Fishing rod type flexible rope drive clearance equipment and nonlinear discrete sliding mode clearance control method

Abstract

The invention discloses fishing rod type flexible rope drive clearance equipment and a nonlinear discrete sliding mode clearance control method, and belongs to the technical field of intelligent storage and flexible rope drive control. The problems that according to a traditional bin cleaning method, the bin cleaning operation range is limited, the bin cleaning efficiency is low, and unfavorable momentum transfer and dust accumulation exist in the bin cleaning process are solved. Compared with traditional single-degree-of-freedom clearance equipment, the fishing rod type flexible rope-driven clearance equipment has the advantages that three-degree-of-freedom movement, namely horizontal movement, vertical movement and circumferential rotation, of the clearance executing mechanism can be achieved, the movement degree of freedom of the clearance equipment is improved, it is guaranteed that the clearance executing mechanism can move to any position of a material bin, and the fishing rod type flexible rope-driven clearance equipment is convenient to use. And cleaning of the wall hanging layer is achieved. According to the nonlinear discrete sliding mode clearance control method, the problem of buffeting in the clearance process is effectively suppressed by combining the fractional order differential reaching law and the hyperbolic tangent function, and the clearance control precision and efficiency are remarkably improved compared with a traditional control method.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent warehousing and flexible rope drive control, and particularly relates to a fishing rod-type flexible rope drive warehouse clearing device and a nonlinear discrete sliding mode warehouse clearing control method. Background Art

[0002] In material storage facilities such as coal silos, granaries, and chemical warehouses, material sticking to the wall is a common and serious problem. As storage time increases, materials gradually accumulate on the silo walls, forming a stable sticking layer. This sticking condition not only affects the normal flow and unloading of materials, but may also cause a bridging effect in the silo, and in severe cases, even cause blockage of the discharge port. The long-standing sticking layer will gradually harden, increasing the difficulty of cleaning, and also provide a base for subsequent materials to adhere, exacerbating the sticking problem. In addition, the difficult-to-handle sticking layer will cause material contamination, affect the storage status of materials, accelerate the corrosion and wear of the silo walls, and shorten the service life of the storage facilities. When dealing with large-scale storage cleaning operations, traditional warehouse clearance solutions have problems such as limited warehouse clearance operation scope, low warehouse clearance efficiency, unfavorable momentum transfer and dust accumulation during the warehouse clearance process.

[0003] Pneumatic cleaning is a common method for removing material buildup from storage walls in coal bunkers, granaries, chemical warehouses, and other storage environments. However, pneumatic cleaning methods, such as using air cannons to impact compacted materials to remove buildup, only remove material buildup around the cannon, leaving a narrow cleaning range. Some areas may remain blind for extended periods, leading to persistent material accumulation and buildup. Furthermore, the air cannon's vertical direction of discharge can easily compress the material, further solidifying the buildup and preventing thorough removal.

[0004] Furthermore, existing warehouse clearance equipment mostly uses traditional control methods such as PID and LQR. These control methods suffer from the following problems: First, insufficient control precision: In warehouse clearance scenarios, uneven material distribution directly affects the accuracy of the clearance trajectory, resulting in an inability to thoroughly clean blind spots and poor clearance results. Second, severe vibration: The violent vibrations generated by traditional control schemes not only exacerbate mechanical wear and significantly shorten the service life of key components of warehouse clearance equipment, but also generate significant impact noise. More critically, this high-frequency vibration energy transfers momentum through structures such as flexible ropes, further amplifying the impact on the mechanical system and causing additional energy consumption. Third, poor digital control adaptability: Continuous-time control methods require discretization when applied to digital control systems, resulting in poor adaptability and the introduction of approximation errors and control delays, further weakening control performance and affecting the accuracy and efficiency of warehouse clearance operations. Therefore, a warehouse clearance method that is compatible with digital control and combines high precision with low vibration is urgently needed. Summary of the Invention

[0005] In view of this, the present invention provides a fishing rod-type flexible rope-driven clearing device and a nonlinear discrete sliding mode clearing control method, which can use a spatial adjustment mechanism to adjust the position of the clearing actuator to achieve the cleaning of the wall layer at any position of the material warehouse; and based on the nonlinear discrete sliding mode control method, it can achieve precise adjustment of the position of the clearing actuator.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] A fishing rod-type flexible rope-driven warehouse cleaning device comprises a warehouse cleaning actuator for clearing the wall layer of a material bin and a space adjustment mechanism for adjusting the position of the warehouse cleaning actuator; the space adjustment mechanism comprises an intermediate connecting seat, a retractable cantilever unit, a flexible rope drive unit and a steering unit; the head end of the retractable cantilever unit is installed on the intermediate connecting seat, and the end extends toward the warehouse wall side of the material bin, for realizing the horizontal movement of the warehouse cleaning actuator; the flexible rope drive unit comprises a first servo motor, a winding drum and a flexible lifting rope, the first servo motor is installed on the intermediate connecting seat, the winding drum is connected to the first servo motor drive, one end of the flexible lifting rope is wound around the winding drum, and the other end is movably connected to the end of the retractable cantilever unit, then extends downward and connects to the warehouse cleaning actuator, for realizing the vertical movement of the warehouse cleaning actuator; the steering unit is connected to the intermediate connecting seat, for realizing the circumferential rotation of the warehouse cleaning actuator; the warehouse cleaning actuator rotates to knock the wall layer of the material bin off.

[0008] Furthermore, the clearance actuator includes a reaction flywheel, a momentum disk and a chain momentum hammer. The reaction flywheel is connected to a flexible suspension rope to isolate the torque of the clearance actuator; the momentum disk is connected to the reaction flywheel and can rotate; the chain momentum hammer is connected to the momentum disk; when the space adjustment mechanism moves the clearance actuator to the target position, the momentum disk rotates, and the chain momentum hammer rotates with the momentum disk to hit the wall layer of the material bin.

