Vehicle-mounted electronic control device and vehicle-mounted equipment control method

Abstract

The present invention applies to an in-vehicle electronic control unit equipped with a relay control driver circuit for controlling the on / off switching of a relay, wherein the relay is used to connect and disconnect wiring leading from a vehicle-mounted battery. The system includes a switch circuit connected to the output of the relay control driver circuit for extracting current; and a control circuit that, when an abnormality occurs in the vehicle, activates the switch circuit to extract current from the output and prevent the relay from turning on. This prevents the relay from sticking even if the output wiring harness of the relay control driver shorts with other signal wiring harnesses or power / GND lines.

Description

Technical Field

[0001] The present invention relates to a vehicle-mounted electronic control device and a vehicle-mounted equipment control method. Background Art

[0002] In recent years, the electrification of vehicles has been advancing, and the number of HEVs (Hybrid Electric Vehicles) equipped with both an engine and an electric motor is expected to increase. HEVs are equipped with an engine ECU (Engine Control Module, ECM) that controls the engine and an HEV controller (HEVC) that coordinates motor drive and engine control. However, to reduce costs, the integration of the ECM and HEVC is being studied. In the following description, the integrated ECM and HEVC is referred to as an integrated control unit.

[0003] One of the important functions of HEVC is controlling the connection relay (high-voltage relay) for the high-voltage wiring between the high-voltage battery and the inverter. This function controls the disconnection of the high-voltage relay in the event of a malfunction or failure in various functions. In particular, in the event of a collision, where the high-voltage battery wiring breaks and contacts the vehicle body, reliable disconnection of the high-voltage relay is required to prevent electric shock to vehicle occupants.

[0004] Conventionally, the ECM is typically located in the engine compartment, the HEVC is located in the cabin, and the high-voltage battery is located lower in the vehicle (e.g., under the front seat). Therefore, the HEVC and the high-voltage battery controlled by the HEVC are routed away from the front of the vehicle, where the risk of damage in a collision is higher, eliminating the risk of wiring harness damage.

[0005] On the other hand, the integrated control unit, which integrates the ECM and HEVC, also plays a crucial role in engine control, so it is preferably located in the engine compartment. In this case, there is a risk that the wiring harness that controls the high-current relay from the ECU could be damaged during a vehicle collision. For example, in the event of a power short circuit, even if the relay driver output is stopped, there is a concern that the high-current relay may not be disconnected in the existing configuration.

[0006] Patent Document 1 describes a technology for preventing the relay from sticking due to damage to the control harness of the main relay when the vehicle is damaged, by arranging the control harness of the main relay and the power supply harness close to each other outside the vehicle, so that both harnesses are inevitably damaged at the same time.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-241055 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] The technology described in Patent Document 1 is a technology that prevents relay connection and adhesion by simultaneously damaging multiple wiring harnesses when the wiring harness is damaged due to a collision. However, the degree of damage varies greatly, and the possibility of only some of the multiple wiring harnesses being damaged cannot be completely eliminated. In addition, if the integrated control unit itself is installed in the engine compartment, especially near the connector, not only the high-current relay control harness but also various signal, power, and ground harnesses are present. In the event of a collision, there is a possibility that these harnesses will short-circuit with the high-current relay control harness.

[0012] Furthermore, in order to arrange the control harness and the power supply harness of the main relay close to each other outside the vehicle cabin, it is necessary to consider the arrangement position including the layout of the vehicle.

[0013] As described above, it is required that the relays do not become stuck even if the output harness of the relay control driver is short-circuited with other signal harnesses or power / GND lines during an abnormality such as a vehicle collision.

[0014] Technical solutions to problems

[0015] In order to solve the above-mentioned problems, for example, the configuration described in the claims is adopted.

[0016] The present application includes multiple technical solutions to the above-mentioned problems. For example, it is a vehicle-mounted electronic control device having a relay control driver circuit for controlling the on-off of a relay, wherein the relay is used to connect and disconnect the wiring led out from the battery mounted on the vehicle. The vehicle-mounted electronic control device includes: a switching circuit, which is connected to the output part of the relay control driver circuit and is used to extract current; and a control circuit, which, when an abnormality occurs in the vehicle, operates the switching circuit to extract current from the output part and does not turn on the relay.

[0017] Effects of the Invention

[0018] According to the present invention, when an abnormality occurs in the vehicle, even if a short circuit occurs between the wiring harness that transmits the output of the relay control driver circuit and other signal wiring harnesses or power lines, the relay can be maintained in a non-connected state. Thus, when an abnormality occurs in the vehicle, power to the vehicle battery can be reliably cut off.

[0019] Problems, structures, and effects other than those described above will be explained through the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram showing the configuration of an example of a vehicle-mounted electronic control device according to the first embodiment of the present invention.

