An automatic clamping pneumatic device and intelligent control method

Abstract

The present application relates to the technical field of automatic clamping control, and particularly relates to a kind of automatically clamped pneumatic device and intelligent control method.The device improves the adaptability of clamping different shape materials through replaceable modular jaw, determines the moment needing regulation and control by analyzing the unstable results of monitoring material vibration state in material cleaning process;In the process of occlusion regulation, considering the vibration influence of pneumatic vice operation, through the component decomposition analysis of collected vibration data, eliminating the interference of mechanism vibration itself to material vibration state, obtaining vibration influence signal;Combining the unstable situation on vibration influence signal with the final stable occlusion force obtained by occlusion force prediction, the regulation and control of clamping is completed by stable occlusion force.The present application analyzes the vibration influence interference of starting vice work, makes the occlusion force regulation more accurate, and improves the stability in material clamping process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic clamping control, in particular to a pneumatic device capable of automatic clamping and an intelligent control method. BACKGROUND

[0002] The pneumatic vice is a commonly used clamping tool in industrial production, also known as pneumatic bench vice, and is widely used in the fields of automobile, machinery, electronics, etc. The workpiece can be fixed by the pneumatic vice and cleaned by the cleaning nozzle, so as to realize a stable and safe cleaning process. The traditional pneumatic vice still needs to be manually swung by a lever, and the clamping is driven by a pneumatic cylinder. The clamping of the workpiece depends on the experience of the technician, and the clamping force is experienced and unreliable. Therefore, a pneumatic device capable of automatic clamping is needed.

[0003] In the existing pneumatic vice, the key structure is often directly exposed to the cleaning liquid. After the cleaning liquid stays on the jaw and the surface of the material, the friction coefficient is reduced. If the bite force is too large, the edges of the material may directly contact the plane where the jaw is located, resulting in wear of the material profile. If the bite force is too small, the material may fall off during the cleaning process. In addition, since the vice is in the working tradition, the vibration of the mechanism will affect the adjustment and judgment of the bite force, resulting in inaccurate control of the bite force and errors. SUMMARY

[0004] In order to solve the above problems in the prior art, the purpose of the present application is to provide a pneumatic device capable of automatic clamping and an intelligent control method. The technical scheme adopted is as follows:

[0005] The present application provides an intelligent control method for a pneumatic device capable of automatic clamping, which comprises:

[0006] In the metal material cleaning process, the vibration data at each sampling time is obtained. According to the amplitude at each sampling time and the amplitude change fluctuation in the local range, the instability coefficient at each sampling time is obtained. The start time of bite force control is determined by the size of the instability coefficient.

[0007] After the start time of bite force control, the vibration data and the bite force in time sequence are obtained. The vibration data in time sequence is decomposed, and the feature peak sharpness in frequency domain of the decomposed data is analyzed. The decomposed data is denoised and reconstructed based on the feature peak sharpness, and the vibration influence signal is obtained.

[0008] According to the instability coefficient and the size of the bite force in the vibration influence signal, the bite force adjustment coefficient is obtained. The final stable bite force is determined according to the predicted change of the bite force adjustment coefficient. The clamping is controlled according to the final stable bite force.

[0009] Further, the method for obtaining the instability coefficient comprises:

[0010] For any sampling time, in a preset local range at the sampling time, a maximum value and a minimum value of the vibration data are obtained; a difference between adjacent maximum value and minimum value is taken as an amplitude; an amplitude closest to the sampling time in time sequence is taken as a vibration instability of the sampling time;

[0011] The amplitudes in the preset local range are arranged in time sequence to obtain a local amplitude sequence of the sampling time; after calculating the difference between each amplitude and the previous amplitude in the local amplitude sequence, the mean of all differences is obtained to obtain a change instability of the sampling time;

[0012] The vibration instability and the change instability of the sampling time are combined to obtain the instability coefficient of the sampling time.

[0013] Further, the method for determining the occlusal force regulation start time comprises:

[0014] When the value of the normalized instability coefficient is greater than a preset adjustment threshold, the corresponding sampling time is taken as the occlusal force regulation start time.

[0015] Further, the method for obtaining the feature peak sharpness comprises:

[0016] After the occlusal force regulation start time, the vibration data in time sequence is decomposed by an ICA algorithm to obtain a regular component signal and a random component signal;

[0017] In the frequency domain space of the regular component signal, the kurtosis is calculated and normalized to obtain the feature peak sharpness.

