End force closed-loop control method, device, equipment and medium

Abstract

The invention discloses an end force closed-loop control method, device and equipment and a medium, and relates to the technical field of force control, and the method comprises the steps: obtaining a target force value; a feedback signal output by the pressure sensor is obtained, and the amplitude of the feedback signal corresponds to the magnitude of the counter-acting force borne by the execution component when the execution component makes contact with the workpiece; generating a control signal according to a difference value between the target force value and an actual force value represented by the feedback signal; the control signal is output to the driving part to drive the guiding part to drive the execution part to move, and the actual contact force is adjusted; and repeating the steps until the deviation between the actual contact force and the target force value meets a preset condition. According to the force control method provided by the invention, on the basis of eliminating the interference source influence, the rapid response and accurate and stable control of the micro acting force in the contact process of the executing mechanism and the chip can be realized.

Description

Technical Field

[0001] This invention relates to the field of force control technology, and in particular to a method, apparatus, equipment and medium for end-force closed-loop control. Background Technology

[0002] In precision chip adsorption and gripping operations, the actuator must first move downwards to contact the surface of the workpiece (e.g., a chip). Once contact is stable, the adsorption function is activated to pick up the chip. During this process, the force exerted by the actuator at the moment of contact with the chip must be precisely controllable. If the contact force is too large, it can easily cause damage or breakage to the chip.

[0003] Traditional open-loop control methods typically rely on the current of the drive motor to estimate the output force. However, this method is susceptible to interference from factors such as temperature fluctuations and load changes, resulting in significant force estimation errors and failing to meet the requirements of precision operations. Furthermore, to improve control accuracy, some solutions introduce force sensors for real-time monitoring. However, in practical applications, the force sensor measurements are highly susceptible to interference from sources such as drive component vibration and cable dragging, leading to distorted feedback signals that fail to accurately reflect the contact force between the actuator and the chip. Simultaneously, in existing solutions, sensors are often only used for monitoring and do not provide real-time feedback to the control system to form a closed-loop adjustment mechanism. This limits the system's response speed and makes it difficult to effectively compensate for instantaneous force changes at contact, further exacerbating the instability of force control. Summary of the Invention

[0004] This invention provides a method, apparatus, device, and medium for end-effector closed-loop control of force. The technical problem it aims to solve is how to provide a force control method that can achieve rapid response and precise and stable control of minute forces during the contact process between the actuator and the chip, while eliminating the influence of interference sources.

[0005] In a first aspect, embodiments of the present invention provide an end-effector force closed-loop control method applied to an actuator, the actuator including a drive member, a guide member, a pressure sensor, and an actuating component, the pressure sensor having a fixed end and a measuring end connected together, the fixed end being connected to the guide member, the measuring end being connected to the actuating component, and the drive member being connected to the guide member, the method comprising: S1, obtain the target force value; S2, Obtain the feedback signal output by the pressure sensor, the amplitude of the feedback signal corresponding to the magnitude of the reaction force received by the actuator when it contacts the workpiece; S3, generate a control signal based on the difference between the target force value and the actual force value represented by the feedback signal; S4, the control signal is output to the drive member to drive the guide member to move the execution component, thereby adjusting the actual contact force between the execution component and the workpiece; S5. Repeat steps S2 to S4 until the deviation between the actual contact force and the target force value meets the preset condition.

[0006] Optionally, the feedback signal is generated by the pressure sensor detecting the relative displacement or stress of its measuring end relative to its fixed end; The fixed end of the pressure sensor receives the vibration generated during the operation of the drive component and the drag force generated by the cable or air pipe connected to the drive component. The measuring end of the pressure sensor receives the reaction force generated when the actuator contacts the workpiece. The pressure sensor generates the feedback signal based solely on the relative displacement or stress of the measuring end relative to the fixed end.

[0007] Optionally, generating a control signal based on the difference between the target force value and the actual force value represented by the feedback signal includes: The feedback signal is converted from analog to digital to obtain a digitized actual force value, wherein the feedback signal is an analog voltage signal; The difference between the target force value and the actual force value is calculated as the force deviation; The force deviation is proportionally calculated to obtain the proportional control value; The force deviation is integrated to obtain the integral control quantity; The differential operation is performed on the force deviation to obtain the differential control quantity; The control signal is generated by summing the proportional control quantity, the integral control quantity, and the derivative control quantity.

[0008] Optionally, the guide includes a mounting shaft and an air bearing. The mounting shaft extends along a preset direction and is fixedly installed. The air bearing is sleeved on the outer periphery of the mounting shaft and is connected to the output end of the drive and the fixed end of the pressure sensor, respectively. The method further includes: after the drive outputs a driving force to the air bearing according to the control signal, compressed gas is introduced between the air bearing and the mounting shaft. During the movement of the air bearing along the mounting shaft, the compressed gas forms an air film between the air bearing and the mounting shaft.

[0009] Optionally, the target force value is a constant contact force value that needs to be maintained when the actuating component contacts the workpiece and activates the adsorption function.

[0010] Optionally, repeating steps S2 to S4 as described above includes: Steps S2, S3, and S4 are executed cyclically at a preset sampling period; Within each sampling period, based on the difference between the actual force value represented by the feedback signal obtained in the current execution step S2 and the target force value, step S3 is executed to generate the current control signal; Step S4 outputs the control signal for the current time to the drive unit so that the actual contact force is adjusted in each sampling period.

[0011] Optionally, before performing analog-to-digital conversion on the feedback signal to obtain the digitized actual force value, the method further includes a step of filtering the analog voltage signal.

[0012] Secondly, embodiments of the present invention also provide an end-force closed-loop control device for isolating interference sources, which includes a unit for performing the above-described method.

[0013] Thirdly, embodiments of the present invention also provide a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0014] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the above-described method.

