A soft soil free fall penetration instrument test system
By using a drone to carry the penetrator, combined with multiple sensors and a cleaning unit, the problem of terrain and environmental limitations in traditional soft soil exploration technology has been solved, enabling high-precision survey data acquisition and equipment reuse.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN RESEARCH INSTITUTE OF CHINA UNIVERSITY OF MINING & TECHNOLOGY
- Filing Date
- 2025-05-14
- Publication Date
- 2026-05-29
AI Technical Summary
Traditional soft soil exploration techniques are limited by terrain and environment, making it difficult to accurately reach the designated location, resulting in limited survey range and insufficient data collection accuracy.
The device employs a drone to carry the penetrator, combined with clamping and winch components. It utilizes RTK and visual positioning systems to achieve precise hovering and release. In conjunction with data collection from multiple sensors, a cleaning unit is designed to ensure the equipment can be reused.
It enables high-precision surveying in complex terrain, expands the survey range, improves the accuracy of data acquisition and the reusability of equipment, and reduces surveying costs.
Smart Images
Figure CN224299930U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of geotechnical engineering investigation technology, specifically relating to a soft soil free-fall penetration test system. Background Technology
[0002] A free-fall penetrometer (FFP) is an instrument used to measure the undrained shear strength of cohesive soils. It is a new type of in-situ marine instrument developed based on static cone penetration testing. The FFP relies on the kinetic energy gained during its free fall to contact the cohesive seabed surface with a certain initial velocity, which then gradually decreases to zero under the influence of resistance. By installing an accelerometer on the FFP, the real-time acceleration of the penetrometer during its fall in water and penetration into the soil can be measured. Then, by solving the equations of motion, the undrained strength of the seabed soil can be calculated.
[0003] Traditional soft soil exploration techniques primarily rely on shipborne or land-based equipment, severely limiting the accuracy and applicability of soft soil exploration. For example, shipborne penetrators depend on large engineering vessels (such as geological survey vessels), which are inaccessible in intertidal zones with significant water depth variations, especially in shallow areas less than 3 meters deep. This restricts the exploration range, requiring operation only during specific tidal windows, making it difficult to accurately locate the survey position and ensuring data acquisition accuracy. Furthermore, wheeled or tracked land-based penetrators are prone to getting stuck in soft soil areas such as tidal flats and swamps, exhibiting extremely poor maneuverability. In silty soil layers with high water content, the equipment's weight leads to insufficient ground bearing capacity, necessitating the laying of temporary steel plates or gravel roadbeds. Limited by the exploration environment, it is difficult to reach specific survey areas, affecting the positioning and detection accuracy of the exploration. Utility Model Content
[0004] In order to solve the problems existing in the prior art, the purpose of this utility model is to provide a soft soil free fall penetration test system that is not limited by the terrain environment during the test process, makes it easy to reach the designated test location, obtain more accurate survey data, and has a wider range of applications.
[0005] The technical solution of this utility model is:
[0006] A soft soil free-fall penetration test system includes a penetration instrument body and further includes:
[0007] Flight equipment;
[0008] The carrying unit includes a gimbal and a clamping assembly. The gimbal is fixedly mounted on the flight equipment, and the clamping assembly is fixed to the bottom of the gimbal for clamping and releasing the penetrator body.
[0009] The traction unit includes a traction rope and a winch assembly. One end of the traction rope is fixed to the body of the penetrator, and the other end is connected to the winch assembly. The winch assembly is fixed to the gimbal and is used to wind and release the traction rope.
[0010] The control unit includes a positioning module and a processing module. The positioning module is used to locate the target point and hovering position of the flight equipment. The processing module is used to control the operation of the clamping assembly and the winch assembly to release and retrieve the penetrator body.
[0011] Preferably, the clamping assembly includes:
[0012] The housing is a cylindrical hollow structure used to realize the retrieval and insertion of the penetrator body. The upper end of the housing is fixedly connected to the gimbal, and an electromagnet assembly is provided inside the side wall of the housing.
[0013] Two magnetic blocks are symmetrically arranged on the penetrator body, and the magnetic blocks are inserted into the side wall of the penetrator body. The magnetic blocks are connected to the penetrator body through an elastic element.
