Data reading circuit of vehicle driving recorder

Abstract

This utility model provides a data reading circuit for a vehicle-mounted driving recorder, including: a USB port for connecting to an external data reading device via a USB cable, the USB port having a power input pin; a power conversion module including a first power management unit connected to the power input pin and a second power management unit connected to the vehicle power supply; a power management module for turning off the first power management unit and starting the second power management unit when the vehicle power supply output is normal, and turning on the first power management unit and turning off the second power management unit when the vehicle power supply output is abnormal; and a data management module for powering on using the supply voltage output by the first or second power management unit, and interacting with the external data reading device via the USB port and USB cable. This embodiment offers convenient data reading, enabling simultaneous power supply and data reading using the USB port.

Description

Technical Field

[0001] This utility model relates to the field of vehicle recorder technology, and in particular to a data reading circuit for a vehicle driving recorder. Background Technology

[0002] To record vehicle data in real time, vehicles are usually equipped with onboard driving recorders. In the event of an accident, the vehicle driving data stored in the onboard driving recorder can be read to identify and analyze the accident.

[0003] One existing method for reading data from a vehicle-mounted driving recorder involves using a vehicle power supply (e.g., a vehicle battery) to power the recorder via a vehicle power supply harness. Then, an external data reading device (e.g., a computer) interacts with the recorder via a vehicle Ethernet communication module to read the data.

[0004] However, the inventors found in practice that the above data reading method requires the construction of complex data communication and power supply lines, making the operation relatively complicated and the cost relatively high. Utility Model Content

[0005] The technical problem to be solved by this utility model embodiment is to provide a data reading circuit for a vehicle driving recorder, which facilitates data reading and can simultaneously achieve power supply and data reading using a USB port.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a data reading circuit for a vehicle-mounted driving recorder, comprising:

[0007] A USB port is provided for connecting to an external data reading device via a USB cable harness to read data from the vehicle driving recorder. The USB port is provided with a power input pin for interfacing with the power supply terminal of the USB cable harness to obtain a first power supply voltage from the external data reading device.

[0008] The power conversion module includes a first power management unit connected to the power input pin for processing and outputting the first power supply voltage, and a second power management unit connected to the vehicle power supply for processing and outputting the second power supply voltage output by the vehicle power supply.

[0009] A power management module, connected to the power input pin, the output terminal of the vehicle power supply, the first power management unit, and the second power management unit, is used to shut down the first power management unit and start the second power management unit when the vehicle power supply output is normal, and to turn on the first power management unit and shut down the second power management unit when the vehicle power supply output is abnormal; and

[0010] The data management module is connected to the USB port, the first power management unit, and the second power management unit, respectively. It is used to power on and start using the power supply voltage output by the first power management unit or the second power management unit, and to interact with the external data reading device via the USB port and the USB cable.

[0011] Furthermore, the power management module has a first voltage acquisition pin connected to the power input pin to monitor whether the power input pin has an output voltage, and a second voltage acquisition pin connected to the output terminal of the vehicle power supply to monitor whether the vehicle power supply is outputting a normal voltage; the power management module is connected to the data management module to control the data management module to power on and start when at least one of the output terminal of the vehicle power supply and the power input pin is detected to have an output voltage.

[0012] Furthermore, the USB port is also provided with a voltage feedback pin for reflecting the status of the first power supply voltage. The power management module is also provided with a third voltage acquisition pin connected to the voltage feedback pin to obtain the actual voltage value of the first power supply voltage. When the vehicle power supply output is abnormal and the power input pin has an output voltage, the power management module determines whether the actual voltage value is greater than a preset voltage threshold. If so, the first power management unit is turned on and the second power management unit is turned off.

[0013] Furthermore, the third voltage acquisition pin is also connected to the ground terminal through the first resistor R1.

