Crawler-mounted dual-boom hoist

Abstract

This invention discloses a tracked double-arm lifting device, belonging to the field of engineering machinery technology. To solve the problems of single-arm cranes easily tilting when lifting long workpieces and the inability of fixed lifting points to adapt to different lengths, this invention employs: a tracked chassis, a slewing platform, and a main arm hinged at the lower end. A Y-shaped connecting seat is fixed to the top of the main arm, with its first and second connecting ends hinged to the first and second auxiliary arms, respectively. An angle adjustment and locking mechanism is provided between the Y-shaped connecting seat and the two auxiliary arms. Fixed pulley blocks are provided on the two auxiliary arms. Independently controlled first and second winches are located on the slewing platform, with their wire ropes passing over corresponding pulley blocks and connecting to the first and second hooks, respectively. The two winches are independently controlled so that the two hooks achieve independent height positions in the lifting direction. This device is used for lifting long workpieces, allowing for flexible adjustment of the lifting point spacing and independent control of the hook height, improving adaptability and balance.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically relating to a tracked double boom lifting device. Background Technology

[0002] In lifting operations, single-arm cranes are typically used for lifting long workpieces (such as steel bars or I-beams exceeding 9 meters in length). However, because a single-arm crane only provides one lifting point, it's difficult to accurately align the center of gravity of long workpieces with the lifting point during lifting, causing the workpiece to tilt and sway during hoisting and transportation, affecting operational safety. To improve this situation, some lifting devices have attempted to set up two lifting points with a fixed spacing. However, due to the significant differences in length among different workpieces, the fixed-spacing lifting points cannot adjust the horizontal distance between the two points according to the workpiece length, making it difficult to adapt to the lifting needs of various long workpiece specifications. How to ensure lifting stability while flexibly adapting the lifting point spacing to workpieces of different lengths remains a long-standing and unresolved technical challenge in this field. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] Another objective of this invention is to provide a tracked double-arm lifting device that can adjust the horizontal distance between the two lifting points according to the length of the workpiece to be lifted, and maintain the horizontal posture of the long workpiece during the lifting process by independently controlling the lifting height of the two hooks.

[0005] To achieve these objectives and other advantages of the present invention, a tracked double boom lifting device is provided, including a tracked chassis, a slewing platform mounted on the tracked chassis, and a main boom with its lower end hinged to the slewing platform. A Y-shaped connecting seat is fixed to the top of the main boom. The Y-shaped connecting seat has a first connecting end and a second connecting end. The lower end of a first auxiliary boom is hinged to the first connecting end, and the lower end of a second auxiliary boom is hinged to the second connecting end. A first angle adjustment and locking mechanism is provided between the Y-type connecting seat and the first auxiliary arm, and a second angle adjustment and locking mechanism is provided between the Y-type connecting seat and the second auxiliary arm. The first angle adjustment and locking mechanism and the second angle adjustment and locking mechanism are respectively used to adjust and lock the included angle of the first auxiliary arm and the second auxiliary arm relative to the Y-type connecting seat. The first auxiliary boom is equipped with a first pulley group, and the second auxiliary boom is equipped with a second pulley group. Both the first pulley group and the second pulley group are fixed pulley groups. The slewing platform is equipped with a first winch and a second winch. The first winch is wound with a first wire rope, which passes through a first pulley block and is connected to a first hook. The second winch is wound with a second wire rope, which passes through a second pulley block and is connected to a second hook. The first winch and the second winch are controlled and operated independently, driving the first wire rope and the second wire rope to be wound and released independently, so that the first hook and the second hook can obtain independent height positions in the lifting direction.

[0006] Preferably, the rotary platform is also equipped with a controller, and the first angle adjustment and locking mechanism and the second angle adjustment and locking mechanism are respectively a first angle-changing hydraulic cylinder and a second angle-changing hydraulic cylinder; The cylinder bodies of the first and second variable angle hydraulic cylinders are both hinged to the Y-type connecting seat, and the piston rods of the first and second variable angle hydraulic cylinders are respectively hinged to the middle of the first and second auxiliary arms. The first and second variable angle hydraulic cylinders are respectively equipped with a first two-way hydraulic lock and a second two-way hydraulic lock. The two oil outlets of the first and second two-way hydraulic locks are respectively connected to the rod chamber and rodless chamber of the corresponding variable angle hydraulic cylinder, and the two oil inlets are respectively connected to the oil inlet and oil return circuit of the hydraulic system. The control terminals of the first and second two-way hydraulic locks are electrically connected to the controller, and can be unlocked and locked in a controlled manner. The first and second auxiliary booms are respectively equipped with a first tilt sensor and a second tilt sensor; the first and second hooks are respectively equipped with a first pressure sensor and a second pressure sensor. The first tilt sensor, the second tilt sensor, the first pressure sensor, and the second pressure sensor are all electrically connected to the input terminal of the controller, and the output terminal of the controller is respectively connected to the drive mechanism of the first winch and the drive mechanism of the second winch. The controller calculates the speed adjustment amount of the first winch and the second winch based on the auxiliary boom angle signal fed back by the first tilt sensor and the second tilt sensor, as well as the hook load signal fed back by the first pressure sensor and the second pressure sensor. The controller then outputs speed adjustment commands to the drive mechanisms of the first winch and the second winch, respectively, so that the height difference between the first hook and the second hook during the lifting process is kept within the allowable range.

[0007] Preferably, the controller is equipped with a speed compensation module, which calculates the speed adjustment of the first and second winches according to the following steps: First, the controller reads the angle α between the first secondary arm and the vertical direction collected by the first tilt sensor, and reads the angle β between the second secondary arm and the vertical direction collected by the second tilt sensor; Then, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor; the controller sends the included angle α, included angle β, the first hook load value F1 and the second hook load value F2 to the speed compensation module; The speed compensation module calculates the first linear velocity compensation coefficient K1=cosα and the second linear velocity compensation coefficient K2=cosβ; The speed compensation module calculates the first speed reference value N. 1_base When F1≥F min At that time, N 1_base =N0×(F1+F2) / (2×F1), when F1 <F min At that time, N 1_base =N0; Second speed reference value N 2_base When F2≥F mi When n, N 2_base =N0×(F1+F2) / (2×F2), when F2 <F min At that time, N 2_base =N0; where N0 is the winch reference speed corresponding to the target lifting speed given by the operating handle; F min The preset minimum load threshold is not less than 0.5% of the rated lifting capacity; The speed compensation module sets the first target rotational speed to N. 1_target =N 1_base / K1, the second target rotational speed is set to N. 2_targe t=N 2_base / K2; The speed compensation module takes the difference between the first target speed and the current speed of the first winch as the first speed adjustment amount, and takes the difference between the second target speed and the current speed of the second winch as the second speed adjustment amount, and outputs them to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The speed compensation module recalculates α, β, F1, and F2 every 0.1 seconds and updates the first and second speed adjustment values.

[0008] Preferably, a first rotary encoder is installed on the drum shaft of the first winch, and a second rotary encoder is installed on the drum shaft of the second winch; both the first and second rotary encoders are electrically connected to the input terminal of the controller; the controller is also equipped with a height difference closed-loop adjustment module. The controller reads the first actual released wire rope length L1 collected by the first rotary encoder and the second actual released wire rope length L2 collected by the second rotary encoder; and pre-stores the length L of the first fixed section of the wire rope. 01 Length L of the second fixed section of the steel wire rope 02 The L 01 L 02 This refers to the fixed path length of the wire rope from the winch to the corresponding pulley block. The controller calculates the actual lifting height H1 of the first hook as H1 = (L1 - L 01)×cosα, calculate the actual lifting height H2 of the second hook: H2 = (L2 - L 02 )×cosβ; The controller calculates the height difference ΔH = H1 - H2; The controller sends the height difference ΔH to the height difference closed-loop control module. The height difference closed-loop control module has a built-in proportional-integral-derivative control algorithm and outputs the speed correction ΔN=K. p ×ΔH+K i ×∫ΔHdt+K d ×d(ΔH) / dt; Where K p For proportionality coefficient, K i For the integral coefficient, K d These are the differential coefficients; The controller will use the first target rotational speed N calculated by the speed compensation module. 1_target Subtracting the speed correction amount ΔN from the first final speed command, the calculated second target speed N is then used to obtain the first final speed command. 2_target The second final speed command is obtained by adding the speed correction amount ΔN, and then output to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The controller repeats the above reading and calculation steps every 0.05 seconds.

[0009] Preferably, the controller is equipped with an angle optimization module, which determines the target extension length of the first and second variable-angle hydraulic cylinders according to the following steps: First, the operator inputs the estimated length L of the workpiece to be hoisted through the control panel. 估 The controller is based on the estimated length L 估 And the fixed geometric parameters of the first and second auxiliary booms, calculate the first initial included angle α0 and the second initial included angle β0, such that the horizontal distance D0 between the two hooks is equal to the estimated length L. 估 The difference is within the preset difference range; The controller controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to unlock, drives the first variable angle hydraulic cylinder and the second variable angle hydraulic cylinder to move, so that the first auxiliary arm and the second auxiliary arm reach the first initial included angle α0 and the second initial included angle β0 respectively, and then controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to lock. The operator controls the first and second winches to lower the wire rope, attaches the first hook and the second hook to the two ends of the workpiece to be lifted, and then controls the first and second winches to slowly lift the workpiece to tighten the wire rope. The controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load ratio R=F1 / F2, and compares the load ratio R with the preset load ratio threshold range. When the load ratio R exceeds the preset load ratio threshold range, the angle optimization module iteratively adjusts according to the following rules: The controller first unlocks the first and second bidirectional hydraulic locks, and then performs the angle adjustment action: when R is greater than the upper limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously reduce the angle α between the first auxiliary arm and the vertical direction and the angle β between the second auxiliary arm and the vertical direction, so as to reduce the horizontal distance between the two hooks. When R is less than the lower limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously increase the included angle α and included angle β to increase the horizontal distance between the two hooks. After each adjustment, the controller controls the first and second bidirectional hydraulic locks to lock, the controller rereads the load ratio R and compares it with the preset load ratio threshold range, and repeats the above iterative adjustment process until the load ratio R falls within the preset load ratio threshold range, the controller stops adjusting and maintains the current angle; The controller repeats the above read and compare steps every 0.2 seconds.

[0010] Preferably, the lower end of the main boom is hinged to the slewing platform via a ball joint; the slewing platform is also equipped with a first luffing cylinder and a second luffing cylinder, the cylinder bodies of the first luffing cylinder and the second luffing cylinder are respectively hinged to the left and right sides of the slewing platform, the first luffing cylinder and the second luffing cylinder are respectively equipped with a third bidirectional hydraulic lock and a fourth bidirectional hydraulic lock, as well as a first proportional flow valve and a second proportional flow valve, the third bidirectional hydraulic lock, the fourth bidirectional hydraulic lock, the first proportional flow valve and the second proportional flow valve are all electrically connected to the hydraulic system and the controller; the slewing platform is also equipped with a lateral tilt sensor for detecting the lateral tilt angle of the main boom, the lateral tilt sensor is electrically connected to the input end of the controller; the controller is equipped with a main boom attitude adjustment module.

[0011] Preferably, the main arm attitude adjustment module adjusts the lateral attitude of the main arm according to the following steps: First, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load difference ΔF=F1-F2, and at the same time reads the boom lateral tilt angle γ collected by the lateral tilt angle sensor. Then, the main boom attitude adjustment module calculates the target lateral tilt angle γ based on the load difference ΔF. target =k×ΔF, where k is a preset proportionality coefficient, and its value ranges from 0.001 to 0.01 (° / N); γ targetThe positive and negative directions correspond to the swing direction of the main arm towards the first / second auxiliary arm side. A negative value corresponds to the swing of the main arm towards the second auxiliary arm side, ensuring that the main arm swings towards the side with the heavier load. The main arm attitude adjustment module sets the target lateral tilt angle γ. target Comparing it with the current lateral tilt angle γ, the tilt deviation e = γ is obtained. target -γ; The boom attitude adjustment module incorporates a proportional-integral control algorithm, which calculates the differential flow adjustment Q=K between the first and second luffing cylinders based on the tilt angle deviation e. p' ×e+K i' ×∫edt; Among them, K p' For proportionality coefficient, K i' The integral coefficient; The controller controls the proportional flow valves of the first and second luffing cylinders respectively based on the differential flow adjustment Q, causing the extension lengths of the first and second luffing cylinders to change slightly in opposite directions. Specifically, one cylinder extends while the other shortens, driving the boom to swing around the ball joint towards the side with the heavier load until the lateral tilt angle γ of the boom matches the target lateral tilt angle γ. target The deviation is less than the preset threshold; The controller repeats the above reading and calculation steps every 0.1 seconds.

