JP2818077B2 - Target location system and location method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to position location systems, and more particularly, to a radio location system adapted for use in environments where multiple communication effects are available. More specifically, the present invention provides (a) an arrival time difference (high resolution) for radio detection transmission received by a large number of receivers, or (b)
The present invention relates to a system for performing position location using area detection (low resolution) using a receiver that receives radio wave detection transmission from an allocated area.

[0002] In the present invention, reference is made to Hillier.
Technologies Limited Part
US Patent No. 4,864, assigned to Nership.
No. 588, the subject of remote control systems, components and methods are incorporated.

[0003]

BACKGROUND OF THE INVENTION Position or target location systems are increasingly being applied in manufacturing and material handling environments. For example, such systems include tool automation, process control, robotics, unmanned vehicles, computer integrated manufacturing (CIM), and just-in-time (J
IT) Used for factory automation including applications such as inventory management.

[0004] One location system uses a transmitter or tag attached to the target to be tracked and a receiver array that receives tag transmissions throughout the tracking area. Tag transmission can be by radio, ultrasonic, or optical communication using various techniques to identify or locate the movement of the target within range of the receiver.

[0005] The wireless communication includes (a) a distance per 1 W of electric power,
And (b) in terms of transparency of the transparent structure, accuracy and performance are superior to ultrasonic and optical communication. However,
The problem of wireless communication in a typical business environment, including walls, silvered windows and other fixed structures, is (100 MHz
For the associated frequencies (higher), diffuse reflection will cause multipath distortion in the tag transmission arriving at a given receiver. Further, in such an environment, only a small signal strength is useful for communicating distance / location information due to the unpredictable attenuation of transmission through walls and other structures.

Therefore, there is a need for a position location system that can be used for target location in environments affected by multiple reflections.

[0007]

SUMMARY OF THE INVENTION The present invention is a location system adapted for use in an environment subject to the multipath effect, comprising: (a) an arrival time difference using a tag transmission received by multiple receivers ( Target orientation is performed by area detection (low-resolution embodiment) using a receiver that receives tag transmission from the allocated area (high-resolution embodiment) or (b). In either the high resolution or low resolution embodiments, the radio detection system can be implemented by spread spectrum communication for unlicensed operation.

In accordance with one aspect of the present invention, the target location system transmits a TAG transmission including at least one unique TAG ID at selected intervals to each target in the tracking area. Includes machine. The receiver array is distributed in the tracking area.

For high resolution embodiments, TAG transmissions from a given TAG transmitter located somewhere in the tracking area are received (for two-dimensional tracking) by at least three receivers. The receiver array is distributed as follows. Each receiver includes an arrival time circuit and a data communication controller. The arrival time circuit is triggered in response to the direct path TAG transmission and the arrival time TOA COUN synchronized with the system synchronization clock obtained from each receiver.
Output T. The data communication controller responds to the trigger of the arrival time circuit by at least the TAG from the TAG transmission.
Corresponding TOA- including ID and TOA COUNT
Output a DETECTION packet.

A location processor receives the TOA-DETECTION packets communicated from each receiver and TAGs (and associated targets) from at least three TOA-DETECTION packets corresponding to TAG transmissions to TAGs received by different receivers. ).

[0011] For a low resolution embodiment, each receiver in the array is assigned a specific location area so that it receives TAG transmissions only from TAGs located approximately in that area. Radio detection systems based on receiver allocation areas use directional antennas of the receivers, or cooperatively select receiver spacing and TAG transmitter output so that most neighboring receivers receive TAG transmissions. It can be implemented in various ways such as

Each receiver includes a data communication controller. The data communication controller of each receiver responds to the receipt of the TAG transmission by at least the TAG from the TAG transmission.
The corresponding AREA-DETECTION including the ID is output.

[0013] The orientation processor is provided with an AREA from each receiver.
-Receive DETECTION and determine the position of each target based on each receiver that received the closest TAG transmission.

The orientation system can be implemented using unlicensed, spread-spectrum wireless communication.
In this aspect of the invention, each transmitter follows at least a TX with a TAG ID according to a spread spectrum communication protocol.
Includes a spread spectrum transmitter that outputs packets. The TAG transmitter operates at a predetermined power level. Each radio detection receiver receives a spread spectrum TAG transmission,
Includes a spread spectrum receiver that recovers the TAG ID and outputs an RX-packet containing the TAG ID.

The data communication controller of each receiver is RX
A DETECTION including at least a TAG ID for communicating with the orientation processor in response to the packet;
Output a packet. The orientation processor sends D from each receiver.
An ATA-packet is received to determine a target location.

According to a more particular feature of the present invention, a target
Target orientation such wafer box in a semiconductor manufacturing facility using a high resolution embodiment of the constant system occurs. A radio detection receiver array is coupled to the radio detection system via a LAN (Local Area Network).

Each TAG transmitter includes a movement detection circuit and a period control circuit in addition to the spread spectrum transmitter.
The TAG transmitter is enabled only when the movement detector detects movement of the target. While the target is moving, TA
The G transmitter transmits at regular intervals determined by the period controller. Each TAG transmission includes a moving state (start, continue, stop) in addition to the TAG ID. Further, the TAG may include means for entering other information (such as by an operator) to communicate with the system processor.

Each radio detection receiver includes a TOA trigger circuit, a time base latch circuit, and a programmable controller in addition to a spread spectrum receiver. TOA
The trigger circuit triggers within the early cycle of the incoming TAG transmission and outputs a TOA DETECT trigger. A time base latch circuit responsive to the TOA DETECT trigger latches a time base TOA COUNT from an 800 MHz time base counter synchronized to a 200 MHz system synchronization clock provided by the system processor via the LAN. The programmable controller uses the T signal recovered by the spread spectrum receiver.
TOA-DETECT which receives the AG ID and the moving state and the TOA COUNT from the time-based latching circuit and communicates with the system processor via the LAN
Output the ION packet.

An arrival time detection circuit in the receiver outputs an adjustable noise sensitivity that makes a difference between the TAG transmission and the random noise. The TOA trigger circuit outputs the TOA-DETECT trigger when the input signal value exceeds the adjustable signal level threshold, and the time-based latch circuit outputs the TOA-DETECT.
If the duration of the CT exceeds the programmable signal duration threshold, it indicates that a valid TAG transmission has been received.

The technical advantages of the present invention include the following. The radio detection system is adapted for use in a multipath environment such as a manufacturing or other business facility where the reception of a direct path transmission is affected by multipath noise. The target orientation can be performed by a high resolution method using arrival time difference or a low resolution (low cost) method using area detection by a receiver configured to detect TAG transmission from the allocated area. Commercially available unlicensed spread spectrum equipment facilitates identification of the direct path transmission of interest and multipath noise. To save power, each TAG transmitter includes a movement detector,
G transmission can be limited (or concentrated) only to the interval during which the target is moving. For TAG transmission, TAG I
In addition to D, other information such as the moving state and the operator can be included.

For the high resolution embodiment, the TOA-DE
TECTION triggering and time-based TOA
COUNT latching can be separated from the spread spectrum communication function so that a commercially available spread spectrum device can be used. TOA-DET during the early cycle of TAG transmission when the fast TOA trigger circuit arrives
Outputs the ECTION trigger. 3.0 with a synchronized time base counter operating in the 800 MHz range
A resolution of the order of 5 meters (10 feet) is provided. Noise filtering optimizes the time-of-arrival detection for TAG transmissions and provides adjustable signal levels and signal duration thresholds that reduce random pulse noise effects.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The description of an embodiment of the radio wave detection system of the present invention adapted to be used in a multipath environment is constituted as follows.

1. Radio wave detection system-TOA detection 1.1. TAG transmission 1.2. Reception and TOA detection 1.3. LAN communication 1.4. Positioning processing 1.5. Calibration 2. 2. Radio detection system-area detection 3. Spread spectrum communication TAG transmitter 5. Radio wave detection receiver 5.1. TOA trigger circuit 5.2. Time-based latch circuit 5.3. Programmable controller 5.4. Example of area detection Appendix A Appendix B

This detailed description includes Hillier Te
channels Limited Partne
U.S. Pat. No. 4,864,58 assigned to rship.
No. 8, the remote control system, components and methods are incorporated by reference with the parts.

1. Radio Locating System--In a TOA detection embodiment, a radio locating system is used to track a target (such as a wafer box) in an automated semiconductor manufacturing facility. The radio detection system is configured to perform a high resolution target location of 3.05 m (10 feet) or less using an arrival time difference and an 800 MHz synchronized time base clock.

FIG. 1a shows various segments, such as GaAs lithography 11, photolithography 12, GaAs etch 13, metallization 14, and ion implantation 15, each surrounded by a partition or wall containing walls 16, 17, 18. 1 shows a semiconductor manufacturing facility 10 having a designated area.

FIG. 1 b shows a manufacturing facility 10 showing only the walls 16, 17, 18. Inside the facility (inside or near the ceiling)
, A radio detection receiver array 20 including individual receivers 22, 24, and 26 is arranged. Various targets, such as wafer boxes transferred on a conveyor system, move through the facility. These targets must be tracked, their locations identified, and efficient automated manufacturing operations performed.

A TAG transmitter is attached to each target to be tracked. Each TAG transmitter associated with the target transmits a TAG transmission, which is received by the receiver array. For example, a TAG transmission from a TAG transmitter located at reference numeral 30 is received by at least the radio wave detection receivers 22, 24, 26. Each TAG transmission includes a TAG IC that uniquely identifies each tag (ie, target).

In addition to the TAG transmitter on each target, several fixed position TAG transmitters 35 are located around the facility.
These TAG transmitters, which have a known location for each receiver, are used for system calibration.

Each radio detection receiver in the receiver array 20 receives the TAG transmission and accurately detects the time of arrival using an 800 MHz time base counter. For each TX-packet in the TAG transmission, the receiver sends the corresponding TOA-
Generate a DETECTION packet, which is
It is communicated to the radio wave detection system processor 40 via a (local area network).

The system processor 40 performs all target orientation calculations. Further, the system processor is 200 MH
A z-system synchronization clock 42 is generated, from which the 800 MHz time base count in each receiver is derived. The system processor 40 is used for data communication between the system processor and the receiver array and has a 200 MHz
LA to network to provide z-system synchronization clock
It is connected via an N interface 44.

The system processor includes a target tracking database storage device, wherein user access to the target location information is provided by a graphic workstation via a graphic interface.

1.1. TAG transmission The transmission between the TAG (target) and the receiver array is 902-92.
This is performed using spread spectrum communication in the 8 MHz band. In the embodiment shown in FIG. 1, wireless communication in that frequency band is affected by multiple reflections. The use of spread spectrum communication for TAG transmission is advantageous for separating direct path transmission from multiple reflections (see section 2).

FIG. 2a is a functional block diagram of the TAG transmitter 50, which includes: (A) a spread spectrum transmitter 52 for transmitting a spread spectrum TAG transmission (TX-packet); (b) a battery power saving circuit 54 for enabling the spread spectrum transmitter when the TAG (target) is moving; A movement detection circuit 56 for detecting movement of the TAG (target); and (d) a periodicity control circuit 58 for controlling the retransmission interval of the spread spectrum transmitter.

