CN115928689B - Free falling body type dynamic sounding instrument - Google Patents

Abstract

The invention discloses a free falling type dynamic penetration tester, which comprises a penetration tester, a penetration probe, a communication module and a power supply, wherein the penetration tester is connected with the penetration probe through the communication module; the penetrometer is a revolving body and is sequentially divided into a head section, a middle section and a tail section along the axial direction of the penetrometer, the gravity center of the penetrometer is close to the head section, the diameter of the head section is equal to that of the middle section and smaller than that of the tail section, and one end of the tail section far away from the middle section is connected with a flexible stabilizing surface; the penetration probe is mounted on the head section. The penetrometer vertically falls down in free falling through the appearance of the penetrometer and the aerodynamic guiding of the flexible stabilizing surface, the head section and the middle section penetrate into the soil, the tail section is left outside the soil, the tip resistance and the side friction resistance of the penetrometer are perceived through the sounding probe, and the acquired data are remotely and wirelessly transmitted through the communication module, so that the purposes of remote and in-situ surveying of ground mechanics are realized.

Description

A free-fall dynamic probe

Technical Field

The invention relates to the field of dynamic penetration instruments, in particular to a free-fall type dynamic penetration instrument.

Background technique

At present, the technical means of ground mechanics survey mainly include non-contact measurement and contact measurement.

Non-contact measurement technologies include space-based remote sensing, air-based geophysical exploration, vehicle-mounted ground-penetrating radar, etc., which can meet the needs of long-distance and rapid surveys. However, these technologies cannot accurately invert the mechanical information of ground soil strength, but can only invert soil type and properties, and their reliability and resolution are insufficient.

Contact measurement technology includes static penetration testing, which has a wide range of applications, can achieve in-situ measurement, accurate identification of rock and soil types and mechanical parameters, reliable measurement data and rich theoretical research, etc. However, static penetration testing belongs to the category of manual close-range survey and cannot meet the needs of remote and rapid survey of ground mechanics in the target area.

To this end, people need a technology that can not only conduct remote and rapid exploration, but also achieve in-situ measurement and accurate identification of soil strength mechanical information.

Summary of the invention

The purpose of the present invention is to provide a free-fall type dynamic probe to solve the technical problem that the remote exploration technology is difficult to combine with the in-situ measurement technology.

In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

A free-fall dynamic penetration instrument comprises: a penetration instrument, the appearance of the penetration instrument is a rotating body, and is divided into a head section, a middle section and a tail section in sequence along the axial direction of the penetration instrument, the center of gravity of the penetration instrument is close to the head section, the diameter of the middle section is the same as the diameter of the head section, the diameter of the tail section is larger than the diameter of the middle section, the end of the tail section connected to the middle section forms a cone, and the end of the tail section away from the middle section is connected to a flexible stabilizing surface, the flexible stabilizing surface is used to generate an aerodynamic guiding function and a deceleration function to make the penetration instrument fall vertically when it is in free fall; a penetration probe, installed in the head section, the penetration probe is used to collect at least one of the end resistance and the side friction resistance of the penetration instrument when the penetration instrument penetrates into the soil; a communication module, installed in the tail section, the communication module is used to send data collected by the penetration probe; a power supply, arranged in the middle section or the tail section, the power supply is electrically connected to the penetration probe and the communication module and is used to supply power.

A free-fall type dynamic penetration instrument, the penetrator is transported by a carrier and performs an airdrop operation to achieve free fall at a specified position, and the communication module transmits data to a base station using the carrier as a relay.

Furthermore, the communication module includes a communication antenna and a self-organizing network data link, and data is wirelessly sent to the carrier through the self-organizing network data link and the communication antenna, and then sent to the base station using the carrier as a relay.

Furthermore, the flexible stabilizing surface is a flexible cloth strip.

Furthermore, the diameter of the sounding probe is 35.7 mm.

Furthermore, the diameter of the tail section is 55 mm, and in the longitudinal section of the tail section, the angle between the conical surface and the wall surface of the tail section is 147°.

