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.

Remote control device with pointing capacity

Abstract: A hand held remote control device that allows a user to select the position and movement of a cursor on a display screen or other selected functions by rotating or translating the input device in three-dimensional space. A signal is emitted from a beacon at a first location and is received by the remote control device at a second location. The remote control device detects, about two non-parallel axes, components of an angular displacement between the incident direction of the signal and a selected axis of the remote control device. Optical structures, such as cylindrical lenses, are used to project portions of the signal onto detectors in order to measure the angular displacement. Information corresponding to the detected angular displacement is transmitted to a control box, which controls the position and movement of the cursor on the display screen in response to the transmitted information.

Trajectory control of a non-linear one-link flexible arm

Abstract: The trajectory-tracking control problem is considered for a one-link flexible arm described by a non-linear model. Two meaningful system outputs are chosen; namely, the joint angle and the angular position of a suitable point along the link. The common goal is to stiffen the behaviour of the flexible link with respect to the chosen output. Based on the input-output inversion algorithm, a state-feedback control law is designed that enables exact tracking of any smooth trajectory specified for the output. In the closed loop an unobservable dynamics naturally arises, related to the variables describing the arm's distributed flexibility. Joint-based design is shown to be always stable, whereas in the link-point design the closed-loop dynamics may become unstable depending on the location of the output along the link. Open- versus closed-loop strategies are developed and compared. Extensive simulation results are included.

Angular position sensing and control system, apparatus and method

Abstract: A structural body is monitored in angular position about at least one axis by utilizing a level sensor and a sensor responsive to angular motion of the body about the axis being monitored. An output indicative of long term angular variations of the body about the axis is provided by the level sensor and short term angular variations are indicated by the output from the sensor responsive to angular motion about the axis. The signals indicative of long term and short term angular variations are combined to provide a broad band output signal indicative of angular position which is immune to high frequency translational variations appearing at the level sensor output, but which is responsive to high frequency angular inputs. The fast response angular sensor output is compared with the slow response level sensor output and an error signal is produced which drives the angular sensor output signal into coincidence with the level sensor output signal. The combined broad band angular output indication may be utilized for angular position monitoring for controlling one part of a machine relative to a predetermined external angular position reference for driving a stable platform to assume a predetermined angle about the axis.

Radiation therapy for cancer patients

Abstract: Apparatus for irradiating a patient comprises a source of a radiation beam directed along a radiation axis. The source is mounted for pivotable movement about a first horizontal axis substantially normal to the radiation axis, whereby the beam is capable of an angular scan in a vertical plane. In a preferred embodiment the apparatus is positioned so that the midplane between the pole surfaces substantially includes the first horizontal axis. A table is adapted to support a patient to be irradiated. A suspension unit mounts the table for arcuate movement to any of a plurality of positions angularly spaced about the first horizontal axis and for pivoting movement about a second horizontal axis displaced from and substantially parallel to the first horizontal axis. The suspension unit maintains the second horizontal axis in substantially intersecting relation to the radiation axis in each such position while maintaining a fixed angular position of the table with respect to the environment.

Angular Displacement and Velocity Sensors Based on Electric-LC (ELC) Loaded Microstrip Lines

Abstract: Planar microwave angular displacement and angular velocity sensors implemented in microstrip technology are proposed. The transducer element is a circularly shaped divider/combiner, whereas the sensing element is an electric-LC resonator, attached to the rotating object and magnetically coupled to the circular (active) region of the transducer. The angular variables are measured by inspection of the transmission characteristics, which are modulated by the magnetic coupling between the resonator and the divider/combiner. The degree of coupling is hence sensitive to the angular position of the resonator. As compared with coplanar waveguide angular displacement and velocity sensors, the proposed microstrip sensors do not require air bridges, and the ground plane provides backside isolation.