Description:[0001] The present invention relates to wildlife safety and conservation technology, specifically to an ultrasonic defense mechanism designed to enhance the safety of forest rangers in tiger-prone habitats. More particularly, this invention utilizes ultrasonic waves to create a non-lethal deterrent system that repels tigers while maintaining ecological integrity.

Background of the Invention
[0002] Forest rangers working in tiger-dense regions face significant risks of wildlife encounters, which can result in life-threatening situations. Traditional methods for safeguarding human lives from wild animals include physical barriers, tranquilizers, or lethal force, which can disturb the natural ecosystem or harm wildlife.
[0003] Recent studies indicate that tigers are sensitive to ultrasonic frequencies, specifically around 40 kHz, which causes discomfort but no physical harm. Leveraging this sensitivity, ultrasonic deterrent systems present a humane and eco-friendly approach to preventing tiger attacks.
[0004] However, existing systems either lack portability or are cost-prohibitive, making them unsuitable for extensive forest patrols. Furthermore, many conventional devices emit continuous ultrasonic waves, leading to habituation, where tigers become accustomed to the sound and cease to respond to it as a deterrent.
[0005] This invention addresses these limitations by developing a cost-effective, portable, and intelligent ultrasonic repellent system that enhances ranger safety without endangering the wildlife or disrupting the ecosystem.

Objects of the Invention
[0006] An object of the present invention is to provide a reliable, non-lethal safety mechanism for forest rangers by detecting tiger movement and emitting ultrasonic waves to repel them, thus reducing human-wildlife conflicts.
[0007] Another object of the present invention is to develop a human repellent system that does not physically harm tigers, ensuring their protection while maintaining the natural balance of the ecosystem.
[0008] Yet another object of the present invention is to introduce a portable, energy-efficient, and environmentally friendly system for long-term use in forest management and wildlife conservation.
[0009] Another object of the present invention is to design a lightweight and cost-effective device that is easy to carry during forest patrols, ensuring accessibility for ranger teams with limited resources.
[0010] Another object of the present invention is to implement sequential ultrasonic wave emission and movement-triggered activation, preventing tigers from becoming accustomed to the sound and enhancing the effectiveness of the deterrent.

Summary of the Invention
[0011] The present invention discloses a system and method for ultrasonic tiger repellent to enhance forest ranger safety, utilizing an Arduino-based platform integrated with HC-SR04 ultrasonic sensors to detect movement and emit ultrasonic waves at 40 kHz, a frequency discomforting for tigers.
[0012] The system includes two strategically positioned ultrasonic sensors that sequentially activate to avoid cross-interference and continuously monitor the surrounding area. When motion is detected, the system emits high-frequency ultrasonic waves, creating a non-lethal barrier that repels tigers without causing harm. The device is powered by a lithium-ion battery, ensuring portability and extended usage during forest patrols. Real-time monitoring is achieved through a serial plotter, providing rangers with immediate feedback on movement detection.
[0013] The system further implements a directional ultrasonic emission module with frequency-hopping between 35–45 kHz and randomized burst timing (50–300 ms bursts, 0.3–1.7 s spacing) under a duty-cycle cap ≤10%, thereby mitigating habituation in target fauna while maintaining non-lethal acoustic exposure. Emission is permitted only when a fused distance estimate from dual ground-level rangers crosses a programmable 2–8 m threshold with 0.5–1.5 m hysteresis.
[0014] This cost-effective, portable, and eco-friendly system not only enhances the safety of forest rangers but also promotes wildlife conservation by providing a humane solution to mitigate tiger encounters.
[0015] In this respect, before explaining at least one object of the invention in detail, it is to be understood that the invention is not limited in its application to the details of set of rules and to the arrangements of the various models set forth in the following description or illustrated in the drawings. The invention is capable of other objects and of being practiced and carried out in various ways, according to the need of that industry. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0016] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.

Brief Description of Drawings
[0017] The advantages and features of the present invention will be understood better with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:
[0018] Figure 1 illustrates the circuit diagram for ultrasonic tiger repellent system in accordance with the present invention.
[0019] Figure 2 and 3 illustrates the ultrasonic tiger repellent system in accordance with the present invention.

