Product pressing detection method and system based on a linear actuator

Abstract

The present invention relates to the technical field of pressing tests. Specifically, it relates to a product pressing detection method and system based on a linear actuator. The closed-loop force control process of the product pressing detection method in the embodiments of the present invention is divided into multiple segments, and the soft landing control with position / velocity / torque mode switching can set different operation modes and operation parameters for different motion strokes. When an effective torque feedback is detected, the closed-loop force control mode can be quickly switched to, reducing the torque overshoot phenomenon while reducing the cycle time of the entire processing process, improving the accuracy and processing efficiency; and the closed-loop force control mode adopts a multi-step torque control logic, which can set the step force change amount according to different industry requirements, and the parameters can be set through the upper computer debugging software or the master station controller in real time, and can more flexibly and conveniently meet various customization requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of pressing tests, and in particular, to a product pressing detection method and system based on a linear actuator. Background Art

[0002] A pressing test is a test method used to evaluate the durability, reliability, and performance of a product when subjected to pressure. For example, the durability and reliability test of a tablet device can simulate the pressure exerted by a user on the tablet device during daily use to test whether it can withstand and operate normally; the force test, stroke test, life test, and feedback force test of the keys of an electronic device can test the feel, durability, and accuracy of the keys of the electronic device.

[0003] Existing pressing test solutions generally use a linear motor, and the traditional open-loop force control method of the linear motor cannot simultaneously meet the requirements of high-precision, high-response, and non-overshoot force control effects, resulting in insufficient accuracy, response speed, and overshoot problems in the pressing test. Summary of the Invention

[0004] An embodiment of the present invention provides a product pressing detection method based on a linear actuator. The method includes: in the first stage of pressing the output shaft of the linear actuator, controlling the output shaft to accelerate to a preset position in a position control mode; in the second stage of pressing the output shaft, controlling the output shaft to decelerate to detect the reaction force received when the end of the output shaft just touches the target object in a speed control mode; in the third stage of pressing the output shaft, controlling the output shaft to decelerate to make the reaction force received when the end of the output shaft presses the target object reach a preset torque in a torque control mode; the preset torque is greater than 0; in the fourth stage of pressing the output shaft, controlling the output shaft to move in a stepped torque control mode, and making the torque of the reaction force received when the end of the output shaft presses the target object increase step by step, and the torque increased each time is not greater than the torque increased in the previous time until the target torque is reached.

[0005] The product pressing detection method based on a linear actuator provided by the embodiment of the present invention divides the closed-loop force control process into multiple segments, and the soft landing control with position / speed / torque mode switching can set different operating modes and operating parameters for different movement strokes. When an effective torque feedback is detected, the closed-loop force control mode can be quickly switched to reduce the torque overshoot phenomenon and reduce the cycle time of the entire processing process, improving the accuracy and processing efficiency; and the closed-loop force control mode adopts a multi-step torque control logic, which can set the stepped force change amount according to different industry requirements, and the parameters can be set through the upper computer debugging software or the main station controller in real time, which can more flexibly and conveniently meet various customization requirements.

[0006] Optionally, the method further includes: controlling the output shaft to return to the initial position, and then re - executing the control processes of each of the above - mentioned stages; or, controlling the output shaft to return to the disengaged position, then controlling the output shaft to perform uniformly accelerated motion until the reaction force received when the end of the output shaft just touches the target object is detected, and re - executing the control processes of the third stage and the fourth stage; at the disengaged position, the output shaft is in a non - contact state with the target object.

[0007] In the embodiment of the present invention, the output shaft can return to the initial position or a certain position where it is non - contact with the target object, and then repeat all or part of the stages of the first pressing stroke described above.

[0008] Optionally, controlling the movement of the output shaft by using a stepped torque control mode, and making the torque of the reaction force received when the end of the output shaft presses the target object increase step - by - step until the target torque is reached, includes: increasing the first torque to a first preset torque with a first torque gain parameter within a preset time duration, and maintaining the first preset torque for a certain time duration; increasing the second torque to a second preset torque with a second torque gain parameter within a preset time duration, and maintaining the second preset torque for a certain time duration; the second torque gain parameter is not greater than the first torque gain parameter; repeating the above torque increasing and maintaining processes until the detected torque is the target torque, and maintaining the target torque for a certain time duration or until a return command is received.

