An eccentric edge finder safety monitoring system

Abstract

This utility model discloses a safety monitoring system for an eccentric edge finder, including a status monitoring mechanism and a status receiving mechanism. The status monitoring mechanism includes a base, a magnetic sticker, a linear Hall sensor, a status monitoring circuit board, and a battery. An eccentric edge finder is installed in the central hole of the base, the magnetic sticker is attached to the clamping end of the eccentric edge finder, the linear Hall sensor is mounted on the status monitoring circuit board, and the battery is wired to the input end of the status monitoring circuit board. The status receiving mechanism includes a housing and a status receiving circuit board. The status receiving circuit board is installed in the housing, and the status receiving circuit board and the status monitoring circuit board communicate wirelessly to achieve bidirectional data transmission. Once a foreign object enters the central hole of the base, the statistical characteristics of the voltage signal output by the linear Hall sensor will not match the device fingerprint of the eccentric edge finder, thereby preventing the safety monitoring system from mistakenly identifying the foreign object as an eccentric edge finder.

Description

Technical Field

[0001] This utility model discloses an eccentric edge finder safety monitoring system, which belongs to the field of CNC machining training safety management. Background Technology

[0002] Eccentric edge finders are commonly used auxiliary positioning tools in CNC milling training, primarily used to determine the origin position of the workpiece in the XY plane. In actual operation, the eccentric edge finder is mounted on the tool holder, and the spindle speed is set to 300-500 r / min to generate an eccentricity of approximately 0.5 mm. At this point, the probe of the eccentric edge finder is brought into contact with the workpiece end face, and the workpiece is slowly moved. By observing the point where the probe slips out, the reference position of the workpiece can be determined. However, most students participating in the training are new to CNC milling machines or machining centers and are not yet familiar with the operating procedures. When using eccentric edge finders, improper operation often leads to incorrect spindle speed settings. If the speed is set too high, it can damage the connecting spring, or even cause the probe to be thrown out due to excessive centrifugal force, resulting in a safety accident.

[0003] Real-time monitoring of the eccentric edge finder's operating status and dynamic spindle speed limiting are crucial measures to ensure safety during practical training and an important aspect of improving students' professional skills and safety awareness. Therefore, developing an eccentric edge finder safety monitoring system is of significant practical importance for improving the safety management level of CNC milling training.

[0004] A search of existing technical literature revealed that Chinese patent CN221425620U discloses a 3D edge finder, which focuses on placing easily breakable material between the measuring head and the transmission rod to protect the internal structure of the edge finder. Chinese patent CN215091461U discloses a protective device for a laser edge finder, which focuses on preventing damage to the laser edge finder from molten metal slag, thereby extending its service life. Both of these patents focus on protecting the edge finder itself, without considering real-time monitoring of the edge finder's operating status and dynamic control of the spindle speed to prevent personal safety accidents. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an eccentric edge finder safety monitoring system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An eccentric edge finder safety monitoring system includes a status monitoring mechanism and a status receiving mechanism;

[0008] The condition monitoring mechanism includes a base, magnetic sticker, linear Hall sensor, condition monitoring circuit board, battery and separator;

[0009] An eccentric edge finder is installed in the central hole of the base. The magnetic sticker is attached to the clamping end of the eccentric edge finder. The linear Hall sensor is installed on the status monitoring circuit board to detect the magnetic flux density of the magnetic sticker and output an analog voltage signal. The status monitoring circuit board is installed on a partition set inside the base. The battery is connected to the input terminal of the status monitoring circuit board by wires to power the status monitoring circuit board. Both are installed in the cavity inside the base.

[0010] The status receiving mechanism includes a housing, a status receiving circuit board, and connecting screws. The housing consists of upper and lower housings. The status receiving circuit board is installed inside the lower housing and is fixedly connected to the lower housing by the connecting screws.

[0011] The status receiving circuit board and the status monitoring circuit board achieve bidirectional data transmission via wireless communication.

[0012] This utility model further defines the technical solution as follows:

[0013] Preferably, the output voltage signal of the linear Hall sensor is linearly related to the magnetic flux density of the magnetic patch.

[0014] Preferably, the status monitoring circuit board includes a battery charging circuit, a status monitoring power supply circuit, a position monitoring circuit, a data storage circuit, a wireless communication circuit, an audible and visual alarm circuit, and a status monitoring microcontroller.