Detailed Description of the Invention
[0020] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof are intended to be equivalent in meaning and be open-ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.
[0021] The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0022] The present invention provides a wearable, directional ultrasonic repellent system for forest-ranger safety in tiger-prone habitats. By leveraging high-frequency, non-lethal acoustic deterrence, the system discourages approach while preserving wildlife integrity. The device employs a controller-driven acoustic emitter operating within 35–45 kHz and dual ground-level ultrasonic rangers to detect proximity and trigger emission only under predefined thresholds. The electronics are integrated into gum boots for hands-free use, with an IP67-sealed enclosure, downward-tilted directional emitter (15–25°) and weight limits suitable for long patrols. This innovative approach provides a cost-effective and sustainable solution for wildlife conservation and ranger safety.
[0023] The system includes: a microcontroller with hardware capture/compare, a sequencer enforcing dead-time Δt = 5–20 ms between rangers to prevent cross-talk, two ultrasonic ranging modules (toe and heel placement), a directional piezo horn emitter driven by a half-bridge + step-up transformer, a burst scheduler that randomizes burst length (50–300 ms) and inter-burst spacing (0.3–1.7 s) with carrier hopping (35–45 kHz), a Li-ion battery with protection (OVP/UVP/OCP), a buck-boost PMIC providing 5 V (driver) and 3.3 V (logic), optional IMU/thermistor for safety interlocks, and telemetry (UART and/or BLE). The control stack implements threshold/hysteresis (e.g., 2–8 m threshold with 0.5–1.5 m hysteresis) and a duty-cycle governor ≤10% over any 60 s window to mitigate habituation.
[0024] Arduino Uno Microcontroller: The controller orchestrates sequential ranging with interrupt-driven echo timing, applies Δt dead-time and first-order filtering to suppress spurious returns, fuses toe/heel measurements to a conservative distance estimate, and commands the drive stage to emit only when (distance ≤ threshold) and safety gates are satisfied (battery above brown-out, acceptable device pitch, temperature below limit).
[0025] Ultrasonic Sensors (HC-SR04): Two ultrasonic rangers one at the toe and one at the heel emit brief pulses and listen for echoes to estimate distance. Placement at ground level increases sensitivity to low-profile approach vectors; the dual geometry acts as an angle-of-arrival proxy to reduce false positives from foliage or elevated objects.
[0026] The rangers operate sequentially with Δt = 5–20 ms to eliminate acoustic cross-interference. Echoes within a guard window after the second trigger are discarded. The controller forms a fused distance (e.g., minimum of filtered toe/heel values). Telemetry provides live visualization (Serial Plotter and/or BLE) for diagnostics without affecting operation.
[0027] Directional Ultrasonic Emitter - Upon a valid trigger, the drive stage energizes a directional piezo horn emitter at a carrier within 35–45 kHz, producing a peak acoustic output of ~110–125 dB re 20 µPa at 1 m. In one embodiment, the emitter comprises a piezoelectric ceramic disc bonded to a conical or exponential horn whose acoustic axis is oriented 15–25° downward relative to horizontal. The horn provides a −6 dB beam-width of 20–40°, concentrating acoustic energy toward the approach vector while limiting collateral exposure. The drive stage includes a half-bridge MOSFET topology referenced to a step-up transformer (turns ratio 1:6–1:12) coupled to the piezo element; the controller sets the PWM frequency to the selected carrier and regulates burst duration while a current-sense resistor (e.g., 0.1–0.33 Ω) and comparator limit instantaneous drive to maintain SPL within a configured set-point. The emitter assembly is mechanically decoupled from the boot shell using 30–50 Shore A grommets to reduce vibration feed-through and maintain beam pointing consistency during gait. Calibration is performed at manufacture by a brief closed-loop routine that adjusts the drive amplitude to achieve a target SPL at 1 m (±2 dB), stored as a nonvolatile SPL set-point; field drift ≤ ±3 dB is tolerated and corrected during scheduled maintenance.
