A synchronous control method for compound movements of excavators

Abstract

This invention discloses a method for synchronously controlling the compound movements of an excavator, comprising the following steps: adjusting the opening of an electronically controlled handle to control the changes in high-speed on / off valves 3 and 4, thereby controlling the movement of the boom; a boom end angle sensor acquires the boom angle change in real time and transmits it to a controller; the controller calculates the horizontal velocity change of the boom-arm hinge, thereby determining the relationship between the linear velocity of the arm cylinder and the handle opening, and further deriving the control currents for high-speed on / off valves 1 and 2. By replacing traditional dual-handle control with a single-handle control, this invention reduces operational difficulty and improves system coordination, reliability, and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a method for synchronously controlling compound actions of an excavator. Background Art

[0002] The performance of an excavator's dual-action synchronization control is a key indicator of its ease of operation. Currently, simultaneous activation of both excavator actions is achieved through separate control. This approach suffers from poor synchronization, making it difficult to guarantee construction quality under certain conditions. Furthermore, the complexity of the operation requires high operator skills.

[0003] Key performance indicators for large hydraulic excavators, both domestically and internationally, include system reliability and stability. Frequent starting, reversing, and braking operations result in significant fluctuations in the external load on the hydraulic system, leading to significant vibration and impact, which seriously impacts the coordination of excavation operations. The performance of an excavator's hydraulic system depends not only on component reliability and overall machine installation, but also on the degree of system compatibility. Excavators place high demands on the complexity and coordinated movement of actuators such as the boom, arm, and bucket.

[0004] With the improvement of people's living standards and the needs of special working occasions, operators have increasingly higher requirements for the operating comfort and intelligent control of excavators. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention proposes a method and system for synchronous control of compound actions of an excavator, which can be operated by only a single handle and has high synchronization, reliability and stability.

[0006] The specific technical solutions are as follows:

[0007] A method for synchronously controlling compound motions of an excavator is implemented based on a synchronous control system for compound motions of the excavator. The synchronous control system for compound motions of the excavator comprises: a bucket cylinder, a boom cylinder, a high-speed switch valve 1, a high-speed switch valve 2, a high-speed switch valve 3, a high-speed switch valve 4, a boom, a bucket, a bucket, and a controller.

[0008] The head end of the boom is hinged to the boom, and the tail end is hinged to the excavator base, and the tail end of the boom is provided with an angle sensor; one end of the boom cylinder is hinged to the middle part of the boom, and the other end is hinged to the excavator base, the upper chamber of the boom cylinder is connected to the oil tank through a high-speed switch valve four, and the lower chamber is connected to the oil tank through a high-speed switch valve three; one end of the arm cylinder is hinged to the boom, and the other end is hinged to the boom; the upper chamber of the arm cylinder is connected to the oil tank through a high-speed switch valve one, and the lower chamber is connected to the oil tank through a high-speed switch valve two; the lower end of the boom is hinged to the bucket; the controller is connected to the angle sensor, high-speed switch valve one, high-speed switch valve two, high-speed switch valve three, and high-speed switch valve four, respectively;

[0009] The excavator compound motion synchronous control method specifically comprises the following steps:

[0010] S1: The controller obtains the control current of the high-speed switch valve 3 and the high-speed switch valve 4 according to the handle opening, and controls the opening and closing of the high-speed switch valve 3 and the high-speed switch valve 4 to control the contraction or extension of the boom cylinder at this time, thereby driving the movement of the boom;

[0011] S2: The angle sensor at the tail end of the boom sends the change in boom rotation angle to the controller, which calculates the angular velocity of the boom tail hinge point, and then obtains the change in linear velocity of the boom-arm hinge point. Based on the angle between the linear velocity of the boom-arm hinge point and the horizontal direction, the change in horizontal velocity of the boom-arm hinge point is obtained. The boom rotation angle is the angle formed by the line connecting the upper hinge point of the boom cylinder and the boom tail hinge point and the horizontal direction. The change in boom rotation angle is measured by the angle sensor at the tail end of the boom.

