On-vehicle control device

Abstract

To provide an on-vehicle control device capable of securing electric power supply to a load which is needed to be operated during a collision of a vehicle.SOLUTION: An on-vehicle control device 10 is included in an on-vehicle system 100. The on-vehicle control device 10 has: a first switch part 30 provided between a second power passage 52 and a first load 70 in a first branch passage 55; and a control unit 34 which controls the first switch part 30 to turn the first switch part 30 into an off state when receiving a collision detection signal Cs.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an in-vehicle control device. [Background technology]

[0002] Patent Document 1 discloses a technology for predicting a collision based on the output of an obstacle detection sensor that detects obstacles around the vehicle, and for reliably supplying power to equipment required for passenger protection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-165406 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a configuration in which a single battery supplies power to all loads in the first to third groups. Therefore, the configuration of Patent Document 1 requires a larger battery to ensure sufficient power to supply each load. Furthermore, in vehicles with a high-voltage battery, voltage-converted power is supplied from the high-voltage battery to each load, but the high-voltage battery is shut off when the vehicle collides. In this case, even if the vehicle also has a low-voltage battery, the low-voltage battery alone may not be able to supply power to the loads that need to be operated when the vehicle collides. Therefore, there is a demand for technology that can prioritize power supply to high-priority loads when a collision is detected.

[0005] The present disclosure has been made based on the above-mentioned circumstances, and aims to provide an in-vehicle control device that can reliably supply power to a load that needs to be operated when a vehicle collides. [Means for solving the problem]

[0006] The in-vehicle control device of the present disclosure includes: an on-board control device included in an on-board system comprising: a high-voltage battery; a voltage conversion unit; a low-voltage battery; a first power path provided between the high-voltage battery and the voltage conversion unit; a second power path provided between the voltage conversion unit and the low-voltage battery; a relay provided on the first power path; a relay control unit that switches the relay to an off state when a vehicle collision is detected; an output unit that outputs a collision detection signal when a vehicle collision is detected; a first branch path branching from the second power path; a first load electrically connected to the first branch path; a second branch path branching from the second power path; and a second load electrically connected to the second branch path, wherein the voltage conversion unit steps down a voltage input from the first power path and outputs the voltage to the second power path; a first switch unit provided in the first branch path between the second power path and the first load; a control unit that controls the first switch unit to an off state when the collision detection signal is received; It has. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to reliably supply power to a load that needs to be operated when a vehicle crashes. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a circuit diagram schematically illustrating the configuration of an in-vehicle system according to the first embodiment. [Figure 2] FIG. 2 is a table showing the state of each switch unit when the vehicle is parked, running, and in the event of a collision. [Figure 3] FIG. 3 is a flowchart showing an example of control in the control unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] In the following, embodiments of the present disclosure are listed and illustrated.

[0010] (1) An on-vehicle control device included in an on-vehicle system including: a high-voltage battery; a voltage conversion unit; a low-voltage battery; a first power path provided between the high-voltage battery and the voltage conversion unit; a second power path provided between the voltage conversion unit and the low-voltage battery; a relay provided on the first power path; a relay control unit that switches the relay to an off state when a vehicle collision is detected; an output unit that outputs a collision detection signal when a vehicle collision is detected; a first branch path branching from the second power path; a first load electrically connected to the first branch path; a second branch path branching from the second power path; and a second load electrically connected to the second branch path, wherein the voltage conversion unit steps down a voltage input from the first power path and outputs the voltage to the second power path; a first switch unit provided in the first branch path between the second power path and the first load; a control unit that controls the first switch unit to an off state when the collision detection signal is received; An in-vehicle control device having the above.

[0011] (1) The vehicle control device can be configured to supply power intensively to the second load when the vehicle collides by setting a load that is not necessary for the vehicle to run as the first load and a load that is necessary for the vehicle to run as the second load.

[0012] (2) The vehicle control device described in (1), wherein when the control unit receives the collision detection signal, the control unit confirms that the output of the voltage conversion unit has stopped and then controls the first switch unit to an off state.

