JPH06186316A - Target orienting system and orienting method - Google Patents

Abstract

PURPOSE: To provide an electric wave detecting system, which follows up a target in semiconductor manufacturing equipment, for a multipass environment. CONSTITUTION: Receiver arrays 20, each of which is connected to a system processor 40 via a LAN, are distributed in a follow up area. By means of a TAG transmitter 30 arranged in each target, a spectral diffusion TAG transmission containing a unique TAG at least is sent at a selected interval. For a high resolution embodiment a target is oriented on the basis of an arrival time (TOA) difference, and each receiver includes a TOA trigger circuit, which is triggered on an arrival of the TAG transmission, and a time base latching circuit, which latches a TOA count from a 800MHz time base counter. For a low resolution embodiment, a specific position area is allocated in each receiver in the array, and the TAG transmission is received solely from the TAG arranged in the area, so that an arrival time circuit is dispensable.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to position location systems, and more particularly to radio frequency detection systems adapted for use in environments subject to multiplex communications. More specifically, the present invention includes (a) arrival time difference (high resolution) for radio wave 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 transmissions from allocated areas.

As a reference to the present invention, Hillier
Technologies Limited Part
US Pat. No. 4,864, assigned to Nership
No. 588, Remote Control Systems, Parts and Methods subject matter.

[0003]

BACKGROUND OF THE INVENTION Position or target locating systems are being increasingly 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.

One position 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 done by radio, ultrasound or optical communication using various techniques to identify or localize the movement of the target within a range close to the receiver.

Wireless communication is (a) distance per 1 W of electric power,
And (b) the transparent structure is superior in accuracy and performance to ultrasonic waves and optical communication in terms of transparency. However,
Wireless communication issues in typical business environments, including walls, silver-plated windows and other fixed structures have been
For higher (and higher) related frequencies, diffuse reflections cause multipath distortion in the tag transmissions arriving at a given receiver. Moreover, in such environments, the signal strength useful for communicating distance / location information is negligible due to the unpredictable attenuation of transmissions through walls and other structures.

[0006] Therefore, there is a need for a position location system that can be used for target location in environments that are subject to multiple reflections.

[0007]

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

According to one feature of the invention, the radio frequency detection system includes a transmitter for transmitting a TAG transmission including at least one unique TAG ID to each target in the tracking area at a selected interval. . 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 described above. 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 COUNT is synchronized to the system synchronization clock obtained from each receiver.
Output T. The data communication controller responds to the trigger of the arrival time circuit with at least the TAG from the TAG transmission.
Corresponding TOA including ID and TOA COUNT-
Output the DETECTION packet.

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

For the low resolution embodiment, each receiver in the array is assigned a specific location area so that it will only receive TAG transmissions from TAGs located in that area. Radio detection systems based on receiver allocation areas use directional antennas on the receiver, or cooperatively select receiver spacing and TAG transmitter output so that most nearby receivers receive TAG transmissions. Can be implemented in various ways.

Each receiver includes a data communication controller. The data communication controller of each receiver responds to the reception of the TAG transmission by at least the TAG from the TAG transmission.
Output the corresponding AREA-DETECTION containing the ID.

The orientation processor uses the AREA from each receiver.
-Determine the position of each target based on each receiver that received the DETECTION and received the closest TAG transmission.

The location system may be implemented using unlicensed spread spectrum wireless communications.
In this aspect of the invention, each transmitter complies with a spread spectrum communication protocol and includes a TX including at least a TAG ID.
It includes a spread spectrum transmitter that outputs packets. The TAG transmitter operates at a given power level. Each radio detection receiver receives a spread spectrum TAG transmission,
It includes a spread spectrum receiver that recovers the TAG ID and outputs RX-packets containing the TAG ID.

The data communication controller of each receiver is RX
-DETECTION containing at least a TAG ID for communicating with the orientation processor in response to the packet-
Output a packet. Orientation processor D from each receiver
ATA-Receive packet to determine target location.

In accordance with a more specific feature of the present invention, a high resolution embodiment of a radio frequency detection system is used to target a wafer box or the like in a semiconductor manufacturing facility. 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 if the movement detector detects movement of the target. TA while the target is moving
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. In addition, the TAG may include means for inputting other information (such as by an operator) to communicate with the system processor.

In addition to the spread spectrum receiver, each radio detection receiver includes a TOA trigger circuit, a time base latch circuit and a programmable controller. TOA
The trigger circuit triggers within the early cycle of the incoming TAG transmission and outputs a TOA DETECT trigger. The time base latch circuit responds to the TOA DETECT trigger by latching the time base TOA COUNT from the 800 MHz time base counter synchronized to the 200 MHz system synchronization clock provided by the system processor over the LAN. The programmable controller has a T recovered by a spread spectrum receiver.
TOA-DETECT communicates with the system processor via the LAN by receiving the AG ID and the movement status and the TOA COUNT from the time base latching circuit.
Output ION packet.

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

The technical advantages of the present invention include the following. The radio frequency detection system is adapted for use in a multipath environment such as manufacturing or other business facility where the reception of direct path transmissions is subject to multipath noise. Target orientation can be done by a high resolution method using time difference of arrival or a low resolution (low cost) method using area detection by a receiver configured to detect TAG transmissions from the allocated area. Commercially available unlicensed spread spectrum devices facilitate the identification of direct path transmissions and multipath noise of interest. To save power, each TAG transmitter includes a motion detector,
It is possible to limit (or concentrate) G transmissions only to the intervals that the target is moving. For TAG transmission, TAG I
In addition to D, other information such as movement status and operator can be included.

For high resolution embodiments, TOA-DE
TECTION triggering and time-based TOA
COUNT latching can be separated from the spread spectrum communication function to allow the use of commercially available spread spectrum devices. The high-speed TOA trigger circuit arrives at the TOA-DET within the early cycle of TAG transmission.
Outputs an ACTION trigger. 3.0 with a synchronized time base counter operating in the 800 MHz range
A resolution of about 5 m (10 ft) is provided. Noise filtering optimizes arrival time 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 EMBODIMENT A description of an embodiment of a radio frequency detection system of the present invention adapted for use in a multipath environment is organized as follows.

1. Radio Detection System --- TOA Detection 1.1. TAG transmission 1.2. Reception and TOA detection 1.3. LAN communication 1.4. Position location processing 1.5. Calibration 2. Radio detection system --- Area detection 3. Spread spectrum communication 4. TAG transmitter 5. Radio detection receiver 5.1. TOA trigger circuit 5.2. Time base latch circuit 5.3. Programmable controller 5.4. Example of area detection Appendix A Appendix B

In this detailed description, Hillier Te
chnologies Limited Partner
US Pat. No. 4,864,58 assigned to rship
No. 8, Remote Control Systems, Parts and Methods, is incorporated by reference with parts.

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

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

FIG. 1b shows a manufacturing facility 10 showing only walls 16,17,18. In the facility (in or near the ceiling)
The radio detection receiver array 20 including the individual receivers 22, 24, and 26 is arranged in. Various targets, such as wafer boxes transported on a conveyor system, move within the facility. These goals must be tracked, 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 30 is received by at least the radio detection receivers 22, 24, 26. Each TAG transmission contains a TAG IC that uniquely identifies each tag (ie, target).

In addition to the TAG transmitters on each target, several fixed position TAG transmitters 35 are located around the facility.
These TAG transmitters with known positions for each receiver are used for system calibration.

Each radio sensing receiver in receiver array 20 receives the TAG transmission and uses an 800 MHz time base counter to accurately detect the arrival time. For each TX-packet in the TAG transmission, the receiver has a corresponding TOA-
Generates DETECTION packet, which is LAN
Communication is performed to the radio wave detection system processor 40 via the (local area network).

