Vehicle control devices

Abstract

To suppress deviation of optical axis control of a head lamp, even when an output value of an acceleration sensor is influenced by deflection of a vehicle by a live load, in a control device for the vehicle for performing the optical axis control of the head lamp by using the acceleration sensor.SOLUTION: The vehicular control apparatus 1 is a vehicular control apparatus having the control section 2a for performing the optical axis control of the headlamp in the vehicle 10 based on the acceleration sensor value outputted from the acceleration sensor 4 mounted in the vehicle 10, wherein the acceleration sensor 4 is mounted at a position where the acceleration sensor value is affected by the deflection due to the movable load, and the control section 2a performs the optical axis control of the headlamp in the vehicle 10 by adding the compensation value A in which the deflection due to the movable load is taken into consideration.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that controls the optical axis of a vehicle's headlights based on output values ​​from an acceleration sensor mounted on the vehicle. [Background technology]

[0002] Conventionally, to prevent dazzling oncoming vehicles, there is an auto-leveling control that automatically adjusts the tilt angle of the headlamp's optical axis according to the vehicle's tilt angle. For example, in the vehicle lighting control device described in Patent Document 1, the sum of the road surface angle and the vehicle's tilt angle is derived based on the output value of an acceleration sensor mounted on the vehicle. Here, the amount of change in this sum of angles while the vehicle is stopped is estimated as the amount of change in the vehicle's tilt angle, and the headlamp's optical axis is automatically adjusted according to this amount of change. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-94643 [Overview of the project] [Problems that the invention aims to solve]

[0004] As described in Patent Document 1, in auto-leveling control using an acceleration sensor, the change in the vehicle's tilt angle is derived using the gravity-direction component of the acceleration sensor's detected value. In this case, when the vehicle is loaded with luggage or other items, if the part of the vehicle body on which the acceleration sensor is mounted flexes, the change in the gravity-direction component of the acceleration sensor will include both the change due to the actual change in the vehicle's pitch angle and the change due to the flexing of the part of the vehicle body. As a result, the flexing of the vehicle body becomes an error when deriving the vehicle's tilt angle, which can lead to a problem where the control angle of the headlamp's optical axis deviates from the angle that should be adjusted.

[0005] One way to mitigate the effects of such body deflection is to reinforce the parts of the vehicle where the acceleration sensors are mounted to prevent deflection. However, changing to a stronger material would increase costs, and changing the plate thickness while using the same material would increase both costs and weight.

[0006] Therefore, the present invention aims to realize a vehicle control device that uses an acceleration sensor to control the optical axis of a headlamp, which can suppress deviations in the optical axis control of the headlamp even when the output value of the acceleration sensor is affected by the deflection of the vehicle due to the load, and to realize the vehicle control device with an inexpensive configuration. [Means for solving the problem]

[0007] (1) The vehicle control device of the present invention, provided to solve the above-mentioned problems, is a vehicle control device having an optical axis control unit that controls the optical axis of the vehicle's headlamp based on acceleration sensor values ​​output from an acceleration sensor mounted on the vehicle, wherein the acceleration sensor is mounted at a location where the acceleration sensor value is affected by deflection due to the load, and the optical axis control unit controls the optical axis of the vehicle's headlamp by taking into account a correction value that takes into account the deflection due to the load.

[0008] In the vehicle control device of the present invention, the optical axis control unit controls the optical axis of the vehicle's headlamp by taking into account a correction value that takes into account the deflection due to the load. In this way, the vehicle control device of the present invention can suppress deviations in optical axis control caused by the acceleration sensor value being affected by the deflection of the vehicle when the optical axis control unit controls the headlamp optical axis. Furthermore, since the deviation of the optical axis during optical axis control is suppressed even when the vehicle is deflected due to the load, there is no need to change the material of the deflected area to a stronger material or change the thickness in order to suppress such deviations. Therefore, the vehicle control device of the present invention can suppress deviations in headlamp optical axis control caused by the load without increasing costs or the weight of the vehicle. In addition, since the mounting location of the acceleration sensor in the vehicle control device of the present invention is not restricted to a location where deflection due to the load does not occur, the degree of freedom in the mounting location of the acceleration sensor is improved.

[0009] (2) before The correction value should preferably be set to increase as the pitch angle of the vehicle increases.

[0010] It is assumed that the relationship between the load and the vehicle's pitch angle (inclination angle), and the relationship between the load and the vehicle's deflection, are both approximately proportional. Under this assumption, a smaller vehicle pitch angle results in less vehicle deflection, requiring a smaller correction value. Conversely, a larger pitch angle results in greater vehicle deflection, requiring a larger correction value. Therefore, the vehicle control device of the present invention is configured to increase the correction value as the vehicle's pitch angle increases, thereby further improving the accuracy of optical axis control.

[0011] (3) The correction value should be set according to the mounting position of the acceleration sensor.

[0012] The deflection of a vehicle due to load varies depending on the part of the vehicle. Therefore, the vehicle control device of the present invention can perform optical axis control using an appropriate correction value according to the mounting position of the acceleration sensor by setting a correction value according to the mounting position of the acceleration sensor. Furthermore, this further improves the accuracy of optical axis control in the vehicle control device of the present invention.

[0013] (4) The correction value should be set to a larger value when the acceleration sensor is mounted on the rear side of the vehicle than when it is mounted on the front side of the vehicle.

