Hoops Road Detection Device and Vehicle Control Method

Abstract

The present invention provides a whoops road detection device and a vehicle control method that can appropriately determine whether or not the road a vehicle is traveling on is a whoops road, even when the vehicle is traveling on rough terrain such as so-called off-road roads. [Solution] The hoops road determination device 100' includes: an acquisition unit 161 that acquires a first value corresponding to pitch information relating to the pitch motion of the vehicle 1 based on output signals from sensors 202, 204, and 208 mounted on the vehicle; a calculation unit 163 that calculates a second value which is a prerequisite value for determining whether or not the road the vehicle 1 is traveling on is a hoops road R when the first value crosses a first threshold; an accumulation unit 165 that accumulates the second value as an accumulated value over time; and a determination unit 169 that determines whether or not the road R is a hoops road based on the accumulated value.

Description

[Technical Field]

[0001] The present invention relates to a potholed road determination device and a vehicle control method.

[0002] In recent years, for vehicles such as automobiles, configurations have been proposed that determine whether a road on which a vehicle travels falls under a predetermined target road for determination in consideration of the driving performance of the vehicle and the like.

[0003] Under such circumstances, Patent Document 1 discloses an undulating road detection device 10, which comprises: an accelerometer 14 that detects the acceleration of an unsprung component of a vehicle at predetermined sampling intervals; a vehicle speed sensor 16 that detects the vehicle speed; and a control device 12 that accumulates variations in the acceleration detected by the accelerometer, calculates a difference between the accumulated variation for each sampling period, determines that the road on which the vehicle travels is an undulating road when the calculation result of the difference indicates that acceleration equal to or higher than a predetermined acceleration has continued for a predetermined time or longer and the vehicle speed detected by the vehicle speed sensor 16 is equal to or higher than a predetermined vehicle speed. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No.2010-215150 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, according to the inventor's research, the configuration disclosed in Patent Document 1 determines that the vehicle's travel path is a wavy road when the calculation result, which is calculated by accumulating the variation of acceleration detected by the accelerometer and calculating the difference of the cumulative result for each sampling period, indicates that an acceleration of a predetermined acceleration or higher continues for a predetermined time or longer, and the vehicle speed detected by the vehicle speed sensor 16 is a predetermined vehicle speed or higher. Therefore, when a vehicle travels on rough roads such as so-called off-road roads, the acceleration of its unsprung components is constantly fluctuating, making it difficult to accurately determine whether the vehicle's travel path is a wavy road, and thus there is room for improvement. Furthermore, the same situation applies when the road to be determined is a so-called whoops road, which has a more pronounced uneven shape than the uneven shape of a wavy road and exhibits an undulating shape.

[0006] The present invention has been made after the above considerations, and aims to provide a whoops road determination device and a vehicle control method that can appropriately determine whether the road on which a vehicle is traveling is a whoops road, even when the vehicle is traveling on rough roads such as so-called off-road roads. [Means for solving the problem]

[0007] To achieve the above objectives, in one aspect of the present invention, the hoop road determination device includes: an acquisition unit that acquires a first value corresponding to pitch information relating to the pitch motion of the vehicle based on an output signal from a sensor mounted on the vehicle; a calculation unit that calculates a second value which is a prerequisite value for determining whether or not the vehicle's travel path is a hoop road when the first value crosses a first threshold; an accumulation unit that accumulates the second value as a cumulative value over time; and a determination unit that determines whether or not the travel path is a hoop road based on the accumulated value.

[0008] Furthermore, in another aspect of the present invention, the vehicle control method comprises: an acquisition step of acquiring a first value corresponding to pitch information relating to the pitch motion of the vehicle based on an output signal from a sensor mounted on the vehicle; a calculation step of calculating a second value which is a prerequisite value for determining whether or not the vehicle's travel path is a whoops road when the first value crosses a first threshold; an accumulation step of accumulating the second value as an accumulated value over time; a determination step of determining whether or not the travel path is a whoops road based on the accumulated value; and a control step of adjusting the damping force of the vehicle's suspension. [Effects of the Invention]

[0009] According to one aspect of the present invention, a whoops road determination device includes: an acquisition unit that acquires a first value corresponding to pitch information relating to the pitch motion of a vehicle based on an output signal from a sensor mounted on the vehicle; a calculation unit that calculates a second value which is a prerequisite value for determining whether or not the road the vehicle is traveling on is a whoops road when the first value crosses a first threshold; an accumulation unit that accumulates the second value as a cumulative value over time; and a determination unit that determines whether or not the road is a whoops road based on the accumulated value. By including these components, it is possible to appropriately determine whether or not the road the vehicle is traveling on is a whoops road, even when the vehicle is traveling on rough roads such as so-called off-road roads.

[0010] Furthermore, according to another aspect of the present invention, a vehicle control method comprises: an acquisition step of acquiring a first value corresponding to pitch information relating to the pitch motion of the vehicle based on an output signal from a sensor mounted on the vehicle; a calculation step of calculating a second value which is a prerequisite value for determining whether or not the vehicle's travel path is a whoops road when the first value crosses a first threshold; an accumulation step of accumulating the second value as an accumulated value over time; a determination step of determining whether or not the travel path is a whoops road based on the accumulated value; and a control step of adjusting the damping force of the vehicle's suspension. This method allows for appropriate determination of whether or not the travel path on which the vehicle is traveling is a whoops road, and also allows for appropriate adjustment of the vehicle's attitude even when the travel path is a whoops road. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a side view showing the right side of a vehicle on which the vehicle control system and device according to an embodiment of the present invention are mounted. [Figure 2] Figure 2 is a schematic diagram showing the configuration of the vehicle control system and device in this embodiment. [Figure 3] Figure 3 is a side view showing the right side of a vehicle in motion, equipped with the vehicle control system and device according to this embodiment. [Figure 4] Figure 4 is a time chart showing an example of the pitch speed detected by a sensor in a vehicle equipped with the vehicle control system and device according to this embodiment, and the timing time of the timer applied to the vehicle control system and device according to this embodiment. [Figure 5] Figure 5 is a schematic diagram of data illustrating, as an example, the relationship between the timing time and probability value of the timer applied to the vehicle control system and device in this embodiment. [Figure 6] Figure 6 is a flowchart showing an example of a vehicle control process performed by the vehicle control system and device in this embodiment. [Modes for carrying out the invention]

[0012] Hereinafter, with due reference to the drawings, the vehicle control system, apparatus, and method according to embodiments of the present invention will be described in detail. In the figures, the x, y, and z axes form a three-axis Cartesian coordinate system, where the x-axis direction is the longitudinal direction and direction of travel of the vehicle, with its forward direction indicated by the positive x-axis; the y-axis direction is the width direction of the vehicle, with its left direction indicated in Figures 1 and 3 as the direction that penetrates the paper from the near side to the far side; and the z-axis direction is the vertical direction and direction of up of the vehicle, with its upward direction indicated by the positive z-axis. Furthermore, the horizontal plane is assumed to be parallel to the plane defined by the x and y axes.

