JP2009097863A - Instrument position detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect positional information of a wireless transmitting station, without providing high-precision clocks both in the wireless transmitting station and in a wireless receiving station. <P>SOLUTION: A temperature measuring instrument 14 includes a first transceiver means for transmitting response frame data to wireless base stations 11-13, and the base stations 11-13 are provided with second transceiver means for receiving response frame data transmitted from the measuring instrument 14, after receiving reference frame data transmitted from wireless stations 11-13 other than an own station, when no request for transmission of the reference frame data is made, and a time measuring means for measuring, as a response time, the time interval from the point of time of reception completion of the reference frame data by the second transceiver means up to the point of time of a reception start of the response frame data. A position detection device 20 includes a distance calculation means for calculating a difference distance based on the calculated response time and a delay time, and a position calculation means for calculating positional information representing the position of the measuring instrument 14 based on the calculated difference distance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides wireless transmission based on a wireless transmission station, a plurality of wireless reception stations whose positional relationships are known, and transmission / reception results when wirelessly transmitting / receiving frame data between the wireless transmission station and the wireless reception station. The present invention relates to a device position detection system including a position detection device that detects a position of a station.

  For example, in an air conditioning system that controls air conditioning equipment installed in a room, a temperature measuring device capable of wirelessly transmitting temperature data, a wireless base station that receives temperature measurement values transmitted from the temperature measuring device, and a wireless base There are some which consist of a control device which controls indoor air-conditioning equipment based on the temperature measurement value received by the station.

  In such a conventional air conditioning system, in order to control the indoor space to have a comfortable temperature, the control device is based on the temperature measurement value transmitted from the temperature measuring device and the position information of the temperature measuring device. It is necessary to control the temperature appropriately. Therefore, the provider or user of the air conditioning system accurately measures the distance between the radio base station and the temperature measuring device, calculates the position of the temperature measuring device based on the measured distance, and calculates the calculated position information. Had to be set in the control unit.

  Therefore, for example, when a provider or a user moves or adds a temperature measuring device, the provider or the user controls the distance between the radio base station and the temperature measuring device each time. Had to be set to be very cumbersome.

  In view of this, it is conceivable to apply a position detection system in which a GPS (Global Positioning System) sensor is mounted on the temperature measuring device and the position information of the temperature measuring device is transmitted to the radio base station to the air conditioning system. However, since such an air conditioning system using GPS is installed indoors, the radio wave from the temperature measuring device becomes weak, and the position cannot be accurately detected. Moreover, since the GPS sensor is mounted on the temperature measuring device, there is a problem that the manufacturing cost of the entire air conditioning system increases.

  Therefore, Patent Document 1 includes a plurality of base stations and terminals, has a plurality of channels, each terminal performs packet communication asynchronously with the base station, and the base station without synchronizing the terminal and the base station. A position estimation system for a radio station that measures the signal propagation time between the terminals and identifies the position of the terminal based on the measured propagation time has been proposed.

  FIG. 7 shows a data packet based on the IEEE802.11 standard between a base station that is a data packet transmission side and a terminal that is a data packet reception side in the wireless station position estimation system described in Patent Document 1. It is the figure which showed the transmission / reception relationship.

  As shown in FIG. 7, the propagation delay time required for the data packet transmitted from the base station to reach the terminal is T1, and the propagation delay necessary for the ACK transmitted from the terminal to reach the base station. Is T2, and the time required from the end of reception of the data packet until the terminal transmits ACK is T3. Here, in the IEEE802.11 standard, T3 is defined as SIFS (Short Inter Frame Space) as a time until an ACK response on the receiving side. The time required for transmitting the data packet is T4, and this T4 depends on the data packet length and the transmission rate. T5 is the time from the start of data packet transmission to the start of ACK reception at the transmitting base station, and is the time obtained by adding T1, T2, T3, and T4.

  Here, T4 is a time determined by the data packet length and the transmission rate, and can be calculated by the base station on the transmission side. SIFS indicated by T3 is a value determined by the standard used for the physical layer in the IEEE 802.11 standard. For example, in the IEEE 802.11a standard, a value of 16 μs (microseconds) is defined as the SIFS time. Similarly, the IEEE802.11B standard defines a value of 10 μs (microseconds) as the SIFS time. Therefore, in a wireless LAN system that communicates according to the IEEE 802.11 standard, the SIFS value varies depending on the standard of the physical layer used, but in a wireless station that communicates according to the same physical layer standard, the SIFS value is a fixed value. It becomes. Therefore, T3 and T4 of the time elements constituting T5 are estimated at the base station on the transmission side, and time (T1 + T2) is derived.

When using a wireless LAN, the base station starts from the start of data packet transmission to ACK reception on the assumption that the propagation delay T1 from the base station to the terminal and the propagation delay T2 from the terminal to the base station are the same. Time T5 is measured, and the propagation delay (T1 = T2) between the base station and the terminal is obtained, thereby estimating the propagation time between the base station and the terminal and estimating the propagation distance.
JP 2004-350088 A

  However, in the position estimation system of the wireless station described in Patent Document 1, the base station measures T5 and transmits accurately so that the terminal becomes T3. Based on the measured T3 and T5, A propagation delay (T1 = T2) between the base station and the terminal is obtained. Therefore, it is difficult to calculate the propagation delay (T1 = T2) with high accuracy.

