Rockfill dam concrete panel construction chute dredging device and dredging method

Abstract

The invention discloses a dredging device and a dredging method for a rock-fill dam concrete panel construction chute. An intelligent control unit dominates automatic cycle operation and a dredging operation unit, and starts from the top end of a chute, the intelligent control unit dynamically adjusts the stirring rotating speed according to a blockage index, and blades are rotated while moving to conduct downward dredging; after the visual identification module identifies an end point, the stirring rod is controlled to rotate and fold, and equipment returns to the top end without load; then the stirring rod is put down, a new round of downward dredging is started, and circulation is conducted till construction is finished; the rotating speed of the stirring rod and the blade angle can be automatically adjusted, and self-adaptive dredging control is achieved; according to the comprehensive expression of visual characteristics and stirring load characteristics, the flowing state of concrete in the chute is divided into four typical categories through the blockage index, and the advancing speed, the stirring rotating speed and the blade angle are correspondingly adjusted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water conservancy and hydropower engineering construction, and particularly relates to a rockfill dam concrete face plate construction chute dredging device and method. BACKGROUND

[0002] In water conservancy and hydropower engineering, the construction quality of the rockfill dam concrete face plate directly affects the dam's anti-seepage performance and long-term stability, and the concrete is usually transported by a chute conveying system. However, due to concrete aggregate segregation, long conveying distance, large height difference, etc., the concrete is prone to blockage during the chute conveying process. At present, the blockage dredging operation mainly relies on manual work, which is time-consuming and labor-intensive, and the efficiency is extremely low. Moreover, the personnel need to operate in high altitude or dangerous environment, facing huge safety risks. In addition, the traditional dredging technology control strategy is fixed and cannot be self-adaptively adjusted according to the flow state, and the dredging is blind and the degree of automation is low, which is difficult to meet the requirements of modern high-standard construction. SUMMARY

[0003] The present application aims to provide a rockfill dam concrete face plate construction chute dredging device that combines visual recognition and torque sensing. Another object of the present application is to provide a rockfill dam concrete face plate construction chute dredging method that realizes automatic blockage identification, self-adaptive dredging, digital monitoring and predictive control.

[0004] Technical solution: The rockfill dam concrete face plate construction chute dredging device of the present application is installed on a U-shaped chute and includes a mobile walking unit, a dredging operation unit and an intelligent control unit. The mobile walking unit is used to drive the dredging operation unit to reciprocate along the gear track laid on the chute. The dredging operation unit includes a retractable stirring rod and a motor, and the stirring rod is provided with angle-adjustable rotating blades. The intelligent control unit includes a visual recognition module, a torque sensing module and a control module. The visual recognition module is used to identify and determine the concrete state and the chute end point. The torque sensing module is used to determine the stirring torque and judge the concrete state. The control module is used to coordinate and control the mobile walking unit and the dredging operation unit, realizing the automatic circulation operation of downward dredging and rod returning.

[0005] Further, the angle adjustment of the rotating blades is driven by a brushless DC servo motor to rotate a servo ring, and the servo ring drives the blades to rotate around their blade axes through a rocker arm, realizing variable adjustment of the blade attack angle. Further, the three retractable stirring rods are arranged side by side, and the stirring rods on both sides are shorter than the stirring rod in the middle, forming a non-uniform distribution.

[0006] The rockfill dam concrete face plate construction chute dredging method of the present application is realized by the above-mentioned rockfill dam concrete face plate construction chute dredging device, and the method includes the following steps: (1) The dredging unit is located at the starting position at the upper end of the chute, and the stirring rods are lowered into the chute to enter the preparatory working state; (2) When the concrete in the chute is identified as a mild blockage state or a serious blockage state, the dredging unit runs uniformly from top to bottom along the gear track laid on the chute under the combined drive of gravity and electricity; (3) During the downward process, the three stirring rods of the dredging unit are started simultaneously and maintain a rotating speed, and when the stirring rod torque rises, the intelligent control unit controls the dredging unit to slow down the downward speed and expand the rotating angle of the blades; (4) When the end of the chute is identified, the stirring rods stop rotating and are lifted vertically away from the concrete surface, and are rotated and folded into the main body of the dredging unit, and the dredging unit returns quickly to the starting position along the gear track under load; according to the concrete pouring process, the chute bottom will be recycled in sections; (5) Repeat steps (1) to (4) until the pouring is completed.

[0007] Further, during the downward dredging process, the following constraints are met: The output power P of the stirring rod driving motor satisfies: ; Where P is the power of the stirring rod driving motor; T is the sum of the resistance torques of the three stirring rods; ω is the rotating angular velocity of the stirring rod; η is the mechanical efficiency of the transmission system; The walking speed v of the dredging unit and the stirring rod rotating speed n satisfy: ; Where, L eff is the effective length of the stirring rod blade in the length direction of the chute; C is a dimensionless empirical coefficient.

