Showing papers on "Angular displacement published in 1981"

Structure from motion of rigid and jointed objects

Abstract: A method for structure from motion is presented. The method makes a motion assumption about the objects being viewed. The motion assumption is that all motion consists of translations and rotations about a fixed axis. Parallel projection is also assumed. This makes it possible to interpret the motion of as few as two rigidly connected points. The method works for both rigid and jointed objects. Results of a test of this method on Johansson's data are presented.

Flexure joint, particularly for connecting a gyroscope to its driving shaft

Abstract: The flexure joint for connecting two members for relative angular displacement comprises a pair of flexure leaves which merge with the members at their ends and cross each other and are rigidly connected with each other at the crossing point. Relative angular displacement of the members results in a flexure of the leaves. The flexure universal joint for connecting a gyroscope to its driving member comprises a Cardan member hinged by a pair of co-axial spaced flexure joints of the kind described hereinabove for relative angular displacement about a first hinge axis to the driving member and hinged by a second pair of co-axial spaced flexure joints of the same type to the gyroscope member for relative angular displacement about a second hinge axis, which intersects the axis of rotation of said gyroscope at right angles, said first hinge axis intersecting said second hinge axis and the axis of rotation of said driving member at right angles.

Cyclic drilling machine

Abstract: A drilling machine is provided with a quill feed device for reciprocating a quill, a driving member and a driven member, disposed between a spindle rotatably supported by the quill and a driving source therefor in such a manner as to produce a relative angular displacement therebetween according to magnitude of a load applied on a tool held by the spindle, a detector generating a series of pulse signals correlated to the relative angular displacement between both members, a counter numerically counting the pulse signals generated from the detector in respect of one rotation of the spindle, a memory memorizing numerical data, corresponding to the relative angular displacement while the tool being separated from a workpiece, counted by the counter device, and a comparator for comparing the value memorized in the memory and an actual counted value in the counter. The quill is, in the event the actual counted becomes larger than the memorized value by a predetermined limit, returned backwards once before being re-advanced.

Detection of angular location of unbalance of a rotor and positioning of the location to a predetermined angular position

Abstract: In a dynamic balancing machine for measuring amount and angular location of unbalance of a rotor piece during rotating the rotor piece by a drive motor, in order to position automatically the unbalance angular location to a predetermined angular position on bearings at a time of detection of the unbalance, a preset counter is used for providing a signal to stop the drive motor. Angular pulses each of which indicates rotation of the test rotor piece over a unit angular extent are generated by a rotary encoder, and phase indicating pulses are formed from the vibration signal from a vibration velocity pickup. After constant rotation of the drive motor, motor speed is reduced by a motor speed reduction signal, and, thereafter, the preset counter begins to count the angular pulses in response to presence of one pulse of the phase indicating pulses. When the preset counter counts up to a number preset therein, the drive motor stops, then the unbalance location is positioned to an angular position which is determined by the number in the preset counter and the unit angular extent. An automatic marking device is fixedly disposed at the predetermined stop angular position and is driven after the motor stops. Thus, it is correctly and automatically performed to mark the unbalance location onto the test rotor piece.

Locking key with memory

Abstract: A locking key, designed to retain an indication of the lock-shifting (opening or closing) operation last performed, has a head and a shank interconnected by a screw coupling with limited axial play enabling their relative rotation through 90° or 180°. The shank and its bit can thus be positively entrained for a lock-opening or a lock-closing motion only after the head has arrived in one or the other limiting angular position relative thereto. When the idle rotation of the head is 180°, the relative angular position of the two parts can be indicated by special markings thereon.

Galvo position sensor for track selection in optical data disk system

Abstract: Disclosed is a radiant energy optoelectronic position monitor system which detects the angular position of a "galvanometer mirror" (beam scanner) used in an optical disk memory arrangement. Using a single infra-red monitor beam, angular motion is converted to linear displacement of an image on a detector cell so as to produce a corresponding electrical signal. This signal is presented to a processing circuit with an analog divider to normalize output scale factor. The result is a high gain electrical circuit for recovering output signals in an environment with strong magnetic interference.