[0018] Further, the method for obtaining the vibration influence signal comprises:

[0019] The feature peak sharpness is negatively correlated to obtain a reserved weight; the product of the regular component signal and the reserved weight is taken as a denoising signal, and the vibration influence signal is reconstructed from the denoising signal and the random component signal.

[0020] Further, the method for obtaining the occlusal force adjustment coefficient comprises:

[0021] Based on the vibration data in the vibration influence signal, the instability coefficient of each time is obtained;

[0022] In the time sequence of the vibration influence signal, the product of the instability coefficient of the time and the occlusal force is taken as the occlusal force adjustment coefficient of the time.

[0023] Further, the method for determining the final stable occlusal force comprises:

[0024] The occlusal force adjustment coefficient is fitted to obtain an adjustment curve; the adjustment curve is predicted by using an ARIMA algorithm to obtain a predicted occlusal force adjustment coefficient;

[0025] The occlusal force adjustment coefficient is fitted to obtain an adjustment curve; the adjustment curve is predicted by using an ARIMA algorithm to obtain a predicted occlusal force adjustment coefficient;

[0026] Further, after the occlusal force regulation starting moment, the occlusal force is increased from the minimum value in the expected occlusal force range, and the vibration data and the occlusal force at each moment are collected.

[0027] Further, after the occlusal force regulation starting moment, when the occlusal force reaches the final stable occlusal force, the regulation is stopped to complete clamping.

[0028] The application also provides a pneumatic device capable of automatic clamping, comprising a vice mechanism, a transmission mechanism and a regulation mechanism; the vice mechanism comprises replaceable modular jaws for occluding metal materials; the transmission mechanism comprises a cylinder mechanism and a self-locking mechanism; the regulation mechanism comprises a collection unit, a data processing unit and a control unit;

[0029] The signal output end of the collection unit is connected to the signal input end of the data processing unit, and the signal output end of the data processing unit is connected to the signal input end of the control unit, and the control unit is used for outputting control instructions to the transmission mechanism;

[0030] The collection unit acquires vibration data at each sampling moment through a vibration sensor and acquires the occlusal force on the material through a pressure sensor; the acquired data is transmitted to the data processing unit;

[0031] The data processing unit is used for obtaining an instability coefficient at each sampling moment according to the amplitude size and the local range amplitude change fluctuation at each sampling moment during the metal material cleaning process; the instability coefficient is used for determining the occlusal force regulation starting moment;

[0032] After the occlusal force regulation starting moment, the vibration data in time sequence is decomposed, the feature peak sharpness of the decomposed signal in the frequency domain is analyzed, the decomposed signal is denoised and reconstructed based on the feature peak sharpness, and a vibration influence signal is obtained;

[0033] According to the instability coefficient and the occlusal force size in the vibration influence signal, the occlusal force adjustment coefficient is obtained; and the final stable occlusal force is determined according to the predicted change of the occlusal force adjustment coefficient;

[0034] The occlusal force regulation starting moment and the final stable occlusal force are transmitted to the transmission mechanism through the control unit, the cylinder mechanism is operated after the occlusal force regulation starting moment, and the cylinder mechanism operation stop determination and the self-locking mechanism clamping are performed according to the final stable occlusal force.

[0035] The present application has the following beneficial effects:

[0036] The present application improves the adaptability of clamping different shaped materials by replaceable modular jaws, monitors the material vibration state in the material cleaning process to analyze the unstable results, and determines the moment that needs to be regulated. In the clamping regulation process, the vibration influence of the pneumatic vice operation is considered, the vibration data collected is analyzed by component decomposition, the characteristic peak sharpness is expressed, the regular component is inhibited, the interference of the mechanism itself vibration on the material itself vibration state is eliminated, and the vibration influence signal is obtained. The final stable clamping force is obtained by combining the unstable situation of the vibration influence signal and the clamping force prediction, and the regulation clamping is completed through the stable clamping force. The present application analyzes the vibration influence interference of starting the vice work, makes the clamping force regulation more accurate, and improves the stability in the material clamping process. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art and the advantages thereof, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 A flow chart of an intelligent control method of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0039] Figure 2 A structural schematic diagram of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0040] Figure 3 Another structural schematic diagram of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0041] Figure 4 A structural top view schematic diagram of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0042] Figure 5 A structural front view schematic diagram of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0043] Figure 6 A partial top view schematic diagram of a modular jaw of an automatic clamping pneumatic device provided by an embodiment of the present application;

