Abstract:
Described herein are devices and techniques for automating vehicle mounted spreading systems such as deicing systems for winter road maintenance vehicles and/or agricultural spreading systems by use of an electronic control system configured to operate a distribution element drive system.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Provisional U.S. Patent Application Ser. No. 61/857,017 filed on Jul. 22, 2013, and Provisional U.S. Patent Application Ser. No. 61/726,207 filed on Nov. 14, 2012, both of which are fully incorporated by reference herein for all purposes. This application is also a continuation in part of the following U.S. patent application Ser. No. 14/080,142 entitled “Automated Control of Spreading Systems”, filed on Nov. 14, 2013, the entirety of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The spreader system, road maintenance equipment, monitoring equipment and methods (“Technology”) described herein, encompass a series of innovations that are aimed at increasing the efficiency of the winter road maintenance industry, improving operational efficiencies, saving money, increasing safety and reducing the impact of chloride on the environment (and infrastructure). 
         [0003]    In the parts of the world that receive various amounts of snow fall each winter, keeping roads clear of ice and snow is a necessity. This is typically achieved by plowing roadways and then spreading deicing and/or abrasive aggregate on road surfaces with spreaders. Chloride based deicers typically come in two different forms, granulated and liquid. Granulated forms (usually chloride based) are typically spread using conveyor type conveyance systems. Liquid based deicers are also used in winter road maintenance operations. Liquid deicers are typically held in liquid storage tanks and use liquid pumps to spray the road ways with brine liquids before winter events occur in order to coat the roadway with a brine solution, thus reducing the ability for ice to form on the road surface. 
         [0004]    There are a large assortment of spreader and spreader controller manufacturers on the market. Existing Spreader Controllers rely on wired connections for connectivity to sensory devices throughout the truck for feedback on system function. These systems are typically controlled manually by the driver, set at a single speed or calibrated for various speeds of the vehicle through a velocity controlled system. Like spreader controllers, plow controller sensors also rely on hardwiring for feedback on plow function. 
         [0005]    According to best management practices in the winter road maintenance industry (for example), certain spread rates should be prescribed for different temperatures and environments. Some spreader controllers take variations in temperature (and environment) into account through the use of externally wired sensors enabling the detection of changes in temperature and in the environment. 
         [0006]    Chloride based deicers are the most widely used of the deicers because of their availability and low cost, however their use has long lasting negative impacts on the areas in which they are used. Such deicers negatively impact at least the following: drinking water quality, aquatic ecosystems, and infrastructure (bridges in particular). 
         [0007]    Winter road maintainers (and plow truck operators in particular) have the propensity to overuse aggregates, this is largely due to the fact that they need to manage many different aspects of the plowing operation concurrently (controlling multiple plow controls, controlling the spreader, driving in tedious driving conditions, navigating traffic, communicating with their supervisor and typically working very long hours). While dispensing material during a winter event, it can be difficult to see where material has been applied, and when in doubt, maintainers typically choose to apply material rather than not applying material (often reapplying it redundantly). The winter road maintenance industry is in need of new technologies that can assist the winter road maintainers in applying deicer and abrasives in the most efficient manner. Furthermore, the installation of wired sensory systems on the maintenance vehicles can be tedious and expensive. 
         [0008]    In addition to driving the vehicle on which a spreading system is mounted, the operators of such systems are typically relied on for activation and volumetric control of the spreader, which commonly results in excessive use of aggregate. Excessive use of material usually is caused by: utilizing open loop control systems, fear of not applying enough material and overcompensating and overlapping (or redundant applications within short time periods). 
         [0009]    Winter road maintenance operations can offer very corrosive and tough environments that tend to damage electrical wiring and connections. Also, many municipalities are slow to adopt new and advantageous technologies because of the lack of technical man-power needed to install and maintain them, especially for hardwired or hardware based systems. 
         [0010]    Furthermore, even absent the operator&#39;s other responsibilities, because the operator is generally responsible for using manual throttling controls for activation and volumetric control of the spreading system (e.g., to increase or decrease application rates), it can be very difficult for the operator to provide precise, efficient, optimized application of deicing material. This problem is compounded in systems without mass flow feedback and/or systems with coarse application rate controls. 
