Suspension system for a vehicle

Abstract

To solve the above problems, the present application provides a suspension system (1) for a vehicle (V) including: a road surface sensor provided at a vehicle body portion more forward than a front wheel (Fw) to detect unevenness of a road surface (R); an electromagnetic shock absorber (2) imparting a damping force and a propulsive force in a stroke direction to the vehicle body (B) and the front wheel (Fw) by a motor element (23); and an ECU (3) controlling the motor element (23) based on a detection value of the road surface sensor; and the road surface sensor has: a first road surface sensor (11); and a second road surface sensor (12) overlapping the first road surface sensor (11) in a vehicle width direction and provided at a position more rearward than the first road surface sensor (11); and the ECU (3) includes: a road surface height calculation portion (34) calculating a road surface height (x r ) based on the detection values of these road surface sensors and a moving amount of the vehicle (V); and a shock absorber control portion (35) controlling the motor element (23) based on the calculated road surface height (x r ).

Description

Technical Field

[0001] This invention relates to a vehicle suspension system. Background Technology

[0002] Previously, a vehicle suspension system was disclosed that uses a road surface sensor mounted on the lower front of the vehicle body and facing downward toward the front of the vehicle to detect road surface irregularities and control the shock absorber based on the detection results (for example, see Patent Document 1).

[0003] [Previous Technical Documents]

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-142127 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] However, in the suspension system of Patent Document 1, a road surface sensor is used to detect road surface unevenness. Therefore, if the vehicle body sways when decelerating or crossing road unevenness, the road surface sensor's detection value will include the vehicle body swaying, making it impossible to accurately and precisely detect road surface unevenness. Consequently, it is impossible to properly control the shock absorbers based on road surface unevenness.

[0008] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a vehicle suspension system that can accurately and precisely detect the unevenness of the road surface and appropriately control the shock absorbers according to the unevenness of the road surface.

[0009] [Technical means to solve the problem]

[0010] (1) The suspension system (e.g., suspension system 1) of the vehicle (e.g., vehicle V described later) of the present invention includes: a road surface sensor disposed in a body portion further forward than the front wheel (e.g., front wheel Fw described later) to detect the unevenness (e.g., step S described later) of the road surface (e.g., road surface R described later); a shock absorber (e.g., electromagnetic shock absorber 2 described later) disposed between the upper spring component of the vehicle, i.e., the body (e.g., body B described later) and the lower spring component, i.e., the wheel, and applying a damping force and a propulsive force along the stroke direction to the aforementioned body and the aforementioned wheel by means of an actuator (e.g., motor element 23 described later); and a control device (e.g., ECU 3 described later) to control the aforementioned actuator based on the detection value of the aforementioned road surface sensor. The aforementioned road surface sensor includes: a front road surface sensor (e.g., a first road surface sensor 11); and a rear road surface sensor (a second road surface sensor 12), whose position in the vehicle width direction overlaps with the aforementioned front road surface sensor and is located further rearward than the aforementioned front road surface sensor; and the aforementioned control device includes: a vehicle movement acquisition unit (e.g., a vehicle movement acquisition unit 33 described later), which acquires the aforementioned vehicle movement; a road surface height calculation unit (e.g., a road surface height calculation unit 34 described later), which calculates the road surface height based on the detection value of the aforementioned road surface sensor and the vehicle movement acquired by the aforementioned vehicle movement acquisition unit; and a shock absorber control unit (e.g., a shock absorber control unit 35 described later), which controls the aforementioned actuator based on the road surface height calculated by the aforementioned road surface height calculation unit.

[0011] According to the invention of (1), the road height is calculated based on the detection values ​​of the front road surface sensor and the rear road surface sensor, along with the amount of vehicle movement. The vehicle body sway included in the detection values ​​of each road surface sensor can be subtracted, thus accurately and precisely calculating the road height. Furthermore, the actuator of the shock absorber can be controlled based on the accurately and precisely calculated road height, thereby further improving the vehicle's ride comfort.

