Torque-based monitor in a hybrid electric vehicle

A torque based monitor system to control a torque splitting hybrid electric vehicle powertrain and regenerative brake system including a powertrain control module having a main controller processor comprising:

• an independent plausibility check processor independent of the main controller processor, the independent plausibility check processor performing a monitoring function in a first operating mode including reading a set of vehicle state sensors and communication interfaces shared with the main controller processor and determining when detected output shaft torque is greater than desired output shaft torque;
• the independent plausibility check processor performing a limiting function of torque output of the hybrid electric vehicle powertrain in a second operating mode by limiting detected output shaft torque to less than desired output shaft torque when detected output shaft torque is greater than desired output shaft torque;
• the independent plausibility check processor performing a shut down function of the torque output of the hybrid electric vehicle powertrain in the second operating mode when a fault is detected in the powertrain control module;
• the main controller processor determining a main controller desired output shaft torque from the vehicle state sensors and the independent plausibility check processor independently determining an independent plausibility check desired output shaft torque from the vehicle state sensors;
• and
• the independent plausibility check processor includes a minimizer function, wherein the minimizer function determines a vehicle desired output shaft torque as the smaller of the main controller desired output shaft torque and the independent plausibility check desired output shaft torque.

A method for monitoring torque of a torque splitting hybrid electric vehicle powertrain and regenerative braking system with a powertrain control module having a main controller comprising the steps of:

• monitoring a set of vehicle state sensors and communication interfaces through the main controller;
• determining a main controller detected output shaft torque from the vehicle state sensors;
• determining when the main controller detected output shaft torque is greater than a main controller desired output shaft torque;
• monitoring the set of vehicle state sensors and communication interfaces shared with the main controller through an independent plausibility check;
• determining an independent plausibility check detected output shaft torque from the vehicle state sensors;
• determining when the independent plausibility check detected output shaft torque is greater than an independent plausibility check desired output shaft torque;
• limiting torque output of the hybrid electric vehicle powertrain when the independent plausibility check detected output shaft torque is greater than the independent plausibility check desired output shaft torque;
• shutting down torque output of the hybrid electric vehicle powertrain when a fault is detected in the powertrain control module;
• comparing the main controller desired output shaft torque with the independent plausibility check desired output shaft torque;
• and
• choosing the smaller of the main controller desired output shaft torque and the independent plausibility check desired output shaft torque.