JPH0441952B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention measures the distance, speed, etc. of a ship that is about to approach the berth using ultrasonic waves, and notifies the ship.
The present invention relates to a berthing guidance assistance system that provides guidance assistance for berthing at an appropriate speed.

[Prior Art] In this type of berthing guidance support system, the berthing speed of a ship is generally measured by detecting the distance at a predetermined sampling period using an ultrasonic range finder and measuring the change in this distance over time. ing.

The ultrasonic range finder emits ultrasonic pulses from a quay toward a ship, receives reflected waves that are reflected by the ship's hull, and calculates the distance from the round trip time and the speed of sound. In this case, the round trip time is
The transmission of the transmitted wave is used as a trigger to open the gate, the reception of the reflected wave is used as the trigger to close the gate, and while the gate is open, the reference clock pulses output from the clock circuit are counted, and the counted value is based on the gate. It is obtained by calculating the time.

By the way, this type of berthing guidance support system is
At the site where it is installed, for example, the transmitted waves are likely to be reflected in front of the target ship's hull due to the entrainment of bubbles by the tugboat's screw, fish, floating objects, etc. When such a reflection is measured, an abnormal value is obtained, that is, the gate closes in a shorter time than the originally required time, resulting in an abnormal measured value.

Such a situation may occur frequently depending on the situation at the site, and if left untreated, the ship may be guided using incorrect data, which is dangerous. Therefore, it is necessary to detect that the measured value is an abnormal value and remove it from the display data.

Conventionally, abnormal values have been detected by comparing measured values with reference values to determine whether or not they are abnormal. In other words, the previous measurement value is used as the reference value, a certain tolerance range is set based on this reference value, and when the current measurement value is within the range, it is determined to be a "normal value".
When it was outside the range, it was considered an "abnormal value."

[Problems to be Solved by the Invention] However, in the conventional abnormal value detection described above, since the allowable range was set to a constant value, the following problems occurred.

In other words, the data that forms the basis for setting the standard values are:
Because it is based on measured values up to that point, it includes measurement errors. In determining whether or not a measured value is normal, especially when the tolerance range is narrow, a normal value may be determined to be an "abnormal value" due to this error.

On the other hand, if the allowable range is too wide, a value that is originally an abnormal value may be determined to be a "normal value." In this case, incorrect data will be output. This has little effect when the ship is far from the quay, but it has a significant effect when the ship is close to the quay.

Furthermore, if the allowable range is narrow, when the speed of the ship is high, the allowable range is likely to be exceeded, so even a normal value becomes an abnormal value. On the other hand, if the allowable range is widened, even an abnormal value becomes a normal value when the speed is small.

By the way, when a ship approaches a berth, the speed of the ship decreases as the distance goes from long distance to short distance, so it is unreasonable for the above-mentioned situation to occur.

The present invention has been made to solve these problems, and it is possible to maintain a tolerable range between long distances where the ship's speed is high and relatively accuracy is not required, and short distances where the ship's speed is slow but requires precision. We provide a berthing guidance assistance system that has a highly reliable abnormal value removal function by changing the width and narrowness of the berth to reduce the occurrence of abnormal values at distant points, while reducing the error in abnormal value detection at short distances. The purpose is to

[Means for solving the problem] The present invention measures the distance, speed, etc. of a ship that is about to berth using ultrasonic waves, and notifies the ship.
This relates to a berthing guidance assistance system that provides guidance assistance so that the berthing can be done at an appropriate speed. The present invention
For example, as shown in Fig. 1, a transmission wave is formed to a transducer and a received wave is received from the transducer, and the time required for ultrasonic wave reflection is detected and output as measurement data. An ultrasonic measurement system comprising a front end section, a measurement data processing section that calculates the speed of the ship, the distance to the quay, etc. from the measurement data and outputs it as display data, and a display section that displays the display data. Applicable to berthing guidance assistance systems with

That is, the present invention provides the first problem-solving means.
As shown in the figure, the presence or absence of an abnormality in the round trip time of the received ultrasonic waves is detected by comparing it with a value set within a permissible range for the round trip time of the received ultrasound waves up to that point, and if there is an abnormality, it is detected. , an abnormal value detection means for rejecting, and the above tolerance range has at least two levels, a wide tolerance range for long distances and a narrow tolerance range for short distances,
Tolerance range changing means for determining to which stage the measured distance belongs, and changing the tolerance range to a tolerance range corresponding to the stage to which the determination result belongs if the determination result is different from the stage to which the determined distance belongs. It is characterized by being configured with:

The abnormal value detection means compares the measured value with a reference value and checks whether there is an abnormal value by checking whether the measured value has changed significantly. That is, it has a function of subtracting the measured value from the previous value, and a function of determining whether there is an abnormality based on whether the difference falls within the above-mentioned allowable range. The latter function determines that the measured value is "abnormal" if it is outside the above-mentioned allowable range, and outputs an abnormal value status.