[0009] Furthermore, the chain momentum hammer includes a semi-flexible momentum chain and a momentum hammer. The semi-flexible momentum chain is composed of multiple circular rings connected in series. The semi-flexible momentum chain connects the momentum disk and the momentum hammer so that the momentum hammer rotates with the momentum disk.

[0010] Furthermore, the telescopic cantilever unit includes a first drive motor, a first-level lead screw, a second-level lead screw, a first-level sleeve, a second-level sleeve, a third-level sleeve and a lead screw nut. The third-level sleeve, the second-level sleeve and the first-level sleeve are sequentially connected to form a telescopic sleeve. The first-level lead screw and the second-level lead screw are coaxially fixedly connected and pass through the telescopic sleeve. The first drive motor is drive-connected to the first-level lead screw. The lead screw nut is screwed to the first-level lead screw and fixedly connected to the second-level sleeve. The third-level sleeve has an internal thread, and the third-level sleeve is screwed to the second-level lead screw.

[0011] Another technical solution of the present invention is:

[0012] A nonlinear discrete sliding mode warehouse clearance control method is implemented using a fishing rod-type flexible rope-driven warehouse clearance device. The warehouse clearance control steps are as follows:

[0013] S1. Establishing a discrete-time system model: establishing dynamic models of the flexible rope drive unit and the steering unit respectively;

[0014] S2. Calculate the actual length, angle, speed of retracting and releasing the flexible rope and the actual angular velocity through the inverse kinematics model to determine the clearance actuator Rope length error at time , angular error , rope speed error and angular velocity error , and design nonlinear discrete sliding surface;

[0015] S3. Based on the nonlinear discrete sliding surface, the error terms of the sliding modes at adjacent moments are calculated, and the actual retraction and extension acceleration and actual angular acceleration of the flexible rope are obtained;

[0016] S4. Based on the dynamic model of the flexible rope drive unit and the dynamic model of the steering unit, the equivalent control rate of the nonlinear discrete sliding mode clearance controller is obtained. Based on the designed nonlinear discrete sliding mode surface, the switching control rate based on fractional order differential is obtained.

[0017] S5. Based on the equivalent control rate and the switching control rate, the control output of the nonlinear discrete sliding mode clearance controller is obtained to control the rope length of the flexible rope and the rotation angle of the clearance actuator.

[0018] Furthermore, in S1, the dynamic model of the flexible rope drive unit is:

[0019] (1)

[0020] in, 、 and are the inertia matrix, viscous friction matrix and Coulomb friction matrix of the flexible rope drive unit respectively; Indicates the actual retraction and extension speed of the flexible lifting rope. represents the actual retraction and extension acceleration of the flexible rope; k represents the kth moment; is the transmission ratio from the first servo motor rotation angle to the length of the flexible rope, is the inverse of the transmission ratio, is the tension of the flexible rope; is the torque output by the first servo motor, i.e., the control input; represents a symbolic function;

[0021] The dynamic model of the steering unit is:

[0022] (2)

[0023] in, represents the mass of the telescopic cantilever unit, Indicates the length of the telescopic cantilever unit, Indicates that the clearance execution agency is The actual angular velocity at the moment, represents the actual angular acceleration of the flexible rope, represents the damping coefficient, Indicates the torque exerted by the steering unit on the telescopic boom unit.

[0024] Furthermore, in S2, the design steps of the nonlinear discrete sliding surface are as follows:

[0025] S21, establish a spatial coordinate system, obtain the clearance execution mechanism through sampling Actual location at the moment and actual speed :

[0026] (3)

[0027] (4);

[0028] S22. Obtain the location of the compacted material to be cleared in the material bin, set the location as the reference location of the end point, perform path planning for the bin clearing actuator based on the reference location of the end point, and obtain discrete points on the path planning as the path reference position and reference speed;

[0029] S23, based on the reference position, reference speed of the hardened material and the clearance actuator Actual location at the moment and actual speed , the actual length, actual angle, actual retraction and extension speed and actual angular velocity of the flexible rope are calculated through the inverse kinematics model to determine the clearance actuator Rope length error at time , angular error , rope speed error and angular velocity error It can be expressed as:

[0030] (5)

[0031] (6)

[0032] (7)

[0033] (8)

[0034] in, 、 、 and represent the reference rope length, reference angle, reference rope speed and reference angular velocity respectively; 、 、 and They represent actual rope length, actual angle, actual rope speed and actual angular velocity respectively;

[0035] S24, rope length error calculated based on S23 , angular error , rope speed error and angular velocity error Design a nonlinear discrete sliding surface, the specific form of the nonlinear discrete sliding surface is:

[0036] (9)

[0037] (10)

[0038] in, is the nonlinear discrete sliding surface of the rope length, is the nonlinear discrete sliding surface of angle; and They represent rope length error and angle error respectively; Indicates the A moment, , Indicates the time interval between adjacent moments.

[0039] Furthermore, in S3, the process of calculating the error terms of the sliding modes at adjacent moments based on the nonlinear discrete sliding mode surface and obtaining the actual retraction and extension acceleration and the actual angular acceleration of the flexible rope includes:

[0040] First, calculate the error term of the sliding mode at adjacent moments , :

[0041] (11)

[0042] (12)

[0043] Let the derivative of the nonlinear discrete sliding surface be and ;

[0044] (13)

[0045] (14)

[0046] (15)

[0047] (16)

[0048] Combining formulas (13), (14), (15) and (16) we can obtain and :

[0049] (17)

[0050] (18)

[0051] in, and They represent the acceleration error and angular acceleration error of the flexible rope retraction and extension, and They represent the reference flexible rope retraction acceleration and reference angular acceleration respectively, and They represent the actual retraction and extension acceleration and actual angular acceleration of the flexible rope respectively.

