Product pressing detection method and system based on linear actuator

Abstract

The invention relates to the technical field of pressing testing, in particular to a product pressing detection method and system based on a linear executor, and the closed-loop force control process of the product pressing detection method is divided into multiple sections, soft landing control is achieved through position / speed / torque mode switching, and the product pressing detection accuracy is improved. Different operation modes and operation parameters can be set according to different movement strokes, when effective torque feedback is detected, a closed-loop force control mode can be rapidly switched into, the torque overshoot phenomenon is reduced, meanwhile, the takt time of the whole machining process is shortened, and precision and machining efficiency are improved; a closed-loop force control mode adopts multi-step torque control logic, step force variation can be set according to different industry requirements, parameters can be set through upper computer debugging software or a main station controller in real time, and various customization requirements can be met more flexibly and conveniently.

Description

Technical Field

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

[0002] Compression testing 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 users on the tablet device during daily use to test whether it can withstand and work properly; the force test, travel test, life test and feedback force test of electronic device buttons can test the feel, durability and accuracy of electronic device buttons.

[0003] Existing press test solutions generally use linear motors, but the traditional open-loop force control method of linear motors cannot simultaneously take into account the requirements of high precision, high response and no overshoot in force control, resulting in insufficient accuracy, insufficient response speed and overshoot problems in press tests. Summary of the invention

[0004] An embodiment of the present invention provides a product pressing detection method based on a linear actuator, the method comprising: in a first stage of pressing the output shaft of the linear actuator, using a position control mode to control the output shaft to accelerate to a preset position; in a second stage of pressing the output shaft, using a speed control mode to control the output shaft to decelerate until a reaction force is detected on the end of the output shaft when it just contacts a target object; in a third stage of pressing the output shaft, using a torque control mode to control the output shaft to decelerate until the reaction force on the end of the output shaft when pressing the target object reaches a preset torque; the preset torque is greater than 0; in a fourth stage of pressing the output shaft, using a step torque control mode to control the output shaft to move, so that the torque of the reaction force on the end of the output shaft when pressing the target object increases in a stepwise manner, and each increase in torque 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 linear actuator provided by the embodiment of the present invention has a closed-loop force control process divided into multiple sections, and a soft landing control with position / speed / torque mode switching. Different operating modes and operating parameters can be set for different motion strokes. When effective torque feedback is detected, the closed-loop force control mode can be quickly switched to reduce the torque overshoot phenomenon while reducing the beat time of the entire processing process, thereby improving accuracy and processing efficiency; and the closed-loop force control mode adopts multi-step torque control logic, and the step force change amount can be set according to different industry requirements, and the parameters can be set through the host computer debugging software or the master station controller in real time, which can meet various customization needs more flexibly and conveniently.

[0006] Optionally, the method further includes: controlling the output shaft to return to an initial position, and then re-executing the control process of each stage; or, controlling the output shaft to return to a disengaged position, and then controlling the output shaft to uniformly accelerate until a reaction force is detected on the end of the output shaft when it just contacts the target object, and re-executing the control process of the third stage and the fourth stage; in 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 may return to the initial position, or to a certain position that is not in contact with the target object, and then repeat all or part of the above-mentioned first pressing stroke.

[0008] Optionally, the step torque control mode is adopted to control the movement of the output shaft, and 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 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 length, and maintaining the first preset torque for a certain time length; 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; repeating the above torque increase and maintenance process until the detected torque is the target torque, and maintaining the target torque for a certain time length or until a return command is received.

[0009] The embodiment of the present invention provides a specific control process of the step torque control mode, which can output a torque value with high precision, high response and no overshoot, and can dynamically switch the gain parameters according to different torque given values ​​to perform closed-loop adjustment to obtain a better force control effect.

[0010] Optionally, 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: using the position control mode 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 the preset position is reached first during the acceleration process, the control process of the second stage is directly executed; if the reaction force received by 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.

[0011] The embodiment of the present invention provides a specific control process of the position control mode, which greatly reduces the time of the entire processing process while meeting the high-performance closed-loop force control performance.

[0012] Optionally, 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 received by the end of the output shaft when it just contacts the target object is detected, including: using the speed control mode to control the output shaft to decelerate at a2; if the speed reaches the preset speed V2 first, then moving 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 executing the control process of the third stage; 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, then directly executing the control process of the third stage.

[0013] The embodiment of the present invention provides a specific control process of the speed control mode, which greatly reduces the time of the entire processing process while meeting the high-performance closed-loop force control performance.

[0014] Optionally, 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: using the torque control mode to control the output shaft to decelerate at a3; 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.