[0012] S3: The horizontal speed of the boom cylinder-arm hinge is equal to the horizontal speed of the boom-arm hinge, thereby obtaining the relationship between the speed of the boom cylinder-arm hinge, i.e., the linear speed of the boom cylinder and the handle opening;

[0013] S4: According to the relationship between the linear velocity of the boom cylinder and the control current of the high-speed switch valve 1 and the high-speed switch valve 2, the control current of the high-speed switch valve 1 and the high-speed switch valve 2 is obtained to realize synchronous control of the excavator's compound action.

[0014] Furthermore, in step S1, the relationship between the handle opening S and the control current I1 is expressed as follows:

[0015] I1=K*S

[0016] Where K is a parameter set artificially.

[0017] Furthermore, in step S2, the control current I1, the boom angle θ1, the boom angle change Δθ1, the angular velocity ω of the boom tail hinge, and the linear velocity change V of the boom-arm hinge are X2 The relationship between the linear velocity of the boom-arm hinge and the horizontal angle θ2, the angle θ3 formed by the three hinge points of the boom cylinder upper hinge point, the boom tail hinge point and the boom-arm hinge point, and the horizontal velocity change V2 of the boom-arm hinge point is expressed as follows:

[0018] Δθ1=I1*K1

[0019] θ2=90°-(θ1-θ3)

[0020] y X2 =ω*X B

[0021] V2=V X2 *Cos(62)

[0022] In the formula, K1 is a parameter set by humans, X B It is the length of the line segment connecting the boom tail hinge and the boom-arm hinge.

[0023] Furthermore, in step S3, the relationship between the linear velocity V3 of the boom cylinder and the handle opening S is expressed as:

[0024] V3=ω*X B *Cos(90°-(K1*K*S).

[0025] Furthermore, in step S4, the relationship between the linear velocity V3 of the boom cylinder and the control current I2 of the high-speed switch valve 1 and the high-speed switch valve 2 is expressed as follows:

[0026] V3=K2*I2.

[0027] Furthermore, in step S1, when the high-speed switch valve three is opened and the high-speed switch valve four is closed, the pressure oil enters the lower chamber of the boom cylinder through the high-speed switch valve three, and the boom cylinder extends; when the high-speed switch valve three is closed and the high-speed switch valve four is opened, the pressure oil enters the upper chamber of the boom cylinder through the high-speed switch valve four, and the boom cylinder contracts.

[0028] Furthermore, when the high-speed switch valve 1 is opened and the high-speed switch valve 2 is closed, the pressure oil enters the upper chamber of the boom cylinder through the high-speed switch valve 1, and the boom cylinder contracts; when the high-speed switch valve 1 is closed and the high-speed switch valve 2 is opened, the pressure oil enters the lower chamber of the boom cylinder through the high-speed switch valve 2, and the boom cylinder extends.

[0029] The beneficial effects of the present invention are:

[0030] (1) The present invention replaces the double-handle control in the prior art with a single-handle control in some special working conditions requiring complex actions, thereby reducing the difficulty of operation. At the same time, the improvement of control accuracy greatly improves the construction quality.

[0031] (2) The present invention replaces the traditional double-handle control with a single handle control under the working condition of compound actions, thereby solving the problem in the prior art that the double-handle control needs to be frequently started and stopped during construction, causing the system to constantly impact and oscillate, resulting in serious damage to the handles of hydraulic components and poor coordination. The system of the present invention does not have the impact caused by frequent switching of two actions, thereby greatly improving coordination and having higher reliability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a hydraulic principle diagram of the excavator compound motion synchronous control system of the present invention.

[0033] Figure 2 It is a principle diagram of the motion mechanism of the excavator compound motion synchronization control system of the present invention.

[0034] Figure 3 It is a flow chart of the excavator compound action synchronous control method of the present invention.

