Abstract:
A device for controlling and monitoring an electrical system of a vehicle and trailer while the vehicle and trailer are stationary or in motion.

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
       [0001]    This non-provisional patent application claims the priority to and the benefit of U.S. Provisional Application Ser. No. 62/013,354, filed Jun. 17, 2014, and entitled System for Controlling and Detecting the Integrity of an Electrical System in a Vehicle, the entire contents of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to the field of lighting systems for trucks, trailers, and other motor vehicles. 
         [0003]    Trailers that are hitched to, and towed behind, tractors, trucks, or other vehicles have electrical systems that typically include stop lights, turn signals, brake lights, exterior lights, interior lights, and/or other external electrical devices. These devices are often operated using controls at the interior of the vehicle towing the trailer. This may be accomplished electrically by coupling one or more electrical wires from the trailer to corresponding wires of the vehicle used to tow the trailer (e.g., via a plug and socket, such as a 7-way connector). Accordingly, by operating controls of the vehicle (e.g., a brake pedal, a turn signal switch, or another type of switch), a signal may be sent via one or more of the wires of the vehicle through the electrical coupling, and to the corresponding wire(s) of the trailer, thereby enabling the vehicle operator to effectively control circuits or devices of the trailer. 
         [0004]    One or more electrical devices in a trailer electrical system may fail for a number of reasons including voltages not being within adequate range to power an electrical device, electrical shorts in one or more external devices or in the electrical wiring, electrical opens caused, for example, by a loose or burned out bulb, loose wiring, corrosion and rust, etc. 
         [0005]    A driver/operator of a tractor towing a trailer may not be aware of deterioration of the truck or trailer electrical systems because the operator does not have a direct line-of-sight to many of the trailer&#39;s electrical devices (such as a trailer&#39;s lighting fixtures) from the cab of the tractor. This can create safety hazards due to inconsistent or non-existent power transmission to components of the trailer. Additionally, the operator of the truck may potentially receive a traffic citation for improperly working equipment. 
         [0006]    Currently used lighting/electrical signal testers may be plugged into a cord located at the back of a tractor to test various electrical circuits. For example, a tester may be plugged into a T-way connector coupled to the tractor&#39;s electrical system. The operator can then switch on the trailer&#39;s lights, for example, and the light tester will indicate whether or not there is a voltage at one or more pins of the electrical connector. However, commonly used circuit testers cannot be used when a tractor-trailer is in motion, as they require that the electrical system of the tractor be disconnected from the electrical system of the trailer. This is due to the hardwiring of the electrical system, which is constantly actively running. 
       SUMMARY 
       [0007]    Accordingly, to provide better monitoring of the various auxiliary devices coupled to a vehicle&#39;s electrical system, embodiments of the present invention control and monitor the various auxiliary devices, such as lights of the trailer&#39;s lighting system, individually. Embodiments of the invention may be built into the circuitry of the vehicle&#39;s electrical systems. Furthermore, embodiments of the invention may notify the operator of the tractor when a fault is detected in one or more auxiliary devices, and may identify which of the auxiliary devices is faulty. According to embodiments of the present invention, the identification of one or more faulty auxiliary devices may occur while the vehicle is in motion and/or when the vehicle is stopped. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The accompanying drawings, together with the specification, illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain aspects of embodiments of the present invention. In the drawings, like reference numerals are used throughout the figures to reference like features and components. The figures are not necessarily drawn to scale. The above and other features and aspects of the present invention will become more apparent by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which: 
           [0009]      FIG. 1  is a perspective view of a trailer employing an electrical control and monitoring system, according to some illustrative embodiments of the present invention; 
           [0010]      FIG. 2  is a schematic diagram of the electrical control and monitoring system of the embodiment shown in  FIG. 1  utilizing serially-coupled addressable nodes, according to some illustrative embodiments of the present invention; 
           [0011]      FIG. 3  is a schematic diagram of the electrical control and monitoring system of the embodiment shown in  FIG. 1  having external devices coupled in a hybrid serial-star formation, according to some illustrative embodiments of the present invention; 
           [0012]      FIG. 4  is a schematic diagram of an addressable node of the electrical control and monitoring system of the embodiment shown in  FIG. 1 , according to some illustrative embodiments of the present invention; and 
           [0013]      FIG. 5  is a schematic diagram of a control and monitoring unit interface of the electrical control and monitoring system, according to some illustrative embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]      FIG. 1  is a perspective view of a trailer  10  employing an electrical control and monitoring system  100 , according to some illustrative embodiments of the present invention. 