As the above reference value, for example, the previous measurement value,
Use the moving average value of the measured values up to the previous time. If the previous measured value is an abnormal value, that data cannot be used, so a previous normal value is used, or a moving average value that includes the normal value is used.

The above-mentioned allowable range is set to vary depending on the current position of the ship, that is, the distance from the quay. For example, the allowable range is set narrow for short distances and wide for long distances. In this case, the allowable range changing means has a function of detecting when the current position of the ship has reached a preset distance from the quay;
At this time, it has a function of changing the width of the allowable range in the abnormal value detection means.

When the settings are made in two stages, one for short distance and one for long distance, for example, the average movement distance in the short distance area and the average movement distance in the long distance area are determined. This can be determined by experiment, past experience, etc.

In addition, the tolerance range is not necessarily set fixedly in the two stages of far and near described above, but by dividing the distance into multiple stages,
A configuration may be adopted in which the allowable range is sequentially set narrower from a long distance to a short distance.

Furthermore, it may be set in proportion to the speed of the ship using measured values of the ship. In other words, the speed data from the previous measurement is used to calculate the distance traveled by the ship, assuming that the ship is moving at the same speed as the speed data from the previous measurement to the current measurement. , the calculated travel distance is subtracted from the previous distance to calculate an estimated distance value, and a tolerance range is set around this value.

If the previous measured value is an abnormal value, that data cannot be used, so a previous normal value is used, or a moving average value that includes the normal value is used.

[Operation] In the problem-solving means of the present invention configured as described above, the abnormal value detection means checks whether or not there is an abnormality in the measured data based on the input received wave, and when there is an abnormality, the abnormal value detection means detects the abnormality. , and outputs an output to that effect, for example, an abnormal value status.
That is, if the measured value is an abnormal value, the measured data processing unit is instructed to reject the measured value.

The presence or absence of this abnormality is determined by determining the difference between the currently measured value and the reference value, and if the difference exceeds a preset tolerance range, the measured value is determined to be an abnormal value. The reference value and tolerance range are set as described above.

Note that when a measured value is rejected as an abnormal value, it can be either not displayed or the maximum distance can be fixedly displayed, but preferably, the value set as the above-mentioned tolerance range is temporarily displayed as an estimated value. .

[Example] An example of the present invention will be described with reference to the drawings.

<Configuration of Embodiment> FIG. 2 shows the configuration of an embodiment of the berthing guidance assistance system having an abnormal value removal function of the present invention.

The abnormal value removal function of the embodiment shown in the figure includes a microcomputer as a main part, and this microcomputer is responsible for forming a transmission wave to a transducer 6 and receiving a reception wave from the transducer 6. A front end section 5 which detects the time required for ultrasonic wave reflection and outputs it as measurement data, and a keyboard 8 which inputs data to the microcomputer.
and a display device 9 that outputs information formed by the microcomputer.

The microcomputer includes a microprocessor 1 that executes various processes such as calculation, comparison, judgment, and control of input data, a ROM 2 that stores operating programs for the microprocessor 1, and a work area for the microprocessor 1. and RAM 3 for storing input data, etc., and the keyboard 8 mentioned above.
and an input/output port 7 for connection with a display device 9, and a bus 4 for connecting these.

This microcomputer functions not only as a measurement data processing section but also as an abnormal value detection means and an allowable range changing means among the elements constituting the above-mentioned problem solving means of the present invention.

As shown in FIG. 3, the front end unit 5 includes a transmitting circuit 51, a receiving circuit 52, a time measuring circuit 53 that measures the time required for ultrasonic round trip from transmitted and received signals, and a timing signal generating circuit 54. .

The transmission circuit 51 transmits pulses in the form of burst pulses at regular time intervals according to the transmission timing from the timing signal generation circuit 54.

