Abstract:
A snow grooming device suitable for grooming ski hills, trails, or other snow park areas is provided with one or more of a series of improved electronic controls and/or instrumentation that can include track adjustment position control, tiller pressure control, ignition control and data collection, slope angle, halfpipe tool angle, tiller positioning, winch operational data, figure-8 counter, snow profiler, vehicle trace, and weather information. Depending on the particular result desired and the actual operating conditions, these controllers and instruments can be used independently or, in various combinations to improve the performance of the device, the efficiency of the snow grooming operation, the life of particular components, and the information available for the evaluation and tracking of slope condition.

Description:
[0001]    This application claims priority from U.S. provisional application 60/178,774 filed Jan. 28, 2000, the contents of which are incorporated herein by reference. 
     
    
     
       FIELD OF INVENTION  
         [0002]    This invention relates to snow grooming devices for snow areas and, more particularly, the invention is directed to control and instrumentation systems for snow grooming vehicles.  
         BACKGROUND OF THE INACTION  
         [0003]    At modern ski resorts, with increased skier traffic and the frequent need to accommodate a wide variety of ski terrain, skier skills, interests, and equipment, snow making and snow grooming have become essential operations at any successful ski center. Tracked vehicles are widely used in these operations, providing the propulsion and/or power for a number of snow grooming attachments including plows, tillers, and halfpipe tools.  
           [0004]    Generally, a tracked vehicle used in a grooming operation has a blade on the front for collecting snow from areas where there is too much and moving it to areas which are worn or require an excess of snow for the creation of particular snow profiles. The tracked vehicle may also include a tiller attached to the rear that breaks up ice chunks or other undesirable types of snow.  
           [0005]    Typical snow grooming vehicles use manually controlled and adjusted implements. Such manual control makes it difficult to obtain carefully groomed snow surfaces, especially surfaces that require special grooming techniques, have irregular terrain, or contain unmarked obstacles.  
           [0006]    One of the problems encountered by traditional snow grooming devices is slippage of the track that propels the vehicle. During grooming operations, it is preferable to reduce track slippage as much as possible as track slippage may damage or blemish the snow surface or formation the grooming operation is intended to produce. Current tracked vehicles rely on the operator to reduce track slippage by manually adjusting the speed of the tracked vehicle or manually adjusting the position of the wheels around which the track is arranged to adjust the track tension. Current tracked vehicles do not provide dynamic monitoring and control of track tension, nor do current tracked vehicles provide dynamic setting of a target track tension either automatically or by the operator.  
           [0007]    Other problems encountered during grooming relate to controlling the tiller. The tiller can be provided in a variety of configurations and employ a variety of control systems. One such tiller configuration, disclosed in U.S. patent application Ser. No. 60/172,157, which was filed on Dec. 17, 1999 and is incorporated herein by reference, includes a plurality of tiller subassemblies, each subassembly including at lease one tiller element, coupled with a control system for adjusting the relative orientation of the tiller subassemblies to provide automatic control of the tiller for safely maintaining a selected snow profile.  
           [0008]    Other variations to the tiller assembly itself have been used to provide greater control over the tiller performance. For example, the volume and configuration of the incorporated snow chamber may be varied during snow grooming operation according to the teachings of U.S. Pat. No. 5,067,263 to Pelletier, which is incorporated herein by reference. A flexible mat (or mats) having grooved finishing elements is generally provided at the rear of the tiller assembly to provide the final snow surface conditioning by smoothing or, alternatively, by providing a “corduroy” texture to the surface of the tilled snow. U.S. Pat. No. 5,067,263 does not disclose or suggest, however, dynamically providing information to the operator regarding the tiller chamber, pressure, position, and direction and dynamic control of the tiller chamber, pressure, position, and direction during grooming operations.  
           [0009]    U.S. Pat. No. 5,632,106 to Sinykin, which is herein incorporated by reference, discloses a tiller with an adjustable depth cutter and snow comb entry angle including an adjustable cover that directs the snow to the snow comb. The operator determines the till depth and time in response to snow conditions. U.S. Pat. No. 5,632,106 does not disclose or suggest dynamically providing information regarding the tiller pressure and direction to the operator and dynamically controlling the tiller pressure and direction during grooming operations.  