[0009] In the embodiment of the present invention, the specific control process of the stepped torque control mode is provided, which can output a torque value with high precision, high response and no overshoot, and can dynamically switch the gain parameter according to different torque given values to perform closed - loop regulation to obtain a better force control effect.

[0010] Optionally, in the first stage of pressing by the output shaft of the linear actuator, controlling the output shaft to perform accelerated motion to a preset position by using a position control mode includes: controlling the output shaft to accelerate at a1 by using a position control mode; if the speed reaches the preset speed V1 first, then performing uniform motion to the preset position, and then executing the control process of the second stage; if the preset position is reached first during the acceleration process, then directly executing the control process of the second stage; if the reaction force received when the end of the output shaft just touches the target object is detected in the first stage, then skipping the control process of the second stage and directly executing the control process of the third stage.

[0011] In the embodiment of the present invention, the specific control process of the position control mode is provided, which greatly reduces the time of the entire processing process on the premise of meeting the high - performance closed - loop force control performance.

[0012] Optionally, in the second stage of the output shaft pressing, controlling the output shaft to decelerate to the reaction force received when the end of the output shaft just contacts the target object in the speed control mode includes: controlling the output shaft to decelerate at a2 in the speed control mode; if the speed first reaches the preset speed V2, moving at a constant speed until the reaction force received when the end of the output shaft just contacts the target object is detected, and then performing the control process of the third stage; if the reaction force received when the end of the output shaft just contacts the target object is detected first during the deceleration process, directly performing the control process of the third stage.

[0013] In the embodiment of the present invention, a specific control process of the speed control mode is provided, which greatly reduces the time of the entire processing process on the premise of meeting the high-performance closed-loop force control performance.

[0014] Optionally, in the third stage of the output shaft pressing, controlling the output shaft to decelerate to the reaction force received when the end of the output shaft presses the target object reaches a preset torque in the torque control mode includes: controlling the output shaft to decelerate at a3 in the torque control mode; if the speed first reaches the preset speed V3, moving at a constant speed until the preset torque is reached, and then performing the control process of the fourth stage; if the preset torque is reached first during the deceleration process, directly performing the control process of the fourth stage.

[0015] In the embodiment of the present invention, a specific control process of the torque control mode is provided, which greatly reduces the time of the entire processing process on the premise of meeting the high-performance closed-loop force control performance.

[0016] Optionally, before re-executing the control process of each stage, the method further includes: if moving at a constant speed to the preset position W after accelerating to V1, updating the preset position W to the position reached when accelerating to V1; if moving to the preset position W before accelerating to V1, updating the preset position W to the position reached during the acceleration process, and updating V1 to the speed reached during the acceleration process.

[0017] In the embodiment of the present invention, targeted parameter adjustment is performed on different situations in each stage of the first pressing stroke, so as to output a torque value with high precision, high response and no overshoot, and reduce the cycle time of the entire processing process.

[0018] Optionally, before re-executing the control process of each stage, the method further includes: if the reaction force received when the end of the output shaft just contacts the target object is detected first during the deceleration process, updating V2 to V2`, V2` = V1 - a2t2, and updating a2 to V2`a2 / V2, where t2 is the duration of the deceleration process.

[0019] In the embodiments of the present invention, parameter adjustments are made for different situations in each stage of the first pressing stroke, so as to output a torque value with high precision, high response and no overshoot, and reduce the cycle time of the entire processing process.

[0020] Optionally, before re-executing the control process of each of the stages, or before re-executing the control processes of the third stage and the fourth stage, the method further includes: if the preset torque is reached first during the deceleration process, update V3 to V3`, where V3` = V2 – a3t3, and update a3 to V3`a3 / V3, where t3 is the duration of the deceleration process.

[0021] In the embodiments of the present invention, parameter adjustments are made for different situations in each stage of the first pressing stroke, so as to output a torque value with high precision, high response and no overshoot, and reduce the cycle time of the entire processing process.