  That is, in order to calculate the propagation delay (T1 = T2) with high accuracy, it is necessary to provide a clock that measures time with high accuracy in both the base station and the terminal. For example, when T5 is measured using a quartz crystal resonator having a measurement accuracy of about 10 ppm, which is a relatively low price that is generally distributed, if T5 is several hundred μs (microseconds), The measurement error may be several meters. With such an accuracy, for example, when the position estimation system of the wireless station described in Patent Document 1 has a large error and is applied to an air conditioning system, temperature control may not be performed appropriately.

  Further, if the base station and the terminal are provided with a timepiece having high measurement accuracy, there is a problem that the manufacturing cost is increased and the entire apparatus is expensive.

  The present invention has been made in view of the above problems, and is provided with a high-accuracy timepiece without providing both a wireless transmission station on the data transmission side and a wireless reception station on the data reception side. An object of the present invention is to provide a device position detection system capable of accurately detecting position information of a transmitting station.

  In order to achieve the above object, a first feature of the device position detection system according to the present invention is that a wireless transmitting station receives reference frame data transmitted from any one of a plurality of wireless receiving stations, and receives the received reference frame data. A first transmission / reception means for transmitting response frame data to a plurality of radio reception stations as a response to the reference frame data, and when the plurality of radio reception stations have requested transmission of reference frame data from the position detection device. The reference frame data is transmitted to the radio transmitting station and other radio receiving stations other than the own station, and when there is no transmission request, after receiving the reference frame data transmitted from other radio receiving stations other than the own station, Second transmission / reception means for receiving response frame data transmitted from the wireless transmission station as a response to the reference frame data; and reference frame data by the second transmission / reception means. Time measuring means for measuring the time from when the transmission is completed to when the reception of the response frame data is started as a response time, and the position detection device includes any one of a plurality of wireless reception stations, a wireless transmission station, The time from when the reference frame data has been transmitted to other radio receiving stations other than the own station until the time when the other radio receiving station has completed receiving the reference frame data is calculated as a delay time, and the calculated delay time Based on the response time measured by the time measuring means, the distance to any one of the plurality of radio receiving stations that received the reference frame data from the radio transmitting station, and other than the radio receiving station A distance calculating means for calculating a difference from a distance from any one of a plurality of radio base stations receiving the reference frame data to a radio transmitting station as a difference distance; Based on the difference distance calculated by the step, and having a position calculation means for calculating position information indicating the position of the radio transmission station.

  According to the device position detection system of the present invention, it is possible to accurately detect the position of the wireless transmission station without providing a high-accuracy timepiece for both the wireless transmission station and the wireless reception station.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The first embodiment of the present invention is applied to an air conditioning system that controls an air conditioner installed indoors, and a positional relationship between a temperature measuring device that measures the temperature of the room and a plane with a predetermined position as a reference point A device position detection system that detects the position of the temperature measuring device based on the transmission / reception results of wirelessly transmitting / receiving frame data to / from three wireless base stations of which is known will be described as an example. Here, the frame data is one unit that is divided when data is transmitted / received. The frame data includes reference frame data that requests a response and response frame data that indicates a response to the reference frame data. .

  FIG. 1 is a configuration diagram illustrating a configuration of an air conditioning system to which a device position detection system that is Embodiment 1 of the present invention is applied.

  As shown in FIG. 1, the air conditioning system 2 includes a device position detection system 1 that is Embodiment 1 of the present invention, a control device 3, and an air conditioning device 4. The device position detection system 1 is connected to a control device 3, and an air conditioning device 4 is connected to the control device 3.

  The control device 3 controls the air conditioner 4 based on position information of a temperature measuring device 14 (described later) supplied from the device position detection system 1 and temperature data measured by the temperature measuring device 14.

  The air conditioner 4 adjusts the air volume and the like for air conditioning according to the control signal from the control device 3.

  A device position detection system 1 that is Embodiment 1 of the present invention includes wireless base stations 11 to 13 that are wireless reception stations, a temperature measuring device 14 that is a wireless transmission station, and a position detection device 20. The base stations 11 to 13 and the position detection device 20 are connected via a network 30.

  The temperature measuring device 14 includes a temperature sensor and first transmission / reception means.

  The temperature sensor of the temperature measuring instrument 14 measures the ambient temperature and supplies the measured temperature data to the first transmitting / receiving means.

  The first transmission / reception means of the temperature measuring device 14 receives the reference frame data transmitted from any one of the radio base stations 11 to 13, and sends the response frame data as a response to the received reference frame data. To ~ 13. When the reference frame data is data requesting transmission of the measured temperature, the temperature data measured by the temperature sensor is included in the response frame data and transmitted to the radio base stations 11 to 13.

