Abstract:
Golf cart movements at a golf course are controlled by a limited access controller that compares a golf cart&#39;s GPS-determined position against a limited access map to restrict performance of inputs by the golf cart&#39;s driver to the golf cart&#39;s motor under predetermined conditions, such as if a golf cart enters or has a predetermined likelihood of entering a limited access area. The limited access controller inhibits motor responses, such as by preventing motor operation, limiting available motor speeds, or allowing motor operation only in a vector that removes the golf cart from the limited access area, such as operation in reverse. Golf carts of a golf course communicate with a base station that updates the limited access map by defining limited access area perimeters and allowable actions within a limited access area and that directly commands allowable motor operations. For example, golf carts are prohibited from entering green areas, are restricted to golf cart paths during cart-path-only periods, and are restricted to reduced speeds in driving hazard areas.

Description:
RELATED APPLICATIONS 
     This application claims priority to and incorporates by reference U.S. Provisional Patent Application Ser. No. 60/440,894, entitled “Golf Cart Monitoring and Management System,” filed Jan. 17, 2003. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to the field of vehicle control, and more particularly to a method and system for control of a golf cart based on location of the golf cart. 
     2. Description of the Related Art 
     Golf course owners generally make a substantial financial investment in a golf course in order to develop and maintain the appearance and quality of play expected by golfers. A significant portion of the investment is made in the preparation and maintenance of golfing areas such as greens, fairways and golfing hazards. In addition to the financial investment made to develop and maintain golfing areas, a substantial investment is made in the time that it typically takes for grass and other greenery to grow and mature into acceptable playing surfaces. Another significant portion of the investment made in a golf course is the equipment and maintenance needed to keep a golf course operating on a daily basis, including the purchase and maintenance of golf carts for golfers to drive. Generally, golf courses protect the grounds and equipment with a marshal who keeps watch over golfers and attempts to ensure that golfers maintain a desired pace of play. However, golf courses are typically large areas with hills and foliage that makes a marshal&#39;s job difficult to accomplish. In a relatively short period of time, a thoughtless golfer can create considerable damage to sensitive golfing areas, such as greens, simply by driving a golf cart in the wrong place, such as locations having wet turf that is particularly susceptible to damage. Inattentive and even malicious golf cart drivers can cause even greater amounts of damage and also present a safety hazard by driving too fast or recklessly near other golfers or natural hazards, such as cliffs, water, steep inclines or sharp turns. 
     One solution that aids in the monitoring of golf course activity by a marshal is the use of golf carts equipped with positioning equipment, such as Global Positioning System (“GPS”) equipment. GPS positions of a golf cart are compared with a map of the golf course so that the golfer knows his position for play, such as distance from the green, and is given tips and instructions for more efficient play. GPS positions available at a golf cart can be used to inform a golf cart driver when the golf cart travels to an unauthorized location and may be stored for later analysis to identify the source of damage caused on a golf course by a golf cart. However, even if a marshal knows the location of a golf cart on a golf course and foresees the potential for damage to the golf course or injury to the golf cart driver, the marshal is unlikely to be close enough to the golf cart to preempt the damage or driving safety hazard. 
     SUMMARY OF THE INVENTION 
     Therefore a need has arisen for a method and system which applies a golf cart&#39;s GPS position on a golf course to preempt or otherwise reduce damage from golf cart movement. 
     A further need exists for a method and system which defines areas of a golf course to which golf carts have limited access imposed by restrictions on golf cart movements within or proximate to the limited access areas. 
     In accordance with the present invention, a method and system are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for managing and controlling golf cart movements on a golf course. A golf cart&#39;s position is compared with defined limited access areas of a golf course so that the golf cart&#39;s movements are restricted if the golf cart violates a limited access area. Golf cart movement restrictions are defined by golf cart position relative to a limited access area and other factors such as the type of limited access area, the golf cart type, golf course conditions, time of day, and defined access codes. Golf cart movement restrictions include a prohibition against any movement, a prohibition of movement in defined areas, a prohibition of movement in a defined gear, such as forward or reverse, and a limitation of golf cart speeds, such as a specific maximum speed. 