[0012] Preferably, the first and second luffing cylinders are respectively equipped with a first displacement sensor and a second displacement sensor for detecting the cylinder extension length; the rod-side and rodless-side chambers of the first and second luffing cylinders are respectively connected to a first pressure detection port and a second pressure detection port, and the first and second pressure detection ports are respectively equipped with a first cavity pressure sensor and a second cavity pressure sensor; the first cavity pressure sensor, the second cavity pressure sensor, the first displacement sensor, and the second displacement sensor are all electrically connected to the input terminal of the controller; the controller is also equipped with a flow feedforward compensation module; when the controller controls the proportional flow valves of the first and second luffing cylinders according to the differential flow adjustment amount Q, the following steps are performed: Step 1: The controller reads the current lateral tilt angle γ of the main boom collected by the lateral tilt angle sensor, and reads the current length S1 of the first cylinder collected by the first displacement sensor and the current length S2 of the second cylinder collected by the second displacement sensor; Step 2: Based on the tilt deviation e output by the boom attitude adjustment module, the controller calculates the desired lateral swing angular velocity ω=K of the boom using a proportional-integral control algorithm. ω ×e, where K ω This is the preset angular velocity proportionality coefficient; Step 3: Based on the rotational geometry of the boom around the ball joint, and under the lateral attitude adjustment condition where the boom's forward and backward luffing angle remains constant, the controller calculates the desired extension / retraction speed v of the first luffing cylinder using the current boom tilt angle γ, the length of the first cylinder S1, and the length of the second cylinder S2. 1_exp The expected extension / retraction speed v of the second variable amplitude cylinder 2_exp , where v 1_exp =-v 2_exp , and v 1_exp The relationship with ω is determined by the instantaneous kinematic Jacobian matrix of the ball joint and the hydraulic cylinder hinge point; Step 4: The controller reads the rod chamber pressure P of the first cylinder collected by the first chamber pressure sensor. 1_rod and rodless chamber pressure P 1_cap Read the pressure P in the rod chamber of the second cylinder collected by the second chamber pressure sensor. 2_rod and rodless chamber pressure P 2_cap The flow feedforward compensation module calculates the desired extension / retraction speed v of the first hydraulic cylinder. 1_exp Piston area A of the hydraulic cylinder cap and piston rod area A rod Calculate the desired flow rate Q required by the proportional flow valve of the first hydraulic cylinder. 1_exp =|v 1_exp |×(when v 1_exp >0 is A cap When v 1_exp <0 is A rod Simultaneously calculate the valve port pressure difference ΔP1 = |P_sup>1 of the proportional flow valve of the first cylinder. 1_cap -P 1_rod |; Step 5: The flow feedforward compensation module uses the flow-pressure difference characteristic curve function f(Q,ΔP) of the proportional flow valve of the first oil cylinder to solve for the desired flow rate Q. 1_exp Required proportional flow valve opening command U1=f -1 (Q 1_exp Similarly, based on the desired extension / retraction speed v of the second cylinder... 2_exp Calculate the expected flow Q 2_exp Given the pressure difference ΔP2 at the valve orifice, the opening command U2=f is obtained by inverse solving. -1 (Q 2_exp ,ΔP2); Step 6: The controller outputs opening commands U1 and U2 to the proportional flow valves of the first and second luffing cylinders respectively, driving the first and second luffing cylinders to extend and retract at the desired speed; the controller reads the first and second displacement sensors every 0.05 seconds, compares the actual cylinder length with the desired length, and fine-tunes the opening commands U1 and U2 using a PID algorithm.

[0013] Preferably, the controller also includes a collaborative disturbance rejection adjustment module; the collaborative disturbance rejection adjustment module contains a first PID calculation unit and a second PID calculation unit, and when the collaborative disturbance rejection adjustment module performs fine-tuning correction of the opening commands U1 and U2 using the PID algorithm, it performs the following steps: Step A: The controller reads the current length S1 of the first hydraulic cylinder collected by the first displacement sensor and the current length S2 of the second hydraulic cylinder collected by the second displacement sensor, and reads the desired lateral tilt angle γ of the main boom output by the main boom attitude adjustment module. target And the current boom lateral tilt angle γ collected by the lateral tilt sensor; Step B: Based on the kinematic geometry of the main boom around the ball joint, the collaborative disturbance rejection module adjusts the desired lateral tilt angle γ of the main boom under the condition that the forward and backward amplitude angle of the main boom remains unchanged. target The desired length S converted to the first hydraulic cylinder 1_ref The expected length S of the second cylinder 2_ref S 1_ref With S 2_ref Satisfy S 1_ref +S 2_ref = constant C, where constant C is the sum of the lengths of the two cylinders in their initial installation positions; Step C: The collaborative disturbance rejection adjustment module calculates the length deviation e1=S of the first hydraulic cylinder. 1_ref -S1, the length deviation of the second cylinder e2=S 2_ref -S2, and calculate the common mode deviation e sum =e1+e2 and differential mode deviation e diff =e1-e2; Step D: The collaborative disturbance rejection adjustment module will adjust the common mode deviation e sum Input to the first PID calculation unit, output common mode correction ΔU sum =K p_sum ×e sum +K i_sum ×∫e sum dt+K d_sum ×d(e sum ) / dt; The differential mode deviation e diff Input to the second PID calculation unit, output differential mode correction ΔU diff =K p_diff ×e diff +K i_diff ×∫e diff dt+K d_diff ×d(e diff ) / dt; Step E: The collaborative disturbance rejection adjustment module calculates the opening correction ΔU acting on the first proportional flow valve based on the common-mode correction and differential-mode correction.1_corr =(ΔU sum +ΔU diff ) / 2, and the opening correction ΔU acting on the second proportional flow valve. 2_corr =(ΔU sum -ΔU diff ) / 2; Step F: The controller combines the opening command U1 output by the flow feedforward compensation module with the opening correction amount ΔU. 1_corr Add them together to obtain the first final opening instruction U. 1_final =U1+ΔU 1_corr ; Compare U2 with ΔU 2_corr Adding them together, we get the second final opening instruction U. 2_final =U2+ΔU 2_corr ; proportional flow valves that output to the first and second luffing cylinders respectively; Step G: The collaborative disturbance rejection adjustment module repeats steps A to F every 0.02 seconds, and limits the integral terms of the first PID calculation unit and the second PID calculation unit during each execution to prevent integral saturation.

[0014] The present invention has at least the following beneficial effects: First, when lifting long workpieces with a single-arm crane, the center of gravity of the workpiece is difficult to align due to the single lifting point, making it prone to tilting and swaying during lifting. Even with two lifting points at a fixed distance, it is still insufficient to accommodate workpieces of varying lengths. This device connects two independently adjustable auxiliary booms via a Y-shaped connecting seat and is equipped with two independently controlled winches. This allows for adjustment of the horizontal distance between the two lifting points according to the workpiece length, while simultaneously adjusting the lifting height of the two hooks. This enables long pieces to automatically achieve horizontal balance at the moment of lifting, significantly improving the adaptability and stability of the lifting process.

[0015] Secondly, during the lifting process, after the two auxiliary booms independently adjust their angles using their respective hydraulic cylinders, the two hooks are prone to developing a height difference due to load differences and the nonlinear characteristics of the hydraulic system, causing long items to tilt and requiring repeated manual intervention. This device installs a two-way hydraulic lock on the angle-adjusting hydraulic cylinder, locking the cylinder after angle adjustment to prevent external impacts from causing angular displacement; simultaneously, tilt and pressure sensors provide real-time feedback on the auxiliary boom angle and hook load, and the controller dynamically adjusts the speed of the two winches to keep the hook height difference within the allowable range, eliminating the need for frequent manual corrections during the lifting process.

[0016] Third, when the two auxiliary booms have different deployment angles, even if the winch speed is the same, the actual lifting linear speed of the hook will differ due to the different angles between the wire rope direction and the vertical direction, causing additional tilting of the long piece during lifting. This device uses an inclination sensor to obtain the angle between the auxiliary boom and the vertical direction, calculates the linear speed compensation coefficient using the cosine value, and makes the winch speed inversely proportional to the compensation coefficient. At the same time, it combines the inversely proportional speed distribution with the load, thereby eliminating the inconsistency in linear speed caused by angle and load differences, keeping the long piece horizontal throughout the lifting process.

[0017] Fourth, even after adopting angle and load-based feedforward compensation, slight deviations in the actual height of the two hooks still occur during the lifting process due to factors such as the elastic deformation of the wire rope, the mechanical clearance of the winch, and differences in the response of the hydraulic system. These deviations accumulate, causing the long component to slowly tilt. This device measures the actual length of the wire rope released by the two winches in real time using a rotary encoder, calculates the true height of the two hooks based on the angle of the jib, and then uses the height difference as feedback. It employs a proportional-integral-derivative control algorithm to dynamically correct the winch speed command, forming a closed-loop control that eliminates accumulated errors and automatically keeps the long component level throughout the lifting process.

[0018] Fifth, operators typically need to manually estimate the initial angle between the two auxiliary booms based on the workpiece length. However, the actual center of gravity of the workpiece deviates from the theoretical center of gravity, resulting in a severe imbalance in the load on the two hooks after lifting. This necessitates repeated trial lifts for adjustment, which is inefficient and relies heavily on operator experience. This device has a built-in angle optimization module that uses the load ratio of the two hooks fed back by the pressure sensor as a criterion to automatically and iteratively adjust the angle between the two auxiliary booms and synchronously increase or decrease the distance between the lifting points. This makes the load on the two hooks tend to be balanced, thus automatically finding the optimal lifting point position in one go before lifting, eliminating the need for repeated manual trial lifts.

[0019] Sixth, in traditional lifting devices, the main boom is connected to the slewing platform via a simple hinge. When the two auxiliary booms independently suspend long workpieces with unbalanced loads, the top of the main boom bears an asymmetrical resultant force, generating additional bending moments and torsional stresses inside the main boom. Long-term use can easily lead to fatigue cracking. This device uses a ball joint to connect the main boom and the slewing platform, giving the main boom lateral swing freedom. It is also equipped with two luffing cylinders on the left and right sides, along with corresponding hydraulic locks and proportional flow valves, providing a structural basis for actively adjusting the lateral attitude of the main boom.

[0020] Seventh, based on the ball joint and dual luffing cylinders, the differential extension length of the left and right luffing cylinders is independently controlled to actively adjust the lateral tilt angle of the main boom, causing the main boom axis to align with the direction of the resultant external force. This converts the additional bending moment into compressive stress along the main boom axis, utilizing the main boom's own compressive strength to bear the load. Simultaneously, the target lateral tilt angle is calculated using the load difference between the two hooks as a feedforward, and closed-loop adjustment is achieved through feedback from a lateral tilt angle sensor. This allows the main boom to adaptively maintain a pure axial force state under any unbalanced load conditions, avoiding the increased weight and cost associated with traditionally reinforced main boom sections.

[0021] Eighth, during differential adjustment, the two luffing cylinders, one pushing and the other pulling, experience significant differences in load pressure. Furthermore, the actual flow rate of the proportional flow valve is significantly affected by the valve port pressure difference. This results in different actual flow rates under different pressure differences for the same valve opening command, easily causing a mismatch between the actual extension and retraction speeds of the two cylinders and the desired speed. This leads to unstable lateral swing speeds of the main boom, resulting in impacts or vibrations. This device uses displacement and chamber pressure sensors to acquire the cylinder length and pressure in both chambers in real time. It utilizes kinematic geometry to convert the desired lateral swing angular velocity into the desired extension and retraction speed of each cylinder. Then, based on the flow-pressure difference characteristic curve of each proportional flow valve, it calculates the precise opening command required to achieve the desired flow rate, realizing flow feedforward compensation. Simultaneously, it employs displacement closed-loop PID fine-tuning to eliminate modeling errors and nonlinear interference, ensuring precise synchronization of the extension and retraction speeds of the two cylinders and guaranteeing smooth, impact-free lateral swing of the main boom.

[0022] Ninth, if independent PID algorithms are used to fine-tune the opening commands of the two cylinders separately, the two cylinders are mechanically strongly coupled through the main boom and ball joint (one extension inevitably leads to the other shortening), and there is pressure coupling between the rod-side and rodless sides of the two cylinders in the hydraulic system. Independent PID control will cause the correction commands of the two cylinders to conflict with each other, resulting in a "chasing" oscillation phenomenon, manifested as non-convergent lateral swing of the main boom and frequent shaking. This device obtains the actual length of the two cylinders through displacement sensors, converts their respective positional deviations into common-mode deviation (reflecting the total length drift) and differential-mode deviation (reflecting the lateral swing angle error), uses two independent PID controllers to process the common-mode and differential-mode deviations respectively, and then uses linear transformation to solve for the correction amount of each cylinder, achieving decoupled control, thereby avoiding mutual interference between the adjustment commands of the two cylinders and ensuring smooth and rapid lateral swing of the main boom.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the structure of one technical solution of the present invention.