[0015] This invention provides a method, apparatus, device, and medium for closed-loop control of end force. The method includes: acquiring a target force value; acquiring a feedback signal output by a pressure sensor, the amplitude of which corresponds to the magnitude of the reaction force experienced by the actuator when it contacts the workpiece; generating a control signal based on the difference between the target force value and the actual force value represented by the feedback signal; outputting the control signal to a drive component to drive a guide component to move the actuator, thereby adjusting the actual contact force between the actuator and the workpiece. Steps S2 to S4 are repeated until the deviation between the actual contact force and the target force value meets a preset condition. This invention utilizes a specific connection method where the fixed end of the pressure sensor is connected to the guide component and the measuring end is connected to the actuator. This allows the fixed end to absorb interference forces such as vibrations from the drive component and cable dragging, while the measuring end absorbs the reaction force generated by the contact between the actuator and the workpiece. The pressure sensor outputs a feedback signal based on the relative displacement or stress of the measuring end relative to the fixed end, thereby achieving physical isolation of interference forces and ensuring that the feedback signal accurately represents the pure contact force. Furthermore, based on this, by acquiring the target force value, a control signal is generated and output to the drive component based on the difference between the target force value and the actual force value represented by the feedback signal. This signal drives the guide component to move the actuator to adjust the actual contact force, and the above steps are repeated until the deviation meets the preset conditions, forming a complete closed-loop control. This method not only eliminates the influence of interference forces on force measurement but also achieves real-time monitoring and dynamic adjustment of the contact force. This enables precise and stable control of minute forces even under interference environments such as drive component vibration, effectively avoiding workpiece damage or pickup failure due to inaccurate contact force, and meeting the requirements of precision operations for force control accuracy and stability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic flowchart of an end-force closed-loop control method provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the actuator provided in an embodiment of the present invention; Figure 3 for Figure 2 A structural diagram of part of the actuator; Figure 4 for Figure 3 Schematic diagram of the structure of the air-bearing system; Figure 5for Figure 4 A schematic diagram of the exploded structure of a medium-sized air-bearing bearing; Figure 6 for Figure 4 Cross-sectional schematic diagram of a medium-sized air-bearing bearing; Figure 7 for Figure 5 Schematic diagram of the middle connecting ring; Figure 8 Another structural schematic diagram of the actuator provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the assembly of the mounting shaft and the support structure provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the support structure provided in an embodiment of the present invention; Figure 11 A schematic block diagram of a computer device provided for an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0023] Please see Figure 1 This invention provides an end-effector force closed-loop control method applied to an actuator (specifically, to the actuator's controller). The actuator includes a drive component, a guide component, a pressure sensor, and an actuating component. The pressure sensor has a fixed end and a measuring end connected together. The fixed end is connected to the guide component, and the measuring end is connected to the actuating component. The drive component is connected to the guide component. S1, obtain the target force value.

[0024] In practical implementation, a target force value is obtained. The target force value is a pre-set magnitude of the force required to maintain contact between the desired actuator and the workpiece. Furthermore, the target force value can be determined according to specific process requirements. For example, in chip adsorption and gripping operations, the target force value can be set to a force that ensures stable chip adsorption without causing chip damage, such as 5 grams of force. Furthermore, the target force value is usually stored digitally in the controller's register or memory as a reference value for subsequent closed-loop control. The target force value can be obtained by receiving external input commands, reading preset parameter files, or communicating with a higher-level control system; this invention does not specifically limit the method.

[0025] In some preferred embodiments, the target force value is a constant contact force value that needs to be maintained when the actuating component contacts the workpiece and activates the adsorption function.

[0026] In practice, this target force value is the constant contact force required to be maintained when the actuator contacts the workpiece and the adsorption function is activated. In chip adsorption and gripping operations, the end of the actuator is typically equipped with a suction nozzle, which is connected to a vacuum adsorption system. The vacuum adsorption system includes a vacuum pump, a vacuum valve, and vacuum tubing, used to generate negative pressure inside the suction nozzle. Further, the actuator first drives the actuator downwards, bringing the suction nozzle into contact with the chip surface. At the moment of contact, a contact force is generated between the actuator and the chip. Once the suction nozzle contacts the chip and reaches a stable state, the vacuum adsorption function is activated. The vacuum valve opens, and the vacuum pump creates negative pressure inside the suction nozzle through the tubing, adsorbing the chip onto the nozzle. Then, the actuator moves the chip to the target position.

[0027] Furthermore, the contact force needs to be precisely controlled throughout the entire contact and adsorption process. If the contact force is too large, the nozzle may crush the chip, especially for very thin or fragile chips; if the contact force is too small, the nozzle may not be able to fit tightly against the chip, resulting in a gap between the nozzle and the chip, air leakage during vacuum adsorption, insufficient adsorption force, and the chip may fall off during movement. Therefore, the target force value is set to a constant value that ensures sufficient contact between the nozzle and the chip to form a seal without causing damage to the chip. This target force value is set before the nozzle contacts the chip and is continuously maintained through a closed-loop control process after contact occurs.

[0028] S2, Obtain the feedback signal output by the pressure sensor, the amplitude of the feedback signal corresponding to the magnitude of the reaction force received by the actuator when it comes into contact with the workpiece.

[0029] In specific implementation, the feedback signal output by the pressure sensor is acquired. The pressure sensor has a fixed end and a measuring end connected together. The fixed end is connected to a guide, and the measuring end is connected to the actuating component. Furthermore, the pressure sensor detects the relative displacement or stress change of its measuring end relative to the fixed end in real time and outputs an electrical signal corresponding to the detection result as a feedback signal. The amplitude of the feedback signal corresponds to the magnitude of the reaction force experienced by the actuating component when it contacts the workpiece; the greater the reaction force, the greater the amplitude of the feedback signal. Further, the feedback signal is provided to the controller in the form of an analog voltage signal. The value range of the analog voltage signal can be, for example, 0 to 10 volts, corresponding to a force value from 0 to the maximum range. Further, when the actuating component is not in contact with the workpiece, the feedback signal is zero or close to zero; when the actuating component contacts the workpiece, the workpiece generates a reaction force on the actuating component. This reaction force acts on the measuring end of the pressure sensor, causing a small relative displacement or stress change of the measuring end relative to the fixed end. The pressure sensor converts this relative displacement or stress change into an electrical signal output, thus the feedback signal carries information about the actual contact force.

[0030] In some preferred embodiments, the feedback signal is generated by the pressure sensor detecting the relative displacement or stress of its measuring end relative to its fixed end; wherein, the fixed end of the pressure sensor bears the vibration generated by the operation of the drive component and the drag force generated by the cable or air pipe connected to the drive component, the measuring end of the pressure sensor bears the reaction force generated when the actuator contacts the workpiece, and the pressure sensor generates the feedback signal solely based on the relative displacement or stress of the measuring end relative to the fixed end.

[0031] In practice, the pressure sensor detects the relative displacement or stress between its measuring end and the fixed end, generating a feedback signal. Furthermore, the internal structure of the pressure sensor typically includes an elastic body or a sensitive element. When relative displacement or stress occurs between the measuring end and the fixed end, the elastic body deforms, and the sensitive element converts this deformation into changes in resistance, capacitance, or voltage, ultimately outputting an electrical signal. The feedback signal is the direct product of this conversion process.