[0013] (2) In the case where a collision detection signal is output even though the vehicle has not collided, the vehicle control device confirms that the output of the voltage conversion unit has stopped and then turns off the first switch unit, thereby preventing the power to the first load from being inadvertently cut off.

[0014] (3) The second branch path has a second switch unit provided between the second power path and the second load, The vehicle control device according to (1) or (2), wherein the control unit, when receiving the collision detection signal, controls the first switch unit to an off state and maintains the second switch unit in an on state.

[0015] (3) The vehicle control device can prevent power from being supplied from the low-voltage battery to the first load by turning off the first switch unit during a collision, while supplying power from the low-voltage battery to the second load by maintaining the second switch unit in the on state.

[0016] (4) a third switch unit disposed on the second power path closer to the voltage conversion unit than the first load and the second load; The vehicle-mounted control device according to any one of (1) to (3), wherein the control unit controls the first switch unit and the third switch unit to an off state when the collision detection signal is received.

[0017] The in-vehicle control device (4) can prevent the output voltage of the low-voltage battery from being reduced by the failed voltage conversion unit when the voltage conversion unit itself fails (such as a short circuit).

[0018] <Embodiment 1> [In-vehicle system configuration] 1 is a system mounted on a vehicle. The vehicle system 100 includes a high-voltage battery 90, a voltage conversion unit 92, a low-voltage battery 91, a first power path 50, a relay 51, a second power path 52, an output unit 53, a relay control unit 54, a first branch path 55, a second branch path 56, a first load 70, and a second load 71. The vehicle system 100 further includes an in-vehicle control device 10. The vehicle system 100 supplies power based on the high-voltage battery 90 and the low-voltage battery 91 to the first load 70 and the second load 71.

[0019] The high-voltage battery 90 is, for example, an assembled battery configured by combining a plurality of unit cells such as lithium-ion batteries or nickel-metal hydride batteries in series, and outputs an output voltage of, for example, about 400 V. The voltage conversion unit 92 is a known DC-DC converter that can step down the voltage input from the high-voltage battery 90 side (first power path 50 side) and output it to the second power path 52 side. The low-voltage battery 91 can be, for example, a lead-acid battery or a configuration using the same type of unit cells as the high-voltage battery 90, with fewer cells connected in series than the high-voltage battery 90. For example, the low-voltage battery 91 can output an output voltage of about 12 V.

[0020] The first power path 50 is provided between the high-voltage battery 90 and the voltage conversion unit 92. The relay 51 is a so-called system main relay, and is, for example, a mechanical relay switch. The relay 51 is provided on the first power path 50. The second power path 52 is provided between the voltage conversion unit 92 and the low-voltage battery 91.

[0021] The output unit 53 and the relay control unit 54 are configured, for example, as separate ECUs (Electronic Control Units), each including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The output unit 53 is, for example, an ECU that controls the operation of an airbag (not shown). A collision detection sensor 53A is electrically connected to the output unit 53. The collision detection sensor 53A may be a known sensor, such as a satellite sensor. For example, the collision detection sensor 53A is configured to output a voltage signal S corresponding to the acceleration of the vehicle to the output unit 53. When the vehicle collides or is hit, the acceleration of the vehicle changes rapidly in a short period of time. Therefore, the magnitude of the signal S output from the collision detection sensor 53A changes rapidly when the vehicle collides or is hit. When the signal S changes rapidly, the output unit 53 determines that the vehicle has collided or been hit, and activates the airbag. At the same time, the output unit 53 outputs a collision detection signal Cs to the relay control unit 54 and a control unit 34 (described later). That is, the output unit 53 outputs a collision detection signal Cs when it detects that the vehicle has collided or been collided.

[0022] In the present disclosure, "electrically connected" preferably means a configuration in which the connection objects are connected in a mutually conductive state (a state in which a current can flow) so that the potentials of both connection objects are equal. However, this configuration is not limited to this. For example, "electrically connected" may also mean a configuration in which the connection objects are connected in a state in which the two connection objects can be electrically connected with an electrical component interposed between them.

