A method for suppressing vibration of a boom tip during pumping operation of a concrete pump truck based on independent control of valve groups of a load port

Abstract

The application relates to a method for inhibiting vibration of the end of an arm support during pumping operation of a concrete pump truck, and relates to a method for inhibiting vibration of the end of an arm support during pumping operation of a concrete pump truck. The application aims to solve the technical problem that the method for inhibiting vibration of the end of an arm support during pumping operation of a concrete pump truck is difficult to take effect and is prone to causing personnel injury. The application inhibits vibration of the end of an arm support based on force generated by an arm support control hydraulic cylinder; the application sets a load port independent control valve group, adopts a novel feed-forward-feedback compound control algorithm to realize inhibition of vibration of the end of an arm support of a pump truck during pumping operation, improves operation efficiency and precision, and protects operation safety. The application adopts an active vibration inhibition method, is based on the original hydraulic system of an arm support of a concrete pump truck, does not need to add extra hardware, and can be easily realized on an existing pump truck.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for inhibiting the vibration of the end of the boom of a concrete pump truck during pumping operation. BACKGROUND

[0002] During the pumping operation of the concrete pump truck, the end of the boom will vibrate greatly during the pouring operation under the action of the pumping system and external excitation, etc. and thus the end hose will swing, affecting the construction accuracy. Therefore, multiple construction personnel often use ropes to tie the hose to control the direction to reduce the influence of vibration on the pumping construction accuracy. When large-area flat pouring operation is performed, it is easy to control, but when point pouring of beams, columns, walls, etc. is performed, the control difficulty is significantly increased. According to the description of the construction personnel, in the case of poor feeding, the vibration amplitude of the end hose of the boom can reach more than 1 meter. At this time, the method of rope traction and worker hand holding is difficult to work, and is easy to cause personnel injury.

[0003] Active boom control is a control method for generating appropriate signals for the hydraulic valve to control the movement of the hydraulic cylinder of the boom. Although it has greater energy consumption compared to passive control method which does not require any current to control the hydraulic valve, active control can be based on the original hydraulic system of the boom of the concrete pump truck, without the need for additional hardware, so it can be easily implemented on existing pump trucks. SUMMARY

[0004] The present application is to solve the technical problem that the current method for inhibiting the vibration of the end of the boom of a concrete pump truck during pumping operation is difficult to work and easy to cause personnel injury, and to provide a method for inhibiting the vibration of the end of the boom of a concrete pump truck during pumping operation based on independent control of valve groups at the load port.

[0005] The method for inhibiting the vibration of the end of the boom of a concrete pump truck during pumping operation based on independent control of valve groups at the load port of the present application is performed according to the following steps:

[0006] Step 1, build a hydraulic system for independent control of the load port of the boom of a concrete pump truck, which includes a hydraulic module, a control module and a sensing module; the concrete pump truck is a six-section concrete pump truck;

[0007] The hydraulic module is a rodless cavity control valve group for controlling the rodless cavity of the hydraulic cylinder and a rod cavity control valve group for controlling the rod cavity of the hydraulic cylinder, the hydraulic cylinder is installed between each arm support of the concrete pump truck, the rodless cavity control valve group and the rod cavity control valve group each contain two plug-in proportional flow valves, which are an oil inlet proportional flow valve for controlling oil inlet and an oil return proportional flow valve for controlling oil return, the two proportional flow valves in each valve group have a one-way conduction function without input, the conduction direction of the oil inlet proportional flow valve is from the working port to the high-pressure oil pipeline, and the conduction direction of the oil return proportional flow valve is from the oil return pipeline to the working port, a one-way valve is installed at the oil return pipeline of the oil return proportional flow valve and the working cavity of the oil inlet proportional flow valve respectively to realize locking of the oil cylinder at a specified position, and a pressure compensator is installed at the front end of the oil inlet proportional flow valve to improve the linearity level of flow control under high pressure difference.

[0008] The control module includes a core controller and a proportional valve coil amplifier with double output channels, the core controller is responsible for collection of sensor signals, calculation of proportional flow valve control values and transmission and reception of CAN bus signals, the rodless cavity control valve group and the rod cavity control valve group are each provided with a proportional valve coil amplifier with double output channels, the proportional valve coil amplifier with double output channels receives CAN bus instructions sent by the core controller to generate excitation current for controlling the valve core stroke of the oil inlet proportional flow valve and the oil return proportional flow valve in the valve group.

[0009] The sensing module includes 12 pressure sensors and two acceleration sensors, the 12 pressure sensors are installed at the working ports connected to the hydraulic cylinders of the respective hydraulic valve blocks, and the two acceleration sensors are installed at the bottom of the pump truck arm support and the end of the last section of the arm support respectively.

[0010] Step 2: calculate the feedforward compensation control value based on the vibration acceleration signal of the bottom of the concrete pump truck, the control value is the excitation current value of the proportional flow valve, and the calculation is as follows: the output acceleration value r(k) of the acceleration sensor installed at the bottom of the pump truck arm support is used as the excitation-related parameter of the arm support system, r(k) passes through a feedforward compensation control filter to generate a feedforward compensation control value u F (k) to suppress the vibration at the end of the arm support, u F (k) is current, and the calculation process is as follows:

[0011] 2.1: the calculation method of the feedforward compensation control value: the feedforward compensation control filter in the last paragraph adopts an adaptive FIR filter, the i-th coefficient at the k-th sampling time is defined as h i (k), and the calculation formula of the output feedforward compensation control value u F (k) of the filter is:

[0012]

[0013] where N is the order of the filter, i.e. the number of its coefficients; since r(k) is measured, it is only necessary to find the filter coefficients h i (k) to obtain the feedforward compensation control u F (k); the optimization condition for the filter coefficients h i (k) is to minimize the vibration acceleration a S (k) at the end of the boom, i.e. to minimize;

[0014] 2.2: Calculate the vibration acceleration a F (k) of the boom system due to the feedforward control input only, from:

[0015]

[0016] where g j is the discrete impulse response of the control input to output path P F (k) of order M, j = 1,...,M; the control signal needs to go through a part of the boom physical system before the output is measured by the acceleration sensor, g j is obtained from experimental tests;

[0017] 2.3: Calculate the vibration acceleration a S (k) at the end of the boom system, expressed as:

[0018] a S (k) = a u (k) + a F (k)

[0019] By step 2.2 change to

[0020]

[0021] where a u (k) is the boom end acceleration response due to the main disturbance (boom base vibration) only (a known quantity, obtained from acceleration sensor tests), the order of the convolution can be interchanged without changing the calculation result, the above equation can be rewritten as:

[0022]

[0023] where:

[0024]

[0025] By rearranging the convolution, define a virtual signal denoted as the estimate of which is

[0026] 2.4: In order to obtain the most suitable filter coefficient h i (k), design a cost function J that is quadratically related to the output:

[0027]

[0028] Therefore, the vibration of the boom end can be minimized by adjusting the coefficients to minimize the cost function J;