[0025] 1. Tracked chassis; 2. Slewing platform; 3. Main boom; 4. First auxiliary boom; 5. Second auxiliary boom; 6. First angle adjustment and locking mechanism; 7. Second angle adjustment and locking mechanism; 8. First winch; 9. Second winch. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0027] like Figure 1 As shown, the present invention provides a tracked double-arm lifting device, including a tracked chassis, a slewing platform mounted on the tracked chassis, and a main arm with its lower end hinged to the slewing platform. A Y-shaped connecting seat is fixed to the top of the main arm, and the Y-shaped connecting seat has a first connecting end and a second connecting end. The lower end of the first auxiliary arm is hinged to the first connecting end, and the lower end of the second auxiliary arm is hinged to the second connecting end. The main arm, the first auxiliary arm, and the second auxiliary arm are all telescopic structures. A first angle adjustment and locking mechanism is provided between the Y-type connecting seat and the first auxiliary arm, and a second angle adjustment and locking mechanism is provided between the Y-type connecting seat and the second auxiliary arm. The first angle adjustment and locking mechanism and the second angle adjustment and locking mechanism are respectively used to adjust and lock the included angle of the first auxiliary arm and the second auxiliary arm relative to the Y-type connecting seat. The first auxiliary boom is equipped with a first pulley group, and the second auxiliary boom is equipped with a second pulley group. Both the first pulley group and the second pulley group are fixed pulley groups. The slewing platform is equipped with a first winch and a second winch. The first winch is wound with a first wire rope, which passes through a first pulley block and is connected to a first hook. The second winch is wound with a second wire rope, which passes through a second pulley block and is connected to a second hook. The first winch and the second winch are controlled and operated independently, driving the first wire rope and the second wire rope to be wound and released independently, so that the first hook and the second hook can obtain independent height positions in the lifting direction.

[0028] In one feasible implementation, the tracked chassis can use rubber or steel tracks with a width selectable between 300 mm and 600 mm, and a travel speed controllable between 0 and 5 km / h. A slewing platform is mounted on top of the tracked chassis, and a slewing bearing can be installed between the platform and the chassis, allowing the platform to rotate continuously 360 degrees relative to the chassis. The lower end of the main boom is hinged to the front of the slewing platform, and a hydraulic cylinder for controlling the boom's tilt angle is installed between the main boom and the slewing platform. For example, the main boom can adopt a box-type telescopic boom structure, consisting of a base boom and one or more telescopic boom sections, with sliders and clearance adjustment mechanisms between the sections. A telescopic cylinder is installed inside the main boom, with the cylinder body hinged to the tail of the base boom and the piston rod end connected to the innermost telescopic boom section, used to drive the main boom to extend and retract sequentially. After extension and retraction, the boom length is locked by a built-in pin mechanism or hydraulic lock. A Y-shaped connecting seat is fixed at the top of the main boom. This Y-shaped connecting seat can be made of cast carbon steel or welded steel plate and has a first connecting end and a second connecting end, which are located on the left and right sides of the Y-shaped fork, respectively. The lower end of the first auxiliary boom is hinged to the first connecting end by a pin, and the lower end of the second auxiliary boom is hinged to the second connecting end by a pin. A self-lubricating copper sleeve can be installed at the hinge to reduce friction. The first and second auxiliary booms also adopt a box-type telescopic structure. Each auxiliary boom consists of a fixed boom section and a movable boom section. The lower end of the fixed boom section is hinged to the Y-shaped connecting seat, and the movable boom section is fitted inside the fixed boom section. A nylon slider is provided between the two. Each auxiliary boom has a built-in telescopic cylinder installed inside. The cylinder body of the telescopic cylinder is hinged to the fixed boom section, and the piston rod end is connected to the movable boom section for independently controlling the length of the auxiliary boom. After telescopic extension, the boom length is locked by a two-way hydraulic lock or mechanical pin set on the auxiliary boom. A first angle adjustment and locking mechanism is provided between the Y-type connecting seat and the first auxiliary arm. This mechanism can be a manual screw jack, an electric push rod, or a hydraulic cylinder. The cylinder end is hinged to the middle or base of the Y-type connecting seat, and the push rod end is hinged to the middle or upper part of the first auxiliary arm. Similarly, the second angle adjustment and locking mechanism adopts the same form. When it is necessary to adjust the angle of the first auxiliary arm relative to the vertical direction, the first angle adjustment and locking mechanism can be driven to extend or retract, causing the first auxiliary arm to rotate around its lower hinge point. The angle adjustment range can be between 0 degrees and 60 degrees. After adjustment, the mechanism is locked by locking the nut, a two-way hydraulic lock, or a mechanical pin to prevent the angle from changing due to external impact during lifting.

[0029] A first pulley system is installed near the top of the first auxiliary boom, and a second pulley system is installed at the corresponding position on the second auxiliary boom. The first pulley system may contain one or more fixed pulleys. The number of pulleys can be selected according to the lifting wire rope ratio; for example, using a single pulley simplifies the rope system, while using two pulleys side-by-side reduces the bending radius of the wire rope. The pulleys can be made of ductile iron or nylon, and the pulley groove surface can be hardened to improve wear resistance. The first pulley system is mounted on the first auxiliary boom via a pulley axle, and a rolling bearing can be installed between the pulley axle and the first auxiliary boom. The second pulley system is similar. Both pulley systems are fixed pulley systems, meaning the pulleys only rotate around their own axes and do not move with the wire rope. During operation, after the wire rope is drawn from the winch, it first passes through the pulley groove of the first pulley system and then hangs downwards to connect to the hook. When the winch winds up or unwinds the wire rope, the pulley system only changes the direction of the wire rope, not its linear velocity.

[0030] A first winch and a second winch are fixedly installed on the slewing platform. They can be arranged side-by-side at the rear of the platform or separately on the left and right sides of the main boom hinge point. The first winch's drum is wound with a first wire rope, the diameter of which can be selected according to the rated lifting capacity; for example, for a 5-ton lifting device, the wire rope diameter can be 8 mm to 12 mm. The second winch corresponds to the second wire rope. After being drawn from the first winch, the first wire rope extends upwards and passes over the first pulley block on the first auxiliary boom, then hangs downwards, its end connecting to the first hook; the second wire rope connects to the second hook in the same way. Both the first and second hooks can be forged hooks conforming to national standard GB / T 10051, with anti-derailment clips at the hook openings. The first and second winches are each equipped with an independent drive motor or hydraulic motor, and both are controlled by the same operating handle or two independent handles, allowing for independent forward and reverse rotation and speed adjustment. During operation, the operator can adjust the winding and unwinding lengths of the two winches according to the actual center of gravity of the long workpiece to be lifted, so that the two hooks achieve different heights in the lifting direction, thereby automatically leveling the workpiece at the moment of lifting. For example, when the center of gravity of the workpiece is biased towards the first hook, the unwinding length of the first winch can be appropriately increased or the unwinding length of the second winch can be decreased to compensate for the shift in the center of gravity. Throughout the process, the operation of the two winches does not interfere with each other, and the lifting height can be independently controlled.

[0031] Two independently adjustable auxiliary booms are hinged by a Y-shaped connecting seat, and with the angle adjustment and locking mechanism, the horizontal distance between the two lifting points can be adjusted and locked according to workpieces of different lengths. Then, two independently controlled winches drive the two hooks respectively, so that the two hooks obtain independent height positions in the lifting direction. Thus, when lifting long workpieces, the horizontal balance can be automatically achieved at the moment of lifting according to the actual center of gravity distribution of the workpiece, reducing tilting and swaying, and improving the adaptability to workpieces of different lengths and the lifting stability.

[0032] In another technical solution, the first angle adjusting and locking mechanism and the second angle adjusting and locking mechanism are respectively the first variable angle hydraulic cylinder and the second variable angle hydraulic cylinder; The cylinder bodies of the first and second variable angle hydraulic cylinders are both hinged to the Y-type connecting seat, and the piston rods of the first and second variable angle hydraulic cylinders are respectively hinged to the middle of the first and second auxiliary arms. The first and second variable angle hydraulic cylinders are respectively equipped with a first two-way hydraulic lock and a second two-way hydraulic lock. The two oil outlets of the first and second two-way hydraulic locks are respectively connected to the rod chamber and rodless chamber of the corresponding variable angle hydraulic cylinder, and the two oil inlets are respectively connected to the oil inlet and oil return circuit of the hydraulic system. The control terminals of the first and second two-way hydraulic locks are electrically connected to the controller, and can be unlocked and locked in a controlled manner. The slewing platform is also equipped with a controller, and the first and second auxiliary booms are respectively equipped with a first tilt sensor and a second tilt sensor; the first and second hooks are respectively equipped with a first pressure sensor and a second pressure sensor. The first tilt sensor, the second tilt sensor, the first pressure sensor, and the second pressure sensor are all electrically connected to the input terminal of the controller, and the output terminal of the controller is respectively connected to the drive mechanism of the first winch and the drive mechanism of the second winch. The controller calculates the speed adjustment amount of the first winch and the second winch based on the auxiliary boom angle signal fed back by the first tilt sensor and the second tilt sensor, as well as the hook load signal fed back by the first pressure sensor and the second pressure sensor. The controller then outputs speed adjustment commands to the drive mechanisms of the first winch and the second winch, respectively, so that the height difference between the first hook and the second hook during the lifting process is kept within the allowable range.

[0033] The first angle adjusting locking mechanism and the second angle locking mechanism can respectively employ a first variable angle hydraulic cylinder and a second variable angle hydraulic cylinder. The cylinder diameter can be selected from 40 mm to 80 mm, the piston rod diameter from 20 mm to 45 mm, and the working pressure can be set from 16 MPa to 25 MPa. The tail end of the cylinder body can be hinged to the middle or side lugs of the Y-type connecting seat via a pin, and a self-lubricating bearing can be installed at the hinge point; the end of the piston rod is hinged to the middle position of the first or second auxiliary arm via a fisheye joint, which is one-third to one-half of the total length of the auxiliary arm from the lower hinge point. The stroke of the cylinder can be determined according to the required angle adjustment range, for example, the stroke can be selected from 100 mm to 300 mm. A first double-acting hydraulic lock and a second double-acting hydraulic lock are respectively installed on the cylinder body of the first variable angle hydraulic cylinder or on the pipeline near the oil port. The two-way hydraulic lock can be an integrated valve block composed of two hydraulically controlled check valves. Its two outlets are connected via high-pressure hoses to the rod-side and rodless-side connectors of the strain angle hydraulic cylinder, respectively. Its two inlets are connected to the main inlet and return lines of the hydraulic system, respectively. The control terminal (hydraulic control port) of the two-way hydraulic lock is electrically connected to the corresponding output terminal of a controller (e.g., a programmable logic controller or microcontroller) via a cable. When the controller outputs an unlocking signal (e.g., 24V DC voltage) to the solenoid pilot valve of the two-way hydraulic lock, the hydraulically controlled check valve opens, allowing hydraulic oil to enter and exit the cylinder, at which point the auxiliary boom angle can be adjusted. When the controller sends a cancellation signal or outputs a locking signal, the hydraulically controlled check valve closes, sealing the oil in both chambers of the cylinder, thereby locking the cylinder and preventing the piston rod from moving under external force. During operation, the operator first unlocks the two bidirectional hydraulic locks through the controller, then supplies oil to the oil inlet of the variable angle hydraulic cylinder, causing the piston rod to extend or retract, pushing the auxiliary arm to rotate around the lower hinge point to achieve angle adjustment; after adjustment, the controller controls the bidirectional hydraulic locks to lock, and then the oil circuit can be cut off, and the cylinder remains in the same position.

[0034] A controller can be installed on the rotating platform. This controller can be an industrial-grade microcontroller or an embedded controller, operating at 12V or 24V DC, and featuring multiple analog input channels and digital output channels. A first tilt sensor is installed on the side of the first auxiliary arm, near the top or middle. This sensor can be a microelectromechanical system (MEMS) dual-axis tilt sensor, with a measurement range selectable at ±45 degrees or ±60 degrees. The output signal can be 4 to 20 mA current or 0 to 10 V voltage, with a resolution of 0.1 degrees. A second tilt sensor is installed on the second auxiliary arm. The sensitive axes of both tilt sensors should be parallel to the longitudinal axis of the auxiliary arm. During installation, it is necessary to ensure that the bottom surface of the sensor is in contact with the surface of the auxiliary arm and that the zero position is calibrated. A first pressure sensor is installed on the upper part of the lifting ring or at the hook nut of the first hook. This sensor can be a spoke-type or column-type tension / compression sensor, and the rated load can be selected according to the maximum lifting capacity of the device. For example, for a 10-ton device, a sensor with a range of 10 tons or 15 tons can be selected. The output is a millivolt-level voltage signal, and a transmitter is required to convert it into a standard signal. A second pressure sensor is installed on the second hook. The output signal lines of all sensors are connected to the analog input terminal of the controller. The output terminal of the controller (e.g., pulse width modulation output or relay output) is connected to the drive mechanism of the first winch (such as the electro-proportional valve of the hydraulic motor or the frequency converter of the motor) and the drive mechanism of the second winch, respectively. During assembly, the sensor cables should be laid along the auxiliary boom and the slewing platform, and protective sleeves should be used to avoid mechanical damage. After the device is powered on, the controller periodically collects data from the tilt sensor and the pressure sensor. The sampling frequency can be set from 10 Hz to 50 Hz.

