CN117724539A

CN117724539A - Control method and device of rotating speed and vibrating pile sinking machine

Info

Publication number: CN117724539A
Application number: CN202311726375.1A
Authority: CN
Inventors: 居世昊; 解朝蓬; 彭振; 邹佳运; 李闯; 王世阳
Original assignee: Xuzhou XCMG Excavator Machinery Co Ltd
Current assignee: Xuzhou XCMG Excavator Machinery Co Ltd
Priority date: 2023-12-14
Filing date: 2023-12-14
Publication date: 2024-03-19

Abstract

The disclosure provides a control method and device of rotating speed and a vibration pile driver, and relates to the technical field of engineering machinery, wherein the method comprises the following steps: acquiring a first moment when a first absolute value of exciting force of an eccentric block of a vibrator of the vibrating pile driver in a first state is the maximum value and a second moment when a second absolute value of vibration acceleration of a shell of the vibrator is the maximum value, wherein the first state is load-carrying work of the vibrating pile driver; determining a phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the first moment and the second moment; the rotational speed of the eccentric mass is controlled so that the absolute value of the difference between the phase difference and the target value, which is the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass in the state where the housing and the eccentric mass are in resonance, is reduced.

Description

Control method and device of rotating speed and vibrating pile sinking machine

Technical Field

The disclosure relates to the technical field of engineering machinery, in particular to a rotating speed control method and device and a vibrating pile driver.

Background

A vibrating pile driver is a mechanical device commonly used in operations. The vibratory pile driver may utilize a vibratory method to vibrate the pile and surrounding soil so that the pile may be driven into the formation.

Disclosure of Invention

The inventor finds that the vibration pile driver in the related art has the problem of low operation efficiency.

The inventors further analyzed and found that the eccentric mass of the vibrator (which may also be referred to as a hammer head) of the vibrating pile driver, the housing of the vibrator, the pile connected to the housing of the vibrator, and the soil into which the pile is inserted are easily sunk into the ground when they are in a resonance state, and that the rotational speed of the eccentric mass of the vibrating pile driver affects the resonance state of the eccentric mass and the housing of the vibrator, and thus affects the resonance state of the eccentric mass, the housing of the vibrator, the pile connected to the housing of the vibrator, and the soil into which the pile is inserted.

The vibrating pile driver in the related art has a smaller rotating speed of the eccentric block of the vibrator under the condition of heavy load and heavy load, and has a larger rotating speed of the eccentric block of the vibrator under the condition of heavy load and heavy load. In this case, the eccentric mass and the housing of the vibrator cannot enter a resonance state, so that the eccentric mass, the housing of the vibrator, the pile connected to the housing of the vibrator, and soil into which the pile is inserted cannot enter a resonance state, and the pile is not easily sunk into the ground.

In order to solve the above-described problems, the embodiments of the present disclosure propose the following solutions.

According to an aspect of the embodiments of the present disclosure, there is provided a method for controlling a rotational speed, including: acquiring a first moment when a first absolute value of exciting force of an eccentric block of a vibrator of a vibrating pile driver in a first state is the maximum value and a second moment when a second absolute value of vibration acceleration of a shell of the vibrator is the maximum value, wherein the first state is load-carrying work of the vibrating pile driver; determining a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the first time and the second time; and controlling the rotating speed of the eccentric block so that the absolute value of the difference between the phase difference and a target value is reduced, wherein the target value is a phase difference value between the vibration acceleration of the shell and the vibration acceleration of the eccentric block when the shell and the eccentric block are in a resonance state.

In some embodiments, the second time is between two adjacent first times, and the phase difference is determined according to a first time interval between one of the two first times and the second time and a second time interval between the two first times.

In some embodiments, at least one of the first time instant and the second time instant satisfies a corresponding condition, wherein: the conditions corresponding to the first time are as follows: the first moment is the moment when the first absolute value is the minimum value; the conditions corresponding to the second moment are as follows: the second time is a time when the second absolute value is the minimum value.

In some embodiments, the one of the first moments in time is a relatively earlier moment in time of the two of the first moments in time.

In some embodiments, the first time is a time when the exciting force changes from greater than 0 to 0, and the second time is a time when the vibration acceleration of the housing changes from less than 0 to 0; or the first time is a time when the exciting force changes from less than 0 to 0, and the second time is a time when the vibration acceleration of the case changes from more than 0 to 0.

In some embodiments, the first time is when a sensor emits a trigger signal, wherein the sensor is mounted on an eccentric shaft connected to the eccentric mass and emits the trigger signal when the center of mass of the eccentric mass is in an uppermost, lowermost, or intermediate position.

In some embodiments, the method further comprises: acquiring a third moment when the first absolute value is the highest value and a fourth moment when the second absolute value is the highest value of the vibrating pile driver in a second state, wherein the second state is that the vibrating pile driver works without load and the rotating speed of the eccentric block is larger than a preset rotating speed, and a desired preset phase difference exists between the vibrating acceleration of the shell and the vibrating acceleration of the eccentric block in the second state; according to the third moment and the fourth moment, determining an idle phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block; and under the condition that the no-load phase difference and the preset phase difference deviate, determining the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the first moment, the second moment and the deviation.

According to still another aspect of the embodiments of the present disclosure, there is provided a control method of a rotational speed, including: acquiring a phase difference between the vibration acceleration of a shell of a vibrator of the vibrating pile driver in a first state and the vibration acceleration of an eccentric block of the vibrator, wherein the first state is that the vibrating pile driver works under load; and controlling the rotating speed of the eccentric block so that the absolute value of the difference between the phase difference and a target value is reduced, wherein the target value is a phase difference value between the vibration acceleration of the shell and the vibration acceleration of the eccentric block when the shell and the eccentric block are in a resonance state.

