3D printer nozzle low contact force touch detection system and corresponding detection method

Abstract

The application provides a 3D printer nozzle low contact force touch detection system and a corresponding detection method. The system comprises a controller, an eddy current induction coil, an induction plate and an eddy current detection circuit. The eddy current induction coil and the induction plate are respectively arranged on the nozzle structure and the mounting seat, and the induction plate is located on the induction path of the eddy current induction coil. The eddy current detection circuit drives the eddy current induction coil to work in a resonant state, and collects the electrical characteristic parameter signal at a preset sampling frequency. The signal monitoring module monitors the signal in real time during the movement of the nozzle structure along the Z axis, and the judgment and recording module judges whether the nozzle structure and the hot bed have been in contact according to the signal change and records the Z axis zero point coordinate. The application realizes low contact force and high precision touch detection by detecting the transient mutation of the electrical characteristic parameter caused by the slight displacement generated by the nozzle touching the hot bed, effectively avoids nozzle wear and hot bed scratches, reduces the dependence on independent pressure sensors, and simplifies the hardware structure.

Description

Technical Field

[0001] This invention relates to the field of 3D printers, and in particular to a 3D printer nozzle low contact force touch detection system and corresponding detection method. Background Technology

[0002] In the 3D printing process, the Z-axis zero-point calibration between the nozzle and the heated bed is the primary step determining printing accuracy. Any deviation in the initial distance between the nozzle and the heated bed will directly affect the quality of the first layer and may even lead to printing failure. Therefore, accurately detecting the contact state between the nozzle and the heated bed before printing and determining the Z-axis zero-point coordinates accordingly is a crucial technical challenge in this field.

[0003] In existing technologies, nozzle contact detection mainly employs the following technical approaches: First, mechanical contact pressure / strain detection. This type of solution typically obtains the contact pressure between the nozzle and the heated bed by measuring the deformation of a sensor. The strain gauge converts this pressure into a voltage signal, which is then compared with a preset threshold to determine the contact state. This type of solution requires a separate pressure or strain sensor, resulting in a relatively complex hardware structure and higher cost. Furthermore, the sensor requires a certain contact force to trigger, making it prone to fatigue drift after long-term use, and potentially causing nozzle wear or scratches on the heated bed.

[0004] Second, eddy current non-contact detection. This type of solution directly uses an eddy current sensor to detect the distance between the nozzle and the heated bed, thus providing feedback on the distance between the nozzle and the heated bed. In this solution, the eddy current sensor is only used as a ranging element to obtain distance values, while the nozzle and the target being measured remain in a non-contact state. Due to potential installation errors between the eddy current sensor and the nozzle, the feedback data on the distance between the nozzle and the heated bed will also contain errors, resulting in insufficient detection accuracy.

[0005] Therefore, there is a need to provide a 3D printer nozzle low contact force touch detection system and corresponding detection method to solve the above technical problems. Summary of the Invention

[0006] This invention provides a 3D printer nozzle low contact force touch detection system and corresponding detection method to solve the problems of low detection accuracy and potential nozzle wear or hot bed scratches in existing detection schemes.

[0007] To solve the above technical problems, the technical solution of the present invention is: a 3D printer nozzle low contact force touch detection system, which includes: a controller, an eddy current induction coil, an induction plate and an eddy current detection circuit, wherein the controller includes a signal monitoring module, a judgment and recording module and a motion control module; The nozzle structure is mounted on the mounting base, the eddy current induction coil is mounted on the nozzle structure, and the induction plate is mounted on the mounting base. The positions of the eddy current induction coil and the induction plate are interchangeable. The induction plate is located on the induction path of the eddy current induction coil. The eddy current induction coil is electrically connected to the eddy current detection circuit, and the eddy current detection circuit is electrically connected to the controller. The eddy current detection circuit is used to drive the eddy current induction coil to work in a resonant state and to collect the electrical characteristic parameter signal of the eddy current induction coil at a preset sampling frequency. The signal monitoring module is used to monitor the electrical characteristic parameter signal in real time during the movement of the nozzle structure along the Z-axis. The determination and recording module is used to determine that the nozzle structure is in contact with the heated bed according to the electrical characteristic parameter signal, and to record the current Z-axis coordinate as the zero point coordinate after the contact is determined. The motion control module is used to control the movement of the nozzle structure.

