Rail ultrasonic flaw detection mechanical arm

Abstract

The utility model belongs to the steel rail ultrasonic detection technical field especially relates to a kind of steel rail ultrasonic flaw detection mechanical arm, comprising: mechanical arm component, the end of mechanical arm component is connected with fourth drive part, the output end of fourth drive part is connected with ultrasonic probe, pressure sensor is arranged between fourth drive part and ultrasonic probe, pressure sensor, mechanical arm component, fourth drive part, ultrasonic probe are electrically connected with controller, and controller is used to receive the signal of pressure sensor and controls fourth drive part to adjust the pressure suffered by ultrasonic probe according to the signal of pressure sensor.The utility model can ensure that probe keeps uniform, stable and adhering state with steel rail surface during moving, solve the problem that ultrasonic coupling state is inconsistent caused by unstable contact pressure in prior art, effectively reduce detection signal attenuation, improve the accuracy and efficiency of steel rail flaw detection.

Description

Technical Field

[0001] This utility model belongs to the field of ultrasonic testing technology for rails, and particularly relates to a robotic arm for ultrasonic flaw detection of rails. Background Technology

[0002] Rail transit is the backbone of modern urban transportation systems. As a key component that directly bears and transmits train loads, the integrity of the rails, both internally and externally, is fundamental to operational safety. Under long-term cyclic loading and environmental influences, rails are prone to fatigue cracks, spalling, and other damage. If these defects are not detected and addressed promptly, they will seriously threaten operational safety. Therefore, rail flaw detection has become an indispensable core component of railway maintenance. Its core task is to accurately identify rail damage through detection, providing crucial information for condition-based maintenance and risk control.

[0003] Currently, rail flaw detection mainly relies on ultrasonic testing technology, which identifies internal defects in key areas such as the rail head, rail web, and rail base by exciting ultrasonic signals and receiving their reflected signals. Existing technologies mostly use robotic arms or multi-degree-of-freedom mechanical devices to drive ultrasonic probes for scanning. Although such solutions can achieve multi-angle detection, they have significant technical bottlenecks in practical applications: the mechanical transmission mechanism is difficult to maintain the dynamic coupling stability between the probe and the rail surface during complex movements, and fluctuations in contact pressure can lead to a significant decrease in ultrasonic energy transfer efficiency. In addition, although traditional sliding rail flaw detection devices can achieve directional detection, their rigid guiding structure is not adaptable enough to changes in the rail surface curvature, especially in the gauge angle region where it is difficult to maintain uniform fit, causing the ultrasonic incident angle to deviate, which in turn affects the accurate reception of defect signals.

[0004] Specifically, insufficient damping characteristics at the joints of the robotic arm cause intermittent detachment of the probe from the rail surface due to minute vibrations during movement, resulting in momentary interruptions in ultrasonic coupling. Contact pressure adjustment mechanisms often employ fixed parameter designs, failing to compensate in real-time for changes in rail surface roughness, leading to contact impedance fluctuations exceeding permissible thresholds. Furthermore, sliding rail flaw detection devices, constrained by the geometric design of the guide rail, are prone to probe suspension at special locations such as rail joints and welds, and cannot adapt to complex deformations on the rail surface caused by long-term service, such as wavy wear, resulting in uncontrollable deviations in the ultrasonic propagation path, ultimately affecting defect location accuracy and detection reliability.

[0005] The aforementioned unstable coupling states can all lead to missed or false detections, posing a hidden danger to rail transit safety. Utility Model Content

[0006] The purpose of this invention is to provide a robotic arm for ultrasonic flaw detection of rails to solve the above-mentioned problems.

[0007] To achieve the above objectives, this utility model provides the following solution:

[0008] A robotic arm for ultrasonic flaw detection of rails includes: a robotic arm assembly, a fourth drive unit connected to the end of the robotic arm assembly, an ultrasonic probe connected to the output end of the fourth drive unit, a pressure sensor disposed between the fourth drive unit and the ultrasonic probe, and the pressure sensor, the robotic arm assembly, the fourth drive unit, and the ultrasonic probe all being electrically connected to a controller. The controller is used to receive the signal from the pressure sensor and control the fourth drive unit to adjust the pressure on the ultrasonic probe according to the signal from the pressure sensor.

[0009] Preferably, the output end of the fourth drive unit is connected to a buffer unit, the movable end of the buffer unit is connected to the ultrasonic probe, and the pressure sensor is located between the buffer unit and the ultrasonic probe.

