Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/239,370, filed on Oct. 11, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an adjustable pedal assembly for a motor vehicle, and more particularly, to an adjustable pedal assembly that can be disabled due to J1850 messages. 
     2. Description of the Related Art 
     Motor vehicles are likely to be driven by more than one person including family vehicles and company vehicles. Even for an individual driver, vehicles are driven by different people for maintenance purposes or in case of an emergency. Most likely, different drivers have different anatomy. Thus, motor vehicles are required to have suitable adjustment features to provide desirable driving conditions for more than one driver. 
     Conventional vehicular pedals are foot operated by the driver. The positional relationship between a vehicle occupant and a pedal is set by adjusting the front seat. Typically, the front seat is slidably mounted on a seat track with means for securing the seat along the track in a plurality of adjustment positions. However, due to difference in anatomical dimensions, the use of front seat tracks has been a growing concern since such adjustment could not accommodate all vehicle occupants. 
     Several attempts have been made over many years to provide selective adjustment of the pedal system to accommodate various size drivers. Recently, a control pedal mechanism has been developed that accomplishes the pedal adjustment without altering further dimensional relationships between the driver and the pedal assembly. However, none of these developments has been adapted to take into consideration certain safety concerns. 
     Therefore, it would be highly desirable to provide an adjustable pedal assembly that is simple, inexpensive and easy to operate, yet capable of providing the adjustment of the pedal assembly to a desired position. It would also be highly desirable to provide an adjustable pedal assembly that can disable the adjustment of the pedal assembly under certain conditions. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is provided an adjustable pedal assembly for a motor vehicle. The invention is capable of disabling the required adjustment under certain conditions while the adjustable pedal assembly is active. 
     To achieve this object, the present invention provides an adjustable pedal system for a motor vehicle. The adjustable pedal system includes an adjustable pedal assembly and an adjustable pedal module. The pedal assembly is movable to at least two pedal positions. The adjustable pedal module is responsive to a pedal command. The adjustable pedal module controls the movement of the adjustable pedal assembly. The pedal module further includes a lockout module to disable the movement of the adjustable pedal assembly when a predetermined lockout condition is detected. The adjustable pedal module is interconnected through a data bus to several vehicle electronic modules. The predetermined lockout condition is communicated to the adjustable pedal module over the data bus. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is a perspective view depicting the adjustable pedal assembly system of the presently preferred embodiment of the invention; 
     FIG. 2 is a block diagram depicting the adjustable pedal assembly system of the presently preferred embodiment of the invention; 
     FIG. 3 is a flow chart depicting the acquisition of a required adjustment of the pedal assembly of the presently preferred embodiment of the invention; 
     FIG. 4 is a flow chart depicting the method of verifying the integrity of data bus of the presently preferred embodiment of the invention; 
     FIG. 5 is a table describing the data bus message communication during different ignition states; and 
     FIG. 6 is a table describing fault condition lockouts according to the presently preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, an adjustable pedal module system (APMS)  10  for a motor vehicle is illustrated in accordance with the teachings of the present invention. The APMS  10  includes a brake pedal assembly  12 , an accelerator pedal assembly  14 , an adjustable pedal module (APM)  16 , and supporting electrical circuits (not shown). The APM  16  controls the pedal assemblies  12  and  14  and communicates with other vehicle electronic control units (ECUs)  30 . The APM  16  may receive a manual interrupt input from either a manual switch  28  or from memory  26 . The APM  16  is connected to the ECUs via a data bus  32 . Movements of the accelerator pedal assembly  14  are monitored by a movement sensor  22 . The movement sensor is connected to a motor module  18  through a cable  24 . The brake pedal assembly  12  is also connected to the motor module  18 . 