[0008] In this invention, the mounting base is provided with a mounting groove for mounting the nozzle structure. The mounting base is made of non-metallic material. The eddy current induction coil is disposed on the top wall of the mounting groove. A heat sink is disposed on the top of the nozzle structure. The induction plate is the top plate of the heat sink.

[0009] In this invention, the eddy current induction coil is disposed on the vertical side of the nozzle structure, the induction path of the eddy current induction coil is along the Z-axis, and the induction plate is fixedly connected to the mounting base.

[0010] This invention also includes a method for detecting low-contact-force contact at the nozzle of a 3D printer, which uses the aforementioned contact detection system for contact detection. The contact detection method includes: Step S11: The controller controls the nozzle structure to move horizontally from the initial height position to above a set detection point, and controls the nozzle structure to move from above the detection point along the Z-axis toward the direction closer to the heated bed; Step S12: The controller controls the eddy current detection circuit to acquire the electrical characteristic parameter signal of the eddy current induction coil at a preset sampling frequency, and monitors the electrical characteristic parameter signal in real time; Step S13: When the controller detects a transient change in the electrical characteristic parameter signal and the change in the electrical characteristic parameter signal exceeds a preset change threshold, it determines that the nozzle structure is in contact with the heated bed. The controller controls the nozzle structure to stop moving along the Z-axis and records the current Z-axis coordinate as the zero point coordinate. Step S14: The controller controls the nozzle structure to move along the Z-axis to the starting height position, repeats steps S11 to S13, and sequentially performs touch detection on all the detection points according to the preset detection point sequence.

[0011] In this invention, in step S12, the electrical characteristic parameter signal includes at least one of resonant frequency, inductance, impedance, and quality factor Q.

[0012] In this invention, in step S11, the nozzle structure first moves a set distance along the Z-axis toward the hot bed at a first speed, and then moves along the Z-axis toward the hot bed at a second speed, wherein the first speed is greater than the second speed.

[0013] In this invention, in step S12, the electrical characteristic parameter signal is the resonant frequency; The eddy current detection circuit drives the eddy current induction coil to work at a set resonant frequency, and acquires digital measurement values ​​characterizing the resonant frequency at a preset sampling frequency. The ratio of the sampling frequency to the set resonant frequency is 1:3000 to 1:7000. In step S13, the mutation threshold is the amount of change in the digital measurement of the resonant frequency between consecutive sampling points that exceeds 0.1% to 0.4% of the resonant frequency.

[0014] In step S12, the electrical characteristic parameter signal is the resonant frequency. The eddy current detection circuit drives the eddy current induction coil to operate at a resonant frequency of 5MHz and acquires digital measurement values ​​characterizing the resonant frequency at a sampling frequency of 1kHz. In step S13, the preset mutation threshold is the change in the digital measurement value of the resonant frequency between consecutive sampling points exceeding 10 kHz.

[0015] In this invention, step S14 further includes a verification step, which includes: Step S21: After the controller moves the nozzle structure along the Z-axis to the starting height position, it moves the nozzle structure along the Z-axis again to the same distance as before, in the direction closer to the heated bed. Step S22: If the change in the electrical characteristic parameter signal is detected again to exceed the preset abrupt change threshold, the contact determination is confirmed to be valid; Step S23: If no transient change in the electrical characteristic parameter signal is detected again, it is determined to be a misjudgment caused by electromagnetic interference, and a prompt is given in the set form.

[0016] In this invention, in step S14, the first detection point, the middle detection point, and the last detection point in the preset detection point sequence are selected to perform the verification step.

[0017] Compared to existing technologies, the advantages of this invention are as follows: This invention utilizes the change in the relative distance between the eddy current induction coil and the induction plate to detect contact. When the nozzle comes into contact with the heated bed, the nozzle structure undergoes a slight displacement due to the reaction force of the heated bed. This displacement changes the relative distance between the eddy current induction coil and the induction plate, thereby causing a transient change in electrical characteristic parameters (such as resonant frequency, inductance, impedance, quality factor Q, etc.). The system determines contact by monitoring this change, eliminating the need for the large contact force required by traditional mechanical pressure sensors. This achieves the goal of low contact force and high-precision detection, significantly reducing the risk of nozzle wear and heated bed scratches.