In an embodiment, the TX-packet in each periodic TAG transmission contains not only the appropriate TAGID, but also one of the following three movement status indications. Start moving, continue moving, stop moving.

In order to save power and increase the number of available TAG transmitters, each spread spectrum transmitter 52 is always in a power saving mode and transmits by the battery power saving circuit 54 only while the associated target moves to a new position. It is possible. The movement of the target is detected by the movement detector 56, and an appropriate indication is given to the battery power saving circuit.

In response to the movement display, the battery power saving circuit 5
4 initiates the transmission mode by enabling the spread spectrum transmitter 52 for initial TAG transmission. The TX-packet in this initial TAG transmission has a TAG ID
In addition, a Motion Initiated state is included.

While the target is moving (as detected by the movement detector 56), the periodicity controller 58 causes the spectral transmitter 52 to retransmit the TAG transmission at selected intervals (such as every 15 seconds). . TX in these periodic TAG retransmissions
-In the packet, besides the TAG ID, the Motion
Continuing state is included.

When the target reaches a new position and comes to rest,
The movement detector 56 stops providing the movement indication to the battery power saving circuit 54. After a predetermined period (for example, 30 seconds) during which the target is stationary, the battery power saving circuit
8 is disabled and the spectral transmitter is
n Send a final TAG transmission with a TX-packet containing the Stopped state.

The TAG transmitter remains in the non-transmission power saving mode until the next movement of the target. T while the target is stationary
Instead of completely disabling the AG transmission, during such a transmission period, the TAG transmitter can be programmed to send a low duty cycle TAG transmission that gives a No Motion status indication.

The transmission propagates through the facility and is received by the receiver array. Since these transmissions must propagate through partitions, walls and other obstacles that produce unpredictable attenuation, the signal strength at the receiver cannot provide any useful information from which the target position can be estimated. Further, even after the direct path transmission, these obstacles cause multiple reflections and are received by the receiver.

1.2. Multipath transmitter and TAG transmitter (target) for reception and TOA detection TAG transmission
Arrive at the various receivers with arrival time differences that depend on the corresponding arrival time (ie, path length) differences between
Unaffected by signal attenuation obstacles in the AG transmission path.

In order to implement a high-resolution radio wave detection system, a target position is determined with high resolution when each receiver uses the arrival time difference to detect the arrival time of TAG transmission accurately and accurately. Can be. For TOA detection,
There is a need for (a) a reliable trigger by the arrival time of the direct path TAG transmission, and (b) a stable synchronized time base.

If the early cycle of a direct path TAG transmission (arriving before any associated multiple reflections) cannot be triggered consistently and accurately, the temperature,
Irrespective of random changes in humidity and / or circuit performance, reliability issues arise resulting in TOA detection errors and therefore orientation calculation errors. However, even if TOA
Even if the trigger is accurate, failure to obtain a stable synchronized time base (or knowledge of the relative time difference) will reduce the accuracy of arrival time detection based on TOA triggering.

In addition, TOA triggering must be independent of the strength of the TAG transmit signal (attenuated in the path between the target and a given receiver). If not made independent of signal strength, known as dispersion delay, there will be arrival time triggering differences that depend on direct path attenuation.

For the preferred embodiment, the radio detection system processor 40 sends a signal to each receiver in the array 20 via the LAN.
Send a 00 MHz system synchronization clock. At each receiver, the 200 MHz system clock is converted to an 800 MHz TOA time base clock synchronized with all other receivers by conventional phase coherent frequency multiplexing. With this method of providing a time base for time-of-arrival detection, the receiver is synchronized within approximately 1.25 ns and the TO
The orientation resolution based on the A difference can be within about 0.61 m (2 feet).

A 200 MHz system synchronization clock is converted to a desired 800 MHz by up-conversion of each receiver.
Choosing a z-time base clock is a design choice that results from the choice of a particular LAN data communication that provides a system synchronization clock (see Section 1.3). The radio detection system of the present invention can be readily applied to other schemes for providing a system synchronization clock to provide an appropriate receiver time base for a desired orientation resolution.

FIG. 2B is a functional block diagram of the radio wave detection receiver 60. (a) Receiver front end 62 for amplifying and adjusting received TAG transmission (TX-packet), (b)
TOA DE detects arrival of direct path TAG transmission
TOA detection trigger 64 giving TECT indication, (c) T
800 synchronized in response to OA DETECT indication
Associated time base TOA of MHz time base counter
Time-based latching circuit 6 for latching COUNT
5, (d) a spread spectrum receiver 66 which receives a TX-packet from each TAG transmission and generates an RX-packet including a TAG ID and a moving state, (e) a latched TOA COUNT from a time-based latching circuit.
TOA with recovered TAG ID and moving status
-A programmable controller 68 that assembles into DETECTION packets; and (f) a network interface 69 that interfaces the communication of TOA-DETECTION packets over the LAN. In addition, a power supply supplies power to the TTL, ECL and radio circuits.

The receiver front end 62 receives each TAG transmission and performs conventional amplification and filtering.

The received TAG transmission is sent to the TOA trigger for arrival time trigger 64, which provides a TOA DETECT indication during the early cycle of the TAG transmission. Rapid detection of the trigger event is provided by a high-speed comparator using conventional peak energy detection in the TOA trigger.

The TOA DETECT is sent to the time-based latching circuit 65 as an indication of the arrival of the TAG transmission wave front. Time-based latching circuit is 800 MHz (up-converted from 200 MHz system synchronization clock)
Latch the relevant time base count of the time base clock. In addition, the time-based latching circuit performs digital noise filtering to remove the TOA DE from the TOA trigger.
It attempts to ensure that the TECT indication is accompanied by spread spectrum TAG transmission rather than random pulse noise.

When the time-based latching circuit 65 indicates that a TAG transmission has arrived, the accompanying TX-packet is provided to a spread spectrum receiver 66. The spread spectrum receiver extracts the TAG ID and the moving state from the TX-packet, and outputs the R including the TAG ID and the moving state.
Output X-packet.

For each TAG transmission, the programmed controller 68, along with the RX-packet from the spread spectrum receiver 66,
Retrieve the latched time base count from 5.
The programmed controller sends this arrival time information (T
AG ID, movement status and time-based TOA COU
NT) into a TOA-DETECTION packet and communicate with the radio wave detection system processor via the LAN.

When the target moves from one location to another location that is far from one receiver but close to the other,
Each radio sniffer detects a varying arrival time measurement for the associated TAG transmission. For a given TAG transmission, the arrival time detection operation of each receiver discriminates between the arrival of the direct path TAG transmission and the multiple reflection signals arriving after that, and the early stage of the direct path TAG transmission before the multipath components merge. Triggered on cycle arrival.

Relevant TAG regardless of multipath effect
The ability to receive IDs is enhanced by the spatial diversity inherent in spread spectrum communication. In practice, each receiver can be considered a spatial diversity antenna element to facilitate multipath noise removal. After detecting the TOA of the received direct path TAG transmission, the TOA-DE assembled by the programmed controller is used.
The TECTION packet is communicated via the LAN to the radio wave detection system.

1.3. LAN Communication Referring to FIG. 1b, each receiver in the radio wave detection receiver array is connected to the radio wave detection system processor 40 via the LAN (the LAN cable is not shown). When the system processor 40 detects a TAG transmission, the TOA-DETECTION packet (T
AG ID, movement status and time-based TOA COU
NT).

The receiver is connected to the system processor for the following two independent communication operations. (A) Data communication, (b) Receiver time-based synchronization (providing repeatability within a few hundred pS). In an embodiment, these two communication operations are performed using one coaxial cable-based ARCNET local area network.

The ARCNET LAN uses a token passing protocol and a data transmission rate of 2.5 Mbit / sec. Communication is standard RG6 which addresses signal frequencies up to 200 MHz without significant attenuation problems
This is performed via two coaxial cables. Thus, the 200 MHz system synchronization clock can be multiplexed onto legitimate ARCNET data communication traffic without significant degradation.

FIG. 2C is a functional block diagram showing the LAN interface of the radio wave detection system processor and the receiver. In the system processor, the LAN interface 81 is an ARCNET interface (RI
M) Includes card 82 and 200 MHz clock interface. The diplex filter 84 is 20
0 MHz system synchronization clock 83 is 2.5 MHz
It is multiplexed into ARCNET signals and the resulting LAN signals are output to the network as regular ARCNET packet traffic.

The LAN communication from the system processor is received by the receiver of the radio wave detection array. In each receiver, LAN interface 86 includes a diplex filter 87 that demultiplexes the LAN signal to recover a 200 MHz system synchronization clock.
The ARCNET packet is sent to an ARCNET interface (RIM) 88 and the 200 MHz clock is sent via a clock interface 89 to a time-based latching circuit (not shown).

The choice of data communication network is primarily a design choice. The performance condition of the data communication operation is not particularly required, and can be performed by several methods such as telephone, microwave or wireless. The synchronization operation is less adaptable because it is constrained by the conditions that maintain synchronization between receivers within a few hundred pS, and if this synchronization cannot be maintained, position accuracy is lost.

1.4. Positioning processing The radio wave detection system processor receives the TOA-DETECTION packet communicated from the receiver via the LAN (data acquisition) and processes the arrival time data to obtain position location information (data reduction).

FIG. 3 is a flowchart showing the position locating processing operation. For each TOA-DETECTION packet received (TAG ID, time-based TOA COUNT, and moving state), the system processor identifies the moving TAG (target) (82). By this operation,
If possible, the TAG ID is recovered from the TOA-DETECTION packet and the TAG ID cannot be extracted.
An attempt is made to reconcile OA-DETECTION packets. For example, the receiver may not be able to recover the TAG ID for the transmitting TAG transmitter due to the multipath noise received by the receiver, even though the TOA data is accurate regardless of the reason that TAG identification cannot be performed. .

A valid TAG ID is checked for all TOA-DETECTION packets (8
3). Without a valid TAG ID, for example, 1000
TOA-DETEC arriving in a given time, such as nS
TION packets are assigned to the same TAG transmitter (84). A valid TOA-DETECTION packet (ie, a valid TAG ID) and the assigned T
Any TOA-DETECTION enabled and assigned data reduction algorithm with receiver redundancy including OA-DETECTION packet combinations
Validity and non-validity are determined.

TOA-DE with a given TAG transmission
When TECTION is identified or assigned (8
2) its T using the conventional time difference of arrival algorithm
The arrival time data for the AG transmitter is processed (8
5) Target position information is obtained. For two-dimensional target tracking, if at least three TOA-DETECTION packets have been identified (86), the target position can be calculated using the receiver ID and arrival time data (three-dimensional tracking). Requires at least four TOA measurements). The additional TOA-DETECTION packet represents (88) redundant position location information that can also be used in the target location algorithm. Positioning information calculated from the received TOA packet is stored in a completely indexed target tracking database as before (92), which includes (a) TAGID (16 bits), (b) moving state,
(C) target position, (d) position qualification vector, and (e) time.

