Vehicle-mounted unit and ETC device

Abstract

The vehicle-mounted unit comprises a vehicle-mounted interface, a power supply module, a first processor, a CAN transceiver and an anti-tamper detection circuit, the vehicle-mounted interface forms an anti-tamper assembly of the vehicle-mounted unit, when the vehicle-mounted unit is in a normal anti-tamper state, a CANH interface and / or a CANL interface of the vehicle-mounted interface are / is in a short-circuit state, and when the vehicle-mounted unit is in a normal anti-tamper state, the CANH interface and / or the CANL interface of the vehicle-mounted interface are / is in a short-circuit state. The anti-tamper detection circuit outputs a first detection signal to the first processor, the first processor determines that the vehicle-mounted unit is in a normal anti-tamper state at present and executes normal anti-tamper action, and when the CANH interface and the CANL interface are broken due to damage, the anti-tamper detection circuit outputs a second detection signal; and the first processor determines that the current vehicle-mounted unit is in an anti-disassembly abnormal state and executes an anti-disassembly abnormal action. An additional anti-disassembly key and CAN development do not need to be arranged, the structure of the vehicle-mounted unit is simplified, and the design cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the ETC technical field especially relates to a kind of vehicle-mounted unit and ETC equipment. BACKGROUND

[0002] Vehicle-mounted unit (On Board Unit, OBU) is the part of Electronic Toll Collection (ETC), and the anti-disassembly of vehicle-mounted unit currently uses mechanical anti-disassembly or CAN anti-disassembly.

[0003] As shown in Figure 1 In the mechanical anti-disassembly scheme, the car machine supplies power to the anti-disassembly module and MCU through the connector and power module, and the MCU judges the anti-disassembly state by detecting the level state of the anti-disassembly module. When the anti-disassembly key in the anti-disassembly module is in the pressed / raised state, the corresponding output level will become high / low level, and the anti-disassembly is judged according to the level state. Among them, mechanical anti-disassembly needs to use anti-disassembly key alone, which is large in size and occupies too much circuit board space, and needs to drill anti-disassembly hole on the shell, increasing the electrostatic interference.

[0004] As shown in Figure 2 In the CAN anti-disassembly scheme, the vehicle identification code of the vehicle is stored in the MCU module after the vehicle-mounted unit is activated. After the vehicle-mounted unit is powered on, the MCU module of the vehicle-mounted unit sends the request vehicle identification code information to the car machine through the CAN transceiver module and the connector. After receiving the request signal, the car machine sends the vehicle identification code information to the vehicle-mounted unit end. When the vehicle identification code sent by the car machine is consistent with the stored vehicle identification code in the MCU, the anti-disassembly is normal, otherwise the anti-disassembly is abnormal. Among them, the CAN anti-disassembly scheme has long CAN development period in the project development process, which is easy to cause resource waste and increase the cost. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a kind of vehicle-mounted unit, to solve the problem of complex structure or high cost of traditional vehicle-mounted unit anti-disassembly mode.

[0006] The first aspect of the utility model embodiment proposes a kind of vehicle-mounted unit, comprising:

[0007] Vehicle-mounted interface, the vehicle-mounted interface is used to connect car machine, the vehicle-mounted interface includes power interface and CAN interface, the CAN interface includes CAN_H interface and CAN_L interface;

[0008] Power module, connected with the power interface, for obtaining direct-current power and outputting working power;

[0009] The first processor is connected with the power module, the first processor is triggered by the first detection signal to execute the normal anti-disassembly action, and the second detection signal is triggered to execute the abnormal anti-disassembly action;

[0010] The CAN transceiver is connected between the CAN interface and the first processor, and the CAN transceiver is also connected with the power module, and the CAN transceiver is used for CAN communication;

[0011] The anti-disassembly detection circuit is connected with the CAN interface, the power module and the first processor respectively, the anti-disassembly detection circuit is triggered to output the first detection signal by the level signal of the CAN_H interface and / or the CAN_L interface, or the second detection signal is triggered when there is no level signal in the CAN_H interface and the CAN_L interface.

[0012] Optionally, the vehicle-mounted unit further comprises:

[0013] The connecting piece is used for connecting the vehicle-mounted interface and the car machine, and when the connecting piece is not connected with the car machine, the connecting piece at least shorts the corresponding two interfaces of the power interface, the CAN_H interface and the CAN_L interface.

[0014] Optionally, the anti-disassembly detection circuit comprises:

[0015] The first level diagnosis circuit is connected with the CAN_H interface and the power module respectively, the first level diagnosis circuit is triggered to output the first level signal when the CAN_H interface has the level signal, or the second level signal is outputted when the CAN_H interface has no level signal;

[0016] The second level diagnosis circuit is connected with the CAN_L interface and the power module respectively, the second level diagnosis circuit is triggered to output the third level signal when the CAN_L interface has the level signal, or the fourth level signal is outputted when the CAN_L interface has no level signal;

[0017] The level conversion circuit is connected with the power module, the first level diagnosis circuit, the second level diagnosis circuit and the first processor respectively, the level conversion circuit is converted to output the first detection signal when at least one of the first level signal and the third level signal is received, or the second detection signal is converted to output when the second level signal and the fourth level signal are received.

[0018] Optionally, the first level diagnosis circuit comprises a first resistor, a second resistor, a first switch tube, a first inverter and a first or gate;

[0019] The input end of the first inverter and the first input end of the first OR gate are connected to constitute the input end of the first level diagnosis circuit, the output end of the first inverter is connected with the second input end of the first OR gate, the first end of the first resistor is connected with the positive power supply end, the second end of the first resistor is connected with the first end of the first switch tube to constitute the output end of the first level diagnosis circuit, the control end of the first switch tube is connected with the output end of the first OR gate, the second end of the first switch tube is connected with the first end of the second resistor, and the second end of the second resistor is grounded.

