Abstract: A powertrain system includes a transmission, torque generating device, load coupled to a drive axle, a final drive unit in meshed gear engagement with the output shaft and the drive axle, and a controller. A requested output torque is processed using an open-loop lash state model populated with a capped output torque request table and a lash closure rate estimate table respectively providing a capped torque value and an estimated lash closure rate. Output speed is determined using a plant model, the capped torque value, and the estimated lash closure rate. The powertrain is controlled during the transition using the output speed. A lash angle may be calculated from the closure rate using an integrator logic block. A calibrated lash offset profile may be determined using the lash angle, and a reference speed may be generated using the lash offset profile.

Abstract: A powertrain system includes a transmission, torque generating device, load coupled to a drive axle, a final drive unit in meshed gear engagement with the output shaft and the drive axle, and a controller. A requested output torque is processed using an open-loop lash state model populated with a capped output torque request table and a lash closure rate estimate table respectively providing a capped torque value and an estimated lash closure rate. Output speed is determined using a plant model, the capped torque value, and the estimated lash closure rate. The powertrain is controlled during the transition using the output speed. A lash angle may be calculated from the closure rate using an integrator logic block. A calibrated lash offset profile may be determined using the lash angle, and a reference speed may be generated using the lash offset profile.

Abstract: A driveline system includes a drive axle coupled to a load, an electric machine, and a control system. The electric machine is responsive to a commanded torque, has a rotor shaft coupled to the axle, and produces an output torque that rotates the axle and load to produce driveline oscillation at a high resonant frequency. The control system generates the commanded torque using a nested control loop architecture in which an outer control loop operates at a sampling rate that is below a critical rate necessary for controlling the resonant frequency, and an inner control loop operates at a sampling rate that is above the critical rate. The inner loop determines a modified torque command and acceleration value in response to a commanded torque from the outer loop. The electric machine is thereafter controlled via the commanded torque.

Abstract: A method for managing output bump/clunk in a neutral state in a strong hybrid vehicle includes calculating a motor torque for an electric traction motor connected to a third node of a planetary gear set. The motor torque is calculated as a product of a predetermined inertia of the electric traction motor, the calculated acceleration of the engine, and a gear ratio of the planetary gear set. The calculated motor torque is commanded from the electric traction motor via a controller in a direction opposite the calculated acceleration of the output shaft, including transmitting a motor torque command to the electric traction motor for the duration of the neutral state. The vehicle includes the engine, a damper assembly, the transmission, and the controller.

Abstract: A method for managing output bump/clunk in a neutral state in a strong hybrid vehicle includes calculating a motor torque for an electric traction motor connected to a third node of a planetary gear set. The motor torque is calculated as a product of a predetermined inertia of the electric traction motor, the calculated acceleration of the engine, and a gear ratio of the planetary gear set. The calculated motor torque is commanded from the electric traction motor via a controller in a direction opposite the calculated acceleration of the output shaft, including transmitting a motor torque command to the electric traction motor for the duration of the neutral state. The vehicle includes the engine, a damper assembly, the transmission, and the controller.