           [0010]    Current tiller assemblies also may include a relief valve that reduces the tiller pressure upon detection of a pressure exceeding a threshold value. The pressure must be manually re-increased or recharged, however, in the event that the tiller pressure is reduced. The operator must then discontinue the grooming operation to manually recharge the pressure.  
           [0011]    Determining the vehicle path and controlling the vehicle based on terrain are also problems experienced by operators of snow grooming vehicles. Typically, during grooming, the operator manually monitors and controls the tracked vehicle&#39;s path to maintain a desired grooming path or configuration relative to the grooming staring position. Current tracked vehicles do not include the ability to dynamically monitor and display the vehicle&#39;s tilt and roll angles relative to the starting position and the slope being groomed. Therefore, the skill of the operator is relied upon to control the vehicle to accurately groom the slope.  
           [0012]    In order to groom steep slopes, the tracked vehicle including a blade, a tiller, and/or other grooming device, may also include a winch and cable. The cable is attached to the top of the slope and guides and supports the tracked vehicle while it performs grooming operations along the slope. When the vehicle turns, the cable inherently twists. To avoid undue twisting of the cable, operators must remember to alternate turning and must be careful to alternately turn the tracked vehicle left and right in a figure-8 motion. Presently, the operator must device his own mental system to keep track of the number and direction of each left and right turn during the grooming operation If the operator fails to alternate correctly between the number of left and right turns, the cable will become twisted and may become damaged and possibly break.  
           [0013]    A further problem encountered during grooming is the lack of information about the surface. As snow depth varies and obstacles are often obscured by snow, it is difficult for an operator to adjust the grooming operation to account for variations in the surface condition. To accurately perform grooming operations, it is necessary to have accurate and complete information regarding the snow depth at each point of the snow area. The snow depth should be controlled by moving snow from areas where there is more than needed to perform the grooming operations to areas where there is less than needed to perform grooming operations, so that it is unnecessary to make snow.  
           [0014]    U.S. Pat. No. 5,761,095 to Warren discloses a system for monitoring the depth of snow that includes global positioning system and an initialization unit that generates ground surface data representative of the surface of the ground without snow and a snow surface data acquisition unit that generates snow surface data representative of the surface of the snow. The difference between the snow surface data and the ground surface data is then used to generate snow depth data representative of the area between the ground and snow surfaces.  
           [0015]    U.S. Pat. No. 5,761,095 does not disclose or suggest, however, dynamically collecting, displaying, and recording snow depth data during snow grooming operations, including displaying an instant snow depth corresponding to the tracked vehicle&#39;s location during a snow grooming operation and/or a snow depth history of the tracked vehicle&#39;s path during a snow grooming operation. In addition, U.S. Pat. No. 5,761,095 does not disclose or suggest dynamically displaying and recording a trace of the vehicle&#39;s path over a map of the snow area during a grooming operation so that an operator or even a base location can monitor the vehicles progress with respect to obstacles in the terrain.  
           [0016]    Problems encountered during grooming have also increased with respect to the special terrain features that many resorts now provide, especially snow boarding features. The popularity of snow boarding has caused many ski centers to form halfpipe ramps for snow board use. Currently, tools used to form halfpipe ramps are manually controlled by the operator. This is difficult when maneuvering on a slope, especially when the terrain or snow conditions are variable. Presently, there does not exist a control mechanism for a halfpipe tool that allows for dynamic monitoring and manipulation of the halfpipe tool during formation of the halfpipe ramp.  
           [0017]    At the present time, much of the actual operation of the snow grooming vehicle remains in the direct manual control of the operator who is provided with a limited amount of information regarding the conditions of the tools and terrain. Although many operators are quite skilled, their ability to create, accurately and efficiently, the desired snow conditions and profiles varies, limited in part by the complexity inherent in consistently coordinating the action of the various components and operations of the snow grooming vehicle and by the scope and format of information readily available to the operator. There remains, therefore, a need to provide more automated control and expand the scope and utility of information available to the operator and others.  
         SUMMARY OF THE INVENTION  
         [0018]    The invention provides a number of control and data collection/display features that can be incorporated into a vehicle for improving the snow grooming operation and aiding the operator in efficiently achieving the desired snow profiles.  
           [0019]    It is therefore an aspect of the invention to provide improved control over various facets of snow grooming operation.  
