Optimization design method for hydrographic measurement heavy hammer, heavy hammer, measuring instrument and measuring method

Abstract

The invention discloses an optimal design method of a hydrographic measurement heavy hammer, the heavy hammer and a measurement system. The method comprises the following steps: determining a water surface and water bottom tension change threshold value, a sinking speed and mass and volume constraints; establishing an optimization model which takes the weight volume V, the material density rho and the shape parameter as decision variables and takes the minimum mass m as a target function; and solving the model to obtain an optimal solution and determining the specification of the heavy hammer. The heavy hammer is designed and manufactured according to the method, the shape of the heavy hammer can be spherical, drop-shaped or torpedo-shaped, and the optimal parameters are as follows: the volume V0 is approximately equal to 1.3265 * 10 <-4 > m < 3 >, the density rho0 is approximately equal to 2922kg / m < 3 >, and the mass m0 is approximately equal to 0.3875 kg. The heavy hammer body can adopt a separable assembly structure, a balancing weight can be arranged in the heavy hammer body to adjust the density, and a temperature sensor and a wireless communication module can be integrated. According to the invention, empirical design is converted into scientific optimization, a tension change signal (deltaT1 is greater than or equal to 1.3 N, and deltaT2 is greater than or equal to 2.5 N) is ensured to be obvious, the sinking speed is high (greater than or equal to 1m / s), meanwhile, light weight (m is less than or equal to 0.5 kg) and multifunctional integration are realized, and the contradiction among measurement reliability, efficiency and equipment portability is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrological measuring instruments, in particular to a heavy weight optimization design method for hydrological measurement, a heavy weight designed by the method, and a hydrological measurement system and a measurement method comprising the heavy weight. In particular, the present application focuses on optimizing the design parameters (such as volume, density and shape) of the heavy weight through multiple constraint conditions to achieve high tension detection sensitivity, sinking efficiency and portability at the same time, and relates to the corresponding measuring instrument control strategy and measurement method. BACKGROUND

[0002] In hydrological measurement, underwater topographic survey, channel maintenance and mine blasting blast hole acceptance, it is often necessary to accurately determine the position of the water surface and the water bottom. A widely used traditional method is to use a rope to suspend a heavy weight for contact measurement. When the heavy weight contacts the water surface, the tension of the rope will decrease due to the action of buoyancy; when the heavy weight contacts the water bottom, the tension will decrease again due to the support of the water bottom to the heavy weight. By detecting the two tension change points, the depth of the water surface and the water bottom can be determined.

[0003] However, the existing heavy weight design method has significant shortcomings, mainly relying on the experience of designers and repeated trial and error, lacking systematic theoretical guidance. This experience-based design method is difficult to consider multiple key performance indicators at the same time, often having the following problems:

[0004] 1. Performance indicators contradict each other, difficult to balance: measurement practice puts forward multiple technical requirements for the heavy weight, which are mutually restrictive.

[0005] 1.1 Conflict between high sensitivity and portability: In order to clearly detect the weak signals of the heavy weight contacting the water surface (tension suddenly decreases) and the water bottom (tension further decreases), it is required that the net gravity (i.e. the difference between gravity and buoyancy) generated by the heavy weight in water be large enough to ensure that the tension change is significantly higher than the noise level of the sensor. This usually means that a larger mass or volume is needed. However, field hydrological measurement emphasizes the portability of the equipment, and there are strict upper limit constraints on the mass (m) and volume (V) of the heavy weight. A heavy heavy weight not only is inconvenient to carry, but also puts higher requirements on the driving mechanism (such as the motor) of the measuring instrument and the strength of the rope, increasing the system cost and volume.

[0006] 1.2 Conflict between sinking efficiency and volume / shape: In order to improve the measurement efficiency, it is required that the heavy weight has a fast terminal sinking speed to shorten the time of a single measurement. According to fluid mechanics, the terminal speed is positively related to the net gravity of the heavy weight in water, but is inversely related to the projected area (A) of the heavy weight in the direction of motion and the drag coefficient (C d) negative correlation. A heavy weight with high density but small volume may not have enough net gravity; while a heavy weight with large volume and large shape resistance (e.g. flat disc shape), even with larger mass, may have a slow sinking speed. Therefore, how to reduce the resistance by optimizing the shape under the given mass and volume constraints is the key to achieving high efficiency sinking.

[0007] 2. Lack of systematic optimization in the design process: In the prior art, the selection of design parameters (such as material density, volume, shape) of the weight is often isolated and based on trial and error, lacking a mathematical model and optimization design process that considers multiple key performance indicators such as tension detection sensitivity (AT1, AT2), sinking speed (v min ), portability (m max , V max ) in a unified manner. This results in a weight that can only perform well in one aspect, making it difficult to achieve the best balance between sensitivity, efficiency, and portability, restricting the improvement of the overall measuring instrument performance.

[0008] 3. Control strategy and reliability issues of the measuring system: In existing automated hydrological measuring instruments, the weight is usually controlled to be released by a motor-driven rotation, and the tension of the rope is detected in real time to determine whether the weight has reached the water bottom (or "hole bottom" in the acceptance operation of mine blasting holes). However, this active release control mode faces serious challenges in reliability in complex environments, especially when there is external collision interference (commonly seen in mine blasting holes). The specific manifestations are:

[0009] 3.1 Misjudgment leading to rope entanglement: When the weight has actually reached the water bottom / hole bottom, if the collision interference causes the tension sensor to fail to capture a clear characteristic signal, the system will continue to release the rope. At this time, the rope is prone to entanglement and knotting with internal components of the measuring system or the hole wall due to the loss of traction from the weight, resulting in equipment jamming, measurement failure, and even the need for on-site disassembly and repair, severely affecting operational efficiency.

[0010] 3.2 Misjudgment leading to measurement error: When the weight has not yet reached the water bottom / hole bottom, but collides with obstacles such as the hole wall during the falling process, a "bottom touch" like tension mutation signal is generated, and the system may mistakenly stop the release. This will result in a measured depth much smaller than the actual depth, causing a large measurement error and posing a risk to engineering decisions.

[0011] 3.3 Contradiction between efficiency and reliability: When the weight is required to sink quickly to improve measurement efficiency, the above problems are particularly prominent. Because the system must complete the identification and judgment of the tension characteristic within a very short time, any slight delay may result in a large amount of excess rope being released, causing serious entanglement accidents.

[0012] 4. The contradiction between the free-fall mode and the inherent electromagnetic resistance of the motor: To circumvent the control difficulties of the aforementioned active-fall mode, theoretically, the weight could be allowed to fall freely under its own weight, with the drive motor in a non-powered follow-up state. However, the physical structure of stepper motors, servo motors, DC motors, and other types of motors dictates that when their rotors rotate under external force, the stator and rotor will move relative to each other and cut magnetic lines of force, generating a reverse electromagnetic resistance torque (i.e., the motor enters a generator-like working state). This inherent electromagnetic resistance severely hinders the free fall of the weight, causing it to fail to fall or fall too slowly. To solve this problem, a common approach is to further increase the mass of the weight to overcome this resistance. However, this directly violates the core requirement of portability for the measurement system and creates a vicious cycle: increasing the weight's mass requires increasing the motor's drive power to complete the wire reeling; and a more powerful motor in follow-up mode usually generates greater electromagnetic resistance, which in turn requires the weight to become even heavier. This fundamental contradiction makes traditional motor solutions face insurmountable obstacles in achieving efficient and reliable free-fall of the weight.