[0035] In the figure, the arm cylinder 1, the boom cylinder 2, the high-speed switch valve 1 3, the high-speed switch valve 2 4, the high-speed switch valve 3 5, the high-speed switch valve 4 6, the boom 7, and the arm 8. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become more apparent. The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0037] like Figure 1 、 2 As shown, the excavator compound action synchronization control system includes: bucket cylinder 1, boom cylinder 2, high-speed switch valve 1 3, high-speed switch valve 2 4, high-speed switch valve 3 5, high-speed switch valve 4 6, boom 7, bucket 8, and controller (not shown in the figure).

[0038] The boom 7 is V-shaped, with its forward end hinged to the middle of the boom 8 and its rear end hinged to the excavator base (not shown). The hinge point between the boom 7 and the excavator base is the boom tail hinge. Both the forward and rear ends of the boom 7 are equipped with angle sensors (not shown). The telescopic end of the boom cylinder 2 is hinged to the middle of the boom 7, at this hinge point known as the boom cylinder upper hinge. The fixed end of the boom cylinder 2 is hinged to the excavator base, and the upper and lower chambers of the boom cylinder 2 are connected to the fuel tank via high-speed on / off valves 3 and 4, respectively. The fixed end of the boom cylinder 1 is hinged to the middle upper end of the boom 7, and its telescopic end is hinged to the upper end of the boom 8. The upper and lower chambers of the boom cylinder 1 are connected to the fuel tank via high-speed on / off valves 1 and 3, respectively. A telescopic rod for adaptive adjustment is hinged to the left side of the boom 8. The extended end of this telescopic rod and the lower end of the boom 8 are hinged to the bucket. The controller is connected to the angle sensor, the high-speed switch valve 1 3 , the high-speed switch valve 2 4 , the high-speed switch valve 3 5 , and the high-speed switch valve 4 6 respectively.

[0039] like Figure 3 As shown, based on the above excavator compound motion synchronization control system, a method for excavator compound motion synchronization control is proposed, and the specific steps are as follows:

[0040] S1: Set the handle opening of the excavator's control handle to S. The controller calculates the control current I1 for high-speed switch valve 3 5 and high-speed switch valve 4 6 connected to the boom cylinder 2 based on the handle opening S. The relationship between the handle opening S and the control current I1 is as follows:

[0041] I1=K*S

[0042] Where K is a parameter set artificially.

[0043] Pressurized oil enters the P2 port from the oil tank, passes through high-speed switch valve 35 or high-speed switch valve 46, and then enters the boom cylinder 2. The boom cylinder 2 extends or retracts, thereby driving the movement of the boom 7. When the high-speed switch valve 35 is open and the high-speed switch valve 46 is closed, the pressurized oil passes through the high-speed switch valve 35 and enters the lower chamber of the boom cylinder 2, and the boom cylinder 2 extends; when the high-speed switch valve 35 is closed and the high-speed switch valve 46 is open, the pressurized oil passes through the high-speed switch valve 46 and enters the upper chamber of the boom cylinder 2, and the boom cylinder 2 retracts. The relationship between the linear velocity of the boom cylinder 2 and the control current I1 is expressed as:

[0044] V1=K2*I1

[0045] Where K2 is a parameter set artificially.

[0046] At the same time, arm cylinder 1 contracts or extends under the action of pressurized oil. When high-speed on-off valve 13 is open and high-speed on-off valve 24 is closed, pressurized oil flows from port P1, passes through high-speed on-off valve 13, and enters the upper chamber of arm cylinder 1, causing arm cylinder 1 to contract. When high-speed on-off valve 13 is closed and high-speed on-off valve 24 is open, pressurized oil flows from port P1, passes through high-speed on-off valve 24, and enters the lower chamber of arm cylinder 1, causing arm cylinder 1 to extend. The control current for high-speed on-off valve 13 and high-speed on-off valve 24 is I2. The relationship between the linear velocity V3 of arm cylinder 1 and the control current I2 is expressed as:

[0047] V3=K2*I2

[0048] S2: After the boom 7 starts to move, the angle sensor at the tail end of the boom 7 sends the boom angle change Δθ1 to the controller. The controller calculates the angular velocity ω of the boom tail hinge point = Δθ1 / Δt based on the feedback of the boom angle change Δθ1, and then obtains the linear velocity change V of the boom-arm hinge point. X2 According to the angle θ2 between the linear velocity of the boom-arm hinge and the horizontal direction, the horizontal velocity change V2 of the boom-arm hinge is obtained.

