Electric rock grab and its driving and control method

Abstract

The application discloses an electric rock grabber and a driving and control method thereof, and belongs to the field of vertical shaft construction rock grabbing equipment. The electric rock grabber comprises a rack, an amplitude changing mechanism, a grab bucket mechanism, a rotating mechanism and a lifting mechanism. An upper computer is used to control the grab bucket electric cylinder to perform a grabbing work, and an S-shaped speed curve of the grab bucket electric cylinder is planned. The grab bucket mechanism performs the grabbing according to the S-shaped speed curve, information of the grab bucket electric cylinder in the grabbing process is collected, and a maximum grabbing weight prediction value of the grab bucket is obtained. When working, working condition judgment is performed in real time. When the maximum grabbing weight prediction value is less than an initial grabbing weight, it is judged that the working state of the grab bucket mechanism is light load, and vice versa. If the working state is heavy load, the S-shaped speed curve needs to be re-planned to ensure the smooth work. The application is based on the speed control and torque limitation of working condition identification and prediction, so that the impact of the motion process on the grab bucket electric cylinder is reduced.

Description

Technical Field

[0001] This invention relates to an electric rock grabber and its driving and control method, belonging to the field of rock grabber equipment for vertical shaft construction. Background Technology

[0002] During vertical shaft construction in mines, the main purpose of rock grabbers is to grab loose rocks and minerals after blasting and load them into buckets to meet the rock loading needs of vertical shaft construction. Existing rock grabbers are either pneumatic or hydraulically driven. Pneumatic rock grabbers have low installed power and high noise, while hydraulic rock grabbers are prone to leakage, have low transmission efficiency, and high energy consumption. Neither of these can meet the higher requirements for rock loading efficiency in deep vertical shaft construction.

[0003] To ensure the efficiency of vertical shaft construction, the lifting / lowering, luffing, grab opening and closing, and rotation actions of the rock grabber must be executed in a complex and rapid manner. This results in a high installed power of the rock grabber. In addition, the complex loading conditions of the rock grabber place extremely high demands on the stability of the electrical drive system. However, traditional electric actuator drive control methods all set fixed speed and torque limits on the motor, preventing the electric actuator from outputting full torque and speed during operation. This wastes the working capacity of the electric actuator and limits the development and application of electric rock grabbers with high transmission efficiency and fast response.

[0004] Prior art, disclosed in CN101531327A, describes a method for gripping objects using a hydraulic rotary rock grabber and its hydraulic grab bucket. It employs a vertically mounted hydraulic cylinder on a fixed frame as the power source for gripping the object. A drive frame is connected to a downward-extending hydraulic cylinder arm, with tie rods distributed along the outer edge of the drive frame. The tops of the tie rods are hinged to a tie rod frame fixed to the fixed frame. One end of a hook-arm structure is hinged to the drive frame, while the bent portion of the hook is hinged to the lower end of the tie rod, forming a system where multiple hooks and tie rods work together. The hydraulic cylinder drives the extension and retraction of the hydraulic cylinder arm, causing the hooks to open and grip the object. However, this method uses a hydraulic system to control the grab bucket, which cannot achieve rapid and precise operation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an electric rock grabber and its driving and control method. By real-time sensing, working condition identification, and prediction of the power output of the electric actuator, the method makes real-time decisions on the power output control target of the electric actuator. While ensuring the stability of the heavy-duty electric actuator, it maximizes the energy efficiency of the heavy-duty electric actuator, thereby achieving stable and reliable electrical drive and precise control of the heavy-duty rock grabber.

[0006] To achieve the above objectives, the present invention discloses an electric rock grabber, including a hanging platform, a slewing mechanism provided on the hanging platform, a lifting mechanism provided on the slewing mechanism, a frame connected below the slewing mechanism, and a grab bucket mechanism movably connected to the frame through a luffing mechanism;

[0007] The frame includes a frame body, with a connecting plate at the top. Hinged supports for the luffing mechanism, the buffer device, and the luffing electric cylinder are respectively located on the upper, middle, and lower sides of the frame body. A reinforcing plate is installed on the frame body at the luffing mechanism hinged support location.

[0008] The luffing mechanism includes a boom, the left end of which is movably connected to the grab bucket mechanism, and the right end of which is movably connected to the luffing mechanism hinge support of the frame; a support shaft is provided in the middle of the boom, and a luffing electric cylinder is movably connected between the boom and the luffing electric cylinder hinge support through the support shaft.

[0009] The grab mechanism includes a cylindrical shell, inside which is a grab electric cylinder that controls the operation of the grab below. Multiple grab plates that make up the grab are connected to the lower part of the grab electric cylinder via a lug.

[0010] Both the luffing electric cylinder and the grab bucket electric cylinder have a structure in which two servo motors drive the roller screw.

[0011] When the grab bucket mechanism performs the grabbing action, the host computer performs speed planning, grabbing weight sensing, maximum grabbing weight prediction and working condition judgment on the grab bucket electric cylinder. In this way, the speed planning of the grab bucket electric cylinder is adjusted according to the actual working conditions, so as to reduce the impact on the grab bucket electric cylinder during the movement while ensuring the normal operation of the grab bucket mechanism and ensuring the service life of the grab bucket electric cylinder.

[0012] Furthermore, a fixed pulley a is coaxially provided at one end of the luffing mechanism and the hinged support of the luffing electric cylinder, and a fixed pulley b is provided at the other end of the luffing mechanism. A tie rod assembly that is movably connected to the luffing mechanism is provided on one side of the fixed pulley b.

[0013] Furthermore, the grab mechanism includes a cylindrical outer shell with a movable pulley at the top. The grab electric cylinder is located inside the cylindrical outer shell. The roller screw end of the grab electric cylinder is controlled and connected to multiple grab plates that make up the grab through an ear plate. Each grab plate is connected to the cylindrical outer shell with an auxiliary opening and closing lever.

[0014] Furthermore, the lifting mechanism includes an electric winch and a buffer device mounted on the slewing mechanism via a winch support;

[0015] The electric winch includes a drum mounted via a drum support, a steel wire rope wound on the drum, and a power source connected to one side of the drum. The power source includes a permanent magnet synchronous motor, which is connected to the drum via a reducer a.

