Method and system for assisting the start-up of a motor vehicle

Abstract

The present invention provides start-up assistance for a motor vehicle having braking equipment which, in the stationary state of the mo-or vehicle, automatically or under the control of a vehicle driver summons up braking forces needed for the stationary state. To assist start-up of the motor vehicle through a reduction of the braking forces generated in the stationary state, a start-up request of a vehicle driver is determined when defined conditions, which are to be met for start-up of the motor vehicle, exist in the stationary state. Once a start-up request has been recognized, the operating state of the motor vehicle is checked until an operating state required for start-up exists. Once such an operating state is reached, the braking equipment of the motor vehicle is controlled in such a way that its braking forces generated in the stationary state are reduced to allow start-up of the vehicle.

1 . Method of assisting the start-up of a motor vehicle having a braking equipment ( 6 ) which is activated in the stationary state, comprising the following steps: 
 determination of starting parameters characterizing an operating state of the motor vehicle in which the motor vehicle is to be brought from a stationary state into a traveling state;    determination of current operating states of the motor vehicle until an operating state is determined which is occasioned by an active connection between an engine ( 40 ) and driving wheels of the motor vehicle, and    control of braking equipment ( 6 ) which is activated in the stationary state so as to reduce the braking forces generated in the stationary state in order to allow startup of the motor vehicle,    characterized in that    the determination of actual operating states is effected until an operating state is determined in which a current inclination of the motor vehicle has varied by a defined value relative to an inclination of the motor vehicle in the stationary state.    
     
     
         2 . Method according to  claim 1 , wherein 
 the determination of current operating states is effected until an operating state is determined in which a current inclination change of the motor vehicle reaches a predetermined value.    
     
     
         3 . Method according to  claim 1  or  2 , comprising the following steps: 
 definition, for the stationary state, of an initial operating state which has to exist prior to determination of the starting parameters, and  
 determination of current operating states of the motor vehicle in the stationary state until an operating state is determined which corresponds to the initial operating state.  
 
     
     
         4 . Method according to  claim 3 , wherein 
 when defining the initial operating state, an operating state is defined in which an ignition system ( 10 ) is activated and/or the vehicle velocity equals zero and/or the braking equipment ( 6 ) is generating braking forces.    
     
     
         5 . Method according to  claim 3  or  4 , wherein 
 when defining the initial operating state an operating state is defined in which a clutch pedal ( 30 ) and/or a clutch pedal switch ( 32 ) and/or a clutch switch has/have been operated.  
 
     
     
         6 . Method according to one of the preceding claims, wherein 
 when determining the starting parameters at least one of the parameters is determined which indicate that an accelerator pedal ( 18 ) has been actuated and/or a current rotation speed of the engine ( 40 ) is higher than a defined rotational speed of the engine ( 40 ) during no-load operation, and/or a requested engine torque is higher than the current engine torque, and/or the current engine torque is higher than an idling torque defined for no-load operation of the engine ( 40 ).    
     
     
         7 . Method according to one of the preceding claims, wherein 
 when determining the starting parameters at least one of the parameters is determined which indicate that an accelerator pedal switch ( 20 ) has been actuated and/or the accelerator pedal has been dynamically actuated, and/or a current change of the engine torque is greater than zero.    
     
     
         8 . Method according to one of the preceding claims, wherein 
 determination of the starting parameters is effected until at least one of the starting parameters characterizes an operating state which differs from the operating state of the motor vehicle in the stationary state.    
     
     
         9 . Method according to one of the preceding claims, wherein 
 when determining current operating states a current engine torque and/or a current change of the engine torque and/or a change of a requested engine torque and/or a time-averaged change of a current engine torque is/are determined.    
     
     
         10 . Method according to  claim 9 , wherein 
 the determination of operating states is effected until the current engine torque is higher than a combination of an engine torque, which is defined for no-load operation of the engine ( 40 ), and a correction factor, and/or the current change of the engine torque and/or the current change of the requested engine torque is greater than zero, and/or the current time-averaged change of the engine torque during a defined period of time lies within a defined range.    
     
     
         11 . Method according to one of the preceding claims, wherein 
 control of the braking equipment ( 6 ) is effected in response to an operating state of the braking equipment ( 6 ) in the stationary state, and/or the determined starting parameters, and/or the determined current operating state, and/or a current operating state during control of the braking equipment ( 6 ).    
     
     
         12 . Method according to one of the preceding claims, wherein 
 during control of the braking equipment ( 6 ) the current operating state of the motor vehicle is controlled in response to an operating state of the braking equipment ( 6 ) in the stationary state, and/or the detected startup parameters, and/or the detected current operating state, and/or a current operating state when controlling the braking equipment ( 6 ).    
     
     
         13 . Method according to  claim 12 , wherein 
 during control of the braking equipment ( 6 ) a current speed and/or a current torque of the engine ( 40 ) is/are controlled.    
     
     
         14 . System for assisting the start-up of a motor vehicle having a braking equipment ( 6 ) that is activated in the stationary state, comprising 
 a control device ( 2 ) and    detection devices ( 8 ,  16 ,  22 ,  28 ,  34 ,  38 ,  42 ,  44 ,  46 ,  48 ,  54 ) for acquiring parameters characterizing operating states of the motor vehicle, and an interface ( 4 ) for control of the braking equipment ( 6 ), the control device ( 2 ) being designed to be operated in accordance with one of the methods according to  claims 1  to  13 .    
     
     
         15 . Computer program product having: 
 program code portions for carrying out the steps according to one of patent  claims 1  to  14 .    
     
     
         16 . Computer program product according to  claim 15 , stored on a computer-readable recording medium or in a computer-readable recording device.