KR100446670B1 - Remote monitoring apparatus of GPS receiver and controlling method there of - Google Patents

Abstract

The present invention relates to an effective configuration technology of a remote monitoring device of a GPS receiver (GPS) used for visual synchronization in a CDMA base station for mobile communication. The present invention relates to a method for transmitting a program to a centralized management center and updating a program remotely. The method includes a GPS receiver, a GPS receiver remote monitoring device, a base station communication device, and a remote host computer to minimize the influence of the environment. Increase the accuracy and reliability of the remote monitoring device by reducing the CPU load through the application and asynchronous adaptive digital frequency measurement method, and predict the failure based on the remote monitoring device's program update and inquiry function and accumulated measurement data. It has a very good effect with notification function.

Description

Remote monitoring apparatus of GPS receiver and controlling method there of}

The present invention relates to a GPS receiver remote monitoring apparatus and a control method thereof, and more particularly, to accurately determine an internal operation state and an output signal of a GPS receiver, and to remotely monitor a GPS receiver for predicting a current operation situation and a possibility of a problem. An apparatus and a control method thereof are provided.

In the technical field of the present invention, the accurate time synchronization between the base stations and the accurate timing signal generation based on the GPS receiver in the CDMA mobile communication plays a decisive role in the call quality as well as the system operation. Stable operation is very important.

In the conventional technology, the CDMA base station is equipped with self-diagnostic equipment for monitoring the environment and the whole system, but the detailed operation status and output signal of the GPS receiver are omitted.

The problems of the prior art include the inconvenience of smoothly operating and maintaining the existing base station, and the difficulty of flexibly adapting to the model variation of the receiver and the application of the new model.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to reduce the burden on the CPU through the application of a precise analog signal measuring method for minimizing the influence of the environment and the asynchronous adaptive digital frequency measuring method. The purpose is to increase the accuracy and reliability of the remote monitoring system and to have the function of remote program update and inquiry function and the failure prediction notification function based on the accumulated measurement data.

In order to achieve the object of the present invention, the present invention provides a GPS receiver remote monitoring device comprising a digital input unit, an analog input unit, a serial communication RS232C unit, a central processing unit, and a serial communication HDLC; A GPS receiver; It is composed of a base station communication device and the central processing unit is a CDMA base station consisting of the CPU, flash ROM, RAM, input and output unit, AD converter, communication control unit and the GPS receiver remote monitoring device that transmits and receives signals to and from the remote host computer. Minimize errors due to environmental effects by applying circuits and program algorithms to prevent fluctuations. In digital pulse signal measurement, the division ratio is adjusted by software as needed, so that there is no need to change hardware even when the frequency to be measured changes. It is possible to measure and the counting unit operates independently and maintains the counting value after completion of counting, so it does not burden the execution of the program, so it is simple and accurate measurement and accumulates the diagnosis results based on the trend and various alarms and abnormal conditions. Anticipate and inform the likelihood of This is achieved by automatically detecting the model of the S receiver, reducing operational errors, and providing a GPS receiver remote monitor that remotely updates the program of the GPS monitor when the GPS receiver itself changes.

1 is a schematic diagram of the entire system of a GPS receiver remote monitoring apparatus according to a preferred embodiment of the present invention;

2 is an exemplary diagram representing an analog signal measuring unit and a temperature compensation part of a remote monitoring apparatus according to a preferred embodiment of the present invention;

3 is an additional compensation flowchart of the diode non-linear region and the temperature variation of the temperature compensation portion of FIG. 2 of the preferred embodiment of the present invention;

4 is an exemplary diagram of a digital frequency measuring unit of the digital input unit of the preferred embodiment of the present invention;

5 is a remote update flowchart of a program of a preferred embodiment of the present invention;

6a is a failure prediction graph of a preferred embodiment of the present invention,

6B is a flowchart of a malfunction rate notification algorithm of a preferred embodiment of the present invention.

Description of the main parts of the drawing

1 GPS receiver 2 digital frequency input unit

3: analog frequency input part 4: serial communication RS232C

5: central processing unit 6: serial communication HDLC

7: base station communication device 8: remote host computer

9: CDMA base station 10: GPS receiver remote monitoring device

Hereinafter, the configuration of the present invention will be described in detail with the working effect with reference to the accompanying drawings for a preferred embodiment.