[0012] (2) In the suspension system of the vehicle of (1), optionally, at least one of the aforementioned front road surface sensor and the aforementioned rear road surface sensor has: a central road surface sensor, whose position in the vehicle width direction overlaps with the other; an inner road surface sensor, disposed inside the aforementioned central road surface sensor in the vehicle width direction; and an outer road surface sensor, disposed outside the aforementioned central road surface sensor in the vehicle width direction.

[0013] According to the invention of (2), since at least one of the front road surface sensor and the rear road surface sensor has a central road surface sensor, an inner road surface sensor and an outer road surface sensor arranged in the vehicle width direction, even when the vehicle is turning, the same road surface unevenness can be easily detected by the front road surface sensor and the rear road surface sensor. As a result, the road surface height can be calculated accurately and with good precision.

[0014] (3) In the suspension system of the vehicle in (1) or (2), optionally, the aforementioned rear road surface sensor includes: a rear center road surface sensor (e.g., the second road surface sensor 12 described later), whose position in the vehicle width direction overlaps with the aforementioned front road surface sensor; a rear inner road surface sensor (e.g., the third road surface sensor 13 described later), disposed inside the aforementioned rear center road surface sensor in the vehicle width direction; and a rear outer road surface sensor (e.g., the fourth road surface sensor 14 described later), disposed outside the aforementioned rear center road surface sensor in the vehicle width direction; and the aforementioned road surface height calculation unit uses the detection values ​​of the aforementioned plurality of rear road surface sensors to calculate the road surface height at the position where the aforementioned front road surface sensor passes between the aforementioned plurality of rear road surface sensors by interpolation.

[0015] According to the invention of (3), since the rear road surface sensor has a rear center road surface sensor, a rear inner road surface sensor and a rear outer road surface sensor arranged in the vehicle width direction, even when the vehicle is turning, the detection values ​​of multiple rear road surface sensors can be used to interpolate and calculate the road surface height at the position where the front road surface sensor passes between multiple rear road surface sensors, so that the road surface height can be calculated accurately and with good precision.

[0016] (The effect of the invention)

[0017] According to the present invention, a vehicle suspension system can be provided that can accurately and precisely detect the unevenness of the road surface and appropriately control the shock absorbers according to the unevenness of the road surface. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating a vehicle suspension system according to an embodiment of the present invention.

[0019] Figure 2 This is a functional block diagram of the Electronic Control Unit (ECU) of the suspension system of the vehicle described above.

[0020] Figure 3 This is a diagram illustrating the situation when the road surface step is located below the first road surface sensor.

[0021] Figure 4This is a diagram illustrating the situation when the road surface step is located below the second road surface sensor.

[0022] Figure 5 This is a flowchart illustrating the processing flow of the ECU in the suspension system of the vehicle described above.

[0023] Figure 6 This is a plan view of the vehicle according to the above-described implementation method when traveling straight.

[0024] Figure 7 It is a graph showing the detection values ​​of the first road surface sensor and the second road surface sensor when the vehicle is traveling in a fixed position without acceleration, deceleration, or turning.

[0025] Figure 8 It is Figure 7 The graph is a composite image of the time axis of the detection values ​​from each road surface sensor.

[0026] Figure 9 It is a graph showing the detection values ​​of the first road surface sensor and the second road surface sensor during deceleration.

[0027] Figure 10 It is Figure 9 The graph is a composite image of the time axis of the detection values ​​from each road surface sensor.

[0028] Figure 11 This is a plan view of the vehicle according to the above-described implementation method when turning.

[0029] Figure 12 This is a plan view of a vehicle in a modified embodiment of the above-described method when traveling straight.

[0030] Figure 13 This is a plan view of a vehicle in a modified embodiment of the above-described turning situation.

[0031] Figure 14 It is a diagram showing the movement trajectory of the first road surface sensor when turning.

[0032] Figure 15 It is a graph showing the detection values ​​of the second road surface sensor and the third road surface sensor.

