A measuring device for electronic multi-arm electromagnet suction dynamic response time

Abstract

A kind of electronic multi-arm electromagnet suction dynamic response time measuring device, belong to textile electrical control technical field.It includes microprocessor unit, isolation driving unit, current voltage conversion unit, AD conversion unit and display unit, the microprocessor unit is electrically connected with isolation driving unit, AD conversion unit and display unit respectively, the isolation driving unit is connected with one end of multi-arm electromagnet coil, the other end of multi-arm electromagnet coil is connected with the anode of direct current power supply by a current collector T1, the AD conversion unit is connected with the current voltage conversion unit, and the current voltage conversion unit is connected with the current collector T1.Advantages: the dynamic measurement of electromagnetic performance can be realized, and data is accurate;Measurement efficiency is high, time is fast.

Description

Technical Field

[0001] This invention belongs to the field of textile electrical control technology, specifically relating to a device for measuring the dynamic response time of the attraction force of an electronic multi-arm electromagnet. Background Technology

[0002] Almost all existing textile technologies involve electronic dobby mechanisms. These mechanisms are one of the shedding components of a loom, converting fabric pattern signals into shedding actions that drive the heald frames to move up and down. The signaling component primarily relies on the electromagnetic force generated by electromagnets to drive the actuator, lifting the heald frames and thus shedding the warp yarns to complete the weaving of the pattern. Therefore, electromagnets are a crucial component of electronic dobby mechanisms. Each electromagnet corresponds to a contact plate, whose contact surface mates with the working end face of the magnet. Its working contact controls the swing arm's movement, which in turn drives the heald frames, thereby achieving the weaving function. Dobby mechanisms require very high electromagnet engagement speeds, typically only tens of milliseconds.

[0003] Currently, when electronic multi-arm electromagnets operate at high speeds, if the helical frame malfunctions, aside from obvious mechanical faults, it's difficult for users to determine the specific cause on-site, making it impossible to assess the reliability and effectiveness of the electromagnet's action on the attractor. In particular, sometimes the multi-arm electromagnet may suddenly experience a single malfunction, occurring multiple times a day or once every few days. This irregular malfunction may be due to the dynamic response time between the electromagnet and the attractor operating near a critical point, making it difficult for technicians to diagnose on-site. If it were possible to know in advance whether the attractor's response time under the electromagnet's magnetic force is within a safe range and has a safety margin, the electromagnet and attractor could be adjusted to their optimal state before leaving the factory. The aforementioned dynamic response time of the electromagnet is directly related to the characteristics of the electromagnet coil itself, the installation position of the electromagnet and the attractor (i.e., the gap between the electromagnet and the attractor), and the return spring force. For example, when the electronic dobby loom is running at 800 rpm, according to the electronic dobby loom's operating sequence and action requirements, the electromagnet's energizing switching angle is around 240°. If it runs to 360°, the suction plate will be completely attracted. The angle change range of this process is about 120°, which can be calculated to be about 25 milliseconds. Therefore, the response time for the electromagnet to attract the suction plate must be completed within 25 milliseconds. If the response time is slow and exceeds 25 milliseconds, the dobby loom will malfunction, leading to weaving errors.

[0004] In view of the aforementioned existing technology, the applicant has made beneficial designs, and the technical solutions to be introduced below are produced in this context. Summary of the Invention

[0005] The purpose of this invention is to provide a measuring device for the dynamic response time of the attraction force of an electronic multi-arm electromagnet, which can dynamically measure the response time of the electromagnet coil attracting the attractor plate, and the data is accurate and the measurement efficiency is high.

[0006] The objective of this invention is achieved by providing a device for measuring the dynamic response time of an electronic multi-arm electromagnet's attraction force. The device includes a microprocessor unit, an isolation drive unit, a current-to-voltage conversion unit, an AD conversion unit, and a display unit. The microprocessor unit is electrically connected to the isolation drive unit, the AD conversion unit, and the display unit. The isolation drive unit is connected to one end of the multi-arm electromagnet coil, and the other end of the multi-arm electromagnet coil is connected to the positive terminal of a DC power supply via a current acquisition device T1. The AD conversion unit is connected to the current-to-voltage conversion unit, which in turn is connected to the current acquisition device T1. The current acquisition device T1 is used to acquire the current signal when the electromagnet coil is energized. The detected current signal is converted into a voltage signal, amplified, and then converted into the time of the attracting action via AD conversion. Simultaneously, the display unit displays the response time value.

[0007] In a specific embodiment of the present invention, the current-to-voltage conversion unit includes operational amplifiers U4 and U5, transistor Q1, and resistors R11 to R19. Operational amplifiers U4 and U5 are OP07. One end of resistor R13 and one end of resistor R14 are connected as the current input terminal to the current acquisition unit T1. The other end of resistor R13 is connected to pin 3 of operational amplifier U4. Pin 2 of operational amplifier U4 is connected to one end of resistor R11 and one end of resistor R12. The other end of resistor R11 is connected to pin 6 of operational amplifier U4, forming the voltage output terminal, which is connected to the AD conversion unit. The other end of resistor R14, one end of resistor R15, and transistor Q1 are connected to the current acquisition unit T1. The emitter of pin 1 is connected, the other end of resistor R15 is connected to pin 2 of op-amp U5, pin 3 of op-amp U5 is connected to one end of resistor R17, the other end of resistor R17 is connected to one end of resistor R16 and one end of resistor R18, pin 6 of op-amp U5 is connected to the base of transistor Q1, the collector of transistor Q1 is connected to one end of resistor R19, pin 7 of op-amp U4 and pin 7 of op-amp U5 are connected to +12V DC power supply, pin 4 of op-amp U4, pin 4 of op-amp U5 and the other end of resistor R16 are connected to -12V DC power supply, the other end of resistor R19 is connected to -15V DC power supply, and the other ends of resistor R12 and resistor R18 are grounded.

