Vehicle control device

Abstract

To provide a vehicle control device capable of appropriately detecting or estimating a change in ride quality of a vehicle due to engine vibration.SOLUTION: A vehicle control device evaluates or estimates ride quality of a vehicle mounted with an engine as a power source, based on vibration generated by the engine. The device calculates an initial value of a ratio between vehicle body acceleration as a numerator and engine acceleration as a denominator, and a temporal variation of the ratio when a vehicle speed is at or below a predetermined value and the engine is idling. If the temporal variation exceeds the initial value by a predetermined determination condition, the device notifies a driver of reduction in the ride quality (Step S8).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle equipped with an engine, and more particularly to a control device for a vehicle that detects or estimates a change in ride comfort caused by engine vibration. [Background technology]

[0002] Patent Document 1 describes a vehicle control device that aims to suppress the transmission of engine vibration to the vehicle body when starting the engine in a hybrid vehicle. The vehicle control device described in Patent Document 1 is configured to correct the engine starting torque and engine starting power related to the driver's depressing the accelerator pedal according to the fluctuation state of the hardness of the engine mount provided between the engine and the vehicle body. Patent Document 1 also describes determining the hardness and deterioration state of the engine mount based on the longitudinal acceleration of the vehicle, and issuing a warning recommending replacement of the engine mount when deterioration of the engine mount is determined. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-107512 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle control device described in the above Patent Document 1, for example, the hardening and softening states of the engine mount are determined based on the longitudinal acceleration of the vehicle caused by the vibration at the time of engine start. The deterioration state of the engine mount can be determined or estimated from the hardening or softening state of the engine mount. Then, the vibration of the vehicle body caused by the vibration of the engine and the change in the ride comfort of the vehicle can be estimated from the deterioration state of the engine mount. However, the vehicle control device described in Patent Document 1 does not take into consideration the forcing force or excitation force that generates the vibration. Therefore, it is not sufficient to evaluate the deterioration state of the engine mount and the ride comfort of the vehicle. For example, when the vibration generated by the engine becomes large due to the influence of the fuel properties, it is determined that the engine mount is apparently deteriorated. As a result, there is a possibility that the ride comfort of the vehicle cannot be properly evaluated. Thus, there is still room for improvement in order to properly detect or estimate the change in the ride comfort of the vehicle caused by the vibration of the engine.

[0005] This invention has been devised with an eye on the technical challenges described above, and aims to provide a vehicle control device that can appropriately detect or estimate changes in the ride comfort of the vehicle caused by engine vibrations. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a control device for a vehicle that is equipped with at least an engine as a power source and that evaluates or estimates the ride quality or comfort of the vehicle caused by vibrations generated by the engine, the control device comprising: a detection unit that detects the operating state of the vehicle and the operating state of the engine, as well as the acceleration of the engine body and the acceleration of the vehicle body, and a controller that controls the vehicle and quantitatively evaluates or estimates the ride quality, the controller calculating, when the vehicle speed is equal to or less than a predetermined value near 0 and the engine is idling, an initial value of a ratio with the acceleration of the engine as the denominator and the acceleration of the vehicle body as the numerator, and a time-dependent change value of the ratio, and when the time-dependent change value becomes greater than the initial value by a predetermined judgment condition or more, notifying the driver that the ride quality has deteriorated or is showing signs of deterioration.

[0007] The controller in the present invention may be configured to perform frequency analysis on each of the detected acceleration values, and calculate the initial value and the time-dependent change value using a primary explosion frequency component of the engine as a result of the frequency analysis.