[0049] Among them, the boom angle θ1 is the angle formed by the line between the upper hinge point of the boom cylinder and the boom tail hinge point and the horizontal direction, which is measured by the sensor on the boom tail hinge point; the angle θ3 formed by the three hinge points of the boom cylinder upper hinge point, the boom tail hinge point, and the boom-arm hinge point is fixed and measurable, and the angle θ4 formed by the line between the boom tail hinge point and the boom-arm hinge point and the horizontal direction is complementary to θ2, and θ4 = θ1-θ3, so θ2 = 90°-(θ1-θ3).

[0050] The relationship between the control current I1 and the arm angle change Δθ1 is expressed as follows:

[0051] Δθ1=I1*K1

[0052] Where K1 is a parameter set artificially.

[0053] Linear velocity change of the boom-arm hinge point V X2 The expression of the horizontal velocity change V2 of the boom-arm hinge is as follows:

[0054] V x2 =ω*X B

[0055] V2=V X2 *Cos(θ2)

[0056] Where, X B It is the length of the line segment connecting the boom tail hinge and the boom-arm hinge.

[0057] S3: Since the horizontal velocity change V2 of the boom-arm hinge is approximately equal to the compensation velocity V3 of the arm cylinder-arm hinge, that is, the linear velocity V3 of the arm cylinder 1, V3 = V2. In summary, the relationship between the linear velocity V3 of the arm cylinder 1 and the handle opening S is expressed as follows:

[0058] V3=ω*X B *Cos(90°-(K1*K*S)

[0059] S4: Based on the relationship between the linear velocity of arm cylinder 1 and the control current I2 of the corresponding high-speed on / off valves 1-3 and 2-4 (V3 = K2 * I2), the value of control current I2 is calculated, causing the arm cylinder to perform corresponding compensation to maintain the horizontal distance between the bucket and the cab. At this point, the values ​​of control currents I1 and I2 are adjusted according to the handle opening S, achieving synchronous control of the excavator's compound movements.

[0060] In the present invention's compound-action synchronous control mode, when the handle opening S of the excavator's control handle changes, the controller determines the required linear velocity of the boom cylinder 1 based on the feedback of the boom angle change, and further determines the control current I2 for high-speed on / off valves 1 3 and 2 4 connected to the boom cylinder 1. This ensures that any opening of the electronic control handle corresponds to a constant boom rotation speed. Compensatory control maintains a constant distance between the bucket and the cab at any rotation speed, greatly simplifying the operation of dual-action synchronous control and reducing operational difficulty.

[0061] Those skilled in the art will understand that the foregoing descriptions are merely preferred embodiments of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art will still be able to modify the technical solutions described in the foregoing examples or substitute equivalents for some of the technical features therein. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the invention shall be included within the scope of protection of the invention.