In some embodiments, the control reduces the absolute value of the difference of the phase difference from the target value to 0.

In some embodiments, the method further comprises: acquiring an idle-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block of the vibration pile driver in a second state, wherein the second state is that the vibration pile driver works without load and the rotating speed of the eccentric block is larger than a preset rotating speed, and the vibration acceleration of the shell and the vibration acceleration of the eccentric block have an expected preset phase difference in the second state; and under the condition that the no-load phase difference and the preset phase difference deviate, determining the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the deviation.

In some embodiments, the preset phase difference is 180 degrees.

In some embodiments, the preset rotation speed is greater than or equal to a resonance rotation speed, wherein the resonance rotation speed is a rotation speed of the eccentric block when the shell and the buffer device resonate, and the shell is connected with the arm support of the vibrating pile sinking machine through the buffer device.

In some embodiments, the preset rotational speed is at least twice the resonance rotational speed.

According to still another aspect of the embodiments of the present disclosure, there is provided a control device for a rotational speed, including a module for executing the method according to any one of the embodiments.

According to still another aspect of the embodiments of the present disclosure, there is provided a control device for rotational speed, including: a memory; and a processor coupled to the memory, the processor configured to perform the method of any of the embodiments described above based on instructions stored in the memory.

According to still another aspect of the embodiments of the present disclosure, there is provided a vibratory pile driver comprising: the apparatus of any one of the above embodiments.

According to a further aspect of the disclosed embodiments, a computer readable storage medium is provided, comprising computer program instructions, wherein the computer program instructions, when executed by a processor, implement the method according to any of the embodiments described above.

In the embodiment of the disclosure, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is determined through the moment when the absolute value of the exciting force of the eccentric block of the vibrator under load of the vibrating pile driver is the maximum value and the moment when the absolute value of the vibration acceleration of the shell of the vibrator is the maximum value, and then the rotating speed of the eccentric block is controlled so that the absolute value of the difference between the phase difference and the target value is reduced, so that the eccentric block and the shell of the vibrator are closer to enter a resonance state, the eccentric block, the shell of the vibrator, the pile connected with the shell of the vibrator and the soil into which the pile is inserted are closer to enter the resonance state, and the working efficiency of the vibrating pile driver is improved.

The technical scheme of the present disclosure is described in further detail below through the accompanying drawings and examples.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.

Fig. 1 is a flow chart of a method of controlling rotational speed according to some embodiments of the present disclosure.

Fig. 2 is a schematic diagram of the relationship between the motion position of an eccentric mass and the excitation force according to some embodiments of the present disclosure.

Fig. 3 is a schematic diagram of an excitation force, a vibration acceleration of an eccentric mass, and a vibration acceleration of a housing according to some embodiments of the present disclosure.

Fig. 4 is a schematic illustration of excitation forces and vibration acceleration of a housing according to some embodiments of the present disclosure.

Fig. 5 is a schematic view of excitation forces and vibration acceleration of a housing according to further embodiments of the present disclosure.

Fig. 6 is a schematic structural view of a rotational speed control apparatus according to some embodiments of the present disclosure.

Fig. 7 is a schematic structural view of a rotational speed control apparatus according to other embodiments of the present disclosure.

Detailed Description

The following description of the technical solutions in the embodiments of the present disclosure will be made clearly and completely with reference to the accompanying drawings in the embodiments of the present disclosure, and it is apparent that the described embodiments are only some embodiments of the present disclosure, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments in this disclosure without inventive faculty, are intended to fall within the scope of this disclosure.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless it is specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In addition, in the description of the present disclosure, the terms "first," "second," "third," etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or order. Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous.

In step 102, a first time when the first absolute value of the excitation force of the eccentric mass of the vibrator in the first state of the vibrating pile driver is the maximum value and a second time when the second absolute value of the vibration acceleration of the casing of the vibrator is the maximum value are acquired. Here, the first state is a state in which the vibration pile driver works on load. The state of the load operation may be, for example, an operation state when the vibration pile driver is in pile driving operation.

It should be understood that the maximum value includes a maximum value or a minimum value. For example, the first time is a time when the first absolute value of the exciting force of the eccentric mass of the vibrator in the first state of the vibrating pile driver is a maximum value or a minimum value, and the second time is a time when the second absolute value of the vibration acceleration of the casing of the vibrator is a maximum value or a minimum value.

Next, the relationship between the motion position of the eccentric mass and the exciting force is described with reference to fig. 2.

Fig. 2 is a schematic diagram of the relationship between the motion position of an eccentric mass and the excitation force according to some embodiments of the present disclosure. In fig. 2, the horizontal axis represents time, and the vertical axis represents the magnitude of excitation force.

In some embodiments, as shown in fig. 2, the eccentric mass includes an eccentric mass 201 and an eccentric mass 202. As some embodiments, the eccentric mass 201 and the eccentric mass 202 are symmetrically arranged, the eccentric mass 201 rotates clockwise, the eccentric mass 202 rotates counterclockwise, and the rotational speeds of the eccentric mass 201 and the eccentric mass 202 are the same. It should be understood that the number of eccentric masses of the vibrator of the vibratory pile driver is not limited to two, but may be more, and the number of eccentric masses is not limited herein.

Curve 207 indicates the magnitude and direction of the excitation force, and in the case where the excitation force is greater than 0, indicates that the excitation force is vertically upward; in the case where the exciting force is less than 0, it means that the exciting force is vertically downward.