Fig. 1 is a schematic diagram of a GPS receiver remote monitoring system of a preferred embodiment, which is composed of a CDMA base station 9 and a remote host computer 8, which includes a GPS receiver 1; GPS receiver remote monitoring device (10) constructed of digital frequency input unit (2), analog frequency input unit (3), serial communication RS232C unit (4), central processing unit (5), and serial communication HDLC unit (6) Wow; The central processing unit 5 of the GPS receiver remote monitoring apparatus is composed of a CPU, a flash RAM, a RAM, an input / output unit, an A / D converter, and a communication control unit.

The GPS receiver remote monitoring apparatus 10 directly measures the output signal of the GPS receiver 1 through the digital frequency input unit 2 and the analog frequency input unit 3, and performs the GPS receiver (through the serial communication RS232C unit 4). It reads various internal condition of 1) precisely.

The central processing unit (5) collects and analyzes data to constantly monitor the status of the GPS receiver (1) and, upon request from the remote host computer (8), transmits the base station communication device (7) through the serial communication HDLC (6). Transfer the data to the remote site via a new one, download a new program from the remote host computer 8 as needed, and the internal state of the GPS receiver 1 is based on the collected data even if there is no request from the remote host computer 8 If exceeded, immediately send detailed data with advance warning to the remote host computer (8).

In addition, the central processing unit 5 has a built-in execution program in the internal flash ROM, so that the existing program is not only maintained even when the power is cut off, but also the data can be downloaded from the remote host computer 8 to start a new program.

2 is an analog signal measuring circuit of the remote monitoring apparatus according to the preferred embodiment of the present invention. A 10 MHz precision AC analog signal 11 having a strength of about 13 dBm is connected to a diode 14 D1-1 through a termination resistor 12 and a capacitor 13; It rectifies by D1-2 and the capacitor | condenser 15, and changes into an analog DC value.

The analog DC value is converted into a digital value by the analog-to-digital converter 24 via the operational amplifier 17 and finally stored in the central processing unit 5.

In addition, a large number of diodes are used in measuring the power intensity of a conventional high frequency small signal. The biggest problem is that, in the case of a small signal, the forward voltage drop of the diode is a major obstacle to the precision measurement. Since it varies greatly with temperature, the biggest obstacle in the measurement of a small signal high frequency range is the ambient temperature fluctuation problem.

In order to solve this problem, the present invention implements temperature compensation through a temperature offset circuit and a temperature sensor in hardware in order to overcome the internal resistance change in the forward voltage drop and temperature, which are the two obstacles of high frequency small signal measurement using a diode. In terms of software, an exponential function table for each temperature is prepared to simultaneously operate the temperature fluctuations in the nonlinear region due to the forward voltage drop of the diode.

The temperature cancellation circuit is implemented by adopting the same varieties of the rectifying diode 14 and the operational amplifier 17 and the reference potential diode 22 in FIG. As a result, when one input value of the operational amplifier 17 is increased, the other input value is also increased by the same ratio so as to cancel each other.

In addition, a temperature sensor is fitted for additional temperature compensation in software.

In terms of software, the nonlinear region compensation and temperature change additional compensation method according to the forward voltage drop of the diode is generally expressed as an exponential function, but the function varies with temperature, and the multitasking and fast response At the same time, the load on the computational part is great for real time processing in a required monitoring device or the like. On the other hand, the circuit shown in Fig. 2 is composed of a rectifying circuit, a temperature canceling circuit, an operational amplifier circuit, a temperature compensation circuit and a counting circuit. Is a circuit for converting an AC signal into a DC signal by smoothing it with a capacitor through a diode, and constitutes a rectifier circuit as diodes D1-1, D1-2 (14), and condense C2 (15). In order to offset the fluctuations of the operation according to the temperature of the part, a signal in which the temperature change characteristic is reversed is generated and canceled with each other. That is, the output of diodes D1-1 (14) and D1-2 is applied to one input terminal of the voltage comparison IC 17, and the output of another diode D1-3 and D1-4 (22) is applied to the other input terminal. The operational amplifier circuit compensates for variations in the operation of electronic components due to temperature changes. The operational amplifier circuit is an integral operational amplifier circuit including a voltage comparison IC 17, a peripheral resistor R6, and a capacitor C3. The voltage comparison IC 17 basically has two input stages and amplifies the difference between the input voltages and outputs them to the output stage. An integrated circuit is formed by adding a resistor and a capacitor to the voltage comparison IC as shown in FIG. do. The integral operational amplifier circuit suppresses noise in the signal by acting as a low pass filter for the input signal. The temperature compensation circuit compensates for the variation of the nonlinear region operating function according to the temperature of the diodes 14 and 22. In order to compensate for the variation of the operating function of the diode according to the temperature variation, a temperature detector 18 is attached to detect the current temperature and selectively refer to the variable table which compensates the operating function variation value in advance for each warm zone accordingly. In other words. The detection value 25 is not used as it is, but is converted into a corrected data value by referring to the corresponding variable table according to the temperature detection value 20 so as to output an accurate value excluding the temperature influence.