Body referenced gimballed sensor system

Abstract: A system for proportionally navigating an airframe to a target wherein the airframe is maneuvered by an onboard flight control system including body rate gyros for detecting the movement of the airframe relative to a fixed reference. A target sensor is mounted for pivotal movement in the pitch and yaw planes on a gimbal assembly rigidly connected to the airframe body. Mechanisms, such as motor/tachometer/potentiometer assemblies, pivot the sensor in the pitch and yaw planes and provide signals representative of the angular rate of motion and angular position of the sensor. These signals, along with the sensor output, are utilized in a gimbal track loop for pivoting the sensor so that it tracks the target. The outputs of the body rate gyros are utilized to remove or decouple the airframe body motion from the gimbal track loop signal. The system eliminates the need for a costly and complex space stabilized gimballed sensor while offering improved performance over a system utilizing a pure body fixed sensor.

Mode selecting device for a video signal reproducing apparatus

Abstract: A mode selecting device for a video tape reproducing apparatus of the type in which a magnetic tape is transported past rotary magnetic heads, includes a control shaft adapted to rotate about an axis, a control knob connected to the upper end of the control shaft for manually controlling the rotation of the control shaft, a photo-disk rotatable with the control shaft, a pair of photo-detectors associated with the photo-disk for detecting the rotational speed, the angular position and the direction of rotation of the control shaft about the axis, a latch mechanism for maintaining the control shaft in either a first or second axial position along the axis and for effecting successive change-overs between the first and second axial positions in response to successive depressions of the control knob, the speed of movement of the tape being controlled in response to the detection of the angular position when the control shaft is maintained in the first axial position and the speed of movement of the tape being controlled in response to the detection of the rotational speed when the control shaft is maintained in the second axial position.

Distribution chute control apparatus and method

Abstract: Control over the direction and inclination of a charge distribution chute within a blast furnace is accomplished with a compact and reliable drive mechanism. The drive mechanism includes a rigid control rod for varying chute inclination angle and a gear drive which translates angular position commands in the form of rotation about a vertical axis to reciprocation of the control rod. The control rod and its gear drive rotate with the chute while simultaneously varying the inclination angle.

Electro-optical angular displacement

Abstract: An electro-optical angular displacement transducer incorporates a pair of encoding disks to produce a varying moire interference pattern sensitive to angular displacement of one disk relative to the other. The disks are illuminated by a fiber optic bundle over substantially a full 360 degree annulus concentric with the disks. A similar fiber optic bundle is used to collect the light transmitted through the disks and supply it to a detector.

Digitized displacement transducer

Abstract: A displacement measuring transducer performs a direct conversion of changes in physical position, particularly angular position, into a digital form suitable for input to a digital microprocessor. The transducer is of the inductive type. Two inductance legs are connected at a common input to form a three-terminal bridge device. To sense positional changes, a step voltage is applied to the input and the transient response at the output of each leg is sampled periodically. Digital circuitry compares the responses of each leg to a fixed reference voltage and produces a binary digital count proportional to the motion sensed by the transducer. This transducer provides high resolution and low noise over a wide dynamic range. It also allows temperature compensation and scale factor calibration.

Torque detecting apparatus

Abstract: An apparatus for detecting torque transmitted between two rotary members. A driving member and a driven member are connected via a transmission spring, permitting relative angular displacement therebetween. On either one of the two rotary members a wheel disk having a number of slits arranged in a circle is provided. A detector, such as a photocoupler, for detecting the slits is disposed on a frame adjacent to the wheel disk. A shutter disk with a shutter portion for partially covering the slits is attached to the other rotary member at an opposed posture to the wheel disk. The number of slits detected by the detector is varied according to the relative angular displacement between the driving member and the driven member while they are in rotation, and the torque between both rotary members may be numerically determined from the number of slits detected.

Motor vehicle power-assisted steering system - uses transformer to couple angular position sensor to control system

Abstract: The power assisted steering system includes an electrical transformer (41) comprising two coaxial coils (40,42). One coil is fixed whilst the other is able to rotate with the moving shaft which operates the steering mechanism. A sensor (55) is attached to the mechanism in order to provide a signal representing the angular movement between these two parts. The sensor is supplied with power via the transformer, and also provides its output to the control system via this same transformer. This obviates the need for any sliding electrical contacts which can cause poor transmission of the control signals. The sensor includes an emitter (56) and a receiver (57) of light in order to sense the relative angular positions of the two components of the steering mechanism.

