A control system and method for a work device to actuate unstably

Abstract

This invention relates to the field of engineering machinery technology, and discloses a control system and method for preventing unstable operation of a working device. In the initial stage of operating the working device's control handle, a working device control sensor collects control signals and transmits them to a controller. When the working device is in the initial stage and its corresponding gravity provides assistance, the control method is activated, and the controller controls the working device's action valve to be in a partially open state. When the working device is in the initial stage and its corresponding gravity provides no assistance, the control method strategy is not used. The beneficial effect of this invention is that it prevents unstable operation from the very beginning of the working device's movement, thus preventing instability during the initial stage of the entire working device operation.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and specifically to a control system and method for unstable operation of a working device. Background Technology

[0002] The working devices of construction machinery (such as excavators) can experience instability due to gravity during single-action movements. For example, during the outward swing of the boom, the main forces are gravity and hydraulic pressure. Gravity initially acts as a positive pull (assistance), but beyond 90°, it becomes a resistance force. The angle of the working device before operation (the initial stage) significantly affects the system pressure. For instance, if the angle between the working device and the cab is acute before operation, the outward swing angle gradually changes from acute to obtuse after startup. Since system pressure builds up relatively slowly in the initial stage, this shift from an acute assist to an obtuse resistance force causes a drastic change in system pressure, leading to instability. This instability results in unstable boom force, causing problems such as second-speed issues and jamming during operation. The same applies to other working devices. Therefore, it is essential to improve the stability of system pressure during the initial stage of the working device operation.

[0003] Currently, methods such as reducing flow acceleration, delaying the start time of flow loading, and not loading the flow rates of the two pumps simultaneously are generally used to attempt to counteract the instability caused by gravity. However, the optimization of flow loading methods has limited effectiveness in improving the aforementioned problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a control system and method for unstable operation of a working device, which prevents instability from occurring at the beginning of the operation of the working device, thereby ensuring that the entire working device does not experience instability at the beginning stage.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention proposes a method for controlling unstable operation of a working device, comprising the following steps:

[0007] At the beginning stage of operating the control handle of the working device, the control sensor of the working device collects the control signal and transmits the control signal to the controller. After receiving the control signal, the controller sends a command to the main pump to increase the flow rate, and sends a command to the main valve to increase the opening degree of the corresponding working device action valve through the solenoid valve of the working device action valve.

[0008] When the working device is in the initial stage and the gravity of its corresponding working device provides assistance, the control method of the present invention is activated, and the controller controls the working device's action valve to be in a non-fully open state; when the working device is in the initial stage and the gravity of its corresponding working device provides no assistance (i.e., resistance), the control method strategy of the present invention is not used / is exited.

[0009] It should be noted that at the beginning of operating the working device, the operating handle is in the fully open position.

[0010] In conjunction with the first aspect, further, in the initial stage of the working device, the method for determining whether gravity plays an assisting role is as follows: by observing the system pressure and time, it is determined whether gravity of the working device plays an assisting role; if the system pressure is greater than N within T milliseconds after the start of the action, it is determined that the gravity of the current working device plays an assisting role; otherwise, the gravity of the current working device does not play an assisting role.

[0011] In conjunction with the first aspect, further, the value range of T is 100ms to 150ms, and the value range of N is 8 to 20 bar.

[0012] In conjunction with the first aspect, further, a working device angle sensor is added to the control system on which the control method is based to replace the method of judging whether the gravity of the working device plays an assisting role by observing the system pressure value and time. The working device angle sensor directly detects the position of the working device (i.e., the outward swing angle), thereby directly determining whether gravity plays an assisting role in the initial stage of the working device (e.g., gravity plays an assisting role in the outward swing of the stick when the stick is at 90° to the position on the driver's side, and plays a resistance role when it exceeds 90°).

[0013] In conjunction with the first aspect, further, the specific method by which the controller controls the working device actuation valve to maintain a non-fully open state at a certain opening value is as follows: throughout the entire process of the working device actuation valve being in a non-fully open state, the opening degree of the working device actuation valve and the corresponding holding time of the opening degree are adjusted according to the system pressure value and the slope of the system pressure change.