[0008] The controller in the present invention may be configured to calculate the initial value and the time-varying value when the engine has completed warming up. Effect of the Invention

[0009] In the vehicle control device of the present invention, in order to quantitatively express the ride quality and comfort of the vehicle, the vehicle body vibration, i.e., the acceleration of the vehicle body, is detected. In addition, the vibration of the engine, which is the source of the vehicle body vibration, i.e., the acceleration of the engine, is also detected. Then, the ride quality or comfort of the vehicle is evaluated based on the change state (i.e., the change value over time) of the acceleration of the vehicle body and the acceleration of the engine with respect to the initial value. For example, when the change value of the acceleration over time becomes larger than the initial value by a predetermined value or more, or when the ratio of the initial value of the acceleration to the change value over time becomes larger by a predetermined multiple or more, it is evaluated that the ride quality of the vehicle has deteriorated to a level requiring inspection of the vehicle or replacement of parts, or that there is a sign of the deterioration of the ride quality. At the same time, the driver is notified of the evaluation result. Therefore, when the vibration of the vehicle body increases and the ride quality of the vehicle deteriorates, such a state can be appropriately detected and the driver can be made aware of it quickly, and the driver can be prompted to inspect the vehicle or replace parts.

[0010] When calculating the initial value and the change over time of the acceleration as described above, a frequency analysis of the acceleration is performed, and the initial value and the change over time of the acceleration are obtained using the primary engine explosion frequency component obtained by the frequency analysis. That is, the frequency component with the largest engine vibration component is extracted to calculate the initial value and the change over time of the acceleration. Therefore, the change in the ride comfort of the vehicle caused by the engine vibration can be appropriately detected.

[0011] The initial value and the change over time of the acceleration are calculated when the engine has finished warming up and the idling speed is stable, so that the change in the ride comfort of the vehicle caused by engine vibration can be appropriately detected under conditions suitable for measuring the acceleration.

[0012] Therefore, the vehicle control device of the present invention can appropriately estimate and evaluate changes in the ride quality of the vehicle caused by engine vibrations. Also, by notifying the driver based on the evaluation result of the ride quality, the driver can be made aware of the need for vehicle inspection or part replacement, and can carry out inspection or part replacement at an appropriate time. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle to be controlled by a vehicle control device of the present invention. [Diagram 2] FIG. 2 is a flowchart for explaining an example of control executed by the vehicle control device of the present invention. [Diagram 3] FIG. 3 is a diagram for explaining an example of frequency analysis performed in the control shown in the flowchart of FIG. 2, where FIG. 3(a) shows the result of frequency analysis of the acceleration (vibration) of the engine body, and FIG. 3(b) shows the result of frequency analysis of the acceleration (vibration) of the vehicle body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings. Note that the following embodiment is merely an example of a specific embodiment of the present invention, and is not intended to limit the present invention.

[0015] An example of a drive system and a control system of a vehicle Ve to be controlled in an embodiment of the present invention is shown in Fig. 1. The vehicle Ve shown in Fig. 1 is equipped with an engine (ENG) 1 as a drive power source, and is configured to transmit the output torque of the engine 1 to drive wheels 3 via a transaxle 2, a differential gear (not shown), etc. The vehicle Ve also includes a detection unit 4 and a controller (ECU) 5.

[0016] In the embodiment of the present invention, the vehicle Ve to be controlled may be any vehicle Ve equipped with an internal combustion engine such as the engine 1, and is not limited to a so-called engine vehicle equipped with only the engine 1 as a driving force source as shown in Fig. 1. For example, the vehicle may be a hybrid vehicle (not shown) using the engine 1 and a motor (not shown) as driving force sources. Alternatively, the vehicle may be a series type hybrid vehicle (not shown) equipped with the engine 1 as a power source for driving a generator (not shown), or an electric vehicle (not shown) so-called a range extender.

[0017] 1, the vehicle Ve to be controlled in the embodiment of the present invention may be a front-wheel drive vehicle in which drive torque is transmitted to front wheels (drive wheels) 3 and drive force is generated at the front wheels 3. Alternatively, the vehicle Ve may be a rear-wheel drive vehicle (not shown) in which drive torque is transmitted to rear wheels 6 via, for example, a propeller shaft (not shown) and drive force is generated at the rear wheels 6. Alternatively, the vehicle Ve may be a four-wheel drive vehicle (not shown) provided with a transfer mechanism (not shown) in which drive torque is transmitted to both the front wheels 3 and the rear wheels 6 and drive force is generated at both the front wheels 3 and the rear wheels 6.

