Patent Publication Number: US-2004046686-A1

Title: Passcode control system for utility vehicle controller

Description:
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/365,341 filed Mar. 18, 2002. 
    
    
     
       BACKGROUND  
       [0002] The present invention relates to utility vehicles operable in high-speed and lower-speed modes. More particularly, the present invention relates to a passcode protection system for limiting access to the vehicle high-speed mode.  
       [0003] The ANSI Z-130 standard requires that golf car fleets do not exceed a speed of 15 miles per hour (mph) on flat, level ground. Golf cars that are owned by private individuals are not subject to the ANSI Z-130 standard and as such, may be legally operated at speeds up to 20 mph on flat, level ground. There is therefore a desire by private individuals for golf cars that can be inexpensively modified to operate at speeds up to 20 mph. However, while meeting this demand, a means is required to insure that the ANSI Z-130 standard is adhered to by golf cars in fleet applications.  
       [0004] There are several solutions currently employed. One is to physically substitute a high speed (19 mph) electric motor and controller combination for the standard motor and controller. Another method is to physically change the gearing ratio in the vehicle transaxle. Approval procedures are used to insure the customer for this modified vehicle is not required to adhere to the ANSI Z-130 standard. Though generally effective, these solutions are time consuming and costly.  
       [0005] Another solution is to offer an electric motor and controller combination that is designed to operate in several performance modes, one of which is the high-speed private owner mode. The modes are accessed by plug-like devices that physically close different logic circuits. This solution allows for quick and inexpensive access to the high-speed mode, however, the plug-like devices are easily reverse-engineered and duplicated so that they offer little assurance that the ANSI Z-130 standard is met when applicable.  
       [0006] There is a need for a quick and inexpensive method to access the high-speed mode while increasing the difficulty for an unauthorized user to violate the ANSI Z-130 standard.  
       SUMMARY  
       [0007] The present invention relates to a speed control system for a utility vehicle that includes a motor driven drive system. The control system comprises a controller associated with the motor to control the speed of the vehicle. The controller is configured to limit the vehicle to a maximum speed. The maximum speed is set to one of at least two different maximum speed values. The values include a high-speed value and a default low speed value. An input device is associated with the controller and is configured to change the maximum speed value to the high-speed value only upon entry of a preset passcode. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0008]FIG. 1 is a diagrammatic illustration of a first embodiment of the present invention.  
     [0009]FIG. 2 is a diagrammatic illustration of a second embodiment of the present invention.  
     [0010]FIGS. 3 and 4 illustrate a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0011] Referring to FIG. 1, an exemplary utility vehicle  20  incorporating the control system that is a first embodiment of the present invention is illustrated. The utility vehicle  20  has a motor (not shown) that drives the vehicle  20 . The term motor is used herein in a broad sense and can be a gas engine, an electric motor or the like. In each case, motor speed is controlled by on onboard controller  22 .  
     [0012] The controller  22  is preferably a solid-state device containing power semiconductors, an embedded microprocessor, and analog amplifiers for detecting various signals. During normal operation, the controller  22  continuously monitors the input signal from the accelerator pedal to send the appropriate control signals. For example, with a gas powered engine, the controller  22  receives the input signals from the accelerator pedal and then sends the appropriate signal to the fuel system, for example, electrically controlled fuel injectors, to regulate the vehicle speed. In an electric motor, semiconductor switches, such as power field effect transistors (FETs), are used to alternately connect then disconnect the power source to the motor. The controller  22  sends the appropriate control signals to the FETs to regulate the vehicle speed.  
     [0013] The controller  22  is configured to set a maximum speed of the vehicle  20 , for example, a maximum fuel injection or a maximum switching of the FETs. The controller  22  is set with a default lower-speed maximum value that meets the ANSI Z-130 standard, for example, a lower-speed maximum value equal to 15 mph. The controller  22  is generally set in the factory with the maximum vehicle speed equal to the lower-speed maximum value. The controller  22  is also set with at least one other maximum value. For example, the controller  22  may be set to have a second, high-speed maximum value equal 20 mph. The controller  22  can be changed to the high-speed maximum value setting only by entering a preset passcode into the controller  22 .  
     [0014] The vehicle  20  includes a passcode receiver  24  that is associated with the controller  22 . In the embodiment illustrated in FIG. 1, the passcode receiver  24  provides a serial interface for connection of a hand-held input device  30  utilizing a serial cable  36  or the like. The input device  30  includes a key pad  32  and a display screen  34 . A user desiring to operate the vehicle  20  at the high-speed maximum value must enter a preset code that is unique to the particular controller  22 . The passcodes are preferably generated using a proprietary algorithm that is closely controlled by the vehicle manufacturer, distributor or other controlling party.  
     [0015] In order to receive the unique passcode for the vehicle&#39;s controller  22 , the user must go through an approval procedure designed to insure that the user is not required to adhere to the ANSI Z-130 standard. An example passcode would comprise three distinct three digit numbers, each of which may range from 000 to 255. Such a passcode system would yield a total of 16,777,215 possible passcodes. To minimize the possibility of an unauthorized user discovering the unique passcode or the manufacturer&#39;s algorithm, the controller  22  is preferably configured to allow only a limited number of incorrect passcode entries, for example, 20 attempts, before the controller locks out the high-speed capability. In the event of a lock out, the controller  22  requires resetting by the manufacturer before the high-speed maximum value can be accessed.  
     [0016] The utility vehicle  20  may also be provided with an indicator  26 , for example, a single or multicolor light, that displays to the user the mode of the controller  22 . For example, a multicolor light may light a first color when the controller  22  is in the lower-speed mode and a second color when the controller  22  is in the high-speed mode. With the single color light, the light illuminates when the controller  22  is in the high-speed mode. In both instances, the indicator  26  allows a facility manager to recognize if anyone has tempered with the controller  22  and improperly set the controller  22  to the high-speed mode.  
     [0017] Referring to FIG. 2, a control system which is a second embodiment of the present invention is illustrated. This embodiment is similar to the embodiment of FIG. 1, except that the input device  50  includes a transmitter  56  that communicates with the passcode receiver  24  via wireless technology, for example, using radio frequency or infrared technology. A user still must enter the unique passcode into the controller  22  in order to access the high-speed maximum value.  
     [0018] Referring to FIGS. 3 and 4, a control system which is a third embodiment of the present invention is illustrated. This embodiment is similar to the embodiment of FIG. 1, except that the input device  70  is incorporated into the body of the vehicle  22 . The input device  70  is preferably protected by a key locked  74  cover  72 . The vehicle owner is provided with a key (not shown) to access the input device  70 . A key pad  76  is provided inside the cover  72 . The user can enter the unique passcode into the controller  22  in order to access the high-speed maximum value. The specific configurations of key pads and displays shown in the various embodiments are for illustration purposes only. Other configurations are also possible without departing from the scope or spirit of the present invention.