[0052] Furthermore, the specific process of S4 is as follows:

[0053] S41. Determine the equivalent control rate of nonlinear discrete sliding mode control:

[0054] Will and Substituting into formula (1) and formula (2), we get:

[0055] (19)

[0056] (20)

[0057] The symbol function Perform hyperbolic tangent smoothing:

[0058] (twenty one)

[0059] in, is the equivalent control rate of the flexible rope drive unit controlling the length of the flexible rope, An equivalent control rate for the steering unit to control the turning angle of the telescopic boom unit;

[0060] S42. Determine the switching control rate based on fractional-order differential:

[0061] (twenty two)

[0062] (twenty three)

[0063] The sign function is smoothed by hyperbolic tangent, which can be expressed as:

[0064] (twenty four)

[0065] (25)

[0066] in, is the switching control rate of the flexible rope drive unit to control the rope length, is the switching control rate of the telescopic cantilever unit to control the rotation angle, and represents a positive constant, Express The fractional differential of represents the fractional order, .

[0067] Furthermore, in said S5, the control output of the nonlinear discrete sliding mode clearance controller is and They are:

[0068] (26)

[0069] (27).

[0070] The beneficial effects of the present invention compared with the prior art are:

[0071] 1. Compared with the traditional single-degree-of-freedom warehouse cleaning equipment, the space adjustment mechanism designed in the present invention can realize the three-degree-of-freedom movement of the warehouse cleaning actuator, namely horizontal movement, vertical movement and circumferential rotation, thereby improving the freedom of movement of the warehouse cleaning equipment to ensure that the warehouse cleaning actuator can be moved to any position in the material warehouse to realize the cleaning of the wall layer.

[0072] 2. The reaction flywheel and semi-flexible momentum chain in the warehouse clearance actuator designed by the present invention can form two-level momentum isolation, which can reduce the adverse momentum transfer in complex dynamic environments compared to traditional equipment without momentum isolation. The reaction flywheel is mainly used to isolate the impact of the momentum generated by the rotation of the momentum disk below it on the space adjustment mechanism, prevent the transfer of adverse momentum during the warehouse clearance process, and further ensure the positioning of the warehouse clearance actuator and the stability of the warehouse clearance action. The semi-flexible momentum chain can reduce the adverse momentum generated by the momentum hammer during the warehouse clearance operation and transfer it to the momentum disk and the second drive motor, ensuring the stability of the momentum disk and the service life of the second drive motor. At the same time, a dust cover design is added to the warehouse clearance actuator to protect the motor shaft and the reaction flywheel from dust intrusion, reduce dust friction, extend the service life of the equipment, and improve the long-term reliability of the equipment.

[0073] 3. The balancing cone in the momentum disk of this invention balances the clearance actuator, helping to stabilize the center of gravity of the momentum hammer, making the entire rope-driven hammer clearance system more stable. Multiple circular holes are circumferentially formed on the connecting disk of the momentum disk. This reduces the load on the clearance actuator, saving energy, and facilitates material removal during the clearance process, reducing the adverse effects of compacted material accumulation on the momentum disk.

[0074] By introducing a nonlinear discrete sliding surface, combining it with the convergence law of fractional differentials, and replacing the traditional sign function with a hyperbolic tangent function, this present invention significantly improves the momentum hammer trajectory tracking accuracy, accelerates control convergence, and effectively suppresses high-frequency chattering in sliding mode control. Compared to traditional PID methods, this present invention can more accurately track the reference trajectory. In particular, when materials are unevenly distributed or friction resistance changes suddenly, the present invention can rapidly adjust the control variable, allowing the system state to quickly converge to the sliding surface, significantly shortening the adjustment time for warehouse clearance operations. Furthermore, thanks to the historical memory effect of the convergence law of fractional differentials, the control signal is smoother, reducing wear on mechanical components and extending the service life of the equipment. The smooth control process also reduces energy loss and improves system energy efficiency.

[0075] 5. The control method designed in the present invention can improve the digital control adaptability of the system. Compared with the continuous-time control method, the discrete controller designed in the present invention no longer needs to select a discretization method to convert the controller into a discrete controller suitable for the digital system. It can ensure that the algorithm can run efficiently in the industrial digital controller, meet high-frequency control requirements, and further enhance the practicality of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The accompanying drawings are incorporated in and constitute a part of this application and are used to provide a further understanding of the present invention.

[0077] Figure 1This is a schematic diagram of a warehouse clearing application of a fishing rod-type flexible rope-driven warehouse clearing device of the present invention.

[0078] Figure 2 The figure is a schematic diagram of the mechanical structure of a fishing rod type flexible rope driven warehouse clearing device of the present invention.

[0079] Figure 3 Schematic diagram of the mechanical structure of the clearance actuator.

[0080] Figure 4 This is a schematic diagram of the system structure of a fishing rod-type flexible rope-driven warehouse cleaning device of the present invention.

[0081] Figure 5 Schematic diagram of the structure of the retractable cantilever unit.

[0082] Figure 6 This is a comparison chart of the momentum hammer positioning results under the traditional control method and the control method of the present invention.

[0083] Description of reference numerals:

[0084] 1- Four corner brackets;

[0085] 2- space adjustment mechanism, 2-1- intermediate connecting seat, 2-2- telescopic cantilever unit, 2-2-1- first drive motor, 2-2-2- first-stage lead screw, 2-2-3- second-stage lead screw, 2-2-4- first-stage sleeve, 2-2-5- second-stage sleeve, 2-2-6- third-stage sleeve, 2-2-7- lead screw nut, 2-3- flexible rope drive unit, 2-3-1- first servo motor, 2-3-2- winding drum, 2-3-4- pulley, 2-3-5- flexible suspension rope, 2-4- steering unit, 2-4-1- second servo motor, 2-4-2- rotating shaft;

[0086] 3- Clearance actuator, 3-2- Momentum disc, 3-2-1- Connecting disc, 3-2-2- Balancing cone, 3-3- Chain momentum hammer, 3-3-1- Semi-flexible momentum chain, 3-3-2- Momentum hammer, 3-4- Reaction flywheel, 3-5- Dust cover;

