JP3352359B2 - Line quality measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line quality measuring device in a radio remote control system, and more particularly to a line quality measuring device for receiving a transmission frame incorporating operation information wirelessly output from an operation terminal. And a line quality measuring device.

[0002]

2. Description of the Related Art For example, as shown in FIG. 9, in a large crane installed in a warehouse, a frame 2 movably bridged by rails 1a and 1b laid near a ceiling.
A movable carriage 3 is mounted on the upper part, and a hoisting machine 5 for lifting a hook 4 on which the luggage is locked is mounted on the carriage 3. Such a large crane is operated by an operation terminal 6 carried by a worker on the floor of the warehouse, and is located in the north, south, east, west and north and west.
Moved and steered in the direction.

FIG. 10 is a schematic configuration diagram of a wireless remote control system for remotely controlling this large crane. As shown in FIG. 11, the operation terminal 6 creates a transmission frame 7 incorporating digital operation information of [1] or [0] performed by a worker, for example, by button operation. The transmission frame 7 is about 50 to 60 ms, and the transmission frame 7 is repeatedly incorporated into the transmission signal 8 at intervals of about 10 ms.

As a result, the transmission frame 7 into which the operation information is incorporated is incorporated into the transmission signal 8 at a period of about 60 to 70 ms. The operation terminal 6 modulates the created transmission signal 8 and outputs the modulated transmission signal 8 on a carrier wave.

Therefore, if the operator keeps pressing one or more buttons in the six directions of east, west, north and south and up and down, during the pressed period, the above-mentioned 60 to 70 ms
Each transmission frame 7 which are sequentially output in the cycle T ₀ of the operation information indicating the presence same procedure [1] is written. Conversely, when no button operation is performed, the operation information of [0] indicating no operation is written in each transmission frame 7. That is, for example, when the power of the operation terminal 6 is turned on, the transmission signal 8 is continuously output wirelessly.

[0006] Transmission signal 8 wirelessly output from operation terminal 6
Is received by the wireless receiver 9 mounted on the truck 3 of the large crane, demodulated, and transmitted as a new transmission signal 13 to the control device 10 via a wired line. The control device 10 extracts the operation information of [0] or [1] from the transmission frame 7 included in the transmission signal 13 and, based on the operation information, transmits the operation information of the hoisting machine 5 and the moving mechanism via the drive circuit 11. The operation control of the operated device 12 including the motor is performed.

In such a radio remote control system, the radio receiver 9 receives the transmission signal 8 transmitted from the operation terminal 6 by radio, but the radio receiver 9 does not transmit a response signal to the operation terminal 6 in one direction. A communication system is adopted.

In order to prevent a malfunction of the large crane, the radio receiver 9 determines whether or not the transmission frame 7 received at each cycle T ₀ via the transmission signal 8 has been normally received. An error detection unit for checking the error is incorporated. Specifically, the error detection unit (1) determines that an error has occurred if the next transmission frame 7 cannot be received even after the period T ₀ has elapsed from the time at which one transmission frame 7 was received.

(2) An error of the transmission frame 7 itself is determined using the CRC of the received transmission frame 7. If normal transmission cannot be performed, the transmission frame 13 that has been normally received immediately before is replaced with the transmission frame 7 that has not been normally received, and is incorporated into the transmission signal 13 so that the next control device 1
Send to 0.

By doing so, the control device 1
In addition to preventing the transmission frame 7 from being lost in the transmission signal 13 received by 0, the erroneous transmission frame 7 is prevented from entering. This is the operator's operation terminal 6
, There is a large difference between the operation speed in the transmission period and the transmission period (period T ₀ ) of each transmission frame 7, so that one period T ₀
Or large crane be operated by using the operation information of several periods T ₀ before the normal transmission frame 7 is because it can be determined that it is not a malfunction increases. In this case, the correct operation information is delayed by one cycle T ₀ or several cycles T _0,
Is input to

Only when four to seven normal transmission frames 7 cannot be received continuously, the radio receiver 9
Stops transmission of the transmission signal 13 to the control device 10 and transmits an abnormality occurrence signal to the control device 10.

