Full-working-condition autonomous control system and method for automobile crane supporting leg system

Abstract

The invention discloses a full-working-condition autonomous control system and method for an automobile crane supporting leg system. The system can be provided with four or more supporting legs in any number and can be unfolded and folded to any degree; the method comprises the following steps: respectively measuring a static stiffness curve of each landing leg assembly and a bearing and deformation combined control matrix of a landing leg system, and implementing initial leveling; then, the chassis posture and landing leg load change caused by loading operation is calculated in advance, the theoretical optimal load is determined with the maximum sum of the load of the landing legs at the far end of the hoisting load as the target, and overturning risk diagnosis is carried out; calculating the compensation amount of the supporting leg based on a feedforward and feedback composite regulation and control concept; and finally, loading operation and supporting leg compensation are synchronized, and closed-loop execution is carried out. According to the system and the method, under the unconventional operation working conditions that any supporting leg system cannot be completely unfolded and the like, the chassis can be constantly kept to be level in a full operation period, meanwhile, the load of each supporting leg approaches to be optimal, and then the safety and the operation efficiency of the automobile crane are comprehensively improved.

Description

Technical Field

[0001] The invention belongs to the field of automobile cranes, and in particular relates to the field of outrigger system control of automobile cranes. Background Art

[0002] Truck cranes, concrete pump trucks, missile launchers, radar carriers, and other vehicles all require an outrigger system to provide baseline support, while the tires are completely suspended. Both Germany and Japan offer ten-outrigger truck cranes. Currently, initial leveling of the outrigger system before operation is still semi-automatic. More importantly, even when ideally adjusted before operation, loading operations repeatedly disrupt the chassis level and outrigger loads, leading to frequent accidents caused by the loss of outrigger system stability. Furthermore, truck cranes must operate in ditches and confined spaces, where the outrigger system cannot fully deploy, placing even greater demands on outrigger control. Therefore, implementing full-condition autonomous control of the outrigger system (rapid initial leveling and maintaining posture during operation) for any outrigger system under unusual operating conditions, such as those where full deployment is impossible, is crucial for improving the safety, reliability, and efficiency of special vehicles.

[0003] Chinese patent application CN202110742181.5 discloses a method for automatically controlling the chassis attitude of a truck crane during loading operations. Its shortcomings are: first, it is limited to geometric attitude adjustment and does not address the reliability of outrigger load distribution, which has been shown to pose control risks; second, the synchronous control of loading operations and outrigger compensation is not closed-loop, resulting in cumulative errors in chassis attitude and outrigger loads during operation, leading to control failure.

[0004] Chinese patent application CN202211559189.9 discloses a stability control method for the outrigger system of a truck crane during operation. This application can keep the chassis posture approaching the geometric level in real time during operation, and at the same time, the load distribution of each outrigger approaches the theoretical optimal load in real time. Its disadvantages are: (1) The proposed outrigger stiffness and joint control matrix test method cannot cover unconventional operating conditions; (2) The outrigger load and chassis inclination angle advanced solution theory adopted has defects, which will cause insufficient control accuracy and generate cumulative errors; (3) The theoretical optimal load model adopted has deficiencies. Under extreme operating conditions, negative loads are calculated, that is, the ground is required to provide tension (which is physically impossible), which may induce serious accidents; (4) It does not include effective overturning risk diagnosis. Implementing control in dangerous conditions is prone to induce serious accidents; (5) The adopted synchronous control of the upper body and outriggers is defective. Since the outrigger load and chassis inclination angle calculated in advance are error-prone estimates, the existing scheme will cause cumulative errors in the chassis posture and outrigger load during operation until the control fails.

[0005] With the development of special vehicles, the number of outriggers in outrigger systems has increased from the typical four to six and even more than a dozen. This has caused the control of the outrigger system to expand from a first-order statically indeterminate problem to a higher-order statically indeterminate problem. Active control of any outrigger will inevitably cause a change in the chassis posture and a redistribution of the load on each outrigger. Implementing autonomous control of the outrigger system under all operating conditions (rapid leveling in the initial operating condition and maintaining the posture under the operating condition) is of great value in improving the safety, reliability, and operating efficiency of various types of special vehicles equipped with outrigger systems and urgently needs to be studied. Summary of the Invention

[0006] In light of the aforementioned shortcomings, this patent discloses a full-operation-condition autonomous control system and method for a truck crane's outrigger system. The truck crane's outrigger system can be configured with any number of outriggers, four or more, and can be extended and retracted to any desired degree. The control method measures the static stiffness curve of each outrigger assembly and the outrigger system's load-bearing and deformation-combined control matrix to implement automatic initial leveling. The system then proactively calculates changes in chassis posture and outrigger load caused by loading operations, determining the theoretical optimal load with the goal of maximizing the sum of the outrigger loads at the far end of the load, and performing overturning risk diagnosis. Furthermore, based on a feedforward-feedback composite control concept, outrigger compensation is proactively calculated with the goal of restoring the chassis to a level state and for the outrigger loads to approach the theoretical optimum. Finally, loading operations and outrigger compensation are executed synchronously and in a closed-loop manner. This system and method can adapt to outrigger systems with any number of outriggers and any extended and retracted state, maintaining a nearly level chassis and optimal outrigger loads throughout the entire operating cycle. This significantly improves the safety, reliability, and operational efficiency of special vehicles equipped with outrigger systems, thus offering significant value.