[0015] The embodiment of the present invention provides a specific control process of the torque control mode, which greatly reduces the time of the entire processing process while meeting the high-performance closed-loop force control performance.

[0016] Optionally, before re-executing the control process of each stage, the method also includes: if the vehicle accelerates to V1 and then moves at a constant speed to a preset position W, updating the preset position W to the position reached when accelerating to V1; if the vehicle accelerates to V1 but moves to the preset position W first, 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, the parameters are adjusted specifically 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, thereby reducing the cycle time of the entire processing process.

[0018] Optionally, before re-executing the control process of each stage, the method also includes: if the reaction force exerted on the end of the output shaft when it just contacts the target object is first 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.

[0019] In the embodiment of the present invention, the parameters are adjusted specifically 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, thereby reducing the cycle time of the entire processing process.

[0020] Optionally, 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, t3 is the duration of the deceleration process.

[0021] In the embodiment of the present invention, the parameters are adjusted specifically 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, thereby reducing 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, comprising a controller; the controller is used to execute any of the methods described above.

[0023] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is read and executed by a processor, any of the above methods is implemented.

[0024] The linear actuator-based product press detection system and computer-readable storage medium provided in the embodiments of the present invention can achieve the same technical effects as the aforementioned linear actuator-based product press detection method. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 A schematic flow chart of a product pressing detection method based on a linear actuator provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0029] Figure 1 A schematic flow chart of a product pressing detection method based on a linear actuator provided by an embodiment of the present invention is shown, and the method includes: S102, 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.

[0030] In this embodiment, the linear actuator can be a linear motor, a voice coil motor, etc. Based on the above linear actuator, a compression test system can be designed, whose output shaft faces the target object to be compressed, and the force sensor can detect the torque of the output shaft in real time.

[0031] The first stage is the initial stage of the output shaft movement. In this stage, the position control mode is used to control the output shaft to accelerate to a preset position, and the preset position is still outside the target object, that is, the end of the output shaft has not yet contacted the target object.

[0032] Exemplarily, the control process of the position control mode is as follows: First, the position control mode is used to control the output shaft to accelerate at a1.

[0033] Secondly, if the speed reaches the preset speed V1 first, it moves at a constant speed to the preset position, and then executes the second stage of the control process; if the preset position is reached first during the acceleration process, the second stage of the control process is directly executed.

[0034] Then, if the reaction force received by the output shaft end just after contacting 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.

[0035] In the first stage, the output shaft is controlled in position control mode, mainly to realize the acceleration process. If it accelerates to the preset speed but not to the preset position, it will continue to run at the preset speed at a constant speed. If it does not accelerate to the preset speed but reaches the preset position first, it will enter the second stage of acceleration. If the reaction force has been detected during the above movement, the third stage of torque increase process will be directly executed.

[0036] S104, 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 it just contacts the target object is detected.

[0037] The second stage is the middle stage of the output shaft movement, when the end of the output shaft changes from not contacting the target object to contacting the target object. During the real-time detection process of the force sensor, the moment when the reaction force changes from 0 to greater than 0 is detected.

[0038] Exemplarily, the control process of the speed control mode is as follows: First, the speed control mode is used to control the output shaft to decelerate at a2; Secondly, 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 just when it contacts the target object is detected, and then the third stage of the control process is executed; if the reaction force received by the end of the output shaft just when it contacts the target object is detected first during the deceleration process, the third stage of the control process is directly executed.

[0039] In the second stage, the output shaft is controlled in speed control mode, mainly to achieve the deceleration process. If the deceleration is completed but the end of the output shaft has not yet touched the target object, it will continue to move at a constant speed until it touches the target object. If the deceleration is not completed but the end of the output shaft has already touched the target object, the torque increase process of the third stage will be directly executed.

[0040] S106, in the third stage of the output shaft pressing, the output shaft is controlled to decelerate in a torque control mode until the reaction force received by the end of the output shaft when pressing the target object reaches a preset torque, which is greater than zero.

[0041] The third stage is the landing stage of the output shaft movement, and the end of the output shaft has already contacted the target object.

[0042] Exemplarily, the control process of the torque control mode is as follows: First, the torque control mode is used to control the output shaft to decelerate at a3; Secondly, if the speed reaches the preset speed V3 first, it moves at a constant speed until the preset torque is reached, and then the fourth stage of control process is executed; if the preset torque is reached first during the deceleration process, the fourth stage of control process is directly executed. It should be noted that the preset torque is a small value close to zero.

[0043] In the third stage, the torque control mode is used to control the output shaft, mainly to achieve the continued deceleration process. If the deceleration is completed first and the force between the end of the output shaft and the target object does not reach the preset torque (or equal to zero), the uniform motion is continued until the preset torque is reached. If the deceleration is not completed and the force between the end of the output shaft and the target object has reached the preset torque, the torque increase process of the fourth stage is directly executed.