[0014] When the electromagnet assembly is energized, it generates a magnetic field, which attracts the magnetic block on the penetrator body to the inner wall of the housing through magnetic attraction, thereby locking the penetrator body and the housing. When the electromagnet assembly is de-energized, the magnetic attraction disappears, and the magnetic block is reset by the resetting action of the elastic element, thereby separating the penetrator body from the housing.
[0015] Preferably, the winch assembly includes a winch motor and a winding reel. The winch motor is fixed on the gimbal, and the output shaft of the winch motor is fixedly connected to the winding reel. One end of the traction rope passes through the top of the housing and is fixedly connected to the penetrator body, while the other end is wound and fixed on the winding reel.
[0016] Preferably, the winch assembly further includes a tension sensor, a cable length sensor, and an encoder. The tension sensor and cable length sensor are used to monitor the tension and length of the traction rope in real time, and the encoder is used to convert the tension and length signals of the traction rope into electrical signals and transmit them to the processing module.
[0017] Preferably, the gimbal is provided with a shock-absorbing plate, which is located at the top of the inner side of the housing and is fixedly connected to the gimbal.
[0018] Preferably, the magnetic block has a slot on the side wall opposite to the first elastic member, and a locking block is provided to match the slot. The locking block is fixed to the side wall of the housing by the second elastic member.
[0019] Preferably, the positioning module includes a real-time dynamic and visual positioning system, which is installed on the flight equipment and connected to the processing module for real-time navigation and positioning of the flight equipment.
[0020] Preferably, the device further includes a cleaning unit for cleaning the recovered penetrator body. The cleaning unit includes an ultrasonic cleaning chamber and a spray assembly. The ultrasonic cleaning chamber is a cylindrical hollow structure with the same structure as the shell. An ultrasonic generator is installed inside the side wall of the ultrasonic cleaning chamber. The spray assembly consists of a water tank, a water pump, and an annular spray pipe. The water tank is mounted on a gimbal. The annular spray pipe is mounted on the inner wall of the ultrasonic cleaning chamber, and multiple atomizing nozzles are arranged on the side wall of the annular spray pipe. The inlet of the water pump is connected to the water tank, and the outlet is connected to the spray pipe.
[0021] Preferably, the penetrator body includes a head penetration section, a middle sensor compartment section, and a tail traction connection section, which are connected by waterproof joints. The head penetration section has a conical structure with a cone tip of 30°~60°. The middle sensor compartment section has a built-in nine-axis motion sensor for real-time acquisition of the three-dimensional acceleration and angular velocity of the penetrator body. The electromagnet group is located in the tail traction connection section.
[0022] Preferably, a resistance sensor and a pore pressure sensor are respectively installed at the connection between the head penetration section and the middle sensor compartment section. The resistance sensor is used to measure the resistance of the head penetration section entering the soft soil, and the pore pressure sensor is used to monitor the pore water pressure change during the penetration process of the penetrator body.
[0023] Compared with the prior art, the soft soil free-fall penetration test system of this utility model has the following advantages:
[0024] This device utilizes a flying device to carry the penetration tester (FFP). During operation, a positioning module facilitates the location of the target point on the flying device, allowing it to hover precisely at the survey target location. Then, through the cooperation of the clamping and winch components, and under the control of the processing module, the FFP is precisely released. This enables the FFP to accurately collect dynamic changes in parameters such as penetration resistance and pore pressure in soft soil, resulting in higher data acquisition accuracy. Furthermore, this device's design allows for all-weather operation in areas such as tidal flats and shallow seas, unaffected by terrain conditions. It facilitates reaching designated test locations, obtaining more accurate survey data, effectively reducing the impact of environmental factors, improving system applicability, and expanding the survey range. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the overall structure of the system in an embodiment of this utility model;
[0026] Figure 2 This is a schematic diagram of the structure of the bearing unit in an embodiment of this utility model;
[0027] Figure 3 This is a schematic diagram of the structure of the penetrator body after it has been recovered in an embodiment of this utility model;
[0028] Figure 4 This is a schematic diagram of the structure of the penetrator body in an embodiment of this utility model.
