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.

Digital position sensor

Abstract: A sensor for providing an indication of the movement of one component of a system with respect to another includes a plurality of discrete electrodes and a common electrode affixed to the non-moving component along the axis of movement of the moving component and a pointer affixed to the moving component also along the axis of movement. As the moving component moves, it positions the pointer at consecutive ones of the plurality of discrete electrodes forming a capacitor structure with each in succession. When interrogated, the capacitor provides a signal indicative of the position of the moving component. The sensor is useful for indicating linear movement, angular displacement and pressure, strain and temperature when adapted to structures which indicate such parameters as a function of displacement. Alternative structures include "Bar Codes" with a laser as a pointer and magnetic stripes with a magnetic read head as the pointer. The output of the sensor may be employed as a feedback signal to a position controller for, for example, a computer-driven machine tool or for a digital hydraulic control system.

Measurement of small angular displacement by a modified moire technique

Abstract: Small angle measurement using a modified moire interference technique is reported. The range of angle measurement for 25-μm pitch gratings is about ± 25 μrad and the accuracy of measurement is of the order of 0.2 μrad with a time constant of 0.1 s. A piezoelectric transducer (PZT) is used for angular displacement. The angular sensitivity under the present experimental conditions is found to be of the order of 21.8 mV/μrad.

A twist-grip control device, in particular for motor vehicles

Abstract: The device (1) comprises: a stator portion (2) which is stationary in operation, a rotor portion (3) which may be gripped and which is mounted such that it can be manually rotated about an axis (A-A) with respect to the stator portion (2), against the action of an opposing spring (13), a first and a second permanent magnet (11a, 11b) connected to the rotor portion (3) in respective separate angular fields about said axis (A-A) and adapted to generate respective predetermined angular distributions of magnetic field intensity about said axis (A-A), first and second magnetic field sensors (14a, 14b) connected to the stator portion (2) in respective separate angular positions about said axis (A-A), and associated with the first and second permanent magnets (11a, 11b) respectively in order to provide, when the rotor portion (3) is rotated by a certain angle with respect to the stator portion (2), respective first and second electrical signals indicative of the relative angular position of the rotor portion (3). These signals are correlated with one another in a predetermined relationship such that one of the signals may be used as a control signal indicative of the extent of an associated controlled physical magnitude desired by the user, and the other signal may be used as a control signal adapted to enable the detection of the occurrence of operating malfunctions or failures when these signals are no longer correlated with one another in the predetermined relationship.

Downhole pressure and/or temperature gauges

Abstract: A pressure or temperature gauge includes a Bourdon tube which is coupled via a shaft to transmit rotation to a stylus carried by the shaft which makes a record on a cylindrical chart which moves axially of the shaft at a constant rate. The shaft is divided into two sections which are joined together by a flexible coupling; the upper section of the shaft is mounted for angular displacement about its longitudinal axis by the thrust bearing. One section has an integrally formed axial extension which is received in a recess in the facing end portion of the other shaft section. This construction of the stylus shaft allows the angular motion produced by the coiling and uncoiling of the Bourdon type generally through an angle less than 360° to be faithfully transmitted without any axial motion of the shaft which would give rise to erroneous recording of pressure or temperature readings in relation to time.

Evaluation of the Intel RealSense T265 for tracking natural human head motion.

Abstract: Accurate and robust tracking of natural human head motion in natural environments is important for a number of applications including virtual and augmented reality, clinical diagnostics, as well as basic scientific research. IMU provide a versatile solution for recording inertial data including linear acceleration and angular velocity, but reconstructing head position is difficult or impossible. This problem can be solved by incorporating visual data using a technique known as visual-inertial simultaneous localization and mapping (VI-SLAM). A recently released commercial solution, the Intel RealSense T265, uses a proprietary VI-SLAM algorithm to estimate linear and angular position and velocity, but the performance of this device for tracking of natural human head motion in natural environments has not yet been comprehensively evaluated against gold-standard methods. In this study, we used a wide range of metrics to evaluate the performance of the T265 with different walking speeds in different environments, both indoor and outdoor, against two gold-standard methods, an optical tracking system and a so-called perambulator. Overall, we find that performance of the T265 relative to these gold-standard methods is most accurate for slow to normal walking speeds in small- to medium-sized environments. The suitability of this device for future scientific studies depends on the application; data presented here can be useful in making that determination.