Abstract: A system for determining the absolute position of a multi-turn shaft is disclosed. The shaft is mounted in an elliptically shaped wave generator. The wave generator is coupled to a flex spline which is deformed to match the wave generator. The exterior surface of the flex spline has a number of gear teeth. The flex spline is installed within a cylindrical, circular spline. The circular spline has an interior diameter which is slightly larger than the largest diameter of the flex spline. The interior surface of the circular spline has a number of teeth which interlock with the teeth of the flex spline. In such a manner, the rotation of the shaft will cause an angular displacement of the circular spline. A position sensor is located on the circular spline and serves to track the position of the circular spline which is proportional to the absolute position of the shaft.

Abstract: A linear position sensing system with improved accuracy is shown. The sensor system has a magnetic field detector which senses the position of a target object. The target object has a magnet which emits a magnetic field. The position of the target object corresponds to the angle of the detected magnetic field. The linearity of the change in magnetic field angle is roughly proportional to the change in position of the target object. The magnet is magnetized on a slope which is determined by the path of traversal of the target object. In this manner, greater linearity in change of field angle relative to target object travel is achieved by altering the slope of the division between the magnetic poles.

Abstract: A variable reluctance sensor is shown for determining the speed or position of a moveable target object. The sensor has a magnet which is coupled to a pole piece. A wire coil is located annularly around the pole piece. The magnet generates flux in the coil which is changed by the movement of the target object. A second bucking magnet is annularly located around the coil and generates a flux field to reinforce the flux in the coil and to prevent flux from leaking from the wire coil and pole piece. In this manner, the voltage output from the coil is increased due to the decrease in flux leakage. A processor unit is coupled to the wire coil. The processor unit measures the reluctance generated in the coil from the movement of the target object.

Abstract: A system for determining the absolute position of a multi-turn shaft is disclosed. The shaft is mounted in an elliptically shaped wave generator. The wave generator is coupled to a flex spline which is deformed to match the wave generator. The exterior surface of the flex spline has a number of gear teeth. The flex spline is installed within a cylindrical, circular spline. The circular spline has an interior diameter which is slightly larger than the largest diameter of the flex spline. The interior surface of the circular spline has a number of teeth which interlock with the teeth of the flex spline. In such a manner, the rotation of the shaft will cause an angular displacement of the circular spline. A position sensor is located on the circular spline and serves to track the position of the circular spline which is proportional to the absolute position of the shaft.

Abstract: A linear position sensing system with improved accuracy is disclosed. The sensor system has a magnetic field detector which senses the position of a target object. The target object has a magnet which emits a magnetic field. The position of the target object corresponds to the angle of the detected magnetic field. The linearity of the change in magnetic field angle is roughly proportional to the change in position of the target object. The magnet is magnetized on a slope which is determined by the path of traversal of the target object. In this manner, greater linearity in change of field angle relative to target object travel is achieved by altering the slope of the division between the magnetic poles.

Abstract: A linear position sensing system is disclosed. The system mounts a pair of magnets on an object which traverses a linear path. The position of the object is determined by a sensor unit which has a magnetic field transducer. The magnetic field transducer detects the field angle from the magnetic field generated between the magnets. The magnetic field transducer is preferably a Wheatstone bridge arrangement with magneto-resistive elements. The output signal of the transducer is a sinusoidal shape representing the angle of the magnetic fields generated by the magnets to the transducer. The transducer signal is sent to a signal processor. The signal processor calculates the position of the magnets and thus the object by determining the arctangent value of the sinusoidal signals. The magnets also are placed at a predetermined angle to one another in order to optimize the linear response of the sensor.

Abstract: A variable reluctance sensor is disclosed for determining the speed or position of a moveable target object. The sensor has a magnet which is coupled to a pole piece. A wire coil is located annularly around the pole piece. The magnet generates flux in the coil which is changed by the movement of the target object. A second bucking magnet is annularly located around the coil and generates a flux field to reinforce the flux in the coil and to prevent flux from leaking from the wire coil and pole piece. In this manner, the voltage output from the coil is increased due to the decrease in flux leakage. A processor unit is coupled to the wire coil. The processor unit measures the reluctance generated in the coil from the movement of the target object.