A vehicle-mounted video acquisition device video interface switching circuit

Abstract

The utility model discloses a kind of vehicle-mounted video acquisition equipment video interface switching circuit, including main control chip, current detection module, transmission module, channel switching module, current detection module is used to detect the current of access equipment, and transmission is to main control chip;Main control chip receives the current of access equipment, sends first enable signal and receiving device protocol to channel switching module, sends second enable signal to channel switching module;Channel switching module receives first enable signal, selects the channel of receiving access equipment transmission protocol type, device protocol is transmitted to transmission module and receives second enable signal, selects the channel of receiving access equipment transmission audio and video, device audio and video are transmitted to transmission module, transmission module receives device protocol, device protocol is sent to main control chip and receiving device audio and video, and transmission is to main control chip.

Description

Technical Field

[0001] This utility model relates to the field of vehicle video switching circuits, and in particular to a video interface switching circuit for vehicle-mounted video acquisition equipment. Background Technology

[0002] With the rapid development of intelligent connected public transportation, in-vehicle video acquisition equipment is becoming increasingly diversified, encompassing heterogeneous devices such as AHD analog cameras, IPC network cameras, and USB streaming rearview mirrors. These devices enable real-time and effective monitoring of road traffic conditions. Existing public transportation vehicle systems typically configure independent video interfaces and decoding modules for each type of device, requiring numerous interfaces for connection. To address the issue of multiple interfaces, existing patents, such as application number 202410310107X (Patent Title: Video Surveillance Circuit, In-vehicle Equipment, and Signal Switching Method), primarily rely on a main control chip that detects the current of the USB port. A high current indicates a USB camera is connected, while a low current indicates an AHD analog camera. The switching of the video interface is achieved by cutting off or connecting the power supply to the AHD conversion chip. However, when a USB camera is connected, fluctuations in the camera model, power requirements, or external load can cause current spikes or waveform changes. Therefore, relying on USB current detection to determine the camera type can lead to misjudgments, resulting in failed video interface switching and an inability to display specific road traffic conditions, thus affecting vehicle safety. Utility Model Content

[0003] The purpose of this invention is to provide a video interface switching circuit for vehicle-mounted video acquisition devices that can effectively identify the type of access device and ensure the effectiveness of video interface switching, thereby improving the safety of vehicle operation.

[0004] The video interface switching circuit of the vehicle-mounted video acquisition device of this utility model includes a main control chip, a current detection module, a transmission module, and a channel switching module.

[0005] The current detection module is used to detect the current of the connected device and transmit it to the main control chip;

[0006] The main control chip receives the current from the access device and sends a first enable signal to the channel switching module; it also receives the device protocol and sends a second enable signal to the channel switching module.

[0007] The channel switching module receives a first enable signal, selects the channel for receiving the transmission protocol type of the access device, and transmits the device protocol to the transmission module; it receives a second enable signal, selects the channel for receiving audio and video transmission from the access device, and transmits the device audio and video to the transmission module.

[0008] The transmission module receives the device protocol and sends it to the main control chip; it also receives the corresponding device audio and video and transmits them to the main control chip.

[0009] The video interface switching circuit of the vehicle-mounted video acquisition device described in this utility model uses a main control chip to identify the type of access device according to the access device protocol. This enables the channel switching module to select the channel for receiving audio and video transmissions from the access device, ensuring the effectiveness of video interface switching and thus improving vehicle driving safety. Furthermore, a current detection module detects the current of the access device and transmits this current to the main control chip, enabling the channel switching module to select the channel for receiving the access device's transmission protocol type. This ensures that the channel switching module only switches channels when an access device is present, otherwise maintaining the information transmission of the current channel. This guarantees the continuity of data transmission on the current channel, thereby ensuring vehicle driving safety.

[0010] As a preferred embodiment of this utility model, the transmission module includes an AHD device transmission module, an IPC device transmission module, and a USB device transmission module; the AHD device transmission module receives the AHD device protocol, converts it into the MIPI-CSI protocol, and sends it to the main control chip; the IPC device transmission module receives the RTSP protocol of the IPC device and sends it to the main control chip; the USB device transmission module receives the USB device protocol and sends it to the main control chip.