Furthermore, the sounding probe includes a cone tip, a lower top sleeve, a cone resistance strain bridge, a side resistance strain bridge, a force transmission head, an upper top sleeve and a friction cylinder; wherein the cone tip, the lower top sleeve, the cone resistance strain bridge, the force transmission head, the upper top sleeve and the middle section are coaxial and sequentially connected; the friction cylinder is sleeved on the outer sides of the lower top sleeve, the cone resistance strain bridge, the force transmission head and the upper top sleeve, and the friction cylinder is slidably connected to the lower top sleeve and the upper top sleeve; a first chamber is formed between the cone resistance strain bridge and the friction cylinder, and an end resistance sensor connected to the cone resistance strain bridge is installed inside the first chamber, and the cone resistance strain bridge is used to withstand axial stress and generate deformation when the cone tip penetrates the soil, so that the end resistance sensor a second chamber is formed between the force transmission jack and the friction cylinder, the side resistance strain bridge is installed inside the second chamber, a first step with an end face facing the upper top sleeve is formed on the inner wall of the friction cylinder, one end of the side resistance strain bridge contacts the first step when the friction cylinder slides axially, and the other end of the side resistance strain bridge is fixedly connected to the force transmission jack or the upper top sleeve, a side resistance sensor connected to the side resistance strain bridge is installed inside the second chamber, and the side resistance strain bridge is used to press against the first step to withstand axial stress and generate deformation when the friction cylinder rubs against the soil, so that the side resistance sensor detects the side friction force of the head section penetrating the soil.

Furthermore, the end resistance sensor is arranged in the form of a patch on the cone resistance strain bridge, and the side resistance sensor is arranged in the form of a patch on the side resistance strain bridge. The end resistance sensor and the side resistance sensor adopt a full-bridge four-arm working mode, and the output voltage is increased through the principle of double differential action.

Furthermore, a shaft sleeve is sleeved on the outer side of the force transmission head, and both end surfaces of the shaft sleeve abut against the side resistance strain bridge and the upper top sleeve, and the shaft sleeve is used to eliminate the gap between the side resistance strain bridge and the upper top sleeve.

Furthermore, the probing probe includes a through hole, which axially penetrates the lower top sleeve, the cone resistance strain bridge, the force transmission head and the upper top sleeve, and the first chamber and the second chamber are respectively formed with a first small hole and a second small hole connected to the interior of the through hole.

Furthermore, at least one of a posture sensor, an acceleration sensor and a positioning module is installed inside the penetrometer; the posture sensor and the acceleration sensor are respectively used to collect the penetration posture and acceleration of the penetrometer when the penetrometer penetrates the soil, and the positioning module is used for satellite positioning; the posture sensor, the acceleration sensor and the positioning module are electrically connected to the power supply and the communication module.

Furthermore, the probing probe, the posture sensor, the acceleration sensor and the positioning module are connected to the communication module through a data acquisition unit, and the data acquisition unit includes an operational amplifier, an ADC acquisition chip, a processor and a storage; the probing probe is connected to the ADC acquisition chip through the operational amplifier; the posture sensor, the acceleration sensor, the ADC acquisition chip, the positioning module, the storage and the communication module are connected to the processor; the processor is used to store the collected data in the storage and send it through the communication module.

Compared with the prior art, this application has the following beneficial effects:

A free-fall dynamic penetration instrument is provided, comprising a penetration instrument that can be transported in the air by a carrier and can be airdropped. The penetration instrument falls vertically during free fall due to the aerodynamic guidance of its own shape and flexible stabilizing surface, and the head section and the middle section penetrate into the soil, while the tail section remains outside the soil. The end resistance and side friction of the penetration instrument are collected by a penetration probe, and the collected data are remotely and wirelessly transmitted through a communication module, thereby achieving the purpose of remote and in-situ ground mechanics survey.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the implementation of the present invention or the technical solution in the prior art, the following briefly introduces the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