[0013] 5. The Inertial Braking Challenge in Free-Descent Mode: Even if the electromagnetic resistance of the motor can be overcome to achieve free-descent of the weight, the drive motor and winding reel will continue to rotate due to their own inertia the instant the weight falls rapidly and hits the bottom of the water / hole. This causes excessive rope release, which can lead to rope slack and entanglement. Therefore, an effective braking mechanism must be provided to stop it in time. However, traditional mechanical friction braking methods have significant shortcomings: First, the braking force is difficult to adjust precisely and conveniently, making it impossible to achieve a smooth and controlled braking process and prone to impact; second, the braking force of traditional brakes usually cannot be adaptively adjusted according to the speed of the winding reel, which may result in insufficient braking force at high speeds and over-braking at low speeds, making the control strategy complex; finally, the friction pads are wear parts, and wear will lead to a decrease in braking performance, requiring frequent manual inspection and clearance adjustment, increasing maintenance costs and inconvenience, and reducing the overall reliability of the equipment.

[0014] Therefore, there is an urgent need in this field for a scientific method for optimizing the design of a weight, capable of systematically solving the aforementioned multi-objective optimization problems and designing a weight product that achieves the optimal balance between tension sensitivity, sinking efficiency, and portability. Simultaneously, there is also a need for a novel measurement system and control strategy that can fundamentally avoid the risks of misjudgment and entanglement, effectively overcome the electromagnetic resistance of the motor to achieve reliable free lowering, and possess intelligent, adaptive braking capabilities. This would comprehensively overcome the inherent defects of existing technical solutions in complex environments, ensuring the reliability, accuracy, and efficiency of measurements. Summary of the Invention

[0015] Based on the deficiencies of the existing technology described in the background section, the purpose of this invention is to provide a complete solution to systematically overcome numerous difficulties in the design, measurement control, and braking processes of the counterweight. Specifically, the objectives of this invention include:

[0016] This paper presents a scientific method for optimizing the design of a weight, aiming to address the shortcomings of contradictory performance indicators (Problem 1) and lack of systematic optimization in the design process (Problem 2) mentioned in the background art. This method establishes an optimization mathematical model under multiple constraints, unifying and quantifying the mutually restrictive technical requirements such as tension detection sensitivity, sinking efficiency, and portability. This allows for the systematic design of a weight that achieves the optimal balance among various performance parameters, laying a physical foundation for subsequent high-reliability measurements (corresponding to the core idea of ​​claims 1-3).

[0017] A weighted hammer product designed and manufactured based on the above method is provided. The weighted hammer has optimized volume, density, and streamlined shape (such as spherical, teardrop, or torpedo-shaped) to ensure that it can generate sufficiently significant tension change signals (ΔT1≥1.3N, ΔT2≥2.5N) and achieve rapid sinking while meeting strict portability requirements (mass ≤0.5kg, compact size). This fundamentally guarantees the sensitivity and efficiency of the measurement (corresponding to the specific products of claims 4-6).

[0018] An innovative hydrological measurement system and its control method are provided, aiming to completely solve the "measurement system control strategy and reliability problem" (Problem 3) mentioned in the background art. This system intelligently switches between two operating modes:

[0019] First working mode (line take-up / positioning mode): used for lifting the counterweight and precise positioning;

[0020] The second working mode (free descent mode): By physically disconnecting the stepper motor driver from the coil, it is put into an open-circuit follow-up state, which fundamentally eliminates the electromagnetic resistance generated by the motor's power generation effect (solving problem 4), ensuring that the hammer can sink freely and quickly entirely by gravity, thereby avoiding rope entanglement or measurement errors caused by misjudgment in the active descent control mode.

[0021] A smart, adaptive electromagnetic braking scheme is provided to solve the "inertial braking problem in free-fall mode" (Problem 5) described in the background art. This scheme utilizes the relative motion between a permanent magnet with alternating polarities on the end face of the wound wheel and a fixed induction coil to generate an induced current and braking torque positively correlated with the rotational speed. This design enables contactless, adaptive (higher braking force at higher speeds, lower braking force at lower speeds) smooth braking, eliminating the need for friction pads and manual adjustments due to wear, greatly improving the reliability and convenience of braking (corresponding to claim 8).

[0022] A hydrological measurement method based on the above system and a weight is provided. Through a specific sequence of steps (such as two free descents and slow lifting judgment), and by comprehensively utilizing tension data and length data, the method can automatically, accurately, and reliably identify the characteristic points of the weight contacting the water surface and the bottom, and calculate the precise water depth and water level. The entire measurement process is highly automated and the results are reliable (corresponding to claims 9-10).

[0023] In summary, the overall objective of this invention is to provide a complete high-performance, high-reliability, and highly portable hydrological measurement solution by combining "optimized counterweight design," "innovative system control strategy," and "intelligent braking technology," thereby comprehensively overcoming the shortcomings of existing technologies.

[0024] To achieve the above-mentioned objectives, the present invention adopts the following technical solution.

[0025] In a first aspect, the present invention provides a method for optimizing the design of a plumb bob for hydrological measurements, characterized by comprising the following steps:

[0026] S1: Based on the technical requirements for tension detection sensitivity, sinking efficiency, and portability in hydrological measurements, several interrelated design constraints are determined; these design constraints include at least the water surface tension change threshold ΔT1 caused by buoyancy, the water bottom tension change threshold ΔT2 caused by bottom support, and the terminal sinking velocity threshold v. min Maximum mass m max and the maximum volume V max ;

[0027] S2: Establish an optimization mathematical model, with the volume V, material density ρ, and shape parameters of the hammer as the core decision variables; take minimizing the mass m of the hammer as the objective function, where m = ρ × V; and transform the design constraints into constraint functions expressed by the decision variables V and ρ.

[0028] The constraint functions include at least:

[0029] The function used to constrain changes in surface tension: (ρ w ×g×V)≥ΔT1, where ρ w Let g be the density of water and g be the acceleration due to gravity.

[0030] The function used to constrain changes in seabed tension is: (ρ×V×g-ρ w ×g×V)≥ΔT2;

[0031] The function used to constrain the terminal's sinking speed is expressed as follows:

[0032] sqrt((2×g×V×(ρ-ρw )) / (ρ w ×A×C d ))≥v min

[0033] Where A is the projected area of ​​the weight in the direction of motion, and is a function of volume V and shape parameters; C d The drag coefficient corresponding to the shape parameter depends on the shape category;

[0034] S3: Solve the optimization mathematical model to obtain the solution that optimizes the objective function under the premise of satisfying all constraint functions, namely the combination of optimal volume V0, optimal density ρ0 and optimal shape parameter;

[0035] S4: Based on the solution, manufacture a physical product of the hammer that meets the technical requirements.

[0036] Furthermore, the shape parameters include the shape category of the weight, which is one of spherical, teardrop-shaped, or torpedo-shaped; and wherein, when the shape category is spherical, its drag coefficient C d The value is 0.4-0.5; when the shape category is teardrop, its drag coefficient C is... d The value ranges from 0.05 to 0.1; when the shape category is torpedo-shaped, its drag coefficient C d The value ranges from 0.03 to 0.05. The design constraints also include a maximum external dimension constraint, which is determined by the maximum length L. max and maximum radial dimension D max Common definition.

[0037] Preferably, the specific design parameters determined by the method are: the water surface tension change threshold ΔT1 is 1.3N, the water bottom tension change threshold ΔT2 is 2.5N, and the terminal sinking velocity threshold v min ≥1m / s, the maximum mass m max ≤0.5kg, the maximum length L max ≤100mm, the maximum radial dimension D max ≤65mm.

[0038] Secondly, the present invention provides a weight for hydrological measurement, characterized in that the weight is designed and manufactured using the method described in the first aspect, and the combination of its volume V, material density ρ, and shape parameters satisfies the following relationship, so that it can simultaneously achieve the following during hydrological measurement: tension change ΔT1 ≥ 1.3 N at water surface contact, tension change ΔT2 ≥ 2.5 N at water bottom contact, and terminal sinking velocity v. min ≥1m / s, total mass m≤0.5kg, maximum length L max≤100mm, maximum radial dimension D max ≤65mm, the shape is spherical, teardrop-shaped or torpedo-shaped.