           [0020]    It is also an aspect of the invention to provide data having expanded scope and improved format available to the snow grooming operator to assist in the efficient operation of the vehicle.  
           [0021]    Another aspect of the invention provides an operator-specific data collection and interface system that controls certain aspects of the tiller operation and provides a means for data collection and transfer.  
           [0022]    The invention can also provide an operator-specific data collection and interface system that controls certain aspects of the track tension adjuster and provides a means for automatic and manual reduction of track slippage.  
           [0023]    Additionally, an operator-specific data collection and interface system can be provided that controls certain aspects of a halfpipe tool operation and provides a means for data collection and transfer.  
           [0024]    Another aspect of the invention provides an operator-specific data collection and interface system that controls certain aspects of the vehicle operation on sloped snow areas and provides a means for data collection and transfer.  
           [0025]    Further, the invention can provide an operator-specific data collection and interface system that controls certain aspects of a vehicle winch and vehicle operation during use of the winch and provides a means for data collection and transfer.  
           [0026]    The invention can also provide for an operator-specific data collection and interface system that controls certain aspects of snow depth data collection and display and provides a means for data collection and transfer.  
           [0027]    Also, an operator-specific data collection and interface system can be provided to control certain aspects of mapping the vehicle&#39;s path over a snow area, display the vehicle&#39;s A position and trace the vehicle&#39;s path over a map of the snow area and to provide a means for data collection and transfer.  
           [0028]    It is to be understood that the invention described herein can be varied in a number of ways and is not restricted to the particular embodiments described below, but generally includes any vehicle that incorporates one or more of the disclosed control or data collection elements to assist in snow grooming. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    The invention will be described in greater detail in conjunction with the following drawings wherein:  
         [0030]    [0030]FIG. 1 is a schematic of a vehicle including a track tension control system according to one embodiment of the invention;  
         [0031]    [0031]FIG. 2 is a schematic of vehicle including a tiller up-down position control system according to one embodiment of the invention;  
         [0032]    [0032]FIG. 3 is a schematic of a data and mapping collecting and transferring system according to one embodiment of the invention;  
         [0033]    FIGS.  4 ( a )- 4 ( c ) are representations of slope angle calculation and display systems according to one embodiment of the invention;  
         [0034]    FIGS.  5 ( a ) and  5 ( b ) are representations of a halfpipe tool angle calculation and display system according to one embodiment of the invention;  
         [0035]    FIGS.  6 ( a ) and  6 ( b ) are representations of a tiller information collection and display system according to one embodiment of the invention;  
         [0036]    FIGS.  7 ( a )- 7 ( c ) are representations of a Figure-8 counting, winch information collection and display system according to one embodiment of the invention;  
         [0037]    FIGS.  8 ( a ) and  8 ( b ) are representations of a weather information collection and display system according to one embodiment of the invention; and  
         [0038]    FIGS.  9 ( a ) and  9 ( b ) are representations of a snow depth information collection and display system according to one embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0039]    The system described herein is explained in conjunction with a tracked vehicle having snow grooming implements. The various systems are used to provide automatic and dynamic operation of the snow grooming implements and vehicle. It is understood that such systems could be used independently or in any number of combinations depending on the desired use. It is also understood that the various systems can be used on different vehicles and devices and is not limited to the tracked snow grooming device described herein.  
         [0040]    To provide an operator with information and dynamic automatically controlled functions, the following systems explained in detail below are provided in accordance with this invention. The device can be provided with the following functions: track slippage control; track tension adjustment control; tiller pressure control; a memory card and data module; slope angle control and display; half-pipe tool angle control and display; tiller control and display; figure-8 count and display; winch control and display; weather information collection and display; snow depth information collection and display, and, vehicle position trace control and display.  
         [0041]    These systems can be implemented by connection to the eating electronic system in a snow grooming vehicle or can be provided as separate components and connected to the vehicle in a manner as would be known by one of ordinary skill in the art.  
         [0042]    The systems are hereafter described separately in detail.  
         [0043]    Track Slippage Control  
         [0044]    Referring to FIG. 1, one of the parameters of particular concern during the operation of the vehicle  1  is track slippage, i.e., linear movement of the track  60  that exceeds the linear movement of the vehicle  1 . According to the invention, in addition to the automatic track tension adjustment control by the microcontroller  50 , the operator has the ability to reduce the track slippage manually by incrementing the track adjuster position.  