[0044] The following reference signs are marked on the drawings in conjunction with the drawings: 1, self-locking mechanism; 2, fixed jaw; 3, screw rod; 4, movable jaw; 5, sliding block nut; 6, threaded shaft; 7, threaded shaft gear; 8, transmission gear; 9, central processing unit and central control panel; 10, cylinder mechanism; 11, base; 12, vibration sensor; 13, modular jaw; 131, dovetail; 14, pressure sensor. DETAILED DESCRIPTION

[0045] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined object, the specific implementation, structure, features and effects of the automatic clamping pneumatic device and intelligent control method according to the present application are described in detail as follows in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0047] The specific scheme of the automatic clamping pneumatic device and intelligent control method provided by the present application is described in detail below in combination with the drawings. The specific scheme of the automatic clamping pneumatic device and intelligent control method provided by the present application is described in detail below in combination with the drawings. Figures 2 to 6 The vice mechanism of the automatic clamping pneumatic device includes a fixed jaw 2, a screw rod 3, a movable jaw 4, a sliding block nut 5, a base 11, a modular jaw 13 and a dovetail 131. The transmission mechanism includes a self-locking mechanism 1, a threaded shaft 6, a threaded shaft gear 7, a transmission gear 8 and a cylinder mechanism 10. The control mechanism includes a vibration sensor 12, a pressure sensor 14 and a central processing unit and central control panel 9.

[0048] Among them, the base 11 is provided with a transmission mechanism and a vice mechanism, and in order to avoid excessive accumulation of cleaning liquid in the entire mechanism and groove during material cleaning, the base 11 is provided with an opening below, i.e. below the threaded shaft 6, which can guide the cleaning liquid out.

[0049] The two ends of the fixed jaw 2 and the movable jaw 4 in the vice mechanism are respectively fixed by a smooth screw rod 3, so that the two can move along the screw rod 3. The fixed jaw 2 can be manually adjusted so that it can cope with different forms of materials. The movable jaw 4 is fixed on the sliding block nut 5, the sliding block nut 5 is connected with the threaded shaft 6, the movable jaw 4 can be manually or device double mode adjustment, at this time when the movable jaw 4 is fixed, the threaded shaft 6 itself does not displace. The sliding block nut 5 is fixed on the movable jaw 4 and the screw rod 3, so that the sliding block nut 5 moves forward and backward along the thread direction of the threaded shaft 6 by rotating the transmission gear 8 by the cylinder mechanism 10 and rotating the threaded shaft gear 7 and the threaded shaft 6, thereby driving the movable jaw 4 to move, realizing the occlusion of the material.

[0050] Because different materials have different complex external profiles, in order to make the material stable, a larger occlusion force is usually used, but using mutually parallel jaws may not be able to stably occlude the material, and too large occlusion force may cause, for example, the corners of the material to directly contact the plane of the jaw, resulting in wear of the material profile, and too small occlusion force will cause the material to fall off during the cleaning process. Therefore, in order to make the jaws more stably occlude the material, the vice mechanism uses replaceable modular jaws 13, the contact surface profile of the modular jaws 13 can be designed according to actual needs, and the connection mode between the modular jaws 13 and the fixed jaw 2 and the movable jaw 4 uses dovetail 131, which is replaced by pulling perpendicular to the base plane 11.

[0051] For the transmission mechanism, since the automatic clamping pneumatic device is used for cleaning metal workpieces, it is necessary to reduce the area of the device itself exposed to the cleaning liquid, especially some power and transmission structures, to avoid oxidation and corrosion. Therefore, the cylinder mechanism 10 is placed outside the base 11, and the cylinder mechanism 10 is connected with the transmission gear 8 to provide power to rotate the transmission gear 8.

[0052] The existing pneumatic vice usually fixes the jaw on a smooth screw rod, and provides power to the jaw by a cylinder to move the jaw. In this embodiment, the rod that drives the jaw to move is set as a threaded shaft 6, and the part of the threaded shaft 6 that extends outside the base 11 uses a threaded shaft gear 7, so that the threaded shaft gear 7 is engaged with the transmission gear 8.