[0013] [Vehicle configuration] First, with reference to Figure 1, the configuration of the vehicle to which the vehicle control system and device in this embodiment are applied will be described in detail.

[0014] Figure 1 is a side view showing the right side of a vehicle on which the vehicle control system and device according to this embodiment are installed. In the figure, only the front suspension, front wheels, rear suspension, and rear wheels located on the right side are shown, but typically these are arranged in pairs on the left and right sides, similarly positioned on the left side as well.

[0015] As shown in Figure 1 as a typical example of a small, lightweight four-wheeled off-road vehicle, a side-by-side vehicle, the vehicle 1 typically comprises a body 10 made of metal frame members such as iron (steel) pipes or steel plates (not shown), a drive source 20 that outputs the driving force of the vehicle 1, a front suspension 30 interposed between the body 10 and the front wheels 32 to suspend the front wheels 32, and a rear suspension 40 interposed between the body 10 and the rear wheels 42 to suspend the rear wheels 42. In addition to being called a side-by-side vehicle, the vehicle 1 may also be called a UTV (Utility Task Vehicle) or ROV (Recreational Off-highway Vehicle), and may be a three-wheeled vehicle in addition to a four-wheeled vehicle. The drive source 20 can be an internal combustion engine, an electric motor, or a combination of an engine and an electric motor. Furthermore, in vehicle 1, the drive wheels may be either the front wheels 32 or the rear wheels 42, or both, and the steering wheels may be either the front wheels 32 only or both the front wheels 32 and the rear wheels 42. The road surface on which vehicle 1 travels is indicated by the symbol R.

[0016] The front suspension 30 is electronically controlled and typically includes an oil-type front damper 34 and a front spring 36 which is a coil spring made of metal or the like. By operating an actuator (not shown) to increase or decrease the orifice diameter of the front damper 34, the damping force can be variably adjusted. Furthermore, if necessary, the oil supply amount can be increased or decreased to change the stroke position in the bump and rebound directions, allowing for variable adjustment of the vehicle height, which is the height of the vehicle body 10 from the road surface, at the front of the vehicle 1. Similarly, the rear suspension 40 is electronically controlled and typically includes an oil-type rear damper 44 and a rear spring 46 which is a coil spring made of metal or the like. The damping force of the rear damper 44 can be variably adjusted, and further, if necessary, the vehicle height at the rear of the vehicle 1 can be variably adjusted. In the figures, the front suspension 30 and rear suspension 40 are shown as strut type, but other types with configurations such as separately arranged dampers and springs may also be used.

[0017] Further, in the vehicle 1, a drive source control device 60 that controls the operating state of the drive source 20 is attached to the vehicle body 10, a support member connected thereto, or the like. The drive source control device 60 is mounted on the vehicle 1 and operates using a battery (not shown) as a power supply, and is mainly configured by an ECU (Electronic Control Unit) which is an arithmetic processing device including a microcomputer or the like composed of a CPU (Central Processing Unit) or the like. For example, when an engine is applied as the drive source 20, the drive source (engine) control device 60 controls the operating states of components of an ignition system, a fuel supply system, and an intake system such as an ignition plug, an injector, and a throttle valve (all not shown), thereby controlling the operating state of the drive source (engine) 20. When an electric motor is applied as the drive source 20, the drive source (motor) control device 60 controls the on / off operating state of a switching element of an inverter (not shown), thereby controlling the operating state of the drive source (motor) 20. Note that control programs and control data used by the drive source control device 60 are stored in advance in a memory (not shown), and are read out from the memory when executed.

[0018] Configuration and Operation Related to Vehicle Control System and Apparatus Next, with further reference to FIGS. 2 to 6, the configuration and operation of the vehicle control system and apparatus according to the present embodiment will be described in detail.

[0019] Figure 2 is a schematic diagram showing the configuration of the vehicle control system and device in this embodiment. Figure 3 is a side view showing the right side of a vehicle equipped with the vehicle control system and device in this embodiment while it is in motion. Figure 4 is a time chart showing an example of the pitch speed detected by a sensor in a vehicle equipped with the vehicle control system and device in this embodiment, and the timing time of the timer applied to the vehicle control system and device in this embodiment. Figure 5 is a schematic diagram of data showing an example of the relationship between the timing time of the timer applied to the vehicle control system and device in this embodiment and the probability value. Figure 6 is a flowchart showing an example of the vehicle control processing performed by the vehicle control system and device in this embodiment.

[0020] As shown in Figures 1 and 2, the vehicle control system S includes a vehicle control device 100, along with various sensors 200 including an IMU (Inertial Measurement Unit) 202, a stroke sensor 204, a speed sensor 206, and an acceleration sensor 208, as well as a front suspension 30 and a rear suspension 40.