[0008] In another specific embodiment of the present invention, the AD conversion unit includes operational amplifiers U6A, U6B, U7A, U7B, U8A, U8B, U8C, resistors R20 to R26, diode D1, Zener diodes DZ1 and DZ2, light-emitting diodes LED1 and LED2, and capacitor C4. Operational amplifiers U6A and U6B are LM837, operational amplifiers U7A and U7B are 74HC00, and operational amplifiers U8A, U8B, and U8C are 74HC14. The positive terminal of diode D1 is connected to pin 2 of operational amplifier U6A. The connections form a voltage input terminal connected to the current-to-voltage conversion unit. The cathode of diode D1 is connected to pin 3 of operational amplifier U6A, pin 5 of operational amplifier U6B, one end of resistor R20, and one end of capacitor C4. Pin 1 of operational amplifier U6A is connected to one end of resistor R23. The other end of resistor R23 is connected to pin 5 of operational amplifier U7B, pin 1 of operational amplifier U7A, and the cathode of Zener diode DZ1. Pin 4 of operational amplifier U7B is connected to the microprocessor unit. Pin 6 of operational amplifier U7B is connected to pin 5 of operational amplifier U8C. Pin 6 of operational amplifier U8C is connected to the microprocessor unit. Operational amplifier U7... Pin 2 of operational amplifier U8A is connected to one end of resistor R24, the cathode of Zener diode DZ2, and pin 1 of operational amplifier U8A. The other end of resistor R24 ​​is connected to pin 7 of operational amplifier U6B. Pin 6 of operational amplifier U6B is connected to one end of resistor R21 and one end of resistor R22. Pin 2 of operational amplifier U8A is connected to the cathode of LED2 and pin 3 of operational amplifier U8B. The anode of LED2 is connected to one end of resistor R26. Pin 4 of operational amplifier U8B is connected to the microprocessor unit. Pin 3 of operational amplifier U7A is connected to the cathode of LED1. The positive terminal of LED1 is connected to one end of resistor R25. Pins 4 of op-amp U6A and pins 4 of op-amp U6B are connected to a +15V DC power supply. Pins 11 of op-amp U6A and pins 11 of op-amp U6B are connected to a -15V DC power supply. The other ends of resistors R25 and R26 are connected to a +5V DC power supply. Pin 14 of op-amp U7A is connected to the DC power supply VCC. The other ends of capacitor C4, resistor R20, resistor R21, the positive terminals of Zener diodes DZ1 and DZ2, and pin 7 of op-amp U7A are grounded together.

[0009] In another specific embodiment of the present invention, the microprocessor unit includes a microprocessor U0, which is an AT89C51. The isolation drive unit includes decoder chips U11, U12, and U13, drive signal chips U21, U22, and U23, Darlington transistor drivers U31, U32, and U33, and resistors R27, R28, and R29. The decoder chips U11, U12, and U13 are 74HC138, the drive signal chips U21, U22, and U23 are 74HC240, and the Darlington transistor drivers U31, U32, and U33 are ULN2803A. Pin 1 of the decoder chips U11, U12, and U13 is connected to a common pin. Pin 39 of microprocessor U0, pins 2 of decoder chips U11, U12, and U13 are all connected to pin 38 of microprocessor U0, pins 3 of decoder chips U11, U12, and U13 are all connected to pin 37 of microprocessor U0, pin 4 of decoder chip U11, pin 6 of decoder chip U12, and pin 5 of decoder chip U13 are all connected to pin 36 of microprocessor U0, pins 5 of decoder chip U11, pin 5 of decoder chip U12, and pin 6 of decoder chip U13 are all connected to pin 35 of microprocessor U0, and pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U11 are respectively connected to pins 2, 4, 6, 8, 11, 13, and 1 of drive signal chip U21. Pins 5 and 17 of the drive signal chip U21 are connected to pins 18, 16, 14, 12, 3, 5, 7, and 9 of the Darlington transistor driver U31, respectively. Pins 15, 14, 13, 12, 11, 10, 9, and 7 of the decoder chip U12 are connected to pins 2, 4, 6, 8, 11, 13, 15, and 17 of the drive signal chip U22, respectively. Pins 18, 16, 14, 12, 3, 5, 7, and 9 of the drive signal chip U22 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of the Darlington transistor driver U32, respectively. Pins 15, 14, 13, 12, 11, 10, 9, and 7 of the decoder chip U13 are connected to pins 2, 4, 6, 8, and 11 of the drive signal chip U23, respectively. Pins 13, 15, and 17, and pins 18, 16, 14, 12, 3, 5, 7, and 9 of the drive signal chip U23 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of the Darlington transistor driver U33, respectively. Pin 10 of the Darlington transistor driver U31 is connected to one end of resistor R27. The other end of resistor R27 is connected to one end of resistor R28 and one end of resistor R29. The other end of resistor R28 is connected to pin 10 of the Darlington transistor driver U32, and the other end of resistor R29 is connected to pin 10 of the Darlington transistor driver U33. Pins 11-18 of the Darlington transistor drivers U31, U32, and U33 constitute twenty-four output terminals for connecting to the electromagnet coil.Pin 6 of decoder chip U11 and pin 20 of drive signal chips U21, U22, and U23 are connected to the DC power supply VCC. Pins 1, 10, and 19 of drive signal chips U21, U22, and U23, pin 4 of decoder chip U12, and pin 4 of decoder chip U13 are grounded.