  The radio base stations 11 to 13 are provided with second transmission / reception means and time measurement means in terms of their functions.

  When there is a reference frame data transmission request from the position detection device 20, the second transmitting / receiving means of the wireless base stations 11 to 13 transmits the reference frame data to the wireless measuring station 11 other than the temperature measuring device 14 and the own station. To ~ 13. In addition, when there is no reference frame data transmission request from the position detection device 20, the second transmission / reception means receives the reference frame data transmitted from other radio receiving stations 11 to 13 other than the own station, and then references Response frame data transmitted from the temperature measuring device 14 is received as a response to the frame data. Further, the second transmission / reception means supplies the temperature data to the control device 3 when the response frame data received from the temperature measuring device 14 includes temperature data measured by the temperature sensor.

  The time measurement means of the radio base stations 11 to 13 responds to the reference frame data from the time when the second transmission / reception means completes the reception of the reference frame data transmitted from other radio reception stations 11 to 13 other than its own station. As a response time, the time until the reception of response frame data transmitted from the temperature measuring device 14 by the second transmitting / receiving means is measured.

  The position detection device 20 includes a distance calculation unit and a position calculation unit in terms of its function.

  The distance calculation means of the position detection device 20 calculates a delay time when the radio base stations 11 to 13 receive the reference frame data. Here, the delay time means that any one of the radio receiving stations 11 to 13 has transmitted this reference frame data from the temperature measuring instrument 14 and the other radio receiving stations 11 to 13 other than the own station. The time until the time when the other radio receiving stations 11 to 13 complete receiving the reference frame data. Then, the distance calculating means is one of the radio base stations 11 to 13 that have received the reference frame data from the temperature measuring device 14 based on the calculated delay time and the response time measured by the time measuring means. And the difference between the distance from any one of the wireless base stations 11 to 13 that received the reference frame data to the temperature measuring device 14 other than the wireless receiving station and the temperature measuring device 14 is calculated as a difference distance. .

  The position calculation means of the position detection device 20 calculates position information indicating the position of the temperature measuring device 14 based on the difference distance calculated by the distance calculation means. Here, the position information refers to coordinate information with a predetermined position on a plane including the radio base stations 11 to 13 as a reference point.

  FIG. 2 is a configuration diagram illustrating configurations of the radio base stations 11 to 13 of the device position detection system 1 according to the first embodiment of the present invention.

  Since the radio base stations 11 to 13 have the same configuration, the radio base station 12 will be described below, and the description of the radio base stations 11 and 13 will be omitted.

  As shown in FIG. 2, the radio base station 12 includes a BPF (BAND PASS FILTER) 101, a switch 102, an amplifier 103, a BPF 104, a receiving circuit 105, a detection unit 106, a level determination unit 107, A falling detection unit 108, a timer 109, a rising detection unit 110, a latch 111, a CPU 112, a transmission circuit 113, a BPF 114, a power amplifier 115, and a network I / F 116 are provided.

  The BPFs 101, 104, and 114 allow only radio waves in a specific frequency band to pass and cut other unnecessary radio waves.

  The switch 102 supplies the supplied radio wave to the amplifier 103 when the radio wave is supplied from the BPF 101, and supplies the supplied radio wave to the BPF 101 when the radio wave is supplied from the power amplifier 115.

  The amplifier 103 amplifies the radio wave supplied from the switch 102.

  The receiving circuit 105 supplies the radio wave supplied from the BPF 104 to the CPU 112.

  The detection unit 106 measures the radio wave intensity at a predetermined interval from the radio wave from which the unnecessary radio wave is cut by the BPF 104, and supplies the measured radio wave intensity to the level determination unit 107.

  When the level determination unit 107 determines that the supplied radio wave intensity is greater than or equal to a predetermined value, the level determination unit 107 supplies the determination result to the fall detection unit 108 and the rise detection unit 110.

  The falling detection unit 108 detects the end of the frame data included in the radio wave based on the determination result supplied from the level determination unit 107, resets the timer 109 from that point, and then starts the timer 109.

  When the timer 109 is started, the count value is supplied to the latch 111.

  The rising edge detection unit 110 supplies a detection signal to the latch 111 when detecting the head of the frame data.

  The latch 111 holds the count value supplied from the timer 109, and then supplies the count value at that time to the CPU 112 when a detection signal is supplied from the rise detection unit 110.

  Thus, the time from when the trailing edge of the frame data is detected by the falling edge detection unit 108 to when the leading edge of the frame data is detected by the rising edge detection unit 109 is supplied to the CPU 112 as a count value.

  The CPU 112 performs central control, and controls transmission / reception of reference frame data and reception of response frame data. In addition, various calculation processes such as calculation of response time are performed.

  The transmission unit 113 supplies the frame data generated by the CPU 112 to the BPF 114.

  The power amplifier 115 amplifies the signal with unnecessary frequency cut supplied by the BPF 114 and transmits frame data via the switch 102 and the BPF.

