A diamond floor condition detection device

Abstract

The application is suitable for the technical field of ground detection equipment, and provides a diamond sand ground state detection device, which comprises a shell, a control module arranged in the shell, a roller arranged at the bottom of the shell, a detection assembly rotatably connected to the bottom of the shell, a rotating disc rotatably connected to the bottom of the shell, a driving piece arranged in the shell and used for driving the rotating disc to rotate, and a plurality of detection contacts arranged at the bottom of the rotating disc and rotatably connected to the bottom of the rotating disc. When the detection contacts abut against an abnormal ground, the abutment state of the detection contacts changes. Thus, the detection device is arranged to automatically walk on the ground, so that whether the passing road surface has defects or cracks and other phenomena can be judged in an automatic walking manner, thereby realizing automatic detection of the road surface state.

Description

Technical Field

[0001] This invention relates to the field of ground inspection equipment technology, and in particular to a device for detecting the condition of corundum ground. Background Technology

[0002] Currently, corundum is mainly used in underground garage floors in civil buildings. Corundum can reduce unevenness of the ground, thereby reducing the impact and wear of vehicles and extending the service life of the floor. In addition, corundum has good anti-slip properties, effectively reducing the phenomenon of slipping on the ground, thus improving driving safety.

[0003] However, after the emery aggregate pavement is poured, it needs to solidify before surface processing and inspection. This ensures that if cracks or partial wear appear, the corresponding areas can be repaired to guarantee the quality of the emery aggregate pavement. In the current technology, the condition inspection of emery aggregate pavement can only be done by human eyes to identify whether there is wear or cracks. This increases labor costs, is prone to missed inspections, has large errors, and has a low degree of automation.

[0004] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0005] To address the aforementioned shortcomings, the present invention aims to provide a diamond abrasive ground condition detection device. This device can automatically move along the ground to determine whether there are defects or cracks in the road surface it traverses, thereby achieving automated detection of road surface condition.

[0006] To achieve the above objectives, the present invention provides a device for detecting the condition of a corundum surface, comprising:

[0007] The housing has a control module inside, and a walking component is located at the bottom of the housing. The control module controls the walking component to rotate and drive the housing to move.

[0008] A detection assembly rotatably connected to the bottom of the housing, the detection assembly comprising:

[0009] A rotating disk is rotatably connected to the bottom of the housing, and a driving component for driving the rotating disk to rotate is provided inside the housing;

[0010] A plurality of detection contacts are disposed at the bottom of the rotating disk, and the plurality of detection contacts are rotatably connected to the bottom of the rotating disk. When in use, the plurality of detection contacts are in contact with the ground to be detected. When the detection contacts are in contact with abnormal ground, the contact state of the detection contacts changes and a signal is generated and transmitted to the control module. The control module determines the abnormality of the ground based on the signal.

[0011] In one embodiment, the bottom of the rotating disk is provided with a rotating shaft evenly arranged around an axis, the detection contact is rotatably connected to the rotating shaft, a plurality of the detection contacts are evenly arranged outside the rotating shaft, and the bottom of the rotating disk is provided with a detection element corresponding to the detection contact, the detection element detecting the rotation angle of the detection contact.

[0012] In one embodiment, the detection element is a detection button, and the detection contact includes a rotating sleeve rotatably connected to the rotating shaft and a cam disposed on the side wall of the rotating sleeve. The detection button abuts against the outer wall of the cam. The detection contact rotates, pushing the detection button to move. The detection button detects the rotation angle of the cam and feeds it back to the control module.

[0013] In one embodiment, the detection element is a detection column with a detection notch in the middle. The detection contact includes a rotating sleeve rotatably connected to the rotating shaft and an arc-shaped protrusion disposed on the outer side of the rotating sleeve. The arc-shaped protrusion is correspondingly disposed to the detection notch.

[0014] In one embodiment, the detection column and the arc-shaped protrusion are Hall sensors.

[0015] In one embodiment, the rotating sleeve is provided with an abutment rod on the side near the ground, and the end of the abutment rod abuts against the ground during use. A torque sensor is provided between the driving member and the rotating disk.