FIG1 is a schematic diagram of the appearance of a penetrometer according to an embodiment of the present invention;

FIG2 is a schematic cross-sectional view of a probe head according to an embodiment of the present invention;

FIG3 is a schematic diagram of the operation of a full-bridge four-arm resistor according to an embodiment of the present invention;

FIG4 is a schematic diagram of a half-section structure of an embodiment of the present invention;

5 is a schematic diagram of a three-dimensional layout structure of a posture and acceleration sensing module and a communication module according to an embodiment of the present invention;

6 is a schematic diagram of a two-dimensional layout structure of a posture and acceleration sensing module and a communication module according to an embodiment of the present invention;

FIG7 is a schematic diagram of the overall circuit of a data acquisition unit according to an embodiment of the present invention;

The numbers in the figure represent the following:

1-head segment;

2-probe; 21-cone tip; 211-connector; 22-lower top sleeve; 23-cone resistance strain bridge; 231-first chamber; 232-end resistance sensor; 233-first small hole; 24-side resistance strain bridge; 241-side resistance sensor; 25-force transmission head; 251-second chamber; 252-second step; 253-shaft sleeve; 254-second small hole; 26-upper top sleeve; 27-friction cylinder; 271-first step; 28-sealing ring; 29-through hole;

3-middle section; 31-middle section shell; 32-power supply; 33-top plug;

4- attitude and acceleration sensing module; 41- attitude sensor; 42- acceleration sensor; 43- operational amplifier; 44- ADC acquisition chip; 45- processor; 46- memory; 47- power IC;

5-tail section; 51-conical surface; 52-cambered surface; 53-tail section shell;

6-communication module; 61-communication antenna; 62-ad hoc network data link;

7-Flexible stable surface;

8- Positioning module; 81- GPS antenna.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Due to earthquakes, climate change and human activities, natural disasters such as landslides, mudslides and debris flows occur frequently. The barrier lakes formed by landslides and mudslides carry huge risks of flooding upstream villages and towns, and the floods from the barrier lakes destroy the towns along the river downstream. Disaster relief and emergency response are becoming increasingly important. When a disaster occurs, rescue vehicles and engineering machinery need to rush to the scene quickly. In order to quickly grasp the accessible routes to the scene and the site conditions for vehicles and machinery to operate at the emergency response site, on the one hand, satellite images and drone detection can be used to obtain remote sensing information, and the terrain and landform conditions of possible routes and disaster conditions can be obtained. The rapid acquisition of ground mechanics in the disaster area is a necessary condition for judging the accessibility of rescue vehicles and the deployment of construction, and is also an important prerequisite for decision-making and command of emergency response plans.

At present, the technical means of remote and wide-area ground mechanical survey mainly include space-based remote sensing, air-based geophysical exploration, vehicle-mounted ground penetrating radar, etc. The inversion and evaluation of remote and wide-area ground soil material properties are achieved by using technical methods based on hyperspectral remote sensing methods, gamma-ray energy spectrum methods, and advanced pattern recognition and correlation matching algorithms such as neural networks. However, these technical means are all non-contact measurements and cannot accurately invert the ground soil strength mechanical information (bearing capacity, driving force). They can only invert the soil type and properties, and the credibility and resolution are insufficient.

Static penetration testing has the following technical advantages: (1) wide application range; (2) in-situ measurement can be achieved; (3) accurate identification of rock and soil types and mechanical parameters; (4) reliable measurement data and rich theoretical research. Therefore, static penetration testing technology is widely used in the survey of soft clay strength parameters in military geology, port engineering, offshore wind power, offshore oil and gas platforms, and submarine pipelines. In the in-situ measurement technology scheme of ground soil mechanical parameters, domestic and foreign researchers mainly adopt the uniform speed (2.5cm/s) static penetration testing method.