  The network I / F 116 is a communication device such as a network card. By connecting the radio base station 12 to the network 30 via the network I / F 116, the radio base station 12 can measure the response time measured by the time measuring unit. Can be transmitted to the position detection device 20, and the temperature data measured by the temperature measuring device 14 can be transmitted to the control device 3.

  As described above, the radio base station 12 includes a BPF (BAND PASS FILTER) 101, a switch 102, an amplifier 103, a BPF 104, a reception circuit 105, a detection unit 106, a level determination unit 107, and a fall detection unit. 108, a timer 109, a rising edge detection unit 110, a latch 111, a CPU 112, a transmission circuit 113, a BPF 114, and a power amplifier 115, thereby realizing the second transmission / reception means described above. Further, the CPU 112 is provided with the above-described time measuring means in terms of its function.

  FIG. 3 is a configuration diagram illustrating the configuration of the position detection device 20 of the device position detection system 1 according to the first embodiment of the present invention.

  As shown in FIG. 3, the CPU 201 and the main memory 203 in the position detection device 20 are connected to each other via a bus 205, and an I / O bus 207 is also connected to the bus 205. .

  A storage unit 215, an input unit 217, a display unit 219, and network I / Fs 221 and 223 are connected to the I / O bus 207 via an input / output controller.

  The storage unit 215 is a magnetic disk drive or the like, and stores a position detection program in addition to a program such as an operating system.

  The input unit 217 is configured by an input device such as a keyboard and a mouse through which an operator inputs various operations. For example, the position information of the temperature measuring device 14 is controlled via the network 30 by the operator's push button operation. 3 is generated, and the request command is transmitted to the CPU 201 via the input / output controller 211, the I / O bus 207, and the memory bus 205.

  The display unit 219 is a CRT (Cathode Ray Tube) display, a liquid crystal display, or the like, and based on the output signal received from the CPU 201 via the memory bus 205, the I / O bus 207, and the input / output controller 211, a temperature measuring device. 14 is a device that displays position information and the like.

  The network I / F 221 is a communication device such as a network card. By connecting the position detection device 20 to the network 30 via the network I / F 121, the network I / F 221 is connected between the temperature measuring device 14 and the radio base stations 11 to 13. The transmission / reception result of transmission / reception of frame data by radio can be received and the position of the temperature measuring device 14 can be calculated based on the reception / transmission result.

  The network I / F 223 is a communication device such as a network card. By connecting the position detection device 20 to the control device 3 via the network I / F 121, the position detection device 20 is connected to the calculated temperature measuring device 14. The position information can be updated to the control device 3.

  Further, the CPU 201 executes various processes according to a program such as a position detection program loaded in the main memory 203. And CPU201 is mounted with distance calculation means 201a and position calculation means 201b on the function by running a position detection program.

  The distance calculation unit 201a calculates a delay time when the radio base stations 11 to 13 receive the reference frame data, and based on the calculated delay time and the response time measured by the radio base stations 11 to 13. The distance to any one of the radio base stations 11 to 13 that received the reference frame data from the temperature measuring device 14 and the radio base stations 11 to 13 that received the reference frame data other than the radio base station The difference from the distance from any one of these to the temperature measuring device 14 is calculated as a difference distance.

  The position calculation unit 201b calculates position information indicating the position of the temperature measuring device 14 based on the difference distance calculated by the distance calculation unit 201a.

<Action>
Next, the operation of the device position detection system 1 that is Embodiment 1 of the present invention will be described.

  FIG. 4 shows frame data between the radio base stations 11 to 13 and the temperature measuring device 14 when the radio base station 11 transmits reference frame data in the device position detection system 1 according to the first embodiment of the present invention. It is the time chart which showed the transmission / reception relationship.

  First, when the wireless base station 11 receives a reference frame data transmission request from the position detection device 20 via the network 30 at time t1, the wireless base station 11 transmits reference frame data R. After completing the transmission of the reference frame data R, the radio base station 11 transmits the time at the end of the reference frame data R, that is, the time information at t5 to the position detection device 20 via the network 30.

  Next, when the temperature measuring device 14 receives the reference frame data R transmitted from the radio base station 11 at time t2, it detects the head of the received reference frame data R, and receives the received reference frame data at time t6. The end of R is detected, and then response frame data M is transmitted.

  At time t3, the radio base station 12 receives the reference frame data R transmitted from the radio base station 11, detects the head of the received reference frame data R, and receives the received reference frame data R at time t7. Detect the end of. Thereafter, at time t12, the radio base station 12 receives the response frame data M transmitted from the temperature measuring device 14, and detects the head of the received response frame data M. At this time, the radio base station 12 measures the response time TB, which is the time from time t7 to time t12, and transmits the measured response time TB to the position detection device 20 via the network 30. Further, the radio base station 12 transmits the time information of t7, which is the time when reception of the reference frame data R is completed, that is, the end time of the reference frame data R, to the position detection device 20 via the network 30.

