Vehicular control device

Abstract

To provide a vehicular control device which suppresses unwanted writing while performing necessary writing, on a non-volatile memory, of setting information concerning following-running control of a vehicle, although there is no mechanism of hardware that can supply electric power to an ECU after IG-off.SOLUTION: A vehicular control device comprises: a control part that executes following-running control of enabling an own vehicle to run while maintaining a certain inter-vehicle distance between the own vehicle and a preceding vehicle; a volatile memory that memorizes setting information concerning current following-running control; a non-volatile memory that memorizes setting information concerning the following-running control; and a processing part that writes, when the following-running control is released, the setting information memorized in the volatile memory on the non-volatile memory, when the setting information memorized in the volatile memory is different from the setting information memorized in the non-volatile memory and when the own vehicle is stopped and a shift range of the own vehicle is set to a range other than a range concerning forward movement.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] One of the controls used in recent vehicles (passenger cars, etc.) is ACC (Adaptive Cruise Control), which controls the vehicle to travel while maintaining a constant distance between the vehicle and the vehicle ahead.

[0003] In the ACC, a target inter-vehicle distance from the vehicle ahead can be set. Specifically, for example, the target inter-vehicle distance can be set in three stages: "long," "normal," and "short." In the conventional technology, the target inter-vehicle distance is set to, for example, "long" as a standard. Then, when the user changes the target inter-vehicle distance to "normal" or "short" by operating a switch or the like, the ACC is executed based on the changed "normal" or "short." After that, when the user turns off the IG (ignition power), the setting of the target inter-vehicle distance returns to "long."

[0004] In this case, if the user desires a "normal" or "short" target inter-vehicle distance, the user must change the target inter-vehicle distance setting every time the IG is turned on (ignition power is turned on), which is bothersome. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-184464 A Summary of the Invention [Problem to be solved by the invention]

[0006] As a countermeasure against the above, for example, there is a method of writing the setting information of the target inter-vehicle distance stored in the volatile memory at that time to the non-volatile memory after the IG is turned off. However, this method has a problem in that it requires a hardware mechanism (such as a capacitor) that can supply power to the ECU (Electronic Control Unit) for writing the setting information of the target inter-vehicle distance to the non-volatile memory even after the IG is turned off.

[0007] Another method is to write the setting information of the target inter-vehicle distance to a non-volatile memory every time the setting information is changed. However, this method has a problem in that the non-volatile memory has a maximum number of times that the setting information can be written, and once the maximum number of times is reached, the setting information can no longer be written to.

[0008] Therefore, the present invention has been made in consideration of the above circumstances, and has an objective of providing a vehicle control device that can write necessary setting information related to the vehicle's adaptive cruise control to a non-volatile memory while suppressing unnecessary writing, even if there is no hardware mechanism that can supply power to the ECU after the IG is turned off. [Means for solving the problem]

[0009] In order to solve the above problem, the vehicle control device of the present invention comprises a control unit that executes following driving control to drive the host vehicle while maintaining a constant inter-vehicle distance between the host vehicle and a vehicle in front, a volatile memory that stores setting information related to the current following driving control, a non-volatile memory that stores setting information related to the following driving control, and a processing unit that writes the setting information stored in the volatile memory to the non-volatile memory when the following driving control is released, the setting information stored in the volatile memory and the setting information stored in the non-volatile memory are different, the host vehicle is stopped, and the shift range of the host vehicle is set to a range other than a range for forward movement.

[0010] According to this configuration, when the following cruise control is released, the setting information related to the following cruise control stored in the volatile memory is written to the non-volatile memory only when the above-mentioned conditions are satisfied. This makes it possible to perform necessary writing to the non-volatile memory while suppressing unnecessary writing, even if there is no hardware mechanism that can supply power to the ECU after the IG is turned off.

[0011] In the vehicle control device of the present invention, the setting information includes at least information of a target inter-vehicle distance used in the following driving control.

[0012] According to this configuration, by targeting information on the target inter-vehicle distance, which is considered to be changed frequently, unnecessary writing to the non-volatile memory can be more effectively suppressed.

[0013] In the vehicle control device of the present invention, the range other than the range related to forward movement is a P range (parking range).

