摘要:
A method for determining the position of a shaft of a commutated direct current (DC) motor based on the current ripples contained in an armature current signal includes digitally sampling the armature current signal to generate signal values at sampling points. The signal value corresponding to a current sampling point and selected signal values corresponding to previous sampling points in a time interval containing the sampling points are compared. Either a rising or falling slope detection signal is generated if the comparison is indicative of either an increasing or decreasing tendency in the magnitudes of the signal values. The rising and falling slope detection signals are respectively indicative of rising and falling current ripple slopes. A current ripple signal is generated if rising and falling slope detection signals are generated one after the other in a given period. The shaft position is determined based on the current ripple signal count.
摘要:
A first set of coordinates (100) of a device and an estimated positional error (nullEPEnull) radius (102) is measured. An EPE circle (104) is derived, in which the device is approximately located, from the first set of coordinates (100) and the EPE radius (102). When it is determined that the EPE radius (102) exceeds a predetermined threshold, a first range (106) between the device and a ranging site (108) is measured, and a locus of points (110) on and within the EPE circle (104) is determined, wherein a distance between the ranging site (108) and each point in the locus of points (110) approximately equals the first range (106).
摘要:
An electronic compass comprises a saturable core sensor (2) with a core (3) made of ferromagnetic material surrounded by an electric winding (3null), a first couple of electric windings (4, 5) around the sensor (2) having reciprocally orthogonal turns, a second couple of electric windings (8, 9) around said first couple (4, 5) having reciprocally orthogonal turns. The gap between the winding (3null) and the first couple of windings (4, 5) and between the first couple of windings (4, 5) and the second couple of windings (8, 9) is filled with a material having a low thermal expansion coefficient, preferably epoxy fibreglass reinforced plastic, supporting the windings of said first (4, 5) and second (8, 9) couple of windings. It is also provided an electronic control circuit (20, 21, 22).
摘要:
A system, apparatus (60) and method (20) of determining an average axis of rotation (Wf) and defined center of rotation (Cr) of a rotatable device (10) having a rotation axis which is nominally fixed in global coordinates (X,Y,Z) and having a plurality of target points (P1-PN) affixed thereon. It comprise a data collector (62) for obtaining target point location data from the device target points (P1-PN) for a plurality of rotated positions, a transformer (64) for translating and rotating the target point data in global coordinates, and an iterative algorithm (66) for positioning a secondary coordinate system (U,V,W) to be coincident with the axis of rotation (Wf), and defined center of rotation (Cr) of the rotatable device (10).
摘要:
A system of sensing elevator car position is presented that dynamically compensates for problems due to frictional slippage of its mechanical connection and/or building settlement. The system comprises an elevator car within an elevator hoistway. An encoder is mounted within the elevator hoistway and mechanically connected to the elevator car. The mechanical connection drives the encoder which generates data indicative of the position of the elevator car. Either one of a position sensor and a position sensor actuator is mounted to a landing of the hoistway. The other one of the position sensor and position sensor actuator is mounted to the elevator car. The position sensor generates data indicative of the elevator car floor reaching a predetermined distance from the elevator landing when actuated by the position sensor actuator. An elevator position controller receives the data generated by both the position sensor and the encoder. The mechanical connection may include an elevator rope frictionally driving a governor sheave of an elevator speed governor system upon which the encoder is mounted.
摘要:
This present invention is subjected to the field of instrument & measurement technology based on Micro Electro-mechanical Systems (MEMS). A micro azimuth-level detector comprises multi-sensors (triaxial silicon accelerometers with the processing circuit and triaxial silicon magnetometers with the processing circuit), A/D converter for converting the analog signals of the sensors to the digital signals, microprocessor in which the signal-processing and attitude computation are carried out, RS-232 for connecting the microprocessor with PC, and Operation-Display interface. An attitude computation method uses the Orientation Cosine Conversion of the earth's gravity and magnetic field.
摘要:
A head stack assembly installation system with a frame supporting a head stack installation tool including a robotic assembly supporting a measurement assembly communicating with a computer hosting an installation software program. The robotic assembly picks and places the head stack assembly into the head disc assembly and the measurement assembly collects and communicates process positions and force parameters to the computer, the computer calculating distance and force data. The installation software program directs and controls enactment of process steps followed by the head stack installation tool to install or abort installation of the head stack assembly based on the position and force data.
摘要:
A method and apparatus for estimating angular rates for movable bodies in space. A high-pass component qg is produced by a reasonable rate gyro connected in cascade with an internal or external high-pass filter. A low-frequency component ql is produced by an accelerometer and a multiplier, which includes the axial velocity Vm of the body, and a transfer function H(s), where the properties of the transfer function H(s) are adapted to the properties of the high-pass filter. The cascade-connected rate gyro and high-pass filter are interconnected with the low-frequency rate estimator and fixedly mounted in a movable body, such as a guided weapon, and produce a resultant rate gyro signal qc that is am estimate of the body's angular rate about the relevant axis.
摘要:
A system which derives the attitude of a body as it rotates and travels through the earth's magnetic field. At least one magnetometer is placed in the body and provides an output signal during flight of the body. The zero crossings of the output signal are used to formulate a time discriminant. This time discriminant is compared with a roll angle discriminant for which a value of attitude has been previously determined. From the comparison, the attitude during flight may be determined. A time discriminant can also be formulated using two magnetometers.
摘要:
A method for the determination of the position, in particular the future position, of an object, in particular of a particle or the like, in which case the progression of the position of a reference object is determined, in which case the reference object passes through a process and in which case the differences of the positions of the object and of the reference object are formed, has been designed for the purpose of a good determination of the position of the object with simultaneously the lowest possible technical expenditure in such a manner that error position terms are formed from the differences, and that the error position terms are weighted with at least one correction factor.