         [0045]    For instance, should the operator detect unacceptable track slippage, the operator can toggle a switch  70  to a “release position.” Each time the switch  70  is toggled, the target track adjuster position of the track adjuster  30  will be decreased by a predefined increment, typically less than one inch, to reduce the track tension and reduce track slippage.  
         [0046]    According to one embodiment of the invention, the presence of a track slippage condition will be automatically detected by using a combination of speed radar  80  and at least one track speed sensor  90 , which may be, for example, a motor speed sensor. Any difference between track speed and ground speed indicates that a track slippage condition exists and the measured speed values and the detected difference may be used to calculate a corresponding track slippage percentage that can be continuously or intermittently displayed to the operator.  
         [0047]    The calculated track slippage percentage can also be monitored by the microcontroller  50  and compared with a predetermined value so if excessive track slippage is detected, the track adjuster position can be adjusted automatically to reduce track slippage. The microcontroller  50  can also be configured to provide a visual and/or auditory alert to the operator that an excessive track slippage has been detected or is likely to occur unless corrective action is taken  
         [0048]    In a preferred embodiment of the invention, the vehicle tracks  60  include a large rubber band or belt with metal cross-links arranged around a plurality of aligned wheels  10 ,  11 ,  12 , and  20 . The track adjuster  30  may include a hydraulic cylinder installed between the two forwardmost wheels  10  and  20  on each side of the vehicle  1 . Extending the cylinder will move the front wheel  20  forward relative to the fixed position of the second wheel  10 , increasing the distance between the two wheels  10  and  20 . Increasing this distance results in a corresponding increase to the track tension Similarly, retracting the cylinder will move the front wheel  20  backward, bringing the wheels  10  and  20  closer together, thus reducing the track tension.  
         [0049]    The movement and position of the track adjuster cylinder is monitored and controlled by the microcontroller  50 . The target cylinder position is set in the microcontroller  50  using a potentiometer installed in the vehicle cab  160  as the operator input  40 . In response to the target position input and the detected track adjuster position, the microcontroller  50  will activate and adjust the appropriate hydraulic valves until a cylinder position sensor  35  indicates that the target position has been reached. The cylinder position is constantly monitored by the microcontroller  50 . If an external event shifts the position of the track adjuster  30 , the microcontroller  50  will automatically reposition the track adjuster  30  to reestablish the target position.  
         [0050]    In some instances, it may not be convenient or advisable to adjust the track adjuster target position (as set by the potentiometer of the operator input  40 ) during vehicle operation. To accommodate “on-the-fly” adjustments, the invention provides the switch  70 , installed, for example on the dashboard, to provide incremental adjustments of track tension. Depending on the conditions, the operator can toggle the switch  70  to adjust the track tension by incremental movements of the track adjuster  30 .  
         [0051]    If, for example, the operator wishes to reduce the track tension (as this would be desired in case of slippage), the operator would toggle the switch  70  to send a signal  71  to the microcontroller  50 . In response to the signal  71 , the microcontroller  50  will establish a new retracted target position for the track adjuster  30  and operate the appropriate hydraulic circuits and valves to automatically retract the cylinder of the track adjuster  30  to the new target position. Typically the increment of adjustment in the target track adjuster position would be less than one inch (approx. ¾″ or approx. 19 mm), but may be set as desired.  
         [0052]    When the vehicle  1  is climbing up a slope or working against a particular load, the track  60  will tend to slip. Track slippage is not desired because it can damage the snow surface as the track  60  churns and digs into the snow. One way to reduce the track slippage is to reduce the track tension. This reduction in track tension produces additional grip for the track  60 .  
         [0053]    In order to automatically improve the situation, an on-board computer  100 , installed in the vehicle cab  160  monitors the track slippage. This may be done by comparing the track speed (by sensing the motor speed using the motor speed sensor  90 ) with the actual speed (given by the speed radar  80  installed on the vehicle  1 ). Using these measured values, the on-board computer  100  can calculate a percentage of slippage. If the slippage percent exceeds a preset value, the on-board computer  100  will send a signal  110  to the microcontroller  50 . The microcontroller  50  will then retract the cylinder of the track adjuster  30  a predefined distance (approx. ¾″ or approx. 19 mm) to reduce the belt tension and reduce the track slippage.  