  At time t4, the radio base station 13 receives the reference frame data R transmitted from the radio base station 11, detects the head of the received reference frame data R, and receives the received reference frame data R at time t8. Detect the end of. Thereafter, at time t11, the radio base station 13 receives the response frame data M transmitted from the temperature measuring device 14, and detects the head of the received response frame data. At this time, the radio base station 12 measures the response time TC that is the time from the time point t8 to the time point t11, and transmits the measured response time TC to the position detection device 20 via the network 30. Further, the radio base station 13 transmits the time information of t8, which is the time when reception of the reference frame data R is completed, that is, the last time of the reference frame data R, to the position detection device 20 via the network 30.

  Then, the position detection device 20 is configured so that the radio base station 12 receives the reference frame data from time t5 when the radio base station 11 finishes transmitting the reference frame data R based on the time information transmitted from the radio base stations 11 to 13. The delay time TAB is calculated from the time t5 when the radio base station 11 finishes transmitting the reference frame data R to the time t8 when the radio base station 13 finishes receiving the reference frame data R. The delay time TAC up to the time is calculated.

  Next, the position detection device 20 that has received the response time TB and the response time TC uses the received TB, TC, calculated TAB, and TAC to determine whether the radio base station 12 and the temperature measuring device 14 A difference time TBCX, which is a difference between a propagation time required for the radio wave to propagate through the distance and a propagation time required for the radio wave to propagate through the distance between the radio base station 13 and the temperature measuring device 14, is calculated. Then, the position detection device 20 multiplies the calculated difference time TBCX by the speed of light to obtain the difference between the distance between the radio base station 12 and the temperature measurement device 14 and the distance between the radio base station 13 and the temperature measurement device 14. A certain difference distance LBCX is calculated.

Specifically, the position detection device 20 includes:
TBCX = TB-TC + TAB-TAC (Formula 1)
The difference time TBCX is calculated by substituting the received TB and TC, and the calculated TAB and TAC, and the difference distance LBCX is calculated by multiplying the calculated difference time TBCX by the speed of light. Here, as shown in FIG. 4, TAB is a delay from time t5 when the radio base station 11 finishes transmitting the reference frame data R to time t7 when the radio base station 12 finishes receiving the reference frame data R. As shown in FIG. 4, the TAC is from time t5 when the radio base station 11 has finished transmitting the reference frame data R to time t8 when the radio base station 13 has finished receiving the reference frame data R. The delay time is shown.

  Here, the derivation of Equation 1 will be described below.

Focusing on the elapsed time from the time point t5 to the time point t12 in the temperature measuring device 14 and the wireless base station 12 shown in FIG.
TAX + TD + TBX = TAB + TB (Formula 2)
Can be derived. Here, TAX indicates a delay time from time t5 when the radio base station 11 has finished transmitting the reference frame data R to time t6 when the temperature measuring device 14 detects the end of the reference frame data R, and TBX is As shown in FIG. 4, the delay time from the time t9 when the temperature measuring device 14 detects the head of the response frame data M to the time t12 when the radio base station 12 detects the head of the response frame data M is shown.

In addition, paying attention to the elapsed time from the time t5 to the time t11 in the temperature measuring device 14 and the wireless base station 13 shown in FIG.
TAX + TD + TCX = TAC + TC (Formula 3)
Can be derived. Here, similarly, TAX indicates a delay time from time t5 when the radio base station 11 detects the end of the reference frame data R to time t6 when the temperature measuring device 14 detects the end of the reference frame data R, As shown in FIG. 4, TCX indicates a delay time from time t9 when the temperature measuring device 14 detects the head of the response frame data M to time t11 when the radio base station 13 detects the head of the response frame data M. ing.

And when subtracting both sides of Equation 3 from Equation 2 above and rearranging,
TBX-TCX = TB-TC + TAB-TAC (Formula 4)
Can be derived.

  Here, (TBX-TCX) on the left side represents the propagation time required for radio waves to propagate through the distance between the radio base station 12 and the temperature measuring device 14 and the distance between the radio base station 13 and the temperature measuring device 14. Since this is the difference from the propagation time required for the radio wave to propagate, that is, TBCX, and Equation 1 can be derived.

  Similarly to the above, when the radio base station 13 transmits the reference frame data, the position detection device 20 causes the distance between the radio base station 11 and the temperature measuring device 14, and the radio base station 12 and the temperature measuring device 14. The difference in distance from is calculated.

  FIG. 5 shows frame data between the radio base stations 11 to 13 and the temperature measuring device 14 when the radio base station 13 transmits frame data in the device position detection system 1 according to the first embodiment of the present invention. It is the time chart which showed the transmission / reception relationship.

  First, when the wireless base station 13 receives a reference frame data transmission request from the position detection device 20 via the network 30 at time t21, the wireless base station 13 transmits reference frame data R. After completing the transmission of the reference frame data R, the radio base station 13 transmits the time point at the end of the reference frame data R, that is, time information at t25 to the position detection device 20 via the network 30.