[0053] At the same time, in the process of clamping the material, the limit stress of different materials, that is, the limit stress when deformation occurs, is different, and more accurate regulation is needed when regulating the occlusion force. Therefore, the diameter of the transmission gear 8 is larger and the number of teeth is more, and the diameter of the threaded shaft gear 7 is relatively smaller and the number of teeth is less, at this time, when the cylinder mechanism 10 is used to rotate the transmission gear 8 and drive the threaded shaft gear 7 and the threaded shaft 6 to rotate, the final occlusion force adjustment accuracy is higher.

[0054] In order to get rid of the cylinder failure, power outage and other factors leading to the sudden drop of the power output of the cylinder mechanism 10, so that the vice mechanism clamps the material more stably, and at the same time reduces the additional energy loss in the cleaning process, a self-locking mechanism 1 is adopted on the other side of the base 11 where the threaded shaft 6 extends. When the output power of the cylinder mechanism 10 is abnormal, or the vice has reached a fixed clamping force, the threaded shaft 6 is fixed and locked so that it cannot rotate in reverse direction to cause the clamping force to decrease.

[0055] It should be noted that the mechanical analysis, for example, for two jaws parallel to each other and perpendicular to the horizontal plane, when there is material between them, the material itself is affected by the combined action of the vertical downward gravity, the horizontal jaw pressure and the vertical upward friction between the jaw and the material. The jaw pressure on both sides cancels each other out, in order to balance the material, the gravity of the material and the friction between the jaw and the material should be the same, so as to increase the friction by adjusting the clamping force.

[0056] Because the shape, structure and material properties of the material to be clamped are different, the limit stress during deformation is different. When artificially controlled, there is a large error in the clamping force, which may cause the material to deform, wear or fall off. Therefore, automatic adjustment is performed through the control mechanism.

[0057] During the cleaning process of metal materials, a large water pressure is usually used. At this time, when the material comes into contact with high-pressure water, it may vibrate to a certain extent. At the same time, the cleaning liquid stays on the surface of the jaw and the material, which reduces the friction coefficient. At this time, the vibration will cause the balance between the material and the jaw to fluctuate, which will reduce the friction and cause the material to shift or even fall off. Therefore, the power output of the cylinder mechanism 10 needs to be controlled by monitoring the vibration of the material in real time, so as to adjust the clamping force.

[0058] Because the force is mutual, and according to the specifications and quality requirements of the material, the limit stress during deformation can be obtained. The pressure sensor 14 is installed on the surface between the jaw and the modular jaw 13, which is used to monitor the clamping force during clamping. The running vibration is conducted through the medium, so the vibration sensor 12 is installed on the fixed jaw 4 to collect vibration data.

[0059] The control mechanism includes a collection unit, a data processing unit and a control unit. The collection unit obtains vibration data and clamping force at each sampling time through the vibration sensor 12 and the pressure sensor 14, and monitors the vibration and clamping force of the pneumatic vice during cleaning and control. The obtained data is transmitted to the data processing unit, which is analyzed and processed by the high-speed central processor and the central control panel 9 installed on the cylinder mechanism 10. The control unit receives the feedback control result for subsequent feedback control.

[0060] The method for analysis control by the regulating mechanism is described in Figure 1 The method comprises the following steps:

[0061] S1: In the metal material cleaning process, the vibration data at each sampling time is obtained; according to the amplitude at each sampling time and the amplitude change fluctuation in the local range, the instability coefficient at each sampling time is obtained; the occlusion force regulation start time is determined by the size of the instability coefficient.

[0062] When the material itself is clamped and in a balanced state, it is subjected to lateral pressure formed by the two sides of the clamp, and together makes the material in a relatively static state of the clamping device. After the metal material contacts with the high-pressure water for cleaning, a certain degree of vibration may be generated, which is conducted through the medium and can be monitored by the installed sensor during the cleaning process. In the embodiment of the present application, the sampling time interval of the vibration data can be set to 0.5 seconds, and the specific sampling frequency can be adjusted by the implementer according to the specific implementation scene, which is not limited here.

[0063] The greater the vibration amplitude of the material, the greater the decrease in the friction coefficient caused by the cleaning liquid at this time, and the worse the stability at this time, and the higher the demand for occlusion adjustment. Therefore, the instability characteristics are analyzed through the amplitude at each sampling time. In the embodiment of the present application, the method for obtaining the instability coefficient at each sampling time comprises:

[0064] For any sampling time, the maximum value and the minimum value of the vibration data are obtained in the preset local range at the sampling time, and the difference between the adjacent maximum value and the minimum value is taken as each amplitude. In order to analyze the influence of the vibration amplitude, the amplitude is reflected by the change amplitude of the extreme value in the local range, and there is an amplitude between each adjacent minimum value and maximum value. In this embodiment, the range size of 10 seconds with each sampling time as the center is set as the preset local range, and the selection of the local range is specifically referred to, which can be adjusted by the implementer.

