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Ultrasonic Positioning !!Obsolete!!

Ultrasound remains the lowest cost positioning option, with respect to accuracy, superior repeatability and positioning resolution.  Ultrasound is completely confined to the area in which it operates. This means that neither can it affect operation outside its boundaries, nor can anything outside the boundaries affect it. Operation in one room can be completely separated from operation in nearby rooms. 

Hx11 is a high speed versatile Ultrasonic Positioning System. It is a General Purpose Ultrasonic Positioning System. It can be set up to track from one up to a thousand ultrasonic transmitters. The position of hx11 ultrasonic transmitters can be computed from an ever expandable receiver grid, covering thousands of square meters. The HX11TR also has the ability to transpond using ultrasonic identity exchange for absolute positioning. This makes it very useful for small scale applications as well. With reasonable precautions, ultrasound can be used outdoors as well as indoors.   

****Any HX11TR can measure the distance to any other HX11TR in the system****

Wireless setup time of flight measurement

Ultrasonic Positioning of Multiple Objects

Ultrasonic Positioning relative to a transmitter frame

Time of flight used to determine the location of every device in the system with respect to all other devices

Synchronized High Speed Ultrasonic Distance Measurement

Synchronized High Speed and Robust Ultrasonic Echolocation

Time of flight measurement for robust echo location

The ultrasonic tracking application

It is possible to set the HX11TR to measure the time difference of flight as shown below. The user can write his own triangulation programs for the positioning.

For the tracking operation shown above the hardware required consists of HX11TR (as receivers), HX11T transmitters, HX11C controller and some long telephone cable to connect all the receivers to the controller, and the controller to the readout device, PC or other logic logging devices. Software used for this operation is either dataLog (it logs the data from the receivers onto the PC disk) or the XYZ program (it displays the xyz coordinates as it stores. a. id of the transmitter, b. the coordinates of the transmitter and c. the time the signal arrived on a file). Both the XYZ and dataLog distribute the incoming data from the HX11 devices through DDE (dynamic data exchange). Real time data is therefore available for number of programs running simultaneously (this is explained in the technical manuals). 

The density of the ultrasonic receiver grid shown above depends on how high it is from the ultrasonic transmitters. As a rule of thumb it can be said (because of the directionality), that the distance d between receivers in the grid plane, is proportional to distance from the grid plane to the parallel plane of motion for the transmitters. In other words the higher it is to the ceiling the fewer receivers are needed to cover the same area below. So if the transmitters are moving on a plane approximately three meters from the receiver grid, the distance d is 1.5m, likewise if the plane is 6 meters from the grid then the distance d is 3meters. 

The Medium Size Evaluation System (Ultrasonic Tracking).

The illustration below shows the typical setup for the medium size evaluation system with two free moving transmitters set in random mode (see transmitter technical manual). A network is shown below with respect to xy motion where the z motion is limited. To measure the z motion one diagonal receiver pair should be at different z coordinates relative to the other. 

Hexamite offers small and medium evaluation systems. 

The small evaluation system: is suited for small scale operation, device to device time of flight application. It is composed of three HX11TR units only and all the software required for setup, real time monitoring and logging of distances.

The Medium evaluation system: can be used for all applications covered in the manual. The Medium evaluation system is set up by default for tracking operation as depicted above. It contains four HX11TR, two HX11T battery transmitters and one HX11C network controller. It also contains all the software required for the setup, real time monitoring and logging of 3d positions. The medium evaluation system covers area up to 25 square meters.

Note: the coverage is calculated with regard to eight meters from the transmitter plain to the receiver plain. 

For questions and quotations email: service@hexamite.com


Copyright 1999 [Hexamite]. All rights reserved. Revised: .