[0039] In a preferred embodiment of the present invention, the weight is spherical in shape, with an optimal volume V0 ≈ 1.3265 × 10⁻⁶. -4 m 3 Based on this volume, its diameter D0≈63.27mm; its optimal density ρ0≈2922kg / m³ 3 Its optimal mass is approximately 0.3875 kg.

[0040] In another preferred embodiment of the present invention, the shape of the weight is teardrop-shaped, and its contour curve is generated by the following formula: In the Cartesian coordinate system, the curve is generated by the function y = ±(D0 / 2) × sqrt(1 - (x / L0)). 2 It is formed by rotating around the X-axis for one revolution, where L0 is the length and D0 is the maximum diameter; its optimal volume V0≈1.3265×10 -4 m 3 The optimal density ρ0≈2922kg / m³ 3 The optimal mass is m0≈0.3875kg, the length is L0≈80mm, and the maximum diameter is D0≈49.2mm.

[0041] In another preferred embodiment of the present invention, the shape of the hammer is torpedo-shaped, and its outline consists of a semi-elliptical head, a cylindrical middle section, and a frustum-shaped tail; the head curve is derived from the function y = ±(D0 / 2) × sqrt(1 - (x / (L_h))). 2 Define (x from 0 to L_h), where L_h is the head length, taken as L_h = 20mm; the middle length L_m = 43.3mm; the length of the frustum at the tail L_t = 26.7mm; and the diameter of the frustum's end d = 10mm; its optimal volume V0 ≈ 1.3265 × 10 -4 m 3 The optimal density ρ0≈2922kg / m³ 3 The optimal mass is m0≈0.3875kg, the total length is L0=L_h+L_m+L_t=90mm, and the maximum diameter is D0≈50mm.

[0042] Furthermore, the main body of the hammer adopts a separable assembly structure. The hammer has an internal cavity and one or more counterweight metal blocks. By adding, removing, or replacing the counterweight metal blocks of different masses, the overall density ρ and mass m of the hammer can be adjusted.

[0043] Thirdly, the present invention provides a hydrological measuring instrument, comprising: a weight as described in the second aspect;

[0044] A rope, used to suspend the weight;

[0045] A reel is used to wind and unwind the rope;

[0046] A stepper motor module, the output shaft of which is fixedly connected to the winding wheel, is used to drive the winding wheel to perform winding and unwinding operations;

[0047] A tension sensing module is used to detect the tension of the rope;

[0048] A length measurement module, used to measure the lowering length of the rope, includes an encoder and a length measuring pulley;

[0049] The processing control unit is signal-connected to the tension sensing module, length measurement module, and stepper motor module;

[0050] The stepper motor module includes a stepper motor, a driver, and a switch module;

[0051] The processing control unit is configured to have at least two operating modes:

[0052] In the first working mode, the switch module is closed to make the coil of the stepper motor conduct with the motor driver, so that the stepper motor provides power for active winding or precise positioning.

[0053] In the second working mode, the control switch module is disconnected, so that the stepper motor coil is physically disconnected from the motor driver, the stepper motor coil is in an open circuit state, the hammer falls freely under its own gravity, and the stepper motor is in a follow-up state.

[0054] The processing control unit is further configured to:

[0055] Based on the tension data detected by the tension sensing module, the tension change characteristics when the weight is lifted out of the water and when it contacts the bottom of the water are identified; based on the data detected by the length measurement module and the identified tension change characteristics, the distance from the measuring instrument to the bottom of the water and the water surface is calculated.

[0056] Furthermore, a plurality of permanent magnets are uniformly distributed along the circumferential direction on at least one end face of the winding wheel, and the magnetic poles of two adjacent permanent magnets are opposite.

[0057] The hydrological measuring instrument also includes a braking module, which includes a fixedly installed induction coil. The shape of the induction coil is arranged to have multiple continuously alternating S-shaped bends. The number of S-shaped bends is half the number of permanent magnets. The induction coil is installed in a position that keeps it adjacent to but not in contact with the end face of the winding wheel on which the permanent magnets are located.

[0058] When the winding wheel rotates, the change in the magnetic field of the permanent magnet causes the magnetic lines of force to cut the induction coil, thereby generating an induced current in the induction coil. By connecting or disconnecting the induction coil through the control circuit, the magnetic reluctance torque generated by the induced current can be used to achieve electromagnetic braking or release of the winding wheel.

[0059] Fourthly, the present invention provides a hydrological measurement method using a hydrological measuring instrument as described in the third aspect, characterized by comprising the following steps:

[0060] S1: Control the stepper motor module to enter the first working mode and lift the weight to the initial measurement point;

[0061] S2: Switch to the second working mode, allowing the hammer to fall freely under gravity, continuously collecting tension data, automatically identifying tension change feature points, and determining that the hammer has fallen to the bottom of the water.

[0062] S3: Switch to the first working mode, slowly raise the hammer so that it is lifted off the bottom of the water and suspended in the air;

[0063] S4: Switch to the second working mode, allowing the hammer to be lowered freely for the second time by gravity, continuously collecting tension data and rope lowering length data, automatically identifying tension change feature points, determining that the hammer has fallen to the bottom of the water, and calculating the distance from the bottom of the water to the initial measurement point;

[0064] S5: Switch to the first working mode, slowly retract the hammer so that it is suspended in the air above the water, collect tension data, automatically identify tension change feature points, and determine whether the hammer is in the air or in the water.

[0065] S6: If the weight is in the air, switch back to the first working mode and quickly retrieve the weight to the initial measurement point; if the weight is in the water, switch back to the first working mode, slowly raise the weight, continuously collect tension data and rope lowering length data, automatically identify tension change characteristic points, determine whether the weight has been raised out of the water, calculate the distance from the water surface to the initial measurement point, and quickly retrieve the weight to the initial measurement point.

[0066] Preferably, in step S2, the second working mode is switched so that the weight is lowered freely to the bottom of the water by gravity. During this process, the induction coil is turned on to form a closed circuit. The magnetic resistance torque generated by the induced current is used to achieve electromagnetic braking of the winding wheel. The electromagnetic braking force is adjusted by controlling the duty cycle of the induction coil being turned on and off. In steps S1, S3 to S6, the induction coil is turned off.

[0067] Compared with existing technologies, the technical solution provided by this invention, through the combination of systematic counterweight design, innovative measurement and control strategies, and intelligent braking technology, brings the following significant beneficial effects:

[0068] 1. Achieved global optimization of the overall performance of the hammer: By establishing a mathematical model with the goal of minimizing mass and integrating multiple constraints such as tension sensitivity, sinking speed, and portability, the previous experience-based, isolated trial-and-error design process was transformed into a scientific and systematic optimization process. This method can automatically find the optimal combination of the hammer's volume, density, and shape, fundamentally solving the long-standing technical problem of conflicting and difficult-to-balance performance indicators. It ensures that the designed hammer meets strict portability requirements (m≤0.5kg) while also possessing high tension detection sensitivity (ΔT1≥1.3N, ΔT2≥2.5N) and rapid sinking capability (v... min ≥1m / s).