[0021] The vehicle control device 100 is mounted on a vehicle 1 and operates using a battery (not shown) as a power source, and is mainly configured by an ECU, which is an arithmetic processing device including a microcomputer or the like composed of a CPU 160 or the like. Various sensors 200 including an IMU 202, a stroke sensor 204, a speed sensor 206, and an acceleration sensor 208 are electrically connected to the vehicle control device 100. The vehicle control device 100 variably controls the damping force and stroke position of each of the front suspension 30 and the rear suspension 40 by executing a control program with reference to control data based on electrical signals output from such sensors and the like. Although shown as individual functional blocks, it functions as a control device that includes first to fourth input units 151 to 157, and an acquisition unit 161, a calculation unit 163, a timer unit 165, an accumulation unit 167, a determination unit 169, and a control unit 171 in the CPU 160. Note that such control programs and the like are stored in advance in a memory (not shown) and are read from the memory when executed. The vehicle control device 100 may be a control device integrated with the drive source control device 60; in such a case, the vehicle control device 100 functions as a control device that controls the operating state of the engine, which is the drive source 20, and also functions as a control device that variably controls the damping force and stroke position of each of the front suspension 30 and the rear suspension 40. Further, the vehicle control device 100 may be integrated with a dash panel display control device or a vehicle body control device. In addition, the hoop road determination device 100' is typically included in the vehicle control device 100, and corresponds to a configuration including the first to fourth input units 151 to 157, and the acquisition unit 161, calculation unit 163, timer unit 165, accumulation unit 167, and determination unit 169 in the CPU 160, and its operation is the same as the operation of the vehicle control device 100 except for the operation of the control unit 171. Furthermore, the control unit 171 may be added to the hoop road determination device 100', and the hoop road determination device 100' having such a control unit 171 is equivalent to the vehicle control device 100.

[0022] The first input unit 151 is an electrical circuit that receives an output from the IMU 202, which detects acceleration in three axial directions parallel to the x, y, and z axes of the vehicle, as well as angular velocity around these three axes, and also receives electrical signals indicating such acceleration and angular velocity. The IMU 202 has an acceleration sensor (G sensor) and a gyro sensor, both of which are not shown in the diagram. The acceleration sensor detects acceleration in three axial directions parallel to the x, y, and z axes, and the gyro sensor detects angular velocity around these three axes parallel to the x, y, and z axes.

[0023] The second input unit 153 is an electrical circuit to which an electrical signal indicating the stroke amount, i.e., the stroke position, is input. This signal is output from a stroke sensor 204 that detects the stroke amount within the effective stroke length range between full bump and full rebound of the left and right front suspensions 30 and rear suspensions 40, respectively, using the 1G position as a reference. Typically, the stroke sensor 204 is provided on each of the front suspensions 30 and rear suspensions 40.

[0024] The third input unit 155 is an electrical circuit that receives an output from a speed sensor 206, which is provided on the front suspension 30 and the rear suspension 40 to detect the extension (extension motion) and compression (compression motion) speeds of the front and rear of the vehicle body 10 of the vehicle 1, as well as an electrical signal indicating that speed. Typically, the speed sensor 206 is provided on each of the front suspension 30 and the rear suspension 40.

[0025] The fourth input unit 157 is an electrical circuit that receives an output from an acceleration sensor (G sensor) 208 that detects acceleration in the x, y, and z axes, as well as an electrical signal indicating such acceleration. The acceleration sensor 208 may typically be replaced by an IMU 202.

[0026] The acquisition unit 161 acquires pitch information relating to the pitch motion of the vehicle 1, in which the front wheels 32 and rear wheels 42 move relative to each other in the vertical direction, based on the electrical signal output from the IMU 202 and input to the first input unit 151. Specifically, it is preferable for the acquisition unit 161 to acquire the pitch speed of the vehicle 1 in order to appropriately acquire the pitch information relating to the pitch motion of the vehicle 1. Here, the pitch speed of the vehicle 1 is an angular velocity A about the pitch axis of the vehicle 1, which can be acquired by the acquisition unit 161 based on the output signal output from the gyro sensor of the IMU 202. This pitch axis is typically an axis that extends parallel to the width direction (y-axis direction) through the center of gravity of the vehicle 1.

[0027] Here, from the viewpoint of accurately detecting the pitch motion of vehicle 1 caused by the vehicle's travel path R, it is preferable that the acquisition unit 161 calculates the pitch speed A of vehicle 1 based on the difference between an acquired value, which is the overall pitch speed of vehicle 1 acquired from the overall pitch information of vehicle 1, and an estimated value, which is the pitch speed of vehicle 1 due to the driver's operation, calculated from the pitch information related to the pitch motion of vehicle 1 caused by the driver's operation.

[0028] In this case, from the viewpoint of appropriately calculating an estimated value which is the pitch speed of vehicle 1 due to the driver's operation, it is preferable that the acquisition unit 161 calculates such an estimated value using a predetermined vehicle model defined by the equation of motion which shows the motion of vehicle 1. Furthermore, from the viewpoint of appropriately identifying the estimated value corresponding to the pitch speed due to the driver's operation, it is preferable that such an estimated value is calculated from pitch information related to the pitch motion of vehicle 1, specifically the pitch speed, which is calculated based on the electrical signal output from the acceleration sensor 208 and input to the fourth input unit 157, while applying filtering as necessary.

[0029] Furthermore, the acquisition unit 161 may calculate the pitch speed A of the vehicle 1 based on the electrical signal output from the stroke sensor 204 and input to the second input unit 153, in order to appropriately acquire pitch information relating to the pitch motion of the vehicle 1. In this case, for example, the pitch speed A can be calculated by the acquisition unit 161 performing a differential operation on the pitch angle of the vehicle 1, which is calculated by the acquisition unit 161 based on the output signals output from the left and right front and rear stroke sensors 204, which are provided corresponding to the left and right front suspensions 30 and rear suspension 40. The pitch angle of the vehicle 1 can be calculated by the acquisition unit 161 using the difference in front and rear stroke amounts based on the output signals output from the left and right front and rear stroke sensors 204. Also, even when based on the electrical signal output from the stroke sensor 204 and input to the second input unit 153, the pitch information of the vehicle 1 that is generated due to the operation of the driver of the vehicle 1 may be subtracted from the overall pitch information of the vehicle 1 to detect the pitch motion of the vehicle 1 that is generated due to the road R of the vehicle 1.