[0021] Figure 2 It is a timing chart showing an operation example of the first embodiment of the present invention.

[0022] Figure 3 This is a configuration diagram showing a path connected to a control signal harness according to the first embodiment of the present invention.

[0023] Figure 4 yes Figure 3 The equivalent circuit diagram of the structural diagram.

[0024] Figure 5 This is a configuration diagram showing an example of a vehicle-mounted electronic control device according to a second embodiment of the present invention.

[0025] Figure 6 This is a configuration diagram showing an example of a vehicle-mounted electronic control device according to a third embodiment of the present invention.

[0026] Figure 7 It is a configuration diagram showing an example of a vehicle-mounted electronic control device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0027] <First embodiment>

[0028] Below, reference Figures 1 to 4 A first embodiment of the present invention will be described.

[0029] Figure 1 The configurations of a vehicle-mounted electronic control unit 10 and a high-voltage battery pack 20 controlled by the vehicle-mounted electronic control unit 10 according to this embodiment are shown.

[0030] An onboard electronic control unit 10 and a high-voltage battery pack 20 are installed in a vehicle. The vehicle here is, for example, an HEV equipped with both an engine and an electric motor as driving sources. In this embodiment, the onboard electronic control unit 10 is installed in the vehicle's engine compartment 1, and the high-voltage battery pack 20 is installed in the vehicle's cabin 2. The onboard electronic control unit 10 and the high-voltage battery pack 20 are connected via control signal harnesses 111 and 112.

[0031] The high-voltage battery pack 20 has an output voltage of, for example, 100V or higher. The positive (+) and negative (-) electrodes of the cells 200 within the high-voltage battery pack 20 are connected to a high-voltage line (+) 211 and a high-voltage line (-) 212 via high-voltage relays 201 and 202. The high-voltage relays 201 and 202 are switches that connect and disconnect the cells 200 from the high-voltage lines 211 and 212, and this connection and disconnection is controlled by the vehicle-mounted electronic control unit 10.

[0032] High-voltage line (+) 211 and high-voltage line (-) 212 are connected to a DC-DC converter, a motor for driving, and a generator for power generation (not shown). The high-voltage battery pack 20 typically includes a pre-charging line for pre-charging high-voltage line (+) 211 and a connection relay, but these are omitted here for simplicity.

[0033] The vehicle-mounted electronic control device 10 includes a microcomputer (hereinafter referred to as a microcomputer) 100 , control output drivers 101 and 102 , and a control circuit 103 .

[0034] Control output drivers 101 and 102 are N-channel field-effect transistors that control high-current relays 201 and 202. A positive power source is supplied to the drain of each control output driver 101 and 102 from a 12V battery (not shown) via relay 131. This relay 131 is a failsafe function, and its connection and disconnection are controlled by the output of driver 132 within the in-vehicle electronic control unit 10.

[0035] The source electrodes of the control output drivers 101 and 102 are connected to one end of the control signal harnesses 111 and 112 via the driver output terminals OUTP and OUTN. The other ends of the control signal harnesses 111 and 112 are connected to the control terminals of the high-voltage relays 201 and 202. This connection allows the outputs of the control output drivers 101 and 102 to be connected and disconnected by the high-voltage relays 201 and 202.

[0036] The control circuit 103 controls the high-current relays 201 and 202 and controls the voltage of the gate signal 114 based on instructions from the microcomputer 100. The gate signal 114 output from the control circuit 103 is supplied to the gates of the control output drivers 101 and 102.

[0037] One end of a Zener diode 104 is connected between the source of each of the control output drivers 101 and 102 and the driver output terminals OUTP and OUTN. The other end of the Zener diode 104 is connected to a ground potential portion via a diode 105 .

[0038] Thus, by connecting the Zener diode 104 and the diode 105 to the driver output terminals OUTP and OUTN, it is possible to appropriately protect the control output drivers 101 and 102. Specifically, the Zener diode 104 and the diode 105 can prevent the reverse electromotive force caused by the inductance of the high-voltage relays 201 and 202 from causing a breakdown between the drain and source of the control output drivers 101 and 102 after the control output drivers 101 and 102 are turned off.

[0039] In addition, a switching element such as a field effect transistor having an active clamp function may be used instead of the Zener diode 104 and the diode 105 .

[0040] An external signal 113, serving as a vehicle abnormality detection signal, is supplied to the vehicle-mounted electronic control unit 10. Here, the external signal 113 is a signal notifying the vehicle that a collision has occurred. For example, the external signal 113 is supplied to the vehicle-mounted electronic control unit 10 from an airbag controller (not shown) installed in the vehicle. In the following description, the external signal 113 is referred to as the collision notification signal 113.

