication system or the like. Such car2car or vehicle to vehicle (V2V) and vehicle-to-infrastructure (car2X or V2X or V2I or 4G or 5G) technology provides for communication between vehicles and/or infrastructure based on information provided by one or more vehicles and/or information provided by a remote server or the like. Such vehicle communication systems may utilize aspects of the systems described in U.S. Pat. Nos. 6,690,268; 6,693,517 and/or 7,580,795, and/or U.S. Publication Nos. US-2014-0375476; US-2014-0218529; US-2013-0222592; US-2012-0218412; US-2012-0062743; US-2015-0251599; US-2015-0158499: US-2015-0124096; US-2015-0352953; US-2016-0036917 and/or US-2016-0210853, which are hereby incorporated herein by reference in their entireties. 
         [0036]    Optionally, vehicle dynamic control systems for emergency handling, such as of the types described in U.S. Publication No. US-2017-0144658, which is hereby incorporated herein by reference in its entirety, may take advantage of the tire bolt torque or tire loose or tire lost information to prepare for emergency handling or to control emergency steering interventions more properly. This is since the system can take the according wheel and the control system behavior of a loose or lost tire into account for its control (control behavior and parameter). Optionally, when the driver is carrying on driving despite human interface (HMI) prompts or alerts to stop, the vehicle dynamic control for emergency handling systems may substantially or massively reduce and limit (control) the driving speed automatically for the safety of the vehicle driver and occupants, and for the safety of other vehicles&#39; occupants and bystanders. 
         [0037]    Optionally, the vision system may include a display for displaying the alert or message and/or for displaying images captured by one or more vehicle cameras for viewing by the driver of the vehicle while the driver is normally operating the vehicle. Optionally, for example, the system may include a display device that may utilize aspects of the display systems described in U.S. Pat. Nos. 5,530,240; 6,329,925; 7,855,755; 7,626,749; 7,581,859; 7,446,650; 7,338,177; 7,274,501; 7,255,451; 7,195,381; 7,184,190; 5,668,663; 5,724,187; 6,690,268; 7,370,983; 7,329,013; 7,308,341; 7,289,037; 7,249,860; 7,004,593; 4,546,551; 5,699,044; 4,953,305; 5,576,687; 5,632,092; 5,677,851; 5,708,410; 5,737,226; 5,802,727; 5,878,370; 6,087,953; 6,173,508; 6,222,460; 6,513,252 and/or 6,642,851, and/or U.S. Publication Nos. US-2012-0162427; US-2006-0050018 and/or US-2006-0061008, which are all hereby incorporated herein by reference in their entireties. 
         [0038]    Optionally, the display or displays and any associated user inputs may be associated with various accessories or systems, such as, for example, a tire pressure monitoring system or a passenger air bag status or a garage door opening system or a telematics system or any other accessory or system of the mirror assembly or of the vehicle or of an accessory module or console of the vehicle, such as an accessory module or console of the types described in U.S. Pat. Nos. 7,289,037; 6,877,888; 6,824,281; 6,690,268; 6,672,744; 6,386,742 and/or 6,124,886, and/or U.S. Publication No. US-2006-0050018, which are hereby incorporated herein by reference in their entireties. 
         [0039]    Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.