[0007] The present invention provides a full-operation-condition autonomous control system for an outrigger system of a truck crane. The truck crane comprises a chassis, an outrigger system, and a superstructure. The superstructure is driven by a luffing cylinder to raise and lower the boom, a telescopic mechanism to extend and retract the boom at each stage, and a slewing mechanism to slew the boom relative to the chassis. The outrigger system has a horizontal fixed end fixedly connected to the chassis, and horizontally movable outriggers that can be controlled to extend and retract within the horizontal fixed end. The vertical outriggers, referred to as outriggers, have upper ends fixedly connected to the horizontal fixed end or the horizontally movable outriggers and lower ends that can be vertically extended to lift the chassis off the ground. The control system comprises the following components:

[0008] The number of outriggers supported by the full-condition autonomous control system includes any number of 4 or more, and the layout of the outrigger system includes but is not limited to frog-type, H-type, X-type, radial type and swing type; the degree of outrigger deployment includes but is not limited to full deployment, partial or no deployment; and it supports some outriggers not participating in support.

[0009] The full-condition autonomous control system is equipped with a posture sensor near the slewing mechanism for measuring the two-dimensional inclination of the chassis relative to the horizontal plane; each leg has an independent actuation function and is respectively equipped with a vertical displacement and load measurement module; the luffing cylinder is equipped with a luffing angle and luffing angular velocity measurement module, the slewing mechanism is equipped with a slewing angle and slewing angular velocity measurement module, and the boom is equipped with an elongation and elongation velocity measurement module.

[0010] The host computer of the full-working condition autonomous control system has touch and digital display functions; the touch function is used to set the layout of the outriggers, the selection of outriggers participating in the support, the degree of outrigger extension, the chassis inclination control accuracy, the outrigger load control accuracy, and the step angle of the posture control during rotation, amplitude change, and extension; the digital display function is used to display the real-time status of the upper installation operation, chassis posture and outrigger load.

[0011] The present invention also provides a full-condition autonomous control method for the outrigger system of a truck crane. The coordinate system of the method is defined with the geometric center of the slewing mechanism as the coordinate origin, the x-axis is parallel to the ground and points to the front of the operator, the y-axis points to the left of the operator, and the z-axis is vertically upward; the outrigger numbering rule is that the outrigger on the left of the operator is the first outrigger, and the other outriggers are assigned numbers 2 to n in a counterclockwise direction. The longitudinal and transverse coordinates of each outrigger are marked as (x i ,y i ), i = 1, 2, ..., n, and the corresponding horizontal fixed ends and horizontal movable legs are also declared with the same serial numbers; the positive direction of the vertical force of each leg is in the same direction as the coordinate axis, and the positive direction of the moment and inclination angle is determined by the right-hand rule; the following steps are included:

[0012] Step 1: Before leaving the factory, the horizontal fixed end, chassis and rigid stand are fixedly connected, and the static stiffness curve of each leg assembly is tested and fitted: the i-th horizontal movable leg is controlled to be extended to a specific length, and the i-th leg is controlled to be extended to touch the ground; the i-th leg is driven to extend one unit displacement and retract, and the load measurement module measures the load increment of the leg to obtain the static stiffness of the i-th horizontal fixed end-horizontally movable leg-specific length leg assembly; the specific length is adjusted from zero to the maximum extended length, and the static stiffness at each length is tested in turn, and then the static stiffness curve of the i-th leg assembly with respect to different leg extended lengths is fitted.

[0013] Step 2, initial setup: After arriving at the work site, the operator deploys and retracts the horizontally movable outriggers and selects the outriggers that participate in the support according to the actual situation on site, and implements the hanging of the load without lifting. The operator completes the outrigger system layout, deployment degree, and setting of the outriggers that participate in the support on the host computer in sequence, and displays a two-dimensional digital model image of the truck crane on the digital display screen.

[0014] Step 3: Measure the joint control matrix of the load and deformation of the leg system: drive the i-th leg to extend by one unit displacement and retract to its original length, i = 1, 2, ..., n, during which the other legs are kept inactive. The load increment of each leg is measured by the load measurement module in order from 1 to n, and each load increment is divided by the unit displacement and placed in the i-th column, 1st row to nth row of the (n+2) × n-dimensional matrix shown in Formula 1. At the same time, the attitude sensor measures the inclination increment of the platform around the x-axis and y-axis respectively, and divides each inclination increment by the unit displacement to obtain Δθ xi , Δθ yi , and sequentially put them into the n+1th and n+2th rows of the i-th column of the (n+2)×n-dimensional matrix; until the formula is constructed

[0015] The (n+2)×n dimensional load-bearing and deformation joint control matrix shown in Equation 1 is

[0016]

[0017] Step 4: The attitude sensor measures the current chassis inclination angle m=x,y;The load measurement module measures the current load of each leg {F i t}.