Static penetration technology has mainly gone through four stages: rough detection, mechanical detection, electrical detection and cable-free multi-parameter detection. At present, static penetration technology has accounted for more than 70% of the soil survey volume in some developed countries, and has become an important testing method that complements and references geological drilling and indoor tests. Many countries have also included static penetration in national standards or regulations. Today, static penetration technology in developed countries such as Europe and the United States has become relatively mature and commercialized. The main research and development units include Fugro and A.P. Vandenberg in the Netherlands, the Institute of Marine Science (IOS), Datem and Lankelma in the United Kingdom, Minnesota and Conetec in the United States, etc.

The above-mentioned static penetration testing belongs to the category of manual close-range survey and cannot meet the needs of long-distance and rapid ground mechanics survey in the target area.

Based on the basic methodology of static penetration, this specific implementation proposes a new type of free-fall dynamic penetration survey technology, which uses an unmanned aerial vehicle carrier to carry the penetrometer to a certain height, and then drills into the ground soil under the action of gravity to obtain the penetration speed and penetration kinetic energy, and inverts the ground mechanical characteristic parameters from the soil resistance data obtained during the penetration process to achieve remote and rapid in-situ survey of the ground mechanics of the target area. Compared with static penetration, the impact penetration penetrometer has basic measurement functions such as end resistance, lateral resistance and acceleration, and also needs to have positioning, remote data communication and attitude measurement functions.

Please refer to Figure 1 for details as follows:

A free-fall type dynamic penetration instrument comprises a head section 1, a middle section 3 and a tail section 5;

The head section 1 is equipped with a probe 2, the middle section 3 is equipped with a posture and acceleration sensing module 4, the tail section 5 is equipped with a communication module 6, the middle section 3 or the tail section 5 is equipped with a power supply 32, the power supply 32 is used to supply power to the probe 2, the posture and acceleration sensing module 4 and the communication module 6, and the communication module 6 is used to transmit the data collected by the probe 2 and the posture and acceleration sensing module 4;

Among them, the shapes of the head section 1, the middle section 3 and the tail section 5 are all rotating bodies and are coaxially connected in sequence to form a penetrometer. The center of gravity of the penetrometer is close to the head section 1, the diameter of the middle section 3 is the same as that of the head section 1, the diameter of the tail section 5 is larger than the diameter of the middle section 3, one end of the tail section 5 is connected to the middle section 3 to form a conical surface 51, and the end of the tail section 5 away from the middle section 3 is connected to a flexible stabilizing surface 7.

Optional:

The flexible stabilizing surface 7 is a flexible fabric strip.

The working principle of the free-fall dynamic probe is as follows:

The penetrometer uses a drone as a carrier. The staff loads the penetrometer into the drone's delivery platform, locks the delivery mechanism, and then powers on the penetrometer and the drone. After the penetrometer, drone and base station are connected, the drone takes off and flies along the preset route. After arriving at the mission area, it delivers the penetrometer.

The penetrometer is airdropped by a drone to achieve free fall at a designated location. The penetrometer achieves vertical fall and landing of the head section 1 through the shape of its own variable diameter cylinder, the weight of the head section 1 and the flexible stabilizing surface 7. The purpose of the flexible cloth strip is to generate aerodynamic guidance and deceleration functions during the airdrop process to meet the aerodynamic requirements of the penetrometer's vertical free fall.

The penetrometer obtains penetration velocity and kinetic energy under the action of gravity. The penetrometer goes through four stages in the process of penetrating the soil: collision impact, penetration into the soil, initial braking, oscillation rebound and final braking. The soil profile characteristics and ground mechanical characteristics parameters are interpreted based on the collision and penetration resistance.

Among them, the head section 1 and the middle section 3 are used to penetrate the soil, and the conical surface 51 is used to prevent the tail section 5 from penetrating the soil to prevent the communication module 6 from being immersed in the soil. After a part of the head section 1 and the middle section 3 are separated from the soil due to rebound, final braking is achieved under the action of friction.

After the delivery is completed, the drone reaches the designated location and hovers.