[0016] In one embodiment, the control module acquires the detection signals from the detection element and the torque sensor, and judges the detection signals to determine the state of the ground, and determines whether the inspected ground is in a cracked or worn state.

[0017] In one embodiment, the determination steps of the control module are as follows:

[0018] S1, Reference Calibration: Place the device on a flat ground, and the control module detects and records the initial angle α1 of each abutment rod and the initial torque P1 of the rotating disk as a reference.

[0019] S2. Movement Detection: The control roller moves the housing, the drive unit drives the rotating disk to rotate, the contact rod contacts the ground and rotates, and the angle α of each contact rod is detected in real time. i (i=1~M, where M is the total number of detection contacts) and the torque P of the rotating disk;

[0020] S3. Data Processing: Calculate the angle change ratio k for each detection contact. i = α i / α1, set the pothole threshold θ L , convex threshold θ H Count the number of the following parameters:

[0021] Number of pit detection contacts C L : Satisfying k i <θ L The number of detection contacts;

[0022] Normal detection contact number C N : Satisfies θ L ≤k i ≤θ H The number of detection contacts;

[0023] Number of protrusion detection contacts C H : satisfy ki>θ H The number of detection contacts;

[0024] Calculate the torque change ΔP = P - P1;

[0025] S4. Comprehensive Judgment: Simultaneously detect the number of detection contacts in different states to comprehensively judge whether the ground is in a state of potholes, bumps, cracks, or wear.

[0026] S5. Dynamic calibration: During long-term testing, the baseline values ​​α1 and P1 can be updated periodically to adapt to overall changes in the ground.

[0027] In one embodiment, in step S3, if C L + C H If the value is >0, then an anomaly is identified on the ground.

[0028] When C L >0 and C H When the value is 0, the ground is in a depression.

[0029] When C H >0 and C L = 0: The ground is raised at this time;

[0030] When C L >0 and C H When the value is >0: This indicates a complex and uneven surface.

[0031] When C L + C H When the value is 0, all detection contact angles are normal. Further analysis of the torque value is then performed to determine if there are any abnormalities on the ground.

[0032] In one implementation, when C L + C H When ΔP = 0, compare ΔP and ε, where ε is the positive torque threshold and is adjusted according to requirements:

[0033] If ΔP>ε, it is determined that the ground is rough or the surface is worn.

[0034] If ΔP < -ε, the ground is considered smooth.

[0035] If |ΔP|≤ε, the ground is considered normal.

[0036] This invention provides a device for detecting the condition of a corundum surface, comprising:

[0037] The housing contains a control module. The bottom of the housing has rollers, and the housing contains a roller motor that controls the rotation direction of the rollers. The roller motor can control the overall walking direction of the device. The rollers can be integrated with the motor to ensure the control of the movement and direction of the housing. The control module controls the rotation of the rollers and drives the housing to move, ensuring the control of the overall movement of the device.

[0038] A detection component connected to the bottom of the housing is rotated to detect the condition of the top surface of the ground. The detection component includes:

[0039] A rotating disk rotatably connected to the bottom of the housing allows for continuous monitoring of the ground condition. The housing contains a drive unit that rotates the disk. Several detection contacts are rotatably connected to the bottom of the rotating disk, ensuring contact with the ground surface for effective condition monitoring. These contacts move against the surface to be monitored, and their rotation angle reflects the ground condition. When a contact touches an abnormal surface, its contact state changes, generating a signal transmitted to the control module. The control module uses this signal to determine the abnormality and thus monitor the ground condition. In summary, this application provides an automated detection device that automatically moves across the ground to detect defects or cracks, achieving automated road condition monitoring. Attached Figure Description

[0040] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0041] Figure 2 This is a three-dimensional structural schematic diagram of the first embodiment of the present invention;

[0042] Figure 3 This is a cross-sectional structural diagram of the first embodiment of the present invention;

[0043] Figure 4 This is the invention Figure 3 Enlarged structural diagram of section A;