         [0054]    Track Tension Adjustment Control  
         [0055]    Track tension can also be adjusted. Referring to FIG. 1, the track tension on a vehicle  1 , for example a tracked snow grooming vehicle, is typically determined by the relative spacing of fixed and moveable components, for instance wheels, plates, or other track guides. According to one embodiment of the invention, the track tension is determined by the spacing between a fixed wheel  10  and a moveable wheel  20 . The position of the moveable wheel  20  is determined by the movement of a track adjuster  30 , such as a hydraulic piston assembly, over a known range of movement The operator can then input a target track adjuster position into an on-board microcontroller  50 . The operator inputs the target track adjuster position using an input  40 , for example, a potentiometer, a keyboard, a touchscreen, or a toggle switch, connected to the microcontroller  50 .  
         [0056]    Once the target track adjuster position is set, the microcontroller  50  monitors and automatically repositions the track adjuster  30  to maintain the target track adjuster position. If, for example, some external event causes a change in the track adjuster position, the microcontroller  50  automatically resets the track adjuster  30  to the target track adjuster position without further input from the operator.  
         [0057]    Up and Down Tiller Pressure Control  
         [0058]    Referring to FIG. 2, according to the invention, tiller pressure can also be controlled. A target pressure for a tiller  120  is set within a second microcontroller  51  using a second operator input  41 , for example, a potentiometer. In addition to the target pressure, the hydraulic system may include an electrically operated pressure relief valve  130 . Depending on the system capabilities, the release pressure may be set as a percentage above the target pressure, some predetermined increment above the target pressure, or at some predetermined pressure necessary to protect the system components.  
         [0059]    Regardless of how the release pressure is set, should an overpressure condition be detected, the microprocessor  51  will open the relief valve  130  to bleed off hydraulic fluid thereby bringing the system pressure back into the target range. Similarly, if the microcontroller  51  detects an underpressure condition, it will automatically operate the appropriate hydraulic circuits and/or valves to feed hydraulic fluid into the cylinders controlling a rear lift frame position to reestablish the target pressure. The microcontroller  51  will automatically maintain the target pressure and prevent overpressure conditions despite fluctuations resulting from external events acting on the tiller  120  or the vehicle  1 .  
         [0060]    The movement involved in controlling the tiller pressure is the up and down movement, depicted by the arrow Y in FIG. 2, of the vehicle rear lift frame (not shown). Moving the frame up tends to lift the tiller  120 , resulting in a corresponding reduction in the pressure the tiller  120  exerts against the snow pack. Similarly, lowering the rear lift frame tends to press the tiller  120  into the snow pack, resulting in a corresponding increase in the applied pressure. During the snow grooming work, depending on snow condition or desired snow finish, it may be useful to maintain a target pressure on the tiller  120 . Again based on the desired result, the target pressure could be reduced to prevent the tiller  120  from digging too deeply into the snow pack or increased to provide for deeper tilling action. These two conditions will be called respectively up pressure and down pressure.  
         [0061]    The second operator input  41 , in this embodiment a potentiometer, in the cab  160  allows the operator to indicate to the microcontroller  51  the target pressure. The microcontroller  51  will then set the current and/or voltage applied to the electrically operated relief valve  130  according to the potentiometer position to set the maximum target pressure. Once the relief valve  130  is set, its mechanical features will allow it to open at all pressures in excess of the target pressure.  
         [0062]    The microcontroller  51  monitors the actual pressure within the appropriate cylinders using one or more pressure sensors  140  installed at various points throughout in the hydraulic system. If the pressure is below the target pressure by a preset value, the microcontroller  51  activates a feed valve  150 , which will feed oil into the hydraulic system, thereby increasing the pressure until the target pressure is reached.  
         [0063]    This system will be activated according to the operation mode. The actual tiller direction and operation mode is controlled by a third microcontroller  52 . The operation mode is communicated to the second microcontroller  51  using a signal  111 , for example a digital signal.  