[0011] In a preferred embodiment of this utility model, the current detection module includes a current detection sensor chip, the AHD device transmission module includes an AHD device transmission chip, the IPC device transmission module includes an IPC device transmission chip, the USB device transmission module includes a USB device transmission chip, and the channel switching module includes a channel switching chip. The current detection input pin of the current detection sensor chip is electrically connected to the current output pin of the connected device, and the current detection output pin of the current detection sensor chip is electrically connected to the current detection input pin of the main control chip. The AHD channel input pin of the channel switching chip is electrically connected to the interface of the connected AHD device, and the IPC channel input pin is electrically connected to the interface of the connected IPC device. The USB device transmission module includes a channel switching chip. The channel input pin is electrically connected to the interface of the connected USB device; the AHD channel output pin of the channel switching chip is electrically connected to the input pin of the AHD device transmission chip, the IPC channel output pin is electrically connected to the input pin of the IPC device transmission chip, and the USB channel output pin is electrically connected to the input pin of the USB device transmission chip; the enable pin of the channel switching chip is electrically connected to the enable control pin of the main control chip; the output pin of the AHD device transmission chip is electrically connected to the AHD control pin of the main control chip; the output pin of the IPC device transmission chip is electrically connected to the IPC control pin of the main control chip; and the output pin of the USB device transmission chip is electrically connected to the USB control pin of the main control chip.

[0012] As a preferred embodiment of this utility model, the output pins of the AHD device transmission chip include MIPI-CSI protocol pins and I2C bus pins, and the AHD control pins of the main control chip include MIPI-CSI protocol control pins and I2C bus control pins. The MIPI-CSI protocol pins of the AHD device transmission chip are electrically connected to the MIPI-CSI protocol control pins of the main control chip, and the I2C bus pins of the AHD device transmission chip are electrically connected to the I2C bus control pins of the main control chip.

[0013] As a preferred embodiment of this utility model, a current-limiting resistor is provided between the current detection output pin of the current detection sensor chip and the current detection input pin of the main control chip. One end of the current-limiting resistor is electrically connected to the current detection output pin of the current detection sensor chip, and the other end is electrically connected to the current detection input pin of the main control chip.

[0014] As a preferred embodiment of this utility model, a first interface protection circuit for preventing surges and overvoltage / overcurrent short circuits is provided between the current detection input pin of the current detection sensor chip and the current output pin of the connected device.

[0015] As a preferred embodiment of this utility model, the first interface protection circuit includes a resettable fuse and a TVS transient suppression transistor. One end of the resettable fuse is electrically connected to the current output pin of the connected device, and the other end is electrically connected to one end of the TVS transient suppression transistor and the current detection input pin of the current detection sensor chip. The other end of the TVS transient suppression transistor is grounded.

[0016] As a preferred embodiment of this utility model, a second interface protection circuit for anti-static protection is provided between the AHD channel input pin of the channel switching chip and the connected AHD device interface, between the IPC channel input pin and the connected IPC device interface, and between the USB channel input pin and the connected USB device interface.

[0017] As a preferred embodiment of this utility model, the second interface protection circuit includes an ESD protection tube.

[0018] As a preferred embodiment of this utility model, it also includes a power management module that provides power to the main control chip, current detection module, transmission module, and channel switching module. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the video interface switching circuit of the vehicle-mounted video acquisition device of this utility model;

[0020] Figure 2 The circuit diagram for power management chip U1;

[0021] Figure 3 The circuit diagram for power management chip U2;

[0022] Figure 4 The circuit diagram for power management chip U3;

[0023] Figure 5 The circuit diagram shows the current detection sensor chip U4 and the channel switching chip U5.

[0024] Figure 6 The circuit diagram of the main control chip U6;

[0025] Figure 7 Circuit diagram for the U7 chip used in AHD devices;

[0026] Figure 8 Circuit diagram for the U8 chip used for transmitting data to IPC devices;

[0027] Figure 9 Circuit diagram of chip U9 for USB device transmission. Detailed Implementation

[0028] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] A video interface switching circuit for a vehicle-mounted video acquisition device, such as Figure 1 As shown, the system includes a main control chip, a current detection module, a transmission module, and a channel switching module. The current detection module detects the current of the access device and transmits it to the main control chip. The main control chip receives the current from the access device and sends a first enable signal to the channel switching module; it also receives the device protocol and sends a second enable signal to the channel switching module. The channel switching module receives the first enable signal, selects the channel for receiving the access device's transmission protocol type, and transmits the device protocol to the transmission module; it also receives the second enable signal, selects the channel for receiving audio and video transmissions from the access device, and transmits the device's audio and video to the transmission module. The transmission module receives the device protocol, sends the device protocol to the main control chip, and receives and transmits the device's audio and video to the main control chip. A power management module provides power to the main control chip, current detection module, transmission module, and channel switching module.

