A system for calculating observed applied brake force, comprising: a current sensor , in communication with a controller ; a position sensor , in communication with the controller and configured to measure a rotational speed of a motor shaft; and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: receiving, by the controller, a motor current from the current sensor at a first time; calculating , by the controller, a first electromagnetic torque from the motor current; calculating , by the controller, a first flywheel angular velocity ; receiving, by the controller, a motor shaft angular velocity from the position sensor at a second time; subtracting , by the controller, the first flywheel angular velocity and the motor shaft angular velocity received at the second time to obtain a first angular velocity difference; calculating , by the controller , a first observed disturbance torque from the first angular velocity difference; and calculating , by the controller, a first observed applied brake force from the first observed disturbance torque. a current sensor , in communication with a controller ; a position sensor , in communication with the controller and configured to measure a rotational speed of a motor shaft; and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: receiving, by the controller, a motor current from the current sensor at a first time; calculating , by the controller, a first electromagnetic torque from the motor current; calculating , by the controller, a first flywheel angular velocity ; receiving, by the controller, a motor shaft angular velocity from the position sensor at a second time; subtracting , by the controller, the first flywheel angular velocity and the motor shaft angular velocity received at the second time to obtain a first angular velocity difference; calculating , by the controller , a first observed disturbance torque from the first angular velocity difference; and calculating , by the controller, a first observed applied brake force from the first observed disturbance torque. receiving, by the controller, a motor current from the current sensor at a first time; calculating , by the controller, a first electromagnetic torque from the motor current; calculating , by the controller, a first flywheel angular velocity ; receiving, by the controller, a motor shaft angular velocity from the position sensor at a second time; subtracting , by the controller, the first flywheel angular velocity and the motor shaft angular velocity received at the second time to obtain a first angular velocity difference; calculating , by the controller , a first observed disturbance torque from the first angular velocity difference; and calculating , by the controller, a first observed applied brake force from the first observed disturbance torque. <EOS>