Vehicle control system

Abstract

To provide a vehicle control system that can sense submergence of a portion of a vehicle body, without increasing costs.SOLUTION: A second ECU is mounted on a position (a position P2) that is the same position as a high-voltage system or is lower than the high-voltage system in a vehicle vertical direction. When a first ECU that controls the high-voltage system cannot receive a signal by communication from the second ECU, the first ECU prohibits the high-voltage system from applying high voltages. The second ECU is mounted on a position outside a vehicle interior or below a seat in the vehicle interior. The first ECU is mounted on a position (a position P1) higher than the position of the second ECU.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle control system.

Background Art

[0002] Patent Document 1 describes a technique for detecting submersion of a part of the vehicle body of an electric vehicle by attaching a submersion detection sensor at a position closer to the road surface at the lower part of the vehicle body.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, what is described in Patent Document 1 has a problem of causing an increase in cost by adding a submersion detection sensor.

[0005] An object of the present invention is to provide a vehicle control system that can detect submersion of a part of the vehicle body without increasing the cost.

Means for Solving the Problems

[0006] The vehicle control system according to the present invention is mounted on a vehicle equipped with a high-voltage system, and includes a first ECU that controls the high-voltage system and a second ECU different from the first ECU, and the vehicle control system is set such that the first ECU and the second ECU communicate with each other. The second ECU is attached at the same position as the high-voltage system or at a position lower than the high-voltage system in the vehicle vertical direction, and the first ECU prohibits application of a high voltage in the high-voltage system when a signal by communication cannot be received from the second ECU.

Effects of the Invention

[0007] The present invention can provide a vehicle control system that can detect the submersion of a part of the vehicle body without increasing the cost.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] A vehicle control system according to an embodiment of the present invention is mounted on a vehicle equipped with a high-voltage system, and includes a first ECU that controls the high-voltage system and a second ECU that is different from the first ECU, and is a vehicle control system configured such that the first ECU and the second ECU communicate with each other. The second ECU is attached at the same position as the high-voltage system or at a position lower than the high-voltage system in the vertical direction of the vehicle. The first ECU is characterized in that when a signal by communication cannot be received from the second ECU, it prohibits the application of high voltage in the high-voltage system. Thereby, the vehicle control system according to an embodiment of the present invention can detect the submersion of a part of the vehicle body without increasing the cost.

Examples

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a vehicle 1 equipped with a vehicle control system according to an embodiment of the present invention constitutes a hybrid vehicle having a motor and an internal combustion engine type engine as drive sources.

[0011] Vehicle 1 includes a high-voltage battery 10, a negative-side relay 11a, a positive-side relay 11b, a pre-charge circuit 12, a smoothing capacitor 13, an inverter 14, a motor generator 15, a first ECU (Electronic Control Unit) 16, and a second ECU (Electronic Control Unit) 17. The inverter 14 and the motor generator 15 constitute a high-voltage system 18.

[0012] The high-voltage battery 10 is composed of a secondary battery and constitutes a DC power source. In the present embodiment, the high-voltage battery 10 has a positive electrode as the first electrode and a negative electrode as the second electrode. The smoothing capacitor 13 has an anode as the first electrode and a cathode as the second electrode. The smoothing capacitor 13 is configured to smooth the voltage of the DC power generated between the positive electrode line PL to which the anode is connected and the negative electrode line NL to which the cathode is connected.

[0013] The negative-side relay 11a is configured to take either a connected state in which the negative electrode of the high-voltage battery 10 and the cathode of the smoothing capacitor 13 are connected or a disconnected state in which the negative electrode of the high-voltage battery 10 and the cathode of the smoothing capacitor 13 are disconnected according to the control of the first ECU 16.

[0014] For example, the negative-side relay 11a is controlled by the first ECU 16 to take the connected state when the motor generator 15 is in the operating state.

[0015] The positive-side relay 11b is configured to take either a connected state in which the positive electrode of the high-voltage battery 10 and the anode of the smoothing capacitor 13 are connected or a disconnected state in which the positive electrode of the high-voltage battery 10 and the anode of the smoothing capacitor 13 are disconnected according to the control of the first ECU 16.

[0016] For example, the positive-side relay 11b is controlled by the first ECU 16 to take the connected state when the motor generator 15 is in the operating state.

[0017] The precharge circuit 12 is composed of a precharge relay 12a and a resistor Rp connected in series with the precharge relay 12a. The precharge relay 12a is configured to take either a connected state in which the precharge circuit 12 is connected in parallel to the positive-side relay 11b or a disconnected state in which the precharge circuit 12 is electrically disconnected from the positive-side relay 11b according to the control of the first ECU 16.