Directional data stabilization system

Abstract: An azimuth data stabilization system for a shipborne mechanically scanned arch-track system. A unitary package is provided mounted on the roll and pitch stabilized search-track system platform. The package includes a gyro stabilized turntable with the axis of rotation thereof aligned parallel to the axis of rotation of the search-track system. A gyro-torquer loop is provided to inertially stabilize the turntable and a synchro or resolver chain is provided to align the turntable with an azimuth reference. Corrected ships heading signals, derived from the angular position of the turntable, are either coupled directly to appropriate data processing equipment or are combined differentially as compensating signals with the azimuth data signals from the search-track system to provide a true azimuth data output.

Vibrator for ground compaction - with variable operational frequency obtained by varying eccentric rotation and adjusting its centre of gravity

Abstract: The vibrator has an outer vibration pipe with a closed bottom end forming a point and containing an eccentric with a large striking weight above the closed end This eccentric can be driven at a variable rate of rotation and the distance of the centre of gravity of the eccentric from its rotary shaft is also variable, eg in conjunction with the variation in its rate of rotation Pref the eccentric is in at least two parts, with the division between them extending perpendicular to the rotary shaft The coupling between the two parts allows adjustment of their relative angular position The vibrator allows the vibration frequency to be varied during operation to obtain the required compaction with the min number of operations The vibrator can have an electric or hydraulic drive motor

Detector for center position of object to be measured

Abstract: PURPOSE:To enable to detect the center position with simplified operational processing, by enabling to rotate the line sensor and the object to be measured relatively and processing the measured data for operation through scanning the object to be measured toward circumference. CONSTITUTION:The line sensor 10 is located opposingly to measure the radius corresponding part of the circular object to be measured 1, it is enabled for rotation for an arbitary angle with the rotary driving unit 12, and it is scanned toward circumference. Further, the measured data is converted into digital signal at the binary circuit 14, and the count value corresponding to the radius size of the object to be measured opposing to each rotating angular position of the line sensor 10 is counted 15 and operational processing is made at the processor 16 to detect the center position. Thus, since the measured data for the part corresponding to radius direction from the line sensor possible for relative rotation is processed only with the count value, the operational processing is simplified and the processing speed can be increased.

Automatic and self-adapting process for fusion-welding a joint between two surfaces

Abstract: The invention relates to an automatic and self-adapting process for fusion-welding a joint between two surfaces, with the aid of a welding head which essentially comprises a joint detector and a torch supported by a carrier mobile along the joint. This welding head is mobile in rotation about a main axis related to the carrier and substantially perpendicular to the plane tangential to the surfaces to be welded at the location of the joint, and mobile in translation along this main axis. The torch and the detector are mobile in rotation about a secondary axis related to the head and parallel to the main axis and the torch is able to pass through the main axis in the course of its rotation about the secondary axis. A reference direction for all the degrees of freedom of the head is defined when the above-mentioned axes as well as the axes of the torch and the detector are in the same plane. This process is characterized in that it consists: in recording the electric voltage corresponding to the angular position of the reference direction; in measuring, in the course of welding and for each position of the holder, the angle of the detector with respect to the reference direction of the head, when the detector is above the joint; in correcting, during the operations following the trial operation, the angular position of the torch when the latter occupies the position previously occupied by the detector, by an angular displacement which is a function, on the one hand, of the angular deviation of the detector with respect to the corresponding reference direction at this point of the joint and, on the other hand, of the speed of displacement of the head on its path. The invention relates also to an automatic device for carrying out this process.

Wheel unbalance measurement apparatus

Abstract: A wheel balance measuring apparatus has a wheel- mounting shaft (23) together with force transducers (29, 31). The transducers (29,31) are coupled to the shaft and provide signals indicative of unbalance forces transmitted through the rotating shaft. The angular position of the shaft is monitored with respect to an angular datum at a predetermined number of angular increments during each shaft revolution. The signals are converted to digital form. and the digitized signals are multipled at each angular increment using sine and cosine representative factors corresponding to that particular angular increment. The sine and cosine factors are stored in a memory within a computer 61 and are called up from storage in accordance with the monitored angular position of the shaft. Digitized signals including sine and cosine factors are summed thereby providing operating data from which unbalance force magnitude and angular position is calculated.