[0020] Optionally, the second level diagnosis circuit comprises a third resistor, a fourth resistor, a second switch tube, a second inverter and a second OR gate.

[0021] The input end of the second inverter and the second input end of the second OR gate are connected to constitute the input end of the second level diagnosis circuit, the output end of the second inverter is connected with the second input end of the second OR gate, the first end of the third resistor is connected with the positive power supply end, the second end of the third resistor is connected with the second end of the second switch tube to constitute the output end of the second level diagnosis circuit, the control end of the second switch tube is connected with the output end of the second OR gate, the second end of the second switch tube is connected with the first end of the fourth resistor, and the second end of the fourth resistor is grounded.

[0022] Optionally, the level conversion circuit comprises an AND gate and a signal amplifier.

[0023] The first input end of the AND gate is connected with the output end of the first level diagnosis circuit, the second input end of the AND gate is connected with the output end of the second level diagnosis circuit, the output end of the AND gate is connected with the input end of the signal amplifier, and the output end of the signal amplifier constitutes the output end of the level conversion circuit.

[0024] Optionally, the anti-disassembly detection circuit comprises:

[0025] A second processor connected with the CAN interface and the power module respectively, the second processor outputs a fifth level signal when detecting that at least one of the CAN_H interface and the CAN_L interface has a level signal, or outputs a sixth level signal when detecting that neither of the CAN_H interface and the CAN_L interface has a level signal.

[0026] A third processor connected with the second processor, the first processor and the power module respectively, the third processor converts the fifth level signal into the first detection signal and converts the sixth level signal into the second detection signal.

[0027] Optionally, the second processor is multiplexed as a logic circuit inside the CAN transceiver, and the third processor is multiplexed as a receiver inside the CAN transceiver.

[0028] Optionally, the vehicle-mounted unit further comprises:

[0029] a delay power-off circuit, a power input end of the delay power-off circuit being connected with a power output end of the power module, and a power output end of the delay power-off circuit being connected with the CAN transceiver, the anti-disassembly detection circuit and the first processor respectively, the delay power-off circuit being configured to provide a preset time length of working power to the CAN transceiver, the anti-disassembly detection circuit and the first processor when the power module is powered off.

[0030] The second aspect of the embodiment of the utility model discloses an ETC device, comprising the vehicle-mounted unit as described above.

[0031] The vehicle-mounted unit comprises a vehicle-mounted interface, a power module, a first processor, a CAN transceiver and an anti-disassembly detection circuit, the vehicle-mounted interface constitutes an anti-disassembly component of the vehicle-mounted unit, when the vehicle-mounted unit is in a normal anti-disassembly state, the CAN_H interface and / or the CAN_L interface of the vehicle-mounted interface are in a short-circuit state, the anti-disassembly detection circuit outputs a first detection signal to the first processor, the first processor determines that the current vehicle-mounted unit is in the normal anti-disassembly state and executes a normal anti-disassembly action, when the CAN_H interface and the CAN_L interface are broken due to being damaged, the anti-disassembly detection circuit outputs a second detection signal, the first processor determines that the current vehicle-mounted unit is in an abnormal anti-disassembly state and executes an abnormal anti-disassembly action, anti-disassembly protection is realized, the anti-disassembly protection can be realized by monitoring the state of the CAN_H interface and the CAN_L interface of the vehicle-mounted interface, and it is not necessary to set an additional anti-disassembly button and develop CAN, so that the structure of the vehicle-mounted unit is simplified and the design cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0033] Figure 1 It is a structural schematic diagram of the mechanical anti-disassembly of the traditional vehicle-mounted unit.

[0034] Figure 2 It is a structural schematic diagram of the CAN anti-disassembly of the traditional vehicle-mounted unit.

[0035] Figure 3 A first structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0036] Figure 4 A second structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0037] Figure 5 A third structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0038] Figure 6 A fourth structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0039] Figure 7 A circuit schematic view of a tamper-proof detection circuit provided by the embodiment of the present application is provided.

[0040] Figure 8 A fifth structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0041] Figure 9 A sixth structure schematic view of a vehicle-mounted unit provided by the embodiment of the present application is provided.

[0042] Figure 10 A circuit schematic view of a delay power-off circuit provided by the embodiment of the present application is provided. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0044] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0045] A first aspect of the embodiment of the present application proposes a vehicle-mounted unit 100.

[0046] As shown in Figure 3 In the present embodiment, the vehicle-mounted unit 100 comprises:

[0047] The vehicle interface J1 is used to connect the car machine 200, and includes a power interface and a CAN interface, and the CAN interface includes a CAN_H interface and a CAN_L interface;

[0048] The power module 10 is connected with the power interface, and is used to obtain a direct current power supply and output a working power supply;

[0049] The first processor 20 is connected with the power module 10, and is triggered by the first detection signal to execute a normal anti-disassembly action, and is triggered by the second detection signal to execute an abnormal anti-disassembly action;

[0050] The CAN transceiver 30 is connected between the CAN interface and the first processor 20, and is also connected with the power module 10, and is used to perform CAN communication;

[0051] The anti-disassembly detection circuit 40 is connected with the CAN interface, the power module 10 and the first processor 20 respectively, and is triggered by the level signal of the CAN_H interface and / or the CAN_L interface to output the first detection signal, or is triggered to output the second detection signal when there is no level signal in the CAN_H interface and the CAN_L interface.

[0052] In the embodiment, when the CAN transceiver 30 is not developed and used, the power interface of the vehicle interface J1 is connected with the car machine 200, and the CAN interface is not connected with the car machine 200, and this connection state is a normal anti-disassembly state of the vehicle-mounted unit 100, and the CAN_H interface and / or the CAN_L interface of the vehicle interface J1 is in a short-circuit state.