As shown in fig. 2, position 203 indicates that the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are in the intermediate position and the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are furthest apart, position 204 indicates that the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are uppermost, position 205 indicates that the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are in the intermediate position and the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are closest apart, and position 206 indicates that the center of mass of eccentric mass 201 and the center of mass of eccentric mass 202 are lowermost.

When the eccentric mass 201 and the eccentric mass 202 are at the position 203, centrifugal forces of the eccentric mass 201 and the eccentric mass 202 cancel each other, and the exciting force is 0. Here, directions of centrifugal forces of the eccentric masses 201 and 202 are shown as arrow directions in the direction 208, and directions of centrifugal forces of the eccentric masses 201 and 202 at the subsequent positions 204, 205, and 206 may refer to corresponding arrow directions in the direction 208, and will not be described in detail.

Similarly, with eccentric masses 201 and 202 in position 204, the centrifugal forces of eccentric masses 201 and 202 are both vertically upward, with the excitation force being a positive maximum; when the eccentric mass 201 and the eccentric mass 202 are at the position 205, centrifugal forces of the eccentric mass 201 and the eccentric mass 202 cancel each other, and the exciting force is 0; with eccentric masses 201 and 202 in position 206, the centrifugal forces of eccentric masses 201 and 202 are both vertically downward, with the excitation force being a negative minimum.

That is, the first absolute value of the exciting force of the eccentric mass of the vibrator is the minimum value at the positions 203 and 205; at positions 204 and 206, the first absolute value of the excitation force of the eccentric mass of the vibrator is at a maximum.

It will be appreciated that eccentric mass 201 and eccentric mass 202 rotate over time, and that the positions of eccentric mass 201 and eccentric mass 202 cyclically change from position 203 to position 206.

In some embodiments, the first time is the time when the sensor issues the trigger signal. Here, the sensor is mounted on an eccentric shaft connected to the eccentric mass and emits a trigger signal when the centre of mass of the eccentric mass is at the uppermost (corresponding position 204), lowermost (corresponding position 206) or intermediate (corresponding position 203 or position 206). The sensor may comprise, for example, a hall-type rotational speed sensor and a magneto-electric rotational speed sensor. It will be appreciated that the eccentric shaft may rotate the eccentric mass.

It should be understood that the first absolute value of the exciting force is maximum in the case where the eccentric mass is in a moving state and the center of mass of the eccentric mass is at the uppermost and lowermost; the first absolute value of the excitation force is smallest in the case where the eccentric mass is in a motion state and the center of mass of the eccentric mass is in an intermediate position.

In some embodiments, the vibration acceleration of the housing of the vibrator may be acquired by a sensor. The sensor may comprise, for example, an acceleration sensor. The sensor may be mounted, for example, in the housing of the vibrator.

In step 104, a phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator is determined from the first time and the second time.

For example, the phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator may be determined from a first time when the first absolute value of the exciting force of the eccentric mass of the vibrator is the maximum value and a second time when the second absolute value of the vibration acceleration of the housing of the vibrator is the maximum value; for another example, a phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator may be determined from a first time when the first absolute value is at a maximum value and a second time when the second absolute value is at a minimum value; also for example, a phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator may be determined from a first time when the first absolute value is the minimum value and a second time when the second absolute value is the maximum value; for another example, the phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator may be determined from the first time when the first absolute value is the minimum value and the second time when the second absolute value is the minimum value. Specific implementations will be described later herein, and are not described in detail herein.

In step 106, the rotational speed of the eccentric mass of the vibrator is controlled such that the absolute value of the difference between the phase difference between the vibration acceleration of the housing of the vibrator and the vibration acceleration of the eccentric mass of the vibrator and the target value is reduced. Here, the target value is a phase difference value between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass in the resonance state of the housing and the eccentric mass. The unit of the rotational speed of the eccentric mass may be, for example, revolutions per minute (rpm).

It should be appreciated that the rotational speed of the eccentric mass may be determined by the time the eccentric mass rotates one revolution, and the manner in which the rotational speed of the eccentric mass is obtained is not limited herein.

In some embodiments, the rotational speed of the eccentric mass of the vibrator may be controlled by adjusting the instantaneous displacement of the hydraulic pump driving the eccentric mass to rotate through a proportional-integral-derivative control (PID) control algorithm.

In this way, the phase difference between the vibration acceleration of the casing and the vibration acceleration of the eccentric block is determined by the moment when the absolute value of the exciting force of the eccentric block of the vibrator is the maximum value and the moment when the absolute value of the vibration acceleration of the casing of the vibrator is the maximum value of the vibration pile driver under load operation, and then the rotating speed of the eccentric block is controlled so that the absolute value of the difference between the phase difference and the target value is reduced, thereby the eccentric block and the casing of the vibrator are more close to enter a resonance state, and the eccentric block, the casing of the vibrator, the pile connected with the casing of the vibrator and the soil into which the pile is inserted are more close to enter the resonance state, thereby improving the working efficiency of the vibration pile driver.

In some embodiments, the target value is 90 degrees. Therefore, the phase difference between the vibration acceleration of the shell of the vibrator and the vibration acceleration of the eccentric block of the vibrator can be close to 90 degrees by controlling the rotating speed of the eccentric block of the vibrator, so that the eccentric block and the shell of the vibrator are closer to enter a resonance state, and the working efficiency of the vibrating pile sinking machine is improved.

In some embodiments, the rotational speed of the eccentric mass may be controlled such that the absolute value of the difference between the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass and the target value is reduced to 0. That is, the rotational speed of the eccentric mass is controlled so that the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass is equal to the target value.