[0035] The controller has a pre-set allowable height difference threshold range; for example, the allowable height difference between the first and second hooks during lifting can be set to ±30 mm. The controller reads in real time the angle α between the jib and the vertical direction measured by the first tilt sensor and the angle β measured by the second tilt sensor, as well as the load values ​​F1 and F2 measured by the first and second pressure sensors. Based on these signals, the controller calculates the speed adjustment amount for the first and second winches according to its built-in calculation model. One feasible calculation method is to first estimate the ratio of the linear velocities of the two hooks required to maintain the workpiece level based on the load values, then combine this with the influence of the jib angle on the vertical component of the wire rope to calculate the target speeds of the two winches, and finally use the difference between the target speed and the current speed as the speed adjustment amount. The controller adjusts the winch speed by outputting pulse-width modulation signals or analog signals to change the input current or voltage of the winch drive mechanism. The entire adjustment process is continuously performed in a closed loop, updating the adjustment value every 0.1 to 0.5 seconds. This ensures that even if the workpiece's center of gravity shifts or the jib angle changes during lifting, the height difference between the two hooks can be actively maintained within ±30 mm. In actual operation, the operator only needs to lift the workpiece normally, and the controller will automatically complete the speed adjustment, eliminating the need for repeated manual adjustments.

[0036] The boom angle is precisely adjusted and reliably locked by a variable-angle hydraulic cylinder and a two-way hydraulic lock to prevent accidental changes in angle during lifting. At the same time, tilt sensors and pressure sensors monitor the boom posture and hook load in real time. The controller automatically calculates and adjusts the speed of the two winches, thereby keeping the height difference between the two hooks within a small range during lifting, reducing the tilting of long workpieces and reducing the frequency of manual intervention.

[0037] In another technical solution, the controller is equipped with a speed compensation module, which calculates the speed adjustment of the first and second winches according to the following steps: First, the controller reads the angle α between the first secondary arm and the vertical direction collected by the first tilt sensor, and reads the angle β between the second secondary arm and the vertical direction collected by the second tilt sensor; Then, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor; the controller sends the included angle α, included angle β, the first hook load value F1 and the second hook load value F2 to the speed compensation module; The speed compensation module calculates the first linear velocity compensation coefficient K1=cosα and the second linear velocity compensation coefficient K2=cosβ; The speed compensation module calculates the first speed reference value N. 1_base When F1≥F min At that time, N 1_base=N0×(F1+F2) / (2×F1), when F1 <F min At that time, N 1_base =N0; Second speed reference value N 2_base When F2≥F mi When n, N 2_base =N0×(F1+F2) / (2×F2), when F2 <F min At that time, N 2_base =N0; where N0 is the winch reference speed corresponding to the target lifting speed given by the operating handle; F min The preset minimum load threshold is not less than 0.5% of the rated lifting capacity; The speed compensation module sets the first target rotational speed to N. 1_target =N 1_base / K1, the second target rotational speed is set to N. 2_targe t=N 2_base / K2; The speed compensation module takes the difference between the first target speed and the current speed of the first winch as the first speed adjustment amount, and takes the difference between the second target speed and the current speed of the second winch as the second speed adjustment amount, and outputs them to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The speed compensation module recalculates α, β, F1, and F2 every 0.1 seconds and updates the first and second speed adjustment values.

[0038] When using the above-mentioned method to lift long workpieces, the controller adjusts the speed of the two winches based on signals from the tilt and pressure sensors, which can maintain the height difference between the two hooks to a certain extent. However, in actual use, it has been found that when the two booms have different unfolding angles relative to the vertical direction, even if the drum speeds of the two winches are the same, the actual lifting linear speed of the two hooks will differ due to the angle between the wire rope direction and the vertical direction. Specifically, the linear speed of the hook is equal to the linear speed of the wire rope released by the winch multiplied by the cosine of the angle between the boom and the vertical direction; the larger the angle, the smaller the actual lifting linear speed. Since the angles of the two booms are often different, even if the speeds of the two winches are exactly the same, the actual lifting speeds of the two hooks will not be the same, causing additional tilting of the long workpiece during lifting. At the same time, when the loads borne by the two hooks are different, the center of gravity of the workpiece will deviate from its geometric center. If the two winches still lift at the same speed, the workpiece will also tilt towards the side with the heavier load. The aforementioned problems have not been specifically addressed in the solution of claim 2. Operators still need to manually intervene during the lifting process to adjust the speeds of the two winches separately to compensate for these effects, which is cumbersome and makes it difficult to achieve precise synchronization.

[0039] To address this issue, this implementation adds a speed compensation module within the controller. This speed compensation module automatically calculates and outputs the speed adjustment amount according to the following steps: First, the controller reads the angle α between the first auxiliary boom and the vertical direction, collected by the first tilt sensor, and the angle β between the second auxiliary boom and the vertical direction, collected by the second tilt sensor, every 0.1 seconds. Simultaneously, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor. The controller sends these data to the speed compensation module. The speed compensation module first calculates two linear speed compensation coefficients, letting K1 = cosα and K2 = cosβ. Since the actual lifting linear speed is proportional to the cosine value, to make the actual linear speeds of the two hooks equal, the winch speed needs to be inversely proportional to the cosine value; therefore, K1 and K2 will be used as the denominator for subsequent compensation. Then, the speed compensation module calculates the reference speed values ​​of the two winches based on the load values. Set N0 as the winch reference speed corresponding to the target lifting speed given by the operating handle (for example, N0 corresponds to the winch's rated speed when the handle is pushed to the maximum position, and N0 is zero when the handle is in the neutral position). The first speed reference value is calculated according to the formula. The second speed reference value is calculated according to the formula. Among them, F min The preset minimum load threshold is set to no less than 0.5% of the rated lifting capacity. As can be seen from the formula, when a hook has a larger load, its corresponding speed reference value is smaller, thus allowing heavier hooks to lift more slowly and lighter hooks to lift more quickly, thereby compensating for the tilting tendency caused by the shift in the center of gravity. Next, the speed compensation module sets the first target speed to N. 1_target =N 1_base / K1, the second target rotational speed is set to N. 2_target =N 2_base / K2. Since both K1 and K2 are less than or equal to 1, dividing by K1 and K2 is equivalent to increasing the target speed, thereby offsetting the actual linear speed loss caused by the wire rope tilt. Then, the speed compensation module calculates the first speed adjustment, which is the difference between the first target speed and the current speed of the first winch; and calculates the second speed adjustment, which is the difference between the second target speed and the current speed of the second winch. These two adjustments are output to the drive mechanisms of the first and second winches respectively, and the drive mechanisms change the actual speed of the winches accordingly. The speed compensation module rereads α, β, F1, and F2 every 0.1 seconds and updates the two speed adjustment values. Through this continuous, high-frequency feedforward compensation, the actual lifting linear speeds of the two hooks can remain synchronized, and the workpiece will not tilt additionally during the entire lifting process due to differences in the jib angle or load. The operator only needs to push the handle to set the lifting speed as if operating a regular crane, and the speed compensation module will automatically complete the above calculations and adjustments without manual intervention. Compared to adjustment methods that rely solely on height difference feedback, this implementation method can provide more accurate speed commands at the beginning of the lifting process, avoiding initial tilting caused by response lag and making the lifting process of long workpieces more stable.

[0040] In another technical solution, a first rotary encoder is installed on the drum shaft of the first winch, and a second rotary encoder is installed on the drum shaft of the second winch; both the first and second rotary encoders are electrically connected to the input terminal of the controller; the controller is also equipped with a height difference closed-loop adjustment module. The controller reads the first actual released wire rope length L1 collected by the first rotary encoder and the second actual released wire rope length L2 collected by the second rotary encoder; and pre-stores the length L of the first fixed section of the wire rope. 01 Length L of the second fixed section of the steel wire rope 02 The L 01 L 02 This refers to the fixed path length of the wire rope from the winch to the corresponding pulley block. The controller calculates the actual lifting height H1 of the first hook as H1 = (L1 - L 01 )×cosα, calculate the actual lifting height H2 of the second hook: H2 = (L2 - L 02 )×cosβ; The controller calculates the height difference ΔH = H1 - H2; The controller sends the height difference ΔH to the height difference closed-loop control module. The height difference closed-loop control module has a built-in proportional-integral-derivative control algorithm and outputs the speed correction ΔN=K. p ×ΔH+K i ×∫ΔHdt+K d ×d(ΔH) / dt; Where K pFor proportionality coefficient, K i For the integral coefficient, K d These are the differential coefficients; The controller will use the first target rotational speed N calculated by the speed compensation module. 1_target Subtracting the speed correction amount ΔN from the first final speed command, the calculated second target speed N is then used to obtain the first final speed command. 2_target The second final speed command is obtained by adding the speed correction amount ΔN, and then output to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The controller repeats the above reading and calculation steps every 0.05 seconds.

[0041] When using a speed compensation module to feedforward adjust the speeds of the two winches, although relatively accurate speed commands can be pre-programmed based on the boom angle and hook load, ensuring near-synchronous lifting speeds of the two hooks, some factors remain that are difficult to eliminate through feedforward compensation during actual lifting. For example, the wire rope undergoes elastic elongation under load, and the amount of elongation varies with the load; mechanical clearance exists between the winch drum and the reducer, causing a deviation between the actual released wire rope length and the theoretical value; and there are individual differences in the response speed of the hydraulic system. These factors accumulate, causing a slight but continuous deviation in the actual height of the two hooks during lifting, and long workpieces will slowly tilt to one side. While operators can manually correct this, frequent observation and adjustments are required, increasing the operational burden and making it difficult to achieve a completely tilt-free lifting process.

[0042] To eliminate the aforementioned accumulated errors, this embodiment further incorporates closed-loop feedback regulation based on the above scheme. Specifically, a first rotary encoder is installed on the drum shaft of the first winch, and a second rotary encoder is installed on the drum shaft of the second winch. The rotary encoders can be incremental encoders, outputting 1024 to 4096 pulses per revolution. Their housings are fixed to the winch frame via brackets, and their shafts are connected to the drum shafts via flexible couplings. The A and B phase signal lines of the encoder are connected to the high-speed counting input terminal of the controller. The controller calculates the actual number of revolutions the drum has made by counting the pulses, and then, combining this with the drum diameter and the number of layers of wire rope, converts it into the first actual released wire rope length L1 and the second actual released wire rope length L2. The controller simultaneously reads the angle α between the first auxiliary arm and the vertical direction measured by the first tilt sensor and the angle β measured by the second tilt sensor. Since the section of the wire rope from the pulley block to the hook is parallel to the jib, the vertical offset of the hook relative to the top of the jib is negligible. Therefore, the controller pre-stores the length L of the first fixed section of the wire rope. 01 Length L of the second fixed section of the steel wire rope 02(The fixed path length of the wire rope from the winch to the corresponding pulley block), then calculate the actual lifting height H1 of the first hook = (L1 - L 01 )×cosα, the actual lifting height H2 of the second hook is H2=(L2-L 02 The controller calculates the height difference ΔH = H1 - H2 and sends ΔH to the internal height difference closed-loop control module. This module has a built-in proportional-integral-derivative (PID) control algorithm, and its output is the speed correction ΔN, calculated as ΔN = K. p ×ΔH+K i ×∫ΔHdt+K d ×d(ΔH) / dt, where K p K i K d These are coefficients determined in advance through on-site commissioning, for example, K. p 5 revolutions per minute per millimeter, K i 0.1 revolutions per minute per millimeter per second, K d The speed is 0.2 revolutions per minute per millimeter per minute. The controller will use the first target speed N calculated by the speed compensation module. 1_target Subtracting from ΔN yields the first final speed command; the second target speed N is then calculated. 2_target Adding ΔN to the first hoist speed command yields the second final speed command. The reason for subtraction and addition is that when ΔH is positive (i.e., the first hook is higher than the second hook), the speed of the first winch needs to be reduced while the speed of the second winch is increased to decrease the height difference. These two final speed commands are output to the drive mechanisms of the first and second winches, respectively. The controller repeats the steps of reading the encoder, calculating the height difference, and updating the PID output and speed command every 0.05 seconds, forming a fast closed-loop control. Through this real-time feedback adjustment, even if factors such as wire rope elastic deformation and mechanical clearance cause deviations in the height after feedforward compensation, the PID controller can correct them in time, ensuring the height difference always approaches zero. In actual use, operators no longer need to monitor whether the long workpiece is slowly tilting; the controller automatically eliminates accumulated errors, ensuring the workpiece remains horizontal throughout the lifting process.