[0087] 4-Control mechanism. DETAILED DESCRIPTION

[0088] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0089] Example 1:

[0090] Figure 1 FIG. 1 shows a schematic diagram of a structure in which a fishing rod-type flexible rope-driven warehouse clearing device is installed in a material warehouse. Figure 1As shown, the fishing rod-type warehouse cleaning device includes a four-corner bracket 1, a space adjustment mechanism 2, a warehouse cleaning actuator 3, and a control mechanism 4. The four-corner bracket 1 is installed on the top of the material bin, and the space adjustment mechanism 2 is hoisted on the four-corner bracket 1 and extends into the material bin. The space adjustment mechanism 2 is connected to the warehouse cleaning actuator 3 and is used to adjust the position of the warehouse cleaning actuator 3. The space adjustment mechanism 2 can achieve three degrees of freedom of movement of the warehouse cleaning actuator 3, namely horizontal movement, vertical movement, and circumferential rotation, to ensure that the warehouse cleaning actuator 3 can be moved to any position in the material bin, realizing the cleaning of the wall layer of a large-scale storage area. The control mechanism 4 connects the space adjustment mechanism 2 and the warehouse cleaning actuator 3 to control the space adjustment mechanism 2 to adjust the position of the warehouse cleaning actuator 3 and to control the opening and closing of the warehouse cleaning actuator 3.

[0091] Figure 2 The schematic diagram of the structure of the clearing actuator is shown in FIG. Figure 2 As shown, the bin cleaning actuator 3 of this embodiment uses hammering to clean the bin wall of the material bin. Specifically, the bin cleaning actuator 3 includes a second drive motor, a momentum disk 3-2, a plurality of chain momentum hammers 3-3 and a reaction flywheel 3-4; the motor shaft of the second drive motor is connected to the momentum disk 3-2 and can drive the momentum disk 3-2 to rotate, and the plurality of chain momentum hammers 3-3 are evenly arranged along the circumferential direction of the momentum disk 3-2 and connected to the momentum disk 3-2. When it is necessary to clean the hanging layer of the material bin, the second drive motor drives the momentum disk 3-2 to rotate, and the momentum disk 3-2 drives the chain momentum hammer 3-3 to rotate, and the hammer part of the chain momentum hammer 3-3 opens outward under centrifugal force and knocks on the bin wall of the material bin to achieve material dropping. Combined with Figure 3 The momentum disk 3-2 of this embodiment includes a connecting disk 3-2-1 and a balancing cone 3-2-2. The balancing cone 3-2-2 is installed at the center of the bottom of the connecting disk 3-2-1 to balance the clearance actuator 3, which helps to stabilize the center of gravity of the momentum hammer 3-3-2, making the entire rope-driven hammer clearance system more stable. The connecting disk 3-2-1 is provided with multiple circular holes along the circumferential direction. On the one hand, this reduces the load of the clearance actuator 3 to achieve energy saving. On the other hand, it facilitates the blanking process and reduces the adverse effects of the accumulation of compacted materials on the momentum disk 3-2. Figure 3The chain momentum hammer 3-3 of this embodiment includes a semi-flexible momentum chain 3-3-1 and a momentum hammer 3-3-2. The semi-flexible momentum chain 3-3-1 connects the momentum disk 3-2 and the momentum hammer 3-3-2 so that the momentum hammer 3-3-2 rotates with the momentum disk 3-2. Since the chain momentum hammer 3-3 is realized by striking the inner wall of the material warehouse during the warehouse cleaning operation, the vibration and impact force generated will be directly transmitted to the momentum disk 3-2 and the second drive motor, which will also affect the service life of the momentum disk 3-2 and the second drive motor. Therefore, the semi-flexible momentum chain 3-3-1 of this embodiment is composed of multiple rings connected in series. The semi-flexible momentum chain 3-3-1 composed of multiple sections of loosely coupled stainless steel rings connected in series can reduce the adverse momentum generated by the momentum hammer during the warehouse cleaning operation and transfer it to the momentum disk 3-2 and the second drive motor, thereby ensuring the stability of the momentum disk 3-2 and the service life of the second drive motor.

[0092] Since the bin-clearing actuator 3 is connected to the space-regulating mechanism 2, and the momentum disk 3-2 and the multiple chain momentum hammers 3-3 need to rotate and hit the wall layer of the material bin during cleaning, the vibration and impact force generated by the collision between the bin-clearing actuator 3 and the inner wall of the material bin will be directly transmitted to the space-regulating mechanism 2. Long-term use will cause wear and fatigue of the space-regulating mechanism 2. At the same time, the high-speed rotation of the momentum disk 3-2 will generate a large counter-torque, which may cause the center of gravity of the space-regulating mechanism 2 to shift. Therefore, in this embodiment, a reaction flywheel 3-4 is set between the bin-clearing actuator 3 and the execution end of the space-regulating mechanism 2. Specifically, the reaction flywheel 3-4 is connected to the execution end of the space-regulating mechanism 2 and the motor housing of the second drive motor, and is used to isolate the impact of the momentum generated by the rotation of the momentum disk 3-2 below it on the space-regulating mechanism 2. Prevent the transmission of adverse momentum during the bin-clearing process, and further ensure the positioning of the bin-clearing actuator 3 and the stability of the bin-clearing action.

[0093] Since dust is inevitably generated when the wall layer is removed, if the dust falls onto the second drive motor and the reaction flywheel 3-4 and other components as the cleaning actuator 3 is used, it will affect the use of the above components. Figure 3 As shown, the bin clearance actuator 3 of this embodiment also includes two dust covers 3-5, one of which covers the outside of the reaction flywheel 3-4, and the other covers the outside of the second drive motor. The design of the dust covers 3-5 can protect the reaction flywheel 3-4 and the second drive motor from dust intrusion, reduce dust friction, extend the service life of the equipment, and improve the long-term reliability of the equipment.