[0014] In conjunction with the first aspect, the method for adjusting the opening degree of the working device's actuating valve is as follows:

[0015] S=k*cosθ*P1 / Pm*a*S0

[0016] Where S is the opening value of the working device's actuating valve, θ is the angle between the working device's movement direction and the vertical direction at the beginning, P1 is the maximum value of the system pressure reached in the initial stage when the control method is not used, Pm is the system overflow pressure, which is generally 340 bar, a is the flow acceleration set by the control system, which is a preset target value of the control system and is a constant, S0 is the maximum opening of the working device's actuating valve, and k is a debugging coefficient, a parameter related to the working device of the excavator, which is an unknown quantity.

[0017] In conjunction with the first aspect, the method for determining the holding time of the corresponding opening degree is as follows: when the current system pressure reaches its maximum value, the holding limit of the current corresponding opening degree ends, and the system enters another opening degree state.

[0018] In conjunction with the first aspect, the method for determining whether the current system pressure has reached its maximum value is as follows: four pressure values ​​continuously changing in the system pressure are collected in real time by a system pressure sensor, namely point1, point2, point3, and point4. The slope between point1 and point2 is dp0, the slope between point2 and point3 is dp1, and the slope between point3 and point4 is dp2. When dp0 > 0 and dp2 < 0, it is determined that the system pressure has reached its maximum value; otherwise, the system pressure has not reached its maximum value.

[0019] Secondly, this invention proposes a control system for unstable operation of a working device, comprising a working device operation sensor, a controller, a main pump, a main pump pressure sensor, a working device actuation valve, and a solenoid valve corresponding to the working device actuation valve; it also includes a working device angle sensor; the working device operation sensor and the working device angle sensor are respectively communicatively connected to the controller for transmitting their respective collected data to the controller; the main pump pressure sensor and the solenoid valve corresponding to the working device actuation valve are respectively electrically connected to the controller; the main pump pressure sensor is mechanically connected to the main pump, and the solenoid valve corresponding to the working device actuation valve is mechanically connected to the working device actuation valve; the main pump pressure sensor is used to collect the pressure of the main pump and transmit the main pump pressure data to the controller; the solenoid valve corresponding to the working device actuation valve is used to receive instructions transmitted by the controller and adjust the opening degree of the working device actuation valve.

[0020] In conjunction with the second aspect, the operating sensor of the working device further includes a pressure sensor for detecting the electric control handle and the corresponding action pilot pressure. The electric control handle and the pressure sensor for the corresponding action pilot pressure are respectively communicatively connected to the controller. The electric control handle sends the signal of the operator operating the handle to the controller. The pressure sensor for the corresponding action pilot pressure is used to collect the pilot pressure data of each action of the corresponding working device and transmit the pressure data to the controller.

[0021] In conjunction with the second aspect, the pressure sensor corresponding to the action pilot pressure further includes a pressure sensor for collecting the stick outward swing pilot pressure, a pressure sensor for collecting the bucket outward swing pilot pressure, and a pressure sensor for collecting the boom outward swing pilot pressure.

[0022] In conjunction with the second aspect, the operating device manipulation sensor and the operating device angle sensor are further connected to the controller via CAN communication or electrical connection.

[0023] In conjunction with the second aspect, the working device actuation valve further includes a stick selection valve, a bucket selection valve, and a boom selection valve, and the solenoid valves corresponding to the working device actuation valve include a stick selection valve solenoid valve, a bucket selection valve solenoid valve, and a boom selection valve solenoid valve.

[0024] In conjunction with the second aspect, further, the working device actuation valve is integrated into the main valve of the construction machinery; the boom selector valve, bucket selector valve, and boom selector valve are assembled and integrated together, and the assembly and integration method is existing technology.

