Electronic module

Abstract

The electronic module of the present application can reduce the current flowing when the electronic module is turned off, i.e. the dark current, and help prevent the battery of a vehicle or the like from being depleted. To this end, the electronic module connected to the first electronic module via a communication line has a structure including a microcomputer, a power IC that supplies power to the microcomputer, a power control circuit that supplies power to the power IC from a battery power source, a control line connected to the communication line, and a first switching circuit that connects the control line to the power control circuit.

Description

Technical Field

[0001] This invention relates to reducing dark current in electronic modules. Background Technology

[0002] The electronic modules that control a vehicle, namely electronic control units (ECUs), typically consist of a main ECU that outputs control commands and multiple sub-ECUs connected to the main ECU that implement engine control, automatic braking control, display control, etc., based on the control commands from the main ECU. Furthermore, the ECU processes various sensor signals used to identify external conditions. Therefore, as the number of sensors increases, so does the number of sub-ECUs connected to and processing sensor signals, or sub-ECUs equipped with sensors.

[0003] Generally speaking, there are methods to start the ECU based on the ignition signal. However, as the number of auxiliary ECUs increases, more ignition signal wires are required, which leads to an increase in the number of wires needed for the entire vehicle.

[0004] Prior art in this technical field includes Patent Document 1. Patent Document 1 describes a method for starting an ECU by controlling the power supply IC to power a microcomputer via a communication bus by monitoring the communication status on a communication line in an electronic control device using a communication signal.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-51422 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In the ECU startup method described in Patent Document 1, even when the ECU is off, current flows to the power IC to monitor the communication status on the communication line. In order to continuously supply power to the power IC itself, in the case of an autonomous driving system that needs to connect multiple sub-ECUs, the amount of current flowing to the sub-ECUs cannot be ignored, which affects the consumption of the vehicle's battery.

[0010] The purpose of this invention is to provide an electronic module that, in view of the above-mentioned issues, reduces the current flowing when the electronic module is turned off, i.e., the dark current, and helps to prevent battery damage in vehicles and the like.

[0011] Technical solutions for solving the problem

[0012] As an example of the present invention, an electronic module connected to a first electronic module via a communication line is provided, which has the following structure: a microcomputer; a power supply IC that supplies power to the microcomputer; a power control circuit that supplies power to the power supply IC from a battery; a control line connected to the communication line; and a first switching circuit that connects the control line to the power control circuit.

[0013] The effects of the invention

[0014] According to the present invention, an electronic module capable of reducing dark current can be provided. Attached Figure Description

[0015] Figure 1 This is a schematic structural diagram of the autonomous driving system in Example 1.

[0016] Figure 2 This is a schematic diagram of the connection between the main ECU and the first auxiliary ECU in Embodiment 1.

[0017] Figure 3 This is a diagram illustrating the power supply / power cut-off sequence of the first ECU in Embodiment 1.

[0018] Figure 4 This is a schematic diagram of the connection between the main ECU, the first auxiliary ECU, and the second auxiliary ECU in Embodiment 2.

[0019] Figure 5 This is a schematic structural diagram of the main ECU in Example 3.

[0020] Figure 6 This is a diagram illustrating the power-on / power-off sequence of the sub-circuit board using UART communication in Embodiment 3.

[0021] Figure 7 This is a diagram illustrating the power-on / power-off sequence of the sub-circuit board using SPI communication in Embodiment 3. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the following embodiments will use an autonomous driving system (vehicle control system) to which the present invention is applied as an example.

[0023] Example 1

[0024] Figure 1 This is a schematic structural example of the autonomous driving system in this embodiment. Figure 1In the autonomous driving system, radars 11, 12, 13, and 14 (first main ECU 111, second auxiliary ECU 12, third auxiliary ECU 13, and fourth auxiliary ECU 14) and cameras 15 and 16 (fifth auxiliary ECU 15 and sixth auxiliary ECU 16) are used as external identification sensors to identify the external conditions of the vehicle.