The movement state is stored as a 4-bit amount (16 combinations), and in the embodiment, indicates movement start, movement continuation, or movement stop. Examples of additional state information that can be communicated include: (a) transmitted at selected intervals when the target is stationary to provide an updated record of whether the active TAG transmitter is moving and to help identify the TAG transmitter failure Non-moving state, and (b) Membrane-type key press on the TAG transmitter (such as operator-activated warning) that allows the key-type state to pass directly from the TAG transmitter or an automatic source (such as an unmanned vehicle) to the system processor .

The target position is stored as a 32-bit vertical and horizontal amount. The location qualification vector can provide error radial, TOA trigger randomness, synchronization randomness, and other factors that impair the accuracy of the position location calculation (up to approximately 10 feet) based on the accumulation of appropriate calculations. Express.

The target tracking database can be queried 95 via a graphic user interface 95 using conventional database search and search software. In an embodiment, the location coordinates of any target are preferably posted on a facility map using a mapping database search software package. Depending on the type of search, the mapping database search software can post item clusters, temporal locations, item streams through points in space or various combinations of such information at the facility map location of a particular item.

1.5. In order for the calibration radio detection system to operate at a TOA resolution of nanoseconds, small changes in circuit operating parameters and propagation characteristics caused by temperature and humidity changes in the facility must be taken into account. Such changes are handled by system calibration.

Referring to FIG. 2 b, the radio wave detection system includes a calibration transmitter 35. These transmitters are mounted at predetermined positions on the ceiling surface of the facility, in the ceiling, and the like, similarly to the radio wave detection receiver. The number and location of the calibration transmitters 50 are primarily determined to ensure that each receiver in the array 20 can receive the calibration transmissions of at least three calibration transmitters.

Distributing the calibration transmitters such that each receiver receives the additional calibration transmission provides calibration redundancy for handling communication errors (such as calibration transmitter ID). If the calibration transmitter is co-located with the receiver, the T
Time difference of arrival processing for AG transmissions can be used to generate an overview of the receiver array.

In operation, the calibration transmitter is programmed to generate calibration signals at predetermined intervals, such as every 100 seconds. Each calibration transmission is accompanied by a calibration transmitter ID.

The calibration transmission is received by the radio wave detection receiver, and the arrival time is detected in the same manner as the TAG transmission.
The receiver sends a calibration data packet (calibration transmitter ID and TOA COU) to the system processor 40 via the LAN.
NT).

The system processor 40 receives the calibration packet and calculates the position of the calibration transmitter from the time of arrival using the same procedure that works for target tracking. The calculated position for each calibration transmitter and the associated receiver arrival time difference are compared to the known position and the associated arrival time difference for these transmitters, and the apparent position and TOA difference are converted to each receiver's new calibration coefficient. Is done. For each calibration interval,
The updated coefficients are stored in the target orientation database and used to adjust the time of arrival data sent from each receiver during a normal target tracking operation.

2. Radio Detection System--As a low cost alternative to the high resolution embodiment of the radio detection system using area detection arrival time differences, the radio detection system of the present invention is configured to receive TAG transmissions only from each assigned area. It can be implemented as a low-resolution embodiment using a receiver. This embodiment differs from the high resolution embodiment described in Section 1 mainly in the following two points.

(A) The target orientation resolution is determined not by the arrival time difference but by the size of the allocated receiver area. (B) The receiver receives only TAG transmissions from TAG transmitters in each allocation area, and the target orientation is performed when the receiver receives a TAG transmission having a TAG ID.

In the low-resolution embodiment, the arrival time detection (TO
There is no need for A-triggering and time-based latching, resulting in significant cost savings.

Referring to FIG. 2a, for the low resolution embodiment, the receiver of radio detection array 20 uses a TAG located within each target location area of a given size (giving a given target location resolution). Is configured to detect the TAG transmission of For example, using a directional antenna at the selected receiver location, the size of the target orientation area can be determined by a predetermined antenna beam width. In this case, the selection of the receiver position is flexible and can cover the allocated target orientation area.

Further, the receivers can be distributed in a grid and determine the size of the target orientation area by a predetermined interval between the receivers. In this case, the target orientation resolution is a function of the receiver spacing, and the TAG transmitter output is cooperatively selected so that TAG transmissions are received by most neighboring receivers. Receipt of a TAG transmission by the machine indicates a loss of target orientation resolution).

Referring to FIG. 2a, for the low resolution embodiment, the TAG transmitter 50 can be implemented as described in Sections 1.1 and 4 for the high resolution radio detection embodiment. Thus, the TAG transmitter includes a spread spectrum transmitter 52 that sends a TAG transmission only when a TAG (target) movement is detected using the battery power saving circuit 54 and the movement detector 56, and a periodic retransmission during the target movement. Is determined by the periodicity controller 58.

The major difference in the design is the output selection of the spread spectrum transmitter. In a configuration in which the target position is based on the receiver interval, the TAG transmission output is relatively low and the distance is limited, so that two or more receivers are used. TAG transmissions may be received by the device. For example, for a high resolution embodiment (preferably the TAG transmission is received by multiple receivers), the TAG transmission power can be in the range of 0.01-1 W (see section 3) and low. For the resolution embodiment, the TAG transmission output can be about 1 μW and the effective range is about 10 m.

Referring to FIG. 2b, for the low resolution embodiment, the complexity and cost of the radiometric receiver 60 can be significantly reduced by omitting the components associated with arrival time detection. Thus, although some receiver front ends may require amplifiers and filters, the only circuits that need to be included are the spread spectrum receiver 66 and the programmed controller 68.

In particular, the TOA trigger circuit 64 and the time-based latching circuit 65 need not support arrival time detection. Further, the programmable controller need not be programmed to control these circuits.

Thus, in operation, the spread spectrum receiver operates as described in Section 3 and receives TAG transmissions from the receiver front end to recover the TAG ID and mobile state from the TAG packet, and recovers. The RX packet having the TAG ID and the moving state is output. The RX packet is retrieved by the programmed controller.

The programmed controller is TAG
Corresponding AREA-DETE including ID and moving status
Generate a CION packet. AREA-DETEC
The TION packet is communicated to the radio wave detection system processor via the LAN.

The radio wave detection system processor receives the AREA-DETECTION packet from the receiver of the radio wave detection array, performs a target location process, and updates the target location database. In this embodiment using area detection rather than arrival time difference, the target orientation for the TAG does not need to be calculated and the AREA-DE containing the TAG ID from the receiver assigned to the area where the TAG (target) is located.
It is only recorded based on the reception of the TECTION packet.

[0087] 3. In the spread spectrum communication embodiment, the radio wave detection system is 902-928M.
Uses spread spectrum communication under the FCC section 15.247 rules for unlicensed operation in the Hz band. Not only is licensing unnecessary, but spread-spectrum communication identifies direct-path TAG transmissions from accompanying multipath noise and enables low-power operation (maximum allowed transmitter output in Chapter 15.247 is 1 W). This is advantageous.

Spread spectrum transmission involves a constant frequency shift called "frequency hopping". Due to the frequency shift, there is a difference in the reflection angle on the rough reflection surface, and the multiple reflection enters into the frequency component that fluctuates in space.

Because spread spectrum multiple reflection is a spatial diversification, these components do not arrive as coherently as direct path transmission. The reception of the direct path TAG transmission and the TAG ID
Recovery becomes easier.

The use of spread spectrum communication allows relatively long distance operation with low power TAG transmitters (less than 1 W) by transmitting in short bursts of high peak power. High peak transmit power is radio-detected because the number of receivers required to ensure that at least three (usually more for redundancy) receivers receive TAG transmissions is reduced Important for high resolution embodiments of the system.

The pulse operation characterizing spread spectrum communication requires non-coherent data reception. That is, unlike coherent data communication in which reception is fixed to a carrier signal and demodulation is performed, a spread spectrum receiver has a TAG that arrives at a sufficient speed to guarantee recovery of TAG ID data included in a TX-packet. Synchronization with transmission must be fixed.

A significant advantage of using short spread pulse communication and non-coherent data reception using spread spectrum communication is that while the data integrity and bit error rate (BER) are somewhat worse, battery usage is reduced. This is a significant decrease. For example, in a representative manner the non-coherent receiver design is one of the errors ^105, the design of the coherent receiver is one of the errors ^109.

The high resolution embodiment of the radio wave detection system of the present invention can withstand a high error rate for the following reasons. (A) data reception is usually redundant because receivers are superimposed (ie, typically four or more receivers receive a given TAG transmission), and (b) a triggering event occurs TAG ID received by other receiver
Is often determined by the system processor, it is not always necessary to use the specific TAG for the arrival time detection.
There is no need to properly receive the ID.

The choice of a particular spread spectrum communication system is primarily a design choice based on commercial considerations.
Several spread spectrum communication systems are commercially available. For example, Hillier Technology
es Limited radio wave detection system SPREADEX --- available from Partnership
There are short range spread spectrum wireless control, telemetry and data radio communication systems. This spread spectrum system is described in Appendix A (transmitter) and Appendix B (receiver), and related U.S. patents incorporated herein by reference.

FIG. 4A is a functional block diagram of the SPREADEX spread spectrum communication system. The spread spectrum system includes a transmitter 100 (integrated in each TAG transmitter) and a receiver 110 (integrated in each receiver in the receiver array).

The spread-spectrum transmitter 100 includes a control module 102 that generates a receiver master clock (using a standard digital logic crystal oscillator at approximately 2 MHz) and outputs power control, control data, and operating sequences. The spreader 103 performs an appropriate spreading (chipping) sequence to generate a spectral spread T
Generate an X-packet (TAG transmission).

TX-packet is a modulator 1 including a shaping circuit for modulating a temperature stabilized oscillator and a varactor diode.
04. The output of the modulator is shaped into a frequency shift keying signal. By the final transmitter RF stage 106,
Appropriate amplification is provided for the selected power level (typically between 0.01 W and regulatory 1 W), with output filtering to ensure compliance with FCC regulation of out-of-band emissions. The TAG transmission thus obtained is broadcast from the antenna 108 (on-vehicle or external).

FIG. 4B shows the format of a TX-packet. It includes a preamble, a sync bit, a 16-bit TAG ID field, and in the preferred embodiment a 16-bit data field consisting of 12 filler bits and 4 state (data) bits. This TAG transmission packet is spread in the spreader 103 by combining the packet bits with the appropriate chipping sequence. The chip clock is approximately 1 MHz (half of the spread-spectrum transmitter crystal oscillator clock frequency) and the packets are transmitted at 619 μS (619 chip clock cycles), the first 128 μS of which is the preamble and sy.
nc bits (ie, TAG I
D and before the data field). Thus, the packet bits (including the synchronization) are transmitted at approximately 60 Kbps and the actual data bits are transmitted at approximately 52 Kbps.