[0008] Further, the concrete state is judged by the blockage index The blockage index is ; Where, is the average value of the flow velocity; is the maximum optical flow average value in the smooth state; is the average value of the gray scale gradient, indicating the texture complexity and boundary definition of the image; is the maximum gray scale gradient in the smooth state; the weight , , satisfies ; The comprehensive mechanical index based on the stirring rod torque is used to represent the degree of resistance of the concrete to the stirring rod. The index comprehensively considers the static deviation and dynamic change rate of the stirring torque.

[0009] Further, the average value of the flow velocity is ; wherein, is the total number of pixels in the internal region of the chute, is the optical flow vector.

[0010] Further, the average value of the gray scale gradient is ; wherein, is the gray scale value of the image at time t.

[0011] Further, the comprehensive mechanical index of the stirring rod torque is ; wherein, the weight , satisfies ; is the instantaneous deviation of the torque, i.e., the deviation of the current torque relative to the reference; is the torque normalization factor; is the speed of the change of the torque over time; is the typical range of the change of the torque under normal working conditions.

[0012] Further, the state of the concrete is determined by the blockage index The determination method is as follows: When , the concrete is in a smooth flow state, and the initial preset speed , the initial preset stirring speed and the initial preset blade angle are maintained; When , the concrete is in a mild resistance state, the speed is 0.8 , the stirring speed is 1.1 , and the blade angle is ; When , the concrete is in a serious blockage state, and the speed is stopped, the blade angle is the maximum blade angle ; When , the video stream of the visual recognition module is interrupted, the optical flow is zero, the stirring is stopped, the stirring rod is retracted, the torque is zero, and the speed is the maximum speed .

[0013] Advantages: Compared with the prior art, the present application has the following advantages: 1. The automatic circulation operation of the present application is dominated by the intelligent control unit. The unblocking operation unit and the top end of the chute start. The intelligent control unit dynamically adjusts the stirring speed and the rotating blade moves downward. After the visual recognition module identifies the end point, the stirring rod is rotated and folded. The equipment returns to the top end under no load. Then the stirring rod is lowered and a new round of downward unblocking begins. This cycle continues until the construction is completed. 2. The present application can automatically adjust the stirring speed and the blade angle to achieve adaptive unblocking control. 3. According to the comprehensive performance of the visual features and the stirring load features, the present application divides the flow state of the concrete in the chute into four typical categories through the blockage index, and makes corresponding adjustments to the travel speed, stirring speed and blade angle. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The flowchart of the method of the present application; Figure 2 The structural schematic diagram of the device of the present application; Figure 3 The schematic diagram of the stirring rod working; Figure 4 The schematic diagram of the stirring rod folding; Figure 5 The cross-sectional schematic diagram of the unblocking operation unit. DETAILED DESCRIPTION

[0015] The rockfill dam concrete face construction chute unblocking device of the present application is installed on the U-shaped chute, including a mobile walking unit, an unblocking operation unit and an intelligent control unit. The mobile walking unit is used to drive the unblocking operation unit to reciprocate along the gear track laid on the chute. The unblocking operation unit includes a retractable stirring rod and a motor. The upper end of the stirring rod is provided with an angle adjusting mechanism, including a brushless DC servo motor, a servo ring and a rocker mechanism connected with the servo ring. The servo motor drives the servo ring to rotate. The servo ring drives the blade to rotate around its blade axis through the rocker, realizing variable adjustment of the blade attack angle. Three retractable stirring rods are arranged side by side. The stirring rods on both sides are shorter than the stirring rod in the middle, forming a non-uniform distribution. The intelligent control unit includes a visual recognition module, a torque sensing module and a control module. The visual recognition module is used to identify and judge the concrete state and the chute end. The torque sensing module is used to determine the stirring torque and judge the concrete state. The control module is used to coordinate and control the mobile walking unit and the unblocking operation unit, realizing the automatic circulation operation of downward unblocking and rod returning.

[0016] The rockfill dam concrete face construction chute unblocking method of the present application is realized by the above-mentioned rockfill dam concrete face construction chute unblocking device. The method includes the following steps: (1) The dredging unit is located at the starting position at the upper end of the chute, and the three stirring rods are lowered into the chute to enter the preparatory working state.

[0017] (2) When the concrete in the chute is identified as being in a mild blockage state or a serious blockage state, the dredging unit runs at a uniform speed along the gear track laid on the chute under the combined driving of gravity and electricity.

[0018] In the downward dredging process, the three stirring rods rotate around their own axes to overcome the shear resistance of the concrete in the chute. The output power P of the stirring rod driving motor should satisfy the following relationship: ; Wherein, P is the power of the stirring rod driving motor (kW); T is the total resistance moment (kN·m) that the three stirring rods need to overcome under the design working condition, i.e. the sum of the resistance moments of the three stirring rods; ω is the rotation angular velocity of the stirring rod (rad / s); and η is the mechanical efficiency of the transmission system (dimensionless).