[0018] Step 5: Calculate the theoretical optimal load of each leg using Formula 2 and the basic theoretical load model: Calculate the total weight G of the truck crane and its center of mass coordinates (x com ,y com ); Taking the total weight evenly distributed among the legs as the load expectation, calculate the basic theoretical optimal load of each leg {F i *}

[0019]

[0020] Step 6: Calculate the initial leveling leg compensation: the load and deformation joint control matrix, the chassis inclination angle and leg load in the initial state, the basic theoretical optimal load, and the optimal posture {0°, 0°} T , construct the geometry and load coupling leveling equation, formula 3, and then calculate the compensation amount of each leg {e i}

[0021]

[0022] Step 7: According to the compensation amount {e i}Perform initial leveling, then measure the chassis inclination and outrigger load, and determine whether the leveling is successful: if so, that is, the chassis inclination and outrigger load are both better than the control accuracy, then proceed to the next step; if not, return to step 4 to iterate.

[0023] Step 8: Lift the load, measure the chassis inclination and outrigger load again, calculate the total weight of the truck crane after lifting according to formula 4, still record it as G, calculate the new center of mass coordinates, still record it as (x com ,y com ); Determine whether further leveling is required: If yes, return to steps 4 to 7 and skip the lifting step to perform leveling again; if no, proceed to the next step

[0024]

[0025] Step 9: monitor the operator's rotation, amplitude change, extension and retraction and their combined operation instructions, and calculate in advance the new centroid coordinates (x′) that will be generated by the operation instructions at the next step. com ,y′ com ) and the load coordinates (x M ,y M ); assign new serial numbers z, c, d to any three legs that are not in a straight line, and calculate the vertical displacement Δz of each leg caused by the corresponding operation in advance according to formula 5 i

[0026]

[0027] In formula 5, N z 、N c 、N d is the shape function of the three legs;

[0028] Then calculate the outrigger load {F i ′} and chassis inclination {θ′ m}

[0029]

[0030] In formula 6, Δz g It is defined as the vertical displacement that will be produced by the leg with the same longitudinal coordinate as leg 1 and the largest transverse span b, Δz h It is defined as the vertical displacement that will be produced by the leg with the same transverse coordinate as leg 1 and the largest longitudinal span L;

[0031] In particular, the equivalent stiffness k of each leg used in the advance calculation in Equations 5 and 6 is i e , is determined in the following way: according to the degree of extension of each leg in the leg system, the corresponding stiffness value k is calculated from the static stiffness curve of each leg assembly. i1 ; Pick up the main diagonal element Δf of the upper n×n dimensional matrix of the joint control matrix of load and deformation ii As the stiffness value k i 2 ; Define the initial equivalent stiffness of each leg as the superposition of stiffness value 1 and stiffness value 2, k i e =α·k i 1 +β·k i 2 , where the sum of the weight coefficients α and β is 1; drive the truck crane to perform the upper loader mode operation (upper loader rotation, boom extension, bell hoisting and its combined operation conditions under specific loads), and adjust the weight coefficients α and β with the goal of minimizing the error between the measured chassis inclination angle and the theoretical chassis inclination angle, and then obtain the optimized equivalent stiffness k of each leg i e .

[0032] Step 10: Based on Formula 7, the theoretical load model is strengthened to calculate the optimal load of the next step angle in advance, which is recorded as {F i *}: With the maximum sum of the loads on the distal outriggers as the goal, the mechanical balance of the truck crane as the equality constraint, and the upper and lower limits of the distal and proximal outriggers as the inequality constraints, solve the optimal load of the strengthening theory.

[0033]

[0034] Among them, F k is the load on the remote outrigger of the hoist, and its upper and lower limits are set as and the total weight of the truck crane G; F m is the load on the proximal leg of the hoist, and its upper and lower limits are set to 0 and The far leg k is used to solve the distance between each leg i and the load And judge whether it is greater than the mean distance Sure.

[0035] Step 11, overturning risk diagnosis: set the lower limit load of the hoisting weight distal leg described in the enhanced theoretical load model to zero and negative values ​​respectively, and calculate two sets of enhanced theoretical optimal loads {F i *}0 and {F i *}-; define the capsizing risk index V e0 and V e -

[0036] V e0 =min{F i *}0,Ve- =min{F i *} - Formula 8,

[0037] Capsizing risk diagnosis and intervention are performed according to the following rules: If V e0 and V e - are all positive, then it is absolutely safe and proceed to the next step; if V e0 V is positive e - is negative, the load will approach the safety limit, warning the operator to proceed with the next step with caution; if V e0 and V e If both the zero and negative values ​​are negative, continuing the operation will inevitably lead to overturning, warning the operator and requiring immediate termination of the loading operation. The zero value in the lower load limit zero and negative values ​​can be an appropriate positive value considering engineering practice and sensor accuracy; the negative value is a set value that is less than the appropriate positive value.