[0022] An embodiment of the present invention provides a product pressing detection system based on a linear actuator, including a controller; the controller is used to execute the method described in any one of the above.

[0023] An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is read and run by a processor, the method described in any one of the above is implemented.

[0024] The product pressing detection system and computer-readable storage medium based on a linear actuator provided by the embodiments of the present invention can achieve the same technical effects as the foregoing product pressing detection method based on a linear actuator. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0026] Figure 1 It is a schematic flowchart of a product pressing detection method based on a linear actuator provided by an embodiment of the present invention. Detailed Embodiments

[0027] The following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0028] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0029] Figure 1 The flowchart of a product pressing detection method based on a linear actuator provided by an embodiment of the present invention is shown. The method includes:

[0030] S102. In the first stage of the output shaft of the linear actuator pressing, a position control mode is adopted to control the output shaft to accelerate to a preset position.

[0031] In this embodiment, the linear actuator can be a linear motor, a voice coil motor, etc. Based on the above linear actuator, a pressing test system can be designed, and its output shaft faces the target object to be subjected to the pressing test. The force sensor can detect the torque of the output shaft in real time.

[0032] This first stage is the initial stage of the output shaft movement. In this stage, a position control mode is adopted to control the output shaft to accelerate to the preset position, and this preset position is still outside the target object, that is, the end of the output shaft has not yet contacted the target object.

[0033] Exemplarily, the control process of this position control mode is as follows:

[0034] First, the output shaft is controlled to accelerate at a1 in the position control mode.

[0035] Secondly, if the speed first reaches the preset speed V1, it will move uniformly to the preset position, and then execute the control process of the second stage; if the preset position is reached first during the acceleration process, the control process of the second stage will be directly executed.

[0036] Then, if the reaction force received when the end of the output shaft just contacts the target object is detected in the first stage, the control process of the second stage will be skipped and the control process of the third stage will be directly executed.

[0037] In the first stage, the output shaft is controlled in the position control mode, mainly to achieve the acceleration process. If the preset speed is reached but the preset position is not reached, it will continue to run uniformly at this preset speed. If the preset position is reached before the preset speed is reached, it will enter the acceleration process of the second stage. If the reaction force has been detected during the above movement process, the torque increase process of the third stage will be directly executed.

[0038] S104. In the second stage of the output shaft pressing, a speed control mode is adopted to control the output shaft to decelerate until the reaction force received when the end of the output shaft just contacts the target object is detected.

[0039] This second stage is the intermediate stage of the output shaft movement, where the end of the output shaft changes from not contacting the target object to contacting the target object. During the real-time detection of the force sensor, the moment when the reaction force changes from 0 to greater than 0 will be detected.

[0040] Exemplarily, the control process of this speed control mode is as follows:

[0041] First, control the output shaft to decelerate at a2 using the speed control mode;

[0042] Second, if the speed reaches the preset speed V2 first, then move uniformly until the reaction force received when the end of the output shaft just contacts the target object is detected, and then execute the control process of the third stage; if the reaction force received when the end of the output shaft just contacts the target object is detected first during the deceleration process, then directly execute the control process of the third stage.

[0043] In the second stage, control the output shaft using the speed control mode, mainly to achieve the deceleration process. If the deceleration is completed but the end of the output shaft has not yet contacted the target object, then continue to move uniformly until contact; if the deceleration is not completed but the end of the output shaft has already contacted the target object, then directly execute the torque increase process of the third stage.

[0044] S106. In the third stage of the output shaft pressing, control the output shaft to decelerate using the torque control mode until the reaction force received when the end of the output shaft presses the target object reaches a preset torque. This preset torque is greater than 0.

[0045] This third stage is the landing stage of the output shaft movement, where the end of the output shaft has already contacted the target object.

[0046] Exemplarily, the control process of this torque control mode is as follows:

[0047] First, control the output shaft to decelerate at a3 using the torque control mode;

[0048] Second, if the speed reaches the preset speed V3 first, then move uniformly until the preset torque is reached, and then execute the control process of the fourth stage; if the preset torque is reached first during the deceleration process, then directly execute the control process of the fourth stage. It should be noted that this preset torque is a relatively small value close to zero.

