Control Method, System and Excavator for Reducing Instantaneous Flow Rate Fluctuation of Main Pump

Abstract

The present invention discloses a control method, system and excavator for reducing the instantaneous flow rate fluctuation of a main pump. The method includes calculating the average current duty ratio based on the acquired average current of the main pump; calculating the rotational speed fluctuation amount based on the acquired average rotational speed and instantaneous rotational speed of the engine; calculating the flutter current based on the rotational speed fluctuation amount and the average current of the main pump; calculating the flutter current duty ratio based on the flutter current; summing the average current duty ratio and the flutter current duty ratio to obtain the total duty ratio; using the rising edge or falling edge of the acquired engine speed signal as the trigger conduction signal; and generating and outputting a displacement control current for controlling the main pump based on the trigger signal and the total duty ratio. The present invention deeply integrates the average rotational speed and instantaneous rotational speed of the engine with the displacement control current parameter of the main pump, realizes the direct modulation of the displacement control current by using the engine speed parameter, and can be used to reduce the output flow rate fluctuation of the main pump caused by the engine speed fluctuation.

Description

Technical Field

[0001] The present invention belongs to the technical field of construction machinery, and particularly relates to a control system, a method and an excavator for reducing the instantaneous flow rate fluctuation of a main pump. Background Art

[0002] When the engine is in a low-speed and high-torque working state, it will cause large instantaneous speed fluctuations, especially for engines with less than 4 cylinders. Large instantaneous engine speed fluctuations will bring problems such as large vibrations in the hydraulic system, the engine, and the whole vehicle. In the prior art, in order to solve the problem of large instantaneous engine speed fluctuations, usually increasing the engine speed or restricting the engine torque is adopted to reduce the instantaneous engine speed fluctuations, but these two methods often affect the performance of the excavator at low speeds. Summary of the Invention

[0003] In view of the above problems, the present invention proposes a control system, a method and an excavator for reducing the instantaneous flow rate fluctuation of a main pump, which deeply integrates the average speed and the instantaneous speed of the engine with the displacement control current parameter of the main pump for controlling the main pump, and realizes the direct modulation of the displacement control current for controlling the main pump by using the engine speed parameter.

[0004] In order to achieve the above technical objectives and reach the above technical effects, the present invention is realized through the following technical solutions:

[0005] In a first aspect, the present invention provides a control method for reducing the instantaneous flow rate fluctuation of a main pump, including:

[0006] Calculating the average current duty ratio based on the obtained average current of the main pump;

[0007] Calculating the speed fluctuation amount based on the obtained average engine speed and the instantaneous engine speed;

[0008] Calculating the flutter current based on the speed fluctuation amount and the average current of the main pump;

[0009] Calculating the flutter current duty ratio based on the flutter current;

[0010] Summing the average current duty ratio and the flutter current duty ratio to obtain the total duty ratio;

[0011] Taking the rising edge or the falling edge of the obtained engine speed signal as the trigger conduction signal of the current module;

[0012] Generating and outputting a displacement control current for controlling the main pump by using the current module based on the trigger signal and the total duty ratio.

[0013] Optionally, the calculation formula for the speed fluctuation amount is:

[0014]

[0015] Wherein, η i is the rotational speed fluctuation amount, n i is the instantaneous rotational speed of the engine at the i-th moment, i = 0, 1, 2,..., is the average rotational speed of the engine.

[0016] Optionally, the calculation formula for the flutter current is:

[0017] I ci = kη i I si

[0018] Wherein, I ci is the flutter current, k is the proportionality coefficient, η i is the rotational speed fluctuation amount, I si is the average current of the main pump.

[0019] Optionally, the calculation formula for the current value of the displacement control current for controlling the main pump is:

[0020] I i = I si + I ci

[0021] Wherein, I i is the displacement control current for controlling the main pump, I si is the average current of the main pump, I ci is the flutter current.

[0022] Optionally, based on the trigger signal and the total duty cycle, generating a displacement control current for controlling the main pump, specifically:

[0023] Taking the trigger signal as the trigger conduction signal of the current module, and taking the time interval between the current trigger and the previous trigger as the on-off cycle of the current module;

[0024] Taking the total duty cycle as the signal of the conduction time amount within the on-off cycle of the current module, and using the current module to generate and output a displacement control current for controlling the main pump.