Thus, the rotational speed of the eccentric block of the vibrator is controlled to enable the phase difference between the vibration acceleration of the shell of the vibrator and the vibration acceleration of the eccentric block of the vibrator to be a target value, so that the eccentric block and the shell of the vibrator enter a resonance state, and the working efficiency of the vibrating pile sinking machine is further improved.

Next, how the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass is determined based on the first time and the second time is described with reference to fig. 3.

Fig. 3 is a schematic diagram of an excitation force, a vibration acceleration of an eccentric mass, and a vibration acceleration of a housing according to some embodiments of the present disclosure. In fig. 3, the horizontal axis represents time, and the vertical axis represents the magnitude of the exciting force and the magnitude of the vibration acceleration, respectively.

As shown in fig. 3, a curve 310 indicates the magnitude and direction of the vibration acceleration of the housing of the vibrator, and in the case where the vibration acceleration of the housing of the vibrator is greater than 0, indicates that the vibration acceleration of the housing of the vibrator is vertically upward; in the case where the vibration acceleration of the housing of the vibrator is less than 0, it means that the vibration acceleration of the housing of the vibrator is vertically downward.

Curve 311 is in anti-phase with curve 207, curve 311 indicates the magnitude and direction of the vibration acceleration of the eccentric mass, and in the case that the vibration acceleration of the eccentric mass is greater than 0, the vibration acceleration of the eccentric mass is represented as being vertically upward; in the case where the vibration acceleration of the eccentric mass is less than 0, it means that the vibration acceleration of the eccentric mass is vertically downward.

In some embodiments, the phase difference may be determined from a first time interval between one of the two first moments in time and the second moment in time and a second time interval between the two first moments in time. Here, the second time is between two adjacent ones of the first times.

As some embodiments, the first time is when the first absolute value is at a maximum, and the second time is when the second absolute value is at a maximum. That is, the first time is the time when the exciting force is maximum (positive value) or minimum (negative value), and the second time is the time when the vibration acceleration of the case is maximum (positive value) or minimum (negative value).

That is, the first time is the time corresponding to position 204 (i.e., time 306) or the time corresponding to position 206 (i.e., time 309), and the second time is time 307 or time 308.

Next, a manner of determining the phase difference is exemplified with the time interval between the time 306 and the time 309 as the second time interval.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between time 306 and time 308 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

For another example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between time 308 and time 309 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees to obtain a calculation result, and the calculation result may be subtracted by 180 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In this way, when the first moment is the moment when the first absolute value is the maximum value and the second moment is the moment when the second absolute value is the maximum value, according to the first time interval between one first moment of two adjacent first moments and the second moment between the two first moments and the second time interval between the two first moments, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block can be accurately determined, and the rotating speed of the eccentric block can be accurately controlled so that the absolute value of the difference value between the phase difference and the target value is reduced, thereby enabling the shell of the eccentric block and the vibrator to be closer to enter the resonance state, and further improving the working efficiency of the vibrating pile sinking machine.

The inventors have noted that, in the case of measuring the maximum values of the first absolute value and the second absolute value, there is a tendency that the maximum values of the plurality of first absolute values having the same value and the maximum values of the plurality of second absolute values having the same value occur in a short time, and thus the corresponding first time and second time cannot be accurately acquired. The inventors further analyzed and found that this is because the obtained exciting force of the eccentric mass and the vibration acceleration of the housing of the vibrator are both output in the form of analog signals, the slope at the peak of which is small, i.e., there may be a plurality of values close in value in a short time in the vicinity of the peak. In this case, since the measurement accuracy is limited, a plurality of identical values may be output in the case of outputting a value in the vicinity of the peak. In this regard, the present disclosure also proposes the following solutions.

In some embodiments, at least one of the first time instant and the second time instant also satisfies the corresponding condition. Here, the condition corresponding to the first time is that the first time is a time when the first absolute value is the minimum value; the condition corresponding to the second time is that the second time is a time when the second absolute value is the minimum value.

As some embodiments, the first time is when the first absolute value is at a minimum, and the second time is when the second absolute value is at a maximum. That is, the first time is a time when the exciting force is 0, and the second time is a time when the vibration acceleration of the case is maximum (positive value) or minimum (negative value).

That is, the first time is a time corresponding to the position 203 (time 301 or time 305) or a time corresponding to the position 205 (time 303), and the second time is a time 307 or time 308.

Next, a manner of determining the phase difference is exemplified with the time interval between the time 301 and the time 303 as the second time interval.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between the time 301 and the time 308 and the second time interval. For example, the ratio of the first time interval to the second time interval multiplied by 180 degrees may be subtracted by 90 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

For another example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between time 308 and time 303 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees to obtain a calculation result, and the calculation result may be subtracted by 90 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In this way, the analog signal of the excitation force of the eccentric mass has the largest slope when it is 0, that is, the difference between the plurality of values in a short time in the vicinity of where the analog signal is 0 is large, so that the analog signal of 0 can be accurately output, and the corresponding first time can be accurately acquired.

In this way, according to the first time interval between one of the two adjacent first moments and the second time interval between the two first moments, the phase difference between the vibration acceleration of the casing and the vibration acceleration of the eccentric block can be more accurately determined, and the rotating speed of the eccentric block is further more accurately controlled so that the absolute value of the difference between the phase difference and the target value is reduced, and therefore the eccentric block and the casing of the vibrator are further more close to enter a resonance state, and the operation efficiency of the vibrating pile sinking machine is further improved.

In another embodiment, the first time is a time when the first absolute value is at a maximum, and the second time is a time when the second absolute value is at a minimum. That is, the first time is the time when the exciting force is maximum (positive value) or minimum (negative value), and the second time is the time when the vibration acceleration of the case is 0, that is, the second time is the time when the analog signal of the vibration acceleration of the case is 0.