[0065] The greater the amplitude at the sampling time, the higher the instability of the material at this time, and the amplitude closest to the sampling time in time sequence is taken as the vibration instability of the sampling time.

[0066] Considering the continuous drop in amplitude caused by the cleaning fluid, the amplitudes within a preset local range are arranged in chronological order to obtain the local amplitude sequence at that sampling moment, and the amplitude variation over time is analyzed. After calculating the difference between each amplitude and the previous amplitude in the local amplitude sequence, the mean of all differences is calculated as the instability of change at that sampling moment. When the instability is positive and larger, it reflects a greater continuous change in the material under impact and a higher degree of instability.

[0067] Finally, combining the vibration instability and the change instability at that sampling moment, the instability coefficient at that sampling moment is obtained. In this embodiment of the invention, the Euclidean norm between the vibration instability and the change instability is calculated to obtain the instability coefficient. By solving the Euclidean norm simultaneously, the greater the vibration instability and the change instability, the higher the impact on the current material. In other embodiments of the invention, the product of the vibration instability and the change instability can also be used as the instability coefficient, which will not be elaborated further.

[0068] The more severe the instability of the vibration in the timing sequence, the more necessary it is for the material to undergo clamping adjustment to ensure stable clamping under high-pressure water impact. In this embodiment of the invention, when the normalized value of the instability coefficient is greater than the preset adjustment threshold, it indicates poor clamping stability and the need for clamping control. The corresponding sampling time is taken as the start time of clamping force control, and the preset adjustment threshold is set to 0.5. The specific value can be adjusted by the implementer.

[0069] It should be noted that normalization is a technique well known to those skilled in the art. The choice of normalization can be linear normalization or standard normalization, etc., and the specific normalization method is not limited here.

[0070] S2: After the start of bite force regulation, acquire temporal vibration data and bite force; decompose the temporal vibration data and analyze the characteristic peak sharpness of the decomposed data in the frequency domain; based on the characteristic peak sharpness, denoise and reconstruct the decomposed data to obtain the vibration influence signal.

[0071] At the start of the bite force adjustment, the control unit transmits the signal to the transmission mechanism, activating the cylinder mechanism for bite control. The vise has a rated increase or decrease coefficient when increasing or decreasing the bite force, meaning that the bite force adjustment for the material changes steadily over time. Therefore, the rated gear speed can be obtained based on the cylinder specifications, and the adjustment of the bite force is a linear process.

[0072] Due to the difference of the material, the range of the bite force can be changed, so in the bite force clamping adjustment, the allowable range of the bite force of the clamped material needs to be obtained in advance, so that the subsequent regulated bite force is in the expected bite force range. In the embodiment of the present application, the maximum bite force is input as the limit stress size of the current material, and the minimum bite force at the material balance is directly output according to the contact angle between the material and the jaw and the horizontal plane, the mass of the material and other prior characteristics, so as to obtain the expected bite force range of the corresponding material.

[0073] When adjusting the actual stress of the material, the greater the stress of the material, the greater the probability of deformation, and the higher the instability, so when adjusting the bite force, the final bite force should be as small as possible. Therefore, after the start of the bite force regulation, the bite force starts from the minimum value in the expected bite force range, and the rated power of the cylinder mechanism is operated, the bite force is linearly increased, and the bite force and vibration data of the material are continuously monitored and collected during the process, and the bite force is analyzed.

[0074] When the pneumatic vice is in working state, the automatic locking structure is unlocked, and the cylinder mechanism, gear, screw shaft and other mechanisms will produce certain vibration. The vibration is transmitted through each mechanism, and is also collected by the vibration sensor, which causes interference in the collected vibration data, resulting in error in the final regulation of the bite force. Therefore, the vibration data needs to be denoised.

[0075] The vibration generated by the vice itself in the working state is more stable than the vibration generated by the high-pressure water impact on the object, and the random change trend is smaller, so the denoising analysis can be performed through signal decomposition. Since the vibration signal is composed of regular signals and random signals generated by the material cleaning, the regular signal part can be set to zero to achieve denoising.