In this embodiment, the time measurement circuit 53 includes a time measurement gate GA that opens according to the transmission timing and closes according to the reception signal, and a counter CN that counts clock pulses that are input while the gate GA is open.
It is composed of:

The receiving circuit 52 performs processing such as noise discrimination and waveform shaping, and outputs a pulsed received signal. Note that it is possible to adopt a prediction gate method in which reception is possible only in a time period centered around the time when the arrival of the current number of reflections is predicted, based on the previous reflection time and reception time. According to this method, noise pulses that are incident at times other than the predicted time can be removed.

The timing signal generation circuit 54 generates timing signals required by each part of the front end section 5. For example, it generates signals such as transmission timing and gate opening/closing timing.

<Operation of the Embodiment> Next, the present embodiment configured as described above will be described with reference to the above-mentioned figures and FIG. 4.

In this embodiment, in the front end section 5,
It transmits and receives ultrasonic pulses, measures the round trip time from transmission to reception, and outputs measurement data.

The ultrasonic waves are transmitted from the transmission circuit 51 as burst pulses at regular time intervals.

The reflected wave is received by the receiving circuit 52 after the transmitted wave is transmitted and before the next transmission. That is, the receiving circuit 52 opens the receiving gate and receives the reflected wave after a preset time has elapsed based on the transmission timing from the timing signal generating circuit 54 and before transmitting the next transmitted wave. Wait as possible. If the reflected wave enters the transducer 6 during this time,
The reflected signal is input to the receiving circuit 52. The reflected signal is subjected to processing such as discrimination from noise and waveform shaping in this receiving circuit 52, and is sent to a time measuring circuit 53 as a pulsed received signal.

The time measurement circuit 53 receives a time measurement gate based on the transmission timing from the timing signal generation circuit 54.
The clock pulses sent from the timing signal generation circuit 54 that have passed through the gate GA are counted until the gate GA is opened and the gate GA is closed by the received signal. This count value measures the time required for the ultrasonic waves to travel back and forth. This measurement data is sent to the microprocessor 1 via the bus 4.

Thereafter, processing moves from the front end section 5 to the microprocessor 1. The processing by the microprocessor 1 will be explained with reference to the flowchart shown in FIG.

The microprocessor 1 first takes in measurement data from the time measurement circuit 53 (step 1).

Further, the microprocessor 1 checks whether the previous value (or the moving average value up to the previous time) is closer or farther than a preset distance, and if it is a long distance, it directly uses a wide allowable range. On the other hand, if the distance is short, a narrow tolerance range is read from the ROM 2 and set in the RAM 3 as a new tolerance range (steps 2 and 3). In this embodiment, the set distance is set to 30 m, and the allowable range is set to 1 m for long distances and 0.5 m for short distances.

Next, the microprocessor 1 checks whether this measurement data is an abnormal value (step 4). Whether this is an abnormal value is determined by comparing it with the previous value (or moving average value up to the previous time) stored in the RAM 3 and checking whether the measured value has changed significantly. That is, subtraction is performed between the measured value and the previous value, and whether or not the difference is within the above-mentioned tolerance range is used to detect whether or not there is an abnormality. If the measured value is outside the above-mentioned allowable range, it is determined to be "abnormal" and an abnormal value status is output.

The reason why this kind of situation occurs is, for example, when the ultrasonic waves are reflected by migrating fish or floating objects, and the ultrasonic waves return before the ship, resulting in a measurement value that is shorter than the actual position of the ship. It depends.

If there is no abnormality, microprocessor 1
Based on the captured measurement data, the controller performs normal arithmetic processing, that is, calculates data such as distance and speed (step 7). The distance is calculated from the measured value and the speed of sound, and the speed is calculated from the difference between the previous distance and the current distance, and the elapsed time from the previous measurement to the current measurement.

This elapsed time corresponds to the above-mentioned transmission timing interval. Therefore, the clock pulses outputted between each transmission timing can be counted and measured. However, since this elapsed time is almost fixed, it may be given as a constant without being measured.

In addition, in calculating the data, a moving average value may be calculated not only from the previous value and the current value, but also data from several times before, and this may be used as the current value. Moving averages can remove fluctuations in data to some extent.

The calculated data is stored in the RAM 3 to update the previous value and is sent to the display device 9.

The display device 9 converts the sent data into display numbers and displays them with appropriate units attached (step 8). This completes one measurement cycle.

On the other hand, if the abnormal value status in step 4 is output, the microprocessor 1
sends an instruction to the measurement data processing unit to reject the abnormal value (step 5). Further, in this embodiment, a value set as an allowable range is displayed as an estimated value (step 6).

