Suspension control system and suspension control method for vehicle

Abstract

A suspension control system and a suspension control method for a vehicle control the suspension based on the condition of the road surface traveled by the vehicle in addition to information pertaining to a corner obtained from a navigation device when the vehicle approaches the corner. A microprocessor controls damping forces of suspension devices on the basis of a degree of irregularity of the road surface detected immediately preceding entry of the automobile into a turn around the corner, and corner information from the navigation device.

1 . A suspension control system for a vehicle equipped with a navigational device, said suspension control system comprising: 
 a plurality of suspension devices, each mounted between a suspension arm and a body portion of the vehicle, in association with a wheel of the vehicle, each of said suspension devices expanding and contracting in accordance with a damping force to damp forces on the vehicle received from a road surface traveled by the vehicle;    irregularity detecting means for detecting a degree of irregularity of the road surface;    vehicle speed detecting means for detecting vehicle speed;    calculating means for calculating an adjustment value corresponding to the damping force on the basis of the detected vehicle speed, the detected degree of irregularity and information relative to a corner in the road surface received from the navigation device when the vehicle approaches the corner; and    output means for outputting the adjustment value to a suspension device so as to control the damping force of the suspension device.    
   
   
       2 . The suspension control system for a vehicle according to  claim 1 , wherein the suspension control system further comprises: 
 turn detecting means for detecting turning of the vehicle; and    entry judging means for judging whether or not the vehicle has entered into a turn around corner on the basis of the turning of the vehicle detected by said turning detecting means; and    wherein said output means outputs said adjustment value to the suspension devices so as to control the damping forces in accordance with the adjustment value responsive to a judgment by said entry judging means that the vehicle has entered into the turn around the corner.    
   
   
       3 . The suspension control system for a vehicle according to  claim 2 , wherein said calculating means extracts an irregularity component corresponding to a predetermined frequency from the degree of irregularity detected by said irregularity detecting means, and calculates the adjustment value corresponding to the damping force of said suspension means on the basis of the irregularity component.  
   
   
       4 . The suspension control system for a vehicle according to  claim 2 , wherein said calculating means stops the calculation of the adjustment value in accordance with a judgment by said entry judging means that the vehicle has entered into a turn around said corner, and wherein the adjustment value last calculated before stopping the calculation is used to control the damping force of said suspension devices in travel of the vehicle around the corner.  
   
   
       5 . The suspension control system for a vehicle according to  claim 1 , wherein said calculating means extracts an irregularity component corresponding to a predetermined frequency from the degree of irregularity detected by said irregularity detecting means, and calculates the adjustment value corresponding to the damping force of said suspension means on the basis of the irregularity component.  
   
   
       6 . A suspension control system for a vehicle equipped with a navigational device, said suspension control system comprising: 
 a plurality of suspension devices, each mounted between a suspension arm and a body portion of the vehicle, in association with a wheel of the vehicle, each of said suspension devices expanding and contracting in accordance with a damping force to damp forces on the vehicle received from a road surface traveled by the vehicle;    slip state detecting means for detecting a slip state of the road surface;    vehicle speed detecting means for detecting vehicle speed;    calculating means for calculating an adjustment value corresponding to the damping force on the basis of said detected vehicle speed, said detected slip state and information relative to a corner in the road surface received from the navigation device when the vehicle approaches the corner; and    output means for outputting the adjustment value to a suspension device so as to control the damping force of the suspension device.    
   
   
       7 . The suspension control system for a vehicle according to  claim 6 , wherein the suspension control system further comprises: 
 entry judging means for judging whether or not the vehicle has entered into a turn around corner on the basis of the turning of the vehicle detected by said turning detecting means; and    wherein said output means outputs said adjustment value to the suspension devices so as to control the damping forces in accordance with the adjustment value, responsive to a judgment by said entry judging means that the vehicle has entered into the turn around the corner.    
   
   
       8 . The suspension control system for a vehicle according to  claim 6 , wherein said calculating means stops the calculation of the adjustment value in accordance with a judgment by said entry judging means that the vehicle has entered into a turn around said corner, and wherein the adjustment value last calculated before the stopping the calculation is used to control the damping force of said suspension devices in travel of the vehicle around the corner.  
   
   
       9 . A suspension control method for cornering of a vehicle equipped with a navigation device and with wheel suspension devices, said suspension control method comprising: 
 detecting present position of the vehicle;    detecting approach of the vehicle to a corner;    detecting road surface condition at the detected present position;    obtaining information for the corner from the navigation device;    calculating an adjustment value corresponding to damping force of the suspension devices on the basis of both the detected road surface condition and the information for the corner obtained from the navigation device; and    controlling the damping force of the suspension devices in accordance with the calculated adjustment value.    
   
   
       10 . A suspension control method for cornering of a vehicle equipped with a navigation device and with wheel suspension devices, said suspension control method comprising: 
 detecting present position of the vehicle;    detecting approach of the vehicle to a corner;    obtaining information for the corner from the navigation device;    detecting a degree of irregularity of the road surface at the detected present position of the vehicle;    calculating an adjustment value corresponding to damping force of the suspension devices on the basis of the detected vehicle speed, the detected degree of irregularity of the road surface, and the information for the corner obtained from the navigation device; and    controlling the damping force of the suspension devices in accordance with the calculated adjustment value.    
   
   
       11 . A suspension control method for cornering of a vehicle equipped with a navigation device and with wheel suspension devices, said suspension control method comprising: 
 detecting present position of the vehicle;    detecting approach of the vehicle to a corner;    obtaining information for the corner from the navigation device;    detecting a slip state of the road surface at the detected present position of the vehicle;    calculating an adjustment value corresponding to damping force of the suspension devices on the basis of the detected vehicle speed, the detected slip state of the road surface, and the information for said corner obtained from the navigation device; and    controlling the damping force of the suspension devices in accordance with the calculated adjustment value.