JPH0431553B2 - - 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 distance meter emits ultrasonic pulses from the 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 pulse output from the clock circuit is calculated, and the calculated value is used as the basis. 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 some kind of countermeasure is required.

Conventionally, as a countermeasure for this, abnormal values are used to
When a normal measurement value cannot be obtained, it is possible to decide whether to display the distance calculated based on the previous measurement value, display the maximum display distance (fixed value), or even interrupt the display. It was being processed.

[Problems to be Solved by the Invention] However, the conventional abnormality countermeasures described above depend on displaying a fixed value or interrupting the display, so there is a short period between when a normal measured value is obtained and when it is not. If repeated over time, the displayed output may change drastically or the values may fluctuate. This resulted in noticeable fluctuations in the displayed values, making it difficult to use as data for guiding ships.

The present invention has been made to solve the above problems, and even when a normal measured value cannot be obtained, an estimated value is calculated based on the measured values obtained up to that point and displayed. Even if normal measurement values are not obtained repeatedly within a short period of time, display output can be obtained continuously, so that the so-called erratic display values are not noticeable, and it is useful when assisting ship guidance. An object of the present invention is to provide a berthing guidance assistance system that can display easy-to-use data and has an abnormal value compensation function.

[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.
As a means to solve the above problems in the berthing guidance assistance system so that berthing can be done at an appropriate speed,
The means shown in FIGS. 1 and 2 are provided.

The present invention, for example, as shown in these figures,
A front end unit that forms transmission waves to a transducer and receives waves received from the transducer, detects the time required for ultrasonic wave reflection, and outputs it as measurement data, and The present invention is applied to a berthing guidance assistance system having an ultrasonic measurement system including a measurement data processing unit that calculates the speed of the vehicle, distance to the quay, etc., and outputs it as display data, and a display unit that displays the display data. .

That is, the present invention provides the first problem-solving means.
As shown in the figure, there is an abnormal value detection means for detecting the presence or absence of an abnormality in the round trip time of the received ultrasonic waves by comparing it with a preset tolerance range; Calculate the estimated travel distance using the speed data obtained in having at least two levels of the tolerance range, a wide tolerance range for long distances and a narrow range for short distances, and determining to which stage the measured distance belongs;
The present invention is characterized in that, when the determination result is different from the stage to which the determination result belongs up to that point, it is configured to include a tolerance range changing means for changing the tolerance range to a tolerance range corresponding to the stage to which the determination result belongs.

Further, in the present invention, as shown in FIG. 2, an estimation limit determining means can be added to the above problem solving means. The estimation limit determining means is configured to stop outputting the estimated distance and output an alarm signal when the calculated distance estimation value enters a preset warning range.

The known data includes a previous measurement value, a moving average value of measurement values up to the previous time, and the like.

Furthermore, in the present invention, as shown in FIGS. 1 and 2, a wave receiving off detection means for detecting that no received wave is input can be added. In this case, when receiving wave off is detected, the estimated value generating means, as in the case when the abnormal value is detected,
The above distance estimation value is calculated.

The distance at which the above-mentioned tolerance range is changed is generally set at the boundary of two stages, far and near, but the configuration is such that the distance is divided into multiple stages and the tolerance range is set sequentially narrower from the farthest distance to the shortest distance. You can also use it as

Note that although the above-mentioned warning range and the distance for changing the allowable range are set separately, they may be made to match.

[Operation] In the problem-solving means of the present invention configured as described above, the abnormal value detection means checks whether there is an abnormality in the round trip time of the received ultrasonic waves, and if there is an abnormality, determines that there is an abnormality. It makes a determination and outputs an output to that effect, for example, an abnormal value status. The presence or absence of this abnormality can be determined, for example, if there has been a significant change compared to known data obtained up to that point.
It is determined that there is an abnormality. For example, if an ultrasonic transmission wave is reflected by a floating object in front of the target ship, known data indicates that the ultrasonic wave will go back and forth in a very short time, so this is determined to be an abnormality.

Further, in determining the presence or absence of an abnormality, a certain tolerance range is set for the known data, and if the measured data is within this tolerance range, it is determined that there is no abnormality.

By the way, in the case of the present invention, this allowable range is made to vary depending on the current position of the ship, that is, the distance from the quay. For example, the tolerance range is
Set it narrower for short distances and wider for far distances. As a result, although the error increases at long distances, the occurrence of abnormal values decreases, and on the other hand, the error decreases at short distances, making it safer.