[0019] In engineering design, the resistance moment of a single stirring rod under the design working condition can be estimated first, and when the structures and stress working conditions of the three stirring rods are basically the same, .

[0020] The walking speed v (m / s) of the equipment and the stirring rod rotation speed n (rpm) need to be matched to ensure that the chute of unit length is fully stirred, and their relationship satisfies: ; Wherein, L eff is the effective action length of the stirring rod blade in the length direction of the chute (m); and C is an empirical coefficient (dimensionless), representing the average number of times that a section is repeatedly swept by the stirring blade during the passage of the equipment through the section, i.e. the "blade overlap times". When the equipment travels downward along the chute at a speed v and the stirring rod rotates at a speed n, a fixed section will be repeatedly swept by the blade during the whole passage process. The larger the value of C, the more times the section is repeatedly cut and turned by the blade during this passage process, and the higher the degree of stirring of the concrete. In practical applications, in order to balance the dredging effect and the running efficiency, C can be taken as 1.5-3 in the empirical range, and is used to guide the linkage control of v and n after being calibrated through tests.

[0021] In the downward process, the three stirring rods of the dredging unit are started simultaneously and kept rotating at a speed, and when the stirring rod torque rises, the intelligent control unit controls the dredging unit to slow down the downward speed and expand the blade rotation angle.

[0022] ​By using multimodal fusion of camera images obtained from a visual recognition module and stirring torque signals, real-time and robust detection of concrete blockage in chutes is achieved, driving adaptive unblocking control and determining the blockage index. as follows: ; ; ; ; in, This represents the average flow velocity. The grayscale value of the image at time t; The mean of the grayscale gradient represents the texture complexity and boundary sharpness of the image. This is the instantaneous torque deviation, which is the amount of deviation of the current torque relative to the reference. The rate at which torque changes with time (N·m / s); weight , , satisfy ; This represents the average maximum optical flow under unobstructed conditions. This represents the maximum grayscale gradient under unobstructed conditions. This is a comprehensive mechanical index based on the torque of the stirring rod. This represents the total number of pixels within the chute's internal region. For optical flow vectors, , This is the torque normalization factor, which is usually taken as a constant multiple of the baseline torque or the maximum torque; The rate at which torque changes over time; This is the typical range of torque variation under normal operating conditions (e.g., ±50 N·m / s).

[0023] According to the congestion index It can determine different flow conditions of concrete within the flow channel: (1) When High optical flow and stable torque, the concrete is in a smooth flow state; (2) When The optical flow decreased slightly, the torque increased slightly, and the concrete was in a state of mild stagnation. (3) When The optical flow is near zero, the torque fluctuates wildly, and the concrete is severely blocked. (4) When At this point, the video stream is interrupted, the default light stream is zero, and the torque is zero after the stirring rod is retracted, indicating an unloaded return state.

[0024] The intelligent control unit coordinates and controls the automated operation of the entire equipment. This system integrates a vision recognition module and a torque sensing module. Based on a combination of visual characteristics and mixing load characteristics, it can classify the flow state of concrete in the chute into four typical categories, and also monitor the travel speed v, mixing speed n, and blade angle. Make the following adjustments: In a smooth flow state, the image exhibits high optical flow, rich grayscale gradients, and low torque fluctuations. At this point, normal parameters should be maintained. , , .

[0025] In a state of mild hindrance, the optical flow decreases slightly, and the torque increases slightly. At this point, the travel speed should be reduced slightly. Slightly increase the stirring speed blade angle Keep unchanged; In a severely clogged state, optical flow is close to zero, grayscale images remain stable, and torque increases significantly with drastic fluctuations. At this point, forward movement is stopped, and the three stirring rods repeatedly stir at full power, with the blade angle increased to its maximum. ; In the no-load return state, image features are weak, and torque is extremely low or at baseline. At this point, retract the stirring rod and resume return mode. Stirring stops, and the blades close up.

[0026] When the end point of the chute is detected, the mixing rod stops rotating and is vertically lifted off the concrete surface. It then rotates and retracts into the main body of the dredging unit to avoid interference with the concrete in the chute during the upward movement. The dredging unit then quickly returns to the starting position without load along the gear track. Depending on the progress of concrete pouring, the bottom of the chute will be recovered section by section.

[0027] (5) After returning to the starting position, the mixing rod rotates and descends to the working position in the chute. Repeat steps (1) to (4) to form a fully automatic cycle operation mode of "downward dredging → end point identification and rod collection → empty return → reset and downward again". As the concrete pouring proceeds, the chute below will be collected section by section. The camera identifies the change in the actual length of the chute and adaptively adjusts the end point position of each downward dredging to ensure that the dredging operation always covers the effective chute section until the entire pouring is completed.

