Method for reducing steering torque in a steering system of a vehicle

Abstract

A method for reducing the steering torque in a steering system of a vehicle. A method including the steps of monitoring a driver's torque as applied by a driver of the vehicle; providing a plurality of torques that can be imposed on the steering system; and reducing the torques that can be imposed on the steering system by a central reduction factor if monitoring of the steering system reveals a violation of a safety criterion.

What is claimed is: 
     
         1 . A method for the reduction of steering torque in a steering system of a vehicle comprising the steps of:
 monitoring a torque applied by a driver of the vehicle;   providing a plurality of torques that can be imposed in the steering system; and   reducing the torques imposed by a reduction factor if monitoring reveals a violation of a safety criterion.   
     
     
         2 . The method of  claim 1  wherein the imposed torques are continuously reduced in the event of a violation. 
     
     
         3 . The method of  claim 1  wherein the reduction factor has a hysteresis. 
     
     
         4 . The method of  claim 1  wherein the monitoring includes the maximum permissible driver's torque. 
     
     
         5 . The method of  claim 1  wherein the monitoring includes the lateral dynamic reactions or yaw rates of the vehicle. 
     
     
         6 . The method of  claim 1  including the step of imposing said plurality of torques individually wherein each individually imposed torque can be individually reduced with the reduction factor. 
     
     
         7 . The method of  claim 1  wherein the imposed torques are reduced together with the reduction factor. 
     
     
         8 . A method for the reduction of steering torque in a steering system of a vehicle comprising the steps of:
 monitoring a torque applied by a driver of the vehicle;   providing a plurality of torques that can be imposed in the steering system;   establishing a safety criterion based on vehicle dynamics;   performing a plausibility check to determine if a violation occurs;   reducing torques imposed by the steering system in the event of a violation: and   increasing torques imposed by the steering system upon cessation of the violation.   
     
     
         9 . The method of  claim 9  including the steps of rapidly ramping out the imposed torque if a violation is detected; and
 smoothly increasing the imposed torque when a violation is no longer detected. 
 
     
     
         10 . A steering system of a vehicle comprising:
 a plurality of functional units for imposing torques on the steering system;   a monitoring unit for monitoring a driver's torque applied by a driver of the vehicle; and   a reduction unit for reduction of imposed torques by a reduction factor depending on the monitoring.   
     
     
         11 . The steering system of  claim 10  wherein the reduction unit is in communication with each functional unit. 
     
     
         12 . The steering system  claim 10  including a plurality of reduction units each reduction unit paired with a corresponding functional unit. 
     
     
         13 . The steering system of  claim 10  including a controller, said controller operative to determine a reduction factor and transmit said reduction factor to said reduction unit.