[0025] Furthermore, the autonomous driving system includes an autonomous driving control unit 1 (hereinafter referred to as the main ECU 1), a braking control unit 2, an engine control unit 3, a power steering control unit 4, and a gateway control unit 5. Among these, the braking control unit 2, engine control unit 3, and power steering control unit 4 are collectively referred to as the actuator control unit for controlling the vehicle's movements. Additionally, Figure 1 The main ECU1 and auxiliary ECU, among other components, constitute the electronic module.

[0026] The radar, namely the first auxiliary ECU11, the second auxiliary ECU12, the third auxiliary ECU13, the fourth auxiliary ECU14, the main ECU1, the brake control device 2, the engine control device 3, the power steering control device 4, and the gateway control device 5, can communicate with each other through vehicle networks (such as CAN (Controller Area Network) and Ethernet (registered trademark)).

[0027] Braking control unit 2 is a control unit that performs braking control (braking force control) of the vehicle, and engine control unit 3 is a control unit that controls the engine that generates the driving force of the vehicle. Additionally, power steering control unit 4 is a control unit that controls the power steering of the vehicle. Gateway control unit 5 is a control unit that relays communication with other domains outside the autonomous driving system.

[0028] Here, when the main ECU1 receives a request for autonomous driving, it calculates the vehicle's trajectory based on external information from the first auxiliary ECU 11 to the sixth auxiliary ECU 16, etc. Then, the main ECU1 outputs control commands for braking and driving force to the braking control unit 2, engine control unit 3, and power steering control unit 4 in a manner that causes the vehicle to move along the calculated trajectory. The braking control unit 2, engine control unit 3, and power steering control unit 4 receive the control commands for autonomous driving control from the main ECU1 and output operating signals to each controlled object (actuator).

[0029] Figure 2 This is a schematic diagram showing the connection between the main ECU1 and the radar 11 (hereinafter referred to as the first auxiliary ECU11) in this embodiment.

[0030] Figure 2In this configuration, the main ECU1 includes a power supply IC1a, a microcomputer 1b, and a communication IC1c. The power supply IC1a supplies a specified voltage to the microcomputer 1b, and there is an enable signal line 1d and a transmit / receive communication line 1e between the microcomputer 1b and the communication IC1c.

[0031] The first auxiliary ECU 11 includes a power supply IC 11a, a microcomputer 11b, and a communication IC 11c. The power supply IC 11a supplies a specified voltage to the microcomputer 11b. The microcomputer 11b communicates with the microcomputer 1b of the main ECU 1 via the communication ICs 11c and 11c, transmitting external information acquired by sensors to the microcomputer 1b. The sensor body is omitted. Communication between the main ECU 1 and the first auxiliary ECU 11 may be configured as, for example, a CAN bus.

[0032] In addition, the first ECU11 has a power control circuit 11d that supplies power to the power IC11a from the battery power supply VBAT, and has a first switching circuit 11e and a second switching circuit 11f for controlling the power control circuit 11d.

[0033] The first switch control line 11g introduces the communication line from the CAN_H or CAN_L signal line of the CAN bus into the internal circuit and connects to the first switch circuit 11e. The voltage fluctuation of the communication line controls the first switch circuit 11e. In addition, the first switch control line 11g is connected to the first switch circuit 11e from the communication line via a high resistor, thereby reducing the impact on the communication line.

[0034] The second switch control line 11h is connected to the microcomputer 11b. By controlling the microcomputer 11b, even if the first switch circuit 11e switches ON / OFF due to communication status, the power control circuit 11d is kept in a power supply state.

[0035] Alternatively, if the first switch control line 11g is connected to the positive side (CAN_H signal) of the communication line, the second switch circuit 11f and the second switch control line 11h may not be present.

[0036] An enable signal line 11i and a transmit / receive communication line 11j are provided between the microcomputer 11b and the communication IC 11c.

