Vehicle control devices

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 Art

[0002] One of the controls in recent vehicles (such as passenger cars) is ACC (Adaptive Cruise Control: following driving control). In ACC, control is performed to drive the host vehicle while maintaining a constant inter-vehicle distance between the host vehicle and the preceding vehicle.

[0003] In ACC, the target inter-vehicle distance from the preceding vehicle can be set. Specifically, for example, the target inter-vehicle distance can be set in three levels: "long", "normal", and "short". In the prior art, the target inter-vehicle distance is set to "long" as a standard, for example. And when the user changes the target inter-vehicle distance to "normal" or "short" by a switch operation or the like, ACC is executed based on the changed "normal" or "short". After that, when the user performs an IG off (ignition power off) operation, the setting of the target inter-vehicle distance returns to "long".

[0004] In that case, when the user desires "normal" or "short" as the target inter-vehicle distance, it is necessary to change the setting of the target inter-vehicle distance every time the IG is turned on (ignition power on), which is troublesome.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One countermeasure mentioned above is to write the target distance setting information, which is currently stored in volatile memory, to non-volatile memory after the ignition is turned off. However, this method has the problem that it requires a hardware mechanism (such as a capacitor) that can supply power to the ECU (Electronic Control Unit) to write the target distance setting information to non-volatile memory even after the ignition is turned off.

[0007] Another method involves writing the target distance setting information to non-volatile memory each time it is changed. However, this method has a problem: non-volatile memory has a limit on the number of writes, and once that limit is reached, further writing becomes impossible.

[0008] Therefore, the present invention has been made in view of the above circumstances, and aims to provide a vehicle control device that can write necessary setting information related to vehicle follow-me driving control to a non-volatile memory while suppressing unnecessary writing, even without a hardware mechanism that can supply power to the ECU after the ignition is turned off. [Means for solving the problem]

[0009] To solve the above problems, the vehicle control device of the present invention includes a control unit that performs follow-driving control to drive the vehicle while maintaining a constant distance between the vehicle and the vehicle in front, a volatile memory that stores current setting information for the follow-driving control, a non-volatile memory that stores setting information for the follow-driving control, and when the follow-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 vehicle is stopped, and the shift range of the vehicle is Parking When set to range (P range), the setting information stored in the volatile memory is written to the non-volatile memory. Furthermore, the setting information that has been changed while the follow-me driving control is not in operation will not be written to the non-volatile memory. It comprises a processing unit and

[0010] With this configuration, when the follow-me driving control is deactivated, the setting information related to the follow-me driving control stored in volatile memory is written to non-volatile memory only when the above conditions are met. This makes it possible to perform necessary writes to the non-volatile memory while suppressing unnecessary writes, even without a hardware mechanism that can supply power to the ECU after the ignition is turned off. Furthermore, when the vehicle's shift range is in the parking range (P range), that is, when the shift range is in the P range (a range other than the forward range) after the follow-me control is deactivated, there is a high probability that the ignition will be turned off afterward, allowing the setting information to be written to the non-volatile memory at a more appropriate timing.

[0011] Furthermore, in the vehicle control device of the present invention, the setting information includes at least information on the target inter-vehicle distance used in the follow-me driving control.

[0012] This configuration allows for more effective suppression of unnecessary writes to non-volatile memory by targeting information such as the target inter-vehicle distance, which is likely to be changed frequently. [Effects of the Invention]

[0015] According to the vehicle control device of the present invention, even without a hardware mechanism that can supply power to the ECU after the ignition is turned off, it is possible to write necessary setting information related to vehicle follow-me driving control to non-volatile memory while suppressing unnecessary writes. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a block diagram illustrating the overall configuration of the hybrid vehicle according to the embodiment. [Figure 2] Figure 2 shows an image illustrating the switching of target inter-vehicle distance setting information in the embodiment. [Figure 3] Figure 3 is a flowchart showing the processing performed by the ECU in the embodiment. [Modes for carrying out the invention]

[0017] Hereinafter, embodiments of the vehicle control device of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is a block diagram showing an overview of the overall configuration of a hybrid vehicle 1 according to an embodiment. The hybrid vehicle 1 is an example of a vehicle (own vehicle) and is equipped with a series hybrid system 2. The hybrid system 2 includes an engine 11, a power generation 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, and the like.

[0020] The power generation motor 12 is a motor that generates electric power using the power of the engine 11 and is, for example, a permanent magnet synchronous motor. The rotating shaft of the power generation 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 to each other, and a motor gear is supported on the rotating shaft of the power generation motor 12 so as not to rotate relative to each other, and the engine output gear and the motor gear are meshed with each other.