         [0011]    The ability to maintain winter roads with an easily-integrated automated spreading system may allow the maintainer to focus on other aspects of the operation and enable material to be spread, for example, based on the trucks location and historical spreading information while using materials in the most economical fashion, thus contributing to safer and more sustainable winter road maintenance. 
         [0012]    A need therefore exists for easy-to-integrate systems and methods of monitoring and automatically dispensing aggregate in order to avoid waste and optimize (winter) road maintenance operations. A system that is easy to integrate into existing vehicles with minimal or no modification to the vehicle would decrease the cost, time, and skill-level required to integrate the monitoring system. Such a system would allow municipalities, for example, with tight budgets to keep their existing vehicle fleet while retrofitting a control system to monitor and control a vehicle&#39;s operations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention. 
           [0014]      FIG. 1  is a schematic illustrating a plurality of mobile vehicles having sensors in wireless communication with a database in the cloud which in turn communicates wirelessly with a mobile device. 
           [0015]      FIG. 2  illustrates typical components comprising a wireless sensor. 
           [0016]      FIG. 3  illustrates a schematic of a wireless system for monitoring equipment on a road maintenance truck. 
           [0017]      FIG. 4  illustrates a schematic of a wireless system for monitoring and controlling spreading equipment on a road maintenance truck. 
           [0018]      FIG. 5  illustrates a schematic of a wireless system for monitoring and controlling plowing equipment on a road maintenance truck. 
           [0019]      FIG. 6  illustrates a schematic of a wireless system for monitoring local weather conditions at a vehicle. 
           [0020]      FIG. 7  illustrates a schematic of a wireless system for monitoring weather conditions at a vehicle and automated wireless control of a spreader system based on observed local conditions. 
           [0021]      FIG. 8  illustrates a schematic of a wireless system for monitoring wearable wireless sensor information through a wireless hub, communicating maintenance equipment function at a maintenance vehicle wirelessly to the operator for the control and regulation of maintenance equipment. 
           [0022]      FIG. 9  illustrates a schematic of a wireless system for monitoring wearable wireless sensory information, and communicating maintenance equipment function at a maintenance vehicle wirelessly to the operator for the control and regulation of maintenance equipment. 
           [0023]      FIG. 10  illustrates a schematic of a wireless system for monitoring system and operator information through multiple wireless hubs for the control and regulation of maintenance equipment. 
           [0024]      FIG. 11  illustrates a schematic of a wireless system for monitoring the status of critical switches for the control of maintenance equipment using current sensing and wireless communications for operational monitoring. 
           [0025]      FIG. 12  illustrates a schematic of a wireless system for monitoring the status of critical switches for the control of maintenance equipment using current sensing and wireless Bluetooth (or other forms of wireless) communications for operational monitoring. 
           [0026]      FIG. 13  illustrates a schematic of a wireless system for monitoring wireless sensory information at various locations onboard a vehicle, and communicating maintenance equipment function at a maintenance vehicle wirelessly to a mobile device to communicate information to the operator and for the control of maintenance equipment. 
           [0027]      FIG. 14  illustrates the location, onboard a vehicle, of a wireless rotational rate sensor for sensing the rotation of a conveyance system. 
           [0028]      FIG. 15A  illustrates another view of the mounting location of a wireless rotational rate sensor for retrofit mounting on a winter road maintenance vehicle. 
           [0029]      FIG. 15B  illustrates an example of a mounting configuration for a wireless rotational rate sensor. 
           [0030]      FIG. 15C  is a more detailed view of an embodiment of a wireless rotational rate sensor that is mounted to a conveyor shaft. 
           [0031]      FIG. 15D  is an exploded view showing the electronic components inside of a wireless rotational rate sensor that is mounted to a conveyor. 
           [0032]      FIG. 16  is a detailed view of the rear of a spreader hopper illustrating one embodiment of an angle measurement sensor. The angle measurement sensor is shown mounted at one end to the hopper and at the other end to the gate. 
           [0033]      FIG. 17  illustrates an embodiment of a rear view of a gate showing a wireless angle sensor and the associated mounting configuration. 
           [0034]      FIG. 18A  illustrates a rear view of a gate showing a wireless angle sensor and the angle created when the gate is at first gate height setting. 
