Systems and Methods for Electrified Fish Barriers

Abstract

The inventive subject matter describes an electrical barrier for the deterrence of fish having an electrical barrier with a computer system capable of executing a modified soft-start algorithm, the computer system further having a detector input and a switch output; a bio-electric fish proximity detector, the bio-electric fish proximity detector having a anode-cathode detecting pair input and a signal output, wherein said signal output is connected to the detector input; a time varying voltage source.

Claims

1. The electrical barrier for the deterrence of fish comprising: a computer system capable of executing a modified soft-start algorithm, the computer system having a detector input and a switch output; a fish proximity detector, the fish proximity detector having an anode-cathode detecting pair input and a signal output, wherein said signal output is connected to the detector input; a time varying voltage source, the time varying current source increasing from a minimum potential to a maximum potential; a time varying current source, the time varying current source increasing from a minimum potential to a maximum potential; a controllable A-B switch having an A electrical path, a B electrical path, a common output, and a control input, such that the control input can select either the A electrical path or the B electrical path to be connected to the common output; the A electrical path electrically coupled to the signal output of the bio-electric fish proximity detector, the B electrical path electrically coupled to the electrode array; whereby the computer system sets the control input of the controllable A-B switch to the A electrical path to connect the bio-electric fish proximity detectors signal out to the detector input; such that when the bio-electric fish proximity detector detects a fish, the computer system the computer system sets the control input of the controllable A-B switch to the B electrical path and initiates the modified soft-start algorithm.

2. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a constant current source; a time varying voltage source, the time varying voltage source increasing from a minimum potential to a maximum potential; such that the product of the constant current source and the time varying voltage source will transfer increasing amounts of energy to the fish thereby evoking a flight response.

3. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a voltage of a pulse width varying from a minimal value to a maximum value; such that the energy field is increased over time from a minimal value to a maximal value.

4. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a voltage of a pulse width varying from a minimal value of 11 microseconds to a maximum value of 250 microseconds in 9 microsecond intervals over a 500-microsecond period; such that the energy field is increased over time from a minimal value to a maximal value.

5. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a voltage of a pulse width of 11 microseconds to yield a 2.2% duty cycle.

6. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a voltage of a pulse width of 20 microseconds to yield a 4.0% duty cycle.

7. The electrical barrier for the deterrence of fish according to claim 1, wherein the energy increasing field further comprises: a voltage of a pulse width of 29 microseconds to yield a 5.8% duty cycle.

8. The electrical barrier for the deterrence of fish according to claim 1, wherein the time varying voltage source has a sine-like waveform.

9. The electrical barrier for the deterrence of fish according to claim 1, wherein the time varying voltage source has a triangle-like waveform.

10. The electrical barrier for the deterrence of fish according to claim 1, wherein the fish proximity detector is a bio-electric fish proximity detector.

11. An electrical barrier system for the deterrence of fish in a media, comprising: a pulsator unit, the pulsator unit generating an electrical field, between an anode and a cathode in the media and the electrical field passing through the fish; the pulsator unit further comprising: a computer system capable of executing a modified soft-start algorithm, the computer system having a central processing unit, a library of waveform inputs and a power output unit.

12. The electrical barrier system for the deterrence of fish in a media according to claim 11, wherein during an initiation of soft-start algorithm, the central processing unit is capable of accessing the library of waveform inputs and to programmatically provide one or more parameters to the power output unit.

13. The electrical barrier system for the deterrence of fish in a media according to claim 12, wherein the power output unit creates a time-varying potential difference on the anode and the cathode in the media.

14. The electrical barrier system for the deterrence of fish in a media according to claim 11, wherein the soft-start algorithm can be implemented by a programming language chosen from group comprising of C, Perl or Python.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a prior art diagram of an electrified fish barrier depicting a pulsator unit, an electrode array, and a support structure for the electrode array.

[0024] FIG. 2 is a prior art system diagram of an electrified fish barrier.

[0025] FIG. 3 is a diagram of an exemplary electrical field lines of an energized barrier between two anodes and a single cathode.

[0026] FIG. 4 is a diagram of the exemplary electrical field lines of an energized barrier with representative fish in different positions relative to the electrical barrier.

[0027] FIG. 5 is a diagram of representative electric pulses for the proposed soft-start electrical fish barrier where the barrier voltage pulses increase over time from a minimum amplitude to the maximum amplitude.

[0028] FIG. 6 is a diagram of representative square wave electric pulses for the soft-start electrical fish barrier where the pulse width is increased from a minimum width to a maximum width.

[0029] FIGS. 7A and 7B are diagrams of representative electric pulses having triangle waveforms (FIG. 7 A) and partial sine waveforms (FIG. 7 B).

[0030] FIGS. 8A, 8B and 8C are diagrams of representative square wave electric pulses for the soft-start electrical fish barrier. Where the first pulse is 11 microseconds (FIG. 8A), 20 microseconds (FIG. 8B) and 29 microseconds (FIG. 8C) followed by a 479 microsecond to the next pulse.