[0014] In this way, the vehicle control device of the present invention can perform headlamp optical axis control with a more accurate correction value for vehicles in which the amount of deflection due to the load is greater on the rear side than on the front side.

[0015] (5) The acceleration sensor may be mounted directly or indirectly on the floor of the vehicle.

[0016] In this way, the vehicle control device of the present invention can perform optical axis control of the headlights by taking into account a correction value that takes into account the deflection of the vehicle floor.

[0017] Herein, the vehicle control device of the present invention described above may be equipped with a vehicle tilt angle derivation unit that derives the vehicle tilt angle. In such a configuration, there is a concern that the vehicle tilt angle derived by the vehicle tilt angle derivation unit will include errors in the actual pitch angle of the vehicle due to the influence of the acceleration sensor value on deflection caused by the load.

[0018] (6) Based on the above findings, the vehicle control device of the present invention includes a vehicle tilt angle derivation unit that derives a vehicle tilt angle based on the acceleration sensor value output from the acceleration sensor, the vehicle tilt angle includes an error that occurs because the acceleration sensor value is affected by deflection due to the load on the vehicle relative to the actual pitch angle of the vehicle, the correction value corrects the error due to the deflection, and the optical axis control unit controls the optical axis of the vehicle's headlamp based on the vehicle tilt angle derivation unit and the correction value.

[0019] The vehicle control device of the present invention, by having the configuration described in (6) above, can perform optical axis control of the headlamp after correcting the vehicle tilt angle derived based on the acceleration sensor value with a correction value for correcting errors caused by deflection as described above. In this way, the vehicle control device of the present invention can suppress deviations in optical axis control that occur when performing optical axis control of the headlamp assuming that the vehicle tilt angle derived based on the acceleration sensor value is the actual pitch angle of the vehicle.

[0020] (7) The vehicle tilt angle derivation unit derives the vehicle tilt angle on the condition that the vehicle is at least stopped, and the optical axis control unit controls the optical axis of the headlamp based on the vehicle tilt angle derivation unit and the correction value.

[0021] When the acceleration sensor value changes while the vehicle is in motion, it can be estimated that the change is due to a change in the road surface angle or a change in the vehicle's acceleration. On the other hand, when the acceleration sensor value changes while the vehicle is stopped, it can be estimated that the change is due to a change in the vehicle's tilt angle. Based on this understanding, the vehicle control device of the present invention derives the vehicle tilt angle on the condition that the vehicle is at least stopped. As a result, when a change occurs in the derived vehicle tilt angle, the vehicle control device of the present invention can control the optical axis of the headlights by assuming that the change is due to a change in the vehicle tilt angle. In this way, since the vehicle control device of the present invention can derive the vehicle tilt angle without being affected by changes in the road surface angle or changes in the vehicle's acceleration, it can perform accurate optical axis control of the headlights.

[0022] (8) The above conditions may further include that the vehicle is in a stable stopped state.

[0023] Immediately after a vehicle comes to a stop, the acceleration sensor value changes due to vehicle vibrations and other factors. Therefore, the vehicle tilt angle derivation unit derives the vehicle tilt angle on the condition that the vehicle's stopped state is stable. In this way, the vehicle control device of the present invention can perform headlamp optical axis control with even greater precision. [Effects of the Invention]

[0024] According to the present invention, in a vehicle control device that controls the optical axis of a headlamp using an acceleration sensor, it is possible to realize a vehicle control device that can suppress deviations in the optical axis control of the headlamp even when the output value of the acceleration sensor is affected by the deflection of the vehicle due to the load, and the vehicle control device can be realized with an inexpensive configuration. [Brief explanation of the drawing]

[0025] [Figure 1] This is a block diagram of a vehicle control device according to one embodiment of the present invention. [Figure 2]This diagram illustrates the difference in vehicle tilt angle derived from acceleration sensor values ​​when the vehicle does not deflect due to load and when it does. [Figure 3] This figure shows the vehicle tilt angle derived from the output value of the acceleration sensor, and the control angle of the optical axis at that vehicle tilt angle. [Figure 4] This figure shows the relationship between the vehicle tilt angle derived from the output value of the acceleration sensor, which is affected by the deflection due to the load, and the actual vehicle tilt angle. [Figure 5] This flowchart shows an example of the optical axis control process of the present invention. [Modes for carrying out the invention]

[0026] The following describes in detail a vehicle control device 1 according to one embodiment of the present invention, with reference to the drawings.

[0027] The vehicle control device 1 of this embodiment automatically adjusts (controls) the optical axis of the headlamp according to the tilt angle (pitch angle) of the vehicle 10. The vehicle control device 1 comprises an optical axis control ECU 2, a wheel speed sensor 3, an acceleration sensor 4, and a headlamp optical axis adjustment unit 5.

[0028] The wheel speed sensor 3 detects the wheel speed of each wheel of the vehicle 10. The wheel speed sensor 3 outputs the detected wheel speed value to the optical axis control ECU 2.