[0038] Step 12, advance calculation of the chassis inclination angle and leg load of the feedforward feedback composite control at the next step of the distance angle: In step 9, the chassis inclination angle {θ′ m Subtract the current chassis inclination angle measured in step 8 from Then subtract the optimal posture {0°, 0°} T , get the chassis inclination angle of feedforward feedback compound control The loads for each leg {F i Subtract the current load of each leg measured in step 8 from {F i t}, minus the theoretical optimal load {F i *}, and obtain the outrigger load {F i * -F i t -F i ′}.

[0039] Step 13, using formula 9, the geometry and load coupling control equation, calculate the base leg compensation required for chassis state control {e i}

[0040]

[0041] Furthermore, the foundation leg compensation amount {e i} minus the average value to obtain the actual outrigger compensation {e′ i} n×1

[0042]

[0043] In formula 10, {e′ i} is the compensation amount for each leg required to restore the chassis to a level state and maintain the theoretical optimal load for each leg when the upper body reaches the next step angle according to the operation instruction.

[0044] Step 14, control the upper body to operate according to the instruction; at the same time, control each leg to move synchronously according to the compensation amount of each leg; the actuation speed is based on the upper body completing the next step of the angle operation and all legs completing the corresponding compensation amount, that is, satisfying formula 11

[0045]

[0046] In formula 11, Δt is the time interval for completing the next angle operation.

[0047] In step 15, the chassis inclination angle and the outrigger load are measured and the operator's operation instructions are monitored cyclically: if there are still instructions input, the process returns to step 9 for iteration; if the instructions stop, the control ends.

[0048] The beneficial effects of the present invention are:

[0049] 1. The system can adapt to the outrigger system in any extended or retracted state, covering almost all operating scenarios of truck cranes. It performs outrigger compensation during loading operations, effectively keeping the truck crane chassis close to the geometric level in real time during operation. At the same time, the load distribution of each outrigger approaches the theoretical optimal load in real time. It also provides a novel overturning risk diagnosis and intervention solution, effectively resolving outrigger empty leg, overload, posture damage, and even vehicle overturning problems caused by load migration during operation.

[0050] 2. Compared with the earlier patent application, the patent expands the scope of situations with unconventional outrigger arrangements; improves the outrigger load and chassis inclination advance solution theory, the theoretical optimal load model, and innovatively proposes a feedforward-feedback composite outrigger compensation control scheme, which fundamentally avoids the cumulative error of chassis posture and outrigger load caused by the control principle, significantly improving the chassis control accuracy during operation. Simulation and experimental verification have confirmed that the operation control scheme in this patent can reduce posture disturbances by more than 80% throughout the entire operation cycle, reduce the number of weak outriggers / suspended outriggers by more than 80%, and achieve real-time optimal load bearing of the outriggers throughout the entire operation. This enables autonomous control of the outrigger system under all working conditions (rapid leveling of the initial working condition and maintenance of the working condition posture), laying the foundation for the automation and unmanned operation of truck cranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] Figure 1This is a flow chart of the full-operating-condition autonomous control system and method of the outrigger system of the truck crane of the present invention;

[0053] Figure 2 Schematic diagram of the host computer of the full-operating-condition autonomous control system and method of the outrigger system of the truck crane of the present invention;

[0054] Figure 3 Schematic diagram of a truck crane with an autonomous control system and method for the outrigger system of the truck crane according to the present invention;

[0055] Figure 4 Schematic diagram of the feedforward and feedback composite regulation of the full-operating-condition autonomous control system and method of the truck crane outrigger system of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0057] The present invention provides a full-operation-condition autonomous control system for a truck crane outrigger system, wherein the truck crane, for example Figure 3 As shown, it consists of a chassis 4, an outrigger system and an upper body; the upper body is driven by a luffing cylinder 1 to drive the boom 2 to rise and fall, the telescopic mechanism drives the boom 2 at each level to extend and retract, and the slewing mechanism 3 drives the boom 2 to rotate relative to the chassis 4; the horizontal fixed end of the outrigger system is fixedly connected to the chassis 4, and the horizontally movable outrigger 6 can be controlled to extend and retract within the horizontal fixed end; the vertical outrigger 7, referred to as the outrigger 7, has its upper end fixedly connected to the horizontally movable outrigger 6, and its lower end can be vertically extended to support the chassis 4 off the ground; its characteristics are as follows: the number of outriggers supported by the full-condition autonomous control system can be 4 or any number above 4, such as Figure 2 As shown, the layout of the outrigger system can be in the form of frog-type, H-type, X-type, radial type and swing type; the degree of extension of the outrigger 7 can be fully extended, partially or not extended; and some outriggers are supported and do not participate in the support. The full-condition autonomous control system is equipped with a posture sensor for measuring the two-dimensional inclination of the chassis 4 relative to the horizontal plane near the slewing mechanism 3; each outrigger 7 has an independent actuation function and is respectively equipped with a vertical displacement and load measurement module; the amplitude cylinder 1 is equipped with an amplitude angle and amplitude angular velocity measurement module, the slewing mechanism 3 is equipped with a slewing angle and slewing angular velocity measurement module, and the boom 2 is equipped with an elongation and elongation speed measurement module. The host computer of the full-condition autonomous control system has touch and digital display functions, and its schematic diagram is shown as follows. Figure 2As shown; the touch function is used to set the layout of the outriggers, the selection of outriggers participating in the support, the degree of outrigger extension, the chassis inclination control accuracy, the outrigger load control accuracy, and the step angle of the posture control during rotation, amplitude change, and extension; the digital display function is used to display the real-time status of the upper installation operation, chassis posture and outrigger load.

