Abstract:
A control system for a vehicle includes a safety device controller (restraint control module) to control initiation of at least one safety device in the vehicle and a brake controller to control braking in the vehicle for roll stability control. The control system includes at least one sensor operably connected to the safety device controller. The control system also includes a single angular roll rate sensor operably connected to the safety device controller and brake controller. The single angular roll rate sensor, which includes a gyroscope, is operably connected to a precision A/D converter and is configured to detect a crash event for the safety device controller and vehicle motion for the brake controller.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application claims priority to U.S. Provisional Patent Application 60/758,559 filed Jan. 13, 2006, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND  
       [0002]     The application relates to a control module for a vehicle that contains both crash detection and motion detection. More specifically, the application relates to a control module for both crash detection and motion detection that utilizes only one gyro.  
         [0003]     Conventional modules include brake control modules, such as shown in U.S. Pat. Nos. 6,338,012; 6,834,218; and 6,324,446 (which are incorporated by reference in their entirety).  
       SUMMARY  
       [0004]     One exemplary embodiment relates to a control system for a vehicle. The control system comprises a safety device controller to control initiation of a safety device in the vehicle, a brake controller to control braking in the vehicle, and a single angular roll rate sensor operably connected to an A/D converter. The single angular roll rate sensor is configured to provide sufficient sensitivity for both the safety device controller and the brake controller.  
         [0005]     Another exemplary embodiment relates vehicle sensory system. The system comprises a single angular roll rate sensor, an A/D converter connected to the angular rate sensor, and a mechanism to connect the digital signal from the A/D converter to more than one actuation system in the vehicle.  
         [0006]     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     These and other features, aspects, and advantages of the present invention will become apparent from the following description and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.  
         [0008]     FIGS.  1 ( a ) and  1 ( b ) are schematic representations of a restraint control module (RCM) and a separate braking control module, in which  FIG. 1 ( a ) illustrates the RCM and  FIG. 1 ( b ) illustrates the braking control module.  
         [0009]      FIG. 2  is a schematic representation of a combined RCM and braking control module that utilizes two separate gyros.  
         [0010]      FIG. 3  is a schematic representation of a combined RCM and braking control module that utilizes a single gyro according to an embodiment.  
         [0011]      FIG. 4  is a schematic representation of a vehicle illustrating the position of the RCM of  FIG. 3 . 
     
    
     DETAILED DESCRIPTION  
       [0012]     A vehicle may contain two separate control systems (or actuation systems), such as can be seen in  FIG. 1 : a restraint (safety) control module (RCM)  100  and a braking (roll and stability) control module  150 . Each control module  100 ,  150  utilizes sensors  110 ,  160  and an angular roll rate sensor  120 ,  170  in order to determine what action to take. The angular roll rate sensor  120  may be, for example, a gyro. The angular roll rate sensor  120 , such as a gyro, may determine the direction of a vehicle and provide an output voltage, which is proportional to the rate of turn at its sensitive axis.  
         [0013]     The RCM  100  determines which, if any, airbags or other safety devices should deploy and sends a control signal to any required safety devices  130 . The braking control module  150  determines the amount of braking pressure to apply to each tire in the case of a skid or roll over situation. The braking control module  150  determines a roll angle estimate in response to lateral acceleration, longitudinal acceleration, roll rate, and other factors, and changes the distribution of braking force to each tire in response to the roll angle estimate. The RCM  100  and braking control module  150  are operated independent of each other and do not utilize the same sensors, gyros or other equipment.  
         [0014]     The RCM  100  utilizes a plurality of sensors  110  in various locations in a vehicle. The number, type and location of the sensors  110  may vary. For example, the sensors  110  may be accelerometers or pressure sensors, or any other suitable sensor. The sensors  110  may be located in the B-pillar, C-pillar, door, seat, and/or front portion of the vehicle. Further, an angular roll rate sensor  120 , such as a gyro, is used to determine angular rate of a vehicle. The RCM  100  receives output from the sensors  110  and angular roll rate sensor  120  and may interface with various safety components  130 . The RCM  100 , after computing all possible data from the sensors  110  and angular roll rate sensor  120 , determines which, if any, safety device should be activated. For example, the RCM  100  determines whether an airbag, pretensioner, or other safety device need by deployed or activated. The angular roll rate sensor  120  (gyro) generally has a detection range of ±240 deg/sec. The angular roll rate sensor  120  may be a part of or separate from the RCM.  
         [0015]     The same vehicle may also utilize a braking control (roll stability) module (or controller)  150 . The braking control module  150  controls a brake control  180 , which in turn controls the braking of the front right brake  181 , front left brake  182 , rear right brake  183 , and rear left brake  184 . The braking control module  150  receives output from various sensors  160 . For example, the sensors  160  may determine yaw rate, speed, lateral acceleration, roll rate, steering angle, longitudinal acceleration, and a pitch rate sensor. Of course, the sensors  160  described are exemplary only and any other suitable sensor may be used. Further, any suitable combination of type, amount, and location may be used. In addition, an angular roll rate sensor  170 , such as a gyro, is used, which is separate from the gyro  120  in the RCM  100 . The angular roll rate sensor  170  generally has a detection range of ±80 deg/sec.  
