High-precision CCD sensor and metal strip edge position detection system

Abstract

The utility model provides a kind of high-precision CCD sensor and metal plate strip edge position detection system, wherein, CCD sensor includes: linear array CCD chip, towards metal plate strip direction detection, obtain including the analog detection signal of metal plate strip edge;For the analog detection signal of linear array CCD chip is sampled and converted into digital detection signal AD signal sampling chip, AD signal sampling chip is connected with linear array CCD chip;For respectively driving linear array CCD chip and AD signal sampling chip FPGA chip, FPGA chip is connected with linear array CCD chip and AD signal sampling chip respectively;The MCU chip of interpolation processing generation detection result to digital detection signal, MCU chip is connected with FPGA chip, and for achieving and outside equipment communication communication interface, communication interface is connected with MCU chip. Real-time, high-precision detection to metal plate strip edge position can be realized.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, and in particular to a high-precision CCD sensor and a metal strip edge position detection system. Background Technology

[0002] In the production and processing of non-ferrous metal strips, metal strips run at high speeds on continuous production lines. The winding system then moves the winding mechanism to the corresponding position based on the real-time position of the metal strip, achieving edge-to-edge winding. However, due to various factors such as production installation and strip tension, the strip may deviate from its fixed position on the production line, affecting the winding process. Therefore, high-speed real-time position detection of the metal strip is crucial in this process. Utility Model Content

[0003] To overcome the above shortcomings, this utility model provides a high-precision CCD sensor and a metal strip edge position detection system, which can realize real-time, high-precision detection of the edge position of metal strips.

[0004] The technical solution provided by this utility model is as follows:

[0005] On the one hand, this utility model provides a high-precision CCD sensor for detecting the position of a metal strip, the high-precision CCD sensor comprising:

[0006] A linear CCD chip is positioned above a metal strip and detects in the direction of the metal strip to obtain an analog detection signal including the edge of the metal strip.

[0007] An AD signal sampling chip is used to sample and convert the analog detection signal of the linear CCD chip into a digital detection signal, and the AD signal sampling chip is connected to the linear CCD chip.

[0008] An FPGA chip is used to drive the linear CCD chip and the AD signal sampling chip respectively, and the FPGA chip is connected to the linear CCD chip and the AD signal sampling chip respectively.

[0009] An MCU chip performs interpolation processing on the digital detection signal to generate the detection result; the MCU chip is connected to the FPGA chip.

[0010] A communication interface for communicating with external devices, the communication interface being connected to the MCU chip.

[0011] On the other hand, this invention provides a metal strip edge position detection system, wherein the metal strip runs on guide rollers, and the metal strip edge position detection system includes:

[0012] The high-precision CCD sensor mentioned above is positioned above the metal strip and performs position detection in the direction of the metal strip.

[0013] A light source device is positioned below the metal strip and emits light in the direction of the metal strip; and

[0014] A display screen for displaying detection data from a high-precision CCD sensor, the display screen being connected to the high-precision CCD sensor.

[0015] The high-precision CCD sensor and metal strip edge position detection system provided by this utility model can achieve at least the following beneficial effects:

[0016] 1) After obtaining the initial digital detection signal by driving the high-speed CCD chip and AD signal sampling chip through the FPGA chip, the MCU chip is further used for interpolation optimization to obtain a high-precision strip edge position signal with a resolution of 30,000 points, thereby improving the detection accuracy of the metal strip edge position and enabling the rapid output of the metal strip signal.

[0017] 2) By symmetrically setting detection light sources and CCD sensors below and above the metal strip, respectively, and applying them to the dual CCD width measuring instrument scenario, real-time detection of the edge position of the metal strip can be achieved, thereby realizing accurate detection of the width of the metal strip and the crescent-shaped notch.

[0018] 3) Configure a human-machine interface (display screen) for the CCD sensor for stand-alone debugging and testing. This allows the CCD sensor to be debugged and calibrated without the need to connect to the correction controller, providing accurate and fast detection of the metal strip edge position for the correction control system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the high-precision CCD sensor structure of this utility model;

[0020] Figure 2 This is a schematic diagram of one embodiment of the metal strip edge position detection system of this utility model;

[0021] Figure 3 This is a schematic diagram of another embodiment of the metal strip edge position detection system of this utility model.