[0028] Anti-Habituation Burst Scheduling -To prevent habituation, emission uses burst packets of 3–7 bursts with ±20% jitter in both burst length (50–300 ms) and inter-burst spacing (0.3–1.7 s), and carrier hopping among discrete tones (e.g., 38/40/42/44 kHz). A duty limiter ensures ≤10% average duty over any rolling 60-second window. The burst scheduler selects a packet size N∈[3,7] and draws {duration_i, spacing_i} from bounded pseudo-random distributions seeded at power-on and re-seeded every 5–10 minutes to avoid predictability. The controller enforces emitter dead-time ≥150 ms after any packet to cap thermal rise and supervises junction temperature via a thermistor near the driver, throttling duty when >55 °C and inhibiting emission ≥60 °C. The scheduler can down-bias burst amplitude and/or reduce packet size N based on battery state-of-charge (SOC) to preserve runtime while maintaining repellency within the allowed SPL window. Emission is inhibited if IMU pitch >30°, battery is in brown-out (≤~3.4 V under load), or internal temperature ≥60 °C; a cool-off timer (e.g., 60–120 s) prevents rapid cycling after an inhibit clears.
[0029] Power Source -A single-cell Li-ion battery feeds a protection circuit (OVP/UVP/OCP) and a buck-boost regulator supplying regulated 5.0 V ±5% (driver) and 3.3 V (logic). The enclosure includes ESD protection on TRIG/ECHO lines. In one embodiment, the cell is 2000–3200 mAh, with OVP 4.25–4.35 V, UVP 2.7–2.9 V, and OCP 2.5–3.0 A trip threshold. The PMIC quiescent current is ≤ 50 µA and the controller enters sleep between ranging cycles with wake on timer or IMU movement, yielding an average idle current <2 mA. A reverse-polarity MOSFET and transient suppressor protect the driver rail, and EMI filtering (LC π network) on the piezo line reduces conducted emissions into the logic rail.
[0030] Power Management - The controller monitors battery state via an ADC channel and applies load-compensated SOC estimation (open-circuit voltage model with recent load history). Brown-out (e.g., ≤3.4 V) disables emission and reverts to safe idle until voltage recovery persists for ≥10 s. The system records (i) emission packet count, (ii) duty-cycle usage, (iii) battery SOC and minimum under-load voltage, and (iv) inhibit reasons (brown-out/thermal/IMU) to nonvolatile memory or rolling logs for maintenance analysis. A watchdog resets the controller from a wedged state and a graceful-shutoff routine is invoked if SOC falls below 10%, notifying the user via telemetry before disabling emission.
[0031] Real-Time Monitoring -The device streams distance, fused threshold state, duty usage, SPL set-point, and battery status over UART and/or BLE advertisements. Local serial plotting is provided for bench verification. BLE frames may include a condensed payload (e.g., 1-Hz broadcast of {toe_cm, heel_cm, fused_cm, emit_flag, duty_pct, vbat_mV}) and a diagnostic service accessible when the unit is in maintenance mode. Telemetry is read-only during patrol; emission cannot be remotely forced, and configuration changes require physical access or paired maintenance mode to avoid misuse.
[0032] Reliability & Self-Test - At startup, a self-test excites the emitter at three frequencies (e.g., 38/40/44 kHz) and verifies response using ranger echo statistics (or an optional reference microphone) to confirm acoustic output path continuity. The controller runs ranger loopback checks (TRIG/ECHO timing sanity, no-echo timeout) and a PMIC rail check (5 V/3.3 V within tolerance). Periodic background self-tests (e.g., every 10–15 minutes) perform a short, low-amplitude tick below deterrent SPL to verify driver health without producing a repellent stimulus. Failures block emission, raise a fault flag in telemetry, and prompt an audible/LED maintenance indicator if configured.
[0033] Gum-Boot Integration - Electronics are housed in an ankle-level IP67 module with shock-isolating grommets (30–50 Shore A); the directional emitter is tilted 15–25° downward. The module uses sealed connectors, strain-relieved wiring, and internal potting for high-vibration areas while keeping the controller cavity serviceable. Mass limits are maintained module ≤250 g, per-boot assembly ≤600 g and the center of mass is kept proximal to the ankle to reduce gait fatigue. Toe and heel rangers are mounted flush with the sole perimeter behind hydrophobic acoustic meshes to maintain performance in rain and mud while resisting clogging.
[0034] Ergonomics & Durability - The design tolerates rain, mud, and vibration encountered during patrol, with sealed connectors and strain-relieved wiring. The mechanical layout allows easy battery replacement and service. The enclosure meets IP67 for dust/water ingress; fasteners are corrosion-resistant; and exposed edges are radiused to prevent snags. Environmental validation may include drop tests (e.g., 1.0 m onto hard surface), thermal cycling (e.g., −10 °C to +50 °C), and splash-mud spray without functional loss.