Claims

1. A rockfill dam concrete face slab construction chute unblocking device installed on a U-shaped chute, characterized in that, The device comprises a mobile walking unit, a dredging unit and an intelligent control unit, the mobile walking unit is used to drive the dredging unit to run back and forth along the gear track laid on the chute, the dredging unit comprises a retractable stirring rod and a motor, the stirring rod is provided with angle-adjustable rotating blades, the intelligent control unit comprises a visual recognition module, a torque sensing module and a control module, the visual recognition module is used to identify and judge the concrete state and the end point of the chute, the torque sensing module is used to determine the stirring torque and judge the concrete state, and the control module is used to coordinate and control the mobile walking unit and the dredging unit, so as to realize the automatic circulation operation of down-dredging and rod returning.

2. The device according to claim 1, characterized in that, An angle adjusting mechanism is arranged at the upper end of the stirring rod, the angle adjusting mechanism comprises a brushless DC servo motor, a servo ring and a rocker mechanism connected with the servo ring, the servo motor drives the servo ring to rotate, the servo ring drives the blades to rotate around the blade axis through the rocker, and variable adjustment of the blade attack angle is realized.

3. The device according to claim 1, wherein Three retractable stirring rods are arranged side by side, the stirring rods on the two sides are shorter than the stirring rod in the middle, and a non-uniform distribution is formed.

4. A method for dredging a construction chute of a concrete face rockfill dam, characterized in that, The method is realized by the rock-fill dam concrete panel construction chute dredging device of any one of claims 1-3, and the method comprises the following steps: (1) the dredging unit is located at the starting position at the uppermost end of the chute, the stirring rod is lowered into the chute, and a preparatory working state is entered; (2) when it is identified that the concrete in the chute is in a mild blockage state or a serious blockage state, the dredging unit runs at a uniform speed from top to bottom along the gear track laid on the chute under the combined driving of gravity and power; (3) during the downward process, the three stirring rods of the dredging unit are started at the same time and the rotating speed is maintained, when the stirring rod torque rises, the intelligent control unit controls the dredging unit to slow down the downward speed and expand the rotating angle of the blades; (4) when the end point of the chute is identified, the stirring rod stops rotating and is vertically lifted to separate from the concrete surface, is rotated and retracted into the main body of the dredging unit, and the dredging unit returns to the starting position along the gear track at a high speed under no load; according to the concrete pouring process, the chute bottom is recycled in sections; (5) steps (1) to (4) are repeated until pouring is completed.

5. The method of claim 4, wherein the method further comprises, During the downward dredging process, the following constraint conditions are met: The output power P of the stirring rod driving motor satisfies: ； Wherein, P is the power of the stirring rod driving motor; T is the sum of the resistance torques of the three stirring rods; ω is the rotating angular velocity of the stirring rod; η is the mechanical efficiency of the transmission system; The walking speed v of the dredging unit and the stirring rod rotating speed n satisfy: ； wherein L eff Ceffis the effective length of the blade of the stirrer in the length direction of the chute; C is a dimensionless empirical coefficient.

6. The method of claim 4, wherein the method further comprises, The state of the concrete is determined by the blockage index The blockage index is determined is ； wherein, is the average value of the flow velocity; is the maximum average value of the light flow in the unobstructed state; is the average value of the gray gradient, representing the texture complexity and boundary definition of the image; is the maximum gray gradient in the unobstructed state; the weight , , satisfies ; is the comprehensive mechanical index based on the stirring rod torque.

7. The method of claim 6, wherein the method further comprises, Flow rate average To ； wherein, is the total number of pixels in the chute interior region, is the optical flow vector.

8. The method of claim 6, wherein the method further comprises, gray scale gradient mean to ； wherein, is the gray value of the image at time t.

9. The method of claim 6, wherein the method further comprises, Comprehensive mechanical index of stirring rod torque To ； wherein the weight , satisfies ; is the torque instantaneous deviation, i.e., the deviation of the current torque relative to the reference; is the torque normalization factor; is the speed of the change of the torque over time; is the typical range of the torque change under normal working conditions.

10. The method of claim 6, wherein the method further comprises, The state of the concrete is determined by the blockage index The method is determined as follows: When , the concrete is in a smooth flow state, maintaining the initial preset speed , the initial preset stirring speed and the initial preset blade angle ; When , the concrete is in a slightly retarded state, the speed is 0.8 , the stirring speed is 1.1 , the blade angle is ; When , the concrete is in a serious jam state, stop advancing, the blade angle is the maximum blade angle ; When , interrupt the visual recognition module video stream, take the light flow to be zero, stop stirring, collect the stirring rod after the torque is zero, return to the state of empty load, the speed is the maximum speed .

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