[0030] Furthermore, the acquisition unit 161 may calculate the pitch speed A of the vehicle 1 based on the electrical signal output from the acceleration sensor 208 and input to the fourth input unit 157, in order to appropriately acquire pitch information relating to the pitch motion of the vehicle 1. In this case, for example, at least two acceleration sensors 208 are provided at a predetermined distance from each other in the longitudinal direction of the vehicle 1, and the pitch speed A can be calculated from the acceleration in the z-axis direction indicated by the electrical signal output from the acceleration sensors 208 and input to the fourth input unit 157. Also, even when based on the electrical signal output from the acceleration sensor 208 and input to the fourth input unit 157 in this way, the pitch motion of the vehicle 1 caused by the vehicle's driving path R may be detected by subtracting the pitch information of the vehicle 1 caused by the driver's operation of the vehicle 1 from the overall pitch information of the vehicle 1. Furthermore, for example, the pitch speed A can be calculated by the acquisition unit 161 performing a differential operation on the pitch angle of the vehicle 1, which is calculated by the acquisition unit 161 based on the output signal output from the acceleration sensor 208. The pitch angle of the vehicle 1 can be calculated by the acquisition unit 161 based on the output signal output from the acceleration sensor 208, corresponding to the component ratio of the acceleration, etc.

[0031] The calculation unit 163 calculates a second value that serves as a prerequisite for determining whether the vehicle 1's travel path R is a whoops road. Specifically, as shown in Figure 4, this second value is calculated by the calculation unit 163 from the moment the pitch speed A of the vehicle 1, acquired by the acquisition unit 161, crosses a predetermined threshold. This predetermined threshold is preferably set closer to the minimum or maximum value between the minimum and maximum values ​​of the pitch speed A that exhibits a value corresponding to the whoops road's uneven shape, in order to reliably detect the uneven shape of the whoops road, so that the second value becomes an appropriate prerequisite for the determination. For example, if the predetermined threshold is set closer to the minimum value between the minimum and maximum values ​​of the pitch speed A, it is preferable that the calculation unit 163 starts calculating the second value when the pitch speed A crosses the predetermined threshold TH1 while decreasing (for example, at time t1 shown in Figure 4). On the other hand, if the predetermined threshold is set closer to the maximum value between the minimum and maximum values ​​of pitch velocity A, it is preferable that the calculation unit 163 starts calculating the second value when the pitch velocity A crosses the predetermined threshold TH2 (>0>TH1: for example) while increasing (for example, at time t2 shown in Figure 4). In Figure 4, the calculation unit 163 starts calculating the second value at time t1 when the pitch velocity A first crosses the predetermined threshold TH1 while decreasing.

[0032] Here, from the viewpoint of being able to appropriately determine whether or not the road R is a whoops road, it is preferable that the second value calculated by the calculation unit 163 is a probability value indicating the probability that the road R is a whoops road, and that such a probability value is set to decrease as the timing time by the timer unit 165 increases. In other words, such a probability value is typically predetermined to correspond to the value of the pitch speed A of the vehicle 1, and as shown in Figure 5, it is preferable that such a predetermined probability value decreases as the timing time by the timer unit 165 increases, and furthermore, from the viewpoint of being able to more appropriately determine whether or not the road R is a whoops road, it is even more preferable that such a probability value decreases and shows a negative value as the timing time by the timer unit 165 increases. In other words, from the viewpoint of adjusting the cumulative value by the accumulation unit 167 to ensure the degree of freedom of determination by the determination unit 169, it is preferable that such a probability value decreases as the timing time by the timer unit 165 increases, so that the cumulative value by the accumulation unit 167 can be adjusted. Furthermore, it is preferable that such probability values ​​are pre-documented, and that these pre-documented probability values ​​are stored in the memory of the vehicle control device 100 and can be referenced by the vehicle control device 100 reading them.

[0033] The timer unit 165 starts timing when the pitch speed A of the vehicle 1 acquired by the acquisition unit 161 crosses a predetermined threshold, and then stops timing when the pitch speed A crosses another predetermined threshold. For example, as shown in Figure 4, if predetermined thresholds TH1 and TH2 are defined, the timer unit 165 starts timing at times t1, t3, and t5, etc., when the pitch speed A crosses the predetermined threshold TH1 downwards, and then stops timing at times t2, t4, and t6, etc., when the pitch speed A crosses the predetermined threshold TH1 upwards and then crosses the predetermined threshold TH2 upwards, and resets the timing time, which is the result of the timing, to an initial value (for example, 0). In addition, the timer unit 165 starts timing at times t2, t4, and t6, etc., when the pitch speed A crosses above a predetermined threshold TH2, and then stops timing at times t1, t3, and t5, etc., when the pitch speed A crosses below a predetermined threshold TH2 and then crosses below a predetermined threshold TH1, and resets the timing time to an initial value (e.g., 0). This makes it possible to reliably reflect, based on timing, the state in which the vehicle 1 crosses a recess in the whoops road and ascends the slope of the adjacent protrusion, or the state in which the vehicle 1 crosses a protrusion in the whoops road and descends the slope of the adjacent recess.

[0034] Furthermore, the longer the time elapsed from when the pitch speed A crosses a predetermined threshold TH1 downwards, then crosses that threshold TH1 upwards, and then immediately crosses a predetermined threshold TH2 upwards, and the longer the time elapsed from when the pitch speed A crosses a predetermined threshold TH2 upwards, then crosses that threshold TH2 downwards, and then immediately crosses a predetermined threshold TH1 downwards, the longer the timing time measured by the timer unit 165 becomes. For example, in Figure 4, the time interval (t4-t3) from when pitch velocity A crosses a predetermined threshold TH1 downwards at time t3, then crosses that threshold TH1 upwards, and then immediately crosses a predetermined threshold TH2 upwards at time t4 is longer than the time interval (t5-t4) from when pitch velocity A crosses a predetermined threshold TH2 upwards at time t4, then crosses that threshold TH2 downwards, and then immediately crosses a predetermined threshold TH1 downwards at time t5. Therefore, the timing time CT34 from time t3 to t4 is longer than the timing time CT45 from time t4 to t5.

[0035] The accumulation unit 167 accumulates the second value calculated by the calculation unit 163 as an accumulated value over time. This accumulated value is used to determine whether or not the vehicle 1's travel path R is a whoops path. For example, referring to the timing by the timer unit 165 shown in Figure 4, the calculation unit 163 accumulates the second value calculated by the calculation unit 163 for each of the following periods, which are the periods from time t1 to t2, time t2 to t3, time t3 to t4, time t4 to t5, time t5 to t6, and time t6 to t7, which are the periods from when the timer unit 165 starts timing until it finishes timing. For each of these periods, the current value of the second value (calculated by the calculation unit 163 during the calculation of the current second value) is added to the previous value of the accumulated value (calculated by the accumulation unit 167 during the previous calculation of the accumulated value: if this is the first calculation of the accumulated value, the current value is set to zero, etc.).