[0032] Furthermore, the fixed end of the pressure sensor is connected to the guide, and the measuring end is connected to the actuator. During the operation of the drive component, the vibration generated by the drive component is transmitted to the guide through a mechanical connection, and then acts on the fixed end of the pressure sensor. Furthermore, the cables or air tubes connected to the drive component generate drag forces during movement, which are also transmitted to the fixed end of the pressure sensor through the guide. These forces acting on the fixed end are disturbance forces; they may cause displacement or vibration of the fixed end. However, since the measurement principle of the pressure sensor is based on the relative change of the measuring end relative to the fixed end, the displacement or vibration of the fixed end itself will not cause a change in the relative displacement or stress of the measuring end relative to the fixed end.

[0033] Furthermore, when the actuating component comes into contact with the workpiece, the workpiece generates a reaction force on the actuating component, which acts directly on the measuring end of the pressure sensor. This force causes a relative displacement or stress change at the measuring end relative to the fixed end, and the pressure sensor detects this change and converts it into an electrical signal output.

[0034] In this embodiment of the invention, the feedback signal output by the pressure sensor corresponds only to the relative displacement or stress of the measuring end relative to the fixed end, that is, it only characterizes the magnitude of the reaction force generated when the actuator contacts the workpiece. Interference forces such as vibration and dragging forces acting on the fixed end do not affect the feedback signal because they do not cause relative changes in the measuring end relative to the fixed end. This sensor installation method based on the principle of relative measurement achieves physical isolation from interference forces, enabling the feedback signal to accurately reflect pure contact force information. The feedback signal is output in the form of an analog voltage signal, and its amplitude corresponds to the magnitude of the reaction force; the greater the reaction force, the greater the amplitude of the feedback signal.

[0035] S3, generate a control signal based on the difference between the target force value and the actual force value represented by the feedback signal.

[0036] In practice, a control signal is generated based on the difference between the target force value and the actual force value represented by the feedback signal. First, the acquired feedback signal is converted into an actual force value. Since the feedback signal is an analog voltage signal, it needs to be converted into a digital quantity using an analog-to-digital converter. Then, according to a pre-defined voltage-force value correspondence, the digital voltage quantity is converted into an actual force value in units of force (such as grams or newtons). Furthermore, the actual force value reflects the magnitude of the actual contact force between the actuator and the workpiece at the current moment. Then, the difference between the target force value and the actual force value is calculated. This difference represents the degree to which the current actual contact force deviates from the target force value, and is referred to as the force deviation. The force deviation is a signed value; when the actual force value is less than the target force value, the force deviation is positive; when the actual force value is greater than the target force value, the force deviation is negative. The absolute value of the force deviation represents the magnitude of the deviation. Further, based on this force deviation, calculations are performed to generate a control signal for adjusting the output of the drive component. The control signal can be a voltage command, a current command, or a pulse width modulation signal. Its amplitude or duty cycle corresponds to the magnitude of the force deviation; the larger the force deviation, the larger the amplitude or duty cycle of the control signal. Furthermore, the polarity of the control signal is determined according to the direction of the force deviation. For example, when the force deviation is positive, the output force needs to be increased; when the force deviation is negative, the output force needs to be decreased.

[0037] In some preferred embodiments, generating a control signal based on the difference between the target force value and the actual force value represented by the feedback signal includes: performing analog-to-digital conversion on the feedback signal to obtain a digitized actual force value, wherein the feedback signal is an analog voltage signal; calculating the difference between the target force value and the actual force value as a force deviation; performing a proportional operation on the force deviation to obtain a proportional control quantity; performing an integral operation on the force deviation to obtain an integral control quantity; performing a differential operation on the force deviation to obtain a differential control quantity; and summing the proportional control quantity, the integral control quantity, and the differential control quantity to generate the control signal.

[0038] In practice, the feedback signal is first converted from analog to digital. The feedback signal is an analog voltage signal output by the pressure sensor, and its voltage value is proportional to the magnitude of the reaction force experienced by the actuator. The analog voltage signal is converted into a digital quantity by an analog-to-digital converter (ADC), resulting in a sampled value of the actual force value expressed digitally. Furthermore, the accuracy of the analog-to-digital conversion is determined by the number of bits in the converter; for example, a 12-bit or 16-bit ADC can convert the analog signal into 4096 or 65536 discrete levels, and the conversion result is stored in binary digital form. This actual force value is then expressed numerically; for example, after calibration, it can be converted into a force value in millinewtons or grams, reflecting the magnitude of the actual contact force between the actuator and the workpiece at the current moment.

[0039] Furthermore, the difference between the target force value and the actual force value is calculated as the force deviation. The target force value is a pre-set expected force value in digital form, while the actual force value is the current actual contact force value obtained through analog-to-digital conversion. Both are digital quantities and can be directly arithmetically calculated. The force deviation is calculated as: force deviation equals target force value minus actual force value. The force deviation is a signed value; a positive value indicates that the actual force value is less than the target force value, and a negative value indicates that the actual force value is greater than the target force value. Its absolute value represents the magnitude of the deviation.

[0040] Furthermore, proportional, integral, and derivative operations are performed on the force deviation. The proportional operation multiplies the force deviation by a proportional gain to obtain the proportional control quantity. The proportional control quantity reflects the contribution of the current deviation to the control action; the larger the deviation, the larger the proportional control quantity. The magnitude of the proportional gain determines the speed of the system response; a larger proportional gain results in a faster response, but an excessively large one may lead to system oscillation. The integral operation accumulates the force deviation over time and multiplies it by an integral gain to obtain the integral control quantity. The integral control quantity is used to eliminate long-term static errors in the system. When a persistent deviation exists, the integral term gradually increases over time until the deviation is eliminated. The integral gain determines the strength of the integral action. The derivative operation calculates the rate of change of the force deviation, i.e., the difference between the current force deviation and the force deviation at the previous moment, divided by the sampling time interval, and multiplied by a derivative gain to obtain the derivative control quantity. The derivative control quantity reflects the trend of deviation change and is used to predict the future direction of the deviation. It applies suppression in advance when the deviation increases rapidly to prevent overshoot and reduces the control action in advance when the deviation decreases rapidly to prevent excessive backoff.

[0041] Furthermore, the proportional control quantity, integral control quantity, and derivative control quantity are summed to generate the final control signal. The control signal can be a voltage command, current command, or pulse width modulation signal, and its amplitude corresponds to the sum of the three control quantities. Further, the expression for the control signal is: the control signal equals the proportional control quantity plus the integral control quantity plus the derivative control quantity. The control signal is output to the driver of the driving component to adjust the output force or output displacement of the driving component.