[0022] Figure label:

[0023] 10-High-precision CCD sensor, 11-Linear CCD chip, 12-AD signal sampling chip, 13-FPGA chip, 14-MCU chip, 15-Communication interface, 16-First CCD sensor, 17-Second CCD sensor, 20-Metal strip, 30-Light source device, 31-First light source device, 32-Second light source device. Detailed Implementation

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0025] This invention relates to a high-precision CCD sensor 10 for detecting the position of a metal strip. For example... Figure 1 As shown, the high-precision CCD sensor 10 includes: a linear CCD chip 11, disposed above a metal strip, detecting in the direction of the metal strip to obtain an analog detection signal including the edge of the metal strip; an AD signal sampling chip 12 for sampling and converting the analog detection signal of the linear CCD chip 11 into a digital detection signal, the AD signal sampling chip 12 being connected to the linear CCD chip 11; an FPGA chip 13 for driving the linear CCD chip 11 and the AD signal sampling chip 12 respectively, the FPGA chip 13 being connected to the linear CCD chip 11 and the AD signal sampling chip 12 respectively; an MCU chip 14 for interpolating the digital detection signal to generate a detection result, the MCU chip 14 being connected to the FPGA chip 13; and a communication interface 15 for communicating with external devices, the communication interface 15 being connected to the MCU chip 14.

[0026] In this CCD sensor 10, the selection of the linear CCD chip 11 can be based on the actual application, such as using a Toshiba high-precision linear CCD chip 11. When applied to the detection of high-speed metal strips, not only high accuracy but also fast detection response time are required. In addition to selecting the high-precision linear CCD chip 11, a high-speed AD signal sampling chip 12 must also be selected for cooperation. After the FPGA chip 13 drives the high-speed linear CCD chip 11 and the AD signal sampling chip 12 to obtain the initial analog signal, the precise edge position of the strip is obtained through the MCU chip 14. Finally, the strip signal is quickly output to the external controller through the digital communication interface 15. After the controller receives the edge signal of the metal strip, the relevant actuators of the controller act to push the metal strip to the predetermined position.

[0027] In one example, the selection of chips in a high-precision CCD sensor is as follows:

[0028] The linear CCD chip used is a Toshiba high-precision linear CCD chip (resolution of 5000).

[0029] The AD signal sampling chip used is the AD9822 chip. The AD9822 is a complete analog signal processor suitable for CCD imaging applications, featuring a 3-channel architecture designed for sampling and conditioning the output of a three-line color CCD array. Each channel consists of an input clamp, a correlated dual sampler (CDS), an offset DAC, and a programmable gain amplifier (PGA), multiplexed to a high-performance 14-bit analog-to-digital converter.

[0030] The FPGA chip used is the XC6SLX16 / 25. The Spartan6 series is a low-cost, high-capacity FPGA that employs 45nm low-power copper plating technology, achieving a good balance between power consumption, performance, and cost. Internally, the Spartan6 series features a dual-register, 6-input LUT, and a series of built-in system-level modules. These modules include 18Kb Block RAM, a second-generation DSP48A21 slice, an SDRAM memory interface (DDR interface), a robust hybrid clock management module, SelectIO technology, an optimized high-speed serial transceiver (GTP), a PCIe interface, advanced system-level power management modes, automatic configuration detection, and enhanced IP with AES and Device DNA protection. The Spartan6 is particularly suitable for high-capacity logic designs, user-oriented DSP designs, and low-cost designs.

[0031] The MCU chip selected is the STM32F407, a high-performance microcontroller based on the ARM Cortex-M4 core from STMicroelectronics. It utilizes a 90nm NVM process and ART (Adaptive Real-Time Memory Accelerator) technology, boasting powerful performance and abundant peripheral resources.12 Key features include: 1) Memory and Storage: The STM32F407 has 1MB of built-in Flash memory and 192KB of SRAM, sufficient for most application needs. 2) Clock Frequency: After PLL multiplication, the clock frequency can reach 168MHz. The chip incorporates a 16MHz high-speed crystal oscillator and a 32kHz low-speed crystal oscillator. 3) ADC and DAC: Equipped with three 12-bit fast ADCs, each with multiple channels, which can be used in combination. Additionally, there are two 12-bit DACs. 4) DMA Controller: It has two DMA controllers, each with multiple channels, enabling different data transfer needs such as peripheral-to-memory and memory-to-periphery transfers. 5) Timers: Provides up to 17 timers, including two 32-bit timers, with a timer frequency up to 168MHz. 6) GPIO: Up to 120 GPIOs, each multiplexed as a different peripheral pin. 7) Communication Interfaces: Built-in interfaces for multiple communication protocols including I2C, SPI, USART, I2S, CAN, and SDIO; provides up to 6 serial ports, with a fractional baud rate generator, supports synchronous single-wire and half-duplex single-wire communication, LIN support, modem operation support, smart card protocol and IrDASIRENDEC specification, and DMA functionality. The FSMC (Flexible Static Memory Controller) is an important feature of the STM32F407 microcontroller. It primarily drives SRAM, NOR FLASH, and NAND FLASH memory types. The FSMC provides a communication interface with external memory, allowing the STM32F407 to expand its storage capacity.