[0037] Figure 3 This is a diagram illustrating the power supply / power cut-off sequence of the first ECU11 in this embodiment.

[0038] Figure 3 In the process, the enable signal line 1d is controlled by the microcomputer 1b of the main ECU1, and the voltage in the communication line, i.e., the CAN_H / L signal, rises to the recessive voltage (the voltage in standby mode).

[0039] The voltage in the first switch control line 11g of the first ECU 11 increases with the voltage of the communication line. When the voltage exceeds a certain threshold, the first switch circuit 11e operates, enabling the power control circuit 11d to be powered on. During power supply, the power supply IC 11a operates, supplying a specified voltage to the microcomputer 11b, which then starts up.

[0040] When the microcomputer 11b starts up, it controls the second switch control line 11h to stabilize the power supply to the power control circuit 11d. Finally, the microcomputer 11b controls the enable signal line 11i to enable it to communicate with the main ECU1.

[0041] During the power cut-off sequence, the microcomputer 1b of the main ECU1 transmits an end notification to the microcomputer 11b of the first auxiliary ECU11 via a communication line, controls the enable signal line 1d, and disables the communication IC1c.

[0042] When the microcomputer 11b of the first auxiliary ECU 11 receives the end notification, it controls the enable signal line 11i, thus disabling the communication IC 11c. Because the communication IC 1c of the main ECU 1 and the communication IC 11c of the first auxiliary ECU are disabled, the voltage of the communication line decreases, and the first switching circuit becomes ineffective.

[0043] The microcomputer 11b of the first ECU 11 performs the final processing. After the final processing is completed, it controls the second switch control line to disable the second switch circuit 11f, thereby turning the power control circuit 11d into a power-off state.

[0044] Thus, according to this embodiment, the main ECU and the auxiliary ECU are connected via a communication line, such as CAN. When the main ECU can communicate, the communication line enters a standby state, and the voltage rises. The auxiliary ECU introduces the communication line as a signal line to control the power control circuit, using the rising voltage to control the power control circuit to supply power to the auxiliary ECU. That is, the standby voltage (latent voltage) of the communication line turns the switching circuit ON, thus starting the auxiliary ECU. Because the auxiliary ECU's power IC does not need to monitor the communication status on the communication line, it does not need to supply power to the power IC when the auxiliary ECU is off, and the auxiliary ECU can provide a wake-up function that reduces dark current.

[0045] Therefore, in the ECU of advanced driver assistance systems such as autonomous driving, which are prone to generating dark currents due to the connection of multiple sensors, it can help prevent low battery power.

[0046] Example 2

[0047] Figure 4 This is a schematic structural diagram of the main ECU1 connecting the first auxiliary ECU11 and the radar 12 (hereinafter referred to as the second auxiliary ECU12) in this embodiment.

[0048] Figure 4 In this configuration, the second ECU 12, like the first ECU 11, includes a power supply IC 12a, a microcomputer 12b, and a communication IC 12c. It also has a power control circuit 12d that supplies power to the power supply IC 12a from a battery power source VBAT, and a first switching circuit 12e and a second switching circuit 12f for controlling the power control circuit 12d. The sensor body is omitted.

[0049] In order to communicate with the microcomputer 1b of the main ECU 1, the microcomputer 12b is connected to the same CAN bus as the first auxiliary ECU 11.

[0050] The first switch control line 12g introduces the communication line from the CAN_H signal line or CAN_L signal line of the CAN bus into the interior and connects to the first switch circuit 12e, using the voltage variation of the communication line for control.

[0051] The second switch control line 12h is connected to the microcomputer 12b. By controlling the microcomputer 12b, even if the first switch circuit 12e switches ON / OFF due to communication status, the power control circuit 12d is kept in a power supply state.

[0052] An enable signal line 12i and a transmit / receive communication line 12j are provided between the microcomputer 12b and the communication IC 12c.