[0053] The power interface includes a positive power interface P+ and a negative power interface P-, the power module 10 obtains a direct current power supply from the power interface, and converts and outputs a working power supply to each power-receiving module inside the vehicle-mounted unit 100, and the power module 10 can adopt a battery, a power conversion circuit and the like.

[0054] The vehicle-mounted unit 100 adopts the vehicle-mounted interface J1 as an anti-disassembly component. In a normal anti-disassembly state, the CAN_H interface CAN_H and / or the CAN_L interface CAN_L are short-circuited by welding or a connecting wire, and the short-circuit state can be that the CAN_H interface CAN_H and the CAN_L interface CAN_L are short-circuited with each other, the CAN_H interface CAN_H and / or the CAN_L interface CAN_L are short-circuited with the power supply interface, the CAN_H interface CAN_H and / or the CAN_L interface CAN_L are short-circuited with the corresponding ground terminal, and the like. The anti-disassembly detection circuit 40 monitors the level state of the CAN_H interface CAN_H and the CAN_L interface CAN_L, and outputs a corresponding detection signal to the first processor 20 to trigger the first processor 20 to perform corresponding anti-disassembly protection work.

[0055] For example, assuming that the CAN_H interface CAN_H and the CAN_L interface CAN_L are short-circuited, when the vehicle-mounted interface J1 is not damaged normally, the anti-disassembly detection circuit 40 monitors that the level on the CAN_H interface CAN_H and the CAN_L interface CAN_L is 0, the anti-disassembly detection circuit 40 outputs a first detection signal, and triggers the first processor 20 to perform normal anti-disassembly work, and the vehicle-mounted unit 100 works normally. When the vehicle-mounted interface J1 is damaged to cause the CAN_H interface CAN_H and the CAN_L interface CAN_L to be disconnected, the anti-disassembly detection circuit 40 monitors that there is no level signal on the CAN_H interface CAN_H and the CAN_L interface CAN_L, the anti-disassembly detection circuit 40 outputs a second detection signal, and triggers the first processor 20 to perform abnormal anti-disassembly action, such as performing erasing work of sensitive information such as a key, data, and the like, to achieve anti-disassembly protection.

[0056] Alternatively, assuming that the CAN_H interface CAN_H and the CAN_L interface CAN_L are respectively short-circuited with the positive power supply interface P+, when the vehicle-mounted interface J1 is not damaged normally, the anti-disassembly detection circuit 40 monitors that the level on the CAN_H interface CAN_H and the CAN_L interface CAN_L is a high level, the anti-disassembly detection circuit 40 outputs a first detection signal, and triggers the first processor 20 to perform normal anti-disassembly work, and the vehicle-mounted unit 100 works normally. When the vehicle-mounted interface J1 is damaged to cause the CAN_H interface CAN_H, the CAN_L interface CAN_L, and the positive power supply interface P+ to be disconnected respectively, the anti-disassembly detection circuit 40 monitors that there is no level signal on the CAN_H interface CAN_H and the CAN_L interface CAN_L, the anti-disassembly detection circuit 40 outputs a second detection signal, and triggers the first processor 20 to perform abnormal anti-disassembly action, such as performing erasing work of sensitive information such as a key, data, and the like, to achieve anti-disassembly protection.

[0057] Or, assuming that the CAN_H interface CAN_H is shorted with the positive power supply interface P+, and the CAN_L interface CAN_L is shorted with the negative power supply interface P-, when the vehicle interface J1 is normal and not damaged, the anti-tamper detection circuit 40 monitors that the level signal on the CAN_H interface CAN_H is high, and the level on the CAN_L interface CAN_L is low, the anti-tamper detection circuit 40 outputs a first detection signal, and triggers the first processor 20 to perform normal anti-tamper work, and the vehicle-mounted unit 100 works normally. When the vehicle interface J1 is damaged to disconnect the CAN_H interface CAN_H, the CAN_L interface CAN_L, and the positive power supply interface P+ and the negative power supply interface P- respectively, the anti-tamper detection circuit 40 monitors that there is no level signal on the CAN_H interface CAN_H and the CAN_L interface CAN_L, the anti-tamper detection circuit 40 outputs a second detection signal, and triggers the first processor 20 to perform an abnormal anti-tamper action, for example, to perform a sensitive information such as key, data, and the like. Erasing work, realizing anti-tamper protection.

[0058] By taking the vehicle interface J1 as the anti-tamper component of the vehicle-mounted unit 100, no additional anti-tamper component needs to be set, the structure of the vehicle-mounted unit 100 is simplified, and only one anti-tamper detection circuit 40 is needed to detect the level change state of the CAN_H interface CAN_H and the CAN_L interface CAN_L to determine whether the vehicle-mounted unit 100 is damaged, realize anti-tamper protection, and no development of the CAN transceiver 30 is needed, reducing the development cost.

[0059] When the CAN transceiver 30 is developed or the vehicle-mounted unit 100 needs to be upgraded, the CAN interface can be connected to the car machine 200, that is, the CAN_H interface CAN_H and the CAN_L interface CAN_L are normally connected to the car machine 200, and switched to the CAN anti-tamper mode, without changing the hardware structure of the vehicle-mounted unit 100.

[0060] When the CAN anti-tamper is performed, the vehicle identification code of the vehicle is stored in the first processor 20 after the vehicle-mounted unit 100 is activated. After the vehicle-mounted unit 100 is powered on, the first processor 20 of the vehicle-mounted unit 100 sends a request for vehicle identification code information to the car machine 200 through the CAN transceiver 30 and the vehicle interface J1. After the car machine 200 receives the request signal, the car machine 200 sends the vehicle identification code information to the vehicle-mounted unit 100. When the vehicle identification code sent by the car machine 200 is consistent with the stored vehicle identification code of the first processor 20, the anti-tamper is normal, otherwise the anti-tamper is abnormal.