  At time t22, the temperature measuring device 14 receives the reference frame data R transmitted by the radio base station 13, detects the head of the received reference frame data R, and receives the received reference frame data R at time t26. After that, the response frame data M is transmitted at time t29.

  At time t23, the radio base station 12 receives the reference frame data R transmitted by the radio base station 13, detects the head of the received reference frame data R, and receives the received reference frame data R at time t27. Detect the end of. Thereafter, at time t31, the radio base station 12 receives the response frame data M transmitted from the temperature measuring device 14, and detects the head of the received response frame data M. At this time, the radio base station 12 measures the response time TB, which is the time from the time t27 to the time t31, and transmits the measured response time TB to the position detection device 20 via the network 30. Further, the radio base station 12 transmits the time information of t27, which is the time when reception of the reference frame data R, that is, the end time of the reference frame data R, is transmitted to the position detection device 20 via the network 30.

  At time t24, the radio base station 11 receives the reference frame data R transmitted from the radio base station 13, detects the head of the received reference frame data R, and receives the received reference frame data R at time t28. Detect the end of. Thereafter, at time t32, the response frame data M transmitted from the temperature measuring device 14 is received, and the head of the received response frame data M is detected. At this time, the radio base station 12 measures the response time TA, which is the time from the time t28 to the time t32, and transmits the measured response time TA to the position detection device 20 via the network 30. Further, the radio base station 11 transmits the time information at time t28 when the reference frame data R is received, that is, at the end of the reference frame data R, to the position detection device 20 via the network 30.

  Then, the position detection device 20 is configured so that the radio base station 12 receives the reference frame data from time t25 when the radio base station 13 finishes transmitting the reference frame data R based on the time information transmitted from the radio base stations 11 to 13. The delay time TCB until the time t27 when R has been received is calculated, and t28 when the radio base station 11 has finished receiving the reference frame data R from the time t25 when the radio base station 11 has finished transmitting the reference frame data R. The delay time TCA until the time is calculated.

  Next, the position detection device 20 that has received the response time TB and the response time TA uses the received TB, TA, calculated TCA, and TCB to determine whether the radio base station 11 and the temperature measuring device 14 A difference time TABX, which is a difference between a propagation time necessary for the radio wave to propagate through the distance and a propagation time necessary for the radio wave to propagate through the distance between the radio base station 12 and the temperature measuring device 14, is calculated. And the position detection apparatus 20 is the difference between the distance between the radio base station 11 and the temperature measurement device 14 and the distance between the radio base station 12 and the temperature measurement device 14 by multiplying the calculated time TABX by the speed of light. The difference distance LABX is calculated.

Specifically, the position detection device 20 includes:
TABX = TB-TA + TCA-TCB (Formula 5)
Is used to calculate the difference time TABX by substituting the received TB and TA with the calculated TCA and TCB, and the difference time LABX is calculated by multiplying the calculated difference time TABX by the speed of light. Here, as shown in FIG. 5, the TCA is a delay from time t25 when the radio base station 13 finishes transmitting the reference frame data R to time t28 when the radio base station 11 finishes receiving the reference frame data R. As shown in FIG. 5, the TCB indicates time from a time t25 when the radio base station 13 finishes transmitting the reference frame data R to a time t27 when the radio base station 12 finishes receiving the reference frame data R. The delay time is shown.

  Here, the derivation of Equation 5 will be described below.

Focusing on the elapsed time from the time t25 to the time t31 in the temperature measuring device 14 and the wireless base station 12 shown in FIG.
TCX + TD + TBX = TCB + TB (Formula 6)
Can be derived. Here, TCX indicates a delay time from time t25 when the radio base station 13 detects the end of the reference frame data R to time t26 when the temperature measuring device 14 detects the end of the reference frame data R, and TBX is As shown in FIG. 4, the delay time from time t29 when the temperature measuring device 14 detects the head of the response frame data M to time t31 when the radio base station 12 detects the head of the response frame data M is shown.

In addition, paying attention to the elapsed time from the time t25 to the time t32 in the temperature measuring device 14 and the wireless base station 11 shown in FIG.
TCX + TD + TAX = TCA + TA (Formula 7)
Can be derived. Here, similarly, TCX indicates a delay time from time t25 when the radio base station 11 finishes transmitting the reference frame data R to time t26 when the temperature measuring device 14 detects the end of the reference frame data R, As shown in FIG. 5, TAX indicates a delay time from time t29 when the temperature measuring device 14 detects the head of the response frame data M to time t32 when the radio base station 11 detects the head of the response frame data M. ing.

Then, by subtracting both sides of Equation 6 from Equation 7 and rearranging,
TAX-TBX = TB-TA + TCA-TCB (Formula 8)
Can be derived.

  Here, (TAX-TBX) on the left side indicates the propagation time required for radio waves to propagate through the distance between the radio base station 11 and the temperature measuring device 14 and the distance between the radio base station 12 and the temperature measuring device 14. Since this is the difference in propagation time necessary for radio waves to propagate, that is, TABX, and Equation 5 can be derived.

