Hexamite Ultrasonic Positioning Wide Area Coverage

HX5 The Next Generation Ultrasonic Positioning

Hexamite is proud to present the Next Generation (hx5) in ultrasonic positioning. The hx5 utilizes modulated signal exchange to extract precision position timing. The modular construction facilitates easy installation, maintenance and expansion. The hx5 is cost effective with high noise immunity and high accuracy. Using multiple networks an object can be positioned to within 2 centimeters anywhere in an area of many square kilometers. There is no fixed limit of coverage; about 0.5 square kilometer can be covered to a reasonable accuracy using a single network. And of course the Internet can be harnessed to locate anything globally to within 2 centimeters. As many as 20 positions, can be registered by each receiver per second. In a medium system counting hundreds of transmitters and receivers, there can be thousands of positions registered each second.

The illustration below shows how the monitors can be configured in the XY plane, these can be mounted similarly on an office ceiling.

Wide Area Coverage

The illustration below suggests how a large area can be covered using monitors. Any formation can be chosen, but a honeycomb formation will provide one of the best coverage per unit cost. In the following the D distances between monitors are everywhere the same. The monitors form 60-degree triangles. Depending on the density of the network, many monitors may contribute to the positioning of a given tag. The higher then number of monitors that detect the tag, the more accurate and stable will be the positioning.

Receiver/Monitor Setup

The HX5M can be connected to a network of devices utilizing FCC RJ11 style port. The RJ11 socket can be found on most domestic telephones, it is the socket which connects the telephone to the wall fixture. Each HX5M has two RJ11 sockets, which are identical. The communications and power to the HX5M is supplied via the RJ11 port.

The total cable length should not exceed 10 miles or 16 kilometers. All receivers have a direction diode on the input, reverse polarization does not harm the units.

The Network Controller HX5C

HX5C controls the network and the communications with the PC, it should be located within 2 meters of the PC. The programs hx5data.exe and xyz.exe read the data from the HX5C and calculate the position of the transmitters detected. The power points on the HX5C are connected to the network power lines via diode, and can serve to supply power to the whole network. Be aware that telephone lines carry limited amperes and there is a voltage drop in direct proportions to the wire length. In case of long lines, and high number of receivers it may be necessary to use local power for a far away cluster of receivers.

FCC RJ11 and telephone cables

The figure on the right shows how the rj11 needs to be attached to the cable. It is important that the colors match when the cable ends are held side by side. Inexpensive tools are available to help join the RJ11 to the telephone cable. It does not damage the monitors if they are connected via inverted cable. But it could block out the network until removed and corrected.

Using T connectors

T-Connectors are generally available at hardware stores selling telephone cables and accessories. The T connector joins 3 separate telephone cables, and it has 3 RJ11 sockets A, B and C. Some T connectors have the C input inverted. In this case the cable connected via the C input must be inverted too. This means that the colors as shown in the figure a3 should not match, the RJ11 should be joined to the cable rotated 180
degrees.

Long Line Considerations

If the network becomes kilometers long, a twisted pair should be used to carry the communicationssignal and the receivers should be supplied with power locally. The network 4 conductors are (see manual for details)

HX5 Network

The illustration on the right shows a RJ11 plug, the yellow wire is the supply power and the black line is the return (ground). The red and the green conduct the communications signal. In the case of a long line application with many power supplies only two lines i.e. the Green and the Red should be connected throughout the network. The common mode voltage on the communication wires is +/- 7V.

Specification
Supply Voltage (battery)	2.7 to
Output Power	1 Watt
Range	8m
Sound Pressure Level	123 db
Noise Immunity	118 db
Maximum Average Transmission Rate	20 positions/second
Battery Life @ 20 positions/second Battery source 3.6V lithium 2000mAhrs	15 days (15*24hrs)
Battery Life @ 0.2 positions/second Battery source 3.6V lithium 2000mAhrs	4 years

Noise immunity is defined as the sound pressure level of a source located at the same distance from the monitor as the tag and will overwhelm the transmission from the tag to the monitor.

Battery Life Expectancy

The following graphs show battery life expectancy versus position update rate. A single 3.6V lithium battery 2000mAhrs was used as reference for the graphs. The batteries are replaceable and are shipped with the HX5T1 uninstalled. Batteries for the HX5T1 are available in most places selling electronic components, and can be obtained in the USA at www.mouser.com the mouser part number is 667-TL2100P. The leads must be cut to about 1/3" or 1cm lengths and fitted into the HX5T1 battery socket. Vendors like www.digikey.com, avnet, arrow, allied electronics and etc should also carry similar batteries. In Australia www.jaycar.com.au part number SB-1775. The HX5T1 will run on any batteries supplying 3 to 7 volts.

Position Update Rate control

Pressing the membrane push button on the side of the HX5T1 doubles the average identification and localization rate (position update rate) as follows:

0.1, 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, 12.8, 25.6, Off (positions/second)

HX5M1 Ultrasonic Monitor/Receiver

HX5M1 is a HX5 ultrasonic monitor, the monitor times and stores the identification of each tag transmitting within it's range. The monitors have RJ11 data ports, the HX5C reads the data from all the monitors on the network through these ports. The data is relayed to a PC through the RS232 port and the position of the tags detected is calculated. Up to 55000 monitors may be connected for wide coverage to a single telephone cable stretching up to 10 km.

The HX5M1 has two RJ11 ports; these ports are identical. Two ports are provided to make serial connection of thousands of devices simple. Weather and watertight IP67 versions are available, contact hexamite for more information.

Figure 2. Hexamite Ultrasonic Position Receiver. Size 20mm x 80mm x 40mm

Size 20mm x 80mm x 40mm

The power points on the HX5C are connected to the network power lines via diode, and can serve to supply power to the whole network. There is a ground pin on the HX5C which may be needed to eliminate noise on the network. Note that the network should be grounded in one place close to the PC server.

HX5NC-USB Network Controller

The HX5NC-USB network controller looks and works like the HX5C-RS232 series controller. It connects directly to the USB port on the computer.

Weather and watertight IP67 versions are available, contact hexamite for more information.

Specification
Supply Voltage	7-16Vdc
Current Consumption	40mA
Network Drive Capacity	128 devices

Be aware that telephone lines carry limited amperes and there is a voltage drop in direct proportions to the wire length. In case of long lines, and high number of receivers it may be necessary to use local power for a far away cluster of receivers.

HX5R1 Repeater

HX5R1 is a repeater, used to boost up power and communications on the network. Each repeater will drive extra 128 HX5M1 receivers. The repeater also has power points to allow the network power to be boosted from local power.

Specification
Supply Voltage	7-16Vdc
Current Consumption	10mA
Network Drive Capacity	128 devices

Application Machinery Position Feedback Robotics Guidance and Tracking High Security Object Tracking High Security Object Guidance Indoor Positioning Systems
	Figure 1. Hexamite Ultrasonic Position Transmitters/Tags