[0010] In another specific embodiment of the present invention, the microprocessor unit includes buttons S1 to S5. Button S1 is connected to pin 13 of the microprocessor U0, button S2 is connected to pin 14 of the microprocessor U0, button S3 is connected to pin 15 of the microprocessor U0, button S4 is connected to pin 16 of the microprocessor U0, and button S5 is connected to pin 17 of the microprocessor U0. Button S1 is used for switching between automatic and manual measurement, buttons S2 and S3 are used for inputting the addition and subtraction control signals of the measurement channel, and buttons S4 and S5 are used for inputting the addition and subtraction control signals of the measurement speed.

[0011] In another specific embodiment of the present invention, the current collector T1 is a Hall current sensor.

[0012] In a further specific embodiment of the present invention, the isolation drive unit controls the on / off switching of the electromagnet coil by isolating and amplifying the signal.

[0013] Compared with existing technologies, this invention, due to the aforementioned structure, offers the following advantages: It assists in judging the performance of electromagnets during manufacturing and installation, determining whether they meet factory requirements, thus effectively ensuring the quality of electronic multi-arm products; it quantifies the dynamic response time of electromagnets, providing standard data for factory inspection; it overcomes the shortcomings of previous factory inspections, which were limited by time constraints and could only test the multi-arm's movement for a certain period, and only provided static data on electromagnetic performance; it enables dynamic measurement of electromagnetic performance with accurate data; and it boasts high measurement efficiency and speed. Attached Figure Description

[0014] Figure 1 This is a block diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the electrical connection of the microprocessor unit described in this invention; Figure 3 This is a schematic diagram of the electrical connection of the isolation drive unit described in this invention; Figure 4 This is a pin diagram of the current acquisition device described in this invention; Figure 5 This is a schematic diagram of the electrical connection of the current-to-voltage conversion unit described in this invention. Figure 6This is a graph showing the relationship between the voltage converted by the current-to-voltage conversion unit of the present invention and the response time. Figure 7 This is a schematic diagram of the electrical connection of the AD conversion unit described in this invention. Detailed Implementation

[0015] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of the present invention should be considered within the scope of protection of the present invention.

[0016] In the following description, all directional (or orientational) concepts involving up, down, left, right, front, and back refer to the position of the figure being described, and are intended to facilitate public understanding. Therefore, they should not be construed as a special limitation on the technical solution provided by this invention.

[0017] This invention relates to a device for detecting the dynamic response time of the attraction force of an electronic multi-arm electromagnet, for use in pre-shipment inspection of products and for quickly determining the cause of malfunctions of the electronic multi-arm at the user's site. As is known in the art, an electronic multi-arm mechanism includes an electromagnet and a suction plate. During high-speed operation of the multi-arm, the electromagnet and suction plate rapidly attract and release, causing a slight change in the inductance of the electromagnet coil, resulting in a slight change in the current flowing through the electromagnet coil. This solution utilizes the change in current in the electromagnet coil to detect the time required for the electromagnet to attract the suction plate from the start to complete attraction.

[0018] Please see Figure 1 The measuring device includes a microprocessor unit, an isolation drive unit, a current-to-voltage conversion unit, an analog-to-digital (A / D) conversion unit, and a display unit. The microprocessor unit is electrically connected to the isolation drive unit, the A / D conversion unit, and the display unit. The isolation drive unit is connected to one end of a multi-arm electromagnet coil, and the other end of the multi-arm electromagnet coil is connected to the positive terminal of a DC power supply via a current acquisition unit T1. The A / D conversion unit is connected to the current-to-voltage conversion unit, and the current-to-voltage conversion unit is connected to the current acquisition unit T1. The current acquisition unit T1 is used to acquire the current signal when the electromagnet coil is energized, convert the detected current signal into a voltage signal, amplify the signal, and then perform an A / D conversion to convert the current change into the time of the pull-in action. Simultaneously, the display unit visually displays the response time value.

[0019] Specifically, when the microprocessor unit sends a signal to the electromagnet coil, the driving capability of the microprocessor unit's pins cannot drive the electromagnet. Furthermore, the large back voltage generated when the electromagnet coil is switched on and off interferes with and disrupts the information processed by the microprocessor unit. Therefore, this solution adds an isolation drive unit between the microprocessor unit and the electromagnet coil to isolate and amplify the signal, controlling the switching on and off of the electromagnet coil. The other end of the multi-arm electromagnet coil is connected to the positive terminal of a DC24V power supply via a current acquisition unit T1. The current acquired by the current acquisition unit T1 is transmitted to a current-to-voltage conversion unit, which converts and amplifies the acquired current signal into a voltage signal. This voltage signal is then transmitted to an AD conversion unit for conversion, obtaining the time points of the current change in the coil during the electromagnet's movement and the pull-up tab's action. The AD-converted time points are then transmitted to the microprocessor unit for processing. The microprocessor unit calculates the response time and sends it to the display unit for visual display.