[0058] The present invention also provides a full-condition autonomous control method for the outrigger system of a truck crane. The coordinate system of the method is defined with the geometric center of the slewing mechanism 3 as the coordinate origin, the x-axis is parallel to the ground and points to the front of the operator, the y-axis points to the left of the operator, and the z-axis is vertically upward; the numbering rule of the outriggers 7 is that the outrigger 7 on the left side of the operator is the first outrigger 7, denoted as Leg1, and the other outriggers 7 are assigned numbers 2 to n in a counterclockwise direction. The longitudinal and transverse coordinates of each outrigger are marked as (x i ,y i ), i = 1, 2, ..., n, the corresponding horizontal fixed end and horizontal movable leg 6 are also declared with the same serial number; the positive direction of the vertical force of each leg is in the same direction as the coordinate axis, and the positive direction of the moment and the inclination angle is determined by the right-hand rule; including the following steps, the control flow chart is as follows Figure 1 As shown:

[0059] Step 1: Before leaving the factory, the horizontal fixed end, chassis 4, and rigid stand are fixedly connected, and the static stiffness curve of each leg assembly is tested and fitted: the i-th horizontal movable leg 6 is controlled to be extended to a specific length, and the i-th leg 7 is controlled to be extended until it touches the ground; the i-th leg 7 is driven to extend one unit displacement and retract, and the load increment of the leg 7 is measured by the load measurement module to obtain the static stiffness of the i-th horizontal fixed end-horizontally movable leg 6-specific length leg assembly; the specific length is adjusted from zero to the maximum extended length, and the static stiffness at each length is tested in turn, thereby fitting the static stiffness curve of the i-th leg assembly for different leg extended lengths;

[0060] Step 2: After arriving at the work site, the operator completes the outrigger system layout, the degree of deployment, and the settings of the supporting outriggers on the host computer according to the situation. A two-dimensional digital model of the truck crane is displayed on the digital display screen. The operator then performs the hanging of the load without lifting.

[0061] Step 3: Measure the load-bearing and deformation joint control matrix of the leg system: drive the i-th leg 7 to extend by one unit displacement and retract to its original length, i = 1, 2, ..., n. During this period, keep the other legs 7 inactive. The load increment of each leg 7 is measured by the load measurement module in the order from 1 to n. Each load increment is divided by the unit displacement and placed in the i-th column, 1st row to nth row of the (n+2)×n-dimensional matrix shown in Formula 1. At the same time, the attitude sensor measures the inclination increment of the platform around the x-axis and y-axis respectively, and divides each inclination increment by the unit displacement to obtain Δθxi , Δθ yi , and sequentially put them into the n+1 and n+2 rows of the i-th column of the (n+2)×n dimensional matrix; until the (n+2)×n dimensional load and deformation joint control matrix is ​​constructed

[0062]

[0063] Step 4: The attitude sensor measures the current chassis inclination angle m=x,y;The load measurement module measures the current load of each leg {F i t}.

[0064] Step 5: Calculate the theoretical optimal load of each leg using Formula 2 and the basic theoretical load model: Calculate the total weight G of the truck crane and its center of mass coordinates (x com ,y com ); Taking the total weight evenly distributed among the legs as the load expectation, calculate the basic theoretical optimal load of each leg {F i *}

[0065]

[0066] Step 6: Calculate the initial leveling leg compensation: the load and deformation joint control matrix, the chassis inclination angle and leg load in the initial state, the basic theoretical optimal load, and the optimal posture {0°, 0°} T , construct the geometry and load coupling leveling equation, formula 3, and then calculate the compensation amount of each leg {e i}

[0067]

[0068] Step 7: According to the compensation amount {e i}Perform initial leveling, then measure the chassis inclination and outrigger load, and determine whether the leveling is successful: if so, that is, the chassis inclination and outrigger load are both better than the control accuracy, then proceed to the next step; if not, return to step 4 to iterate.