[0018] The detection unit 4 is a device or apparatus for acquiring various data and information required for controlling the vehicle Ve, and includes, for example, a power supply unit, a microcomputer, a sensor, and an input / output interface. In particular, the detection unit 4 in the embodiment of the present invention detects the driving state of the vehicle Ve and the driving state of the engine 1, and detects various data for quantitatively evaluating the ride quality and comfort of the vehicle Ve. Specifically, the detection unit 4 has an engine acceleration sensor 4a for detecting the acceleration of the engine 1 main body, and a vehicle body acceleration sensor 4b for detecting the acceleration of the vehicle body 7. In addition, the detection unit 4 has, for example, a vehicle speed sensor 4c for detecting the vehicle speed, an engine speed sensor 4d for detecting the rotation speed (engine speed) of the engine 1, a water temperature sensor 4e for detecting the temperature of the cooling water of the engine 1, and an oil temperature sensor 4f for detecting the temperature of the oil in the engine 1. The detection unit 4 is electrically connected to the controller 5 described later, and outputs, as detection data, electric signals and the like corresponding to the detection values ​​or calculated values ​​of the various sensors, devices, and the like described above to the controller 5.

[0019] The controller 5 is an electronic control device mainly composed of a microcomputer, for example. The controller 5 in the embodiment of the present invention controls the vehicle Ve and, in particular, quantitatively evaluates or estimates the ride quality and comfort of the vehicle Ve. The controller 5 receives various data detected or calculated by the detection unit 4. The controller 5 performs calculations using the input various data and pre-stored data, calculation formulas, and the like. The controller 5 outputs the calculation results as a control command signal and controls the vehicle Ve as described above. The vehicle Ve includes a "notification means" for notifying the driver of the evaluation or estimation result of the ride quality and comfort of the vehicle Ve as described above, and the controller 5 controls the operation (notification content) of the "notification means". In the example shown in FIG. 1, the vehicle Ve includes a display 8 as the "notification means". Therefore, the controller 5 controls the operation (display content) of the display 8 to display the evaluation result or estimation result of the ride quality and comfort of the vehicle Ve to the driver and make him / her aware of it. Although FIG. 1 shows an example in which one controller 5 is provided, a plurality of controllers 5 may be provided for each device or equipment to be controlled, or for each control content.

[0020] As described above, in the vehicle Ve equipped with the engine 1 as a power source, when vibrations generated by the engine 1 are transmitted to the vehicle body 7 and the driver and passengers of the vehicle Ve, the ride quality or comfort of the vehicle Ve is affected. For example, when the vibrations transmitted from the engine 1 to the vehicle body 7 become large due to aging or deterioration of the engine 1 main body and peripheral parts (not shown) of the engine 1, the ride quality or comfort of the vehicle Ve may decrease, and inspection, repair, part replacement, etc. of the vehicle Ve may become necessary. In order to detect such a change in the ride quality of the vehicle Ve and to determine the necessity of inspection, repair, part replacement, etc. of the vehicle Ve at an early stage, the controller 5 of the vehicle Ve in the embodiment of the present invention is configured to execute, for example, the control shown in the flowchart of FIG. 2 below.

[0021] 2 is executed when the vehicle Ve is stopped and the engine 1 is idling. Therefore, first, in step S1, it is determined whether the vehicle speed is 0 and the engine 1 is idling. In this case, the determination may include a state in which the vehicle Ve is almost stopped, and therefore, instead of determining whether the vehicle speed is 0, it may be determined whether the vehicle speed is equal to or lower than a predetermined vehicle speed (close to 0).

[0022] If the answer to step S1 is "No" because the vehicle speed is not 0 or the engine 1 is not idling, the routine shown in the flowchart of FIG. 2 is temporarily terminated without executing the control of the subsequent steps.

[0023] On the other hand, if the vehicle speed is 0 and the engine 1 is idling, so that "Yes" is determined in step S1, the process proceeds to step S2.

[0024] In step S2, it is determined whether the temperature of the cooling water of the engine 1 (engine water temperature) is within a predetermined temperature range. The predetermined temperature range in this case is determined in advance as a threshold value for determining whether the warm-up of the engine 1 is complete. If the engine water temperature is within the predetermined temperature range, it is determined that the warm-up of the engine 1 is complete and the idling operation of the engine 1 is stable.