[0035] Working Principle - During patrol, the controller sequentially pings toe then heel rangers with Δt (e.g., 10 ms), filters and fuses the readings, and if distance ≤ threshold (e.g., 5 m) with hysteresis (e.g., 1 m) activates the directional emitter using the randomized burst schedule. When conditions clear or safety gates are triggered (IMU/thermal/brown-out), the system idles in low-power mode and resumes monitoring. [ADD] An event counter increments on each emission packet; if repeated triggers occur >K times within T minutes (e.g., K=5, T=10), the scheduler may step-up frequency diversity and widen inter-burst jitter to further reduce habituation while staying within the duty-cycle governor.
[0036] The invention provides a non-lethal, wildlife-safe deterrent that directs ultrasonic energy toward an approaching tiger without physical contact or chemical irritants. By employing a directional piezo horn with a defined beam width and a downward tilt, acoustic exposure is concentrated near ground level where it is most effective, thereby reducing collateral impact on non-target fauna and on human users while maintaining humane operation.
[0037] The system delivers reliable detection with reduced false triggers through dual ground-level ultrasonic rangers positioned at the toe and heel. Sequential actuation with a defined dead-time suppresses cross-talk, while fused ranging with hysteresis ensures that emission is initiated only when proximity falls within a programmable threshold. This geometry improves sensitivity to low-profile approach vectors and enhances robustness in cluttered or rainy environments.
[0038] To limit habituation and preserve efficacy over time, emission is governed by a burst scheduler that randomizes burst length and spacing and hops carriers within the 35–45 kHz band. A duty-cycle governor caps average on-time and a cool-off interval prevents rapid cycling, producing a stimulus profile that is effective yet non-predictable and thermally safe for the hardware.
[0039] The device incorporates multi-layer safety controls and compliance features. Brown-out detection, thermal supervision, and IMU-based pose checks inhibit emission under unsafe conditions, while current-limited drive and SPL set-point calibration constrain acoustic output within specified bounds. ESD protection and rail filtering enhance electrical reliability in field conditions.
[0040] A power-efficient architecture extends field runtime. A protected Li-ion source feeds a buck-boost PMIC that provides regulated rails for logic and the driver stage, while firmware uses sleep states and low-quiescent components to minimize idle current. The system adapts burst amplitude and packet size to battery state-of-charge, preserving deterrence capability as energy reserves decline.
[0041] The rugged, wearable integration maintains ranger mobility and comfort. An ankle-level IP67 enclosure with shock-isolating grommets resists water, mud, and vibration, while mass and center-of-gravity are controlled to reduce gait fatigue. Flush-mounted rangers protected by hydrophobic meshes sustain ranging performance in adverse terrain without frequent maintenance.
[0042] Finally, telemetry and maintainability accelerate deployment and service. UART/BLE outputs provide live distance, fused trigger state, duty usage, SPL set-point, and battery status for diagnostics. Startup and periodic self-tests verify the acoustic path, power rails, and sensor timing without requiring disassembly, and logged inhibit reasons aid root-cause analysis. Collectively, these features yield a durable, field-ready repellent platform that enhances ranger safety while supporting humane wildlife conservation.
[0043] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described to best explain the principles of the present invention, and its practical application to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.
, Claims:1. A wearable, directional ultrasonic repellent system, integrated into a gum-boot, comprising:
a microcontroller having hardware capture/compare;
first and second ultrasonic ranging modules positioned at toe and heel;
a sequencer configured to trigger the modules sequentially with a dead-time Δt of 5–20 ms to reduce cross-talk;
a directional piezo horn emitter driven at a carrier within 35–45 kHz;
a burst scheduler configured to trigger emission only when a proximity threshold is met and to enforce a duty-cycle governor ≤10% over any 60-second window; and a power subsystem including a Li-ion battery with OVP/UVP/OCP and a buck-boost PMIC supplying 5 V for a driver stage and 3.3 V for logic;
the system further comprising an IP67-sealed enclosure with the emitter tilted 15–25° downward and a control stack implementing threshold/hysteresis for proximity decision.