[0029] Explanation of reference numerals in the attached figures:
[0030] 1. Penetrator body; 2. Flight equipment; 3. Gimbal; 4. Clamping assembly; 41. Housing; 42. Electromagnet assembly; 43. Magnetic block; 44. Elastic component one; 5. Traction rope; 6. Winch assembly; 7. Positioning module; 8. Shock absorber; 9. Slot; 10. Locking block; 11. Elastic component two; 12. Cleaning unit; 121. Ultrasonic cleaning chamber; 122. Spray assembly; 123. Ultrasonic generator; 124. Annular spray pipe; 125. Atomizing nozzle; 13. Nine-axis motion sensor; 14. Resistance sensor; 15. Pore pressure sensor. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0032] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0033] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0034] See Figures 1 to 4As shown, in order to obtain more accurate survey data while adapting to complex terrain and weather conditions, and to expand the application range of the testing system, this embodiment provides a soft soil free-fall penetration test system, including a penetration body 1, a flight device 2, a support unit, a traction unit, and a control unit. The flight device 2 is an unmanned aerial vehicle (UAV); the support unit includes a gimbal 3 and a clamping assembly 4. The gimbal 3 is fixedly installed on the flight device 2, and the clamping assembly 4 is fixed to the bottom of the gimbal 3 for clamping and releasing the penetration body 1; the traction unit includes a traction rope 5 and a winch assembly 6. One end of the traction rope 5 is fixed to the penetration body 1, and the other end is connected to the winch assembly 6. The winch assembly 6 is fixed to the gimbal 3 for winding and releasing the traction rope 5 to realize the retrieval and release of the penetration body 1; the control unit includes a positioning module 7 and a processing module. The positioning module 7 is used to locate the target point and hovering position of the flight device 2, and the processing module is used to control the operation of the clamping assembly 4 and the winch assembly 6 to realize the release and retrieval of the penetration body 1.
[0035] See Figure 2 and Figure 3 As shown, the clamping assembly 4 includes a housing 41 and a magnetic block 43. The housing 41 is a cylindrical hollow structure. The upper end of the housing 41 is fixedly connected to the gimbal 3, and an electromagnet assembly 42 is installed inside the side wall of the housing 41. Preferably, the traction rope 5 passes through the gimbal 3 and enters the housing 41 to be fixedly connected to the upper end of the penetrator body 1, so that the housing 41 can be used to realize the retrieval and insertion of the penetrator body 1. Then, two magnetic blocks 43 are symmetrically arranged on the penetrator body 1. The magnetic blocks 43 are inserted into the side wall of the penetrator body 1, and the magnetic blocks 43 are connected to the penetrator body 1 through the elastic element 44. When the electromagnet assembly 42 is energized, it generates a magnetic field, which attracts the magnetic blocks 43 on the penetrator body 1 to abut against the inner wall of the housing 41 through magnetic attraction, thereby locking the penetrator body 1 and the housing 41. When the electromagnet assembly 42 is de-energized, the magnetic attraction disappears, and the magnetic blocks 43 are reset by the reset action of the elastic element 44, thereby separating the penetrator body 1 from the housing 41.
[0036] See Figure 1 As shown, the winch assembly 6 includes a winch motor and a winding reel. The winch motor is fixed on the gimbal 3, and its output shaft is fixedly connected to the winding reel. One end of the traction rope 5 passes through the top of the housing 41 and is fixedly connected to the penetrator body 1, while the other end is wound and fixed on the winding reel. Additionally, the winch assembly 6 also includes a tension sensor, a cable length sensor, and an encoder. The tension sensor and cable length sensor are used to monitor the tension and length of the traction rope 5 in real time, and the encoder is used to convert the tension and length signals of the traction rope 5 into electrical signals for transmission to the processing module.
[0037] See Figure 2As shown, the gimbal 3 is equipped with a shock-absorbing plate 8, which is located on the top inner side of the housing 41 and is fixedly connected to the gimbal 3. Preferably, the shock-absorbing plate 8 is made of double-layer rubber plate, and multiple springs are set between the two rubber plates. This can prevent rigid collision between the penetrator body 1 and the gimbal 3 when the penetrator body 1 is fully retracted when the traction rope 5 winds around and retracts it, ensuring the safety of the internal components of the penetrator body 1, facilitating subsequent high-precision acquisition of monitoring data, and extending its service life.