[0094] As can be seen, the dust cover 3-5 of the present embodiment protects the motor shaft and reaction flywheel 3-4 from dust intrusion, reducing dust friction, extending the equipment's service life, and enhancing its long-term reliability. The circumferentially distributed perforations of the momentum disk 3-2 facilitate material removal, prevent dust accumulation, and reduce friction between the material and dust. The balancing cone 3-2-2 design enhances terminal stability, ensuring robust stability throughout the rope-driven rotary sweeping process. A momentum hammer self-oscillation algorithm removes debris during the sweeping process, as well as material and dust that fall onto the momentum disk 3-2. Furthermore, the reaction flywheel 3-4 and semi-flexible momentum chain 3-3-1 form a momentum isolation design, preventing the transfer of adverse momentum and counter-torque during the sweeping process. This not only prevents the momentum hammer and second drive motor from affecting the space adjustment mechanism 2, but also further ensures the stability of the momentum hammer's positioning and sweeping action, minimizing the loss of the sweeping equipment's service life due to collisions with material. This facilitates adaptation to complex sweeping environments and ensures stable and efficient operation in diverse environments.

[0095] like Figure 3 and Figure 4 As shown, the space adjustment mechanism 2 of this embodiment includes an intermediate connecting seat 2-1, a retractable cantilever unit 2-2, a flexible rope drive unit 2-3 and a steering unit 2-4; the retractable cantilever unit 2-2 is installed on one side of the intermediate connecting seat 2-1, and the retractable cantilever unit 2-2 is used to realize the horizontal movement of the clearing actuator 3, that is, the retractable cantilever unit 2-2 can move the clearing actuator 3 close to the warehouse wall; the flexible rope drive unit 2-3 is installed on the intermediate connecting seat 2-1, and the flexible rope drive unit 2-3 is used to realize the vertical movement of the clearing actuator 3, that is, the flexible rope drive unit 2-3 drives the clearing actuator 3 to move up and down along the warehouse wall; the steering unit 2-4 connects the four-corner bracket 1 and the intermediate connecting seat 2-1, and is used to realize the circumferential rotation of the clearing actuator 3, that is, the steering unit 2-4 rotates the intermediate connecting seat 2-1, the retractable cantilever unit 2-2, the flexible rope drive unit 2-3 and the clearing actuator 3.

[0096] like Figure 4 As shown, the telescopic cantilever unit 2-2 of this embodiment can adopt a multi-stage telescopic structure, and the telescopic structure is used to realize the horizontal movement of the clearance actuator 3. Figure 4As shown, the telescopic cantilever unit 2-2 of this embodiment includes a first drive motor 2-2-1, a first-level screw 2-2-2, a second-level screw 2-2-3, a first-level sleeve 2-2-4, a second-level sleeve 2-2-5, a third-level sleeve 2-2-6 and a screw nut 2-2-7. The third-level sleeve 2-2-6, the second-level sleeve 2-2-5 and the first-level sleeve 2-2-4 are sequentially socketed to form a telescopic sleeve with a single degree of freedom, that is, one end of the second-level sleeve 2-2-5 is provided with a first slider, and the first-level sleeve 2-2-4 is provided with a first sliding groove along its length direction. The second-level sleeve 2-2-5 is provided with an end of the first slider extending into the first-level sleeve 2-2-4 and realizing a sliding connection through the cooperation of the first slider and the first sliding groove. Due to the cooperation of the first slider and the first sliding groove, the second-level sleeve 2-2-5 can only be telescopic along the axis of the first-level sleeve 2-2-4, and cannot rotate around the axis. A second slider is provided at one end of the tertiary sleeve 2-2-6, and a second sliding groove is provided inside the secondary sleeve 2-2-5 along its length direction. One end of the tertiary sleeve 2-2-6 with the second slider extends into the secondary sleeve 2-2-5 and is slidably connected through the cooperation between the second slider and the second sliding groove. Due to the cooperation between the second slider and the second sliding groove, the tertiary sleeve 2-2-6 can only be extended and retracted along the axis of the secondary sleeve 2-2-5, and cannot rotate around the axis. The first-level lead screw 2-2-2 and the second-level lead screw 2-2-3 are coaxially fixedly connected and pass through the telescopic sleeve formed by the first-level sleeve 2-2-4, the second-level sleeve 2-2-5 and the third-level sleeve 2-2-6. The first drive motor 2-2-1 is drive-connected to the first-level lead screw 2-2-2. The lead screw nut 2-2-7 is screwed to the first-level lead screw 2-2-2 and is fixedly connected to one end of the second-level sleeve 2-2-5 provided with a first slider. The tertiary sleeve 2-2-6 is provided with an internal thread on one end of the second slider. The tertiary sleeve 2-2-6 is screwed to the second-level lead screw 2-2-3. When the first drive motor 2-2-1 drives the primary screw 2-2-2 and the secondary screw 2-2-3 to rotate, the secondary sleeve 2-2-5 moves along the axis of the primary screw 2-2-2 with the screw nut 2-2-7, and at the same time the tertiary sleeve 2-2-6 moves along the axis of the secondary screw 2-2-3, thereby realizing the horizontal movement of the clearance actuator 3.

[0097] like Figure 3As shown, the flexible rope drive unit 2-3 of this embodiment includes a first servo motor 2-3-1, a winding drum 2-3-2, an encoder, a pulley 2-3-4 and a flexible suspension rope 2-3-5. The pulley 2-3-4 is installed on the end of the tertiary sleeve 2-2-6 away from the first drive motor 2-2-1, so that the horizontal displacement can be changed as the tertiary sleeve 2-2-6 is extended and retracted. The winding drum 2-3-2 is connected to the motor shaft of the first servo motor 2-3-1 and rotates with the motor shaft. One end of the flexible suspension rope 2-3-5 is fixed and wound around the winding drum 2-3-2, and the other end passes around the pulley 2-3-4 and is connected to the clearance actuator 3. The encoder is connected to the motor shaft of the first servo motor 2-3-1. When the vertical position of the clearance actuator 3 needs to be adjusted, the first servo motor 2-3-1 is activated, which drives the winding drum 2-3-2 to rotate. The winding drum 2-3-2 reels or unwinds the wire, thereby adjusting the extended length of the flexible suspension rope 2-3-5 and thus adjusting the position of the clearance actuator 3. An encoder is used to measure the number of coils reeled or unreeled by the winding drum 2-3-2 to determine the length of the flexible suspension rope 2-3-5, so that the extension and retraction speed of the telescopic boom unit 2-2 and the position of the clearance actuator 3 can be accurately controlled.

