TWI663031B - Control method for adaptive clamping and electric gripper - Google Patents

Abstract

An adaptive gripping control method is performed by an electric gripper. The electric gripper includes a pick-up module and a control module. The method stores N different set speed values for the control module, N ≧ 2 And taking the i-th set speed value as the current target speed value, i = 1 ~ N, the control module is in a steady state interval where the pick-up module performs a first action, so that the pick-up mode can be made Sampling the voltage range of the group to obtain a plurality of sampling voltage values, and averaging according to the plurality of sampling voltage values to obtain a plurality of average voltage values corresponding to each ith set speed value, and then a plurality of average voltages The value and its corresponding offset value are calculated to obtain a plurality of voltage thresholds respectively corresponding to the i-th set speed value.

Description

Control method for adaptive clamping and electric gripper

The present invention relates to a clamping control method and device, and more particularly, to an adaptive clamping control method and an electric gripper.

In the existing operation mode of the electric gripper, a control module sends a driving signal to control a picking module to perform a required action at a desired speed. However, the driving signal is written in the control module in advance, and Without taking into account the actual operation of the retrieval module, it may be caused by various environmental factors (such as temperature, size error of the object to be retrieved, machine vibration, etc.) when the clamping action is performed at certain set clamping speeds. Occasionally, abnormal clamping action will occur, causing the machine to stop and reduce the production line capacity.

Therefore, it is an object of the present invention to provide an adaptive clamping control method that can avoid machine stoppage due to abnormal clamping action and can increase production line productivity.

Therefore, an adaptive clamping control method of the present invention consists of an electric clamp The claw is executed. The electric gripper includes a picking module and a control module that generates a plurality of driving voltages that change the operating state of the picking module. The method includes a step (A), a step (B), One step (C), one step (D), one step (E), one step (F), and one step (G).

In step (A), the control module stores N different set speed values, N ≧ 2.

This step (B) is that the control module takes the i-th set speed value as the current target speed value, i = 1,2,3 ... N.

The step (C) is to obtain a plurality of sampling voltage values by sampling the control module within a steady-state interval where the picking module performs a first action within a voltage range in which the picking module can operate. The steady state interval is defined as a time interval in which the actual running speed of the retrieval module is equal to the ith set speed value. This step (C) further includes a step (C-1) and a step (C-2). ), One step (C-3), and one step (C-4).

This step (C-1) generates the driving voltage related to the i-th set speed value for the control module to control the object taking module to perform the first action.

This step (C-2) is for the control module to determine whether the actual running speed of the picking module is equal to the i-th set speed value. When the control module determines that the actual running speed of the picking module is not When it is equal to the i-th set speed value, return to this step (C-1).

This step (C-3) is when the control module judges that the actual running speed of the pick-up module is equal to the i-th set speed value, then the control module stores a plurality of sampling voltages in the steady state interval value.

This step (C-4) is for the control module to determine whether an actual position reached by the picking module operating at the actual running speed is equal to a set position. The set position is related to the picking module being driven to The position reached when the i-th set speed value executes the first action. When the control module determines that the actual position of the pick-up module is not equal to the set position, it returns to step (C-1) .

In step (D), the control module performs averaging according to a plurality of sampling voltage values to obtain a pair of average voltage values corresponding to the first action and the i-th set speed value.

The step (E) is that the control module samples the driving voltage in the steady-state interval within the steady-state interval during which the object taking module performs a second action to obtain a plurality of sampling voltage values.

In step (F), the control module averages the sampling voltage values to obtain a pair of average voltage values corresponding to the second action and the i-th set speed value.

In step (G), the control module calculates a plurality of average voltage values and their corresponding offset values to obtain a plurality of voltage threshold values respectively corresponding to the i-th set speed value.

In addition, another object of the present invention is to provide an electric gripper that can prevent the machine from being stopped due to abnormal clamping action and can increase the production line productivity.

Therefore, the electric gripper of the present invention includes an object taking module and a control module.

The control module is used to generate a plurality of driving voltages for changing the operating state of the object taking module.