The system processor 40 performs all target orientation calculations. In addition, the system processor is 200MH
The 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 is 200 MH
LA for network providing z system synchronization clock
It is coupled via the N interface 44.

The system processor includes target tracking database storage, and user access to target orientation information is provided by the graphics workstation via a graphics interface.

1.1. TAG transmission 902-92 transmission between TAG (target) and receiver array
It 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 reflection. The use of spread spectrum communication for TAG transmission is advantageous in 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) Spread spectrum transmitter 52 for transmitting spread spectrum TAG transmission (TX-packet), (b) Battery power saving circuit 54, (c) for enabling spread spectrum transmitter when TAG (target) is moving. ) A movement detection circuit 56 for detecting the movement of the TAG (target), (d) a periodicity control circuit 58 for controlling the retransmission interval of the spread spectrum transmitter.

In the preferred embodiment, the TX-packet in each periodic TAG transmission contains not only the appropriate TAGID, but one of the following three mobility status indicators: Start movement, continue movement, stop movement.

In order to save power and increase the available group of TAG transmitters, each spread spectrum transmitter 52 is placed in a constant power save mode and transmitted by the battery save circuit 54 only while the associated target moves to a new position. Made possible. Movement of the target is detected by movement detector 56 and an appropriate indication is provided to the battery power saving circuit.

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

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

When the target arrives at a new position and stands still,
The movement detector 56 stops providing a movement indication to the battery power saving circuit 54. After a predetermined period (for example, 30 seconds) in which the target is stationary, the battery power saving circuit operates in the periodic controller 5
Disable 8 and Spectral Transmitter is Motionio
n Send the final TAG transmission with TX-packet containing Stopped state.

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

The transmission is propagated through the facility and received by the receiver array. Since these transmissions must propagate through partitions, walls and other obstacles that result in unpredictable attenuation, the signal strength at the receiver cannot provide any useful information with which the target position can be estimated. Moreover, even after direct path transmission, these impairments cause multiple reflections to be received by the receiver.

1.2. Multipath transmitter and TAG transmitter (target) for reception and TOA detection TAG transmission
Arriving at 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 can be determined with high resolution when each receiver uses the arrival time difference to reliably and accurately detect the arrival time of TAG transmission. You can To detect TOA,
There is a need for (a) a reliable trigger by the arrival time of a direct path TAG transmission, and (b) a stable synchronized time base.

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

Furthermore, TOA triggering must be independent of the strength of the TAG transmit signal (which is attenuated in the path between the target and a given receiver). Known as dispersion delay, there is a time-of-arrival triggering difference that depends on the direct path attenuation if it is not made independent of signal strength.

For the embodiment, the radio frequency detection system processor 40 sends to each receiver in the array 20 via the LAN.
Send the 00 MHz system synchronization clock. At each receiver, the 200 MHz system clock is converted to 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 arrival time detection, the receiver is synchronized within approximately 1.25 nS
The orientation resolution based on the A difference can be set within about 0.61 m (2 feet).

The 200 MHz system synchronization clock is converted to the desired 800 MHz by the up conversion of each receiver.
The choice for the z-time base clock is a design choice that results from the selection of the particular LAN data communication that provides the system synchronization clock (see Section 1.3). The radio detection system of the present invention can easily be applied to other schemes for providing a system synchronization clock to provide a proper 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 the received TAG transmission (TX-packet), (b)
The arrival of Direct Path TAG transmission is detected and TOA DE
TOA detection trigger 64 giving a TECT display, (c) T
800 synchronized in response to OA DETECT indication
Associated time-based TOA of MHz time-based counter
Time base latching circuit 6 for latching COUNT
5, (d) a spread spectrum receiver 66 that receives the TX-packet from each TAG transmission and generates an RX-packet containing the TAG ID and movement state, (e) the latched TOA COUNT from the time base latching circuit.
TOA with recovered TAG ID and movement status
-Includes 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, the power supply provides power for the TTL, ECL and wireless circuitry.

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 64 for the time of arrival trigger, which gives the TOA DETECT indication within the early cycle of the TAG transmission. Rapid detection of trigger events is done by a fast comparator using conventional peak energy detection in the TOA trigger.

TOA DETECT is sent to the time base latching circuit 65 as an arrival indication of the TAG transmission wave front. Time-based latching circuit is 800 MHz (up-converted from 200 MHz system synchronization clock)
Latch the associated 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.
One tries to ensure that the TECT display is accompanied by spread spectrum TAG transmission rather than random pulse noise.

When the time base latching circuit 65 indicates the arrival of the TAG transmission, the accompanying TX-packet is provided to the spread spectrum receiver 66. The spread spectrum receiver extracts the TAG ID and the moving state from the TX-packet, and includes the R including the TAG ID and the moving state.
Output X-packet.

For each TAG transmission, the programmed controller 68, along with RX-packets from the spread spectrum receiver 66, time-based latching circuit 6
Retrieve the latched time base count from 5.
The programmed controller uses this arrival time information (T
AG ID, movement status and time-based TOA COU
NT) to a TOA-DETECTION packet and communicate with the radio detection system processor via the LAN.

If the target moves from one position to another position far from one receiver but close to another,
Each radio-sensing receiver detects varying arrival time measurements for the associated TAG transmission. For a given TAG transmission, the arrival time detection operation of each receiver discriminates the arrival of the direct path TAG transmission from the multiple reflected signals arriving after that, and the direct path TAG transmission early before the multipath components merge. Triggered on cycle arrival.

Valid TAG regardless of multipath effect
The ability to receive IDs is enhanced by the spatial diversity inherent in spread spectrum communications. In fact, each receiver can be considered a spatially diverse antenna element to facilitate multipath noise rejection. TOA-DE assembled by the programmed controller after performing TOA detection of the received direct path TAG transmission
The TECTION packet is communicated to the radio detection system via the LAN.

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

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 hundreds of pS). In the exemplary embodiment, one coaxial cable based ARCNET local area network is used to perform these two communication operations.

The ARCNET LAN uses a token passing protocol and a data transmission rate of 2.5 Mbit / sec. The standard RG6 communication handles signal frequencies up to 200 MHz without causing significant attenuation problems.
This is done via two coaxial cables. Therefore, the 200 MHz system synchronization clock can be multiplexed with regular ARCNET data communication traffic without significant degradation.

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

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

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

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

FIG. 3 is a flow chart showing the position location processing operation. For each TOA-DETECTION packet (TAG ID, time-based TOA COUNT, and move state) received, the system processor identifies the TAG to move to (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, even if the TOA data is accurate regardless of the reason why the TAG identification cannot be performed, the receiver may not be able to recover the TAG ID from the transmitting TAG transmitter due to multipath noise received by the receiver. .

A valid TAG ID is checked for all TOA-DETECTION packets (8
3). For example, 1000 without a valid TAG ID
TOA-DETEC that arrives within a given time, such as nS
The TION packet is assigned to the same TAG transmitter (84). A valid TOA-DETECTION packet (ie, a valid TAG ID) and the assigned T
Any TOA-DETECTION with the data reduction algorithm enabled and assigned due to receiver redundancy, which includes a combination of OA-DETECTION packets.
The validity and invalidity of is determined.

TOA-DE with a given TAG transmission
When the TION is identified or assigned (8
2) its T using the conventional time difference of arrival algorithm
Arrival time data for the AG transmitter is processed (8
5) The target position information is obtained. For two-dimensional target tracking, if at least three TOA-DETECTION packets are identified (86), the receiver ID and arrival time data can be used to calculate the target position (three-dimensional target tracking). Requires at least 4 TOA measurements). The additional TOA-DETECTION packet also represents (88) redundant position location information that can be used in the target location algorithm. The position location information calculated from the received TOA packet is stored in the fully indexed target tracking database as usual (92), which includes (a) TAGID (16 bits), (b) moving state,
It includes (c) target position, (d) position qualification vector, and (e) time.

