Control and regulation device for a vehicle travel drive

A control and regulation device for a vehicle travel drive, which comprises two hydrostatic transmissions (3, 4), drivable in parallel by at least on drive motor (1), each transmission comprising at least a hydraulic pump (12, 13) and a hydraulic motor (14, 15) and having an adjustable transmission ratio, which are drivingly connected with a right or left wheel or track arrangement (18, 19) of the vehicle, and each transmission having at least one adjustment device (30, 24;

• 31, 25) controlled by control signals (v.sub.l, v.sub.r) for adjusting the transmission ratio, and a control section, which comprises a desired-value setting means (5) and a signal processing means (42, 43), wherein the desired-value setting means sets desired-values of the transmission ratio of each of the hydrostatic transmissions, employing respective adjustable control levers (36, 37), and for generating corresponding desired-value signals (s.sub.l, s.sub.r), and the signal processing means processes the desired-Value signals to form output control signals, characterised by,
• the signal processing means (42, 43) executes signal processing steps of:
• forming a min./max.-window from the desired-value signals (s.sub.l, s.sub.r) in accordance with the relations
• min.=minimum (s.sub.l, s.sub.r)
• max.=maximum (s.sub.l, s.sub.r)
• wherein in each case the lower value of the desired-value signal (s.sub.l or s.sub.r) represents the minimum value of the min./max.-window, and the higher value of the desired-value signal (s.sub.l or s.sub.r) represents the maximum value of the min./max.window, and
• determining control signals (v.sub.;, v.sub.r) to be outputted in accordance with the equations
• v.sub.l .nu..sub.m +(s.sub.l -s.sub.r)
• v.sub.r =.nu..sub.m +(s.sub.r -s.sub.l),
• if a mean value .nu..sub.m =(.nu..sub.l +.nu..sub.r)/2, corresponding to a speed of travel relative to the longitudinal axis of the vehicle, of the determined control signals (.nu..sub.l,.nu..sub.r) lies within the min./max. window, or
• correcting the determined control signals (.nu..sub.l +.nu..sub.r) of the preceding determining step, for deriving corrected control signals (v.sub.l,v.sub.r) to be outputted in accordance with the equations
• .nu..sub.m <min.:
• v.sub.l =.nu..sub.l +(min.-.nu..sub.m)
• v.sub.r =.nu..sub.r +(min.-.nu..sub.m)
• v.sub.m =min.
• and
• .nu..sub.m >max.:
• v.sub.l =.nu..sub.l -(.nu..sub.m -max.)
• v.sub.r =.nu..sub.r -(.nu..sub.m -max.)
• v.sub.m =max.
• if the mean value (.nu..sub.m) of the determined control signals (.nu..sub.r) lies outside the min./max. window.