         [0016]     Another approach, as shown in  FIG. 2 , for RCM and braking control modules is to utilize a RCM  200  in which all of the sensors are incorporated into a single module  200 . The vehicle uses only a single sensor cluster incorporating sensors  210 . The sensors  210  send their output to the RCM  200  which sends output to the brake control  240 . The RCM module  200  utilizes two separate gyros  220  and  230 . One gyro  220  senses vehicle motion for the braking system and a second gyro  230  functions as a crash detector for use with the safety restraints (airbags, pretensioners, and the like). The gyro  220  for sensing motion for the braking system has a detection range of about ±80 deg/sec. The gyro  230  for the restraint control module for sensing crash detection has a detection range of about ±240 deg/sec.  
         [0017]     The RCM  200  incorporates information from a variety of sensors  210  and, in addition, controls safety devices  130  (airbags, pretensioners, etc.) and may also control a brake control  240 . The brake control  240 , in turn, controls the distribution of braking force applied to the front right brake  241 , front left brake  242 , rear right brake  243  and rear left brake  244 .  
         [0018]     According to an embodiment, a single angular roll rate sensor  320  is utilized, such as shown in the schematic of  FIG. 3 . The angular roll rate sensor  320  is used in a RCM  300  and the angular roll rate sensor  320  determines roll-rate data, vehicle motion, and impending crashes. Thus, the single sensor  320  is capable of collecting data for both the restraint (safety) control and vehicle braking (roll stability) control functions. The angular roll rate sensor  320  may be part of the RCM  300  or outside the RCM  300  and the output of the angular roll rate sensor  320 , along with output from a variety of other sensors  310  (such as those described above) are processed by the RCM  300 . The RCM  300 , in turn, sends the corresponding output to the brake control  340 , which controls the distribution of braking force applied to the front right brake  341 , front left brake  342 , rear right brake  343  and rear left brake  344 . The angular roll rate sensor  320  may be a gyro. The RCM  300  also controls the deployment of any required safety devices  130 .  
         [0019]     In order to provide the resolution required by the braking system (braking systems typically use a gyro with a detection range of ±80 deg/sec), an A/D (analog to digital) converter  350  is provided. The digital signal may be processed to provide the desired resolution such that the single gyro  320  can be used for both detection purposes; a low resolution (high range) for the necessary sensing for the RCM  300  and a high resolution (low range) for the necessary sensing for the brake control  340 . The gyro  320  has a detection range of around ±240 deg/sec. The A/D converter  350  may be external or internal to the controller  300 .  
         [0020]     The gyro  320  may be a Panasonic 2 nd  Generation sensor with an analog output, a Bosch sensor, or any other suitable sensor. The A/D converter  350  may be an 8 bit converter or a 13 bit converter. Alternatively, the A/D converter  350  may be a 14 bit or higher converter, or any other suitable type of A/D converter.  
         [0021]     According to an embodiment, the drive or sense frequency of the gyro  320  should be significantly greater than the majority of any anticipated vibrations. When vibration in the vehicle approaches the drive or sense frequency of the gyro  320 , the mechanical elements may perform frequency shifting, which may cause false data outputs. Thus, the drive or sense frequency of the gyro  320  should be high.  
         [0022]     The RCM  300 , such as shown in  FIG. 4 , may be positioned in a tunnel  350  of a vehicle  360 . The tunnel  350  generally runs through the middle of a vehicle  360  in the lengthwise direction. The controller module  300  may be positioned in the tunnel  350  between the driver seat area  370  and front passenger seat area  380 . It will be recognized that  FIG. 3  is not drawn to scale and is shown for exemplary purposes only. Alternatively, the controller module  300  may be positioned on a B or C pillar, or any other suitable location.  
         [0023]     On possible advantage of the embodiment is that the amount of parts required will be minimized, thus decreasing the cost to manufacture and decreasing the amount of space required for the safety/crash detection and braking/motion detection modules. For example, in the embodiment of  FIG. 3 , only a single gyro  320  is required. By only requiring the single gyro  320  to perform the necessary sensing operations for the RCM  300  and brake control  340  instead of two gyros, a manufacturer can save on costs for the system. For example, a manufacturer could realize substantial cost savings per control system by utilizing the single gyro  320  with the precision A/D converter  350 .  
         [0024]     It will be recognized that any type, location, and amount of sensors may be used. The types of sensors listed above (yaw rate, speed) are listed for exemplary purposes only.  
         [0025]     Given the disclosure of the present invention, one versed in the art would appreciate that there may be other embodiments and modifications within the scope and spirit of the invention. Accordingly, all modifications attainable by one versed in the art from the present disclosure within the scope and spirit of the present invention are to be included as further embodiments of the present invention. The scope of the present invention is to be defined as set forth in the following claims.