[0033] Figure 16 It is a graph that illustrates the estimated value of the road sensor behind the position traversed by the first road sensor, which is estimated by interpolation using the detection values ​​of the second road sensor and the third road sensor.

[0034] Figure 17 It is a graph showing the estimated value of the road surface sensor behind the position through which the first road surface sensor passes, as determined by interpolation, and the detection value of the first road surface sensor.

[0035] Figure 18 It is a diagram depicting the situation when the front wheels of a vehicle drive onto a step.

[0036] Figure 19 It is a diagram showing the results of previous road height measurements when the vehicle body undergoes displacement caused by pitching. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 This is a diagram illustrating a vehicle suspension system 1 according to an embodiment of the present invention. The vehicle V is, for example, a four-wheeled vehicle with four wheels, and each wheel is provided with a suspension system 1. Figure 1 The diagram shows only one of the four suspension systems 1.

[0039] The suspension system 1 includes a first road surface sensor 11, a second road surface sensor 12, an electromagnetic shock absorber 2, and an electronic control unit 3 (hereinafter referred to as "ECU (Electronic Control Unit) 3") as a control device.

[0040] The first road surface sensor 11 is located on the vehicle body further forward than the front wheel Fw, and detects the unevenness of the road surface R (e.g., Figure 1 The first road surface sensor 11 functions as a forward road surface sensor. The detection signal of the first road surface sensor 11 is sent to the forward road surface sensor value acquisition unit 31, which will be described later.

[0041] The second road surface sensor 12, like the first road surface sensor 11, is located on the vehicle body further forward than the front wheel Fw, detecting the unevenness of the road surface R. Furthermore, the position of the second road surface sensor 12 in the vehicle width direction overlaps with that of the first road surface sensor 11, and it is located further rearward than the first road surface sensor 11. That is, the second road surface sensor 12 functions as a rear road surface sensor, detecting the unevenness of the road surface R at the same location as the first road surface sensor 11 when the vehicle V is traveling straight. The detection signal from the second road surface sensor 12 is sent to the rear road surface sensor value acquisition unit 32, which will be described later.

[0042] As the first road surface sensor 11 and the second road surface sensor 12, conventionally known road surface sensors can be used. For example, in addition to laser-type ranging sensors such as infrared lasers, vision sensors such as cameras can also be used.

[0043] The electromagnetic damper 2 is installed between the upper spring component (body B) and the lower spring component (front wheel Fw) of the vehicle V, connecting the body B and the front wheel Fw. The electromagnetic damper 2 has a damper element 21, a spring element 22, and a motor element 23.

[0044] exist Figure 1 The mechanical model of the electromagnetic shock absorber 2 is also shown in the diagram. Figure 1 As shown, the body B is composed of a spring mass M. b upper part of the spring E b The front wheel Fw forms the lower mass M of the spring. t lower spring component E t The front wheel Fw has a wheel (not shown) and a tire T, which is an elastic body represented by the spring constant Kt and the viscous damping coefficient Ct.

[0045] Shock absorber element 21 is a shock absorber represented by a viscous damping coefficient Cs. Spring element 22 is a spring represented by a spring constant Ks. Motor element 23, acting as an actuator, is powered by a battery (also not shown) via an inverter (not shown), thereby driving rotation. This motor element 23 is driven and controlled by the shock absorber control unit 35 of the ECU 3 (described later). The electromagnetic shock absorber 2, incorporating these elements, imparts damping force and propulsion force along the stroke direction to the vehicle body B and the front wheel Fw.

[0046] The ECU 3 controls the motor element 23 of the electromagnetic shock absorber 2 based on the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12.

[0047] Figure 2 This is a functional block diagram of the ECU 3 in the suspension system 1 of the vehicle V in this embodiment. Figure 2 As shown, the ECU 3 of this embodiment includes a front road surface sensor value acquisition unit 31, a rear road surface sensor value acquisition unit 32, a vehicle movement acquisition unit 33, a road surface height calculation unit 34, and a shock absorber control unit 35.