[0016] The buffer device includes a cylinder and a spring rod partially disposed within the cylinder. The cylinder has a fixed seat a for connecting with the hinge support of the buffer device. Both ends of the cylinder are sealed. One end of the spring rod has a piston. The portion of the spring rod with the piston extends into the cylinder to the end. Between the piston and the other end of the cylinder, there are a small spring and a large spring nested together on the outside of the spring rod. The other end of the spring rod without the piston extends out of the cylinder and is connected to a fixed pulley c through a rope wheel seat.

[0017] One end of the wire rope is fixed to the drum, and the other end is wound around the lifting mechanism. It first extends through the wire rope hole set on the slewing mechanism, and then passes through the buffer device, fixed pulley c, fixed pulley a, fixed pulley b, and the moving pulley of the grab bucket in sequence, and is finally fixed on the tie rod group. The grab bucket mechanism is raised or lowered by the winding and unwinding of the wire rope when the drum rotates, and the buffer device is used to buffer the impact generated when the lifting mechanism changes direction.

[0018] Furthermore, the rotary mechanism includes a rotary fixed base, a rotary body, and a rotary drive assembly, wherein: the rotary body is mounted on the rotary fixed base and can rotate in the center, and the rotary drive assembly is fixed on the rotary body;

[0019] The slewing fixed seat includes a slewing support seat, a slewing bearing, and an internal gear ring. The slewing bearing is a single-row four-point contact ball slewing bearing that can rotate on the slewing support seat. The slewing support seat is fixed on the hanging plate, and the internal gear ring is set on the slewing support seat. The slewing bearing is fixed to the lower part of the slewing support seat.

[0020] The rotary drive assembly includes a drive base b, a rotary servo motor, a reducer b, a drive gear, and a transition gear. The output shaft of the rotary servo motor is connected to a gear set of the base via the reducer b. The base b is located below the gear set of the base. The gear set of the base includes a drive gear mounted on the drive gear shaft and a transition gear meshing with the drive gear. The rotary servo motor drives the drive gear via the reducer b. The drive gear meshes with the internal gear ring of the rotary base via the transition gear.

[0021] The rotating body includes a cylinder, flange, stiffening plates, and I-beams. The flange is located on the top of the cylinder, and multiple stiffening plates are welded between the cylinder and the flange to increase strength. An I-beam is located in the middle of the top of the flange, and the two sides of the I-beam have holes for the drive gear shaft and wire rope on the flange. The drive gear shaft is inserted into the drive gear shaft hole to avoid interference between the rotary drive assembly and the rotating body.

[0022] The rotating body is placed in the slewing support seat and fixed to the slewing bearing through the flange, so that the slewing mechanism can rotate together with the slewing bearing, and the cylinder is connected to the frame;

[0023] When the slewing servo motor is working, the transition gear of the slewing drive assembly rotates both on its own axis and revolves within the internal gear ring of the slewing fixed seat, driving the slewing mechanism, frame, luffing mechanism, and grab mechanism to rotate together in a central rotation.

[0024] A method for driving and controlling an electric rock grabber, the specific steps of which involve controlling the electric cylinder of the grab bucket to perform the material grabbing operation using a host computer are as follows:

[0025] S1. Before the grab bucket mechanism performs the grabbing action, plan the S-shaped speed curve of the grab bucket electric cylinder; calculate the maximum acceleration, maximum speed, and jerk to plan the S-shaped speed curve;

[0026] S2. The grab bucket electric cylinder in the grab bucket mechanism performs grabbing according to the S-shaped speed curve specified by the host computer, and at the same time collects the information of the grab bucket electric cylinder during the grabbing process: the host computer calculates the real-time speed of the grab bucket electric cylinder based on the real-time displacement of the grab bucket electric cylinder fed back by the built-in encoder, and determines the real-time output force of the grab bucket electric cylinder based on the internal current sensor of the grab bucket electric cylinder.

[0027] S3. The host computer calculates the real-time weight of the material being grabbed by the grab bucket based on the real-time output force of the grab bucket electric cylinder and the real-time acceleration of the grab bucket electric cylinder determined by the S-shaped velocity curve.

[0028] S4. The host computer determines the current loading volume of the grab bucket based on the correlation between the real-time displacement of the grab bucket and the loading volume of the grab bucket. The correlation is determined by historical data. The average density of the material is calculated using the current loading volume of the grab bucket and the real-time weight of the grab bucket. The maximum weight of the grab bucket is then calculated using the average density of the material.

[0029] S5. During the material grabbing process, the host computer judges the working condition based on the real-time calculated maximum material grabbing weight prediction value. When the maximum material grabbing weight prediction value is less than the initial material grabbing weight, the working state of the grabbing mechanism is judged to be light load; otherwise, the working state of the grabbing mechanism is judged to be heavy load.

[0030] When the host computer determines that the grab mechanism is in a light-load working state, the speed of the grab electric cylinder is not adjusted, and it continues to work according to the S-shaped speed curve planned by the host computer.

[0031] When the host computer determines that the grab mechanism is in a heavy-load working state, the host computer re-plans the S-shaped speed curve of the grab electric cylinder.

[0032] When the host computer detects that the output force of the grab bucket electric cylinder exceeds the rated output force, the host computer judges that the grab bucket mechanism has malfunctioned, and at this time the machine needs to be stopped for self-reset.

[0033] Furthermore, the S-shaped speed curve planned for the grab bucket electric cylinder includes seven motion stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration, and is measured through the maximum speed. Maximum acceleration The derivative of acceleration, jerk j, and preset working time T are determined.