[0025] In a second aspect, the present invention provides a control system for reducing the instantaneous flow rate fluctuation of the main pump, including a vehicle controller and a current module connected to each other;

[0026] The vehicle controller calculates the average current duty ratio based on the obtained average current of the main pump; calculates the rotational speed fluctuation amount based on the obtained average engine speed and the instantaneous engine speed; calculates the flutter current based on the rotational speed fluctuation amount and the average current of the main pump; calculates the flutter current duty ratio based on the flutter current; sums the average current duty ratio and the flutter current duty ratio to obtain the total duty ratio; uses the rising edge or falling edge of the obtained engine speed signal as the trigger conduction signal for the current module;

[0027] The current module generates and outputs a displacement control current for controlling the main pump based on the trigger signal and the total duty ratio.

[0028] Optionally, the calculation formula for the rotational speed fluctuation amount is:

[0029]

[0030] where η i is the rotational speed fluctuation amount, n i is the instantaneous engine speed at the i-th moment, i = 0, 1, 2... is the average engine speed.

[0031] Optionally, the calculation formula for the flutter current is:

[0032] I ci = kη i I si

[0033] where I ci is the flutter current, k is the proportionality coefficient, η i is the rotational speed fluctuation amount, I si is the average current of the main pump;

[0034] The calculation formula for the displacement control current for controlling the main pump is:

[0035] I i = I si + I ci

[0036] where I i is the displacement control current for controlling the main pump, I si is the average current of the main pump, I ci is the flutter current.

[0037] Optionally, generating the displacement control current for controlling the main pump based on the trigger signal and the total duty ratio specifically includes:

[0038] Using the trigger signal as the trigger conduction signal for the current module, and using the time interval between the current trigger and the previous trigger as the on-off cycle of the current module;

[0039] Take the total duty cycle as a signal of the conduction time amount within the on - off cycle of the current module, and use the current module to generate and output a displacement control current for controlling the main pump.

[0040] In a third aspect, the present invention provides an excavator, including the control system for reducing the instantaneous flow rate fluctuation of the main pump described in the second aspect.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] The present invention proposes a control system, a method and an excavator for reducing the instantaneous flow rate fluctuation of the main pump, which deeply integrates the average speed and the instantaneous speed of the engine with the displacement control current parameter for controlling the main pump, and realizes the direct modulation of the displacement control current for controlling the main pump by using the engine speed parameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0044] Figure 1 It is a schematic flow chart of a control method for reducing the instantaneous flow rate fluctuation of the main pump according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0046] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] Example 1

[0048] In an embodiment of the present invention, a control method for reducing the instantaneous flow rate fluctuation of a main pump is provided. As Figure 1 shown, it includes the following steps:

[0049] (1) Calculate the average current duty ratio based on the obtained average current of the main pump;

[0050] (2) Calculate the rotational speed fluctuation amount based on the obtained average engine speed and the instantaneous engine speed; In the specific implementation process, the average engine speed can be obtained by reading the engine speed signal broadcast by the engine controller or collecting rotational speed sensors such as the flywheel disk, crankshaft, and camshaft, and using the weekly average method; the instantaneous engine speed can be obtained by collecting rotational speed sensors such as the flywheel disk and crankshaft. Taking the flywheel rotational speed sensor with 120 teeth as an example, 120 instantaneous engine speeds can be obtained when the flywheel rotates one week.

[0051] (3) Calculate the flutter current based on the rotational speed fluctuation amount and the average current of the main pump;

[0052] (4) Calculate the flutter current duty ratio based on the flutter current;

[0053] (5) Sum the average current duty ratio and the flutter current duty ratio to obtain the total duty ratio;

[0054] (6) Use the rising edge or falling edge of the obtained engine speed signal as the trigger signal of the current module; In the specific implementation process, taking the flywheel rotational speed sensor with 120 teeth as an example, 120 trigger signals can be obtained when the flywheel rotates one week;

[0055] (7) Based on the trigger signal and the total duty ratio, use the current module to generate and output a displacement control current for controlling the main pump, and the displacement control current for controlling the main pump is used to control the displacement of the main pump.

[0056] Based on the method in the embodiment of the present invention, it is possible to reduce the instantaneous output flow rate fluctuation of the main pump and effectively reduce the influence of the instantaneous rotational speed fluctuation on the main pump flow rate.