[0014] According to this configuration, if the shift range is in P range after the following cruise control is released, there is a high possibility that the IG will be turned off afterwards, so that the setting information can be written to the non-volatile memory at a more appropriate timing. Effect of the Invention

[0015] According to the vehicle control device of the present invention, even if there is no hardware mechanism that can supply power to the ECU after the IG is turned off, it is possible to perform necessary writing to non-volatile memory while suppressing unnecessary writing of setting information related to the vehicle's adaptive cruise control. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a block diagram showing an outline of the overall configuration of a hybrid vehicle according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an image of switching of setting information of a target inter-vehicle distance in the embodiment. [Diagram 3] FIG. 3 is a flowchart showing a process performed by the ECU according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle control device of the present invention will be described with reference to the drawings.

[0018] 1 is a block diagram showing an outline of the overall configuration of a hybrid vehicle 1 according to an embodiment. The hybrid vehicle 1 is an example of a vehicle (host vehicle) and is equipped with a series hybrid system 2. The hybrid system 2 includes an engine 11, a generator motor 12, a drive motor 13, a battery 14, and a PCU (Power Control Unit) 15.

[0019] The engine 11 is, for example, a gasoline engine, and includes a throttle body, a fuel injector that injects fuel into intake air, a starter for starting the engine, and the like.

[0020] The generator motor 12 is a motor that generates electricity using the power of the engine 11, and is, for example, a permanent magnet synchronous motor. The rotating shaft of the generator motor 12 is mechanically connected to the crankshaft of the engine 11 via a gear (not shown). For example, an engine output gear is supported on the crankshaft of the engine 11 so as not to rotate relative thereto, and a motor gear is supported on the rotating shaft of the generator motor 12 so as not to rotate relative thereto, and the engine output gear and the motor gear mesh with each other.

[0021] The drive motor 13 is a motor that generates power for driving, and is, for example, a permanent magnet synchronous motor that is larger than the generator motor 12. The rotating shaft of the drive motor 13 is connected to a drive system 16 of the hybrid vehicle 1. The drive system 16 includes a differential gear, and the power of the drive motor 13 is transmitted to the differential gear, and is distributed and transmitted from the differential gear to drive wheels 17 consisting of left and right front wheels or rear wheels. This causes the left and right drive wheels 17 to rotate, and the hybrid vehicle 1 moves forward or backward.

[0022] The battery 14 is an assembled battery made up of a plurality of secondary batteries, and stores electric power. The secondary batteries are, for example, lithium ion batteries. The battery 14 outputs DC power of, for example, about 200 to 350 V (volts).

[0023] The PCU 15 is a unit for controlling the driving of the generator motor 12 and the drive motor 13, and includes a first inverter 21, a second inverter 22, and a converter .

[0024] When starting the engine 11, the DC power output from the battery 14 is boosted by the converter 23, the boosted DC power is converted to AC power by the first inverter 21, and the AC power is supplied to the generator motor 12. This causes the generator motor 12 to perform power running, and the engine 11 is motored (cranked) by the generator motor 12. When the rotation speed of the crankshaft of the engine 11 has increased to a rotation speed required for starting due to motoring, the ignition plug of the engine 11 is sparked, and the engine 11 starts.

[0025] When the hybrid vehicle 1 is traveling, the drive motor 13 is operated in a power running mode, and generates power.

[0026] When the output required for the drive motor 13 is smaller than the output of the battery 14, the hybrid vehicle 1 runs in EV mode. That is, the engine 11 is stopped, power generation by the generator motor 12 is not performed, and power is supplied from the battery 14 to the drive motor 13, which drives the drive motor 13.

[0027] On the other hand, when the output required for the drive motor 13 exceeds the output of the battery 14, the hybrid vehicle 1 runs as an HV. That is, the engine 11 is operated and the generator motor 12 is operated to generate electricity (regenerative operation), so that the power of the engine 11 is converted to AC power by the generator motor 12. Then, the AC power from the generator motor 12 is converted to DC power by the first inverter 21, and the DC power output from the first inverter 21 is converted to AC power by the second inverter 22, and the AC power is supplied to the drive motor 13, thereby driving the drive motor 13.