[0049] In the third stage, control the output shaft using the torque control mode, mainly to achieve the continuous deceleration process. If the deceleration is completed first but the force between the end of the output shaft and the target object has not reached the preset torque (or is equal to zero), then continue to move uniformly until the preset torque is reached; if the deceleration is not completed but the force between the end of the output shaft and the target object has reached the preset torque, then directly execute the torque increase process of the fourth stage.

[0050] S108. In the fourth stage of pressing the output shaft, a stepped torque control mode is adopted to control the movement of the output shaft, so that the torque of the reaction force received by the end of the output shaft when pressing the target object increases step by step, and the torque increased each time is not greater than the torque increased in the previous time until the target torque is reached.

[0051] This fourth stage is the pressing stage of the movement of the output shaft. The torque applied to the target object by the end of the output shaft is continuously increased, so as to meet the condition requirements of the pressing test. It should be noted that the above four stages are not all available in each pressing stroke, and some of these stages can be included based on the actual situation.

[0052] In this embodiment, a stepped torque control mode is adopted to control the movement of the output shaft, and the torque increased in each step is not greater than the torque increased in the previous step. At each step, the pressing is maintained for a certain duration with the increased torque.

[0053] Exemplarily, within a preset duration, the first torque is increased to the first preset torque with the first torque gain parameter, and is maintained for a certain duration with the first preset torque; within a preset duration, the second torque is increased to the second preset torque with the second torque gain parameter, and is maintained for a certain duration with the second preset torque; the second torque gain parameter is not greater than the first torque gain parameter;

[0054] The above process of torque increase and maintenance is repeated until the detected torque is the target torque, and is maintained for a certain duration with the target torque or until a return command is received.

[0055] In this embodiment, the amount of torque increased in each step can be set according to different industry requirements, and the torque gain parameter can be dynamically switched according to different torque given values for closed-loop adjustment, so as to obtain a better force control effect.

[0056] The product pressing detection method based on a linear actuator provided by the embodiment of the present invention divides the closed-loop force control process into multiple segments, and performs soft landing control by switching between position / velocity / torque modes. Different operating modes and operating parameters can be set for different movement strokes. When an effective torque feedback is detected, the closed-loop force control mode can be quickly switched to, reducing the torque overshoot phenomenon while reducing the cycle time of the entire processing process and improving the processing efficiency; and the closed-loop force control mode adopts a multi-step torque control logic, and the amount of stepwise force change can be set according to different industry requirements, and the parameters can be set through the upper computer debugging software or the main station controller in real time, which can more flexibly and conveniently meet various customization requirements.

[0057] After completing the first pressing stroke, the above method further includes: controlling the output shaft to return to the initial position, and then re-executing the control process of each stage; or

[0058] Control the output shaft to return to the disengaged position, then control the output shaft to accelerate uniformly until the reaction force received when the end of the output shaft just touches the target object is detected, and re - execute the control processes of the third stage and the fourth stage. At the disengaged position, the end of the output shaft is in a non - contact state with the target object.

[0059] In this embodiment, the output shaft can return to the initial position or a position where it is non - contact with the target object, and then repeat all or part of the stages of the first pressing stroke described above.

[0060] Considering the influence of different situations in each stage of the first pressing stroke on the actual closed - loop force control effect, parameter adjustment can be carried out specifically, so as to output a torque value with high precision, high response and no overshoot, and reduce the cycle time of the entire processing process.

[0061] For the first stage, before re - executing the control processes of each stage, the above - mentioned method further includes:

[0062] If it accelerates to V1 and then moves uniformly to the preset position W, update the preset position W to the position reached when accelerating to V1. That is, move the preset position forward to make it farther from the target object.

[0063] If it does not accelerate to V1 but first moves to the preset position W, update the preset position W to the position reached during the acceleration process, and update V1 to the speed reached during the acceleration process. That is, move the preset position backward to make it closer to the target object.

[0064] For the second stage, before re - executing the control processes of each stage, the above - mentioned method further includes:

[0065] If the reaction force received when the end of the output shaft just touches the target object is detected first during the deceleration process, update V2 to V2`, where V2` = V1 - a2t2, update a2 to V2`a2 / V2, and t2 is the duration of the deceleration process. That is, reduce the value of the preset speed V2 so that the end of the output shaft completes the deceleration of this stage before touching the target object.