[0041] The collision notification signal 113 is supplied to the microcomputer 100 and the control circuit 103 via the logic circuit 133. The collision notification signal 113 is also supplied to the control circuit 125 described later via the logic circuit 133.

[0042] Then, when the microcomputer 100 detects an abnormality based on the collision notification signal 113, it controls the driver 132 to disconnect the fail-safe relay 131, thereby shutting off the power supply to the control output drivers 101 and 102. Thus, when an abnormality occurs, the high-current relays 201 and 202 are disconnected.

[0043] In this case, when the microcomputer 100 detects an abnormality based on the collision notification signal 113, the control circuit 103 directly controls the control output drivers 101 and 102 to disconnect the high-voltage relays 201 and 202.

[0044] Furthermore, in the in-vehicle electronic control device 10 of this embodiment, a series circuit consisting of a backflow prevention circuit 123 and a switch circuit 121 is connected to the source of the control output driver 101, and a series circuit consisting of a backflow prevention circuit 124 and a switch circuit 122 is connected to the source of the control output driver 102. The backflow prevention circuits 123 and 124 and the switch circuits 121 and 122 are each formed of an N-channel field-effect transistor.

[0045] Specifically, the source of the control output driver 101 is connected to the source of the field effect transistor serving as the backflow prevention circuit 123, and the drain of the field effect transistor serving as the backflow prevention circuit 123 is connected to the drain of the field effect transistor serving as the switch circuit 121. Furthermore, the source of the field effect transistor serving as the switch circuit 121 is connected to the ground potential portion.

[0046] Similarly, the source of the control output driver 102 is connected to the source of the field effect transistor serving as the backflow prevention circuit 124, and the drain of the field effect transistor serving as the backflow prevention circuit 124 is connected to the drain of the field effect transistor serving as the switch circuit 122. Furthermore, the source of the field effect transistor serving as the switch circuit 122 is connected to the ground potential portion.

[0047] The backflow prevention circuits 123 and 124 and the switch circuits 121 and 122 are controlled by gate signals from a control circuit 125. When the control circuit 125 detects an abnormality based on the collision notification signal 113, it outputs a gate signal to activate the backflow prevention circuits 123 and 124 and the switch circuits 121 and 122. Alternatively, the control circuit 125 activates the backflow prevention circuits 123 and 124 and the switch circuits 121 and 122 based on an instruction from the microcomputer 100.

[0048] When the microcomputer 100 receives the collision notification signal 113, the timing at which the control circuit 125 activates the backflow prevention circuits 123 and 124 and the switch circuits 121 and 122 is set to be slightly later than the timing at which the control circuit 103 turns off the control output drivers 101 and 102 in response to the collision notification signal 113. In other words, a certain time difference needs to be provided between the timing at which the backflow prevention circuits 123 and 124 and the switch circuits 121 and 122 are activated and the timing at which the control output drivers 101 and 102 are turned off.

[0049] In addition, although an example using N-channel field-effect transistors as the backflow prevention circuits 123 and 124 is shown here, diode elements can also be used instead of N-channel field-effect transistors. However, since a large current is assumed to flow through the backflow prevention circuits 123 and 124 in this embodiment, it is more preferable to use field-effect transistors to suppress heat generation.

[0050] Figure 2 1 is a timing chart showing an example of control of the high-current relay 201 by the vehicle-mounted electronic control unit 10 . Figure 2 , the control state of one strong electric relay 201 is shown, but the same description can be given for the other strong electric relay 202 using the same control state.

[0051] Figure 2 The collision notification signal 113 shown in the first row of FIG is normally at a low level, and is at a high level after a collision is detected.

[0052] Figure 2 The gate signal 114 shown in the second row of FIG is the gate signal 114 output by the control circuit 103 to the control output driver 101. Regarding gate signal 114, the vehicle-mounted electronic control unit 10 begins operation. At time t1, gate signal 114 transitions from a low level to a high level, turning the control output driver 101 on. This turns the control output driver 101 on, causing the output voltage at the driver output terminal OUTP to rise, and coil current to flow through the high-current relay 201.

[0053] in addition, Figure 2 The coil current of the high-voltage relay 201 shown in the 7th row of FIG begins to flow at time t1 and exceeds the relay closing threshold current I_close at time t2. Figure 2 As shown in the 8th row of , the state of the high-current relay 201 changes from the disconnected state to the connected state at time t2.

[0054] In this way, the high-voltage relay 201 (and the high-voltage relay 202) are connected, thereby connecting the high-voltage battery pack 20 to the DC-DC converter and the like, and driving the motor using power from the high-voltage battery pack 20. In addition, the high-voltage battery pack 20 is charged by the generator.

