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.

Control of motor winding energisation according to rotor angle

Abstract: An electrical machine, such as a switched reluctance motor 7, has a rotor and at least one electrically energisable phase winding. A control map is derived during production, comprising a predetermined advance angle profile representing energisation of the phase winding with respect to angular position of the rotor over a range of rotor speeds. This is stored in memory in a controller 9, together with an angle correction factor to be applied to a predetermined portion of the advance angle profile. The angle correction factor compensates for the difference between a desired input power and the measured input power. The correction factor may be transmitted to the controller by means of radio frequency signals.

Angular displacement of visual feedback in motion and learning.

Abstract: The main hypothesis was that angular displacement of the visual feedback of motion produces no disturbance of behavior within a limited “normal” range, but that a breakdown angle can be found beyond this range which will produce disturbance in motion control in proportion to the magnitude of the feedback displacement. Experimental results concerning maze tracing and circle drawing specifically supported the hypothesis. In circle drawing, both compensatory visual displacement errors and direct motor error in control of the pattern of motion conformed to the theoretical assumptions. In addition, data on learning in the two tasks conformed to theoretical assumptions that specific sensory-feedback factors determine differences in motor learning and that the spatial properties of such feedback determine the level of performance during learning. The guiding hypothesis was derived from a neurogeometric conception of brain function, which assumes that each internuncial cell acts as a space detector to record the ...

On the evolution of rigid-body rotations

Abstract: The perturbed rotational motion of a rigid body with a nearly Lagrangian mass distribution is studied. It is assumed that the angular velocity of the body is sufficiently high, its direction is close to the axis of dynamic symmetry of the body, and the perturbing moments are small in comparison with the gravity moment. A small parameter is introduced in a special manner and the acceleration method is used. Averaged systems of motion equations are obtained in first and second approximations. The evolution of the precession angle is determined in the second approximation.

An application of EKF for the position control of a single link arm

Abstract: This study is on the development of an extended Kalman filter (EKF) used in conjunction with a simple PD+ controller for the position control of a direct drive system (DDS) The DDS consists of, specially, a single link arm driven by a permanent magnet synchronous motor (PMSM) and controlled by a DSP32 based motion control unit The EKF is used to estimate the angular position and velocity, beside the total inertia of the system, which is used to calculate the load information for the PD+ controller The estimation algorithm is based on the Bayes method known for its high accuracy Precision being the main objective of the study, the control input error usually ignored in past literature is also take into account in the filter design The control method thus developed demonstrates an improved performance over the classical PID in terms of accuracy and robustness through simulations and experiments that were carried out

Optimal-arrangement-based four-scanning-heads error separation technique for self-calibration of angle encoders

Abstract: Conventional methods for the calibration of angle encoders typically only consider the graduation error of the encoder's circular scale. However, the radial motion of the circular scale during its rotation, due to its eccentricity and the axis of rotation radial error motion, can also introduce noticeable errors to the angle measurement in most practical applications. Based on the analysis of the influence of radial motion, an optimal-arrangement-based four-scanning-heads error separation technique for in situ self-calibration of angle encoders is presented. This Fourier-based technique uses the basic self-calibration model to measure the first-order Fourier component of the encoder error which includes the contribution of eccentricity. Meanwhile, the separation technique is utilized to separate the residual Fourier components of the graduation error from the measurement deviation due to radial error motion. The effect of the scanning heads' angular position errors on the calibration results is discussed. Optimal arrangements of the four heads are achieved to avoid the suppression of the Fourier components, and reduce the propagation of errors. Numerical results and experimental comparisons demonstrate the effectiveness of the proposed method. Moreover, this technique can also be used for measuring the spindle radial error motion for some users.