[0066] For the third stage, before re - executing the control processes of each stage, or before re - executing the control processes of the third stage and the fourth stage, the above - mentioned method further includes:

[0067] If the preset torque is reached first during the deceleration process, update V3 to V3`, where V3` = V2 – a3t3, update a3 to V3`a3 / V3, and t3 is the duration of the deceleration process. That is, reduce the value of the preset speed V3 so that the contact force between the end of the output shaft and the target object completes the deceleration of this stage before reaching the preset torque.

[0068] The following introduces a specific embodiment of the product pressing detection method based on a linear motor. Premise: The force sensor detects the torque F between the output shaft and the target object in real time.

[0069] The first step: In the initial stage of the output shaft movement, the position control mode (PP mode) is adopted - the preset speed V1 is set.

[0070] The output shaft accelerates at a1. If the speed reaches the preset speed V1 first, it moves uniformly to the predetermined position W and then enters the second step; if it reaches the predetermined position W first during the acceleration process, it directly enters the second step; if the torque F is detected in the first step, the second step is skipped and the third step is directly entered.

[0071] When performing the second press, the following adjustments are made to the first step in this time according to the situation of the previous first step: If it accelerates to V1 and then moves uniformly to W, F > 0; it can be known that W is too large, and W is modified to the distance when accelerating to V1; if it does not accelerate to V1 but reaches W, F > 0, and the acceleration time is t1; it can be known that a1 is too small, V 1， W is too large, and W is modified to the moving distance W` during the acceleration process (W` = 1 / 2 × a1t1 2 ) and V1 is modified to W`V1 / W.

[0072] The second step: In the intermediate stage of the output shaft movement, the speed control mode (PV mode) is adopted - the preset speed V2 (V2 is less than V1) and the preset deceleration -a2 (a2 is less than a1) are set.

[0073] The output shaft decelerates at -a2. If the speed first decreases to the preset speed V2, it moves uniformly until the force sensor detects the torque F and enters the third step. If the torque is detected first, it directly enters the third step.

[0074] When performing the second press, the following adjustments are made to the second step in this time according to the situation of the previous second step: If it decelerates to V2 and then moves uniformly, F > 0; it remains unchanged; if it does not decelerate to V2, F > 0, and the deceleration time is t2; then V2` is modified to V1 - a2t2 (that is, V2`), and a2` is V2`a2 / V2.

[0075] The third step: In the landing stage of the output shaft movement, the force sensor has detected the torque F. The torque control mode (PT mode) is adopted, adjusted to move uniformly - the preset speed V3 (V3 is less than V2), the preset deceleration is -a3, and the preset torque is F1.

[0076] The output shaft decelerates at -a3. If the speed first decreases to the preset speed V3, it moves uniformly until it is detected that the torque F reaches the preset torque F1 and enters the fourth step; if the torque F first reaches the preset torque F1, it directly enters the fourth step.

[0077] When performing the second press, the following adjustments are made to the third step in this time according to the situation of the previous third step: If during the deceleration process, the torque F reaches the preset torque F1 first, and the deceleration time is t3; then V3` is modified to V3 - a3t3, and a3` is V3`a3 / V3.

[0078] Fourth step: When the force sensor approaches the target torque (after reaching the preset torque 1), enter the stepped force control closed-loop force control mode. The increase in force per unit time is A.

[0079] Within the predetermined time T, increase the torque by A1, increase the torque by △F1, and the time is T1, and maintain the pressure for a certain time (set according to actual requirements);

[0080] Within the predetermined time T, increase the torque by A2, increase the torque by △F2, and the time is T2, and maintain the pressure for a certain time (set according to actual requirements);

[0081] Within the predetermined time T, increase the torque by A3, increase the torque by △F3, and the time is T3, and maintain the pressure for a certain time (set according to actual requirements); ......

[0083] Until the detected torque is the target torque. After maintaining the pressure for a certain time, return or wait for the return command and enter the fifth step.