[0053] Alternatively, if the first switch control line 12g is connected to the positive side (CAN_H signal) of the communication line, the second switch circuit 12f and the second switch control line 12h may not be present.

[0054] The power supply / disconnection sequence of the first sub-ECU11 and the second sub-ECU12 in this embodiment is similar to... Figure 3 The sequence of Example 1 shown is the same, so its description is omitted. Furthermore, this example describes the case where the main ECU is connected to two auxiliary ECUs, but the same structure and effect can be obtained even with three or more connected ECUs.

[0055] Thus, according to this embodiment, in the case of a main ECU and multiple sub-ECUs, similar to Embodiment 1, the sub-ECUs can provide a wake-up function that can reduce dark current. In ECUs of advanced driver assistance systems such as autonomous driving, which are prone to generating dark current due to the connection of multiple sensors, this can help prevent low battery power.

[0056] Example 3

[0057] Figure 5 This is a schematic structural diagram of the main ECU1 in this embodiment.

[0058] Figure 5 In this configuration, the main ECU1 consists of a main circuit board 100 and sub-circuit boards 101 and 102. Sub-circuit boards 101 and 102 implement additional options required for autonomous driving scenarios. Communication between the main circuit board 100 and sub-circuit boards 101, and between the main circuit board 100 and sub-circuit boards 102, is achieved, for example, via UART (Universal Asynchronous Receiver / Transmitter) or SPI (Serial Peripheral Interface). Furthermore, the main circuit board 100, sub-circuit boards 101, and 102 each constitute an electronic module.

[0059] Figure 5 In this circuit, the main circuit board 100 includes a power supply IC 100a and a first microcomputer 100b. Communication with the sub-circuit board 101 is achieved via a UART communication line 100c, and communication with the sub-circuit board 102 is achieved via an SPI communication line 100e. It is connected to the sub-circuit board via connectors 100g and 100h.

[0060] The secondary circuit board 101 has a power supply IC 101a and a second microcomputer 101b, a power control circuit 101c that supplies power to the power supply IC 101a from a battery power source VBAT, and a first switching circuit 101d and a second switching circuit 101e for controlling the power control circuit 101c. It is connected to the main circuit board via a connector 101h.

[0061] The first switch control line 101f introduces the communication line from the UART's TX signal line into the internal circuit and connects to the first switch circuit 101d, using voltage fluctuations in the communication line for control.

[0062] The second switch control line 101g is connected to the second microcomputer 101b. By controlling the second microcomputer 101b, even if the first switch circuit 101d switches ON / OFF due to communication status, the power control circuit 101c remains in the power supply state.

[0063] Similar to sub-circuit board 101, sub-circuit board 102 has a power supply IC 102a and a third microcomputer 102b. It also has a power control circuit 102c that supplies power to the power supply IC 102a from battery power VBAT, and a first switching circuit 102d and a second switching circuit 102e for controlling the power control circuit 102c. It is connected to the main circuit board via connector 102h.

[0064] The first switch control line 102f introduces the communication line from the CS signal line of the SPI into the internal circuit and connects to the first switch circuit 102d, using the voltage variation of the communication line for control.

[0065] The second switch control line 102g is connected to the third microcomputer 102b. By controlling the third microcomputer 102b, even if the first switch circuit 102d switches ON / OFF due to communication status, the power control circuit 102c remains in the power supply state.

[0066] Figure 6 This is a diagram illustrating the power supply / power cut-off sequence of the sub-circuit board 101 in this embodiment.

[0067] Figure 6 In this process, the UART communication line 100c of the first microcomputer 100b on the main circuit board 100 becomes communicable, thereby causing the voltage in the TX signal line 100d to rise to a High level. The voltage in the first switch control line 101f of the sub-circuit board 101 rises along with the voltage of the communication line. When it exceeds a certain threshold voltage, the first switch circuit 101d operates, enabling the power control circuit 101c to be powered on. During power supply, the power supply IC 101a operates, and the second microcomputer 101b starts up.