[0036] Here, if a probability value is applied as the second value, the accumulation unit 167 accumulates the probability value calculated by the calculation unit 163 as an accumulated value over time. Furthermore, if the probability value is specified to decrease as the timing time by the timer unit 165 increases, the rate of increase of the accumulated value decreases accordingly. Moreover, if the probability value is specified to decrease and show a negative value as the timing time by the timer unit 165 increases, the rate of increase of the accumulated value decreases accordingly, and the value of the accumulated value itself also decreases. In other words, the accumulated value calculated by the accumulation unit 167 can be adjusted by specifying that it decreases as the timing time by the timer unit 165 increases. Note that if the front wheels 32 and rear wheels 42 of vehicle 1 are lifted off the road R, there is no longer any point in the accumulation unit 167 calculating the accumulated value. Therefore, when the accumulation unit 167 determines that the front wheels 32 and rear wheels 42 are lifted off the road R, the accumulated value should be reduced before being sent to the determination unit 169. It is preferable to correct the accumulated value, for example, by multiplying it by a planned gain and reducing it.

[0037] The determination unit 169 determines whether the vehicle's travel path R is a whoops road based on the cumulative value accumulated by the accumulation unit 167. For example, assuming that the determination threshold is set to a predetermined value such that when a probability value is applied as the second value and it is greater than or equal to a predetermined value, the determination unit 169 will determine that the vehicle's travel path R is a whoops road if it determines that the cumulative value, which is the probability value accumulated by the accumulation unit 167, is greater than or equal to the predetermined determination threshold. The timing for such a determination by the determination unit 169 can, in principle, be anytime within the period from time t1 to t2, time t2 to t3, time t3 to t4, time t4 to t5, time t5 to t6, and time t6 to t7, which are the periods from when the timer unit 165 starts timing until it finishes timing, as shown in Figure 4. However, from the viewpoint of improving the determination accuracy of the determination unit 169 in determining whether the road R corresponds to a whoops road, it is more preferable that the timing for such determination by the determination unit 169 is at times t2, t3, t4, t5, t6, and t7, which are the timings when the timer unit 165 finishes timing.

[0038] From the standpoint of adjusting the attitude of the vehicle 1, the control unit 171 adjusts at least one of the damping force or vehicle height of the vehicle 1 when the determination unit 169 determines that the road R is the whoops road. In this case, the components of the vehicle 1 that are controlled by the control unit 171 are preferably at least one of the front suspension 30 and the rear suspension 40, and in this case, the control unit 171 controls the damping force or stroke position of at least one of these.

[0039] Here, when the control unit 171 adjusts the damping force of the vehicle 1, it is preferable that the control unit 171 adjusts the damping force of the vehicle 1 according to the extension and compression speeds of the front and rear of the vehicle body 10, so as to adjust the attitude of the vehicle 1 and improve its off-road capability, when the determination unit 169 determines that the road R is a whoops road. Furthermore, from the viewpoint of reliably lowering the rear of the vehicle body 10 relative to the front, it is preferable that the control unit 171 increases the compression damping force of the front suspension 30 or decreases the extension damping force of the front suspension 30, and decreases the compression damping force of the rear suspension 40 or increases the extension damping force of the rear suspension 40, when the determination unit 169 determines that the road R is a whoops road. Furthermore, from the viewpoint of adjusting the degree of change in the attitude of the vehicle 1 in accordance with improving the stability of the vehicle 1, it is preferable that the control unit 171 increases or decreases the damping force of the vehicle 1 when the determination unit 169 determines that the road R is a whoops road, compared to the normal case when the road R is not determined to be a whoops road. The relationship between the speed value calculated by the acquisition unit 161 and the damping force of the vehicle 1, typically the damping force of the front suspension 30 and the damping force of the rear suspension 40, may be predetermined, converted into data, and stored in memory, and the control unit 171 may read and refer to the data stored in memory when adjusting the damping force of the vehicle 1. The extension and compression speeds of the front and rear of the vehicle body 10 may be calculated by the acquisition unit 161 as the differential values ​​of the respective stroke positions based on electrical signals output from the stroke sensors 204 provided on each of the front suspension 30 and rear suspension 40 and input to the second input unit 153.Furthermore, the acquisition unit 161 may calculate such speed based on electrical signals output from acceleration sensors 208 provided on the vehicle body 10 side, the unsprung mass of the front suspension 30 and the front wheel 32 side, and the unsprung mass of the rear suspension 40 and the rear wheel 42 side, respectively, and input to the fourth input unit 157, as the integral value of the difference between the acceleration on the vehicle body 10 side and the acceleration on the unsprung mass of the front suspension 30 and the front wheel 32 side, and the difference between the acceleration on the vehicle body 10 side and the acceleration on the unsprung mass of the rear suspension 40 and the rear wheel 42 side. Alternatively, the acquisition unit 161 may calculate such speed based on electrical signals output from speed sensor 206 and input to the third input unit 155.

[0040] Furthermore, when the control unit 171 adjusts the vehicle height of the vehicle 1, it is preferable that the control unit 171 adjusts the posture of the vehicle 1 to improve its off-road capability by lowering the rear of the vehicle body 10 relative to the front, that is, by raising the vehicle height of the front of the vehicle body 10 or lowering the vehicle height of the rear of the vehicle body 10, when the determination unit 169 determines that the roadway R is the whoops road.

[0041] Now, focusing on the operation of the acquisition unit 161, calculation unit 163, timer unit 165, accumulation unit 167, determination unit 169, and control unit 171 in the vehicle control device 100, an example of such operation is the vehicle control process shown in the flowchart in Figure 6. The vehicle control process shown in Figure 6 typically starts when the power switch (vehicle not shown) is switched from the off state to the on state and the CPU 160 of the vehicle control device 100 becomes operational, and the vehicle control process proceeds to step S1. This vehicle control process is executed repeatedly at predetermined intervals within the period in which the CPU 160 is operational.