     More specifically, a limited access controller installed on a golf cart communicates with a GPS receiver and a limited access area map to analyze golf cart GPS or dead reckoning position and velocity information and impose restrictions on golf cart movement if a limited access area is violated. The limited access area controller interfaces with the golf cart motor controller to override driver inputs to the motor, such as overriding driver accelerator commands for a selected forward speed by imposing a reduced forward speed or prohibiting movement by switching off the motor current supply. The limited access controller communicates movement restrictions through a driver interface for display to the golf cart driver and through a wireless network to a base station for notice to golf course personnel. A limited access configuration module associated with the base station provides a graphical user interface for defining limited access areas and associated movement restrictions and for deploying selected limited access areas for activation on one or more golf carts through a wireless network. Limited access areas are selectively activated based on time of day and course conditions. The base station also displays golf cart position and status information and permits direct application of golf cart movement restrictions to one or more golf carts through the wireless network. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that a golf cart&#39;s GPS position on a golf course is applied to preempt damage to the golf course or injury to golfers from golf cart movement. The limited access controller automatically imposes restrictions on a golf cart&#39;s movement by overriding driver accelerator inputs to the golf cart motor if the golf cart is positioned to enter a limited access area, such as an area in which damage is likely to occur to the golf course or the risk of injury to a golfer is increased. The limitations imposed on a golf cart&#39;s movement are tailored to the type of golf cart, type of limited access area and the projected golf cart path based on GPS positioning or dead reckoning, and notice of golf cart movement restrictions are displayed to the golf cart&#39;s driver and communicated to golf course personnel. Thus, golf cart drivers are provided with ample opportunity to avoid limited access areas without substantial interference with a golf game or driver duties, and golf course management are provided with a convenient system for managing golf cart movement on a golf course that reduces incidents of damage, injury and theft, and also educates golfers on proper golf course procedures. 
     Another example of an important technical advantage of the present invention is the simplified definition and imposition of areas of a golf course to which golf carts have limited access enforced by restrictions on golf cart movements within or proximate to the limited access areas. A graphical user interface presents a map of the golf course for defining the perimeters of limited access areas and associating golf cart movement restrictions with the limited access areas. Active limited access areas are distributed to golf carts through a wireless network so that golf course management may adapt the limited access areas as golfing conditions change, including the type of restrictions, such as golf cart speed restrictions for an associated limited access area, the identity of limited access areas, such as transitions to and from golf cart path only conditions, or the golf carts to which restrictions apply, such as golf carts in use by golfers versus golf carts in use by golf course staff, such as the marshal, beverage distributors or utility workers and golf carts used by handicapped golfers who may need access by golf cart to limited access areas due to health concerns. Management of golf carts by GPS position, authorization codes and time of day decreases incidence of theft of golf carts during off hours and unauthorized golf course use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
         FIG. 1  depicts a functional block diagram of a golf cart having a limited access controller; 
         FIG. 2  depicts a functional block diagram of a golf course system for control of golf cart movement; 
         FIG. 3  depicts an example of a graphical user interface for configuring limited access areas of a golf course; and 
         FIG. 4  depicts an example of a graphical user interface for display of golf carts in play on a golf course. 