Shaft angular position encoder calibration

Abstract: The method is for calibrating a shaft encoder, which provides an indication of the angular position of a shaft, and involves the use of stored sine and cosine values as used in a wheel balancing system. Angular position data containing a reference indication and information about the increasing angular value are stored in an RAM associated with a processor. As the shaft is turned, angular position data is reproduced from the memory and the angle values monitored and compared with the stored values.It is determined whether a define number of angle values occurs between each reference value and whether the values occur in a defined sequence for a partic. direction of shaft rotation. The stored data is updated using the current information

Universal parallel ruler including scale setting device

Abstract: A universal parallel ruler is disclosed. A desired angle of rotation of a preset member relative to a base line is selected. This angle of rotation is introduced into the ruler via an input station mounted on the ruler. The desired angle of rotation of the preset member is displayed on a display and an input signal representative of this desired angle of rotation is input to a comparator. The preset member is rotated. A detector detects the actual angular position of the preset member relative to the base line and it introduces another input signal to the comparator representative of the actual position of the preset member relative to the base line. When the actual angular position of the preset member equals the desired angle of rotation, of the preset member that is, when the two input signals to the comparator are approximately equal, a coincidence signal is generated which may light a lamp, indicative of this coincidence, and may activate a braking mechanism which will function to apply a braking force to the preset member, thereby preventing further angular rotation of the preset member and preventing the actual angular position of the preset member from exceeding the desired angle of rotation of the preset member input via the input station. The scale is then rotated to the new position of the preset member and locked in its new position. Alternatively, a desired angle is memorized in the input station and input to a comparator. The actual position of the scale is input to the comparator. Upon coincidence, an output from the comparator brakes the scale rotation.

System for controlling the movement of a rotatable member

Abstract: A rotatable member, such as a turret at a weapons station, is controllable about an azimuth axis. A weapon is carried in the turret with the weapon being controllable therewithin about an elevation axis. The moments of inertia of the turret and weapon about the azimuth axis and of the weapon about the elevation axis are relatively high. The disclosed system provides for elevation and azimuth control through elevation and azimuth drive trains having reflected drive train inertias which are at least two orders of magnitude smaller than the inertia of the turret and weapon about the azimuth axis and at least one order of magnitude smaller than the inertia of the weapon about the elevation axis. Further, the system senses spurious torque applied about either axis, as for example due to the recoil of the fixed weapon, and provides automatic repositioning of the controlled members about either axis to compensate for angular displacement caused by the spurious torque.

Method for determining north direction by means of north-seeking gyroscope

Abstract: 1. A method of determining the north direction by means of a north-seeking gyroscope containing, in an inner frame, a gyroscope motor with a spin axis which can be aligned horizontally, an outer frame or pendulum member in which the inner frame is disposed for rotation about an axis of rotation which can be aligned vertically, a verticality device for the vertical alignment of the rotatable pendulum member which is suspended in a housing, particularly by means of a universal joint, a restraining device with a signal producing pick-up for the angular position of the inner frame in relation to the pendulum member with respect to a preset zero angular position and a torque producer, controlled by the pick-up signal, to restrain the inner frame in its zero angular position, the current in the torque producer representing a measure of the moment driving the spin axis of the gyroscope towards the north and caused by the input angular velocity, and a regulating element, particularly a stepping motor, which causes a rotation of the pendulum member in relation to the housing with reference to a preset zero rotation, this housing comprising a zero mark for determination of the north direction, this is to say of the angle gamma existing between the zero mark and north, characterised in that, in order to determine the angle gamma, at least three measurements of an output quantity ~Xi depending on the input angular velocity omega are carried out in different positions of the pendulum member, turned through defined angles alpha i in relation to the zero rotation, and that the angle gamma is calculated from the equations ~Xi = K [OMEGA H sin (gamma + alpha i ) + D], in which OMEGA H is the horizontal component of the speed of rotation of the earth, D is the gyroscope drift and K is the scale factor.

North-seeking vehicle navigation course reference device - has two-axis gyroscope with azimuth frame rotation motor

Abstract: A course reference device for navigation of a vehicle has a North-seeking facility involving an initial North alignment and a subsequent continuously computed course angle produced during course reference operation. It is sufficiently economical to be applicable over a wide range of uses, including in battle tanks. A two axis gyroscope has its vector axis perpendicular to the azimuth axis (10) of an azimuth frame (12). The first gyroscope input axis is parallel to the azimuth axis. The second (XK) is perpendicular to the vector and first input axis. The frame is rotated by a position motor (28). An angular position sensor operates about the azimuth axis. The tapping (16) on the first input axis (YK) is connected to the motor (28). An earth rotation vertical component original is fed to a torquer (22) on the second input axis (XK). The course signal comes from the azimuth transducer (30).