[0034] Furthermore, the calculation methods for the maximum acceleration, maximum velocity, jerk, and the time of the seven motion stages used in planning the S-shaped velocity curve are as follows:

[0035] The maximum acceleration of the S-shaped velocity curve can be calculated using the following formula. :

[0036] ,

[0037] In the formula, To initially set the material gripping weight, The weight of the gripper (303) To ensure stable impact force limitation for the grab mechanism;

[0038] Calculate the maximum velocity of the S-shaped velocity curve using the following formula. :

[0039] ,

[0040] In the formula, This refers to the rated power of the motor in the grab bucket electric cylinder. To improve the transmission efficiency of the grab bucket electric cylinder. To initially set the material gripping weight, It is the acceleration due to gravity;

[0041] Calculate the jerk of the S-shaped velocity curve using the following formula. :

[0042] ,

[0043] In the formula, T is the preset working time and S is the preset working stroke;

[0044] The time for the seven motion phases can be calculated using the following formula:

[0045] ,

[0046] In the formula, To preset working hours, To increase the duration of the acceleration phase, For the time of the uniformly accelerated motion phase, To reduce the duration of the acceleration phase, The time of the uniformly decelerated motion phase. The time for the acceleration and deceleration phases. To reduce the time of the deceleration phase, This refers to the time of the uniform motion phase.

[0047] Furthermore, the process of calculating the predicted maximum material grabbing weight of the grab bucket is as follows:

[0048] The host computer calculates the real-time material gripping weight of the grab bucket using the following formula. :

[0049] ,

[0050] In the formula For the real-time output force of the grab bucket electric cylinder, The real-time acceleration of the grab bucket electric cylinder is determined by the S-shaped velocity curve.

[0051] The host computer calculates the average density of the material using the following formula. :

[0052] ,

[0053] In the formula, This refers to the real-time material grabbing volume of the grab bucket;

[0054] The host computer uses the following formula to calculate the predicted maximum material gripping weight of the grab bucket. :

[0055] ,

[0056] In the formula, This refers to the maximum volume of the grab bucket.

[0057] Furthermore, when the host computer determines that the grab mechanism is in a heavy-load working state, it re-plans the S-shaped velocity curve of the grab electric cylinder: based on the recalculated maximum acceleration, maximum speed, unchanged jerk, and real-time speed, it determines whether there is a uniform acceleration phase in the S-shaped velocity curve, and calculates the time of each motion phase of the S-shaped velocity curve, reducing acceleration and extending the preset working time to reduce the impact on the grab electric cylinder. The specific steps are as follows:

[0058] Solve for the maximum acceleration of the redesigned S-shaped velocity curve. and maximum speed :

[0059] ,

[0060] ,

[0061] Based on the recalculated maximum acceleration, maximum velocity, unchanged jerk, and real-time velocity of the grab bucket electric cylinder, determine whether the redesigned S-shaped velocity curve has a uniform acceleration phase:

[0062] Based on maximum speed Initial velocity Maximum acceleration and accelerometer Determine whether the redesigned S-shaped velocity curve has a uniform acceleration phase during acceleration:

[0063] when The S-shaped velocity curve has seven stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, and deceleration. The motion time for each stage is as follows:

[0064] ,

[0065] when At that time, the S-shaped velocity curve does not have a uniform acceleration phase, but has six phases: acceleration / deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration. The motion time for each phase is as follows:

[0066] ,

[0067] In the formula, For the total time of the redesigned S-shaped velocity curve motion, To accelerate the motion time of the redesigned S-shaped velocity curve, The redesigned S-shaped velocity curve motion is the deceleration motion time. The redesigned S-shaped velocity curve motion is an acceleration / deceleration motion time. To reduce the acceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion acceleration and deceleration time, To reduce the deceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion uniform motion time, The remaining stroke for the replanned S-shaped velocity curve motion is obtained by subtracting the real-time displacement at the time of determination from the total stroke of the grab bucket electric cylinder. The initial velocity of the redesigned S-shaped velocity curve motion is the velocity before the redesigned S-shaped velocity curve.

[0068] Beneficial effects: All working mechanisms of this invention are electrically driven, and a speed control and torque limiting method based on working condition identification and prediction is adopted. This enables the electric actuator to prevent damage from large impacts and ensure service life when performing actions, while also maximizing the output torque and speed, thereby improving the working capacity of the electric actuator. It has the advantages of low noise, high control precision, fast response speed, smooth compound actions, stable action and high working efficiency. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the specific structure of the electric rock grabber of the present invention.

[0070] Figure 2 This is a schematic diagram of the frame structure of the electric rock grabber of the present invention.

[0071] Figure 3 This is a top view of the frame of the electric rock grabber of the present invention.

[0072] Figure 4 This is a schematic diagram of the amplitude-changing mechanism in the electric rock grabber of the present invention.

[0073] Figure 5 This is a schematic diagram of the electric cylinder for the grab bucket in this invention.

[0074] Figure 6 This is a schematic diagram of the grab bucket mechanism in this invention.

[0075] Figure 7 This is a schematic diagram of the structure of the electric winch in this invention.

[0076] Figure 8 This is a schematic diagram of the buffer device structure in this invention.

[0077] Figure 9 This is a schematic diagram of the rotating fixed base structure in this invention.

[0078] Figure 10 This is a schematic diagram of the rotating body structure in this invention.

[0079] Figure 11 This is a schematic diagram of the flange structure in the rotating body of the present invention.

[0080] Figure 12 This is a schematic diagram of the rotary drive component structure in this invention.

[0081] Figure 13 This is a flowchart of the driving and control method of the electric rock grabber in this invention.

[0082] Figure 14 The diagram shows the redesigned S-shaped velocity curve. The curve on the left represents the initial S-shaped velocity curve, and the curve on the right represents the redesigned S-shaped velocity curve.