[0068] When the second microcomputer 101b starts up, it controls the second switch control line 101g to stabilize the power supply of the power control circuit 101c.

[0069] During the power-off sequence, the first microcomputer 100b of the main circuit board 100 transmits an end notification to the second microcomputer 101b of the sub-circuit board 101 via a communication line, causing the voltage of the TX signal line 100d of the UART communication line 100c to drop to a Low level, thus invalidating the UART communication.

[0070] Because the TX signal line 100d drops to a Low level, the voltage of the first switch control line 101f decreases, and the first switch circuit 101d becomes ineffective.

[0071] When the second microcomputer 101b receives the termination notification, it performs termination processing. After the termination processing is completed, it controls the second switch control line 101g to disable the second switch circuit 101e, thereby putting the power control circuit 101c into a power-off state.

[0072] The first microcomputer 100b of the main circuit board 100 can confirm that the power supply to the sub-circuit board 101 has been cut off by monitoring the voltage of the RX signal line of the UART communication line 100c.

[0073] Figure 7 This is a diagram illustrating the power supply / power cut-off sequence of the sub-circuit board 102 in this embodiment.

[0074] Figure 7In this process, the SPI communication line 100e of the first microcomputer 100b on the main circuit board 100 becomes communicable, thereby causing the voltage in the CS signal line 100f to rise to a High level. The voltage in the first switch control line 102f of the sub-circuit board 102 rises along with the voltage of the communication line. When it exceeds a certain threshold voltage, the first switch circuit 102d operates, enabling the power control circuit 102c to be powered on. During power supply, the power supply IC 102a operates, and the third microcomputer 102b starts up.

[0075] When the third microcomputer 102b starts up, it controls the second switch control line 102g to stabilize the power supply to the power control circuit 102c. The third microcomputer 102b controls the enable signal line to achieve a state where it can communicate with the first microcomputer 100b on the main circuit board 100.

[0076] During the power-off sequence, the first microcomputer 100b of the main circuit board 100 transmits an end notification to the third microcomputer 102b of the sub-circuit board 102 via a communication line, causing the voltage of the CS signal line 100f of the SPI communication line 100e to drop to a Low level, thus invalidating the SPI communication.

[0077] Because the CS signal line 100f drops to a Low level, the voltage of the first switch control line 102f decreases, and the first switch circuit 102d becomes invalid.

[0078] When the third microcomputer 102b receives the termination notification, it performs termination processing. After the termination processing is completed, it controls the second switch control line 102g to disable the second switch circuit 102e, thereby putting the power control circuit 102c into a power-off state.

[0079] By making improvements such as setting the IDLE state of the DIN signal line of the SPI communication line 100e to High (pull-up setting), the first microcomputer 100b of the main circuit board 100 can confirm that the power supply to the sub-circuit board 102 has been cut off by monitoring the DIN signal line.

[0080] Thus, according to this embodiment, since the standby voltage of the communication line turns the switching circuit ON and starts the sub-circuit board, there is no need to supply power to the power IC when the sub-circuit board is off. The sub-circuit board can provide power control that reduces dark current.

[0081] The embodiments have been described above, but the present invention is not limited to the above embodiments and includes various modifications. For example, the present invention is not limited to vehicles and motor vehicles; it can be applied to any electronic module connected via a communication line. Furthermore, the above embodiments are described in detail for ease of understanding of the present invention and are not limited to having all the described structures. Additionally, a part of the structure of one embodiment can be replaced with the structure of another embodiment, and structures of other embodiments can be added to the structure of one embodiment. Furthermore, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0082] Explanation of reference numerals in the attached figures