[0010] Preferably, the buffer includes a housing with an opening at the top and a through hole at the bottom. An upper slide plate and a lower slide plate are vertically slidably connected inside the housing. The lower slide plate is close to the through hole. A spring is provided between the upper slide plate and the lower slide plate, with both ends of the spring fixedly connected to the upper slide plate and the lower slide plate, respectively. The housing is fixedly connected to the fourth driving unit. The output end of the fourth driving unit extends from the top of the housing into the housing and is fixedly connected to the upper slide plate. The pressure sensor is fixedly connected to the lower slide plate. The detection end of the pressure sensor extends out of the through hole and is detachably connected to the ultrasonic probe.

[0011] Preferably, the robotic arm assembly includes a first drive unit, an output end of the first drive unit connected to a first arm, a second drive unit connected to the end of the first arm away from the first drive unit, an output end of the second drive unit connected to a second arm, a third drive unit connected to the end of the second arm away from the second drive unit, and a fourth drive unit connected to the output end of the third drive unit. The first drive unit, the second drive unit, and the third drive unit are all electrically connected to the controller.

[0012] Preferably, the robotic arm assembly further includes a base, the base including a rotating base, the first drive unit is fixedly installed on the movable end of the base, the controller is fixedly installed on the movable end of the base, and the controller is electrically connected to the base.

[0013] Preferably, the controller includes a PLC controller.

[0014] Preferably, the first drive unit, the second drive unit, and the third drive unit all include a servo motor, and the axes of the first drive unit, the second drive unit, and the third drive unit are arranged in parallel.

[0015] Preferably, the fourth drive unit includes a linear motor.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] This invention uses a pressure sensor to monitor the contact pressure between the ultrasonic probe and the rail surface in real time. The controller controls the fourth drive unit to adjust the pressure on the ultrasonic probe based on the signal from the pressure sensor, thereby ensuring that the probe maintains a uniform and stable contact with the rail surface during movement. This solves the problem of inconsistent ultrasonic coupling caused by unstable contact pressure in the prior art, effectively reduces the attenuation of the detection signal, and improves the accuracy and efficiency of rail flaw detection. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a top view of the present invention;

[0020] Figure 2 This is the front view of the present invention;

[0021] Figure 3 This is a schematic diagram of the buffer section in this utility model;

[0022] The components are as follows: 1. Base; 2. Controller; 3. First drive unit; 4. First support arm; 5. Second drive unit; 6. Second support arm; 7. Third drive unit; 8. Fourth drive unit; 9. Buffer unit; 10. Pressure sensor; 11. Ultrasonic probe; 901. Housing; 902. Spring; 903. Lower slide plate; 904. Upper slide plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Reference Figures 1 to 3 This utility model discloses a robotic arm for ultrasonic flaw detection of rails, comprising: a robotic arm assembly, a fourth drive unit 8 connected to the end of the robotic arm assembly, an ultrasonic probe 11 connected to the output end of the fourth drive unit 8, a pressure sensor 10 disposed between the fourth drive unit 8 and the ultrasonic probe 11, and the pressure sensor 10, the robotic arm assembly, the fourth drive unit 8, and the ultrasonic probe 11 all being electrically connected to a controller 2. The controller 2 is used to receive the signal from the pressure sensor 10 and control the fourth drive unit 8 to adjust the pressure on the ultrasonic probe 11 according to the signal from the pressure sensor 10.

[0026] The controller 2 is connected to the ultrasound probe 11 and is used to receive the reflected signal from the ultrasound probe and convert it into an observable ultrasound image. At the same time, the controller 2 sends operation commands to the ultrasound probe 11 to adjust parameters such as ultrasound emission frequency and focusing position.

[0027] The ultrasonic probe 11 can be a phased array ultrasonic probe or a similar non-destructive testing probe.

[0028] The pressure sensor 10 monitors the contact pressure between the ultrasonic probe 11 and the rail surface in real time and feeds the signal back to the controller 2. The controller 2 controls the fourth drive unit 8 to operate accordingly, realizing closed-loop automatic adjustment of the probe pressure, actively maintaining the stability of the pressure between the ultrasonic probe 11 and the rail surface, ensuring consistent ultrasonic coupling state, and thus improving detection accuracy.

[0029] In a further optimized design, the output end of the fourth drive unit 8 is connected to a buffer unit 9, the movable end of the buffer unit 9 is connected to the ultrasonic probe 11, and the pressure sensor 10 is located between the buffer unit 9 and the ultrasonic probe 11.