Referring to FIG. 4 a, the spread spectrum receiver 110 includes, in addition to the antenna 112, three main stages: a receiver RF front end 114, a receiver IF demodulator and a spreader 116. The receiver front end 114 converts the incoming TAG transmission signal to a representative 45M
It includes a preamplifier and a mixer for converting to a Hz intermediate frequency (IF) signal. The signal is then passed to a receiver IF demodulator 115, which is a Motorola 13055 IF processor integrated circuit that performs demodulation.

The demodulated signal is applied to a spreader 116 and despread by a digital matched filter using analog addition and comparison. Synchronization of the spreading is performed by a 2 MHz crystal oscillator 118, which must ensure that the clock of the spread spectrum transmitter 100 ± 400 ppm gets a synchronization lock.

The spread spectrum receiver must obtain a synchronization fix that can recover the TAG ID and status data. That is, for each TX-packet, the spread-spectrum receiver 110 has approximately 128 μS to obtain the synchronization fix before the TAG ID and status data arrives (ie, allocates the preamble and sync bits). Time). Once the TX-packet synchronization lock is obtained, the TAG ID and status data are recovered and an RX-packet is generated.

While the spread-spectrum receiver is trying to achieve synchronization lock, it locks up to prevent any other signal from being received. Therefore, TAG
It is a design goal to reduce the number of times that a randomized pulsed signal, rather than a transmission, is actually applied to a spread spectrum receiver--see Section 5.2.

FIG. 4c shows the format of an RX-packet. This includes the preamble, sync bits, and 32 data bits. The 32-bit data field includes a 16-bit TAG ID and a 2-bit move state (in the preferred embodiment, the other 14 bits are preserved). Each RX-packet generated from the spread spectrum receiver 110 in response to the TAG transmission is transmitted to a programmed controller (6 in FIG. 2b) in the radio detection receiver.
8) and the corresponding TOA-DETECTI
Used to assemble ON packets.

The specific embodiment of spread spectrum communication does not form part of the present invention. The main reason for choosing a SPREADEX system is that it is available not only as a transceiver but also as a separate transmitter / receiver. The receiver components are significantly simpler (and therefore inexpensive) compared to the receiver components, and the number of TAG transmitters (even in low resolution embodiments) is typically less than the receiver in the radio detection array. Greatly increases the cost of constructing the radio wave detection system only by using the transmission for the TAG transmitter component.

[0105] 4. TAG Transmitter Referring to FIG. 2a, the TAG transmitter performs the following three basic functions. (A) spread spectrum communication by TAG transmission, (b) movement detection enabling TAG transmission,
(C) Periodic control for establishing a TAG transmission interval.

The spread spectrum transmitter 52 is described in Section 2 and Appendix A, and related patents. Each TAG
For the transmitter, etch or scratch diode connections on the spread spectrum transmitter card.
By doing so, a unique 16-bit TAG ID is given to the address selection operation.

Spread spectrum transmitter 52 starts transmission when strobe line transition is active.

In response to inputs TX1 and TX2, spread spectrum TAG transmission is started. TX1 is provided from battery power saving circuit 54 and TX1 is provided from periodicity controller 58. Both of these transmission start inputs are inactive during the power saving mode. For each TAG transmission, the spread spectrum transmitter provides a TXENABLE output indicating the end of the TX-packet transmission.

The spread spectrum transmitter 52 also receives two moving state (data) inputs STAT1 and STAT2, and STAT1 is supplied from the battery power saving circuit 54 to S
TAT2 is provided from the periodicity controller 58. Both of these STAT inputs are inactive when the TAG transmitter is in power save mode (indicating no operation).

The battery power saving circuit 54 is a conventional multivibrator that triggers in response to each movement (jitter) indication from the movement detector 56 to actively drive its TX1 / STAT1 output line. The reset cycle of the multivibrator is 1 to 6 using the potentiometer 54a.
It is adjustable within the range of 0 seconds and the adjustable reset period is TX1 / ST when the multivibrator is intermittently retriggered during the target move before the reset period is limited.
It is chosen to keep AT1 active. That is, the reset period establishes the length of time that the spread spectrum transmitter 52 will continue the periodic TAG retransmission after the target movement stops (indicated by the final jitter signal from the movement detector).

The movement detector 56 is a conventional mercury tilt (jitter) switch that sends a movement display signal to the battery power saving circuit 54 every time movement is detected. The movement switch is generally sensitive enough to produce a movement indication even for steady movement of a target, such as on a conveyor belt.

The periodicity controller 58 is a conventional multivibrator that makes TX2 / STAT2 make an active transition in response to TXENABLE (end of TAG transmission) from the spread spectrum transmitter 52. The multivibrator is reset after an adjustable reset period within 1 to 60 seconds using potentiometer 58a and TX
2 / STAT2 transitions to inactive, the reset period establishes the length of time that the periodicity control circuit outputs a TX2 transmission start strobe to the spread spectrum transmitter 52 after the TAG transmission (indicated by TXENABLE), and retransmission is initiated. Be started.

At the start of the target movement, the battery power saving circuit 5
4 responds to the initial movement indication from the movement detector 56, and
1 / STAT1 strobe is output, and T
Perform AG transmission.

During the target movement, the movement detector 56 outputs a movement indication (jitter) to continuously re-trigger the multivibrator in the battery power saving circuit 54, and the TX1 / STAT
Leave 1 active. After each TAG transmission, the TXENABLE strobe from the spread spectrum transmitter 52 triggers the multivibrator in the periodicity controller 58, which is reset after a predetermined reset period to output the TX2 / STAT2 strobe. By this operation, periodic TAG retransmission is started in the movement continuation state.

When the target movement is stopped, the movement detector 56 stops outputting the movement display and triggers the multivibrator in the battery power saving circuit 54. After a predetermined reset period, the multivibrator is reset, and the battery power saving circuit switches TX1 / STAT1 to inactive,
At the same time, a reset strobe is sent to the periodicity controller 58. By this operation, the multivibrator is immediately reset, and the transmission of the last movement stop state TAG is started by the TX2 / STAT2 strobe.

In the embodiment, the battery power saving circuit 54 and the periodicity controller 58 are the dual multivibrator integrated circuit package No. Implemented with 79HC123. Potentiometer adjustments are set based on the expected target movement and TAG transmitter (target) number within each other's transmission range. Typically, the TAG transmitter is set to retrigger every 15 seconds, and will continue transmitting for an additional 30 seconds after the target stops moving. When the TAG transmitter is in power saving mode, the IC package typically uses less than 10 μA.

Although reduced by spread spectrum frequency hopping, system design should consider that temporal collision of messages is inevitable. To reduce message collisions and enable TAG hordes, two parameters must be optimized: (A). Shorten the transmission time, (b). Randomize the periodicity. If the transmission time cannot be limited appropriately, the permissible group will be small due to increased overlap and collision transmission. Failure to properly randomize the periodicity may cause the two TAG transmitters to synchronize and not receive any messages.

In the embodiment, the duration of the TAG transmission (61
9 μS) is short for wireless devices. If the TAG transmitter can be synchronized, more than 1,000 TAGs can be transmitted per second. Because TAG transmitters are not synchronized, collisions can be reduced by acting on random bursts and adjusting the periodicity for a given TAG group using conventional statistical analysis.

The randomness of periodic TAG transmission is achieved as a result of two factors. First, movement initiation is based on mechanical movement, which is a random event in the context of radio detection systems, (by a belt conveyor, etc.)
Even if many goals move together, the goal is about 1
There is no synchronous movement in the synchronization window of the ms. In addition, a potentiometer can be used to add random periodicity. Second, multivibrators in battery power saving and periodicity control circuits typically have decay times that are affected by Schmitt trigger voltage levels, which can fluctuate by more than one volt depending on location. Accordingly, the periodicity provided by the periodicity control circuit varies sufficiently to provide considerable randomness.

[0120] 5. Referring to radiolocation receiver Figure 2b, each receiver of the array to perform the following four basic functions. (A). Receiving spread spectrum communication, (b). Trigger on arrival time of TAG transmission,
(C). Latching the time base TOA COUNT of the 800 MHz synchronization counter in response to the TOA trigger,
(D). L containing arrival time data for each TAG transmission
Output to AN TOA-DETECTION packet.
Highly stable 800 MHz time base clock (1.25 ns
/ Cycle) approximately 0.305m (1 foot)
Is obtained.

TAG transmission is performed by the receiver front end 62.
(ANT PORT) and immediately given to the TOA trigger 64. The TOA trigger circuit sends a TOA trigger (TOA DETEC) to the time-based latching circuit 65.
T). Time base latching circuit is 200MHZ
8 derived from the z synchronization clock (200 MIN)
Latch the time base count of the 00 MHz time base clock. In addition, the time-based latching circuit attempts to perform digital noise filtering to ensure that the TOA trigger circuit is triggered by a TAG transmission rather than random pulse noise, and when a valid TAG transmission is indicated,
The time-based latching circuit enables the (SSOUTEN) receiver front end 62 to send a TX-packet to the spread spectrum receiver 66 (SSOUT / SSIN).

FIG. 5A is a circuit diagram of the receiver front end 120. Receiver front end is antenna port 1
21 (ANT PORT in FIG. 2a). The radio signal is transmitted to the amplifier 12
, Two-stage amplification by the helical filter 12
4,125. The TAG transmit signal propagates through the receiver front end with some amount of propagation delay.

After being amplified and filtered, the received TAG transmission is passed to power splitter 126, and the radio signal is transmitted to (a).
A spread spectrum receiver via solid state switch 128 (66 in FIG. 2a) and (b). It is split into inputs to the TOA trigger circuit 130 (64 in FIG. 2a). The receiver front end TAGs to the spread spectrum receiver until the solid state switch is enabled by SSOUTEN from the time-based latch circuit (65 in FIG. 2a).
Do not send TX-packets for transmission.

Referring to FIG. 2a, the spread spectrum receiver 66 is described in Section 2 and Appendix B, and related patents. The receiver operates the receiver front end 62 (SSOUT / SS) until the radio signal received by the time-based latching circuit 65 is determined to be TAG transmission instead of random pulse noise and SSOUTEN is output.
IN), the delay reduces the 128 μS window to obtain synchronization fixation (see sections 3 and 5.2).

When the receiver 66 acquires the synchronization fixed,
Outputs CQLK signal and TAG from TX-packet
The ID and the moving state are recovered. Next, the receiver assembles the corresponding RX-packet (including the TAG ID and the movement status) and switches RRDY to active when the RX-packet is obtained and retrieved by the programmed controller at the serial port RSO.

The programmed controller 68 is RR
Output the RSCLK clock signal in response to DY active to clock the RX-packet from the RSO signal port.

5.1. TOA Trigger Circuit Referring to FIG. 2a, the TOA trigger circuit 64 is located on the same card as the receiver front end 62, with mechanical separation for signal separation.

TOA triggering is performed to obtain a down-converted intermediate frequency without mixing. Although the sensitivity required for the TOA trigger circuit decreases due to the down conversion, the trigger accuracy also decreases due to the period of the intermediate frequency. That is,
The phase difference between the transmitter oscillator and the receiver local oscillator can cause errors up to one full IF period, and the inaccuracies can be amplified.