[0043] In another technical solution, the controller is equipped with an angle optimization module, which determines the target extension length of the first and second variable angle hydraulic cylinders according to the following steps: First, the operator inputs the estimated length L of the workpiece to be hoisted through the control panel. 估 The controller is based on the estimated length L 估 And the fixed geometric parameters of the first and second auxiliary booms, calculate the first initial included angle α0 and the second initial included angle β0, such that the horizontal distance D0 between the two hooks is equal to the estimated length L. 估 The difference is within the preset difference range; The controller controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to unlock, drives the first variable angle hydraulic cylinder and the second variable angle hydraulic cylinder to move, so that the first auxiliary arm and the second auxiliary arm reach the first initial included angle α0 and the second initial included angle β0 respectively, and then controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to lock. The operator controls the first and second winches to lower the wire rope, attaches the first hook and the second hook to the two ends of the workpiece to be lifted, and then controls the first and second winches to slowly lift the workpiece to tighten the wire rope. The controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load ratio R=F1 / F2, and compares the load ratio R with the preset load ratio threshold range. When the load ratio R exceeds the preset load ratio threshold range, the angle optimization module iteratively adjusts according to the following rules: The controller first unlocks the first and second bidirectional hydraulic locks, and then performs the angle adjustment action: when R is greater than the upper limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously reduce the angle α between the first auxiliary arm and the vertical direction and the angle β between the second auxiliary arm and the vertical direction, so as to reduce the horizontal distance between the two hooks. When R is less than the lower limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously increase the included angle α and included angle β to increase the horizontal distance between the two hooks. After each adjustment, the controller controls the first and second bidirectional hydraulic locks to lock, the controller rereads the load ratio R and compares it with the preset load ratio threshold range, and repeats the above iterative adjustment process until the load ratio R falls within the preset load ratio threshold range, the controller stops adjusting and maintains the current angle; The controller repeats the above read and compare steps every 0.2 seconds.

[0044] When adjusting the angle between the two auxiliary booms using the aforementioned method, the operator needs to manually input the estimated length of the workpiece to be lifted via the control panel. The controller then calculates the initial angle between the two auxiliary booms and drives the variable-angle hydraulic cylinder to that position. However, in actual use, it has been found that due to potential issues such as workpiece bending, uneven wall thickness, or asymmetrical internal rib distribution, the actual center of gravity often deviates from the theoretical center of gravity. Even if the horizontal distance between the two hooks is roughly matched to the workpiece length, the load borne by the two hooks after lifting may still differ significantly, causing the workpiece to tilt severely to the heavier side. In this case, the operator can only lower the workpiece back down, manually adjust the angle between the two auxiliary booms, and then lift it again to observe the load. This process of repeated trial lifting is necessary to barely achieve a near-balanced load on the two hooks. This trial lifting process is not only inefficient but also highly dependent on the operator's experience. Inexperienced operators often need to attempt the process many times and may even be unable to adjust the load to an acceptable range.

[0045] To automatically resolve the aforementioned uneven load issue, this implementation adds an angle optimization module to the controller. This module automatically determines the optimal extension length of the two variable-angle hydraulic cylinders according to the following steps. First, the operator inputs the estimated length L of the workpiece to be lifted via the control panel, for example, 9.5 meters via the numeric keypad. Based on the estimated length and the fixed geometric parameters of the first and second auxiliary booms (such as boom length, hinge point position, etc.), the controller calculates the first initial angle α0 and the second initial angle β0, ensuring that the difference between the horizontal distance D0 between the two hooks and the estimated length L is within a preset range, for example, ±100 mm. Subsequently, the controller unlocks the first and second bidirectional hydraulic locks, driving the first and second variable-angle hydraulic cylinders to move, causing the first and second auxiliary booms to reach the first initial angle α0 and the second initial angle β0 respectively, and then re-locks the bidirectional hydraulic locks. The operator controls the first and second winches to lower the wire ropes, attaching the first and second hooks to the ends of the workpiece to be lifted, respectively. The crane is then slowly raised until the wire ropes are just taut but the workpiece is not yet off the ground. At this point, the controller reads the load value F1 of the first hook collected by the first pressure sensor and the load value F2 of the second hook collected by the second pressure sensor, and calculates the load ratio R = F1 / F2. The controller has a preset load ratio threshold range, for example, between 0.95 and 1.05. If R falls within this range, it indicates that the loads on the two hooks are basically balanced, and no adjustment is needed. If R exceeds this range, an iterative adjustment process begins. When R is greater than 1.05, it indicates that the first hook is overloaded, and the horizontal distance between the two hooks needs to be reduced to bring the lifting point closer to the workpiece's center of gravity. Therefore, the controller controls the two variable-angle hydraulic cylinders to simultaneously reduce the angle α between the first auxiliary boom and the vertical direction and the angle β between the second auxiliary boom and the vertical direction, thereby reducing the horizontal distance between the two hooks. When R is less than 0.95, it indicates that the second hook is overloaded, requiring an increase in the horizontal distance between the two hooks. Therefore, the controller controls two variable-angle hydraulic cylinders to simultaneously increase the included angles α and β, thereby increasing the horizontal distance between the two hooks. The adjustment step can be set to a change of 1 to 2 degrees in the included angle. After adjustment, the controller re-locks the bidirectional hydraulic lock, rereads the load ratio R, and compares it with the threshold range. This process is repeated iteratively, with the load ratio R approaching 1.0 after each adjustment, until R falls within the range of 0.95 to 1.05. At this point, the controller stops adjusting and maintains the current included angle. The controller repeats the reading and comparison steps every 0.2 seconds to ensure all adjustments are completed before lifting. Through this automatic optimization process, repeated manual trial lifting is unnecessary. The load on the two hooks can be adjusted to a basically balanced state before lifting, preventing significant unilateral overload tilting after the workpiece is lifted, greatly improving lifting efficiency and safety. The operator only needs to input the approximate length of the workpiece and attach the hooks; the remaining adjustments are completed automatically by the controller.

[0046] In another technical solution, the lower end of the main boom is hinged to the slewing platform via a ball joint. The slewing platform is also equipped with a first luffing cylinder and a second luffing cylinder, the cylinder bodies of which are respectively hinged to the left and right sides of the slewing platform. The first and second luffing cylinders are respectively equipped with a third and a fourth bidirectional hydraulic lock, as well as a first and a second proportional flow valve. The third and fourth bidirectional hydraulic locks, the first and second proportional flow valves are all electrically connected to the hydraulic system and the controller. The slewing platform is also equipped with a lateral tilt sensor for detecting the lateral tilt angle of the main boom, and the lateral tilt sensor is electrically connected to the input of the controller. The controller contains a main boom attitude adjustment module.

[0047] The lower end of the main boom is connected to the slewing platform via a ball joint. The diameter of the ball head in the ball joint can be selected from 80 mm to 150 mm, and the ball seat material can be 40Cr steel or 42CrMo steel, with a surface hardened to improve wear resistance. The clearance between the ball head and the ball seat can be controlled between 0.05 mm and 0.15 mm, and the ball joint can be filled with grease. During assembly, the ball head is fixed to the lower end of the main boom, and the ball seat is mounted on a bracket on the slewing platform, allowing the main boom to swing freely around the center of the ball joint in the forward and backward and left and right directions. The lateral swing range can be set to ±5 degrees to ±10 degrees. The slewing platform is also equipped with a first luffing cylinder and a second luffing cylinder. The cylinder diameters of the two cylinders can be selected from 50 mm to 100 mm, the piston rod diameter can be selected from 25 mm to 56 mm, and the working pressure can be set from 16 MPa to 21 MPa. The tail ends of the two hydraulic cylinders are hinged to the left and right lugs on the slewing platform via pins. The horizontal distance between the hinge point and the lower hinge point (ball joint center) of the main boom can be selected from 500 mm to 1200 mm. The piston rod ends of the hydraulic cylinders are hinged to the lower middle lugs on both sides of the main boom via spherical joints. The hinge points of the two hydraulic cylinders are at the same height on the main boom. The stroke of the hydraulic cylinders can be selected from 150 mm to 300 mm, so that when the main boom swings laterally, one cylinder can extend and the other can retract, and the absolute values ​​of the extension and retraction are equal.

[0048] Near the rodless and rod-side ports of the first and second luffing cylinders, respectively, are installed a third and a fourth two-way hydraulic lock. Each two-way hydraulic lock can be a valve block integrating two hydraulically controlled check valves. Its two outlet ports are connected to the two chambers of the corresponding cylinder via high-pressure hoses, and its two inlets are connected to the supply and return lines of the hydraulic system, respectively. The control terminal (solenoid pilot valve) of each two-way hydraulic lock is electrically connected to the digital output terminal of the controller via a cable. It can unlock when the controller outputs a 24V DC voltage and automatically locks when the power is off. Between each two-way hydraulic lock and the cylinder, or on the inlet side of the two-way hydraulic lock, a first proportional flow valve and a second proportional flow valve are also provided. The proportional flow valve can be an electro-hydraulic proportional throttle valve or a proportional directional valve, with an input signal of 4 to 20 mA current or 0 to 10V voltage. The rated flow rate of the valve can be selected from 30 liters per minute to 80 liters per minute. The coil of the proportional flow valve is electrically connected to the analog output terminal of the controller. All hydraulic valves are mounted on the hydraulic valve assembly block of the rotary platform, and the valve body material can be ductile iron. The main hydraulic circuit, after being drawn from the hydraulic pump, passes through a filter and a relief valve, and then supplies two proportional flow valves. The outlet of the proportional flow valves then enters the cylinder via a two-way hydraulic lock. During operation, the controller adjusts the flow rate into the cylinder by changing the opening command of the proportional flow valves, thereby controlling the cylinder's extension and retraction speed. The two-way hydraulic lock automatically maintains the cylinder position when the controller does not issue an unlocking signal, preventing the cylinder from retracting or extending due to external force.

[0049] A lateral tilt sensor is installed on the upper surface of the slewing platform near the lower hinge point of the boom. This sensor can be a MEMS dual-axis tilt sensor, with a measurement range selectable between ±15 degrees and ±30 degrees. The output signal is 4 to 20 mA current, and the resolution can reach 0.05 degrees. The sensor's sensitive axis is parallel to the lateral (left-right) direction of the slewing platform, and its mounting plane needs to be leveled. The signal line of the lateral tilt sensor is connected to the analog input terminal of the controller. The controller internally includes a boom attitude adjustment module, which can be a software function block. This module reads the boom lateral tilt angle γ collected by the lateral tilt sensor every 0.1 seconds, and simultaneously reads the hook load values ​​collected by the first and second pressure sensors. The boom attitude adjustment module calculates the target lateral tilt angle γ based on the load difference ΔF (F1 minus F2). target =k×ΔF, where k is a preset scaling factor, which can be taken as 0.002 (° / N) to 0.005 (° / N). The module will... targetThe deviation e is obtained by comparing the current γ with the actual γ. Then, the differential flow adjustment Q is calculated using the built-in proportional-integral (PI) control algorithm. This Q value determines the flow difference between the first and second luffing cylinders. Based on the Q value, the controller outputs opening commands to the first and second proportional flow valves respectively, causing one cylinder to extend its oil inlet and the other cylinder to shorten its oil outlet. This drives the boom to swing around the ball joint towards the side with the heavier load until the deviation between the actual lateral tilt angle and the target lateral tilt angle is less than a preset threshold (e.g., ±0.1 degrees). The entire process continues in a closed-loop manner, ensuring that the boom can actively adjust its lateral tilt angle under any unbalanced load conditions, bringing the boom axis close to the direction of the net external force.

[0050] The main boom has lateral swing freedom through the ball joint. Combined with the two luffing cylinders on the left and right, the proportional flow valve, the two-way hydraulic lock, the lateral tilt angle sensor and the main boom attitude adjustment module, the lateral tilt angle of the main boom can be actively adjusted. This converts the additional bending moment caused by the unbalanced load of the two hooks into axial pressure on the main boom, reduces the bending stress inside the main boom and improves the structural life of the main boom.