The penetration probe 2 collects the end resistance and lateral resistance of the head section 1 penetrating the soil, the attitude and acceleration sensing module 4 collects the attitude and acceleration of the middle section 3, and the communication module 6 transmits the data to the drone via wireless, which is then transmitted to a distant data analysis center by the drone, thus forming a data transmission network from the penetration probe to the drone (relay) and then to the data analysis center.

Ideally, the communication distance between the probe and the drone can reach 6km, and the communication distance between the drone and the data center can reach 20km. After the data transmission is completed, the drone returns along the route, and the process is completed.

The advantages of free-fall dynamic probe compared with existing technologies are:

(1) It breaks through the technical bottlenecks of traditional manual close-in surveys and the inaccurate space-based remote sensing and air-based geophysical measurements, and realizes remote and in-situ precise surveys of ground mechanics. It can be applied to remote and rapid surveys of ground mechanics in disaster areas and areas that are difficult for personnel to reach.

(2) The penetration probe 2, the attitude and acceleration sensing module 4 and the communication module 6 are integrated into the penetrometer, achieving system integration, miniaturization and light weight.

further:

The head section 1 has no entity and is directly replaced by the sounding probe 2. The diameter of the sounding probe 2 is 35.7 mm and the length is 253 mm.

The middle section 3 includes a middle section housing 31, the diameter of the middle section housing 31 is 35.7 mm, and the length is 255 mm;

The tail section 5 includes a tail section outer shell 53, the diameter of the tail section outer shell 53 is 55 mm, and the length is 91.8 mm. In the longitudinal section of the tail section 5, the angle between the conical surface 51 and the wall surface of the tail section 5 is 147°, and the conical surface 51 and the middle section 3 are smoothly connected by a curved surface 52 with a radius of 10 mm.

Based on the above dimensions, the probe weighs approximately 3.5kg and has a total length of 600mm.

Optional:

The penetration probe 2 adopts a size of Φ35.7 mm, which is equivalent to that of a static penetration probe that complies with international standards, to ensure that the static penetration empirical formula of the existing standard can be used for reference in the subsequent interpretation of the ground mechanical characteristic parameters, thereby facilitating the correction of the correlation coefficient in the empirical formula.

Optional, as shown in Figure 2:

Header segment 1 has no entity.

The probe 2 includes: a cone tip 21, a lower top sleeve 22, a cone resistance strain bridge 23, a side resistance strain bridge 24, a force transmission head 25, an upper top sleeve 26 and a friction cylinder 27;

The cone tip 21, the lower top sleeve 22, the cone resistance strain bridge 23, the force transmission plug 25, and the upper top sleeve 26 are coaxial and sequentially connected. The lower top sleeve 22, the cone resistance strain bridge 23, and the force transmission plug 25 are an integrated part and a hollow cylinder. The upper top sleeve 26 is detachably connected to the middle section 3. A connector 211 is formed at the thicker end of the cone tip 21. The lower top sleeve 22 is detachably connected to the connector 211. The force transmission plug 25 is detachably connected to the upper top sleeve 26.

The friction cylinder 27 is sleeved on the outer sides of the lower top sleeve 22, the cone resistance strain bridge 23, the force transmission head 25 and the upper top sleeve 26. The friction cylinder 27 is slidably connected with the lower top sleeve 22 and the upper top sleeve 26, and the connection parts are sealed by the sealing ring 28.

A first chamber 231 is formed between the cone resistance strain bridge 23 and the friction cylinder 27. The end resistance sensor 232 is installed inside the first chamber 231 and fits the cone resistance strain bridge 23. The cone resistance strain bridge 23 is used to withstand axial stress and generate deformation when the cone tip 21 penetrates the soil, so that the end resistance sensor 232 detects the end resistance of the head section 1 penetrating the soil.