[0044] Figure 5 This is a three-dimensional structural diagram of the rotating disk according to the first embodiment of the present invention;

[0045] Figure 6 This is a cross-sectional structural diagram of the second embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of the three-dimensional structure of the rotating disk according to the second embodiment of the present invention;

[0047] Figure 8 yes Figure 7 Enlarged structural diagram of section B;

[0048] Figure 9 This is a schematic diagram of the three-dimensional structure of the detection contact in the first embodiment of the present invention;

[0049] Figure 10This is a schematic diagram of the cross-sectional structure of the detection contact in the second embodiment of the present invention;

[0050] Figure 11 This is a schematic diagram of the judgment process structure of the present invention;

[0051] Figure 12 This is a schematic diagram of the control flow structure of the present invention;

[0052] Figure 13 This is a schematic diagram of the internal structure of the present invention; in the figure, 1-housing, 2-infrared sensor, 3-display screen, 4-control button, 5-rotating disk, 51-drive shaft, 52-detection notch, 53-rotation hole, 54-mounting flange, 55-detection post, 6-roller, 7-detection contact, 71-abutting rod, 72-rotating sleeve, 73-cam, 74-arc-shaped protrusion, 8-rotating shaft, 9-detection button, 10-drive component, 11-roller motor, 12-power management module, 13-microprocessor. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0054] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0055] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0056] See Figure 1 and Figure 2 This invention provides a diamond abrasive ground condition detection device, which includes a housing 1, an internal control module, and a walking component at the bottom of the housing 1, which can be a roller 6. Inside the housing 1, there is a roller motor 11 that controls the rotation direction of the roller 6. The roller motor 11 can control the overall walking direction of the device. At the same time, the roller 6 can be set as an integral part of the motor, thereby ensuring the control of the walking and walking direction of the housing 1. The control module controls the rotation of the roller 6 and drives the housing 1 to walk, ensuring the control of the overall walking of the device.

[0057] The detection component connected to the bottom of the housing 1 is rotated to detect the condition of the top surface of the ground. The detection component includes:

[0058] The rotating disk 5 is rotatably connected to the bottom of the housing 1. By setting the rotating disk 5 to rotate during use, it can ensure that the ground condition can be detected at all times. The housing 1 is equipped with a drive component 10 to drive the rotating disk 5 to rotate. The drive component 10 drives the rotating disk 5 to rotate.

[0059] Several detection contacts 7 are arranged at the bottom of the rotating disk 5. These contacts 7 are rotatably connected to the bottom of the rotating disk 5, ensuring that the top surface of the ground can be contacted during use, thereby effectively detecting the state of the ground. When in use, the detection contacts 7 are pressed against the ground to be detected, and the state of the ground can be detected by the rotation angle of the detection contacts 7. When the detection contacts 7 are pressed against abnormal ground, the contact state of the detection contacts 7 changes, and a signal is transmitted to the control module. The control module judges the abnormal situation of the ground based on the signal, thereby realizing the detection of the ground state.

[0060] Among them, combined Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 9 To ensure the trajectory of the housing 1 during its movement, infrared sensors 2 or vision sensors (existing technology, the same as the control method of walking robots in the prior art) can be installed around the housing 1 to ensure that the surroundings of the housing 1 can be monitored. At the same time, a display screen 3 and control buttons 4 are installed on the top of the housing 1 to ensure that the detection results can be displayed and that the walking speed of the housing 1 can be controlled and parameters can be input. The driving component is a rotary motor, and the output shaft of the rotary motor is connected to the drive shaft 51 of the rotating disk to ensure the normal rotation of the rotating disk.