FIG. 5A is a circuit diagram of the TOA trigger circuit. The TOA trigger circuit is of a conventional peak hold design--the TAG transmit signal is passed through a diode 132 to a signal level threshold capacitor 133, which maintains charge as a function of the most recent signal.

The TOA trigger function is a high-speed comparator 135
, Which receives the TAG transmit signal and the programmable signal level reference voltage from the digital potentiometer 136. The digital potentiometer is set by the INCPOT signal from the programmed controller (see FIG. 2a).

The comparator 135 is an FFD96687B
High speed minimum dispersion characteristics such as Q are selected. By minimizing the variance, the comparator output responds at the same or similar rate when driven with a high output (comparator overdrive) or low output signal. The comparator reference voltage is adjusted by the programmable potentiometer 136 and a predetermined signal level threshold is output.

Receiver front end 1 (via power splitter 126) exceeding signal level threshold set by comparator reference voltage from potentiometer 136
Upon receiving the signal from 20, comparator 135 will quickly trigger to assert the TOA DETECT trigger signal. The TOA DETECT trigger is sent to the time-based latching circuit (65 in FIG. 2a) as an indication of possible arrival of a TAG transmission, at which point the asserted TOA
The DETECT trigger can indicate TAG transmission or random pulse noise.

TOA DETECT remains asserted as long as the input signal remains above the comparator reference voltage, and when the signal disappears near its predetermined signal level threshold, at the end of the TAG signal or at the end of random pulse noise, Detector capacitor 133 decays and switches comparator 135 and does not assert TOA DETECT.
Based on the length of time that the TOA DETECT trigger remains asserted, the time-based latching circuit determines that
It is determined whether to process as G transmission.

4.2. Time-Based Latching Circuit Referring to FIG. 2a, the time-based latching circuit
In addition to the TOA DETECT trigger from A trigger circuit 64, a 200 MHz system synchronization clock from LAN interface 69 (200 MIN), and (indicating that the receiver has achieved the synchronization required for data recovery)
The ACQLK from the spread spectrum receiver 66 is received.

The time-based latching circuit is a high-speed latch circuit that performs time-based latching and digital filtering while reducing the metastability problem associated with synchronous latching. The circuit includes a high-speed ECL and a TTL register unit. These registers are REGSE
The data is read and written by the controller 68 programmed using L and R / -W, and the type of register and operation is selected by data / parameter transfer on REGDATA.

FIG. 5b shows the register configuration 140 of the time-based latching circuit. The registers are used for time-based latching or digital filtering operations. All registers are connected to the Control Bus and can be read and written through it.

The time-based latching operation is performed using the following register designation. TIME BASE 24 bit 800 MHz counter TIME BASE OV overflow interrupt (msbit of TIME BASE register) TOA LATCH 24 bit latch These registers are sectioned using high speed ECL logic.

The TIME BASE register is 800 MH
800 MH clocked by z time base clock
A z-time base counter (unreadable), this clock being derived from a 200 MHz system synchronization clock provided by a radiometric system processor by conventional phase coherent frequency multiplexing. TOA DET
When the ECT trigger is asserted, indicating the arrival of a signal that can be a TAG transmission, the time-based TOA COUNT in the TIME BASE register will quickly return to TO.
A Latched into the LATCH register.

The most significant bit of the TIME BASE register is a time-based overflow TIME BASE OV that outputs an interrupt on the Control Bus, whose overflow indication is latched into the STAATUS register and read by the programmable controller, which maintains a full overflow count. I do. 80
At 0 MHz, a period of 1.25 nS, the 32-bit counter counts approximately 21 mS before overflowing.

The TOA LATCH register is TIME
Receive parallel input from BASE register, and read TOA DE
When the TECT trigger is asserted, latch the time base TOA COUNT in that register. TOA LAT
The CH register contains an asynchronous trigger event (TOA) during the time window when the TIMEBASE counter is incrementing.
Digital latching metastability problems caused by the occurrence of DETECT are reduced. Such a conditioning scheme typically uses a Josephson (or Gray code) counter as the high frequency (least significant) part of the 800 MHz TIME BASE counter to reduce the number of transition bits.

When the time-based latching circuit determines by the digital filtering function that the TOA DETECT trigger indicates the arrival of a TAG transmission, the TOA LATC
The H register is set to Co by the programmed controller.
The data is read out for each section via the control bus.

The digital filtering function is implemented by the following control and writable register designations. MAX NOISE LENGTH 16-bit signal duration threshold parameter TOA TO ACQLK 16-bit counter TOA DETECT LENGTH 24-bit counter NOISE COUNT 16-bit counter STATUS 8-bit latch These registers are sectioned using TTL logic.

The three states of the radio wave detection receiver are defined by the digital filtering function.

(A). ARMED1--TOA DETECT The trigger is negated and has a signal that exceeds the signal level established by the comparator reference voltage. (B). ARMED2--TOA DETECT is affirmed, MAX NOI that regards trigger signal as TAG transmission
Wait for the count of SE LENGTH. (C). DISARMED--TOA DETECT is asserted longer than MAX NOISELENGTH. When the time-based latching circuit recognizes the received signal as a TAG transmission and generates a DISARMED state, the circuit:
(A). TAG transmission to the spread spectrum receiver (TX-
(B). Outputs an interrupt to notify the programmed controller that the TAG transmission has been received and the latched time base TOA COUNT can be read from the TOA LATCH.

When DISARMED occurs, the REA of the radio wave detection receiver (that is, the time-based latching circuit)
RMing requires a REARM from the programmed controller (even if the TOA DETECT trigger is denied). The programmed controller is TOA LATC via Control Bus
A REARM command is sent to the flip-flop 142 that controls H.

The contents of the TOA LATCH register when the radio wave detection receiver is in the DISARMED state are valid. That is, TX-DETECT is a valid TX-
If asserted long enough to indicate a packet, the resulting interrupt will signal that the TOALATCH register contains a time-based TOA COUNT.

The radio wave detection receiver includes (a). Reasonable TX-
When the packet is detected and the lowest register of the TOA LATCH is read, from DISARMED,
(B). TOA DETECT is MAX NOISE
ARMED2 to ARMED1 if no longer asserted before LENGTH indicating reasonable noise reception
REARM is performed.

The MAX NOISE LENGTH register is set to ARMED2 by the programmed controller.
Is stabilized to a value that determines the transition from the to the DISARMED state. That is, TOA DET is stored in this register.
A predetermined signal duration threshold parameter, typically on the order of 1 μS, is loaded that defines the duration threshold at which the received signal asserting the ECT trigger is likely to be a TAG transmission rather than random pulse noise.

Therefore, MAX NOISE LEN
The signal duration threshold parameter in GTH is used to control TOA detection sensitivity. In particular, MAX NOISE L
If the ENGTH parameter is too large, (MAX
SSOUTE after reaching NOISE LENGTH
(No TX-packet is received until N is provided.) A spread spectrum receiver has enough 12 to obtain synchronization fixation.
No 8 μS preamble window (ACQL
K must be received to recover the TAGID).

The TOA TO ACQLK is obtained by a time-based latching circuit (a). T from TOA trigger circuit
OA DETECT trigger reception and (b). A 1 MHz 16 bit counter that measures the time between receipt of the ACQLK signal from the spread spectrum receiver. This register is used for the following two operations. (A). MAX
TOA together with NOISE LENGTH register
MAX NOIS after DETECT trigger is asserted
Notify that the count of E LENGTH has elapsed,
(B). The elapsed time after the TOA DETECT trigger is displayed on the spread spectrum receiver and ACQLK (programmed controller is set to MAX NOISE LENG
Value that can be used to adjust the TH parameter).

The count of TOA TO ACQLK is M
When AX NOISE LENGTH is reached, comparator 144 triggers and flip-flop 142 (DIS
(ARM / REAM) transitions. At this time TOAD
If ETECT is still asserted, a DISARM condition occurs to indicate a valid TAG transmission. The controller programmed by the interrupt is notified that the TOA LATCH contains a valid time-based TOACOUNT, which indicates that the TOA DETECT trigger has not been asserted and T
Read by programmed controller after indicating end of AG transmission.

The TOA DETECT LENGTH register is a 10 MHz 24-bit counter that measures the count that elapses while TOA DETECT is asserted, ie, the duration of a TX-packet.
Only valid in ARMED state. This register is determined to be approximately 1 μS and can count beyond 619 (standard TX-packet duration is 619 μS
Is). It ’s MAX NOISE LENGTH
The TOA DETECT trigger asserted above can be used to confirm that it is in fact a valid TX-packet.

The NOISE COUNTER register has been updated since the last REARMing (ie, the last TOA DE
TECT trigger asserted longer than MAX NOISE LENGTH and associated time-based TOA COU
T since NT was read from TOA LATCH)
Output OA DETECT trigger assertion count,
It outputs a count of the number of TOA DETECTs discarded due to random pulse noise instead of G transmission. This count is stored in the programmed controller 68
Used to adjust the two noise sensitivity thresholds--comparator reference voltage and MAXNOISE LENGTH--to reduce TOA DETECT trigger-off random pulse noise.

In summary, the effect of the digital filtering function is T
OA DETECT trigger is MAXNOISE LEN
To delay the application of the received signal to the spread-spectrum receiver until asserted for more than a predetermined (programmable) count of GTH, indicating that the received signal is a TAG transmission rather than a random pulse. This digital filtering function enables non-TA of the spread spectrum receiver.
Lock-up to X-packets is reduced.

The choice of the MAX NOISE LENGTH parameter depends on how fast a spread spectrum receiver can acquire synchronization fixation and the distribution of random pulse noise in the receiver environment. In addition to temporary digital filtering by the time-based latching circuit, signal level filtering by selecting a comparator reference level to trigger a comparator in the TOA detector circuit (using INCPOT from a programmed controller) Is performed.

For example, MAX NOISE LENGT
H parameter is too short and non-TX-packet causes AR
DISA (indicating a valid TX-packet) from MED2
If a legitimate transition to RMED is made and the reasonable noise is also of short duration, MAX NOISE LENG
These noise signals can be implemented with a longer TH.

[0157] Also, MAX NO on non-TX-packets
If ISE LENGTH is exceeded and the noise signal strength is low, incrementing INCPOT can increase the comparator reference level to eliminate these interfering signals. Care must be taken to ensure that the comparator reference level does not become too high and prevent the TOA detector circuit from asserting the TOA DETECT trigger properly for attenuated valid TX-packets.

The recommended design method is MAX NOIS
E LENGTH is maximized (signal duration threshold is minimized) and INCPO is set to the comparator reference voltage.
T setting is minimized (signal level threshold is minimized).