[0098] like Figure 3 As shown, the steering unit 2-4 of this embodiment includes a second servo motor 2-4-1 and a rotating shaft 2-4-2, one end of the rotating shaft 2-4-2 is connected to the motor shaft of the second servo motor 2-4-1 and rotates with the motor shaft, and the other end of the rotating shaft 2-4-2 is connected to the intermediate connecting seat 2-1 to drive the intermediate connecting seat 2-1 to rotate.

[0099] It can be seen from this that the clearance actuator 3 of this embodiment controls the spatial position of the momentum hammer at the end of the flexible suspension rope through the coordinated adjustment of the three parts: the telescopic cantilever unit 2-2, the flexible rope drive unit 2-3 and the steering unit 2-4, so as to achieve momentum hammer positioning and precise clearance operations.

[0100] The control mechanism of this embodiment includes a control module, a host computer and sensors, etc. The host computer sends control instructions to the control module, and the control module that receives the control instructions drives the motor to work. The sensor feeds back data to the host computer in real time, and the host computer updates the control instructions again, and this process is repeated.

[0101] Example 2:

[0102] This embodiment proposes a warehouse clearance control method based on nonlinear discrete sliding mode control. The warehouse clearance method designs a nonlinear discrete sliding mode surface on the basis of sliding mode control to increase the control accuracy of the fishing rod type warehouse clearance equipment. Then, based on the designed nonlinear discrete sliding mode surface, the equivalent control rate of the nonlinear discrete sliding mode control and the switching control rate based on fractional-order differential are obtained to increase the adaptability of digital control. At the same time, the sign function in the equivalent control rate and the switching control rate is smoothed to suppress the chattering of the fishing rod type warehouse clearance equipment, thereby reducing the motor torque fluctuation. The specific warehouse clearance control steps are as follows:

[0103] S1. Establish a discrete-time system model: establish dynamic models of the flexible rope-driven unit and the steering unit respectively; the dynamic model of the flexible rope-driven unit can be written as follows:

[0104] (1)

[0105] in, 、 and are the inertia matrix, viscous friction matrix and Coulomb friction matrix of the flexible rope drive unit respectively; Indicates the actual retraction and extension speed of the flexible lifting rope. represents the actual retraction and extension acceleration of the flexible rope; k represents the kth moment; is the transmission ratio from the first servo motor rotation angle to the length of the flexible rope, is the inverse of the transmission ratio, is the tension of the flexible rope, is the torque output by the first servo motor (control input), Represents a symbolic function.

[0106] The dynamic model of the steering unit can be written as follows:

[0107] (2)

[0108] in, represents the mass of the telescopic cantilever unit, Indicates the length of the telescopic cantilever unit, Indicates that the clearing executive agency 3 is The actual angular velocity at the moment, represents the actual angular acceleration of the flexible rope, represents the damping coefficient, Represents the torque (control input) applied by the steering unit to the telescopic boom unit.

[0109] S2. Design a nonlinear discrete sliding surface: Integral terms for rope length error and angle error are introduced into the sliding surface. System friction and external disturbances are compensated for by accumulating historical errors, significantly reducing steady-state error. Steady-state accuracy is enhanced through the integral term. Furthermore, differential terms for rope length error and angle error are added to the sliding surface to enhance the fishing rod-type warehouse clearing machine's ability to respond quickly to sudden trajectory changes, improving its dynamic response. Specifically:

[0110] S21, establish a spatial coordinate system (x, y, z), obtain the clearance actuator 3 by sampling Actual location at the moment and actual speed , the actual speed Including the circumferential rotation speed of the momentum hammer and the speed of the flexible rope retraction and extension:

[0111] (3)

[0112] (4).

[0113] S22. Obtain the location of the compacted material to be cleared in the material bin and set this location as the reference position of the endpoint. This reference position can be detected by multi-source sensors on the clearance actuator. Specifically, during the clearance operation, sensors on the clearance actuator, such as lidar and infrared array sensors, are used to obtain target clearance position information. Based on this target clearance position information, the clearance actuator is path-planned, and discrete points on the planned path are obtained as path reference positions, reference speeds, and other information. This information can then be used to calculate the reference rope length, reference angle, reference rope speed, and reference angular velocity using an inverse kinematics model.

[0114] S23, based on the reference position, reference speed of the hardened material and the clearance actuator Actual location at the moment and actual speed , calculate the actual rope length, actual angle, actual rope speed and actual angular velocity through the inverse kinematics model to determine the clearance actuator Rope length error at time , angular error , rope speed error and angular velocity error It can be expressed as:

[0115] (5)

[0116] (6)

[0117] (7)

[0118] (8)

[0119] in, 、 、 and represent the reference rope length, reference angle, reference rope speed and reference angular velocity respectively; 、 、 and They represent the actual rope length, actual angle, actual rope speed and actual angular velocity respectively.

[0120] S24, rope length error calculated based on S23 , angular error , rope speed error and angular velocity error Design a nonlinear discrete sliding surface, the specific form of the nonlinear discrete sliding surface is:

[0121] (9)

[0122] (10)

[0123] in, is the nonlinear discrete sliding surface of the rope length, is the nonlinear discrete sliding surface of angle; and They represent rope length error and angle error respectively; Indicates the A moment, , Indicates the time interval between adjacent moments.