[0061] In one embodiment, to achieve a uniform arrangement of the detection contacts 7 and ensure the subsequent detection process, the bottom of the rotating disk 5 is provided with a rotating shaft 8 evenly arranged around the axis of the rotating disk. A rotating hole 53 is provided on the mounting flange 54 and the drive shaft 51 on the outer side of the rotating disk. The rotating shaft is connected inside the rotating hole 53, which can be a fixed connection or a rotatable connection. The detection contacts 7 are rotatably connected to the rotating shaft 8 to ensure that the detection contacts 7 can rotate effectively. This ensures that when the state of the road surface changes, the detection contacts 7 can effectively realize the corresponding state change, thereby detecting the state of the road surface. Several detection contacts 7 are evenly arranged outside the rotating shaft 8. The bottom of the rotating disk 5 is provided with a detection element corresponding to the detection contacts 7. The detection element detects the rotation angle of the detection contacts 7, thereby realizing the detection of the state of the road surface by detecting the change of the signal of the detection contacts 7.

[0062] Specifically, in order to enable the detection element to effectively detect the state of the detection contact 7, the detection element is a detection button 9. The detection contact 7 includes a rotating sleeve 72 rotatably connected to the rotating shaft 8 and a cam 73 disposed on the side wall of the rotating sleeve 72. The detection button 9 abuts against the outer wall of the cam 73. By rotating the detection contact 7, the detection button 9 is pushed to move. The detection button 9 can be in the form of a stroke sensor or a pressure sensor, which can directly calculate the rotation position of the cam and further calculate the rotation angle. Thus, the rotation angle of the detection contact 7 can be calculated by the pressing position of the detection button 9 (existing technology, not described in detail). The detection button 9 detects the rotation angle of the cam 73 and feeds it back to the control module to ensure that the control module can effectively judge the state of the detection contact 7 and the road surface.

[0063] In another embodiment, combined Figure 6 , Figure 7 , Figure 8 and Figure 10 To achieve accurate detection of the angle of the detection contact 7, the detection element is a detection column 55 with a detection notch 52 in the middle. The detection contact 7 includes a rotating sleeve 72 rotatably connected to the rotating shaft 8 and an arc-shaped protrusion 74 on the outer side of the rotating sleeve 72. The arc-shaped protrusion 74 is correspondingly arranged with the detection notch 52. The detection column 55 and the arc-shaped protrusion 74 are Hall sensors to ensure the detection accuracy of the rotation angle of the detection contact 7. The reset force of the detection contact 7 can be directly controlled by the gravity of the abutment rod 71 or by a torsion spring to ensure the force of the abutment rod 71 against the ground and to ensure the detection accuracy of the detection contact 7. To protect the abutment rod 71, a wear-resistant coating, ball bearings, or rollers can be provided at the bottom of the abutment rod 71 to protect the bottom of the abutment rod 71 and prevent friction damage.

[0064] In one embodiment, in order to better determine the condition of the top surface of the ground, an abutment rod 71 is provided on the side of the rotating sleeve 72 near the ground. The end of the abutment rod 71 abuts against the ground during use. A torque sensor is provided between the drive member 10 and the rotating disk 5. The condition of the ground can be better determined by simultaneously judging the rotation angle of the torque sensor and the detection contact 7.

[0065] Specifically, the control module collects detection signals from the detection components and torque sensor, and judges the detection signals to determine the condition of the ground, such as whether the inspected ground is cracked or worn, to ensure the detection effect. To enable the use of the device, the control module can use a microprocessor 13, such as the STM32 series or ESP32. At the same time, the detection components at the bottom of the rotating disk can be connected to the control module wirelessly, so that the detection signals can be transmitted to the internal part of the control module. Various driving components can be rotating motors to ensure the control of the walking direction and the rotation of the rotating disk. A power management module 12 is embedded inside the housing 1 to ensure power supply to the control module and driving components. A micro power supply is embedded at the bottom of the rotating disk to power the wireless communication module and the detection components, ensuring the power supply and communication process of each component.