[0029] The acceleration sensor 4 is, for example, a 3-axis acceleration sensor that detects acceleration in the longitudinal direction (parallel to the direction of travel), the lateral direction (width direction of the vehicle), and the vertical direction of the vehicle 10. The acceleration sensor 4 outputs the longitudinal output value X and the vertical output value Z of the vehicle 10 to the optical axis control ECU 2. The acceleration sensor 4 is mounted in a location where its output values ​​X and Z are affected by deflection caused by the load of cargo etc. loaded onto the vehicle 10. For example, in this embodiment, the acceleration sensor 4 is mounted directly or indirectly on the floor of the vehicle (floor panel, etc.). Note that the acceleration sensor 4 is not limited to 3 axes; 1-axis or 2-axis acceleration sensors can also be used.

[0030] The headlamp optical axis adjustment unit 5 adjusts the optical axis of the vehicle 10's headlamps based on control signals from the optical axis control ECU 2, which will be described later.

[0031] The optical axis control ECU2 is responsible for deriving the tilt angle of the vehicle 10 (vehicle tilt angle), calculating the control angle when controlling the optical axis of the headlamp, and so on. The optical axis control ECU2 comprises a control unit 2a, a calculation unit 2b, and a storage unit 2c.

[0032] The calculation unit 2b calculates the inclination angle θ of the vehicle 10 relative to the road surface based on the speed of each wheel of the vehicle 10 output from the wheel speed sensor 3 and the output value output from the acceleration sensor 4. v (Vehicle tilt angle) and the tilt angle θ of the road surface on which the vehicle 10 is traveling with respect to the horizontal plane. r This is used to derive the (road surface angle).

[0033] The tilt angle θ of the vehicle 10 calculated by the calculation unit 2b v and the slope angle θ of the road surface r For example, the calculation of can be performed using the techniques described in Japanese Patent Publication No. 2023-104163, Japanese Patent Publication No. 2023-154744, Japanese Patent Publication No. 2023-154745, Japanese Patent Publication No. 2023-101092, etc. Here, the inclination angle θ of the vehicle 10 v and the slope angle θ of the road surface r These are all angles in the pitch direction of vehicle 10.

[0034] In this embodiment, the calculation unit 2b calculates the inclination angle θ when the vehicle 10 is stationary v . This is based on the following concept. That is, the irradiation range in front of the headlamp changes according to the change in the inclination angle θ of the vehicle 10 relative to the road surface v . Therefore, the optical axis control of the headlamp aims to adjust this change to maintain the optimal irradiation range. For this reason, the adjustment (control) of the optical axis of the headlamp is desirably performed when the inclination angle θ of the vehicle 10 v changes. The inclination angle θ of the vehicle 10 v rarely changes while the vehicle 10 is traveling. Therefore, in this embodiment, the calculation unit 2b calculates the inclination angle θ when the vehicle 10 is stationary v , and the optical axis control of the headlamp is performed by the control unit 2a based on the change in the inclination angle θ v .

[0035] The storage unit 2c stores control programs related to the control of the control unit 2a and various data required for optical axis control.

[0036] The control unit 2a performs the optical axis control of the headlamp based on the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b v . The control unit 2a calculates the control angle from the initial position of the optical axis of the headlamp based on the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b v , and transmits a control signal to the headlamp optical axis adjustment unit 5 to change the optical axis of the headlamp to the calculated control angle. The headlamp optical axis adjustment unit 5 that has received the signal adjusts the optical axis of the headlamp to the control angle. Thereby, the control unit 2a controls the optical axis of the headlamp.

[0037] The initial position of the optical axis of the headlamp is set in a predetermined environment (for example, the vehicle 10 is placed on a horizontal surface, the vehicle 10 is stationary, etc.) at a vehicle manufacturing plant or the like, and the initial position is stored in the vehicle 10.

[0038] The inclination angle θ of the vehicle 10 calculated by the calculation unit 2bv When the angle changes, the control unit 2a calculates the control angle of the headlamp's optical axis (control angle from the initial position) corresponding to the changed angle, and similarly transmits a control signal to the headlamp optical axis adjustment unit 5 to perform headlamp optical axis control (optical axis adjustment: auto-leveling control). In this embodiment, when controlling the headlamp's optical axis, the control unit 2a compensates for the calculation error of the calculation unit 2b that occurs due to the deflection of the floor of the vehicle 10 caused by the load (vehicle 10's inclination angle θ). v The optical axis control is performed after correcting the calculation error. This correction will be described later.

[0039] The control unit 2a and the arithmetic unit 2b are composed of a CPU (Central Processing Unit). The storage unit 2c is composed of ROM (Read Only Memory) and RAM (Random Access Memory). In this embodiment, the control unit 2a and the arithmetic unit 2b are configured with a single CPU, but they can also be configured with separate CPUs.

[0040] The above describes the configuration of the vehicle control device 1 of this embodiment. Next, with reference to Figures 2 and 4, the optical axis control of the vehicle 10's headlamps, performed by the optical axis control ECU 2, etc., will be described in detail. Before describing the optical axis control of the headlamps, first, the error in the vehicle tilt angle calculated by the calculation unit 2b of the optical axis control ECU 2 will be explained with reference to Figure 2. Next, the optical axis control of the headlamps will be described while explaining the method for correcting this error with reference to Figure 4.

[0041] Figure 2(a) shows vehicle 10 stopped on a flat road (road surface angle = 0 degrees) with no load. At this time, vehicle 10 is not inclined with respect to the road surface, and the inclination angle θ v The result is "0".