[0124] S3. Calculate the error term of the sliding mode at adjacent moments based on the nonlinear discrete sliding surface , :

[0125] (11)

[0126] (12)

[0127] Let the derivative of the nonlinear discrete sliding surface be and ;

[0128] (13)

[0129] (14)

[0130] (15)

[0131] (16)

[0132] Combining formulas (13), (14), (15) and (16) we can obtain and :

[0133] (17)

[0134] (18)

[0135] in, and They represent the acceleration error and angular acceleration error of the flexible rope retraction and extension, and They represent the reference flexible rope retraction acceleration and reference angular acceleration respectively, and They represent the actual retraction and extension acceleration and actual angular acceleration of the flexible rope respectively.

[0136] S4 is implemented using a nonlinear discrete sliding mode control method, adapted to a digital controller, and combined with the historical dependence characteristics of fractional-order differentials. This ensures fast response while avoiding the high-frequency noise amplification problem of integer-order differentials. Specifically:

[0137] S41, based on the dynamic model of the flexible rope drive unit and the dynamic model of the steering unit, obtain the equivalent control rate of the nonlinear discrete sliding mode control. Specifically, and Substituting into formula (1) and formula (2), we get:

[0138] (19)

[0139] (20)

[0140] The symbol function Perform hyperbolic tangent smoothing, that is, use the hyperbolic tangent function instead of the sign function to suppress the chattering of the clearance actuator, thereby reducing the motor torque fluctuation through the smooth switching function. Specifically, it can be expressed as:

[0141] (twenty one)

[0142] in, is the equivalent control rate of the flexible rope drive unit controlling the length of the flexible rope, The equivalent control rate of the steering unit for controlling the turning angle of the telescopic boom unit.

[0143] S42. Based on the designed nonlinear discrete sliding mode surface, obtain a switching control rate based on fractional-order differentials, wherein the switching control rate based on fractional-order differentials is:

[0144] (twenty two)

[0145] (twenty three)

[0146] The sign function is smoothed by hyperbolic tangent, which can be expressed as:

[0147] (twenty four)

[0148] (25)

[0149] in, is the switching control rate of the flexible rope drive unit to control the rope length, is the switching control rate of the telescopic cantilever unit to control the rotation angle, and represents a positive constant, Express The fractional differential of represents the fractional order, .

[0150] S5. Based on the equivalent control rate and switching control rate, the control output of the nonlinear discrete sliding mode clearance controller is obtained. and ;

[0151] (26)

[0152] (27)

[0153] The control output and The information is sent to the motor driver and motor to control the length of the flexible rope and the rotation angle of the cleaning actuator. The sensor senses the cleaning information of the cleaning actuator. If the cleaning is completed, the control process ends. Otherwise, the fishing rod-type cleaning equipment continues to clean until it is completed.

[0154] It can be seen that this embodiment significantly improves the trajectory tracking accuracy of the momentum hammer and suppresses the chattering phenomenon by integrating the history memory effect of fractional-order calculus with the strong robustness of sliding mode control.

[0155] This embodiment is based on a nonlinear discrete sliding mode control model to verify the control performance of a warehouse clearance control method based on nonlinear discrete sliding mode control and a fishing rod type warehouse clearance device proposed in this embodiment. Figure 6The following figure compares the momentum hammer position results under the traditional control method and the control method of the present invention. Simulation results show that traditional PID control exhibits significant deviations in the X, Y, and Z axes, while the actual position of the clearance actuator of this embodiment closely matches the reference trajectory. This means that the present embodiment's clearance control method demonstrates significant advantages in trajectory tracking accuracy, convergence speed, and control smoothness in the X, Y, and Z axes, achieving high-precision, low-jitter, and highly robust momentum hammer trajectory tracking. This provides a reliable technical solution for automated clearance under complex working conditions.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A fishing rod type flexible rope driven warehouse clearing equipment, characterized in that: It includes a clearing actuator for removing the wall layer of the material bin and a space adjustment mechanism for adjusting the position of the clearing actuator; the space adjustment mechanism includes an intermediate connecting seat, a retractable cantilever unit, a flexible rope drive unit and a steering unit; the head end of the retractable cantilever unit is installed on the intermediate connecting seat, and the end extends toward the bin wall side of the material bin, for realizing the horizontal movement of the clearing actuator; the flexible rope drive unit includes a first servo motor, a winding drum and a flexible lifting rope, the first servo motor is installed to the intermediate connecting seat, the winding drum is connected to the first servo motor drive, one end of the flexible lifting rope is wound around the winding drum, and the other end is movably connected to the end of the retractable cantilever unit, then extends downward and connects to the clearing actuator, for realizing the vertical movement of the clearing actuator; the steering unit is connected to the intermediate connecting seat, for realizing the circumferential rotation of the clearing actuator; the clearing actuator rotates to knock the wall layer of the material bin off.

2. A fishing rod type flexible rope driven warehouse clearing device according to claim 1, characterized in that: The clearance actuator includes a reaction flywheel, a momentum disk and a chain momentum hammer. The reaction flywheel is connected to a flexible suspension rope to isolate the torque of the clearance actuator; the momentum disk is connected to the reaction flywheel and can rotate; the chain momentum hammer is connected to the momentum disk; when the space adjustment mechanism moves the clearance actuator to the target position, the momentum disk rotates, and the chain momentum hammer rotates with the momentum disk to hit the wall layer of the material bin.

3. The fishing rod type flexible rope driven warehouse clearing equipment according to claim 2, characterized in that: The chain momentum hammer comprises a semi-flexible momentum chain and a momentum hammer. The semi-flexible momentum chain is formed by a plurality of circular rings connected in series. The semi-flexible momentum chain connects the momentum disk and the momentum hammer so that the momentum hammer rotates with the momentum disk.