The control module stores N different set speed values, N ≧ 2, and uses the i-th set speed value as the current target speed value, i = 1 ~ N, the control module generates a value corresponding to the i-th set speed. The value of the driving voltage is used to control the retrieval module to perform a first action. When the retrieval module performs the first action, the control module determines whether an actual operating speed of the retrieval module is equal to the first movement speed. i set speed values, when the control module judges that the actual running speed of the pick-up module is not equal to the i-th set speed value, the control module continues to generate the related to the i-th set speed value Drive voltage to control the picking module to perform the first action. When the control module judges that the actual running speed of the picking module is equal to the i-th set speed value, the control module is in a steady state interval. A plurality of sampling voltage values are stored therein. The steady state interval is defined as a time interval in which the actual running speed of the retrieval module is equal to the i-th set speed value. The control module judges that the retrieval module uses the actual The actual position reached by the running speed operation is Is equal to a set position, the set position associated with the module are driven to extract the i-th to the set speed value when performing the first operation position reached, when the control module determines that the take When the actual position of the object module is not equal to the set position, the control module continues to generate the driving voltage related to the i-th set speed value to control the object taking module to perform the first action. When the module determines that the actual position of the pick-up module is equal to the set position, the control module averages the plurality of sampling voltage values to obtain a pair of averages corresponding to the first action and the i-th set speed value Voltage value, the control module samples the driving voltage within the steady-state interval within the steady-state interval during which the fetch module performs a second action to obtain multiple sampling voltage values, and the control module The sampling voltage values are averaged to obtain a pair of average voltage values corresponding to the second action and the i-th set speed value. The control module then calculates a plurality of average voltage values and their corresponding offset values. A plurality of voltage thresholds corresponding to the i-th set speed value are obtained.

The effect of the present invention is that by using the control module to obtain a plurality of sampling voltage values by sampling a plurality of driving voltages corresponding to the steady state interval when the picking module executes the first steady state interval of the first action. , And average multiple sampling voltage values to obtain an average voltage value corresponding to the first action and the i-th set speed value, and then calculate each average voltage value and a corresponding offset value. The corresponding voltage threshold can be correctly used to drive the object taking module to perform the required speed and object taking action.

2‧‧‧Control Module

21‧‧‧controller

22‧‧‧Driver

23‧‧‧Memory

C‧‧‧Measurement steps

D‧‧‧ Procedure for calculating values

E‧‧‧Measurement steps

F‧‧‧ Procedure for calculating values

3‧‧‧ Pickup Module

31‧‧‧Motor

32‧‧‧ Clamp

33‧‧‧ Encoder

T‧‧‧steady-state interval

SGV‧‧‧Average voltage

SGT_H‧‧‧ Upper limit of voltage valve

SGT_L‧‧‧Lower limit of voltage valve

A‧‧‧ Procedure for storing values

B‧‧‧ steps to read the value

G‧‧‧Steps to generate numerical values

H‧‧‧ Loading steps

I‧‧‧ steps to perform actions

J ~ K‧‧‧ Judgment steps

L‧‧‧ steps to calculate the value

M‧‧‧Steps to Generate Values

C-1 ~ C-4‧‧‧Sub-steps for judging values

E-1 ~ E-4‧‧‧Sub-steps for judging values

G-1 ~ G-2‧‧‧ Substeps for generating values

I-1 ~ I-3‧‧‧ Substeps for numerical sampling

Other features and effects of the present invention will be described with reference to the embodiments of the drawings. 1 is a block diagram illustrating an electric gripper for performing an embodiment of a control method of adaptive grip of the present invention; FIG. 2A is a flowchart illustrating an initial procedure of the embodiment ; Figure 2B is a flowchart to help explain the initial procedure; Figure 2C is a flowchart to help explain the initial procedure; Figure 2D is a flowchart to help explain the initial procedure; Figure 3 is a waveform diagram illustrating a setting Correspondence between speed value and voltage; Fig. 4 is a waveform diagram illustrating the correspondence between a steady state interval and a sampling voltage; Fig. 5A is a flowchart illustrating an update procedure of this embodiment; Fig. 5B is a flowchart to assist Explain the update procedure; Figure 6 is a waveform diagram to assist in explaining the voltage threshold range; Figure 7 is a waveform diagram to illustrate the correspondence between the set speed value and the steady state interval; and Figure 8 is a waveform diagram to illustrate a setting The position corresponds to this steady state interval.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