[0020] Please see Figure 2 The microprocessor unit includes a microprocessor and its peripheral circuitry, specifically including a microprocessor U0, capacitors C1 to C3, resistors R0 to R10, and a crystal oscillator Y1. It also includes buttons S1 to S5. The microprocessor U0 can be a microcontroller; in this embodiment, an AT89C51 microcontroller is used. The P0 port of the microprocessor U0, pins 39, 38, 37, 36, and 35, outputs five control signals NET138_1 to NET138_3, NET138_EN1, and NET138_EN2 to the isolated drive unit. The P1 port of the microprocessor U0 serves as the control output of the display unit and is connected to it. The P3 port of the microprocessor U0, pins 13, 14, 15, 16, and 17, are the signal input terminals for buttons S1 to S5. Button S1 is used for switching between automatic and manual measurement. Buttons S2 and S3 are used to input measurement channel increment / decrement control signals, and buttons S4 and S5 are used to input measurement speed increment / decrement control signals. Assuming the electromagnet coils have n paths, L1 to Ln, pressing button S1 starts automatic measurement, beginning with the first electromagnet coil L1. The measurement is set to 5 times for each electromagnet, and the average value is taken. Releasing button S1 and pressing buttons S2 and S3 manually switches between energizing the electromagnet coils L1 to Ln sequentially. Resistors R1 to R10 are pull-up resistors.

[0021] Please see Figure 3The isolation drive unit includes decoder chips U11, U12, and U13, drive signal chips U21, U22, and U23, Darlington transistor drivers U31, U32, and U33, and resistors R27, R28, and R29. The decoder chips U11, U12, and U13 are 74HC138, a high-speed CMOS device that accepts 3-bit binary weighted address input and provides eight mutually exclusive active-low outputs (Y0-Y7) when enabled. The drive signal chips U21, U22, and U23 are 74HC240, a dual-wire eight-channel inverting buffer / line driver commonly used in various microcontroller systems. Microcontroller I / O ports output very small currents, while the 74HC240 chip can amplify the current and invert the output, and it also has tri-state outputs. The Darlington transistor drivers U31, U32, and U33 are ULN2803A, high-voltage, high-current drive chips.Pin 1 of decoder chips U11, U12, and U13 is connected to pin 39 of microprocessor U0; pin 2 of decoder chips U11, U12, and U13 is connected to pin 38 of microprocessor U0; pin 3 of decoder chips U11, U12, and U13 is connected to pin 37 of microprocessor U0; pin 4 of decoder chip U11, pin 6 of decoder chip U12, and pin 5 of decoder chip U13 are connected to pin 36 of microprocessor U0; pin 5 of decoder chip U11, pin 5 of decoder chip U12, and pin 6 of decoder chip U13 are connected to pin 39 of microprocessor U0. Pins 35 of the microprocessor U0 are connected to the following pins: pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U11 are connected to pins 2, 4, 6, 8, 11, 13, 15, and 17 of drive signal chip U21, pins 18, 16, 14, 12, 3, 5, 7, and 9 of drive signal chip U21 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of Darlington transistor driver U31, and pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U12 are connected to pins 2, 4, 6, and 8 of drive signal chip U22. Pins 11, 13, 15, and 17 of the drive signal chip U22, and pins 18, 16, 14, 12, 3, 5, 7, and 9 of the drive signal chip U22, are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of the Darlington transistor driver U32, respectively. Pins 15, 14, 13, 12, 11, 10, 9, and 7 of the decoder chip U13 are connected to pins 2, 4, 6, 8, 11, 13, 15, and 17 of the drive signal chip U23, and pins 18, 16, 14, 12, 3, 5, 7, and 9 of the drive signal chip U23 are connected to pins 1, 2, 3, 4, 5, 6, and 8 of the Darlington transistor driver U33, respectively. Pins 7 and 8, and pin 10 of Darlington transistor driver U31, are connected to one end of resistor R27. The other end of resistor R27 is connected to one end of resistor R28 and one end of resistor R29. The other end of resistor R28 is connected to pin 10 of Darlington transistor driver U32, and the other end of resistor R29 is connected to pin 10 of Darlington transistor driver U33. Pins 11-18 of Darlington transistor drivers U31, U32, and U33 constitute a 24-channel output terminal for connecting electromagnet coils. This embodiment can connect 24 electromagnets. It is also suitable for 16-channel and 20-channel electromagnets. Taking decoder chip U11 as an example, when both enable signals NET138_EN1 and NET138_EN2 are low, decoder chip U11 is enabled, and its output terminal outputs a low-level signal to pins 2, 4, 6, 8, 11, 13, 15, and 17 of drive signal chip U21. After inverting the low-level signal, drive signal chip U21 outputs a high level to pins 1, 2, 3, 4, 5, 6, 7, and 8 of Darlington transistor driver U31. Pins 11 to 18 of Darlington transistor driver U31 form an eight-channel output, which outputs a low level to the connected electromagnet coils L1 to L8.Taking electromagnet coil L1 as an example, a changing current signal is generated in electromagnet coil L1. This current signal is transmitted to the current-to-voltage conversion unit after passing through the current sensor T1, thereby detecting the dynamic response time of the attraction force of electromagnet coil L1. Therefore, when the P0 port of microprocessor U0 outputs NET138_1~NET138_2, NET138_EN1, and NET138_EN2 as 0, and NET138_3 as 1, the output terminal OUT_2 of Darlington transistor driver U31 is at a low level. This low level is transmitted to electromagnet coil L2, thus detecting the response time of electromagnet coil L2. Please see Figure 4 The current sensor T1 is a Hall effect current sensor HA25, which features closed-loop operation, built-in busbar, and circuit board soldering. When a certain electromagnet coil is energized, its current is input from pin 1 of the current sensor T1, and the current sensor T1 sends the collected current from pin 5 to the current input terminal of the current-to-voltage conversion unit.