[0029] 2.5: Calculate the filter coefficient h i (k), the adaptive iterative algorithm used can be written as:

[0030]

[0031] Where λ is the convergence coefficient (known quantity); according to the definition of the cost function J, the differential term in the above formula can be changed to:

[0032]

[0033] 2.6: For step 2.5 h i The calculation formula of (k) is simplified, because a S (k) to h i The derivative of (k) is Therefore, using the estimated to replace So the steepest descent algorithm of the adaptive FIR filter coefficients in step 2.5 can be rewritten as:

[0034]

[0035] Among them, λ determines the speed and stability of the controller coefficient adaptation process, a S (k) is obtained through acceleration sensor testing;

[0036] So far, we have obtained h i The value of (k) is substituted into the formula in 2.1 to obtain the feedforward compensation control quantity u F (k);

[0037] Step 3: Model the rigid-flexible coupling structure of the pump truck boom system: Use the symbol right subscript (*) s To distinguish symbols represented by the same letter, superscript (*) s To specify the affiliation with an object (coordinate system, arm section, etc.); for example, the Jacobian matrix The right subscript v indicates that the matrix is ​​a translation Jacob matrix, and the right superscript i indicates that the matrix is ​​based on the rectangular coordinate system ∑ i , the calculation process is as follows:

[0038] 3.1: Define the joint angles of the six single-DOF revolute joints of the six-section concrete pump truck boom as θ i , i = 1...6; combine all joint angles into a vector, defined as the driving variable θ ∈ R 6 ; add a virtual joint on each boom section, defined as a twist around the Z-axis of the local coordinate system, to simulate the elastic DOF of each boom section in the vertical plane, define the angle of the virtual joint in the orthogonal coordinate system fixed to the i-th boom section as γ i , combine all virtual joint angles into a vector, defined as the elastic variable γ ∈ R 6 ; the resulting lumped parameter model can be used to approximate the deformation of the boom in the vertical plane, combine the driving and elastic variables into the generalized variable q = [θ T γ T ] T ∈ R 12 ;

[0039] 3.2: Calculate the forward kinematics formula of the local coordinate system ∑ i :

[0040]

[0041] where v i and ω i ∈ R 3 are the translational and rotational velocities of the i-th boom section's local coordinate system ∑ i relative to the inertial coordinate system ∑ I , and are the corresponding translational and rotational Jacobian matrices;

[0042] In general, to simplify the analysis, the boom system is assumed to be a rigid structure, i.e. γ = 0, so we have:

[0043]

[0044] 3.3: Add the flexible deformation part γ, divide the Jacobian matrix into rigid and elastic parts:

[0045]

[0046] where the Jacobian matrix describes the influence of the driving velocity on v i ; describes the influence of the driving velocity on ω i ; describes the influence of the elastic velocity on vi of the influence of the The elastic velocity of the influence of the i of the influence of the

[0047] 3.4: Calculate the planar mechanical structure model of the concrete pump truck boom system based on 3.2 and 3.3, which is given by the following formula:

[0048]

[0049] where M ∈ R 12×12 is the mass matrix, c ∈ R 12 is the Coriolis force and centrifugal force vector, g ∈ R 12 is the gravity vector, which is divided into the driving variable block g θ (θ, γ) ∈ R 6 and the elastic variable block g γ (θ, γ) ∈ R 6 , K ∈ R 6×6 and D ∈ R 6 ×6 are the system stiffness and damping matrices, respectively, T u represents the kinematic transformation relationship between the length vector of each hydraulic cylinder and the driving coordinate vector θ; u ∈ R 6 is the input vector of the boom system, which is composed of the output forces of the six hydraulic cylinders;

[0050] Step 4: Calculate the feedback compensation control based on the concrete pump truck boom end acceleration signal, the calculation process is as follows:

[0051] 4.1: Linearize the model obtained in step 3.4 near the working point q = q i , at the same time, since the gravity and Coriolis force external force terms have little effect on the boom vibration, the corresponding terms are ignored, and the linearized equation of the boom system is obtained:

[0052]

[0053] where M i , D i and K i represent the inertia matrix, damping matrix and stiffness matrix, respectively;

[0054] 4.2: In order to simplify the analysis, refer to the general second-order mechanical system, define the state space vector z:

[0055]

[0056] Rewrite the linearized equation of the boom system in step 4.1 with z as the state variable, which is:

[0057]

[0058] 4.3: Define the vector as the first two modal coordinates of the boom system, and perform the coordinate transformation:

[0059] δq = φ q,i β i q,i

[0060] where φ i represents the eigenvector related to the controlled mode extracted from the eigenvector matrix of the boom system; Substitute the above equation into the linearized equation of the boom system in 4.1 to obtain a set of independent modal equations:

[0061]

[0062] where m i , d i and k i are all 2x2 diagonal matrices;

[0063] 4.4: In order to apply the state-space control method to the modal-reduced boom system, rewrite the second equation in 4.3 into the state-space form to obtain the modal state-space equation:

[0064]

[0065] where:

[0066]

[0067] 4.5: Define the feedback control as:

[0068]

[0069] Substitute the above equation into the first equation of 4.4, i.e., the modal state-space equation, to obtain:

[0070]

[0071] where the eigenvalue λc of matrix A c represents the pole of the controlled boom system;

[0072] 4.6: Define U β,i as the right eigenvector matrix of the boom system, and design the gain matrix of the feedback control as follows:

[0073]

[0074] where, represents the upper half of B β,i ; when B β,i ​For square matrix, the input quantity is as many as the degree of freedom, this formula can be applied to any second order system (G β ) is calculated in this step

[0075] 4.7: The formula for calculating the feedback control quantity in step 4.5 requires the modal coordinate β i , which cannot be directly measured, so a modal observer needs to be constructed to estimate the relevant mode, and the state space equation of the modal observer is written as:

[0076]

[0077] Where G o is the modal observer gain matrix, represents the estimated modal coordinate, i.e. β i , a and represent the acceleration sensor measurement vector and the acceleration estimation vector respectively, a is the input of the modal observer, is determined by the acceleration observer, and its calculation formula is:

[0078]

[0079] Where matrix C o and matrix D o represent the dependence of the estimated modal coordinate and the control force respectively;

[0080] 4.8: The modal observer gain matrix G o is calculated by using the pole placement method, and the calculation method of the gain matrix G o is:

[0081] G ο = G T (c o -c)

[0082] Where G T is a Toeplitz matrix, and the matrix column vector c and c o contain the characteristic polynomial coefficients of the reduced modal space matrix A β and the modal observer state space matrix (A β -G ο C ο ), respectively; u1 and u2 can be obtained by G o , 4.7 and 4.5, both of which are currents;

[0083] Step 5: The feedforward compensation control quantity u F ​(k) and the feedback compensation control amount obtained in step 4, to obtain the output control amount of the oil inlet proportional flow valve of the rodless chamber of the first arm section hydraulic cylinder, and the feedback compensation control amount u1 obtained in step 4 is the output control amount of the oil inlet proportional flow valve of the rodless chamber of the second arm section hydraulic cylinder; the oil return proportional flow valve of the rodless chamber of the first arm section hydraulic cylinder is opened by 10%; the oil return proportional flow valve of the rodless chamber of the second arm section hydraulic cylinder is opened by 10%; the two proportional flow valves of the rod chamber of the first arm section hydraulic cylinder are closed, and the two proportional flow valves of the rod chamber of the second arm section hydraulic cylinder are closed; all valves of the third arm section hydraulic cylinder to the sixth arm section hydraulic cylinder are closed; and the vibration of the arm tip in the pumping operation of the concrete pump truck can be inhibited through the operation of step 5.