[0066] Among them, combined Figure 12 and Figure 13In operation, the system's workflow begins with real-time data acquisition of ground conditions from various sensors. This includes angle sensors acquiring the deflection angle of the abutment rod and torque sensors measuring the resistance of the rotating disk. Angle sensors can be potentiometer-type (e.g., Bourns 3386 and Alps RK09K), magnetic encoder-type (AS5600 or AS5048), photoelectric encoders (Broadcom AEDR-8500), or Tindie MPU9250. Wireless angle sensors using Bluetooth transmission, and torque sensors mounted on the rotating shaft of the rotating disk to detect its rotational torque. These torque sensors can be strain gauge type (HX711 module + strain gauge, etc.). The original analog signal is amplified and filtered by a signal conditioning circuit, then converted into a digital signal by an analog-to-digital converter. Microprocessor 13 receives and processes this data. Microprocessor 13 can be an STM32F407VET6, ESP32-S3-WROOM, or similar processor. Microprocessor 13 is connected to various modules via communication lines, executes a preset ground condition judgment algorithm, and combines geometric anomaly detection and material analysis to obtain results. The processed information is then used to generate intuitive display data, which is driven by the SPI / I2C interface. The screen displays the detection values ​​and status interface in real time, and the display screen can be an OLED display. On the other hand, it generates control commands based on the analysis results to adjust the motor to perform corresponding actions. The motor can be a servo motor or other speed-controllable motor from manufacturers such as Siemens. Users can input operation commands through control button 4. The stable operation of the entire system is guaranteed by the power management module 12. Each module is connected to the power management module 12 through a power cable, forming a complete closed loop from data perception to decision output. The power management module 12 can be powered by a lithium battery and adopts a traditional embedded cover structure. It can also be charged via a USB port, which is located on the side or bottom of the housing. The core processor (such as STM32F407) integrates a complete system-on-a-chip.

[0067] In this embodiment, see Figure 10 and Figure 11 When in use, the control module's judgment steps are as follows:

[0068] S1, Reference Calibration: Place the device on a flat ground, and the control module detects and records the initial angle α1 of each abutment rod and the initial torque P1 of the rotating disk as a reference.

[0069] S2. Movement Detection: Control roller 6 moves housing 1, drive component drives rotating disk to rotate, contact rods with ground and rotate, real-time detection of angle α of each contact rod. i (i=1~M, M is the total number of detection contacts 7) and the torque P of the rotating disk;

[0070] S3. Data Processing: Calculate the angle change ratio k of each detection contact 7. i =α i / α1, set the pothole threshold θ L (e.g., 0.75), convex threshold θ H (e.g., 1.25), the four-part method can be used to set various thresholds and count the following quantities:

[0071] Number of pit detection contacts C L : Satisfying k i <θ L The number of detection contacts;

[0072] Normal detection contact number C N : Satisfies θ L ≤k i ≤θ H The number of detection contacts;

[0073] Number of protrusion detection contacts C H : Satisfying k i >θ H The number of detection contacts;

[0074] Calculate the torque change ΔP = P - P1;

[0075] S4. Comprehensive judgment:

[0076] A. If C L + C H >0 (geometric anomaly exists), indicating a ground depression:

[0077] b. Protrusion-dominant (C) H >0 and C L = 0), at which point there is a ground protrusion;

[0078] c. Mixed anomalies (C L >0 and C H >0): The surface is judged to be complex and uneven (such as gravel, damaged road surface);

[0079] If C L + C H = 0 (All test contacts at 7-degree angle are normal):

[0080] a. If ΔP>ε (ε is the positive torque threshold, such as 0.1P1, which can be adjusted according to specific circumstances or experience), it is judged as rough ground or surface wear;

[0081] b. If ΔP < -ε, the ground is considered smooth;

[0082] c. If |ΔP|≤ε, the ground is considered normal;