The movement state is stored as a 4-bit amount (16 combinations), and indicates movement start, movement continuation or movement stop in the embodiment. Examples of the additional state information that can be communicated include the following: (a) When the target is stationary, it is transmitted at selected intervals to give an updated record of whether the active TAG transmitter is moving or not, and to help identify the failure of the TAG transmitter. A non-moving state and (b) a TAG transmitter or an automated source (such as an unmanned vehicle) can pass a keyed state directly to the system processor (such as an operator activated warning) a membrane key press on the TAG transmitter. .

The target position is stored as a 32-bit vertical and horizontal amount. The position qualification vector causes error radials, TOA trigger randomness, synchronized randomness, and other factors (up to approximately 3.05m (10 feet)) to reduce the accuracy of position location calculations based on the accumulation of proper calculations. Represent.

The target tracking database can be queried 95 via a graphic user interface 95 using conventional database search and retrieval software. In an embodiment, the mapping database search software package is preferably used to post the location coordinates of any target on the facility map. Depending on the type of search, the mapping database search software may post at the facility map location for a particular item, a group of items, a temporal location, a flow of items through points in space, or various combinations of such information.

1.5. In order for the calibrated radio detection system to operate with nanosecond TOA resolution, small changes in circuit operating parameters and propagation characteristics caused by temperature and humidity changes in the facility must be considered. Such changes are handled by system calibration.

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

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

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

These calibration transmissions are received by the radio detection receiver, and the arrival time is detected similarly to 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 location of the calibration transmitter from the time of arrival using the same procedure that affects target tracking. The calculated position and associated receiver arrival time differences for each calibration transmitter are compared to known positions and associated transmitter arrival time differences, and the apparent position and TOA differences are converted to new calibration factors for each receiver. To be done. For each calibration interval,
The updated coefficients are stored in the target orientation database and are used to adjust the arrival time data sent from each receiver during normal target tracking operations.

2. Radio Detection System--As a low cost alternative to the high resolution embodiment of the radio detection system using area detection arrival time difference, the radio detection system of the present invention is configured to receive TAG transmissions from each allocated area only. 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 the TAG transmissions from the TAG transmitters within each allocation area, and the target orientation is performed when the receiver receives the TAG transmission with the TAG ID.

In the low resolution embodiment, arrival time detection (TO
Since there is no need for A-triggering and time-based latching), there is a significant cost savings.

With reference to FIG. 2a, for the low resolution embodiment, the receiver of the radio detection array 20 is provided with TAGs located within each target orientation area of a given size (given a given target orientation resolution). Is configured to detect TAG transmissions of For example, a directional antenna may be used at the selected receiver location to determine the size of the target orientation area with a given antenna beamwidth. 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 pattern and the size of the target orientation area can be determined by a predetermined interval between the receivers. In this case, the target orientation resolution is a function of receiver spacing and the TAG transmitter output is cooperatively selected so that the TAG transmission is received by most neighboring receivers (in this configuration, two or more receivers are received). A TAG transmission received by the machine represents a loss of target orientation resolution).

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

The main design difference is the power selection of the spread spectrum transmitter, the TAG transmission power is relatively low and the distance is limited in the configuration where the target position is based on the receiver spacing, and therefore the reception of two or more receivers is limited. A TAG transmission may be received by the machine. For example, for high resolution embodiments (where it is desirable for multiple receivers to receive the TAG transmission), the TAG transmission power can range from 0.01 to 1 W (see Section 3) and low. For the resolution embodiment, the TAG transmission output can be set to about 1 μW and set to an effective range of about 10 m.

Referring to FIG. 2b, for the low resolution embodiment, the complexity and cost of the radio detection receiver 60 can be significantly reduced by eliminating the components associated with arrival time detection. Therefore, although some receiver front-ends may require amplifiers and filters, the only circuitry that needs to be included is the spread spectrum receiver 66 and the programmed controller 68.

In particular, the TOA trigger circuit 64 and the time base latching circuit 65 need not support arrival time detection. Moreover, the programmable controller does not have to be programmed to control these circuits.

In operation, therefore, the spread spectrum receiver operates as described in Section 3, receives a TAG transmission from the receiver front end and recovers and recovers the TAG ID and movement state from the TAG packet. The RX packet having the TAG ID and the moving state is output. RX packets are retrieved by the programmed controller.

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

The radio detection system processor receives the AREA-DETECTION packet from the receiver of the radio detection array, performs target orientation processing, and updates the target orientation database. In this embodiment, which uses area detection instead of time difference of arrival, 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 upon receipt of a STATEION packet.

3. In the spread spectrum communication embodiment, the radio detection system is 902 to 928M.
Uses spread spectrum communications under FCC 15.247 rules for unlicensed operation in the Hz band. Not only is a license unnecessary, spread spectrum communication identifies direct path TAG transmissions from the associated multipath noise, allowing low power operation (Chapter 15.247, maximum authorized transmitter output is 1W). It is advantageous in terms.

Spectral spread transmission is accompanied by a constant frequency shift called "frequency hopping". The frequency shift causes a difference in the reflection angle on the rough reflecting surface, and the multiple reflection enters into the frequency component that fluctuates in space.

Since spread spectrum multiple reflections are spatially diverse, these components do not arrive as coherently as in direct path transmission. Due to this difference in coherence, the reception of the direct path TAG transmission and the TAG ID
Will be easier to recover.

Spectral spread communication allows relatively long range 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-sensing because it reduces the number of receivers required to ensure that at least 3 (typically more due to redundancy) receivers receive the TAG transmissions. Important for high resolution implementations of the system.

Pulse operation, which is characteristic of spread spectrum communication, requires non-coherent data reception. That is, unlike coherent data communication in which reception is fixed to a carrier signal for demodulation, a TAG that arrives at a speed sufficient to guarantee recovery of TAG ID data included in a TX-packet in a spread spectrum receiver You have to get a fixed synchronization with the transmission.

The significant advantage of using a spread spectrum communication to obtain short transmit pulses and non-coherent data reception is that data integrity and bit error rate (BER) are somewhat worse, but battery usage is This is a significant decrease. For example, one non-coherent receiver design typically has one error in 10 ⁵ while a coherent receiver design has one error in 10 ⁹ .

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 the receivers are superimposed (ie, typically four or more receivers receive a given TAG transmission), (b) a triggering event occurs. TAG ID received by another receiver
Since it is often possible for the system processor to determine that the TAG is attached, arrival time detection is not necessarily a specific TAG.
There is no need to receive the ID properly.

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

FIG. 4a is a functional block diagram of the SPREADEX spectral spreading communication system. The spectral spreading system includes a transmitter 100 (embedded in each TAG transmitter) and a receiver 110 (embedded in each receiver in the receiver array).

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

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

The format of the TX-packet is shown in FIG. 4b. It contains 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 the spectral spread transmitter crystal oscillator clock frequency) and the packet is transmitted at 619 μS (619 chip clock cycles), the first 128 μS of which is the preamble and sy.
used to transmit nc bits (ie, TAG I
D and before the data field). Therefore, packet bits (including synchronization) are transmitted at approximately 60 Kbps and actual data bits are transmitted at approximately 52 Kbps.

Referring to FIG. 4a, 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 represents the incoming TAG transmission signal as a typical 45M signal.
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 spreader 116 and despread by a digital matched filter using analog summation and comparison. The synchronization of the spreading is done by a 2 MHz crystal oscillator 118, which must ensure that a synchronization lock is obtained as a frequency of the spectral spread transmitter 100 ± 400 ppm.

The spread spectrum receiver must obtain a synchronization lock 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 lock before the TAG ID and status data arrives (ie, assign preamble and sync bits). Time). Once the sync lock of the TX-packet is obtained, the TAG ID and status data are recovered and the RX-packet is generated.