[0028] Furthermore, when the remaining capacity of the battery 14 falls below a predetermined level, the generator motor 12 operates to generate electricity while the engine 11 is running, regardless of whether the drive motor 13 is driven or stopped. At this time, AC power from the generator motor 12 is converted to DC power by the first inverter 21, and the DC power output from the first inverter 21 is stepped down by the converter 23, and the stepped-down DC power is supplied to the battery 14, thereby charging the battery 14.

[0029] When the hybrid vehicle 1 decelerates, the drive motor 13 is operated in a regenerative manner, and the power transmitted from the drive wheels 17 to the drive motor 13 is converted into AC power. At this time, the drive motor 13 acts as a resistance in the running drive system, and the resistance acts as a braking force (regenerative braking force) that brakes the hybrid vehicle 1. At this time, in the PCU 15, the AC power supplied from the drive motor 13 to the second inverter 22 is converted into DC power by the second inverter 22, and the DC power output from the second inverter 22 is stepped down by the converter 23. The stepped-down DC power is then supplied to the battery 14, thereby charging the battery 14.

[0030] Hybrid vehicle 1 is equipped with multiple ECUs (Electronic Control Units). Each ECU has a microcontroller unit (microcontroller unit). The multiple ECUs are connected to enable two-way communication using a CAN (Controller Area Network) communication protocol. Each ECU is connected to various sensors required for control and processing, and receives detection signals from the connected sensors. In addition to the detection signals input from the various sensors, each ECU also receives information required for control from other ECUs. Of the multiple ECUs, ECU 3, which controls hybrid system 2, will be described below.

[0031] The ECU 3 is connected to a vehicle distance setting switch 41, a vehicle speed sensor 42, a shift sensor 43, an ACC changeover switch 44, a forward recognition camera 45, and an accelerator sensor 46.

[0032] The following distance setting switch 41 is a switch for the user to change (switch) the setting of the target following distance in the ACC control. Here, Fig. 2 is a diagram showing an image of switching the setting information of the target following distance in the embodiment.

[0033] The target inter-vehicle distance has three levels, for example, "long", "normal", and "short". Each time the user operates the inter-vehicle distance setting switch 41, the setting of the target inter-vehicle distance switches in the following order: "long" → "normal" → "short" → "long" →...

[0034] Returning to FIG. 1, the vehicle speed sensor 42 outputs, as a detection signal, a pulse signal synchronized with the rotation of a rotating body (such as a wheel) that rotates as the hybrid vehicle 1 travels.

[0035] The shift sensor 43 is a sensor that detects which range the shift range is in. The shift ranges include, for example, D range (forward range), R range (reverse range), N range (neutral range), and P range (parking range). The shift sensor 43 outputs a signal indicating the detected range. Note that, in addition to the D range, a 1st gear range and a 2nd gear range may be provided as forward ranges.

[0036] The ACC changeover switch 44 is provided, for example, on the steering wheel, receives an operation to switch the ACC control on / off, and outputs an operation signal.

[0037] The forward recognition camera 45 is, for example, a stereo camera. The stereo camera is a camera capable of continuously capturing still images at a predetermined frame rate, and detects the distance to the position of a target in the captured images based on parallax information. The stereo camera is installed, for example, on the windshield surface behind the rearview mirror in the center of the front part of the vehicle interior so that it can capture an image of the area in front of the hybrid vehicle 1 at a wide angle. The forward recognition camera 45 outputs a detection signal. Note that the forward recognition camera 45 is not limited to a stereo camera, and may be, for example, a sensor other than a camera, such as a millimeter wave sensor.

[0038] The accelerator sensor 46 outputs a detection signal corresponding to the amount of depression of the accelerator pedal operated by the driver.

[0039] The ECU 3 includes, as functional components, an acquisition unit 31, a control unit 32, a processing unit 33, a volatile memory 34, and a non-volatile memory 35. The acquisition unit 31, the control unit 32, and the processing unit 33 are realized, for example, by a CPU (Central Processing Unit) executing various programs stored in the non-volatile memory 35. Note that this is not limiting, and some or all of them may be realized by hardware.