[0038] See Figure 3 and Figure 4 As shown, to ensure the stability of the penetrator body 1 within the housing 41, enabling a stable descent during test release and achieving the preset trajectory, and to prevent accidental disengagement of the penetrator body 1 during the movement of the flight device 2, a slot 9 is provided on the side wall of the magnetic block 43 opposite to the elastic element 44. A locking block 10 is provided to match the slot 9, and the locking block 10 is fixed to the side wall of the housing 41 by the elastic element 11. When the electromagnet assembly 42 generates magnetic attraction and attracts the magnetic block 43, the locking block 10 engages with the slot 9 on the magnetic block 43, forming a mechanical lock, thereby achieving double locking of the penetrator body 1 and ensuring its stability. During release, the electromagnet assembly 42 is de-energized, and the locking block 10 disengages from the slot 9 through the reset of the elastic element 11, facilitating the release of the penetrator body 1. Preferably, both the elastic element 44 and the elastic element 11 are springs.
[0039] See Figure 1 As shown, the positioning module 7 includes a real-time kinematic (RTK) and visual positioning system, installed on the flight equipment 2 and connected to the processing module, for real-time navigation and positioning of the flight equipment 2. RTK stands for Real-Time Kinematic, a high-precision positioning technology based on the Global Navigation Satellite System (GNSS). Building upon traditional GPS positioning technology, it achieves centimeter-level high-precision positioning by processing carrier phase data between the base station and the user station in real time.
[0040] See Figure 2 and Figure 3As shown, the device also includes a cleaning unit 12 for cleaning the recovered penetrator body 1. The cleaning unit 12 includes an ultrasonic cleaning chamber 121 and a spray assembly 122. The ultrasonic cleaning chamber 121 is a cylindrical hollow structure with the same structure as the shell 41. The upper end of the ultrasonic cleaning chamber 121 is fixedly connected to the shell 41, and the cavities of the two are connected. An ultrasonic generator 123 is installed inside the side wall of the ultrasonic cleaning chamber 121. The spray assembly 122 consists of a water tank, a water pump, and an annular spray pipe 124. The water tank is mounted on the gimbal 3. The annular spray pipe 124 is mounted on the inner wall of the ultrasonic cleaning chamber 121, and multiple atomizing nozzles 125 are arranged on the side wall of the annular spray pipe 124. The inlet of the water pump is connected to the water tank, and the outlet is connected to the spray pipe. Preferably, multiple sets of annular spray pipes 124 are evenly distributed along the axial direction of the ultrasonic cleaning chamber 121. During the process of recovering the penetrator body 1, the sludge and impurities on the surface of the penetrator can be cleaned by the ultrasonic waves generated by the ultrasonic generator 123 and the water mist from the atomizing nozzle 125, which facilitates the accuracy of the next test.
[0041] See Figure 4 As shown, the penetrator body 1 includes a head penetration section, a middle sensor compartment section, and a tail traction connection section. The sections are connected by waterproof connectors. The head penetration section has a conical structure with a cone tip angle of 30° to 60°. The middle sensor compartment section houses a nine-axis motion sensor 13 (a nine-axis sensor is an integrated sensor module that combines a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer. Each axis corresponds to the three orthogonal directions X, Y, and Z in space, and can comprehensively capture the position changes, angular velocity, and magnetic field strength information of an object), used to collect the three-dimensional acceleration and angular velocity of the penetrator body 1 in real time. The tail traction section is equipped with a traction rope 5 locking mechanism and a clamp interface.
[0042] See Figure 4 As shown, a resistance sensor 14 and a pore pressure sensor 15 are respectively installed at the connection between the head penetration section and the middle sensor compartment. The resistance sensor 14 is used to measure the resistance of the head penetration section entering the soft soil, and the pore pressure sensor 15 is used to monitor the pore water pressure change during the penetration process of the penetrometer body 1.