While the spectral spread receiver is trying to achieve synchronization lock, it locks up and prevents the reception of any other signal. Therefore, TAG
The design goal is to reduce the number of times a random pulsed signal, rather than transmission, is actually added to the spread spectrum receiver--see Section 5.2.

The format of the RX-packet is shown in FIG. 4c. This includes the preamble, sync bits, and 32 data bits. The 32-bit data field contains a 16-bit TAG ID and a 2-bit move state (in the example, the other 14 bits are saved). Each RX-packet generated by the spread spectrum receiver 110 in response to a TAG transmission is a programmed controller (6 in FIG. 2b) within the radio sensing receiver.
8) retrieved and corresponding TOA-DETECTI
Used to assemble ON packets.

The particular embodiment of spectral spread communication does not form part of the present invention. The main reason for choosing the 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 cheaper) than the receiver components, and the number of TAG transmitters is typically (even in the low resolution embodiment) the receiver in a radio sensing array. , The cost of constructing the radio wave detection system is significantly reduced only by using the TAG transmitter component for transmission.

4. TAG Transmitter Referring to FIG. 2a, the TAG transmitter performs three basic functions: (A) Spectral spread communication by TAG transmission, (b) Movement detection that enables TAG transmission,
(C) Periodic control for establishing a TAG transmission interval.

Spectral spreading transmitter 52 is described in Section 2 and Appendix A, and related patents. Each TAG
Etching or scratching the diode connection on the spectral spread transmitter card to the transmitter 16
By doing so, a unique 16-bit TAG ID is given to the address selection operation.

Spectral spreading transmitter 52 starts transmission when strobe line transition is active.

Spectral spread TAG transmission is initiated in response to inputs TX1 and TX2, with TX1 provided by battery power save circuit 54 and TX1 provided by periodicity controller 58. Both of these transmission start inputs are inactive during the power saving mode. For each TAG transmission, the spectral spread transmitter provides a TXENABLE output that signals the end of the TX-packet transmission.

Spectral spread transmitter 52 also receives two movement state (data) inputs STAT1, STAT2, STAT1 being provided by battery power save circuit 54 to S
TAT2 is provided by the periodicity controller 58. Both of these STAT inputs are inactive when the TAG transmitter is in a power save mode (indicating no operation).

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

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

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

At the start of the target movement, the battery power saving circuit 5
4 is a TX in response to the initial movement display from the movement detector 56.
Outputs 1 / STAT1 strobe and T
Sends AG.

During the target movement, the movement detector 56 outputs a movement indication (jitter) to continuously retrigger the multivibrator in the battery power saving circuit 54, and 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. Due to this action, periodic TAG retransmission is started in the continuous movement state.

When the target movement is stopped, the movement detector 56 stops outputting the movement indication and triggers the multivibrator in the battery power saving circuit 54. After a predetermined reset period, the multivibrator is reset, the battery power saving circuit switches TX1 / STAT1 to inactive,
At the same time, it sends a reset strobe to the periodicity controller 58. Due to this action, the multivibrator is immediately reset and the TX2 / STAT2 strobe initiates the final TAG transmission of the stop motion state.

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. The 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 continues to transmit for an additional 30 seconds after the target has stopped moving. When the TAG transmitter is in power saving mode, IC packages typically use less than 10 μA.

Although reduced by spectral spread frequency hopping, system design should consider that message temporal collisions are unavoidable. In order to reduce message collisions and enable TAG hordes, the following two parameters must be optimized. (A). Shorten the transmission time, (b). Randomize the periodicity. If the transmission time cannot be properly limited, the number of allowable groups will be small due to the increase in superposition and collision transmission. Failure to properly randomize the periodicity can result in two TAG transmitters synchronizing and not receiving any messages.

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

The randomness of periodic TAG transmission is achieved as a result of two factors. First, the start of movement is based on mechanical movement, which in the context of radio detection systems is a random event (due to belt conveyors etc.)
Even if many goals move together, the goal is about 1
It does not move synchronously within the sync window of the mS. In addition, potentiometers can be used to add random periodicity. Second, multivibrators in battery power saving and periodic control circuits typically have decay times that are affected by Schmitt trigger voltage levels which can vary by as much as 1V or more depending on location. Therefore, the periodicity provided by the periodicity control circuit is sufficiently variable to provide a considerable degree of randomness.

5. Radio Finding Receiver Referring to FIG. 2b, each receiver of the array performs the following four basic functions. (A). Reception of spectral spread communication, (b). Trigger on arrival time of TAG transmission,
(C). 800 MHz synchronization counter time-based TOA COUNT latching in response to a TOA trigger,
(D). L containing arrival time data for each TAG transmission
Output to AN TOA-DETECTION packet.
Highly stable 800MHz time base clock (1.25nS
/ Cycle) approx. 0.305 m (1 ft)
The ideal range resolution of is obtained.

The TAG transmission is performed by the receiver front end 62.
It is received from (ANT PORT) and immediately given to the TOA trigger 64. The TOA trigger circuit sends the TOA trigger (TOA DETEC) to the time base latching circuit 65.
T) is given. Time base latching circuit is 200MH
8 derived from the z synchronization clock (200MIN)
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 displayed,
The time-based latching circuit enables the (SSOUTEN) receiver front end 62 to send TX-packets 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 to receive the spread spectrum TAG transmission via 21 (ANT PORT in FIG. 2a). Radio signal is amplifier 12
Two-stage amplification by 2,123, helical filter 12
Filtered by 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 (a).
Spectral spread receiver via solid state switch 128 (66 in FIG. 2a) and (b). It is split into inputs to 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 base latch circuit (65 in Figure 2a).
TX TX-Do not send packet.

Referring to FIG. 2a, a spread spectrum receiver 66 is described in Section 2 and Appendix B, and related patents. 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, the receiver receives the receiver front end 62 (SSOUT / SS
IN-) does not receive TX-packets, and this delay reduces the 128 μS window to obtain synchronization lock (see Sections 3 and 5.2).

When the receiver 66 obtains the synchronization lock, A
Output CQLK signal and TAG from TX-packet
Recovers the ID and movement status. The receiver then assembles the corresponding RX-packet (including the TAG ID and the move state) and switches RRDY active when the RX-packet is obtained at the serial port RSO and retrieved by the programmed controller.

The programmed controller 68 is RR
It outputs the RSCLK clock signal in response to DY active to clock RX-packets 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 and provides mechanical isolation for signal isolation.

TOA triggering is performed to obtain the down-converted intermediate frequency without mixing. The down conversion lowers the sensitivity required for the TOA trigger circuit, but the cycle of the intermediate frequency also lowers the trigger accuracy. That is,
The phase difference between the transmitter oscillator and the receiver local oscillator can result in errors of up to one complete IF period, amplifying the inaccuracy.

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

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

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

Receiver front end 1 (via power splitter 126) above the signal level threshold set by the comparator reference voltage from potentiometer 136.
Upon receiving the signal from 20, comparator 135 quickly triggers and asserts the TOA DETECT trigger signal. The TOA DETECT trigger is sent to the time base latching circuit (65 in FIG. 2a) as a possible arrival indication for the TAG transmission, at which point the TOA asserted is asserted.
The DETECT trigger can display TAG transmission or random pulse noise.

As long as the input signal remains higher than the comparator reference voltage, TOA DETECT remains affirmed, and when the signal disappears near its predetermined signal level threshold, at the end of the TAG signal or the end of random pulse noise, The detector capacitor 132 decays and switches the comparator 135, which does not assert TOA DETECT.
Based on the length of time the TOA DETECT trigger remains asserted, the time-based latching circuit sets it to TA
It is determined whether to process as G transmission.