           [0035]      FIG. 18B  illustrates rear view of a wireless angle sensor and the angle created when the gate is in an alternative position. 
           [0036]      FIG. 19A  illustrates a rear view of a gate showing a wireless angle sensor and the angle created when the gate is at first gate height setting along with a reference angle measurement sensor. 
           [0037]      FIG. 19B  illustrates a rear view of a gate showing a wireless angle sensor and the angle created when the gate is at an alternative gate height setting along with a reference angle measurement sensor. 
           [0038]      FIG. 19C  is a perspective view of a gate showing a wireless angle sensor and the angle created when the gate is at an alternative gate height setting along with a reference angle measurement sensor. 
           [0039]      FIG. 20  illustrates a detailed view of a wireless angle sensor mounted on a plow frame for measuring the orientation of the plow. 
           [0040]      FIG. 21A  illustrates an example of an angle created when the plow is lifted up. 
           [0041]      FIG. 21B  illustrates an example of an angle created when the plow is in a down configuration. 
           [0042]      FIG. 22  is a schematic of a wireless sensor for measuring the status of electrical switches communicating wirelessly to a mobile device. 
           [0043]      FIG. 23  is an exploded view of an embodiment of a retrofitted wireless rotational rate sensor attached to the axle shaft of a material spreader. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]    Several embodiments of the present invention are described in the following detailed description with references to  FIGS. 1-23 . Other embodiments may be used and may incorporate changes in structural, logical, software, and hardware elements; such changes may be made without departing from the scope of the present invention. For simplicity, the embodiments of this invention are described with reference to a winter road maintenance vehicle. However, it is within the scope of this invention that the vehicle may be any utility vehicle, for example, a vehicle for use in farming or affecting on or off-road landscapes. 
         [0045]    The present embodiments teach systems that use wireless sensors that wirelessly connect to mobile devices (or other types of computers) using, but not limited to, Bluetooth (and BLE Bluetooth low energy), wifi, ZigBee, and other types of radio communicators to communicate sensor device(s) to mobile device(s). 
         [0046]    Road maintenance operations may be significantly optimized through the use of mobile devices along with wireless sensors capable of communicating these mobile devices (and or computer) for several reasons.
       a) Mobile devices are increasingly common and will continue to be at the leading edge of technological advancement.   b) The ability to quickly and easily mount sensors throughout a vehicular system is appealing, in contrast to the difficulty in connecting and routing wired sensors throughout a vehicle.   c) The combination of sensors and mobile devices (connected to the World Wide Web) allows for the collection, storage, and analysis of stored or real-time data.       
 
         [0050]    A system connected to the World Wide Web capable of receiving real-time fleet data and also capable of providing real-time fleet data to the vehicle operator will not only help the operator make more informed decisions but will also provide real-time insight to managers of the operation. 
         [0051]    Now with reference to  FIG. 1 , it can be seen how information flow may function using wireless sensors with mobile devices in certain embodiments. In  FIGS. 1 :  1   a ,  1   b ,  1   c ,  1   d ,  1   e , and  5  all represent mobile devices communicating information (flow indicated by the arrows) gathered from wireless sensors and transmitted to a cloud computer  9  communicating with the mobile devices, wherein  1   a  through  1   e  represent vehicles equipped with wireless communication capabilities.  FIG. 1  also illustrates a more detailed schematic  1   e  of onboard wireless sensors on a vehicle gathering information and communicating the information wirelessly with a mobile device that may reside in the vehicle (additional detail provided throughout this disclosure). A cellular antenna  7  (or other type of antenna or dish) transmits wireless data to remote servers (as well as to other mobile devices). It will be understood by one skilled in the art that the “antenna”  7  may be any other current or future technology for relaying communications signals, such as a cellular antenna or satellite. Cloud based Servers, Software and Databases  9  which may be capable of collecting, storing, sorting and sharing information from mobile networks and devices, which may in-turn store, analyze, and relay the information to other servers or, for example, back to the vehicle fleet  1   a  through  1   e.    