[0083] In the diagram: 1. Frame; 2. Luffing mechanism; 3. Grab mechanism; 4. Lifting mechanism; 5. Slewing mechanism; 6. Hoisting platform;

[0084] 101. Frame; 102. Reinforcing plate; 103. Connecting plate; 104. Hinged support for luffing mechanism; 105. Hinged support for buffer device; 106. Hinged support for luffing electric cylinder;

[0085] 201. Lamp-type electric cylinder; 202. Support shaft; 203. Fixed pulley a; 204. Fixed pulley b; 205. Tie rod assembly; 206. Boom;

[0086] 301. Pull rod; 302. Movable pulley; 303. Grab plate; 304. Cylindrical outer casing; 305. Grab bucket electric cylinder; 306. Ear plate;

[0087] 401. Permanent magnet synchronous motor; 402. Drum support; 403. Reducer a; 404. Wire rope; 405. Drum; 406. Winch support; 407. Fixed seat a; 408. Cylinder body; 409. Large spring; 410. Small spring; 411. Spring rod; 412. Sheave seat; 413. Fixed pulley c;

[0088] 501. Slewing support seat; 502. Slewing bearing; 503. Internal gear ring; 504. Flange; 505. Cylinder; 506. Rib plate; 507. I-beam; 508. Drive gear shaft hole; 509. Wire rope hole; 510. Slewing servo motor; 511. Drive gear; 512. Transition gear; 513. Fixed seat b; 514. Drive gear shaft; 515. Reducer b. Detailed Implementation

[0089] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0090] like Figure 1 As shown, the present invention discloses an electric rock grabber, including a hanging platform 6, a slewing mechanism 5 provided on the hanging platform 6, a lifting mechanism 4 connected to the slewing mechanism 5, a frame 1 connected below the slewing mechanism 5, and a grab bucket mechanism 3 movably connected to the frame 1 through a luffing mechanism 2; the slewing mechanism 5 drives the frame 1, together with the luffing mechanism 2 and the grab bucket mechanism 3, to rotate.

[0091] like Figure 2 and Figure 3As shown, the frame 1 includes a frame body 101, a reinforcing plate 102, a connecting plate 103, a luffing mechanism hinge support 104, a buffer device hinge support 105, and a luffing electric cylinder hinge support 106; wherein the frame body 101 is provided with a connecting plate 103 at the top, and the frame body 101 is provided with a luffing mechanism hinge support 104, a buffer device hinge support 105, and a luffing electric cylinder hinge support 106 on the upper, middle, and lower sides respectively; the luffing mechanism hinge support 104 and the frame body 101 are provided with a reinforcing plate 102.

[0092] like Figure 4 As shown, the luffing mechanism 2 includes a luffing electric cylinder 201, a support shaft 202, a fixed pulley a 203, a fixed pulley b 204, a tie rod assembly 205, and a boom 206. The left end of the boom 206 is movably connected to the grab mechanism 3, and the right end of the boom 206 is movably connected to the luffing mechanism hinge support 104 of the frame 1. The middle part of the boom 206 is connected to the luffing electric cylinder 201 through the support shaft 202, and the other end of the luffing electric cylinder 201 is hinged to the luffing electric cylinder hinge support 106. The luffing mechanism 2 is coaxially provided with a fixed pulley a 203 at one end of the hinged part of the luffing electric cylinder hinge support 106, and a fixed pulley b 204 at the other end. A tie rod assembly 205 is provided on one side of the fixed pulley b 204, which is movably connected to the luffing mechanism 2.

[0093] like Figure 6 As shown, the grab mechanism 3 includes a pull rod 301, a movable pulley 302, grab plates 303, a cylindrical housing 304, a grab electric cylinder 305, and an ear plate 306. The cylindrical housing 304 houses the grab electric cylinder 305, which controls the operation of the grab. The lower end of the lead screw of the grab electric cylinder 305 is connected to the multiple grab plates 303 that make up the grab via the ear plate 306. When the grab mechanism 3 performs the grabbing action, a host computer performs speed planning, grabbing weight sensing, maximum grabbing weight prediction, and other functions for the grab electric cylinder 305. The system judges the situation and adjusts the speed planning of the grab bucket electric cylinder 305 according to the actual working conditions, so as to effectively ensure the service life of the grab bucket electric cylinder 305 while ensuring the normal operation of the grab bucket mechanism 3. The grab bucket mechanism 3 includes a cylindrical shell 304, and a movable pulley 302 is provided on the top of the cylindrical shell 304. The grab bucket electric cylinder 305 is installed inside the cylindrical shell 304. The lower end of the grab bucket electric cylinder 305 controls and connects to multiple grab plates 303 that make up the grab bucket. Each grab plate 303 is connected to a pull rod 301 that controls its opening and closing.

[0094] Both the luffing electric cylinder 201 and the grab bucket electric cylinder 305 are structures driven by two servo motors on a ball screw, as detailed below. Figure 5 As shown.

[0095] like Figure 7As shown, the lifting mechanism 4 includes a permanent magnet synchronous motor 401, a drum support 402, a reducer a 403; a wire rope 404, a drum 405, a winch support 406, a fixed seat a 407, a cylinder 408, a large spring 409, a small spring 410, a spring rod 411, a rope wheel seat 412, and a fixed pulley c 413; an electric winch and a buffer device are provided on the rotary mechanism 5 via the winch support 406; the connecting plate 103 is a rotating I-beam.

[0096] The electric winch includes a drum 405 mounted on a drum support 402, a steel wire rope 404 wound on the drum 405, and a power source on one side of the drum 405. The power source includes a permanent magnet synchronous motor 401, which is connected to the drum 405 through a reducer a403.

[0097] like Figure 8 As shown, the buffer device includes a cylinder 408 and a spring rod 411. The cylinder 408 is provided with a fixed seat a407 for connecting to the hinge support 105 of the buffer device. Both ends of the cylinder 408 are sealed. One end of the spring rod 411 is provided with a piston. The part of the spring rod 411 with the piston extends into the cylinder 408 to the end. Between the piston and the other side of the cylinder 408, there are small springs 410 and large springs 409 nested on the outside of the spring rod 411. The other end of the spring rod 411 without the piston is connected to the pulley seat 412. There is a fixed pulley c413; the drum 405 is connected to a wire rope 404, one end of which is fixed to the drum 405, and the other end is wound around the lifting mechanism 4. It extends out through the wire rope hole 509 set on the rotary mechanism 5, passes through the fixed pulley c413, fixed pulley a203, fixed pulley b204 of the buffer device, and the movable pulley 302 of the grab bucket, and is finally fixed on the tie rod group 205. The grab bucket mechanism 3 is raised and lowered by the raising and lowering of the wire rope 404 when the drum 405 rotates, and the impact generated when the lifting mechanism 4 changes direction is buffered by the buffer mechanism.