4. The fishing rod type flexible rope driven warehouse clearing equipment according to claim 1, characterized in that: The telescopic cantilever unit includes a first drive motor, a first-level lead screw, a second-level lead screw, a first-level sleeve, a second-level sleeve, a third-level sleeve and a lead screw nut. The third-level sleeve, the second-level sleeve and the first-level sleeve are sequentially connected to form a telescopic sleeve. The first-level lead screw and the second-level lead screw are coaxially fixedly connected and pass through the telescopic sleeve. The first drive motor is drive-connected to the first-level lead screw. The lead screw nut is screwed to the first-level lead screw and fixedly connected to the second-level sleeve. The third-level sleeve has an internal thread, and the third-level sleeve is screwed to the second-level lead screw.

5. A nonlinear discrete sliding mode clearance control method, characterized in that: The cleaning control steps are as follows: S1. Establishing a discrete-time system model: establishing dynamic models of the flexible rope drive unit and the steering unit respectively; S2. Calculate the actual length, angle, speed of retracting and releasing the flexible rope and the actual angular velocity through the inverse kinematics model to determine the clearance actuator Rope length error at time , angular error , rope speed error and angular velocity error , and design nonlinear discrete sliding surface; S3. Based on the nonlinear discrete sliding surface, the error terms of the sliding modes at adjacent moments are calculated, and the actual retraction and extension acceleration and actual angular acceleration of the flexible rope are obtained; S4. Based on the dynamic model of the flexible rope drive unit and the dynamic model of the steering unit, the equivalent control rate of the nonlinear discrete sliding mode clearance controller is obtained. Based on the designed nonlinear discrete sliding mode surface, the switching control rate based on fractional order differential is obtained. S5. Based on the equivalent control rate and the switching control rate, the control output of the nonlinear discrete sliding mode clearance controller is obtained to control the rope length of the flexible rope and the rotation angle of the clearance actuator.

6. The nonlinear discrete sliding mode clearance control method according to claim 5, characterized in that: In S1, the dynamic model of the flexible rope drive unit is: （1） in, 、 and are the inertia matrix, viscous friction matrix and Coulomb friction matrix of the flexible rope drive unit respectively; Indicates the actual retraction and extension speed of the flexible lifting rope. represents the actual retraction and extension acceleration of the flexible rope; k represents the kth moment; is the transmission ratio from the first servo motor rotation angle to the length of the flexible rope, is the inverse of the transmission ratio, is the tension of the flexible rope; is the torque output by the first servo motor, i.e., the control input; represents a symbolic function; The dynamic model of the steering unit is: （2） in, represents the mass of the telescopic cantilever unit, Indicates the length of the telescopic cantilever unit, Indicates that the clearance execution agency is The actual angular velocity at the moment, represents the actual angular acceleration of the flexible rope, represents the damping coefficient, Indicates the torque exerted by the steering unit on the telescopic boom unit.

7. The nonlinear discrete sliding mode clearance control method according to claim 6, characterized in that: In S2, the design steps of the nonlinear discrete sliding surface are as follows: S21, establish a spatial coordinate system, obtain the clearance execution mechanism through sampling Actual location at the moment and actual speed : （3） （4）； S22. Obtain the location of the compacted material to be cleared in the material bin, set the location as the reference location of the end point, perform path planning for the bin clearing actuator based on the reference location of the end point, and obtain discrete points on the path planning as the path reference position and reference speed; S23, based on the reference position, reference speed of the hardened material and the clearance actuator Actual location at the moment and actual speed , the actual length, actual angle, actual retraction and extension speed and actual angular velocity of the flexible rope are calculated through the inverse kinematics model to determine the clearance actuator Rope length error at time , angular error , rope speed error and angular velocity error It can be expressed as: （5） （6） （7） （8） in, 、 、 and represent the reference rope length, reference angle, reference rope speed and reference angular velocity respectively; 、 、 and They represent actual rope length, actual angle, actual rope speed and actual angular velocity respectively; S24, rope length error calculated based on S23 , angular error , rope speed error and angular velocity error Design a nonlinear discrete sliding surface, the specific form of the nonlinear discrete sliding surface is: （9） （10） in, is the nonlinear discrete sliding surface of the rope length, is the nonlinear discrete sliding surface of angle; and They represent rope length error and angle error respectively; Indicates the A moment, , Indicates the time interval between adjacent moments.

8. The nonlinear discrete sliding mode clearance control method according to claim 7, characterized in that: In S3, the process of calculating the error terms of the sliding modes at adjacent moments based on the nonlinear discrete sliding mode surface and obtaining the actual retraction and extension acceleration and the actual angular acceleration of the flexible rope includes: First, calculate the error term of the sliding mode at adjacent moments , : （11） （12） Let the derivative of the nonlinear discrete sliding surface be and ; （13） （14） （15） （16） Combining formulas (13), (14), (15) and (16) we can obtain and : （17） （18） in, and They represent the acceleration error and angular acceleration error of the flexible rope retraction and extension, and They represent the reference flexible rope retraction acceleration and reference angular acceleration respectively, and They represent the actual retraction and extension acceleration and actual angular acceleration of the flexible rope respectively.

9. The nonlinear discrete sliding mode clearance control method according to claim 8, characterized in that: The specific process of S4 is as follows: S41. Determine the equivalent control rate of nonlinear discrete sliding mode control: Will and Substituting into formula (1) and formula (2), we get: （19） （20） The symbol function Perform hyperbolic tangent smoothing: （21） in, is the equivalent control rate of the flexible rope drive unit controlling the length of the flexible rope, An equivalent control rate for the steering unit to control the turning angle of the telescopic boom unit; S42. Determine the switching control rate based on fractional-order differential: （22） （23） The sign function is smoothed by hyperbolic tangent, which can be expressed as: （24） （25） in, is the switching control rate of the flexible rope drive unit to control the rope length, is the switching control rate of the telescopic cantilever unit to control the rotation angle, and represents a positive constant, Express The fractional differential of represents the fractional order, .

10. The nonlinear discrete sliding mode clearance control method according to claim 9, characterized in that: In S5, the control output of the nonlinear discrete sliding mode clearance controller and They are: （26） （27）。

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