         [0052]    In addition to using wireless devices to communicate to and from vehicles, wireless technology may also be used to communicate between devices within a vehicle. With reference to  FIG. 2  a schematic of a wireless device  11  is illustrated. The device, which may for example be a sensor attached to a mechanism on the vehicle comprises a power source  13 , an antenna  15 , a sensor  17 , and optionally a controller  19 . These device elements enable the device to communicate wirelessly with, for example, a mobile device in the passenger compartment of the vehicle. The information communicated therein, may be stored, analyzed, and/or relayed to any other device as illustrated in  FIG. 1 . 
         [0053]    The power source  13  illustrated in  FIG. 2  may be a storage device such as a battery. Additionally, the power source  13  may comprise a power generating device such as a dynamo, generator, or inertial power generator that takes advantage of a dynamic motion inherent in the vehicle, such as a drive shaft rotation, to generate energy (from kinetic energy) which can be used directly, thus obviating a battery, or used to charge a battery electrically attached to the sensor. The sensor  17  may be used to detect attributes of the vehicle such as the plow angle or the spread rate of material. 
         [0054]      FIG. 3  illustrates an example of wireless sensors incorporated into a winter road maintenance operation. With regard to the Plow Function Sensor  21 , the mobile device  27  may receive information from wireless sensors which may include but are not be limited to: proximity sensors, optical sensors, switch sensors, angle sensors or other types of sensors to detect plow function (plow up and plow down for example). The Spreader Conveyor Speed sensor  23  may be mounted in such a way that it can monitor the actual speed at which the conveyance mechanism is operating. Conveyance speed sensing on a spreader may be achieved utilizing proximity sensors, optical sensors, angle sensors, rotation rate sensors, gravity or other types of sensors. In winter road maintenance operations, the gate height typically controls the amount of material that falls out of the hopper. As such, the Gate Height sensor  25  offers another application where a wireless sensor may be mounted to detect changes in height of the gate which may in turn be used to calculate quantities of material expelled. 
         [0055]    As illustrated in  FIG. 4 , additional system components can also be connected wirelessly to communicate with a mobile device  27  in order to improve a winter road maintenance operation (for example). Such additional components may include a wireless GPS antenna  29  for increased position system accuracy. For example, utilizing wireless communication to control the spreader control valve  31  via a conveyor speed sensor  23  may be achieved through the combination of an accurate positioning system and sensory feedback from wireless sensors throughout the vehicle. Additionally a mobile device  27  may be utilized to automate a spreader&#39;s hydraulic system based on location, spreading history and the specific environment the vehicle was transiting. Wireless capability may enable easier integration, easier installation, and more direct connection to the mobile device computer. Moreover, in certain embodiments the wireless communication may be “plug and play,” that is, a sensor may be added to a vehicle component, such as a spreader, and when the sensor device is activated the mobile device may automatically communicate with, or “see” the device and automatically configure the device for interaction with the software running on the mobile device. 
         [0056]    Additionally, or alternatively, each of the wireless sensors illustrated in  FIGS. 1-23  may contain components similar to those included in the embodiment of  FIG. 4 , but it is within the scope of this disclosure that the wireless sensors may have additional (fewer) or other components as well. 
         [0057]      FIG. 5  illustrates an embodiment that is similar to that in  FIG. 4 , however it includes the concept of controlling plow controls  33  wirelessly through a mobile device  27  based on the input data from the various wireless sensors, such GPS  29 , plow function  21 , conveyer speed  23 , and gate height  25 . The plow may be controlled concurrently with any other controlled devices such as the spreader ( FIG. 4 ) or it may be controlled individually and independently of any other devices. 
         [0058]    Road maintenance operations are greatly affected by weather conditions. Having the ability to remotely mount multiple weather sensors throughout a maintenance vehicle would be helpful in collecting data as well as in helping operators make better decisions in the field (and remotely) and in real-time.  FIG. 6  provides an example of an embodiment comprising sensors mounted to a mobile vehicle for measuring and recording information about the weather which may include but is not limited to: barometric pressure  35 , air temperature  37 , ground temperature  39 , ice detection  41 , thermal sensors  45  as well as optical sensors  43  (utilizing cameras etc.). 