[0055] In addition, normally, the gate signal of the backflow prevention circuit 123 and the gate signal of the switch circuit 121 are both at a low level, and the backflow prevention circuit 123 and the switch circuit 121 are in an off state.

[0056] Here, Figure 2 In the example, a vehicle collision occurs at time t3, and at the subsequent time t4, Figure 2 The collision notification signal 113 shown in the first row of FIG becomes a high level. Figure 2 , a state in which a collision occurrence is notified at time t4 is shown.

[0057] At this time, the control circuit 103 makes Figure 2 The gate signal 114 shown in the second row of becomes low level. As a result, the control output driver 101 becomes OFF, and the current from the control output driver 101 is cut off. Figure 2 The OUTP voltage of the 6th row decreases due to the reverse electromotive force caused by the inductance of the high-current relay 201.

[0058] Then, the OUTP voltage is clamped by the Zener diode 104 and the diode 105 to protect the drain-source voltage of the control output driver 101. At the same time, as the coil current decreases, OUTP converges to the ground potential (GND).

[0059] When performing such control, Figure 2 At time t6 when the coil current of the high-current relay 201 shown in the seventh row drops below the relay opening threshold current I_open, the state of the high-current relay 201 changes from the connected state (CLOSE) to the disconnected state (OPEN).

[0060] As a result, the high-voltage relay 201 is turned off, thereby shutting off the output of the high voltage from the high-voltage battery pack 20 .

[0061] However, in this case, in the absence of the backflow prevention circuit 123, even if the switch circuit 121 is disconnected, the reverse electromotive force flows from the ground potential (GND) through the body diode of the switch element 121 to the high-voltage relay 201 before it drops to the voltage clamped by the Zener diode 104 and the diode 105. Therefore, the OUTP voltage drops only to a voltage of the forward voltage of the body diode, and the time it takes for the coil current to decrease becomes longer, so the time it takes for the high-voltage relay 201 to reach the relay disconnection threshold current I_open becomes longer. In addition, there is also the risk of heat generation and component damage caused by the continuous flow of current in the body diode. Therefore, it is preferable to connect the backflow prevention circuits 123 and 124 to each of the switch circuits 121 and 122.

[0062] Furthermore, in this embodiment, at time t7, a predetermined time after the collision notification signal 113 reaches a high level, the control circuit 125 turns on the switch circuit 121 and the backflow prevention circuit 123. If the time difference between time t5, when the control output driver 101 is turned off, and time t7, when the switch circuit 121 and the backflow prevention circuit 123 are turned on, is too short, there is a possibility that the control output driver 101 and the switch circuit 121 will be turned on simultaneously. This can cause a through-current from the power supply to the ground potential (GND), so a time difference must be set between time t5 and time t7 to prevent this through-current.

[0063] By turning on the switch circuit 121 and the backflow prevention circuit 123 , the current caused by the inductance of the high-voltage relay 201 flows not through the Zener diode 104 and the diode 105 but through the switch circuit 121 and the backflow prevention circuit 123 .

[0064] In addition, in the clamping action performed by the Zener diode 104 and the diode 105, if you want to consume the electric energy caused by the inductance more quickly, you need to adopt a timing design that turns on the switch circuit 121 and the backflow prevention circuit 123 after the clamping action performed by the clamping diode is fully performed.

[0065] Figure 2In the example of , thereafter, at time t8, due to the impact caused by the collision, the control signal harness 111 comes into contact with the wiring of the power system harness, causing a short circuit.

[0066] When such a short circuit occurs, in a conventional structure in which the switch circuit 121 and the backflow prevention circuit 123 are not provided, current flows from the short-circuited portion to the coil of the high-current relay 201 .

[0067] On the other hand, in the case of the vehicle-mounted electronic control device 10 of this embodiment, since the switch circuit 121 is in the on state, the current from the short-circuit portion flows as the current of the switch circuit 121. Figure 2 As shown, the OUTP voltage does not rise, and the current flowing in the coil of the high-voltage relay 201 decreases, which can prevent the high-voltage relay 201 from being turned on. As a result, even if a harness short circuit occurs during a collision, the high-voltage battery pack 20 and the high-voltage wires 211 and 212 can be reliably disconnected.

[0068] Figure 3 Is extracted with Figure 1 The circuit diagram shows the path where the control signal harness 111 is connected. Figure 2 The wiring harness short circuit occurs at time t8, indicating that Figure 3 The path shown shows an abnormal state in which the external damaged power system harness 151 comes into contact with the harness 111 . Figure 4 yes Figure 3 Equivalent circuit diagram of the circuit structure shown.