[0061] In order to facilitate connection to the car machine 200, in an optional embodiment, as shown in Figure 4 The vehicle-mounted unit 100 further comprises:

[0062] The connecting piece is used for connecting the vehicle interface J1 and the car machine 200. When the connecting piece is not connected with the car machine 200, the connecting piece at least shorts the corresponding two interfaces of the power supply interface, the CAN_H interface CAN_H and the CAN_L interface CAN_L.

[0063] In the embodiment, the connecting piece can be a structure such as a board-mounted plug, a connector, etc. The connecting piece generally at least includes a connecting terminal J2 connected with the vehicle interface J1 and a connecting line connected with the connecting terminal J2. The connecting line includes a positive power line LP+ and a negative power line LP- connected with the power supply interface, a first signal line L1 connected with the CAN_H interface CAN_H and a second signal line L2 connected with the CAN_L interface CAN_L.

[0064] When the CAN transceiver 30 is not developed and used, the power line is connected with the car machine 200, and the first signal line L1 and the second signal line L2 are not connected with the car machine 200. This connection state is a normal anti-disassembly state of the vehicle unit 100, and the CAN_H interface CAN_H and / or the CAN_L interface CAN_L of the vehicle interface J1 is in a short-circuit state.

[0065] The vehicle unit 100 adopts the vehicle interface J1 as an anti-disassembly component. In the normal anti-disassembly state, the first signal line L1 and the second signal line L2 connected with the CAN_H interface CAN_H and the CAN_L interface CAN_L are correspondingly short-circuited, so as to short-circuit the CAN_H interface CAN_H and / or the CAN_L interface CAN_L.

[0066] The short-circuit mode can be that the first signal line L1 and the second signal line L2 are short-circuited with each other, the first signal line L1 and the second signal line L2 are correspondingly short-circuited with the positive power line LP+ respectively, the first signal line L1 and the second signal line L2 are short-circuited with the corresponding ground terminal, etc. The anti-disassembly detection circuit 40 monitors the level state of the CAN_H interface CAN_H and the CAN_L interface CAN_L and outputs a corresponding detection signal to the first processor 20, so as to trigger the first processor 20 to perform a corresponding anti-disassembly protection work.

[0067] For example, as shown in FIG. 2, it is assumed that the first signal line L1 is short-circuited with the positive power line LP+, the CAN_H interface CAN_H is correspondingly short-circuited with the positive power supply interface P+, the second signal line L2 is short-circuited with the negative power line LP-, and the CAN_L interface CAN_L is correspondingly short-circuited with the negative power supply interface P-. Figure 5 When the vehicle interface J1 is not normally damaged, the anti-disassembly detection circuit 40 monitors that the level signal on the CAN_H interface CAN_H is a high level and the level on the CAN_L interface CAN_L is a low level, outputs a first detection signal, triggers the first processor 20 to perform a normal anti-disassembly work, and the vehicle unit 100 normally works.

[0068] When the vehicle interface J1 is damaged, causing the first signal line L1 and the second signal line L2 to be disconnected from the positive power supply line LP+ and the negative power supply line LP- respectively, the anti-disassembly detection circuit 40 detects that there is no level signal on the CAN_H interface CAN_H and the CAN_L interface CAN_L, outputs a second detection signal, and triggers the first processor 20 to perform an anti-disassembly abnormal action, such as erasing sensitive information such as keys, data, and the like, to achieve anti-disassembly protection.

[0069] When the CAN transceiver 30 is developed or the vehicle-mounted unit 100 needs to be upgraded, the first signal line L1 and the second signal line L2 can be connected to the vehicle machine 200, that is, as shown in Figure 4 , the CAN_H interface CAN_H and the CAN_L interface CAN_L are normally connected to the vehicle machine 200, and are switched to the CAN anti-disassembly mode, without the need to change the hardware structure of the vehicle-mounted unit 100.

[0070] The anti-disassembly detection circuit 40 can be implemented by two independent detection circuits, or an additional processor can be used for signal judgment, and the specific structure is not limited.

[0071] The first processor 20 can be a single-chip microcomputer, MCU, CPU, or the like, and the specific type is not limited.

[0072] In an optional embodiment, as shown in Figure 6 , the anti-disassembly detection circuit 40 includes:

[0073] A first level diagnosis circuit 41 connected to the CAN_H interface CAN_H and the power supply module 10, respectively, the first level diagnosis circuit 41 triggers to output a first level signal when detecting that the CAN_H interface CAN_H has a level signal, or outputs a second level signal when detecting that the CAN_H interface CAN_H has no level signal;

[0074] A second level diagnosis circuit 42 connected to the CAN_L interface CAN_L and the power supply module 10, respectively, the second level diagnosis circuit 42 triggers to output a third level signal when detecting that the CAN_L interface CAN_L has a level signal, or outputs a fourth level signal when detecting that the CAN_L interface CAN_L has no level signal;

[0075] A level conversion circuit 43 connected to the power supply module 10, the first level diagnosis circuit 41, the second level diagnosis circuit 42, and the first processor 20, respectively, the level conversion circuit 43 converts to output a first detection signal when receiving at least one of the first level signal and the third level signal, or converts to output a second detection signal when receiving the second level signal and the fourth level signal.

[0076] In this embodiment, two separate level diagnosis circuits are used to detect the level of CAN_H interface CAN_H and CAN_L interface CAN_L. When the CAN transceiver 30 is not developed and used, the power line is connected with the vehicle machine 200, and the first signal line L1 and the second signal line L2 are not connected with the vehicle machine 200. In this connection state, the vehicle-mounted unit 100 is in a normal anti-disassembly state, and the CAN_H interface CAN_H and / or the CAN_L interface CAN_L of the vehicle-mounted interface J1 is in a short-circuit state.