[0040] The volatile memory 34 is a volatile memory such as a dynamic random access memory (DRAM) and stores various information. The volatile memory 34 stores, for example, setting information related to the current ACC control. In the following, the target inter-vehicle distance is taken as an example of the setting information related to the ACC control.

[0041] The non-volatile memory 35 is a non-volatile memory such as a flash memory, and stores various information. The non-volatile memory 35 stores, for example, setting information for a target inter-vehicle distance for ACC control.

[0042] The acquisition unit 31 acquires various pieces of information from various sensors, other ECUs, and the like.

[0043] The control unit 32 executes various controls. For example, the control unit 32 executes ACC control to drive the hybrid vehicle 1 while maintaining a constant distance between the hybrid vehicle 1 and a vehicle ahead. The start condition of the ACC control is, for example, a start operation using the ACC changeover switch 44. The end condition of the ACC control is, for example, a stop operation using the ACC changeover switch 44 or a depression operation of the brake pedal.

[0044] In ACC control, the control unit 32 calculates, for example, the relative speed between the vehicle in front and the hybrid vehicle 1, the distance between the vehicle in front and the hybrid vehicle 1, and the acceleration / deceleration to follow the vehicle in front based on images captured by the forward recognition camera 45, and controls the driving of the hybrid vehicle 1 using the calculated information.

[0045] The processing unit 33 executes various processes. For example, when the ACC control is released and all of the following conditions 1 to 3 are satisfied, the processing unit 33 writes the setting information of the target inter-vehicle distance stored in the volatile memory 34 to the non-volatile memory 35.

[0046] (Condition 1) The setting information of the target inter-vehicle distance in the volatile memory 34 and the non-volatile memory 35 are different. (Condition 2) Hybrid vehicle 1 is stopped. (Condition 3) The shift range is P range (parking range) (an example of a range other than the range related to forward movement).

[0047] Next, the process performed by the ECU 3 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the process performed by the ECU 3 in the embodiment.

[0048] In step S1, the control unit 32 determines whether or not an operation to start ACC control has been performed using the ACC changeover switch 44, and if Yes, starts ACC control and proceeds to step S2, and if No, returns to step S1. When proceeding to step S2, the setting information of the target inter-vehicle distance stored in the non-volatile memory 35 at that time is written to the volatile memory 34.

[0049] In step S2, the processor 33 determines whether or not the target inter-vehicle distance setting switch 41 has been used to change the setting of the target inter-vehicle distance. If Yes, the process proceeds to step S3, and if No, the process returns to step S2.

[0050] In step S3, the processing unit 33 changes the setting information of the target inter-vehicle distance in the volatile memory .

[0051] Next, in step S4, the control unit 32 determines whether or not to end the ACC control, and if Yes, proceeds to step S5, and if No, returns to step S2. For example, in step S4, if an operation to end the ACC control is performed using the ACC changeover switch 44 or if the brake pedal is depressed, the determination is Yes.

[0052] In step S5, the processing unit 33 determines whether the setting information of the target inter-vehicle distance in the volatile memory 34 and the non-volatile memory 35 matches, and if Yes, ends the processing, and if No (if condition 1 is satisfied), proceeds to step S6.

[0053] In step S6, the processing unit 33 determines whether the hybrid vehicle 1 is stopped and the shift range is P range (parking range), and if Yes (if conditions 2 and 3 are satisfied), proceeds to step S7, and if No, returns to step S6.

[0054] In step S7, the processing unit 33 writes the setting information of the target inter-vehicle distance stored in the volatile memory 34 into the non-volatile memory 35.

[0055] In this way, according to the hybrid vehicle 1 (ECU 3) of this embodiment, when the ACC control is released, only when all of the above-mentioned conditions 1 to 3 are satisfied, the setting information of the target inter-vehicle distance stored in the volatile memory 34 and used for the ACC control is written to the non-volatile memory 35. As a result, even if there is no hardware mechanism that can supply power to the ECU 3 after the IG is turned off (that is, even if the ECU 3 is one whose power is turned off simultaneously with the IG being turned off), it is possible to write necessary setting information of the target inter-vehicle distance to the non-volatile memory 35 while suppressing unnecessary writing.