[0022] Please see Figure 5The current-to-voltage conversion unit includes operational amplifiers U4 and U5, transistor Q1, and resistors R11 to R19. Operational amplifiers U4 and U5 are OP07 types. One end of resistor R13 and one end of resistor R14 are connected as the current input terminal, connected to the current acquisition unit T1. The other end of resistor R13 is connected to pin 3 of operational amplifier U4. Pin 2 of operational amplifier U4 is connected to one end of resistor R11 and one end of resistor R12. The other end of resistor R11 is connected to pin 6 of operational amplifier U4, forming the voltage output terminal, connected to the AD conversion unit. The current acquired by the current acquisition unit T1 flows into the current input terminal. Resistor R14 is a conversion resistor; due to the function of the operational amplifier, this resistor value can be very small, here taken as 43Ω. Operational amplifiers U4 and U5 are bipolar operational amplifiers, characterized by low input bias current, high open-loop gain, and extremely low zero-point offset voltage. Resistors R13, R15, and R17 are matching resistors for the operational amplifier input terminals. Resistors R11 and R12 are the amplification resistors for operational amplifier U4. In this embodiment, resistor R11 is 11.5KΩ and resistor R12 is 1KΩ, with an amplification factor of R11 / R12 = 11.5 / 1 = 11.5 times. Transistor Q1 uses an MMBT2907A chip, a PNP transistor. A 230Ω resistor R19 is connected to its collector pin, and the other end of resistor R19 is connected to a DC 15V negative power supply to extend the output capability of operational amplifier U5. The voltage at the non-inverting input of operational amplifier U5 is divided by resistors R16 and R18. The voltage across resistor R18 is taken. Resistors R16 and R18 are 6.8KΩ and 100Ω respectively. A regulated 12V negative power supply is applied to one end of resistor R16. This voltage is calculated as U = -12*R67 / (R66+R67) = -0.17V, and this voltage value is used as the reference voltage. When a 4mA current flows into the input terminal, it flows through a 43Ω resistor R14. The voltage across R14 is U = 0.004 * 43 = 0.17V, which cancels out the voltage at the non-inverting input of op-amp U5. At this point, pin 6 of op-amp U4 outputs zero voltage. Pin 6 of op-amp U5 is connected to transistor Q1, which is now conducting. As the input current increases, the output voltage of op-amp U4 adjusts from near zero, following the voltage at the non-inverting input. With the increasing input current, when the electromagnet is fully engaged, the current in the electromagnet coil is approximately 10mA. At this 10mA input current, the voltage across R14 is 0.43V. Amplifying this voltage by 11.5 times, the output voltage at pin 6 of op-amp U4 is U = 0.43 × 11.5 ≈ 5V. Therefore, op-amp U4 outputs a voltage ranging from 0V to 5V.

[0023] Please see Figure 6The diagram illustrates the voltage waveform at the output of operational amplifier U4 after current-to-voltage conversion. Point A in the diagram represents the start-up measurement time, point B represents the time when the electromagnet begins to attract the pull plate, and point C represents the time when the electromagnet completely attracts the pull plate. Therefore, the response time is the time between points A and B plus the time from point B to point C, T = t_AB + t_BC.