FIG. 3 is a straight line-by-section approximation by dividing the exponential function portion of the temperature compensation portion in FIG. 2 of the preferred embodiment of the diode nonlinear region and the additional compensation flow curve of the temperature variation into several nodes, and each node based on the temperature value. Multiple tables were created to reduce the load on the burst while minimizing errors due to temperature and nonlinear areas.

That is, a change occurs in the compensation function table changing step (S100), so that the function table download step (S101), the signal strength value input step (S102), the temperature input step (S103), and the nonlinear compensation function for each temperature are selected. Step S104 and the application of the nonlinear compensation function S105.

4 is a circuit configuration diagram of a digital frequency measuring unit of the digital input unit according to the preferred embodiment of the present invention. The digital matching unit 31, the frequency division unit 32, the frequency counting unit 33, the monostable oscillation unit 34 and It consists of a central processing unit 35 and counts using the following relationship.

Frequency = number of pulses per unit time

The digital matching unit 31 converts the input digital differential signal into a general digital signal through the digital matching unit 31.

The frequency divider 32 divides the input high frequency signal by 1 / N to produce a low frequency. The frequency divider 32 generates and controls a reference time signal so that the frequency counter counts only for a predetermined time.

First, when the central processing unit 35 inputs the division ratio value to the frequency divider and issues a counting start signal, the monostable oscillator 34 makes a reference time, and the frequency counting unit 33 starts counting the divided pulses. .

In the meantime, the central processing unit 35 may perform other tasks until the count completion signal is generated.

When the coefficient completion signal is generated, the central processing unit 35 reads the coefficient value from the frequency coefficient unit and calculates the frequency as follows.

Frequency = Division Ratio × Coefficient

A feature of the present invention is that there is almost no load on the central processing unit 35 in the first frequency coefficient, and the second frequency can be actively coped with by adjusting the division ratio even if the input frequency value 30 is changed.

Minimize errors due to environmental effects by applying circuits and program algorithms to prevent fluctuations in measured values due to temperature.

In the measurement of digital pulse signal, the division ratio can be adjusted by software, if necessary, so that the measurement can be performed without changing hardware even when the frequency to be measured changes, and the counting unit operates independently and maintains the count value after completion of counting. Therefore, a simple and accurate measurement is made without burdening the execution of the program. FIG. 4 illustrates the entire counting circuit. The counting circuit indicates a circuit that counts the number of occurrences per unit time of an electronic pulse. The number of pulses per unit time is counted in the frequency coefficient unit 33, and the monostable oscillator 34 generates a control signal informing the prescribed unit time. Allow the unit 33 to accurately measure the number of electronic pulses per unit time Matching unit 31 and the function to change the analog signal to a digital frequency divider 32 is to drop the high frequency signal to the low-frequency signal to be counted with the number of units per hour pulse at best.

5 is a program remote update flow diagram of a preferred embodiment of the present invention by moving the program execution from flash ROM to RAM to update the program execution program and consists of the following steps.

Update command selection step (S200), if changed, variable value storage relationship (S201), new program download step (S202), normal completion step (S203), status notification step (S204), flash ROM data erase A step S205, a data write step in the flash ROM (S206), a program restart step in the flash ROM (S207), a program copy step into the RAM (S208), a move to the RAM area (S209), variable values Return and reset step (S213), the status notification step (S214), the daily work progress step (S215), if not in the normal completion step (S203) of the continuous status notification step (S210) and the command waiting step S211 and a retry step S212.

6 is a failure prediction graph of a preferred embodiment of the present invention, if the operation time of the device is longer, the malfunction rate of the equipment is increased due to the internal factors caused by the deterioration of parts and the external factors such as accumulation and vibration of dust, and finally inoperable Leads to a fault condition.