4.2. Time Base Latching Circuit Referring to FIG. 2a, the time base latching circuit is
A TOA DETECT trigger from the A trigger circuit 64, as well as a 200 MHz system synchronization clock from the LAN interface 69 (200 MIN), and (indicating that the receiver has achieved the necessary synchronization for data recovery).
ACQLK from the spread spectrum receiver 66 is received.

The time base latching circuit is a fast stated latch circuit that performs time base latching and digital filtering while reducing metastability problems associated with synchronous latching. The circuit is composed of a high speed ECL and a TTL register section. These registers are REGSE
It is read and written by the controller 68 programmed using L and R / -W, and data / parameter transfers on REGDATA select the register and the type of operation.

FIG. 5b shows the register configuration 140 of the time base 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 via it.

Time-based latching operations are performed using the following register specifications. 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 fast ECL logic.

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

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

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

When the time-based latching circuit determines that the TOA DETECT trigger represents the arrival of a TAG transmission due to the digital filtering function, the TOA LATC
H register is set to Co by the programmed controller.
It is read section by 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 digital filtering function defines three states of the radio detection receiver.

(A). ARMED1 --- TOA DET
The ECT trigger is negated and has a signal that exceeds the signal level established by the comparator reference voltage. (B). MAX NOI that ARMED2--TOA DETECT is affirmed and the trigger signal is regarded as TAG transmission.
Wait for the SE LENGTH count. (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 causes a DISARMED condition, the circuit
(A). TAG transmission to the spread spectrum receiver (TX-
Packet) and SSOUTEN and (b). The TAG transmission is received and outputs an interrupt that informs the programmed controller that the latched time base TOA COUNT can be read from the TOA LATCH.

When DISARMED occurs, the REA of the radio detection receiver (that is, the time base latching circuit)
RMing requires REARM from the programmed controller (even if TOA DETECT trigger is negated). Programmed controller is TOA LATC via Control Bus
Send the REARM command to the flip-flop 142 that controls H.

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

The radio wave detection receiver is (a). Reasonable TX-
If a packet is detected and the lowest register of TOA LATCH is read, then from DISARMED,
(B). TOA DETECT is MAX NOISE
ARMED2 to ARMED1 if deasserted before LENGTH to indicate reasonable noise reception
Is REARMed to.

The MAX NOISE LENGTH register is set to ARMED2 by the programmed controller.
To a value that determines the transition to the DISARMED state. That is, this register has TOA DET
A predetermined signal duration threshold parameter is loaded, typically on the order of 1 μS, which defines the duration threshold that the received signal asserting the ECT trigger is supposed 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 the TOA detection sensitivity. Especially, MAX NOISE L
If the ENGTH parameter is too large, (MAX
SSOUTE after reaching NOISE LENGTH
The spread spectrum receiver (which does not receive TX-packets until N is given) is sufficient to obtain synchronization lock 12
Does not have 8 μS preamble window (ACQL
K must receive to recover the TAGID).

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

The count of TOA TO ACQLK is M
When the AX NOISE LENGTH is reached, the comparator 144 triggers the flip-flop 142 (DIS
ARM / REARM) transitions. At this time TOAD
If ETECT is still asserted, the DISARM condition will occur indicating a valid TAG transmission. The controller programmed by the interrupt is informed that the TOA LATCH contains a valid time base TOACOUNT, which means that the TOA DETECT trigger has not been asserted.
It is read by the later programmed controller to indicate the 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, DIS.
Only valid in ARMED state. This register is determined to be approximately 1 μS and can count over 619 (standard TX-packet duration is 619 μS.
Is). It is MAX NOISE LENGTH
TOA DETECT triggers that are asserted beyond can be used to confirm that they are actually valid TX-packets.

The NOISE COUNTER register has been on 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)
OA DETECT trigger assert count output, TA
Outputs a count of TOA DETECT numbers that are discarded as due to random pulse noise rather than G transmission. This count is programmed controller 68
Is used to adjust two noise sensitivity thresholds--a 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
Delaying 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 allows the non-TA of the spread spectrum receiver.
Lockup to X-packets is reduced.

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

For example, MAX NOISE LENGT
H parameter is too short and AR due to non-TX-packet
From MED2 (indicating valid TX-packet) DISA
If a regular transition to RMED is made and the valid noise is also of short duration, MAX NOISE LENG
TH can be lengthened to implement these noise signals.

MAX NO on non-TX-packets
If ISE LENGTH is exceeded and the noise signal strength is low, INCPOT can be incremented to increase the comparator reference level and eliminate these interfering signals. Care must be taken not to set the comparator reference level too high to prevent the TOA detector circuit from properly asserting the TOA DETECT trigger for a valid TX-packet that has been attenuated.

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

4.3 Programmable Controller Referring to FIG. 2b, a programmable controller 68 is commercially available and is a system that 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 system is accompanied by the following parts. (A). 256K RAM for program storage,
(B). 32K ROM for driver program with downline loader, (c). A peripheral controller based on Intel 8255, and (d). Arcnet interface.

Once constructed, the programmed controller is equivalent to a diskless network processor standard in the local area network industry. The peripheral controller is (a). Register based read / write time base latching circuit 65 including retrieval of time base TOA COUNT from TOA LATCH register, (b).
Spread spectrum receiver 66 searching for RX-packets (with TAG ID and mobility state), and (c). It interfaces with a TOA trigger 64 which designs a comparator reference level sent from a programmable potentiometer (reference numeral 136 in Figure 5a).

Upon power up, programmed controller 68 performs the following functions. (A). Arc
initialize net8255 and 8088 to a known state, (b). Request a downline load from the radio detection system processor (network file server) via the network, (c). (The Arcnet
Request configuration information from a particular system processor to the receiver (identified by the identification address), (d). Time-based latching circuit (TOA D from TOA trigger
Arm to ARMED1 state (with ETECT trigger).

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 has been received, the TOA DETECT trigger (A
RMED2) followed by MAX NOISE LENGTH counter time limit (DISARMED), MAX NOISE LENG from time-based latching circuit
Wait for TH interrupt.

Upon receipt of a MAX NOISE LENGTH interrupt, the programmed controller 68 will indicate that TOA D (indicating the receipt of the TAG transmission is complete).
Wait for an ETECT trigger, then read the TOA LATCH register to retrieve the time base count of the TX-packet. For statistical reasons, before reading the lowest register of TOA LATCH and performing REARM,
The programmed controller can also read other registers in the time base latch circuit that are still valid prior to REARM.

Operation of HiTEK 1. Overview The Hillier HiTEK kit (see FIG. 6) provides a complete spread spectrum wireless communication link. 902MHz to 9 for transmitter and receiver
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 one unit as a transceiver. A general system description is given below, as well as a more detailed description of the transmitter and receiver cards in the next section.

The transmitter consists of four main blocks. The first two control blocks and spreader block are implemented by custom integrated circuits. The control block is responsible for generating a master clock, controlling the power of the system, controlling data, and controlling the sequence of various operations. The spreader block combines input data and sync 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 a temperature stabilized oscillator. The output of the modulator is a shaped frequency varying polarization modulated signal. The final block of the transmitter is the output stage, ie the stage that obtains the gain corresponding to the desired power level. This level is typically
It will vary from 0.01 watts to the legal limit of 1 watt. Output filtering is also included in this section to ensure compliance with out-of-band emission regulations.

The receiver consists of three main blocks. The first block is the RF front end, which contains the preamplifier and the 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 demodulated in the second block of Motorola 13055I.
F processor integrated circuit.

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

The output data is 3 shown in FIGS. 7a, 7b and 7c.
Packaged in one of two formats. The packet consists of multiple preamble bits, 1 sync 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 1/2 the clock frequency of the crystal oscillator in the transmitter. Package is 619
It is transmitted in clock cycles. The frequency of the reference digital logic crystal oscillator is about 2 MHz. Therefore, the original data including the sync bit is transmitted at about 60,000 bits / second, but the actual data bit is about 52,
It is possible to transmit at 000 bits / second. This data transmission rate depends on the operating mode. Therefore, the data transmission rate is such that a high-speed response and a moderate data throughput can be obtained.