[0057] In a specific implementation manner of the embodiment of the present invention, the calculation formula for the rotational speed fluctuation amount is:

[0058]

[0059] where η i is the rotational speed fluctuation amount, n i is the instantaneous engine speed at the i-th moment (rpm), i = 0, 1, 2... is the average engine speed (rpm).

[0060] In a specific implementation manner of the embodiment of the present invention, the calculation formula of the flutter current is as follows:

[0061] I ci = kη i I si

[0062] In the formula, I ci is the flutter current (A), k is the proportionality coefficient, the positive or negative of the proportionality coefficient changes whether the flutter current increases or decreases, dimensionless, η i is the rotational speed fluctuation amount, and I si is the average current of the main pump (A).

[0063] In a specific implementation manner of the embodiment of the present invention, the calculation formula of the displacement control current for controlling the main pump is as follows:

[0064] I i = I si + I ci

[0065] In the formula, I i is the displacement control current for controlling the main pump, I si is the average current of the main pump, and I ci is the flutter current.

[0066] In a specific implementation manner of the embodiment of the present invention, based on the trigger signal and the total duty cycle, generating a displacement control current for controlling the main pump specifically includes:

[0067] Using the trigger signal as the trigger conduction signal of the current module, and using the time interval between the current trigger and the previous trigger as the on-off cycle of the current module;

[0068] Using the total duty cycle as the signal of the conduction time amount within the on-off cycle of the current module, and using the current module to generate and output a displacement control current for controlling the main pump.

[0069] Embodiment 2

[0070] In the embodiment of the present invention, a control system for reducing the instantaneous flow rate fluctuation of the main pump is provided, including a vehicle controller and a current module connected to each other;

[0071] The vehicle controller calculates the average current duty ratio based on the acquired average current of the main pump; calculates the rotational speed fluctuation amount based on the acquired average engine speed and the instantaneous engine speed; calculates the flutter current based on the rotational speed fluctuation amount and the average current of the main pump; calculates the flutter current duty ratio based on the flutter current; sums the average current duty ratio and the flutter current duty ratio to obtain the total duty ratio; uses the rising edge or falling edge of the acquired engine speed signal as the trigger conduction signal of the current module;

[0072] Based on the trigger signal and the total duty ratio, the current module generates and outputs a displacement control current for controlling the main pump.

[0073] Based on the system in the embodiments of the present invention, it is possible to reduce the fluctuation of the instantaneous output flow of the main pump and effectively reduce the influence of the instantaneous rotational speed fluctuation on the flow of the main pump.

[0074] In a specific implementation manner of the embodiments of the present invention, the calculation formula for the rotational speed fluctuation amount is:

[0075]

[0076] where η i is the rotational speed fluctuation amount, n i is the instantaneous engine speed at the i-th moment (rpm), i = 0, 1, 2,..., is the average engine speed (rpm).

[0077] In a specific implementation manner of the embodiments of the present invention, the calculation formula for the flutter current is:

[0078] I ci = kη i I si

[0079] where I ci is the flutter current (A), k is the proportionality coefficient, the positive or negative of the proportionality coefficient changes whether the flutter current increases or decreases, dimensionless, η i is the rotational speed fluctuation amount, I si is the average current of the main pump (A).

[0080] In a specific implementation manner of the embodiments of the present invention, the calculation formula for the displacement control current for controlling the main pump is:

[0081] I i = I si + I ci

[0082] where I i is the displacement control current for controlling the main pump, I siis the average current of the main pump, I ci is the flutter current.

[0083] In a specific implementation manner of the embodiment of the present invention, generating a displacement control current for controlling the main pump based on the trigger signal and the total duty cycle specifically includes:

[0084] Using the trigger signal as the trigger conduction signal of the current module, and using the time interval between the current trigger and the previous trigger as the on-off cycle of the current module;

[0085] Using the total duty cycle as the signal of the conduction time amount within the on-off cycle of the current module, and using the current module to generate and output a displacement control current for controlling the main pump.

[0086] Embodiment 3

[0087] The present invention provides an excavator, including the control system for reducing the instantaneous flow rate fluctuation of the main pump according to any one of Embodiment 2.

[0088] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0089] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0090] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device realizes the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1The functions specified in one or more boxes.

[0091] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in one Figure 1 one process or more processes and / or boxes Figure 1 or more boxes.

[0092] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope of the present invention as protected by the claims. All of these are within the protection scope of the present invention.