[0098] like Figure 9 , Figure 10 , Figure 11 and Figure 12 As shown, the rotary mechanism 5 includes a rotary fixed seat, a rotary body, and a rotary drive assembly. The rotary fixed seat includes a rotary support seat 501, a rotary bearing 502, and an internal gear ring 503. The rotary body includes a flange 504, a cylinder 505, a stiffening plate 506, an I-beam 507, a drive gear shaft 508, and a wire rope hole 509. The rotary drive assembly includes a rotary servo motor 510, a drive gear 511, a transition gear 512, a fixed seat b513, a drive gear shaft 514, and a reducer b515. The rotary body is mounted on the rotary bearing and can rotate centrally. The rotary drive assembly is fixed on the rotary body.

[0099] like Figure 9As shown, the slewing fixed base includes a slewing support base 501, a slewing bearing 502, and an internal gear ring 503. The slewing bearing 502 is a single-row four-point contact ball slewing bearing that can rotate on the slewing support base 501. The slewing support base 501 is fixed on the hanging plate 6. The internal gear ring 503 is set on the slewing support base 501. The slewing bearing 502 is fixed to the lower part of the slewing support base 501.

[0100] like Figure 10 As shown, the rotating body includes a cylinder 505, a flange 504, stiffening plates 506, and an I-beam 507. The flange 504 is located on the top of the cylinder 505. Multiple stiffening plates 506 are welded between the cylinder 505 and the flange 504 to improve strength. An I-beam 507 is located at the middle of the top of the flange 504. On both sides of the I-beam 507, drive gear shaft holes 508 and wire rope holes 509 are opened on the flange 504. Figure 11 As shown.

[0101] like Figure 12 As shown, the rotary drive assembly includes a drive base b513, a rotary servo motor 510, a reducer b515, a drive gear 511, and a transition gear 512. The output shaft of the rotary servo motor 510 is arranged downwards. The output shaft of the rotary servo motor 510 is connected to the base gear set through the reducer b515. The base b513 is located below the base gear set. The base gear set includes a drive gear 511 arranged through a drive gear shaft 514, and the drive gear 511 meshes with the transition gear 512. The rotary servo motor 510 is connected to the base gear set through the reducer b515. 15 drives the drive gear 511, which meshes with the internal gear ring 503 of the slewing fixed seat through the transition gear 512; the slewing body is placed in the slewing support seat 501 and fixed to the slewing bearing 502 through the flange 504, so that the slewing mechanism 5 can rotate together with the slewing bearing 502, and the cylinder 505 is connected to the frame 1; when the slewing servo motor 510 works, the transition gear 512 of the slewing drive assembly rotates and revolves within the internal gear ring 503 of the slewing fixed seat, driving the slewing mechanism 5, the frame 1, the luffing mechanism 2 and the grab bucket mechanism 3 to rotate together in the center.

[0102] like Figure 13 As shown, a method for driving and controlling an electric rock grabber, using a host computer to control the electric cylinder 305 of the grab bucket to perform the grabbing operation, includes the following specific steps:

[0103] S1. Before the grab bucket mechanism 3 performs the grabbing action, calculate the S-shaped speed curve of the motor in the grab bucket electric cylinder 305; the host computer sets the initial grabbing weight of the grab bucket mechanism 3, calculates the maximum acceleration of the grab bucket electric cylinder 305 based on the initial grabbing weight and the preset stability impact force limit of the grab bucket mechanism 3, calculates the maximum speed of the grab bucket electric cylinder 305 based on the rated power of the motor in the grab bucket electric cylinder 305 and the initial grabbing weight; calculates the jerk based on the preset working time and preset working formation; determine the S-shaped speed curve through the maximum acceleration, maximum speed and jerk of the grab bucket electric cylinder 305.

[0104] S2. The grab bucket electric cylinder 305 in the grab bucket mechanism 3 performs material grabbing according to the S-shaped speed curve specified by the host computer: The host computer calculates the real-time speed of the grab bucket electric cylinder 305 by differential calculation based on the real-time position of the grab bucket electric cylinder fed back by the built-in encoder, and determines the real-time output force of the grab bucket electric cylinder 305 based on the internal current sensor of the grab bucket electric cylinder 305.

[0105] S3. The host computer calculates the real-time weight of the material being grabbed by the grab bucket based on the real-time output force of the grab bucket electric cylinder 305 and the real-time acceleration of the grab bucket electric cylinder determined by the S-shaped speed curve.

[0106] S4. The host computer determines the current loading volume of the grab bucket based on the correlation between the real-time displacement of the grab bucket and the loading volume of the grab bucket. The correlation is determined through historical data. The average density of the material is calculated using the current loading volume of the grab bucket and the real-time weight of the grab bucket. The predicted maximum weight of the grab bucket is then calculated using the average density of the material.

[0107] S5. When the grab bucket mechanism 3 starts grabbing material, the host computer judges the working condition based on the real-time calculated maximum grabbing weight prediction value. The host computer compares the maximum grabbing weight prediction value m2 with the initial set grabbing weight m1. When the maximum grabbing weight prediction value is less than the initial grabbing weight, the grab bucket mechanism 3 is judged to be in a light load working state. When the predicted maximum grabbing weight prediction value is greater than the initial grabbing weight, the grab bucket mechanism 3 is judged to be in a heavy load working state.

[0108] During the construction of the vertical shaft, the electric rock grabber grabs the material excavated in the shaft. When the excavation depth is shallow, the material to be grabbed is mostly soft soil with low density. The weight of the material grabbed by the grab bucket mechanism of the electric rock grabber is small, and the electric rock grabber is in a light load condition. When the host computer determines that the grab bucket mechanism 3 is in a light load working state, the speed of the grab bucket electric cylinder 305 is not adjusted, and it continues to work according to the S-shaped speed curve planned by the host computer.

[0109] As the tunneling depth increases, the material to be grabbed becomes hard rock with high density, such as granite. The grab weight of the electric rock grabber's grab bucket mechanism will increase, and the host computer needs to determine whether it is under heavy load based on the predicted maximum grab weight. When the host computer determines that the grab bucket mechanism 3 is under heavy load, it re-plans the S-shaped speed curve of the grab bucket electric cylinder 305.