[0025] If the engine water temperature is outside the predetermined temperature range and therefore the answer to step S2 is "No," it is determined that the idling operation of the engine 1 is unstable. Therefore, the routine shown in the flowchart of FIG. 2 is temporarily terminated without executing the control of the subsequent steps.

[0026] On the other hand, if the engine water temperature is within the predetermined temperature range and therefore "Yes" is determined in step S2, the process proceeds to step S3.

[0027] In step S3, the acceleration of the engine 1 main body (engine acceleration) and the acceleration of the vehicle body 7 (vehicle body acceleration) are detected. At the same time, a frequency analysis is performed on the detected values ​​of each acceleration. Then, from the frequency analysis results, as shown in FIG. 3, an engine explosion primary frequency component Gpp_F of the engine acceleration and an engine explosion primary frequency component Gb_F of the vehicle body acceleration are respectively obtained. The engine explosion primary frequency is the frequency of vibrations generated due to explosions in the engine 1 when the engine 1 is operating with combustion. In the control example shown in the flowchart of FIG. 3, assuming that the engine speed is Ne [rpm], the number of cylinders of the engine 1 is n, and the engine explosion primary frequency is F [Hz], the engine explosion primary frequency F is expressed as follows: F = Ne × (n / 2) / 60 It is calculated using the formula:

[0028] In step S4, it is determined whether the number of measurements of the engine acceleration and vehicle body acceleration is equal to or greater than a predetermined number, that is, whether the measurement values ​​of each acceleration have been saved or stored a predetermined number of times or more.

[0029] If the number of measurements of the engine acceleration and the vehicle body acceleration is still less than the predetermined number, and therefore "No" is determined in step S4, the process proceeds to step S5.

[0030] In step S5, based on the measurement results of the engine acceleration and vehicle acceleration up to the present, the ratio (Gb_F / Gpp_F) is calculated with the engine acceleration (specifically, the engine explosion primary frequency component Gpp_F of the engine acceleration) as the denominator and the vehicle acceleration (specifically, the engine explosion primary frequency component Gb_F of the vehicle acceleration) as the numerator, and is saved or stored.

[0031] Next, in step S6, the average value of the ratio (Gb_F / Gpp_F) between the engine acceleration and the vehicle body acceleration from the first time to the present is calculated as the initial value α0 of the ratio (Gb_F / Gpp_F) between the engine acceleration and the vehicle body acceleration as described above, and is saved or stored.

[0032] As described above, when the initial value α0 of the ratio (Gb_F / Gpp_F) between the engine acceleration and the vehicle body acceleration is calculated and stored in step S6, the routine shown in the flowchart of FIG. 2 is then temporarily terminated.

[0033] On the other hand, if the number of measurements of the engine acceleration and the vehicle body acceleration reaches or exceeds the predetermined number, and thus "Yes" is determined in the above step S4, the process proceeds to step S7.

[0034] In step S7, the ratio (Gb_F / Gpp_F) between the engine acceleration and the vehicle acceleration is calculated as a time-dependent change value α from the current (latest) measurement results of the engine acceleration and the vehicle acceleration, and it is determined whether the ratio (α / α0) between the time-dependent change value α and the initial value α0 is equal to or greater than a predetermined multiple. The value of the predetermined multiple in this case is a threshold value (i.e., a predetermined determination condition) for determining a state in which the ride quality and comfort of the vehicle Ve have deteriorated due to vibration of the engine 1 to a level at which inspection, repair, part replacement, etc. of the vehicle Ve are recommended. When the ratio (α / α0) between the time-dependent change value α of each acceleration and the initial value α0 is equal to or greater than a predetermined multiple, it is determined that the vehicle Ve is in a state in which inspection, repair, part replacement, etc. are recommended.

[0035] Therefore, if the ratio (α / α0) of the time-varying value α of each acceleration to the initial value α0 is less than the predetermined multiple, and thus the answer to step S7 is "No," it is determined that there is still no need to inspect or repair the vehicle Ve, or to replace parts, or that the need for such inspection or repair is low. Therefore, the routine shown in the flowchart of FIG. 2 is temporarily terminated without executing the control of the subsequent steps.