[0042] As shown in Figure 6, in step S1, the acquisition unit 161 calculates the pitch speed A of the vehicle 1 based on the electrical signal output from the IMU 202 and input to the first input unit 151, as described above. Alternatively, the acquisition unit 161 may calculate the pitch speed A of the vehicle 1 based on the electrical signal output from the stroke sensor 204 and input to the second input unit 153, as described above, or based on the electrical signal output from at least one acceleration sensor 208 and input to the fourth input unit 157. With this, the processing of step S1 is completed, and the vehicle control process proceeds to step S2.

[0043] In step S2, the calculation unit 163 starts calculating a second value when the pitch speed A of the vehicle 1 acquired by the acquisition unit 161 crosses a predetermined threshold, as described above. Here, from the viewpoint of being able to appropriately determine whether or not the travel path R is a whoops road, it is preferable that the second value calculated by the calculation unit 163 is a probability value indicating the probability that the travel path R is a whoops road, and it is preferable that such a probability value is set to decrease as the timing time by the timer unit 165 increases. In other words, from the viewpoint of adjusting the cumulative value by the accumulation unit 167 to ensure the degree of freedom of determination by the determination unit 169, it is preferable that such a probability value is defined to decrease as the timing time by the timer unit 165 increases, in order to adjust the cumulative value by the accumulation unit 167. With this, the processing of step S2 is completed, and the vehicle control processing proceeds to the processing of step S3.

[0044] In step S3, the accumulation unit 167 accumulates the second value calculated by the calculation unit 163 as an accumulated value as time elapses, as measured by the timer unit 165, as described above. Here, if a probability value is applied as the second value, the accumulation unit 167 accumulates the probability value calculated by the calculation unit 163 as an accumulated value as time elapses. Furthermore, if the probability value is specified to decrease as the time measured by the timer unit 165 increases, the rate at which the accumulated value accumulated by the accumulation unit 167 increases decreases accordingly. If the probability value is specified to decrease and show a negative value as the time measured by the timer unit 165 increases, the rate at which the accumulated value accumulated by the accumulation unit 167 increases decreases accordingly, and the value of the accumulated value itself decreases. Note that if the front wheels 32 and rear wheels 42 of vehicle 1 are lifted off the road R, the accumulated value should be reduced before being sent to the determination unit 169. Therefore, it is preferable to correct the accumulated value when the accumulation unit 167 determines, based on electrical signals output from various sensors 200, that the front wheels 32 and rear wheels 42 have lifted off the road surface R. With this, the process of step S3 is completed, and the vehicle control process proceeds to the process of step S4.

[0045] In step S4, the determination unit 169 determines whether the vehicle's travel path R is a whoops road based on the cumulative value accumulated by the accumulation unit 167, as described above. For example, assuming that the determination threshold is set to a predetermined value such that when a probability value is applied as the second value and it is greater than or equal to a predetermined value, the determination unit 169 determines that the vehicle's travel path R is a whoops road if the cumulative value, which is the probability value accumulated by the accumulation unit 167, is greater than or equal to the predetermined determination threshold, then the determination unit 169 determines that the vehicle's travel path R is a whoops road. With this, the process of step S4 is completed, and the vehicle control process proceeds to step S5. If the determination unit 169 does not determine that the vehicle's travel path R is a whoops road, the process of step S4 is repeated.

[0046] In step S5, the control unit 171 adjusts at least one of the damping force or vehicle height of the vehicle 1 if the determination unit 169 determines, as described above, that the travel path R is the whoops road. When the control unit 171 adjusts the damping force of the vehicle 1, if the determination unit 169 determines that the road R is a whoops road, the control unit 171 calculates a corresponding speed based on the electrical signal output from the speed sensor 206 and input to the third input unit 155, and adjusts the damping force of the vehicle 1 according to the calculated speed so that the rear of the vehicle body 10 is lowered relative to the front, from the viewpoint of adjusting the attitude of the vehicle 1 to improve off-road capability. Furthermore, from the viewpoint of reliably lowering the rear of the vehicle body 10 relative to the front, if the determination unit 169 determines that the road R is a whoops road, the control unit 171 preferably increases the compression damping force of the front suspension 30 or decreases the extension damping force of the front suspension 30, and decreases the compression damping force of the rear suspension 40 or increases the extension damping force of the rear suspension 40. Furthermore, from the viewpoint of adjusting the degree of change in the attitude of vehicle 1 in accordance with improving the stability of vehicle 1, it is preferable that the control unit 171 increases or decreases the damping force of vehicle 1 compared to the normal case when it is not determined that the travel path R is a whoops road, when the determination unit 169 determines that the travel path R is a whoops road. On the other hand, when the control unit 171 adjusts the ride height of vehicle 1, it is preferable that the control unit 171 lowers the rear of the vehicle body 10 relative to the front, that is, raises the ride height of the front of the vehicle body 10 or lowers the ride height of the rear of the vehicle body 10, when the determination unit 169 determines that the travel path R is a whoops road, in order to adjust the attitude of vehicle 1 and improve its off-road capability. With this, the processing of step S5 is completed, and this series of vehicle control processing is finished.

[0047] As is clear from the above description, in the first phase of the whoops road determination device 100' in this embodiment, an acquisition unit 161 that acquires a first value corresponding to pitch information relating to the pitch motion of the vehicle 1 based on output signals from sensors 202, 204, and 208 mounted on the vehicle 1; a calculation unit 163 that calculates a second value which is a prerequisite value when determining whether or not the road R on which the vehicle 1 travels is a whoops road, from the time the first value crosses a first threshold; an accumulation unit 167 that accumulates the second value as an accumulated value over time; and a determination unit 169 that determines whether or not the road R on which the vehicle 1 travels is a whoops road based on the accumulated value. By providing these components, even when the vehicle 1 travels on rough roads such as so-called off-road roads, it is possible to appropriately determine whether or not the road R on which the vehicle 1 travels is a whoops road.

[0048] Furthermore, in the second phase of the hoops path determination device 100' in this embodiment, in addition to the first phase, the acquisition unit 161 calculates a first value based on the difference between the acquired value obtained from the pitch information and the estimated value calculated from the pitch information related to the pitch motion of the vehicle 1 caused by the operation of the driver of the vehicle 1. This makes it possible to accurately detect the pitch motion of the vehicle 1 caused by the road R of the vehicle 1.