[0023] The relay control unit 54 controls the operation of the relay 51. For example, the relay control unit 54 keeps the relay 51 in the on state while a start switch (not shown) of the vehicle is in the on state. When a collision detection signal Cs indicating that the vehicle is colliding or has been collided is input while the start switch of the vehicle is in the on state, the relay control unit 54 switches the relay 51 from the on state to the off state.

[0024] The first branched line 55 is provided by branching off from the second power line 52. The second branched line 56 is provided by branching off from the second power line 52.

[0025] The first load 70 is electrically connected to the first branch path 55. The first load 70 is electrically connected to the second power path 52 via the first branch path 55. The first load 70 is, for example, a load that does not affect the safety of the vehicle even if it does not operate while the vehicle is running, and corresponds to, for example, a seat heater or a USB power source. Here, the state in which the vehicle is running refers to a state in which the starter switch of the vehicle is on and the vehicle speed is greater than 0. The state in which the starter switch of the vehicle is on and the vehicle speed is 0 refers to a state in which the vehicle is stopped.

[0026] The second load 71 is electrically connected to the second branch path 56. The second load 71 is electrically connected to the second power path 52 via the second branch path 56. The second load 71 is a load that may affect the safety of the vehicle and is a load that is more important than the first load 70. The importance is determined based on the functional safety level defined in ISO26262, for example. The second load 71 corresponds to, for example, an ECU of an electric brake device, an ECU of a shift-by-wire device, an ECU of a door lock device, a display device, an ECU of an airbag device, a DCM (Data Communication Module), etc.

[0027] [Configuration of on-board control device] The on-board control device 10 includes, for example, a first switch unit 30, a second switch unit 33, a third switch unit 31, a fourth switch unit 32, and a control unit 34. The first switch unit 30 is provided in a first branch path 55 between the second power path 52 and the first load 70. The second switch unit 33 is provided in a second branch path 56 between the second power path 52 and the second load 71. The third switch unit 31 is provided in the second power path 52 closer to the voltage conversion unit 92 than the first branch path 55 to which the first load 70 is electrically connected and the second branch path 56 to which the second load 71 is electrically connected. The fourth switch unit 32 is provided in the second power path 52 closer to the low-voltage battery 91 than the first branch path 55 to which the first load 70 is electrically connected and the second branch path 56 to which the second load 71 is electrically connected. Each of the first switch section 30, the second switch section 33, the third switch section 31, and the fourth switch section 32 uses a switching element such as a FET (Field Effect Transistor), for example.

[0028] A voltage detection unit 57 is provided on the second power path 52 between the third switch unit 31 and the voltage conversion unit 92. The voltage detection unit 57 is configured to be able to output a voltage signal Vs, which is the output voltage of the voltage conversion unit 92 and corresponds to the voltage of the second power path 52, to the control unit 34.

[0029] The control unit 34 is configured as, for example, an ECU, and includes a CPU, a ROM, a RAM, etc. The control unit 34 is configured to receive a collision detection signal Cs from the output unit 53 and a voltage signal Vs from the voltage detection unit 57. Based on the collision detection signal Cs and the voltage signal Vs, the control unit 34 can control the first switch unit 30, the second switch unit 33, the third switch unit 31, and the fourth switch unit 32 to be driven to either an ON state or an OFF state.

[0030] [Example of operation of an in-vehicle control device] Next, an example of the operation of the in-vehicle control device 10 will be described. As shown in Fig. 2, for example, when the vehicle equipped with the in-vehicle system 100 is parked, the first switch unit 30, the second switch unit 33, the third switch unit 31, and the fourth switch unit 32 are controlled by the control unit 34 to be maintained in the ON state. Here, the state in which the vehicle is parked corresponds to the state in which the start switch of the vehicle is in the OFF state.

[0031] When the vehicle equipped with the in-vehicle system 100 is traveling, the first switch unit 30, the second switch unit 33, the third switch unit 31, and the fourth switch unit 32 are each controlled by the control unit 34 to be maintained in the ON state. Even when the vehicle is stopped, the first switch unit 30, the second switch unit 33, the third switch unit 31, and the fourth switch unit 32 may be controlled by the control unit 34 to be maintained in the ON state. The control unit 34 monitors whether a collision detection signal Cs is input while the vehicle is traveling. The control unit 34 receives a voltage signal Vs, which is an output voltage from the voltage conversion unit 92 and corresponds to the voltage of the second power path 52.