[0018] For example, the precharge relay 12a is controlled by the first ECU 16 to take the connected state before the motor generator 15 operates and to take the disconnected state after the positive-side relay 11b takes the connected state.

[0019] The motor generator 15 is composed of a three-phase AC motor driven by three-phase AC power of U-phase, V-phase, and W-phase. For example, the motor generator 15 has a stator that forms a rotating magnetic field and a rotor in which a plurality of permanent magnets are embedded and arranged inside the stator.

[0020] The stator has a stator core and three-phase coils of U-phase, V-phase, and W-phase wound around the stator core. Here, when three-phase AC power is supplied to the three-phase coils of the stator, a rotating magnetic field is formed by the stator, and the permanent magnets embedded in the rotor are attracted by this rotating magnetic field, whereby the rotor is rotationally driven. By this rotational driving force of the rotor, the vehicle 1 is driven. In this way, the motor generator 15 is configured to function as an electric motor.

[0021] Also, when the permanent magnets embedded in the rotor rotate, a rotating magnetic field is formed, and an induced current flows through the three-phase coils of the stator due to this rotating magnetic field, whereby electric power is generated at both ends of the three-phase coils. In this way, the motor generator 15 is also configured to function as a generator.

[0022] The inverter 14 constitutes a power conversion circuit that converts DC power whose voltage has been smoothed by the smoothing capacitor 13 into AC power. The inverter 14 includes switching elements Q3 to Q8 and diodes D3 to D8.

[0023] In the present embodiment, each of the switching elements Q3 to Q8 is constituted by an IGBT (Insulated Gate Bipolar Transistor) having three terminals: a collector, a gate, and an emitter.

[0024] The collector of the switching element Q3 is connected to the positive electrode line PL, the emitter is connected to the input terminal of the U-phase of the motor generator 15, and the gate is connected to the first ECU 16. The source of the switching element Q4 is connected to the emitter of the switching element Q3, the emitter is connected to the negative electrode line NL, and the gate is connected to the first ECU 16.

[0025] The cathode of the diode D3 is connected to the source of the switching element Q3, and the anode is connected to the emitter of the switching element Q3. That is, the diode D3 and the switching element Q3 constitute the upper arm of the U-phase.

[0026] The cathode of the diode D4 is connected to the source of the switching element Q4, and the anode is connected to the emitter of the switching element Q4. That is, the diode D4 and the switching element Q4 constitute the lower arm of the U-phase.

[0027] The collector of the switching element Q5 is connected to the positive electrode line PL, the emitter is connected to the input terminal of the V-phase of the motor generator 15, and the gate is connected to the first ECU 16. The source of the switching element Q6 is connected to the emitter of the switching element Q5, the emitter is connected to the negative electrode line NL, and the gate is connected to the first ECU 16.

[0028] The cathode of diode D5 is connected to the source of switching element Q5, and the anode is connected to the emitter of switching element Q5. That is, diode D5 and switching element Q5 constitute the upper arm of the V phase.

[0029] The cathode of diode D6 is connected to the source of switching element Q6, and the anode is connected to the emitter of switching element Q6. That is, diode D6 and switching element Q6 constitute the lower arm of the V phase.

[0030] The collector of switching element Q7 is connected to the positive electrode line PL, the emitter is connected to the input terminal of the W phase of the motor generator 15, and the gate is connected to the first ECU 16. The source of switching element Q8 is connected to the emitter of switching element Q7, the emitter is connected to the negative electrode line NL, and the gate is connected to the first ECU 16.

[0031] The cathode of diode D7 is connected to the source of switching element Q7, and the anode is connected to the emitter of switching element Q7. That is, diode D7 and switching element Q7 constitute the upper arm of the W phase.

[0032] The cathode of diode D8 is connected to the source of switching element Q8, and the anode is connected to the emitter of switching element Q8. That is, diode D8 and switching element Q8 constitute the lower arm of the W phase.

[0033] The gates of each of the switching elements Q3 to Q8 are controlled by a control signal whose duty ratio is controlled by the first ECU 16 so that the direction and amount of the current flowing through each of the U phase, V phase, and W phase of the motor generator 15 become an alternating current that continuously changes with a 120-degree phase difference. As a result, a rotating magnetic field is formed in the stator of the motor generator 15, and the rotor of the motor generator 15 is rotated.

[0034] The first ECU 16 can control the input current flowing into the inverter 14 by control signals to each of the switching elements Q3 to Q8. That is, the first ECU 16 can control the upper limit value of the input current flowing into the inverter 14.