[0077] In the normal anti-disassembly state, the first signal line L1 and the second signal line L2 connected with the CAN_H interface CAN_H and the CAN_L interface CAN_L are correspondingly short-circuited, so as to short-circuit the CAN_H interface CAN_H and / or the CAN_L interface CAN_L.

[0078] Suppose that the first signal line L1 is short-circuited with the positive power line LP+, and the CAN_H interface CAN_H is short-circuited with the positive power interface P+, and the second signal line L2 is short-circuited with the negative power line LP-, and the CAN_L interface CAN_L is short-circuited with the negative power interface P-. When the vehicle-mounted interface J1 is not damaged normally, the first level diagnosis circuit 41 detects that the CAN_H interface CAN_H is at a high level, and outputs a first level signal, and the second level diagnosis circuit 42 detects that the CAN_L interface CAN_L is at a low level, and outputs a third level signal.

[0079] After receiving the first level signal and the third level signal, the level conversion circuit 43 converts and outputs a first detection signal, and triggers the first processor 20 to perform normal anti-disassembly work, so that the vehicle-mounted unit 100 normally works.

[0080] When the vehicle-mounted interface J1 is damaged to disconnect the first signal line L1 and the second signal line L2 from the positive power line LP+ and the negative power line LP- respectively, the first level diagnosis circuit 41 and the second level diagnosis circuit 42 detect that there is no level signal on the CAN_H interface CAN_H and the CAN_L interface CAN_L, the first level diagnosis circuit 41 outputs a second level signal, the second level diagnosis circuit 42 outputs a fourth level signal, and the level conversion circuit 43 converts and outputs a second detection signal, and triggers the first processor 20 to perform an abnormal anti-disassembly action, such as erasing sensitive information such as keys, data, and the like, to achieve anti-disassembly protection.

[0081] Among them, the first level signal and the second level signal are opposite high and low level signals, and the third level signal and the fourth level signal are opposite level signals.

[0082] Among them, the first level diagnosis circuit 41, the second level diagnosis circuit 42 and the level conversion circuit 43 can adopt corresponding switch tubes, logic gates and the like.

[0083] In an alternative embodiment, such as Figure 7 As shown, the first level diagnostic circuit 41 includes a first resistor R1, a second resistor R2, a first switch Q1, a first inverter U1, and a first OR gate OR1;

[0084] The input terminal of the first inverter U1 and the first input terminal of the first OR gate OR1 are connected to form the input terminal of the first level diagnostic circuit 41. The output terminal of the first inverter U1 is connected to the second input terminal of the first OR gate OR1. The first terminal of the first resistor R1 is connected to the positive power supply terminal VCC. The second terminal of the first resistor R1 is connected to the first terminal of the first switch Q1 to form the output terminal of the first level diagnostic circuit 41. The control terminal of the first switch Q1 is connected to the output terminal of the first OR gate OR1. The second terminal of the first switch Q1 is connected to the first terminal of the second resistor R2. The second terminal of the second resistor R2 is grounded.

[0085] The second-level diagnostic circuit 42 includes a third resistor R3, a fourth resistor R4, a second switch Q2, a second inverter U2, and a second OR gate OR2;

[0086] The input terminal of the second inverter U2 is connected to the second input terminal of the second OR gate OR2 to form the input terminal of the second level diagnostic circuit 42. The output terminal of the second inverter U2 is connected to the second input terminal of the second OR gate OR2. The first terminal of the third resistor R3 is connected to the positive power supply terminal VCC. The second terminal of the third resistor R3 is connected to the second terminal of the second switch Q2 to form the output terminal of the second level diagnostic circuit 42. The control terminal of the second switch Q2 is connected to the output terminal of the second OR gate OR2. The second terminal of the second switch Q2 is connected to the first terminal of the fourth resistor R4. The second terminal of the fourth resistor R4 is grounded.

[0087] Level conversion circuit 43 includes AND gate AND1 and signal amplifier PA;

[0088] The first input terminal of AND gate AND1 is connected to the output terminal of the first level diagnostic circuit 41, the second input terminal of AND gate AND1 is connected to the output terminal of the second level diagnostic circuit 42, the output terminal of AND gate AND1 is connected to the input terminal of signal amplifier PA, and the output terminal of signal amplifier PA constitutes the output terminal of level conversion circuit 43.

[0089] In this embodiment, the first switch Q1 and the second switch Q2 are triggered to turn on when a high level is received, and triggered to turn off when a low level is received. The positive power supply terminal is connected to the power module 10, and is provided with a positive voltage by the power module 10.

[0090] When the CAN_H interface CAN_H is high, the first inverter U1 outputs low, the first OR gate OR1 outputs high, the first switch tube Q1 is turned on, and the first level diagnosis circuit 41 outputs low. When the CAN_H interface CAN_H is low, the first inverter U1 outputs high, the first OR gate OR1 outputs high, the first switch tube Q1 is turned on, and the first level diagnosis circuit 41 outputs low. When the CAN_H interface CAN_H is 0, the first inverter U1 outputs high, the first OR gate OR1 outputs high, the first switch tube Q1 is turned on, and the first level diagnosis circuit 41 outputs low. When the CAN_H interface CAN_H has no level signal, the first OR gate OR1 has no signal output, the first switch tube Q1 remains in the off state, and the first level diagnosis circuit 41 outputs high.