[0069] Step 8: Lift the load, measure the chassis inclination and outrigger load again, calculate the total weight of the truck crane after lifting according to formula 4, still record it as G, calculate the new center of mass coordinates, still record it as (x com ,y com ); Determine whether further leveling is required: If yes, return to steps 4 to 7 and skip the lifting step to perform leveling again; if no, proceed to the next step

[0070]

[0071] Step 9: monitor the operator's rotation, amplitude change, extension and retraction and their combined operation instructions, and the posture sensor, combined with the operator's instructions and the center of mass coordinate parameterized model of formula 5 (only applicable to Figure 3 The structural features of the crane shown in the figure are taken as an example), and the new center of mass coordinate (x′) to be generated by the operation instruction at the next step is calculated in advance. com ,y′ com )

[0072]

[0073] In formula 5, m i is the mass of the i-th level boom 2, i = 1 to 6, l a is the length of boom 2, To complete the initial luffing angle of the crane arm 2 to hang the load 5, ω b is the angular velocity of the boom 2, with the rising of the boom 2 as positive, t b is the amplitude change actuation time, l j is the horizontal distance from the boom 2 axis to the origin, m b is the mass of counterweight 6, l b is the horizontal distance from the counterweight 6 to the origin, l0 is the initial extension length of the crane arm 2 after completing the lifting and hanging of each level, v s is the extension and retraction speed of the boom 2, with extension as positive, t s is the extension and retraction time of the boom 2, ψ0 is the initial rotation angle of the boom 2 after the load is hoisted, ω h is the angular velocity of boom 2, t h is the rotation actuation time, m t is the mass of chassis 4, x t is the x-axis coordinate of the center of mass of chassis 4, y t is the y-axis coordinate of the center of mass of chassis 4. l0 can be measured by the displacement sensor installed between the second-stage boom 2 and the first-stage boom 2, ψ0 can be measured by the inclination sensor of the slewing mechanism 3, and other data can be obtained based on the crane structure manual or three-dimensional model. The chassis 4 is the whole of the front cab, the fixed part of the slewing mechanism 3, and the chassis 4, and the counterweight is the whole of the rear cab, the movable part of the slewing mechanism 3, and the rear counterweight. It is worth noting that this formula is only applicable to this embodiment. Figure 3 It should be understood that this formula is not intended to be limiting, and any method that can obtain the overall center of mass of the truck crane and the load should be included in the scope of protection of this patent.

[0074] According to formula 6, the vertical displacement Δz of each leg caused by the corresponding operation is calculated in advance. i

[0075]

[0076] Then calculate the outrigger load {F i ′} and chassis inclination {θ′ m}

[0077]

[0078] In formula 7, b is the horizontal span and is the vertical span;

[0079] In particular, the equivalent stiffness k of each leg used in the advance calculations in Equations 6 and 7 is i e , is determined in the following way: according to the degree of extension of each leg in the leg system, the corresponding stiffness value k is calculated from the static stiffness curve of each leg assembly. i 1 ; Pick up the main diagonal element Δf of the upper n×n dimensional matrix of the joint control matrix of load and deformation ii As the stiffness value k i 2 ; Define the initial equivalent stiffness of each leg as the superposition of stiffness value 1 and stiffness value 2, k i e =α·k i 1 +β·k i 2 , where the sum of the weight coefficients α and β is 1; drive the truck crane to perform the upper loader mode operation (upper loader rotation, boom extension, bell hoisting and its combined operation conditions under specific loads), and adjust the weight coefficients α and β with the goal of minimizing the error between the measured chassis inclination angle and the theoretical chassis inclination angle, and then obtain the optimized equivalent stiffness k of each leg i e .

[0080] Step 10: Based on formula 8, the theoretical load model is strengthened to calculate the optimal load of the next step angle in advance, which is recorded as {F i *}: With the maximum sum of the loads on the distal outriggers as the goal, the mechanical balance of the truck crane as the equality constraint, and the upper and lower limits of the distal outriggers 7 and the proximal outriggers 7 as the inequality constraints, solve the optimal load of the strengthening theory

[0081]

[0082] Among them, F k is the load on the remote outrigger of the hoist, and its upper and lower limits are set as and the total weight of the truck crane G; F m is the load on the proximal leg of the hoist, and its upper and lower limits are set to 0 and The far leg k is used to solve the distance between each leg i and the load And judge whether it is greater than the mean distance Sure.

[0083] Step 11, overturning risk diagnosis: set the lower limit load of the hoisting weight distal leg described in the enhanced theoretical load model to zero and negative values ​​respectively, and calculate two sets of enhanced theoretical optimal loads {F i *}0 and {F i *}-; define the capsizing risk index V e0 and V e -

[0084] V e0 =min{F i *}0,V e- =min{F i *} - Formula 9,

[0085] Capsizing risk diagnosis and intervention are performed according to the following rules: If V e0 and V e - are all positive, then it is absolutely safe and proceed to the next step; if V e0 V is positive e - is negative, the load will approach the safety limit, warning the operator to proceed with the next step with caution; if V e0 and V e If both the zero and negative values ​​are negative, continuing the operation will inevitably lead to overturning, warning the operator and requiring immediate termination of the loading operation. The zero value in the lower load limit zero and negative values ​​can be an appropriate positive value considering engineering practice and sensor accuracy; the negative value is a set value that is less than the appropriate positive value.