When the abnormal value is detected, the estimated value generating means calculates the estimated value based on known data obtained up to that point. The detection of the abnormal value can be communicated, for example, by the status described above. These statuses may be input directly or indirectly via the measurement data processing section. The known data may be held by itself or may be held by the measurement data processing section. This known data includes previous values, moving average values, and the like.

Estimated values are calculated by using known speed data to calculate the distance traveled by a ship during the time between the previous measurement and the current measurement, assuming that the ship is moving at the same speed as the known data. , the estimated distance is calculated by subtracting the calculated travel distance from the previous distance.

The calculated estimated value is sent via the measurement data processing section or directly and displayed on the display section.

Further, the estimation limit determining means added to the problem solving means compares the calculated distance estimation value with the distance of a preset warning range, and when the estimated value is smaller than the distance, the ship is It determines that the system is approaching the quay, stops outputting the estimated value that is likely to include a larger error than the measured value, and outputs a warning signal.

In addition, in the present invention, the addable wave receiving off detection means detects, for example, when a received signal is not sent from the front end section shown in FIGS. 1 and 2 within a certain period of time after transmitting the transmitted wave. Assuming that normal reception has not been possible, it is determined that "wave reception is off" and outputs an output to that effect, for example, a wave reception off status.

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

<Configuration of Embodiment> FIG. 3A shows the configuration of an embodiment of the berthing guidance assistance system having an abnormal value compensation function of the present invention.

The abnormal value compensation system 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 ROM 2 that stores operating programs for the microprocessor 1. RAM3 serves as a storage area and stores input data, etc.
An input/output port 7 that connects the keyboard 8 and display device 9, and a bus 4 that connects them.
It is composed of:

In addition to functioning as a measurement data processing section, this microcomputer also functions as an abnormal value detection means, an allowable range changing means, and an estimated value generation means among the elements constituting the above-mentioned problem solving means of the present invention. In this embodiment, it also functions as an estimation limit determining means.

As shown in FIG. 3B, 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 trips from transmitted and received signals, and a timing signal generating circuit 54. In addition, in this embodiment, a reception off detection circuit 55 is provided which functions as reception off detection means.

The transmitting circuit 51 transmits the pulse as a burst.
It is transmitted at regular time intervals from 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 count 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 so-called prediction gate method, which allows reception only in a time period centered around the time when the current reflected wave is predicted to arrive, 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.

This wave reception off detection circuit 55 is configured by, for example, a timer.
TM, it is activated in synchronization with the transmission wave output from the transmission circuit 51, and outputs a time-up pulse after a certain period of time has elapsed. Further, this reception off detection circuit 55 is connected so that the reception signal outputted from the reception circuit 52 is inputted to the reset terminal, and is reset if the reception signal is inputted before a certain period of time has elapsed after activation. , no time-up pulse is output. In this embodiment, this effect is utilized to detect that no received wave is received within a certain period of time after transmission of the transmitted wave. The time-up pulse is sent to the microprocessor 1 as a receiving off status.

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 and a reception off detection circuit 55 as a pulsed received signal.
sent to.

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.

The reception off detection circuit 55 uses a timer according to the transmission timing from the timing signal generation circuit 54.
When the TM is activated and a certain period of time elapses, a time-up pulse is output. After starting the timer TM,
If a received signal is input before a certain period of time has elapsed, it is reset and no time-up pulse is output. The time-up pulse is sent to the microprocessor 1 via the bus 4 as a receiving off status.

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 always checks whether the reception off status is input (steps 1 and 2). When no input is being made, that is, when wave reception is not off, measurement data is taken from the time measurement circuit 53 (step 3).

Additionally, 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 tolerance 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 4 and 5). In addition, in this example,
The setting distance is 30m, and the allowable range is 1 for long distances.
m, and 0.5m for short distances.

Next, the microprocessor 1 checks whether this measurement data is an abnormal value (step 6). 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 displays the sent data in numerical form with appropriate units attached (step 10). This completes one measurement cycle.

On the other hand, if the reception off status in step 2 is output, or if the abnormal value status is output in step 4, the microprocessor 1 does not perform the normal calculation process described above, but performs the estimation calculation. Execute the process (step 8). That is, without using the measurement data, known data up to that point stored in the RAM 3, for example, the previous value, is read out, and the estimated value is calculated based on this data. As known data, for example,
Use speed data. The estimation is performed by calculating the estimated distance value by multiplying the elapsed time from the previous measurement to the current measurement, assuming that this speed is constant.