In addition, in the above embodiment, the allowable range is changed at the boundary between two distances, far and near, but it can be changed at multiple stages, such as three stages of long distance, middle distance, and short distance. It can also be changed. Furthermore, the allowable range changing means can also be omitted.

<Other Embodiments> In the above embodiments, the allowable range changing means is configured to change the allowable range from wide to narrow when the current position of the ship reaches a preset distance from the quay. , the following method different from this can also be used.

That is, the allowable range changing means can be configured to set the allowable range in accordance with the distance from the quay of the ship obtained by previous measurements.
This system is the same as the above embodiment in terms of hardware configuration, but differs in software.

FIG. 5 shows a flowchart representing the procedure for implementing this method.

In this embodiment, the same processing as in the above embodiment is performed up to the front end section.

After that, the microprocessor 1 first takes in measurement data from the time measurement circuit 53 (step
11).

The microprocessor 1 also checks whether this measurement data is an abnormal value (step 12). Whether this is an abnormal value is determined by comparing it with the previous value (or moving average value up to the previous time) stored in the RAM 3 and checking whether the measured value has changed significantly. That is, subtraction is performed between the measured value and the previous value, and whether or not the difference is within the above-mentioned tolerance range is used to detect whether or not there is an abnormality. If the measured value is outside the above-mentioned allowable range, it is determined to be "abnormal" and an abnormal value status is output. This allowable range is calculated based on the data up to the previous time, and is read out and used from what is stored in the RAM 3.

If there is no abnormality, the microprocessor 1
Based on the captured measurement data, normal arithmetic processing, that is, calculation of data such as distance and speed, is performed (step 13). These calculations are the same as in the embodiment described above.

The calculated data is stored in the RAM 3 to update the previous value and is sent to the display device 9.

The display device 9 converts the sent data into display numbers and displays them with appropriate units attached (step 16).

After these processes, the microprocessor 1 performs calculations to change the allowable range (step 17). The calculation result is stored in the RAM 3 and updates the previous value. As a result, the allowable range changes as the ship moves.

This tolerance range change operation is performed using known data stored in RAM3 up to that point, for example,
Read the previous value and calculate based on this data. For example, speed data is used as the known data. The estimation assumes that this speed is constant,
This is executed by multiplying the elapsed time from the previous measurement to the current measurement to calculate the distance estimate.

On the other hand, if the abnormal value status in step 12 is output, the microprocessor 1
sends an instruction to the measurement data processing unit to reject the abnormal value (step 14). Further, in this embodiment, a value set as an allowable range is displayed as an estimated value (step 15).

One cycle of measurement is completed by executing the above series of steps.

[Effects of the Invention] As explained above, the present invention changes the width of the allowable range between long distances where the ship speed is high and requires relatively little precision, and short distances where the ship speed is slow but requires precision. As a result, abnormal values are less likely to occur at distant points, while errors in abnormal value detection can be reduced at short distances, resulting in the realization of a highly reliable berthing guidance assistance system.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of the present invention, Figure 2 is a block diagram showing the configuration of the present invention.
The figure is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of the front end section of the above embodiment, FIG. 4 is a flowchart for explaining the operation of the above embodiment, and FIG. 5 is for explaining the operation of another embodiment of the present invention. This is a flowchart for 1...Microprocessor, 2...ROM, 3
...RAM, 4...Bus, 5...Front end section, 6...Transducer/receiver, 7...I/O port, 8...
... Keyboard, 9 ... Display device, 51 ... Transmission circuit, 52 ... Receiving circuit, 53 ... Time measurement circuit,
54...Timing signal generation circuit.

Claims (1)

[Claims] 1. A transducer that transmits ultrasonic waves to a ship that is about to berth and receives reflected waves from the ship;
The round trip time of the received ultrasonic waves in a berthing guidance assistance system that uses the round trip time of the ultrasonic waves to measure the distance, speed, etc. of the ship, notifies the ship, and provides guidance assistance so that the ship approaches the berth at an appropriate speed. an abnormal value detection means for detecting the presence or absence of an abnormality by comparing it with a value set with an allowable range for the round trip time of the ultrasonic waves received up to that point, and rejecting the above-mentioned allowable range in the case of an abnormality; It has at least two levels: a wide tolerance range for long distances and a narrow tolerance range for short distances,
Tolerance range changing means for determining to which stage the measured distance belongs, and changing the tolerance range to a tolerance range corresponding to the stage to which the determination result belongs if the determination result is different from the stage to which the determination result belongs. A berthing guidance assistance system with an abnormal value removal function.