The reason for performing such control is that the probability of a single transmission error occurring in a wireless communication line is higher than that of a wired connection, but the probability of a continuous transmission error occurring is much higher. This is because, when a single transmission error occurs, an emergency stop of a large crane causes a reduction in work efficiency.

[0013]

However, the above-mentioned wireless remote control system still has the following problems to be solved. That is, as described above, the wireless receiver 9 continuously transmits the normal transmission frames 7 to 4 to 7.
The transmission of the transmission signal 13 to the control device 10 is stopped and the abnormality occurrence signal is transmitted only when the data cannot be received normally.

Therefore, if a bit error occurs in the transmission frame 7 sporadically or the transmission frame 7 cannot be received sporadically, the radio receiver 9 does not output an abnormality occurrence signal. The transmission frame 7 in the communication line with the wireless receiver 9 is not normally received, and detailed statistical information cannot be obtained.

A transmission frame incorporating test data instead of the operation information is transmitted from the operation terminal 6 to the radio receiver 9, and the radio receiver 9 extracts the test data embedded in the received transmission frame. Thus, it is possible to detect a bit error included in the test data and measure a bit error rate (BER) of the operation information (test data) included in the transmission signal 8.

[0016] However, in a wireless communication line, there is a tendency that one transmission frame is largely divided into a case where many bit errors are included and a case where one bit is not included at all. Then, in the wireless remote control system, it is only necessary to identify whether or not the transmission frame is correct. Therefore, the average bit error rate (BER) over all transmitted frames
Measurement does not mean that the line quality of this wireless remote control system has been correctly evaluated.

Further, for example, the operation terminal 6 and the radio receiver 9
In the case where HDLC (high-level data link control procedure) is adopted as the data transmission protocol between, the start flag and the end flag are both [7E] _{H as shown} in FIG. When this [7E] _H is incorporated into the transmission frame 7, for example, if [7E] _H exists in the operation information, this [7E] _H
Is erroneously determined as a start flag and an end flag. For example, when five bits of [1] continue, a bit of [0] is forcibly inserted.

Therefore, the length (transmission time) of the transmission frame 7 is variable, and is 50 ms to 60 m as described above.
s. As a result, the required transmission time of one cycle including the 10 ms interval varies between 60 and 70 ms.

In general, when evaluating the transmission quality of the transmission frame 7, a predetermined number of transmission frames 7 such as 64 included in the transmission signal 8 are defined as one transmission block 14 as shown in FIG. The number of transmission errors or the number of normal transmission frames of the transmission frame 7 included in the block 14 is detected, the number of transmission errors is obtained, and the number is divided by the number of transmission frames constituting one transmission block 14 to calculate an error rate. .

Therefore, it is necessary to detect the start timing of the transmission block 14 and start counting the number of transmission errors, and detect the end timing to end counting the number of transmission errors. However, as described above, the end of the transmission block 14 cannot be detected because the required transmission time of the transmission frame 7 including each interval varies within a range of 60 to 70 ms.

For example, as shown in FIG. 11, in the transmission block 14 in which 64 transmission frames 7 are incorporated, the longest transmission time T _B max is 4.48 s, and the shortest transmission time T _B min is 3,84 s. Becomes Therefore, if the start timing and the end timing are set assuming that the transmission time of one transmission block 14 is a fixed length, there is a concern that an error of a maximum of 11 transmission frames may occur in one transmission block 14. As a result, the measurement accuracy of the error rate of the transmission frame decreases.

The number of transmission frames 7 sequentially received is counted, and the timing at which the counted value reaches the number of transmission frames constituting one transmission block 14 is determined.
However, this method cannot be adopted because the transmission frame 7 itself cannot be received due to a transmission error in some cases.

Even if the transmission system is not HDLC and the transmission frame 7 has a fixed length, there is a time error of a clock circuit for measuring the duration of the transmission block 14, and the like. The end timing cannot be detected correctly.

The present invention has been made in view of such circumstances, and the end of a transmission block is reliably detected by monitoring the frame number and the elapsed time of the frame time incorporated in each transmission frame. To provide a line quality measurement device capable of counting the number of normal frames or error frames included in one transmission block, accurately calculating the error rate of a transmission frame, and measuring more accurate line quality in a wireless remote control system. With the goal.