[0084] The present application suppresses the vibration of the arm tip based on the force generated by the arm control hydraulic cylinder; the present application sets a load port independent control valve group, and uses a novel feedforward-feedback composite control algorithm to realize the suppression of the vibration of the arm tip of the pump truck in the pumping operation, improves the operation efficiency and precision, protects the operation safety, and can solve the problems mentioned in the background art.

[0085] The present application has the following beneficial effects:

[0086] Firstly, the present application adopts a concrete pump truck arm hydraulic system based on a load port independent control valve, so that the problems of increased energy consumption and low control freedom caused by the control coupling of the oil inlet and outlet ports of the cylinder in the prior art are overcome, and the pressure impact generated in the reversing process of the hydraulic cylinder is avoided;

[0087] Secondly, the present application adopts an active vibration suppression method, and based on the original hydraulic system of the concrete pump truck arm, no additional hardware is needed, so that the present application can be easily realized on the existing pump truck;

[0088] Thirdly, the external disturbance applied to the arm system is composed of many continuous pulse excitation signals, in the composite vibration suppression method of the present application, in the control strategy, the feedforward vibration suppression algorithm can offset the specific frequency pulse disturbance generated by the pumping system, and the feedback vibration suppression algorithm can offset the remaining external disturbance, thereby effectively avoiding the situation of personnel injury. BRIEF DESCRIPTION OF DRAWINGS

[0089] Figure 1 is a flowchart of the concrete pump truck arm tip vibration suppression method based on the load port independent control valve group of the present application;

[0090] Figure 2 is a hydraulic principle diagram of the distributed load port independent control valve group in test one;

[0091] Figure 3 is a feedforward vibration suppression algorithm diagram of the present application (corresponding to step 2).

[0092] Figure 4 is a schematic diagram of the structure of the concrete pump truck boom system (6 boom sections);

[0093] Figure 5 is a schematic diagram of the rigid-flexible coupling model of the boom section of the present application (corresponding to step 3);

[0094] Figure 6 is a schematic diagram of the modal observer scheme of the present application (corresponding to steps 4.7 and 4.8);

[0095] Figure 7 is a schematic diagram of the feedforward-feedback composite vibration suppression method of the present application (corresponding to step 5);

[0096] Figure 8 is a schematic diagram of three typical postures of the concrete pump truck boom during the pumping operation in Test 1;

[0097] Figure 9 is the effect of the vibration suppression method under the low-end arch-type posture in Test 1;

[0098] Figure 10 is the effect of the vibration suppression method under the high-end arch-type posture in Test 1;

[0099] Figure 11 is the effect of the vibration suppression method under the horizontal straight-type posture in Test 1. DETAILED DESCRIPTION

[0100] Embodiment 1: The present embodiment is a method for suppressing the vibration of the boom end of a concrete pump truck during the pumping operation based on the independent control valve group of the load port, which is specifically performed according to the following steps:

[0101] Step 1, build a hydraulic system for independent control of the load port of the boom of a concrete pump truck, which includes a hydraulic module, a control module and a sensing module; the concrete pump truck is a six-section concrete pump truck.

[0102] The hydraulic module is a rodless cavity control valve group for controlling the rodless cavity of the hydraulic cylinder and a rod cavity control valve group for controlling the rod cavity of the hydraulic cylinder, and the hydraulic cylinder is a hydraulic cylinder installed between each boom of the concrete pump truck; the rodless cavity control valve group and the rod cavity control valve group each contain two cartridge-type proportional flow valves, which are an oil inlet proportional flow valve for controlling oil inlet and an oil return proportional flow valve for controlling oil return.

[0103] The control module comprises a core controller and a double-output channel proportional valve coil amplifier; the core controller is responsible for sensor signal acquisition, proportional flow valve control quantity calculation and CAN bus signal transmission and reception; the rodless cavity control valve group and the rod cavity control valve group each are provided with a double-output channel proportional valve coil amplifier, the double-output channel proportional valve coil amplifier receives the CAN bus instruction sent by the core controller, and generates an excitation current used to control the spool stroke of the oil inlet proportional flow valve and the oil return proportional flow valve in the valve group;

[0104] The sensing module comprises 12 pressure sensors and two acceleration sensors; the 12 pressure sensors are installed at the working ports of the hydraulic valve blocks connected with the hydraulic cylinders, and the two acceleration sensors are respectively installed at the bottom of the pump truck boom and the end of the last section boom;

[0105] Step 2: calculate the feedforward compensation control quantity based on the vibration acceleration signal of the bottom of the concrete pump truck, the control quantity is the excitation current value of the proportional flow valve, and the specific process is as follows: the output acceleration value r(k) of the acceleration sensor installed at the bottom of the pump truck boom is used as the excitation-related parameter of the boom system, r(k) passes through the feedforward compensation control filter to generate the feedforward compensation control quantity u F (k) to suppress the vibration at the end of the boom, u F (k) is the current, and the calculation process is as follows:

[0106] 2.1: define the calculation method of the feedforward compensation control quantity: the feedforward compensation control filter process described in the above paragraph adopts an adaptive FIR filter, and the i-th order coefficient of the filter at the k-th sampling time is defined as h i (k), and the calculation formula of the output feedforward compensation control quantity u F (k) of the filter is:

[0107]

[0108] Wherein, N is the order of the filter, that is, the number of its coefficients; since r(k) is measured, the filter coefficient h i (k) can be obtained, and the feedforward compensation control quantity u F (k) can be obtained; the optimization condition for solving the filter coefficient h i (k) is to make the vibration acceleration a S (k) at the end of the last section boom be 0;

[0109] 2.2: calculate the vibration acceleration a F (k) of the boom system caused only by the feedforward control input, which is obtained by the following formula:

[0110]

[0111] where g j is the discrete impulse response of the control input to the output path P F (k), of order M, j = 1,..., M ; the control signal needs to pass through a part of the physical system of the boom before being measured by the output acceleration sensor, g j is obtained by experimental testing;

[0112] 2.3: Calculate the end of boom vibration acceleration a S (k), expressed as:

[0113] a S (k) = a u (k) + a F (k)

[0114] By changing 2.2 to

[0115]

[0116] where a u (k) is the end of boom acceleration response due to the main disturbance (boom base vibration r(k) ) alone (a known quantity, obtained by acceleration sensor testing), the above equation can be rewritten as:

[0117]

[0118] where:

[0119]

[0120] By rearranging the convolution, define a virtual signal denoted by whose estimate is

[0121] 2.4: In order to obtain the most suitable filter coefficients h i (k), design a cost function J that is quadratic in the output:

[0122]

[0123] Therefore, adjusting the coefficients to minimize the cost function J will minimize the vibration at the end of the boom;

[0124] 2.5: Calculate the filter coefficients h i (k), using an adaptive iterative algorithm that can be written as:

[0125]

[0126] Where λ is the convergence coefficient (known quantity); according to the definition of the cost function J, the differential term in the above formula can be changed to:

[0127]

[0128] 2.6: For h in step 2.5 i The calculation formula of (k) is simplified, because a S (k) to h i The derivative of (k) is Therefore, using the estimated to replace So the steepest descent algorithm of the adaptive FIR filter coefficients in step 2.5 can be rewritten as:

[0129]

[0130] Among them, λ determines the speed and stability of the controller coefficient adaptation process, a S (k) is obtained through acceleration sensor testing; so far, h i The value of (k) is substituted into the formula in 2.1 to obtain the feedforward compensation control quantity u F (k);

[0131] Step 3: Model the rigid-flexible coupling structure of the pump truck boom system: Use the symbol right subscript (*) s To distinguish symbols represented by the same letter, superscript (*) s To specify the affiliation with an object (coordinate system, arm section, etc.); for example, the Jacobian matrix The right subscript v indicates that the matrix is ​​a translation Jacob matrix, and the right superscript i indicates that the matrix is ​​based on the rectangular coordinate system ∑ i , the calculation process is as follows:

[0132] 3.1: Define the six single-degree-of-freedom articulated rotation joint angles of the six-section concrete pump truck boom as θ i , i = 1...6; all joint angles are combined into a vector, defined as the driving variable θ∈R 6 Add a virtual joint defined as a twist around the Z axis of each local coordinate system on each arm segment to simulate the elastic freedom of each arm segment on the vertical plane. Define the angle of the virtual joint in the fixed orthogonal coordinate system of the arm segment i as γ i , all virtual joint angles are combined into a vector, defined as the elastic variable γ∈R 6 The resulting lumped parameter model can be used to approximate the arm segment deformation in the vertical plane, combining the drive and elastic variables into a generalized variable q = [θ T γ T ] T ∈R12 ;

[0133] 3.2: Calculate the local coordinate system ∑ i The forward kinematics formula is:

[0134]

[0135] Among them, v i and ω i ∈R 3 are the local coordinate system ∑ of the i-th arm segment i Relative to the inertial coordinate system ∑ I The translation and rotation speeds, and are the Jacobian matrices of the corresponding translation and rotation, respectively;

[0136] In order to simplify the analysis, the boom system is usually assumed to be a rigid structure, that is, γ = 0, so:

[0137]

[0138] 3.3: Add the flexible deformation part γ and divide the Jacobian matrix into the rigid part and the elastic part:

[0139]

[0140] Among them, the Jacobian matrix Describes the drive speed v i the impact of; Describes the drive speed Right i the impact of; Describes the elastic velocity v i the impact of; Describes the elastic velocity Right i the impact of;

[0141] 3.4: Calculate the plane mechanical structure model of the concrete pump truck boom system, which is given by the following formula:

[0142]

[0143] where M∈R 12×12 is the mass matrix, c∈R 12 are the Coriolis and centrifugal force vectors, g∈R 12 is the gravity vector, which is divided into the driving variable block g θ (θ,γ)∈R 6 and elastic variable block g γ (θ,γ)∈R6 , K e R 6×6 and D e R 6 ×6 are system stiffness and damping matrices, respectively, T u represents the kinematic transformation between the length vector of each hydraulic cylinder and the driving coordinate vector θ; u e R 6 is the input vector of the boom system, which is composed of the output forces of the six hydraulic cylinders;

[0144] Step 4: Calculate the feedback compensation control amount based on the acceleration signal of the end of the concrete pump truck boom, and the calculation process is as follows:

[0145] 4.1: Linearize the model obtained in step 3.4 near the working point generalized variable q = q i At the same time, since the influence of gravity and Coriolis force external force terms on the boom vibration is small, the corresponding terms are ignored, and the linearized equation of the boom system is obtained:

[0146]

[0147] where M i , D i and K i represent the inertia matrix, the damping matrix and the stiffness matrix, respectively;

[0148] 4.2: In order to simplify the analysis, refer to the general second-order mechanical system, and define the state space vector z:

[0149]

[0150] Rewrite the linearized equation of the boom system in step 4.1 with z as the state variable, which has:

[0151]

[0152] 4.3: Define β q,i as the vector of the first two modal coordinates of the boom system, and perform coordinate transformation:

[0153] δq = φ i β q,i

[0154] where φ i represents the characteristic vector related to the controlled mode extracted from the characteristic vector matrix of the boom system; Substitute the above equation into the linearized equation of the boom system in 4.1 to obtain a group of independent modal equations:

[0155]

[0156] where m i , d i and ki are both 2x2 diagonal matrices;

[0157] 4.4: To apply the state-space control method to the modal-reduced jumbo system, the second formula in 4.3 is rewritten in state-space form, and the modal state-space equation is obtained:

[0158]

[0159] where:

[0160]

[0161] 4.5: The feedback control quantity is defined as:

[0162]

[0163] Substitute the above formula into the first formula of 4.4, i.e., the modal state-space equation, and we have:

[0164]

[0165] where the matrix A c has eigenvalues λcrepresenting the poles of the controlled jumbo system;

[0166] 4.6: Define U β,i as the right eigenvector matrix of the jumbo system, and the gain matrix of the feedback control is designed as follows:

[0167]

[0168] where, represents the upper half of B β,i ; when B β,i is a square matrix, it has as many inputs as degrees of freedom, and this formula can be applied to any second-order system (G β is calculated in this step);

[0169] 4.7: The calculation formula of the feedback control quantity in step 4.5 requires the system modal coordinates β i , which cannot be directly measured, so a modal observer needs to be constructed to estimate the relevant modes. The state-space equation of the modal observer is written as:

[0170]

[0171] where G o is the modal observer gain matrix, represents the estimated modal coordinates, i.e., β i , a and represent the acceleration sensor measurement vector and the acceleration estimation vector, respectively, a is the input of the modal observer, is determined by the acceleration observer, and its calculation formula is:

[0172]

[0173] wherein matrix C o and matrix D o respectively represent the dependence on the estimated modal coordinates and the control force;

[0174] 4.8: The modal observer gain matrix G o is calculated by using the pole placement method, and the calculation method of the gain matrix G o is:

[0175] G ο = G T (c o -c)

[0176] wherein G T is a Toeplitz matrix, and the matrix column vector c and c o respectively contain the characteristic polynomial coefficients of the reduced modal space matrix A β and the modal observer state space matrix (A β -G ο C ο ); u1 and u2 can be obtained by G o , 4.7 and 4.5, and u1 and u2 are both currents;

[0177] Step 5: The feedforward compensation control amount u F (k) obtained in step 2 and the feedback compensation control amount u2 obtained in step 4 are added to obtain the output control amount of the oil inlet proportional flow valve of the rodless cavity of the hydraulic cylinder of the first arm section of the boom; the feedback compensation control amount u1 obtained in step 4 is the output control amount of the oil inlet proportional flow valve of the rodless cavity of the hydraulic cylinder of the second arm section of the boom.