[0069] 2. Significantly Improved Reliability and Accuracy of Hydrological Measurements: The invention's unique "free-descent mode" (second working mode) completely eliminates the electromagnetic resistance generated by the motor in its follow-up state by physically disconnecting the stepper motor driver from the coil, allowing the weight to sink freely and rapidly under gravity. This not only avoids the drawbacks of poor sinking due to motor resistance or the need to increase the weight's mass, but more importantly, it reduces the requirements for judging the tension signal when the weight contacts the bottom. Because of the free-descent mode, the stepper motor and winding wheel automatically stop after the weight reaches the bottom, preventing excessive rope release that could lead to rope slack or tangling. This effectively avoids misjudgments caused by external collisions in the traditional active-descent mode (such as premature stopping or excessive rope release), thus greatly improving the accuracy and reliability of water depth measurement and fundamentally eliminating rope tangling problems caused by misjudgments.

[0070] 3. Provides intelligent, adaptive, and maintenance-free braking capability: This invention utilizes an electromagnetic braking scheme based on permanent magnets and specially shaped induction coils to achieve contactless and wear-free braking. This completely eliminates the hassle of manual adjustment or replacement required after traditional friction brake pads wear out, improving the equipment's maintenance-free nature and long-term reliability. The magnetic resistance torque generated by this braking scheme is positively correlated with the rotational speed of the winding reel, enabling adaptive and smooth braking: high speed results in greater braking force, effectively suppressing inertia; low speed results in less braking force, avoiding excessive braking and impact. This "speed feedback" intelligent braking characteristic, without the need for complex control algorithms, can quickly and smoothly suppress the inertial rotation of the winding reel after the weight hits the bottom, effectively preventing excessive rope release and further ensuring smooth measurement and safe equipment operation.

[0071] 4. Enhanced portability and environmental adaptability: Through optimized design, the weight of the hammer is strictly controlled to within 0.5kg while ensuring performance. Its compact size greatly facilitates carrying and operation in the field. The hammer's assemblable structure and internal counterweight design allow users to adjust the hammer's density and weight through internal counterweights, improving product manufacturability.

[0072] 5. Achieves a high degree of automation and precision in the measurement process: The hydrological measurement method provided by this invention automates the entire process from the start of measurement to data calculation by intelligently switching working modes, automatically identifying tension characteristic points, and precisely controlling braking timing through the processing control unit. This not only reduces the technical requirements for operators but also minimizes errors introduced by human intervention, resulting in more objective and accurate measurement results and significantly improved work efficiency. Attached Figure Description

[0073] Figure 1 This is a flowchart of the weight optimization design method provided by the present invention.

[0074] Figure 2 This is a schematic diagram of the spherical weight provided by the present invention.

[0075] Figure 3 This is a schematic diagram of the contour curve of the teardrop-shaped weight provided by the present invention.

[0076] Figure 4 This is a schematic diagram of the torpedo-shaped hammer provided by the present invention.

[0077] Figure 5 This is a schematic diagram of the hydrological measuring instrument provided by the present invention.

[0078] Figure 6 This is a schematic diagram of the structural principle of the braking module in the hydrological measuring instrument provided by the present invention. Detailed Implementation

[0079] The hydrological measurement plumb bob optimization design method of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This part is intended to provide a thorough understanding of the technical solution of the present invention, but not to limit the present invention.

[0080] Example 1: An optimized design of a counterweight for a hydrological measuring instrument

[0081] This embodiment aims to design a weight for a handheld hydrographic measuring instrument that is lightweight and can quickly and accurately measure water depth.

[0082] S1: Determine design constraints

[0083] Based on the actual needs of hydrological measurement and the portability requirements of instruments, the following key design constraints were determined. The values ​​of these constraints were determined by a comprehensive consideration of sensor performance, measurement reliability, operational efficiency, and ergonomics.

[0084] Water surface tension change threshold ΔT1 ≥ 1.3N: This threshold is primarily to ensure that the measurement system can reliably detect the event of the weight entering the water. This value is set based on the typical performance of commonly used miniature tension sensors (such as strain gauge or MEMS sensors). The threshold of 1.3N (approximately 133 grams of force) is much greater than the sensor's background noise and the amplitude of random environmental interference (such as water surface fluctuations), providing a sufficient signal-to-noise ratio to ensure that the system can clearly and unambiguously identify the water entry signal, while not unnecessarily requiring the weight to be very large.

[0085] The underwater tension change threshold ΔT2 ≥ 2.5N: This threshold ensures the system can accurately determine whether the hammer has made stable contact with the bottom (or the bottom of the hole). The setting of 2.5N (approximately 255 grams of force) is primarily based on anti-interference considerations. In complex underwater environments (especially mine blast holes), this threshold is much larger than the tension fluctuation amplitude caused by non-supporting collisions between the hammer and silt, gravel, or the hole wall. Only when the hammer receives stable support and the tension continuously and significantly decreases will it be judged as "bottom contact," effectively avoiding misjudgments. Simultaneously, ΔT2 > ΔT1, which provides the processing control unit with two distinct characteristic signals of different values, enhancing the reliability of pattern recognition.

[0086] Terminal sinking speed threshold v min ≥1 m / s: This threshold directly affects the efficiency of field measurements. For a 10-meter-deep body of water, increasing the terminal velocity to 1 m / s can shorten the single descent time to about 10 seconds, significantly improving the speed of single-point measurements. At 1 m / s, this speed ensures efficiency without being too fast to control or generating excessive fluid impact.

[0087] Portability constraints: Considering the user experience and system integration of handheld devices, a maximum mass m is set. max ≤0.5kg, maximum length L max ≤100mm and maximum radial dimension D max ≤65mm. Limiting the weight of the counterweight to within 0.5kg is key to ensuring the overall lightweight design and ease of long-term field transport and operation. The corresponding size limitation ensures the counterweight can be compactly integrated into a reasonably sized instrument body, resulting in a harmonious overall appearance, resembling a cane, ideal for single-handed operation. This weight and size limit also matches the capabilities of the selected micro-stepping motor and electromagnetic braking module, achieving system-level optimization.

[0088] S2: Establish an optimization mathematical model

[0089] The volume V, material density ρ, and shape parameters of the weight are used as the core decision variables. The following mathematical model is established:

[0090] Objective function: Minimize the mass of the hammer, i.e., min m=ρ×V.

[0091] Constraint functions:

[0092] Water surface tension constraint: The buoyant force on the weight when it is fully submerged must be greater than or equal to ΔT1.

[0093] (ρ w ×g×V)≥ΔT1

[0094] Wherein, the density ρ of water w Take 1000 kg / m 3 The acceleration due to gravity g is taken as 9.8 m / s². 2 .

[0095] Substituting the value: (1000 × 9.8 × V) ≥ 1.3

[0096] Bottom tension constraint: When the weight is at the bottom of the water, the difference between its weight and buoyancy (i.e., net weight) must be greater than or equal to ΔT2.

[0097] (ρ×V×g-ρ w ×g×V)≥ΔT2

[0098] Substituting the values: (ρ×V×9.8-1000×9.8×V)≥2.5

[0099] Terminal speed constraint: The terminal sinking speed must be greater than or equal to v. min .

[0100] sqrt((2×g×V×(ρ-ρ w )) / (ρ w ×A×C d ))≥v min

[0101] Among them, the projected area A and the drag coefficient C d It is determined by shape parameters.

[0102] Shape and size constraints: We initially selected three streamlined shapes for optimization and comparison.

[0103] Sphere: Its projected area A = π × (3V) / (4π))^(2 / 3), drag coefficient C d Take 0.47.

[0104] Teardrop shape: Its projected area A is a function of volume V and aspect ratio, and its drag coefficient C...d Take 0.07.

[0105] Torpedo shape: Its projected area A can be approximated by the maximum cross-sectional area of ​​the cylindrical part, and the drag coefficient C d Take 0.04.

[0106] At the same time, the overall dimensions of all shapes must meet the requirements of L0≤100mm and D0≤65mm.