In addition, the malfunction of the equipment is a sudden malfunction due to rapid internal and external factors and the natural and gradual rise of the malfunction rate with the passage of time, and the rise of the malfunction rate can be predicted to some extent by accurately diagnosing the situation inside the equipment.

The present invention has a failure prediction function by predicting the possibility of malfunction of the GPS receiver monitoring apparatus through a statistical method through accurate diagnosis and accumulation of data exceeding a set reference value, and has a failure prediction function. Is as follows.

Formula 1

Malfunction probability = K × ∑ (number of exceeded events per unit time × elapsed time share)

Where K = proportionality constant

That is, the malfunction probability decreases the specific gravity as the elapsed time is longer by applying the elapsed time as a Gaussian distribution function.

Formula 2

Elapsed time share = 1 / × exp

X: elapsed time, σ: standard deviation

Therefore, it is a graph like FIG. 6 which shows the relationship between elapsed time and elapsed time specific gravity.

FIG. 7 is a flowchart illustrating a malfunction rate notification procedure according to a preferred embodiment of the present invention, in which a reference range is set in advance to ensure stable operation for each of the output signal measurement values from the GPS receiver and internal events of the GPS receiver obtained through communication, and events are set at predetermined periods. Accumulate by checking if it is outside the range of stability criteria.

In addition, the accumulated events calculate the probability of a malfunction in the future according to Formula 1 shown in FIG. 6 and notify the boundary condition when the expected probability of the malfunction exceeds a threshold so that the event can be prepared in advance.

6 is an event measurement occurring exponentially, and FIG. 7 shows a malfunction rate notification algorithm process, wherein the setting criteria change step (S300), the setting criteria download step (S301), the event collection step (S302), Event diagnosis step (S303), setting reference exceeding determination step (S304), event recording step (S305), overall completion determination step (S306), malfunction rate prediction value calculation step (S307), threshold value determination step (S308), the alert state notification step (S309), and the overall completion step (S310).

As described above, the GPS receiver remote monitoring apparatus and its control method of the present invention can more accurately determine the operation status of the GPS receiver by the detailed internal diagnosis of the GPS receiver and measurement of the output signal with minimal environmental influence. It is effective, and it can be applied to other general measuring equipment by using it, and it has the effect of automatically predicting the possibility of problem occurrence, so that it can respond in advance before the actual problem occurs. Flexibility is applied to general equipment, and it can be applied to general equipment and can update remotely GPS monitoring device when changing GPS receiver specification by remote program update function. It is a very useful invention.

Claims (4)

In the remote monitoring device of the GPS receiver for measuring the small power strength of the analog signal, Generated by a rectifier circuit that converts an AC signal into a DC signal, a temperature canceling circuit that generates a signal whose temperature change characteristics are reversed in order to compensate for variations in operation due to temperature changes, and an operational amplifier circuit that suppresses signal noise A temperature canceling circuit comprising means for controlling the temperature and the diode and the capacitor to minimize the influence of the diode nonlinear region; The remote monitoring apparatus further includes a temperature compensation circuit for converting the operating function variation value for each temperature band into a corrected data value corresponding to a variable table that has been compensated in advance according to the temperature detected value detected by the temperature detector detecting the current temperature. GPS receiver remote monitoring device. delete How to update a program remotely An update command selection step (S200); Variable value storage relationship (S201) if changed; Downloading a new program (S202); Normal completion step (ST203); Status notification step (S204); Flash ROM data erasing step (S205); Writing data into the flash ROM (S206); Restarting the program in the flash ROM (S207); Program copying to the RAM (S208); Moving to the RAM area (S209); A variable value return and reset step (S213); Status notification step (S214); Routine work progress step (S215); If not in the normal completion step (S203) of continuing status notification step (S204) and; Command waiting step S211; GPS receiver control method comprising the step of retrying (S212) to update the program of the GPS receiver remote monitoring device from a remote location. Remotely detect and send malfunctions Changing the setting criteria (S300); Downloading the setting criteria (S301); Collecting and diagnosing an event (S302, S303); Setting criterion exceeding determination step (S304); Recording an event (S305); Determining the total completion (S306); Calculating a malfunction rate prediction value (S307); A threshold exceeded determination step (S308); Notifying the alert state (S309); GPS receiver remote monitoring device and its control method comprising the step of totally completed (S310) to apply a statistical prediction priority for the failure and to automatically notify the possibility of failure.