[0042] This embodiment obtains the actual force value by performing analog-to-digital conversion on the feedback signal, calculates the force deviation, and then sums the proportional, integral, and derivative operations on the force deviation to generate a control signal. The proportional operation enables the system to respond quickly based on the current deviation magnitude; the integral operation eliminates static errors by accumulating historical deviations; and the derivative operation suppresses overshoot in advance by predicting deviation change trends. The combined effect of these three operations gives the system the advantages of fast response, no static error, and good dynamic stability. Furthermore, the control signal generated based on this PID control method can dynamically adjust the output of the drive component according to the real-time changes in the force deviation, enabling the actual contact force to quickly and smoothly approach the target force value and rapidly recover stability after being disturbed. This achieves a dual guarantee of high dynamic performance and steady-state accuracy for small forces.

[0043] In some preferred embodiments, before performing analog-to-digital conversion on the feedback signal to obtain the digitized actual force value, the method further includes a step of filtering the analog voltage signal.

[0044] In practice, before performing analog-to-digital conversion on the feedback signal, the analog voltage signal is first filtered. The feedback signal output by the pressure sensor is a continuous signal existing in the form of analog voltage, which may be interfered with by various noise sources during transmission. These noise sources include electromagnetic radiation in the environment, power frequency interference from power lines, high-frequency ripple generated by the switching power supply, electromagnetic interference generated by the motor drive, and thermal noise from the sensor itself. These noise components are superimposed on the useful feedback signal, forming a signal waveform with glitches or fluctuations.

[0045] Furthermore, the filtering process employs an analog filter circuit to process the feedback signal. The analog filter can consist of resistors, capacitors, and operational amplifiers; commonly used filter types include low-pass filters, band-pass filters, and band-stop filters, which are not specifically limited in this invention.

[0046] Furthermore, the filtered feedback signal becomes a smoothed analog voltage signal, containing the same useful components as the original feedback signal. The filtered analog voltage signal is then input to an analog-to-digital converter (ADC) for conversion. The ADC samples and quantizes the smoothed signal to obtain a digitized value of the actual force. Because noise has been filtered out, the sampled digital value more accurately reflects the true magnitude of the reaction force experienced by the actuator, preventing noise components from being mistakenly sampled as valid signals.

[0047] S4, the control signal is output to the drive member to drive the guide member to move the execution component, thereby adjusting the actual contact force between the execution component and the workpiece.

[0048] In practice, the generated control signal is output to the drive component. The drive component is connected to the guide component, and the control signal is sent to the driver or control interface of the drive component. Further, the drive component can be an actuator capable of outputting linear motion, such as a linear motor, servo motor, or voice coil motor. The drive component outputs a corresponding driving force or displacement according to the control signal, and this driving force acts on the guide component. Further, the guide component moves along a preset direction under the action of the driving force, thereby driving the actuator connected to the guide component via a pressure sensor to move. The movement of the actuator changes its contact state with the workpiece; for example, when the actuator moves downward, the contact force with the workpiece increases, and when the actuator moves upward, the contact force decreases, thereby adjusting the magnitude of the actual contact force.

[0049] S5. Repeat steps S2 to S4 until the deviation between the actual contact force and the target force value meets the preset condition.

[0050] In practice, steps S2 to S4 are repeated. Within each control cycle, step S2 is first executed to obtain the latest feedback signal, then step S3 is executed to generate a new control signal based on the latest actual force value, and finally step S4 is executed to output the new control signal to the drive component to update the actual contact force. By continuously repeating the above steps, the actual contact force gradually approaches the target force value until the deviation between the actual contact force and the target force value meets a preset condition. Further, the preset condition can be that the absolute value of the force deviation is less than a certain threshold, for example, the difference between the actual contact force and the target force value is less than 0.1 g / L, or that the actual contact force stabilizes within a certain error band plus or minus the target force value and remains stable for a certain period of time. When the preset condition is met, the cycle can be stopped or continued to maintain a stable state.

[0051] This embodiment uses a target force value as a control benchmark and acquires the feedback signal representing the actual contact force from the pressure sensor in real time. A control signal is generated based on the difference between the target and actual force values ​​to drive the guide component and move the actuator, thereby adjusting the actual contact force. This process is repeated until the deviation meets a preset condition. This constitutes a complete closed-loop control system, realizing real-time monitoring and dynamic adjustment of the contact force between the actuator and the workpiece. Furthermore, since the feedback signal directly originates from the pressure sensor's measurement of the actual contact force, and the control signal is generated based on the real-time force deviation, the system can quickly respond to changes in the contact force and make corrections. Furthermore, through continuous cyclic adjustment, the actual contact force is eventually stabilized near the target force value, thus achieving precise and stable control of minute forces and avoiding workpiece damage or pickup failure due to excessive or insufficient contact force.

[0052] In some preferred embodiments, the repeated execution of steps S2 to S4 includes: cyclically executing steps S2, S3, and S4 at a preset sampling period; within each sampling period, generating a control signal for the current sampling period by executing step S3 based on the difference between the actual force value represented by the feedback signal obtained in the current sampling period and the target force value; and outputting the control signal to the drive unit by executing step S4, so that the actual contact force is adjusted in each sampling period.

[0053] In specific implementation, when repeating steps S2 to S4, these steps are executed cyclically with a preset sampling period. The sampling period is a preset time interval, such as 1 millisecond or 100 microseconds, which can be determined according to the performance and process requirements of the control system; this invention does not specifically limit it. The selection of the sampling period needs to consider factors such as the response time of the pressure sensor, the conversion time of the analog-to-digital converter, the calculation time of the control algorithm, and the response speed of the drive components. It is usually set to the minimum feasible period that can ensure the stability of the control system.

[0054] Furthermore, at the beginning of each sampling period, step S2 is triggered to acquire the feedback signal output by the pressure sensor at the current moment. The feedback signal is an analog voltage that changes continuously with time. It is sampled and held at the sampling moment to obtain the instantaneous voltage value at that moment.

[0055] Furthermore, after acquiring the feedback signal, an analog-to-digital conversion is performed on it to obtain the actual force value for the current sampling period. The analog-to-digital converter initiates conversion after sample-and-hold, converting the analog voltage value into a digital quantity and calculating the corresponding force value based on the calibration curve. Then, this actual force value is compared with the target force value, and the difference between the two is calculated to obtain the force deviation for the current sampling period.