[0030] The transmission module includes an AHD device transmission module, an IPC device transmission module, and a USB device transmission module. The current detection module includes a current detection sensor chip U4. The AHD device transmission module includes an AHD device transmission chip U7. The IPC device transmission module includes an IPC device transmission chip U8. The USB device transmission module includes a USB device transmission chip U9. The channel switching module includes a channel switching chip U5.

[0031] like Figures 2-4 As shown, the power management module includes power management chips U1, U2, and U3. Power management chip U1 converts 12V DC power to 5V DC power to provide power to the current detection sensor chip, main control chip, channel switching chip, and USB device transmission chip. Power management chip U2 converts 12V to 3.3V DC power to provide power to the AHD device transmission chip and IPC device transmission chip. Power management chip U3 converts 12V to 1.1V DC power to provide power to the AHD device transmission chip and IPC device transmission chip.

[0032] like Figure 5 and Figure 6As shown, the current detection input pin IP- of the current detection sensor chip U4 is electrically connected to the current output pin of the access device, and the current detection output pin CURR of the current detection sensor chip is electrically connected to the current detection input pin CURR of the main control chip U6. The current detection module detects the current of the access device and then transmits this current to the main control chip. The enabled channel switching module selects the channel that receives the access device's transmission protocol type. This ensures that the channel switching module only switches channels when an access device is present; otherwise, it maintains the information transmission of the current channel, thus guaranteeing the continuity of data transmission and consequently ensuring vehicle driving safety.

[0033] A first interface protection circuit is provided between the current detection input pin of the current sensing sensor chip and the current output pin of the connected device to prevent surges, overvoltages, overcurrents, and short circuits. This first interface protection circuit includes a resettable fuse F1 and a TVS transient voltage suppressor (TVS) diode TVSD1. One end of the resettable fuse is electrically connected to the current output pin of the connected device, and the other end is electrically connected to one end of the TVS diode and the current detection input pin of the current sensing sensor chip. The other end of the TVS diode is grounded. The resettable fuse F1 and TVS diode TVSD1 provide dual protection. The resettable fuse F1 cuts off the power supply when the current exceeds 2A, thus preventing short-circuit impacts on internal components. The resettable fuse F1 is connected in series with the VCC power supply link; it cuts off the circuit after being triggered by an abnormal current and automatically resets after the fault is cleared. The TVS diode TVSD1 can withstand 10 / 1000µs surge protection with 30kV and a response time of less than 1µs.

[0034] In addition, a current-limiting resistor R1 is provided between the current detection output pin CURR of the current detection sensor chip U4 and the current detection input pin CURR of the main control chip U6. One end of the current-limiting resistor is electrically connected to the current detection output pin of the current detection sensor chip, and the other end is electrically connected to the current detection input pin of the main control chip. The current-limiting resistor R1 provides a stable current to the main control chip, preventing excessively rapid current changes, thereby reducing circuit fluctuations and interference.

[0035] like Figure 5As shown, a second interface protection circuit for electrostatic discharge (ESD) is provided between the AHD channel input pins of the channel switching chip U5 and the connected AHD device interface, between the IPC channel input pins and the connected IPC device interface, and between the USB channel input pins and the connected USB device interface. The second interface protection circuit includes ESD protection transistors ESD1, ESD2, ESD3, and ESD4. These ESD protection transistors effectively prevent ESD generation on the AHD channel input pins AHD / IPC-TX+, IPC channel input pins PC-TX-, IPC-RX-, and IPC-RX+, and the USB channel input pins USBDM and USBDP of the channel switching chip.

[0036] like Figures 5-9 As shown, the enable pins SEL1 and SEL2 of the channel switching chip U5 are electrically connected to the enable control pins SEL1 and SEL2 of the main control chip U6. The AHD channel output pin AHD of the channel switching chip is electrically connected to the input pin AHD of the AHD device transmission chip U7. The IPC channel output pins IPCTX-, IPCTX+, IPCRX-, and IPCRX+ are electrically connected to the input pins IPCTX-, IPCTX+, IPCRX-, and IPCRX+ of the IPC device transmission chip U8. The USB channel output pins USBDM and USBDP are electrically connected to the input pins USBDM and USBDP of the USB device transmission chip U9.