         [0064]    Memory Card and Data Module  
         [0065]    Referring to FIG. 3, a memory card  101 , for example, a PCMCIA card, can be provided for collecting and transferring operational data and mapping data This allows operational and mapping data to be carried from a base computer  500  to the on-board computer and on-board microcontrollers  50 - 59  of the vehicle  1 . Similarly, the memory card  101  allows operational and mapping data gathered during the operation of the vehicle I to be transferred from the vehicle  1  to the base computer  500 . The memory card  101  also identifies a particular operator and controls the operation of the vehicle  1 . For example, unless the operator number provided on the memory card  101  matches a number included on a validation list stored in the on-board computer  100 , the computer  100  will not allow the engine start system to be enabled.  
         [0066]    According to the present invention, the memory card  101  is a standard PCMCIA computer memory card. The on-board computer  100  in the vehicle  1  can access the memory card  101  through a data module  102 , for example a PCMCIA module. In the operator validation mode, a particular file containing the operator ID is saved to the memory card  101 . When the on-board computer  101  is turned ON, it sets a digital output to prevent engine cranking. It then reads the operator ID from the memory card  101 . If there is a file on the memory card  101  and it matches a number already registered in the on-board computer  100  as a valid operator number, the output is closed and the engine may be started.  
         [0067]    The on-board computer  100  may also be configured to save data to the memory card  101  periodically and/or upon the occurrence of a certain event or events. This data remains resident on the memory card  101  after it is removed from the on-board computer  100  and may be transferred to the base computer  500 , for example a desktop computer, or a server for review and analysis.  
         [0068]    Slope Angle Control and Display  
         [0069]    Referring to FIGS.  4 ( a )- 4 ( c ), slope angle control can also be provided, along with a display. Using a dual axis inclinometer  170  or a pair of single axis inclinometers  175 , a pair of signals  180  and  181 , for example 0-5V analog signals, corresponding to actual tilt and pitch angles  211  and  212 , respectively, of the vehicle  1  are received by a fourth microcontroller  53 . The inclinometers may be attached to the vehicle  1 , the tiller  120  or to a plow (blade) attached to the front of the vehicle  1 .  
         [0070]    The actual tilt and pitch angles  211  and  212  are graphically depicted on a display  200 , for example a touch screen display, connected to and controlled by the on-board computer  100 . Based on the signals  180  and  181 , the actual slope angle  213  is calculated and displayed to the operator on the display  200 , by selecting a tab  218 . In one embodiment, the operator can also set the present actual values of the tilt, pitch, and slope angles,  211 - 213 , respectively, as new zero references  214 - 216 , respectively, by selecting a reference (REF) button  217 . Activating this option allows the operator to monitor the differential pitch, tilt and slope angles, thereby improving the operator&#39;s ability to monitor the progress of the grooming operation relative to the starting position. The vehicle  1  or the grooming device may also be automatically controlled on the basis of the signals  180  and  181 , for example, to prevent the vehicle  1  or the grooming device from exceeding predetermined pitch, tilt, and slope angles.  
         [0071]    Half Pipe Tool Angle Control and Display  
         [0072]    Referring to FIGS.  5 ( a ) and  5 ( b ), according to the invention, an additional inclinometer  176  may be installed on a halfpipe tool (grinder) frame  220  (shown graphically depicted on the display  200  in FIG. 5( b )) pivotally connected to the vehicle  1 . This allows the operator to monitor the actual tilt and roll angles  231  and  232 , respectively, being worked during the formation of a halfpipe tool by selecting a tab  236 . The signal  182  from the additional inclinometer  176  also allows a fifth microcontroller  54  to calculate and display the differential angles  233  and  234 , respectively, between the halfpipe tool tilt and roll angles  231  and  232  and the vehicle tilt and roll angles  211  and  212 , which permits the halfpipe tool frame&#39;s position in reference to the vehicle  1  to be shown on the display  200 .  
         [0073]    The operator can set a target working angle and a tolerance  235 , by selecting a button  237 , that will be monitored by the microcontroller  54 . If the difference between halfpipe tool frame actual angle and the target working angle  235  is higher then tolerance, an alarm can be sounded, be flashed on the display  200 , and/or trigger a warning light. The signals  180 - 182  from the inclinometers  170 ,  175 , and  176  and the target working angles provided by the microcontrollers  53  and  54 , read from the memory card  101 , or input in some other fashion, can also be used to automatically control the positioning of the halfpipe tool frame  220 , either relative to the vehicle  1  or relative to a target slope.  