[0025] Compared with the prior art, the present invention provides a control system and method for unstable operation of a working device, which has the following beneficial effects:

[0026] (1) The control system of the present invention adds an angle sensor of the working device to transmit the real-time collected outward swing angle of the working device (such as the boom) to the controller. The controller compares it with the preset angle value to obtain the result of whether the action valve is fully open or not fully open. Then, the problem of unstable action of the working device is solved by not fully opening the action valve and maintaining it for a certain period of time.

[0027] (2) The control method of the present invention prevents the occurrence of motion instability problems from the beginning stage of the operation of the working device, so that the motion instability problem will not occur in the beginning stage of the entire working device.

[0028] (3) The control method of the present invention is applied to the operation of the excavator working device. When the operating handle is fully open, the main valve maintains a certain opening degree and continues for a certain period of time according to the system pressure at the beginning of the operation, so as to solve the problem of unstable operation of the working device. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the control system in Embodiment 1 of the present invention;

[0030] Figure 2 This is a flowchart of the control method of Embodiment 1 of the present invention;

[0031] Figure 3The main pump pressure change diagram and the boom swing pilot pressure change diagram recorded on the recorder before implementing the control method of the present invention;

[0032] Figure 4 The main pump pressure change diagram and the boom swing pilot pressure change diagram are recorded on the recorder after implementing the control method of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention. Example 1

[0036] like Figure 2 As shown, the control method of the present invention includes the following steps:

[0037] At the beginning stage of operating the control handle of the working device, the control sensor of the working device collects the control signal and transmits the control signal to the controller. After receiving the control signal, the controller sends a command to the main pump to increase the flow rate, and sends a command to the main valve to increase the opening degree of the corresponding working device action valve through the solenoid valve of the working device action valve.

[0038] When the working device is in the initial stage and the gravity of its corresponding working device provides assistance, the control method of the present invention is activated, and the controller controls the working device's action valve to be in a non-fully open state; when the working device is in the initial stage and the gravity of its corresponding working device provides no assistance (i.e., resistance), the control method strategy of the present invention is not used / is exited.

[0039] It should be noted that at the beginning of operating the working device, the operating handle is in the fully open position.

[0040] In one specific embodiment of this example, the method for determining whether gravity plays a supporting role in the initial stage of the working device is as follows: the gravity of the working device is determined by observing the system pressure and time; if the system pressure is greater than N within T milliseconds after the start of the action, it is determined that the gravity of the current working device plays a supporting role; otherwise, the gravity of the current working device does not play a supporting role.

[0041] In one specific embodiment of this example, the value of T ranges from 100ms to 150ms, and the value of N ranges from 8 to 20 bar. The values ​​of T and N are different for different working devices, and are usually determined based on experience. For example, when the working device is a boom, T is generally 100ms or 150ms, and N is 10 bar.

[0042] In one specific embodiment of this example, the method by which the controller controls the working device actuation valve to remain in a non-fully open state at a certain opening value is as follows: throughout the entire process of the working device actuation valve being in a non-fully open state, the opening degree of the working device actuation valve and the corresponding holding time of the opening degree are adjusted according to the system pressure value and the slope of the system pressure change.

[0043] In one specific embodiment of this invention, the method for adjusting the opening degree of the working device's actuation valve is as follows:

[0044] S=k*cosθ*P1 / Pm*a*S0

[0045] Where S is the opening value of the working device's actuating valve, θ is the angle between the working device's movement direction and the vertical direction at the beginning, P1 is the maximum value of the system pressure reached in the initial stage when the control method is not used, Pm is the system overflow pressure, which is generally 340 bar, a is the flow acceleration set by the control system, which is a preset target value of the control system and is a constant, S0 is the maximum opening of the working device's actuating valve, and k is a debugging coefficient, a parameter related to the working device of the excavator, which is an unknown quantity.

[0046] In one specific embodiment of this example, the method for determining the holding time of the corresponding opening degree is as follows: when the current system pressure reaches the maximum value, the holding limit of the current corresponding opening degree ends, and the system enters another opening degree state.

