Down-shift acceleration overshoot compensation in automotive electronic longitudinal dynamics control of autonomous motor vehicles

An automotive electronic longitudinal dynamics control system (LDM) of a motor vehicle (MV);

• the motor vehicle (MV) comprises a powertrain (PWT) comprising a propulsor (P) electronically controlled by an electronic engine control module (ECM) and an automatic transmission (T) electronically controlled by an electronic automatic transmission control module (ATM) to transmit mechanical power generated by the propulsor (P) to drive wheels (W) of the motor vehicle (MV) and comprising an automatic gearbox (G) having a plurality of gears (gi) with corresponding gear ratios (R(gi));
• the electronic automatic transmission control module (ATM) is designed to output data indicative of a currently engaged gear (gi) and a next engaged gear (gi+1) that will be engaged after the currently engaged gear (gi);
• the electronic engine control module (ECM) is designed to receive data indicative of an engine torque request (ET(t, gi)) and to responsively control the propulsor (P) based on the received engine torque request (ET(t, gi)) to cause the propulsor (P) to output an engine torque equal to the requested engine torque ((ET(t, gi));
• the automotive electronic longitudinal dynamics control system (LDM) is designed to:
• receive from the electronic automatic transmission control module (ATM) data indicative of the currently engaged gear (gi) and the next engaged gear (gi+1) that will be engaged after the currently engaged gear (gi);
• receive a reference quantity indicative of a reference longitudinal dynamics (aref (t)) to be followed and a measured quantity indicative of a measured longitudinal dynamics (a(t));
• compute the engine torque request (ET(t,gi)) for the electronic engine control module (ECM) based on a longitudinal dynamics error (ea(t)) indicative of a deviation of the measured longitudinal dynamics (a(t)) from the reference longitudinal dynamics (aref(t)), on a control law (f(ea(t), gi)) and on the currently engaged gear (gi) and the next engaged gear (gi+1);
• the automotive electronic longitudinal dynamics control system (LDM) is characterized in that it is further designed to:
• compute a current engine torque request (ET(t, gi)) based on the longitudinal dynamics error (ea(t)), the control law (f(ea(t), gi)) and the currently engaged gear (gi);
• compute a fit factor (k) based on the gear ratios (R(gi), R(gi+1)) of the currently engaged gear (gi) and the next engaged gear (gi+1);
• and
• compute an adjusted engine torque request (ET(t, gi+1)) based on the current engine torque request (ET(t, gi)) and the fit factor (k).