[0048] The ECU 3 is an onboard computer consisting of a central processing unit (CPU), read-only memory (ROM), random-access memory (RAM), a data bus, and input / output interfaces. The ECU 3 executes various calculations and processing operations in the CPU according to the programs stored in the ROM.

[0049] The forward road surface sensor value acquisition unit 31 acquires the detection value of the forward road surface sensor, namely the first road surface sensor 11. The acquired detection value of the first road surface sensor 11 is used in the road surface height calculation performed by the road surface height calculation unit 34, which will be described later.

[0050] The rear road surface sensor value acquisition unit 32 acquires the detection value of the rear road surface sensor, namely the second road surface sensor 12. The acquired detection value of the second road surface sensor 12 is used in the road surface height calculation performed by the road surface height calculation unit 34, which will be described later.

[0051] The vehicle movement acquisition unit 33 acquires the movement of vehicle V. Specifically, the vehicle movement acquisition unit 33 calculates and acquires the movement of vehicle V in the driving direction, for example, based on the vehicle speed detected by a vehicle speed sensor (not shown) mounted on vehicle V. Alternatively, the vehicle movement acquisition unit 33 calculates and acquires the movement of vehicle V in the driving direction, for example, based on the position information of vehicle V detected by a global positioning system (GPS) (not shown) mounted on vehicle V. Or, for example, the vehicle movement acquisition unit 33 calculates and acquires the movement of vehicle V in the driving direction based on image information obtained by an image sensor such as a camera (not shown) mounted on vehicle V. The acquired movement of vehicle V is used in the road surface height calculation performed later by the road surface height calculation unit 34.

[0052] The road height calculation unit 34 calculates the road height based on the detection values ​​of each of the aforementioned road surface sensors and the movement amount of the vehicle V. Specifically, the road height calculation unit 34 calculates the road height based on the detection values ​​of the first road surface sensor 11 obtained by the front road surface sensor value acquisition unit 31, the detection values ​​of the second road surface sensor 12 obtained by the rear road surface sensor value acquisition unit 32, and the movement amount of the vehicle V obtained by the vehicle movement amount acquisition unit 33. The calculation of the road height performed by this road height calculation unit 34 will be described in detail below.

[0053] The shock absorber control unit 35 controls the motor element 23 of the electromagnetic shock absorber 2 based on the road surface height calculated by the road surface height calculation unit 34. Specifically, the shock absorber control unit 35 controls the motor element 23 based on the calculated road surface height to suppress the vibration of the vehicle body B, so as to impart damping force and propulsion force to the vehicle body B and the front wheel Fw along the stroke direction.

[0054] Next, the calculation of road surface height performed by the road surface height calculation unit 34 will be explained in detail.

[0055] First, refer to Figure 18 and Figure 19 The previous methods for measuring road surface height are explained here. Figure 18 This is a diagram illustrating the situation when the front wheel Fw of vehicle V travels onto the step S of road surface R. For example... Figure 18 As shown, when the front wheel Fw of vehicle V reaches the step S, as Figure 18As indicated by the arrow, the component on the spring, i.e., the vehicle body B, undergoes a rotational motion about the left and right sides of the vehicle body B, i.e., pitch P. This pitch P also occurs when the vehicle V accelerates or decelerates.

[0056] Figure 19 This is a graph showing the previous road height measurements when the vehicle body B experiences displacement caused by pitch P. Specifically, Figure 19 The road height measurement results are based on previous road height measurement results from a road sensor installed on vehicle body B. Figure 19 In the diagram, the horizontal axis represents the travel distance (m), and the vertical axis represents the road surface height (mm). For example... Figure 19 As shown, in previous road surface height measurement results, in addition to the actual road surface height, the displacement of vehicle body B caused by the pitch P when vehicle body B pitches also includes the actual road surface height.