[0024] Please see Figure 7The AD conversion unit includes operational amplifiers U6A, U6B, U7A, U7B, U8A, U8B, and U8C, resistors R20 to R26, diode D1, Zener diodes DZ1 and DZ2, LEDs LED1 and LED2, and capacitor C4. Operational amplifiers U6A and U6B use the LM837, a low-noise quad operational amplifier chip that can be used as a voltage comparator. They compare the magnitudes of two input voltages; when the "+" input voltage is higher than the "-" input voltage, the comparator outputs a high level; when the "+" input voltage is lower than the "-" input voltage, it outputs a low level. Operational amplifiers U7A and U7B use the 74HC00, a four-channel NAND gate chip. Operational amplifiers U8A, U8B, and U8C use the 74HC14, a six-channel Schmitt trigger inverter, which is low-power and fast, converting slowly changing input signals into clear, jitter-free output signals and enabling high-to-low level switching. The positive terminal of diode D1 is connected to pin 2 of operational amplifier U6A, forming a voltage input terminal connected to the current-to-voltage conversion unit. The negative terminal of diode D1 is connected to pin 3 of operational amplifier U6A, pin 5 of operational amplifier U6B, one end of resistor R20, and one end of capacitor C4. The voltage drop of diode D1 is 0.3V. The resistances of resistors R21 and R22 are 1 kΩ and 10 kΩ, respectively. After voltage division by these two resistors, the voltage at the negative input terminal of operational amplifier U6B, taken from the voltage across resistor R21, is U = 5 * 1 / (10 + 1) = 0.45V. Resistors R23 and R24 are the output pull-up resistors for operational amplifiers U6A and U6B, respectively. Zener diodes DZ1 and DZ2 are reverse-biased diodes for the operational amplifiers, serving to protect them. Pin 1 of operational amplifier U6A is connected to one end of resistor R23. The other end of resistor R23 is connected to pin 5 of operational amplifier U7B, pin 1 of operational amplifier U7A, and the cathode of Zener diode DZ1. Pin 4 of operational amplifier U7B is connected to pin 10 of microprocessor U0 in the aforementioned microprocessor unit. Pin 6 of operational amplifier U7B is connected to pin 5 of operational amplifier U8C. Pin 6 of operational amplifier U8C is connected to pin 12 of microprocessor U0. Pin 2 of operational amplifier U7A is connected to one end of resistor R24 ​​and the cathode of Zener diode DZ1. The negative terminal of diode DZ2 is connected to pin 1 of op-amp U8A. The other end of resistor R24 ​​is connected to pin 7 of op-amp U6B. Pin 6 of op-amp U6B is connected to one end of resistor R21 and one end of resistor R22. Pin 2 of op-amp U8A is connected to the negative terminal of LED2 and pin 3 of op-amp U8B. The positive terminal of LED2 is connected to one end of resistor R26. Pin 4 of op-amp U8B is connected to pin 11 of the microprocessor U0.

[0025] Please continue reading. Figure 6 and Figure 7The voltage at the voltage input terminal of the AD conversion unit is the 0V-5V voltage obtained by the current-to-voltage conversion unit. When detection is enabled, the microprocessor unit sends a high-level control signal C to pin 4 of the operational amplifier U7B in the AD conversion unit. This scheme converts the time point of voltage value change into a signal through AD conversion. The microcontroller has a built-in timer, which can be used to determine the time.

[0026] As the voltage at the input terminal gradually increases, the input voltage minus the voltage drop of diode D34 (0.3V)... Figure 7 At this point, the voltage at point A is 0.75V. When the input voltage is greater than the reference voltage of 0.45V on pin 6 of op-amp U6B, a high level is output on pin 7 of op-amp U6B. This high level goes through resistor R24 ​​to pin 2 of op-amp U7A, and another path goes to pin 1 of op-amp U8A. After being inverted by op-amp U8A, pin 2 of op-amp U8A outputs a low level. Pin 2 of op-amp U8A is connected to the negative terminal of LED2, and the positive terminal of LED2 is connected to the positive terminal of DC 5V power supply through resistor R26, lighting up LED2. At the same time, pin 2 of op-amp U8A is connected to pin 3 of op-amp U8B. After being inverted by op-amp U8B, pin 4 of op-amp U8B outputs a high level, which is sent to the microprocessor unit as a zero-point signal to start the measurement. This time point serves as the starting point for calculating the action between the electromagnet and the pull plate. LED2 can be used as a start indicator. Similarly, when the input voltage increases from A, the voltage at the negative input terminal of op-amp U6A is greater than the voltage at the positive input terminal. Therefore, pin 1 of op-amp U6A outputs a low level, which is transmitted to pin 5 of op-amp U7B and pin 2 of op-amp U7A through resistor R23. After NAND gate conversion, pin 6 of op-amp U7B outputs a high level. This high level is then inverted by op-amp U8C, and pin 6 of op-amp U8C outputs a low level to the microprocessor unit. At this time, the high level output at pin 2 of op-amp U7A, after NAND gate conversion, outputs a high level at pin 3 of op-amp U7A to the negative terminal of LED1. The positive terminal of LED1 is connected to the positive terminal of DC 5V through resistor R25. Therefore, LED1 is not lit at this time.