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

[0022] The battery 14 is a battery pack combining a plurality of secondary batteries and stores electric power. The secondary battery is, for example, a lithium ion battery. 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 power generation motor 12 and the driving motor 13, and includes a first inverter 21, a second inverter 22, and a converter 23.

[0024] When the engine 11 is started, the DC power output from the battery 14 is boosted by the converter 23, the boosted DC power is converted into AC power by the first inverter 21, and the AC power is supplied to the power generation motor 12. As a result, the power generation motor 12 is operated in power running, and the engine 11 is motored (cranked) by the power generation motor 12. When the rotational speed of the crankshaft of the engine 11 has risen to the rotational speed required for starting due to motoring and the spark plug of the engine 11 is sparked, the engine 11 starts.

[0025] When the hybrid vehicle 1 is running, the driving motor 13 is operated in power running, and the driving motor 13 generates power.

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

[0027] On the other hand, when the output required for the driving motor 13 exceeds the output of the battery 14, the hybrid vehicle 1 runs in HV mode. That is, the engine 11 is put into an operating state, and the power generation motor 12 is operated in power generation (regenerative operation), so that the power of the engine 11 is converted into AC power by the power generation motor 12. Then, the AC power from the power generation motor 12 is converted into DC power by the first inverter 21, the DC power output from the first inverter 21 is converted into AC power by the second inverter 22, and the AC power is supplied to the driving motor 13, whereby the driving motor 13 is driven.

[0028] Furthermore, when the remaining capacity of the battery 14 falls below a predetermined level, the generator motor 12 is operated to generate power while the engine 11 is running, regardless of whether the drive motor 13 is running or stopped. At this time, the AC power from the generator motor 12 is converted to DC power by the first inverter 21, 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 regenerated, and the power transmitted from the drive wheels 17 to the drive motor 13 is converted into alternating current (AC) power. At this time, the drive motor 13 becomes a resistance in the drive system, and this 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 in the second inverter 22, and the DC power output from the second inverter 22 is stepped down by the converter 23. Then, the stepped-down DC power is 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. The multiple ECUs are connected to enable bidirectional communication using the CAN (Controller Area Network) communication protocol. Various sensors necessary for control and processing are connected to each ECU, and detection signals from these connected sensors are input to it. In addition to detection signals from the various sensors, each ECU also receives control information from other ECUs. Below, we will describe ECU 3, which controls hybrid system 2, among the multiple ECUs.

[0031] The ECU3 is connected to a distance setting switch 41, a vehicle speed sensor 42, a shift sensor 43, an ACC switch 44, a forward recognition camera 45, and an accelerator sensor 46.

[0032] The inter-vehicle distance setting switch 41 is a switch that allows the user to change (switch) the target inter-vehicle distance setting in ACC control. Here, Figure 2 is a diagram illustrating the switching of the target inter-vehicle distance setting information in this embodiment.

[0033] The target following distance can be set to, for example, "long," "normal," or "short." Each time the user operates the following distance setting switch 41, the target following distance setting switches between "long" → "normal" → "short" → "long" → ...

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

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

[0036] The ACC selector switch 44 is, for example, located on the steering wheel, and accepts an operation to switch the ACC control on or off, and outputs an operation signal.

[0037] The forward recognition camera 45 is, for example, a stereo camera. A stereo camera is a camera capable of continuously capturing still images at a predetermined frame rate and detects the distance to the position of an object in the captured image based on parallax information. The stereo camera is installed, for example, on the windshield surface behind the rearview mirror in the front center of the passenger compartment, so as to be able to capture a wide-angle image of the area in front of the hybrid vehicle 1. 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 also be 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 operation performed on the accelerator pedal by the driver.

[0039] The ECU3 comprises, functionally, 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, control unit 32, and processing unit 33 are realized, for example, by the CPU (Central Processing Unit) executing various programs stored in the non-volatile memory 35. However, it is not limited to this, and some or all of these may be realized by hardware.

[0040] The volatile memory 34 is a volatile memory such as DRAM (Dynamic Random Access Memory) that stores various types of information. For example, the volatile memory 34 stores setting information related to the current ACC control. In the following example, the target distance between vehicles will be used as setting information related to ACC control.

[0041] The non-volatile memory 35 is a non-volatile memory such as flash memory that stores various types of information. For example, the non-volatile memory 35 stores the setting information for the target distance between vehicles in ACC control.

[0042] The acquisition unit 31 acquires various information from various sensors and other ECUs.

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

[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 required to follow the vehicle in front, based on images taken by the forward recognition camera 45, and uses the calculated information to control the driving of the hybrid vehicle 1.

