[0001] Hydrosound Marine Anti-fouling System FIELD

[0002] There is described an improved system for preventing marine growth on the external immersed surfaces of a hull and salt water exposed internal components of a vessel, using sound waves and resonation.

BACKGROUND

[0003] Marine growth on a hull of a vessel requires expensive periodic cleaning and can account for speed losses of up to 30% with resulting increased fuel costs and emissions. Expensive periodic cleaning is similarly required for internal components that are exposed to salt water, such as sea chests, cross-over tanks and associated plumbing. [0004] "Hydrosound" is a term used to describe sound propagations in water. Hydrosound marine anti-fouling systems were introduced into the marine environment by Hull Tender International Inc in 1974. Hydrosound systems will not remove existing growth on a hull of a vessel but, when installed on an uncontaminated hull, will keep the hull free and clear of marine growth.

[0005] The system developed by Hull Tender International Inc involves attaching transducers directly to the hull of the vessel on the inboard side of the hull. An oscillator creates sound, with the hull acting as a soundboard for propagating the sound waves as hydrosound. Hull Tender International Inc determined that resonating surfaces at frequencies of 17-20 Hertz creates an environment which barnacles and muscles avoid.

[0006] Although they have achieved a reasonable degree of success, the systems of Hull Tender International Inc are not successful in all marine environments and are sometimes subject to system failure.

SUMMARY

[0007] There is provided a hydrosound marine anti-fouling system that includes a transducer array for converting a hull of a vessel into a soundboard for generating hydrosound. A sonic pulse generator is provided along with a microcontroller controlling the pulse rate and frequency of sound waves generated by the sonic pulse generator. An interface is provided for facilitating human interaction with the microcontroller. At least one output amplifier is provided to amplify an output from the sonic pulse generator and communicates the amplified output to the transducer array. A volume generated by the output amplifier is also controlled by the microcontroller. At least one sensor is provided in communication with the microcontroller. The at least one sensor monitors the output of the at least one output amplifier. A power supply is provided for supplying power as required to the microcontroller, the sonic pulse generator, the at least one output amplifier and the at least one sensor.

[0008] With the prior art hydrosound marine anti-fouling systems, there was not an ability to modify the hydrosound output frequencies and volume level. With the hydrosound marine anti-fouling system, described above, there is an ability to modify the hydrosound pulse rate, output frequencies and volume level. If it is discovered that the hydrosound marine anti-fouling system is not effective for a local marine growth in the 17-20 Hertz range, the hydrosound output frequency can be changed until a hydrosound output frequency and volume level is found that is determined to be effective. For example, 30 Hertz has been required to achieve effective results with local marine growth in some locations.

[0009] Although beneficial results can be obtained with the hydrosound marine anti- fouling system described above, even more beneficial results may be obtained when there is added to the hydrosound marine anti-fouling system an automatic testing function. In accordance with this aspect, the microcontroller is programmed to test an output level of each amplifier at pre-set intervals. The microcontroller controls the pulse rate and frequency of the output from the sonic pulse generator and the volume of each output amplifier and compares input from the at least one sensor to a set of internal reference tables to determine whether operation is within parameters. The microcontroller sends a signal to the interface should results of the test not be in conformity with the internal reference tables.

[0010] With prior art hydrosonic marine anti-fouling systems, failures sometimes occurred due to the fact that one or more components of the system were not working. With the hydrosonic marine anti-fouling system, described above, one is able to monitor the output of the output amplifier. Furthermore, the operator can see the output voltage change while the volume level is adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

[0012] FIG. 1 is a schematic diagram of components used for a functioning hydrosound marine anti-fouling system.

[0013] FIG. 2 is a flow chart of an automatic testing process of the hydrosound marine anti-fouling system of FIG. 1.

[0014] FIG. 3 is a graphic representation of the reference waveform used for the automatic testing process of FIG. 2.