[0056] Further, based on this force deviation, step S3 is executed to generate the control signal for the current sampling period. The control signal can be generated using the PID calculation method described in the above embodiments, where the proportional, integral, and derivative operations are all calculated based on the force deviation of the current sampling period and the previously accumulated historical deviation data. The integral term requires the accumulation of historical deviations, and the derivative term requires the difference between the current deviation and the deviation of the previous sampling period.

[0057] Further, after generating the control signal, step S4 outputs the control signal for the current sampling period to the drive unit. The control signal is typically output in digital form to a digital-to-analog converter for conversion into an analog voltage, or directly as a pulse-width modulation (PWM) signal. The drive unit adjusts its output force or displacement according to the control signal, thereby changing the actual contact force between the actuator and the workpiece. After the adjustment for the current sampling period is completed, the controller enters a waiting state until the trigger signal for the next sampling period arrives.

[0058] Furthermore, at the start of the next sampling period, step S2 is executed again to obtain a new feedback signal, and the above process is repeated. This cycle continues, with each sampling period generating a new control signal based on the latest actual force value and performing corresponding adjustments. Through this periodic cyclical control, the actual contact force is sampled, evaluated, and adjusted in each sampling period, enabling the actual contact force to dynamically follow changes in the target force value and recover quickly after being disturbed.

[0059] In this embodiment, steps S2 to S4 are executed cyclically with a preset sampling period. Within each sampling period, a control signal is generated based on the acquired feedback signal and output to the drive unit. This periodic discrete control method divides the continuous time process into a series of discrete control moments, sampling the system state and applying control at each moment. Furthermore, since the sampling period can be set very short, the control system can monitor and adjust the actual contact force at a very high frequency, ensuring that the actual contact force closely follows the target force value. Even if the target force value changes or the system is subjected to external disturbances, corrections can be completed in a very short time. This high-frequency sampling closed-loop control method significantly improves the system's response speed and dynamic tracking capability, making the control of minute forces more precise and reliable.

[0060] In some preferred embodiments, the guide includes a mounting shaft and an air bearing. The mounting shaft extends along a preset direction and is fixedly installed. The air bearing is sleeved on the outer periphery of the mounting shaft and connected to the output end of the drive component and the fixed end of the pressure sensor, respectively. The method further includes: after the drive component outputs a driving force to the air bearing according to the control signal, compressed gas is introduced between the air bearing and the mounting shaft. During the movement of the air bearing along the mounting shaft, the compressed gas forms an air film between the air bearing and the mounting shaft.

[0061] In practice, the guide components include a mounting shaft and an air bearing. The mounting shaft extends in a predetermined direction, such as vertically, and is fixedly mounted on the housing or base of the actuator. The mounting shaft is typically made of a high-hardness, high-gloss material, such as ceramic or hardened steel, to ensure its straightness and surface quality. The air bearing is fitted around the outer circumference of the mounting shaft, with its inner diameter slightly larger than the outer diameter of the mounting shaft, forming a small gap. The air bearing can move axially along the mounting shaft. The exterior of the air bearing is connected to the output end of the drive unit and the fixed end of the pressure sensor, respectively. The output end of the drive unit provides driving force to move the air bearing, and the fixed end of the pressure sensor moves together with the air bearing.

[0062] Furthermore, the air bearing incorporates an internal air guide channel and a throttling structure. The air guide channel connects to an external air source to introduce compressed gas. The throttling structure can be a porous material layer or an array of micropores, used to control the gas outflow velocity and pressure distribution. The porous material can be, for example, silicon carbide, graphite, or ceramics, which contains a large number of interconnected micron-sized pores, enabling a uniform throttling effect on the gas.

[0063] Further, after executing step S4 and outputting a control signal to the drive unit, the drive unit outputs a driving force to the air bearing according to the control signal. Before or simultaneously with the drive unit moving the air bearing, compressed gas is introduced between the air bearing and the mounting shaft. The compressed gas originates from an external gas source and is delivered to the air guide channel of the air bearing through a gas pipeline. The pressure of the compressed gas is typically stabilized at a set value, for example, 0.4 to 0.6 MPa, by a regulating valve.

[0064] Furthermore, during the movement of the air bearing along the mounting shaft, the compressed gas introduced enters the throttling structure inside the air bearing through the air guide channel, and then seeps out uniformly from the pores of the throttling structure, forming a gas film with a certain pressure and rigidity in the fit clearance between the air bearing and the mounting shaft. This gas film completely separates the air bearing from the mounting shaft, placing them in a non-contact suspension state. The thickness of the gas film is typically between a few micrometers and tens of micrometers, determined by the gas pressure and load balance. Due to the extremely low gas viscosity, the frictional resistance provided by the gas film is almost zero, allowing the air bearing to slide smoothly along the mounting shaft with minimal driving force. Under the action of the gas film, the movement of the air bearing is unaffected by mechanical friction; the driving force output by the drive component is mainly used to overcome load inertia and contact force changes, without needing to overcome static and dynamic friction.

[0065] This embodiment uses a mounting shaft and an air bearing to form a guide component, and introduces compressed gas to create an air film during the movement of the air bearing. This air film provides non-contact support between the air bearing and the mounting shaft, transforming the sliding friction present in traditional mechanical guide structures into fluid friction, significantly reducing frictional resistance to a negligible level. This near-zero friction guiding method eliminates the interference of mechanical friction on the force transmission path, allowing the driving force output by the drive component to be transmitted to the actuator more efficiently, and enabling the contact reaction force on the actuator to be transmitted to the pressure sensor more accurately. Furthermore, non-contact motion eliminates the stick-slip effect and creep phenomenon that may exist in traditional guide rails, making the movement of the actuator smoother and more continuous, avoiding motion jitter and force fluctuations caused by sudden changes in frictional force. Smooth motion and a pure force transmission path together create favorable mechanical conditions for high-precision force control, contributing to further improvements in the accuracy and stability of force control.

[0066] See Figures 2-10To further illustrate the technical solution of the present invention, in one embodiment, the specific structure of the actuator (understandably, this embodiment is merely an example, and the structure of the actuator is not limited to the manner described in this embodiment) is described as follows: Please see Figures 2 to 10 This embodiment provides an actuator 10, which includes a housing 100, a guide 200, a drive 300, an actuation component 400, a pressure sensor 50, and a controller (not shown). The guide 200 is movably disposed within the housing 100 along a preset direction. The drive 300 is disposed within the housing 100 and has an output end 310 connected to the guide 200 to drive the guide 200 to move along the preset direction. The actuation component 400... Both the pressure sensor 50 and the actuator 400 are disposed in the housing 100. The pressure sensor 50 has a fixed end 510 and a measuring end 520 connected to each other. The fixed end 510 is connected to the guide member 200, and the measuring end 520 is connected to the actuator 400 and is used to measure the reaction force received by the end of the actuator 400 when it contacts the workpiece. The controller is electrically connected to the actuator 300 and the pressure sensor 50. The controller is configured to control the actuator 300 to work according to the measurement result of the pressure sensor 50.