[0027] When the input voltage continues to increase to the voltage at point B, the magnetic field generated by the electromagnet begins to attract the retaining plate. During this process, the current in the electromagnet coil will decrease slightly, resulting in a slight decrease in the input voltage after the current is converted into voltage. At this moment, the voltage at pin 2 of op-amp U6A decreases instantaneously, while the voltage at pin 3 of op-amp U6A remains unchanged due to the effect of capacitor C4. Meanwhile, the output of pin 7 of op-amp U6B is still high. Pin 2 of op-amp U7A is connected to one end of resistor R24, and the voltage at pin 2 of op-amp U7A is the high level output of op-amp U6B. This high level is inverted by op-amp U8A, resulting in a low level output at pin 2 of op-amp U8A, turning off LED2. Simultaneously, pin 2 of op-amp U8A is connected to pin 3 of op-amp U8B. After being inverted by op-amp U8B, pin 4 of op-amp U8B outputs a low level, which is sent to the microprocessor unit. After processing by microprocessor U0, the final output is... Figure 6 The time from point A to point B is t_AB. At the instant of point B, the voltage on pin 2 of op-amp U6A is less than the voltage on pin 3 of op-amp U6A, so pin 1 of op-amp U6A outputs a high level. This high level is supplied to pin 1 of op-amp U7A and pin 5 of op-amp U7B through resistor R23. After being converted by the NAND gate logic of op-amp U7B, pin 6 of op-amp U7B outputs a low level. After being inverted by op-amp U8C, op-amp U8C outputs a high level, which is then processed by the microprocessor unit as the time node of point B. At this time, the voltage on pin 2 of op-amp U7A is the high level output by U7B. After being converted by logic, op-amp U7A outputs a high level. This high level is inverted by op-amp U8A, and pin 2 of op-amp U8A outputs a low level, and LED1 lights up, serving as the time indicator for point B. When the input voltage drops to point C, it instantly increases. At this point, the electromagnet and the attractor are fully engaged. The voltage at pin 2 of op-amp U6A is greater than the voltage at pin 3, resulting in a low-level output at pin 1. Meanwhile, pin 7 of op-amp U6B still outputs a high-level signal. After the same logic conversion, pin 1 of op-amp U7A outputs a high-level signal to LED1, turning off LED1. Pin 6 of op-amp U7B outputs a low-level signal to op-amp U8C. Op-amp U8C outputs a low-level signal as the time node at point C to the microprocessor unit. After processing, the microprocessor unit calculates the time from point B to point C as t_BC, and further calculates the response time T = t_AB + t_BC for the electromagnet to engage the attractor. This response time is synchronously displayed through the display unit. The application of microprocessor U0 in this solution is known technology and is not an improvement point of this solution.

[0028] Practical verification has shown that, using this device, each electronic multi-arm machine with 16 or 20 electromagnets can quickly complete the detection within 2-3 minutes, which is fast and has high measurement efficiency.

Claims

1. A device for measuring the dynamic response time of the attraction force of an electronic multi-arm electromagnet, characterized in that: The system includes a microprocessor unit, an isolation drive unit, a current-to-voltage conversion unit, an AD conversion unit, and a display unit. The microprocessor unit is electrically connected to the isolation drive unit, the AD conversion unit, and the display unit. The isolation drive unit is connected to one end of the multi-arm electromagnet coil, and the other end of the multi-arm electromagnet coil is connected to the positive terminal of a DC power supply through a current acquisition device T1. The AD conversion unit is connected to the current-to-voltage conversion unit, and the current-to-voltage conversion unit is connected to the current acquisition device T1. The current acquisition device T1 is used to collect the current signal when the electromagnet coil is energized, convert the detected current signal into a voltage signal, amplify the signal, and then perform AD conversion to convert the change in current into the time of the pull-up action. The display unit displays the response time value. The current-to-voltage conversion unit includes operational amplifiers U4 and U5, transistor Q1, and resistors R11 to R19. Operational amplifiers U4 and U5 are OP07, and one end of resistor R13 and one end of resistor R14 are also included. The circuit is as follows: The current input terminal is connected to the current acquisition unit T1; the other end of resistor R13 is connected to pin 3 of operational amplifier U4; pin 2 of operational amplifier U4 is connected to one end of resistor R11 and one end of resistor R12; the other end of resistor R11 is connected to pin 6 of operational amplifier U4, forming the voltage output terminal, which is connected to the AD conversion unit; the other end of resistor R14 is connected to one end of resistor R15 and the emitter of transistor Q1; the other end of resistor R15 is connected to pin 2 of operational amplifier U5; and pin 3 of operational amplifier U5 is connected to one end of resistor R17. The other end of resistor R17 is connected to one end of resistor R16 and one end of resistor R18. Pin 6 of op-amp U5 is connected to the base of transistor Q1. The collector of transistor Q1 is connected to one end of resistor R19. Pins 7 of op-amp U4 and pins 7 of op-amp U5 are connected to a +12V DC power supply. Pins 4 of op-amp U4, pins 4 of op-amp U5, and the other end of resistor R16 are connected to a -12V DC power supply. The other end of resistor R19 is connected to a -15V DC power supply. The other ends of resistor R12 and the other ends of resistor R18 are grounded.The AD conversion unit includes operational amplifiers U6A, U6B, U7A, U7B, U8A, U8B, U8C, resistors R20 to R26, diode D1, Zener diodes DZ1 and DZ2, LEDs LED1 and LED2, and capacitor C4. Operational amplifiers U6A and U6B are LM837, operational amplifiers U7A and U7B are 74HC00, and operational amplifiers U8A, U8B, and U8C are 74HC14. The anode of diode D1 is connected to pin 2 of operational amplifier U6A, forming the voltage input terminal. In the current-to-voltage conversion unit described above, the cathode of diode D1 is connected to pin 3 of operational amplifier U6A, pin 5 of operational amplifier U6B, one end of resistor R20, and one end of capacitor C4. Pin 1 of operational amplifier U6A is connected to one end of resistor R23. The other end of resistor R23 is connected to pin 5 of operational amplifier U7B, pin 1 of operational amplifier U7A, and the cathode of Zener diode DZ1. Pin 4 of operational amplifier U7B is connected to the microprocessor unit described above. Pin 6 of operational amplifier U7B is connected to pin 5 of operational amplifier U8C. Pin 6 of operational amplifier U8C is connected to the microprocessor unit described above. Pin 2 of operational amplifier U7A is connected to resistor R20. One end of resistor R24 ​​is connected to the cathode of Zener diode DZ2 and pin 1 of operational amplifier U8A. The other end of resistor R24 ​​is connected to pin 7 of operational amplifier U6B. Pin 6 of operational amplifier U6B is connected to one end of resistor R21 and one end of resistor R22. Pin 2 of operational amplifier U8A is connected to the cathode of LED2 and pin 3 of operational amplifier U8B. The anode of LED2 is connected to one end of resistor R26. Pin 4 of operational amplifier U8B is connected to the microprocessor unit. Pin 3 of operational amplifier U7A is connected to the cathode of LED1. The positive terminal of pin 1 is connected to one end of resistor R25. Pins 4 of op-amp U6A and pin 4 of op-amp U6B are connected to a +15V DC power supply. Pins 11 of op-amp U6A and pin 11 of op-amp U6B are connected to a -15V DC power supply. The other ends of resistors R25 and R26 are connected to a +5V DC power supply. Pin 14 of op-amp U7A is connected to the DC power supply VCC. The other ends of capacitor C4, resistors R20 and R21, the positive terminals of Zener diodes DZ1 and DZ2, and pin 7 of op-amp U7A are grounded together.