[0084] Among them, the above A1, A2, A3, etc. are torque gain coefficients, and F1, F1 + △F1, F1 + △F1 + △F2, F1 + △F1 + △F2 + △F2, etc. are preset torques. Exemplarily, F1:△F1:△F2:△F3:△F4:△F5:...... = 4:3:3:2:1:1:1, and T1 = T2 < T3 < T4 = T5 < T.

[0085] Fifth step: Return

[0086] 1. Directly return to the initial position, and then repeat steps one, two, three, and four.

[0087] Accelerate and then decelerate to the initial position; or, accelerate and then move at a constant speed and decelerate to the initial position.

[0088] 2. Return to the initial position in the order of four, three, two, one, and then repeat steps one, two, three, and four. If the original steps are one, three, four, then return to the initial position in the order of four, three, one.

[0089] 3. First accelerate to the preset speed V3 and move at a constant speed at this speed. During this constant speed process, the position where the torque is 0 will be passed through. Record this position and name it p. Continue to move a distance A, then press down, accelerate uniformly to position p, and then repeat steps three and four.

[0090] Step 6: Perform the second press

[0091] Before performing the second press, refer to the description of the second press adjustment in the above Step 1 - Step 3.

[0092] The above method of the embodiment of the present invention has the following advantages:

[0093] 1. For the customer's one - dimensional or multi - dimensional closed - loop force control requirements, select a matching single - channel or multi - channel torque sensor. The single - axis or multi - axis driver samples the torque value (analog signal or bus signal) input by the torque sensor in real time, and performs closed - loop adjustment through a specific closed - loop force control algorithm, so as to output a torque value with high precision, high response and no overshoot.

[0094] 2. The closed - loop force control algorithm is divided into multiple segments, and the soft landing control for position / speed / torque mode switching can set different operating modes and operating parameters for different motion strokes. When the driver detects effective torque feedback, the driver can quickly switch to the closed - loop force control mode, reducing the torque overshoot phenomenon and at the same time reducing the cycle time of the entire processing process. On the premise of meeting the high - performance closed - loop force control performance, the time of the entire processing process is greatly reduced, improving the processing efficiency.

[0095] 3. The closed - loop force control mode adopts a multi - step force control method, which can set the step force change amount according to different industry requirements. The torque set value can be set and saved through the upper - computer debugging software, or can be set in real time through a master controller such as a PLC (Programmable Logic Controller), so as to more flexibly and conveniently meet various customized requirements.

[0096] 4. The multi - step force control method adopts a step - force - control closed - loop regulation control. The driver dynamically switches and adjusts the torque gain coefficient in real time according to different force - control set values, so as to ensure that better effects can be achieved for different force - control values.

[0097] The embodiment of the present invention provides a product pressing detection system based on a linear actuator, including a controller; the controller is used to execute the above - mentioned product pressing detection method based on a linear actuator. The controller can be a multi - axis driver, a single - axis driver, etc.

[0098] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each process of the above method embodiment and can achieve the same technical effect. To avoid repetition, it will not be elaborated here. Among them, the computer-readable storage medium includes, for example, a read-only memory (ROM for short), a random access memory (RAM for short), a magnetic disk, or an optical disc, etc.

[0099] Of course, those skilled in the art can understand that all or part of the processes of implementing the above method embodiments can be completed by a computer program instructing a control device. The program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the above method embodiments. Among them, the storage medium can be a memory, a magnetic disk, an optical disc, etc.