[0030] In a further optimized design, the buffer unit 9 includes a housing 901 with an opening at the top and a through hole at the bottom. An upper sliding plate 904 and a lower sliding plate 903 are vertically slidably connected inside the housing 901, with the lower sliding plate 903 near the through hole. A spring 902 is positioned between the upper and lower sliding plates 904 and 903, with both ends of the spring 902 fixedly connected to the upper and lower sliding plates 904 and 903 respectively. The housing 901 is fixedly connected to a fourth driving unit 8, with the output end of the fourth driving unit 8 extending from the top of the housing 901 into the housing 901 and fixedly connected to the upper sliding plate 904. A pressure sensor 10 is fixedly connected to the lower sliding plate 903, with the detection end of the pressure sensor 10 extending out of the through hole and detachably connected to the ultrasonic probe 11. The detachable connection methods include bolt connection and snap-fit ​​connection.

[0031] The buffer section 9 is connected between the fourth drive section 8 and the ultrasonic probe 11, and the pressure sensor 10 is located below the buffer section 9, making the buffer section 9 an intermediary link between the fourth drive section 8 and the ultrasonic probe 11, providing a structural basis for realizing mechanical buffering and fine pressure control.

[0032] When the fourth drive unit 8 pushes the upper slide plate 904, the force is transmitted to the lower slide plate 903 and the ultrasonic probe 11 through the spring 902. When encountering undulations on the rail surface, the spring 902 can absorb displacement changes through compression / extension, providing a passive mechanical buffer. Combined with active pressure control, it can more effectively smooth pressure fluctuations, protect the ultrasonic probe 11, and enhance the conformity of the fit.

[0033] Further optimization of the scheme: the robotic arm assembly includes a first drive unit 3, the output end of the first drive unit 3 is connected to a first support arm 4, the end of the first support arm 4 away from the first drive unit 3 is connected to a second drive unit 5, the output end of the second drive unit 5 is connected to a second support arm 6, the end of the second support arm 6 away from the second drive unit 5 is connected to a third drive unit 7, and a fourth drive unit 8 is connected to the output end of the third drive unit 7. The first drive unit 3, the second drive unit 5, and the third drive unit 7 are all electrically connected to the controller.

[0034] Through the combined movement of multiple rotary joints, the robotic arm has multiple degrees of freedom, enabling it to flexibly adjust the spatial position and orientation of the ultrasonic probe 11 to adapt to different detection areas and curved contours on the rail, such as the rail head, rail bottom, and rail web.

[0035] Further optimization of the design includes a base 1, which includes a rotating base, a first drive unit 3 fixedly installed at the movable end of the base 1, and a controller 2 fixedly installed at the movable end of the base 1. The controller 2 is electrically connected to the base 1.

[0036] The base 1 itself includes a rotating base, which can drive the entire robotic arm assembly and controller 2 mounted on it to rotate together, increasing a basic degree of rotational freedom and expanding the working range of the robotic arm assembly, enabling it to cover a wider detection area around the rail circumference.

[0037] The scheme was further optimized, and controller 2 includes a PLC controller.

[0038] The PLC controller can be a Siemens S7-1200 or a Mitsubishi FX3U series. The control program for controller 2 can be written or purchased by those skilled in the art according to their own needs, and will not be elaborated here.

[0039] The scheme is further optimized so that the first drive unit 3, the second drive unit 5, and the third drive unit 7 all include servo motors, and the axes of the first drive unit 3, the second drive unit 5, and the third drive unit 7 are arranged in parallel.

[0040] The servo motor can be the FiiS DS5150 or other similar industrial-grade servo motors.

[0041] The design was further optimized, and the fourth drive unit 8 includes a linear motor.

[0042] The fourth drive unit 8 can use IAI's RCP4 series linear actuator.

[0043] The base 1 can be fixedly installed on the rail inspection vehicle. The controller 2 controls the first drive unit 3 to drive the first support arm 4 to move, the second drive unit 5 to drive the second support arm 6 to move, and the third drive unit 7 to drive the ultrasonic probe 11 to move, so that the ultrasonic probe 11 can be attached to different sides of the rail.