[0110] When the host computer detects that the output force of the grab bucket electric cylinder 305 exceeds the rated output force, the host computer judges that the grab bucket mechanism 3 has malfunctioned, and at this time the machine needs to be stopped for self-reset.

[0111] The S-shaped velocity curve designed for the 305 electric grab cylinder includes seven motion stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration, and is measured through the maximum speed. Maximum acceleration The derivative of acceleration, jerk j, and preset working time T are determined. The calculation methods for the maximum acceleration, maximum velocity, jerk, and the time of the seven motion stages used in planning the S-shaped velocity curve are as follows:

[0112] The maximum acceleration of the S-shaped velocity curve can be calculated using the following formula. :

[0113] ,

[0114] In the formula, To initially set the material gripping weight, For the weight of the 303 gripper, To ensure stable impact force limitation for the grab mechanism;

[0115] Calculate the maximum velocity of the S-shaped velocity curve using the following formula. :

[0116] ,

[0117] In the formula, This refers to the rated power of the motor in the grab bucket electric cylinder 305. To improve the transmission efficiency of the grab bucket electric cylinder 305. To initially set the material gripping weight, It is the acceleration due to gravity;

[0118] Calculate the jerk of the S-shaped velocity curve using the following formula. :

[0119] ,

[0120] In the formula, T is the preset working time and S is the preset working stroke;

[0121] The time for the seven motion phases can be calculated using the following formula:

[0122] ,

[0123] In the formula, To preset working hours, To increase the duration of the acceleration phase, For the time of the uniformly accelerated motion phase, To reduce the duration of the acceleration phase, The time of the uniformly decelerated motion phase. The time for the acceleration and deceleration phases. To reduce the time of the deceleration phase, This refers to the time of the uniform motion phase.

[0124] The process for calculating the predicted maximum material grabbing weight of the grab bucket is as follows:

[0125] The host computer calculates the real-time material gripping weight of the grab bucket using the following formula. :

[0126] ,

[0127] In the formula For the real-time output force of the grab bucket electric cylinder 305, The real-time acceleration of the grab bucket electric cylinder is determined by the S-shaped velocity curve. The weight of the gripper 303;

[0128] The host computer calculates the average density of the material using the following formula. :

[0129] ,

[0130] In the formula, This refers to the real-time weight of material gripped by the grab bucket. To capture the average density of the material, This refers to the real-time material grabbing volume of the grab bucket;

[0131] The host computer uses the following formula to calculate the predicted maximum material gripping weight of the grab bucket. :

[0132] ,

[0133] In the formula, The predicted maximum grab weight of the grab bucket. To capture the average density of the material, This refers to the maximum volume of the grab bucket.

[0134] When the host computer determines that the grab mechanism 3 is in a heavy-load working state, the host computer re-plans the S-shaped velocity curve of the grab electric cylinder 305: based on the recalculated maximum acceleration, maximum speed, unchanged jerk, and real-time speed, it determines whether there is a uniform acceleration phase in the S-shaped velocity curve, and calculates the time of each motion phase of the S-shaped velocity curve, reduces the acceleration, and extends the preset working time to reduce the impact on the grab electric cylinder 305. The specific steps are as follows:

[0135] Solve for the maximum acceleration of the redesigned S-shaped velocity curve. and maximum speed :

[0136] ,

[0137] ,

[0138] Based on the recalculated maximum acceleration, maximum velocity, unchanged jerk, and real-time velocity of the grab bucket electric cylinder 305, determine whether the redesigned S-shaped velocity curve has a uniform acceleration phase:

[0139] Based on maximum speed Initial velocity Maximum acceleration and accelerometer Determine whether the redesigned S-shaped velocity curve has a uniform acceleration phase during acceleration:

[0140] when The S-shaped velocity curve has seven stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, and deceleration. The motion time for each stage is as follows:

[0141] ,

[0142] when At that time, the S-shaped velocity curve does not have a uniform acceleration phase, but has six phases: acceleration / deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration. The motion time for each phase is as follows:

[0143] ,

[0144] In the formula, For the total time of the redesigned S-shaped velocity curve motion, To accelerate the motion time of the redesigned S-shaped velocity curve, The redesigned S-shaped velocity curve motion is the deceleration motion time. The redesigned S-shaped velocity curve motion is an acceleration / deceleration motion time. To reduce the acceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion acceleration and deceleration time, To reduce the deceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion uniform motion time, The remaining stroke for the replanned S-shaped velocity curve motion is obtained by subtracting the real-time displacement at the time of determination from the total stroke of the grab bucket electric cylinder 305. The initial velocity of the redesigned S-shaped velocity curve motion is the velocity before the redesigned S-shaped velocity curve.

[0145] The schematic diagrams of the initially planned S-shaped velocity curve and the replanned S-shaped velocity curve in the embodiment are as follows: Figure 14 As shown.