     FIG. 2 of the drawings illustrates the preferred embodiment of the APM  16  in greater detail. The APM  16  further contains a pedal movement module  19 , an operating condition sensor  34 , and a lockout module  36 . The pedal movement module  19  receives manual interrupt inputs from the manual switch  28  and memory  26 . The pedal movement module  19  communicates with the ECUs  30  through the data bus  32 . The operating condition sensor  34  receives identifying messages from the various modules of the motor vehicle. The operating conditional messages are collected in the operating sensor  34  and sent to the lockout module  36 . The lockout module  36  determines the existence of any lockout conditions based upon the identifying messages received by the operating condition sensor  34 . If any of lockout conditions are detected, the pedal movement module  19  of the APM  16  disables the adjustment of the pedal assemblies  12  and  14 . If lockout conditions are not detected, the pedal movement module  19  adjusts the pedal assemblies  12  and  14  to a desired position. 
     With further reference to FIG. 3 of the drawings, a process for adjusting the pedal assemblies  12  and  14  in accordance with the teachings of the present invention is illustrated. The APMS  10  receives an input at step  40 . The input signal may be from either the manual switch  28 , which is pressed by a vehicle occupant, or memory  26 . The memory  26  retains at least two different pedal positions. Upon a request for adjustment of the pedal assembly  12  and  14  by the vehicle occupant, the input signal is sent to the pedal movement module  19  of the APM  16 . 
     The pedal movement module  19  of the APM  16  controls the movement of both the brake assembly  12  and the accelerator assembly  14 . When the pedal movement module  19  acknowledges an input signal, the APM  16  determines whether the data bus  32  is in an active mode, step  41 . If the data bus  32  is in an active mode, the APM  16  proceeds on to checking lockout conditions, step  44 . On the other hand, if the data bus  32  is in an inactive mode, the integrity of data bus  32  is verified, step  42 . More particularly, at step  42 , the APMS  10  determines the data bus  32  is capable of providing bi-directional communication between the ECUs  30  and the APM  16 . The step of verifying the integrity of data bus  32  will be described below in greater detail with reference to FIG.  4 . 
     In the preferred embodiment, a SAE J1850 bus is used as the data bus  32  for providing bi-directional communication between the APM  16  and the ECUs  30 . However, it should be understood that any data bus, such as a Controller Area Network (CAN) data bus, can also be used so long as bi-directional communication is supported between vehicle ECUs. 
     Once the integrity of the data bus  32  is established, other ECUs place lockout information on the bus. After the integrity of data bus  32  is verified, the APM  16  determines whether lockout conditions exist, step  44 . The pedal movement module  19  interfaces with the vehicle ECUs  30  via data bus  32  in order to monitor operating conditions of the vehicle. 
     The signals from the ECUs  30  are transmitted to the lockout module  36 . The lockout module  36  monitors the signals to determine whether any lockout conditions exist. What constitutes a lockout condition will be more fully described below with reference to FIGS. 5 and 6. 
     The presence of lockout conditions determines whether to adjust the pedal assemblies  12  and  14  to a desired position. If lockout conditions are detected, the APMS  10  does not adjust the pedal assemblies  12  and  14 , but instead terminates the process, step  52 . If no lockout conditions are found, the pedal assemblies  12  and  14  are adjusted to the desired position, step  50 . If the input signal is received from the memory  26  and none of the lockout conditions are identified, the APMS  10  retrieves the desired pedal position from memory  26 . Subsequently, the APMS  10  moves the pedal assemblies  12  and  14  to the stored position, step  48 . At step  52 , the APMS  10  waits for the next input from the vehicle occupant, and enters a sleeping mode, step  54 . 
     With reference to FIG. 4, a more detailed flowchart of the APMS  10  is illustrated. At step  60 , the data bus is in an inactive mode and the APM  16  is in a sleeping mode. As mentioned above, the APMS  10  receives a manual interrupt input signal from a manual switch  28  to adjust the pedal assemblies  12  and  14 , step  62 . Upon receiving the manual interrupt input signal, the APM  16  debounces and decodes the input signal. The maximum rate at which the APMS  10  receives the input signal and adjusts the pedal assemblies  12  and  14  is forty msec. 
     At step  64 , the APMS  10  determines if the SAE J1850 data bus  32  for an active mode. If the SAE J1850 is active, the APM  16  of APMS  10  checks for lockout conditions, step  74 . The following table 1 shows the lockout conditions for the APMS  10 . 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Vehicle conditions 
                 Lockout 
               