[0067] Specifically, in this embodiment, the housing 100 serves as the mounting base for the entire actuator 10, and an internal accommodating space is formed. The guide member 200 performs high-precision linear motion within the housing 100 along a preset direction (e.g., the vertical Z-axis). The drive member 300 is preferably a servo motor or a linear motor, and its output end 310 is rigidly connected to the guide member 200 via a coupling or direct connection, providing a power source for the guide member 200. The actuator 400 can be a suction nozzle, gripper, or other end effector, used to directly act on the workpiece. The pressure sensor 50 is connected in series between the guide member 200 and the actuator 400, with its fixed end 510 fixedly connected to the guide member 200 and its measuring end 520 fixedly connected to the actuator 400. This connection method allows the pressure sensor 50 to directly sense the reaction force from the workpiece at the end of the actuator 400, thereby helping to reduce the influence of factors such as the drive member 300 on the pressure sensor 50, and the force generated by interference factors will not be superimposed on the measuring end 520 of the pressure sensor 50. The controller can be installed directly or indirectly on the housing 100.

[0068] This embodiment achieves high-precision closed-loop force control through the aforementioned structure. The controller acquires the measured values ​​of the pressure sensor 50 in real time and compares them with a preset target force value (e.g., 100 grams). Based on the comparison result, the controller dynamically adjusts the output torque or speed of the drive component 300. For example, when the measured value is less than the target value, the controller controls the drive component 300 to increase its output, causing the actuator 400 to continue pressing downwards; when the measured value is close to the target value, the controller intervenes in advance with a deceleration strategy to prevent instantaneous force overshoot due to inertia. More importantly, this embodiment divides the pressure sensor 50 into an "installation side" and a "measurement side" through structural design, concentrating interference sources such as the drive component 300 on the installation side (i.e., the fixed end 510 side), thereby isolating the direct impact on the measurement side (i.e., the measurement end 520 side). Even if the drive component 300 vibrates or the air tube is dragged, these interference forces will be absorbed or isolated by the guide component 200 and the structure on the installation side, and will not be superimposed on the measurement end 520 of the pressure sensor 50. The controller focuses only on the values ​​monitored by the pressure sensor 50 and performs dynamic compensation through real-time feedback, thereby ensuring the accuracy and stability of force control.

[0069] In some embodiments, there are multiple guide members 200, and the guide members 200 are provided on both sides of the actuating component 400 along a direction perpendicular to the preset direction. Specifically, there are two guide members 200, symmetrically distributed on the left and right sides of the actuating component 400. This symmetrical layout can effectively balance the load and prevent the actuating component 400 from deflecting or tilting due to uneven force during movement, further improving the smoothness of movement and the accuracy of force control.

[0070] Further, the guide member 200 includes a mounting shaft 210 and an air bearing 220. The mounting shaft 210 extends along the preset direction and is connected to the housing 100. The air bearing 220 is sleeved on the outer periphery of the mounting shaft 210 and connected to the output end 310 and the fixed end 510. The mounting shaft 210 is fixedly mounted on the housing 100, serving as a stationary guide rail. The air bearing 220 is sleeved on the mounting shaft 210 and connected to the output end 310 of the drive member 300 and the fixed end 510 of the pressure sensor 50, moving along the mounting shaft 210 together with the drive member 300. The air bearing 220 utilizes external compressed air to form an air film between the shaft and the air bearing 220, achieving non-contact support.

[0071] Specifically, both the output end 310 and the fixed end 510 are connected to the bearing mounting base 221. The air bearing 220 includes a bearing mounting base 221, a connecting ring 224, and a contact ring 227. The bearing mounting base 221 has a first mounting channel 222 and an air guide channel 223, the air guide channel 223 connecting the first mounting channel 222 and an external air source; the connecting ring 224 is disposed within the first mounting channel 222, the connecting ring 224 has a second mounting channel 225 and an air guide hole 226, the air guide hole 226 connecting the second mounting channel 225 and the air guide channel 223; the contact ring 227 is disposed in the second mounting channel 225, the contact ring 227 has a third mounting channel 228 for the mounting shaft 210 to pass through, and the contact ring 227 is made of a porous material. The bearing mounting base 221 is the outer shell of the air bearing 220, and the air guide channel 223 is used to introduce external compressed gas. The connecting ring 224 is installed in the first mounting channel 222 and serves to distribute gas. The contact ring 227 is the core component of the air bearing 220 and is made of porous materials such as silicon carbide, graphite, or ceramic. Compressed gas supplied by an external gas source enters the contact ring 227 sequentially through the gas guide channel 223 and the gas guide hole 226. Because the contact ring 227 is a porous material, it has a large number of interconnected micron-sized pores inside, allowing gas to seep out uniformly from these pores, forming a stable and continuous gas film between the inner surface of the contact ring 227 (i.e., the inner wall of the third mounting channel 228) and the outer surface of the mounting shaft 210.

[0072] This embodiment utilizes the throttling effect of porous materials to achieve a more uniform gas film distribution and higher stiffness. This structure realizes completely non-contact suspension support between the shaft and the bearing, fundamentally eliminating dry friction and boundary friction between solids, making the frictional force approach zero. Especially in micro-feed motion at the micrometer or even nanometer level, this structure effectively avoids the stick-slip effect and positioning jitter caused by the difference in static and dynamic friction coefficients in traditional ball guides, significantly improving the smoothness, speed stability, and repeatability of the motion platform.

[0073] In addition, to prevent gas leakage, the air bearing 220 also includes multiple seals, all of which are disposed within the first mounting channel 222. Each seal is circumferentially arranged around the connecting ring 224 and abuts against the bearing mounting seat 221 and the connecting ring 224. Seals are provided on both sides of the air guide hole 226 along the axial direction of the connecting ring 224. The seals can be O-rings or Teflon sealing rings, and their function is to seal the fitting gap between the bearing mounting seat 221 and the connecting ring 224, ensuring that compressed gas can only enter the contact ring 227 through the air guide hole 226 and cannot leak from the gap between the connecting ring 224 and the bearing mounting seat 221, thereby improving the utilization efficiency of the gas source and the working stability of the bearing.