[0042] In the state shown in Figure 2(a), when heavy objects such as luggage are loaded onto the vehicle 10, the vehicle 10 tilts relative to the road surface. Figure 2(b) shows the state in which the vehicle 10 is tilted due to luggage being loaded on the rear of the vehicle 10 in the state shown in Figure 2(a). The calculation unit 2b calculates the tilt angle θ of the vehicle 10 based on the acceleration of the vehicle 10 calculated based on the wheel speed output from the wheel speed sensor 3 in the state shown in Figure 2(b), and the output value Z output from the acceleration sensor 4. v And the road surface inclination angle θ r It is possible to calculate this.

[0043] Incidentally, Figure 2(b) illustrates a case where no deflection occurs in the floor of the vehicle 10 due to the load, but as shown in Figure 2(c), it is also possible that deflection occurs in the floor of the vehicle 10 due to the load. In this case, the output value Z of the acceleration sensor 4 changes due to the deflection of the floor of the vehicle 10. Therefore, the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b v It also changes due to the flexing of the floor.

[0044] For example, as shown in Figure 2(b), when no deflection occurs in the floor of the vehicle 10, the inclination angle θ of the vehicle 10 is calculated by the calculation unit 2b. v Let this be θa. On the other hand, if deflection occurs in the floor of vehicle 10 as shown in Figure 2(c), the original vehicle tilt angle θ v Despite being θa, the tilt angle θ of the vehicle 10 is calculated by the calculation unit 2b. v This changes to θb. That is, the inclination angle θb of the vehicle 10 calculated by the calculation unit 2b in the state shown in Figure 2(c) includes an error (|θb-θa|) due to the deflection of the floor of the vehicle 10. Therefore, in Figure 2(c), the inclination angle θ of the vehicle 10 v If the optical axis of the headlamp is controlled using θb, the optical axis of the headlamp will deviate from the angle that it should be adjusted to. Therefore, in this embodiment, the control unit 2a controls the optical axis of the headlamp by taking into account a correction value A that takes into account the deflection of the vehicle 10 due to the load.

[0045] (Correction of vehicle tilt angle) The pitch angle of vehicle 10 (the inclination angle of vehicle 10 relative to the road surface) is proportional to the load of cargo and other items loaded onto vehicle 10. Similarly, the amount of deflection of the vehicle 10's floor is also proportional to the load. Here, if the inclination angle of vehicle 10 calculated based on the output value Z of the acceleration sensor 4 is plotted on the vertical axis, and the actual inclination angle of vehicle 10 (inclination angle relative to the road surface: pitch angle) is plotted on the horizontal axis, the result is as shown in Figure 4. In Figure 4, the vehicle's inclination angle on the vertical axis (G-sensor recognition angle) is the inclination angle θ of vehicle 10 calculated by the calculation unit 2b based on the output value Z of the acceleration sensor 4. v In contrast, the vehicle pitch angle on the horizontal axis is the actual inclination angle of the vehicle 10, measured using jigs and the like.

[0046] The solid line in Figure 4 shows the ideal relationship between the inclination angle of vehicle 10 calculated by the calculation unit 2b (vertical axis) when no deflection occurs in the floor of vehicle 10, and the actual inclination angle of vehicle 10 (horizontal axis). In other words, it is ideal that the inclination angle of vehicle 10 calculated by the calculation unit 2b and the actual inclination angle of vehicle 10 (pitch angle of vehicle 10) are the same, so the solid line in Figure 4 is a straight line with a slope of 1.

[0047] In contrast, if there is deflection in the floor of the vehicle 10, the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b v Because the aforementioned error is included, there is a deviation from the solid line in Figure 4. This deviation is shown by the dashed and dotted lines in Figure 4.

[0048] For example, the dashed line shows the case where the acceleration sensor 4 is mounted on the front side of the floor of the vehicle 10. Here, each black circle represents one of the following six loading patterns. That is, the six black circles are arranged in order from the smallest vehicle pitch angle on the horizontal axis: (i) A scenario where no one is in vehicle 10 and no luggage or other items are loaded. (ii) A scenario where only the driver's seat is occupied, and no luggage or other items are loaded. (iii) A scenario where there are occupants only in the front seats (driver's seat and passenger seat) and no luggage or other items are loaded. (iv) A scenario where all seats are occupied by crew members, and no luggage or other items are loaded. (v) A scenario where all seats are occupied and 25 kg of luggage or other items are loaded in the trunk. (vi) A scenario where only the driver is seated and 250 kg of luggage is loaded in the trunk. These are six loading patterns. For example, the black circle with the largest vehicle pitch angle corresponds to loading pattern (vi), and the tilt angle θ of the vehicle 10 is calculated based on the output value Z output from the acceleration sensor 4 when this loading pattern is applied. v This graph shows the relationship between the vertical axis and the actual vehicle pitch angle (horizontal axis).

[0049] Furthermore, the loading patterns show increasing loads in the order from (i) to (vi). Therefore, when an approximate straight line is found based on each black circle, for example using the least squares method, the approximate straight line is an upward-sloping line due to the proportional relationship described above. In addition, the slope of this approximate straight line (dashed line) is, for example, α (α>1). This slope α is a deviation from the ideal slope of 1 and can be seen as a calculation error in the inclination angle of the vehicle 10 caused by the deflection of the floor of the vehicle 10 due to the load.