[0086] Step 12, advance calculation of the chassis inclination angle and leg load of the feedforward feedback composite control at the next step of the distance angle: In step 9, the chassis inclination angle {θ′ m Subtract the current chassis inclination angle measured in step 8 from Then subtract the optimal posture {0°, 0°} T , get the chassis inclination angle of feedforward feedback compound control The loads for each leg {F i Subtract the current load of each leg measured in step 8 from {F i t}, minus the theoretical optimal load {F i *}, and obtain the outrigger load {F i* -F i t -F i ′}.

[0087] Step 13, using formula 10, the geometry and load coupling control equation, calculate the basic leg compensation required for the chassis 4 state control {e i}

[0088]

[0089] Furthermore, the foundation leg compensation amount {e i} minus the average value to obtain the actual outrigger compensation {e′ i} n×1

[0090]

[0091] In formula 11, {e′ i} is the compensation amount of each leg required to restore the chassis 4 to a horizontal level and each leg to maintain the theoretical optimal load when the upper body reaches the next step angle according to the operation instruction.

[0092] Step 14, control the upper body to operate according to the instruction; at the same time, control each leg to move synchronously according to the compensation amount of each leg; the actuation speed is based on the upper body completing the next step of the angle operation and all legs 7 completing the corresponding compensation amount, that is, satisfying formula 12

[0093]

[0094] In formula 12, Δt is the time interval for completing the next angle operation.

[0095] In step 15, the chassis inclination angle and the outrigger load are measured and the operator's operation instructions are monitored cyclically: if there are still instructions input, the process returns to step 9 for iteration; if the instructions stop, the control ends.

[0096] Finally, it should be noted that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A fully autonomous control system for the outrigger system of a truck crane. The truck crane consists of a chassis, an outrigger system, and a superstructure. The superstructure is driven by a luffing cylinder to raise and lower the boom, a telescopic mechanism to extend and retract the boom at each stage, and a slewing mechanism to swivel the boom relative to the chassis. The horizontal fixed ends of the outrigger system are fixedly connected to the chassis, and the horizontally movable outriggers can be controlled to extend and retract relative to the horizontal fixed ends. The vertical outriggers, referred to as outriggers, have upper ends fixedly connected to the horizontally movable outriggers and lower ends that can be extended vertically to lift the chassis off the ground. This system is characterized by: Includes the following sections: The number of outriggers supported by the full-condition autonomous control system includes any number of 4 or more, and the layout of the outrigger system includes but is not limited to frog-type, H-type, X-type, radial type and swing type; the degree of outrigger deployment includes but is not limited to full deployment, partial deployment or non-deployment; and it supports some outriggers not participating in support; The full-operation autonomous control system is equipped with a posture sensor near the slewing mechanism to measure the two-dimensional inclination of the chassis relative to the horizontal plane; each leg has an independent actuation function and is respectively equipped with a vertical displacement and load measurement module; the luffing cylinder is equipped with a luffing angle and luffing angular velocity measurement module, the slewing mechanism is equipped with a rotation angle and rotation angular velocity measurement module, and the boom is equipped with an extension and extension velocity measurement module; The host computer of the full-working condition autonomous control system has touch and digital display functions; the touch function is used to set the layout of the outriggers, the selection of outriggers participating in the support, the degree of outrigger extension, the chassis inclination control accuracy, the outrigger load control accuracy, and the step angle of the posture control during rotation, amplitude change, and extension; the digital display function is used to display the real-time status of the upper installation operation, chassis posture and outrigger load.