[0031] FIG. 9 is a systems diagram of the soft start pulsing waveform.

[0032] FIG. 10 is a flow-chart of the soft start system.

[0033] FIG. 11 is a system diagram of the soft start system with fish activity feedback.

LIST OF REFERENCE CHARACTERS

[0034] 100 Electrified Fish Barrier [0035] 110 Pulsator Unit [0036] 120 Support Structure [0037] 130 Electrode Array [0038] 210 Anode [0039] 220 Cathode [0040] 230 A representative water (or media) resistance [0041] 240 Representative fish resistances [0042] 300 Electric potential field [0043] 310 Representative field lines [0044] 320 Field lines [0045] 510 Output voltage [0046] 520 Time Axis [0047] 530 Pulsed waveforms [0048] 610 Output Voltage [0049] 620 Time Axis [0050] 630 Pulsed Waveforms [0051] 820 Time Axis [0052] 830 Pulsed Waveforms [0053] 900 General systems diagrams [0054] 910 CPU [0055] 920 Wave Input [0056] 930 Power Output [0057] 940 Anode-Cathode pair [0058] 1000 Soft start Flowchart [0059] 1010 Program Initiation [0060] 1020 Detect Fish [0061] 1030 Begin Modified Soft start [0062] 1040 Activate Normal Soft start [0063] 1050 End [0064] 1100 System Diagram [0065] 1110 CPU [0066] 1120 Fish Proximity Detector [0067] 1130 Power Output [0068] 1140 A-B Switch [0069] 1150 Anode-Cathode Pair

DETAILED DESCRIPTION

[0070] Representative embodiments according to the inventive subject matter are shown in FIGS. 1-11, wherein similar features share common reference numerals.

[0071] Now referring to prior art FIG. 1 which illustrates the typical electrical barrier system. This system configuration is an electrified fish barrier 100 which has a pulsator unit 110, an electrode array support structure 120, and an electrode array 130. The pulsator unit 110 provides electrical output as either AC (alternating current) or DC (Direct Current) waveforms. These electrical waveforms may be either continuous or intermittent (e.g. pulsed). The electrical current is passed to the electrode array 130 which is affixed to the support structure 120. During operation, the fish (not shown) that are proximate to the electrode array 130 while the pulsator unit 110 is operating will be entrained or repulsed from the barrier.

[0072] Now referring to prior art FIG. 2 that illustrates a schematic diagram of the pulsator unit 110, the anode 210, the cathode 220, a representative water (or other media) resistance 230, and representative fish resistance 240. As indicated, the pulsator unit 110 generates an electrical field that passes through the media and the fish. A portion of the electrical energy is dissipated by the water resistance 230 and a proportion of the electrical energy is dissipated by the current passing through the fish via the fish's inherent internal resistance 240.

[0073] As indicated, the anode 210 and cathode 220 may be configured as single leads or a multiplicity of leads. Whereas the electrical model of the fish in the diagram is somewhat simplified, it generally conforms to the analysis as provided by Kolz in the prior art patent, U.S. Pat. No. 5,289,133 (Feb. 22, 1994) entitled Power Density Methods for Electroshocking at columns 3 through 6.

[0074] It is the voltage potential created across the body of the fish due to the fish's internal resistance 240 which creates the reactive condition in the fish (flight reaction, narcosis, tetany, etc.). The range for this electrical field can vary from 0.1 volts per em to 4.0 volts per em depending on the type of evoked reaction and/or the species of the fish.

[0075] Now referring to prior art FIGS. 3 and 4 that show the electric potential field 300 and representative field lines 310 that passes between the anodes 210, 210 and the cathode 220. Typically, the field strength will be less the farther it extends from the anode and the cathode. As shown in FIG. 4 the representative field line 320 which passes through a fish resistance 240 will be greater for fish that are closer 240 to the field line 320 than those that are farther away 240 to the field line 320.

[0076] Now referring to FIG. 5 which shows a waveform 500 that depicts the voltage 510 which represents the potential difference between the anode and the cathode as depicted on they-axis. On the x-axis is a representative output for the pulsed waveform 530, 530, 530 depicting the pulses as a function of time.

[0077] In one embodiment of the inventive subject matter, referred to as soft start, the voltage 510 increases from a minimal value pulsed waveform 530 to a maximal value pulsed waveform 530. As a direct result of this increasing voltage, the field strength, as shown in the field lines 320 (see FIGS. 3 and 4), will also increase. The increasing field strength results in an increase in the electrical energy that is present in the field and that can be transferred to the fish. This increasing electrical field will then evoke a flight reaction in most fish that will result in their avoidance of the increasing field. Fish, and aquatic mammals, will then exhibit avoidance behavior of the area where the electrodes are energized, thus improving the effectiveness of the subject electrical barrier. Examples of this avoidance behavior is documented in the report entitled Experimental Integrated Non-Lethal Sea Lion Abatement: Potential Behavioral and Stress Related Effects on Adult White Sturgeon, (Dec. 31, 2008), Ostrand, et. al, (BPA Project No. 2007-524-00).