[0050] Therefore, the control unit 2a calculates the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b. v This is corrected based on the inclination α. ​​Note that the inclination angle θ of the vehicle 10. v If the angle changes, the control unit 2a changes (controls) the optical axis by the same angle as the amount of change. In this embodiment, the control unit 2a controls the tilt angle θ of the vehicle 10 calculated by the calculation unit 2b. v Based on the calculation, a correction value A is applied to the calculated control angle to calculate the corrected control angle. Specifically, the tilt angle of the vehicle 10 calculated by the calculation unit 2b is θ v The control angle calculated based on θ L The corrected control angle is revisedθ L In this case, the control unit 2a will revisedθ L =θ LThe control angle of the optical axis is corrected based on the formula × correction value A(1 / α) (equation (1) described later). As a result, the vehicle control device 1 corrects the error that occurs when the output value Z of the acceleration sensor 4 is affected by the deflection of the floor of the vehicle 10, that is, the tilt angle θ of the vehicle 10 calculated by the calculation unit 2b. v This allows for correction of the error between the actual pitch angle of the vehicle 10 and the actual pitch angle.

[0051] The dashed line in Figure 4 shows the case where the acceleration sensor 4 is mounted on the rear side of the floor of the vehicle 10. Here, each white circle, like each black circle, corresponds to the loading patterns (i) to (vi) in order from the smallest vehicle pitch angle on the horizontal axis, and the tilt angle θ of the vehicle 10 calculated by the calculation unit 2b for each loading pattern. v This shows the relationship between the vertical axis and the actual vehicle pitch angle (horizontal axis). If an approximate straight line is found based on each white circle, for example using the least squares method, the approximate straight line will be an upward-sloping line due to the proportional relationship described above. Furthermore, the approximate straight line (dash-dotted line) has a slope of, for example, β (β<1). This slope β is a deviation from the ideal slope of 1 and can be seen as a calculation error in the inclination angle of the vehicle 10 caused by the deflection of the floor of the vehicle 10 due to the load.

[0052] Therefore, when the acceleration sensor 4 is mounted on the rear side of the floor of the vehicle 10, the control unit 2a controls the optical axis of the headlamp by revisedθ L =θ L The correction is applied based on the formula × correction value A(1 / β).

[0053] Furthermore, information regarding the correction value A is stored in advance in the memory unit 2c of the optical axis control ECU2.

[0054] (Optical axis control processing) Next, an example of the optical axis control process of this embodiment will be described with reference to Figures 3 and 5.

[0055] First, in step S1, the optical axis control ECU 2 determines whether or not the vehicle 10 is stopped. This determination can be made, for example, by the control unit 2a of the optical axis control ECU 2. In this case, the control unit 2a can determine whether or not the vehicle 10 is stopped based on the output value obtained from the wheel speed sensor 3.

[0056] If it is determined in step S1 that the vehicle 10 is stopped (YES in step S1), the optical axis control ECU 2 determines whether the stopped state of the vehicle 10 is stable (step S2). This determination can also be performed by the control unit 2a, for example. In this case, the control unit 2a determines whether the stopped state of the vehicle 10 is stable based on the output values ​​X and Z obtained from the acceleration sensor 4. Specifically, the control unit 2a can determine whether the stopped state of the vehicle 10 is stable based on whether the output values ​​X and Z obtained from the acceleration sensor 4 fall within a predetermined range.

[0057] If it is determined in step S1 that vehicle 10 is not stopped (NO in step S1), the process is terminated.

[0058] Returning to step S2, if it is determined in step S2 that the vehicle 10 is in a stable stopped state (YES in step S2), the optical axis control ECU2 determines whether it was determined in the previous step S1 that the vehicle 10 was not stopped (NO in step S1) (step S3). This determination can be made, for example, by the control unit 2a of the optical axis control ECU2. To make this determination, for example, a memory area (previous stop flag memory area) for storing the previous stop flag is provided in the memory unit 2c of the optical axis control ECU2. Here, when it is determined in step S1 that the vehicle 10 is stopped, the control unit 2a sets the previous stop flag to ON. On the other hand, when it is determined in step S1 that the vehicle 10 is not stopped, the control unit 2a sets the previous stop flag to OFF. In this way, in step S3, the control unit 2a can determine whether the previous determination was that the vehicle was in motion by checking the ON / OFF state of the previous stop flag.

[0059] In step S2, if it is determined that the vehicle 10 is in a stable stopped state (NO in step S2), the process is terminated. The reason for terminating the process when the vehicle 10 is not in a stable stopped state is that if the vehicle 10 is not in a stable stopped state, the output value of the acceleration sensor 4 will not be stable, and the tilt angle θ of the vehicle 10 will not be accurately determined. v This is to calculate [the value]. However, the vehicle control device 1 of the present invention may omit this step.

[0060] In step S3, if the control unit 2a determined in the previous determination that the vehicle 10 was moving (YES in step S3), that is, if it determined that it was the first stop, the calculation unit 2b calculates the inclination angle θ of the vehicle 10. v ( = T θ s (See Figure 3) is calculated (Step S4). The calculation unit 2b calculates the inclination angle of the vehicle 10. T θ s This is stored in the memory unit 2c as the tilt angle of the reference vehicle 10.