2. The system as claimed in claim 1, wherein the control stack forms a fused distance estimate from the toe and heel modules and triggers emission only when distance ≤ a threshold of 2–8 m with hysteresis of 0.5–1.5 m.

3. The system as claimed in claim 1, wherein the piezo horn emitter provides a −6 dB beam-width of 20–40° and is driven to a peak acoustic output of about 110–125 dB re 20 µPa at 1 m.

4. The system as claimed in claim 1, wherein the driver stage comprises a half-bridge MOSFET referenced to a step-up transformer having a turns ratio between 1:6 and 1:12, the microcontroller setting PWM frequency to the selected carrier and regulating burst duration, and a current-sense resistor of 0.1–0.33 Ω with a comparator limiting instantaneous drive.

5. The system as claimed in claim 1, wherein the emitter assembly is mechanically decoupled from the boot shell using 30–50 Shore A grommets.

6. The system as claimed in claim 1, wherein the burst scheduler generates burst packets of 3–7 bursts with ±20% jitter in burst length of 50–300 ms and inter-burst spacing of 0.3–1.7 s, with carrier hopping among 38 kHz, 40 kHz, 42 kHz, and 44 kHz, and enforces emitter dead-time ≥150 ms after any packet.

7. The system as claimed in claim 1, further comprising safety interlocks that inhibit emission when IMU pitch exceeds 30°, when battery voltage is in brown-out at ≤ about 3.4 V under load, or when internal temperature ≥60 °C, and that throttle duty when temperature >55 °C, optionally with a cool-off timer of 60–120s.

8. The system as claimed in claim 1, wherein the Li-ion cell has a capacity of 2000–3200 mAh, the PMIC exhibits quiescent current ≤50 µA, and the controller enters sleep between ranging cycles with wake on timer or IMU movement to achieve average idle current <2 mA.

9. The system as claimed in claim 1, wherein telemetry is provided over UART and/or BLE, including distance, fused threshold state, duty usage, SPL set-point, and battery status, the telemetry being read-only during patrol and configuration changes requiring physical access or paired maintenance mode.

10. A method of deterring tiger approach using a wearable, directional ultrasonic device integrated into a gum-boot, the method comprising:
(a) sequentially actuating a toe ultrasonic ranger and, after a dead-time Δt of 5–20 ms, a heel ultrasonic ranger to obtain respective distance measurements;
(b) filtering the measurements and forming a fused distance estimate from the toe and heel rangers;
(c) comparing the fused distance to a proximity threshold within 2–8 m and applying hysteresis of 0.5–1.5 m to determine an emission state;
(d) when emission is permitted, driving a directional piezo horn emitter at a carrier within 35–45 kHz in burst packets of 3–7 bursts having burst length 50–300 ms and inter-burst spacing 0.3–1.7 s, including carrier hopping among 38, 40, 42, and 44 kHz;
(e) enforcing a duty-cycle governor that limits average ultrasonic emission to ≤10% over any rolling 60-second window and a post-packet emitter dead-time ≥150 ms; and
(f) inhibiting emission upon detection of any safety condition comprising IMU pitch >30°, battery brown-out at ≤ about 3.4 V under load, or internal temperature ≥60 °C, and otherwise resuming steps (a)–(e) during patrol.