Measuring device for angular displacement

Abstract: PURPOSE: To measure a rotational angle and a rotational speed by converting signals from two detecting elements, arranged on a rotary disk nearly symmetrically with respect to rotation into rectangular waves, and then processing them by time-division detection by using a common pulse generator and a counter. CONSTITUTION: When a rotating shaft 11 rotates, an index plate 13 and a rotary disk 12 move relatively, and photoelectric converting elements 15 and 15' output photoelectric conversion signals of sine waves, which are converted into rectangulary wave signals A and B by amplifiers 16 and 16' and Schmitt trigger circuits 17 and 17'. A pulse generating circuit 19 has a frequency much higher than the frequencies of the signals 6A and 6B, and then reads the signals A and B on time-division basis by out-of-phase clock pulses having the same frequency from a generator 18 to generate a pulse at the point in time when the signals A and B vary. The value of the counting 20 of said pulse is halved and averaged to display a value under no influence of a shaft plate and eccentricity on a part 21. COPYRIGHT: (C)1982,JPO&Japio

Working method for workpieces having variable surfaces of rotation and numerically controlled machine tool for machining such surfaces

Abstract: 1. A process for forming evolutive surfaces of revolution, such as the lateral surfaces of internal combustion motor pistons, the generatrices of which are curved and the cross-sections of which are elliptical, by means of a tool-machine comprising a spindle (2) for rotating the work piece, a chuck (4) for holding the work piece and for indexing, and a work piece position detector (34), and further comprising a work table (9) guided in grooves parallel to the axis of the spindle, said table bearing a tool-holder assembly (10) which is transversely movable with respect to said axis, the position of the tool, with respect to the surface of revolution to be formed, being defined on the basis of the angle of rotation of said piece and the position of the tool along the said axis of rotation, and being adjusted by servo means controlling the relative position of the tool and the piece, said servo means comprising means for determining at every moment the value of angle A defining the angular position of the piece and, on the other hand, means for determining the longitudinal position Z of the tool-holder, characterized in that said servo means comprise an electronic computer which computes, in real time, the values of a function Fr (Z, A)=Fp Z+Fo (Z, A) the constants of which are previously determined, the functions Fp and Fo defining the curvatures of the profile and of the oval shape of the cross-section as a function of an axial co-ordinate Z and a reference angle A, while Fo (Z, A) is calculated by a reduced number of terms of a Fourier series of the type see diagramm : EP0043741,P10,F1 for values of Z which are previously determined, the output of the computer controlling, by means of a current of variable intensity, the motor which adjusts the position of the tool along its axis.

Three=dimensional locating system for mobile tool member - assigns position vector for all theoretical locations which is corrected as function of field position

Abstract: The orthogonal axis placement of a sensor or tool is accurately performed without feedback circuits by experimentally measuring the location performance of the mechanism against a theoretical reference location field. Correcting the signals, based on these measurements, are used to position the mechanism on each of its three axes. The movement is controlled by a set of adjustable cams or by electronic control using electronic memories. The errors in the angular position of a vector (V) related to a movable part of a tool which undergoes a translation, and a rotation is determined by evacuating the scalar product of the displacement vector with a tensor. The field of the position vectors is determined by placing either a sphere or a cylinder on a plane surface and contouring them with the extendable part of the tool.

Device for controlling the torque of a dental air turbine

Abstract: Device for controlling the torque of a dental air turbine in a turbine drive by means of which a handpiece can be supplied with compressed air from a source of compressed air via an air supply line. In order to facilitate the control processes for the dentist the device located in the air supply line has a motor whose direction of rotation can be reversed, a compressed air control valve which can be adjusted by means of the motor and is located in the air supply line, a rotation angle positioner and a rotation angle detector. In order to adjust the control valve with the aid of commands given by the rotation angle positioner the actual angular position is determined; the degree of opening of the control valve is adjusted to the target degree of opening by turning and stopping the motor until the control valve reaches the desired angular position.