That is, the first time is the time corresponding to position 204 (i.e., time 306) or the time corresponding to position 206 (i.e., time 309), and the second time is time 302 or time 304.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between the time 306 and the time 304 and the second time interval. For example, the ratio of the first time interval to the second time interval multiplied by 180 degrees may be subtracted by 90 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

For another example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between time 304 and time 309 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees to obtain a calculation result, and the calculation result may be subtracted by 90 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In this way, the analog signal of the vibration acceleration of the case has the largest slope when it is 0, that is, the difference between the plurality of values in a short time in the vicinity of where the analog signal is 0 is large, so that the analog signal of 0 can be accurately output, and the corresponding second time can be accurately acquired.

As still other embodiments, the first time is when the first absolute value is at a minimum, and the second time is when the second absolute value is at a minimum. That is, the first time is a time when the first absolute value is 0, and the second time is a time when the second absolute value is 0.

That is, the first time is a time corresponding to the position 203 (time 301 or time 305) or a time corresponding to the position 205 (time 303), and the second time is a time 302 or a time 304.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between the time 301 and the time 302 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

For another example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between time 302 and time 303 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 180 degrees to obtain a calculation result, and the calculation result may be subtracted by 180 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In this way, the analog signal of the excitation force of the eccentric mass and the analog signal of the vibration acceleration of the case have the largest slope when they are 0, that is, the difference between the plurality of values in a short time in the vicinity of the position where the analog signal is 0 is large, so that the analog signal of 0 can be accurately output, and the corresponding first time and second time can be accurately acquired.

In this way, according to the first time interval between one of the two adjacent first moments and the second time interval between the two first moments, the phase difference between the vibration acceleration of the casing and the vibration acceleration of the eccentric block can be further and more accurately determined, and further, the rotating speed of the eccentric block is further and more accurately controlled so that the absolute value of the difference between the phase difference and the target value is reduced, and therefore the eccentric block and the casing of the vibrator are further and more close to enter a resonance state, and the operation efficiency of the vibrating pile sinking machine is further improved.

In some embodiments, the first instant upon which the first time interval is determined is a relatively earlier instant of the two adjacent first instants.

In this way, under the condition that the relatively earlier moment of the two adjacent first moments is acquired, the first time interval can be determined if the second moment is acquired, and the first time interval is not required to be determined after the relatively later moment of the two adjacent first moments is acquired, so that the speed for determining the first time interval is improved, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is rapidly determined, the eccentric block and the shell of the vibrator are rapidly close to enter a resonance state, and the operation efficiency of the vibrating pile sinking machine is further improved.

In some embodiments, the first time is a time when the excitation force changes from greater than 0 to 0. In this case, the adjacent two first moments are moments when the adjacent two excitation forces change from greater than 0 to 0.

In other embodiments, the first moment is a moment when the excitation force changes from less than 0 to 0. In this case, the adjacent two first moments are moments when the adjacent two excitation forces change from less than 0 to 0.

Therefore, under the condition that the first moment is the moment when the sensor sends out the trigger signal, the time of one circle of rotation of the eccentric block can be measured by only one sensor, namely, one period of vibration exciting force change is obtained, and the cost is reduced.

In some embodiments, the first time at which the first time interval is determined is a relatively earlier time of two adjacent first times, and the first time is a time when the excitation force changes from greater than 0 to 0.

In other embodiments, the first time at which the first time interval is determined is a relatively earlier time of two adjacent first times, and the first time is a time when the exciting force changes from less than 0 to 0.

On the one hand, under the condition that the relatively earlier moment of the two adjacent first moments is acquired, the first time interval can be determined if the second moment is acquired, and the first time interval is not required to be determined after the relatively later moment of the two adjacent first moments is acquired, so that the speed for determining the first time interval is improved, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is rapidly determined, the eccentric block and the shell of the vibrator are rapidly close to enter a resonance state, and the operation efficiency of the vibrating pile sinking machine is further improved.

On the other hand, under the condition that the first moment is the moment when the sensor sends out the trigger signal, the time of one circle of rotation of the eccentric block can be measured by only one sensor, namely, one period of vibration exciting force change is obtained, and therefore cost is reduced.

In some embodiments, the first time at which the first time interval is determined is a relatively earlier time of two adjacent first times, the first time being a time when the excitation force changes from greater than 0 to 0, and the second time being a time when the vibration acceleration of the case changes from less than 0 to 0.

In other embodiments, the first time at which the first time interval is determined is a relatively earlier time of two adjacent first times, the first time being a time when the exciting force changes from less than 0 to 0, and the second time being a time when the vibration acceleration of the case changes from more than 0 to 0.

Next, how the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass is determined in the above two cases is described with reference to fig. 4.

Fig. 4 is a schematic illustration of excitation forces and vibration acceleration of a housing according to some embodiments of the present disclosure. In fig. 4, the horizontal axis represents time, and the vertical axis represents the magnitude of the exciting force and the magnitude of the vibration acceleration, respectively.

As shown in fig. 4, the first time is the time corresponding to the position 205 (i.e., time 303 or time 401), and the second time is time 304; or the first time is the time corresponding to location 203 (i.e., time 301 or time 305) and the second time is time 302.

In the case where the second time interval is the time interval between the time 303 and the time 401, the phase difference is determined as follows.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between the time 303 and the time 304 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 360 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In the case where the second time interval is the time interval between the time 301 and the time 305, the phase difference is determined as follows.