               
                   
               
             
             
               
                 Transmission in Reverse Gear 
                 The switches and memory recall shall 
               
               
                   
                 lockout 
               
               
                 Cruise Control engaged (speed set) 
                 The switches and memory recall shall 
               
               
                   
                 lockout 
               
               
                 Transmission in Neutral, Drive, or 
                 Only memory recall shall lockout 
               
               
                 Low gear 
               
               
                   
               
             
          
         
       
     
     The APMS  10  disables the adjustable pedal feature under certain conditions. In the preferred embodiment of present invention, the APMS  10  has different lockout conditions depending on the source of the manual interrupt input signal. If the input signal is from the memory  26 , the APMS  10  will only adjust the pedal assemblies  12  and  14  when the transmission of vehicle is in Parking. If the input signal is from the manual switch  28 , the pedal assemblies  12  and  14  are locked out only when the transmission is in Reverse or when cruise control is engaged. 
     In order to determine if the vehicle is under any of the lockout conditions, the pedal movement module  18  of the APM  16  monitors signals from various ECUs  30  via the SAE J1850 data bus  32 . The ECUs  30  periodically transmit signals indicative of operating conditions of the vehicle. Tables 2 and 3 shows bus messages used to determine lockout conditions and a description of each bus message. 
     
       
         
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Frame ID # 
                 Description 
                 Source 
                 Rate 
               
               
                   
               
             
             
               
                 $5B 
                 Ignition Switch 
                 Body controller 
                 1 sec. And on 
               
               
                   
                 Status 
                 module (BCM) 
                 change 
               
               
                 $10 
                 Engine RPM, 
                 Engine Controller 
                 86 msec. 
               
               
                   
                 Speed, and 
                 Module (SBEC/DEC) 
               
               
                   
                 MAP 
               
               
                 $35 
                 Misc. Engine 
                 Engine Controller 
                 344 msec. and 
               
               
                   
                 Status 
                 Module (SBEC/DEC) 
                 on change 
               
               
                 $37 
                 PRNDL Display 
                 Transmission 
                 896 msec. and 
               
               
                   
                   
                 Controller Module 
                 on change 
               
               
                   
                   
                 (EATX) 
               
               
                 $54 
                 Warning Data 
                 Front Control Module 
                 2 sec. And on 
               
               
                   
                   
                 (FCM) 
                 change 
               
               
                   
               
             
          
         
       
     
     
       
         
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Frame ID # 
                 Description 
               
               
                   
               
             
             
               
                 $5B 
                 The APM 16 shall receive the $5B bus message to detect 
               
               
                   
                 the ignition switch bus status for logging communication 
               
               
                   
                 faults. 
               
               
                 $10 
                 Also, the APM 16 shall use the $10 bus message to monitor 
               
               
                   
                 the speed during memory recall and determine if the feature 
               
               
                   
                 needs to be locked out. 
               
               
                 $35 
                 The APM 16 shall receive the $35 bus message to detect if 
               
               
                   
                 the cruise control is engaged or detected if the vehicle is in 
               
               
                   
                 Park/Neutral and determine if the feature needs to be locked 
               
               
                   
                 out. 
               
               
                 $37 
                 The APM 16 shall receive $37 bus message to detect if the 
               
               
                   
                 vehicle is in Park, Reverse, Neutral, Drive, or Low Gear. 
               
               
                 $54 
                 The APM 16 shall receive the $54 bus message to detect if 
               
               
                   
                 the vehicle is in Reverse gear and determine if the feature 
               
               
                   
                 needs to be locked out. 
               
               
                   
               
             
          
         
       
     