[0076] However, the vibration generated by the actual pneumatic vice has certain interference components, and the vibration conduction condition causes the components to not be completely regular, so if the denoising is directly set to zero, part of the vibration signal characteristics in the random component may be lost. Therefore, considering the frequency spectrum analysis, the denoising degree is adjusted through the peak characteristics of the regular component to obtain more accurate vibration influence signal.

[0077] Firstly, the vibration data in time sequence is decomposed, and the characteristic peak sharpness of the decomposed data in frequency domain is analyzed. In the embodiment of the present application, the method for obtaining the characteristic peak sharpness comprises:

[0078] After the starting moment of the clamping force regulation, the vibration data in time sequence is decomposed by an ICA decomposition algorithm to obtain regular component signals and random component signals. In this embodiment, the vibration signals mixed in time sequence can be decomposed into statistically independent components by the ICA decomposition algorithm, and the direct current component of the signal is removed. The direct current component refers to the mean value or constant offset part in the signal. If there is a significant direct current component in the signal, it will appear as a peak at zero frequency in the frequency spectrum analysis, which will mask other frequency components. The remaining signal is whitened to eliminate the second-order correlation between channels. Then, the autocorrelation function of the decomposed components is calculated, and the regularity and randomness are distinguished by time domain periodicity verification. The autocorrelation function of the regular periodic signal retains the frequency characteristics, while the random component decays rapidly, and the final regular component signal and random component signal are obtained.

[0079] It should be noted that the ICA decomposition algorithm, whitening and autocorrelation function calculation are all well-known technical means to those skilled in the art, and will not be described here.

[0080] Through the different performances of different components in the frequency domain space, the regular component appears as a single frequency peak in the frequency spectrum, and the random component spectrum has no significant peak. Therefore, the greater the sharpness of the peak representing the regular component, the more the component content, and the greater the need for elimination. Therefore, in the frequency domain space of the regular component signal, the kurtosis is calculated and normalized to obtain the characteristic peak sharpness. The size of the kurtosis calculated represents the steepness and sharpness of the peak. It should be noted that the frequency domain conversion and kurtosis calculation are all well-known technical means to those skilled in the art, and will not be described here.

[0081] In other embodiments of the present application, the peak size of the regular component signal can be obtained as the sharpness extreme value, and the greater the value, the greater the sharpness. The range of the peak frequency domain is taken as the characteristic distribution value, and the smaller the value, the greater the sharpness. The ratio of the extreme value to the characteristic distribution value is normalized as the characteristic peak sharpness, which reflects the sharpness.

[0082] Therefore, based on the characteristic peak sharpness, the decomposed data is denoised and reconstructed to obtain the vibration influence signal. The greater the characteristic peak sharpness, the more significant the regular component, the greater the degree of elimination, and the smaller the signal retention.

[0083] Therefore, in the embodiments of the present application, the characteristic peak sharpness is negatively correlated to obtain the retention weight, which represents the degree of regular component to be retained. The product of the regular component signal and the retention weight is taken as the denoised signal, and the denoised signal and the random component signal are reconstructed to obtain the vibration influence signal, thereby obtaining the signal in which the vibration influence of the starting vice itself is removed.

[0084] It should be noted that the negative correlation mapping and signal reconstruction are well-known technical means to those skilled in the art, for example, the negative correlation mapping adopts an inverse proportional value or a negative exponential power form, and the signal reconstruction can also adopt a wavelet transform, and the like, which are not limited or described herein.

[0085] S3: Obtain a clamping force adjustment coefficient according to the instability coefficient of the time in the vibration influence signal and the size of the clamping force; determine a final stable clamping force according to a predicted change of the clamping force adjustment coefficient; and control clamping according to the final stable clamping force.

[0086] The subsequent instability and clamping force are analyzed through the vibration influence signal after the influence is removed, at this time, in the process of adjusting the clamping force, the greater the clamping force, the greater the inhibitory effect on the vibration, at this time, the smaller the instability, that is, the smaller the amplitude change is better, and therefore the final stable clamping force size is determined by combining the instability coefficient corresponding to the clamping force.

[0087] According to the instability coefficient of the time in the vibration influence signal and the size of the clamping force, a clamping force adjustment coefficient is obtained, in the embodiment of the present application, the instability coefficient of each time is obtained based on the vibration data in the vibration influence signal, and the calculation method and steps of the time instability coefficient are the same as those in step S1, which are not described herein.