In this embodiment, it is further checked whether it is appropriate to use the estimated value calculated above as it is (step 9). That is, microprocessor 1
determines whether or not the calculated distance estimate falls within a preset warning range, and when the distance estimate falls within the preset warning range, stops outputting the estimated value and outputs an alarm signal. The above-mentioned warning range is determined based on the limit at which the vessel can be stopped, and is, for example, 20 meters.

The reason why estimated values are not displayed in the warning range is that it is dangerous to use estimated values with a larger error than the actual measured values at positions close to the quay. We will issue a warning to this effect.

<Modifications of Embodiments> In the above embodiments, an example was shown in which the reception off detection means was configured by providing a timer in the front end section, but it may also be configured by a microcomputer.

When the microcomputer works as a reception off detection means, the microprocessor 1
After the front end unit 5 transmits the ultrasonic transmission wave, it is checked whether a reception wave has arrived before a certain period of time has elapsed. The fixed time to monitor the arrival of received waves is
It is set after the transmission wave is transmitted and before the next transmission.
For example, if a reflected wave does not arrive within the prediction gate as described above, it is determined that wave reception is off.

Further, although the above embodiment includes an estimation limit determining means, it is also possible to omit this.

In the above embodiment, the allowable range is changed at the boundary between two distances, far and near.
It can also be changed to correspond to multiple stages, such as three stages of medium distance and short range.

[Effects of the Invention] As explained above, the present invention allows even when a normal measurement value cannot be obtained, an estimated value can be calculated and displayed based on the measurement values obtained up to that point. Even if normal measurement values are not obtained repeatedly within a short period of time, display output can be obtained continuously, so that the so-called fluctuations in display values are not noticeable, and it can be used as data when guiding ships. This has the effect of displaying data that is easy to use.

[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 another configuration of the present invention, No. 3A.
The figure is a block diagram showing the configuration of an embodiment of the present invention.
FIG. 3B is a block diagram showing the configuration of the front end portion of the above embodiment, and FIG. 4 is a flowchart for explaining the operation of the above embodiment. 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, 55... Receiving off detection 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 the round trip time of ultrasonic waves received up to that point with a value set within a permissible range; The estimated travel distance is calculated using the speed data obtained up to now and the elapsed time since the data was obtained, and the distance is estimated by subtracting the estimated travel distance from the distance data when the speed data was obtained. an estimated value generating means for calculating the value; and having at least two levels of the above tolerance range, a wide tolerance range for long distances and a narrow tolerance range for short distances,
and a tolerance range changing means for determining which stage the measured distance belongs to, 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 it belonged up to then. A berthing guidance assistance system having an abnormal value compensation function. 2. In claim 1, there is provided wave receiving off detection means for detecting that no received wave is input, and when receiving wave off is detected, the estimated value generating means calculates the distance estimated value. A berthing guidance assistance system having an abnormal value compensation function. 3. A berthing guidance assistance system having an abnormal value compensation function according to claim 1 or 2, characterized in that a previous measured value is used as the speed data. 4. A berthing guidance assistance system having an abnormal value compensation function as set forth in claim 1 or 2, characterized in that the average value of the measured values up to the previous time is used as the speed data. 5 Equipped with a transducer that transmits ultrasonic waves to a ship that is about to berth and receives reflected waves from the ship,
In a berthing guidance assistance system that measures the distance, speed, etc. of the ship using the round-trip time of the ultrasonic waves, and notifies the ship to guide the ship so that it can berth at an appropriate speed. an abnormal value detection means for detecting the presence or absence of a time abnormality by comparing the round trip time of the ultrasonic waves received up to that point with a value with an allowable range; The estimated travel distance is calculated using the previously obtained speed data and the elapsed time since the data was obtained, and the distance is calculated by subtracting the estimated travel distance from the distance data when the speed data was obtained. an estimated value generating means for calculating an estimated value; and having at least two levels of the above tolerance range, a wide tolerance range for long distances and a narrow tolerance range for short distances;
Tolerance range changing means for determining which stage the measured distance belongs to, 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 it belongs; A berthing guidance aid having an abnormal value compensation function, characterized by having an estimation limit determination means for stopping the output of the distance estimate and outputting a warning when the distance estimate enters a preset short distance area. system. 6. In claim 5, the invention further comprises receiving wave off detecting means for detecting that no received wave is input, and when receiving wave off is detected, the estimated value generating means calculates the distance estimated value. A berthing guidance assistance system having an abnormal value compensation function. 7. A berthing guidance assistance system having an abnormal value compensation function according to claim 5 or 6, characterized in that a previous measured value is used as the speed data. 8. A berthing guidance assistance system having an abnormal value compensation function according to claim 5 or 6, characterized in that the average value of the measured values up to the previous time is used as the speed data.