[0014] Furthermore, the data reading circuit also includes:

[0015] The data communication module, which is connected to both the data management module and the vehicle body data transmission system, is used to interact with the vehicle body data transmission system under the control of the data management module.

[0016] Furthermore, the data communication module is an Ethernet data communication module.

[0017] Furthermore, the data reading circuit also includes:

[0018] A voltage regulator module has its input terminals connected to the vehicle power supply and the power input pin respectively via a first diode D1 and a second diode D2, and its output terminal connected to the power management module. It is used to convert the output voltage of the vehicle power supply or the power input pin into a second predetermined voltage to power the power management module. The anode of the first diode D1 is connected to the vehicle power supply and the cathode is connected to the voltage regulator module, and the anode of the second diode D2 is connected to the power input pin and the cathode is connected to the voltage regulator module.

[0019] Furthermore, the regulated power supply module is an LDO linear regulator or a DC-DC voltage conversion circuit.

[0020] Furthermore, the data management module includes:

[0021] A data management chip, connected to the USB port and the data communication module, is used for data interaction with the external data reading device via the USB port, and for data interaction with the vehicle body data transmission system via the data communication module; and

[0022] The chip power management unit is connected to the power management module, the first power management unit, the second power management unit, and the data management chip, respectively. It is used to be powered on by the power management module to supply power to the data management chip using the power supply voltage output by the first power management unit or the second power management unit.

[0023] Furthermore, the first power management unit includes a transistor Q1, a first MOSFET Q2, and a second MOSFET Q3, wherein:

[0024] The base of transistor Q1 is connected to the power management module. The collector of transistor Q1 is connected to the gate of the first MOSFET Q2 and the gate of the second MOSFET Q3, respectively, and is connected to the source of the first MOSFET Q2 and the source of the second MOSFET Q3 through the second resistor R2. The emitter of transistor Q1 is connected to the ground terminal.

[0025] The drain of the first MOSFET Q2 is connected to the power input pin;

[0026] The drain of the second MOS transistor Q3 is connected to the data management module, and is connected to the ground terminal through the first capacitor C1 and the second capacitor C2 respectively.

[0027] After adopting the above technical solution, the present utility model embodiment has at least the following beneficial effects: The power management module of the present utility model monitors whether the output of the vehicle power supply is normal. When the output of the vehicle power supply is normal, the first power management unit is turned off and the second power management unit is enabled to process the second power supply voltage output by the vehicle power supply and then supply power to the data management module. When the vehicle power supply has no output or abnormal output voltage, the power management module can turn off the second power management unit and enable the first power management unit to process the first power supply voltage input by the external data reading device through the power input pin of the USB port and then supply power to the data management module. At the same time, the data management module can interact with the external data reading device through the USB port and the USB cable harness. When reading data from the vehicle driving recorder, it is only necessary to connect the external data reading device to the USB port through the USB cable harness to realize power supply and data reading at the same time. The operation is very simple. Attached Figure Description

[0028] Figure 1 This is a schematic block diagram of an optional embodiment of the data reading circuit of the vehicle-mounted driving recorder of this utility model.

[0029] Figure 2 This is a circuit diagram of the first power management unit, which is an optional embodiment of the data reading circuit of the vehicle-mounted driving recorder of this utility model. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the following illustrative embodiments and descriptions are only used to explain the present utility model and are not intended to limit the present utility model. Moreover, the embodiments and features in the embodiments of the present application can be combined with each other unless otherwise specified.

[0031] like Figure 1 As shown, an optional embodiment of this utility model provides a data reading circuit for a vehicle-mounted driving recorder, comprising:

[0032] USB port 1 is used to connect to an external data reading device A via a USB cable harness so that the external data reading device A can read data from the vehicle driving recorder. USB port 1 is provided with a power input pin 10 for obtaining a first power supply voltage from the external data reading device A.