[0178] Specific implementation method two: The difference between this implementation method and the specific implementation method one is that the rodless cavity control valve group in step 1 further contains a safety valve for realizing the overpressure protection of the oil cylinder. The others are the same as the specific implementation method one.

[0179] Specific implementation method three: The difference between this implementation method and the specific implementation method two is that the rod cavity control valve group in step 1 further contains a safety valve for realizing the overpressure protection of the oil cylinder. The others are the same as the specific implementation method two.

[0180] Specific implementation four: the difference between this implementation and one of the specific implementations one to three is that the no-input middle function of the two proportional flow valves in each valve group in step 1 is one-way conduction. The others are the same as one of the specific implementations one to three.

[0181] Specific implementation five: the difference between this implementation and specific implementation four is that the conduction direction of the oil inlet proportional flow valve in step 1 is from the working port to the high-pressure oil line. The others are the same as specific implementation four.

[0182] Specific implementation six: the difference between this implementation and specific implementation five is that the conduction direction of the oil return proportional flow valve in step 1 is from the oil return line to the working port. The others are the same as specific implementation five.

[0183] Specific implementation seven: the difference between this implementation and specific implementation six is that a one-way valve is installed at the oil return proportional flow valve flow to the oil return line in step 1 to achieve the locking of the oil cylinder at the specified position. The others are the same as specific implementation six.

[0184] Specific implementation eight: the difference between this implementation and specific implementation seven is that a one-way valve is installed at the oil inlet proportional flow valve flow to the hydraulic cylinder working chamber in step 1 to achieve the locking of the oil cylinder at the specified position. The others are the same as specific implementation seven.

[0185] Specific implementation nine: the difference between this implementation and specific implementation eight is that a pressure compensator is installed at the front end of the oil inlet proportional flow valve in step 1 to improve the linearity level of flow control under high pressure difference. The others are the same as specific implementation eight.

[0186] Specific implementation ten: the difference between this implementation and specific implementation nine is that the oil return proportional flow valve of the rodless chamber of the first arm section hydraulic cylinder is opened by 10% in step 5; the oil return proportional flow valve of the rodless chamber of the second arm section hydraulic cylinder is opened by 10%; the two proportional flow valves of the rod chamber of the first arm section hydraulic cylinder are closed, and the two proportional flow valves of the rod chamber of the second arm section hydraulic cylinder are closed; all valves of the third arm section hydraulic cylinder to the sixth arm section hydraulic cylinder are closed; through the operation of step 5, the vibration of the arm end during the pumping operation of the concrete pump truck can be suppressed. The others are the same as specific implementation nine.

[0187] The following test is used to verify the present application:

[0188] Test one: this test is a method for suppressing the vibration of the arm end of a concrete pump truck during the pumping operation of the concrete pump truck based on the independent control of the valve group at the load port, which is specifically performed according to the following steps:

[0189] During the construction operation, the arm of the concrete pump truck is controlled by the valve group at the load port. Figure 4is a structural schematic diagram of an arm system of a concrete pump truck) is usually in three postures of a low end position arch posture a, a high end position arch posture b and a horizontal linear posture c as shown. Figure 8 In order to verify the effectiveness of the vibration suppression method proposed in the present application, an arm end vibration suppression test during pumping operation is carried out based on a 63-meter-long 6-section arm pump truck;

[0190] Step 1, build a hydraulic system based on independent control of the load port of the concrete pump truck arm, which includes a hydraulic module, a control module and a sensing module; the concrete pump truck is a six-section concrete pump truck;

[0191] The hydraulic module is as shown in Figure 2 Figure 2 is a hydraulic cylinder of one arm section), specifically a rodless cavity control valve group (left part in the figure) for controlling the rodless cavity of the hydraulic cylinder and a rod cavity control valve group (right part in the figure) for controlling the rod cavity of the hydraulic cylinder, the hydraulic cylinder 1 is a hydraulic cylinder installed between each arm of the concrete pump truck; the rodless cavity control valve group a and the rod cavity control valve group b each contain two cartridge type proportional flow valves, which are an oil inlet proportional flow valve (6-2 for the rodless cavity and 6-3 for the rod cavity) for controlling oil inlet and an oil return proportional flow valve (6-1 for the rodless cavity and 6-4 for the rod cavity) for controlling oil return; each valve group contains a safety valve 3-1 and 3-2 for realizing overpressure protection of the oil cylinder; each valve group contains a hydraulic lock 4-1 and 4-2; the no-input mid-function of the two proportional flow valves in each valve group is one-way conduction, the conduction direction of the oil inlet proportional flow valve (6-2 and 6-3) is from the working port to the high-pressure oil pipeline, and the conduction direction of the oil return proportional flow valve (6-1 and 6-4) is from the oil return pipeline to the working port, a one-way valve (5-1, 5-2, 5-3 and 5-4) is installed at the oil return proportional flow valve flow to the oil return pipeline and the oil inlet proportional flow valve flow to the hydraulic cylinder working cavity respectively to realize locking of the oil cylinder at the specified position; a pressure compensator (7-1 and 7-2) is installed at the front end of the oil inlet proportional flow valve to improve the linearity level of flow control under high pressure difference;

[0192] The control module includes a core controller and a proportional valve coil amplifier with double output channels; the core controller is responsible for acquisition of sensor signals, calculation of proportional flow valve control values and transceiving of CAN bus signals; the rodless cavity control valve group and the rod cavity control valve group are each configured with a proportional valve coil amplifier with double output channels, the proportional valve coil amplifier with double output channels receives the CAN bus instructions sent by the core controller to generate excitation current for controlling the valve core stroke of the oil inlet proportional flow valve and the oil return proportional flow valve in the valve group;

[0193] The sensing module includes 12 pressure sensors Figure 2 ​two acceleration sensors, because there are six arm sections, 12 pressure sensors are needed; the 12 pressure sensors are installed at the working ports of the hydraulic valve blocks connected to the hydraulic cylinders, and the two acceleration sensors are installed at the bottom of the pump truck boom and the end of the last section boom, respectively;

[0194] Step 2: calculate the feedforward compensation control amount based on the vibration acceleration signal at the bottom of the concrete pump truck, the control amount is the excitation current value of the proportional flow valve, and the calculation is as follows: the output acceleration value r(k) of the acceleration sensor installed at the bottom of the pump truck boom is used as the excitation-related parameter of the boom system, r(k) passes through the feedforward compensation control filter to generate the feedforward compensation control amount u F (k) to suppress the vibration at the end of the boom, u F (k) is the current, and the calculation process is as follows:

[0195] 2.1: define the calculation method of the feedforward compensation control amount: the feedforward compensation control filter process described in the previous paragraph uses an adaptive FIR filter, and the i-th coefficient at the k-th sampling time is defined as h i (k), and the calculation formula of the filter output feedforward compensation control amount u F (k) is:

[0196]

[0197] where N is the order of the filter, that is, the number of its coefficients; since r(k) is measured, only the filter coefficients h i (k) need to be solved to obtain the feedforward compensation control amount u F (k); the optimization condition for solving the filter coefficients h i (k) is to make the vibration acceleration a S (k) at the end of the last section boom zero;

[0198] 2.2: calculate the vibration acceleration a F (k) of the boom system caused only by the feedforward control input, which is obtained by the following formula:

[0199]

[0200] where g j is the discrete impulse response of the control input to output path P F (k), which is M order, j = 1,...,M; before being measured by the acceleration sensor, the control signal needs to pass through a part of the boom physical system, g j is obtained through experimental testing;

[0201] 2.3: calculate the vibration acceleration a S(k) = a

[0202] a S (k) = a u (k) + a F (k) by changing 2.2 to

[0203]

[0204] where a u (k) is the arm tip acceleration response due to the main disturbance (jib bottom vibration r(k)) alone (a known quantity, obtained by acceleration sensor testing), and since the order of convolution can be interchanged without changing the result of the calculation, the above equation can be rewritten as:

[0205]

[0206] where:

[0207]

[0208] By rearranging the convolution, define a virtual signal Let the estimate of

[0209] 2.4: To obtain the most suitable filter coefficients h i (k), design a cost function J that is quadratic in the output:

[0210]

[0211] Therefore, adjusting the coefficients to minimize the cost function J will minimize the vibration at the arm tip;

[0212] 2.5: Calculate the filter coefficients h i (k) using an adaptive iterative algorithm that can be written as:

[0213]

[0214] where λ is a convergence coefficient (a known quantity); according to the definition of the cost function J, the differential term in the above equation can be replaced by:

[0215]

[0216] 2.6: Simplify the calculation formula for h i (k) in step 2.5, since the derivative of a S (k) with respect to h i (k) is Therefore, use the estimate to replace So the steepest descent algorithm of the adaptive FIR filter coefficients in step 2.5 can be rewritten as:

[0217]

[0218] Among them, λ determines the speed and stability of the controller coefficient adaptation process, a S (k) is obtained through acceleration sensor testing; so far, h i The value of (k) is substituted into the formula in 2.1 to obtain the feedforward compensation control quantity u F (k);

[0219] Step 3: Model the rigid-flexible coupling structure of the pump truck boom system: Use the symbol right subscript (*) s To distinguish symbols represented by the same letter, superscript (*) s To specify the affiliation with an object (coordinate system, arm section, etc.); for example, the Jacobian matrix The right subscript v indicates that the matrix is ​​a translation Jacob matrix, and the right superscript i indicates that the matrix is ​​based on the rectangular coordinate system ∑ i , the calculation process is as follows:

[0220] 3.1: Define the six single-degree-of-freedom articulated rotation joint angles of the six-section concrete pump truck boom as θ i , i = 1...6; all joint angles are combined into a vector, defined as the driving variable θ∈R 6 Add a virtual joint defined as a twist around the Z axis of each local coordinate system on each arm segment to simulate the elastic freedom of each arm segment on the vertical plane. Define the angle of the virtual joint in the fixed orthogonal coordinate system of the arm segment i as γ i , all virtual joint angles are combined into a vector, defined as the elastic variable γ∈R 6 The resulting lumped parameter model can be used to approximate the arm segment deformation in the vertical plane, combining the drive and elastic variables into a generalized variable q = [θ T γ T ] T ∈R 12 ;

[0221] 3.2: Calculate the local coordinate system ∑ i The forward kinematics formula is:

[0222]

[0223] Among them, v i and ω i ∈R 3 are the local coordinate system ∑ of the i-th arm segment i Relative to the inertial coordinate system ∑I translation and rotation velocities, and are the corresponding Jacobian matrices of translation and rotation, respectively;

[0224] Generally, the arm system is assumed to be a rigid structure for simplicity of analysis, i.e. γ = 0, so that

[0225]

[0226] 3.3: Add the flexible deformation part γ, and divide the Jacobian matrix into rigid and elastic parts:

[0227]

[0228] where the Jacobian matrix describes the influence of the driving velocity on v i ; describes the influence of the driving velocity on ω i ; describes the influence of the elastic velocity on v i ; describes the influence of the elastic velocity on ω i ;

[0229] 3.4: Calculate the planar mechanical structure model of the concrete pump truck arm system, which is given by the following formula:

[0230]

[0231] where M ∈ R 12×12 is the mass matrix, c ∈ R 12 is the Coriolis force and centrifugal force vector, g ∈ R 12 is the gravity vector, which is divided into the driving variable block g θ (θ, γ) ∈ R 6 and the elastic variable block g γ (θ, γ) ∈ R 6 , K ∈ R 6×6 and D ∈ R 6 ×6 are the system stiffness and damping matrices, respectively, T u represents the kinematic transformation relationship between the length vector of each hydraulic cylinder and the driving coordinate vector θ; u ∈ R 6 is the input vector of the arm system, which is composed of the output forces of the six hydraulic cylinders;

[0232] Step 4: Calculate the feedback compensation control amount based on the concrete pump truck arm end acceleration signal, the calculation process is as follows:

[0233] 4.1: Linearize the model obtained in step 3.4 around the operating point q = q i Meanwhile, since the effects of gravity and Coriolis force on the vibration of the boom system are small, the corresponding terms are ignored, and the linearized equation of the boom system is obtained:

[0234]

[0235] where M i , D i and K i represent the inertia matrix, the damping matrix and the stiffness matrix, respectively;

[0236] 4.2: To simplify the analysis, refer to a general second-order mechanical system, and define the state space vector z:

[0237]

[0238] Rewrite the linearized equation of the boom system in step 4.1 with z as the state variable, and there is:

[0239]

[0240] 4.3: Define β q,i as the vector of the first two modal coordinates of the boom system, and perform coordinate transformation:

[0241] δq = φ i β q,i

[0242] where φ i represents the eigenvector related to the controlled mode extracted from the eigenvector matrix of the boom system; Substitute the above equation into the linearized equation of the boom system in 4.1 to obtain a group of independent modal equations:

[0243]

[0244] where m i , d i and k i are all 2 × 2 diagonal matrices;

[0245] 4.4: In order to apply the state space control method to the boom system after modal order reduction, rewrite the second formula in 4.3 into the state space form to obtain the modal state space equation:

[0246]

[0247] where:

[0248]

[0249] 4.5: Define the feedback control quantity as:

[0250]

[0251] Substituting the above equation into the first formula of 4.4, which is the modal state space equation, we have:

[0252]