[0025]

According to the present invention, a transmission block comprising a predetermined number of transmission frames incorporating operation information wirelessly output from an operation terminal is received, and each transmission block included in the received transmission block is received. This is a line quality measurement device in a wireless remote control system that transmits a frame to a control device that controls the operation of the steered device by a wire.

In order to solve the above-mentioned problem, in the line quality measuring apparatus of the present invention, an input section for inputting only normally received transmission frames among sequentially received transmission frames has a maximum required time of transmission frames. equipped with a frame time counter for counting the number of elapsed frames time indicated, a number of good frames counter for counting the number of frame transmission frame input via the input unit
You. Further, the frame number indicating the order in the transmission block read from the transmission frame input via the input unit reaches the number of transmission frames constituting one transmission block.
Time and, when the number of frames elapsed time of the frame time counter arrives earlier among the total of two time points with the time of <br/> us number of transmission frames constituting one transmission block
At this point, a transmission block reception end determining means for determining that the reception of one transmission block has been completed, and a corresponding one based on the number of normal frames counted by the normal frame number counter in response to the reception end determination of the transmission block. Error rate calculating means for calculating an error rate of a transmission frame in the transmission block.

In the line quality measuring apparatus thus configured, only the normally received transmission frames among the sequentially received transmission frames are input to the input unit. Further, the frame numbers of the sequentially input transmission frames are read.

Therefore, the read frame number is 1
When the number of transmission frames constituting the transmission block has been reached, it can be determined that reception of one transmission block has been completed.
Further, even if the transmission frame of the last frame number cannot be received normally, the number of elapsed frame times of the frame time elapsed counter reaches the number of transmission frames constituting one transmission block. It can be determined that the reception of is completed.

Accordingly, the error rate of the transmission frame in the one transmission block can be accurately calculated based on the number of normal frames of the normal frame number counter at the time when the end of the reception of one transmission block is determined first.

Another aspect of the present invention is a line quality measuring apparatus as described above, wherein a normal reception among transmission frames received sequentially is performed.
An input section for inputting only transmitted transmission frames, and a transmission frame
The number of elapsed frame times indicated by the maximum required
Through the counter for counting the number of elapsed frame times and the input unit
Normally counts the number of transmission frames input
Frame number counter and transmission input via input unit
The order in the transmission block read from the frame
Before storing the indicated frame number as the previous frame number
Times received frame number memory). further,
Read from the transmission frame input via the input unit
Transmission frame whose frame number constitutes one transmission block
Number of frames and the number of frames elapsed
A transmission frame whose number of elapsed frame times constitutes one transmission block
When the number of frames is reached, a transmission frame is input via the input unit.
Frame number included in this transmission frame when input
Is the last frame stored in the last received frame number memory.
And the transmission frame via the input unit
Frame included in this transmission frame when is input
Number is the elapsed frame time of the elapsed frame counter
The first of a total of four points in time
At which point, the reception of one transmission block ends.
Transmission block reception end determination means for determining that
The number of normal frames is counted according to
Counter based on the number of normal frames stored in the
Error in calculating error rate of transmission frame in transmission block
Rate calculation means,

In the line quality measuring apparatus thus configured, the frame number of the input transmission frame is stored and held in the previously received frame number memory as the previous frame number. Therefore, if the frame number of the next input transmission frame is smaller than the previously stored frame number, the currently input transmission frame can be determined to be a transmission frame belonging to the next transmission block. Thus, it can be determined that reception of one transmission block has been completed.

Further, even when the frame number of the input transmission frame is smaller than the number of elapsed frame times of the frame time counter, the currently input transmission frame can be determined to be a transmission frame belonging to the next transmission block. At this point, it can be determined that the reception of one transmission block has been completed.

Therefore, the reception end detection of the transmission block in the above invention can be detected more accurately under various conditions, and the error rate of the transmission frame can be calculated more accurately.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a wireless remote control system in which a line quality measuring device according to an embodiment of the present invention is incorporated. The same parts as those of the conventional wireless remote control system shown in FIG. 10 are denoted by the same reference numerals. Therefore, the detailed description of the overlapping part will be omitted.