Referring to FIG. 1 and FIG. 2A, an embodiment of the electric gripper of the present invention, the electric The clamping jaw includes a control module 2 and a pick-up module 3 driven by a control voltage generated by the control module 2. The control module 2 includes a controller 21 and a driver electrically connected to the controller 21. 22. A storage 23 electrically connected to the controller 21, and a receiver 24 electrically connected to the controller 21. The retrieval module 3 includes a motor 31 electrically connected to the driver 22, and a motor 31 A gripper 32 and an encoder 33 electrically connected to the motor 31, the motor 31 is driven to control the gripper 32 to perform one of a first action and a second action. The electric gripper is mainly composed of the control module 2 and the pick-up module 3, but it is not limited here to separate the two, and the control module 2 can also be integrated into the pick-up module 3. The receiver 24 is used for the user to transmit the operation-related information of the controller 21, the storage 23 is used to record the developer creation data and model data, the driver 22 is used to drive the motor 31 and the feedback voltage signal, the The holder 32 is driven by the rotation of the motor 31 and is converted into a linear motion of reciprocating opening and closing. The encoder 33 is used to sense the position of the motor 31.

The electric gripper performs an adaptive clamping control method. The adaptive clamping control method includes an initial program and an updated program. The initial procedure includes a step (A), a step (B), a step (C), a step (D), a step (E), a step (F), and a step (G).

In step (A), the memory 23 of the control module 2 stores N different set speed values, N ≧ 2.

Referring to FIG. 3, each set speed value corresponds to a voltage waveform of a related driving voltage. Taking the first interval as an example, that is, the corresponding voltage value when the speed is 1 (mm / s), taking the second interval as an example. , Which is the corresponding voltage value when the speed is 2 (mm / s).

Referring to FIG. 2A again, in step (B), the controller 21 of the control module 2 sequentially uses the i-th set speed value as the current target speed value, i = 1,2,3 ... N.

In this step (C), the controller 21 controls the driver 22 to drive the motor 31 to run, and then controls the gripper 32 to execute the first action within a steady state interval T, and samples the driving voltage to obtain Multiple sampling voltage values.

Referring to FIG. 4, at the initial moment when the object-removing module 3 is driven by a voltage, since there will be a large voltage surge at this time, causing the driving voltage to be unstable, the controller 21 corresponds to when the voltage reaches a steady state. The driving voltage is sampled only in the steady state interval T. The steady state interval T is defined as an actual operating speed of the fetch module 3 equal to the i-th set speed value, and is the value when the voltage surge is eliminated. Time interval.

Referring to FIG. 7, in the steady state interval T, the i-th set speed value is a fixed value at this time, and is the actual running speed.

Referring to FIG. 2B and FIG. 8, the step (C) further includes the following sub-step (C-1), a sub-step (C-2), a sub-step (C-3), and a sub-step (C -4) detailed process.

In the sub-step (C-1), the controller 21 generates a parameter corresponding to the i-th device. The driving voltage with a constant speed value is used to drive the motor 31 through the driver 22 to control the holder 32 to perform the first action.

In this sub-step (C-2), the controller 21 determines whether the actual running speed of the gripper 32 is equal to the i-th set speed value via the voltage signal fed back by the encoder 33. When the controller 21 judges When the actual running speed of the gripper 32 is not equal to the i-th set speed value, the process returns to step (C-1).

In this sub-step (C-3), when the controller 21 judges that the actual running speed of the gripper 32 is equal to the i-th set speed value, the controller 21 will be within the steady state interval T The sampled voltage values are stored in the memory 23.

In this sub-step (C-4), the controller 21 determines whether an actual position reached by the gripper 32 operating at the actual running speed is equal to a set position. The set position is related to the position where the motor 31 is driven. The i-th set speed value controls the position reached by the gripper 32 when performing the first action. When the controller 21 determines that the actual position of the gripper 32 is not equal to the set position, it returns to step (C-1), when the controller 21 determines that the actual position of the holder 32 is equal to the set position, it proceeds to step (D). The encoder 33 is used to sense the position of the motor 31 and return position information to the controller 21.

Referring to FIG. 2A again, in step (D), the controller 21 averages according to a plurality of sampling voltage values to obtain a pair of first actions and the i-th set speed. The average voltage value is SGV.

In step (E), the controller 21 samples the driving voltage to obtain a plurality of sampling voltage values within the steady state interval T in which the gripper 32 performs the second action.

Referring to FIG. 2C, the step (E) further includes the following sub-step (E-1), a sub-step (E-2), a sub-step (E-3), and a sub-step (E-4) Detailed process.

In the sub-step (E-1), the controller 21 generates the driving voltage related to the i-th set speed value to drive the motor 31 through the driver 22, and then controls the holder 32 to execute the second action.