[0057] Therefore, because previous road height measurements based on the detection values ​​of a road surface sensor installed on vehicle body B included the displacement of vehicle body B caused by pitch P, the absolute road height could not be obtained. Therefore, conventionally, the displacement of vehicle body B was estimated by integrating the detection values ​​of the acceleration sensor installed on vehicle body B twice, and this estimated value was used to correct the road height measurement. However, due to drift in the integrated waveform caused by factors such as temperature, occupant weight, and deformation of vehicle body B, the estimation accuracy of vehicle body B's displacement is poor, thus making it impossible to obtain an accurate road height.

[0058] Therefore, in this embodiment, in the vehicle body section further forward than the front wheel Fw, two road surface sensors are installed at different positions in the longitudinal direction of the vehicle V to detect the same road surface twice. The displacement of the vehicle body B and the road surface height are calculated based on the difference between the detected values ​​and the amount of movement of the vehicle V. Thus, according to this embodiment, the displacement of the vehicle body B and the road surface height can be calculated accurately. Hereinafter, the calculation logic of the road surface height performed by the road surface height calculation unit 34 will be explained with reference to the accompanying drawings.

[0059] The above Figure 1 Let V represent the state of vehicle V at time t = 0. For example... Figure 1 As shown, the step S on the road surface R is located in front of the vehicle V. At this time, the detection value x of the first road surface sensor 11 at time t=0 is... 11 (0) and the detection value x of the second road surface sensor 12 12 (0) The displacement x of the vehicle body B at time t=0 can be used. b (0) and road surface height x r (0) is represented by the following mathematical expressions (1) and (2).

[0060] x 11 (0)=x b (0)-x r (0)...Mathematical expression (1)

[0061] x 12 (0)=x b (0)-x r (0)...Mathematical expression (2)

[0062] Here, time t = 0 represents the displacement x of vehicle body B in the initial state of vehicle V. b (0) and road surface height x r (0) is represented by the following mathematical expressions (3) and (4).

[0063] x b (0)=0…Mathematical expression (3)

[0064] x r (0) = Initial value of road surface... Mathematical formula (4)

[0065] Figure 3 This is a diagram illustrating the situation when the step S of the road surface R is located below the first road surface sensor 11. This... Figure 3 Let S represent the state of vehicle V at time t = 1. Furthermore, let S be defined as follows: during the period from time t = 0 to time t = 1, vehicle V travels straight until the step difference S is below, specifically directly below, the first road surface sensor 11. That is, the amount of movement of vehicle V in the travel direction from time t = 0 to time t = 1 is defined as equivalent to the longitudinal distance between the first road surface sensor 11 and the second road surface sensor 12.

[0066] The detection value x of the first road surface sensor 11 at time t=1 11 (1) and the detection value x of the second road surface sensor 12 12 (1) The displacement x of the vehicle body B at time t=1 can be used. b (1) and road surface height x r (1) is represented by the following mathematical expressions (5) and (6).

[0067] x 11 (1) = x b (1)-x r (1)...Mathematical expression (5)

[0068] x 12 (1) = x b (1)-x r (1)...Mathematical expression (6)

[0069] Here, the detection value x of the second road surface sensor 12 at time t=112 (1) is the detection value x of the first road surface sensor 11 at time t = 0. 11 (0) has the same value, so it can be represented by the following mathematical expression (7).

[0070] x 12 (1) = x b (1)-x r (0)...Mathematical expression (7)

[0071] Therefore, by rearranging terms in mathematical expressions (5) and (7), we can use the road surface height x at time t=0 as an example. r (0) represents the following mathematical expressions (8) to (10), which are used to calculate the displacement of vehicle body B and road surface height x at time t=1. r (1).

[0072] x b (1) = x 12 (1)+x r (0)...Mathematical expression (8)

[0073] x r (1) = x b (1)-x 11 (1)...Mathematical expression (9)

[0074] x r (1) = x 12 (1)-x 11 (1)+x r (0)...Mathematical expression (10)

[0075] Figure 4 This is a diagram illustrating the situation when the step S of the road surface R is located below the second road surface sensor 12. This... Figure 4 Let S represent the state of vehicle V at time t = 2. Furthermore, let S be defined as follows: during the period from time t = 1 to time t = 2, vehicle V continues to travel straight until the step S is below, specifically directly below, the second road surface sensor 12. That is, the amount of movement of vehicle V in the driving direction from time t = 1 to time t = 2 is defined as equivalent to the longitudinal distance between the first road surface sensor 11 and the second road surface sensor 12.