[0033] The power conversion module 3 includes a first power management unit 30 connected to the power input pin 10 for processing and outputting the first power supply voltage, and a second power management unit 32 connected to the vehicle power supply B for processing and outputting the second power supply voltage output by the vehicle power supply B.

[0034] Power management module 5, connected to power input pin 10, output terminal of vehicle power supply B, first power management unit 30, and second power management unit 32 respectively, is used to shut down first power management unit 30 and start second power management unit 32 when vehicle power supply B output is normal, and to turn on first power management unit 30 and shut down second power management unit 32 when vehicle power supply B output is abnormal; and

[0035] The data management module 7 is connected to the USB port 1, the first power management unit 30 and the second power management unit 32 respectively, and is used to power on and start using the power supply voltage output by the first power management unit 30 or the second power management unit 32, and to interact with the external data reading device A via the USB port 1 and the USB cable harness.

[0036] In this embodiment of the utility model, the power management module 5 monitors whether the output of the vehicle power supply B is normal. When the output of the vehicle power supply B is normal, the first power management unit 30 is turned off and the second power management unit 32 is enabled to process the second power supply voltage output by the vehicle power supply B and then supply power to the data management module 7. When the vehicle power supply B has no output or abnormal output voltage, the power management module 5 can turn off the second power management unit 32 and enable the first power management unit 30 to process the first power supply voltage input by the external data reading device A through the power input pin 10 of the USB port 1 and then supply power to the data management module 7. At the same time, the data management module 7 can interact with the external data reading device A through the USB port 1 and the USB cable harness. When reading data from the vehicle driving recorder, simply connect the external data reading device A to the USB port 10 through the USB cable harness to achieve power supply and data reading simultaneously. The operation is very simple.

[0037] In specific implementation, the USB port 1 can be a Type-C port, which has strong versatility; the vehicle power supply B usually refers to a vehicle battery; the external data reading device A refers to a computer or data storage device that can provide the first power supply voltage. The second power management unit 32 can use common voltage conversion circuits such as LDO linear regulators or DC-DC voltage conversion circuits to convert the 12V input voltage to 5V.

[0038] In one optional embodiment of this utility model, such as Figure 1As shown, the power management module 5 has a first voltage acquisition pin 50 connected to the power input pin 10 to monitor whether there is an output voltage on the power input pin 10, and a second voltage acquisition pin 52 connected to the output terminal of the vehicle-mounted power supply B to monitor whether the vehicle-mounted power supply B outputs a normal voltage; the power management module 5 is connected to the data management module 7 to control the data management module 7 to power on and start up when it is monitored that at least one of the output terminal of the vehicle-mounted power supply B and the power input pin 10 has an output voltage. In this embodiment, the power management module 5 monitors whether there is an output voltage at the power input pin 10 through the first voltage acquisition pin 50, and monitors whether there is an output voltage at the vehicle-mounted power supply B through the second voltage acquisition pin 52, so as to supply power to the system with the supply voltage of the vehicle-mounted power supply B when data is not read through the USB port 1; moreover, when at least one of the vehicle-mounted power supply B and the power input pin 10 has an output voltage, the data management module 7 is controlled to power on and start up, ensuring the normal startup operation of the system.

[0039] In an optional embodiment of the present invention, as Figure 1 shown, the USB port 1 further has a voltage reflection pin 12 for reflecting the status of the first supply voltage (for example: voltage value, positive and negative directions), and the power management module 5 further has a third voltage acquisition pin 54 connected to the voltage reflection pin 12 to obtain the actual voltage value of the first supply voltage. When the output of the vehicle-mounted power supply B is abnormal and the power input pin 10 has an output voltage, the power management module 5 determines whether the actual voltage value is greater than a preset voltage threshold. If so, the first power management unit 30 is turned on and the second power management unit 32 is turned off. In this embodiment, in the USB port 1, a voltage reflection pin 12 (for example: CC_DET pin) is usually designed. When the actual voltage of the voltage reflection pin 12 is less than the preset voltage threshold, it indicates that the USB cable connected to the USB port 1 may be abnormally connected. At this time, data cannot be read normally through the USB port 1, so the stability of data interaction is improved.

