ETM Crankshaft Position Control for Lightweight Engine Starting

The patent applies dynamic control by varying the torque output of the motor-generator unit based on the real-time position of the piston in the combustion chamber. The controller adjusts the torque profile according to the crankshaft angle, providing maximum torque when the piston is near bottom dead center and reducing torque as the piston approaches top dead center. This dynamic torque adjustment allows a smaller motor-generator unit to provide sufficient starting torque throughout the entire starting sequence without requiring excessive weight or size.

The patent changes the operational parameters of the motor-generator unit during the starting sequence by adjusting the torque delivery based on piston position. The controller modifies the electrical parameters (current, voltage) supplied to the motor-generator to optimize torque output at different crankshaft angles. This parameter adjustment allows the system to achieve reliable starting with a lighter motor-generator unit compared to conventional electric starting systems that deliver constant or excessive torque throughout the entire rotation.

The patent implements a feedback control system where the controller continuously monitors the crankshaft position (and thus piston position) and adjusts the torque output of the motor-generator unit in real-time. This closed-loop feedback mechanism ensures that the precise torque profile is maintained even during rapid starting sequences. The controller uses the position feedback to calculate the required torque at each instant, enabling both fast starting and precise torque control to be achieved simultaneously.