[0032] The collision detection sensor 53A outputs a voltage signal S corresponding to the acceleration of the vehicle to the output unit 53. For example, when the vehicle collides or is hit and the magnitude of the signal S output from the collision detection sensor 53A changes suddenly, the output unit 53 determines that the vehicle has collided or been hit, and outputs a collision detection signal Cs to each of the relay control unit 54 and the control unit 34. When the collision detection signal Cs is input, the relay control unit 54 executes control to switch the relay 51 from an on state to an off state.

[0033] The operation of the control unit 34 will be described with reference to FIG. 3 and other figures. When the control unit 34 receives the collision detection signal Cs (Yes in step S1), the control unit 34 proceeds to step S2 and determines whether the output from the voltage conversion unit 92 has stopped. Specifically, when the control unit 34 receives the collision detection signal Cs, the control unit 34 determines whether the magnitude of the voltage signal Vs is equal to or less than the voltage threshold. The voltage threshold is set, for example, to a magnitude corresponding to a state in which no voltage is being output from the voltage conversion unit 92 and is stored in a ROM or the like included in the control unit 34. When the control unit 34 receives the collision detection signal Cs and determines that the voltage signal Vs is equal to or less than the voltage threshold (Yes in step S2) (i.e., after confirming that the output from the voltage conversion unit 92 has stopped), the control unit 34 proceeds to step S3. When proceeding to step S3, the control unit 34 switches the first switch unit 30 and the third switch unit 31 from the ON state to the OFF state, and maintains the fourth switch unit 32 and the second switch unit 33 in the ON state (see FIG. 2).

[0034] If the control unit 34 does not receive the collision detection signal Cs (No in step S1), it ends the process shown in Fig. 3 and executes the process shown in Fig. 3 again. If the control unit 34 determines that the output from the voltage conversion unit 92 has not stopped, that is, that the voltage signal Vs is greater than the voltage threshold value (No in step S2), it ends the process shown in Fig. 3 and executes the process shown in Fig. 3 again.

[0035] Next, the effects of this configuration will be illustrated. The on-vehicle control device 10 is included in an on-vehicle system 100. The on-vehicle system 100 includes a high-voltage battery 90, a voltage conversion unit 92, a low-voltage battery 91, a first power path 50 provided between the high-voltage battery 90 and the voltage conversion unit 92, a second power path 52 provided between the voltage conversion unit 92 and the low-voltage battery 91, a relay 51 provided on the first power path 50, a relay control unit 54 that switches the relay 51 to an off state when a vehicle collision or a collision occurrence is detected, an output unit 53 that outputs a collision detection signal Cs when a vehicle collision or a collision occurrence is detected, a first branch path 55 branching from the second power path 52, a first load 70 electrically connected to the first branch path 55, a second branch path 56 branching from the second power path 52, and a second load 71 electrically connected to the second branch path 56. The voltage conversion unit 92 steps down the voltage input from the first power path 50 and outputs it to the second power path 52. The in-vehicle control device 10 has a first switch unit 30 provided in the first branch path 55 between the second power path 52 and the first load 70, and a control unit 34 that controls the first switch unit 30 to an off state when a collision detection signal Cs is received.

[0036] According to this configuration, by setting a load unnecessary for the vehicle to run as the first load 70 and a load necessary for the vehicle to run as the second load 71, it becomes possible to configure the system to supply power intensively to the second load 71 when the vehicle collides or is crashed.

[0037] When the control unit 34 receives the collision detection signal Cs, the control unit 34 confirms that the output of the voltage conversion unit 92 has stopped, and then controls the first switch unit 30 to the OFF state. According to this configuration, in cases where the collision detection signal Cs is output even though the vehicle has collided or has not been collided, the control unit 34 confirms that the output of the voltage conversion unit 92 has stopped, and then controls the first switch unit 30 to the OFF state, thereby preventing the power to the first load 70 from being inadvertently stopped.