[0018] This invention records the current Z-axis coordinate as the zero-point coordinate after contact is determined, and through sequential contact detection at multiple detection points, it can more accurately obtain the height information of different positions on the heated bed, thereby compensating for heated bed flatness errors, ensuring printing quality, and improving printing success rate. Furthermore, by selecting preset detection points for verification steps, the detection has strong anti-interference capabilities, high reliability, and high efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments are briefly introduced below. The drawings described below are only the corresponding drawings of some embodiments of the present invention.

[0020] Figure 1 This is a schematic diagram of a preferred embodiment of the 3D printer nozzle low contact force touch detection system of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the 3D printer nozzle low contact force touch detection system of the present invention.

[0022] Figure 3 This is a flowchart of the 3D printer nozzle low contact force touch detection method of the present invention.

[0023] Figure 4 This is a flowchart illustrating the verification steps of the 3D printer nozzle low contact force touch detection method of the present invention.

[0024] Figure 5 This is a waveform diagram showing the transient change in electrical characteristic parameters of the nozzle structure in this invention at the moment of contact with the heated bed. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The directional terms mentioned in this invention, such as "up", "down", "front", "back", "left", "right", "inner", "outer", "side", "top" and "bottom", are only for reference to the orientation of the accompanying drawings. The directional terms used are for the purpose of explaining and understanding this invention, and are not intended to limit this invention.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, a connection can be a detachable connection or a connection of an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components or an interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Existing detection methods suffer from low detection accuracy and may cause nozzle wear or hot bed scratches.

[0029] The following is a preferred embodiment of a 3D printer nozzle low contact force touch detection method provided by the present invention, which can solve the above technical problems.

[0030] Please refer to Figure 2 ,in Figure 2 This is a schematic diagram of the structure of the 3D printer nozzle low contact force touch detection system of the present invention.

[0031] In the diagram, units with similar structures are represented by the same labels.

[0032] This embodiment provides a low-contact-force touch detection system for a 3D printer nozzle, which includes: a controller, an eddy current induction coil 13, an induction plate, and an eddy current detection circuit. The controller includes a signal monitoring module, a judgment and recording module, and a motion control module.

[0033] The nozzle structure 11 is mounted on the mounting base 12, the eddy current induction coil 13 is mounted on the nozzle structure 11, and the sensing plate is mounted on the mounting base 12. The positions of the eddy current induction coil 13 and the sensing plate are interchangeable, allowing for flexible selection of the installation method based on the specific structure of the nozzle structure 11 and the mounting base 12, thus improving system compatibility. The sensing plate is located on the sensing path of the eddy current induction coil 13, which is electrically connected to the eddy current detection circuit, which is electrically connected to the controller.

[0034] The eddy current detection circuit is used to drive the eddy current induction coil 13 to work in the resonant state and to collect the electrical characteristic parameter signal of the eddy current induction coil 13 at a preset sampling frequency. The signal monitoring module is used to monitor the electrical characteristic parameter signal in real time during the movement of the nozzle structure 11 along the Z-axis. The determination and recording module is used to determine that the nozzle structure 11 is in contact with the hot bed according to the electrical characteristic parameter signal, and to record the current Z-axis coordinate as the zero point coordinate after the contact is determined. The motion control module is used to control the movement of the nozzle structure 11.

[0035] Please refer to Figure 1 In this embodiment, the mounting base 12 is provided with a mounting groove 121 for mounting the nozzle structure 11. The mounting base 12 is made of non-metallic material. The eddy current induction coil 13 is disposed on the top wall of the mounting groove 121. A heat sink 111 is disposed on the top of the nozzle structure 11. The heat sink 111 is made of conductive material, and the induction plate is the top plate of the heat sink 111. The eddy current induction coil 13 senses the top plate of the heat sink 111. When the nozzle structure 11 comes into contact with the heated bed, the entire nozzle structure 11 undergoes a slight displacement due to the reaction force of the heated bed. This displacement changes the relative distance between the eddy current induction coil 13 and the induction plate, thereby causing a transient change in the electrical characteristic parameters.