[0015] Preferably, the battery charging circuit is constructed using a charging management chip of model ETA6003;

[0016] The status monitoring power supply circuit includes a two-stage voltage conversion module:

[0017] The first stage uses an ETA1136S2F DC / DC power module to boost the battery voltage to 5V;

[0018] The second stage uses an ME6217C33M5G linear regulator to step down the 5V voltage to 3.3V, providing power to the linear Hall sensor, microcontroller, and wireless communication module.

[0019] The position monitoring circuit uses a DRV5053VAQLPG linear Hall sensor to monitor whether the eccentric edge finder is placed inside the base.

[0020] The data storage circuit uses a W25Q64JVSSIQ type SPI interface memory to store device fingerprint data and system operation logs.

[0021] The wireless communication circuit uses a serial Bluetooth module of model HC-08B, which enables bidirectional wireless communication between the status monitoring circuit board and the status receiving circuit board via the Bluetooth protocol.

[0022] The sound and light alarm circuit uses a Darlington transistor array of model ULN2003ADR to drive the LED lights and buzzer;

[0023] The status monitoring microcontroller uses an STM32F103C8T6 as its main control chip.

[0024] Preferably, the status receiving circuit board includes a status receiving power supply circuit, a relay driving circuit, a wireless communication module, a status indication circuit, and a status receiving microcontroller.

[0025] Preferably, the status monitoring power supply circuit includes a two-stage voltage conversion module:

[0026] The first stage uses an HLK-10M05 AD / DC module to convert 220V AC power to DC 5V output;

[0027] The second stage uses an ME6217C33M5G linear regulator to step down the 5V voltage to 3.3V, providing power for the status receiving microcontroller and wireless communication module.

[0028] The relay drive circuit consists of a signal relay KA2, an NPN transistor Q2, a freewheeling diode D4, a base resistor R7, and an auxiliary contact terminal J2.

[0029] The status indicator circuit consists of an LED and a current-limiting resistor;

[0030] The status receiving microcontroller uses an STM32F103C8T6 as its main control chip.

[0031] Preferably, the battery is installed inside a battery case. The battery is a 3.7V 3000mAh lithium-ion battery with built-in cells and has overcharge, over-discharge and overcurrent protection functions.

[0032] Beneficial effects:

[0033] Compared to traditional switch-type proximity sensors, this invention uses a linear Hall sensor to monitor the operating status of the eccentric edge finder. The analog voltage signal output by the linear Hall sensor has a linear relationship with the magnetic flux density generated by the magnetic sticker. By statistically analyzing the sampled voltage signal, a device fingerprint can be generated. Once a foreign object enters the center hole of the base, the statistical characteristics of the voltage signal output by the linear Hall sensor will not match the device fingerprint of the eccentric edge finder, thereby preventing the safety monitoring system from mistakenly identifying the foreign object as the eccentric edge finder.

[0034] This invention uses wireless communication technology to send the usage status of the eccentric edge finder to the CNC system PMC. This not only solves the problems of difficult wiring and lack of layout flexibility in the CNC machining training environment of traditional wired connections, but also reduces the safety hazards caused by wear and tear or accidental breakage of cables due to long-term use. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the condition monitoring mechanism of this utility model;

[0036] Figure 2 This is a schematic diagram of the status receiving mechanism of this utility model;

[0037] Figure 3 This is a circuit diagram of the battery charging circuit in the condition monitoring circuit board of this utility model;

[0038] Figure 4 This is a circuit diagram of the state monitoring power supply circuit in the state monitoring circuit board of this utility model;

[0039] Figure 5 This is a circuit diagram of the position monitoring circuit in the status monitoring circuit board of this utility model;

[0040] Figure 6 This is a circuit diagram of the data storage circuit in the status monitoring circuit board of this utility model;

[0041] Figure 7 This is a circuit diagram of the wireless communication circuit in the condition monitoring circuit board of this utility model;

[0042] Figure 8 This is a circuit diagram of the audible and visual alarm circuit in the status monitoring circuit board of this utility model;

[0043] Figure 9 This is a circuit diagram of the state monitoring microcontroller in the state monitoring circuit board of this utility model;

[0044] Figure 10 This is a circuit diagram of the status receiving power supply circuit in the status receiving circuit board of this utility model;