         [0059]    Having real-time weather information wirelessly connected to a mobile device at the vehicle may allow a winter road maintenance system to automatically control equipment thus optimizing spreading quantities appropriately. Both air temperatures and ground temperature sensors may provide useful information to operators engaged in winter road maintenance. For example, when deicing roadways, best management practices suggest that winter road maintainers should apply less material if temperatures are warming and more material if temperatures are cooling and not to apply any material bellow certain temperatures. Also, winter road maintainers may find certain areas of the roadway that may require more material than others (frozen shadow areas, low lands, wind drifts, and bridges as examples).  FIG. 7  illustrates an embodiment comprising a number of sensors that may be utilized to observe present road and weather conditions at the vehicle; the sensors  35 ,  37 ,  39 ,  41 ,  43 , and  45  may be connected wirelessly to a mobile device  27 , which in turn may have the capability to electronically control the spreader&#39;s hydraulic valve  31  wirelessly from the mobile device. Furthermore, this embodiment may comprise sensors allowing it to regulate flow of material depending on the environment that the truck is transiting, for example whether the truck is transiting a typical road section or transiting an area of the road that may stay colder than other sections of roadway such as shadowy streets and bridges. 
         [0060]    With reference now to  FIG. 8 ; in certain scenarios the inclusion of a Wireless Sensor Hub  49  may be advantageous in the wireless system. The inclusion of a wireless sensor hub may be included in the system for numerous reasons including (but not limited to) extending the range of transmission/reception of sensor information and/or to increase the number of sensors able to communicate with a given mobile device.  FIG. 8  illustrates an embodiment wherein multiple sensors, for example optical sensors  43  or wearable sensors  51 , share a wireless hub which may enable wireless communication to a mobile device  27 . The mobile device  27  may process the information locally or remotely and adjust the control of the system shown using the E-valve  53 , in the embodiment. As an example, electronic valves (or E-Valves)  53  are typically utilized to regulate the hydraulic flow on hydraulic systems. In the case of winter road maintenance vehicles, the E-valve  53  may be used in controlling the hydraulics that controls the spreading system. 
         [0061]    When individuals are working long hours and operating heavy machinery it is important to make sure that they are awake and healthy enough to properly perform the operation. Wearable sensors can help to monitor the state of the driver and adjust the spreader controls appropriately.  FIG. 9  shows several examples of wearable sensors that may assist the operator in conducting maintenance operations. Wearable optical sensors  55  are capable of seeing both the perspective of the driver as well as monitoring the state of the drivers eyes and his blink status. This information may also be made available to the operator. Heart rate  57  and blood pressure  59  may also be monitored through wearable sensors. For example, monitoring health status of the operator while operating maintenance equipment may not only be helpful for collecting useful information, but may also be useful in monitoring alertness, assisting in the establishment and regulation of certain minimum alertness and health thresholds, or for controlling the operation of heavy equipment or accessories such as the spreader hydraulic valve  31 . 
         [0062]      FIG. 10  provides an example of how many sensors may be employed though the utilization of multiple wireless hubs  49   a  and  49   b  with the mobile device  27  for optimization and control of a spreading system, such as for example controlling an electric valve  53  which is typically used to regulate the hydraulic flow on hydraulic systems. These sensors may comprise environmental sensors such as, for example, barometric pressure  35 , ice detection  41 , temperature of the air  37  or ground  39 , and optical sensors  43 . In addition, the sensor array may include onboard sensors that detect various status&#39; and metrics on the vehicle such as plow function  21 , conveyor speed  23 , gate height  25 , gutter broom state  104 , and angle of any structure on the vehicle  71 . Finally, the sensor array may comprise one or more sensors that detect an attribute of the driver such as wearable sensors  105 . 
         [0063]      FIG. 11  provides an example of a current sensor  61  (or voltage sensor) integrated with a mobile device  27  using a wireless communication system (or control system). There are a wide array of switches and control panels on utility vehicles where the easiest way to detect the function of critical switches on a panel may be through the implementation of wireless current (or voltage) sensing retrofits capable of communicating the status of a switch wirelessly to a mobile device. A common application for monitoring the status of a critical switch would be in street sweeping operations, where there are limited areas on the exterior of the truck to mount retrofit sensors, making the voltage monitoring of critical switches a practical alternative for operational monitoring of equipment when integrated with mobile devices and wireless communication capability. The signal from the retrofitted sensor  61  may be transmitted to the mobile device  27  and processed along with the multitude of other signals depicting the status of various systems and devices in or on a vehicle. 