[0040] In specific implementation, usually when the actual voltage U of the voltage reflection pin 12 ≤ 0.25V, it indicates that the USB cable is abnormally connected; when 0.25 V < U ≤ 0.7 V, the external data reading device A can provide a supply current of 500 mA and a supply voltage of 5V; when 0.7V < U ≤ 1.31V, the external data reading device A can provide a supply current of 1500 mA and a supply voltage of 5V; when U > 1.31V, the external data reading device A can provide a supply current of 3000 mA and a supply voltage of 5V; and to achieve data reading, a supply voltage of at least 5V is required. Therefore, when the actual voltage U of the voltage reflection pin 12 is greater than 0.25 V, data reading can be achieved.

[0041] In one optional embodiment of this utility model, such as Figure 1 As shown, the third voltage acquisition pin 54 is also connected to the ground terminal through the first resistor R1. In this embodiment, the third voltage acquisition pin 54 is also connected to the ground terminal through the first resistor R1. The resistance value of the first resistor R1 is usually 5.1 kΩ, which serves as a pull-up resistor for the voltage reflection pin 12, thereby facilitating the third voltage acquisition pin 54 to accurately obtain the voltage of the voltage reflection pin 12.

[0042] In one optional embodiment of this utility model, such as Figure 1 As shown, the data reading circuit further includes:

[0043] The data communication module 8, connected to both the data management module 7 and the vehicle body data transmission system C, is used to interact with the vehicle body data transmission system C under the control of the data management module 7. In this embodiment, when the vehicle-mounted driving recorder does not need to read data, it typically interacts with the vehicle body data transmission system C through the Ethernet data communication module 8 to record and store vehicle body data.

[0044] In an optional embodiment of this invention, the data communication module 8 is an Ethernet data communication module. In this embodiment, the Ethernet data communication module 8 can easily and quickly achieve data interaction with the vehicle body data transmission system C.

[0045] In one optional embodiment of this utility model, such as Figure 1 As shown, the data reading circuit further includes:

[0046] The voltage regulator module 9 has its input terminals connected to the vehicle power supply B and the power input pin 10 via a first diode D1 and a second diode D2, respectively, and its output terminal connected to the power management module 5. It is used to convert the output voltage of the vehicle power supply B or the power input pin 10 into a second predetermined voltage to power the power management module 5. The anode of the first diode D1 is connected to the vehicle power supply B and the cathode is connected to the voltage regulator module 9. The anode of the second diode D2 is connected to the power input pin 10 and the cathode is connected to the voltage regulator module 9.

[0047] In this embodiment, the voltage conversion is achieved by the voltage regulator module 9 to ensure the normal and stable operation of the power management module 5. Furthermore, by setting the first diode D1 and the second diode D2, the vehicle power supply B, which is powered by the voltage regulator module 9, and the power input pin 10 of the USB port 1 are isolated to prevent current backflow between the two power supply circuits and improve the safety of the circuit.

[0048] In an optional embodiment of this utility model, the regulated power supply module 9 is an LDO linear regulator or a DC-DC voltage conversion circuit. In this embodiment, since the operating voltage of the power management module 5 and the operating voltage of the data management module 7 may differ from the input voltage of the vehicle power supply B and / or the power input pin 10, the regulated power supply module 9 can use common voltage conversion circuits such as an LDO linear regulator or a DC-DC voltage conversion circuit to achieve voltage conversion.

[0049] In practice, the operating voltage of the power management module 5 (which can be an MCU chip) is usually 3.3V, the operating voltage of the data management chip 70 (which can be a SOC chip) and the chip power management unit 72 is 5V, while the output voltage of the vehicle power supply B is usually 12V, and the normal input voltage of the power input pin 10 is 5V. Therefore, the voltage regulator module 9 needs to convert the 12V or 5V input voltage to 3.3V.