A second chamber 251 is formed between the force transmission head 25 and the friction cylinder 27, and the side resistance strain bridge 24 is installed inside the second chamber 251. The inner wall of the friction cylinder 27 is formed with a first step 271 with the end face facing the upper top sleeve 26, and the outer wall of the force transmission head 25 is formed with a second step 252 with the end face facing the upper top sleeve 26. One end of the side resistance strain bridge 24 is in contact with the first step 271, and the other end of the side resistance strain bridge 24 is clamped between the second step 252 and the upper top sleeve 26. The side resistance sensor 241 is installed inside the second chamber 251 and fits the side resistance strain bridge 24. The side resistance strain bridge 24 is used to bear axial stress and generate deformation when the friction cylinder 27 rubs against the soil, so that the side resistance sensor 241 detects the side friction force of the head section 1 penetrating into the soil;

The outer side of the force transmission head 25 is also provided with a sleeve 253, and the two end surfaces of the sleeve 253 abut against the side resistance strain bridge 24 and the upper top sleeve 26. The sleeve 253 is used to eliminate the gap between the side resistance strain bridge 24 and the upper top sleeve 26. The sleeve 253 can be rigid or elastic, such as a disc spring.

The through hole 29 axially penetrates the lower top sleeve 22, the cone resistance strain bridge 23, the force transmission head 25 and the upper top sleeve 26. The first chamber 231 and the second chamber 251 are respectively formed with a first small hole 233 and a second small hole 254 connected to the through hole 29. The through hole 29, the first small hole 233 and the second small hole 254 are used for arranging lines.

further:

Under high-speed impact, the time it takes for the penetrometer to penetrate the soil is in milliseconds. In order to accurately record the penetration resistance and acceleration values of the penetrometer, various sensors such as resistance and accelerometers should have functional requirements such as high sensitivity, high precision, wide range and impact resistance. At the same time, the data acquisition and output system must meet performance requirements such as high-speed acquisition (≥20kHz) and high output response frequency (≥20kHz).

The measuring elements of end resistance and side resistance are high-precision resistance strain sensors, which use stress-strain conversion to convert the deformation of the probe caused by penetration resistance into a measurable electrical signal.

As shown in Figure 3, the measurement circuit is arranged in the form of a patch on the hollow cylinder of the penetrometer, adopts a full-bridge four-arm working mode, and fully utilizes the double differential action principle to make the output voltage four times that of a single-arm operation, thereby improving the measurement sensitivity and accuracy of the terminal resistance and side resistance.

The final result is——

The parameters of the end resistance sensor 232 are: range 0-30MPa, accuracy better than 1%, resolution 10kpa, sampling frequency 20kHz;

The parameters of the side resistance sensor 241 are: measuring range 0-600KPa, accuracy better than 1%, resolution 1kPa, sampling frequency 20kHz.

Optional, as shown in Figures 4 and 5:

The attitude and acceleration sensing module 4 includes a middle shell 31 , and an attitude sensor 41 and an acceleration sensor 42 installed inside the middle shell 31 .

The attitude sensor 41 uses a three-axis gyroscope, model ICM20689, with parameters as follows: range 0-90°, accuracy better than 0.5°, and sampling frequency 1kHz.

The acceleration sensor 42 adopts a MEMS accelerometer, model ADXL1004BCPZ, with parameters as follows: range 0-400g, accuracy 3g, sampling frequency 20kHz.

Optional, as shown in Figures 4 and 6:

The tail section 5 includes a tail section housing 53 and a positioning module 8 installed inside the tail section housing 53 . The positioning module 8 is electrically connected to the power supply 32 and the communication module 6 .

The positioning module 8 includes a GPS antenna 81, model NEO-M8N, with parameters of: accuracy 3m, satellite search time 29s, sampling frequency 1Hz.

Optional:

The communication module 6 includes a communication antenna 61 and an ad hoc network data link 62 installed inside the tail section housing 53.

The self-organizing data link 62 adopts MESH networking, and the parameters of the communication antenna 61 are: line-of-sight distance 3km.