[0037] The MIPI-CSI protocol pins PR1_D0_N, PR1_D0_P, PR1_D1_N, PR1_D1_P, PR1_CLK_N, and PR1_CLK_P of the AHD device transmission chip U7 are electrically connected to the MIPI-CSI protocol control pins PR1_D0_N, PR1_D0_P, PR1_D1_N, PR1_D1_P, PR1_CLK_N, and PR1_CLK_P of the main control chip. The I2C bus pins PR_SCL and PR_SDA of the AHD device transmission chip are electrically connected to the I2C bus control pins PR_SCL and PR_SDA of the main control chip.

[0038] The output pins RKRX1_P, RKRX1_N, RKTX1_N, and RKTX1_P of the IPC device transmission chip U8 are electrically connected to the IPC control pins RKRX1_P, RKRX1_N, RKTX1_N, and RKTX1_P of the main control chip.

[0039] The output pins RKUSB_DP and RKUSB_DM of the USB device transmission chip U9 are electrically connected to the USB control pins RKUSB_DP and RKUSB_DM of the host control chip.

[0040] The current sensing sensor chip U4 reads the current of the access device through the current sensing input pin IP- and transmits this current to the current sensing input pin CURR of the main control chip U6 through the current sensing output pin CURR. Based on the received current value, the main control chip U6 sends a first enable signal to the enable pins SEL1 and SEL2 of the channel switching chip U5 through the enable control pins SEL1 and SEL2. This enables the channel switching chip U5 to select the channel that receives the access device's transmission protocol type. When the access device's transmission protocol type is AHD device protocol, the channel switching chip U5 selects the AHD channel input pin AHD / IPC-TX+ to receive the AHD device protocol from the AHD access camera. The AHD output pin AHD of the channel switching chip U5 transmits the data to the AHD device transmission chip via the input pin AHD of the AHD device transmission chip U7. The AHD device transmission chip converts the data to the MIPI-CSI protocol and sends it to the main control chip. The main control chip sends a second enable signal to the enable pins SEL1 and SEL2 of the channel switching chip U5 via the enable control pins SEL1 and SEL2. The channel switching chip then switches the AHD channel input pin AHD / IPC-TX+ to receive the audio and video transmitted from the AHD access camera. When the access device's transmission protocol type is RTSP, the channel switching chip U5 selects the IPC channel input pins PC-TX-, IPC-RX-, and IPC-RX+ to receive the RTSP protocol from the IPC access camera. The IPC channel output pins IPCTX-, IPCTX+, IPCRX-, and IPCRX+ of the channel switching chip U5 transmit the data to the IPC device transmission chip via the input pins IPCTX-, IPCTX+, IPCRX-, and IPCRX+ of the IPC device transmission chip U8. The IPC device transmission chip then sends the data to the main control chip. The main control chip sends a second enable signal to the enable pins SEL1 and SEL2 of the channel switching chip U5 via the enable control pins SEL1 and SEL2. The channel switching chip then switches the IPC channel input pins PC-TX-, IPC-RX-, and IPC-RX+ to receive the audio and video transmitted from the IPC access camera. When the access device's transmission protocol type is USB device protocol, the channel switching chip U5 selects the USB channel input pins USBDM and USBDP to receive the USB device protocol from the USB access camera. The USB channel output pins USBDM and USBDP of the channel switching chip U5 are transmitted to the USB device transmission chip through the input pins USBDM and USBDP of the USB device transmission chip U9. The USB device transmission chip then sends the data to the main control chip. The main control chip sends a second enable signal to the enable pins SEL1 and SEL2 of the channel switching chip U5 through the enable control pins SEL1 and SEL2. The channel switching chip then switches the USB channel input pins USBDM and USBDP to receive the audio and video transmitted from the USB access camera.This ensures the effectiveness of video interface switching, thereby improving vehicle driving safety.

[0041] The above embodiments are only used to illustrate the detailed solution of this utility model. This utility model is not limited to the above detailed solution, that is, it does not mean that this utility model must rely on the above detailed solution to be implemented. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of the raw materials of this utility model product, addition of auxiliary components, selection of specific methods, etc., are all within the protection scope and disclosure scope of this utility model.