[0107] S3: Solving the optimal mathematical model

[0108] The established model is solved using mathematical optimization software (such as MATLAB's fmincon function, Python's scipy.optimize library, or commercial software like ISIGHT). The solution process involves finding the combination of V, ρ, and shape that minimizes the objective function (mass m) within the feasible region defined by the constraints.

[0109] S4: Manufacturing physical products of the heavy hammer

[0110] The solver outputs the optimal solution, namely the optimal volume V0, optimal density ρ0, and recommended optimal shape. Designers then select the commercially available material closest to ρ0 based on this result and manufacture the product according to V0 and the determined shape.

[0111] Example 2: A spherical weight for a hydrological measuring instrument

[0112] This embodiment uses the design of a spherical weight as an example to explain in detail the implementation process of this method.

[0113] Step 1: Determine design constraints

[0114] Based on actual engineering requirements, the following constraint values ​​are set:

[0115] The threshold for water surface tension change is ΔT1 = 1.3 N.

[0116] The threshold for change in underwater tension is ΔT2 = 2.5 N.

[0117] Terminal sinking speed threshold v min =1.0m / s

[0118] Maximum mass m max =0.5kg

[0119] Maximum diameter d max = 0.065m (65mm)

[0120] The density of water is taken as ρ w =1000kg / m 3 Take the acceleration due to gravity as g = 9.8 m / s² 2 The spherical drag coefficient is taken as C.d =0.47.

[0121] Step 2: Establish an optimization model

[0122] Decision variables: volume V, material density ρ.

[0123] Objective function: min m=ρ×V.

[0124] Constraint functions:

[0125] Surface tension constraint: 1000 × 9.8 × V ≥ 1.3

[0126] Bottom surface tension constraint: (ρ×V×9.8)-(1000×V×9.8)≥2.5

[0127] Sinking velocity constraint: Spherical projected area A=π×((3V) / (4π))^(2 / 3), Substituting into the terminal velocity formula:

[0128] sqrt((2×9.8×V×(ρ-1000)) / (1000×π×((3V) / (4π))^(2 / 3)×0.47))≥1.0

[0129] Mass constraint: ρ×V≤0.5

[0130] Volume / Size Constraint: Volume of a sphere V ≤ (π × 0.065) 3 ) / 6

[0131] Density constraint: ρ > 1000 kg / m³ 3

[0132] Step 3: Solving the model

[0133] The above model is input into the optimization solver for solution. The solver iteratively calculates and finds the values ​​of V and ρ that minimize the mass m, while satisfying all constraints.

[0134] Step 4: Output and Results

[0135] The solver obtains a set of optimal solutions:

[0136] Optimal volume V0: approximately 1.3265e-4m 3

[0137] Optimal density ρ0: approximately 2922 kg / m³ 3

[0138] Therefore, we can calculate:

[0139] The optimal mass m0 = ρ0 × V × ≈ 2922 × 1.3265e-4 ≈ 0.3875 kg

[0140] The diameter D0 of the sphere is determined by the volume formula V = πD. 3 / 6. By reverse calculation, D=(6V / π)^(1 / 3)≈(6×1.3265e-4 / 3.1416)^(1 / 3)≈0.06327m, which is 63.27mm.

[0141] Terminal sinking speed verification:

[0142] The projected area of ​​the sphere is A = π × (D0 / 2). 2 =π×(0.06327 / 2) 2 ≈3.167e-3m 2 .

[0143] Let V0, ρ0, A, and C be... d Substituting 0.47 into the terminal speed formula:

[0144] v t =sqrt((2×9.8×1.3265e-4×(2922-1000)) / (1000×3.167e-3×0.47))≈1.08m / s

[0145] Conclusion: The terminal sinking velocity of the spherical weight is approximately 1.08 m / s, which satisfies and is slightly higher than v. min Design constraint ≥1.0m / s.

[0146] Verification has shown that the spherical weight fully satisfies all initial constraints.

[0147] like Figure 2 The diagram shown is a structural schematic of an embodiment of the spherical weight. The spherical weight is a composite structure, consisting of an aluminum alloy sphere 218 with a diameter of 63.27 mm and a steel core 217 with a diameter of 10 mm. The density of the aluminum alloy sphere is 2700 kg / m³. 3 The steel core density is 7700 kg / m³. 3 .

[0148] Example 3: A teardrop-shaped weight for a hydrological measuring instrument

[0149] This embodiment designs a teardrop-shaped weight. It uses the same design inputs (ΔT1, ΔT2, v) as embodiment 2. min m max ), and the maximum length L max Set to 100mm, maximum diameter D max The drag coefficient C of the teardrop shape is set to 65mm. d Take 0.06.

[0150] The teardrop-shaped profile is typically derived from a standard teardrop curve (such as the Haken shape) or by the function y = ±(D / 2) × sqrt(1 - (x / L)). 2 It is formed by rotating around the X-axis once, and its projected area A has a definite geometric relationship with its volume V, length L and diameter D.

[0151] Optimization model establishment and solution:

[0152] The objective function and constraints 1, 2, and 4 of the optimization model are the same as in Example 1. The key changes are in the sinking velocity constraint and the size constraint.

[0153] Sinking velocity constraint: It is necessary to establish a functional relationship between the projected area A of the teardrop shape, the volume V, and the aspect ratio (L / D), and substitute them into the terminal velocity formula for constraint.

[0154] Size constraints: L≤0.1m and D≤0.065m must be met.

[0155] The solver solves the model with the new constraints. Under the premise of satisfying all performance constraints, the solver adjusts V, ρ, and the aspect ratio (L / D) to obtain the solution that minimizes the mass. The optimal solution is:

[0156] Optimal volume V0: approximately 1.3265e-4m 3 (To satisfy the same ΔT1 and ΔT2, the required volume is the same as that for a sphere)

[0157] Optimal density ρ0: approximately 2922 kg / m³ 3

[0158] Optimal mass m0: approximately 0.3875 kg

[0159] Optimal length L0: 80mm

[0160] Optimal diameter D0: 49.2 mm

[0161] Terminal sinking speed verification:

[0162] The maximum projected area of ​​a teardrop shape in the direction of motion is a circle.

[0163] A = π × (D0 / 2) 2 =π×(0.0492 / 2) 2 ≈1.963e-3m 2 .

[0164] Let V0, ρ0, A, and C be... d Substituting 0.06 into the terminal speed formula:

[0165] v t=sqrt((2×9.8×1.3265e-4×(2922-1000)) / (1000×1.963e-3×0.06))≈3.47m / s

[0166] Conclusion: The terminal sinking velocity of the teardrop-shaped weight is approximately 3.47 m / s, which is significantly higher than the minimum requirement of 1.0 m / s, demonstrating the great advantage of its streamlined design.

[0167] like Figure 3 The figure shown is a schematic diagram of the contour curve of an embodiment of the teardrop-shaped weight.

[0168] Example 4: A torpedo-shaped weight for a hydrological measuring instrument

[0169] This embodiment designs a torpedo-shaped weight. Its design inputs are exactly the same as in Embodiment 2. The drag coefficient C of the torpedo shape... d Take 0.04.

[0170] A torpedo-shaped profile typically consists of a semi-elliptical head, a cylindrical middle section, and a frustum-shaped tail. The head curve can be represented by the function y = ±(D / 2) × sqrt(1 - (x / L_h)). 2 Define a system with length L_h as the head length, length L_m as the middle cylinder length, length L_t as the tail frustum length, and diameter d as the frustum diameter. Its projected area A and volume V are functions of length L, diameter D, the semi-ellipse of the head, the middle cylinder, and the tail frustum.

[0171] Optimization model establishment and solution:

[0172] The modeling and solution process is similar to that of Example 2, but the torpedo-shaped geometric relationship must be used. Set the head length L_h = 20mm, the middle cylinder length L_m = 43.3mm, the tail truncated cone length L_t = 26.7mm, the truncated cone diameter d = 10mm, and the total length L = 90mm.