Claims

1. A method for synchronous control of compound motions of an excavator, characterized in that: It is realized based on the excavator compound motion synchronization control system, which includes: a bucket rod cylinder, a boom cylinder, a high-speed switch valve 1, a high-speed switch valve 2, a high-speed switch valve 3, a high-speed switch valve 4, a boom, a bucket rod, a bucket, and a controller; The head end of the boom is hinged to the boom, and the tail end is hinged to the excavator base, and the tail end of the boom is provided with an angle sensor; one end of the boom cylinder is hinged to the middle part of the boom, and the other end is hinged to the excavator base, the upper chamber of the boom cylinder is connected to the oil tank through a high-speed switch valve four, and the lower chamber is connected to the oil tank through a high-speed switch valve three; one end of the arm cylinder is hinged to the boom, and the other end is hinged to the boom; the upper chamber of the arm cylinder is connected to the oil tank through a high-speed switch valve one, and the lower chamber is connected to the oil tank through a high-speed switch valve two; the lower end of the boom is hinged to the bucket; the controller is connected to the angle sensor, high-speed switch valve one, high-speed switch valve two, high-speed switch valve three, and high-speed switch valve four, respectively; The excavator compound motion synchronous control method specifically comprises the following steps: S1: The controller obtains the control current of the high-speed switch valve 3 and the high-speed switch valve 4 according to the handle opening, and controls the opening and closing of the high-speed switch valve 3 and the high-speed switch valve 4 to control the contraction or extension of the boom cylinder at this time, thereby driving the movement of the boom; S2: The angle sensor at the tail end of the boom sends the change in boom rotation angle to the controller, which calculates the angular velocity of the boom tail hinge point, and then obtains the change in linear velocity of the boom-arm hinge point. Based on the angle between the linear velocity of the boom-arm hinge point and the horizontal direction, the change in horizontal velocity of the boom-arm hinge point is obtained. The boom rotation angle is the angle formed by the line connecting the upper hinge point of the boom cylinder and the boom tail hinge point and the horizontal direction. The change in boom rotation angle is measured by the angle sensor at the tail end of the boom. S3: The horizontal speed of the boom cylinder-arm hinge is equal to the horizontal speed of the boom-arm hinge, thereby obtaining the relationship between the speed of the boom cylinder-arm hinge, i.e., the linear speed of the boom cylinder and the handle opening; S4: According to the relationship between the linear velocity of the boom cylinder and the control current of the high-speed switch valve 1 and the high-speed switch valve 2, the control current of the high-speed switch valve 1 and the high-speed switch valve 2 is obtained to realize synchronous control of the excavator's compound action.

2. The excavator compound motion synchronization control method according to claim 1, characterized in that: In step S1, the relationship between the handle opening S and the control current I1 is expressed as follows: I1=K*S Where K is a parameter set artificially.

3. The excavator compound motion synchronization control method according to claim 2, characterized in that: In step S2, the control current I1, the boom angle θ1, the boom angle change Δθ1, the angular velocity ω of the boom tail hinge, and the linear velocity change V of the boom-arm hinge are X2 The relationship between the linear velocity of the boom-arm hinge and the horizontal angle θ2, the angle θ3 formed by the three hinge points of the boom cylinder upper hinge point, the boom tail hinge point and the boom-arm hinge point, and the horizontal velocity change V2 of the boom-arm hinge point is expressed as follows: Δθ1=I1*K1 θ2=90°-(θ1-θ3) V X2 =ω*X B V2=V X2 *Cos(θ2) In the formula, K1 is a parameter set by humans, X B It is the length of the line segment connecting the boom tail hinge and the boom-arm hinge.

4. The excavator compound motion synchronization control method according to claim 3, characterized in that: In step S3, the relationship between the linear velocity V3 of the boom cylinder and the handle opening 2 is expressed as follows: V3=ω*X B *Cos(90°-(K1*K*S)).

5. The excavator compound motion synchronization control method according to claim 4, characterized in that: In step S4, the relationship between the linear velocity V3 of the boom cylinder and the control current I2 of the high-speed switch valve 1 and the high-speed switch valve 2 is expressed as follows: V3=K2*I2.

6. The excavator compound motion synchronization control method according to claim 1, characterized in that: In step S1, when the high-speed switch valve 3 is opened and the high-speed switch valve 4 is closed, the pressure oil enters the lower chamber of the boom cylinder through the high-speed switch valve 3, and the boom cylinder extends; When the high-speed switch valve three is closed and the high-speed switch valve four is opened, the pressure oil enters the upper chamber of the boom cylinder through the high-speed switch valve four, and the boom cylinder contracts.

7. The excavator compound motion synchronization control method according to claim 1, characterized in that: When the high-speed switch valve 1 is opened and the high-speed switch valve 2 is closed, the pressure oil enters the upper chamber of the boom cylinder through the high-speed switch valve 1, and the boom cylinder contracts; when the high-speed switch valve 1 is closed and the high-speed switch valve 2 is opened, the pressure oil enters the lower chamber of the boom cylinder through the high-speed switch valve 2, and the boom cylinder extends.

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