[0049] Furthermore, in the third phase of the hoops path determination device 100' in this embodiment, in addition to the second phase, the acquisition unit 161 calculates estimated values ​​using a vehicle model defined by the equations of motion representing the motion of the vehicle 1, thereby enabling more appropriate calculation of estimated values ​​caused by the driver's operation.

[0050] Furthermore, in the fourth phase of the hoop path determination device 100' in this embodiment, in addition to the second or third phase, the estimated value is calculated from pitch information related to the pitch motion of the vehicle 1, which is calculated based on the output signal from the acceleration sensor 208 mounted on the vehicle 1. This makes it possible to calculate the estimated value caused by the driver's operation more appropriately.

[0051] Furthermore, in the fifth phase of the whoops road determination device 100' in this embodiment, in addition to any of the first to fourth phases, the vehicle 1's attitude can be adjusted by further including a control unit 171 that adjusts the damping force of the vehicle 1 when it is determined that the road R is a whoops road.

[0052] Furthermore, in the sixth aspect of the whoops road determination device 100' in this embodiment, in addition to the fifth aspect, the vehicle 1 is equipped with suspensions 30 and 40 having sensors 204, 206, and 208 that detect the extension and compression speeds of the front and rear of the vehicle 1. When the control unit 171 determines that the road R is a whoops road, it adjusts the damping force of the suspensions 30 and 40 based on the output signals from the sensors 204, 206, and 208 so that the rear of the vehicle body 10 of the vehicle 1 is lowered, thereby allowing for more appropriate adjustment of the vehicle 1's posture.

[0053] Furthermore, in the seventh aspect of the whoops road determination device 100' in this embodiment, in addition to the fifth or sixth aspect, the control unit 171 can improve the off-road capability by adjusting the attitude of the vehicle 1 when it determines that the road R is a whoops road, by increasing the compression damping force of the front of the vehicle 1 or decreasing the extension damping force of the front of the vehicle 1, and by decreasing the compression damping force of the rear of the vehicle 1 or increasing the extension damping force of the rear of the vehicle 1.

[0054] Furthermore, in the eighth aspect of the whoops road determination device 100' in this embodiment, in addition to any of the fifth to seventh aspects, the control unit 171 can adjust the degree of change in the vehicle's attitude in accordance with improving the stability of the vehicle 1 by increasing or decreasing the damping force of the vehicle 1 compared to the normal case where the travel path R is not determined to be a whoops road, when it is determined that the travel path R is a whoops road.

[0055] Furthermore, in the ninth phase of the whoops road determination device 100' in this embodiment, in addition to any of the first to fourth phases, the vehicle's attitude can be adjusted by further including a control unit 171 that adjusts the vehicle height of the vehicle 1 when it is determined that the road R is a whoops road.

[0056] Furthermore, in the tenth aspect of the whoops road determination device 100' in this embodiment, in addition to the ninth aspect, the control unit 171 can improve the off-road capability by adjusting the attitude of the vehicle 1 by raising the height of the front of the vehicle 1 or lowering the height of the rear of the vehicle 1 when the travel path R is determined to be a whoops road.

[0057] Furthermore, in the 11th phase of the hoops road determination device 100' in this embodiment, in addition to any of the first to 10th phases, the device further includes a timer unit 165 which starts timing when a first value calculated based on pitch information crosses below a first threshold, and then stops timing and resets the timing time when the first value subsequently exceeds the first threshold and crosses above a second threshold that is greater than the first threshold, or starts timing when the first value crosses above a second threshold, and then stops timing and resets the timing time when the first value subsequently falls below the second threshold and crosses below the first threshold, thereby enabling timing to be performed to determine whether or not the road R of the vehicle 1 is a hoops road.

[0058] Furthermore, in the twelfth phase of the hoops road determination device 100' in this embodiment, in addition to the eleventh phase, the second value is a probability value indicating the probability that the road R is a hoops road, and the probability value is set to decrease as the timing time increases, thereby enabling accurate determination of whether or not the road R of the vehicle 1 is a hoops road.

[0059] Furthermore, in the 13th phase of the hoop road determination device 100' in this embodiment, in addition to the 12th phase, the probability value is set to become negative as the timing time increases, and as the negative probability value accumulates in the cumulative value, the cumulative value decreases, thereby enabling a more appropriate determination of whether or not the road R traveled by the vehicle 1 is a hoop road.

[0060] Furthermore, in the 14th phase of the hoops road determination device 100' in this embodiment, in addition to the 12th or 13th phase, the probability value decreases as the timing time increases, so that the cumulative value can be adjusted, thereby adjusting the degree of change in the attitude of the vehicle 1 in accordance with improving the stability of the vehicle 1.

[0061] Furthermore, in the 15th phase of the hoops path determination device 100' in this embodiment, in addition to any of the 1st to 14th phases, if the front wheels 32 and rear wheels 42 of the vehicle 1 are lifted off the road surface R, the cumulative value is corrected, thereby suppressing the calculation of unnecessary cumulative values.

[0062] Furthermore, in the 16th phase of the hoops path determination device 100' in this embodiment, in addition to any of the 1st to 15th phases, the pitch information is the pitch speed of the vehicle 1, and the pitch speed is acquired based on the output signal output from the inertial measurement unit 202, thereby enabling the acquisition of appropriate pitch information.

[0063] Furthermore, in the 17th phase of the hoops path determination device 100' in this embodiment, in addition to any of the first to 15 phases, the pitch information is the pitch speed of the vehicle 1, and the pitch speed is acquired based on the output signal output from the stroke sensor 204, thereby enabling the acquisition of appropriate pitch information.

[0064] Furthermore, in the 18th phase of the hoops path determination device 100' in this embodiment, in addition to any of the first to 15 phases, the pitch information is the pitch speed of the vehicle 1, and the pitch speed is acquired based on the output signal output from at least one acceleration sensor 208, thereby enabling the acquisition of appropriate pitch information.

[0065] Furthermore, according to another aspect of the present invention, a vehicle control method comprising: an acquisition step of acquiring a first value corresponding to pitch information relating to the pitch motion of the vehicle 1 based on output signals from sensors 202, 204, and 208 mounted on the vehicle 1; a calculation step of calculating a second value used when determining whether the road R on which the vehicle 1 travels is a whoops road, from the time the first value crosses a first threshold; an accumulation step of accumulating the second value as an accumulated value over time; a determination step of determining whether the road R on which the vehicle 1 travels is a whoops road, based on the accumulated value; and a control step of adjusting the damping force of the suspensions 30 and 40 of the vehicle 1, allows for appropriate determination of whether the road R on which the vehicle 1 travels is a whoops road, and even if the road R on which the vehicle 1 travels is a whoops road, the attitude of the vehicle 1 can be appropriately adjusted.