[0036] On the other hand, if the ratio (α / α0) of the time-varying value α of each acceleration to the initial value α0 is equal to or greater than the predetermined multiple, so that "Yes" is determined in step S7, the process proceeds to step S8.

[0037] In step S8, the driver is notified that the ride quality or comfort of the vehicle Ve has deteriorated to a level that requires inspection, repair, or part replacement, or that there are signs that the ride quality or comfort of the vehicle Ve will deteriorate to such a level. Since the vehicle Ve shown in Fig. 1 above is equipped with the display 8 as a "notification means", the display 8 displays the above-mentioned deterioration in the ride quality or comfort of the vehicle Ve, so that the driver is made aware of this.

[0038] It should be noted that the "notification means" in the embodiment of the present invention is not limited to the display 8 as shown in Fig. 1. As the "notification means", for example, the driver may be notified by voice guidance using an audio device (not shown) of the vehicle Ve. Alternatively, the driver may be notified by a simple device such as an indicator lamp (not shown) or a warning light (not shown).

[0039] As described above, when the notification that the ride quality or comfort of the vehicle Ve has deteriorated is given in step S8, the routine shown in the flowchart of FIG. 2 is then temporarily terminated.

[0040] As described above, in the vehicle control device according to the embodiment of the present invention, in order to quantitatively express the ride quality and comfort of the vehicle Ve, the vehicle body vibration, i.e., the vehicle body acceleration, is detected. In addition, the engine vibration, which is the source of the vehicle body vibration, i.e., the engine acceleration, is also detected. Then, the ride quality or comfort of the vehicle Ve is evaluated based on the initial values ​​and the time-varying values ​​of the vehicle body acceleration and the engine acceleration. Then, when it is evaluated that the ride quality of the vehicle Ve has deteriorated to a level that requires inspection or part replacement of the vehicle Ve, or that there is a sign of the ride quality deterioration, the driver is notified of the evaluation result. Therefore, when the vibration of the vehicle body 7 becomes large and the ride quality of the vehicle Ve deteriorates, such a state can be appropriately detected and the driver can be made aware of it promptly, and the driver can be prompted to inspect the vehicle Ve or replace parts.

[0041] Therefore, the vehicle control device according to the embodiment of the present invention can appropriately estimate and evaluate changes in ride comfort of the vehicle Ve caused by vibrations of the engine 1. Furthermore, by notifying the driver based on the results of the ride comfort evaluation, the driver can be made aware of the need for inspection or part replacement of the vehicle Ve, and can carry out inspection or part replacement at an appropriate time. [Explanation of symbols]

[0042] 1 Engine (ENG) 2 Transaxle (TA) 3 Drive wheels (front wheels) 4. Detection section 4a (Detection section) Engine acceleration sensor 4b (Detection section) vehicle acceleration sensor 4c (detection section) vehicle speed sensor 4d (Detection section) Engine speed sensor 4e (Detection section) Water temperature sensor 4f (Detection section) Oil temperature sensor 5 Controller (ECU) 6 Rear wheel 7. Body 8 Display (notification means) Vehicle

Claims

[Claim 1] A control device for a vehicle equipped with at least an engine as a power source, the control device evaluating or estimating a ride comfort of the vehicle caused by vibrations generated by the engine, a detection unit that detects an operating state of the vehicle, an operating state of the engine, an acceleration of the engine, and an acceleration of a vehicle body; A controller that controls the vehicle and quantitatively evaluates or estimates the ride comfort, The controller: When the vehicle speed is equal to or lower than a predetermined value and the engine is idling, an initial value of a ratio having an acceleration of the engine as a denominator and an acceleration of the vehicle body as a numerator, and a time-dependent change value of the ratio are calculated, When the time-varying value becomes larger than the initial value by a predetermined judgment condition or more, the driver is notified that the ride comfort has deteriorated or there is a sign of deterioration. A vehicle control device comprising:

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