[0173] The optimal solution obtained by the solver is:

[0174] Optimal volume V0: approximately 1.3265e-4m 3

[0175] Optimal density ρ0: approximately 2922 kg / m³ 3

[0176] Optimal mass m0: approximately 0.3875 kg

[0177] Total length L0: 90mm

[0178] Maximum diameter D0: 50mm

[0179] Terminal sinking speed verification:

[0180] The maximum projected area of ​​a torpedo-shaped object is a circle with its maximum diameter as its width, A = π × (D0 / 2). 2 =π×(0.050 / 2) 2 ≈1.963e-3m 2 .

[0181] Let V0, ρ0, A, and C be... d Substituting 0.04 into the terminal speed formula:

[0182] v t =sqrt((2×9.8×1.3265e-4×(2922-1000)) / (1000×1.963e-3×0.04))≈4.25m / s

[0183] Conclusion: The terminal sinking velocity of the torpedo-shaped hammer is approximately 4.25 m / s, which is the highest among the three shapes, fully verifying its optimal aerodynamic performance.

[0184] Comprehensive comparison and conclusion:

[0185] Through the aforementioned optimization design method, this invention successfully obtained three optimal counterweight designs with different shapes. All of them can meet the rigid constraints of tension variation (ΔT1≥1.3N, ΔT2≥2.5N) and mass (m≤0.5kg).

[0186] Spherical weight: simple structure, easy to manufacture, and meets the sinking speed (1.08m / s).

[0187] Teardrop-shaped weight: Its sinking speed (3.47 m / s) is more than 3 times that of a spherical weight, significantly improving measurement efficiency.

[0188] Torpedo-shaped hammer: It has the highest sinking speed (4.25m / s), representing the best performance.

[0189] Example 5: A weight with adjustable density and intelligent measurement functions

[0190] This embodiment uses an optimal spherical weight as a basis to further illustrate how its adjustable density and intelligent measurement functions are implemented.

[0191] like Figure 4 As shown, the weight body adopts a detachable assembly structure, for example, through a threaded connection ( Figure 4 In the diagram, 111 is the upper housing and 112 is the lower housing, which are connected by thread 113. The counterweight has a sealed accommodating cavity 114 machined inside.

[0192] The cavity 114 contains two parts: a counterweight metal block 115 and a measurement and communication module 116.

[0193] Counterweight metal block 115: Made of high-density materials (such as lead and tungsten alloys), designed as multiple small modules of different masses. By increasing or decreasing the number of counterweight blocks, the final total mass and overall density of the weight can be precisely adjusted to infinitely approach the optimal values ​​m and ρ obtained from optimization calculations.

[0194] Measurement and Communication Module 116: This module integrates,

[0195] Temperature sensors (such as the DS18B20) are used to detect water temperature in real time;

[0196] The signal processing module (such as a microcontroller MCU) is used to acquire signals from the temperature sensor and perform analog-to-digital conversion and processing.

[0197] A wireless signal transmission module (Zigbee CC2530 or Bluetooth module) is used to package and send the processed temperature data to a mobile phone, tablet or dedicated receiver on the water surface.

[0198] A power module (such as a button battery) supplies power to the entire circuit.

[0199] All electronic components are waterproofed and sealed with potting compound.

[0200] Its workflow is as follows: A weight is dropped into the water. During its descent, a temperature sensor continuously measures the water temperature. The microcontroller reads the data and transmits it wirelessly via a wireless signal transmission module (Zigbee CC2530 or Bluetooth module). A receiving device on the water surface can then display the temperature value at the current water depth in real time. Simultaneously, the controller records the points of tension change at the water surface and bottom using a tension sensor, thus completing the depth measurement.

[0201] These five embodiments clearly and powerfully demonstrate that the optimized design method provided by this invention not only ensures the core detection performance of the plumb bob but also actively and significantly improves its operational efficiency through shape optimization. Designers can select the most suitable shape based on a comprehensive consideration of sinking speed, manufacturing process, and cost. Furthermore, Embodiment 5 not only perfectly realizes the core function of depth measurement but also provides additional value-added functions such as water temperature measurement and wireless data transmission. Moreover, the structural design allows for density adjustment, reflecting the high degree of integration and practicality of this invention. This fully demonstrates the effectiveness, scientific nature, and flexibility of the method of this invention.

[0202] Example 6: A hydrological measuring instrument

[0203] like Figure 5 As shown, the hydrological measuring instrument in this embodiment includes a weight 1, a rope 2, a winding reel 3, a stepper motor module 4, a tension sensing module 5, a length measuring module 6, a processing control unit 7, and a braking module 8.

[0204] The weight 1 is manufactured using the aforementioned optimized design method, and its specific parameters and shape can adopt any one of the schemes in Embodiments 2 to 5. As a further optimization, the winding wheel 3 is fixedly connected to the output shaft of the stepper motor module 4, and its hub is provided with regular rope grooves to ensure that the rope 2 is wound neatly.

[0205] The stepper motor module 4 includes a stepper motor 41, a motor driver 42, and a switching module 43. The output shaft of the stepper motor 41 is fixedly connected to the winding wheel 3. The switching module 43 is preferably a MOSFET switching circuit with high current carrying capacity, which is controlled by the GPIO port of the processing control unit 7 and is used to connect or physically disconnect the connection between the coil of the stepper motor 41 and the motor driver 42.

[0206] The tension sensing module 5 employs a high-precision strain gauge sensor, mounted on the side of the winding reel 3, with a fixed pulley 51 installed on it for real-time detection of the tension in the rope 2. Its analog signal is amplified by an instrumentation amplifier and converted by an ADC before being transmitted to the processing and control unit 7.

[0207] The length measurement module 6 includes a high-precision rotary encoder and a length measuring pulley 61, which is located below the winding wheel 3. The rope 2 passes sequentially through the winding wheel 3, the fixed pulley 51, and the length measuring pulley 61. The length measuring pulley 61 is fixedly connected to the output shaft of the rotary encoder and is used to measure the number of rotations of the length measuring pulley 61. Combined with the effective diameter of the length measuring pulley 61, the lowering length of the rope 2 is calculated.

[0208] The processing control unit 7 is the core control component, employing a 32-bit microcontroller based on an ARM Cortex-M4 core. It stores preset programs and is configured to have at least two operating modes:

[0209] First working mode (reel in / positioning mode): The control switch module 43 is closed, so that the coil of the stepper motor 41 is connected to the motor driver 42. At this time, the stepper motor 41 is used as a motor, and the motor driver 42 provides power according to the instructions of the processing control unit 7 to perform active reel in or precise positioning operation.

[0210] Second working mode (free fall mode): The control switch module 43 is completely disconnected, so that the coil of the stepper motor 41 is physically and completely separated from the motor driver 42, and the coil of the stepper motor 41 is in an open circuit state. At this time, the hammer 1 falls freely under its own weight, dragging the winding wheel 3 to rotate, while the rotor of the stepper motor 41 spins freely, in a follow-up state with almost no electromagnetic resistance, ensuring the free fall of the hammer.

[0211] like Figure 6As shown, 40 neodymium iron boron permanent magnets 81 are uniformly embedded in the circumferential direction on at least one end face of the winding wheel 3, with the magnetic poles (N / S poles) of adjacent permanent magnets 81 arranged in opposite polarities. This arrangement creates an alternating magnetic field environment.

