Circuit configuration and method for controlling a traction slip control system with brake and/or engine management

For an automotive vehicle having an undriven axle with two wheels mounted thereon and a driven axle with two wheels mounted thereon, one of said wheels mounted on said driven axle being a spare wheel which is smaller in diameter than a normal wheel, a circuit configuration for controlling traction slip of said automotive vehicle comprising:

• means for developing speed rotation signals representative of the rotating speeds of said wheels;
• means for developing a correction factor signal prior to traction slip control;
• said means for developing said correction factor signal including:
• (a) first comparison means responsive to said speed rotation signals representative of said rotating speeds of said wheels mounted on said undriven axle for developing a first difference signal representative of the difference in said rotating speeds of said wheels mounted on said undriven axle,
• (b) second comparison means responsive to said speed rotation signals representative of said rotating speeds of said wheels mounted on said driven axle for developing a second difference signal representative of the difference in said rotating speeds of said wheels mounted on said driven axle, and
• (c) third comparison means responsive to said first and said second difference signals for developing a correction factor signal representative of the between said difference in said rotating speeds of said wheels mounted on said undriven axle and said difference in said rotating speeds of said wheels mounted on said driven axle;
• means for adapting said speed rotation signal representative of said rotating speed of said spare wheel by said correction factor signal to said speed rotation signal representative of said rotating speed of the other wheel mounted on said driven axle;
• means for establishing a slip threshold representative of a traction slip level which must be exceeded before traction slip control can commence;
• means for developing a vehicle speed signal representative of the speed of said automotive vehicle;
• means for comparing said vehicle speed signal and said speed rotation signals, including the speed rotation signal representative of the rotating speed of said spare wheel adapted by said correction factor signal, to develop a signal representative of the onset of traction slip;
• and means for comparing said signal representative of the onset of traction slip with said slip threshold to determine when the onset of traction slip exceeds said slip threshold.