The operation terminal 6, as shown in FIG.
Alternatively, a transmission frame 7 incorporating the operation information of [0] is created. The time length of the transmission frame 7 transmitted by the HDLC transmission method is about 50 to 60 ms, and the transmission frame 7 is set at intervals of about 10 ms thereafter.
It is repeatedly incorporated into the transmission signal 8. In the transmission frame 7, a start flag 15a and an end flag 15b are set at the beginning and end, and one transmission block 14 is placed next to the start flag 15a.
, A frame number 16 having a 6-bit configuration indicating the order of the frame numbers is set. Thereafter, the operation information 18 and the CRC 19 are set.

Therefore, in this embodiment, 1
Since the transmission block 14 is composed of 64 transmission frames 7, the frame numbers are sequentially set to values of 0 to 63, respectively. Since the length of the transmission frame 7 changes in the range of 60 to 70 ms including the interval,
As described above, the length of the transmission block 14 is 3.84 s.
It changes within a range of up to 4.48s.

One cycle of the transmission frame 7 is about 60 to 7
It is incorporated into the transmission signal 8 at a period T ₀ of ₀ ms. The operation terminal 6 modulates the created transmission signal 8 and outputs the modulated transmission signal 8 on a carrier wave.

In the radio receiving apparatus 9, the transmission signal 8 received by the receiving section 9a is input to the next error detecting section 9b. The error detection unit 9b detects the 6
It is checked whether or not the transmission frame 7 received every period T _{0 of 0 to} 70 ms has been normally received. In particular,
As described above, (1) From the time when one transmission frame 7 is received, the period T
_{If the} next transmission frame 7 cannot be received even after ₀ has elapsed, it is determined that an error has occurred.

(2) The CRC of the received transmission frame 7 is used to determine an error in the transmission frame 7 itself. Then, the judgment result is transmitted to the error continuation counter 9e. The error detector 9b discards the erroneous transmission frame and writes only the transmission frame 7 determined to be correct to the output buffer 9c. Therefore, this output buffer 9
When the next correct transmission frame 7 is not written in c, the correct transmission frame 7 stored in the output buffer 9c is not updated.

The transmitting unit 9d is output in the cycle T ₀ buffer 9
The correct transmission frame 7 stored in c is read and transmitted as a new transmission signal 13 to the next control device 10 by wire. That is, the new transmission signal 13 includes only the correct transmission frame 7 with a period T _0.

The error continuation counter 9e instructs the transmission unit 9d to stop transmitting the transmission signal 13 when the error detection unit 9b continuously outputs, for example, 4 to 7 error detection signals, and outputs the abnormality occurrence signal to the control unit 10c. To send to.

The normal transmission frame 7 output from the error detector 9b is input to the output buffer 9c and also to the line quality measuring device 20 according to the embodiment of the present invention.
The line quality measuring device 20 is composed of a kind of information processing device such as a computer.

A CPU 22 for executing various arithmetic processing, an input unit 23 to which a normal transmission frame 7 from an error detection unit 9b of the radio receiver 9 is input, and a system quality measurement unit RO that stored the program
M24, a clock circuit 25 for counting time, a display 26 for displaying a measurement result of line quality such as an error rate, a main memory 27 including a RAM for storing various variable data, and the like are connected.

The input section 23 outputs the normal transmission frame 7 fetched from the radio receiver 9 to the system bus 21. In the main memory 27, a normally received frame number memory 28 for storing the number A of normal transmission frames received in one transmission block 14, and a transmission error rate for storing an error rate B of transmission frames in one transmission block 14. Memory 2
9, the frame number 16 of the input normal transmission frame 7
Is stored as a previous frame number FNO, a previous frame number memory 30, which stores the number of normal frames SFM indicating the number of input normal transmission frames 7, and the like.

Further, in the main memory 27, a flag memory 32 for storing a calculation preparation completion flag FrC indicating that preparation for calculation for the error rate B has been completed, a frame time elapsed number counter 33, and one transmission frame 7 A one-frame time counter 34 for counting the elapsed time Tim within the frame is formed.