[0088] Further, the product of the instability coefficient of the time and the clamping force is taken as the clamping force adjustment coefficient of the time on the time sequence of the vibration influence signal, so that the clamping force is smaller in the case of smaller instability, the clamping is ensured, and the material form is protected.

[0089] The change of the clamping force adjustment coefficient can be predicted subsequently, so as to predict the expected optimal condition through real-time prediction and analysis, in the embodiment of the present application, the method for obtaining the final stable clamping force comprises:

[0090] The clamping force adjustment coefficient on the time sequence is fitted to obtain an adjustment curve, the predicted clamping force adjustment coefficient is obtained by predicting the adjustment curve by using an ARIMA algorithm, it should be noted that the curve fitting and the ARIMA algorithm prediction are well-known technical means to those skilled in the art, the curve fitting can adopt a least square method, and the like, which are not described herein.

[0091] Finally, the clamping force corresponding to the minimum value of the clamping force adjustment coefficient is taken as the final stable clamping force, the clamping force adjustment coefficient is the smallest in the case of the optimal stable condition, and the clamping force is the smallest, which represents the optimal pressure condition of the clamping and cleaning.

[0092] Therefore, the clamping is controlled according to the final stable clamping force, the final stable clamping force is transmitted to the transmission mechanism through the control unit, when the clamping force reaches the final stable clamping force, the operation of the cylinder mechanism and the clamping force adjustment are stopped, and the self-locking mechanism locks the screw shaft to realize automatic clamping.

[0093] In conclusion, the application improves the adaptability of clamping different shaped materials by replaceable modular jaws, monitors the material vibration state in the material cleaning process to analyze the unstable results, and determines the moment that needs to be regulated. In the regulation process of occlusion, the vibration influence of the pneumatic vise operation is considered, the vibration data collected is analyzed by component decomposition, the characteristic peak sharpness is expressed, the regular component is inhibited, the interference of the mechanism itself vibration on the material vibration state is eliminated, and the vibration influence signal is obtained. The final stable occlusion force is obtained by combining the unstable situation of the vibration influence signal and the occlusion force prediction, and the regulation clamping is completed by the stable occlusion force. The application analyzes the vibration influence interference of starting the vise work, makes the occlusion force regulation more accurate, and improves the stability in the material clamping process.

[0094] It should be noted that the above-mentioned embodiment sequence of the application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or may be advantageous.

[0095] Each embodiment in the specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. Each embodiment mainly describes the difference from other embodiments.

Claims

1. A method for intelligent control of an automatically clippable pneumatic device, characterized in that, The method comprises: During the metal material cleaning process, vibration data at each sampling time is obtained; an instability coefficient at each sampling time is obtained according to the amplitude at each sampling time and the amplitude variation fluctuation in a local range; and the start time of the bite force regulation is determined according to the instability coefficient; After the start time of the bite force regulation, the vibration data and the bite force in time sequence are obtained; the vibration data in time sequence are decomposed, and the feature peak sharpness in the frequency domain of the decomposed data is analyzed; the decomposed data are denoised and reconstructed based on the feature peak sharpness, and a vibration influence signal is obtained; The instability coefficient at the time in the vibration influence signal and the size of the bite force are used to obtain a bite force adjustment coefficient; the final stable bite force is determined according to the predicted change of the bite force adjustment coefficient; and the clamping is controlled according to the final stable bite force. The method for obtaining the feature peak sharpness comprises: After the start time of the bite force regulation, the vibration data in time sequence are decomposed by using an ICA decomposition algorithm to obtain regular component signals and random component signals; In the frequency domain space of the regular component signals, the kurtosis is calculated and normalized to obtain the feature peak sharpness. The method for obtaining the vibration influence signal comprises: The feature peak sharpness is negatively correlated and mapped to obtain a reserved weight; the product of the regular component signals and the reserved weight is used as a denoising signal; and the vibration influence signal is obtained by reconstructing the denoising signal and the random component signals. The method for obtaining the bite force adjustment coefficient comprises: The vibration data in the vibration influence signal are used to obtain the instability coefficient at each time; The product of the instability coefficient at each time and the bite force is used as the bite force adjustment coefficient at each time. The method for determining the final stable bite force comprises: The bite force adjustment coefficients in time sequence are fitted to obtain an adjustment curve; the predicted bite force adjustment coefficient is obtained by predicting the adjustment curve by using an ARIMA algorithm; The final stable bite force is the bite force corresponding to the minimum value of the bite force adjustment coefficient.