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

[0046] (Condition 1) The target distance setting information differs between the volatile memory 34 and the non-volatile memory 35. (Condition 2) Hybrid vehicle 1 is stationary. (Condition 3) The shift range is set to P (parking range) (an example of a range other than the forward range).

[0047] Next, the processing performed by ECU3 will be described with reference to Figure 3. Figure 3 is a flowchart showing the processing performed by ECU3 in the embodiment.

[0048] In step S1, the control unit 32 determines whether or not the ACC control start operation has been performed using the ACC changeover switch 44. If Yes, it starts ACC control and proceeds to step S2; otherwise, it returns to step S1. If it proceeds to step S2, the target inter-vehicle distance setting information stored in the non-volatile memory 35 at that time is written to the volatile memory 34.

[0049] In step S2, the processing unit 33 determines whether or not there has been an operation to change the target distance setting using the distance setting switch 41. If yes, the unit proceeds to step S3; otherwise, it returns to step S2.

[0050] In step S3, the processing unit 33 changes the target inter-vehicle distance setting information in the volatile memory 34.

[0051] Next, in step S4, the control unit 32 determines whether or not to terminate ACC control. If Yes, the system proceeds to step S5; otherwise, it returns to step S2. For example, in step S4, the system determines Yes if the ACC control is terminated using the ACC changeover switch 44, or if the brake pedal is pressed.

[0052] In step S5, the processing unit 33 determines whether the target inter-vehicle distance setting information in the volatile memory 34 and the non-volatile memory 35 matches. If the result is Yes, the process ends; otherwise, the unit proceeds to step S6.

[0053] In step S6, the processing unit 33 determines whether the hybrid vehicle 1 is stationary and whether the shift range is in the P range (parking range). If the answer is Yes (conditions 2 and 3 are met), the unit proceeds to step S7; otherwise, it returns to step S6.

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

[0055] Thus, according to the hybrid vehicle 1 (ECU3) of this embodiment, when ACC control is deactivated, the target inter-vehicle distance setting information used for ACC control, stored in the volatile memory 34, is written to the non-volatile memory 35 only when all of the above conditions 1 to 3 are met. This makes it possible to write the target inter-vehicle distance setting information to the non-volatile memory 35 while suppressing unnecessary writes, even if there is no hardware mechanism that can supply power to the ECU3 after the ignition is turned off (i.e., even if the ECU3's power is cut off at the same time as the ignition is turned off).

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

[0057] Furthermore, by using condition 2, "Hybrid vehicle 1 is stopped," and condition 3, "Shift range is in P (parking range)," the following effects are achieved: If the vehicle is stopped and the shift range is in P after the ACC control is released, there is a high probability that the ignition will be turned off afterward. Therefore, the setting information for the target inter-vehicle distance can be written to the non-volatile memory 35 at a more appropriate (necessary) timing. Also, for example, when hybrid vehicle 1 is temporarily stopped at a red light, the shift range is usually not in P (it is in D range), so unnecessary writing to the non-volatile memory 35 in such situations can be avoided. Note that, for example, to more reliably avoid writing to the non-volatile memory 35 when the shift range is in P when hybrid vehicle 1 is temporarily stopped at a red light, condition 2 may be made even more restrictive, such as "Hybrid vehicle 1 is stopped at a location other than a red light."

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

[0059] Furthermore, while the target distance setting information can be changed even when ACC is not in control, drivers are more likely to want to remember the setting information used while ACC was in control. Therefore, by not writing the target distance setting information changed while ACC was not in control to the non-volatile memory 35, unnecessary writing to the non-volatile memory 35 can be further suppressed.

[0060] Furthermore, by suppressing unnecessary writes to the non-volatile memory 35, the possibility of the write cycle reaching its upper limit and subsequently becoming unusable can be significantly reduced.

[0061] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

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

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

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

[0065] 1...Hybrid vehicle (own 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...Distance setting switch, 42...Vehicle speed sensor, 43...Shift sensor, 44...ACC switch, 45...Forward recognition camera, 46...Accelerator sensor

Claims

1. A control unit that performs follow-driving control to drive the vehicle while maintaining a constant distance between the vehicle and the vehicle in front, A volatile memory that stores the current setting information for the aforementioned follow-me driving control, A non-volatile memory that stores setting information related to the aforementioned follow-me driving control, A vehicle control device comprising: a processing unit that, when the follow-me driving control is canceled, the setting information stored in the volatile memory and the setting information stored in the non-volatile memory are different, and when the vehicle is stopped and the vehicle's shift range is set to the parking range, writes the setting information stored in the volatile memory to the non-volatile memory, and does not write the setting information that has been changed while the follow-me driving control is not in operation to the non-volatile memory.

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

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