[0050] In one optional embodiment of this utility model, such as Figure 1 As shown, the data management module 7 includes:

[0051] The data management chip 70 is connected to the USB port 1 and the data communication module 8, and is used to interact with the external data reading device A through the USB port 1 and the USB cable, and to interact with the vehicle body data transmission system C through the data communication module 8; and

[0052] The chip power management unit 72 is connected to the power management module 5, the first power management unit 30, the second power management unit 32, and the data management chip 70, respectively. It is used to be powered on by the power management module 5 so as to supply power to the data management chip 70 using the power supply voltage output by the first power management unit 30 or the second power management unit 32.

[0053] In this embodiment, the chip power management unit 72 is powered on by the power management module 5, and the power supply voltage output by the first power management unit 30 or the second power management unit 32 is used to power the data management chip 70. The data management chip 70 then interacts with the external data reading device A through the USB port 1, or interacts with the vehicle body data transmission system C through the data communication module 8. The circuit structure is simple.

[0054] In one optional embodiment of this utility model, such as Figure 2 As shown, the first power management unit 30 includes a transistor Q1, a first MOSFET Q2, and a second MOSFET Q3, wherein:

[0055] The base of transistor Q1 is connected to the power management module 5. The collector of transistor Q1 is connected to the gate of the first MOSFET Q2 and the gate of the second MOSFET Q3, respectively, and is connected to the source of the first MOSFET Q2 and the source of the second MOSFET Q3 through the second resistor R2. The emitter of transistor Q1 is connected to the ground terminal.

[0056] The drain of the first MOSFET Q2 is connected to the power input pin 10;

[0057] The drain of the second MOS transistor Q3 is connected to the data management module 7, and is connected to the ground terminal through the first capacitor C1 and the second capacitor C2 respectively.

[0058] In this embodiment, the first power management unit 30 includes a transistor Q1, a first MOSFET Q2, and a second MOSFET Q3. Both the first MOSFET Q2 and the second MOSFET Q3 are PMOS transistors. When connected in the above manner, the first MOSFET Q2 and the second MOSFET Q3 form a dual MOSFET anti-reverse current circuit. When the power management module 5 outputs a high level to control the transistor Q1 to conduct, the first MOSFET Q2 and the second MOSFET Q3 will conduct successively, and the power input pin 10 will output a normal power supply voltage to the data management module 7. When the power management module 5 outputs a low level to control the transistor Q1 to turn off, both the first MOSFET Q2 and the second MOSFET Q3 will turn off, and the power input pin 10 will stop supplying power to the data management module 7. Furthermore, the voltage input terminal of the data management module 7 and the power input pin 10 do not interfere with each other. Since the first MOSFET Q2 and the second MOSFET Q3 are connected in reverse, current reverse current prevention can be achieved, improving circuit safety. In addition, by setting a first capacitor C1 and a second capacitor C2, the output voltage is filtered, improving circuit stability.

[0059] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the scope of protection of the present invention.

Claims

1. A data reading circuit of a vehicle-mounted driving recorder, characterized in that, The data reading circuit includes: A USB port is used to connect to an external data reading device via a USB cable harness so that the external data reading device can read data from the vehicle driving recorder. The USB port is provided with a power input pin for interfacing with the power supply terminal of the USB cable harness to obtain a first power supply voltage from the external data reading device. The power conversion module includes a first power management unit connected to the power input pin for processing and outputting the first power supply voltage, and a second power management unit connected to the vehicle power supply for processing and outputting the second power supply voltage output by the vehicle power supply. A power management module, connected to the power input pin, the output terminal of the vehicle power supply, the first power management unit, and the second power management unit, is used to shut down the first power management unit and start the second power management unit when the vehicle power supply output is normal, and to turn on the first power management unit and shut down the second power management unit when the vehicle power supply output is abnormal; and The data management module is connected to the USB port, the first power management unit, and the second power management unit, respectively. It is used to power on and start using the power supply voltage output by the first power management unit or the second power management unit, and to interact with the external data reading device via the USB port and the USB cable.