[0044] S108, in the fourth stage of output shaft pressing, a step torque control mode is used 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 no greater than the previous increase in torque until the target torque is reached.

[0045] The fourth stage is the pressing stage of the output shaft movement, and the end of the output shaft continuously increases the torque applied to the target object, thereby achieving the conditional requirements of the pressing test. It should be noted that the above four stages are not all present in each pressing stroke, and some of them can be included based on actual conditions.

[0046] In this embodiment, a step 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, and the pressing is maintained for a certain period of time at each step with the increased torque.

[0047] Exemplarily, the first torque is increased to the first preset torque by the first torque gain parameter within the preset time, and the first preset torque is maintained for a certain time; the second torque is increased to the second preset torque by the second torque gain parameter within the preset time, and the second preset torque is maintained for a certain time; 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 is maintained at the target torque for a certain period of time or until a return command is received.

[0048] In this embodiment, the amount of torque increase for 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 ​​to perform closed-loop adjustment, thereby obtaining a better force control effect.

[0049] The product pressing detection method based on linear actuator provided by the embodiment of the present invention has a closed-loop force control process divided into multiple sections, and a soft landing control with position / speed / torque mode switching. Different operating modes and operating parameters can be set for different motion strokes. When effective torque feedback is detected, the closed-loop force control mode can be quickly switched to reduce the torque overshoot phenomenon while reducing the beat time of the entire processing process, thereby improving processing efficiency; and the closed-loop force control mode adopts multi-step torque control logic, and the step force change amount can be set according to different industry requirements, and the parameters can be set through the host computer debugging software or the master station controller in real time, which can meet various customized requirements more flexibly and conveniently.

[0050] After the first pressing stroke is completed, the method further includes: controlling the output shaft to return to the initial position, and then re-executing 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 on the end of the output shaft just touching the target object is detected, and the control process of the third and fourth stages is re-executed. At the disengaged position, the end of the output shaft is in a non-contact state with the target object.

[0051] In this embodiment, the output shaft can return to the initial position, or to a position that is not in contact with the target object, and then repeat all or part of the above-mentioned first pressing stroke.

[0052] Taking into account the impact of different conditions at each stage of the first pressing stroke on the actual closed-loop force control effect, targeted parameter adjustments can be made to output a high-precision, high-response, non-overshoot torque value, thereby reducing the cycle time of the entire machining process.

[0053] For the first stage, before re-executing the control process of each stage, the method further includes: If the vehicle accelerates to V1 and then moves to the preset position W at a constant speed, the preset position W is updated to the position reached when the vehicle accelerates to V1. That is, the preset position is adjusted forward to be away from the target object.

[0054] 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. That is, the preset position is adjusted back to make it closer to the target object.

[0055] For the second stage, before re-executing the control process of each stage, the method further includes: If the reaction force on the output shaft end just after contacting 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. That is, the value of the preset speed V2 is reduced so that the output shaft end completes the deceleration at this stage before contacting the target object.

[0056] For the third stage, 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 above 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. That is, the value of the preset speed V3 is reduced so that the deceleration of this stage is completed before the contact force between the output shaft end and the target object reaches the preset torque.

[0057] The following introduces a specific embodiment of the product pressing detection method based on the linear motor. Prerequisite: The force sensor detects the torque F between the output shaft and the target object in real time.

[0058] Step 1: Initial stage of output shaft movement, using position control mode (PP mode) - preset speed V1.

[0059] The output shaft accelerates at a1. If the speed reaches the preset speed V1 first, it moves at a constant speed to the preset position W and then enters the second step. If it reaches the preset 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 entered directly.

[0060] When pressing for the second time, make the following adjustments to the first step of this time according to the situation of the first step of the previous time: if the acceleration reaches V1 and then reaches W at a constant speed, F>0; it is known that W is too large, and W is changed to the distance of acceleration to V1; if the acceleration does not reach V1 but reaches W, F>0, and the acceleration time is t1; it is known that a1 is too small, V 1， W is too large, W is changed to the distance W` moved during the acceleration process (W`=1 / 2×a1t1 2 ), V1 is changed to W`V1 / W.

[0061] Step 2: In the middle stage of the output shaft movement, the speed control mode (PV mode) is adopted - the preset speed V2 (V2 is less than V1), the preset deceleration - a2 (a2 is less than a1).

[0062] The output shaft decelerates at -a2. If the speed is first reduced to the preset speed V2, it will maintain a constant speed until the force sensor detects the torque F in real time and enter the third step. If the torque is detected first, it will directly enter the third step.