[0093] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all of these changes and improvements fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A control method for reducing the instantaneous flow rate fluctuation of a main pump, characterized in that, Including: Based on the obtained average current of the main pump, calculate the average current duty cycle; Based on the obtained average engine speed and instantaneous engine speed, calculate the rotational speed fluctuation amount; Based on the rotational speed fluctuation amount and the average current of the main pump, calculate the flutter current; Based on the flutter current, calculate the flutter current duty cycle; Sum the average current duty cycle and the flutter current duty cycle to obtain the total duty cycle; Take the rising edge or falling edge of the obtained engine speed signal as the trigger conduction signal of the current module; Based on the trigger conduction signal and the total duty cycle, use the current module to generate and output a displacement control current for controlling the main pump.

2. The control method for reducing the instantaneous flow rate fluctuation of the main pump according to claim 1, characterized in that: The calculation formula for the rotational speed fluctuation amount is: where η i is the rotational speed fluctuation, n i is the instantaneous engine speed at the i-th moment, i = 0, 1, 2... is the average engine speed.

3. A control method for reducing the instantaneous flow rate fluctuation of the main pump according to claim 1, characterized in that: The calculation formula for the flutter current is: I ci = kη i I si Where, I ci is the flutter current, k is the proportionality coefficient, η i is the rotational speed fluctuation, and I si is the average current of the main pump.

4. A control method for reducing the instantaneous flow rate fluctuation of the main pump according to claim 3, characterized in that: The calculation formula for the current value of the displacement control current for controlling the main pump is: I i = I si + I ci Wherein, I i is the displacement control current for controlling the main pump, I si is the average current of the main pump, and I ci is the flutter current.

5. A control method for reducing the instantaneous flow rate fluctuation of the main pump according to claim 1, characterized in that: Based on the trigger conduction signal and the total duty cycle, generating a displacement control current for controlling the main pump, specifically: Take the trigger conduction signal as the trigger conduction signal of the current module, and take the time interval between the current trigger and the previous trigger as the on-off cycle of the current module; Take the total duty cycle as the signal of the conduction time amount within the on-off cycle of the current module, and use the current module to generate and output a displacement control current for controlling the main pump.

6. A control system for reducing the instantaneous flow rate fluctuation of a main pump, characterized in that, Including a connected vehicle controller and a current module; The vehicle controller calculates the average current duty cycle based on the obtained average current of the main pump; calculates the rotational speed fluctuation amount based on the obtained average engine speed and instantaneous engine speed; Based on the rotational speed fluctuation amount and the average current of the main pump, calculate the flutter current; Based on the flutter current, calculate the flutter current duty cycle; Sum the average current duty cycle and the flutter current duty cycle to obtain the total duty cycle; Take the rising edge or falling edge of the obtained engine speed signal as the trigger conduction signal of the current module; The current module generates and outputs a displacement control current for controlling the main pump based on the trigger conduction signal and the total duty cycle.

7. The control system for reducing the instantaneous flow rate fluctuation of the main pump according to claim 6, wherein The calculation formula for the rotational speed fluctuation amount is: where η i is the rotational speed fluctuation, n i is the instantaneous engine speed at the i-th moment, i = 0, 1, 2..., is the average engine speed.

8. A control system for reducing the instantaneous flow rate fluctuation of a main pump according to claim 6, characterized in that, The calculation formula for the flutter current is: I ci = kη i I si Where, I ci is the flutter current, k is the proportionality coefficient, η i is the rotational speed fluctuation, I si is the average current of the main pump; The calculation formula for the displacement control current for controlling the main pump is: I i = I si + I ci Wherein, I i is the displacement control current for controlling the main pump, I si is the average current of the main pump, and I ci is the flutter current.

9. The control system for reducing the instantaneous flow rate fluctuation of the main pump according to claim 6, wherein Based on the trigger conduction signal and the total duty cycle, generating a displacement control current for controlling the main pump, specifically: Take the trigger conduction signal as the trigger conduction signal of the current module, and take the time interval between the current trigger and the previous trigger as the on-off cycle of the current module; Take the total duty cycle as the signal of the conduction time amount within the on-off cycle of the current module, and use the current module to generate and output a displacement control current for controlling the main pump.

10. An excavator, characterized in that, Including the control system for reducing the instantaneous flow fluctuation of the main pump according to any one of claims 6-9.

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