[0045] Figure 11 This is a circuit diagram of the relay drive circuit in the status receiving circuit board of this utility model;

[0046] Figure 12 This is a circuit diagram of the wireless communication module and the status indication circuit in the status receiving circuit board of this utility model;

[0047] Figure 13 This is a circuit diagram of the status receiving microcontroller in the status receiving circuit board of this utility model;

[0048] Figure 14 This is a block diagram illustrating the working principle of the circuit part of the safety monitoring system for the eccentric edge finder of this utility model;

[0049] Figure 15 This is a data table in the PMC program of the safety monitoring system for the eccentric edge finder of this utility model;

[0050] Figure 16 The PMC program ladder diagram is shown for the safety monitoring system of the eccentric edge finder of this utility model. Detailed Implementation

[0051] Example 1

[0052] This embodiment provides a safety monitoring system for an eccentric edge finder, such as Figure 1-2 As shown, it includes a status monitoring agency and a status receiving agency;

[0053] The condition monitoring mechanism includes a base 1, a magnetic sticker 5, a linear Hall sensor 7, a condition monitoring circuit board 8, a battery 3, and a separator 4;

[0054] An eccentric edge finder 6 is installed in the center hole of the base 1. A magnetic sticker 5 is attached to the clamping end of the eccentric edge finder. A linear Hall sensor 7 is installed on the status monitoring circuit board 8 to detect the magnetic flux density of the magnetic sticker and output an analog voltage signal. A battery is installed in the battery box 2 and connected to the input wire of the status monitoring circuit board 8 to power the status monitoring circuit board. Both are installed in the cavity inside the base.

[0055] The status receiving mechanism includes a housing, a status receiving circuit board, and connecting screws. The housing consists of an upper housing 10 and a lower housing 9. The status receiving circuit board 11 is installed inside the lower housing 9 and is fixedly connected to the lower housing by connecting screws 12.

[0056] The status receiving circuit board and the status monitoring circuit board achieve bidirectional data transmission via wireless communication;

[0057] Furthermore, the status receiving circuit board is connected to the IO unit in the machine tool electrical cabinet through a relay drive circuit, transmitting the usage status of the eccentric edge finder to the CNC system. The PMC program in the CNC system dynamically limits the spindle speed by detecting changes in the level of the IO unit input port pins.

[0058] To prevent magnetic tools or magnetic shavings from interfering with the safety monitoring system, this invention employs a linear Hall effect sensor to monitor the status of an eccentric edge finder. Unlike traditional switch-type Hall effect sensors, which can only simply detect the presence or absence of a magnetic field, the output voltage of a linear Hall effect sensor is linearly related to the applied magnetic flux density and can distinguish the direction of the magnetic field. Therefore, by utilizing the output voltage data of the linear Hall effect sensor, a device fingerprint of the eccentric edge finder is established for status identification and monitoring.

[0059] This embodiment uses a 3.7V 3000mAh lithium-ion battery. The battery has a nominal capacity of 3000mAh and can provide power for more than half a month after being fully charged. The battery has built-in cells and has overcharge, over-discharge and overcurrent protection functions. The maximum discharge current reaches 3A, which can fully meet the power supply requirements of the Hall sensor and the status monitoring circuit board. The battery's voltage output and charging input interfaces both use standard PH2.0-2PZZ connectors, which facilitates quick electrical connection.

[0060] In this embodiment, the status monitoring circuit board includes a battery charging circuit, a status monitoring power supply circuit, a position monitoring circuit, a data storage circuit, a wireless communication circuit, an audible and visual alarm circuit, and a status monitoring microcontroller.

[0061] See Figure 3 The battery charging circuit uses an ETA6003 charging management chip. The IN and PGND pins of this chip are connected to the positive (VIN) and negative (GND) terminals of the input power supply, respectively, to provide charging power. The STAT pin is connected to an LED D1 to indicate the charging status. The ISET1 pin is connected to GND through a 1K pull-down resistor R2, and the USB_DET pin is left floating, allowing the chip to enter fast charging mode with a maximum charging current of 1A. The BATT pin is connected to the positive terminal of the lithium-ion battery BT1 and a 1μF ceramic capacitor C3 is connected to GND to stabilize the battery voltage. The SYS pin is the chip's output pin and is connected to the subsequent load. The NTC pin is connected to VIN through a pull-up resistor R3 and to GND through a pull-down resistor R4 and an NTC thermistor Rt1 to achieve over-temperature and low-temperature protection for the rechargeable lithium battery. If the threshold temperatures for over-temperature and low-temperature protection of the rechargeable lithium battery are set to 70℃ and -20℃, respectively, the values ​​of R3 and R4 should meet the following requirements.