In the sub-step (E-2), the controller 21 determines whether the actual running speed of the gripper 32 is equal to the i-th set speed value via the voltage signal fed back by the encoder 33. When the controller 21 determines When the actual running speed of the gripper 32 is not equal to the i-th set speed value, the process returns to step (E-1).

In the sub-step (E-3), when the controller 21 judges that the actual running speed of the gripper 32 is equal to the i-th set speed value, the controller 21 sets a plurality of The sampling voltage value is stored.

In this sub-step (E-4), the controller 21 determines whether the actual position reached by the gripper 32 operating at the actual running speed is equal to the set position, and the setting The fixed position is related to the position at which the motor 31 is driven to control the gripper 32 to perform the second action at the i-th set speed value. When the controller 21 determines the actual position of the gripper 32 When it is not equal to the set position, it returns to step (E-1). When the controller 21 determines that the actual position of the gripper 32 is equal to the set position, it proceeds to step (F).

In step (F), the controller 21 averages a plurality of sampling voltage values to obtain a pair of average voltage values SGV corresponding to the second action and the i-th set speed value.

Referring to FIG. 2A again, in step (G), the controller 21 calculates each average voltage value SGV and a corresponding offset value to obtain a voltage threshold.

Referring to FIG. 2D, the step (G) further includes a detailed process of the following sub-step (G-1) and a sub-step (G-2).

In this sub-step (G-1), the controller 21 determines whether the set speed value has reached N, and if not, returns to step (B) and executes subsequent steps.

In the sub-step (G-2), when the set speed value has reached N, the controller 21 adds each average voltage value SGV and the corresponding offset value to obtain the voltage threshold value, and applies the voltage The threshold is stored in the storage 23.

The initial program of the above-mentioned adaptive clamping control method is generated by the controller of the control module according to 1 to N different set speed values stored in the memory. The relevant driving voltage is used to drive the motor of the pick-up module through the driver to control the gripper to perform the first action and the second action in sequence with N different set speed values, respectively. When the actual operating speed of the gripper is equal to the i-th set speed value, the controller samples, records, and averages the driving voltage related to the actual operating speed of the gripper within the time interval, and Obtain the average voltage value relative to performing the first and second actions at each set speed value, and then add a relevant offset value to each average voltage value according to the rule of thumb to obtain the corresponding voltage threshold, As a reference industry parameter that the electric gripper can correctly perform the required speed and object picking operation when the object is officially operated, it can indeed make the machine operate normally and increase the production line capacity.

Referring to FIG. 1 and FIG. 5A, the update program includes a step (H), a step (I), a step (J), a step (K), a step (L), and a step (M).

In step (H), the controller 21 loads each voltage threshold from the storage 23.

In step (I), the controller 21 drives the motor 31 to operate via the driver 22, and then controls the gripper 32 to perform the first action and the second action at the i-th set speed value. First, in the steady state interval T when the gripper 32 executes the action, the driving voltage related to the set speed value is sampled to obtain a plurality of sampling voltage values.

Referring to FIG. 5B, the step (I) further includes the detailed flow of the following sub-step (I-1), a sub-step (I-2), and a sub-step (I-3).

In the sub-step (I-1), the controller 21 drives the motor 31 through the driver 22, and then controls the gripper 32 to perform the first action and the second action at the i-th set speed value. One of them.

In the sub-step (I-2), the controller 21 determines whether the actual running speed of the gripper 32 is equal to the i-th set speed value. When the controller 21 determines the actual running speed of the gripper 32 When the speed is not equal to the i-th set speed value, the process returns to step (I-1).

In the sub-step (I-3), when the controller 21 determines that the actual running speed of the gripper 32 is equal to the i-th set speed value, the controller 21 sets a plurality of The sampling voltage value is stored.

5A, in step (J), the controller 21 determines whether the actual position reached after the gripper 32 operates at the i-th set speed value is equal to the set position, and the set position is related to the grip The position reached by the holder 32 when driven by the driven motor 31 and operating at the i-th set speed value.

In step (K), when the controller 21 determines that the actual position of the gripper 32 is not equal to the set position, the controller 21 determines that the gripper 32 operates at the i-th set speed value. Whether the corresponding average voltage value SGV is greater than the relative If the corresponding voltage threshold is not, then return to step (I).