         [0074]    Further, as with the slope angle, the operator can also have the option of setting the present actual values of the tilt and roll angles  231  and  232  as new zero values, allowing the microcontroller  54  to calculate and display the differential tilt and roll angles  233  and  234  as the grooming operation progresses.  
         [0075]    Tiller Control and Display  
         [0076]    Referring to FIGS.  6 ( a ) and  6 ( b ), the invention also provides an operator with the ability to quickly ascertain various tiller parameters (chamber, lateral position, depth, etc.) displayed on display  200  during operation of the vehicle  1 , by selecting a tab  248 . A sixth microcontroller  55  collects and formats the information and provides the operator with a consolidated and simplified display  200 . The relative positions of the tiller components are detected using a transducer  240  in the various positioning cylinders and the pressures applied in various positioning cylinders are detected using a pressure sensor  241 .  
         [0077]    Each of these parameters is monitored and compared by the microcontroller  55  against target position and pressure values  246  and  247 . Each of the transducer  240  and the pressure sensor  241  provides a signal  242  and  243 , for example a 0-5V analog signal, to the on-board computer  100  through the microcontroller  55 . Each of the signals  242  and  243  can be calibrated so that the signals  242  and  243  received correspond to an actual position  244  and an actual pressure  245 , or other parameter. Using the signals  242  and  243 , the on-board computer  100  can also extrapolate the information to provide the operator more useful information. For example, by using the tiller oil pressure and the tiller rpm, the computer  100  can calculate the actual horsepower being consumed by the tiller  120 . Similarly, the on-board computer  100  can use the collected information to approximate fuel consumption.  
         [0078]    Figure-8 Count and Display  
         [0079]    Referring to FIGS.  7 ( a ) and  7 ( c ), in certain situations noted above in the background description, the vehicle I can be equipped to carry a winch and a length of cable. The cable is, in turn, anchored above that portion of the slope upon which the vehicle  1  will be operating. During typical winch dependent operations, the operator attempts to balance the number of right and left turns to avoid subjecting the cable to excessive winding or twisting (and the associated damage and decreased cable life). Balancing the turns results in a vehicle track resembling a “figure-8”  250  (as graphically depicted on display  200 ) across the snowfield.  
         [0080]    In this invention, the on-board computer  100  monitors the turns and upon selection of a tab  256  displays the differential  251  between right and left turns. Using this information, the operator can better balance the vehicle operation and increase the operating life of the cable.  
         [0081]    Two proximity sensors  260  and  261  are installed on the winch tower base (the point at which the end of the cable is fixed). The sensors  260  and  261  are wired to the on-board computer  100  through a seventh microcontroller  56 . A metal block, detectable by both sensors  260  and  261 , is installed on the moving part of the tower of the winch. If the on-board computer  100  detects the output  262  from the sensor  260  followed by the output  263  from sensor  261 , it will define the triggering motion as clockwise tower rotation. Similarly, if it detects the output  263  followed by the output  262 , it will define the triggering motion as counter-clockwise rotation.  
         [0082]    The computer  100  will kept track of these rotational inputs  262  and  263  and advise the operator as to the direction and number of turns necessary to return the cable to the desired untwisted condition. The figure-8 count may be reset by selecting a button  258 .  
         [0083]    Winch Control and Display  
         [0084]    Referring to FIGS.  7 (b) and  7 ( c ), an operator may also quickly ascertain various winch parameters, for example, winch pressure  252 , cable tension  253 , cable length remaining on drum  254 , cable age  255 , that are displayed on the display  200 . An eighth microcontroller  57  collects data from a pressure sensor  270 , a tension sensor  271 , a cable length sensor  272 , and a timer  273  and formats the data and provides the operator with a consolidated and simplified display  200  similar to that for the tiller control described above with respect to FIGS.  6 ( a ) and  6 ( b ). In the event the cable is replaced, the cable age may be reset by selecting a button  257 .  