[0036] The mounting groove 121 may also be provided with a receiving groove 122 on the top wall, and the eddy current induction coil 13 is disposed in the receiving groove 122.

[0037] Optionally, the eddy current induction coil 13 can also be set on the vertical side of the nozzle structure 11. The induction path of the eddy current induction coil 13 is along the Z-axis. The eddy current induction coil 13 can be connected to the fixing ring. The fixing ring is bonded to the nozzle structure 11 with glue. The induction plate is fixedly connected to the mounting base 12.

[0038] Please refer to Figure 3 This embodiment also includes a low-contact-force touch detection method for 3D printer nozzles, which uses the above-mentioned touch detection system for touch detection. The touch detection method includes: Step S11: The controller controls the nozzle structure 11 to move horizontally from the initial height position to above a set detection point, accurately aligning it with the detection point. The controller then controls the nozzle structure 11 to move from above the detection point along the Z-axis toward the direction close to the heated bed. The nozzle structure 11 moves vertically downward from above the detection point to ensure the accuracy of the contact detection position.

[0039] Specifically, the motion control module controls the horizontal and Z-axis movement of the nozzle structure 11.

[0040] Step S12: The controller controls the eddy current detection circuit to acquire the electrical characteristic parameter signals of the eddy current induction coil 13 at a preset sampling frequency, and monitors the electrical characteristic parameter signals in real time. By continuously acquiring data at a preset sampling frequency, the transient signal changes generated when the nozzle contacts the hot bed can be captured in a timely manner, avoiding missed detections due to insufficient sampling, thereby improving the real-time performance and reliability of the detection.

[0041] Please refer to Figure 5 Step S13: When the controller detects a transient change in the electrical characteristic parameter signal and the change in the electrical characteristic parameter signal exceeds the preset change threshold, it determines that the nozzle structure 11 is in contact with the heated bed. The controller controls the nozzle structure 11 to stop moving along the Z-axis and records the current Z-axis coordinate as the zero point coordinate.

[0042] Specifically, the signal monitoring module monitors changes in electrical characteristic parameter signals, and the determination and recording module determines whether the nozzle structure 11 is in contact with the heated bed.

[0043] When the nozzle structure 11 comes into contact with the heated bed, it experiences a reaction force from the heated bed and undergoes a slight displacement. This slight displacement alters the relative distance between the eddy current induction coil 13 and the nozzle structure 11, thereby causing a transient change in the electrical characteristic parameters. Only a very small contact force is required between the nozzle structure 11 and the heated bed to trigger the detection, effectively preventing nozzle wear and scratches on the heated bed.

[0044] Step S14: The controller moves the nozzle structure 11 along the Z-axis to the starting height position, repeating steps S11 to S13, and sequentially performs touch detection on all detection points according to the preset detection point sequence. That is, a detection point is selected according to the preset detection point sequence, and the controller moves above that detection point. By sequentially performing touch detection on multiple detection points, the height information of different positions of the heated bed can be obtained, thereby compensating for the flatness error of the heated bed, ensuring the printing quality of the first layer, and improving the printing success rate.

[0045] In this embodiment, in step S12, the electrical characteristic parameter signal includes at least one of the following: resonant frequency, inductance, impedance, and quality factor Q. This allows for flexible selection based on actual circuit conditions and detection accuracy requirements, improving the applicability of the detection method.

[0046] In this embodiment, in step S11, the nozzle structure 11 first moves a set distance along the Z-axis towards the heated bed at a first speed, and then moves along the Z-axis towards the heated bed at a second speed, where the first speed is greater than the second speed. For example, the first speed can be 1 mm / s, and the second speed can be 0.5 mm / s. This two-stage approach strategy, moving faster initially and then slower, shortens the overall detection time and reduces the moving speed when approaching the heated bed, thereby reducing the impact force at the moment of contact. This further reduces the risk of nozzle wear and heated bed scratches, and also helps improve the recording accuracy of the zero-point coordinates.

[0047] In this embodiment, in step S12, the electrical characteristic parameter signal is the resonant frequency.

[0048] The eddy current detection circuit drives the eddy current induction coil 13 to operate at the set resonant frequency, and acquires digital measurement values ​​characterizing the resonant frequency at a preset sampling frequency. The ratio of the sampling frequency to the set resonant frequency is 1:3000 to 1:7000.