[0212] The braking module 8 includes an induction coil 82 fixedly mounted on the instrument housing. The induction coil 82 is made of enameled wire and its shape is precisely arranged to have 20 consecutive alternating S-shaped bends 821, the number of which is half the number of permanent magnets 81 on the winding reel 3. The induction coil 82 is positioned so that its plane is parallel to the end face of the winding reel 3 where the permanent magnets 81 are located, with a small gap (e.g., 0.5-1 mm) to ensure that the magnetic field of the permanent magnets 81 effectively cuts the straight sections 822 of the induction coil 82 during rotation without making contact. The two ends of the induction coil 82 are connected to a relay or electronic switch controlled by the processing control unit 7.

[0213] Its working mechanism is as follows: When the winding wheel 3 rotates, the permanent magnet 81 with alternating polarities generates a changing magnetic field, causing the magnetic lines of force to continuously cut the straight portion 822 of the fixed induction coil 82. According to Faraday's law of electromagnetic induction, an induced current is generated in the induction coil 82. By connecting the induction coil 82 through the control circuit to form a closed loop, this induced current generates a magnetic resistance torque in the coil itself that interacts with the magnetic field of the permanent magnet, hindering the rotation of the winding wheel, thus achieving electromagnetic braking. When the loop is disconnected, the braking effect disappears. This process is contactless and wear-free, and the braking torque naturally increases with the increase of rotational speed, achieving adaptive and smooth braking.

[0214] Example 7: Specific Implementation of a Hydrological Measurement Method

[0215] This method uses the aforementioned hydrological measuring instrument and specifically includes the following steps:

[0216] S1: Measurement Preparation and Initial Positioning

[0217] The processing control unit 7 controls the stepper motor module 4 to enter the first working mode, driving the winding wheel 3 to rotate, lifting the weight 1 and stabilizing it at the initial measurement point (usually the instrument housing outlet).

[0218] During this process, the processing control unit 7 records the readings of the length measuring module 6 and zeros or calibrates the length reference. At the same time, the circuit of the induction coil 82 of the braking module 8 is disconnected, so that it does not produce a braking effect.

[0219] S2: First Free Drop and Bottom-Touch Detection

[0220] The processing control unit 7 disconnects the control switch module 43, switching to the second working mode (free lowering mode). At the same time, in order to control the lowering speed of the hammer 1 to prevent it from being too fast, the processing control unit 7 controls the relay of the braking module 8 to close, so that the induction coil 82 forms a closed circuit and generates an adaptive electromagnetic braking effect.

[0221] The weight 1 is lowered freely by gravity. The processing control unit 7 continuously acquires data from the tension sensing module 5 at a sampling rate of no less than 100Hz.

[0222] The processing control unit 7 executes a bottom-contact judgment algorithm: This algorithm not only monitors the absolute value of the tension, but more importantly, it monitors the rate of change (differential) of the tension and the time it remains below a certain low threshold (e.g., 20% of the initial tension). When the tension is detected to drop sharply in a very short time (e.g., <100ms) and remain at a low level for more than a preset time (e.g., 200ms), and the magnitude of this drop exceeds ΔT2 (2.5N), it is determined that the weight 1 has reliably contacted the bottom. This algorithm can effectively filter out brief collision interference signals.

[0223] S3: First Promotion and Status Confirmation

[0224] Upon detecting bottoming out, the processing control unit 7 immediately controls the braking module 8 to disconnect the circuit of the induction coil 82, releasing the brake. Subsequently, the control switch module 43 closes, switching back to the first operating mode.

[0225] Stepper motor 41 slowly lifts the weight 1 a short distance (equivalent to a rope length of 40-80cm) at a low speed (e.g., 50-100rpm), causing the weight 1 to detach from the bottom of the water and be suspended in the air. By monitoring the tension to return to a stable value, it is confirmed that the weight 1 has detached from the bottom of the water.

[0226] S4: Second Free Descent and Precise Depth Sounding

[0227] Switch back to the second working mode (free-fall mode) and activate the induction coil 82 of the braking module 8 to perform moderate braking.

[0228] The weight 1 is lowered freely for the second time. The length measurement module 6 synchronously and continuously acquires and records tension data (e.g., 100Hz) from the processing control unit 7.

[0229] When a reliable bottom-touching signal is detected again, the processing control unit 7 immediately records the length measurement value L1 at this moment. This length L1 is the precise distance (hole depth) from the initial measurement point to the bottom.

[0230] S5: Second Lift and Medium Judgment

[0231] Switch back to the first working mode, disconnect the braking module 8, and slowly raise the weight 1 again to lift it off the bottom of the water and put it in a suspended state.

[0232] The processing control unit 7 collects the stable tension value F_c at this time.

[0233] Execute the medium determination algorithm: compare F_c with the initial air tension F_air stored in memory.

[0234] Judgment logic: If |F_c-F_air| < threshold Th (for example, Th = 0.3N), then it is determined that the hammer 1 is in the air.

[0235] If F_c is significantly less than F_air and the difference is greater than Th, then it is determined that the hammer 1 is still in the water.

[0236] This judgment is crucial in determining whether it is necessary to measure the water surface position.

[0237] S6: Final recovery and water surface positioning

[0238] Scenario A (judged as being in the air): The processing control unit 7 controls the stepper motor module 4 to directly retract the weight 1 to the initial measurement point at a high speed (e.g., 400 rpm), and the measurement ends.

[0239] Scenario B (judged as underwater): The processing control unit 7 controls the stepper motor module 4 to slowly lift the weight 1 at a low speed, while continuously and synchronously collecting tension and length data.

[0240] The processing control unit 7 executes the water outlet identification algorithm: monitors tension data, and when it is detected that the tension increases abruptly from a low value (net weight in water) to a value close to the weight in air, and the change exceeds ΔT1 (1.3N), it is determined that the weight 1 has been lifted out of the water.

[0241] Record the length measurement value L2 at this moment. L2 is the distance from the initial measurement point to the water surface, and L1-L2 is the water depth.

[0242] Then, quickly retract the weight 1 to the initial measurement point.

[0243] Finally, the processing control unit 7 can calculate and display the results such as bottom depth (L1), water level (L2), and water depth (L1-L2).

[0244] The above detailed embodiments clearly illustrate the implementation path of the technical solution of the hydrological measuring instrument and hydrological measuring method of the present invention. However, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of knowledge possessed by those skilled in the art. Therefore, the scope of protection of the present invention is not limited to the above examples, and all technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention.

Claims

1. A method for optimizing the design of a weight for hydrological measurements, characterized in that, Includes the following steps: S1: Based on the technical requirements for tension detection sensitivity, sinking efficiency, and portability in hydrological measurements, several interrelated design constraints are determined. These design constraints include at least the water surface tension change threshold ΔT1 caused by buoyancy, the water bottom tension change threshold ΔT2 caused by bottom support, and the terminal sinking velocity threshold v. min Maximum mass m max and the maximum volume V max ; S2: Establish an optimization mathematical model, with the volume V, material density ρ, and shape parameters of the hammer as the core decision variables; take minimizing the mass m of the hammer as the objective function, where m = ρ × V; and transform the design constraints into constraint functions expressed by the decision variables V and ρ. S3: Solve the optimization mathematical model to obtain the solution that optimizes the objective function under the premise of satisfying all constraint functions, namely the combination of optimal volume V0, optimal density ρ0 and optimal shape parameter; S4: Based on the solution, manufacture a physical product of the hammer that meets the technical requirements. In step S2, the constraint function includes at least: The function used to constrain changes in surface tension: (ρ w ×g×V)≥ΔT1, where ρ w Let g be the density of water and g be the acceleration due to gravity. The function used to constrain changes in seabed tension is: (ρ×V×g-ρ w ×g×V)≥ΔT2; The function used to constrain the terminal's sinking speed is expressed as follows: sqrt((2×g×V×(ρ-ρ w )) / (p w ×A×C d ))≥v min Where A is the projected area of ​​the weight in the direction of motion, and is a function of volume V and shape parameters; C d This is the drag coefficient corresponding to the shape parameters.