         [0085]    Weather Information Collection and Display  
         [0086]    Referring to FIGS.  8 ( a ) and  8 ( b ), it is possible with this invention to provide dynamic weather information to the vehicle operator. Upon selection of a tab  284  the display  200  will show outside temperature  280 , wind direction  281  (with calculation considering the vehicle orientation), wind speed  282  (with calculation considering actual vehicle movement) and snow temperature  283  provided by a temperature sensor  290 , a wind direction sensor  291 , a wind speed sensor  292 , and a snow temperature sensor  293 , connected to a ninth microcontroller  58 . Wind speed and direction are calculated considering that the vehicle  1  is not a fixed weather station and calculations are required to compensate for the vehicle movement in order to provide the true wind speed and direction.  
         [0087]    A global positioning system (GPS)  294  is used to detect and provide a signal  294  corresponding to the actual vehicle orientation. It should be appreciated that an electronic compass could also be used. In either case, the on-board computer  100  uses the speed and directional information provided by the sensors  291  and  292  to normalize the measured weather information and provide the true conditions. The wind direction  281  and wind speed  282  displayed on the display  00  are the resulting direction and speed (vehicle+wind). Because the vehicle direction and speed are known, vector calculations will provide wind information.  
         [0088]    Snow Depth Information Collection and Display  
         [0089]    Referring to FIGS.  9 ( a ) and  9 ( b ), data indicative of the snow depth beneath the vehicle  1  may be monitored and collected in conjunction with the GPS signal  295  to generate a snow depth map. Upon selection of a tab  301 , the snow depth will be displayed on the display  200 . The preferred method of collecting this information is described in U.S. patent application Ser. No. 60/167,914, the contents of which are hereby incorporated by reference. The on-board computer  100  processes a signal  311  from ground penetrating radar (GPR)  310  through a tenth microcontroller  59  and provides the operator with a display of the underlying snow depth  320 .  
         [0090]    One possible representation of this information is illustrated in FIG. 9( b ). The operator will be provided with a scan  300  of the snow depth along the vehicle&#39;s path that is based on time, for example, by tang a new measurement every predetermined number of milliseconds. It should also be appreciated, however, that instead of a scan based on time, the GPS  294  may be used by selecting a tab  302  to genie a grid base to be displayed on the display  200 . The GPR  310  generates a signal  311 , for example a 0-5V analog signal, that is provided to the on-board computer  100 . The computer  100  processes the signal  311  and applies any necessary calibration or adjustment information to calculate the snow depth  320 .  
         [0091]    As shown in FIG. 9( b ), in the top right corner of the display  200  the snow depth  320  may be constantly displayed while below a scan  300  provides a graphical representation of the historical snow depth data. According to the operator&#39;s needs, the length of time or the depth scale range displayed can be adjusted manually or can be allowed to self-range in response to the snow depths being measured. The display  200  can also be provided with an alarm should the GPR  310  detect some anomaly, e.g. stumps or rocks above the ground-snow interface, or snow depths less than the minimum required for the safe operation of the tiller  120  as presently configured.  
         [0092]    Vehicle Trace Control and Display  
         [0093]    It is also possible to monitor the position and progress of the vehicle I during its progress throughout the snow area being processed. According to one embodiment of the invention, the display  200  shows the vehicle&#39;s present location and a trace as an overlay against stored map information, stored for example in the on-board computer  100  or the memory card  101 . Based on the GPS signal  295 , the on-board computer  100  will draw the actual passage of the vehicle I on the display  200 . While tracing the vehicle&#39;s passage on the display  200 , the computer  100  will also record the map of the passage. The recorded information can be associated with a slope number and transferred via the memory card  101  to the base computer  500 . The slope information can then be used to maintain a slope database that can be loaded via the memory card  101  into the on-board computer  100  of the vehicle  1  or other vehicles for use during future operations. The trace will then be on top of the slope map. This will allow the operator to locate the vehicle  1  more accurately with regard to the shape of the snowfield as it changes over the season Obstacle location can also be recorded. This information can then be used in future operations to inform the operators and avoid unnecessary damage to the vehicles.  
         [0094]    Although the invention has been described in relation to the various exemplary embodiments outlined above, it should be appreciated that many changes may occur to one of ordinary skill in the art without departing from the spirit of the invention. For example, the microcontrollers  50 - 59  may be provided as a single microcontroller, and the display  200  may be provided as a plurality of displays. Accordingly, the scope of the invention is defined by the claims appended hereto.