[0066] It should be noted that the present invention is not limited to the above-described embodiments in terms of the type, shape, arrangement, number, etc. of the components, and it is of course possible to modify them as appropriate without departing from the spirit of the invention, such as by appropriately substituting the components with those that produce equivalent effects. [Industrial applicability]

[0067] As described above, the present invention provides a whoops road determination device and a vehicle control method that can appropriately determine whether the road a vehicle is traveling on is a whoops road, even when the vehicle is traveling on rough roads such as so-called off-road roads. Due to its general-purpose and universal nature, it is expected to be widely applicable to automobiles, including motorcycles. [Explanation of symbols]

[0068] S... Vehicle control system 1…Vehicle 10... Vehicle body 20…Power source 30…Front suspension 32…Front wheel 34…Front damper 36…Front springs 40... Rear suspension 42... Rear wheel 44... Rear damper 46... Rear spring 60…Drive source control device 100... Vehicle control device 100'...Hoops path determination device 151...First input section 153...Second input section 155...Third input section 157...4th input section 160...CPU 161…Acquisition Department 163...Calculation section 165... Cumulative portion 167... Timer section 169…Judgment section 171... Control Unit 202…IMU 204... Stroke sensor 206... Speed ​​sensor 208...Accelerometer R…Running road

Claims

1. An acquisition unit that acquires a first value corresponding to pitch information relating to the pitch motion of the vehicle based on an output signal from a sensor mounted on the vehicle, A calculation unit calculates a second value which is a prerequisite value for determining whether or not the vehicle's travel path is a whoops road, starting from when the first value crosses a first threshold, A cumulative unit that accumulates the second value as a cumulative value over time, A determination unit that determines whether the road is a hoop road based on the cumulative value, A hoop path determination device equipped with the following features.

2. The hoops path determination device according to claim 1, wherein the acquisition unit calculates the first value based on the difference between the acquired value obtained from the pitch information and the estimated value calculated from the pitch information relating to the pitch motion of the vehicle caused by the operation of the vehicle driver.

3. The hoops path determination device according to claim 2, wherein the acquisition unit calculates the estimated value using a vehicle model defined by the equations of motion representing the motion of the vehicle.

4. The hoop path determination device according to claim 3, wherein the estimated value is calculated from pitch information relating to the pitch motion of the vehicle, which is calculated based on the output signal from the acceleration sensor mounted on the vehicle.

5. The hoop road determination device according to any one of claims 1 to 4, further comprising a control unit for adjusting the damping force of the vehicle when the road is determined to be a hoop road.

6. The vehicle is equipped with a sensor that outputs an output signal based on the calculation of the extension and compression velocities of the front and rear of the vehicle, and a suspension. The whoops road determination device according to claim 5, wherein the control unit determines that the road is a whoops road, and adjusts the damping force of the suspension based on the output signal so that the rear of the vehicle body of the vehicle is lowered according to the extension and compression speeds.

7. The hoop road determination device according to claim 6, wherein the control unit, when it is determined that the travel path is a hoop road, performs at least one of the following: increasing the damping force on the compression side of the front part or decreasing the damping force on the extension side of the front part, and decreasing the damping force on the compression side of the rear part or increasing the damping force on the extension side of the rear part.

8. The hoop road determination device according to claim 7, wherein the control unit, when it is determined that the road is a hoop road, increases or decreases the damping force of the vehicle compared to the normal case when the road is not determined to be a hoop road.

9. The whoops road determination device according to any one of claims 1 to 4, further comprising a control unit for adjusting the vehicle height when the road is determined to be the whoops road.

10. The hoop road determination device according to claim 9, wherein the control unit determines that the road is a hoop road, it performs at least one of raising the vehicle height of the front of the vehicle or lowering the vehicle height of the rear of the vehicle.

11. Hoops path determination device according to any one of claims 1 to 4, further comprising a timer unit which starts timing when the first value calculated based on the pitch information crosses below the first threshold, and then ends timing and resets the timing time when the first value subsequently exceeds the first threshold and crosses above a second threshold that is greater than the first threshold, or starts timing when the first value crosses above the second threshold, and then ends timing and resets the timing time when the first value subsequently falls below the second threshold and crosses below the first threshold.

12. The hoop path determination device according to claim 11, wherein the second value is a probability value indicating the probability that the travel path is the hoop path, and the probability value is set to decrease as the timing time increases.

13. The hoop path determination device according to claim 12, wherein the probability value is set to become negative as the timing time increases, and when the negative probability value is accumulated in the cumulative value, the cumulative value decreases.

14. The hoop path determination device according to claim 12, wherein the probability value decreases as the timing time increases, so that the cumulative value can be adjusted.

15. The hoops path determination device according to any one of claims 1 to 4, wherein the cumulative value is corrected when the front and rear wheels of the vehicle are lifted off the road.

16. The hoops path determination device according to any one of claims 1 to 4, wherein the pitch information is the pitch speed of the vehicle, and the pitch speed is obtained based on an output signal output from an inertial measurement unit.

17. The hoops path determination device according to any one of claims 1 to 4, wherein the pitch information is the pitch speed of the vehicle, and the pitch speed is obtained based on an output signal output from a stroke sensor.

18. The hoops path determination device according to any one of claims 1 to 4, wherein the pitch information is the pitch speed of the vehicle, and the pitch speed is obtained based on an output signal output from at least one acceleration sensor.

19. An acquisition step of acquiring a first value corresponding to pitch information relating to the pitch motion of the vehicle based on an output signal from a sensor mounted on the vehicle, A calculation step to calculate a second value which is a prerequisite value for determining whether or not the vehicle's travel path is a whoops road, starting from when the first value crosses a first threshold, A cumulative step in which the second value is accumulated as a cumulative value over time, A determination step of determining whether the road is a hoop road based on the cumulative value, A control step for adjusting the damping force of the vehicle's suspension, A control method for a vehicle equipped with the following features.

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