[0062]

[0063] In the formula, Rt1 (70℃) and Rt1 (-20℃)These represent the resistance values ​​of the NTC thermistor at 70℃ and -20℃, respectively. This invention uses the MF52A103F3950 thermistor, whose resistance values ​​at 70℃ and -20℃ are 1.725KΩ and 89.682KΩ, respectively. Substituting these two resistance values ​​into formula (1), we obtain R3 = 2.73KΩ and R4 = 9.85KΩ. To simplify the resistor selection process, this invention selects film resistors with nominal values ​​of 2.74KΩ and 9.88KΩ, and an accuracy of 1‰, as R3 and R4. To make the input and output voltages more stable, a 10μF tantalum capacitor C1 and a 0.1μF ceramic capacitor C2 are connected in parallel between the IN pin and the PGND pin. The SYS pin is connected to an inductor L1 to the SW pin and a capacitor C4 to GND. The EP, USB_DET, and ISET2 pins are left floating, and the ENB, ENPPB, and GND pins are connected to GND. To prevent safety hazards caused by over-discharge of the lithium-ion battery BT1, a series voltage divider circuit composed of resistors R15 and R16 is used to collect the battery voltage. When the sampled voltage value is lower than the threshold voltage, an alarm signal is issued through an audible and visual alarm circuit to remind the user to charge the battery in time.

[0064] Considering that the condition monitoring circuit board requires both DC 5V and DC 3.3V power supplies, its power supply circuit employs a two-stage voltage conversion scheme: First, an ETA1136S2F DC / DC power module boosts the output voltage of the rechargeable lithium battery to 5V; then, an ME6217C33M5G linear regulator steps down the 5V voltage to 3.3V, providing DC 3.3V operating power for the Hall sensor, data storage circuit, wireless communication circuit, and microcontroller. Furthermore, the output voltage of the lithium-ion battery gradually decreases as the charge diminishes. Once it falls below 4.3V, it will affect the maximum output power of the ME6217C33M5G linear regulator, resulting in insufficient power supply to the condition monitoring circuit board. In this situation, using the ETA1136S2F DC / DC power module to convert the fluctuating voltage from the lithium-ion battery into a stable 5V output voltage ensures that the ME6217C33M5G linear regulator receives sufficient input voltage, thereby maintaining its maximum output power and ensuring normal power supply to the condition monitoring circuit board.

[0065] See Figure 4The IN pin of the ETA1136S2F DC / DC power module is connected to the SYS pin of the ETA6003 charging management chip via a switch P1 with a power indicator light to input operating power. The SW pin is connected to the IN pin via a 2.2μH inductor L2. The EN pin is connected to the IN pin via a pull-up resistor R1 to ensure that the EN pin is high when switch P1 is turned on, causing the OUT pin to immediately output a DC 5V voltage. To further stabilize the input and output voltages, a 22μF ceramic capacitor C5 and a 22μF capacitor C6 are connected to GND on the IN and OUT pins, respectively.

[0066] The VIN pin of the ME6217C33M5G linear regulator is connected to the OUT pin of the ETA1136S2F DC / DC power module to input a DC 5V voltage. The VOUT pin outputs a DC 3.3V voltage. The VSS pin is connected to GND, and the CE pin is connected to the VIN pin. To make the input and output voltages more stable, a 10μF tantalum capacitor C7 and a 10μF capacitor C8 are connected to GND on both the VIN and VOUT pins.

[0067] See Figure 5 The position monitoring circuit uses a DRV5053VAQLPG linear Hall sensor to monitor whether the eccentric edge finder is placed inside the base. The power supply pins VCC and GND of this linear Hall sensor are connected to the positive terminal of a DC 3.3V power supply (network label: 3V3) and GND, respectively. The OUT pin outputs an analog voltage signal linearly related to the magnetic flux density. To reduce noise interference on the OUT pin and make the sampling data more stable, an RC filter is used to filter the analog voltage signal output from the OUT pin. The cutoff frequency of the RC filter is f0. c for

[0068]

[0069] In the formula, the resistance of resistor R10 is 7.5kΩ, and the capacitance of capacitor C11 is 0.1μF. Therefore, f can be calculated. c The frequency is 212Hz. The analog voltage signal output on the OUT pin is filtered and then sent to the PA0 pin of the microcontroller for analog-to-digital conversion (the selected microcontroller has an integrated 12-bit analog-to-digital converter).