[0061] Once the process in step S4 is complete, the control unit 2a determines the tilt angle of the reference vehicle 10. T θ s Based on this, the control angle of the headlamp's optical axis P. T θ L Determine the (reference control angle: see Figure 3), and then determine the control angle T θ L The data is stored in the memory unit 2c (step S5), and the process is terminated.

[0062] In step S3, if the control unit 2a determined in the previous determination that the vehicle 10 was not moving, that is, if it was determined that it was not the first stop (NO in step S3), the calculation unit 2b calculates the tilt angle θ of the stopped vehicle 10. v Calculate (=θs) (Step S6).

[0063] Following step S6, the control unit 2a reads the reference inclination angle of the vehicle 10 stored in the memory unit 2c. T θ s and the reference control angle T θ L And the tilt angle θ of vehicle 10 calculated this time s Based on this, the control angle θ of the headlamp's optical axis P. L The control unit 2a calculates the control angle θ using the following equation (1). L Calculate. θ L = T θ L +θ s - T θ s ...Equation (1) According to this formula, the inclination angle θ of the vehicle 10 calculated by the calculation unit 2b is s However, the inclination angle of the reference vehicle 10 T θ s If it does not change, the control angle of the optical axis P does not change (θ L = T θ L ). In other words, in step S7, the tilt angle θs of the vehicle 10 calculated by the calculation unit 2b is the initial tilt angle of the vehicle 10 T θ s This step involves calculating the control angle of the optical axis P when it changes from [previous value].

[0064] Note that the control angle of the optical axis P, which is the reference for step S5. T θ L Also, the control angle θ of the optical axis P calculated in step S7 L This includes errors caused by the deflection of the floor of the vehicle 10. Therefore, the control unit 2a controls the optical axis P control angle θ calculated in step S7. L This is corrected by a correction value A that takes into account the deflection of the floor of the vehicle 10 (step S8). At this time, the control unit 2a changes the corrected control angle to revisedθ L In this case, the corrected optical axis control angle revisedθ is obtained by the following equation (2). L Calculate. reiθ L =θ L ×A...Equation (2) Here, if the dashed line in Figure 4, i.e., the acceleration sensor 4, is mounted on the front side of the floor of the vehicle 10, then the correction value A = 1 / α.

[0065] Next, in step S9, the control unit 2a adjusts the corrected control angle of the optical axis P, revisedθ L Based on this, the headlamp's optical axis is controlled, and the process is terminated.

[0066] (Mechanism of Action and Effects) The above describes one embodiment of the vehicle control device 1 of the present invention. Next, the effects and advantages realized by the vehicle control device 1 of this embodiment will be described below.

[0067] The vehicle control device 1 described above has the following characteristic configuration. Therefore, the vehicle control device 1 can achieve unique effects that cannot be achieved with conventional technology, as described below.

[0068] (a) The vehicle control device 1 of the present invention is a vehicle control device 1 having an optical axis control unit (control unit 2a) that controls the optical axis of the headlamp of the vehicle 10 based on acceleration sensor values ​​output from an acceleration sensor 4 mounted on the vehicle 10, wherein the acceleration sensor 4 is mounted in a location where the acceleration sensor value is affected by deflection due to the load, and the optical axis control unit (control unit 2a) controls the optical axis of the headlamp of the vehicle 10 by taking into account a correction value A that takes into account the deflection due to the load.

[0069] In the vehicle control device 1 of the present invention, the optical axis control unit (control unit 2a) controls the optical axis of the vehicle 10's headlamp by taking into account a correction value A that takes into account deflection due to the load. In this way, the vehicle control device 1 of the present invention can suppress deviations in optical axis control caused by the influence of the acceleration sensor value on the deflection of the vehicle 10 when the optical axis control unit (control unit 2a) controls the optical axis of the headlamp. Furthermore, since the vehicle control device 1 of the present invention suppresses deviations in the optical axis during optical axis control even when the vehicle 10 is deflected due to the load, there is no need to change the material of the deflected area to a stronger material or change the thickness in order to suppress such deviations. Therefore, the vehicle control device 1 of the present invention can suppress deviations in optical axis control caused by the load without increasing costs or the weight of the vehicle. In addition, the vehicle control device 1 of the present invention does not restrict the mounting location of the acceleration sensor 4 to an area where deflection due to the load does not occur, thus improving the degree of freedom in the mounting location of the acceleration sensor 4.

[0070] (b) The correction value should preferably be set to increase as the pitch angle of the vehicle increases.

[0071] As described above, it is assumed that the relationship between the load and the pitch angle (inclination angle) of the vehicle 10, and the relationship between the load and the deflection of the vehicle 10, are both approximately proportional. Under this assumption, if the pitch angle of the vehicle 10 is small, the deflection of the vehicle 10 will also be small, so the correction value A needs to be small. On the other hand, if the pitch angle is large, the deflection of the vehicle 10 will also be large, so the correction value A needs to be large. Therefore, in the vehicle control device 1 of the present invention, the control angle θ of the optical axis of the headlamp before correction is used. L By multiplying this by a correction value A (for example, 1 / α), the corrected optical axis control angle is revisedθ L The control angle θ of the optical axis before correction was calculated. L By setting the correction amount to increase as the value increases, the accuracy of the headlamp's optical axis control is further improved.

