摘要:
A three-axis stabilized, earth-oriented satellite has an attitude control system with regulators, actuators, an earth sensor that carries out measurements along two axes and a sun-sensor arrangement that also carries out measurements along two axes. The field of view of the sun-sensor arrangement covers the round angle on a plane of the satellite-fixed coordinate system. Only the sun-sensor arrangement and the earth sensor act as measurement transducers. A sun and earth acquisition process for such a satellite has the following steps: seeking the sun; setting the sun vector in a first direction of reference; setting the speed of rotation of the satellite around the sun vector at a constant value; setting the sun vector in a second direction of reference, so that by rotating the satellite around the latter the optical axis of the earth sensor sweeps over the earth; and picking up the earth. Special regulating rules are disclosed.
摘要:
The invention relates to ternary polymer alloys comprised of thermoplastic polymers which alloys are comprised of the following components:A) 0.1-99.9 wt. % of a polyester-polycarbonate mixture comprised of:a.1) 0.1-99.9 parts by weight (pbw) of a polyester, anda.2) 99.9-0.1 pbw of a polycarbonate; andB) 99.9-0.1 wt. % of a poly(meth)acrylate ester PA containing 20-100 pbw of units of at least one monomer of formula I ##STR1## where R.sub.1 represents hydrogen or methyl, R.sub.2 represents hydrogen a C.sub.1-6 alkyl group or a group --(CH.sub.2).sub.n --QR.sub.3, wheren represents zero or a number in the range 2-6, andQ represents oxygen or a group --NR.sub.4, andR.sub.3 and R.sub.4 mutually independently represent hydrogen or a C.sub.1-4 alkyl group; andA represents a C.sub.1-4 alkylidene group or a group --(CH.sub.2).sub.m --O--, wherem is a number from 2 to 6, andq is zero or 1 wherein the sum of the wt. % of components (A) and (B) is 100% and the sum of the pbw figures of components (a.1) and (a.2) is 100 pbw.
摘要:
The invention relates to polymer blends, which can be processed like a thermoplastic, whose bulk A) (50 to 90 wt. %) is polymethylmethacrylate or a polymethacrylate resin; and which also contain 5 to 40 wt. % of, as component B), a tough polymer, in particular an ABS polymerizate; and contain 5 to 40 wt. % of, as component C), a polycarbonate or a polyester carbonate. By adding component C), the heat resistance, impact strength and notched impact strength are improved in the known polymethacrylate/ABS blends. With the addition of an impact modifying component D), contained in quantities of 0 to 20 wt. % in the polymer blend, the impact strength and notched impact strength can be further raised. Preferably, recycled polymers can be added as the polymeric mix components.
摘要:
A method and arrangement for aligning a space vehicle with respect to a reference object is disclosed. A measuring direction is obtained by determining the angular orientation direction of the space vehicle with respect to the reference object and subsequently the space vehicle is aligned by means of actuators such that the measuring direction corresponds to a reference direction on the space vehicle. The actuators are driven by control signals which are derived from the measuring direction to cause control torques on the space vehicle. The orientation of the space vehicle and reference object is determined only with respect to a single measuring direction along a main axis of a direction sensor. The following steps are taken if the measuring direction does not correspond to the reference direction on the space vehicle:a) the space vehicle is rotated around the reference direction on the space vehicle,b) controlling a fault component of the direction of the reference object situated in the measuring direction by locking on a first control torque perpendicularly with respect to the reference direction on the space vehicle, andc) controlling the unmeasurable component of the direction of the reference object situated perpendicularly with respect to the measuring direction by locking on a second control torque perpendicularly with respect to the reference direction and perpendicularly with respect to the first steering moment.
摘要:
An arrangement of light wave conductors are correlated with the sensor areas of an image sensor array. The individual light wave conductors consist of glass wafers or glass fibers whose width or diameter each corresponds to the width of a sensor area. The light wave conductors are joined to form a block whose top surface area corresponds to the area of a document to be scanned line by line.
摘要:
The invention relates to a process for applying solid layers (14) to an object (12) to be coated by means of at least one radiation source (2), in particular a laser radiation source, which comprises at least the step of removal of a sample (4) in the solid state in at least partially different sections (6) by means of at least one beam (8) emitted by the radiation source (2) to at least partly convert the sample (4) into a gaseous state (10) which deposits at least partially on the object (12) to be coated in order to form a solid layer (14), where at the same time the alignment of a trace of the emitted beam (8) is altered during the step of removal of the sample and the sample (4) is moved.
摘要:
A converter arrangement has at least one AC voltage connection, at which an alternating current can be fed in or drawn, and at least one DC voltage connection, at which a direct current can be fed in or drawn. The converter arrangement contains at least two series circuits connected in parallel. The external connections of the series circuits form the DC voltage connections of the converter arrangement. Each of the series circuits is connected in parallel and contains in each case at least two submodules connected in series, each of the submodules containing at least two switches and a capacitor. An energy store is to be connected to the capacitor of at least one of the submodules, wherein a filter is connected electrically between the capacitor and the energy store.
摘要:
A contact bank, which can be terminated, or is terminated, at least one terminal module serving for signal communication and being adapted to allow telecommunications lines to be connected therewith, or at least one supplementary module, of a telecommunications distribution point, which is connected to a terminal module, whereby the contact bank further is mountable or mounted in the telecommunications distribution point, includes: (a) a plurality of tapping contacts directly and permanently electrically connected to the contacts of the module in the terminated condition of said contact bank; (b) a smaller number of outlet contacts than of tapping contacts; (c) a plurality of remote-controllable switches for selectively electrically connecting said outlet contacts to said tapping contacts; and (d) a control device for controlling the plurality of switches.
摘要:
A digital modulation process and apparatus for converting an input signal comprising a time variable series of sampling values, each of which sampling values remains constant within a fixed sampling period, into output signals representing a sequence of positive and/or negative pulses having a constant amplitude and a variable pulse width and frequency. The input signal and modulator parameters are supplied to a data processor. In order to reduce computing expenditures and at the same time achieve an increase in precision, by means of the computing system, the switch-on and switch-off points in time t.sub.se, t.sub.sa of the pulses as well as their operational signs are computed in one operation directly for each sampling period .DELTA.t.sub.k.
摘要:
This invention relates to high impact strength polymer blends containing at least two two-phase or multiphase polymers P1 and P2, which in turn contain at least one toughening phase A1 or A2 and at least one hardness phase B1 or B2. B1 and B2 differ in chemical structure and are thermodynamically compatible with one another. The polymer blend optionally contains another thermoplastic polymer B'3 and/or another two-phase or multiphase polymer P4 contain at least one toughening phase A4 and at least one hardness phase B4, provided that B'3 and/or B4 are different from B1 and B2 and are thermodynamically compatible with B1 and B2.