In step (L), when the controller 21 determines that the actual position of the gripper 32 is equal to the set position, and the controller 21 determines that the gripper 32 operates at the i-th set speed value When the average voltage value SGV is larger than the corresponding one of the voltage thresholds, the controller 21 averages a plurality of sampling voltage values to obtain an average corresponding to the action and the i-th set speed value. The voltage value is SGV.

In step (M), the controller 21 calculates the average voltage value SGV and the corresponding offset value to obtain an updated voltage threshold.

Referring to FIG. 6, SGT_H and SGT_L are the upper and lower limits of the value that can be changed after the average voltage SGV and the corresponding offset value are calculated, and also the upper and lower limits of the update voltage threshold.

In the above update procedure, the controller of the control module drives the motor of the pick-up module through the driver according to each voltage threshold value loaded from the storage, and then controls the holder to set the i-th setting. The speed value performs one of the first and second actions, and when the actual running speed of the gripper is equal to the i-th set speed value, the controller performs correlation with the gripper within the time interval. The driving voltage of the actual operating speed is sampled, recorded, and averaged to obtain an average voltage value relative to performing one of the first and second actions at the set speed value, and then according to the rule of thumb For the average voltage value plus the related offset value to get the phase The corresponding voltage threshold value is used to update the original voltage threshold value as the operating parameter for the electric gripper to correctly perform the required speed and object picking operation in the next operation of picking, which indeed makes the machine continue to operate normally. And increase production line capacity.

In summary, in the adaptive clamping control method of the present invention, the controller of the control module samples and calculates the voltage signal corresponding to the gripper of the picking module during operation, and obtains Set the speed value to perform the average voltage value of the first and second actions, and then add a relevant offset value to each average voltage value according to the rule of thumb to obtain the corresponding voltage threshold value. As the reference industry parameters, the required speed and object picking movement can be correctly performed when the object is being made, so that the machine can operate normally and the production capacity can be improved, so it can indeed achieve the purpose of cost invention.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, any simple equivalent changes and modifications made according to the scope of the patent application and the contents of the patent specification of the present invention are still Within the scope of the invention patent.

Claims (6)

