Angular displacement

About: Angular displacement is a research topic. Over the lifetime, 5102 publications have been published within this topic receiving 46081 citations. The topic is also known as: rotational displacement.

Method and device for earth acquisition using the pole star for a three-axis stabilized satellite in a low inclination orbit

Abstract: Earth acquisition from the Sun pointing attitude starts with angular displacement of the satellite so that, in the field of view of a Sun sensing system, the direction of the Sun is brought into an orientation S' such that subsequent rotation of the satellite about the orientation S' brings the Pole Star into the field of view of a star sensing system whose optical axis is substantially parallel to the pitch axis. During this rotation the stars sensed are compared with those in a catalog containing, in addition to the Pole Star, stars likely to be encountered upon such movement. At least two of these stars are identified and then the Pole Star is captured. The satellite is then rotated in pitch until the Earth is sensed and captured.

Determining initial rotor position of an alternating current motor

Abstract: Determination of an estimated initial angular position of the rotor of an AC motor includes application of voltages corresponding to a high frequency reference signal vector to the stator windings of the motor and production of an estimated initial angular position of the rotor as a function of the resulting q-axis stator current component iq_HF, adjustment of transformation of signal vectors from stationary to rotating coordinates and vice versa using the estimated angular position and production of an adjusted estimated angular position of the rotor as a function of the q-axis stator current component as adjusted. Determination of an initial estimated angular position of the rotor and production of an adjusted initial estimated angular position of the rotor is performed with the rotor at standstill and before initially applying voltage corresponding to the drive signal vector to the stator windings, and production of an initial value of a drive signal vector command in stationary coordinates uses the adjusted estimated angular position. Determination of an estimated angular position of the rotor after application of stator current may use a different method, such as a physical relative position sensor.

Process cartridge, electrophotographic image forming apparatus and electrographic photosensitive drum unit

Abstract: A process cartridge which is detachably mountable to a main assembly of an electrophotographic image forming apparatus includ-ing a driving shaft (180) having a rotational force applying portion by moving in a direction substantially perpendicular to an axis of the driving shaft, includes i) an electrophotographic photosensitive drum rotatable about an axis; ii) a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the drum, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force, a pre-engagement angular position in which the coupling member is inclined away from the axis and a disengaging angular position in which the coupling member is inclined away from the axis and iii) a regulating portion (170) for regulat-ing an inclination angle of the coupling member such that downward in-clination angle of the coupling member is smaller than an inclination an-gle of the coupling member when the coupling member is at the pre-en-gagement angular position, wherein in mounting the cartridge to the main assembly, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position, and in dis-mounting the cartridge from the main assembly, the coupling member moves from the rotational force transmitting angular position to the disen-gaging angular position to disengage from the driving shaft.

Angular position detection apparatus

Abstract: An angular position detection apparatus, which can improve a detection accuracy of the angular position by improving a linearity of an output characteristic with respect to an angular position detection apparatus, and to downsize an outer size thereof. A permanent magnet is fixed to a side surface of a rotor core, which integrally rotates with a detection target object. An inner surface of a cylindrical portion of the rotor core is closely confronted with an outer surface of a stator core. Thus, the angular position detection apparatus is formed as a radial gap type in which magnetic flux is gone through an air gap G 1 between the cylindrical portion and the stator core along a radial direction. A magnetic flux detection gap portion is formed at a center portion of the stator core so as to go through toward a diametral direction. A Hall IC is arranged in the magnetic flux detection gap portion. The permanent magnet is magnetized so that lines of magnetic force therein are parallel with each other. As a result, it can expand the range, in which the magnetic flux density in the magnetic flux detection gap portion linearly changes in proportion to the angular position of the rotor core, and it can improve the linearity of output characteristic of the Hall IC with respect to the angular position.