[0253] Where the matrix A c The eigenvalue λc represents the pole of the controlled boom system;

[0254] 4.6: Define U β,i is the right eigenvector matrix of the boom system, and the gain matrix of the designed feedback control is as follows:

[0255]

[0256] in, Representative B β,i The upper part; when B β,i When it is a square matrix, the input quantity is as many as the degrees of freedom. This formula can be applied to any second-order system (this step calculates G β );

[0257] 4.7: The calculation formula of the feedback control quantity in step 4.5 requires the system modal coordinate β i , this coordinate cannot be measured directly, so it is necessary to construct a modal observer to estimate the relevant modes. The state space equation of the modal observer is written as:

[0258]

[0259] Among them, G o is the modal observer gain matrix, Represents the estimated modal coordinates, which is β i , a and Represent the acceleration sensor measurement value vector and the acceleration estimation value vector respectively, a is the input of the modal observer, It is determined by the acceleration observer and its calculation formula is:

[0260]

[0261] Where the matrix C o and matrix D o Respectively Dependence on estimated modal coordinates and control forces;

[0262] 4.8: Compute the modal observer gain matrix G by using the pole placement method o, gain matrix G o The calculation method is as follows:

[0263] G ο = G T (c o -c)

[0264] Wherein, G T is a toplex matrix, and the matrix column vectors c and c o respectively contain the characteristic polynomial coefficients of the reduced modal space matrix A β and the modal observer state space matrix (A β -G ο C ο );u1 and u2 can be obtained by G o , 4.7 and 4.5, both of which are currents;

[0265] Step 5: Add the feedforward compensation control quantity u F (k) obtained in step 2 and the feedback compensation control quantity u2 obtained in step 4 to obtain the output control quantity of the oil inlet proportional flow valve of the rodless cavity of the first arm section hydraulic cylinder, and the feedback compensation control quantity u1 obtained in step 4 is the output control quantity of the oil inlet proportional flow valve of the rodless cavity of the second arm section hydraulic cylinder (as shown in Figure 7 ); the oil return proportional flow valve of the rodless cavity of the first arm section hydraulic cylinder is opened by 10%; the oil return proportional flow valve of the rodless cavity of the second arm section hydraulic cylinder is opened by 10%; the two proportional flow valves of the rod cavity of the first arm section hydraulic cylinder are closed, and the two proportional flow valves of the rod cavity of the second arm section hydraulic cylinder are closed; all the valves of the third arm section hydraulic cylinder to the sixth arm section hydraulic cylinder are closed; through the operation of step 5, the vibration of the arm end during the pumping operation of the concrete pump truck can be suppressed.

[0266] At the beginning of the test, the pumping system of the pump truck carries out the water pumping operation, so that the arm is freely vibrated under the action of external force, and when the free vibration state of the arm reaches stability, the vibration signal of the arm end is recorded for 30s. Then, in order to compare the vibration state of the arm with and without active control input, the first arm section hydraulic cylinder and the second arm section hydraulic cylinder are used as control input based on the composite vibration suppression strategy to intervene in the vibration state of the arm, and after the vibration of the arm end stabilizes, the vibration signal of the arm end is also recorded for 30s. The comparison results of the experiment are shown in Figures 9-11 , Figure 9 is the effect of the vibration suppression method in the low end position arch type posture, Figure 10 is the effect of the vibration suppression method in the high end position arch type posture, Figure 11The effect of the vibration suppression method in the horizontal straight posture is shown in the results. According to the results, under the action of the control of the hydraulic cylinders of the first and second arm sections, the end vibration of the flexible long-boom crane in the three pumping postures is reduced by about 47.1%, 51.5%, and 60.9% during the static pumping operation. Therefore, it can be concluded that the proposed composite vibration suppression method can effectively suppress the vibration of the end of the boom caused by the pumping system operation disturbance and the like.