For example, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined from the first time interval between the time 301 and the time 302 and the second time interval. For example, the ratio of the first time interval to the second time interval may be multiplied by 360 degrees as a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In this way, the first instant from which the first time interval is determined is instant 303 or instant 301. Further, the ratio of the first time interval between the time 303 and the time 304 or the first time interval between the time 301 and the time 302 to the corresponding second time interval may be multiplied by 360 degrees as the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass, without multiplying the ratio of the first time interval to the corresponding second time interval by 360 degrees to obtain a calculation result, and subtracting the calculation result from 360 degrees as the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

In a further aspect, when the first time according to which the first time interval is determined is a relatively earlier time of the two adjacent first times, the first time is a time when the exciting force changes from greater than 0 to 0, the second time is a time when the vibration acceleration of the casing changes from less than 0 to 0, or the first time is a time when the exciting force changes from less than 0 to 0, and the second time is a time when the vibration acceleration of the casing changes from greater than 0 to 0, the calculation complexity of determining the phase difference between the vibration acceleration of the casing and the vibration acceleration of the eccentric mass can be simplified, so that the phase difference can be determined more quickly, the casing of the eccentric mass and the vibrator can be brought into the resonance state more quickly, and the operation efficiency of the vibration pile driver can be further improved.

The inventors noted that the phase difference between the determined vibration acceleration of the housing and the vibration acceleration of the eccentric mass is inaccurate. The inventors have further analyzed that this is due to the fact that the sensor that emits the trigger signal does not emit the trigger signal exactly when the center of mass of the eccentric mass is at the uppermost, lowermost or intermediate position, which in turn leads to an inaccurate first moment and thus to a larger or smaller phase difference between the determined vibration acceleration and the vibration acceleration of the eccentric mass. In this regard, the present disclosure also proposes the following solutions.

Next, how to accurately determine the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass is described with reference to fig. 5.

Fig. 5 is a schematic view of excitation forces and vibration acceleration of a housing according to further embodiments of the present disclosure. In fig. 5, the horizontal axis represents time, and the vertical axis represents the magnitude of the exciting force and the magnitude of the vibration acceleration, respectively.

As shown in fig. 5, the sensor is expected to emit the trigger signal at time 303 and time 401, but the actual trigger signal emission times are time 501 and time 502, i.e., the trigger signal is emitted in advance. It will be appreciated that the time from time 303 to time 401 is the same as the time from time 501 to time 502.

In this case, the first time interval between the time 501 and the time 304 is longer than the first time interval between the time 303 and the time 304, thereby making the phase difference between the determined vibration acceleration of the housing and the vibration acceleration of the eccentric mass larger. Therefore, in order to correct the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass, the time interval between the time 501 and the time 303 needs to be removed.

In some embodiments, a third moment when the first absolute value is the most value and a fourth moment when the second absolute value is the most value of the vibrating pile driver can be obtained under the condition that the vibrating pile driver works without load and the rotating speed of the eccentric block is greater than the preset rotating speed; and determining an idle phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the third time and the fourth time.

Here, in the second state, there is a desired preset phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass. The preset phase difference may be 180 degrees, for example.

As some embodiments, the implementation manner of determining the no-load phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the third time and the fourth time is similar to the implementation manner of determining the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the first time and the second time, which are not described herein.

And under the condition that the no-load phase difference and the preset phase difference deviate, determining the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the first moment, the second moment and the deviation. For example, a difference between a phase difference between the vibration acceleration of the case and the vibration acceleration of the eccentric mass, which is determined from the first and second timings, and a deviation (for example, no-load phase difference minus 180 degrees) may be used as a phase difference between the vibration acceleration of the corrected case and the vibration acceleration of the eccentric mass.

It should be appreciated that in the case where the sensor issues a trigger signal in advance, the phase difference determined from the first time and the second time is larger than the actual phase difference, and the no-load phase difference is larger than 180 degrees; in the case of a sensor hysteresis emitting a trigger signal, the phase difference determined from the first and second instants is smaller than the actual phase difference and the no-load phase difference is smaller than 180 degrees.

In this way, by acquiring the third moment when the first absolute value is the most value and the fourth moment when the second absolute value is the most value of the vibrating pile driver in the second state, and determining the no-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the third moment and the fourth moment, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block can be accurately determined according to the first moment, the second moment and the deviation when the no-load phase difference is deviated from the preset phase difference, so that the rotating speed of the eccentric block is accurately controlled to reduce the absolute value of the difference between the phase difference and the target value, the shell of the eccentric block and the vibrator is closer to enter the resonance state, and the operation efficiency of the vibrating pile driver is further improved.

In some embodiments, the preset rotational speed is greater than or equal to the resonant rotational speed. Here, the resonance rotation speed is the rotation speed of the eccentric block when the shell of the vibrator and the buffer device resonate, and the shell of the resonator is connected with the arm support of the vibrating pile sinking machine through the buffer device. The damping means may be, for example, a rubber block.

Therefore, the preset rotating speed is greater than or equal to the resonance rotating speed, namely, the rotating speed of the eccentric block in the second state is greater than the resonance rotating speed, the occurrence of the condition that the shell of the vibrator and the buffer device resonate can be reduced, the no-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is further accurately obtained, further, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is further accurately determined, the rotating speed of the eccentric block is further accurately controlled, the absolute value of the difference between the phase difference and the target value is reduced, the shell of the eccentric block and the shell of the vibrator are further more close to enter the resonance state, and the operation efficiency of the vibration pile sinking machine is further improved.

In some embodiments, the preset rotational speed is at least twice the resonant rotational speed. For example, the preset rotational speed is two, three, four or more times the resonance rotational speed.