4.3 Programmable Controller Referring to FIG. 2b, the programmable controller 68 is a system that is commercially available and can be configured from INTEL (WILDCARD). It is a relatively high-density motherboard that is small and can use other peripherals. The CPU is an Intel 8088 with standard interface logic. The following components accompany the system: (A). 256K RAM for program storage,
(B). 32K ROM for a driver program having a down line loader, (c). A peripheral controller based on Intel 8255, and (d). Arcnet interface.

When configured, the programmed controller is equivalent to a standard diskless network processor in the local area network industry. The peripheral controller includes (a). A time base latching circuit 65 for register read / write including retrieval of the time base TOA COUNT from the TOA LATCH register, (b).
A spread-spectrum receiver 66 searching for RX-packets (with TAG ID and mobility state); and (c). Interfaces with the TOA trigger 64 which designs the comparator reference level sent from the programmable potentiometer (136 in FIG. 5a).

When powered on, the programmed controller 68 performs the following functions. (A). Initialize Arcnet 8255 and 8088 to a known state; (b). Request a downline load from a radio wave detection system processor (network file server) via a network; (c). Request configuration information from a particular system processor to the receiver (identified by its Arcnet identification address); (d). ARMED1 (with TOA DETECT trigger from TOA trigger)
Arm to state.

When the radio detection receiver (ie, the time-based latching circuit) is in the ARMED1 state, the programmed controller indicates that a valid TX-packet is being received by the TOA DETECT trigger (A).
RMED2) followed by the time limit (DISARMED) of the MAX NOISE LENGTH counter, MAX NOISE LENG from the time-based latching circuit.
Wait for a TH interrupt.

Upon receiving the MAX NOISE LENGTH interrupt, the programmed controller 68 causes TOAD (indicating that the TAG transmission has been received) to be completed.
Wait for the ETECT trigger, then read the TOA LATCH register to retrieve the TX-packet time base count. For statistical reasons, before reading the lowest register of TOA LATCH and performing a REARM,
The programmed controller can also read other registers of the time-based latch circuit that are still valid before the REARM.

Operation of HiTEK Overview The Hiller HiTEK kit (see FIG. 6) provides a complete spread spectrum wireless communication link. Transmitter and receiver are 902MHz ~ 9
It is designed to operate in the 28 MHz band. The transmitter and receiver circuits need to load simple 5V CMOS logic interface signals and read data. Although the transmitter and receiver are designed as separate units, they may be combined into a single unit as a transceiver. A general system description is provided below, and a more detailed description of the transmitter and receiver cards is provided in the next section.

[0165] The transmitter consists of four main blocks. The first two control blocks and the spreader block are implemented by a custom integrated circuit. The control block is responsible for master clock generation, system power control, control data, and sequence control of various operations. The spreader block combines input data and synchronization bits according to a spreading sequence.

The spreader data packet is input to the modulator. The modulator includes a shaping circuit and a varactor diode that modulates the temperature stabilized oscillator. The output of the modulator is a shaped frequency modulation key. The last block of the transmitter is the output stage, that is, the stage where the amplification corresponding to the desired power level is obtained. This level is typically
It will vary from 0.01 watts to the legal limit of 1 watt. This section also includes output filtering to ensure compliance with out-of-band emissions regulations.

The receiver consists of three main blocks. The first block is the RF front end, which includes a preamplifier and a mixer that converts the incoming signal to a standard 45 MHz intermediate frequency (IF). Input filter circuits and preamplifiers are used to limit spurious emissions from the local oscillator. This signal is then applied to the second block of demodulating Motorola 13055I
Sent to the F processor integrated circuit.

The signal is then despread by a third block using a digital matched filter, which utilizes analog addition and comparison to minimize cost. The reproduced data can be supplied to the application circuit via the interface connection.

The output data is shown in FIG. 7A, 7B and 7C.
Packetized into one of two formats. The packet has a plurality of preamble bits, one synchronization bit,
And 32 message bits. In mode 0, the message consists of 16 address bits and 16 data bits. In mode 2, the message consists of 32 data bits. The packet is spread by combining the packet with an appropriate chipping sequence.

The chip clock is の of the clock frequency of the crystal oscillator in the transmitter. Packet is 619
Sent by clock cycle. The frequency of the reference digital logic crystal oscillator is about 2 MHz. Thus, while the original data including the synchronization bits is transmitted at about 60,000 bits / sec, the actual data bits are about 52,000 bits / sec.
Transmission is possible at 000 bits / sec. This data transmission rate depends on the operation mode. Therefore, the data transmission speed is such that a high-speed response and a medium data throughput can be obtained.

[0171] 2. FIG. 8 shows the functional blocks and input / output connections of the HiTEK transmitter card. All input / output connections are compatible with 5 volt CMOS logic levels. An overview of each functional block and its associated input / output connections will be given.

Battery selection: BATMODE ^{* The} input is
The ASIC is configured to operate in the BATTERY mode when true (low) and in the NON-BATTERY mode when false (high). Place a short jumper on JP5 and set the BATMODE ^* input high. BA
In the TTERY mode, the ASIC stops the crystal oscillator after each transmission, in a SLEEP (power off) state, and receives a transmission start signal and causes a SYSTEM WAKEEU.
Entering the P state performs additional operations.

Mode selection: The input selects one of three operating modes. The selection is made possible by changing the input lines, ie the wiring of the short-circuit jumpers on the board. The transmitter forms a data packet determined by the MSEL0 and MSEL1 inputs. Place a short jumper on JP4 or JP3 and set the MSEL0 or MSEL1 input high, respectively. These are, as shown, 1 =
Select mode by logic high and 0 = logic low. MSEL1 = 0, MSEL0 = 0 Mode 0 shown in FIG. 7a MSEL1 = 0, MSEL0 = 1 Mode 1 shown in FIG. 7b MSEL1 = 1, MSEL0 = 0 Mode 2 shown in FIG. 7c MSEL1 = 1, MSEL0 = 1 Mode 3 is manufacturing For testing.

Data input: for loading data to be transmitted. READY output is true (logic high)
Indicates that data can be loaded in all modes. In mode 0, four parallel data inputs D0, D
1, the data on D2 and D3 are as shown in FIG.
It is transmitted after the transmission start signal and is latched internally when the READY output goes low. In modes 1 and 2, S
At the rising edge of CLK (shift clock), serial input data at the SI input is clocked into the transmission data register. The data register is 1 in mode 1.
It is 6 bits long and 32 data bits long in mode 2. Attempting to load data while the READY output is low will result in data loss. The data in the data register is transmitted as shown in FIGS. 7B and 7B after the transmission start signal.

Address selection: In operation modes 0 and 1, this is for accommodating a 16-bit address in a data packet to be transmitted. The data and address formats are shown in FIGS. 7a and 7b, respectively. HiTE
The K transmitter card has a 16 dip switch to select the binary address to send. The switch position is detected in a matrix format using four address strobe lines and four address lines.

Crystal oscillator: Standard 2M for digital circuits
Hz clock. It must have an accuracy of ± 200 ppm or more. When operating in BATTERY mode, the crystal oscillator is
Oscillation starts after shifting to the AKEUP state.

Control Logic: A state machine that sets all the correct operations and signal sequences in the ASIC. R
The ESET input is an analog signal, and when true (logic high), resets the transmitter ASIC to a SLEEP state. MSEL0 and MSEL1 inputs are RESET
Goes low and is internally latched. The HiTEK transmitter card is a component that performs a power-up reset when power is applied.

Transmission start: STARTTX0 ^* or STA
When the RTTX1 ^* input is enabled (transition from high to low), it provides an internal transmission start signal. This means that the ASIC can be set to SYS
Shift to TEM WAKEUP state, NON-BAT
In the TERY mode, the state is shifted to the TXWAKEUP state. SYSTEM WAK in BATTERY mode
When in the EUP state, the crystal oscillator starts up immediately, and after 512 clock cycles have elapsed, TXWAK
A transition to the EUP state occurs.

Upon transition to the TXWAKEUP state, TX
The ENABLE output becomes true (high), and transmission of the preamble bit starts. The TXENABLE output becomes false (low) upon completion of transmission.

The on / off output goes true (high) when the STARTTX0 ^* input starts transmitting, and
TTX1 ^* False when input starts transmitting.
This output is connected to one of the parallel data inputs and is designed to transmit it in Mode 0 operation if desired.

Spreader: Combines a chipping sequence with a packet bit. Thereby, a desired spreading operation is obtained.

Modulator: voltage controlled, temperature compensated L
An RF output signal centered at about 915 MHz is generated using a C oscillator (version 3) or a SAW oscillator (version 3). The spread and filtered data stream is applied to a voltage controlled oscillator to modulate the RF signal.

First amplification stage: A gain of about 10 dB is given to the RF output signal coming from the modulator. This amplified signal is expressed by JP
8A, JP8B and JP8C are jumpered and guided to an antenna through a wiring on a printed circuit board, and 10m
A W level RF output operation may be obtained. The transmitter can operate at the 10 mW level using the built-in battery in BATTERY mode.

Second amplification stage: A gain of about 10 dB is added to the RF output signal. This produces an RF output signal level of 100 mW. Further, the RF output signal is JP7, JP
9A and JP8C, jumped to the antenna via the wiring on the printed circuit board, and set to 100 mW RF.
The output signal level may be obtained. Transmitter is BA
In TTERY mode, 10
It can operate at 0 mW level.

Third amplification stage: A gain of about 10 dB is added to the RF output signal. This produces a 1 W RF output signal level. Further, the RF output signal is JP7, JP1
A jumper may be made at 0 and JP11, guided to an antenna via wiring on a printed circuit board, and an RF output signal level of 1 W may be obtained. Transmitter is BATTER
In the Y mode, it can operate at 1 W level using a built-in battery. In addition, large capacity requires an external battery or external power supply.

External power supply: Obtain a regulated 5 volt DC power supply utilizing an 8-10 volt DC input. When operation at 1 watt output level is required, increase the minimum input voltage to 9 volts DC. Operation by external power supply is JP
1B and JP2B are determined by placing a short-circuit jumper.

Battery power: Mounted on a board by a two-coin battery holder. This is 2 lithium Matsushita C
Holds R23303 volt coin battery. Battery powered operation is determined by placing a Berg jumper on JP1A and JP2A.

Built-in antenna: A quarter-wave antenna placed on a printed circuit board. Jumper the wiring of the printed circuit board and use the built-in (JP12) or external antenna (J
P13) may be used. Note: All adjustable parts are preset during calibration and testing. Adjustments should not be made to these parts without first consulting hillier technology.

[0189] 3. FIG. 9 shows a pictorial diagram of the transmitter card showing parts, input / output signals, and jumper positions. It should be noted that many additional signals have been labeled and drawn to the edge of the printed circuit board relative to those described above. This is to monitor internal signals on the transmitter card. For additional information on monitoring signals and signals shown graphically, see HTLP.
You should consult the technical department.

4. Transmitter Timing Diagram FIGS. 10 and 11 show operation timing diagrams of the transmitter.
The operation time is determined as follows.