[0074] In some embodiments, the guide member 200 further includes at least two support structures 230 spaced apart axially along the mounting shaft 210 and a plurality of adjustment structures. Each support structure 230 is provided with a receiving hole 231 through which the mounting shaft 210 passes. Each support structure 230 is provided with a plurality of adjustment structures, which are arranged circumferentially along the support structure 230. The plurality of adjustment structures move radially along different directions of the support structure 230 to directly abut against the mounting shaft 210, thereby adjusting and fixing the radial position of the mounting shaft 210 within the receiving hole 231, thereby adjusting the parallelism of the mounting shaft 210.

[0075] Specifically, the support structure 230 is fixed to the housing 100 and is used to support the mounting shaft 210. To ensure the straightness of each mounting shaft 210, two support structures 230 are usually provided on each mounting shaft 210, located at opposite axial ends of the mounting shaft 210. Each support structure 230 has a receiving hole 231 through which the mounting shaft 210 passes. Around the receiving hole 231, multiple adjustment structures are distributed circumferentially. The adjustment structures can be adjusting screws, eccentric pins, or wedges. By rotating the adjusting screws, their ends move radially along the support structure 230, directly abutting against the outer circumferential surface of the mounting shaft 210. By adjusting the screw depth in different directions, the radial position of the mounting shaft 210 within the receiving hole 231 can be finely adjusted.

[0076] This embodiment transforms the parallelism guarantee method from "relying on the static accuracy of the base 700" to "relying on dynamic adjustment" by setting up axially spaced support structures 230 and circumferentially arranged adjustment structures. Even if the machining accuracy of the base 700 has a certain deviation, or if the base 700 itself adopts a lower precision level due to cost control, the operator can still directly abut the shaft to be installed by driving the adjustment components of different radial directions, and fine-tune the radial position of the shaft within the receiving hole 231. This design significantly reduces the rigid requirement for ultra-high machining accuracy of structural components such as the frame, thereby effectively shortening the equipment manufacturing cycle and reducing the overall production cost.

[0077] In some embodiments, one end of each adjustment structure is threaded to the support structure 230 to which it resides, and the other end is located in the receiving hole 231 of the support structure 230 and abuts against the mounting shaft 210. Threaded connections offer advantages such as simple structure, high adjustment precision, and self-locking capability. Operators can achieve micron-level displacement adjustment simply by turning the adjustment screw with a wrench, and the adjustment is not easily loosened after completion, ensuring long-term stability of parallelism during equipment operation.

[0078] In some embodiments, the actuator 10 further includes an elastic element 600 extending along the preset direction, one end of which is connected to the housing 100, and the other end of which is connected to the guide 200. The elastic element 600 is preferably a tension spring, and its stretching direction is consistent with the preset direction (usually the vertical direction).

[0079] Specifically, the elastic element 600 is connected to the housing 100 and the guide element 200 and is in a pre-stretched state. The pre-tension of the elastic element 600 is designed to be slightly greater than the total weight of the moving load (including the guide element 200, the actuator 400, and the pressure sensor 50, etc.). During the up-and-down movement of the actuator 10, the tension of the elastic element 600 always balances most of the load weight, so that the drive element 300 (such as a motor) only needs to output a small force to overcome the remaining gravity difference to move. This gravity balancing mechanism minimizes the current fluctuation of the motor during up-and-down movement, improves the smoothness of movement, and thus improves the force control accuracy.

[0080] In addition, the elastic element 600 also serves as a power failure protection mechanism. When the equipment is powered off or not powered on, the drive component 300 loses its locking force. At this time, the preload of the elastic element 600 can hold the guide component 200 in place, preventing the load from falling freely due to gravity and avoiding damage to the actuator 400 from impacting the workpiece or worktable.

[0081] Corresponding to the above-described end-force closed-loop control method, the present invention also provides an end-force closed-loop control device for isolating interference sources. This end-force closed-loop control device for isolating interference sources includes a unit for executing the above-described end-force closed-loop control method, and can be configured in a terminal or server. Specifically, the end-force closed-loop control device for isolating interference sources includes: The first acquisition unit is used to execute step S1 to acquire the target force value; The second acquisition unit is used to execute step S2 to acquire the feedback signal output by the pressure sensor, wherein the amplitude of the feedback signal corresponds to the magnitude of the reaction force received by the execution component when it comes into contact with the workpiece. The generation unit is used to execute step S3, which generates a control signal based on the difference between the target force value and the actual force value represented by the feedback signal. The output unit is used to execute step S4, outputting the control signal to the drive member to drive the guide member to move the execution component, thereby adjusting the actual contact force between the execution component and the workpiece; The repeating unit is used to execute step S5, repeating steps S2 to S4 until the deviation between the actual contact force and the target force value meets the preset condition.

[0082] Optionally, the feedback signal is generated by the pressure sensor detecting the relative displacement or stress of its measuring end relative to its fixed end; The fixed end of the pressure sensor receives the vibration generated during the operation of the drive component and the drag force generated by the cable or air pipe connected to the drive component. The measuring end of the pressure sensor receives the reaction force generated when the actuator contacts the workpiece. The pressure sensor generates the feedback signal based solely on the relative displacement or stress of the measuring end relative to the fixed end.

[0083] Optionally, generating a control signal based on the difference between the target force value and the actual force value represented by the feedback signal includes: The feedback signal is converted from analog to digital to obtain a digitized actual force value, wherein the feedback signal is an analog voltage signal; The difference between the target force value and the actual force value is calculated as the force deviation; The force deviation is proportionally calculated to obtain the proportional control value; The force deviation is integrated to obtain the integral control quantity; The differential operation is performed on the force deviation to obtain the differential control quantity; The control signal is generated by summing the proportional control quantity, the integral control quantity, and the derivative control quantity.

[0084] Optionally, the guide includes a mounting shaft and an air bearing. The mounting shaft extends along a preset direction and is fixedly installed. The air bearing is sleeved on the outer periphery of the mounting shaft and connected to the output end of the drive component and the fixed end of the pressure sensor, respectively. The device further includes: A gas input unit is used to introduce compressed gas between the air bearing and the mounting shaft after the drive unit outputs driving force to the air bearing according to the control signal; During the movement of the air bearing along the mounting shaft, the compressed gas forms an air film between the air bearing and the mounting shaft.

[0085] Optionally, the target force value is a constant contact force value that needs to be maintained when the actuating component contacts the workpiece and activates the adsorption function.

[0086] Optionally, repeating steps S2 to S4 as described above includes: Steps S2, S3, and S4 are executed cyclically at a preset sampling period; Within each sampling period, based on the difference between the actual force value represented by the feedback signal obtained in the current execution step S2 and the target force value, step S3 is executed to generate the current control signal; Step S4 outputs the control signal for the current time to the drive unit so that the actual contact force is adjusted in each sampling period.