The frame time elapsed number counter 33 indicates the maximum required time in one transmission frame 7 from the reception start time of one transmission block 14 (70 m in the embodiment).
The number CNT of elapsed time in s) is counted. Therefore, even if a normal transmission frame 7 is not input due to an error or the like within one transmission block 14, the number of elapsed times CNT increases sequentially.

Then, the CP of the line quality measuring device 20
When a time interruption signal of 1 ms is input from the clock circuit 25, the U22 executes a time interruption process for every 1 ms shown in FIG. At S1, the elapsed time Tim of the in-frame time counter 34 in the main memory 27 is updated (Tim = Tim + 1).
If the elapsed time Tim after the update has not reached the maximum required time 70 ms of one transmission frame 7 (S2), the current time interruption processing ends. If the elapsed time Tim after the update reaches the maximum required time 70 ms of one transmission frame 7, (S
3), reset the elapsed time Tim to 0 (Tim =
0). Then, since the maximum required time of one transmission frame 7 has elapsed, in S4, the frame time elapsed number counter 33
Update the number of elapsed times CNT (CNT = CNT +
1).

When the updated elapsed time number CNT reaches 64, which is the number of transmission frames included in one transmission block 14, (S5), the reception of one transmission block 14 has been completed. The previous frame number FNO of the previously received frame number memory 30 is set to a specific value [FF] _H indicating that the frame has not been received (FNO = [FF] _H ).

Next, the normal frame number SFM counted by the normal frame number counter 31 is read (S7).
At S8, the data is written to the normal reception frame number memory 28 (A = SFM). Next, the normal frame number SFM of the normal frame number counter 31 is cleared to 0 (S9), and the calculation preparation completion flag FrC of the flag memory 32 is set to 1 (S10). Further, in S11, the elapsed time number CNT of the elapsed frame time counter 33 is initialized to 0 (C
NT = 0).

Each time the CPU 22 receives a normal transmission frame 7 from the radio receiver 9 via the input unit 23, the CPU 22 executes a reception interrupt process shown in FIG. First, the frame number 16 written in the normal transmission frame 7 received this time is extracted as the received frame number RNO (Q1). Next, the previous frame number FNO stored in the previous received frame number memory 30 is read (Q
2). Then, the read previous frame number FNO is not the specific value [FF] _H indicating not received yet (Q3), the current received frame number RNO is larger than the read previous frame number FNO (Q4), and When it is confirmed that the elapsed time number CNT read out from the elapsed time counter 33 is equal to or smaller than the current reception frame number RNO (Q5, Q6), the transmission frame 7 input this time is a normal one located in the middle of the transmission block 14. It is determined that the frame is the transmission frame 7.

In this case, the process proceeds to Q7, where the current received frame number RNO is written to the previous received frame number memory 30 as the previous frame number FNO (FNO = RNO).
Further, in Q8, the normal frame number SFM of the normal frame number counter 31 is updated (SFM = SFM + 1).

If the previous frame number FNO is the specific value [FF] _H indicating that no reception has been made in Q3, it is determined that reception for the new transmission block 14 has been started, and Q7
To update the previous frame number FNO.

In Q9, the previous frame number FN after updating
If O does not reach 63, which is 1 less than 64, which is the number of transmission frames included in one transmission block 14, Q1
At 0, the time elapsed number CNT of the frame time elapsed number counter 33 is set to a value obtained by adding 1 to the previous frame number FNO (CNT = FNO + 1). Then, the elapsed time Tim in the one-frame time counter 34 is reset to 0 (Q10a).

In Q4, the received frame number RNO of the currently input transmission frame 7 is the previous frame number FNO.
In the following case (corresponding to FIG. 8B) and when the received frame number RNO is smaller than the elapsed time number CNT (FIG.
(Corresponding to (c)) means that the transmission frame 7 having the last frame number has not been input due to some abnormality and the transmission frame 7 of the next transmission block 14 has passed after a lapse of time.
Can be determined to have been entered.

In this case, the process proceeds to Q11, where the received frame number RNO is written in the previous received frame number memory 34 (FNO = RNO), and the normal frame number SFM counted in the normal frame number counter 31 is read out in Q12, and the normal operation is performed. Write to the received frame number memory 28 (A = SF
M). Next, the normal frame number SFM of the normal frame number counter 31 is set to 1 (Q13), and the flag memory 32 is set.
The calculation preparation completion flag FrC is set to 1 (Q1
4).