[0091] Similarly, when the CAN_L interface CAN_L is high, the second inverter U2 outputs low, the second OR gate OR2 outputs high, the second switch tube Q2 is turned on, and the second level diagnosis circuit 42 outputs low. When the CAN_L interface CAN_L is low, the second inverter U2 outputs high, the second OR gate OR2 outputs high, the second switch tube Q2 is turned on, and the second level diagnosis circuit 42 outputs low. When the CAN_L interface CAN_L is 0, the second inverter U2 outputs high, the second OR gate OR2 outputs high, the second switch tube Q2 is turned on, and the second level diagnosis circuit 42 outputs low. When the CAN_L interface CAN_L has no level signal, the second OR gate OR2 has no signal output, the second switch tube Q2 remains in the off state, and the second level diagnosis circuit 41 outputs high.

[0092] In the normal anti-disassembly state, the first signal line L1 and the second signal line L2 connected with the CAN_H interface CAN_H and the CAN_L interface CAN_L are correspondingly short-circuited, so as to short-circuit the CAN_H interface CAN_H and / or the CAN_L interface CAN_L.

[0093] Assuming that the first signal line L1 is short-circuited with the positive power supply line LP+, the CAN_H interface CAN_H is correspondingly short-circuited with the positive power supply interface P+, the second signal line L2 is short-circuited with the negative power supply line LP-, and the CAN_L interface CAN_L is correspondingly short-circuited with the negative power supply interface P-, when the vehicle-mounted interface J1 is not damaged normally, the CAN_H interface CAN_H is high, the first switch tube Q1 outputs the first level signal of low level, the CAN_L interface CAN_L is low, and the second switch tube Q2 outputs the third level signal of low level.

[0094] When the two low-level signals are received by the AND gate AND1, a low-level signal is outputted, the low-level signal outputted by the AND gate AND1 is amplified by the signal amplifier PA, and a low-level first detection signal is outputted, and when the low-level signal is received by the first processor 20, the first processor 20 triggers to execute the anti-disassembly normal operation, and the on-board unit 100 normally operates.

[0095] When the first signal line L1 and the second signal line L2 are disconnected from the positive power supply line LP+ and the negative power supply line LP- respectively, and the CAN_H interface CAN_H and the CAN_L interface CAN_L are detected by the first level diagnosis circuit 41 and the second level diagnosis circuit 42 to have no level signal, the first level diagnosis circuit 41 and the second level diagnosis circuit 42 output high levels respectively, and when the two high-level signals are received by the AND gate AND1, a high-level signal is outputted, the high-level signal outputted by the AND gate AND1 is amplified by the signal amplifier PA, and a high-level second detection signal is outputted, and when the high-level signal is received by the first processor 20, the first processor 20 triggers to execute the anti-disassembly abnormal operation, for example, to perform the erasing operation of sensitive information such as keys and data, and to realize the anti-disassembly protection.

[0096] In the embodiment, the first switch tube Q1 and the second switch tube Q2 are NPN triodes or NMOS tubes.

[0097] In another optional embodiment, as shown in FIG. 4, the anti-disassembly detection circuit 40 includes: Figure 8

[0098] The second processor 44 is connected with the CAN interface and the power supply module 10 respectively, and outputs a fifth level signal when at least one of the CAN_H interface CAN_H and the CAN_L interface CAN_L has a level signal, or outputs a sixth level signal when neither of the CAN_H interface CAN_H and the CAN_L interface CAN_L has a level signal.

[0099] The third processor 45 is connected with the second processor 44, the first processor 20 and the power supply module 10 respectively, and converts the fifth level signal into the first detection signal, and converts the sixth level signal into the second detection signal.

[0100] In the embodiment, two processors are used to perform the level diagnosis and the level conversion respectively, the second processor 44 realizes the level diagnosis work of the first level diagnosis circuit 41 and the second level diagnosis circuit 42, and the third processor 45 realizes the level conversion work of the level conversion circuit 43.

[0101] ​When the CAN transceiver 30 is not developed and used, the power line is connected to the vehicle unit 200, and the first signal line L1 and the second signal line L2 are not connected to the vehicle unit 200. This connection state is the normal anti-tamper state of the vehicle unit 100. The CAN_H interface and / or CAN_L interface of the vehicle interface J1 are in a short-circuited state.

[0102] In the normal tamper protection state, the first signal line L1 and the second signal line L2 connected to the CAN_H interface and the CAN_L interface are shorted respectively, thereby shorting the CAN_H interface and / or the CAN_L interface.

[0103] When the second processor 44 detects a level signal on the CAN_H interface and / or the CAN_L interface, it indicates that the vehicle interface J1 has not been completely destroyed. At this time, the second processor 44 outputs a fifth level signal to the third processor 45, and the third processor 45 converts and outputs a first detection signal, triggering the first processor 20 to perform anti-tamper normal operation, and the vehicle unit 100 operates normally.

[0104] Furthermore, when the second processor 44 detects no voltage level signal on the CAN_H interface and / or the CAN_L interface, it indicates that the vehicle interface J1 is damaged and the CAN_H interface and / or the CAN_L interface are in an open circuit state. At this time, the second processor 44 outputs a sixth voltage level signal to the third processor 45, and the third processor 45 converts and outputs a second detection signal to trigger the first processor 20 to perform anti-tampering abnormal actions, such as erasing sensitive information such as keys and data, to achieve anti-tampering protection.

[0105] Assuming Figure 8 As shown, the first signal line L1 is shorted to the positive power line LP+, corresponding to the CAN_H interface being shorted to the positive power interface P+. The second signal line L2 is shorted to the negative power line LP-, corresponding to the CAN_L interface being shorted to the negative power interface P-. When the vehicle interface J1 is normal and not damaged, the second processor 44 detects that the CAN_H interface is at a high level and the CAN_L interface is at a low level, and outputs a fifth level signal to the third processor 45. The third processor 45 converts and outputs the first detection signal, triggering the first processor 20 to perform anti-tamper normal operation, and the vehicle unit 100 works normally.