     
    
    
     DETAILED DESCRIPTION 
     Golf cart movements on a golf course are managed by defining limited access areas with associated golf cart movement restrictions. A golf cart&#39;s position is determined with a GPS receiver and compared with a limited access area map to determine if a limited access area has been entered or a violation is likely. Limited access area violations are managed by restricting movement of the golf cart to prevent or minimize the violations, or issuing visual and/or audible alerts to a golfer or to course personnel. For instance, driver inputs to command a desired speed from a golf cart motor are overridden, such as by preventing golf cart movement in one or more directions, above a defined speed or in a defined gear. Golf cart movement restrictions protect golf course features that are susceptible to damage, such as greens or even off-cart-path areas during wet weather. Golf cart movement restrictions also help to prevent injury to golfers and golf cart drivers by restricting maximum speeds during driving events susceptible to accidents, such as on steep grades, during sharp turns and in crowded areas. Comparisons between on-board position determinations and defined limited access area maps automatically restrict golf cart movements to preempt violations of limited access areas without intervention by golf course personnel. 
     Referring now to  FIG. 1 , a functional block diagram depicts a golf cart  10  in which movement of the golf cart in response to driver inputs is restricted if the movement violates a limited access area of the golf course. A limited access controller  12  determines limited access area violations by comparing golf cart position determined from a GPS receiver  14  with limited access areas defined in a limited access map  16 . Limited access map  16  stores limited access areas as geographic perimeters and golf cart movement restrictions associated with golf cart positions within the geographic perimeters. Typical limited access areas within a golf course are greens, tees, wet fairways, sand traps, water traps, areas in which driving a golf cart causes damage to the golf course grounds, and areas in which driving a golf cart presents a danger to the driver or others, such as sharp turns, steep hills and crowded parking areas. In some instances, limited access areas exclude substantial portions of a golf course from golf cart movements, such as when a course is wet and golf carts are limited to use on golf cart paths, and the extent of the limited access areas may change during the course of a day. The type of golf cart movement restrictions may vary for different limited access areas to include, for example, a prohibition of any movement, a limitation of movement to a reduced speed, or a limitation of movement in restricted directions, such as reverse. 
     One illustrative example of limited access areas and associated movement restrictions applied by limited access controller  12  is a golf green  18 , approach  20  and fairway  22 , and a prohibition against driving into the approach  20  or anywhere within the perimeter of golf green  18 . Movement by golf cart  10  is restricted if limited access controller  12  analyzes the position provided by GPS receiver  14 , or a dead reckoning position estimate based on the last GPS position, and determines that the likelihood of golf cart  10  entering a limited access area exceeds a given threshold. For instance, if the position provided by GPS receiver  14  matches a position within green  18 , the limited access area associated with green  18  is violated and movement by the golf cart is prevented to reduce the risk of damage to green  18 . In a situation in which a golf cart actually traverses a green, a complete shutdown of the golf cart may be warranted so that the golf course marshal may personally instruct the golf cart driver on golf course rules. 
     Ideally, however, movement of golf cart  10  is restricted before the golf cart position reaches the perimeter of green  18 . For instance, within a predetermined distance of green  18 , limited access controller  12  reduces the maximum available speed of golf cart  10  and notifies the driver with a message and/or audible alert if the projected path of golf cart  10  will traverse green  18  or approach  20 . The path of golf cart  10  is projected from a velocity vector derived by one or more of change of GPS position over time, dead reckoning and the speed selected by the driver. If the GPS position of golf cart  10  enters into approach  20 , the available speeds of golf cart  10  are restricted, such as to selections like reverse gear that will result in a velocity vector out of the approach without crossing into green  18 , and the driver is alerted to proceed from the limited access area in an appropriate manner. Alternatively, the maximum speed available is decreased by greater amounts as the distance of the golf cart to green  18  decreases until all movement is prohibited at the edge of the green. In this manner, the risk is reduced of a violation of green  18  with a positioning of golf cart  10  within the perimeter of green  18  by layering limited access layers to have escalating movement restrictions as golf cart  10  moves closer to green  18 . The selected actions or set of actions are configurable and decided by the course manager based on course rules and preferences. 