[0070] See Figure 6The data storage circuit uses a W25Q64JVSSIQ type memory to store the device fingerprint data of the eccentric edge finder. This memory has a storage capacity of 8MB, communicates with the microcontroller via an SPI interface, and has a clock frequency of up to 133MHz, ensuring fast and stable data storage. The VCC pin of the W25Q64JVSSIQ type memory is connected to the positive terminal of a DC 3.3V power supply, and the GND pin is connected to GND to input a 3.3V operating voltage. Connect the pin to the positive terminal of a DC 3.3V power supply to disable the write protection function and facilitate reading and writing data at any time; Connect the pin to the positive terminal of a DC 3.3V power supply to deselect the suspend function; CLK, DI, DO and The pin is connected to the SPI port pin of the microcontroller for bidirectional data transmission. A 0.1μF ceramic capacitor C12 is connected to GND on the VCC pin to provide a stable operating voltage for the W25Q64JVSSIQ memory and reduce power supply voltage fluctuations caused by high-speed read and write operations.

[0071] See Figure 7 The wireless communication circuit uses an HC-08B serial Bluetooth module to achieve bidirectional wireless communication between the status monitoring mechanism and the status receiving mechanism. This serial Bluetooth module communicates with the microcontroller via a serial port, supporting a maximum baud rate of 115200bps, a transmission distance of up to 80 meters, and high and stable data transmission rates. The module is small and can be directly soldered onto the status monitoring circuit board through a semi-circular stamp hole. The VCC pin of the HC-08B serial Bluetooth module is connected to the positive terminal of the DC 3.3V power supply, and the GND pin is connected to GND to input the DC 3.3V operating voltage. The RST pin is connected to the positive terminal of the DC 3.3V power supply via a pull-up resistor R7, maintaining a high level after the module is powered on to ensure it immediately enters the working mode. Simultaneously, the RST pin is connected to the PB10 pin of the microcontroller; setting the PB10 pin low resets the module. The TXD and RXD pins are connected to the microcontroller's serial port pins PA3 and PA2, respectively, for data transmission via the serial port; the remaining pins do not need to be left floating. In addition, a 4.7μF tantalum capacitor C9 is connected to GND on the VCC pin to improve the stability of the module's operating voltage.

[0072] See Figure 8The audible and visual alarm circuit uses a Darlington transistor array of model ULN2003ADR to drive the LED lights and buzzer. This Darlington transistor array integrates seven independent NPN Darlington pairs and has a built-in freewheeling diode, allowing it to directly drive inductive loads. The COMMON pin of the ULN2003ADR Darlington transistor array is connected to the positive terminal of the DC 5V power supply (the network label indicates 5V), and the GND pin is connected to GND for input power. Pins 1IN, 2IN, 3IN, and 4IN are connected to the PB1, PB0, PA5, and PA4 pins of the microcontroller, respectively. When these pins output a high level, the corresponding Darlington pairs conduct, driving LED indicators D2, D3, and D4 to light up and the active buzzer BP1 to sound. R6, R8, and R14 are current-limiting resistors for the LED lights, with a resistance of 1KΩ.

[0073] See Figure 9 The microcontroller in the status monitoring mechanism uses STM32F103C8T6 as the main control chip, and the peripheral circuits include clock circuit, reset circuit, program download interface circuit, start mode selection circuit, button circuit and power supply filtering circuit.

[0074] The clock circuit consists of an 8MHz crystal oscillator XT1 and oscillation capacitors C13 and C15, and inputs clock signals to the microcontroller through the PD0-OSC_IN and PD1-OSC_OUT pins.