[0044] During rail inspection, the ultrasonic probe 11 is placed on and adheres to the surface of the rail. Simultaneously, the pressure sensor 10 detects the pressure exerted on the ultrasonic probe 11 and transmits the data to the controller 2. The controller 2 receives and analyzes the sensor signal. The controller 2 has a preset target pressure threshold. It compares the real-time pressure value fed back by the pressure sensor 10 with the target threshold to determine if the current pressure meets the "tight fit" requirement. If the pressure value is lower than the threshold, the fit is not tight, and the downward pressure needs to be increased. If the pressure value is higher than the threshold, there may be an overpressure risk, and the downward pressure needs to be reduced. Based on the pressure analysis results, the controller 2 generates a control signal to drive the fourth drive unit 8 to extend and retract. The fourth drive unit 8 moves the outer shell 901 of the buffer unit 9, thereby changing the compression of the internal spring 902. When pressure needs to be increased, the fourth drive unit 8 extends, pushing the upper slide plate 904 to compress the spring 902, increasing the pushing force on the lower slide plate 903 and the ultrasonic probe 11. When pressure needs to be reduced, the fourth drive unit 8 retracts, the spring 902 tends to extend, and the pressure of the probe on the rail surface decreases smoothly. After the ultrasonic probe 11 is adjusted, the pressure sensor 10 detects the pressure value again and feeds it back to the controller 2. This process is repeated until the pressure value stabilizes within the target range, ensuring that the ultrasonic probe 11 remains in close contact with the rail. When the controller 2 determines that the pressure value has reached the optimal contact state, it triggers the ultrasonic probe 11 to emit a detection signal. At this point, the coupling condition is stable, reducing signal attenuation and improving the accuracy of defect detection.

[0045] In this utility model, the methods of fixing and consolidating include, but are not limited to, welding, bolting, and adhesive bonding. The specific connection method can be selected by those skilled in the art according to their own needs, and will not be elaborated here.

[0046] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0047] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A robotic arm for ultrasonic flaw detection of steel rails, characterized in that, include: A robotic arm assembly is provided, the end of which is connected to a fourth drive unit (8). The output end of the fourth drive unit (8) is connected to an ultrasonic probe (11). A pressure sensor (10) is provided between the fourth drive unit (8) and the ultrasonic probe (11). The pressure sensor (10), the robotic arm assembly, the fourth drive unit (8), and the ultrasonic probe (11) are all electrically connected to a controller (2). The controller (2) is used to receive the signal from the pressure sensor (10) and control the fourth drive unit (8) to adjust the pressure on the ultrasonic probe (11) according to the signal from the pressure sensor (10).

2. The ultrasonic flaw detection robotic arm for rails according to claim 1, characterized in that: The output end of the fourth drive unit (8) is connected to a buffer unit (9), the movable end of the buffer unit (9) is connected to the ultrasonic probe (11), and the pressure sensor (10) is located between the buffer unit (9) and the ultrasonic probe (11).

3. The ultrasonic flaw detection robotic arm for rails according to claim 2, characterized in that: The buffer part (9) includes a housing (901), with an opening at the top and a through hole at the bottom. An upper sliding plate (904) and a lower sliding plate (903) are vertically slidably connected inside the housing (901). The lower sliding plate (903) is close to the through hole. A spring (902) is provided between the upper sliding plate (904) and the lower sliding plate (903). The two ends of the spring (902) are fixedly connected to the upper sliding plate (904) and the lower sliding plate (903) respectively. The housing (901) is fixedly connected to the fourth driving part (8). The output end of the fourth driving part (8) extends from the top of the housing (901) into the housing (901) and is fixedly connected to the upper sliding plate (904). The pressure sensor (10) is fixedly connected to the lower sliding plate (903). The detection end of the pressure sensor (10) extends out of the through hole and is detachably connected to the ultrasonic probe (11).

4. The ultrasonic flaw detection robotic arm for rails according to claim 1, characterized in that: The robotic arm assembly includes a first drive unit (3), the output end of the first drive unit (3) is connected to a first arm (4), the end of the first arm (4) away from the first drive unit (3) is connected to a second drive unit (5), the output end of the second drive unit (5) is connected to a second arm (6), the end of the second arm (6) away from the second drive unit (5) is connected to a third drive unit (7), and the fourth drive unit (8) is connected to the output end of the third drive unit (7). The first drive unit (3), the second drive unit (5), and the third drive unit (7) are all electrically connected to the controller.

5. The ultrasonic flaw detection robotic arm for rails according to claim 4, characterized in that: The robotic arm assembly also includes a base (1), the base (1) includes a rotating base, the first drive unit (3) is fixedly installed on the movable end of the base (1), the controller (2) is fixedly installed on the movable end of the base (1), and the controller (2) is electrically connected to the base (1).

6. The ultrasonic flaw detection robotic arm for rails according to claim 1, characterized in that: The controller (2) includes a PLC controller.

7. The ultrasonic flaw detection robotic arm for rails according to claim 5, characterized in that: The first drive unit (3), the second drive unit (5), and the third drive unit (7) all include servo motors, and the axes of the first drive unit (3), the second drive unit (5), and the third drive unit (7) are arranged in parallel.

8. The ultrasonic flaw detection robotic arm for rails according to claim 1, characterized in that: The fourth drive unit (8) includes a linear motor.

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