Therefore, the preset rotating speed is far greater than the resonance rotating speed, namely the rotating speed of the eccentric block in the second state is far greater than the resonance rotating speed, the occurrence of the condition that the shell of the vibrator and the buffer device resonate can be further reduced, the no-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is further and more accurately obtained, further the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block is further and more accurately determined, further the rotating speed of the eccentric block is more accurately controlled, the absolute value of the difference value between the phase difference and the target value is reduced, the shell of the eccentric block and the vibrator is further and more nearly enters the resonance state, and the working efficiency of the vibrating pile sinking machine is further improved.

In other embodiments of the present disclosure, a method of controlling rotational speed is also provided.

In step S1, a phase difference between a vibration acceleration of a housing of a vibrator of the vibratory pile driver in a first state and a vibration acceleration of an eccentric mass of the vibrator is obtained. Here, the first state is the vibration pile driver load operation.

As some embodiments, the manner of acquisition in step S1 is not limited. For example, the phase difference between the vibration acceleration of the case and the vibration acceleration of the eccentric mass may be determined from the first timing related to the exciting force of the eccentric mass and the second timing related to the vibration acceleration of the case in any of the above embodiments; for another example, the vibration acceleration of the eccentric mass and the vibration acceleration of the housing in the first state may be directly acquired, and further, the phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined.

In step S2, the rotational speed of the eccentric mass is controlled such that the absolute value of the difference of the phase difference from the target value decreases. Here, the target value is a phase difference value between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass in the resonance state of the housing and the eccentric mass.

Therefore, the phase difference between the vibration acceleration of the shell of the vibrating pile driver in the first state and the vibration acceleration of the eccentric block is obtained, and the rotating speed of the eccentric block is controlled so that the absolute value of the difference between the phase difference and the target value is reduced, so that the shell of the eccentric block and the shell of the vibrator are closer to enter a resonance state, the eccentric block, the shell of the vibrator, the pile connected with the shell of the vibrator and soil into which the pile is inserted are closer to enter the resonance state, and the working efficiency of the vibrating pile driver is improved.

In some embodiments, an empty load phase difference between the vibratory acceleration of the housing and the vibratory acceleration of the eccentric mass of the vibratory pile driver in the second state may also be obtained. The second state is that the vibration pile sinking machine works without load and the rotating speed of the eccentric block is larger than the preset rotating speed; in the second state, there is a desired preset phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

As some embodiments, the manner of acquiring the no-load phase difference is not limited. For example, the manner of determining the no-load phase difference between the vibration acceleration of the case and the vibration acceleration of the eccentric mass from the third timing related to the exciting force of the eccentric mass and the fourth timing related to the vibration acceleration of the case in any of the above embodiments may be adopted; for another example, the vibration acceleration of the eccentric mass and the vibration acceleration of the housing in the second state may be directly obtained, and thus the no-load phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass may be determined.

In the case that the no-load phase difference has a deviation from a preset phase difference, a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass is determined according to the deviation.

As some embodiments, a phase difference between the vibration acceleration of the case and the vibration acceleration of the eccentric mass determined according to the deviation is taken as an actual phase difference between the vibration acceleration of the case and the vibration acceleration of the eccentric mass. For example, the difference between the phase difference and the deviation obtained by other means (for example, by the first time and the second time) is taken as the actual phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass.

Therefore, by acquiring the no-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block of the vibration pile driver in the second state, and further under the condition that the no-load phase difference has deviation from the preset phase difference, the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block can be accurately determined according to the deviation, so that the rotating speed of the eccentric block is accurately controlled to reduce the absolute value of the difference between the phase difference and the target value, the shell of the eccentric block and the vibrator is more close to enter the resonance state, and the working efficiency of the vibration pile driver is further improved.

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, so that the same or similar parts between the embodiments are mutually referred to. For the device embodiments, since they basically correspond to the method embodiments, the description is relatively simple, and the relevant points are referred to in the description of the method embodiments.

In some embodiments, the control means of the rotational speed comprises a module for performing the method of any of the embodiments described above.

As shown in fig. 6, the control device for the rotational speed includes an acquisition module 601, a determination module 602, and a control module 603.

The acquisition module 601 is configured to acquire a first moment when a first absolute value of an exciting force of an eccentric mass of a vibrator of the vibratory pile driver in a first state is the most value and a second moment when a second absolute value of a vibration acceleration of a housing of the vibrator is the most value, the first state being a load-carrying operation of the vibratory pile driver. Here, the target value is a phase difference value between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass in the resonance state of the housing and the eccentric mass.

The determination module 602 is configured to determine a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass based on the first time and the second time.

The control module 603 is configured to control the rotational speed of the eccentric mass such that the absolute value of the difference in phase difference from the target value decreases.

In some embodiments, the control device of the rotation speed includes an acquisition module 601 and a control module 603.

The acquisition module 601 is configured to acquire a phase difference between a vibration acceleration of a housing of a vibrator and a vibration acceleration of an eccentric mass of the vibrator of the vibratory pile driver in a first state. Here, the first state is the vibration pile driver load operation.

The control module 603 is configured to control the rotational speed of the eccentric mass such that the absolute value of the difference in phase difference from the target value decreases. Here, the target value is a phase difference value between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass in the resonance state of the housing and the eccentric mass.

In some embodiments, the control device of the rotational speed may further include other modules to execute the control method of the rotational speed of any one of the above embodiments.

As shown in fig. 7, the control device 700 of the rotational speed includes a memory 701 and a processor 702 coupled to the memory 701, the processor 702 being configured to perform the method of any of the foregoing embodiments based on instructions stored in the memory 701.

The memory 701 may include, for example, system memory, fixed nonvolatile storage media, and the like. The system memory may store, for example, an operating system, application programs, boot Loader (Boot Loader), and other programs.