[0083] 1: Automatic driving control unit (main ECU), 2: Braking control unit, 3: Engine control unit, 4: Power steering control unit, 5: Gateway control unit, 11, 12, 13, 14: Radar (first to fourth auxiliary ECUs), 15, 16: Camera (fifth to sixth auxiliary ECUs), 1a, 11a, 12a: Power IC, 1b, 11b, 12b: Microcomputer, 1c, 11c, 12c: Communication IC, 11d, 12d, 101c, 102c: Power control circuit, 11e, 12e, 101d, 102d: First switching circuit, 11f, 12f, 101e, 102e: Second switching circuit, 11g, 12 g, 101f, 102f: First switch control lines; 11h, 12h, 101g, 102g: Second switch control lines; 1d, 11i, 12i: Enable signal lines; 1e, 11j, 12j: Transmit / receive communication lines; 100: Main circuit board; 101, 102: Sub-circuit board; 100a, 101a, 102a: Power IC; 100b: First microcomputer; 100c: UART communication line; 100d: TX signal line; 100e: SPI communication line; 100f: CS signal line; 100g, 100h, 101h, 102h: Connectors; 101b: Second microcomputer; 102b: Third microcomputer.

Claims

1. An electronic module capable of being connected to a first electronic module via a communication line, characterized in that, include: Microcomputer; A power supply IC that powers the microcomputer; A power control circuit that supplies power to the power IC from a battery power source; Control line connected to the communication line; A first switching circuit that connects the control line to the power control circuit; and A second switching circuit connects the microcomputer to the power control circuit. The first switching circuit switches the power control circuit between ON and OFF. The control line detects the rising voltage in the communication line caused by the activation of the first electronic module, and switches the first switching circuit to ON to put the power control circuit into a power supply state. The second switching circuit enables the power control circuit to be powered on when the microcomputer is started. The first electronic module is the main ECU, and the second electronic module is the auxiliary ECU. When the power supply to the secondary ECU is cut off, the primary ECU sends a termination signal to the microcomputer via the communication line, causing both the primary and secondary ECUs to set the communication line to an invalid state. Setting the communication line to an invalid state reduces the rising voltage of the communication line. The microcomputer switches the second switching circuit to OFF to deactivate the power control circuit from the ON state.

2. The electronic module as described in claim 1, characterized in that: The communication line is a CAN_H signal line or a CAN_L signal line, and the rising voltage is a recessive voltage.

3. The electronic module as described in claim 2, characterized in that: The control line is connected from the communication line to the first switching circuit via a high resistor.

4. The electronic module as described in claim 2, characterized in that: When the communication line becomes the recessive voltage, the first switching circuit switches to ON, making the power control circuit ON, supplying power to the microcomputer, and switching the second switching circuit ON to maintain the ON state of the power control circuit.

5. The electronic module as described in claim 1, characterized in that: Multiple sub-ECUs are connected via the communication line, and power control of the multiple sub-ECUs is performed simultaneously.

6. An electronic module capable of being connected to a first electronic module via a communication line, characterized in that, include: Microcomputer; A power supply IC that powers the microcomputer; A power control circuit that supplies power to the power IC from a battery power source; Control line connected to the communication line; A first switching circuit connecting the control line to the power control circuit; and A second switching circuit connects the microcomputer to the power control circuit. The first electronic module is the main circuit board. The electronic module is a secondary circuit board. The communication line is a UART or SPI communication line used to send information from the main circuit board to the sub-circuit board. The control line branches off from the communication line within the sub-circuit board and connects to the first switching circuit of the sub-circuit board, enabling power control of the sub-circuit board. The first switching circuit switches the power control circuit between ON and OFF. The control line detects the rising voltage in the communication line caused by the startup of the main circuit board, and switches the first switching circuit to ON to put the power control circuit into a power supply state. The second switching circuit enables the power control circuit to be powered on when the microcomputer is started. When the power supply to the secondary circuit board is cut off, a termination signal is sent from the main circuit board to the microcomputer via the communication line, causing the main circuit board and the secondary circuit board to set the communication line to an invalid state. Setting the communication line to an invalid state reduces the rising voltage of the communication line. The microcomputer switches the second switching circuit to OFF to deactivate the power control circuit from the ON state.

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