[0106] When the vehicle interface J1 is damaged to cause the first signal line L1 and the second signal line L2 to be disconnected from the positive power supply line LP+ and the negative power supply line LP- respectively, the second processor 44 detects that the CAN_H interface CAN_H is at a high level and that there is no level signal on the CAN_L interface CAN_L, and outputs a sixth level signal to the third processor 45, and the third processor 45 converts and outputs a second detection signal, and triggers the first processor 20 to perform anti-disassembly abnormal action, for example, to perform key, data, and other sensitive information erasure work, to achieve anti-disassembly protection.

[0107] Among them, the second processor 44 and the third processor 45 can use an additional processor structure or reuse the processor inside the vehicle-mounted unit 100.

[0108] In an optional embodiment, the second processor 44 is integrated with the first level diagnosis circuit 41 and the second level diagnosis circuit 42, and the third processor 45 is integrated with the level conversion circuit 43.

[0109] And in another optional embodiment, the second processor 44 is reused as a logic circuit inside the CAN transceiver 30, and the third processor 45 is reused as a receiver inside the CAN transceiver 30.

[0110] Among them, the CAN transceiver 30 usually includes a driver, a logic circuit, and a receiver, etc. The driver is used to amplify the signal from the processor and send it to the CAN interface through the CAN_H pin and the CAN_L pin. The logic circuit is responsible for functions such as data synchronization, error detection, level judgment, data filtering, and error reporting, etc., to ensure the accuracy and integrity of data transmission. The receiver is used to convert the differential signal of the CAN interface into a level signal that the processor can process.

[0111] Therefore, by reusing the internal logic circuit and receiver, the level diagnosis and level conversion work can be achieved, that is, the work of the second processor 44 and the third processor 45 described above, which simplifies the structure of the vehicle-mounted unit 100 and reduces the design cost.

[0112] Further, in order to realize the power-off protection of the vehicle-mounted unit 100, to realize that the first processor 20 has a corresponding reaction time to perform the storage work of the anti-disassembly information and other data when the vehicle-mounted unit 100 is powered off, in an optional embodiment, as shown in Figure 9 The vehicle-mounted unit 100 further comprises:

[0113] The power input end of the delay power-off circuit 50 is connected with the power output end of the power module 10, the power output end of the delay power-off circuit 50 is connected with the CAN transceiver 30, the anti-disassembly detection circuit 40 and the first processor 20 respectively, and the delay power-off circuit 50 is used for providing the working power of the preset time length to the CAN transceiver 30, the anti-disassembly detection circuit 40 and the first processor 20 when the power module 10 is powered off.

[0114] In the embodiment, when the vehicle-mounted unit 100 is normally powered and works, the delay power-off circuit 50 stores part of the electric energy, when the power line of the vehicle-mounted unit 100 is disconnected or the car machine 200 cannot supply power to the vehicle-mounted unit 100, the vehicle-mounted unit 100 is powered off, at this time, the power module 10 has no power output, the delay power-off circuit 50 discharges and provides the working power of the preset time length to each power-receiving module in the vehicle-mounted unit 100, and the first processor 20 performs the storage work of the anti-disassembly information and other data after monitoring the power-off, so as to prevent the loss of data information.

[0115] In the embodiment, the delay power-off circuit 50 can adopt a battery, a capacitor C1 and other energy storage devices, in an optional embodiment,

[0116] In order to simplify the structure of the vehicle-mounted unit 100, in an optional embodiment, as shown in Figure 10 The delay power-off circuit 50 includes a fifth resistor R5 and a capacitor C1.

[0117] The first end of the fifth resistor R5 constitutes the power input end of the delay power-off circuit 50, the second end of the fifth resistor R5 is connected with the first end of the capacitor C1 to constitute the power output end of the delay power-off circuit 50, and the second end of the capacitor C1 is grounded.

[0118] In the embodiment, the capacitor C1 constitutes an energy storage element, stores part of the electric energy when the vehicle-mounted unit 100 is normally powered and works, and discharges and provides the working power of the preset time length for the first processor 20 when the power line of the vehicle-mounted unit 100 is disconnected or the car machine 200 cannot supply power to the vehicle-mounted unit 100, so that the first processor 20 can perform the storage work of the anti-disassembly information and other data after monitoring the power-off, thereby preventing the loss of data information.

[0119] The beneficial effects of the embodiment of the utility model compared with prior art are: the vehicle-mounted unit 100 includes vehicle-mounted interface J1, power module 10, first processor 20, CAN transceiver 30 and anti-disassembly detection circuit 40, vehicle-mounted interface J1 constitutes the anti-disassembly assembly of vehicle-mounted unit 100, when vehicle-mounted unit 100 is in normal anti-disassembly state, the CAN_H interface CAN_H and / or CAN_L interface CAN_L of vehicle-mounted interface J1 is in short-circuit state, anti-disassembly detection circuit 40 outputs first detection signal to first processor 20, first processor 20 determines that the current vehicle-mounted unit 100 is in normal anti-disassembly state, and executes anti-disassembly normal action, when the CAN_H interface CAN_H and CAN_L interface CAN_L are broken and open circuit, anti-disassembly detection circuit 40 outputs second detection signal, first processor 20 determines that the current vehicle-mounted unit 100 is in anti-disassembly abnormal state, and executes anti-disassembly abnormal action, realizes anti-disassembly protection, and through the monitoring CAN_H interface CAN_H and CAN_L interface CAN_L state of vehicle-mounted interface J1, anti-disassembly protection can be realized, and it is not necessary to set additional anti-disassembly key and carry out CAN development, simplify the structure of vehicle-mounted unit 100 and reduce design cost.