         [0015]    According to an embodiment of the present invention, the electrical control and monitoring system  100  includes a control and monitoring unit (CMU or a master device)  102 , one or more addressable nodes (henceforth, “nodes”)  120  including external devices (e.g. auxiliary devices), and a cable (e.g., multi-conductor cable or electrical harness)  110  for coupling the CMU  102  to the one or more nodes  120 . In an embodiment, the CMU  102  is configured to control the state (e.g., the on/off state) of each of the external devices and to monitor the status of each of the external devices to, for example, detect a fault condition at each of the external devices. External devices may include stop lights, turn signals, brake lights, exterior lights, interior lights, and/or other electrical devices external to the tractor, which may be attached to the trailer  10 . The CMU  102  may be located in the tractor or the trailer  10 . For example, the CMU  102  may be housed in the junction box  20 , which is a point of entry or egress of electrical connections to or out of the trailer  10 . In an example in which the CMU is inside the tractor, the CMU  102  may be coupled to the cable  110  on the trailer side via either the  7 -way connector  30  or a separate external cable  104 , which may be an extension of the cable  110  to the tractor. 
         [0016]    According to an embodiment, the one or more nodes  120  may be serially coupled to the CMU  102  through the cable  110 , which acts as a serial bus connection, and may be addressed individually through the use of unique identifiers (e.g., a digital address) assigned to each of the one or more nodes  120 . The CMU  102  may communicate with the one or more nodes  120  using a communication protocol, such as the serial peripheral interface (SPI) protocol, the programmable logic controller (PLC) protocol, the z-wire protocol, and/or the like. 
         [0017]      FIG. 2  is a schematic diagram of the electrical control and monitoring system  100 - 1  of the embodiment shown in  FIG. 1  utilizing serially-coupled addressable nodes  120 - 1 , according to some illustrative embodiments of the present invention. 
         [0018]    According to an embodiment of the present invention, there is a one-to-one correspondence between nodes  120 - 1  and external devices  130 , that is, each external device  130  may have a corresponding node  120 - 1  and unique node identifier (e.g., a unique digital address). Each node  120 - 1  is coupled to the same cable  110  and thus, the nodes  120 - 1  are serially coupled to the CMU  102 . 
         [0019]    In some embodiments, the cable  110  may include three or more conducting lines that are electrically coupled to each of the one or more nodes  120 - 1 . For example, the cable  110  may include a first power line (e.g., a ground voltage line)  112 , a second power line (e.g., a power voltage line)  114 , and a data line  116 . The first power line  112  may be electrically coupled to the electrical ground of the trailer  102 . The second power line  114  may supply the necessary voltage to power each of the one or more nodes  120 - 1  and/or the corresponding external devices  130 . In an embodiment, the data line  116  may be a bidirectional line that transmits signals from the CMU  102  to the addressable nodes  120 - 1  and transmits status signals from the nodes  120 - 1  to the CMU  102 . In another embodiment, the data line  116  includes two or more conductive lines for transmitting command and status signals to and from each of the one or more nodes  120 - 1 . The control signal may be a digital or analog signal and may include address data for identifying a target node  120 - 1 , and control data for passing one or more instructions to a target node  120 - 1 . 
         [0020]    According to an embodiment, the node  120 - 1  includes a microcontroller that is programmed with a unique identifier and is programmed to perform one or more processes based on the control signal, when the address data of the control signal matches the microcontroller&#39;s unique identifier. Each of the unique identifiers and the address data may be represented with one or more binary bits (e.g., a binary “0” or “1”). 
         [0021]      FIG. 3  is a schematic diagram of the electrical control and monitoring system of the embodiment shown in  FIG. 1  having external devices  130  coupled in a hybrid serial-star formation, according to some illustrative embodiments of the present invention. 
