For passenger cars propelled by the dedicated compound power-split hybrid powertrain, driveline oscillations-induced vehicle jerks are often excited during clutch-to-clutch shift operations while drive mode changes. To tackle this issue, a coordinated dynamic surface control is developed by integrating clutch slips and motor torque compensation strategies through trajectories tracking of both clutch slip speed and wheel speed. Uncertainties or disturbances are treated to be additional inputs of the system, and model nonlinearities are considered and implemented in discretized form through lookup tables. A complex simulation model including electro-hydraulic system is proposed and validated via experiments. The coordinated controller is validated by collaborative simulation. Numerical examples are made and simulation results verify that the controller is effective and robust enough against parameters uncertainties.

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For fast drive mode transitions by shifting clutches equipped in the dedicated compound power-split hybrid transmission, correct estimations of pressure and torque of the clutches are crucial for control strategies. A hierarchical estimator is proposed herein for individual estimation of the clutch torques, consisting of not only the reference layer containing the unknown input observer of vehicle resistance and the reduced-order observer of drive shaft torque, but also the estimation layer combining the unknown input observer with the reduced-order observer. The estimator is implemented to strike a balance between estimation accuracy in the steady state and real time response in the transient state. For validation of the estimator, simulations and real car tests are carried out in specific drive conditions. By numerical results, it’s demonstrated that excellent predictive abilities are found including reasonably small estimation error and adaptive capability and, as a result, shift to shift induced driveline oscillations and vehicle jerks are reduced significantly.