     Limited access controller  14  enforces restrictions on movement by golf cart  10  by communicating with an on-board motor controller  24  for motor  26 . For instance, limited access controller  14  operates on a Windows CE platform and communicates with a serial port of a 1510 motor controller manufactured by Curtis PMC. The 1510 motor controller allows polling of its configuration settings, such as speed settings, and its status information, such as throttle setting, battery voltage and motor operating parameters, so that limited access controller  14  is able to override driver inputs, such as throttle settings input through an accelerator pedal  28 . For instance, applying the above example, if limited access controller  12  detects that golf cart  10  has entered within the perimeter of green  18 , it may disable movement of golf cart  10  by commanding on board controller  24  to override driver accelerator inputs, to override ignition inputs, to override gear selection inputs or by setting the maximum setting of motor  26  to a speed of zero. Alternatively, limited access controller  12  interfaces with a power switch  30  to shut off main current from a battery  32  to motor  26 . 
     Limited access controller  12  interfaces with the driver of golf cart  10  and with golf course management through a driver interface unit  34 , a driver display  38  and a communication module  36 . Driver interface unit  34  presents limited access information to a driver of golf cart  10  visually through display  38  and audibly through speaker  40 . Driver inputs in response to limited access information is provided through an input interface  42 , such as a touch screen or buttons associated with display  38 , and through an emergency override  44  that allows a driver to override restrictions on movement of golf cart  10  imposed by limited access controller  12 . Communications module  36  communicates with a base station to allow centralized tracking of golf cart movement and status, updates to limited access map  16 , and direct override from the base station of driver inputs. Applying the above example, as limited access controller  12  restricts driver inputs through accelerator  28 , messages from driver interface unit  34  are presented at display  38 . Slowing of the maximum speed as golf cart  10  approaches approach  20  is accompanied with a caution message explaining the reduced speed is to avoid any encroachment on approach  20  or green  18 . Disabling of forward movement based on a golf cart position over approach  20  is accompanied with an audible alert and caution message explaining that golf cart  10  has violated a course rule and may only be operated in reverse. A golf cart position over approach  20  or green  18  also results in a message sent through communication module  36  to alert appropriate golf course management of the violation, such as the marshal. The driver can obtain additional help through input interface  42  or, in the event of an emergency, can override certain restrictions imposed by limited access controller  12  through activation of emergency override interface  44 , such as to make a more rapid return to cover in the event of an electrical storm. 
     Referring now to  FIG. 2 , a functional block diagram is depicted of a golf course system for control of movement of golf carts  10  on a golf course  46 . Overall golf course management is provided by a base station  48  that communicates with golf carts  10  through a wireless network  50 . Base station  48  defines limited access areas and associated golf cart movement restrictions with an access configuration module  52  that maintains a limited access area map database  54 . Limited access area map database  54  relates limited access areas to perimeters having geographic coordinates and to movement restrictions such as slow, no movement or reverse only movement. By maintaining defined limited access areas, database  54  simplifies implementation of golf cart restrictions as conditions warrant. For instance, if a brief rainstorm dampens a portion of the course, the marshal selects a stored golf cart only movement restriction for the wet areas and communicates the updated limited access areas to golf carts  10  through communication module  54  and wireless network  50 . Remote design and selection of limited access areas is supported through a golf course management server  56  that, for instance, allows interaction with access configuration module  52  from a local area network or the Internet. The modules and database for the depicted system may be implemented with multiple and distributed computer systems. 
     In addition to supporting the design and selective activation of limited access areas, base station  48  provides a centralized communication hub for control of golf carts across golf course  46 . An access control module  58  interacts with individual golf cart limited access controllers  12  to directly control functions of that golf cart&#39;s motor  26 . As an example, golf carts in a parking area  66  are prevented from movement by a command communicated from access control module  58  that disconnects main power to each motor to prevent theft of the golf carts. When a driver pays for a round of golf, the driver is provided with an authorization code that the driver inputs through input interface  42  for communication to an authorization module  60  of base station  48 . If the driver authorization code matches the authorization code of authorization module  60 , access control module  58  is commanded to release the authorized golf cart for movement. During movement around the golf course, an alarm module  62  tracks limited access area violations reported from golf carts through communication module  54  and status module  64  tracks golf cart status based on information processed by limited access controllers  12  from on board controllers  24 . Thus, for instance, a marshal may impose movement restrictions on selected golf carts through base station access control module  58  based on status and alarm information. 