         [0022]    According to an embodiment of the present invention, the nodes  120 - 2  of the control and monitoring system  100 - 2  are serially coupled, however, each node  120 - 2  may be coupled to a plurality of corresponding external devices  130  (in a star formation), with each of the external devices  130  being associated with a unique device identifier (e.g., a unique digital address). Thus, the external devices  130  in the system  102 - 2  are coupled to the CMU  102  in a hybrid serial-star formation. 
         [0023]    In an embodiment, the node  120 - 2  is a microcontroller that is programmed to respond to the unique identifiers of each of the plurality of external devices  130  coupled to it in a star formation and is programmed to appropriately control a target external device  130  based on the control signal (e.g., the address data embedded in the control signal) received from the CMU  102 . The microcontroller may also be programmed to transmit back to the CMU  102  status signals related to the status of each of the plurality of external devices coupled to it with the appropriate address data embedded therein, so that the CMU  102  may identify which, if any, of the external devices has experienced a fault condition. 
         [0024]    In other respects, the electrical control and monitoring system  100 - 2  may be substantially similar to the system  100 - 1  described above with reference to the embodiments of  FIG. 2 . 
         [0025]      FIG. 4  is a schematic diagram of an addressable node  120 - 3  in the electrical control and monitoring system  100 - 3  of the embodiment shown in  FIG. 1 , according to some illustrative embodiments of the present invention. 
         [0026]    According to an embodiment of the present invention, the node  120 - 3  is a microcontroller including an input/output (I/O) block  122 , a central processing unit (CPU)  124 , a memory block  125 , a status monitor  128 , a switch  126 , and a switch controller  127 . The I/O block  122  may detect the address data embedded in a data signal from the CMU  102  and signals the CPU  124  if the address data matches the unique identifier of one of the one or more external devices (henceforth, the “target device”)  130  coupled to the node  120 - 3 . The CPU  124  then performs an appropriate function based on the control data embedded in the data signal and the instructions stored on the memory  125 . For example, the CPU  124  may signal the switch controller  127  to close or open the switch  126 , which controls current delivery from the second power line  114  to the target device  130  (and, e.g., turns on or off the target device  130 ). In another example, the CPU  124  may determine the status of the target device  130  by signaling the status monitor  128  to, for example, measure the current passing through the switch  126 , when the switch  126  is in a closed state. In an embodiment, if the measured current is below a lower threshold (e.g., if the current is substantially zero, as may be the case when there is an electrical open) or above an upper threshold (as may be the case if the target device  130  is shorted to ground), the CPU  124  generates (or the CPU  124  in tandem with the I/O block  122  generate) an appropriate status signal indicating a fault signal (and. e.g., the nature of the fault), which identifies the faulty device, to the CMU  102 . 
         [0027]    In an embodiment, the switch  126  may include a plurality of switches  126  each coupled to one of a plurality of external devices  130  coupled to the node  120 - 3 . The plurality of switches  126 . may be individually driven by one or more switch controllers  127 . 
         [0028]      FIG. 5  is a schematic diagram of a CMU interface  150  coupled to the CMU  102 , according to some illustrative embodiments of the present invention. 
         [0029]    According to an embodiment, the CMU interface (e.g., a master device interface)  150  includes a dedicated control switch (e.g., on/off switch or button)  160  and/or a dedicated status indicator light  170  for each of the external devices  130 , and/or a display screen  180 . The operator (e.g., driver) may be able to individually control (e.g., turn on or off) each of the external devices  130  by activating (e.g., toggling) the control switches  160 . 
         [0030]    In an embodiment, each status indicator light  170  indicates the status of a corresponding external device  130  at any given time, even when the truck is in operation and/or moving. For example, when an external device  130  is functioning normally (e.g., operating as designed), the corresponding status indicator light  170  may appear green, and when the external device  130  becomes faulty (e.g., if an external light goes out), the status indicator light  170  may turn red. However, the invention is not limited thereto, and the status indicator lights  170  may exhibit other modalities, such as, flashing on and off at predetermined frequencies, and/or displaying other colors, depending on the type of fault/error detected. 
         [0031]    The display screen  180  may provide further information regarding the status of the external devices  130  and any errors or faults that may have been detected. In one embodiment, upon detection of a fault, the CMU  102  may communicate (e.g., wirelessly communicate) with the carrier to determine the location of nearby truck stops, and may display the location of the nearest truck stop or repair shop on the display screen  180 .