Optional:

The power source 32 uses a 18350 lithium battery, and a top plug 33 is installed between the power source 32 and the tail section 5.

further:

The probe instrument needs to be designed with a special high-speed acquisition circuit to process and collect the output signals of various sensors, which is mainly reflected in the frequency response characteristics, sensitivity response characteristics and impact resistance. At the same time, given that the probe instrument is powered by a battery, in order to meet the long working time requirements of the probe instrument, the digital acquisition unit needs to be designed with low power consumption.

The data acquisition unit is installed in the middle section. The system block diagram and circuit diagram of the data acquisition unit are shown in Figure 7.

The end resistance sensor 232 and the side resistance sensor 241 send data to the ADC acquisition chip (44) through the operational amplifier 43, and the attitude sensor 41, the acceleration sensor 42, the ADC acquisition chip 44 and the positioning module 8 send data to the processor 45. The processor 45 stores the data in the storage 46 and sends the processed data wirelessly to the relay module of the drone through the self-organizing network data link 62 and the communication antenna 61, and then forwards the data to the data analysis center by the drone to complete the remote transmission of the data.

The model of the operational amplifier 43 is AD620B/AD8221, the model of the ADC acquisition chip 44 is LTC2372-18, the model of the processor 45 is STM32F40X, and the model of the memory 46 is W25Q256JV.

The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims (9)

1. A free-fall dynamic feeler, comprising:

The appearance of the penetrometer is a revolution solid, the penetrometer is sequentially divided into a head section (1), a middle section (3) and a tail section (5) along the axis direction of the penetrometer, the gravity center of the penetrometer is close to the head section (1), the diameter of the middle section (3) is the same as that of the head section (1), the diameter of the tail section (5) is larger than that of the middle section (3), one end of the tail section (5) connected with the middle section (3) forms a conical surface (51), one end of the tail section (5) far away from the middle section (3) is connected with a flexible stabilizing surface (7), the penetrometer is transported by a carrier and performs an air-drop operation to realize a free falling body at a specified position, and the flexible stabilizing surface (7) is used for generating an aerodynamic guiding function and a deceleration function for enabling the penetrometer to vertically fall when the penetrometer freely falls down.

A penetration probe (2) mounted on the head section (1), the penetration probe (2) being configured to collect at least one of an end resistance and a side friction resistance of the penetration gauge when the penetration gauge penetrates into the soil;

The communication module (6) is arranged at the tail section (5), the communication module (6) comprises a communication antenna (61) and an ad hoc network data link (62), and data acquired by the sounding probe (2) are wirelessly transmitted to the carrier through the ad hoc network data link (62) and the communication antenna (61) and then transmitted to the base station by taking the carrier as a relay;

A power supply (32) arranged inside the middle section (3) or the tail section (5), wherein the power supply (32) is electrically connected with the sounding probe (2) and the communication module (6) and is used for supplying power; the touch probe (2) comprises a cone tip (21), a lower top sleeve (22), a cone resistance strain bridge (23), a side resistance strain bridge (24), a force transmission top (25), an upper top sleeve (26) and a friction cylinder (27);

The cone tip (21), the lower top sleeve (22), the cone resistance strain bridge (23), the force transmission plug (25), the upper top sleeve (26) and the middle section (3) are coaxially and sequentially connected;

The friction cylinder (27) is sleeved on the outer sides of the lower top sleeve (22), the cone-resistance strain bridge (23), the force transmission top (25) and the upper top sleeve (26), and the friction cylinder (27) is in sliding connection with the lower top sleeve (22) and the upper top sleeve (26);

A first chamber (231) is formed between the cone resistance strain bridge (23) and the friction cylinder (27), an end resistance sensor (232) connected with the cone resistance strain bridge (23) is arranged in the first chamber (231), and the cone resistance strain bridge (23) is used for bearing axial stress and generating deformation when the cone tip (21) penetrates into soil so that the end resistance sensor (232) detects the end resistance of the head section (1) penetrating into the soil;