         [0064]      FIG. 12  provides another schematic example of how a current sensor  63  (or voltage sensor) can be retrofit to an existing control switch  65  for continuously communicating status wirelessly to a mobile device  27 . 
         [0065]      FIG. 13  depicts various sensors mounted at locations in and around a winter road maintenance vehicle. For example, a rotational rate sensor  67  may be affixed to an exposed end of the shaft  79  of a conveyor located on a material spreader; the shaft  79  typically being located either near the front or near the rear of the material spreader  106 .  69  depicts a gate height sensor that can be affixed to the rear of a material spreader&#39;s hopper  107  and can be capable of measuring adjustments to the height of the gate through angle measurements.  71  depicts the location of an angle measurement sensor for measuring the status of the plow  108  using angle measurements (e.g. plow “up” or plow “down”).  73  depicts switches to be monitored within the cab of the truck using wireless current sensing methods to communicate switch status to a mobile device within the cab. In addition, a mobile device  74  may be located in the passenger compartment for receiving wireless communication from sensors mounted throughout the vehicle. 
         [0066]      FIG. 14  depict the location where a rotational sensor  67  (see  FIGS. 15A-D ) may be mounted on a shaft  79  of a material spreader  106 . The sensor (not shown in this figure) may measure rate of rotation and/or absolute angle. The end of the exposed shaft indicated by  79  is a representative location where a rotation rate sensor may be retrofit as this type of shaft  79  arrangement with an exposed end is common in material spreader systems. Mounting in this manner requires that the sensor be wireless, and this mounting location on the shaft  79  provides for easy retrofits on a wide array of spreader types. 
         [0067]    An embodiment of a wireless rotational sensor is depicted in more detail in  FIGS. 15  A-D, which depict various components of a rotational rate sensor in perspective views.  FIG. 15A  depicts a perspective view of the shaft  79  that may be located at a rear end of a conveyer  106 .  FIG. 15B  depicts a rotational sensor  67  mounted to the end of the conveyor shaft  79 . Likewise,  FIG. 15C  provides another, more detailed, view of a rotational sensor  67  comprising a mounting back-plate  80  and a mounting bracket  78  for attaching the rotational sensor  67  to the shaft  79 . The bracket  78  may, for example, be welded, bonded, or bolted onto the end of the shaft  79  in order to mount the rotational rate sensor  67  allowing an easy retrofit for the rotational rate sensor  67  onto the exposed portion of spreader shaft  79 .  FIG. 15D  depicts a rotational rate sensor  67  in an exploded view at the mounting location of wherein a rotational rate sensor would attach to a typical shaft  79  of a material spreader. The rate sensor  67  comprises an electronics module  84  that may be located inside of the back-plate  80 , which is in turn attached to the conveyer shaft  79  via the mounting bracket  78 . 
         [0068]      FIG. 16  is a detail perspective view of the rear end of a material spreader hopper  107  comprising a gate  85  and a conveyer  106 , the gate being positioned open at a height indicated by the arrow h. An angle measurement sensor  82  is configured to measure both absolute gate height h and changes of gate height h on the rear end of the hopper  107 .  81  depicts a wireless angle sensor enabling retrofitting and consisting of a reach arm  83  mounted between the spreader/hopper  107  and the gate  85 ; the reach arm  83  changes its angle respectively with changes in gate height h. The distance that is measured is indicated by h; this opening allows more material to pass along conveyor when gate is in the raised position (increasing h). 
         [0069]      FIG. 17  illustrates one method for mounting an angle sensor  82  to the rear end of a hopper  107  wherein a mounting pin  89  is used with the wireless angle sensing measurement system  82 , in this case depicted on a raised gate.  89  depicts a set pin connection for the sensor  82  as mounted to the gate  85 , and  91  depicts a slot cut into the reach arm  83  or mounting hardware that the sensor is mounted to. As the gate  85  moves up and down, the set pin is able to travel up and down through the slot  91  corresponding to changes in the gate height h, freely altering the angle of the sensor  82  and resulting in different angle measurement readings from the wireless or wired sensor  81  as the sensor  82  pivots on a fixed, but rotatable point  109  on the hopper  107 . 