[0075] The reset circuit supports both automatic power-on reset and manual reset. Automatic power-on reset is achieved through an RC circuit: upon power-on, the current is limited by R11 and charges capacitor C14. Before the voltage reaches 1.2V, the NRST pin remains low, putting the microcontroller into reset mode. As the charging time increases, the voltage across C14 gradually rises. When it exceeds 2.1V, the NRST pin goes high, and the microcontroller automatically enters working mode. Manual reset is achieved through a button circuit. Pressing button K1 lowers the NRST pin, putting the microcontroller into reset mode.

[0076] The program download interface circuit establishes the electrical connection between the DAP emulator and the STM32F103C8T6 microcontroller, providing a program download channel for the microcontroller. This interface uses an XH2.54-5PZZ female connector J2 to connect to the DAP emulator. Pins 1, 2, and 4 of the female connector J2 are connected to the microcontroller's NRST, PA14, and PA13 pins, respectively, while pins 5 and 3 are connected to the positive terminal of the DC 3.3V power supply and GND, respectively.

[0077] The boot mode selection circuit is used to set the storage medium on which the microcontroller begins executing the program after a reset. The STM32F103C8T6 microcontroller determines the boot mode through the voltage levels of the BOOT0 and PB2 pins. This invention uses a header pin and jumper cap to set the voltage levels of the BOOT0 and PB2 pins. Pins 1 and 2 are connected to the positive terminal of the DC 3.3V power supply; pins 3 and 4 are connected to the BOOT0 and PB2 pins of the microcontroller via current-limiting resistors R13 and R14 respectively; pins 5 and 6 are connected to GND. Using a header pin and jumper cap to configure the microcontroller's boot mode offers advantages such as low cost and simple operation.

[0078] The button circuit is used to input control signals to the microcontroller, employing a one-button connection per I / O port pin. Pins PB12, PB13, PB14, and PB15 are connected to buttons K2, K3, K4, and K5, respectively. These I / O port pins are internally configured with pull-up resistors, and are high by default; when a button is pressed, the pin level changes to low.

[0079] The power supply filtering circuit provides a stable DC 3.3V operating voltage for the microcontroller. The VDD_1, VDD_2, VDD_3, and VDD_A pins of the STM32F103C8T6 microcontroller are connected to the positive terminal of the DC 3.3V power supply, while VSS_1, VSS_2, VSS_3, and VSSA are connected to GND. To improve power quality and reduce power impedance, a 1μF tantalum capacitor and a 0.1μF ceramic capacitor are connected to GND for each power supply pin.

[0080] The status receiving circuit board includes a status receiving power supply circuit, a relay driving circuit, a wireless communication module, a status indication circuit, and a status receiving microcontroller.

[0081] The status receiving circuit board requires both DC 5V and DC 3.3V power supplies. This power supply circuit employs a two-stage voltage conversion scheme: first, 220V AC power is drawn from the machine tool's electrical cabinet, converted to DC 5V output via an AD / DC module, and then a low-dropout linear regulator steps down the 5V voltage to 3.3V to provide power for the microcontroller and wireless communication circuits. An LED indicator D1 is connected to the output pin of the low-dropout linear regulator to indicate the power supply's operating status.

[0082] See Figure 10The AD / DC module selected is the HLK-10M05 model, which supports a wide voltage input of 90~265VAC, has a no-load loss of less than 0.1W, and features output short-circuit and overcurrent protection. A 220V AC power supply is connected to terminal J1, with pin 1 connected to the live wire and pin 2 to the ground wire. A fuse FU1 and a common-mode inductor L1 are connected in series to the module's input terminal. Vr1 is a varistor that protects the module from damage during accumulated surges. C1 is a safety capacitor used to suppress EMI conducted interference. The +VO and -VO pins of the module are the positive (5V on the network label) and negative (GND on the network label) terminals of the DC 5V power supply, respectively. To reduce ripple on the +VO pin, a 220μF aluminum electrolytic capacitor C2 is connected in parallel between the +VO and -VO pins.

[0083] The low-dropout linear regulator is model ME6217C33M5G. Its VIN and VSS pins are connected to the +VO and -VO pins of the HLK-10M05 module, respectively, to input a 5V power supply. Connecting the control pin CE to the VIN pin ensures that the VOUT pin immediately outputs 3.3V after the linear regulator is powered on. To further stabilize the input and output voltages, connect two 10μF tantalum capacitors, C3 and C4, to GND on the VIN and VOUT pins, respectively. The NC pin is left floating.