[0056] Specifically, for example, by using condition 1 that "the setting information of the target inter-vehicle distance is different between the volatile memory 34 and the non-volatile memory 35," unnecessary writing to the non-volatile memory 35 when they are the same can be avoided.

[0057] In addition, by using the condition 2 "The hybrid vehicle 1 is stopped" and the condition 3 "The shift range is in the P range (parking range)," the following effects are achieved. If the hybrid vehicle 1 is stopped and the shift range is in the P range after the ACC control is released, there is a high possibility that the IG will be turned off after that. Therefore, the setting information of the target inter-vehicle distance can be written to the non-volatile memory 35 at a more appropriate (writing required) timing. Also, for example, when the hybrid vehicle 1 is temporarily stopped at a red light, the shift range is usually not in the P range (it is in the D range), so unnecessary writing to the non-volatile memory 35 in such a situation can be avoided. Note that, for example, in order to more reliably avoid writing to the non-volatile memory 35 in the case where the shift range is in the P range when the hybrid vehicle 1 is temporarily stopped at a red light, (Condition 2) may be a more restrictive condition such as "The hybrid vehicle 1 is stopped at a light other than a red light."

[0058] Moreover, by targeting the information on the target inter-vehicle distance, which is considered to be changed frequently, unnecessary writing to the non-volatile memory 35 can be more effectively suppressed.

[0059] In addition, although the setting information of the target inter-vehicle distance can be changed even when the ACC is not under control, it is highly likely that the driver wants to store the setting information during ACC control. Therefore, by not writing the setting information of the target inter-vehicle distance changed while the ACC is not under control to the non-volatile memory 35, unnecessary writing to the non-volatile memory 35 can be further suppressed.

[0060] By suppressing unnecessary writing to the non-volatile memory 35, it is possible to significantly reduce the possibility that the number of writing times reaches the upper limit of writing times and writing becomes impossible thereafter.

[0061] Although the embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This new embodiment can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0062] For example, the application of the present invention is not limited to series hybrid vehicles, but may also be to other vehicles equipped with ACC control functions, such as gasoline vehicles, parallel hybrid vehicles, electric vehicles, and fuel cell vehicles.

[0063] In addition, the setting information regarding ACC control written to the non-volatile memory 35 is not limited to the target vehicle distance, but may also be information such as vehicle speed, the increase / decrease range of the vehicle speed setting, and acceleration (for example, three levels: strong, normal, and weak).

[0064] 3 shows a typical process flow, and is not limited thereto. For example, even if the ACC repeatedly starts and ends control until the condition for writing the setting information to the non-volatile memory 35 is satisfied (i.e., until the answer is Yes in step S6), the process of step S6 may be repeated until the power is turned off. [Explanation of symbols]

[0065] 1... hybrid vehicle (host vehicle), 2... hybrid system, 3... ECU, 11... engine, 12... generator motor, 13... drive motor, 14... battery, 15... PCU, 16... drive system, 17... drive wheels, 21... first inverter, 22... second inverter, 23... converter, 31... acquisition unit, 32... control unit, 33... processing unit, 34... volatile memory, 35... non-volatile memory, 41... vehicle distance setting switch, 42... vehicle speed sensor, 43... shift sensor, 44... ACC changeover switch, 45... forward recognition camera, 46... accelerator sensor

Claims

1. a control unit that executes a following driving control for driving the host vehicle while maintaining a constant inter-vehicle distance between the host vehicle and a preceding vehicle; A volatile memory that stores setting information related to the current following cruise control; A non-volatile memory that stores setting information related to the following driving control; a processing unit that writes the setting information stored in the volatile memory to the non-volatile memory when the following driving control is released, the setting information stored in the volatile memory differs from the setting information stored in the non-volatile memory, the vehicle is stopped, and the shift range of the vehicle is set to a range other than a range related to forward movement.

2. The vehicle control device according to claim 1 , wherein the setting information includes at least information on a target inter-vehicle distance used in the following driving control.

3. 2. The vehicle control device according to claim 1, wherein the range other than the range related to forward travel is a P range (parking range).

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