2. The functional blocks and input / output connections of the transmitter HiTEK transmitter card are shown in FIG. All I / O connections are compatible with 5 volt CMOS logic levels. The outline of each functional block and the input / output connection related thereto will be described.

Battery Selection: BATMODE ^* 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 shorting jumper on JP5 and set the BATMODE ^* input high. BA
In the TTERY mode, the ASIC stops the crystal oscillator after each transmission, is in a SLEEP (power off) state, and the SYSTEM WAKEEU is caused by receiving a transmission start signal.
By entering the P state, additional actions are performed.

Mode Select: The input selects one of three operating modes. Selection is possible by changing the wiring of the input lines or short-circuit jumpers on the board. The transmitter forms a data packet determined by the MSEL0 and MSEL1 inputs. Place a shorting jumper on JP4 or JP3 to set the MSEL0 or MSEL1 inputs high, respectively. These are 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 manufactured 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
The data on 1, D2 and D3 are as shown in FIG.
It is sent 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 SI input is clocked into the transmission data register. Data register is 1 in mode 1
It has a 6-bit length and 32 data bits in mode 2. Attempting to load data while the READY output is low will result in the loss of data. The data in the data register is transmitted as shown in FIGS. 7b and 7b after the transmission start signal.

Address selection: This is for accommodating a 16-bit address in the data packet to be transmitted in the operation modes 0 and 1. The data and address formats are shown in Figures 7a and 7b, respectively. HiTE
The K transmitter card has a 16 dip switch that selects the binary address to be transmitted. The switch position is sensed in a matrix format with 4 address strobe lines and 4 address lines.

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

Control Logic: A state machine that sets all correct operations and signal sequences in the ASIC. R
The ESET input is an analog signal which, when true (logic high), causes the transmitter ASIC to reset to the SLEEP state. MSEL0 and MSEL1 inputs are RESET
Latches internally when goes low. 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 transmit start signal. This is the ASIC in the BATTERY mode.
Move to TEM WAKEUP state and NON-BAT
In the TERY mode, the TXWAKEUP state is entered. SYSTEM WAK in BATTERY mode
When in the EUP state, the crystal oscillator starts immediately and 512 clock cycles elapse before TXWAK
A transition to the EUP state occurs.

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

The on / off output goes true (high) when the STARTTX0 ^* input starts transmitting, and STAR
It goes false (low) when the TTX1 ^* input begins transmitting.
This output is hardwired to one of the parallel data inputs and is designed so that it can be transmitted in mode 0 operation if desired.

Spreader: Combine chipping sequences with packet bits. This gives the desired spreading action.

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

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

Second amplification stage: Adds a gain of about 10 dB to the RF output signal. This produces an RF output signal level of 100 mW. Furthermore, the RF output signal is JP7, JP
9A and JP8C are jumpered, guided to the antenna through the wiring on the printed circuit board, and RF of 100mW
The output signal level may be obtained. Transmitter is BA
10 in TTERY mode with built-in battery
It can operate at 0 mW level.

Third amplification stage: Adds a gain of about 10 dB to the RF output signal. This produces an RF output signal level of 1W. Furthermore, the RF output signal is JP7, JP1.
It may be jumpered at 0 and JP11 and guided to the antenna through the wiring on the printed circuit board to obtain an RF output signal level of 1W. The transmitter is BATTER
In the Y mode, the built-in battery can be used to operate at the 1 W level. Furthermore, large capacities require an external battery or power source.

External Power Supply: Obtain a regulated built-in 5 volt DC power supply utilizing an 8-10 volt DC input. The minimum input voltage is increased to 9 volts DC when operation at the 1 watt output level is required. Operation by external power supply is JP
It is determined by placing short-circuit jumpers on 1B and JP2B.

Battery power: Mounted on board by a two coin battery holder. This is 2 Lithium Matsushita C
Holds R2330 3V coin battery. Battery powered operation is determined by placing Berg jumpers on JP1A and JP2A.

Built-in antenna: a quarter-wave antenna arranged on a printed circuit board. The wiring of the printed circuit board is jumpered and built-in (JP12) or external antenna (J
P13) may be used. Note: All adjustable parts are preset during calibration and testing. No adjustments should be made to these parts without first consulting Hillier Technology.

3. Fig. 9 is a pictorial diagram of the transmitter card showing the parts, input / output signals and jumper positions. It should be noted that many additional signals to the above were labeled and brought out to the edge of the printed circuit board. This is to monitor the internal signals on the transmitter card. HTLP for additional information on supervisory signals and graphically indicated signals.
You should consult the technical department.

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

[0191]

[Table 1]

[0192]

[Table 2]

5. Electrical Specifications of Transmitter The following specifications shall not exceed guaranteed performance operation. Power supply voltage range BATTERY mode (VDD) 4.5 to 5.5 volt DC Other mode (VCC) 8 to 10 volt DC VDD = 5V DC generated on printed circuit board Power supply current range BATTERY mode standby <10 μA @ 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 power supply voltage Operating temperature range: -20 to 60 ° C Storage temperature range: −40 ° C. to 125 ° C. Input signal level (VIN): VIH = (0.7 * VDD) ≦ VIN ≦ VDD Volt VIL = −0.5VIN ≦ (0.3 * VDD) Volt Schmitt trigger + threshold (VT +) ): 2.2 volt Schmitt trigger-threshold (VT-): 1.3 Volts Input signal timing: SI setup time for SCLK ≧ 50 ns SI holding time for SCLK = 0 ns Output signal (VO): 0 ≧ IOH ≧ −8 mA VHO = 2.4 ≦ VO ≦ VDD Volts VOL = VO ≦ 0 .4 volt @ 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.

CAUTION: Failure to keep the power supply within the specified range can damage components on the printed circuit board. Failure to keep the input signal within the specified range can damage components on the printed circuit board. Care should be taken in the connection of power and signal lines to the printed circuit board in making sure that the correct polarity is maintained. Failure to do this can damage components on the printed circuit board.

6. Receiver HiTEK receiver functional block and input / output connections are shown in Figure 1.
2 shows. All I / O lines are compatible with 5 volt CMOS logic levels. A general description of each functional block and its associated input / output connections will be given.

Built-in antenna: An approximately ½ wavelength antenna arranged on the 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 oscillator 960 MHz RF signal used by the mixer. The accuracy of the local oscillator over temperature is important for receiver performance. Temperature-compensated LC oscillator (version 3)
Alternatively, an option is possible by using a SAW oscillator (version 3a).

RF / IF modulator: 915 MHz received
Amplifies, mixes, filters, amplitude limits, detects and correlates RF signals. The RF circuit reproduces the chip data stream of about 1 MHz. The ASIC executes the despreading process.

Crystal oscillator: Standard 2M for digital circuits
Supply a clock of Hz. 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 correct synchronization during despreading.

Control Logic: In an ASIC, a state machine 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 the establish / lock state, and set the establish / lock output high. MSEL
The 0 and MSEL1 inputs are internally latched when RESET goes low. The HiTEK receiver card includes components that perform a power-up reset when power is applied. The establish / lock output signal represents the state in which the ASIC is trying to establish synchronization with the RF signal it receives (high) or the state in which synchronization is established (low). This signal must be low until all the data packets have been successfully received. It is set to true (high) when reception is terminated after valid reception, or when reception is terminated by the ASIC (ie loss of sync or bad address).

Mode selection: Select one of the three operation modes. Selection is possible by changing the wiring of the input lines or short-circuit jumpers on the board. The receiver forms a data packet determined by the MSEL0 and MSEL1 inputs. Set the MSEL0 or MSEL1 inputs high by placing a Burk jumper on JP3 or JP4, respectively. They select the mode as shown below with 1 = logical high and 0 = logical 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 manufactured For testing.