Thereafter, in Q15, the elapsed time count CNT of the frame elapsed time counter 33 is set to the previous frame number F.
Set to a value obtained by adding 1 to NO (CNT = FNO +
1). Then, the process proceeds to Q10a, where the elapsed time Tim in the one-frame time counter 34 is reset to 0 (Q1).
0).

In Q9, when the previous frame number FNO after the update reaches 63, which is 1 minus 64, which is the number of transmission frames included in one transmission block 14, the reception of one transmission block 14 is completed. Can be determined, Q16 of FIG.
Proceed to.

In Q16, received frame number RNO
Is written to the previously received frame number memory 34 (FNO =
RNO), the normal frame number SFM counted by the normal frame number counter 31 is read in Q17 and written in the normal reception frame number memory 28 (A = SFM). Next, the normal frame number SF of the normal frame number counter 31
M is cleared to 0 (Q18), and the calculation preparation completion flag FrC of the flag memory 32 is set to 1 (Q19).

Thereafter, in Q20, the elapsed time number CNT of the elapsed frame number counter 33 is reset to the initial value of [0]. Then, the process proceeds to Q10a, where the elapsed time Tim in the one-frame time counter 34 is reset to zero.

The CPU 22 is configured to execute a main process shown in FIG. 6A. At T1, the state of the calculation preparation completion flag FrC in the flag memory 32 is checked, and the calculation preparation completion flag FrC is checked.
Is set to 1, it is determined that the reception of one transmission block 14 has been completed. Normal received frame number memory 2
8 is read (T2), and the error rate B of the transmission frame is calculated based on the following equation (T2).
3).

B = [(64−A) / 64] × 100 (%) The calculated error rate B is written to the transmission error rate memory 29 (T4). Thereafter, the transmission frame number A in the normal reception frame number memory 28 is cleared (T5), and the flag memory 32
The calculation preparation completion flag FrC is reset to 0 (T6).

Further, the CPU 22 is configured to execute a timer interrupt process shown in FIG. 6B. At U1, the error rate B of the transmission frame stored in the transmission error rate memory 29 is read, and the read error rate B of the transmission frame is displayed on the display 26 (U2).

FIG. 7 shows the operation of the line quality measuring device 20 incorporated in the radio remote control system thus constructed.
This will be described with reference to the time charts of FIGS. 8A, 8B, 8A, 8B, and 8C.

FIG. 7A is a diagram showing the input timing of each transmission frame 7 to the line quality measuring device 20 in one transmission block 14 in which 64 transmission frames 7 are incorporated. Then, all 64 transmission frames 7
Indicates the case where is received normally.

Before inputting the transmission frames 7 each having a frame number of 0 to 63, the previous frame number FNO is [FF] _H , the normal frame number SFM is 0, and the time elapses. The number CNT is also 0.

When the first normal transmission frame 7 is input, the previous frame number FNO becomes [0],
The number of normal frames SFM becomes 1, and the number of elapsed times CNT also becomes 1. Therefore, for example, when the sixth transmission frame 7 having the frame number of 5 is input, the previous frame number FNO becomes [5], and the normal frame number SFM
Becomes 6, and the elapsed time number CNT also becomes 6.

Then, the final 64th transmission frame 7
Is input, the previous frame number FNO becomes [63], the normal frame number SFM becomes 64, and the elapsed time number CNT also becomes 64.

In this case, the previous frame number FNO is [6
3], it is determined in Q9 of the flowchart of FIG. 4 that the reception of one transmission block 14 has been completed. Then, the normal frame number SFM and the elapsed time number CNT are reset to 0. Further, the previous frame number FNO is initialized to a state of not receiving [FF] _H.