[0049] In step S13, the mutation threshold is the amount of change in the digital measurement of the resonant frequency between consecutive sampling points that exceeds 0.1% to 0.4% of the resonant frequency.

[0050] Specifically, in step S12, the electrical characteristic parameter signal is the resonant frequency.

[0051] The eddy current detection circuit drives the eddy current induction coil 13 to operate at a resonant frequency of 5MHz and acquires digital measurement values ​​characterizing the resonant frequency at a sampling frequency of 1kHz.

[0052] In step S13, the preset abrupt change threshold is defined as a change in the digital measurement value of the resonant frequency between consecutive sampling points exceeding 10 kHz. At a resonant frequency of 5 MHz, a frequency change of 10 kHz corresponds to a relative change of approximately 0.2%, which provides sufficient detection sensitivity while also facilitating circuit implementation and signal processing.

[0053] In this embodiment, step S14 further includes a verification step, which includes: Step S21: After the controller moves the nozzle structure 11 along the Z-axis to the starting height position, it controls the nozzle structure 11 to move along the Z-axis towards the hot bed by the same distance as before.

[0054] Step S22: If the change in the electrical characteristic parameter signal exceeds the preset abrupt change threshold again, the contact determination is confirmed to be valid. This confirms that the previous determination was not caused by accidental interference, thus improving the reliability of the detection results.

[0055] Step S23: If no transient change in the electrical characteristic parameter signal is detected again, it is determined to be a misjudgment caused by electromagnetic interference, and a prompt is given in a set form. For example, a prompt can be given by lighting an alarm or providing a misjudgment error message on the display screen. Through this verification step, misjudgments caused by occasional factors such as electromagnetic interference can be effectively eliminated, improving detection reliability and avoiding incorrect zero-point coordinates and printing failures due to misjudgments.

[0056] It should be noted that a detection point that needs to be verified is set up in step S14 after the verification step is completed, and then moved along the Z-axis to the starting height position, the next detection point is selected and steps S11 to S13 are repeated.

[0057] In this embodiment, in step S14, the first detection point, one middle detection point, and the last detection point in a preset detection point sequence are selected for the verification step. Since it is not necessary to perform the verification step on all detection points, the detection reliability is ensured while avoiding excessive detection time, thus balancing detection efficiency and detection accuracy.

[0058] This embodiment of the 3D printer nozzle low-contact-force touch detection method detects the contact state between the nozzle and the heated bed by measuring the change in the relative distance between the eddy current induction coil and the induction plate. It eliminates the need for the large contact force required by traditional mechanical pressure sensors, achieving low-contact-force, high-precision touch detection and significantly reducing the risk of nozzle wear and heated bed scratches. Furthermore, by sequentially detecting and verifying touches at multiple points, it can more accurately obtain height information at different positions on the heated bed, compensating for heated bed flatness errors and improving printing success rate and detection reliability. In addition, by selecting preset detection points for the verification step, the detection exhibits strong anti-interference capabilities, high reliability, and high efficiency.

[0059] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A low-contact-force contact detection system for a 3D printer nozzle, characterized in that, include: The controller includes a controller, an eddy current induction coil, an induction plate, and an eddy current detection circuit. The controller includes a signal monitoring module, a judgment and recording module, and a motion control module. The nozzle structure is mounted on the mounting base, the eddy current induction coil is mounted on the nozzle structure, and the induction plate is mounted on the mounting base. The positions of the eddy current induction coil and the induction plate are interchangeable. The induction plate is located on the induction path of the eddy current induction coil. The eddy current induction coil is electrically connected to the eddy current detection circuit, and the eddy current detection circuit is electrically connected to the controller. The eddy current detection circuit is used to drive the eddy current induction coil to work in a resonant state and to collect the electrical characteristic parameter signal of the eddy current induction coil at a preset sampling frequency. The signal monitoring module is used to monitor the electrical characteristic parameter signal in real time during the movement of the nozzle structure along the Z-axis. The determination and recording module is used to determine that the nozzle structure is in contact with the heated bed according to the electrical characteristic parameter signal, and to record the current Z-axis coordinate as the zero point coordinate after the contact is determined. The motion control module is used to control the movement of the nozzle structure.