[0069] Make Figure 3 The state in which the field effect transistor of the switch circuit 121 and the backflow prevention circuit 123 are turned on can be considered as the synthesis of the on-resistance component on the DC side. Figure 4 The resistor Rb is shown. Figure 3 The coil of the strong current relay 201 is in a state of constant DC current, which can be considered as Figure 4 In addition, regarding the short-circuit portion of the power supply system harness 151, it is assumed that the load passing through the contact resistance and the power supply is Figure 4 The resistor Rs is set in .

[0070] Figure 4 In the equivalent circuit shown, it is assumed that a battery power source is connected upstream of the resistor Rs. Then, the current Ir flowing through the resistor Rr is Figure 2 By selecting the characteristics of each element in the manner below I_open shown, it is possible to prevent the high-current relay 201 from being turned on.

[0071] The resistance Rr is determined by the specifications of the high-current relay 201 , but the resistance Rs needs to be assumed to include contact resistance and a resistance component of a harness that may have a short circuit.

[0072] When setting the resistor Rs, the field effect transistors constituting the switch circuit 121 and the backflow prevention circuit 123 are selected so that the current Ir is less than the threshold current I_open. Figure 4 The resistance value of resistor Rb is shown in the equivalent circuit.

[0073] In addition, Figure 4 If the resistance Rs in the equivalent circuit shown is set low, the resistance Rb must be reduced accordingly. However, there are limitations to this resistance Rb, including size and loss. In this case, a battery connection fuse upstream of the power harness can be designed to open when a high current flows, thereby preventing the high-current relay from sticking.

[0074] <Second embodiment>

[0075] Next, refer to Figure 5 A second embodiment of the present invention will be described. Figure 5 In the example of the first embodiment, Figures 1 to 4 The same reference numerals are assigned to corresponding parts, and repeated descriptions are omitted.

[0076] Figure 5 The configuration of a vehicle-mounted electronic control device 10 according to this embodiment is shown.

[0077] Figure 5 The vehicle-mounted electronic control device 10 shown has control output drivers 101 and 102, and the connection and disconnection of the strong electric relays 201 and 202 are controlled by the output of each control output driver 101 and 102. Figure 1 The vehicle-mounted electronic control device 10 shown is the same.

[0078] Then, Figure 5 In the vehicle-mounted electronic control device 10 shown, instead of Figure 1 The difference is that the two switch circuits 121 and 122 shown are shared into one switch circuit 126 .

[0079] Right now, Figure 5 In the illustrated in-vehicle electronic control device 10 , one switching circuit 126 is connected to the sources of the control output drivers 101 and 102 via backflow prevention circuits 123 and 124 .

[0080] As the switch circuit 126, Figure 5Specifically, the drain of the field effect transistor constituting the switch element 126 is connected to the drains of the two field effect transistors constituting the backflow prevention circuits 123 and 124. The source of the field effect transistor constituting the switch circuit 126 is connected to the ground potential portion.

[0081] in addition, Figure 5 In FIG. 1 , a signal obtained at a connection point between the backflow prevention circuits 123 and 124 and the switch circuit 126 is shown as an internal signal 115 .

[0082] A gate signal is supplied from the control circuit 125 to the gate of the field effect transistor serving as the switch circuit 126 , and the control circuit 125 controls the on / off state of the switch circuit 126 .

[0083] Figure 5 The other structures of the vehicle-mounted electronic control device 10 are similar to those of Figure 1 The vehicle-mounted electronic control device 10 shown in FIG. 1 is constructed in the same manner. In addition, the timing of the control circuit 125 controlling the switch circuit 126 is also the same as that of FIG. Figure 1 The control circuit 125 of the illustrated in-vehicle electronic control device 10 controls the switch circuits 121 and 122 at the same timing.

[0084] Below, for Figure 5 The operation of the vehicle-mounted electronic control device 10 having the structure shown will be described.

[0085] When the backflow prevention circuits 123 and 124 are disconnected, for example, when the control output driver 102 is off and the control output driver 101 is on, the driver output terminal OUTP rises to the battery power supply voltage. This rise in the driver output terminal OUTP to the power supply voltage causes the internal signal 115 to rise to near the battery voltage via the body diode of the backflow prevention circuit 123. However, due to the presence of the backflow prevention circuit 124, this voltage is not transmitted to the OUTN output.

[0086] When the output driver 101 is switched from on to off, Figure 2 As described above, the OUTP voltage becomes negative due to the reverse electromotive force caused by the inductance of the high-voltage relay 201. At this time, since the backflow prevention circuit 123 is disconnected, the negative voltage output by OUTP is not transmitted to the internal signal 115 and has no effect on the OUTN output side.

[0087] In addition, when the OUTP output and OUTN output are turned on at the same time, the higher voltage of the OUTP output and OUTN output is transmitted to the internal signal 115 through the body diodes of the components of the backflow prevention circuits 123 and 124 respectively, but its influence does not affect the output of the other.