[0084] See Figure 11 The relay drive circuit consists of a signal relay KA2, an NPN transistor Q2, a freewheeling diode D5, a base resistor R8, and an auxiliary contact terminal J2. The signal relay KA2 is a G5V-1DC5 with a coil rated voltage of 5V and a power consumption of only 150mW, which helps reduce the energy consumption of the status receiving circuit system. The base of the NPN transistor Q2 is connected to the microcontroller's PB9 pin via a resistor R8. When the PB9 pin is high (3.3V), the transistor conducts, energizing the relay KA2 coil and thus changing the connection state of the auxiliary contact. The freewheeling diode D5 is connected in reverse parallel across the signal relay KA2 coil to discharge the reverse induced electromotive force generated by the coil, protecting the transistor from high-voltage breakdown.

[0085] See Figure 12 The status indication circuit consists of LEDs and current-limiting resistors. LEDs D3, D4, and D6 are connected in a common-anode configuration and connected to the microcontroller's I / O port pins after current limiting by the resistors. In the default state, the I / O port pins are high, and the LEDs are off. When the microcontroller program sets the I / O port pins low, the LEDs light up, thus indicating the status. The wireless communication circuit uses an HC-08B serial Bluetooth module to achieve bidirectional wireless communication between the status receiving mechanism and the status monitoring mechanism.

[0086] See Figure 13 The status receiving microcontroller uses STM32F103C8T6 as the main control chip, and the peripheral circuits include clock circuit, reset circuit, program download interface circuit, start mode selection circuit, button circuit and power supply filtering circuit.

[0087] See Figure 14 The status monitoring circuit board converts the magnetic field strength of the magnetic sticker on the eccentric edge finder into a voltage signal through the position monitoring circuit. The microcontroller performs analog-to-digital conversion on this voltage signal and assembles a set of continuously sampled data into a sample. Subsequently, the microcontroller calculates the sample mean and sample variance and reads the device fingerprint from the data storage circuit. If the two match, it indicates that the eccentric edge finder has been placed on the base. At this time, the microcontroller sends this status to the status receiving circuit board through the wireless communication circuit. After receiving the signal through the wireless communication circuit, the status receiving circuit board drives the relay coil to open its normally closed contact, thereby making the input port pin of address X5.0 on the machine tool electrical cabinet IO unit go low. After the PMC program in the CNC unit detects that the value of X5.0 is 0, it releases the spindle speed limit. If the eccentric edge finder is not placed on the base, the relay coil is de-energized, its normally closed contact returns to the closed state, and the input port pin of address X5.0 is 24V high. After the PMC program detects that the value of X5.0 is 1, it activates the spindle speed limit.

[0088] See Figure 15 and Figure 16 The spindle dynamic speed limiting PMC program modifies CNC system parameters through PMC function instructions. Taking the FANUC 0i TF Plus CNC system as an example, firstly, two sub-data tables, 1 and 2, are created in the CNC system's data table screen, with their starting addresses being D0500 and D0550 respectively. In the default state, the eccentric edge finder is placed on the base, and the value of X5.0 is 1. At this time, the WINDW function instruction writes the value at address D0510 in sub-data table 1 into system parameter No. 3772, thus not limiting the maximum spindle speed. When the eccentric edge finder is removed from the base, the value of X5.0 becomes 0, and the WINDW instruction writes the value at address D0560 in sub-data table 2 into system parameter No. 3772, thereby limiting the maximum spindle speed to 400 r / min. In the WINDW instruction, the function code number used to write CNC system parameters is 18, which belongs to the low-speed response type. Therefore, normally closed and normally open contacts of R500.0 are added before the WINDW instruction to ensure that its ACT is immediately set to 0 after the WINDW instruction is executed, so as to achieve interlocking.

[0089] The steps for establishing the device fingerprint of the eccentric edge finder in this embodiment are as follows:

[0090] 1. Place the eccentric edge finder into the center hole of the base, press the K2 key on the status monitoring circuit board, and the microcontroller on the status monitoring circuit board will continuously sample the voltage signal output by the position monitoring circuit, and form a set of samples with a length of n=5000 by continuously sampling data.