2. The 3D printer nozzle low contact force touch detection system according to claim 1, characterized in that, The mounting base is provided with a mounting groove for mounting the nozzle structure. The mounting base is made of non-metallic material. The eddy current induction coil is disposed on the top wall of the mounting groove. A heat sink is disposed on the top of the nozzle structure. The induction plate is the top plate of the heat sink.

3. The 3D printer nozzle low-contact force touch detection system according to claim 1, characterized in that, The eddy current induction coil is disposed on the vertical side of the nozzle structure, the induction path of the eddy current induction coil is along the Z-axis, and the induction plate is fixedly connected to the mounting base.

4. A method for detecting low contact force touch of a 3D printer nozzle, characterized in that, Touch detection is performed using any one of the touch detection systems described in claims 1-3, wherein the touch detection method comprises: Step S11: The controller controls the nozzle structure to move horizontally from the initial height position to above a set detection point, and controls the nozzle structure to move from above the detection point along the Z-axis toward the direction closer to the heated bed; Step S12: The controller controls the eddy current detection circuit to acquire the electrical characteristic parameter signal of the eddy current induction coil at a preset sampling frequency, and monitors the electrical characteristic parameter signal in real time; Step S13: When the controller detects a transient change in the electrical characteristic parameter signal and the change in the electrical characteristic parameter signal exceeds a preset change threshold, it determines that the nozzle structure is in contact with the heated bed. The controller controls the nozzle structure to stop moving along the Z-axis and records the current Z-axis coordinate as the zero point coordinate. Step S14: The controller controls the nozzle structure to move along the Z-axis to the starting height position, repeats steps S11 to S13, and sequentially performs touch detection on all the detection points according to the preset detection point sequence.

5. The 3D printer nozzle low contact force touch detection method according to claim 4, characterized in that, In step S12, the electrical characteristic parameter signal includes at least one of resonant frequency, inductance, impedance, and quality factor Q.

6. The 3D printer nozzle low contact force touch detection method according to claim 4, characterized in that, In step S11, the nozzle structure first moves a set distance along the Z-axis toward the hot bed at a first speed, and then moves along the Z-axis toward the hot bed at a second speed, wherein the first speed is greater than the second speed.

7. The 3D printer nozzle low contact force touch detection method according to claim 4, characterized in that, In step S12, the electrical characteristic parameter signal is the resonant frequency; The eddy current detection circuit drives the eddy current induction coil to work at a set resonant frequency, and acquires digital measurement values ​​characterizing the resonant frequency at a preset sampling frequency. The ratio of the sampling frequency to the set resonant frequency is 1:3000 to 1:7000. In step S13, the mutation threshold is the amount of change in the digital measurement of the resonant frequency between consecutive sampling points that exceeds 0.1% to 0.4% of the resonant frequency.

8. The 3D printer nozzle low contact force touch detection method according to claim 7, characterized in that, In step S12, the electrical characteristic parameter signal is the resonant frequency; The eddy current detection circuit drives the eddy current induction coil to operate at a resonant frequency of 5MHz and acquires digital measurement values ​​characterizing the resonant frequency at a sampling frequency of 1kHz. In step S13, the preset mutation threshold is the change in the digital measurement value of the resonant frequency between consecutive sampling points exceeding 10 kHz.

9. The 3D printer nozzle low contact force touch detection method according to claim 4, characterized in that, Step S14 further includes a verification step, which includes: Step S21: After the controller moves the nozzle structure along the Z-axis to the starting height position, it moves the nozzle structure along the Z-axis again to the same distance as before, in the direction closer to the heated bed. Step S22: If the change in the electrical characteristic parameter signal is detected again to exceed the preset abrupt change threshold, the contact determination is confirmed to be valid; Step S23: If no transient change in the electrical characteristic parameter signal is detected again, it is determined to be a misjudgment caused by electromagnetic interference, and a prompt is given in the set form.

10. The 3D printer nozzle low contact force touch detection method according to claim 9, characterized in that, In step S14, the first detection point, the middle detection point, and the last detection point in the preset detection point sequence are selected for the verification step.

Images