The rotational speed control device 700 may further include an input/output interface 703, a network interface 704, a storage interface 705, and the like. The input/output interface 703, the network interface 704, the storage interface 705, and the memory 701 and the processor 702 may be connected via a bus 706, for example. The input/output interface 703 provides a connection interface for input/output devices such as a display, mouse, keyboard, touch screen, etc. The network interface 704 provides a connection interface for various networking devices. The storage interface 705 provides a connection interface for external storage devices such as SD cards, U discs, and the like.

The embodiment of the disclosure also provides a vibrating pile driver, which comprises the device of any one embodiment.

The disclosed embodiments also provide a computer readable storage medium comprising computer program instructions which, when executed by a processor, implement the method of any of the above embodiments.

Thus, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

It will be appreciated by those skilled in the art that embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that functions specified in one or more of the flowcharts and/or one or more of the blocks in the block diagrams may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that the foregoing embodiments may be modified and equivalents substituted for elements thereof without departing from the scope and spirit of the disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A control method of rotational speed, comprising:

acquiring a first moment when a first absolute value of exciting force of an eccentric block of a vibrator of a vibrating pile driver in a first state is the maximum value and a second moment when a second absolute value of vibration acceleration of a shell of the vibrator is the maximum value, wherein the first state is load-carrying work of the vibrating pile driver;

Determining a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the first time and the second time;

and controlling the rotating speed of the eccentric block so that the absolute value of the difference between the phase difference and a target value is reduced, wherein the target value is a phase difference value between the vibration acceleration of the shell and the vibration acceleration of the eccentric block when the shell and the eccentric block are in a resonance state.

2. The method of claim 1, wherein the second moment is between two adjacent first moments, and the determining a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the first moment and the second moment comprises:

the phase difference is determined from a first time interval between one of the two first times and the second time and a second time interval between the two first times.

3. The method of claim 2, wherein at least one of the first time instant and the second time instant satisfies a corresponding condition, wherein:

the conditions corresponding to the first time are as follows: the first moment is the moment when the first absolute value is the minimum value;

The conditions corresponding to the second moment are as follows: the second time is a time when the second absolute value is the minimum value.

4. The method of claim 2, wherein the one of the first moments in time is a relatively earlier moment in time of the two of the first moments in time.

5. The method according to claim 4, wherein:

the first time is a time when the exciting force changes from more than 0 to 0, and the second time is a time when the vibration acceleration of the housing changes from less than 0 to 0; or (b)

The first time is a time when the exciting force changes from less than 0 to 0, and the second time is a time when the vibration acceleration of the case changes from more than 0 to 0.

6. The method of any of claims 1-5, wherein the first time is a time when a sensor emits a trigger signal, wherein the sensor is mounted on an eccentric shaft connected to the eccentric mass and emits the trigger signal when a center of mass of the eccentric mass is in an uppermost, lowermost, or intermediate position.

7. The method of claim 1, further comprising:

acquiring a third moment when the first absolute value is the highest value and a fourth moment when the second absolute value is the highest value of the vibrating pile driver in a second state, wherein the second state is that the vibrating pile driver works without load and the rotating speed of the eccentric block is larger than a preset rotating speed, and a desired preset phase difference exists between the vibrating acceleration of the shell and the vibrating acceleration of the eccentric block in the second state;

According to the third moment and the fourth moment, determining an idle phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block;

the determining a phase difference between the vibration acceleration of the housing and the vibration acceleration of the eccentric mass according to the first time and the second time includes:

and under the condition that the no-load phase difference and the preset phase difference deviate, determining the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the first moment, the second moment and the deviation.

8. A control method of rotational speed, comprising:

acquiring a phase difference between the vibration acceleration of a shell of a vibrator of the vibrating pile driver in a first state and the vibration acceleration of an eccentric block of the vibrator, wherein the first state is that the vibrating pile driver works under load;

9. The method according to claim 1 or 8, wherein the control is such that an absolute value of a difference of the phase difference from a target value is reduced to 0.

10. The method of claim 8, further comprising:

acquiring an idle-load phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block of the vibration pile driver in a second state, wherein the second state is that the vibration pile driver works without load and the rotating speed of the eccentric block is larger than a preset rotating speed, and the vibration acceleration of the shell and the vibration acceleration of the eccentric block have an expected preset phase difference in the second state;

the obtaining a phase difference between a vibration acceleration of a housing of a vibrator of the vibrating pile driver in a first state and a vibration acceleration of an eccentric mass of the vibrator includes:

and under the condition that the no-load phase difference and the preset phase difference deviate, determining the phase difference between the vibration acceleration of the shell and the vibration acceleration of the eccentric block according to the deviation.

11. The method of claim 7 or 10, wherein the preset phase difference is 180 degrees.

12. The method according to claim 7 or 10, wherein the preset rotational speed is greater than or equal to a resonance rotational speed, the resonance rotational speed being a rotational speed of the eccentric mass when the housing resonates with a damping device, wherein the housing is connected with a boom of the vibratory pile driver via the damping device.

13. The method of claim 12, wherein the preset rotational speed is at least twice the resonant rotational speed.

14. A rotational speed control apparatus comprising means for performing the method of any one of claims 1-13.

15. A rotational speed control apparatus comprising:

a memory; and

a processor coupled to the memory and configured to perform the method of any of claims 1-13 based on instructions stored in the memory.

16. A vibratory pile driver comprising:

the device of claim 14 or 15.

17. A computer readable storage medium comprising computer program instructions, wherein the computer program instructions, when executed by a processor, implement the method of any of claims 1-13.