[0043] The operating procedure for this device is as follows:
[0044] (1) Testing phase
[0045] Step 1: Using a drone equipped with a penetration testing device (FFP), fly to the target location and calibrate the hovering position using RTK and a visual positioning system. RTK stands for Real-Time Kinematic, a high-precision positioning technology based on the Global Navigation Satellite System (GNSS). Building upon traditional GPS positioning technology, it achieves centimeter-level high-precision positioning by processing carrier phase data between the base station and the user station in real time.
[0046] Step 2: Send a command to the electromagnetic clamp on the gimbal 3 through the control unit to release the penetrometer body 1. The penetrometer body 1 falls freely to penetrate the soft soil. Multiple types of sensors, such as the nine-axis sensor, resistance sensor 14, and pore pressure sensor 15, simultaneously collect dynamic data of the penetration (penetration depth, resistance, pore pressure, penetration speed, tilt angle, etc.).
[0047] Step 3: The collected dynamic data is transmitted back to the control unit of the ground station in real time via wireless transmission. The processing module in the control unit automatically determines the test termination condition based on the penetration depth and resistance changes.
[0048] (2) Recycling stage
[0049] Step 4: The winch assembly 6 drives the winding wheel through the winch motor to retrieve the traction rope 5. The tension sensor monitors the change in tension. If the tension exceeds the threshold, the overload protection is triggered to stop the retrieval. At this time, with the assistance of the staff, the penetrator body 1 is extracted from the soft soil.
[0050] Step 5: After the penetrator body 1 is completely detached from the soil, the UAV pulls it to the ultrasonic cleaning chamber 121 via the winch assembly 6 and starts the self-cleaning program to clean the mud and other impurities on the surface of the penetrator body 1.
[0051] Step 6: After cleaning, use clamping component 4 to lock the penetrator body 1, and the drone flies to the next target location to perform the test-recovery process repeatedly, completing the collection of multiple sets of data and effectively improving the test accuracy.
[0052] This solution, through the synergy of the penetrator's mounting design with the UAV and the fully automated operation process, can achieve the following core functions:
[0053] (1) Lightweight exploration: Get rid of dependence on large ships or land-based equipment, and reduce operating costs and personnel risks.
[0054] (2) High-precision data acquisition: Multi-sensor fusion ensures the accuracy of dynamic measurement of soft soil parameters.
[0055] (3) Reliable recycling and maintenance: The dual locking mechanism and winch assembly 6 are designed together with the automatic cleaning function of the cleaning unit 12 to ensure the equipment reuse rate and improve the accuracy of each data collection.
[0056] (4) Adaptability to complex terrain: The maneuverability of UAVs breaks through the limitations of traditional equipment in areas such as tidal flats and shallow seas.
[0057] In summary, this device, through its innovative design of mounting a penetration testing unit (FFP) on a UAV, significantly reduces exploration costs and overcomes the limitations of complex terrain, enabling all-weather operation in areas such as tidal flats and shallow seas. The FFP's nine-axis motion sensor 13, resistance sensor 14, and pore pressure sensor 15, combined with the cleaning components, ensure dynamic and accurate acquisition of parameters such as penetration resistance and pore pressure. The tail traction rope 5's dual-locking mechanism, linked with the UAV winch assembly 6, facilitates stable probe retrieval and release. The UAV platform's RTK+vision dual-mode positioning, gimbal 3, and ultrasonic cleaning chamber 121 design achieve efficient single-point operation cycles with high data acquisition accuracy. The entire system supports unmanned operation, reducing the risk of human intervention and providing a low-cost, high-precision real-time geotechnical parameter acquisition solution for fields such as marine engineering and geological hazard assessment.
[0058] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A soft soil free-fall penetration test system, comprising a penetration instrument body (1), characterized in that, Also includes: Flight equipment (2); The carrying unit includes a gimbal (3) and a clamping assembly (4). The gimbal (3) is fixedly installed on the flight equipment (2), and the clamping assembly (4) is fixed to the bottom of the gimbal (3) for clamping and releasing the penetrator body (1). The traction unit includes a traction rope (5) and a winch assembly (6). One end of the traction rope (5) is fixed to the body (1) of the penetrator, and the other end is connected to the winch assembly (6). The winch assembly (6) is fixed on the gimbal (3) and is used to wind and release the traction rope (5). The control unit includes a positioning module (7) and a processing module. The positioning module (7) is used to locate the target point and hovering position of the flying device (2). The processing module is used to control the operation of the clamping assembly (4) and the winch assembly (6) to release and retrieve the penetrator body (1).