[0146] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An electric rock grabber, characterized in that, Includes a hanging platform (6), a slewing mechanism (5) is provided on the hanging platform (6), a lifting mechanism (4) is provided on the slewing mechanism (5), a frame (1) is connected below the slewing mechanism (5), and a grab bucket mechanism (3) is movably connected to the frame (1) through a luffing mechanism (2). The frame (1) includes a frame body (101), a connecting plate (103) is provided on the top of the frame body (101), and hinge supports (104) for the luffing mechanism, hinge supports (105) for the buffer device and hinge supports (106) for the luffing electric cylinder are provided on the upper, middle and lower sides of the frame body (101); a reinforcing plate (102) is provided on the frame body (101) at the hinge support (104) for the luffing mechanism. The luffing mechanism (2) includes a boom (206), the left end of which is movably connected to the grab mechanism (3), and the right end of which is movably connected to the luffing mechanism hinge support (104) of the frame (1); a support shaft (202) is provided in the middle of the boom (206), and a luffing electric cylinder (201) is movably connected between the boom (206) and the luffing electric cylinder hinge support (106) through the support shaft (202); The grab mechanism (3) includes a cylindrical shell (304), and a grab electric cylinder (305) for controlling the operation of the grab below is provided inside the cylindrical shell (304). Multiple grab plates (303) that make up the grab are connected to the lower part of the grab electric cylinder (305) via an ear plate (306). Both the variable amplitude electric cylinder (201) and the grab bucket electric cylinder (305) are structures with two servo motors driving the roller screw; When the grab bucket mechanism (3) performs the grabbing action, the host computer is used to perform speed planning, grabbing weight perception, maximum grabbing weight prediction and working condition judgment on the grab bucket electric cylinder (305), so as to adjust the speed planning of the grab bucket electric cylinder (305) according to the actual working condition, reduce the impact of the movement process on the grab bucket electric cylinder under the premise of ensuring the normal operation of the grab bucket mechanism (3), and ensure the service life of the grab bucket electric cylinder (305). Before the grabbing mechanism (3) performs the grabbing, the S-shaped speed curve of the grabbing electric cylinder (305) is planned; the S-shaped speed curve is planned by calculating the maximum acceleration, maximum speed and jerk. The grab bucket electric cylinder (305) in the grab bucket mechanism (3) performs grabbing according to the S-shaped speed curve specified by the host computer, and at the same time collects the information of the grab bucket electric cylinder (305) during the grabbing process: the host computer calculates the real-time speed of the grab bucket electric cylinder (305) by differential calculation based on the real-time displacement of the grab bucket electric cylinder (305) fed back by the built-in encoder, and determines the real-time output force of the grab bucket electric cylinder (305) based on the internal current sensor of the grab bucket electric cylinder (305); The host computer calculates the real-time weight of the grab bucket based on the real-time output force of the grab bucket electric cylinder (305) and the real-time acceleration of the grab bucket electric cylinder determined by the S-shaped speed curve. The S-shaped velocity curve planned for the grab bucket electric cylinder (305) includes seven motion stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration, and is measured through the maximum speed. Maximum acceleration The derivative of acceleration, jerk j, and preset working time T are determined.

2. The electric rock grabber according to claim 1, characterized in that, The luffing mechanism (2) is hinged to the luffing electric cylinder hinge support (106) at one end, and a fixed pulley a (203) is provided on the other end, and a fixed pulley b (204) is provided on the other end, and a tie rod group (205) is provided on one side of the fixed pulley b (204) and is movably connected to the luffing mechanism (2).

3. The electric rock grabber according to claim 2, characterized in that, The grab mechanism (3) includes a cylindrical shell (304), a movable pulley (302) is provided on the top of the cylindrical shell (304), and a grab electric cylinder (305) is installed inside the cylindrical shell (304). The roller screw end of the grab electric cylinder (305) is controlled and connected to multiple grab plates (303) that make up the grab through the ear plate (306). Each grab plate (303) is connected to the cylindrical shell (304) with an auxiliary opening and closing pull rod (301).

4. The electric rock grabber according to claim 3, characterized in that, The lifting mechanism (4) includes an electric winch and a buffer device mounted on the slewing mechanism (5) via a winch support (406); The electric winch includes a drum (405) mounted on a drum support (402), a steel wire rope (404) wound on the drum (405), and a power source connected to one side of the drum (405). The power source includes a permanent magnet synchronous motor (401), which is connected to the drum (405) via a reducer a (403). The buffer device includes a cylinder (408) and a spring rod (411) partially disposed within the cylinder (408). The cylinder (408) is provided with a fixed seat a (407) for connecting with the buffer device hinge support (105). The cylinder (408) is sealed at both ends. One end of the spring rod (411) is provided with a piston. The portion of the spring rod (411) with the piston extends into the cylinder (408) to the end. Between the piston and the other end of the cylinder (408), there are a small spring (410) and a large spring (409) nested together on the outside of the spring rod (411). The other end of the spring rod (411) without the piston extends out of the cylinder (408) and is connected to a fixed pulley c (413) through a rope wheel seat (412). One end of the wire rope (404) is fixed to the drum (405), and the other end is wound around the lifting mechanism (4). It first extends through the wire rope hole (509) set on the rotary mechanism (5), and then passes through the buffer device, fixed pulley c (413), fixed pulley a (203), fixed pulley b (204), and the moving pulley (302) of the grab bucket in sequence, and is finally fixed on the tie rod group (205). The grab bucket mechanism (3) is raised or lowered by the wire rope (404) when the drum (405) rotates, and the impact generated when the lifting mechanism (4) changes direction is buffered by the buffer mechanism.

5. The electric rock grabber according to claim 4, characterized in that, The rotary mechanism (5) includes a rotary fixed seat, a rotary body, and a rotary drive assembly, wherein: the rotary body is set on the rotary fixed seat and can rotate in the center, and the rotary drive assembly is fixed on the rotary body; The slewing fixed seat includes a slewing support seat (501), a slewing bearing (502), and an internal gear ring (503). The slewing bearing (502) is a single-row four-point contact ball slewing bearing that can rotate on the slewing support seat (501). The slewing support seat (501) is fixed on the hanging plate (6). The internal gear ring (503) is set on the slewing support seat (501). The slewing bearing (502) is fixed to the lower part of the slewing support seat (501). The rotary drive assembly includes a drive base b (513), a rotary servo motor (510), a reducer b (515), a drive gear (511), and a transition gear (512). The output shaft of the rotary servo motor (510) is connected to a gear set of the base via the reducer b (515). The base b (513) is located below the gear set of the base. The gear set of the base includes a drive gear (511) set via a drive gear shaft (514) and a transition gear (512) meshing with the drive gear (511). The rotary servo motor (510) drives the drive gear (511) via the reducer b (515). The drive gear (511) meshes with the internal gear ring (503) of the rotary base via the transition gear (512). The rotating body includes a cylinder (505), a flange (504), stiffening plates (506), and an I-beam (507). The flange (504) is located on the top of the cylinder (505). Multiple stiffening plates (506) are welded between the cylinder (505) and the flange (504) to improve strength. An I-beam (507) is located at the middle of the top of the flange (504). On both sides of the I-beam (507), there are drive gear shaft holes (508) and wire rope holes (509) on the flange (504). The drive gear shaft (514) is inserted into the drive gear shaft hole (508) to avoid interference between the rotating drive assembly and the rotating body. The rotating body is placed in the slewing support seat (501) and fixed to the slewing bearing (502) through the flange (504), so that the slewing mechanism (5) can rotate together with the slewing bearing (502), and the cylinder (505) is connected to the frame (1); When the rotary servo motor (510) is working, the transition gear (512) of the rotary drive assembly rotates and revolves within the internal gear ring (503) of the rotary fixed seat, driving the rotary mechanism (5), frame (1), luffing mechanism (2) and grab mechanism (3) to rotate together in the center.

