Speed control system for motor vehicles operating in a curved path

Speed control system for a motor vehicle, to control the speed of operation of the vehicle when the vehicle operates in a curved path, comprising

• lateral force sensing means (1d, 1e) secured to the vehicle for sensing lateral forces (S.sub.V, S.sub.H) and deriving sensed lateral force signals;
• means receiving said lateral force signals for determining change in lateral forces (.DELTA.S.sub.V, .DELTA.S.sub.H) with respect to time and deriving lateral force change signals;
• means (1a, 1b, 1c) for determining the slip angle (.delta..sub.V, .delta..sub.H) of the vehicle, as the vehicle operates in the path which is curved and deriving a slip angle signal;
• means coupled to said slip angle determination means (1a, 1b, 1c) for determining the change of the slip angle and deriving a slip angle change signal;
• quotient deriving means (7) coupled to said change in lateral force sensing means and said slip angle change signal deriving means, and receiving said lateral force change signals and said slip angle change signals (.DELTA.S.sub.V /.DELTA..delta..sub.V ;
• .DELTA.S.sub.H /.DELTA..delta..sub.H) for at least one of said front and rear wheels, respectively;
• to obtain a quotient signal representative of the quotient of the lateral force change signals and said slip angle change signals;
• comparator means (8) coupled to said quotient deriving means (7) receiving said quotient signal and comparing said quotient signal with a predetermined reference value (K) and deriving a comparison output signal;
• and
• means (12, 2, 4) responsive to said comparison output signal for controlling the speed of the vehicle if the comparison output signal derived from said comparator means (8) is indicative that said quotient has passed the predetermined reference value.