2. The soft soil free-fall penetration test system according to claim 1, characterized in that, The clamping assembly (4) includes: The housing (41) is a cylindrical hollow structure used to realize the retrieval and insertion of the penetrator body (1). The upper end of the housing (41) is fixedly connected to the gimbal (3), and an electromagnet assembly (42) is provided in the side wall of the housing (41). Two magnetic blocks (43) are symmetrically arranged on the penetrator body (1), and the magnetic blocks (43) are inserted into the side wall of the penetrator body (1). The magnetic blocks (43) are connected to the penetrator body (1) through an elastic element (44).
3. The soft soil free-fall penetration test system according to claim 2, characterized in that, The winch assembly (6) includes a winch motor and a winding wheel. The winch motor is fixed on the gimbal (3). The output shaft of the winch motor is fixedly connected to the winding wheel. One end of the traction rope (5) passes through the top of the housing (41) and is fixedly connected to the penetrator body (1). The other end is wound and fixed on the winding wheel.
4. The soft soil free-fall penetration test system according to claim 1, characterized in that, The winch assembly (6) also includes a tension sensor, a cable length sensor and an encoder. The tension sensor and cable length sensor are used to monitor the tension and winding length of the traction rope (5) in real time. The encoder is used to convert the tension and winding length signals of the traction rope (5) into electrical signals and transmit them to the processing module.
5. The soft soil free-fall penetration test system according to claim 2, characterized in that, The gimbal (3) is provided with a shock-absorbing plate (8), which is located on the top of the inner side of the housing (41) and is fixedly connected to the gimbal (3).
6. The soft soil free-fall penetration test system according to claim 2, characterized in that, The magnetic block (43) has a slot (9) on the side wall away from the elastic element (44), and a card block (10) is provided to match the slot (9). The card block (10) is fixed to the side wall of the housing (41) by the elastic element (11).
7. The soft soil free-fall penetration test system according to claim 1, characterized in that, The positioning module (7) includes a real-time dynamic and visual positioning system, which is installed on the flight equipment (2) and connected to the processing module for real-time navigation and positioning of the flight equipment (2).
8. The soft soil free-fall penetration test system according to claim 2, characterized in that, It also includes a cleaning unit (12) for cleaning the recovered penetrator body (1). The cleaning unit (12) includes an ultrasonic cleaning chamber (121) and a spray assembly (122). The ultrasonic cleaning chamber (121) is a cylindrical hollow structure with the same structure as the shell (41). An ultrasonic generator (123) is provided in the side wall of the ultrasonic cleaning chamber (121). The spray assembly (122) consists of a water tank, a water pump and an annular spray pipe (124). The water tank is set on the gimbal (3). The annular spray pipe (124) is set on the inner wall of the ultrasonic cleaning chamber (121). Multiple atomizing nozzles (125) are arranged on the side wall of the annular spray pipe (124). The water inlet of the water pump is connected to the water tank and the water outlet is connected to the spray pipe.
9. The soft soil free-fall penetration test system according to claim 2, characterized in that, The penetrator body (1) includes a head penetration section, a middle sensor compartment section and a tail traction connection section. The sections are connected by waterproof connectors. The head penetration section has a conical structure with a cone tip of 30°~60°. The middle sensor compartment section has a built-in nine-axis motion sensor (13) for real-time acquisition of the three-dimensional acceleration and angular velocity of the penetrator body (1). The electromagnet group (42) is set in the tail traction connection section.
10. The soft soil free-fall penetration test system according to claim 9, characterized in that, A resistance sensor (14) and a pore pressure sensor (15) are respectively installed at the connection between the head penetration section and the middle sensor compartment. The resistance sensor (14) is used to measure the resistance of the head penetration section entering the soft soil, and the pore pressure sensor (15) is used to monitor the pore water pressure change during the penetration process of the penetrator body (1).