[0051] In another technical solution, the main arm attitude adjustment module adjusts the lateral attitude of the main arm according to the following steps: First, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load difference ΔF=F1-F2, and at the same time reads the boom lateral tilt angle γ collected by the lateral tilt angle sensor. Then, the main boom attitude adjustment module calculates the target lateral tilt angle γ based on the load difference ΔF. target =k×ΔF, where k is a preset proportionality coefficient, and its value ranges from 0.001 to 0.01 (° / N); γ target The positive and negative directions correspond to the swing direction of the main arm towards the first / second auxiliary arm side. A negative value corresponds to the swing of the main arm towards the second auxiliary arm side, ensuring that the main arm swings towards the side with the heavier load. The main arm attitude adjustment module sets the target lateral tilt angle γ. target Comparing it with the current lateral tilt angle γ, the tilt deviation e = γ is obtained. target -γ; The boom attitude adjustment module incorporates a proportional-integral control algorithm, which calculates the differential flow adjustment Q=K between the first and second luffing cylinders based on the tilt angle deviation e. p' ×e+K i' ×∫edt; Among them, K p' For proportionality coefficient, K i' The integral coefficient; The controller controls the proportional flow valves of the first and second luffing cylinders respectively based on the differential flow adjustment Q, causing the extension lengths of the first and second luffing cylinders to change slightly in opposite directions. Specifically, one cylinder extends while the other shortens, driving the boom to swing around the ball joint towards the side with the heavier load until the lateral tilt angle γ of the boom matches the target lateral tilt angle γ. target The deviation is less than the preset threshold; The controller repeats the above reading and calculation steps every 0.1 seconds.

[0052] After adjusting the angle between the two auxiliary booms and synchronizing the hook height using the aforementioned method, when the loads on the two hooks are unbalanced, the top of the main boom will experience an asymmetrical resultant force from the two auxiliary booms. Because traditional lifting devices typically use a simple single-axis hinge between the lower end of the main boom and the slewing platform, the main boom can only luff in the forward and backward direction, and cannot swing laterally in the left and right direction. Therefore, this asymmetrical resultant force will generate additional bending moments and torsional stresses inside the main boom, which may lead to fatigue cracking of the main boom after long-term use. Increasing the cross-section of the main boom to enhance its bending resistance would significantly increase the overall weight and manufacturing cost.

[0053] To address this issue, this embodiment, based on the aforementioned structure, further implements active lateral attitude control through a main boom attitude adjustment module. The specific adjustment steps are as follows: First, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculating the load difference ΔF = F1 - F2. Simultaneously, the controller reads the current lateral tilt angle γ of the main boom collected by the lateral tilt angle sensor mounted on the slewing platform (with the main boom swinging to the right as the positive direction). Then, the main boom attitude adjustment module calculates the target lateral tilt angle γ based on the load difference ΔF. target =k×ΔF, where k is a preset proportionality coefficient, which can take values ​​between 0.001 and 0.01 (° / N), for example, 0.003° / N. This formula ensures that the boom swings towards the side with the heavier load, that is, when F1 is greater than F2, γ target If positive, the main arm swings towards the first auxiliary arm (right side). The module tilts the target laterally at an angle γ. target Comparing it with the current lateral tilt angle γ, the tilt deviation e = γ is obtained. target -γ. Next, the boom attitude adjustment module incorporates a proportional-integral (PI) control algorithm to calculate the differential flow adjustment Q=K between the first and second luffing cylinders based on the tilt angle deviation e. p' ×e+K i' ×∫edt, where K p' and K i' For preset coefficients, such as K p' 10 L / (min·°) can be taken, K i'A value of 2 L / (min·°·s) can be used. This Q value represents the additional flow rate required to supply one cylinder (while the other cylinder decreases by the same amount). Based on the Q value, the controller outputs opening commands to the first and second proportional flow valves, increasing the oil intake of one cylinder and decreasing the oil intake of the other, thus producing opposite extension / retraction actions: for example, when swinging to the right, the first luffing cylinder extends while the second luffing cylinder shortens. The absolute values ​​of the changes in extension / retraction length of the two cylinders are equal, driving the boom to slowly swing around the ball joint towards the side with the heavier load. During the swing, the lateral tilt angle sensor provides real-time feedback of the current tilt angle γ. The controller repeats the steps of reading the load, calculating the target tilt angle, solving for the deviation, and updating the differential flow rate every 0.1 seconds, forming a closed-loop regulation. When the lateral tilt angle γ of the boom is equal to the target lateral tilt angle γ... target When the deviation is less than a preset threshold (e.g., ±0.1 degrees), the adjustment stops, and the main boom maintains this posture. In this way, the axis of the main boom always points in the direction of the resultant external force, transforming the asymmetric resultant force that would normally cause the main boom to bend into compressive stress along the axis of the main boom. Because the compressive strength of the main boom material (such as high-strength structural steel) is much higher than its bending strength, and the compressive stress is evenly distributed, the main boom can withstand large unbalanced loads without additional reinforcement, effectively avoiding the risk of bending fatigue cracking, while also reducing the overall weight of the machine. The entire adjustment process is automatic, requiring no operator intervention.

[0054] In another technical solution, a first displacement sensor and a second displacement sensor for detecting the extension length of the cylinder are respectively installed on the first and second luffing cylinders; the rod-side and rodless-side chambers of the first and second luffing cylinders are respectively connected to a first pressure detection port and a second pressure detection port, and a first cavity pressure sensor and a second cavity pressure sensor are respectively installed on the first and second pressure detection ports; the first cavity pressure sensor, the second cavity pressure sensor, the first displacement sensor, and the second displacement sensor are all electrically connected to the input terminal of the controller; the controller is also equipped with a flow feedforward compensation module; when the controller controls the proportional flow valves of the first and second luffing cylinders according to the differential flow adjustment amount Q, the following steps are performed: Step 1: The controller reads the current lateral tilt angle γ of the main boom collected by the lateral tilt angle sensor, and reads the current length S1 of the first cylinder collected by the first displacement sensor and the current length S2 of the second cylinder collected by the second displacement sensor; Step 2: Based on the tilt deviation e output by the boom attitude adjustment module, the controller calculates the desired lateral swing angular velocity ω=K of the boom using a proportional-integral control algorithm. ω ×e, where K ω This is the preset angular velocity proportionality coefficient; Step 3: Based on the rotational geometry of the boom around the ball joint, and under the lateral attitude adjustment condition where the boom's forward and backward luffing angle remains constant, the controller calculates the desired extension / retraction speed v of the first luffing cylinder using the current boom tilt angle γ, the length of the first cylinder S1, and the length of the second cylinder S2. 1_exp The expected extension / retraction speed v of the second variable amplitude cylinder 2_exp , where v 1_exp =-v 2_exp , and v 1_exp The relationship with ω is determined by the instantaneous kinematic Jacobian matrix of the ball joint and the hydraulic cylinder hinge point; Step 4: The controller reads the rod chamber pressure P of the first cylinder collected by the first chamber pressure sensor. 1_rod and rodless chamber pressure P 1_cap Read the pressure P in the rod chamber of the second cylinder collected by the second chamber pressure sensor. 2_rod and rodless chamber pressure P 2_cap The flow feedforward compensation module calculates the desired extension / retraction speed v of the first hydraulic cylinder. 1_exp Piston area A of the hydraulic cylinder cap and piston rod area A rod Calculate the desired flow rate Q required by the proportional flow valve of the first hydraulic cylinder. 1_exp =|v 1_exp |×(when v 1_exp >0 is A cap When v 1_exp <0 is A rod Simultaneously calculate the valve port pressure difference ΔP1 = |P_sup>1 of the proportional flow valve of the first cylinder. 1_cap -P 1_rod |; Step 5: The flow feedforward compensation module uses the flow-pressure difference characteristic curve function f(Q,ΔP) of the proportional flow valve of the first oil cylinder to solve for the desired flow rate Q. 1_exp Required proportional flow valve opening command U1=f -1 (Q 1_exp Similarly, based on the desired extension / retraction speed v of the second cylinder... 2_exp Calculate the expected flow Q 2_exp Given the pressure difference ΔP2 at the valve orifice, the opening command U2=f is obtained by inverse solving. -1 (Q 2_exp ,ΔP2); Step 6: The controller outputs opening commands U1 and U2 to the proportional flow valves of the first and second luffing cylinders respectively, driving the first and second luffing cylinders to extend and retract at the desired speed; the controller reads the first and second displacement sensors every 0.05 seconds, compares the actual cylinder length with the desired length, and fine-tunes the opening commands U1 and U2 using a PID algorithm.

[0055] When using the above-mentioned boom attitude adjustment scheme, the controller directly calculates the differential flow adjustment amount Q based on the tilt angle deviation e using a proportional-integral algorithm, and outputs opening commands to the two proportional flow valves accordingly. However, in actual operation, it was found that the two luffing cylinders are in a pushing and pulling state during differential adjustment, and the load pressure they bear is very different. The actual flow rate of the proportional flow valve depends not only on the valve opening, but also on the significant influence of the pressure difference across the valve. Under the same opening command, a larger pressure difference results in a larger flow rate, and a smaller pressure difference results in a smaller flow rate. Because the load pressures of the two cylinders are different, the pressure difference between the valves of the two proportional flow valves is also different. Therefore, even if the controller outputs the same opening command to the two valves, the actual flow rate through the two cylinders will be inconsistent, causing the extension and retraction speed of one cylinder to deviate from the expected value, resulting in unstable lateral swing speed of the boom, which is prone to impact or vibration, and in severe cases, may even cause pressure oscillation in the hydraulic system.

[0056] To eliminate the nonlinearity of flow caused by the difference in load pressure, this embodiment further adds a flow feedforward compensation module to the existing structure and performs precise control according to the following steps. First, a first displacement sensor and a second displacement sensor are installed on the first and second luffing cylinders respectively to detect the extension length of the cylinders. The displacement sensors can be magnetostrictive displacement sensors or wire-type displacement sensors, with a measurement accuracy of 0.1 mm. Their signal lines are connected to the analog input terminal of the controller. Simultaneously, a first pressure detection port and a second pressure detection port are set near the oil ports of the rod chamber and rodless chamber of the two cylinders respectively, and a first cavity pressure sensor and a second cavity pressure sensor are installed. The cavity pressure sensors can be strain gauge pressure sensors, with a range selectable from 0 to 25 MPa, and outputting a current signal of 4 to 20 mA. All sensor signals are connected to the controller. The controller has a flow feedforward compensation module inside, which operates according to the following steps: Step 1: The controller reads the current lateral tilt angle γ of the main boom collected by the lateral tilt angle sensor, and reads the current length S1 of the first cylinder collected by the first displacement sensor and the current length S2 of the second cylinder collected by the second displacement sensor. Step 2: Based on the tilt deviation e output by the boom attitude adjustment module, the controller calculates the desired lateral swing angular velocity ω=K of the boom using a proportional-integral control algorithm. ω ×e, where K ω The preset angular velocity proportionality coefficient can be, for example, 0.5 (rad / s) / °. Step 3: Based on the rotational geometry of the boom around the ball joint, and under the lateral attitude adjustment condition where the boom's forward and backward luffing angle remains unchanged, the controller calculates the desired extension / retraction speed v of the first luffing cylinder using the current boom tilt angle γ, the length of the first cylinder S1, and the length of the second cylinder S2. 1_exp The expected extension / retraction speed v of the second variable amplitude cylinder 2_expBecause the extension and retraction movements of the two cylinders are completely opposite, there is v 1_exp =-v 2_exp , and v 1_exp The relationship with ω is determined by the instantaneous kinematic Jacobian matrix of the ball joint and the cylinder hinge point (this matrix can be pre-calibrated according to the installation dimensions of the boom and cylinder). Step 4: The controller reads the rod chamber pressure P of the first cylinder collected by the first chamber pressure sensor. 1_rod and rodless chamber pressure P 1_cap And the corresponding pressure P of the second cylinder. 2_rod and P 2_cap The flow feedforward compensation module calculates the desired extension / retraction speed v of the first hydraulic cylinder. 1_exp Piston area A of the hydraulic cylinder cap and piston rod area A rod Calculate the desired flow rate Q required by the proportional flow valve of the first hydraulic cylinder. 1_exp . Specifically, when v 1_exp When the cylinder is in the positive (elongation) position, oil enters the rodless chamber, and the required flow rate is |v. 1_exp |×A cap When v 1_exp When the value is negative (shortened), oil enters the rod chamber, and the required flow rate is |v. 1_exp |×A rod Simultaneously calculate the valve port pressure difference ΔP1 = |P_c| of the proportional flow valve of the first cylinder. 1_cap -P 1_rod Step 5: The flow feedforward compensation module uses the flow-pressure difference characteristic curve function f(Q,ΔP) of the proportional flow valve of the first cylinder to solve for the desired flow rate Q. 1_exp Required proportional flow valve opening command U1=f -1 (Q 1_exp ,ΔP1). This characteristic curve can be obtained through factory calibration and is usually expressed as Inverse solution Similarly, based on the desired extension / retraction speed v of the second hydraulic cylinder... 2_exp Calculate the expected flow Q 2_expThe valve pressure difference ΔP2 is used to inversely solve for the opening command U2. Step Six: The controller outputs the opening commands U1 and U2 to the proportional flow valves of the first and second luffing cylinders, respectively, driving the two cylinders to extend and retract at the desired speed. Simultaneously, the controller reads the first and second displacement sensors every 0.05 seconds, comparing the actual cylinder length with the desired length, and fine-tunes the opening commands U1 and U2 using a PID algorithm to eliminate modeling errors and external interference. Through this flow feedforward compensation, the actual extension and retraction speed of the two cylinders can accurately follow the desired speed, resulting in smooth and shock-free lateral boom swing, even when there are large differences in load pressure. The operator can clearly feel the smoothness of the boom posture adjustment process, and the hydraulic system pressure no longer fluctuates drastically.