     As briefly mentioned above, the APM  16  determines if lockout conditions exist before the APM  16  adjusts the pedal assemblies  12  and  14 . Frame $35 shows when cruise control is engaged or if the transmission is in Park or Neutral. The APMS  10  locks out the pedal assemblies  12  and  14  when $35 message indicates that cruise control is engaged and the vehicle transmission is in neither Park nor Neutral. 
     The bus message $37 indicates whether the vehicle transmission is in Park, Neutral, Drive, or Low. In bus message $37, the least three significant bits of a data byte may show if the transmission is in Reverse. The status of the vehicle transmission determines whether to lock out the pedal assemblies  12  and  14 . For example, the vehicle transmission must be in Park for the pedal assemblies  12  and  14  to be adjusted when the input signal is transmitted from memory recall  26 . 
     Bus message $37 is available only for vehicles with automatic transmissions. For vehicles with manual transmissions, bus message  37  is not available. This is because the manual transmission is not controlled by ECUs, but is controlled strictly mechanically. For vehicles with automatic transmissions, the APM  16  uses bus messages $35 and $54 to determine which gear the transmission of the vehicle is in. The bus message $35 is indicative of whether the transmission is in PARK or NEUTRAL, and the bus message $54 is used to check if the transmission is in REVERSE. Thus, the APM  16  determines whether the transmission of the vehicle is in DRIVE depending on bus messages $35 and $54 for automatic transmission vehicles only. 
     Referring back to FIG. 4, the APM  16  checks for lockout conditions in step  74  from operating conditions transmitted from the aforementioned bus messages. If conditional step  76  of the APMS  10  detecting any of the lockout conditions is satisfied the APMS  10  does not adjust the pedal assemblies  12  and  14 , and returns to stand-by mode, step  80 . If the lockout conditions are not determined the APMS  10  adjusts the pedal assemblies  12  and  14  to a desired position and returns to the stand-by mode, steps  78  and  80 . 
     The APMS  10  will lockout manual or memory controls due to a diagnostic issues. Still with reference to FIG. 4 of the drawings, if it is determined that the J1850 data bus  32  is inactive at step  64 , the APMS  10  verifies the integrity of the data bus  32 . When the integrity of the data bus  32  is verified, the APMS  10  checks for an open circuit condition. For example, if an open circuit exists and the integrity of the bus  32  is not verified, the APM  16  is likely to determine that the bus is inactive, and the other modules are asleep. Operation of the APM  16  is then excluded because the data bus  32  does not respond to the lockout conditions due to an open circuit. 
     Therefore, in this present invention, the APMS  10  verifies the integrity of the data bus using a handshake method between two vehicle modules which are still active when the vehicle is in a key-off condition. Two vehicle modules that are still used, in an active mode to minimize the current draw from the battery. Thus, the battery size can be kept to a minimum. 
     If the SAE J1850 is inactive, the APM  16  wakes up in 8 msec, step  66 . As the APM  16  wakes up, it transmits the $5C-2A-02-00-CRC message to the Body Control Module (BCM), step  68 . The $5C-2A-02-00-CRC is a motion status message used by the memory system, that is indicative of whether or not the APM  16  is manually performing an adjustment. In the presently preferred embodiment, BCM is used for the handshake method. However, it would be understood that any vehicle module that is still active in key-off condition could also be used. 
     The BCM has been in an inactive mode until it receives $5C-2A-02-00-CRC bus message from the APM  16 . As shown in step  70 , when the BCM receives a signal, the BCM is activated sending $5B bus message back to the APM  16  in 60 msec. Within 25 msec., the APM  16  must receive the $5B bus message in order to verify the integrity of the SAE J1850  32  bus. 
     As indicated in Tables 2 and 3, the $5B bus message is indicative of the ignition status. If APM  16  receives $5B from the BCM within 60 msec., the AMP  16  confirms that the SAE J1850 data bus  32  is capable of receiving and transmitting data signals. If the APM  16  does not receive the $5B bus message within 90 msec. after transmitting $5C bus message, then the APM  16  returns to sleep mode and tries again with the next activation of a manual switch. 
     $5B bus message indicates whether the ignition state is in RUN mode. In RUN mode, the APM  16  retrieves the SAE J1850 bus  32 . The APM  16  logs a fault when the APM  16  does not receive a needed bus message within a maximum period of 5 seconds. Therefore, by monitoring the ignition status, the APM  16  determines which lockout conditions are relevant before adjusting the pedal assemblies  12  and  14 . 
     FIG. 5 is a table  90  depicting the bus messages and transmission rates  92  for different ignition states. The different ignition states are accessory-mode  94 , lock-mode  96 , unlock-mode  98 , run-mode  100  and start-mode  102 . All of the bus messages are available when the ignition state is in run-mode  100 . The PRNDL bus message is available when the ignition state is in unlock-mode  98 . The APMS  10  can adjust the pedal assemblies  12  and  14  if the input signal comes from the memory  26  during unlock mode  98 . Also, $37 message is not available when the ignition state is in start-mode  102 . This is because $37 message is generated by the transmission module such as EATX that is asleep in the ignition start mode. Bus message $37 is, thus, generated only when the associated transmission module is awake. 
     FIG. 6 shows fault lockout conditions  110  to disable the APM  16  when at least one of the bus messages $5B  112 , $10  114 , $35  116 , $37  118  and $54  120  is missing. Comments  126  show where the log fault is located when one or more bus messages are missing. Whether to disable the APM  16  when at least one of the bus messages is missing also depends on whether the input signal comes from the manual switch  28  or the memory  26 . Manual pedal adjustment  122  and memory recall adjustment  124  columns show if the pedal assemblies  12  and  14  are adjusted when various faults are present. 
     The APMS  10  controls the movement of the brake  12  and accelerator  14  pedal assemblies through a full range of adjustment as selected by the vehicle occupant. The pedal assemblies  12  and  14  can be adjusted in the range of 80 mm from the nominal position (fully forward position) by the use of a manual switch. The pedal assembly  12  and  14  adjust at a speed of 11.5 mm/sec under nominal conditions of 13.5 volts and 25° C. The APMS  10  has at least two positions stored in memory  26  for the purpose of the vehicle occupant&#39;s personalization. 
     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of ways. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specifications and following claims.

Technology Category: 4