[0072] Furthermore, in this invention, even when the pitch angle of the vehicle 10 is small, i.e., when the load is small, the optical axis control angle is always corrected by the correction value A. In this case, even if the output value of the acceleration sensor 4 is hardly affected by the deflection of the vehicle 10's floor, the optical axis control angle of the headlamp is corrected, which raises concerns about the impact on the accuracy of optical axis control. However, in the vehicle control device 1 of this invention, when the pitch angle of the vehicle 10 is small, the correction amount is also set to be small, so it is considered that this will have little effect on the accuracy of optical axis control.

[0073] (c) The correction value A is preferably set according to the mounting position of the acceleration sensor 4.

[0074] The deflection of the vehicle 10 due to the load varies depending on the thickness and material of the floor plate of the vehicle 10, the mounting structure of the floor, the loading locations of luggage etc. on the vehicle 10, and the position of the seat rails to which the load is applied. Therefore, the influence of the output value Z of the acceleration sensor 4 also differs depending on the mounting position of the acceleration sensor 4. In the above embodiment, as shown in Figure 4, a correction value A(1 / α) when the acceleration sensor 4 is mounted on the front side of the floor of the vehicle 10 and a correction value A(1 / β) when the acceleration sensor 4 is mounted on the rear side of the floor of the vehicle 10 are determined, and the control angle of the optical axis is configured to be corrected according to each mounting position. In this way, the vehicle control device 1 of the present invention can perform optical axis control with an appropriate correction value A according to the mounting position of the acceleration sensor 4 by setting a correction value A according to the mounting position of the acceleration sensor 4. Furthermore, this further improves the accuracy of optical axis control of the headlamp in the vehicle control device of the present invention. Furthermore, since the vehicle 10 is long in the front-to-rear direction, the influence of the mounting position of the acceleration sensor 4 on the output value Z of the acceleration sensor 4 is considered to be greater in the front-to-rear direction than in the left-to-right direction (vehicle width direction) of the vehicle 10. Therefore, the vehicle control device 1 of the present invention can effectively set the correction value A by distinguishing between the mounting position of the acceleration sensor 4 on the front side and the rear side of the floor and setting the correction value A accordingly.

[0075] (d) The correction value A is preferably set to a larger value when the acceleration sensor 4 is mounted on the rear side of the vehicle 10 than when it is mounted on the front side thereof.

[0076] In this manner, the vehicle control device 1 of the present invention can perform optical axis control with the more accurate correction value A for the vehicle 10 in which the deflection amount caused by the loaded load is larger on the rear side than on the front side.

[0077] (e) The acceleration sensor 4 is preferably mounted directly or indirectly on the floor of the vehicle 10.

[0078] In this manner, the vehicle control device 1 of the present invention can perform the optical axis control of the headlamp by taking the correction value A that considers the deflection of the floor of the vehicle 10 into account.

[0079] Here, the above-described vehicle control device 1 of the present invention may be configured to include a vehicle inclination angle derivation unit (calculation unit 2b) that derives a vehicle inclination angle θ v . When adopting such a configuration, there is a concern that the vehicle inclination angle θ derived by the vehicle inclination angle derivation unit (calculation unit 2b) v may include an error generated due to the acceleration sensor value being affected by deflection caused by the loaded load, relative to the actual pitch angle of the vehicle 10.

[0080] (f) Based on the above findings, the vehicle control device 1 of the present invention includes a vehicle inclination angle derivation unit (calculation unit 2b) that derives a vehicle inclination angle θ based on the acceleration sensor value output from the acceleration sensor 4 v , the vehicle inclination angle θ v includes an error (|θb-θa|) generated due to the acceleration sensor value being affected by deflection caused by a loaded load, relative to the actual pitch angle of the vehicle 10, the correction value A is for correcting the error (|θb-θa|) caused by the deflection, and the optical axis control unit (control unit 2a) uses the vehicle inclination angle θ derived by the vehicle inclination angle derivation unit (calculation unit 2b) vand the correction value A, it is preferable to perform optical axis control of the headlamp of the vehicle 10.

[0081] The vehicle control device 1 of the present invention is configured as in the above (g), whereby the vehicle inclination angle θ calculated based on the acceleration sensor value v The derived control angle θ L is corrected by the correction value A, and then the optical axis control of the headlamp can be performed. In this way, the vehicle control device 1 of the present invention can suppress the deviation of the optical axis control that occurs when the optical axis control of the headlamp is performed on the assumption that the vehicle inclination angle θ derived based on the acceleration sensor value v is the actual pitch angle of the vehicle.

[0082] (g) The vehicle inclination angle deriving unit (calculation unit 2b) derives the vehicle inclination angle θ on the condition that at least the vehicle 10 is stopped v , and the optical axis control unit (control unit 2a) preferably performs the optical axis control of the headlamp based on the vehicle inclination angle θ derived by the vehicle inclination angle deriving unit (calculation unit 2b) v and the correction value A.

[0083] When the acceleration sensor value changes while the vehicle 10 is traveling, the change can be estimated to be caused by a change in road surface angle or a change in acceleration of the vehicle 10. On the other hand, when the acceleration sensor value changes while the vehicle 10 is stopped, the change can be estimated to be caused by a change in the inclination angle of the vehicle 10. Based on such knowledge, the vehicle control device 1 of the present invention derives the vehicle inclination angle θ on the condition that at least the vehicle 10 is stopped v . Thereby, in the vehicle control device 1 of the present invention, when a change occurs in the derived vehicle inclination angle θ v , it is possible to perform the optical axis control of the headlamp assuming that the change is caused by the change of the vehicle inclination angle θ v . In this way, since the vehicle control device 1 of the present invention can derive the vehicle inclination angle θ in a state where the road surface angle and the acceleration of the vehicle 10 do not change v , the optical axis control of the headlamp can be performed with high accuracy.