Claims

1. A method for suppressing boom end vibration during concrete pump truck pumping operation based on a load port independent control valve group, characterized in that The method for suppressing the vibration of the boom end during the pumping operation of a concrete pump truck based on the load port independent control valve group is carried out in the following steps: Step 1: Build an independent control hydraulic system based on the load port of the concrete pump truck boom, which includes a hydraulic module, a control module and a sensor module; The hydraulic module includes a rodless cavity control valve group for controlling the rodless cavity of the hydraulic cylinder and a rod cavity control valve group for controlling the rod cavity of the hydraulic cylinder. The hydraulic cylinder is a hydraulic cylinder installed between each boom of the concrete pump truck; the rodless cavity control valve group and the rod cavity control valve group each include two plug-in proportional flow valves, namely an oil inlet proportional flow valve for controlling oil inlet and an oil return proportional flow valve for controlling oil return; The control module includes a core controller and a dual-output channel proportional valve coil amplifier; the core controller is responsible for collecting sensor signals, calculating the proportional flow valve control quantity, and transmitting and receiving CAN bus signals; the rodless cavity control valve group and the rod cavity control valve group are each equipped with a dual-output channel proportional valve coil amplifier, which receives CAN bus commands sent by the core controller and generates excitation current for controlling the valve core stroke of the oil inlet proportional flow valve and the oil return proportional flow valve in the valve group; The sensing module includes multiple pressure sensors and two acceleration sensors; the pressure sensors are installed at the working ports of each hydraulic valve block connected to the hydraulic cylinder, and the two acceleration sensors are installed at the bottom of the pump truck boom and the end of the last boom respectively; Step 2: Determine the vibration acceleration a of the boom system end based on the vibration acceleration of the boom system caused by the feedforward control input s (k), and then get h i (k) is used to calculate the feedforward compensation control quantity, which is the excitation current value of the proportional flow valve, as follows: The output acceleration value r(k) of the acceleration sensor installed at the bottom of the pump truck boom is used as the excitation-related parameter of the boom system. Based on r(k), the vibration acceleration a of the boom system end is determined. s (k), and then get h i (k), using the feedforward compensation control filter to generate the feedforward compensation control quantity u F (k) To suppress the vibration of the boom end, u F (k) is the current. The feedforward compensation control filtering process uses an adaptive FIR filter, and its i-th order coefficient at the k-th sampling time is defined as h i (k), then the feedforward compensation control quantity u output by the filter is F The calculation formula for (k) is: Where N is the order of the filter, that is, the number of its coefficients; r(k) is the measured acceleration; Step 3: Conduct rigid-flexible coupling modeling of the pump truck boom system structure: Define the six single-degree-of-freedom articulated rotation joint angles of the multi-section concrete pump truck boom as θ i , i = 1...n, n is the number of arm segments; all joint angles are combined into a vector, defined as the driving variable θ∈R 6 Add a virtual joint defined as a twist around the Z axis of each local coordinate system on each arm segment to simulate the elastic freedom of each arm segment on the vertical plane. Define the angle of the virtual joint in the orthogonal coordinate system of the arm segment i as γ i , all virtual joint angles are combined into a vector, defined as the elastic variable γ∈R 6 The resulting lumped parameter model is used for the arm segment deformation in the vertical plane of the arm segment, combining the drive variables and the elastic variables into a generalized variable q = [θ T γ T ] T ∈R 12 ; The plane mechanical structure model of the concrete pump truck boom system is constructed, which is given by the following formula: where M∈R 12×12 is the mass matrix, c∈R 12 are the Coriolis and centrifugal force vectors, g∈R 12 is the gravity vector, which is divided into the driving variable block g θ (θ,γ)∈R 6 and elastic variable block g γ (θ,γ)∈R 6 , K∈R 6×6 and D∈R 6×6 are the system stiffness and damping matrices, T u Represents the kinematic transformation relationship between the length vector of each hydraulic cylinder and the driving coordinate vector θ; u∈R 6 is the input vector of the boom system, which is composed of the output force of the hydraulic cylinder; Step 4: Calculate the feedback compensation control variable u based on the acceleration signal of the concrete pump truck boom end. The process includes the following steps: 4.1: Define the state space vector z: Taking z as the state variable, the model obtained in step 3 is set at the working point q = q i Linearize around and get the linearized equation of the boom system: Among them, M i 、D i and K i represent the inertia matrix, damping matrix and stiffness matrix respectively; 4.2: β q,i Defined as the vector of the first two modal coordinates of the boom system, and perform coordinate transformation: δq=φ i b q,i where φ i represents the eigenvector related to the controlled mode extracted from the eigenvector matrix of the boom system; substituting the above formula into the linearized equation of the boom system in 4.1, the modal state space equation is obtained: in: where m i d i and k i are all 2×2 diagonal matrices; 4.3: Feedback control quantity Substituting the above formula into the modal state space equation, we have: Where the matrix A c The eigenvalue λc represents the pole of the controlled boom system; 4.4: Define U β,i is the right eigenvector matrix of the boom system, and the gain matrix of the feedback control is obtained: in, Representative B β,i the upper part; 4.5: The calculation formula of the feedback control quantity requires the system modal coordinate β i , a modal observer is constructed to estimate the relevant modes. The state space equation of the modal observer is written as: Among them, G o is the modal observer gain matrix, Represents the estimated modal coordinates, which is β i , a and Represent the acceleration sensor measurement value vector and the acceleration estimation value vector respectively, a is the input of the modal observer, It is determined by the acceleration observer and its calculation formula is: Where the matrix C o and matrix D o Respectively Dependence on estimated modal coordinates and control forces; 4.6: Compute the modal observer gain matrix G by using the pole placement method o , the gain matrix G o The calculation method is: G ο =G T (c o -c) Among them, G T is the Toeplitz matrix, the matrix column vectors c and c o Contains the reduced modal space matrix A β and the modal observer state space matrix (A β -G ο C ο ) characteristic polynomial coefficients; through G o , 4.3 and 4.5 can be used to obtain u1 and u2, where u1 and u2 are both currents; Step 5: The feedforward compensation control quantity u obtained in step 2 is F (k) is added to the feedback compensation control quantity u2 obtained in step 4 to obtain the output control quantity of the oil inlet proportional flow valve of the rodless chamber of the hydraulic cylinder of the first arm section of the boom. The feedback compensation control quantity u1 obtained in step 4 is the output control quantity of the oil inlet proportional flow valve of the rodless chamber of the hydraulic cylinder of the second arm section of the boom.

2. A method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 1, characterized in that The rodless chamber control valve group and the rod chamber control valve group described in step 1 each include a safety valve to achieve overpressure protection of the oil cylinder.

3. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 2 is characterized in that The no-input neutral position function of the two proportional flow valves in each valve group in step 1 is unidirectional conduction. The conduction direction of the oil inlet proportional flow valve is from the working port to the high-pressure oil pipeline, and the conduction direction of the oil return proportional flow valve is from the return oil pipeline to the working port.

4. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 3 is characterized in that In step 1, a one-way valve is installed at the oil return line of the return oil proportional flow valve and at the oil inlet proportional flow valve to the working chamber of the hydraulic cylinder to lock the cylinder at the specified position; a pressure compensator is installed at the front end of the oil inlet proportional flow valve to improve the linearity of flow control under high pressure difference.

5. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 1 is characterized in that In step 2, the vibration acceleration of the boom system caused by the feedforward control input is used to determine the end vibration acceleration a of the boom system. S (k) The process includes: First, determine the vibration acceleration a of the boom system caused by the feedforward control input. F (k): Among them, g j is the control input to output path P F (k) is the discrete impulse response of order M, j = 1, ..., M; g j It is obtained through experimental testing; Then according to a S (k) = a u (k)+a F (k) Then determine the vibration acceleration a of the boom system end S (k), where a u (k) is the acceleration response of the boom end due to the influence of the boom bottom vibration r(k) alone.

6. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 5 is characterized in that In step 2, you need to S (k) is converted into the following form, which is then used to obtain h i (k); is a virtual signal, remember The estimated value is 7. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 6 is characterized in that In step 2, based on a S (k) get h i In the process of (k), the steepest descent algorithm of the i-th order coefficient of the adaptive FIR filter is used to determine h i (k); The steepest descent algorithm for the i-th order coefficient of the adaptive FIR filter is: Among them, λ is the convergence coefficient, which determines the speed and stability of the controller coefficient adaptation process. for The estimated value of a S (k) is obtained through acceleration sensor testing; So far, we have obtained h i (k) value, substitute Obtain the feedforward compensation control quantity u F (k).

8. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 1 is characterized in that The plane mechanical structure model of the concrete pump truck boom system in step 3 is based on the following: Jacobian matrix The right subscript v indicates that the matrix is ​​a translation Jacob matrix, and the right superscript i indicates that the matrix is ​​based on the rectangular coordinate system ∑ i , Calculate the local coordinate system ∑ i The forward kinematics formula is: Among them, v i and ω i ∈R 3 are the local coordinate system ∑ of the i-th arm segment i Relative to the inertial coordinate system ∑ I The translation and rotation speeds, and are the Jacobian matrices of the corresponding translation and rotation, respectively; Split the Jacobian matrix into a rigid part and an elastic part: Among them, the Jacobian matrix Describes the drive speed v i the impact of; Describes the drive speed Right i the impact of; Describes the elastic velocity v i the impact of; Describes the elastic velocity Right i impact.

9. The method for suppressing boom end vibration during pumping operation of a concrete pump truck based on a load port independent control valve group according to claim 1 is characterized in that In step 5, the return oil proportional flow valve of the rodless chamber of the first boom section hydraulic cylinder is opened by 10%; the return oil proportional flow valve of the rodless chamber of the second boom section hydraulic cylinder is opened by 10%; the two proportional flow valves of the rod chamber of the first boom section hydraulic cylinder are closed, and the two proportional flow valves of the rod chamber of the second boom section hydraulic cylinder are closed; all valves of the third boom section hydraulic cylinder to the sixth boom section hydraulic cylinder are closed; the operation in step 5 can suppress the vibration of the boom end during the pumping operation of the concrete pump truck.

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