Heuristic multi-corner performance monitoring of brake actuator output for decentralized vehicle brake systems

A non-transient, computer-readable medium (CRM) storing instructions executable by a vehicle controller of a motor vehicle, the motor vehicle including multiple road wheels and a decentralized brake system with multiple brake actuators each operable to decelerate a respective one of the road wheels, the multiple brake actuators including front-left (FL), front-right (FR), rear-left (RL), and rear-right (RR) brake actuators, the instructions, when executed, causing the vehicle controller to perform operations comprising:

• receiving, from each of multiple sensors operatively attached to the brake actuators, sensor data indicative of a measured actuator output of a respective one of the brake actuators, the sensor data including a respective force feedback value and a respective pressure feedback value for each of the FL, FR, RL and RR brake actuators;
• calculating, for each of the brake actuators, a normalized corner output using the measured actuator output and a respective commanded target actuator output for the brake actuator, the normalized corner outputs including FL, FR, RL and RR normalized corner outputs for the FL, FR, RL and RR brake actuators, respectively, and the commanded target actuator outputs including a respective target force value and a respective target pressure value for each of the FL, FR, RL and RR brake actuators;
• determining a vehicle-calibrated weight value from a current vehicle speed and/or a current vehicle steering angle;
• calculating, for each of the brake actuators, a weighted average using the normalized corner output of the brake actuator and the vehicle-calibrated weight value, wherein calculating the weighted average includes calculating a full-system average for the FL, FR, RL and RR brake actuators based on the FL, FR, RL and RR normalized corner outputs;
• calculating an actuator error percentage as an absolute value of a mathematical difference between the weighted averages of the brake actuators;
• determining a vehicle-calibrated fault deviation threshold from the current vehicle speed and/or the current vehicle steering angle;
• detecting an actuator fault when the actuator error percentage is greater than the vehicle-calibrated fault deviation threshold;
• and
• commanding, responsive to determining the actuator error percentage is greater than the vehicle-calibrated fault deviation threshold, operation of the decentralized brake system to execute a vehicle-calibrated brake action to remediate the actuator fault.

A motor vehicle, comprising:

• a vehicle body;
• a plurality of road wheels attached to the vehicle body;
• a prime mover attached to the vehicle body and configured to drive one or more of the road wheels to thereby propel the motor vehicle;
• a decentralized brake system attached to the vehicle body and including a plurality of brake actuators each independently operable to decelerate a respective one of the road wheels to thereby slow or stop the motor vehicle, the brake actuators including front-left (FL), front-right (FR), rear-left (RL), and rear-right (RR) brake actuators;
• a plurality of brake sensors each operatively attached to a respective one of the brake actuators;
• and
• a vehicle controller communicatively connected to the decentralized brake system and the brake sensors, the vehicle controller being programmed to:
• receive a break request to activate the decentralized brake system;
• responsive to receiving the brake request, activate the brake actuators of the decentralized brake system to decelerate the road wheels of the motor vehicle;
• receive, from each of the brake sensors, sensor data indicative of a measured actuator output of a respective one of the brake actuators, the sensor data including a respective force feedback value and a respective pressure feedback value for each of the FL, FR, RL and RR brake actuators;
• calculate, for each of the brake actuators, a normalized corner output using the measured actuator output and a respective commanded target actuator output for the brake actuator, the normalized corner outputs including FL, FR, RL and RR normalized corner outputs for the FL, FR, RL and RR brake actuators, respectively, and the commanded target actuator outputs including a respective target force value and a respective target pressure value for each of the FL, FR, RL and RR brake actuators;
• determine a vehicle-calibrated weight value from a current vehicle speed and/or a current vehicle steering angle
• calculate, for each of the brake actuators, a weighted average using the normalized corner output of the brake actuator and the vehicle-calibrated weight value, wherein calculating the weighted average includes calculating a full-system average for the FL, FR, RL and RR brake actuators based on the FL, FR, RL and RR normalized corner outputs;
• calculate an actuator error percentage as an absolute value of a mathematical difference between the weighted averages of the brake actuators;
• determine a vehicle-calibrated fault deviation threshold from the current vehicle speed and/or the current vehicle steering angle;
• detect an actuator fault when the actuator error percentage is greater than the vehicle-calibrated fault deviation threshold;
• and
• responsive to determining the actuator error percentage is greater than the vehicle-calibrated fault deviation threshold, command operation of the decentralized brake system, a vehicle steering system, and/or a vehicle powertrain system to execute a vehicle-calibrated action to remediate the actuator fault.