2. A method for autonomously controlling the outrigger system of a truck crane under all working conditions. The coordinate system of the method is defined with the geometric center of the slewing mechanism as the coordinate origin, the x-axis parallel to the ground and pointing forward of the vehicle, and the y-axis and z-axis conforming to a right-handed coordinate system. The outriggers are numbered with the outrigger on the operator's left being numbered 1, and the other outriggers are numbered 2 to n in a counterclockwise direction. The longitudinal and transverse coordinates of each outrigger are marked as (x i ,y i ), i = 1, 2, ... n, the corresponding horizontal fixed end and horizontal movable leg are also declared with the same serial number; the positive direction of the vertical force of each leg is in the same direction as the coordinate axis, and the positive direction of the moment and inclination angle is determined by the right-hand rule; it is characterized by: The following steps are involved: Step 1: Before leaving the factory, the horizontal fixed end, chassis, and rigid stand are fixedly connected, and the static stiffness curve of each leg assembly is tested and fitted: the i-th horizontal movable leg is controlled to be extended to a specific length, and the i-th leg is controlled to be extended until it touches the ground; the i-th leg is driven to extend one unit displacement and retract, and the load increment of the leg is measured by the load measurement module to obtain the static stiffness of the i-th horizontal fixed end-horizontally movable leg-specific length leg assembly; the specific length is adjusted from zero to the maximum extended length, and the static stiffness at each length is tested in turn, thereby fitting the static stiffness curve of the i-th leg assembly for different leg extended lengths; Step 2: After arriving at the work site, the operator completes the outrigger system layout, the degree of deployment, and the settings of the supporting outriggers on the host computer according to the situation. A two-dimensional digital model of the truck crane is displayed on the digital display screen. The operator then performs the hanging of the load without lifting. Step 3: Measure the load and deformation joint control matrix of the outrigger system. Step 4: Measure the current chassis inclination angle Measure the current load of each leg i t }; Step 5: Calculate the theoretical optimal load of each leg based on the theoretical load model. Step 6: Calculate the initial leveling leg compensation amount based on the geometry and load coupled leveling equation; Step 7, performing initial leveling according to the outrigger compensation amount; Step 8: Lift the load, measure the chassis inclination and outrigger load again, calculate the total weight of the truck crane after lifting, record it as G, calculate the new center of mass coordinates, record it as (x com ,y com ) ; Determine whether further leveling is needed; Step 9: Monitor the operation instructions and calculate in advance the new centroid coordinates (x′) that will be generated by the next operation instruction at the angle. com ,y′ com ), lifting coordinates (x M ,y M ); Calculate in advance the vertical displacement of each leg caused by the corresponding operation, and then calculate the resulting leg load {F i ′} and chassis inclination {θ′ m }; Among them, the equivalent stiffness k of each leg used in the advance calculation is i e , determined as follows: According to the degree of extension of each leg in the leg system, the stiffness value k is calculated from the static stiffness curve of each leg component. i 1 ; Pick up the main diagonal elements of the upper n×n dimensional matrix of the load and deformation joint control matrix as the stiffness value k i 2 ; Define the initial equivalent stiffness of each leg as the superposition of stiffness value 1 and stiffness value 2, k i e =α·k i 1 +β·k i 2 , the sum of weight coefficients α and β is 1; drive the truck crane to perform the upper execution mode operation, and adjust the weight coefficients α and β with the goal of minimizing the error between the measured chassis inclination angle and the theoretical chassis inclination angle, and then obtain the optimized equivalent stiffness k of each leg i e ; Step 10: Based on formula 1, the theoretical load model is strengthened to calculate the optimal load of the next step angle in advance, which is recorded as {F i * }: With the maximum sum of the loads on the distal outriggers as the goal, the mechanical balance of the truck crane as the equality constraint, and the upper and lower limits of the distal and proximal outriggers as the inequality constraints, solve the optimal load of the strengthening theory. Among them, F k is the load on the remote outrigger of the hoist, and its upper and lower limits are set as and the total weight of the truck crane G; F m is the load on the proximal leg of the hoist, and its upper and lower limits are set to 0 and The far leg k is used to solve the distance between each leg i and the load And judge whether it is greater than the mean distance Sure; Step 11, overturning risk diagnosis: set the lower limit load of the hoisting weight distal leg described in the enhanced theoretical load model to zero and negative values ​​respectively, and calculate two sets of enhanced theoretical optimal loads {F i * }0 and {F i * }-; define the capsizing risk index V e0 and V e - Capsizing risk diagnosis and intervention are performed according to the following rules: If V e0 and V e - are all positive, then it is absolutely safe and proceed to the next step; if V e0 V is positive e - is negative, the load will approach the safety limit, warning the operator to proceed with the next step with caution; if V e0 and V e - If all are negative, the operation will inevitably overturn, warning the operator and cutting off the loading operation; Step 12, advance calculation of the chassis inclination angle and leg load of the feedforward feedback composite control at the next step of the distance angle: In step 9, the chassis inclination angle {θ′ m Subtract the current chassis inclination angle measured in step 8 from Then subtract the optimal posture {0°,0°} T , get the chassis inclination angle of feedforward feedback compound control The loads for each leg {F i Subtract the current load of each leg measured in step 8 from {F i t }, minus the theoretical optimal load {F i * }, and obtain the outrigger load {F i * -F i t -F i '}; Step 13, using formula 3, the geometry and load coupling control equation, calculate the base leg compensation required for chassis state control {e i } Furthermore, the basic outrigger compensation amount is subtracted from its average value to obtain the actual outrigger compensation amount {e i ′} n×1 In formula 4, {e i ′} is the compensation amount of each leg required to restore the chassis to a horizontal level and maintain the theoretical optimal load of each leg when the upper body reaches the next step angle according to the operation instruction; Step 14, control the upper body to operate according to the instruction; at the same time, control each leg to move synchronously according to the compensation amount of each leg; the actuation speed is based on the upper body completing the next step of the angle operation and all legs completing the corresponding compensation amount, that is, satisfying formula 5 In formula 5, Δt is the time interval for completing the next angle operation; In step 15, the chassis inclination angle and the outrigger load are measured and the operator's operation instructions are monitored cyclically: if there are still instructions input, the process returns to step 9 for iteration; if the instructions stop, the control ends.

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