     Position-based movement restrictions for golf carts on a golf course  46  provide enhanced play, safety, and course upkeep by limiting golf carts to authorized use. Improved play begins with player check in by ensuring that only authorized players have access to golf carts  10  taken from parking area  66 . Parking area  66  is a limited access area which permits golf cart movement within the defined perimeter only at a reduced maximum speed to promote safe driving. Further, each golf cart  10  may have a limited access area defined within a predetermined radius so that, when two carts are in proximity to each other a reduced maximum speed is enforced. As golf carts proceed along golf cart path  68  a number of limited access areas may apply, including cart path only access during wet conditions, and reduced speeds applied proximate to sharp turns, steep hills or dangerous driving conditions such as cliffs and water hazards. The specific limited access periods applicable for a golf course  46  may change daily or even through out a day such as when water hazards  70  change dimensions or conditions on fairway  22  change, and may also vary based on the quality of GPS or dead reckoning position accuracy. In the event of an emergency, a driver may override specific limited access controller restrictions for that driver&#39;s golf cart, or alternatively, a message from the base station may disable all or selected limited access controller functions for all or selected golf carts, such as if lightening threatens the golf course. 
     Referring now to  FIG. 3 , one example of a graphical user interface is depicted in which access configuration module  52  defines movement beyond the boundaries of a golf course as movement into a limited access area. A message box  72  provides a text message for display to a driver if the limited access area, i.e., travel outside of the golf course boundary, is violated. An audible alarm is selected along with a restriction of maximum speed to 5 MPH. In one embodiment, maximum speed is further reduced as the golf cart continues movement into the limited access area, such as if the velocity vector of the golf cart increases the distance of the golf cart from the golf course boundary. Alerts of a limited access area violation are provided to the marshal and pro shop based on the type of golf cart that is violating the limited access area. In the depicted example, an alarm is provided for all types of vehicles since movement out from the boundary of the golf course indicates a possible vehicle theft. In alternative limited access areas, different types of defined areas, such as greens and driving ranges, may have different selections for different types of golf carts. For instance, the marshal and utility carts may be permitted to cross the driving range whereas other types of carts, such as player or beverage carts, are limited from such movement for safety reasons. As another example, a handicap vehicle and a mower are allowed on a green while all other types of vehicles are prohibited. The type of golf cart is predefined based on golf cart identifiers or alternatively set with an access code input by the driver. Once the limited access area is defined by access configuration module  52 , it is stored in limited access area map database  54  and, in one embodiment, may be deployed through wireless network  50  to all or selected golf carts. 
     Referring now to  FIG. 4 , a graphical user interface is depicted as an example of the status presentation available from status module  64 . Each active golf cart is identified by a cart number with position, playing pace, playing status, battery charge and fault information displayed in a tabular format. More specific information about a selected golf cart is displayed automatically if a critical situation arises or by selection of the golf cart identifier. For instance, golf cart  21  has a pop-up window that displays a critical battery status. If a golf cart violates a limited access area, the violation is highlighted by a different color, such as yellow or red, and in the case of critical violations, such as violation of a green or a selection of an emergency override by the driver, the golf cart is identified with a pop-up window. The golf course map is presented at the base station or a display in a marshal&#39;s cart to provide an intuitive and easy to understand presentation that allows a marshal or other golf course management to quickly assess the status of all golf carts in play. In alternative embodiments, the golf cart limited access controller and management system described herein may be used to control the movement of other types of vehicles, such as construction vehicles at a construction site, delivery vehicles, maintenance vehicles, etc . . . , to improve the efficiency, safety and security of vehicle use. 
     Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.