  Next, the position calculation unit of the position detection device 20 calculates position information indicating the position of the temperature measuring device 14 based on the difference distance LBCX and the difference distance LABX calculated by the distance calculation unit.

  For example, according to the principle of hyperbolic navigation adopted in the Loran C system, etc., “The trajectory in which the difference in distance from two points (A, B) has a constant value focuses on these two points (A, B). Therefore, the position calculating means of the position detecting device 20 calculates the position of the temperature measuring device 14 using this principle.

  FIG. 6 is a diagram depicting a hyperbola for calculating position information indicating the position of the temperature measuring device 14 by the position calculating means of the position detecting device 20.

  As shown in FIG. 6, the position calculation means of the position detection device 20 determines the distance between the radio base station 12 and the temperature measuring device 14 based on the LCBX and the position information of the radio base stations 12 and 13, and the radio base station. A hyperbola 61 is drawn in which the difference between the distance 13 and the temperature measuring device 14 is constant. Next, similarly, based on LABX and the position information of the radio base stations 11 and 12, the difference between the distance between the radio base station 11 and the temperature measuring device 14 and the distance between the radio base station 12 and the temperature measuring device 14 are the same. A hyperbola 62 is drawn so that becomes constant.

  Then, the coordinates of the intersection of the drawn hyperbola 61 and the hyperbola 61 are generated as position information of the temperature measuring device 14.

  Thus, according to the apparatus position detection system 1 which is Example 1 of this invention, difference distance information, such as LABX and LBCX calculated by the time information measured from the radio base stations 11-13, and the radio base station 11 Based on the position information of ˜13, the position information of the temperature measuring device 14, that is, the coordinate information with a predetermined position on the plane including the radio base stations 11 to 13 as a reference point can be calculated.

  Further, according to the device position detection system 1 that is Embodiment 1 of the present invention, as can be seen from Equations 1 and 5, LABX, LBCX, etc., without using the time (TD) measured by the temperature measuring device 14. Difference distance information can be calculated, and thereby position information of the temperature measuring instrument 14 can be calculated. Therefore, the temperature measuring device 14 does not need to be provided with a highly accurate timepiece, and the manufacturing cost can be reduced as a whole device.

  As described above, according to the device position detection system 1 that is Embodiment 1 of the present invention, both the temperature measuring device 14 that is a wireless transmission station and the wireless base stations 11 to 13 that are wireless reception stations have high accuracy. The position information of the temperature measuring device 14 can be accurately detected without providing the timepiece.

  In addition, in the apparatus position detection system 1 which is Example 1 of this invention, the clock synchronization between the several radio base stations 11-13 is not required at all.

  In the device position detection system 1 according to the first embodiment of the present invention, the position information of the temperature measuring device 14 is calculated using the principle of hyperbolic navigation adopted in the Loran C system or the like. The principle may be used.

  In Embodiment 1 of the present invention, it is applied to an air conditioning system that controls an air conditioner installed indoors, and a temperature measuring device 14 that measures the temperature of the room, and each position on a plane with a predetermined position as a reference point The device position detection system 1 that detects the position of the temperature measuring device 14 on the plane based on the transmission / reception results of wirelessly transmitting / receiving frame data to / from the three wireless base stations 11 to 13 whose relations are known is taken as an example. As described above, the device position detection system of the present invention can also detect the position of the temperature measuring device 14 in space.

  In the second embodiment of the present invention, a wireless base station 15 that is not on the same plane as the three wireless base stations 11 to 13 is further added to the configuration of the device position detection system 1 of the first embodiment of the present invention. Frame data was transmitted and received wirelessly between the temperature measuring device 14 for measuring the temperature and the four wireless base stations 11 to 13 and 15 whose positional relationships in the space with a predetermined position as a reference point are known. The device position detection system 1 that detects the position of the temperature measuring device 14 in the space based on the transmission / reception result will be described.

  Similarly to the device position detection system 1 according to the first embodiment of the present invention, the device position detection system 1 according to the second embodiment of the present invention, when the reference frame data is transmitted from the wireless base station 11, A difference distance LBCX, which is the difference between the distance to the measuring instrument 14 and the distance between the radio base station 13 and the temperature measuring instrument 14, is calculated. When reference frame data is transmitted from the radio base station 13, a difference distance LABX that is a difference between the distance between the radio base station 11 and the temperature measuring device 14 and the distance between the radio base station 12 and the temperature measuring device 14. Is calculated.

  Furthermore, when the reference frame data is transmitted from the radio base station 12, the device position detection system 1 according to the second embodiment of the present invention is similar to the device position detection system 1 according to the first embodiment of the present invention. The difference distance LADX, which is the difference between the distance between the temperature measuring device 14 and the distance between the wireless base station 15 and the temperature measuring device 14, is calculated.

  And the apparatus position detection system 1 of Example 2 of this invention is based on these calculated difference distance LBCX, difference distance LABX, and difference distance LADX, ie, the position of the temperature measuring instrument 14, ie, the temperature measuring instrument 14 Position information indicating spatial coordinates is calculated.