[0083] S5. Dynamic Calibration: During long-term testing, the reference values ​​α1 and P1 can be updated periodically to adapt to overall ground changes. Various parameters can be manually adjusted via buttons to ensure testing reliability. Simultaneously, the processing results can be directly displayed on the screen, ensuring better human-computer interaction. Of course, this invention can have other embodiments. Without departing from the spirit and essence of this invention, those skilled in the art can make various corresponding changes and modifications according to this invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A diamond ground surface condition detection device, characterized by, The utility model relates to a kind of detection device, including: Shell, which is internally provided with a control module, the bottom of the shell is provided with a traveling part, and the control module controls the rotation of the traveling part and drives the shell to travel; A detection assembly is rotatably connected to the bottom of the shell, and the detection assembly includes: A rotating disc is rotatably connected to the bottom of the shell, and the inside of the shell is provided with a driving member for driving the rotating disc to rotate; A plurality of detection contacts are provided on the bottom of the rotating disc, and the plurality of detection contacts are densely arranged on the bottom of the rotating disc, and in use, the plurality of detection contacts abut against the ground to be detected, when the detection contacts abut against an abnormal ground, the abutting state of the detection contacts changes, and a signal is transmitted to the control module, the control module judges the abnormal condition of the ground through the signal, the bottom of the rotating disc is provided with a detection member corresponding to the detection contacts, the detection member detects the rotation angle of the detection contacts, a torque sensor is provided between the driving member and the rotating disc, the bottom of the rotating disc is provided with rotating shafts evenly arranged around the axis of the rotating disc, the detection contacts are rotatably connected to the rotating shafts, and the plurality of detection contacts are evenly arranged on the outside of the rotating shafts, the detection contacts include a rotating sleeve rotatably connected to the rotating shafts, one side of the rotating sleeve near the ground is provided with an abutting rod, and the end of the abutting rod abuts against the ground in use; The control module collects the detection signals of the detection member and the torque sensor, and judges the detection signals to judge the state of the ground, and the judgment steps of the control module are as follows: S1, reference calibration: place the device on a flat ground, and the control module detects and records the initial angle α1 of each abutting rod and the initial torque P1 of the rotating disc as a reference; S2, movement detection: control the walking piece to move the shell, the driving piece drives the rotating disc to rotate, the abutting rod contacts the ground and rotates, and the angle α of each abutting rod is detected in real time i , i = 1 ~ M, M is the total number of detection contacts and the rotating disc torque P; S3, data processing: calculate the angle change ratio k of each detection contact i = a i / a1, set the pit threshold value θ L , the convex threshold value θ H ; count the number of the following parameters: Number of pit detection contacts C L : k is satisfied i <θ L Number of detection contacts Normal number of detection contacts C N : Satisfies θ L ≤ k i ≤ θ H Number of detection contacts; Number of projection detection contacts C H : k i > θ H of detection contacts; Calculate the torque change ΔP = P - P1; S4, comprehensive judgment: the number of detection contacts of different states is detected, and the ground in the pit, bump, crack and wear state is comprehensively judged. If C L + C H > 0, it is judged that there is an abnormal ground condition: When C L > 0 and C H = 0, there is a depression on the ground at this time; When C H > 0 and C L = 0: At this time, the ground exists convex case; When C L > 0 and C H > 0: At this time, it is judged as a complex uneven ground; When C L + C H = 0, at this time all detection contact angle is normal, further to judge the torque value, so as to judge whether there is ground abnormal situation, at this time compared with ΔP and ε, ε is torque positive threshold and can be adjusted according to demand: If ΔP > ε, it is judged that the ground is rough or the surface is worn; If ΔP < -ε, it is judged that the ground is smooth; If |ΔP|≤ε, it is judged that the ground is normal; S5, dynamic calibration: in long-term detection, the reference values α1 and P1 can be updated regularly to adapt to the overall change of the ground.

2. The apparatus according to claim 1, wherein The detection member is a detection button, the detection contacts further include a cam provided on the side wall of the rotating sleeve, the detection button abuts against the outer wall of the cam, the detection contacts rotate, push the detection button to move, the detection button detects the rotation angle of the cam and feeds back to the control module.

3. The apparatus according to claim 1, wherein The detection member is a detection column, and the detection column is provided with a detection gap in the middle, and the detection contacts include an arc-shaped convex edge provided on the outside of the rotating sleeve, and the arc-shaped convex edge is correspondingly arranged with the detection gap.

4. The apparatus according to claim 3, wherein The detection column and the arc-shaped convex edge are Hall sensors.

Images