2. The measuring device for the dynamic response time of the attraction force of an electronic multi-arm electromagnet according to claim 1, characterized in that: The microprocessor unit includes a microprocessor U0, which uses an AT89C51 microcontroller. The isolated driver unit includes decoder chips U11, U12, and U13; drive signal chips U21, U22, and U23; Darlington transistor drivers U31, U32, and U33; and resistors R27, R28, and R29. Decoder chips U11, U12, and U13 use a 74HC138 microcontroller; drive signal chips U21, U22, and U23 use a 74HC240 microcontroller; and Darlington transistor drivers U31, U32, and U33 use a ULN2803A microcontroller. Pin 1 of decoder chips U11, U12, and U13 is connected to pin 39 of microprocessor U0. Pins 2 of decoder chips U11, U12, and U13 are connected to pin 38 of microprocessor U0; pins 3 of decoder chips U11, U12, and U13 are connected to pin 37 of microprocessor U0; pin 4 of decoder chip U11, pin 6 of decoder chip U12, and pin 5 of decoder chip U13 are connected to pin 36 of microprocessor U0; pins 5 of decoder chip U11, pin 5 of decoder chip U12, and pin 6 of decoder chip U13 are connected to pin 35 of microprocessor U0; pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U11 are connected to pins 2, 4, 6, 8, 11, 13, 15, and 17 of drive signal chip U21, respectively, driving... Pins 18, 16, 14, 12, 3, 5, 7, and 9 of signal chip U21 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of Darlington transistor driver U31, respectively. Pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U12 are connected to pins 2, 4, 6, 8, 11, 13, 15, and 17 of drive signal chip U22, respectively. Pins 18, 16, 14, 12, 3, 5, 7, and 9 of drive signal chip U22 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of Darlington transistor driver U32, respectively. Pins 15, 14, 13, 12, 11, 10, 9, and 7 of decoder chip U13 are connected to pins 2, 4, 6, 8, 11, 13, 14, 15, 16, 14, 12, 11, 10, 9, and 7 of drive signal chip U23, respectively. Pins 5 and 17, and pins 18, 16, 14, 12, 3, 5, 7, and 9 of the drive signal chip U23 are connected to pins 1, 2, 3, 4, 5, 6, 7, and 8 of the Darlington transistor driver U33, respectively. Pin 10 of the Darlington transistor driver U31 is connected to one end of resistor R27. The other end of resistor R27 is connected to one end of resistor R28 and one end of resistor R29. The other end of resistor R28 is connected to pin 10 of the Darlington transistor driver U32, and the other end of resistor R29 is connected to pin 10 of the Darlington transistor driver U33. Pins 11-18 of the Darlington transistor drivers U31, U32, and U33 constitute a 24-channel output for connecting the electromagnet coil.Pin 6 of decoder chip U11 and pin 20 of drive signal chips U21, U22, and U23 are connected to the DC power supply VCC. Pins 1, 10, and 19 of drive signal chips U21, U22, and U23, pin 4 of decoder chip U12, and pin 4 of decoder chip U13 are grounded.

3. The measuring device for the dynamic response time of the attraction force of an electronic multi-arm electromagnet according to claim 2, characterized in that: The microprocessor unit includes buttons S1 to S5. Button S1 is connected to pin 13 of the microprocessor U0, button S2 is connected to pin 14 of the microprocessor U0, button S3 is connected to pin 15 of the microprocessor U0, button S4 is connected to pin 16 of the microprocessor U0, and button S5 is connected to pin 17 of the microprocessor U0. Button S1 is used to switch between automatic and manual measurement, buttons S2 and S3 are used to input the addition and subtraction control signals of the measurement channel, and buttons S4 and S5 are used to input the addition and subtraction control signals of the measurement speed.

4. The measuring device for the dynamic response time of the attraction force of an electronic multi-arm electromagnet according to claim 1, characterized in that: The current acquisition device T1 is a Hall current sensor.

5. The measuring device for the dynamic response time of the attraction force of an electronic multi-arm electromagnet according to claim 2, characterized in that: The isolation drive unit controls the on / off state of the electromagnet coil by isolating and amplifying the signal.

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