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

Note: The transmitter (several transmitters) is in mode 0,
While in 1 or 2, the receiver can be operated in mode 2. This is because multiple transmitters have one receiver (mode 2) with preset addresses (mode 0 or 1).
The receiver uses external circuitry to determine which transmitter sent the first 16-bits of the received 32-bits of data. .

Data output: Read the received data. 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 are valid. In modes 1 and 2,
The clock is input to the next serial data bit SO (serial) output line at the rising edge of the normal low SCLK (shift clock). READY output outputs all data bits to SO
Goes low when the output is clocked. The data register is 16 bits long in mode 1, while it is 32 bits long in mode 2. The data in the data register is only valid when both RADY and the establish / lock output lines are high. If the establish / lock output goes low while the data is being read, the data is invalid.

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

Note: All adjustable parts are preset during calibration and testing. First, "Spreadex (S
Do not adjust these parts without reference to the "preread user's manual".

7. Receiver Pictorial FIG. 13 shows a pictorial diagram of the transmitter card showing the components, 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 the internal signals on the transmitter card. For additional information about the above signals and the signals shown on the figure, please refer to the "Spreadex Users Manual".

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

[0209]

[Table 3]

[0210]

[Table 4]

9. Receiver electrical specifications The following specifications must not exceed guaranteed performance operations. 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 in 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 = 3.5VDC ≦ V
IN ≧ 5VDC: VIL = −0.5VIN ≦ VIN ≧ 1.5VDC Schmitt trigger + threshold (VT +): 2.2V Schmitt trigger−threshold (VT−): 1.3V Output signal level (VO ): When 0 ≧ IOH ≧ −8 mA, VHO = 2.4 ≦ VO ≦ VDD volt VLO = VO ≦ 0.4 volt @ IOL ≦ 8 mA Output signal timing: Establish / Lock, READY and ADSTRB outputs are clock rising edges. It shall occur within 100 ns at the edge or trailing edge. SO output for SCLK ≤ 50ns

Caution-If the power supply is not kept within the specified range, it may damage components on the printed circuit board. Failure to keep the input signal within the specified range can damage components on the printed circuit board. Care should be taken in connecting the power and signal lines to the printed circuit board when making sure that the correct polarity is maintained. Failure to do so may damage the components on the printed circuit board.

[Brief description of drawings]

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

FIG. 2 is a functional block diagram of the present invention, in which a is TAG.
Functional block diagram of transmitter, b is (performs arrival time detection)
FIG. 3 is a functional block diagram of the radio detection receiver, and c is a functional block diagram of a LAN interface of the radio detection system.

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

FIG. 4 is a functional diagram of a spread spectrum communication system used in a radio wave detection system, in which a indicates a transmitter and a receiver, b indicates a TX-packet format,
FIG. 7C is a diagram showing a format of RX-packet.

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

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

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

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

FIG. 9 is a diagram showing a first substrate on which components are attached.

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 is a second substrate on which components are attached.

FIG. 14 is a receiver card timing chart.

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

[Explanation of symbols]

 10 Semiconductor Manufacturing Facility 11 GaAs Lithography 12 Photolithography 13 GaAs Etch 14 Metallization 15 Ion Implanting 16 Walls 17 Walls 18 Walls 20 Radio Detecting Receiver Array 22 Receiver 24 Receiver 26 Receiver 30 TAG Transmitter 35 Calibration Transmitter 40 System Processor 50 Calibration Transmitter 52 Spectral Spreading Transmitter 54 Movement Detector 54a Potentiometer 56 Movement Detector 58 Synchronous Controller 58a Potentiometer 60 Radio Finder Receiver 62 Receiver Front End 64 TOA Detection Trigger 65 Time Base Latching Circuit 66 Spectral Spreading 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 spectral spread 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 2MHz 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

Claims (54)