[0057] In another technical solution, the controller also includes a collaborative disturbance rejection adjustment module. This module contains a first PID calculation unit and a second PID calculation unit. When the collaborative disturbance rejection adjustment module performs fine-tuning corrections on the opening commands U1 and U2 using the PID algorithm, it follows these steps: Step A: The controller reads the current length S1 of the first hydraulic cylinder collected by the first displacement sensor and the current length S2 of the second hydraulic cylinder collected by the second displacement sensor, and reads the desired lateral tilt angle γ of the main boom output by the main boom attitude adjustment module. target And the current boom lateral tilt angle γ collected by the lateral tilt sensor; Step B: Based on the kinematic geometry of the main boom around the ball joint, the collaborative disturbance rejection module adjusts the desired lateral tilt angle γ of the main boom under the condition that the forward and backward amplitude angle of the main boom remains unchanged. target The desired length S converted to the first hydraulic cylinder 1_ref The expected length S of the second cylinder 2_ref S 1_ref With S 2_ref Satisfy S 1_ref +S 2_ref = constant C, where constant C is the sum of the lengths of the two cylinders in their initial installation positions; Step C: The collaborative disturbance rejection adjustment module calculates the length deviation e1=S of the first hydraulic cylinder. 1_ref -S1, the length deviation of the second cylinder e2=S 2_ref -S2, and calculate the common mode deviation e sum =e1+e2 and differential mode deviation e diff =e1-e2; Step D: The collaborative disturbance rejection adjustment module will adjust the common mode deviation e sum Input to the first PID calculation unit, output common mode correction ΔU sum =K p_sum ×e sum +Ki_sum ×∫e sum dt+K d_sum ×d(e sum ) / dt; The differential mode deviation e diff Input to the second PID calculation unit, output differential mode correction ΔU diff =K p_diff ×e diff +K i_diff ×∫e diff dt+K d_diff ×d(e diff ) / dt; Step E: The collaborative disturbance rejection adjustment module calculates the opening correction ΔU acting on the first proportional flow valve based on the common-mode correction and differential-mode correction. 1_corr =(ΔU sum +ΔU diff ) / 2, and the opening correction ΔU acting on the second proportional flow valve. 2_corr =(ΔU sum -ΔU diff ) / 2; Step F: The controller combines the opening command U1 output by the flow feedforward compensation module with the opening correction amount ΔU. 1_corr Add them together to obtain the first final opening instruction U. 1_final =U1+ΔU 1_corr ; Compare U2 with ΔU 2_corr Adding them together, we get the second final opening instruction U. 2_final =U2+ΔU 2_corr ; proportional flow valves that output to the first and second luffing cylinders respectively; Step G: The collaborative disturbance rejection adjustment module repeats steps A to F every 0.02 seconds, and limits the integral terms of the first PID calculation unit and the second PID calculation unit during each execution to prevent integral saturation.

[0058] When using a flow feedforward compensation and independent PID fine-tuning scheme, the extension and retraction speeds of the two cylinders can follow the desired value quite well. However, in actual operation, it was found that due to the strong mechanical coupling between the two luffing cylinders through the boom and ball joint (the extension of one cylinder inevitably leads to the shortening of the other, and the sum of their lengths is basically constant), coupled with the pressure coupling between the rod-side and rodless sides of the two cylinders in the hydraulic system, if the opening commands of the two cylinders are independently corrected by PID, the two correction values ​​often conflict with each other. For example, when the actual length of the first cylinder is too long, its independent PID controller will output a correction value that reduces the opening, attempting to retract the first cylinder; while the second cylinder, due to its short length, will output a correction value that increases the opening, attempting to extend the second cylinder. These two correction commands, acting on the coupled mechanical system, cause repeated "chasing" oscillations in the lateral swing of the boom, manifested as the boom shaking back and forth near the target position, unable to converge for a long time, and in severe cases, even causing pressure shocks in the hydraulic system.

[0059] To eliminate this coupled oscillation, this embodiment further incorporates a cooperative disturbance rejection adjustment module within the controller, building upon the aforementioned structure. This module contains a first PID calculation unit and a second PID calculation unit, and is corrected according to the following decoupling steps. First, the controller reads the current length S1 of the first cylinder collected by the first displacement sensor and the current length S2 of the second cylinder collected by the second displacement sensor, while simultaneously reading the desired boom tilt angle γ output by the boom attitude adjustment module. target And the current main boom lateral tilt angle γ collected by the lateral tilt angle sensor. Based on the motion geometry of the main boom around the ball joint, the collaborative disturbance rejection adjustment module adjusts the desired main boom lateral tilt angle γ under the condition that the main boom's forward and backward amplitude angle remains constant during lateral attitude adjustment. target The desired length S converted to the first hydraulic cylinder 1_ref The expected length S of the second cylinder 2_ref Since the two cylinders are structurally designed such that one extends while the other shortens, and the sum of the lengths of the two cylinders is a constant C during initial installation, therefore S 1_ref With S 2_ref Satisfy S 1_ref +S 2_ref =C. Next, the module calculates the length deviation e1=S of the first hydraulic cylinder. 1_ref -S1, the length deviation of the second cylinder e2=S 2_ref -S2. To decouple the coupled bias, the module further calculates the common-mode bias e. sum =e1+e2 and differential mode deviation e diff=e1-e2. Wherein, the common-mode deviation reflects the drift in the total length of the two cylinders (usually caused by oil leakage or installation errors), and the differential-mode deviation reflects the angular error of the main boom's lateral swing. Then, the common-mode deviation e sum Input to the first PID calculation unit, output common mode correction ΔU sum =K p_sum ×e sum +K i_sum ×∫e sum dt+K d_sum ×d(e sum ) / dt; The differential mode deviation e diff Input to the second PID calculation unit, output differential mode correction ΔU diff =K p_diff ×e diff +K i_diff ×∫e diff dt+K d_diff ×d(e diff The coefficients of the two PID units can be set according to the on-site debugging. For example, Kp_sum can be 0.5, K... i_sum 0.1 can be taken, K d_sum 0.05 is acceptable; K p_diff 1.0, K can be selected. i_diff 0.2 can be taken, K d_diff A value of 0.1 can be taken. After obtaining the common-mode and differential-mode corrections, the module uses a linear transformation to solve for the opening correction ΔU acting on the first proportional flow valve. 1_corr =(ΔU sum +ΔU diff ) / 2, and the opening correction ΔU acting on the second proportional flow valve. 2_corr =(ΔU sum -ΔU diff ) / 2. Finally, the controller will input the opening command U1 from the flow feedforward compensation module and ΔU 1_corr Add them together to obtain the first final opening instruction U. 1_final ; Compare U2 with ΔU 2_corr Adding them together, we get the second final opening instruction U. 2_final The outputs are sent to two proportional flow valves. The above calculations are repeated every 0.02 seconds, and the integral terms of the two PID units are limited to prevent integral saturation. Through this common-mode-differential-mode decoupling control, the correction commands of the two cylinders no longer conflict: the common-mode PID is responsible for maintaining the stability of the total length of the two cylinders, while the differential-mode PID is responsible for eliminating the lateral swing angle error; both are adjusted independently. In actual use, the boom can quickly stabilize at the target position after the lateral swing adjustment ends, without any back-and-forth shaking or oscillation. The hydraulic system pressure also remains stable, and the operator can clearly feel the crispness and smoothness of the boom posture adjustment.

[0060] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A tracked double-arm lifting device, comprising a tracked chassis, a slewing platform mounted on the tracked chassis, and a main arm hinged at its lower end to the slewing platform, characterized in that, A Y-shaped connector is fixed to the top of the main arm. The Y-shaped connector has a first connecting end and a second connecting end. The lower end of the first auxiliary arm is hinged to the first connecting end, and the lower end of the second auxiliary arm is hinged to the second connecting end. A first angle adjustment and locking mechanism is provided between the Y-type connecting seat and the first auxiliary arm, and a second angle adjustment and locking mechanism is provided between the Y-type connecting seat and the second auxiliary arm. The first angle adjustment and locking mechanism and the second angle adjustment and locking mechanism are respectively used to adjust and lock the included angle of the first auxiliary arm and the second auxiliary arm relative to the Y-type connecting seat. The first auxiliary boom is equipped with a first pulley group, and the second auxiliary boom is equipped with a second pulley group. Both the first pulley group and the second pulley group are fixed pulley groups. The slewing platform is equipped with a first winch and a second winch. The first winch is wound with a first wire rope, which passes through a first pulley block and is connected to a first hook. The second winch is wound with a second wire rope, which passes through a second pulley block and is connected to a second hook. The first winch and the second winch are controlled and operated independently, driving the first wire rope and the second wire rope to be wound and released independently, so that the first hook and the second hook can obtain independent height positions in the lifting direction.

2. A tracked double-arm lifting device according to claim 1, characterized in that, The slewing platform is also equipped with a controller, and the first angle adjustment and locking mechanism and the second angle adjustment and locking mechanism are respectively the first angle-changing hydraulic cylinder and the second angle-changing hydraulic cylinder; The cylinder bodies of the first and second variable angle hydraulic cylinders are both hinged to the Y-type connecting seat, and the piston rods of the first and second variable angle hydraulic cylinders are respectively hinged to the middle of the first and second auxiliary arms. The first and second variable angle hydraulic cylinders are respectively equipped with a first two-way hydraulic lock and a second two-way hydraulic lock. The two oil outlets of the first and second two-way hydraulic locks are respectively connected to the rod chamber and rodless chamber of the corresponding variable angle hydraulic cylinder, and the two oil inlets are respectively connected to the oil inlet and oil return circuit of the hydraulic system. The control terminals of the first and second two-way hydraulic locks are electrically connected to the controller, and can be unlocked and locked in a controlled manner. The first and second auxiliary booms are respectively equipped with a first tilt sensor and a second tilt sensor; the first and second hooks are respectively equipped with a first pressure sensor and a second pressure sensor. The first tilt sensor, the second tilt sensor, the first pressure sensor, and the second pressure sensor are all electrically connected to the input terminal of the controller, and the output terminal of the controller is respectively connected to the drive mechanism of the first winch and the drive mechanism of the second winch. The controller calculates the speed adjustment amount of the first winch and the second winch based on the auxiliary boom angle signal fed back by the first tilt sensor and the second tilt sensor, as well as the hook load signal fed back by the first pressure sensor and the second pressure sensor. The controller then outputs speed adjustment commands to the drive mechanisms of the first winch and the second winch, respectively, so that the height difference between the first hook and the second hook during the lifting process is kept within the allowable range.

3. A tracked double-arm lifting device according to claim 2, characterized in that, The controller is equipped with a speed compensation module, which calculates the speed adjustment of the first and second winches according to the following steps: First, the controller reads the angle α between the first secondary arm and the vertical direction collected by the first tilt sensor, and reads the angle β between the second secondary arm and the vertical direction collected by the second tilt sensor; Then, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor; the controller sends the included angle α, included angle β, the first hook load value F1 and the second hook load value F2 to the speed compensation module; The speed compensation module calculates the first linear velocity compensation coefficient K1=cosα and the second linear velocity compensation coefficient K2=cosβ; The speed compensation module calculates the first speed reference value N. 1_base When F1≥F min At that time, N 1_base =N0×(F1+F2) / (2×F1), when F1 <F min At that time, N 1_base =N0; Second speed reference value N 2_base When F2≥F mi When n, N 2_base =N0×(F1+F2) / (2×F2), when F2 <F min At that time, N 2_base =N0; where N0 is the winch reference speed corresponding to the target lifting speed given by the operating handle; F min The preset minimum load threshold is not less than 0.5% of the rated lifting capacity; The speed compensation module sets the first target rotational speed to N. 1_target =N 1_base / K1, the second target rotational speed is set to N. 2_targe t=N 2_base / K2; The speed compensation module takes the difference between the first target speed and the current speed of the first winch as the first speed adjustment amount, and takes the difference between the second target speed and the current speed of the second winch as the second speed adjustment amount, and outputs them to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The speed compensation module recalculates α, β, F1, and F2 every 0.1 seconds and updates the first and second speed adjustment values.