[0035] The first ECU 16 and the second ECU 17 are each composed of a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input port, and an output port. In the ROMs of the first ECU 16 and the second ECU 17, programs for causing the computer unit to function as the first ECU 16 and the second ECU 17 are stored, together with various constants and various maps. That is, in the first ECU 16 and the second ECU 17, when the CPU executes the programs stored in the ROM, the computer unit functions as the first ECU 16 and the second ECU 17.

[0036] The first ECU 16 controls the high-voltage system 18. Various sensors (not shown) are connected to the input port of the first ECU 16. Various control targets including the negative-side relay 11a, the positive-side relay 11b, the precharge relay 12a, and the switching elements Q3 to Q8 are connected to the output port of the first ECU 16. The first ECU 16 controls the various control targets based on information obtained from the various sensors. As described above, the first ECU 16 controls the negative-side relay 11a, the positive-side relay 11b, the precharge circuit 12, and the switching elements Q3 to Q8.

[0037] The second ECU 17 is an ECU different from the first ECU 16. Various sensors (not shown) are connected to the input port of the second ECU 17. Various control targets (not shown) are connected to the output port of the second ECU 17. The second ECU 17 controls the various control targets based on information obtained from the various sensors.

[0038] The second ECU 17 consists of an existing ECU that controls control targets that do not affect safety in the event of an abnormality. That is, the second ECU 17 consists of an ECU different from an ECU that controls a high-voltage system 18, an airbag, an ADAS (Advanced Driver-Assistance Systems), etc., which will affect safety in the event of an abnormality. The second ECU 17 consists of, for example, an ECU for air-conditioning control that does not affect safety.

[0039] The first ECU 16 and the second ECU 17 are set to communicate with each other. The first ECU 16 and the second ECU 17 are electrically connected by a communication line 19. The first ECU 16 and the second ECU 17 communicate with each other via the communication line 19. The communication line 19 is an existing communication line.

[0040] Here, if a water immersion detection sensor for detecting water immersion of a part of the vehicle body is provided in the vehicle 1, it is possible to detect that the lower part of the vehicle as a part of the vehicle body has been submerged due to traveling through a crown waterway or the like, but adding a new water immersion detection sensor will cause a cost increase.

[0041] Therefore, in this embodiment, the second ECU 17, which is an existing ECU, is made to function as a water immersion detection sensor. Thereby, it is possible to detect water immersion of a part of the vehicle body without increasing the cost.

[0042] The second ECU 17 is mounted at the same position as the high-voltage system 18 or at a position lower than the high-voltage system 18 in the vertical direction of the vehicle. And when the first ECU 16 cannot receive a signal by communication from the second ECU 17, the first ECU 16 prohibits the application of high voltage in the high-voltage system 18. Specifically, when the second ECU 17 is submerged and the first ECU 16 cannot receive a signal by communication from the second ECU 17, the first ECU 16 cuts off the high-voltage battery 10 and the high-voltage system 18.

[0043] The second ECU 17 is preferably attached at a position outside the vehicle cabin or below the seat inside the vehicle cabin. Also, the first ECU 16 is preferably attached at a position higher than the second ECU 17.

[0044] Referring to FIG. 2, the attachment positions of the first ECU 16 and the second ECU 17 will be described.

[0045] As shown in FIG. 2, the vehicle 1 includes a vehicle body 40. The vehicle body 40 has an engine room 42 at its front end (the left end in FIG. 2). Also, the vehicle body 40 has a vehicle cabin 41 behind the engine room 42 (to the right in FIG. 2). A seat 43 is provided in the vehicle cabin 41.

[0046] The first ECU 16 is attached at a position P1 above the vehicle cabin 41 so that it can continue to operate even when a part of the vehicle body 40 is submerged. At the position P1, the seat 43 and the high-voltage battery 10 are provided. Here, the upper part of the vehicle cabin 41 refers to a part at the same height as the seat 43 or a part higher than the seat 43. Also, the submergence of a part of the vehicle body 40 refers to the submergence of the lower part of the vehicle body 40.

[0047] Since the second ECU 17 serves as a water immersion detection sensor for detecting the submergence of a part of the vehicle body 40, it is attached at a position P2 below the vehicle cabin 41 or the engine room 42. The position P2 is a position below the seat 43. In other words, the position P1 where the first ECU 16 is arranged is a position where the possibility of being submerged during running on a crown waterway or the like of the vehicle 1 is low. Also, the position P2 where the second ECU 17 is arranged is a position where the possibility of being submerged during running on a crown waterway or the like of the vehicle 1 is high.