2. The intelligent control method of the automatic clamping pneumatic device according to claim 1, characterized in that, The method for obtaining the instability coefficient comprises: For any sampling time, the maximum value and the minimum value of the vibration data in a preset local range at the sampling time are obtained; the difference between the adjacent maximum value and the minimum value is used as the amplitude; and the amplitude closest to the sampling time in time sequence is used as the vibration instability at the sampling time. The amplitudes in the preset local range are arranged in time sequence to obtain a local amplitude sequence at the sampling time; the mean value of the difference between each amplitude and the previous amplitude in the local amplitude sequence is calculated to obtain the change instability at the sampling time. The vibration instability and the change instability at the sampling time are combined to obtain the instability coefficient at the sampling time.

3. The intelligent control method of the automatic clamping pneumatic device according to claim 1, characterized in that, The method for determining the start time of the bite force regulation comprises: When the value of the normalized instability coefficient is greater than a preset adjustment threshold, the corresponding sampling time is used as the start time of the bite force regulation.

4. The intelligent control method of the automatic clamping pneumatic device according to claim 1, characterized in that, After the start time of the bite force regulation, the bite force is increased from the minimum value in the expected bite force range, and the vibration data and the bite force at each time are collected.

5. The intelligent control method of the automatic clamping pneumatic device according to claim 1, characterized in that, After the clamping force reaches the final stable clamping force, the regulation is stopped to complete clamping.

6. A self-clamping pneumatic device, characterized in that The device comprises a vice mechanism, a transmission mechanism and a regulation mechanism; the vice mechanism comprises replaceable modular jaws for clamping metal materials; the transmission mechanism comprises a cylinder mechanism and a self-locking mechanism; the regulation mechanism comprises a collection unit, a data processing unit and a control unit; The signal output end of the collection unit is connected to the signal input end of the data processing unit, and the signal output end of the data processing unit is connected to the signal input end of the control unit, which is configured to output control instructions to the transmission mechanism; The collection unit acquires vibration data at each sampling time through a vibration sensor and acquires the clamping force on the material through a pressure sensor; the acquired data is transmitted to the data processing unit; The data processing unit is configured to obtain an instability coefficient at each sampling time according to the amplitude at each sampling time and the amplitude change fluctuation in the local range during the cleaning process of the metal material; the instability coefficient is used to determine the clamping force regulation start time; After the clamping force regulation start time, the vibration data in time sequence is decomposed, the characteristic peak sharpness of the decomposed signal in the frequency domain is analyzed, the decomposed signal is denoised and reconstructed based on the characteristic peak sharpness, and a vibration influence signal is obtained; According to the instability coefficient and the clamping force in the vibration influence signal, a clamping force adjustment coefficient is obtained; According to the predicted change of the clamping force adjustment coefficient, a final stable clamping force is determined. The method for obtaining the characteristic peak sharpness comprises: After the clamping force regulation start time, the vibration data in time sequence is decomposed using an ICA decomposition algorithm to obtain regular component signals and random component signals; In the frequency domain space of the regular component signals, the kurtosis is calculated and normalized to obtain the characteristic peak sharpness. The method for obtaining the vibration influence signal comprises: The characteristic peak sharpness is negatively correlated to obtain a reserved weight; the product of the regular component signals and the reserved weight is used as a denoising signal, and the denoising signal and the random component signals are reconstructed to obtain the vibration influence signal. The method for obtaining the clamping force adjustment coefficient comprises: Based on the vibration data in the vibration influence signal, an instability coefficient at each time is obtained. In the time sequence of the vibration influence signal, the product of the instability coefficient at each time and the clamping force is used as the clamping force adjustment coefficient at each time. The method for determining the final stable clamping force comprises: The clamping force adjustment coefficients in time sequence are fitted to obtain an adjustment curve; the adjustment curve is predicted using an ARIMA algorithm to obtain a predicted clamping force adjustment coefficient; The clamping force corresponding to the minimum clamping force adjustment coefficient is used as the final stable clamping force. The clamping force regulation start time and the final stable clamping force are transmitted to the transmission mechanism through the control unit; the cylinder mechanism operates after the clamping force regulation start time and stops operating according to the final stable clamping force, and the self-locking mechanism clamps.

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