4. A tracked double-arm lifting device according to claim 3, characterized in that, The first winch is equipped with a first rotary encoder on its drum shaft, and the second winch is equipped with a second rotary encoder on its drum shaft; both the first and second rotary encoders are electrically connected to the input terminal of the controller; the controller is also equipped with a height difference closed-loop adjustment module. The controller reads the first actual released wire rope length L1 collected by the first rotary encoder and the second actual released wire rope length L2 collected by the second rotary encoder; and pre-stores the length L of the first fixed section of the wire rope. 01 Length L of the second fixed section of the steel wire rope 02 The L 01 L 02 This refers to the fixed path length of the wire rope from the winch to the corresponding pulley block. The controller calculates the actual lifting height H1 of the first hook as H1 = (L1 - L 01 )×cosα, calculate the actual lifting height H2 of the second hook: H2 = (L2 - L 02 )×cosβ; The controller calculates the height difference ΔH = H1 - H2; The controller sends the height difference ΔH to the height difference closed-loop control module. The height difference closed-loop control module has a built-in proportional-integral-derivative control algorithm and outputs the speed correction ΔN=K. p ×ΔH+K i ×∫ΔHdt+K d ×d(ΔH) / dt; Where K p For proportionality coefficient, K i For the integral coefficient, K d These are the differential coefficients; The controller will use the first target rotational speed N calculated by the speed compensation module. 1_target Subtracting the speed correction amount ΔN from the first final speed command, the calculated second target speed N is then used to obtain the first final speed command. 2_target The second final speed command is obtained by adding the speed correction amount ΔN, and then output to the drive mechanism of the first winch and the drive mechanism of the second winch respectively. The controller repeats the above reading and calculation steps every 0.05 seconds.

5. A tracked double-arm lifting device according to claim 2, characterized in that, The controller is equipped with an angle optimization module, which determines the target extension length of the first and second variable angle hydraulic cylinders according to the following steps: First, the operator inputs the estimated length L of the workpiece to be hoisted through the control panel. 估 The controller is based on the estimated length L 估 And the fixed geometric parameters of the first and second auxiliary booms, calculate the first initial included angle α0 and the second initial included angle β0, such that the horizontal distance D0 between the two hooks is equal to the estimated length L. 估 The difference is within the preset difference range; The controller controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to unlock, drives the first variable angle hydraulic cylinder and the second variable angle hydraulic cylinder to move, so that the first auxiliary arm and the second auxiliary arm reach the first initial included angle α0 and the second initial included angle β0 respectively, and then controls the first bidirectional hydraulic lock and the second bidirectional hydraulic lock to lock. The operator controls the first and second winches to lower the wire rope, attaches the first hook and the second hook to the two ends of the workpiece to be lifted, and then controls the first and second winches to slowly lift the workpiece to tighten the wire rope. The controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load ratio R=F1 / F2, and compares the load ratio R with the preset load ratio threshold range. When the load ratio R exceeds the preset load ratio threshold range, the angle optimization module iteratively adjusts according to the following rules: The controller first unlocks the first and second bidirectional hydraulic locks, and then performs the angle adjustment action: when R is greater than the upper limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously reduce the angle α between the first auxiliary arm and the vertical direction and the angle β between the second auxiliary arm and the vertical direction, so as to reduce the horizontal distance between the two hooks. When R is less than the lower limit of the preset load ratio threshold range, the controller controls the first and second variable angle hydraulic cylinders to simultaneously increase the included angle α and included angle β to increase the horizontal distance between the two hooks. After each adjustment, the controller controls the first and second bidirectional hydraulic locks to lock, the controller rereads the load ratio R and compares it with the preset load ratio threshold range, and repeats the above iterative adjustment process until the load ratio R falls within the preset load ratio threshold range, the controller stops adjusting and maintains the current angle; The controller repeats the above read and compare steps every 0.2 seconds.

6. A tracked double-arm lifting device according to claim 2, characterized in that, The lower end of the main boom is hinged to the slewing platform via a ball joint. The slewing platform is also equipped with a first luffing cylinder and a second luffing cylinder. The cylinder bodies of the first and second luffing cylinders are respectively hinged to the left and right sides of the slewing platform. The first and second luffing cylinders are respectively equipped with a third and a fourth bidirectional hydraulic lock, as well as a first and a second proportional flow valve. The third and fourth bidirectional hydraulic locks, the first and second proportional flow valves are all electrically connected to the hydraulic system and the controller. The slewing platform is also equipped with a lateral tilt sensor for detecting the lateral tilt angle of the main boom. The lateral tilt sensor is electrically connected to the input of the controller. The controller contains a main boom attitude adjustment module.

7. A tracked double-arm lifting device according to claim 6, characterized in that, The main arm attitude adjustment module adjusts the lateral attitude of the main arm according to the following steps: First, the controller reads the first hook load value F1 collected by the first pressure sensor and the second hook load value F2 collected by the second pressure sensor, calculates the load difference ΔF=F1-F2, and at the same time reads the boom lateral tilt angle γ collected by the lateral tilt angle sensor. Then, the main boom attitude adjustment module calculates the target lateral tilt angle γ based on the load difference ΔF. target =k×ΔF, where k is a preset proportionality coefficient, and its value ranges from 0.001 to 0.01 (° / N); γ target The positive and negative directions correspond to the swing direction of the main arm towards the first / second auxiliary arm side. A negative value corresponds to the swing of the main arm towards the second auxiliary arm side, ensuring that the main arm swings towards the side with the heavier load. The main arm attitude adjustment module sets the target lateral tilt angle γ. target Comparing it with the current lateral tilt angle γ, the tilt deviation e = γ is obtained. target -γ; The boom attitude adjustment module incorporates a proportional-integral control algorithm, which calculates the differential flow adjustment Q=K between the first and second luffing cylinders based on the tilt angle deviation e. p' ×e+K i' ×∫edt; Among them, K p' For proportionality coefficient, K i' The integral coefficient; The controller controls the proportional flow valves of the first and second luffing cylinders respectively based on the differential flow adjustment Q, causing the extension lengths of the first and second luffing cylinders to change slightly in opposite directions. Specifically, one cylinder extends while the other shortens, driving the boom to swing around the ball joint towards the side with the heavier load until the lateral tilt angle γ of the boom matches the target lateral tilt angle γ. target The deviation is less than the preset threshold; The controller repeats the above reading and calculation steps every 0.1 seconds.

8. A tracked double-arm lifting device according to claim 7, characterized in that, The first and second luffing cylinders are respectively equipped with a first displacement sensor and a second displacement sensor for detecting the cylinder extension length; the rod-side and rodless-side chambers of the first and second luffing cylinders are respectively connected to a first pressure detection port and a second pressure detection port, and the first and second pressure detection ports are respectively equipped with a first chamber pressure sensor and a second chamber pressure sensor; the first chamber pressure sensor, the second chamber pressure sensor, the first displacement sensor, and the second displacement sensor are all electrically connected to the input terminal of the controller; the controller is also equipped with a flow feedforward compensation module; when the controller controls the proportional flow valves of the first and second luffing cylinders according to the differential flow adjustment amount Q, the following steps are executed: Step 1: The controller reads the current lateral tilt angle γ of the main boom collected by the lateral tilt angle sensor, and reads the current length S1 of the first cylinder collected by the first displacement sensor and the current length S2 of the second cylinder collected by the second displacement sensor; Step 2: Based on the tilt deviation e output by the boom attitude adjustment module, the controller calculates the desired lateral swing angular velocity ω=K of the boom using a proportional-integral control algorithm. ω ×e, where K ω This is the preset angular velocity proportionality coefficient; Step 3: Based on the rotational geometry of the boom around the ball joint, and under the lateral attitude adjustment condition where the boom's forward and backward luffing angle remains constant, the controller calculates the desired extension / retraction speed v of the first luffing cylinder using the current boom tilt angle γ, the length of the first cylinder S1, and the length of the second cylinder S2. 1_exp The expected extension / retraction speed v of the second variable amplitude cylinder 2_exp , where v 1_exp =-v 2_exp , and v 1_exp The relationship with ω is determined by the instantaneous kinematic Jacobian matrix of the ball joint and the hydraulic cylinder hinge point; Step 4: The controller reads the rod chamber pressure P of the first cylinder collected by the first chamber pressure sensor. 1_rod and rodless chamber pressure P 1_cap Read the pressure P in the rod chamber of the second cylinder collected by the second chamber pressure sensor. 2_rod and rodless chamber pressure P 2_cap The flow feedforward compensation module calculates the desired extension / retraction speed v of the first hydraulic cylinder. 1_exp Piston area A of the hydraulic cylinder cap and piston rod area A rod Calculate the desired flow rate Q required by the proportional flow valve of the first hydraulic cylinder. 1_exp =|v 1_exp |×(when v 1_exp >0 is A cap When v 1_exp <0 is A rod Simultaneously calculate the valve port pressure difference ΔP1 = |P_sup>1 of the proportional flow valve of the first cylinder. 1_cap -P 1_rod |; Step 5: The flow feedforward compensation module uses the flow-pressure difference characteristic curve function f(Q,ΔP) of the proportional flow valve of the first oil cylinder to solve for the desired flow rate Q. 1_exp Required proportional flow valve opening command U1=f -1 (Q 1_exp Similarly, based on the desired extension / retraction speed v of the second cylinder... 2_exp Calculate the expected flow Q 2_exp Given the pressure difference ΔP2 at the valve orifice, the opening command U2=f is obtained by inverse solving. -1 (Q 2_exp ,ΔP2); Step 6: The controller outputs opening commands U1 and U2 to the proportional flow valves of the first and second luffing cylinders respectively, driving the first and second luffing cylinders to extend and retract at the desired speed; The controller reads the first and second displacement sensors every 0.05 seconds, compares the actual cylinder length with the expected length, and fine-tunes the opening commands U1 and U2 using a PID algorithm.

9. A tracked double-arm lifting device according to claim 8, characterized in that, The controller also includes a collaborative disturbance rejection adjustment module; the collaborative disturbance rejection adjustment module contains a first PID calculation unit and a second PID calculation unit. When the collaborative disturbance rejection adjustment module performs fine-tuning correction on the opening commands U1 and U2 using the PID algorithm, it performs the following steps: Step A: The controller reads the current length S1 of the first hydraulic cylinder collected by the first displacement sensor and the current length S2 of the second hydraulic cylinder collected by the second displacement sensor, and reads the desired lateral tilt angle γ of the main boom output by the main boom attitude adjustment module. target And the current boom lateral tilt angle γ collected by the lateral tilt sensor; Step B: Based on the kinematic geometry of the main boom around the ball joint, the collaborative disturbance rejection module adjusts the desired lateral tilt angle γ of the main boom under the condition that the forward and backward amplitude angle of the main boom remains unchanged. target The desired length S converted to the first hydraulic cylinder 1_ref The expected length S of the second cylinder 2_ref S 1_ref With S 2_ref Satisfy S 1_ref +S 2_ref = constant C, where constant C is the sum of the lengths of the two cylinders in their initial installation positions; Step C: The collaborative disturbance rejection adjustment module calculates the length deviation e1=S of the first hydraulic cylinder. 1_ref -S1, the length deviation of the second cylinder e2=S 2_ref -S2, and calculate the common mode deviation e sum =e1+e2 and differential mode deviation e diff =e1-e2; Step D: The collaborative disturbance rejection adjustment module will adjust the common mode deviation e sum Input to the first PID calculation unit, output common mode correction ΔU sum =K p_sum ×e sum +K i_sum ×∫e sum dt+K d_sum ×d(e sum ) / dt; The differential mode deviation e diff Input to the second PID calculation unit, output differential mode correction ΔU diff =K p_diff ×e diff +K i_diff ×∫e diff dt+K d_diff ×d(e diff ) / dt; Step E: The collaborative disturbance rejection adjustment module calculates the opening correction ΔU acting on the first proportional flow valve based on the common-mode correction and differential-mode correction. 1_corr =(ΔU sum +ΔU diff ) / 2, and the opening correction ΔU acting on the second proportional flow valve. 2_corr =(ΔU sum -ΔU diff ) / 2; Step F: The controller combines the opening command U1 output by the flow feedforward compensation module with the opening correction amount ΔU. 1_corr Add them together to obtain the first final opening instruction U. 1_final =U1+ΔU 1_corr ; Compare U2 with ΔU 2_corr Adding them together, we get the second final opening instruction U. 2_final =U2+ΔU 2_corr ; proportional flow valves that output to the first and second luffing cylinders respectively; Step G: The collaborative disturbance rejection adjustment module repeats steps A to F every 0.02 seconds, and limits the integral terms of the first PID calculation unit and the second PID calculation unit during each execution to prevent integral saturation.

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