[0088] In this manner, even if the switch circuit 126 is shared, by adopting a configuration in which the OUTP output and the OUTN output each have the backflow prevention circuits 123 and 124 , the operations of each circuit do not affect the other during normal operation.

[0089] When the common switch circuit 126 is turned on, the output drivers 101 and 102 are both turned off. Figure 2 The sequence described in [1] operates without any problems. Specifically, by transmitting collision notification signal 113 to microcomputer 100, control output drivers 101 and 102 are turned off, followed by switching circuit 126. This ensures that the high-voltage relays 201 and 202 function properly to prevent sticking during a harness short.

[0090] in addition, Figure 5 In the illustrated configuration, the vehicle-mounted electronic control device 10 employs two outputs, OUTP and OUTN, as its output section. In contrast, the vehicle-mounted electronic control device 10 can also increase the number of shared output sections, such as precharge outputs.

[0091] As described above, the in-vehicle electronic control device 10 of this embodiment adopts a configuration in which the shared switch circuit 126 is provided, thereby reducing the manufacturing cost of the device and the area of ​​components mounted in the device, thereby contributing to miniaturization of the device.

[0092] <Third embodiment>

[0093] Next, refer to Figure 6 A third embodiment of the present invention will be described. Figure 5 In the example of the first embodiment, Figures 1 to 4 The same reference numerals are assigned to corresponding parts, and repeated descriptions are omitted.

[0094] Figure 6 The configuration of a vehicle-mounted electronic control device 10 according to this embodiment is shown.

[0095] Figure 6 The vehicle-mounted electronic control device 10 shown includes control output drivers 101 and 102 , and controls the connection and disconnection of high-current relays 201 and 202 using the outputs of the control output drivers 101 and 102 .

[0096] in addition, Figure 6 The vehicle-mounted electronic control device 10 shown has switch circuits 121, 122 and backflow prevention circuits 123, 124, and current flows from the OUTP output and OUTN output in an abnormal situation. Figure 1 The vehicle-mounted electronic control device 10 shown is the same.

[0097] Then, Figure 6 The vehicle-mounted electronic control device 10 shown is Figure 1 The vehicle-mounted electronic control device 10 shown is different in that it includes a disconnection / short-circuit detection circuit 127 as a circuit for detecting abnormality.

[0098] The disconnection / short-circuit detection circuit 127 detects whether the state of the OUTP output and the OUTN output is a power failure or a ground fault. When the disconnection / short-circuit detection circuit 127 detects that either the OUTP output or the OUTN output is disconnected or short-circuited, it sends a detection signal to the microcomputer 100.

[0099] When receiving a detection signal from the disconnection / short-circuit detection circuit 127 , the microcomputer 100 turns on the switch circuits 121 and 122 and the backflow prevention circuits 123 and 124 .

[0100] Furthermore, because the coils of high-current relays 201 and 202 are connected to ground potential GND, disconnection / short-circuit detection circuit 127 has difficulty distinguishing between a normal state and a ground fault when control output drivers 101 and 102 are disconnected. However, during a ground fault, high-current relays 201 and 202 may become disconnected and stuck, making it impossible to distinguish between a normal state and a ground fault. However, this is not a fatal safety hazard.

[0101] Furthermore, when the disconnection / short-circuit detection circuit 127 detects a disconnection, the outputs of the control output drivers 101 and 102 cannot cope with the situation, so the switch circuits 121 and 122 and the backflow prevention circuits 123 and 124 remain disconnected.

[0102] Furthermore, when the disconnection / short circuit detection circuit 127 detects a power failure, the control output driver 101 or 102 of the output portion (OUTP output or OUTN output) that detects the power failure is disconnected, and the switching circuit 121 or 122 and the backflow prevention circuit 123 or 124 of the system are disconnected or connected, thereby extracting current and preventing the high-voltage relay from being stuck.

[0103] In addition, the disconnection / short circuit detection circuit 127 is provided. Figure 6 In the illustrated configuration, the control when the collision notification signal 113 is received from the outside as described in the first embodiment may be further performed.

[0104] <Fourth embodiment>

[0105] Next, refer to Figure 7 A fourth embodiment of the present invention will be described. Figure 7 In the example of the first embodiment, Figures 1 to 4 The same reference numerals are assigned to corresponding parts, and repeated descriptions are omitted.

[0106] Figure 7 The configuration of a vehicle-mounted electronic control device 10 according to this embodiment is shown.

[0107] Figure 7 In the figure, only the characteristic places in the vehicle-mounted electronic control device 10 of this embodiment are shown, and the places and components in the vehicle-mounted electronic control device 10 are omitted. Figure 1 The vehicle-mounted electronic control unit 10 shown is configured similarly.