[0191]

[Table 1]

[0192]

[Table 2]

[0193] 5. Transmitter Electrical Specifications The following specifications shall not exceed guaranteed performance operation. Power supply voltage range BATTERY mode (VDD) 4.5 to 5.5 volts DC Other mode (VCC) 8 to 10 volts DC VDD generated on the printed circuit board = 5 V DC Power supply current range BATTERY mode standby <10 μA at 20 ° C. NON-BATTERY mode standby <50mA All mode transmission 0.01W <50mA 0.1W <100mA 1.0W <250mA Power supply regulation: 10% or less within the power supply voltage range Operating temperature range: -20 ° C to 60 ° C Storage temperature range: −40 ° C. to 125 ° C. Input signal level (VIN): VIH = (0.7 * VDD) ≦ VIN ≦ VDD volts VIL = −0.5VIN ≦ (0.3 * VDD) Volt Schmitt trigger + threshold (VT + ): 2.2 volts Schmitt trigger-threshold (VT-): 1.3 Volt Input signal timing: SI setup time for SCLK ≧ 50 ns SI holding time for SCLK = 0 ns Output signal (VO): When 0 ≧ IOH ≧ −8 mA VHO = 2.4 ≦ VO ≦ VDD volts VOL = VO ≦ 0 .4 volts ＠ IOL ≦ 8 mA Output signal timing: All outputs (except asynchronous ON / OFF) shall occur within 100 ns of the rising or falling edge of the clock.

Note: Failure to maintain the power supply within the specified range may damage components on the printed circuit board. Failure to maintain the input signal within the specified range can damage components on the printed circuit board. Care must be taken in connecting the power and signal lines to the printed circuit board when verifying that the correct polarity is maintained. Failure to do so may damage components on the printed circuit board.

[0195] 6. Receiver Figure 1 shows the functional blocks and input / output connections of the HiTEK receiver.
It is shown in FIG. All I / O lines are compatible with 5 volt CMOS logic levels. A brief description of each functional block and its associated input / output connections is provided.

Built-in antenna: An almost half-wavelength antenna placed on a printed circuit board. Jumper the wiring of the printed circuit board (JP1) or external antenna (JP2)
Can also be used.

Local oscillator 960 MHz: Supplies a local 960 MHz RF signal used by the mixer. The accuracy of the local oscillator over temperature is important for receiver performance. LC oscillator with temperature compensation (version 3)
Alternatively, an option is possible by using a SAW oscillator (version 3a).

RF / IF modulator: 915 MHz received
Amplify, mix, filter, limit the amplitude, detect and correlate the RF signal. The RF circuit reproduces a chip data stream of about 1 MHz. The ASIC performs a despreading process.

Crystal oscillator: Standard 2M for digital circuits
Hz clock. This must be accurate to ± 200 ppm or better. The transmitter and receiver crystal oscillators must be at the same frequency (± 400 ppm) to ensure proper synchronization during despreading.

Control Logic: The state machine in the ASIC that gets all the proper processing and signal sequences. It operates at the crystal oscillator frequency. RESET
The input is an analog signal, which when true (logic high) causes the receiver ASIC to reset, go to an established / locked state, and set the established / locked output high. MSEL
The 0 and MSEL1 inputs are latched internally when RESET goes low. HiTEK receiver cards include components that perform a power-up reset when power is applied. The establish / lock output signal indicates a state in which synchronization with the RF signal received by the ASIC is to be established (high) or a state in which synchronization has been established (low). This signal needs to be low until all data packets have been successfully received. It is set to true (high) when reception terminates after a valid reception, or when reception is terminated by the ASIC (ie, loss of synchronization or bad address).

Mode selection: One of three operation modes is selected. The selection is made possible by changing the input lines, ie the wiring of the short-circuit jumpers on the board. The receiver forms a data packet determined by the MSEL0 and MSEL1 inputs. The MSEL0 or MSEL1 input is set high, respectively, by placing a bark jumper on JP3 or JP4. These select the mode as shown below with 1 = logic high and 0 = logic low. MSEL1 = 0, MSEL0 = 0 Mode 0 shown in FIG. 7a MSEL1 = 0, MSEL0 = 1 Mode 1 shown in FIG. 7b MSEL1 = 1, MSEL0 = 0 Mode 2 shown in FIG. 7c MSEL1 = 1, MSEL0 = 1 Mode 3 is manufacturing For testing.

Address selection: The address data received by the data packet while operating in mode 0 or 1 is monitored. The HiTEK receiver card has 16 dip switches, which select a binary address to compare with the 16 bit address field being received. When a mismatch between the transmitted address and the preset receiver address occurs, the reception is terminated, the establishment / lock is set to true (high), and the receiver shifts to the establishment / lock state. The switch position is detected by a matrix format using four address strobe lines and four address sense lines.

Note: If the transmitter (s) is in mode 0,
While it is 1 or 2, the receiver can be operated in mode 2. This means that a number of transmitters can use a preset address (mode 0 or 1) for one receiver (mode 2).
The receiver uses external circuitry to determine which transmitter transmitted the first 16 bits of the received 32-bit data. .

Data output: The received data is read. The READY output, when true (logic high), indicates that data has been received and that it can be read. When READY is true and the receiver is in mode 0, the data on the four parallel data outputs D0, D1, D2 and D3 is valid. In modes 1 and 2,
At the rising edge on the normally low SCLK (shift clock), the clock is input to the next serial data bit SO (serial) output line. READY output sets all data bits to SO.
Goes low when output clocked. The data register is 16 bits long in mode 1 while 32 bits long in mode 2. Data in the data register is only valid when both the RADY and Establish / Lock output lines are high. If the establish / lock output goes low while the data is being read, the data becomes invalid.

Power Supply: Obtain a regulated 5 volt DC power supply using a 7-12 volt DC input.

Note: All adjustable components are preset during calibration and testing. First, "Spredex (S
These components must not be adjusted without reference to the preadex) User's Manual.

[0207] 7. FIG. 13 shows a pictorial diagram of a transmitter card showing parts, input / output signals and jumper positions. It should be noted that many additional signals to the aforementioned signals have been labeled and brought to the edge of the printed circuit board. This is to monitor internal signals on the transmitter card. For additional information on the signals and the signals shown in the figures, reference should be made to the Spreadex User's Manual.

8. 14 and 15 show operation timing diagrams of the receiver. The operation time is determined as follows.

[0209]

[Table 3]

[0210]

[Table 4]

[0211] 9. Receiver electrical specifications The following specifications shall not exceed the guaranteed performance operation. Power supply voltage range (VCC): VCC in all modes = 7 to 12 VDC Power supply current range (IS): IS ≤ 50 mA in all modes Power supply regulation: 10% or less within the power supply voltage range Operating temperature range: -20C to 60C Temperature range: −40 ° C. to 125 ° C. Input signal level (VIN): VIH = 3.5VDC ≦ VIN ≧ 5VDC: VIL = −0.5VIN ≦ VIN ≧ 1.5VDC Schmitt trigger + threshold (VT +): 2. 2 volts Schmitt trigger-threshold (VT-): 1.3 volts Output signal level (VO): when 0 ≧ IOH ≧ −8 mA VHO = 2.4 ≦ VO ≦ VDD volts VLO = VO ≦ 0.4 Volt ＠ IOL ≤ 8 mA Output signal timing: Established / Locked, READY and ADSTRB outputs are at the rising or falling edge of the clock. It is assumed that it occurs within 0 ns. SO output for SCLK ≦ 50 ns

Caution-Failure to maintain the power supply within the specified range may damage components on the printed circuit board. Failure to maintain the input signal within the specified range can damage components on the printed circuit board. When confirming that the correct polarity is maintained, attention should be paid to the connection of the power supply line and the signal line to the printed circuit board. Failure to do so may damage components on the printed circuit board.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a semiconductor manufacturing facility to which the present invention is applied, wherein a is a diagram illustrating a semiconductor manufacturing facility as an environment including walls and other fixed structures that cause multiple reflection, and b is a diagram of a calibration transmitter. FIG. 3 is a diagram showing an example of a receiver array for the radio wave detection system of the present invention together with a fixed array.

FIG. 2 is a functional block diagram of the present invention, wherein a is TAG
Function block diagram of transmitter, b (detects arrival time)
FIG. 4C is a functional block diagram of a radio wave detection receiver, and FIG.

FIG. 3 is a diagram showing a position locating operation for a high-resolution embodiment of the radio wave detection system using the arrival time difference for target locating.

FIG. 4 is a functional diagram of a spread spectrum communication system used in the radio wave detection system, wherein a shows a transmitter and a receiver, b shows a format of a TX-packet,
c is a diagram showing the format of an RX-packet.

FIG. 5 is a circuit diagram showing an arrival time circuit for a high resolution embodiment, wherein a shows a receiver front and TOA detection circuit, and b shows a time base latch circuit.

FIG. 6 is a block diagram of a hillier system.

7A is a diagram showing a mode 0 packet format, FIG. 7B is a diagram showing a mode 1 packet format TX-packet, and FIG. 7C is a mode 2 packet format RX
FIG.

FIG. 8 is a functional diagram of a transmitter card.

FIG. 9 is a view showing a first substrate on which components are mounted.

FIG. 10 is a transmitter card timing diagram.

FIG. 11 is a transmitter card critical timing diagram.

FIG. 12 is a functional diagram of a receiver card.

FIG. 13 shows a second substrate on which components are mounted.

FIG. 14 is a timing chart of a receiver card.

FIG. 15 is a receiver card critical signal timing diagram.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 semiconductor manufacturing facility 11 GaAs lithography 12 photolithography 13 GaAs etch 14 metallization 15 ion implantation 16 wall 17 wall 18 wall 20 radio wave detection receiver array 22 receiver 24 receiver 26 receiver 30 TAG transmitter 35 calibration transmitter 40 System processor 50 Calibration transmitter 52 Spectral spread transmitter 54 Movement detector 54a Potentiometer 56 Movement detector 58 Synchronization controller 58a Potentiometer 60 Radio wave detection receiver 62 Receiver front end 64 TOA detection trigger 65 Time based latching circuit 66 Spectral spread Receiver 68 Programmable controller 69 Network interface 81 LAN interface 82 Interface card 84 Diplex filter 7 Diplex filter 88 ARCNET interface 89 Clock interface 100 Spread spectrum transmitter 102 Control module 103 Spreader 104 Modulator 106 Final transmitter RF stage 108 Antenna 110 Spectral spread receiver 112 Antenna 114 Receiver RF front end 115 IF demodulator 116 IF Demodulator and Disperser 118 2 MHz Crystal Oscillator 120 Receiver Front End 121 Antenna Port 122 Amplifier 123 Amplifier 124 Helical Filter 125 Helical Filter 126 Power Splitter 128 Solid State Switch 130 TOA Trigger Circuit 132 Diode 135 High Speed Comparator 136 Digital Potentiometer 140 Register Configuration 142 Flip Flow Flop

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 5/00-5/30 H04B 7/26

Claims (48)