  As a result, the spatial position information of the temperature measuring device 14 can be obtained without providing a high-accuracy clock in both the temperature measuring device 14 that is a wireless transmitting station and the wireless base stations 11 to 13 and 15 that are wireless receiving stations. Can be detected accurately.

  In the first embodiment of the present invention, a transmission / reception result obtained by wirelessly transmitting / receiving frame data between a temperature measuring device that measures an indoor temperature and a plurality of wireless base stations whose positional relationships are known is applied to an air conditioning system. Based on the above description, the device position detection system 1 that detects the position of the wireless transmission station has been described as an example.

  For example, in the third embodiment of the present invention, the device position detection system 1 is applied to an acoustic system including a speaker that outputs sound and an acoustic controller that controls sound output. A device position detection system 1 that is Embodiment 3 of the present invention includes a plurality of wireless base stations that are wireless reception stations whose positional relationship is known, a speaker that includes a wireless transmission station, a sound measuring device that measures sound, The position of the speaker is detected based on a transmission / reception result of wirelessly transmitting / receiving frame data between the speaker and a plurality of wireless base stations. Then, the sound controller controls the sound output so that sound comfortable for the user can be realized based on the sound data measured from the sound measuring device and the position information of the speaker.

  According to the device position detection system 1 according to the third embodiment of the present invention, it is possible to accurately detect the position of the wireless transmission station without providing a highly accurate clock at both the wireless transmission station and the wireless reception station. Therefore, the user can determine the arrangement of the speakers based on the position of the wireless transmission station. Accordingly, it is possible to realize sound that is comfortable for the user with an inexpensive apparatus configuration.

It is the block diagram which showed the structure of the air-conditioning system to which the apparatus position detection system which is Example 1 of this invention was applied. It is the block diagram which showed the structure of the wireless base stations 11-13 of the apparatus position detection system 1 which is Example 1 of this invention. It is the block diagram which showed the structure of the position detection apparatus 20 of the apparatus position detection system 1 which is Example 1 of this invention. In the device position detection system 1 according to the first embodiment of the present invention, the frame data transmission / reception relationship between the radio base stations 11 to 13 and the temperature measuring device 14 when the radio base station 11 transmits reference frame data. It is the time chart shown. In the apparatus position detection system 1 which is Example 1 of this invention, the transmission / reception relationship of the frame data between the wireless base stations 11-13 when the wireless base station 13 transmits frame data and the temperature measuring device 14 is shown. It is a time chart. It is the figure which drew the hyperbola for calculating the positional information which shows the position of the temperature measuring device 14 by the position calculation means of the position detection apparatus 20. FIG. In the conventional position estimation system of a radio station, it is the figure which showed the transmission / reception relationship of the data packet based on the IEEE802.11 specification between the base station which is a data packet transmission side, and the terminal which is a data packet reception side. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Equipment position detection system 2 ... Air conditioning system 3 ... Control apparatus 4 ... Air conditioning equipment 11-13, 15 ... Wireless base station 14 ... Temperature measuring device 20 ... Position detection apparatus 30 ... Network 201 ... CPU
201a ... Distance calculation means 201b ... Position calculation means 203 ... Main memory 215 ... Storage part 217 ... Input part 219 ... Display part

Claims (1)

Based on a wireless transmission station, a plurality of wireless reception stations having at least three known positional relationships, and a wireless transmission / reception result of frame data between the wireless transmission station and the plurality of wireless reception stations And a device position detection system comprising a position detection device for detecting the position of the wireless transmission station,
The radio transmitting station is
First transmission / reception means for receiving reference frame data transmitted from any one of the plurality of wireless reception stations and transmitting response frame data to the plurality of wireless reception stations as a response to the received reference frame data; Have
The plurality of radio receiving stations are:
When there is a request for transmission of the reference frame data from the position detection device, the reference frame data is transmitted to the wireless transmission station other than the wireless transmission station and the own station, and when there is no transmission request, A second transmission / reception means for receiving response frame data transmitted from the radio transmission station as a response to the reference frame data after receiving the reference frame data transmitted from a radio reception station other than the station;
Time measuring means for measuring, as a response time, a time from a time when reception of the reference frame data is completed by the second transmitting / receiving means to a time when reception of the response frame data is started,
The position detection device includes:
When any one of the plurality of radio receiving stations completes transmitting the reference frame data to other radio receiving stations other than the radio transmitting station and the own station, the other radio receiving stations receive the reference frame data. A plurality of times when the reference frame data is received from the radio transmitting station based on the calculated delay time and the response time measured by the time measurement unit And a distance from any one of the plurality of radio base stations other than the radio receiving station that has received the reference frame data to the radio transmitting station. A distance calculation means for calculating a difference as a difference distance;
A device position detection system comprising: position calculation means for calculating position information indicating the position of the wireless transmission station based on the difference distance calculated by the distance calculation means.

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