[0084] (h) The above condition may further include that the vehicle 10 is in a stable stopped state.

[0085] Immediately after the vehicle 10 stops, the acceleration sensor value changes due to vibrations of the vehicle 10. Therefore, if the tilt angle of the vehicle 10 is calculated based on these acceleration sensor values, the accuracy of the headlamp optical axis control will decrease. For this reason, the vehicle tilt angle derivation unit (calculation unit) 2b calculates the vehicle tilt angle θ on the condition that the stopped state of the vehicle 10 is stable. v This is derived. In this way, the vehicle control device 1 of the present invention can perform headlamp optical axis control with even greater precision.

[0086] The above describes the effects and advantages of the vehicle control device 1 according to the embodiment of the present invention. However, the vehicle control device 1 of the present invention is not limited to the above-described embodiment and can be modified in various ways. That is, the vehicle control device 1 described above is merely one embodiment of the present invention, and the configuration can be changed, omitted, or added as appropriate without departing from the spirit of the present invention. In other words, the vehicle control device 1 can be one that does not have some or all of the configurations related to (a) to (h) above, one that has other configurations, or one that is realized by configurations related to (a) to (h) above that are different from those exemplified in the above embodiment, without departing from the spirit of the present invention.

[0087] For example, in the above embodiment, as shown in Figure 4, the tilt angle θ of the vehicle 10 is calculated by the calculation unit 2b based on the pitch angle of the vehicle 10 for loading patterns (i) to (vi) and the output value Z of the acceleration sensor 4. vThe relationship was plotted, an approximate straight line was calculated using the least squares method, and its slope was derived. However, the method for deriving the slope that yields the correction value A is not limited to this. For example, the correction value A may be determined based on the slope of a straight line passing through two specific plots among the loading patterns (i) to (vi), such as a straight line passing through the plot of the loading pattern (i) with the smallest load and the plot of the loading pattern (vi) with the largest load. Alternatively, the slope for deriving the correction value A may be determined using the least squares method from some of the plots among the loading patterns (i) to (vi). Even in this way, the vehicle control device 1 of the present invention can control the optical axis of the vehicle 10's headlights by taking into account the correction value A that takes into account the deflection due to the load.

[0088] Furthermore, in the above-described embodiment, the value of the vertical axis (inclination angle θv of the vehicle 10) in Figure 4 was determined based on the output value Z (measured value) output from the acceleration sensor 4. However, for example, the theoretical amount of deflection of the vehicle 10 floor in each loading pattern (i) to (vi) may be calculated and plotted. Even in this way, the vehicle control device 1 of the present invention can control the optical axis of the vehicle 10's headlights by taking into account a correction value A that takes into account the deflection due to the load.

[0089] Furthermore, although the above-described embodiment described a case in which the acceleration sensor 4 is mounted directly or indirectly on the floor of the vehicle 10, the mounting location of the acceleration sensor 4 is not limited to this. That is, the mounting location of the acceleration sensor 4 on the vehicle 10 can be changed as appropriate, as long as it is a location where the output value Z of the acceleration sensor 4 is affected by the deflection caused by the load. In this case, it is preferable to set a correction value A in advance according to the location.

[0090] The above describes embodiments and modifications of the vehicle control device 1 according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and teachings thereof, without departing from the scope of the claims. [Industrial applicability]

[0091] The present invention is suitably applicable to vehicle control devices in general that perform optical axis control of a vehicle's headlights based on output values ​​from an acceleration sensor mounted on the vehicle. [Explanation of Symbols]

[0092] 1: Vehicle control device 2a: Control unit (optical axis control unit) 2b: Arithmetic unit (vehicle oblique angle derivation unit) 4: Accelerometer 10: Vehicles

Claims

1. A vehicle control device having an optical axis control unit that controls the optical axis of the vehicle's headlights based on acceleration sensor values ​​output from an acceleration sensor mounted on the vehicle, The acceleration sensor is mounted in a location where the acceleration sensor value is affected by deflection due to the load. The optical axis control unit is characterized by performing optical axis control of the vehicle's headlamp by taking into account a correction value that takes into account deflection due to load.

2. The vehicle control device according to claim 1, characterized in that the correction value is set to increase as the pitch angle of the vehicle increases.

3. The vehicle control device according to claim 1 or 2, characterized in that the correction value is set according to the mounting position of the acceleration sensor.

4. The vehicle tilt angle derivement unit derives the vehicle tilt angle based on the acceleration sensor value output from the acceleration sensor, The aforementioned vehicle tilt angle includes an error that occurs when the acceleration sensor value is affected by deflection due to the load, compared to the actual pitch angle of the vehicle. The aforementioned correction value corrects the error caused by the deflection, The vehicle control device according to claim 1 or 2, characterized in that the optical axis control unit controls the optical axis of the vehicle's headlamp based on the vehicle tilt angle derived by the vehicle tilt angle derivation unit and the correction value.

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