A second cavity (251) is formed between the force transmission plug (25) and the friction cylinder (27), the side resistance strain bridge (24) is installed in the second cavity (251), a first step (271) with the end face facing the upper top sleeve (26) is formed on the inner wall of the friction cylinder (27), one end of the side resistance strain bridge (24) contacts the first step (271) when the friction cylinder (27) axially slides, the other end of the side resistance strain bridge (24) is fixedly connected with the force transmission plug (25) or the upper top sleeve (26), a side resistance sensor (241) connected with the side resistance strain bridge (24) is installed in the second cavity (251), and the side resistance strain bridge (24) is used for propping against the first step (271) when the friction cylinder (27) rubs with soil so as to bear axial stress and deform, so that the side resistance sensor (241) detects the side surface of the head section (1) entering the soil.

2. A free-falling body type dynamic sounding instrument as set forth in claim 1, wherein,

The Ad hoc network data link (62) adopts MESH networking, and the parameter of the communication antenna (61) is a viewing distance of 3km.

3. A free-falling body type dynamic sounding instrument as set forth in claim 1, wherein,

The diameter of the feeler probe (2) is 35.7mm.

4. A free-falling body type dynamic sounding instrument as set forth in claim 3, wherein,

The diameter of the tail section (5) is 55mm, and the included angle between the conical surface (51) and the wall surface of the tail section (5) on the longitudinal section of the tail section (5) is 147 degrees.

5. A free-falling body type dynamic sounding instrument as set forth in claim 4, wherein,

The end resistance sensor (232) is arranged on the cone resistance strain bridge (23) in a patch mode, the side resistance sensor (241) is arranged on the side resistance strain bridge (24) in a patch mode, the end resistance sensor (232) and the side resistance sensor (241) adopt a full-bridge four-arm working mode, and output voltage is improved through a double differential action principle.

6. A free-falling body type dynamic sounding instrument as set forth in claim 4, wherein,

The outer side of the force transmission plug (25) is sleeved with a shaft sleeve (253), two end faces of the shaft sleeve (253) are abutted to the side resistance strain bridge (24) and the upper top sleeve (26), and the shaft sleeve (253) is used for eliminating gaps between the side resistance strain bridge (24) and the upper top sleeve (26).

7. A free-falling body type dynamic sounding instrument as set forth in claim 4, wherein,

The penetration probe (2) comprises a through hole (29), the through hole (29) axially penetrates through the lower top sleeve (22), the cone-resistance strain bridge (23), the force transmission top head (25) and the upper top sleeve (26), and a first small hole (233) and a second small hole (254) which are communicated to the inside of the through hole (29) are formed in the first chamber (231) and the second chamber (251) respectively.

8. A free-falling body type dynamic sounding instrument as set forth in claim 1, wherein,

At least one of an attitude sensor (41), an acceleration sensor (42) and a positioning module (8) is arranged in the penetrometer;

the attitude sensor (41) and the acceleration sensor (42) are respectively used for collecting the penetration attitude and acceleration of the penetration instrument when the penetration instrument penetrates into the soil, and the positioning module (8) is used for satellite positioning;

The attitude sensor (41), the acceleration sensor (42) and the positioning module (8) are electrically connected with the power supply (32) and the communication module (6).

9. A free-falling body type dynamic sounding instrument as set forth in claim 8, wherein,

The touch probe (2), the gesture sensor (41), the acceleration sensor (42) and the positioning module (8) are connected with the communication module (6) through a data acquisition unit, and the data acquisition unit comprises an operational amplifier (43), an ADC acquisition chip (44), a processor (45) and a storage (46);

the sounding probe (2) is connected with the ADC acquisition chip (44) through the operational amplifier (43);

the gesture sensor (41), the acceleration sensor (42), the ADC acquisition chip (44), the positioning module (8), the storage (46) and the communication module (6) are connected with the processor (45);

The processor (45) is configured to store the acquired data to the memory (46) and to transmit the data via the communication module (6).