[0100] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

[0101] Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0102] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0103] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A product pressing detection method based on a linear actuator, characterized in that: The method comprises: In the first stage of pressing the output shaft of the linear actuator, the output shaft is controlled to accelerate to a preset position in a position control mode; In the second stage of pressing the output shaft, the speed control mode is used to control the output shaft to decelerate until the reaction force exerted on the end of the output shaft when just contacting the target object is detected; In the third stage of pressing the output shaft, the torque control mode is used to control the output shaft to decelerate until the reaction force received by the end of the output shaft when pressing the target object reaches a preset torque; the preset torque is greater than 0; In the fourth stage of pressing the output shaft, a step torque control mode is adopted to control the movement of the output shaft, so that the torque of the reaction force received by the end of the output shaft when pressing the target object increases in a step-by-step manner, and each increase in torque is not greater than the previous increase in torque, until the target torque is reached; In the first stage of pressing the output shaft of the linear actuator, the position control mode is used to control the output shaft to accelerate to a preset position, including: The position control mode is used to control the output shaft to accelerate at a1; If the speed reaches the preset speed V1 first, it moves to the preset position at a constant speed, and then executes the control process of the second stage; if it reaches the preset position first during the acceleration process, it directly executes the control process of the second stage; If the reaction force exerted on the end of the output shaft when it just contacts the target object is detected in the first stage, the control process of the second stage is skipped and the control process of the third stage is directly executed.

2. The method according to claim 1, characterized in that The method further comprises: Control the output shaft to return to the initial position, and then re-execute the control process of each stage; or, The output shaft is controlled to return to the disengaged position, and then the output shaft is controlled to uniformly accelerate until the reaction force exerted on the end of the output shaft when it just contacts the target object is detected, and the control process of the third stage and the fourth stage is re-executed; at the disengaged position, the output shaft and the target object are in a non-contact state.

3. The method according to claim 1, characterized in that: The step torque control mode is adopted to control the movement of the output shaft, so that the torque of the reaction force received by the end of the output shaft when pressing the target object increases in a step-wise manner until the target torque is reached, including: Increasing the first torque to a first preset torque with a first torque gain parameter within a preset time period, and maintaining the first preset torque for a certain time period; Increasing the second torque to a second preset torque with a second torque gain parameter within a preset time length, and maintaining the second preset torque for a certain time length; the second torque gain parameter is not greater than the first torque gain parameter; The above torque increase and maintenance process is repeated until the detected torque reaches the target torque, and the target torque is maintained for a certain period of time or until a return command is received.

4. The method according to claim 2, characterized in that: In the second stage of pressing the output shaft, the speed control mode is used to control the output shaft to decelerate until the reaction force exerted on the end of the output shaft when just contacting the target object is detected, including: The speed control mode is used to control the output shaft to decelerate at a2; If the speed reaches the preset speed V2 first, it moves at a constant speed until the reaction force received by the end of the output shaft when it just contacts the target object is detected, and then the control process of the third stage is executed; if the reaction force received by the end of the output shaft when it just contacts the target object is first detected during the deceleration process, the control process of the third stage is directly executed.

5. The method according to claim 4, characterized in that In the third stage of pressing the output shaft, the torque control mode is used to control the output shaft to decelerate until the reaction force received by the end of the output shaft when pressing the target object reaches a preset torque, including: The output shaft is controlled to decelerate at a3 by adopting a torque control mode; If the speed reaches the preset speed V3 first, it moves at a constant speed until the preset torque is reached, and then the control process of the fourth stage is executed; if the preset torque is reached first during the deceleration process, the control process of the fourth stage is directly executed.

6. The method according to claim 2, characterized in that Before re-executing the control process of each stage, the method further includes: If the vehicle accelerates to V1 and then moves to a preset position W at a constant speed, the preset position W is updated to the position reached when the vehicle accelerates to V1; If the acceleration does not reach V1 but moves to the preset position W first, the preset position W is updated to the position reached during the acceleration process, and V1 is updated to the speed reached during the acceleration process.

7. The method according to claim 4, characterized in that Before re-executing the control process of each stage, the method further includes: If the reaction force received by the end of the output shaft when it just contacts the target object is detected during the deceleration process, V2 is updated to V2`, V2`=V1-a2t2, a2 ​​is updated to V2`a2 / V2, and t2 is the duration of the deceleration process.

8. The method according to claim 5, characterized in that Before re-executing the control process of each stage, or before re-executing the control process of the third stage or the fourth stage, the method further includes: If the preset torque is reached first during the deceleration process, V3 is updated to V3`, V3`=V2-a3t3, a3 is updated to V3`a3 / V3, and t3 is the duration of the deceleration process.

9. A product pressing detection system based on a linear actuator, characterized in that: The method comprises a controller; the controller is used to execute the method according to any one of claims 1 to 8.

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