An adaptive clamping control method is executed by an electric clamping jaw, the electric clamping jaw includes an object picking module, and a control module generating a plurality of driving voltages that change the operating state of the object picking module, the method It includes the following steps: (A) the control module stores N different set speed values, N ≧ 2; (B) the control module uses the i-th set speed value as the current target speed value, i = 1,2, 3 ... N; (C) The control module samples a plurality of sampling voltages in a steady-state interval during which the retrieval module performs a first action to obtain a plurality of sampling voltages. Value, the steady state interval is defined as a time interval in which the actual running speed of the retrieval module is equal to the i-th set speed value, including (C-1) the control module generates a value corresponding to the i-th set speed value (C-2) The control module judges whether the actual running speed of the pick-up module is equal to the i-th set speed value. When the control When the module judges that the actual running speed of the retrieval module is not equal to the i-th set speed value, it returns to the (C-1), (C-3) When the control module judges that the actual running speed of the pick-up module is equal to the i-th set speed value, the control module stores the data in the steady state interval. Multiple sampling voltage values, and (C-4) the control module determines whether an actual position reached by the retrieval module operating at the actual running speed is equal to a set position, the set position is related to the retrieval module The position reached when the first action is performed at the i-th set speed value driven by the drive. When the control module determines that the actual position of the pick-up module is not equal to the set position, it returns to this step ( C-1); (D) When the control module judges that the actual position of the pick-up module is equal to the set position, the control module averages the plurality of sampling voltage values to obtain a pair of first Action and the average voltage value of the i-th set speed value; (E) the control module performs the driving voltage in the steady-state range within the steady-state interval during which the pick-up module performs a second action; Sampling to get multiple sampling voltage values; (F) The control module performs sampling on these sampling voltage values To obtain a pair of average voltage values corresponding to the second action and the i-th set speed value; and (G) the control module calculates multiple average voltage values and their corresponding offset values to obtain multiple Voltage thresholds corresponding to the i-th set speed value. The method for controlling adaptive clamping according to claim 1, wherein step (E) includes the following sub-steps: (E-1) the control module generates the driving voltage related to the i-th set speed value To control the picking module to perform the second action, (E-2) the control module judges whether the actual running speed of the picking module is equal to the i-th set speed value, and if the judgment result is no, return Go to step (E-1), (E-3) When the control module judges that the actual running speed of the pick-up module is equal to the i-th set speed value, the control module will Multiple sampling voltage values are stored, and (E-4) the control module judges whether the actual position reached by the picking module operating at the actual running speed is equal to the set position, the set position is related to the picking mode The group is driven to the position reached when the second action is performed at the i-th set speed value. When the control module determines that the actual position of the pick-up module is not equal to the set position, it returns to step ( E-1), when the control module judges that the actual position of the pick-up module is equal to the set position, Proceeds to step (F). The method for controlling adaptive clamping according to claim 2, wherein step (G) includes the following sub-steps: (G-1) The control module determines whether the i-th set speed value is equal to the N-th set Speed value, if not, return to step (B), and (G-2) when the i-th set speed value is equal to the N-th set speed value, the control module compares each average voltage value with the The corresponding offset values are added to obtain the voltage threshold, and each voltage threshold is stored. The method for controlling adaptive clamping as described in claim 2, further comprising the following steps: (H) the control module loads each voltage threshold, (I) the control module controls the fetch module to The i-th set speed value performs one of the first action and the second action, and drives the drive related to the set speed value in the steady-state interval when the picking module performs the action. The voltage is sampled to obtain a plurality of sampling voltage values. (J) The control module judges whether the actual position reached by the picking module after operating at the i-th set speed value is equal to the set position. The set position is related The position reached when the picking module is driven to operate at the i-th set speed value, (K) when the control module judges that the actual position of the picking module is not equal to the set position, the The control module then judges whether the average voltage value corresponding to the object picking module operating at the i-th set speed value is greater than the corresponding voltage threshold. If not, it returns to step (I), ( L) When the control module judges that the actual position of the retrieval module is equal to the set position When the control module determines that the average voltage value corresponding to the fetch module operating at the i-th set speed value is greater than the corresponding one of the voltage thresholds, the control module is based on A plurality of sampling voltage values are averaged to obtain an average voltage value corresponding to the action and the i-th set speed value, and (M) the control module calculates the average voltage value and the corresponding offset value to calculate Get an updated voltage threshold. The method for controlling adaptive clamping according to claim 4, wherein the step (I) includes the following steps: (I-1) The control module controls the fetch module to execute at the i-th set speed value One of the first action and the second action, (I-2) The control module judges whether the actual running speed of the pick-up module is equal to the i-th set speed value. When the control module When it is judged that the actual running speed of the pick-up module is not equal to the i-th set speed value, return to steps (I-1), and (I-3) when the control module judges the When the actual running speed is equal to the i-th set speed value, the control module stores a plurality of sampling voltage values in the steady state interval. An electric gripper includes: a picking module; and a control module for generating a plurality of driving voltages that change the operating state of the picking module. The control module stores N different set speed values, N ≧ 2, and using the i-th set speed value as the current target speed value, i = 1 ~ N, the control module generates the driving voltage related to the i-th set speed value to control the retrieval module to execute a In a first action, the control module determines whether an actual operating speed of the object taking module is equal to the i-th set speed value when the object taking module performs the first operation. When the actual operating speed of the object module is not equal to the i-th set speed value, the control module continues to generate the driving voltage related to the i-th set speed value to control the object-removing module to perform the first action When the control module judges that the actual running speed of the pick-up module is equal to the i-th set speed value, the control module stores a plurality of sampling voltage values in a steady state interval, and the definition of the steady state interval An actual operating speed of the retrieval module is equal to For the time interval of the set speed value, the control module determines whether an actual position reached by the picking module operating at the actual running speed is equal to a set position. The set position is related to the picking module being driven. The position reached when the first action is performed at the i-th set speed value, and when the control module determines that the actual position of the pick-up module is not equal to the set position, the control module continues to generate correlations The driving voltage at the i-th set speed value to control the pick-up module to perform the first action. When the control module determines that the actual position of the pick-up module is equal to the set position, the control module The plurality of sampling voltage values are averaged to obtain a pair of average voltage values corresponding to the first action and the i-th set speed value, and the control module executes the steady state of the second action in the object taking module In the interval, the driving voltage in the steady-state interval is sampled to obtain a plurality of sampling voltage values. The control module averages the sampling voltage values to obtain a pair of second actions and the i-th setting. The average velocity value of the voltage value, the control module then calculates a plurality of average voltage value and its corresponding offset value to obtain a plurality of threshold voltages respectively correspond to the i-th set speed value.