6. A driving and control method for an electric rock grabber according to any one of claims 1-5, characterized in that, The specific steps for using a host computer to control the electric cylinder (305) of the grab bucket to perform the material grabbing operation are as follows: The host computer determines the current loading volume of the grab bucket based on the correlation between the real-time displacement of the grab bucket and the loading volume of the grab bucket. The correlation is determined by historical data. The average density of the material is calculated using the current loading volume of the grab bucket and the real-time weight of the material grabbed by the grab bucket. The maximum weight of the grab bucket is then calculated using the average density of the material. During the material grabbing process of the grab bucket mechanism (3), the host computer judges the working condition based on the predicted value of the maximum material grabbing weight calculated in real time. When the predicted value of the maximum material grabbing weight is less than the initial material grabbing weight, the grab bucket mechanism (3) is judged to be in a light load working state; otherwise, the grab bucket mechanism (3) is judged to be in a heavy load working state. When the host computer determines that the grab mechanism (3) is in a light-load working state, the speed of the grab electric cylinder (305) is not adjusted and continues to work according to the S-shaped speed curve planned by the host computer. When the host computer determines that the grab mechanism (3) is in a heavy-load working state, the host computer re-plans the S-shaped speed curve of the grab electric cylinder (305); When the host computer detects that the output of the grab bucket electric cylinder (305) exceeds the rated output, the host computer judges that the grab bucket mechanism (3) has malfunctioned, and at this time it is necessary to stop the machine for self-reset.

7. The driving and control method according to claim 6, characterized in that, The calculation methods for maximum acceleration, maximum velocity, jerk, and the time of the seven motion stages used in planning an S-shaped velocity curve are as follows: The maximum acceleration of the S-shaped velocity curve can be calculated using the following formula. : ， In the formula, To initially set the material gripping weight, The weight of the gripper (303) To ensure stable impact force limitation for the grab mechanism; Calculate the maximum velocity of the S-shaped velocity curve using the following formula. : ， In the formula, The rated power of the motor in the grab bucket electric cylinder (305) is... For the transmission efficiency of the grab bucket electric cylinder (305), To initially set the material gripping weight, It is the acceleration due to gravity; Calculate the jerk of the S-shaped velocity curve using the following formula. : ， In the formula, T is the preset working time and S is the preset working stroke; The time for the seven motion phases can be calculated using the following formula: ， In the formula, To preset working hours, To increase the duration of the acceleration phase, For the time of the uniformly accelerated motion phase, To reduce the duration of the acceleration phase, The time of the uniformly decelerated motion phase. The time for the acceleration and deceleration phases. To reduce the time of the deceleration phase, This refers to the time of the uniform motion phase.

8. The driving and control method according to claim 7, characterized in that, The process for calculating the predicted maximum material grabbing weight of the grab bucket is as follows: The host computer calculates the real-time material gripping weight of the grab bucket using the following formula. : ， In the formula For the real-time output force of the grab bucket electric cylinder (305), The real-time acceleration of the grab bucket electric cylinder is determined by the S-shaped velocity curve. The host computer calculates the average density of the material using the following formula. : ， In the formula, This refers to the real-time material grabbing volume of the grab bucket; The host computer uses the following formula to calculate the predicted maximum material gripping weight of the grab bucket. : ， In the formula, This refers to the maximum volume of the grab bucket.

9. The driving and control method according to claim 8, characterized in that, When the host computer determines that the grab mechanism (3) is in a heavy-load working state, the host computer re-plans the S-shaped speed curve of the grab electric cylinder (305): based on the recalculated maximum acceleration, maximum speed, unchanged jerk and real-time speed, it determines whether there is a uniform acceleration stage in the S-shaped speed curve, and calculates the time of each motion stage of the S-shaped speed curve, reduces the acceleration, and extends the preset working time to reduce the impact on the grab electric cylinder (305). The specific steps are as follows: Solve for the maximum acceleration of the redesigned S-shaped velocity curve. and maximum speed : ， ， Based on the recalculated maximum acceleration, maximum velocity, unchanged jerk, and real-time velocity of the grab electric cylinder (305), determine whether the replanned S-shaped velocity curve has a uniform acceleration phase: Based on maximum speed Initial velocity Maximum acceleration and accelerometer Determine whether the redesigned S-shaped velocity curve has a uniform acceleration phase during acceleration: when The S-shaped velocity curve has seven stages: acceleration, uniform acceleration, deceleration, constant speed, acceleration / deceleration, and deceleration. The motion time for each stage is as follows: ， when At that time, the S-shaped velocity curve does not have a uniform acceleration phase, but has six phases: acceleration / deceleration, constant speed, acceleration / deceleration, uniform deceleration, and deceleration / deceleration. The motion time for each phase is as follows: ， In the formula, For the total time of the redesigned S-shaped velocity curve motion, To accelerate the motion time of the redesigned S-shaped velocity curve, The redesigned S-shaped velocity curve motion is the deceleration motion time. The redesigned S-shaped velocity curve motion is an acceleration / deceleration motion time. To reduce the acceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion acceleration and deceleration time, To reduce the deceleration time of the redesigned S-shaped velocity curve motion, For the redesigned S-shaped velocity curve motion uniform motion time, The remaining stroke of the replanned S-shaped velocity curve motion is obtained by subtracting the real-time displacement when replanning is required from the total stroke of the grab bucket electric cylinder (305). The initial velocity of the redesigned S-shaped velocity curve motion is the velocity before the redesigned S-shaped velocity curve.

Images