FIG. 7B shows a case where all transmission frames 7 in one transmission block 14 are not normally received due to some abnormality. In this case, even after first transmission block 14 the maximum transmission time T _B max of (= 4.48s), although the previous frame number FNO remains [FF] _H, since time count CNT becomes 64 At S5 in the flowchart of FIG. 3, it is determined that the reception of one transmission block 14 has been completed. Then, the normal frame number SFM and the elapsed time number CNT are reset to 0. Further, the previous frame number FNO is initialized to a state of not receiving [FF] _H.

FIG. 8A shows a case where only two transmission frames 7 of the fourth and 60th frame numbers 3 and 59 are normally received in one transmission block 14 due to some abnormality. Is shown.

In this case, when the fourth transmission frame 7 is input, the previous frame number FNO becomes [3], the normal frame number SFM becomes 1, and the elapsed time number CNT becomes 4
Becomes When the 60th transmission frame 7 is input, the previous frame number FNO becomes [59], and the normal frame number SFM becomes 2. The number of elapsed times CNT is 60.

In this case, the 60th transmission frame 7
When the maximum required transmission time for four transmission frames (70 ms × 4 = 0,28 ms) elapses from the time when the input of the data has been completed, the elapsed time C of the frame elapsed time counter 33
Since NT reaches 64, it is determined at this point that reception of one transmission block 14 has been completed. Then, the number of normal frames SFM and the number of elapsed reception times CNT are reset to zero.
Further, the previous frame number FNO is initialized to a state of not receiving [FF] _H.

FIG. 8B shows that only one transmission frame 7 of the fourth frame number 3 is input in one transmission block 14 due to some abnormality, and then the third frame of the next transmission block 14 is input. This shows a case where the transmission frame 7 of No. 2 is input.

In this case, when the fourth transmission frame 7 of the first transmission block 14 is input, the previous frame number FNO becomes [3], the normal frame number SFM becomes 1, and the elapsed time number CNT becomes 4. . Also, when the third transmission frame 7 of the next transmission block 14 is input, the previous frame number FNO becomes [2], and the normal frame number SFM remains 1 without any change. In this case, the received frame number RNO read from the third transmission frame 7 of the next transmission block 14 is 2.

Since the received frame number RNO of [2] is smaller than the previous frame number FNO before the update of [3], at this point, the reception of the first transmission block 14 is terminated at Q4 in the flowchart of FIG. Is determined.

Then, the number of normal frames SFM is set to 1 and the number of elapsed times CNT is set to 3 to indicate that a measurement operation is being performed on the next transmission block 14. further,
The previous frame number FNO is set to [2].

FIG. 8C shows that only one transmission frame 7 of the fourth frame number 3 is input to one transmission block 14 due to some abnormality, and then the sixth frame of the next transmission block 14 is input. This shows a case where the transmission frame 17 of No. 5 is input.

In this case, when the fourth transmission frame 7 of the first transmission block 14 is input, the previous frame number FNO becomes [3], the normal frame number SFM becomes 1, and the elapsed time number CNT becomes 4. . Also, when the third transmission frame 7 of the next transmission block 14 is input, the previous frame number FNO becomes [2], and the normal frame number SFM remains 1 without any change.

In this case, the reception frame number RNO read from the sixth transmission frame 7 of the next transmission block 14
Becomes 5. The received frame number RNO of [5] is
Naturally, since the number of elapsed times CNT is much smaller, at this point, the first transmission block 14 in Q6 of the flowchart of FIG.
Is determined to be terminated.

Then, the number of normal frames SFM is set to 1 and the number of elapsed times CNT is set to 6 to indicate that a measurement operation is being performed on the next transmission block 14. further,
The previous frame number FNO is set to 5.

As described above, even if the transmission time of the transmission frame 7 fluctuates within a predetermined range, for example, 60 to 70 ms, and the required transmission time T _B fluctuates greatly in one transmission block 14, this transmission is further performed. Even if one or a plurality of transmission frames 7 that cannot be normally received are missing in the block 14, the end timing of the reception of the transmission block 14 can be correctly detected. Therefore,
The error rate B of the transmission frame 7 can be accurately measured.

[0082]

As described above, the line quality measuring device of the present invention monitors the frame number and the elapsed time of the frame reception time incorporated in each transmission frame. Therefore, the end of the transmission block can be reliably detected, the number of normal frames or the number of error frames included in one transmission block can be counted, the error rate of the transmission frame can be calculated accurately, and a more correct line quality in the wireless remote control system can be obtained. Can be measured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a line quality measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a format of a transmission signal in a wireless remote operation system in which the line quality measuring device is incorporated.