[0048] The water immersion detection operation by the first ECU 16 of the vehicle control system according to an embodiment of the present invention configured as described above will be described with reference to FIG. 3. Note that the water immersion detection operation described below is repeatedly executed at predetermined intervals.

[0049] First, the first ECU 16 determines the high-voltage application state in the high-voltage system 18 (step S1).

[0050] Next, the first ECU 16 determines whether a high voltage is being applied in the high voltage system 18 (step S2). If the first ECU 16 determines that a high voltage is not being applied (NO in step S2), it returns to step S1.

[0051] If the first ECU 16 determines that a high voltage is being applied (YES in step S2), it performs in-vehicle communication with the second ECU 17 (step S3).

[0052] Next, the first ECU 16 determines whether communication with the second ECU 17 has been interrupted (step S4). If the first ECU 16 determines that communication with the second ECU 17 has not been interrupted (NO in step S4), it returns to step S1.

[0053] If the first ECU 16 determines that communication with the second ECU 17 has been interrupted (YES in step S4), it disconnects the high voltage battery 10 from the high voltage system 18 (described as a high voltage circuit in the figure) (step S5) and ends the current operation.

[0054] Note that the operation of the first ECU 16 may be varied as follows according to the state of the vehicle 1 at the time of water immersion detection. That is, the first ECU 16 may be configured not to apply a high voltage on the condition that the vehicle 1 is stopped and before the high voltage is applied to the high voltage system 18 at the time of water immersion detection. Further, the first ECU 16 may immediately cut off the high voltage and then not apply the high voltage on the condition that the vehicle 1 is stopped and a high voltage is being applied to the high voltage system 18 at the time of water immersion detection. Further, the first ECU 16 may immediately stop using the high voltage battery 10, prompt the user to make a safe stop, and cut off the high voltage after stopping on the condition that the vehicle 1 is in motion (i.e., a high voltage has already been applied) at the time of water immersion detection.

[0055] As described above, in the vehicle control system according to the present embodiment, the second ECU 17 is attached at the same position as the high-voltage system 18 or at a position lower than the high-voltage system 18 in the vertical direction of the vehicle. And when the first ECU 16 cannot receive a signal by communication from the second ECU 17, the application of high voltage in the high-voltage system 18 is prohibited.

[0056] Thereby, when the second ECU 17 attached at the same position as the high-voltage system 18 or at a position lower than the high-voltage system 18 is submerged and the first ECU 16 cannot receive a signal by communication from the second ECU 17, the application of high voltage in the high-voltage system 18 is prohibited. For this reason, without adding a water immersion detection sensor, by using the existing second ECU 17 as a water immersion detection function, an increase in cost can be suppressed. As a result, it is possible to detect partial water immersion of the vehicle body without increasing the cost.

[0057] Also, in the vehicle control system according to the present embodiment, the second ECU 17 is attached at a position outside the vehicle compartment or below the seat in the vehicle compartment.

[0058] In this way, since the second ECU 17 is attached outside the vehicle compartment or inside the vehicle compartment and under the seat, it is possible to surely detect the intrusion of water into the high-voltage system 18 during flooding.

[0059] Also, in the vehicle control system according to the present embodiment, the first ECU 16 is attached at a position higher than the second ECU 17.

[0060] In this way, since the first ECU 16 is attached at a position higher than the second ECU 17, the first ECU 16 can surely detect the interruption of communication due to the flooding of the second ECU 17.

[0061] Although embodiments of the present invention have been disclosed, it is obvious that those skilled in the art can make changes without departing from the scope of the present invention. It is intended that all such modifications and equivalents be included in the following claims.

Description of Symbols

[0062] 1 Vehicle 16 First ECU 17 Second ECU 18 High-voltage system 41 Passenger compartment 43 Seat P1 Position (Position of the first ECU) P2 Position (Position of the second ECU)

Claims

1. Mounted on a vehicle equipped with a high-voltage system, a first ECU that controls the high-voltage system, and a second ECU different from the first ECU, A vehicle control system configured such that the first ECU and the second ECU communicate with each other, wherein the second ECU is mounted at the same position as the high-voltage system or at a position lower than the high-voltage system in the vertical direction of the vehicle, The vehicle control system is characterized in that the first ECU prohibits application of high voltage in the high-voltage system when a signal by communication cannot be received from the second ECU.

2. The vehicle control system according to claim 1, wherein the second ECU is mounted outside the vehicle compartment or below a seat in the vehicle compartment.

3. The vehicle control system according to claim 1, wherein the first ECU is mounted at a position higher than the second ECU.

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