[0087] Optionally, it further includes a filtering unit for filtering the analog voltage signal.

[0088] It should be noted that those skilled in the art can clearly understand that the specific implementation process of the aforementioned end force closed-loop control device for isolating interference sources and each unit can be referred to the corresponding description in the foregoing method embodiments. For the sake of convenience and brevity, it will not be repeated here.

[0089] The aforementioned closed-loop control device for isolating interference sources can be implemented as a computer program, which can, for example... Figure 11 It runs on the computer device shown.

[0090] Please see Figure 11 , Figure 11 This is a schematic block diagram of a computer device provided in an embodiment of this application. The computer device 500 can be a terminal or a server, wherein the server can be a standalone server or a server cluster composed of multiple servers.

[0091] The computer device 500 includes a processor 502, a memory, and a network interface 505 connected via a system bus 501. The memory may include a non-volatile storage medium 503 and internal memory 504.

[0092] The non-volatile storage medium 503 may store an operating system 5031 and a computer program 5032. When the computer program 5032 is executed, it causes the processor 502 to execute an end-force closed-loop control method.

[0093] The processor 502 provides computing and control capabilities to support the operation of the entire computer device 500.

[0094] The internal memory 504 provides an environment for the operation of the computer program 5032 in the non-volatile storage medium 503. When the computer program 5032 is executed by the processor 502, the processor 502 can execute an end force closed-loop control method.

[0095] The network interface 505 is used for network communication with other devices. Those skilled in the art will understand that the above structure is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device 500 to which the present application is applied. A specific computer device 500 may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements.

[0096] The processor 502 is used to run a computer program 5032 stored in a memory to implement the steps of an end-force closed-loop control method proposed in any of the above method embodiments.

[0097] It should be understood that in the embodiments of this application, the processor 502 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0098] It will be understood by those skilled in the art that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program may be stored in a storage medium, which is a computer-readable storage medium. The computer program is executed by at least one processor in the computer system to implement the process steps of the embodiments of the above methods.

[0099] Therefore, the present invention also provides a storage medium. This storage medium may be a computer-readable storage medium. The storage medium stores a computer program. When executed by a processor, the computer program causes the processor to perform the steps of an end-force closed-loop control method as described in any of the above-described method embodiments.

[0100] The storage medium is a physical, non-transient storage medium, such as a USB flash drive, external hard drive, read-only memory (ROM), magnetic disk, or optical disk, or any other physical storage medium capable of storing program code. The computer-readable storage medium can be non-volatile or volatile.

[0101] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0102] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of each unit is merely a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0103] The steps in the method of this invention can be adjusted, merged, or reduced in order according to actual needs. The units in the device of this invention can be merged, divided, or reduced according to actual needs. Furthermore, the functional units in the various embodiments of this invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0104] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a terminal, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention.

[0105] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0106] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0107] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A closed-loop control method for end-effector force, characterized in that, The method is applied to an actuator, which includes a drive member, a guide member, a pressure sensor, and an actuating component. The pressure sensor has a fixed end and a measuring end connected to each other. The fixed end is connected to the guide member, and the measuring end is connected to the actuating component. The drive member is connected to the guide member. S1, obtain the target force value; S2, Obtain the feedback signal output by the pressure sensor, the amplitude of the feedback signal corresponding to the magnitude of the reaction force received by the actuator when it contacts the workpiece; S3, generate a control signal based on the difference between the target force value and the actual force value represented by the feedback signal; S4, the control signal is output to the drive member to drive the guide member to move the execution component, thereby adjusting the actual contact force between the execution component and the workpiece; S5. Repeat steps S2 to S4 until the deviation between the actual contact force and the target force value meets the preset condition.

2. The end-force closed-loop control method according to claim 1, characterized in that, The feedback signal is generated by the pressure sensor detecting the relative displacement or stress of its measuring end relative to its fixed end; The fixed end of the pressure sensor receives the vibration generated during the operation of the drive component and the drag force generated by the cable or air pipe connected to the drive component. The measuring end of the pressure sensor receives the reaction force generated when the actuator contacts the workpiece. The pressure sensor generates the feedback signal based solely on the relative displacement or stress of the measuring end relative to the fixed end.

3. The end-force closed-loop control method according to claim 1, characterized in that, The step of generating a control signal based on the difference between the target force value and the actual force value represented by the feedback signal includes: The feedback signal is converted from analog to digital to obtain a digitized actual force value, wherein the feedback signal is an analog voltage signal; The difference between the target force value and the actual force value is calculated as the force deviation; The force deviation is proportionally calculated to obtain the proportional control value; The force deviation is integrated to obtain the integral control quantity; The differential operation is performed on the force deviation to obtain the differential control quantity; The control signal is generated by summing the proportional control quantity, the integral control quantity, and the derivative control quantity.

4. The end-force closed-loop control method according to claim 1, characterized in that, The guide includes a mounting shaft and an air bearing. The mounting shaft extends along a preset direction and is fixedly installed. The air bearing is sleeved on the outer periphery of the mounting shaft and is connected to the output end of the drive component and the fixed end of the pressure sensor, respectively. The method further includes: after the drive component outputs driving force to the air bearing according to the control signal, compressed gas is introduced between the air bearing and the mounting shaft. During the movement of the air bearing along the mounting shaft, the compressed gas forms an air film between the air bearing and the mounting shaft.

5. The end-force closed-loop control method according to claim 1, characterized in that, The target force value is the constant contact force value that needs to be maintained when the actuating component contacts the workpiece and activates the adsorption function.

6. The end-force closed-loop control method according to claim 1, characterized in that, The repeated execution of steps S2 to S4 includes: Steps S2, S3, and S4 are executed cyclically at a preset sampling period; Within each sampling period, based on the difference between the actual force value represented by the feedback signal obtained in the current execution step S2 and the target force value, step S3 is executed to generate the current control signal; Step S4 outputs the control signal for the current time to the drive unit so that the actual contact force is adjusted in each sampling period.

7. The end-force closed-loop control method according to claim 3, characterized in that, Before performing analog-to-digital conversion on the feedback signal to obtain the digitized actual force value, the method further includes a step of filtering the analog voltage signal.

8. A closed-loop control device for isolating interference sources at the end of a circuit, characterized in that, Includes a unit for performing the method as described in any one of claims 1-7.

9. A computer device, characterized in that, The computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when executed by a processor, can implement the method as described in any one of claims 1-7.

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