[0047] In one specific embodiment of this example, the method for determining whether the current system pressure has reached its maximum value is as follows: four pressure values ​​(point1, point2, point3, and point4) that continuously change in system pressure are collected in real time by a system pressure sensor. The slope between point1 and point2 is dp0, the slope between point2 and point3 is dp1, and the slope between point3 and point4 is dp2. When dp0 > 0 and dp2 < 0, it is determined that the system pressure has reached its maximum value; otherwise, the system pressure has not reached its maximum value.

[0048] pass Figure 3 and Figure 4 The comparison shows that, using the control method of the present invention, the main pump pressure, i.e. the system pressure fluctuation, is significantly reduced, indicating that the stability of the working device is increased. Example 2

[0049] The difference between Example 2 and Example 1 is that: an angle sensor of the working device is added to the control system on which the control method is based, instead of the method of judging whether the gravity of the working device plays a supporting role by observing the system pressure value and time.

[0050] like Figure 1 and Figure 2 As shown, in the control system on which the control method of the present invention is based, a working device angle sensor is added to replace the method of judging whether the gravity of the working device plays an assisting role by observing the system pressure value and time. The working device angle sensor directly detects the position of the working device (i.e., the outward swing angle), so it is possible to directly determine whether gravity plays an assisting role in the initial stage of the working device (e.g., when the stick is at 90° to the position on the driver's side, gravity plays an assisting role in the outward swing of the stick, and when it exceeds 90°, it plays a resisting role). Example 3

[0051] like Figure 1As shown, the present invention also proposes a control system, including a working device operation sensor, a controller, a main pump, a main pump pressure sensor, a working device actuation valve, and a solenoid valve corresponding to the working device actuation valve; it also includes a working device angle sensor; the working device operation sensor and the working device angle sensor are respectively communicatively connected to the controller for transmitting their respective collected data to the controller; the main pump pressure sensor and the solenoid valve corresponding to the working device actuation valve are respectively electrically connected to the controller; the main pump pressure sensor is mechanically connected to the main pump, and the solenoid valve corresponding to the working device actuation valve is mechanically connected to the working device actuation valve; the main pump pressure sensor is used to collect the pressure of the main pump and transmit the main pump pressure data to the controller; the solenoid valve corresponding to the working device actuation valve is used to receive the instructions transmitted by the controller and adjust the opening degree of the working device actuation valve.

[0052] In one specific embodiment of this example, the working device control sensor includes a pressure sensor for detecting the electric control handle and the corresponding action pilot pressure. The electric control handle and the pressure sensor for the corresponding action pilot pressure are respectively communicatively connected to the controller. The electric control handle sends the signal of the operator operating the handle to the controller. The pressure sensor for the corresponding action pilot pressure is used to collect the pilot pressure data of each action of the corresponding working device and transmit the pressure data to the controller.

[0053] In one specific embodiment of this example, the pressure sensor corresponding to the action pilot pressure includes a pressure sensor for collecting the stick outward swing pilot pressure, a pressure sensor for collecting the bucket outward swing pilot pressure, and a pressure sensor for collecting the boom outward swing pilot pressure.

[0054] In one specific embodiment of this example, the working device manipulation sensor and the working device angle sensor are connected to the controller via CAN communication or electrical connection.

[0055] In one specific embodiment of this example, the working device actuation valve includes a stick selector valve, a bucket selector valve, and a boom selector valve, and the solenoid valves corresponding to the working device actuation valve include a stick selector valve solenoid valve, a bucket selector valve solenoid valve, and a boom selector valve solenoid valve.

[0056] In one specific embodiment of this invention, the working device actuation valve is integrated into the main valve of the construction machinery; the boom selector valve, bucket selector valve, and arm selector valve are assembled and integrated together, and the assembly and integration method is existing technology. It should be noted that in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A control method of work device action instability, characterized by, Includes the following steps: At the beginning of operating the control handle of the working device, the working device control sensor collects the control signal and transmits the control signal to the controller; When the working device is in the initial stage and the gravity of its corresponding working device provides assistance, the control method is activated, and the controller controls the working device's actuation valve to be in a non-fully open state; when the working device is in the initial stage and the gravity of its corresponding working device does not provide assistance, the controller controls the working device's actuation valve to be in a fully open state.