[0032] The MCU chip communicates with the FPGA chip via the FSMC interface. FSMC is a new memory expansion technology used in the STM32 series. It has unique advantages in external memory expansion, allowing for easy expansion of different types of large-capacity static memory according to the application needs of the system. Features of FSMC include: 1) Support for asynchronous read and write operations with different bit widths; 2) Different banks are independent in the mapped address space, which can be used to expand different memories; 3) Support for code to run directly from the external memory expanded by FSMC.

[0033] This CCD sensor incorporates FSMC technology, forming a dual-core FPGA+MCU hardware platform. The FPGA and MCU chips are assigned different tasks: the FPGA chip drives the linear CCD chip and acquires image signals, while the MCU chip receives the large amount of image data from the FPGA chip via the high-speed FSMC interface. Using C language, an efficient interpolation optimization algorithm is written to process the image data, obtaining a position detection signal with a resolution of 30,000. After calculating the board position signal, it is quickly output via a digital communication interface. Any existing interpolation algorithm can be used, such as nearest neighbor or linear interpolation; no specific limitation is made, and the appropriate algorithm is selected based on actual needs.

[0034] In the MCU chip, the detection process for the edge position of the metal strip is as follows: In each scan cycle, the FPGA chip drives the linear CCD chip to acquire 5000 pixel values. After interpolating to obtain 30000 points, starting from the first pixel value, it continuously compares it with the 2nd, 3rd, ..., 30000th pixel values. When a sudden change occurs between two consecutive pixel values, and one pixel value is greater than a set threshold while the other is less than a set threshold, the current pixel is determined to be the edge detection signal point. It should be understood that the number of pixel values ​​obtained by interpolation in the MCU chip can be set according to actual needs, and is not specifically limited here. In other embodiments, it can also be configured to 10000, 20000, or even more.

[0035] This high-precision CCD sensor can be applied in the winding process of metal strips. By sampling the edge signals of the metal strip with high precision, it further improves the winding effect. Additionally, the high-precision CCD sensor can also be used in dual-CCD width measuring instruments. Due to the increased resolution and detection accuracy of the CCD sensor, the width measurement accuracy of the metal strip can be improved. Width measurement is determined based on the edge position of the metal strip; a high-resolution CCD sensor can improve edge detection accuracy, ultimately improving the measurement accuracy of the strip width. Furthermore, this CCD sensor can also be used to detect crescent-shaped defects in metal strips. On production lines, two crescent-shaped features are typically cut on both sides of the metal strip to indicate specific positions. On the metal strip production line, it is necessary to detect the position of these crescents. By using dual CCDs to detect abrupt changes in the width of the metal strip, the position of the crescents is determined, and the signal is output to the production line to control the relevant equipment.

[0036] This utility model also provides a metal strip edge position detection system, wherein the metal strip runs on guide rollers, such as... Figure 2As shown, the metal strip edge position detection system includes: a high-precision CCD sensor 10 as described above, disposed above the metal strip 20, for position detection in the direction of the metal strip; a light source device 30, disposed below the metal strip 20, for emitting light in the direction of the metal strip 20; and a display screen for displaying the detection data of the high-precision CCD sensor 10, the display screen being connected to the high-precision CCD sensor 10.

[0037] For ease of debugging, this system is equipped with a human-machine interface (display screen) for stand-alone debugging and testing. Sensors can be debugged and calibrated without needing to be connected to the web correction controller. This provides accurate and rapid detection of the strip position for the web correction control system.

[0038] To go further, such as Figure 3 As shown, the light source device includes a first light source device 31 and a second light source device 32, which are symmetrically arranged on both sides of the metal strip 20 below the metal strip. Each of them includes a detection light source and emits light towards one side edge of the metal strip. The high-precision CCD sensor includes a first CCD sensor 16 and a second CCD sensor 17, which are symmetrically arranged on both sides of the metal strip 20 above the metal strip. The first CCD sensor 16 is matched with the first light source device 31, and the second CCD sensor 17 is matched with the second light source device 32 to detect the edge position of the metal strip on the corresponding side.

[0039] The first light source device provides light to the first CCD sensor, and the second light source device provides light to the second CCD sensor. The detection light sources in both devices are symmetrically fixed below the metal strip (to avoid the guide rollers blocking the light source, the detection light source is placed in the area between the guide rollers), emitting light towards the metal strip. The linear CCD chips in the two CCD sensors detect the metal strip in real time based on the light source devices, and then achieve the detection purpose based on the detection results. The fixing method of the two light source devices and CCD sensors can be determined according to the actual situation, and no specific limitation is made here. In the first and second light source devices, the detection light source is a light strip including multiple LED chips.