2. The data reading circuit of the vehicle-mounted driving recorder according to claim 1, wherein The power management module has a first voltage acquisition pin connected to the power input pin to monitor whether the power input pin has an output voltage, and a second voltage acquisition pin connected to the output terminal of the vehicle power supply to monitor whether the vehicle power supply is outputting a normal voltage. The power management module is connected to the data management module to control the data management module to power on and start when at least one of the output terminal of the vehicle power supply and the power input pin is detected to have an output voltage.

3. The data reading circuit of the vehicle-mounted driving recorder according to claim 1 or 2, characterized in that, The USB port is also provided with a voltage feedback pin for reflecting the status of the first power supply voltage. The power management module is also provided with a third voltage acquisition pin connected to the voltage feedback pin to obtain the actual voltage value of the first power supply voltage. When the vehicle power supply output is abnormal and the power input pin has an output voltage, the power management module determines whether the actual voltage value is greater than a preset voltage threshold. If so, the first power management unit is turned on and the second power management unit is turned off.

4. The data reading circuit of the vehicle-mounted driving recorder according to claim 3, wherein The third voltage acquisition pin is also connected to the ground terminal through the first resistor R1.

5. The data reading circuit of the vehicle-mounted driving recorder according to claim 2, wherein The data reading circuit also includes: The data communication module is connected to both the data management module and the vehicle body data transmission system, and is used to interact with the vehicle body data transmission system under the control of the data management module.

6. The data reading circuit of the vehicle-mounted driving recorder according to claim 5, wherein The data communication module is an Ethernet data communication module.

7. The data reading circuit of the vehicle-mounted driving recorder according to claim 1, wherein The data reading circuit also includes: A voltage regulator module has its input terminals connected to the vehicle power supply and the power input pin respectively via a first diode D1 and a second diode D2, and its output terminal connected to the power management module. It is used to convert the output voltage of the vehicle power supply or the power input pin into a second predetermined voltage to power the power management module. The anode of the first diode D1 is connected to the vehicle power supply and the cathode is connected to the voltage regulator module, and the anode of the second diode D2 is connected to the power input pin and the cathode is connected to the voltage regulator module.

8. The data reading circuit of the vehicle driving recorder as described in claim 7, characterized in that, The voltage regulator module is an LDO linear regulator or a DC-DC voltage conversion circuit.

9. The data reading circuit of the vehicle-mounted driving recorder as described in claim 5, characterized in that, The data management module includes: A data management chip, connected to the USB port and the data communication module, is used to interact with the external data reading device via the USB port and USB cable, and to interact with the vehicle data transmission system via the data communication module; and The chip power management unit is connected to the power management module, the first power management unit, the second power management unit, and the data management chip, respectively. It is used to be powered on by the power management module to supply power to the data management chip using the power supply voltage output by the first power management unit or the second power management unit.

10. The data reading circuit of the vehicle driving recorder as described in claim 1, characterized in that, The first power management unit includes transistor Q1, first MOSFET Q2, and second MOSFET Q3, wherein: The base of transistor Q1 is connected to the power management module. The collector of transistor Q1 is connected to the gate of the first MOSFET Q2 and the gate of the second MOSFET Q3, respectively, and is connected to the source of the first MOSFET Q2 and the source of the second MOSFET Q3 through the second resistor R2. The emitter of transistor Q1 is connected to the ground terminal. The drain of the first MOSFET Q2 is connected to the power input pin; The drain of the second MOS transistor Q3 is connected to the data management module, and is connected to the ground terminal through the first capacitor C1 and the second capacitor C2 respectively.

Images