[0091] 2. Calculate the sample mean and standard deviation s 2 ;

[0092] 3. With the confidence level set at 1-α, the confidence interval for the population mean μ is: Where z represents the standard normal distribution, z α / 2 It is the z-value when the area to the right of the standard normal distribution is α / 2;

[0093] 4. The sample variance follows a χ² pattern with n-1 degrees of freedom. 2 If the distribution is such that the population variance σ is... 2 The confidence interval is

[0094] In addition to the above embodiments, this utility model may have other implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by this utility model.

Claims

1. A safety monitoring system for an eccentric edge finder, characterized in that, This includes condition monitoring agencies and condition receiving agencies; The status monitoring mechanism includes a base (1), a magnetic sticker (5), a linear Hall sensor (7), a status monitoring circuit board (8), a battery (3), and a separator (4). An eccentric edge finder (6) is installed in the center hole of the base. The magnetic sticker (5) is attached to the clamping end of the eccentric edge finder (6). The linear Hall sensor (7) is installed on the status monitoring circuit board (8) to detect the magnetic flux density of the magnetic sticker (5) and output an analog voltage signal. The status monitoring circuit board (8) is installed on the partition (4) set inside the base. The battery (3) is connected to the input terminal wire of the status monitoring circuit board (8) to power the status monitoring circuit board (8). Both are installed in the cavity inside the base. The status receiving mechanism includes a housing, a status receiving circuit board (11), and connecting screws (12). The housing consists of upper and lower housings. The status receiving circuit board (11) is installed inside the lower housing and is fixedly connected to the lower housing by the connecting screws. The status receiving circuit board (11) and the status monitoring circuit board (8) achieve bidirectional data transmission through wireless communication.

2. The eccentric edge finder safety monitoring system according to claim 1, characterized in that, The output voltage signal of the linear Hall sensor (7) is linearly related to the magnetic flux density of the magnetic sticker (5).

3. The eccentric edge finder safety monitoring system according to claim 1, characterized in that, The status monitoring circuit board includes a battery charging circuit, a status monitoring power supply circuit, a position monitoring circuit, a data storage circuit, a wireless communication circuit, an audible and visual alarm circuit, and a status monitoring microcontroller.

4. The eccentric edge finder safety monitoring system according to claim 3, characterized in that, The battery charging circuit is constructed using a charging management chip of model ETA6003; The status monitoring power supply circuit includes a two-stage voltage conversion module: The first stage uses an ETA1136S2F DC / DC power module to boost the battery voltage to 5V; The second stage uses an ME6217C33M5G linear regulator to step down the 5V voltage to 3.3V, which powers the linear Hall sensor (7), the microcontroller and the wireless communication module. The position monitoring circuit uses a DRV5053VAQLPG linear Hall sensor to monitor whether the eccentric edge finder is placed inside the base. The data storage circuit uses a W25Q64JVSSIQ type SPI interface memory to store device fingerprint data and system operation logs. The wireless communication circuit uses a serial Bluetooth module of model HC-08B, which enables bidirectional wireless communication between the status monitoring circuit board (8) and the status receiving circuit board (11) via Bluetooth protocol. The sound and light alarm circuit uses a Darlington transistor array of model ULN2003ADR to drive the LED lights and buzzer; The status monitoring microcontroller uses an STM32F103C8T6 as its main control chip.

5. The eccentric edge finder safety monitoring system according to claim 1, characterized in that, The status receiving circuit board includes a status receiving power supply circuit, a relay driving circuit, a wireless communication module, a status indication circuit, and a status receiving microcontroller.

6. The eccentric edge finder safety monitoring system according to claim 5, characterized in that, The status monitoring power supply circuit includes a two-stage voltage conversion module: The first stage uses an HLK-10M05 AD / DC module to convert 220V AC power to DC 5V output; The second stage uses an ME6217C33M5G linear regulator to step down the 5V voltage to 3.3V, providing power for the status receiving microcontroller and wireless communication module. The relay drive circuit consists of a signal relay KA2, an NPN transistor Q2, a freewheeling diode D4, a base resistor R8, and an auxiliary contact terminal J2. The status indicator circuit consists of an LED and a current-limiting resistor; The status receiving microcontroller uses an STM32F103C8T6 as its main control chip.

7. The eccentric edge finder safety monitoring system according to claim 1, characterized in that, The battery (3) is installed inside the battery box (2). The battery is a 3.7V 3000mAh lithium-ion battery with built-in cells and has overcharge, over-discharge and overcurrent protection functions.

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