[0040] The first and second CCD sensors acquire the position signal of the strip edge and send it to the display screen (not shown in the figure) for display. Simultaneously, the display screen records the strip data for an extended period, saving it to a USB drive for later reading or parameter configuration via the display screen.

[0041] To ensure that the linear CCD chips in the two CCD sensors can measure stable and linear plate edge position signals, the stability of the corresponding detection light source needs to be guaranteed. In addition to the detection light source, the two light source devices also include: a light intensity detection chip for detecting the light intensity emitted by the detection light source; a CPU processor for processing the light intensity signal detected by the light intensity detection chip to generate a light source control signal, the CPU processor being connected to the light intensity detection chip; and an LED driver chip for driving the light emitted by the detection light source according to the light source control signal generated by the CPU processor, the LED driver chip being connected to both the CPU processor and the detection light source.

[0042] During operation, the two CCD sensors use a light intensity detection chip to detect the light intensity of the light source at a certain frequency. The CPU processor receives the light intensity signal and compares it with a preset light intensity. If the difference between the received light intensity and the preset light intensity exceeds a preset range, a light source control signal is generated and sent to the LED driver chip. The LED driver chip then drives the detection light source to emit light using PWM, resulting in a stable detection light source. In practical applications, the detection light sources in both light source devices are light strips containing multiple LED chips. The length and light-emitting area of ​​the light strip are determined by the area of ​​the metal plate and the detection area of ​​the linear CCD chip, ensuring at least coverage of the edge area of ​​the metal plate. To improve detection accuracy, adjustments can be made as needed. For example, in one instance, the light strip is set to be 1 meter long and 20-30 millimeters wide. Furthermore, the distances between the detection light sources and the two CCD sensors and the metal plate are not specifically limited and can be adjusted according to actual detection requirements.

[0043] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this utility model. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A high-precision CCD sensor, characterized in that, The high-precision CCD sensor, used for detecting the position of metal strips, includes: A linear CCD chip is positioned above a metal strip and detects in the direction of the metal strip to obtain an analog detection signal including the edge of the metal strip. An AD signal sampling chip is used to sample and convert the analog detection signal of the linear CCD chip into a digital detection signal, and the AD signal sampling chip is connected to the linear CCD chip. An FPGA chip is used to drive the linear CCD chip and the AD signal sampling chip respectively, and the FPGA chip is connected to the linear CCD chip and the AD signal sampling chip respectively. An MCU chip performs interpolation processing on the digital detection signal to generate the detection result; the MCU chip is connected to the FPGA chip. A communication interface for communicating with external devices, the communication interface being connected to the MCU chip.

2. The high-precision CCD sensor as described in claim 1, characterized in that, The linear CCD chip has a resolution of 5000, and the MCU chip performs interpolation processing on the digital detection signal to obtain a position detection signal with a resolution of 30000.

3. The high-precision CCD sensor as described in claim 1 or 2, characterized in that, The MCU chip communicates with the FPGA chip through the FSMC interface.

4. A metal strip edge position detection system, characterized in that, The metal strip runs on guide rollers, and the metal strip edge position detection system includes: The high-precision CCD sensor as described in any one of claims 1-3 is disposed above the metal strip and performs position detection in the direction of the metal strip; A light source device is positioned below the metal strip and emits light in the direction of the metal strip; and A display screen for displaying detection data from a high-precision CCD sensor, the display screen being connected to the high-precision CCD sensor.

5. The metal strip edge position detection system as described in claim 4, characterized in that, The light source device includes a first light source device and a second light source device, which are symmetrically arranged on both sides of the metal strip below the metal strip. Each device contains a detection light source and emits light towards one side edge of the metal strip. The high-precision CCD sensor includes a first CCD sensor and a second CCD sensor, which are symmetrically arranged on both sides of the metal strip above the metal strip. The first CCD sensor is matched with the first light source device, and the second CCD sensor is matched with the second light source device to detect the edge position of the metal strip on the corresponding side.

6. The metal strip edge position detection system as described in claim 5, characterized in that, In the first light source device and the second light source device, the detection light source is a light strip comprising multiple LED chips.

7. The metal strip edge position detection system as described in claim 5, characterized in that, The first light source device and the second light source device further include: A light intensity detection chip used to detect the light intensity emitted by a light source; A CPU processor is used to process the light intensity signal detected by the light intensity detection chip to generate a light source control signal, and the CPU processor is connected to the light intensity detection chip. An LED driver chip is used to drive the detection light source to emit light according to the light source control signal generated by the CPU processor. The LED driver chip is connected to both the CPU processor and the detection light source.

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