[0108] Then, Figure 7 The illustrated in-vehicle electronic control device 10 is provided with a diagnosis circuit 141 for the switch circuits 121 , 122 and the backflow prevention circuits 123 , 124 .

[0109] The diagnostic circuit 141 includes a diagnostic current source 128 and a voltage monitoring circuit 129 . The diagnostic current source 128 and the voltage monitoring circuit 129 are connected to a signal line 116 that connects the backflow prevention circuit 123 and the switch circuit 121 .

[0110] The operation of the diagnosis circuit 141 will be described. For example, the control circuit 103 ( Figure 1 ) puts both the backflow prevention circuit 123 and the switch circuit 121 into an OFF state, and the current from the diagnostic current source 128 flows in the signal line 116.

[0111] Here, when both the backflow prevention circuit 123 and the switch circuit 121 are normal, there is no path for current to flow from the signal line 116 , and the voltage value corresponding to the diagnostic current source 128 is detected by the voltage monitoring circuit 129 .

[0112] Next, the control circuit 103 turns on both the backflow prevention circuit 123 and the switch circuit 121, allowing the current from the diagnostic current source 128 to flow through the signal line 116. The voltage of the signal line 116 is detected by the voltage monitoring circuit 129. The voltage detected in the on state varies compared to the voltage in the off state.

[0113] Thus, the diagnosis circuit 141 can confirm that the backflow prevention circuit 123 and the switch circuit 121 are operating normally using the voltage monitoring circuit 129 .

[0114] The diagnosis performed by the diagnosis circuit 141 is performed, for example, when the vehicle-mounted electronic control device 10 is started up or when the output is turned off.

[0115] in addition, Figure 7 The diagnostic circuit 141 shown in FIG. 1 is a structure for diagnosing a switch circuit 121 and a reverse current prevention circuit 123. However, the diagnostic circuit 141 is Figure 7The other switch circuit 122 and the backflow prevention circuit 124 are omitted from the figure, but diagnosis can also be performed using the same structure.

[0116] Thus, the in-vehicle electronic control unit 10 includes a diagnostic circuit 141, which enables reliable confirmation of protective operation. Specifically, the switching circuits 121 and 122 and backflow prevention circuits 123 and 124 included in the in-vehicle electronic control unit 10 are circuits that do not normally require operation. However, for safety reasons, they are required to operate reliably in the event of an abnormality. Therefore, the in-vehicle electronic control unit 10 includes a diagnostic circuit 141, which performs diagnostics during startup or when the output is disconnected, making it possible to confirm that the protective function is effectively functioning in the event of an abnormality.

[0117] Modifications

[0118] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments are described in detail to facilitate understanding of the present invention, and are not necessarily limited to having all the described configurations.

[0119] In addition, for example, Figure 5 The structure of the second embodiment shown is the same as Figure 6 The structural combination of the third embodiment shown in FIG. Figure 5 The structure of the second embodiment shown is the same as Figure 7 The configuration combination of the fourth embodiment shown is obtained by appropriately combining the configurations of the respective embodiments.

[0120] In addition, each circuit diagram adopts a method of controlling a high-current relay connected to the ground potential part by using a high-side driver. Figure 1 Each embodiment example can also be applied to an in-vehicle electronic control device having an opposite structure, that is, a circuit structure in which a high-side high-current relay is driven by a low-side driver.

[0121] In addition, if Figure 1 As shown in FIG. 1 , the placement of the vehicle-mounted electronic control unit 10 in the engine compartment 1 and the placement of the high-voltage battery 20 in the vehicle cabin is merely an example; other configurations are also possible. Furthermore, while the high-voltage battery 20 has an output voltage of 100V or greater in the above-described embodiment, any battery with a higher voltage than a typical vehicle-mounted battery (e.g., 12V) may be used. For example, a battery with an output voltage of 48V or other may be used.

[0122] in addition, Figure 1 In the circuit diagrams, signal lines and control lines are shown only as necessary for explanation, and not necessarily all control lines and information lines on the product are shown. In fact, it can be assumed that almost all structures are connected to each other.

[0123] Description of Reference Numerals

[0124] 10...In-vehicle electronic control unit, 20...High-voltage battery pack, 100...Microcomputer, 101, 102...Control output driver, 103...Control circuit, 104...Zener diode, 105...Diode, 111, 112...Control signal harness, 113...External signal (crash notification signal), 114...Gate signal, 115...Internal signal, 116...Signal line, 121, 122...Switch circuit, 123, 124...Backflow prevention circuit, 125...Control circuit, 126...Switch circuit, 127...Disconnection / short-circuit detection circuit, 128...Diagnostic current source, 129...Voltage monitoring circuit, 131...Fail-safe relay, 132...Driver, 141...Diagnostic circuit, 151...Power supply system harness, 201, 202...High-voltage relay, 211...High-voltage line (+), 212...High-voltage line (-), OUTP, OUTN...Output terminals.

