Automatic hold parking brake

Abstract

The braking system of a vehicle is securely engaged in response to the operator of the vehicle causing the vehicle to stop. The braking system improves vehicle safety by remaining securely engaged upon detection of a fault such as a vehicle collision, an unintentional transmission shift, a vehicle malfunction or a problem with the operator or operation of the vehicle. In the event of a collision, securely engaged brakes can significantly reduce resulting vehicle acceleration, potentially avoiding a secondary collision and reducing injuries experienced by the vehicle operator and passengers. In the event that no fault is detected, the braking system is disengaged in response to the operator accelerating the vehicle, either by pressing the gas pedal or releasing the brake pedal, thereby making the securely engaged brakes virtually unperceivable under normal operating circumstances. The braking system may be released rapidly in response to a substantially depressed gas pedal to facilitate a rapid start or gradually in response to a partially depressed gas pedal to facilitate a smooth start.

We claim:  
     
         1 . A properly operating vehicle having an automatic parking brake comprising: 
 a speed sensor for generating an automatic hold signal in response to the properly operating vehicle coming to a complete stop;    an electromechanical parking brake system;    a controller coupled to said speed sensor and said electromechanical parking brake system for automatically engaging said electromechanical parking brake system with a significant braking force in response to the vehicle coming to a complete stop,    thereby virtually eliminating any roll—forwards or backwards—and any tendency of the vehicle to “creep”.    
     
     
         2 . The vehicle according to  claim 1  wherein the significant braking force is greater than a braking force provided by an operator of the vehicle while the vehicle is completely stopped.  
     
     
         3 . The vehicle according to  claim 1  further comprising 
 an accelerator control and wherein  
 said controller is further coupled to said accelerator control and automatically releases said electromechanical parking brake system in response to the operator activating the accelerator control.  
 
     
     
         4 . The vehicle according to  claim 3  further comprising: 
 a transmission having an operator selectable drive gear; and  
 an engine coupled to said transmission for powering the vehicle, said engine able to stop and restart, wherein  
 said controller is further coupled to said engine and continues to automatically engage said electromechanical braking system when said engine is stopped, and  
 said controller is further coupled to said transmission and continues to automatically engage said electromechanical braking system with the engine is restarted and  
 said controller automatically releases said electromechanical parking brake system in response to the operator selecting the drive gear and touching said accelerator control.  
 
     
     
         5 . The vehicle according to  claim 1  further comprising 
 a dashboard light  
 wherein said controller illuminates said dashboard light in response to automatically engaging said electromechanical braking system.  
 
     
     
         6 . A method of automatically holding a properly operating vehicle comprising the steps of: 
 determining the speed of the properly operating vehicle to fall to zero;    automatically holding the vehicle by applying a vehicle braking system with a braking force greater than a braking force provided to a brake pedal by an operator of the vehicle; and    releasing the vehicle braking system in response to the operator activating a vehicle accelerator pedal,    thereby virtually eliminating any roll—forwards or backwards—and any tendency to “creep” when the operator's foot is removed from the brake pedal.    
     
     
         7 . The method according to  claim 6  further comprising the step of illuminating a dashboard light in response to said step of automatically holding the vehicle.  
     
     
         8 . The method according to  claim 6  wherein said step of automatically holding maintains application of the vehicle braking system in response to the vehicle being turned off, thereby providing an automatic parking brake.  
     
     
         9 . The method according to  claim 6  wherein 
 said step of automatically holding maintains application of the vehicle braking system in response to the vehicle being turned off and further in response to the vehicle being restarted and turned on, and  
 said step of releasing further releases the vehicle braking system in response to the vehicle being shifted into a drive gear.  
 
     
     
         10 . The method according to  claim 9  further comprising the step of illuminating a dashboard light in response to said step of automatically holding the vehicle.  
     
     
         11 . The method according to  claim 6  wherein said step of releasing releases the vehicle braking system according to a predetermined process that is independent of a position of the activate vehicle accelerator pedal.  
     
     
         12 . The method according to  claim 6  wherein the vehicle braking system includes a hydraulic brake system and a parking brake system.  
     
     
         13 . The method according to  claim 6  further comprising the step of 
 detecting an obstruction in the path of the vehicle wherein  
 said step of automatically holding maintains application of the vehicle braking system in response to said step of detecting.  
 
     
     
         14 . An automatic parking brake for a properly operating vehicle comprising: 
 a speed sensor for generating an automatic hold signal in response to the properly operating vehicle coming to a complete stop;    an electromechanical parking brake system;    a controller coupled to said speed sensor and said electromechanical parking brake system for automatically engaging said electromechanical parking brake system with a braking force greater than a braking force provided by an operator of the vehicle in response to the automatic hold signal,    thereby virtually eliminating any roll—forwards or backwards—and any tendency to “creep” when the operator provides insufficient braking force.    
     
     
         15 . The automatic parking brake according to  claim 14  wherein the vehicle further comprises 
 an accelerator control and wherein  
 said controller is further coupled to said accelerator control and automatically releases said electromechanical parking brake system in response to the operator touching said accelerator control.  
 
     
     
         16 . The automatic parking brake according to  claim 15  wherein the vehicle further comprises: 
 a transmission having an operator selectable drive gear; and  
 an engine coupled to said transmission for powering the vehicle, said engine able to stop and restart, wherein  
 said controller is further coupled to said engine and continues to automatically engage  
 said electromechanical braking system when said engine is stopped,  
 said controller is further coupled to said transmission and continues to automatically engage the electromechanical braking system with said engine is restarted and  
 said controller automatically releases said electromechanical parking brake system in response to the operator selecting the drive gear and touching said accelerator control.  
 
     
     
         17 . The automatic parking brake according to  claim 15  wherein 
 said controller releases said electromechanical parking brake system in response to an acceleration signal received from the operator and the vehicle further comprises  
 a collision detector for generating a collision signal in response to detection of a collision and further wherein  
 said controller maintains application of said electromechanical parking brake system in response to the collision signal even if the acceleration signal is received from the operator.  
 
     
     
         18 . The automatic parking brake according to  claim 14  further comprising 
 a dashboard light  
 wherein said controller illuminates said dashboard light in response to automatically engaging said electromechanical braking system.  
 
     
     
         19 . The electromechanical braking system according to  claim 14  further comprising a hydraulic brake system and a parking brake system.  
     
     
         20 . The automatic parking brake according to  claim 14  wherein 
 said controller automatically engages said electromechanical parking brake system with a braking force equivalent to a significant braking force applied by the operator,  
 thereby virtually eliminating any roll—forwards or backwards—and any tendency to “creep” when the operator provides insufficient braking force.