Transmission control apparatus and method for vehicle traveling uphill or downhill

摘要

A control apparatus is disclosed for a road vehicle, which contains a transmission control. The control apparatus includes, among other things, devices which recognize whether the vehicle is on the crest of a hill or in a valley, and whether the vehicle is travelling uphill or downhill over the crest of the hill or through a valley. For this purpose, the control apparatus includes a first devices which compares and calculates the difference between two stationary torques M.sub.stat calculated at different times which are necessary for nonaccelerating travel of the vehicle. In addition, the control apparatus contains a second devices which checks the mathematical sign of the difference M.sub.stat. Finally, the control apparatus contains a third devices which compares the stationary torque M.sub.stat with a specified value a. By way of the output signals of the above-mentioned apparatus, a unilateral impedance element is controlled, which blocks the shift signals of a shift command transmitter in the operating conditions described above.