Claims

1. An in-vehicle electronic control device having a relay control driver circuit for controlling on and off a relay, wherein the relay is used to connect and disconnect wiring drawn from a battery mounted on the vehicle, the in-vehicle electronic control device comprising: a switch circuit connected to the output portion of the relay control driver circuit for extracting current; and a control circuit that operates the switch circuit to extract current from the output unit and does not turn on the relay when an abnormality occurs in the vehicle; The switch circuit is connected to the output unit via a backflow prevention circuit. When the driver circuit is working, the anti-backflow circuit prevents the current caused by the reverse electromotive force from flowing in the switch circuit. The relay includes a first relay connected to one pole of the battery and a second relay connected to the other pole of the battery. The output unit includes a first output unit that controls the first relay and a second output unit that controls the second relay. The switching circuit commonly controls the first output portion and the second output portion via the backflow prevention circuits that are different from each other.

2. The vehicle-mounted electronic control device according to claim 1, wherein: The switch circuit and the backflow prevention circuit are respectively formed of field effect transistors, and the field effect transistor forming the switch circuit and the field effect transistor forming the backflow prevention circuit are connected in series.

3. The vehicle-mounted electronic control device according to claim 1, wherein: having an input portion capable of receiving a collision notification signal of the vehicle, The control circuit operates the switch circuit to extract current from the output portion when the collision notification signal is input to the input portion.

4. The vehicle-mounted electronic control device according to claim 3, wherein: The collision notification signal is a signal output when the air bag of the vehicle is deployed.

5. The vehicle-mounted electronic control device according to claim 3, wherein: The switching circuit operates at a predetermined time difference from a timing of turning off the relay control driver circuit.

6. The vehicle-mounted electronic control device according to claim 1, wherein: A short-circuit detection circuit for detecting a short circuit of an output terminal of the output unit is provided. The switch circuit and the backflow prevention circuit operate when the short-circuit detection circuit detects a power failure or a ground fault at the output terminal.

7. The vehicle-mounted electronic control device according to claim 6, wherein: The short-circuit detection circuit further detects disconnection of the output terminal of the output unit, and does not turn on the switch circuit when disconnection is detected.

8. The vehicle-mounted electronic control device according to claim 1, wherein: having a diagnostic circuit for performing a diagnosis of the switching circuit, The control circuit confirms that the switching circuit is operable based on the diagnosis performed by the diagnostic circuit.

9. The vehicle-mounted electronic control device according to claim 8, wherein: The diagnostic circuit includes a diagnostic current source and a voltage monitor. The voltage value when the current from the diagnostic current source flows through the switching circuit is monitored by the voltage monitor, and the diagnosis is performed by the diagnostic circuit.

10. The vehicle-mounted electronic control device according to claim 9, wherein: The diagnostic circuit performs diagnosis based on the voltage value monitored by the voltage monitor when the current from the diagnostic current source flows through the connection point between the switching circuit and the backflow prevention circuit in a state where the switching circuit and the backflow prevention circuit are disconnected, and the voltage value monitored by the voltage monitor when the current from the diagnostic current source flows through the connection point between the switching circuit and the backflow prevention circuit in a state where the switching circuit and the backflow prevention circuit are connected.

11. The vehicle-mounted electronic control device according to claim 9, wherein: The diagnosis performed by the diagnostic circuit is performed when the device is started or when the output is disconnected.

12. The vehicle-mounted electronic control device according to any one of claims 1 to 11, wherein: The vehicle includes at least an electric motor as a power source for traveling, the battery is a high-voltage battery for supplying power to the electric motor, and the relay is a high-voltage relay for connecting and disconnecting wiring drawn from the high-voltage battery.

13. A method for controlling an on-vehicle device for controlling a relay control driver circuit for on / off-controlling a relay, wherein the relay is used to connect and disconnect wiring extending from a battery mounted on a vehicle, the method comprising: When an abnormality occurs in the vehicle, a current extraction process is performed to extract a current from an output portion of the relay control driver circuit so as not to turn on the relay when an abnormality occurs in the vehicle. When performing the current extraction process, the current is extracted from the output unit via the backflow prevention circuit. When the driver circuit is operating, the backflow prevention circuit prevents the current caused by the reverse electromotive force from flowing in the circuit performing the current extraction process. The relay includes a first relay connected to one pole of the battery and a second relay connected to the other pole of the battery. The output unit includes a first output unit that controls the first relay and a second output unit that controls the second relay. In the current extraction process, the first output section and the second output section are commonly controlled via the backflow prevention circuits that are different from each other.

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