2. The method according to claim 1, characterized in that, The shape parameters include the shape category of the weight, which is one of spherical, teardrop-shaped, or torpedo-shaped; and wherein, when the shape category is spherical, its drag coefficient C is... d The value is 0.4-0.5; when the shape category is teardrop, its drag coefficient C is... d The value ranges from 0.05 to 0.1; when the shape category is torpedo-shaped, its drag coefficient C d The value ranges from 0.03 to 0.

05. The design constraints also include a maximum external dimension constraint, where the maximum external dimension is determined by the maximum length L. max and maximum radial dimension D max Common definition.

3. The method according to any one of claims 1-2, characterized in that, The water surface tension change threshold ΔT1 is 1.3N, the water bottom tension change threshold ΔT2 is 2.5N, and the terminal sinking velocity threshold v min ≥1m / s, the maximum mass m max ≤0.5kg, the maximum length L max ≤100mm, the maximum radial dimension D max ≤65mm.

4. A weight for hydrological measurement, characterized in that, The weight is designed and manufactured using the method described in any one of claims 1-3. Its volume V, material density ρ, and the combination of its shape parameters satisfy the following relationship, enabling it to simultaneously achieve the following during hydrological measurements: tension change ΔT1 ≥ 1.3 N at water surface contact, tension change ΔT2 ≥ 2.5 N at water bottom contact, and terminal sinking velocity v. min ≥1m / s, total mass m≤0.5kg, maximum length L max ≤100mm, maximum radial dimension D max ≤65mm, the shape is spherical, teardrop-shaped or torpedo-shaped.

5. The weight according to claim 4, characterized in that, When its shape is spherical, its optimal volume V0≈1.3265×10 -4 m 3 Based on this volume, its diameter D0≈63.27mm; its optimal density ρ0≈2922kg / m³ 3 Its optimal mass is approximately m0 ≈ 0.3875 kg. When its shape is teardrop-shaped, its contour curve is generated by the following formula: In the Cartesian coordinate system, the curve is generated by the function y = ±(D0 / 2) × sqrt(1 - (x / L0)). 2 It is formed by rotating around the X-axis for one revolution, where L0 is the length and D0 is the maximum diameter; its optimal volume V0≈1.3265×10 -4 m 3 The optimal density ρ0≈2922kg / m³ 3 The optimal mass is m0≈0.3875kg, the length is L0≈80mm, and the maximum diameter is D0≈49.2mm. When its shape is classified as torpedo-shaped, its outline consists of a semi-elliptical head, a cylindrical middle section, and a frustum-shaped tail; the head curve is derived from the function y = ±(D0 / 2) × sqrt(1 - (x / (L_h))). 2 Define (x from 0 to L_h), where L_h is the head length, taken as L_h = 20mm; the middle length L_m = 43.3mm; the length of the frustum at the tail L_t = 26.7mm; and the diameter of the frustum d = 10mm; its optimal volume V0 ≈ 1.3265 × 10 -4 m 3 The optimal density ρ0≈2922kg / m³ 3 The optimal mass is m0≈0.3875kg, the total length is L0=L_h+L_m+L_t=90mm, and the maximum diameter is D0≈50mm.

6. The weight according to any one of claims 4-5, characterized in that, The main body of the hammer adopts a detachable assembly structure. The hammer has an internal cavity and one or more counterweight metal blocks. By adding, removing or replacing the counterweight metal blocks of different masses, the overall density ρ and mass m of the hammer can be adjusted.

7. A hydrological measuring instrument, comprising: The weight according to any one of claims 4-5; A rope, used to suspend the weight; A reel is used to wind and unwind the rope; A stepper motor module, whose output shaft is fixedly connected to the winding wheel, is used to drive the winding wheel to perform winding and unwinding operations; a tension sensing module is used to detect the tension of the rope; A length measurement module, used to measure the lowering length of the rope, includes an encoder and a length measuring pulley; The processing control unit is signal-connected to the tension sensing module, length measurement module, and stepper motor module; wherein, the stepper motor module includes a stepper motor, a driver, and a switch module; The processing control unit is configured to have at least two operating modes: In the first working mode (reel-in / positioning mode), the switch module is closed to connect the coil of the stepper motor to the motor driver, thereby providing power from the stepper motor for active reel-in or precise positioning. In the second working mode (free fall mode), the control switch module is disconnected, so that the stepper motor coil is physically disconnected from the motor driver, the stepper motor coil is in an open circuit state, the hammer falls freely under its own gravity, and the stepper motor is in a follow-up state. The processing control unit is further configured to: Based on the tension data detected by the tension sensing module, the tension change characteristics of the weight when it is lifted out of the water and when it contacts the bottom of the water are identified. The distance from the measuring instrument to the bottom and surface of the water is calculated based on the data detected by the length measurement module and the identified tension change characteristics.

8. The hydrological measuring instrument according to claim 7, characterized in that, The winding reel has a plurality of permanent magnets evenly distributed along the circumferential direction on at least one end face, and the magnetic poles of two adjacent permanent magnets are opposite; the hydrological measuring instrument also includes a braking module, the braking module including a fixedly arranged induction coil, the shape of the induction coil being arranged with a plurality of continuous alternating S-shaped bends, the number of the S-shaped bends being half the number of the permanent magnets, and the induction coil being installed in a position that keeps it adjacent to but not in contact with the end face of the winding reel on which the permanent magnets are located; When the winding wheel rotates, the change in the magnetic field of the permanent magnet causes the magnetic lines of force to cut the induction coil, thereby generating an induced current in the induction coil. By connecting or disconnecting the induction coil through the control circuit, the magnetic reluctance torque generated by the induced current can be used to achieve electromagnetic braking or release of the winding wheel.

9. A hydrological measurement method using a hydrological measuring instrument as described in any one of claims 7-8, characterized in that, Includes the following steps: S1: Control the stepper motor module to enter the first working mode (wind take-up / positioning mode) and lift the weight to the initial measurement point; S2: Switch to the second working mode (free descent mode), allowing the hammer to descend freely under gravity, continuously collecting tension data, automatically identifying tension change feature points, and determining that the hammer has fallen to the bottom of the water; S3: Switch to the first working mode (line reeling / positioning mode), slowly raise the hammer so that it leaves the bottom of the water and is suspended in the air; S4: Switch to the second working mode (free descent mode), allowing the hammer to be lowered freely for the second time by gravity, continuously collecting tension data and rope descent length data, automatically identifying tension change feature points, determining that the hammer has fallen to the bottom of the water, and calculating the distance from the bottom of the water to the initial measurement point; S5: Switch to the first working mode (line reeling / positioning mode), slowly retract the hammer, so that the hammer is lifted off the bottom of the water and suspended in the air, collect tension data, automatically identify tension change feature points, and determine whether the hammer is in the air or in the water. S6: If the weight is in the air, switch back to the first working mode (line reel / positioning mode) and quickly reel the weight back to the initial measurement point; if the weight is in the water, switch back to the first working mode (line reel / positioning mode), slowly raise the weight, continuously collect tension data and rope lowering length data, automatically identify tension change characteristic points, determine whether the weight has been raised out of the water, calculate the distance from the water surface to the initial measurement point, and quickly reel the weight back to the initial measurement point.

10. The hydrological measurement method according to claim 9, characterized in that, In step S2, the system switches to the second working mode (free descent mode), allowing the weight to be freely lowered to the bottom of the water by gravity. During this process, the induction coil is switched on to form a closed circuit. The magnetic resistance torque generated by the induced current is used to achieve electromagnetic braking of the winding wheel. The electromagnetic braking force is adjusted by controlling the duty cycle of the induction coil being switched on and off. In steps S1, S3 to S6, the induction coil is switched off.

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