(57) [Claims] 1. A location system for locating a target in a tracking environment using the time difference of arrival of electromagnetic transmissions received by multiple receivers, the system comprising a unique TAG ID and
Selection start information, three pieces of movement start information, movement continuation information,
TAG transmitters for each target including at least one of the motion stoppage information and transmitting at selected intervals, and receivers distributed within the tracking environment such that the TAG transmissions are received by at least three receivers. An array, wherein each receiver includes an arrival time circuit and a data communication controller, wherein the arrival time circuit responds to the arrival of the TAG transmission by a TO corresponding to the arrival time of the most direct path to such a TAG transmission.
Output the A count, the TOA count is synchronized to the system synchronization clock sent to each receiver, and the data communication controller responds to the receipt of the TAG transmission by responding to the corresponding TOA including the associated TAG ID and TOA count. An orientation processor for outputting a detection packet and further receiving the TOA detection packet and determining the position of each TAG and its associated target from at least three corresponding TOA-detection packets received by different receivers. To do the goal location system. 2. The orientation system according to claim 1, wherein T
A target location system in which spread spectrum communication is used for AG transmission. 3. The target location system according to claim 2, wherein the spread spectrum communication has a frequency range of 900 MHz. 4. The orientation system according to claim 2, wherein T
A target location system, wherein the duration of the AG transmission is approximately 600 μS. 5. The target location system according to claim 1, wherein the selection status information is generated without intervention of an operator. 6. The orientation system according to claim 1, wherein T
The AG transmitter detects the movement of the target and detects T during the movement of the target.
A target location system that includes a movement detection circuit that allows the AG transmitter to send a TAG transmission. 7. The orientation system according to claim 6 , wherein T
A target location system in which the AG transmission is performed for a relatively short period of time during and after the movement of the target. 8. The target location system according to claim 7 , wherein each TAG transmission includes an appropriate movement status indication. 9. The orientation system according to claim 1, wherein T
A target location system, wherein the AG transmitter includes a periodicity control circuit that causes the TAG transmitter to send out TAG transmissions at selected intervals each time the target moves. 10. The orientation system according to claim 9 , wherein:
A target location system, wherein TAG transmissions are sent out at relatively short intervals while the target is moving and at relatively long intervals when the target is stationary. 11. The orientation system according to claim 1, wherein:
A target location system wherein the arrival time circuit provides an adjustable level of noise sensitivity for differential TAG transmission from noise. 12. The location system according to claim 11, wherein the noise sensitivity is determined by a selected signal level threshold and a selected signal duration threshold. 13. The orientation system according to claim 1, wherein:
The arrival time circuit outputs a TOA-DETECT trigger as soon as the direct path TAG transmission arrives.
A target location system comprising a trigger circuit and a time-based latching circuit that latches a synchronized time-based accompanying TOA count in response to a TOA-DETECT trigger. 14. The orientation system according to claim 13, wherein the TOA trigger circuit outputs a TOA-DETECT trigger when the signal level of the received signal exceeds a signal level threshold, indicating that the received signal is a TAG transmission. Target location system. 15. The system according to claim 14 , wherein T
The OA trigger outputs a TOA-DETECT trigger when a signal level of a received signal exceeds a comparator reference level. 16. The orientation system according to claim 15, wherein the signal level comparator reference level is adjustable.
Target location system. 17. The orientation system according to claim 13, wherein the time-based latching circuit indicates when the duration of the received signal exceeds the signal duration threshold and causes the received signal to be TA.
Target orientation system designated as G transmission. 18. The orientation system of claim 17, wherein the TOA-DETECT trigger remains asserted during the reception of the TAG transmission, and the time-based latching circuit selects the duration of the TOA-DETECT trigger for a selected MAX.
A target location system that outputs a signal duration indication when the NOISELENGTH count is exceeded. 19. The target location system according to claim 13, wherein the time-based latching circuit includes a time-based counter that counts at a rate of approximately 800 MHz derived from a system synchronization signal. 20. The orientation system according to claim 1, wherein:
A target location system, wherein the receivers are connected to the location processor by a local area network, each receiver including a LAN interface, and the TOA detection packet is communicated to the location processor via the LAN. 21. A location system according to claim 20, wherein the system synchronization signal is communicated to each receiver via a LAN. 22. The orientation system according to claim 1, wherein:
Furthermore, it comprises at least one calibration transmitter arranged at a known position and transmitting a calibration transmission that each receiver can receive,
Each receiver responds to the calibration transmission with an associated arrival time TOA
A corresponding calibration TOA detection packet containing the count is output to the orientation processor, which determines the calibration coefficients from the calibration TOA detection packet and the known location of the receiver, and uses these coefficients to accompany the TO tag associated with the TAG transmission.
A-A target location system that calibrates the location calculations from the detected packets. 23. A locating system for locating a target in a tracking environment using area detection by a receiver receiving an electromagnetic transmission from an allocated area, the system comprising a unique TAG ID and three information, selection information. Movement start information,
T including at least one of movement continuation information and movement stop information
A TAG transmitter for each target that sends out AG transmissions at selected intervals, and a receiver array distributed within a tracking area each configured to receive TAG transmissions from an allocation area of a predetermined size; The receiver includes a data communication controller that outputs a corresponding area detection packet including a reception TAG ID in response to receiving the TAG transmission, and further receives the area detection packet and receives the TAG of the TAG.
A target location system comprising a location processor that determines the location of each TAG and its associated target based on the identity of the receiver receiving the transmission. 24. The location system according to claim 23 , wherein each receiver includes a directional antenna having a predetermined beam width.
A target location system, wherein the receiver is adapted to receive a TAG transmission originating from its allocation area. 25. The location system according to claim 23, wherein the receivers are distributed in the tracking environment at predetermined intervals, and each TA is distributed.
A target location system, wherein the transmission power of the G transmitter and the spacing between adjacent receivers are cooperatively selected so that TAG transmissions are almost always received by one receiver closest to the TAG. 26. The location system according to claim 23 , wherein spread spectrum communication is used for TAG transmission. 27. The location system according to claim 26, wherein the spread spectrum communication is in the 900 MHz frequency range. 28. The location system according to claim 26 , wherein the duration of the TAG transmission is on the order of 600 μS. 29. The location system according to claim 23, wherein the TAG transmitter detects movement of the target and includes a movement detection circuit that enables the TAG transmitter to transmit a TAG transmission during the movement of the target. . 30. The target location system according to claim 29, wherein the TAG transmission is transmitted for a relatively short predetermined time during the movement of the target and after the movement is stopped. 31. The orientation system according to claim 23, wherein the TAG transmitter includes a periodicity control circuit for transmitting a TAG transmission from the TAG transmitter at predetermined intervals each time the target moves. system. 32. The location system according to claim 31, wherein the TAG transmission is transmitted at a relatively short interval when the target is moving and at a relatively long interval when the target is stationary.
Target location system. 33. The location system according to claim 23 , wherein each receiver provides an adjustable level of noise sensitivity for differential TAG transmission from noise. 34. The location system according to claim 33, wherein the noise sensitivity is determined by a selected signal level threshold and a selected signal duration threshold. 35. The location system according to claim 23 , wherein the receivers are connected to the location processor by a local area network, each receiver includes a LAN interface, and the area detection packet communicates via the LAN to the location processor. A target location system. 36. A method for locating targets in a tracking environment using arrival time differences of electromagnetic transmissions received by multiple receivers, the method comprising the steps of: identifying a unique TA for each target;
G ID and three pieces of movement start information that are selection information,
A TAG transmission including at least one of the connection information and the movement stop information is transmitted at a selected interval, and the receiver array distributed in the tracking environment such that the TAG transmission is received by at least three receivers. Providing a TOA count corresponding to the arrival time of the most direct path for such TAG transmission in response to the arrival of the TAG transmission at the receiver;
The OA count is synchronized to a system synchronization clock sent to each receiver, and outputs a corresponding TOA-detection packet including an associated TAG ID and TOA count in response to receiving a TAG transmission, and outputs a TOA-detection packet. At least 3 received from different receivers using packets
Determining a position of each TAG and its associated target from two corresponding TOA-detection packets. 37. The orientation method according to claim 36 , wherein T
Sending the AG transmission further comprises detecting the movement of the target and enabling the TAG transmission during the movement of the target. 38. The orientation method according to claim 36 , wherein T
Sending the AG transmission comprises sending a TAG transmission at selected intervals each time the target moves. 39. The method of claim 36 , further comprising the step of using the signal level threshold and the signal duration threshold to adjust receiver noise and identify TAG transmissions from the noise. 40. The orientation method according to claim 36 , wherein T
The step of outputting the OA count is the direct path T
Outputting a TOA-DETECT trigger as soon as the AG transmission arrives and latching an associated TOA counter of a time-based counter derived from a system synchronization clock in response to the TOA-DETECT trigger. 41. The location method according to claim 36 , wherein the receivers are connected to the location processor by a local area network, and each receiver includes a LAN interface, and the TOA detection packet is transmitted to the location processor via the LAN. A target location method that is to be communicated. 42. The orientation method according to claim 36 , further comprising: transmitting a calibration transmission from at least one known position where each receiver can receive, and responding to the reception of the calibration communication at the receiver. Output a corresponding calibration TOA detection packet containing an arrival time TOA count, determine calibration coefficients from the calibration TOA detection packet and the known location of the receiver, and use these coefficients to accompany the TAG transmission with the TOA.
A target location method consisting of steps for calibrating the location calculation from the detected packets. 43. A method for locating a target in a tracking environment using area detection by a receiver receiving an electromagnetic transmission from an allocated area, the method comprising the steps of:
D and three pieces of movement start information, selection information, and movement continuation information
A TAG transmitter for transmitting at a selected interval a TAG transmission including at least one of the information and the movement stop information is provided for each target, and each TAG transmitter is configured to receive a TAG transmission from an allocation area of a predetermined size. Receiver arrays are distributed in the tracking area, and each receiver outputs a corresponding area detection packet including a reception TAG ID in response to reception of the TAG transmission, and transmits the corresponding area detection packet from the receiver that receives the TAG transmission. TA for the TAG represented by the area detection packet
Determining the location of each TAG and its associated target based on the identity of the receiver receiving the G transmission. 44. A method according to claim 43 , wherein each receiver includes a directional antenna having a predetermined beam width, wherein the receiver is adapted to receive a TAG transmission emanating from its allocated area. Orientation method. 45. The location method according to claim 43 , wherein the receivers are distributed at predetermined intervals in the tracking environment, and the transmission power for each TAG transmitter and the interval between adjacent receivers are equal to TA.
A target location method wherein the TAG transmission is cooperatively selected to be almost always received by the one receiver closest to G. 46. The orientation method according to claim 43 , wherein T
Sending the AG transmission further comprises detecting the movement of the target and enabling the TAG transmission during the movement of the target. 47. The orientation method according to claim 43 , wherein T
A target location method, wherein sending an AG transmission comprises sending a TAG transmission at selected intervals each time the target moves. 48. The location method according to claim 43 , wherein the receivers are connected to the location processor by a local area network, each receiver includes a LAN interface, and the TOA detection packet is communicated to the location processor via the LAN. , Target location method.