[0038] The on-vehicle control device 10 has a second switch unit 33 provided in the second branch path 56 between the second power path 52 and the second load 71. When the control unit 34 receives the collision detection signal Cs, it controls the first switch unit 30 to an OFF state and maintains the second switch unit 33 in an ON state. With this configuration, when a collision occurs, turning the first switch unit 30 to an OFF state prevents power from being supplied from the low-voltage battery 91 to the first load 70, while maintaining the second switch unit 33 in an ON state allows power to be supplied from the low-voltage battery 91 to the second load 71.

[0039] The vehicle control device 10 has a third switch unit 31 that is arranged on the second power path 52 closer to the voltage conversion unit 92 than the first load 70 and the second load 71. When the control unit 34 receives a collision detection signal Cs, it controls the first switch unit 30 and the third switch unit 31 to the off state. With this configuration, when the voltage conversion unit 92 itself fails (such as due to a short circuit), it is possible to prevent the output voltage of the low-voltage battery 91 from being reduced by the failed voltage conversion unit 92.

[0040] <Other embodiments> The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed herein, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0041] In each switch section, the switching elements may be arranged in series with each other but in opposite directions. Specifically, a pair of switching elements may be arranged so that the anodes or cathodes of the body diodes of each element face each other. Also, each switch section may be configured to use one FET. Also, a switch section may be configured to have a combination of a pair of FETs and a single FET.

[0042] Unlike the above embodiment, each switch unit may be controlled only by a collision detection signal without using a voltage signal.

[0043] Unlike the above embodiment, the control unit may be configured to monitor the drive signals that drive each switching element of the voltage conversion unit, and determine that the output of the voltage conversion unit has stopped based on these drive signals.

[0044] Unlike the above embodiment, the process shown in FIG. 3 may be performed when the vehicle is stopped.

[0045] In the above embodiment, the in-vehicle control device includes four switch sections: the first switch section, the third switch section, the fourth switch section, and the second switch section, but it is sufficient if the in-vehicle control device includes at least the first switch section. [Explanation of symbols]

[0046] 10: In-vehicle control device 30: First switch section 31: Third switch section 32: 4th switch section 33: Second switch section 34: Control section 50: 1st power path 51: Relay 52:Second power path 53: Output section 53A: Collision detection sensor 54: Relay control section 55: First Fork 56: Second fork 57: Voltage detection unit 70: 1st load 71 :Second load 90: High voltage battery 91: Low voltage battery 92: Voltage conversion section 100: In-vehicle systems Cs: Collision detection signal S:Signal Vs: voltage signal

Claims

1. an on-board control device included in an on-board system comprising: a high-voltage battery; a voltage conversion unit; a low-voltage battery; a first power path provided between the high-voltage battery and the voltage conversion unit; a second power path provided between the voltage conversion unit and the low-voltage battery; a relay provided on the first power path; a relay control unit that switches the relay to an off state when a vehicle collision is detected; an output unit that outputs a collision detection signal when a vehicle collision is detected; a first branch path branching from the second power path; a first load electrically connected to the first branch path; a second branch path branching from the second power path; and a second load electrically connected to the second branch path, wherein the voltage conversion unit steps down a voltage input from the first power path and outputs the stepped down voltage to the second power path; a first switch unit provided in the first branch path between the second power path and the first load; a control unit that controls the first switch unit to an off state when the collision detection signal is received; An in-vehicle control device having the above.

2. 2. The vehicle-mounted control device according to claim 1, wherein, when the control unit receives the collision detection signal, the control unit controls the first switch unit to the off state after confirming that the output of the voltage conversion unit has stopped.

3. the second branch path has a second switch unit provided between the second power path and the second load, 3. The vehicle-mounted control device according to claim 1, wherein the control unit controls the first switch unit to an OFF state and maintains the second switch unit in an ON state when the control unit receives the collision detection signal.

4. a third switch unit disposed on the second power path closer to the voltage conversion unit than the first load and the second load; 3. The vehicle-mounted control device according to claim 1, wherein the control unit controls the first switch unit and the third switch unit to an OFF state when the collision detection signal is received.

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