DETAILED DESCRIPTION

[0015] A hydrosound marine anti-fouling system generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 3. Structure and Relationship of Parts:

[0016] Referring to FIG. 1, hydrosound marine anti-fouling system 10 includes a transducer array, generally indicated by reference numeral 12, consisting of a plurality of transducers 14, which attached to a hull 102 of a vessel 100 for the purpose for converting hull 102 of vessel 100 into a resonant soundboard for generating hydrosound. A sonic pulse generator 16 is provided along with a microcontroller 18 controlling the pulse rate and frequency of sound waves generated by sonic pulse generator 16. As noted, the default frequency would normally be in the 17-20 Hertz range. However, this differs from the prior art in that the frequency can be adjusted both within and outside of this default range. An interface is provided for facilitating human interaction with the microcontroller. This interface has been shown as a computer monitor 20 and keyboard 22. It will be appreciated that touch screen technology can be used or other interfaces devices used in industry. A single output amplifier 24 has been illustrated. Output amplifier 24 is provided to amplify an output from sonic pulse generator 16 and communicate the amplified output to transducers 14 of transducer array 12. It will be appreciated that more than one output amplifier 24 may be employed. A volume generated by output amplifier 24 is also controlled by microcontroller 18. Two acoustic sensors 26 and 28 are in communication with the microcontroller 18. Sensors 26 and 28 monitor the output of output amplifier 24. It will be appreciated that a single sensor could be used or more than two sensors could be used. A power supply 30 is provided for supplying power as required to microcontroller 18, sonic pulse generator 16, output amplifier 24 and sensors 26 and 28.

Operation:

[0017] As described above, hydrosound marine anti-fouling system has the ability to modify the hydrosound pulse rate, output frequencies and volume level. If it is discovered that the hydrosound marine anti-fouling system is not effective for a local marine growth in the 17-20 Hertz range, the hydrosound output frequency can be changed until a hydrosound output frequency and volume level is found that is determined to be effective. Referring to FIG. 1, when sensors 26 and 28 are added to the ability to modify the hydrosound pulse rate, output frequencies and volume level, a feedback loop can be created which can be monitored by microcontroller 18. This makes possible an automatic testing function. Referring to the flowchart of FIG. 2, there is shown the automatic testing function performed at timed interval, which can be set between once per minute to once per hour. Referring to FIG. 3, a reference waveform is used to test the output of the amplifier to make sure it is operating correctly. Referring to FIG. 2, the peak voltage output value is measured for its level against a reference input level and checked against a set of internal reference readings. If the measured voltage and amplifier gain are outside of the reference value by more than 10 percent, a fault flag is set which triggers the fault LED and fault relay. The testing function is completely automatic and operates without operator intervention. TMR6 is a 0.01 second interval timer used to provide a time base for a number of timer functions including Ttester. Timers tdl and td2 provide a time delay for the reference waveform to allow the amplifier to reach the maximum or minimum levels set by the reference input signal Vin. At the conclusion of tdl or td2 a voltage sample of the output voltage is taken and recorded for later processing at the completion (Phase 4) of the waveform. This flowchart has enough detail to be used to directly generate the code for this set of operations.

Advantages:

[0018] With prior art hydrosonic marine anti-fouling systems, failures sometimes occurred due to the fact that one or more components of the system were not working. For example, flashing system lights could confirmed that the oscillator component was receiving power and the pulse generator was working; there was no way of knowing whether the output amplifier was functioning to provide power to the transducer array. With the hydrosonic marine anti-fouling system, described above, one is able to monitor the output of the output amplifier. Furthermore, the operator can see the output voltage change while the volume level is adjusted.

[0019] With the hydrosonic marine anti-fouling system, described above, the system can be programmed to perform a "self-check". The output level of each amplifier can be periodically tested by the microcontroller with a pre-set sequence of values sent to the digital volume control to allow several readings to be taken and compared to a set of internal reference tables. The recorded results can be used to provide a fault indication if the tests fail or a no-fault condition if the tests pass. This set of tests can be performed at any set interval without any operator involvement. The microcontroller can be programmed to signal a remote fault condition, if a fault is detected.

[0020] The work pioneered by Hull Tender International Inc established that hydrosound at frequencies of 17-20 Hertz was effective to discourage barnacles and muscles from attaching to a hull of a vessel. As the hydrosound marine anti-fouling systems come to be used throughout the world, it has been determined that frequencies of 17-20 Hertz are not effective to discourage some types of marine growth. With the prior art hydrosound marine anti-fouling systems, there was not an ability to modify the hydrosound output frequencies and volume level. With the hydrosound marine anti-fouling system, described above, there is an ability to modify the hydrosound pulse rate, output frequencies and volume level. If it is discovered that the hydrosound marine anti-fouling system is not effective for a local marine growth in the 17-20 Hertz range, the hydrosound output frequency can be changed until a hydrosound output frequency and volume level is found that is determined to be effective. For example, 30 Hertz has been required to achieve effective results with local marine growth in some locations.

[0021] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0022] The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.