         [0070]      FIGS. 18A-B  illustrates the wireless angle measurement sensor in operation.  FIG. 18A  shows the gate in the lifted position resulting in a larger gate opening h 1 . As such, the wireless angle measurement sensor  81  orients at a significantly different angle a 1  (up position), than can be seen in  FIG. 18B  where the orientation of the wireless angle measurement sensor  81  is seen angled in the down position (angle a 2 ) and the gate height h 2  is observed as minimized. 
         [0071]      FIGS. 19A-C  illustrate a more detailed view of the wireless angle sensor  81  and the difference of the two angle measurement sensors between  FIGS. 19A and 19B  with different gate height settings. The figure also illustrates the implementation of a reference angle measurement sensor  97  mounted to measure changes in the truck&#39;s orientation on the roadway, in addition to the angle sensor  81  mounted to measure changes in gate height.  FIG. 19A  demonstrates the orientation of the angle sensor  81  when the gate is elevated to a raised position with a height h 1 , and  FIG. 19B  indicates the orientation of the angle sensor  81  when the gate is in the lowered position with a height h 2  the reference angle measurement sensor  97  measures the orientation of the truck on the roadway as a reference to the angle sensor system  82  mounted on the gate  85 .  FIG. 19C  further illustrates, in perspective view, one example of a method to mount the sensor system  82  to the rear of a spreader hopper  107  as well as to an adjustable gate  85  with the gate in the raised position h. 
         [0072]    Now with reference to  FIG. 20  which illustrates a potential location of a wireless angle measurement sensor in use on a plow  108  of a plow truck  100 . Typically, proximity sensors  99  are used throughout the industry to indicate whether a plow is up or down, but the use of an angle sensor may be more effective and more easily retrofitted, as indicated by  82  of  FIG. 20 . Thus, an angle sensor system  82  may be used in a similar manner as described elsewhere in this disclosure for gate height sensing (see  FIGS. 16-19 ). In the configuration illustrated in  FIG. 20 , however, the angle sensor system  82  may be pivotally attached on one end  109  to a fixed structure  110  in the front of a vehicle  100  and attached to a movable plow mechanism  103  at the opposite end of a reach arm  83 . 
         [0073]    Plow mechanisms may effectively be equipped with angle sensing to indicate the status of the plow in operational monitoring as shown schematically in  FIGS. 21A-B . In  FIG. 21A  that the plow  108  is up showing a distinct upward angle p 1  of the plow mechanism  103  and  FIG. 21B  shows the plow  108  oriented in a downward angle p 2  of the plow mechanism  103 , the angle of which may be measured as described elsewhere in this disclosure; see for example the angle sensor system  82  in  FIGS. 16-20 . 
         [0074]    With reference to  FIG. 22 , which schematically indicates how a voltage or current sensor  65  may be equipped to transmit the status of the voltage flow (or no flow) wirelessly to a mobile device  27  for indicating the status of critical switches  73 , which reside in the cabin of the vehicle, for operational monitoring. 
         [0075]    With reference to  FIG. 23 , an exemplar embodiment of a rotational rate sensor  67  that is capable of being retrofitted to a vehicle spreader shaft  79  is shown in an exploded view. The sensor  67  is comprised of a back-plate  80  and a front plate  90  that together house the sensor electronics module  84  and may be attached to each other through an array of bolts  92 . The electronics module  84  contains all of the devices required to sense and transmit the rotational rate, including a printed circuit board, rotational sensor, and a battery or other power source which, in general, would be known to one skilled in the art. 
         [0076]    The rotational rate sensor  67  may be retrofitted to the spreader/conveyer shaft in a variety of arrangements.  FIG. 23  illustrates one such arrangement in which two bolts  86  are threaded into the end of the spreader shaft  79  in order to capture and attach a mounting bracket  78 . The mounting bracket is, in turn, attached to the rotational rate sensor  67  via an array of bolts  88 . Thus, the only modification to the truck is the drilling and tapping of holes  111  in the shaft  79 . Furthermore, the sensor  67  may be attached to the shaft  79  via other methods such as, but not limited to, bonding, welding, or clamping. 
         [0077]    While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.