Abstract: Cordless power tools include a pistol housing having an upper portion that merges into a downwardly extending handle, a DC motor residing in the upper portion of the housing, the DC motor having a rotor that drives an output shaft; a torque transducer on board the tool in communication with the output shaft; and a dynamic motor control circuit residing in the housing in communication with the motor and torque transducer. The dynamic motor control circuit includes a Kelvin resistor in communication with the motor for measuring motor current and digital hall switches in communication with the motor for measuring motor speed. The motor current can vary by at least 100 A during operation.

Abstract: A method of identifying an object class uses a model based upon appearance parameters derived by comparing images of objects of different classes. The model includes a representation of a probability density function describing a range over which appearance parameters may vary for a given class of object, the model further including a defined relationship between the appearance parameters and the probability density function. The method generates appearance parameters representative of an unknown object, estimates an appropriate probability density function for the unknown object using the defined relationship between the appearance parameters and the probability density function, then iteratively modifies at least some of the appearance parameters within limits determined using the probability density function to identify the object class.