2. The control method of unstable operation of a work machine according to claim 1, characterized by In the initial stage of the working device, the method for determining whether gravity plays a supporting role is as follows: the gravity of the working device is determined by observing the system pressure and time; if the system pressure is greater than N within T milliseconds after the start of the action, it is determined that the gravity of the current working device is playing a supporting role. Conversely, the gravity of the current working device does not play a supporting role.

3. The method for controlling unstable operation of a working device according to claim 2, characterized in that: Instead of relying on observing system pressure values ​​to determine whether gravity is providing assistance, an angle sensor for the working device is added. The angle sensor directly detects the position of the working device, thus enabling a direct determination of whether gravity is providing assistance in the initial stage of the working process.

4. The control method for unstable operation of a working device according to claim 1, characterized in that, The specific method by which the controller controls the working device actuation valve to remain in a non-fully open state at a certain opening value is as follows: throughout the entire process of the working device actuation valve being in a non-fully open state, the opening degree of the working device actuation valve and the corresponding holding time of the opening degree are adjusted according to the system pressure value and the slope of the system pressure change.

5. The control method for unstable operation of a working device according to claim 4, characterized in that, The method for adjusting the opening degree of the working device's actuating valve is as follows: ； Wherein, S is the opening value of the working device's actuating valve, θ is the angle between the working device's movement direction and the vertical direction at the beginning, P1 is the maximum value of the system pressure reached in the initial stage when the control method is not used, Pm is the system overflow pressure, a is the flow acceleration set by the control system, S0 is the maximum opening of the working device's actuating valve, k is the adjustment coefficient, and a parameter related to the working device of the excavator is an unknown quantity.

6. The control method for unstable operation of a working device according to claim 4, characterized in that, The method for determining the holding time of the corresponding opening degree is as follows: when the current system pressure reaches the maximum value, the holding limit of the current corresponding opening degree ends and enters another opening degree state.

7. The control method for unstable operation of a working device according to claim 6, characterized in that, The method for determining whether the current system pressure has reached its maximum value is as follows: four pressure values ​​(point1, point2, point3, and point4) are continuously collected in real time by the system pressure sensor. The slope between point1 and point2 is dp0, the slope between point2 and point3 is dp1, and the slope between point3 and point4 is dp2. When dp0 > 0 and dp2 < 0, it is determined that the system pressure has reached its maximum value; otherwise, the system pressure has not reached its maximum value.

8. A control system for unstable operation of a working device, comprising a working device operation sensor, a controller, a main pump, a main pump pressure sensor, a working device actuation valve, and a solenoid valve corresponding to the working device actuation valve, characterized in that: It also includes a working device angle sensor; the working device control sensor and the working device angle sensor are respectively communicatively connected to the controller, used to transmit their respective collected data to the controller; the main pump pressure sensor and the solenoid valve corresponding to the working device actuation valve are respectively connected to the controller; the main pump pressure sensor is connected to the main pump, and the solenoid valve corresponding to the working device actuation valve is connected to the working device actuation valve; the main pump pressure sensor is used to collect the pressure of the main pump and transmit the main pump pressure data to the controller; the solenoid valve corresponding to the working device actuation valve is used to receive the instructions transmitted by the controller and adjust the opening degree of the working device actuation valve; When the working device is in the initial stage and the gravity of its corresponding working device provides assistance, the control system is activated, and the controller controls the working device's actuation valve to be in a non-fully open state; when the working device is in the initial stage and the gravity of its corresponding working device does not provide assistance, the controller controls the working device's actuation valve to be in a fully open state.

9. A control system for unstable operation of a working device according to claim 8, characterized in that: The operating sensor of the working device includes a pressure sensor for detecting the electric control handle and the corresponding action pilot pressure. The electric control handle and the pressure sensor for the corresponding action pilot pressure are respectively communicatively connected to the controller. The electric control handle sends the signal of the operator operating the handle to the controller. The pressure sensor for the corresponding action pilot pressure is used to collect the pilot pressure data of each action of the corresponding working device and transmit the pressure data to the controller.

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