[Claims] 1. A location system for locating a target in a tracking environment using time difference of arrival of electromagnetic transmissions received by multiple receivers, the system comprising a unique TAG ID.
Including a TAG transmitter for each target that transmits at selected intervals, and a receiver array distributed in the tracking environment so that the TAG transmission is received by at least three receivers, each receiver being An arrival time circuit includes a data communication controller, the arrival time circuit responding to the arrival of a TAG transmission by outputting a TOA count corresponding to the arrival time of the most direct path for such TAG transmission,
The count is synchronized with the system synchronization clock sent to each receiver, and the data communication controller uses the TAG.
Associated TAG ID and TO in response to receipt of transmission
Outputting a corresponding TOA-detection packet containing the A count, and further receiving each TOA-detection packet from at least three corresponding TOA-detection packets received by different receivers, each TAG and its associated target position. A target orientation system comprising a orientation processor for determining. 2. The orientation system according to claim 1, wherein
A target location system in which spread spectrum communication is used for TAG transmission. 3. The orientation system according to claim 2, wherein
Spectral spread communication is a target location system with a frequency range of 900 MHz. 4. The orientation system according to claim 2,
Target orientation system, where the duration of TAG transmission is approximately 600 μS. 5. The orientation system according to claim 1, wherein
Target orientation system in which each TAG transmission contains selected status information. 6. The orientation system according to claim 5,
Target orientation system where selection status information is generated without operator intervention. 7. The orientation system according to claim 1, wherein
A target orientation system, wherein the TAG transmitter includes movement detection circuitry that detects movement of the target and enables the TAG transmitter to send TAG transmissions during movement of the target. 8. The orientation system according to claim 7,
TAG transmission is a target orientation system in which a target is moved for a relatively short period of time after moving and after moving is stopped. 9. The orientation system according to claim 8, wherein
Target orientation system, where each TAG transmission includes an appropriate travel status indicator. 10. The orientation system of claim 9, wherein each TAG transmission includes at least three of the appropriate ones of movement status indication, movement start, movement continuation, and movement stop. 11. The orientation system according to claim 1, wherein the TAG transmitter performs T at a selection interval each time the target moves.
A target orientation system that includes a periodicity control circuit that causes a TAG transmission to be emitted from an AG transmitter. 12. The location system of claim 11, wherein the TAG transmissions are delivered at relatively short intervals while the target is moving and at relatively long intervals while the target is stationary. 13. The location system of claim 1, wherein the arrival time circuit provides an adjustable level of noise sensitivity for differential TAG transmission from noise. 14. The orientation system of claim 13, wherein noise sensitivity is determined by the selected signal level threshold and the selected signal duration threshold. 15. The location system of claim 1, wherein the arrival time circuit outputs a TOA-DETECT trigger as soon as the direct path TAG transmission arrives.
A target orientation system comprising an OA trigger circuit and a time base latching circuit for latching an associated TOA count of a synchronized time base in response to a TOA-DETECT trigger. 16. The orientation system according to claim 15, wherein the TOA trigger circuit outputs a TOA-DETECT trigger when the signal level of the received signal exceeds a signal level threshold value, indicating that the received signal is TAG transmission. Target orientation system. 17. The system of claim 16, wherein
The TOA trigger is a target orientation system that outputs a TOA-DETECT trigger when the signal level of the received signal exceeds the comparator reference level. 18. The orientation system according to claim 17, wherein the signal level comparator reference level is adjustable.
Target orientation system. 19. The orientation system of claim 15, wherein the time-based latching circuit indicates when the duration of the received signal exceeds the signal duration threshold and the received signal is TA.
Target orientation system designated as G transmission. 20. The orientation system of claim 19, wherein the TOA-DETECT trigger remains asserted during the reception of the TAG transmission and the time-based latching circuit selects the TOA-DETECT trigger duration MAX.
A target orientation system that outputs a signal duration indication when the NOISELENGTH count is exceeded. 21. The orientation system of claim 15, wherein the time-based latching circuit includes a time-based counter that counts at a rate of approximately 800 MHz derived from the system synchronization signal. 22. The orientation system according to claim 1, wherein the receivers are connected to the orientation processor by a local area network, each receiver includes a LAN interface, and the TOA detection packet is transmitted through the LAN to the orientation processor. A targeting system that communicates with. 23. The orientation system of claim 22, wherein the system synchronization signal is communicated with each receiver via a LAN. 24. The orientation system according to claim 1, further comprising at least one calibration transmitter located at a known position for transmitting a calibration transmission receivable by each receiver, each receiver The accompanying arrival time T in response to the calibration transmission
The corresponding calibration TOA detection packet including the OA count is output to the orientation processor, and the orientation processor outputs the calibration TOA
A target orientation system that determines calibration factors from the detection packet and the known position of the receiver and uses these factors to calibrate the orientation calculation from the TOA-detection packet that accompanies the TAG transmission. 25. An orientation system for locating a target within a tracking environment using area detection by a receiver receiving electromagnetic transmissions from an allocated area, the system selecting TAG transmissions including a unique TAG ID at an interval. And a receiver array distributed within a tracking area, each of which is configured to receive TAG transmissions from an allocated area of a predetermined size. Receiving TAG ID in response to receiving
A location for each TAG and its associated target based on the identification of the receiver that receives the area detection packet and receives the TAG transmission of that TAG. A target orientation system that includes an orientation processor. 26. The orientation system according to claim 25, wherein each receiver includes a directional antenna with a predetermined beam width,
A target orientation system in which the receiver is adapted to receive TAG transmissions originating from its allocated area. 27. The orientation system according to claim 25, wherein the receivers are distributed in the tracking environment at predetermined intervals and each TA
A target location system in which the transmission power of the G transmitter and the spacing between adjacent receivers are cooperatively selected so that the TAG transmission is almost always received by the one receiver closest to the TAG. 28. The location system of claim 25, wherein spread spectrum communication is used for TAG transmission. 29. The orientation system of claim 28, wherein the spread spectrum communication is in the 900 MHz frequency range. 30. The target locating system according to claim 28, wherein the duration of the TAG transmission is of the order of 600 μS. 31. The orientation system of claim 25, wherein the TAG transmitter includes a movement detection circuit that detects movement of the target and enables the TAG transmitter to issue a TAG transmission during movement of the target. . 32. The targeting system according to claim 31, wherein the TAG transmission is transmitted for a relatively short predetermined time during the movement of the target and after the movement of the target is stopped. 33. The orientation system of claim 32, wherein each TAG transmission includes an appropriate travel status indicator. 34. The orientation system of claim 33, wherein each TAG transmission includes at least three of the appropriate ones of movement status indication, movement start, movement continuation, and movement stop. . 35. The orientation system of claim 25, wherein the TAG transmitter includes a periodicity control circuit that causes the TAG transmitter to send TAG transmissions at predetermined intervals each time the target moves. system. 36. The orientation system according to claim 35, wherein the TAG transmissions are sent at relatively short intervals while the target is moving, and at relatively long intervals when the target is stationary.
Target orientation system. 37. The targeting system of claim 25, wherein each receiver provides an adjustable level of noise sensitivity for differential TAG transmissions from noise. 38. The targeting system of claim 37, wherein noise sensitivity is determined by a selected signal level threshold and a selected signal duration threshold. 39. The orientation system according to claim 25, wherein the receivers are connected to the orientation processor by a local area network, each receiver includes a LAN interface, and the area detection packet is communicated to the orientation processor via the LAN. Target orientation system 40. A method of locating targets within a tracking environment using time difference of arrival of electromagnetic transmissions received by multiple receivers, the method comprising a unique T for each target.
Send TAG transmission including AG ID at selected intervals, and
Providing a receiver array distributed within the tracking environment such that G transmissions are received by at least three receivers,
T corresponding to the arrival time of the most direct path for such a TAG transmission in response to the arrival of the transmission at the receiver.
The OA count is output and the TOA count is synchronized with the system synchronization clock sent to each receiver.
Responsive to receiving the AG transmission, outputting a corresponding TOA-detection packet containing the associated TAG ID and TOA count, and using the TOA-detection packet, at least three corresponding TOA-detection packets. A target orientation method comprising the steps of determining the position of each TAG and its associated target from the detection packet. 41. The orientation method according to claim 40,
A target orientation method, wherein the step of sending out a TAG transmission further comprises detecting movement of the target and enabling TAG transmission during movement of the target. 42. The orientation method according to claim 41, wherein each T
Target orientation method, in which AG transmission includes proper movement status display. 43. The orientation method according to claim 40,
A target orientation method, wherein the step of sending out TAG transmissions comprises the step of sending out TAG transmissions at selected intervals each time the target moves. 44. The orientation method according to claim 40,
Further, the method of target orientation comprises adjusting receiver noise using a signal level threshold and a signal duration threshold to identify TAG transmissions from the noise. 45. The orientation method according to claim 40,
The step of outputting the TOA count outputs the TOA-DETECT trigger as soon as the direct path TAG transmission arrives, and the associated TOA count of the time-based counter derived from the system synchronization clock in response to the TOA-DETECT trigger. A target orientation method that consists of latching steps. 46. The orientation method according to claim 40,
A target orientation method, wherein the receivers are connected to the orientation processor by a local area network, and each receiver includes a LAN interface so that TOA detection packets are communicated with the orientation processor via the LAN. 47. The orientation method according to claim 40,
In addition, each receiver sends out a calibration transmission from at least one known location receivable and outputs a corresponding calibration TOA detection packet containing an associated time-of-arrival TOA count in response to receipt of calibration communication at the receiver. Then, a calibration factor is determined from the calibration TOA detection packet and the known position of the receiver and these factors are used to attach the TAG transmission to the associated TO.
A-A target orientation method comprising the steps of calibrating orientation calculations from detected packets. 48. A method of locating a target in a tracking environment using area detection by a receiver receiving electromagnetic transmissions from an allocated area, the method comprising a unique TAG.
A TAG transmitter that sends out TAG transmissions including an ID at selected intervals is provided for each target, and a receiver array configured to receive TAG transmissions from an allocated area of a predetermined size is provided in the tracking area. Provided in a distributed manner, each receiver outputs a corresponding area detection packet containing the received TAG ID in response to the reception of the TAG transmission, and the TAG for the TAG represented by the area detection packet sent from the receiver receiving the TAG transmission. Determining the position of each TAG and its associated targets based on the identity of the receiver receiving the transmission,
Target orientation method consisting of things. 49. The orientation method according to claim 48,
A target orientation method, wherein each receiver includes a directional antenna of a predetermined beam width, and the receiver is adapted to receive a TAG transmission emanating from its allocated area. 50. The orientation method according to claim 48,
The receivers are distributed in the tracking environment at regular intervals and each TAG
The transmit power for the transmitter and the spacing between adjacent receivers is T
A target orientation method in which the TAG transmissions are cooperatively selected to be received almost always by the one receiver closest to the AG. 51. The orientation method according to claim 48,
A target orientation method, wherein the step of sending out a TAG transmission further comprises detecting movement of the target and enabling TAG transmission during movement of the target. 52. The orientation method according to claim 51,
Each TAG transmission includes an appropriate travel status indicator,
Target orientation method. 53. The orientation method according to claim 48,
A method of locating a target, wherein the step of sending a TAG transmission comprises the step of sending a TAG transmission at a selected interval each time the target moves. 54. The orientation method according to claim 48,
A target orientation method, wherein the receivers are connected to the orientation processor by a local area network, each receiver includes a LAN interface, and the TOA detection packet is communicated with the orientation processor via the LAN.