[0120] The utility model further provides a kind of ETC equipment, and the ETC equipment includes vehicle-mounted unit 100, and the specific structure of the vehicle-mounted unit 100 refers to above embodiment, since the ETC equipment adopts all technical solutions of above-mentioned all embodiments, at least has all beneficial effects brought by the technical scheme of above-mentioned embodiment, here is not repeated.

[0121] The above-described embodiments are only used to illustrate the technical solutions of the utility model, rather than limit them; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it still can modify the technical scheme recorded in the foregoing each embodiment, or make equivalent replacement to part of technical features; and these modifications or replacements do not make the essence of corresponding technical scheme deviate from the spirit and scope of the technical scheme of each embodiment of the utility model, and all should be included in the protection scope of the utility model.

Claims

1. An in-vehicle unit, characterized by comprising: The vehicle-mounted unit comprises: a vehicle-mounted interface for connecting a car machine, the vehicle-mounted interface comprising a power interface and a CAN interface, the CAN interface comprising a CAN_H interface and a CAN_L interface; a power module connected to the power interface, for obtaining a direct-current power supply and outputting a working power supply; a first processor connected to the power module, the first processor being triggered to execute a normal anti-disassembly action by a first detection signal and to execute an abnormal anti-disassembly action by a second detection signal; a CAN transceiver connected between the CAN interface and the first processor, the CAN transceiver also being connected to the power module, the CAN transceiver being used for CAN communication; an anti-disassembly detection circuit connected to the CAN interface, the power module and the first processor, the anti-disassembly detection circuit being triggered to output the first detection signal by a level signal of the CAN_H interface and / or the CAN_L interface, or being triggered to output the second detection signal when there is no level signal in the CAN_H interface and the CAN_L interface.

2. The vehicle-mounted unit of claim 1, wherein, The vehicle-mounted unit further comprises: a connecting piece for connecting the vehicle-mounted interface and the car machine, wherein when the connecting piece is not connected to the car machine, the connecting piece at least shorts the corresponding two interfaces of the power interface, the CAN_H interface and the CAN_L interface.

3. The car kit of claim 2, wherein, The anti-disassembly detection circuit comprises: a first level diagnosis circuit connected to the CAN_H interface and the power module, the first level diagnosis circuit being triggered to output a first level signal when the CAN_H interface has a level signal, or outputting a second level signal when the CAN_H interface has no level signal; a second level diagnosis circuit connected to the CAN_L interface and the power module, the second level diagnosis circuit being triggered to output a third level signal when the CAN_L interface has a level signal, or outputting a fourth level signal when the CAN_L interface has no level signal; a level conversion circuit connected to the power module, the first level diagnosis circuit, the second level diagnosis circuit and the first processor, the level conversion circuit being triggered to output the first detection signal when receiving at least one of the first level signal and the third level signal, or being triggered to output the second detection signal when receiving the second level signal and the fourth level signal.

4. The car kit of claim 3, wherein, The first level diagnosis circuit comprises a first resistor, a second resistor, a first switch tube, a first inverter and a first OR gate. An input end of the first inverter and a first input end of the first OR gate are connected to constitute an input end of the first level diagnosis circuit, an output end of the first inverter is connected with a second input end of the first OR gate, a first end of the first resistor is connected with a positive power supply end, a second end of the first resistor is connected with a first end of the first switch tube to constitute an output end of the first level diagnosis circuit, a control end of the first switch tube is connected with an output end of the first OR gate, a second end of the first switch tube is connected with a first end of the second resistor, and a second end of the second resistor is grounded.

5. The car kit of claim 3, wherein, The second level diagnosis circuit comprises a third resistor, a fourth resistor, a second switch tube, a second inverter and a second OR gate. An input end of the second inverter and a second input end of the second OR gate are connected to constitute an input end of the second level diagnosis circuit, an output end of the second inverter is connected with a second input end of the second OR gate, a first end of the third resistor is connected with a positive power supply end, a second end of the third resistor is connected with a second end of the second switch tube to constitute an output end of the second level diagnosis circuit, a control end of the second switch tube is connected with an output end of the second OR gate, a second end of the second switch tube is connected with a first end of the fourth resistor, and a second end of the fourth resistor is grounded.

6. The car kit of claim 3, wherein, The level conversion circuit comprises an AND gate and a signal amplifier. A first input end of the AND gate is connected with an output end of the first level diagnosis circuit, a second input end of the AND gate is connected with an output end of the second level diagnosis circuit, an output end of the AND gate is connected with an input end of the signal amplifier, and an output end of the signal amplifier constitutes an output end of the level conversion circuit.

7. The vehicle-mounted unit of claim 2, wherein, The anti-disassembly detection circuit comprises: A second processor connected with the CAN_H interface and the power module respectively, the second processor outputs a fifth level signal when detecting that at least one of the CAN_H interface and the CAN_L interface has a level signal, or outputs a sixth level signal when detecting that neither of the CAN_H interface and the CAN_L interface has a level signal; A third processor connected with the second processor, the first processor and the power module respectively, the third processor converts the fifth level signal into the first detection signal and converts the sixth level signal into the second detection signal.

8. The car kit of claim 7, wherein, The second processor is multiplexed as a logic circuit inside the CAN transceiver, and the third processor is multiplexed as a receiver inside the CAN transceiver.

9. The car kit of any one of claims 1 to 8, characterized in that The vehicle-mounted unit further comprises: A delay power-off circuit, a power input end of the delay power-off circuit is connected with a power output end of the power module, power output ends of the delay power-off circuit are connected with the CAN transceiver, the anti-disassembly detection circuit and the first processor respectively, and the delay power-off circuit is used for providing a preset time length of working power to the CAN transceiver, the anti-disassembly detection circuit and the first processor when the power module is powered off.

10. An ETC apparatus characterized by comprising: The vehicle-mounted unit comprises any one of claims 1-9.

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