[0063] When pressing for the second time, make the following adjustments to the second step according to the situation of the second step last time: if the speed is constant after deceleration to V2, F>0; remain unchanged; if the deceleration does not reach V2, F>0, deceleration time t2; then V2` is modified to V1-a2t2 (that is, V2`), and a2` is V2`a2 / V2.

[0064] Step 3: During the landing phase of the output shaft movement, the force sensor has detected the torque F, and the torque control mode (PT mode) is adopted, which is adjusted to a uniform speed - preset speed V3 (V3 is less than V2), a preset deceleration of -a3, and a preset torque F1.

[0065] The output shaft decelerates at -a3. If the speed is first reduced to the preset speed V3, it will maintain a constant speed until it is detected that the torque F reaches the preset torque F1, and then enter the fourth step; if the torque F reaches the preset torque F1 first, it will directly enter the fourth step.

[0066] When pressing for the second time, make the following adjustments to the third step of this time according to the situation of the third step of the previous time: if during the deceleration process, the torque F first reaches the preset torque F1, and the deceleration time is t3; then V3` is modified to V3-a3t3, and a3` is V3`a3 / V3.

[0067] Step 4: When the force sensor approaches the target torque (after reaching the preset torque 1), it enters the step force control closed-loop force control mode. The increase in force per unit time is A.

[0068] Within the preset time T, increase the torque by A1, increase the torque △F1, the time is T1, and maintain the pressure for a certain time (set according to actual requirements); Within the preset time T, increase the torque by A2, increase the torque △F2, the time is T2, and maintain the pressure for a certain time (set according to actual requirements); Within the preset time T, increase the torque by A3, increase the torque △F3, the time is T3, and maintain the pressure for a certain time (set according to actual requirements); ... ... Until the detected torque reaches the target torque, the pressure is maintained for a certain period of time and then returns or waits for a return command, and then enters the fifth step.

[0069] Among them, the above A1A2A3 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, T1=T2<T3<T4=T5<T.

[0070] Step 5: Return 1. Go straight back to the starting position, and then repeat one, two, three, four.

[0071] Accelerate and then decelerate to the initial position; or, accelerate and then decelerate at a constant speed to the initial position.

[0072] 2. Return to the original position in steps of 4, 3, 2, 1, and then repeat 1, 2, 3, 4. If the original steps were 1, 3, 4, return to the original position in steps of 4, 3, 1.

[0073] 3. First accelerate to the preset speed V3, and then maintain a constant speed at this speed. During this constant speed process, you will pass through the position where the torque is 0. Record this position and name it p. Continue to move distance A, then press down, uniformly accelerate to position p, and then repeat steps three and four.

[0074] Step 6: Perform the second press To make adjustments before the second press, refer to the description of the second press adjustment in steps 1-3 above.

[0075] The above method of the embodiment of the present invention has the following advantages: 1. According to the customer's requirements for one-dimensional or multi-dimensional closed-loop force control, 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, thereby outputting a high-precision, high-response, and non-overshoot torque value.

[0076] 2. The closed-loop force control algorithm is divided into multiple sections, and the soft landing control of 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 into the closed-loop force control mode to reduce the torque overshoot phenomenon while reducing the cycle time of the entire processing process. Under the premise of meeting the high-performance closed-loop force control performance, the time of the entire processing process is greatly reduced, and the processing efficiency is improved.

[0077] 3. The closed-loop force control mode adopts a multi-step force control method. The step force variation can be set according to different industry needs. The torque setting value can be saved through the host computer debugging software, or it can be set in real time through the master controller such as PLC (Programmable Logic Controller), so as to meet various customized needs more flexibly and conveniently.

[0078] 4. The multi-step force control method adopts 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 given values, thereby ensuring that different force control values ​​can achieve better results.

[0079] 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 drive and a single-axis drive, etc.

[0080] This embodiment also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, each process of the above method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it is not repeated here. The computer-readable storage medium is, for example, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0081] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the control device through a computer, and the program can be stored in a computer-readable storage medium. When the program is executed, it may include the processes of the above-mentioned method embodiments, wherein the storage medium may be a memory, a disk, an optical disk, etc.

[0082] 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 shall be subject to the scope defined by the claims.

[0083] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises a..." do not exclude the presence of other identical elements in the process, method, article or device including the elements. The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0084] 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 may 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 widest 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 used 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 no greater than the previous increase in torque until the target torque is reached.

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 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.

5. 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.

6. The method according to claim 2, 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.

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 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.

8. The method according to claim 5, 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.

9. The method according to claim 6, 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.

10. 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 9.

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