[0078] Now referring to FIG. 6, that depicts the electrode voltage 610 on the yaxis and the variation of that voltage on the x-axis 620 as a function of time. In this embodiment, the pulse width is increased as a function of time as shown by the electrical pulse widths 630, 630, and 630. Electrical pulses having smaller widths (i.e. 630) will transfer less energy (and hence evoke a smaller reaction) to the fish in the potential field. Electrical pulses having wider widths (i.e. 630) will impress a potential difference on the fish for a longer duration. The physiological response of the fish to the electric field is dependent on the potential difference and the width of the field and the dimensions of the fish.

[0079] Other variations include modification of the electrical pulse height as illustrated FIG. 7 that incorporate waveforms as shown in FIG. 5 and in addition to the width as shown in FIG. 6. Other variations of the electric field potential are shown in FIGS. 7A and 7B. The voltage potential 610A, 610B is plotted as a function of time 620A, 620B. The peak voltage for each pulse starts at a minimum voltage potential 630A, 630B and increases over time to a maximum potential 630A, 630B. This increase in voltage potential is similar to the increase in voltage potential as shown in FIGS. 7A and 7B.

[0080] Now referring to FIGS. 8A, 8B and 8C which shows one detailed embodiment of the waveform as depicted in FIG. 6. In this embodiment, as in FIG. 8A the first pulse 830A is approximately 11 microseconds followed by a 479 microseconds gap to the next pulse 830A. This waveform has an approximately 2.2% duty cycle. As in FIG. 8B when the pulse 830B is then increased by 9 microseconds to 20 microseconds which provides a 4% duty cycle. As in FIG. 8C when the next pulse 830C is increased to 29 microseconds which increases the duty cycle to 5.8%. The rate of that the duty cycle can be increased will depend on the type of fish that are proximate to the barrier. The waveform is also commonly known as pulse width modulation.

[0081] Now referring to FIG. 9 which shows a general systems diagram 900 of the subcomponents in the pulsator 110. The pulsator 110 contains a CPU or central processing unit 910, library of waveform inputs 920 that are accessible to the central processing unit 910, a power output unit 930, and the power output unit 930 connected to an anode-cathode pair 940A, 940B. During the initiation of soft start, the CPU 910 will access the library of waveform inputs 920 which programmatically provide the parameters to the power output subsystem 930.

[0082] The power output subsystem 930 creates the time-varying potential difference on the anode/cathode pair 940A/940B.

[0083] The algorithm 1000 for implementing the soft start electrical field, as shown in varying embodiments in FIGS. 5 through 8 and as implemented in the CPU 910 of FIG. 9 is shown in FIG. 10. The implementation of algorithm 1000 is not linked to a particular programming language and may be implemented in any programming language, such as, C, Perl, or Python.

[0084] When the electrical barriers are initiated 1010, a test for fish located proximate to the electrodes is performed 1020. If fish are detected very close to the electrodes and/or lying on a particular electrode then the soft start procedure is modified 1030 to account for fish that are proximate to the electrodes. This modified soft start procedure 1030 has lower voltages and/or cycle widths as previously shown in FIGS. 5-7. If fish are not detected in the area proximate to the electrodes, then a normal soft start procedure 1040 is initiated.

[0085] Now referring to FIG. 11 which depicts a system 1100 that incorporates the detection of fish that are closely proximate to the electrodes. This system has a CPU 1110, a fish proximity sensor module 1120, a power output module 1130, A-B switch 1140, and an anode-cathode pair 1150. In this embodiment, the A-B switch 1140 is configured to allow electrical signals to be detected between the anode-cathode pair 1150 by the fish proximity sensor module 1120. The fish proximity detector 1120 amplifies bio-electric signals generated by fish that are generated in the vicinity of the anode-cathode pair. Signal processing algorithms in the fish proximity detector 1120 generate a signal if there is a reasonable probability that fish are present. If the fish are present, then the A-B switch is placed in the A position, and the CPU is set to initiate a modified soft start 1030 as described in FIG. 10. At the end of the modified soft start procedure, a normal soft-start procedure may be initiated, leading to a normal operation.

[0086] Alternately, the A-B switch may be toggled between the power output 1130 generating the modified soft start 1030 and the fish proximity detector 1120 in such a way that fish that are proximate are cleared away using low energy impulses prior to the initiation of high energy impulses.

[0087] It is understood that the algorithms described herein may be implemented in software as a computer program or alternately in firmware. The inventive subject matter is not limited to one specific implementation.

[0088] It is understood that the aforementioned deterrence system can work independently or can work with other deterrence systems, such as sound, visual, and/or other mechanical based methods of deterrence.

[0089] Persons skilled in the art will recognize that many modifications and variations are possible in the details, materials, and arrangements of the parts and actions which have been described and illustrated in order to explain the nature of this inventive concept and that such modifications and variations do not depart from the spirit and scope of the teachings and claims contained therein.

[0090] All patent and non-patent literature cited herein is hereby incorporated by references in its entirety for all purposes.