Apparatus and method for measurement of position and velocity

Abstract

A sensor for locating the position of and measuring the velocity of an impacting object. The sensor employs a net attached at each edge to sensor modules mounted on a frame. Each sensor module includes an output drum, a take up drum, a spring and a motor. The net is attached to the sensor modules by cords wound on a spring loaded output drum. The drum is coaxial with a motor that generates a voltage proportional to the angular velocity of the drum. The diode isolated motor partially dissipates the energy of impact to heat on the return stroke in response to the restorative force of the spring. An object impacting a net draws the cord from the output drum, generating a voltage from an attached motor. A maximum voltage or an integrated voltage generated by the motors determines the velocity of impact. Each particular net has an associated set of axes. A pair of motors, their position known relative to the frame, are placed along these axes attached to one or more strings by a cord. The position of impact is determined by the motors generating the largest voltage. Alternatively, the impact position may be determined by the two pairs of sensors generating the highest voltage, where the sensor pair is connected to the same string. A take up drum and a spring bias the system toward a rest position, returning the object to a predetermined area.