FIG. 3 is a flowchart showing the operation of the line quality measuring apparatus.

FIG. 4 is a flowchart showing the operation of the same line quality measuring apparatus.

FIG. 5 is a flowchart showing the operation of the same line quality measuring apparatus.

FIG. 6 is a flowchart showing the operation of the same line quality measuring apparatus.

FIG. 7 is a time chart showing the operation of the same line quality measuring device.

FIG. 8 is a time chart showing the operation of the same line quality measuring apparatus.

FIG. 9 is a schematic diagram showing a general large crane.

FIG. 10 is a block diagram showing a schematic configuration of a wireless remote control system for operating the large crane;

FIG. 11 is a diagram showing a format of a transmission signal in the wireless remote operation system.

[Explanation of symbols]

 Reference Signs List 6 operation terminal 7 transmission frame 9 radio receiver 10 operation unit 11 drive circuit 12 operated device 16 frame number 20 line quality measuring device 22 CPU 25 clock circuit 30 previously received frame number memory 31: Normal frame number counter 32: Frac memory 33: Elapsed frame time counter 34: Time counter in one frame

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 1/00 H04B 17/00

Claims (2)

(57) [Claims] 1. A transmission block (14) comprising a predetermined number of transmission frames (7) into which operation information wirelessly output from an operation terminal (6) is incorporated, and each of the transmission blocks included in the received transmission block is received. A line quality measuring device (20) in a wireless remote control system for transmitting a transmission frame to a control device (11) that controls the operation of a steered device (12) by wire, wherein a normal reception among the sequentially received transmission frames is performed. An input unit (23) for inputting only the transmitted transmission frame, and a frame time elapsed counter (33) for counting the number of elapsed frame times indicated by the maximum required time of the transmission frame
A normal frame number counter (31) for counting the number of frames of the transmission frame input through the input unit, and an order in the transmission block read from the transmission frame input through the input unit. frame number is reach the number of transmission frames constituting one transmission block shown
Time and, when the frame time elapse number of the frame time counter arrives earlier among the total of two time points with the time of <br/> us number of transmission frames constituting one transmission block
At this point, a transmission block reception end determination unit that determines that reception of one transmission block has been completed, and, based on the number of normal frames counted by the normal frame number counter, according to the reception end determination of the transmission block, A line quality measurement device comprising: an error rate calculation unit that calculates an error rate of a transmission frame in one transmission block. 2. A transmission block (14) comprising a predetermined number of transmission frames (7) into which operation information wirelessly output from an operation terminal (6) is incorporated, and each of the transmission blocks included in the received transmission block is received. A line quality measuring device (20) in a wireless remote control system for transmitting a transmission frame to a control device (11) that controls the operation of a steered device (12) by wire, wherein a normal reception among the sequentially received transmission frames is performed. An input unit (23) for inputting only the transmitted transmission frame, and a frame time elapsed counter (33) for counting the number of elapsed frame times indicated by the maximum required time of the transmission frame.
A normal frame number counter (31) for counting the number of frames of the transmission frame input through the input unit, and an order in the transmission block read from the transmission frame input through the input unit. a previous reception frame number memory (30) for storing a frame number as the previous frame number indicating the frame number read from the transmission frame input through the input to reach the number of transmission frames constituting one transmission block and the time point, frame frame time number of the frame time counter is included in the transmission frame when the transmission frame is input through the time of reach to the number of transmission frames constituting the first transmission block, the input section and when the number becomes equal to or less than the previous reception frame number memory stored previous frame number, the input section If the times transmission frame comprising the small fence frame number included in the transmission frame than the frame time number of the frame time counter when entered by
A transmission block reception end determining means for determining that the reception of one transmission block has been completed at the first time among the total of four time points; and the normal frame number counter according to the reception completion determination of the transmission block. And an error rate calculating means for calculating an error rate of the transmission frame in the one transmission block based on the number of normal frames stored in the line quality measuring apparatus.