Claims

1. A video interface switching circuit for a vehicle-mounted video acquisition device, characterized in that, Includes the main control chip (U6), current detection module, transmission module, and channel switching module; The current detection module is used to detect the current of the connected device and transmit it to the main control chip; The main control chip receives the current from the access device and sends the first enable signal to the channel switching module; Receive device protocol and send a second enable signal to the channel switching module; The channel switching module receives the first enable signal, selects the channel that receives the transmission protocol type of the access device, and transmits the device protocol to the transmission module. Upon receiving the second enable signal, select the channel for receiving audio and video transmission from the access device, and transmit the device's audio and video to the transmission module; The transmission module receives the device protocol and sends it to the main control chip; it also receives the device's audio and video and transmits them to the main control chip.

2. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 1, characterized in that, The transmission modules include an AHD device transmission module, an IPC device transmission module, and a USB device transmission module; The AHD device transmission module receives the AHD device protocol, converts it into the MIPI-CSI protocol, and sends it to the main control chip. The IPC device transmission module receives RTSP protocol data from the IPC device and sends it to the main control chip. The USB device transmission module receives USB device protocols and sends them to the main control chip.

3. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 2, characterized in that, The current detection module includes a current detection sensor chip (U4), the AHD device transmission module includes an AHD device transmission chip (U7), the IPC device transmission module includes an IPC device transmission chip (U8), the USB device transmission module includes a USB device transmission chip (U9), and the channel switching module includes a channel switching chip (U5). The current detection input pin of the current detection sensor chip is electrically connected to the current output pin of the connected device, and the current detection output pin of the current detection sensor chip is electrically connected to the current detection input pin of the main control chip. The AHD channel input pin of the channel switching chip is electrically connected to the interface of the connected AHD device, the IPC channel input pin is electrically connected to the interface of the connected IPC device, and the USB channel input pin is electrically connected to the interface of the connected USB device; the AHD channel output pin of the channel switching chip is electrically connected to the input pin of the AHD device transmission chip, the IPC channel output pin is electrically connected to the input pin of the IPC device transmission chip, and the USB channel output pin is electrically connected to the input pin of the USB device transmission chip; the enable pin of the channel switching chip is electrically connected to the enable control pin of the main control chip. The output pin of the AHD device transmission chip is electrically connected to the AHD control pin of the main control chip. The output pin of the IPC device transmission chip is electrically connected to the IPC control pin of the main control chip; The output pin of the USB device transmission chip is electrically connected to the USB control pin of the main control chip.

4. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 3, characterized in that, The output pins of the AHD device transmission chip include MIPI-CSI protocol pins and I2C bus pins. The AHD control pins of the main control chip include MIPI-CSI protocol control pins and I2C bus control pins. The MIPI-CSI protocol pins of the AHD device transmission chip are electrically connected to the MIPI-CSI protocol control pins of the main control chip, and the I2C bus pins of the AHD device transmission chip are electrically connected to the I2C bus control pins of the main control chip.

5. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 3, characterized in that, A current-limiting resistor (R1) is provided between the current detection output pin of the current detection sensor chip and the current detection input pin of the main control chip. One end of the current-limiting resistor is electrically connected to the current detection output pin of the current detection sensor chip, and the other end is electrically connected to the current detection input pin of the main control chip.

6. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 3, characterized in that, A first interface protection circuit is provided between the current detection input pin of the current detection sensor chip and the current output pin of the connected device to prevent surges, overvoltages, overcurrents and short circuits.

7. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 6, characterized in that, The first interface protection circuit includes a resettable fuse (F1) and a TVS transient suppressor (TVSD1). One end of the resettable fuse is electrically connected to the current output pin of the connected device, and the other end is electrically connected to one end of the TVS transient suppressor and the current detection input pin of the current detection sensor chip. The other end of the TVS transient suppressor is grounded.

8. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 3, characterized in that, A second interface protection circuit for electrostatic discharge protection is provided between the AHD channel input pin of the channel switching chip and the connected AHD device interface, between the IPC channel input pin and the connected IPC device interface, and between the USB channel input pin and the connected USB device interface.

9. The video interface switching circuit of the vehicle-mounted video acquisition device according to claim 8, characterized in that, The second interface protection circuit includes an ESD protection diode.

10. The video interface switching circuit of the vehicle-mounted video acquisition device according to any one of claims 1-9, characterized in that, It also includes a power management module that provides power to the main control chip, current detection module, transmission module, and channel switching module.

Images