[0076] The detection value x of the first road surface sensor 11 at time t=2 11 (2) and the detection value x of the second road surface sensor 12 12 (2) The displacement x of the vehicle body B at time t=2 can be used. b (2) and road surface height x r (2) is represented by the following mathematical expressions (11) and (12).

[0077] x 11 (2) = x b (2)-x r (2)...Mathematical expression (11)

[0078] x 12 (2) = x b (2)-x r (2)...Mathematical expression (12)

[0079] Here, the detection value x of the second road surface sensor 12 at time t=2 12 (2) is the detection value x of the first road surface sensor 11 at time t=1. 11 (1) The same value, therefore it can be represented by the following mathematical expression (13).

[0080] x 12 (2) = x b (2)-x r (1)...Mathematical expression (13)

[0081] Therefore, by rearranging terms in mathematical expressions (11) and (13), and using the road surface height x at time t=1 represented by the aforementioned mathematical expression (10), r (1) The displacement x of the vehicle body B at time t=2 can be calculated as shown in the following mathematical formulas (14) to (16). b (2) and road surface height x r (2).

[0082] x b (2) = x 12 (2)+x r (1)...Mathematical expression (14)

[0083] x r (2) = x b (2)-x 11 (2)...Mathematical expression (15)

[0084] x r (2) = x 12 (1)+x 12 (2)-x 11 (1)-x 11 (2)+x r (0)...Mathematical expression (16)

[0085] Therefore, by repeating the above derivation at each time point, the road surface height x at time t can be calculated using the following mathematical formula (17). r (t). As expressed by the mathematical formula (17), it can be seen that the road surface height x r(t) is calculated by adding the difference between the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 to the initial road surface value. Since the difference between the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 is included in the mathematical formula (17), the swaying of the vehicle body B contained in the detection values ​​of each road surface sensor is subtracted, thereby obtaining the absolute road surface height. Thus, compared to the conventional method of integrating the detection values ​​of the acceleration sensor twice to estimate the displacement of the vehicle body B and using this estimated value to correct the road surface height measurement value, in this embodiment, the road surface height x can be calculated by integrating once by adding the difference between the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12. r (t). Therefore, according to this embodiment, the road surface height x can be calculated more accurately and with higher precision. r (t).

[0086] [Number 1]

[0087]

[0088] Furthermore, in the road surface height x of the above-described embodiment... r In the calculation of (t), the amount of movement of vehicle V in the driving direction during the period from time t=0 to time t=1 and the period from time t=1 to time t=2 is set as equivalent to the arrangement distance between the first road surface sensor 11 and the second road surface sensor 12 in the vehicle's longitudinal direction. Therefore, in the road surface height x of the above embodiment, r In the calculation of (t), it is important to calculate the time when the second road surface sensor 12 detects the road surface detected by the first road surface sensor 11, based on the amount of movement of the vehicle V in the direction of travel, and to set the aforementioned time t based on the calculation result. Therefore, according to this embodiment, the road surface height can be calculated based on the detection values ​​of each road surface sensor and the amount of movement of the vehicle V in the direction of travel.

[0089] The calculation and processing of the road surface height described above are performed by ECU 3. Figure 5 This is a flowchart illustrating the processing flow of the ECU 3 in the suspension system 1 of the vehicle V according to this embodiment. The ECU 3 repeats the process at predetermined intervals. Figure 5 The processing is shown.

[0090] In step S1, the forward road surface sensor value is acquired. Specifically, the forward road surface sensor value acquisition unit 31 acquires the detection value of the first road surface sensor 11. Then, the process proceeds to step S2.

[0091] In step S2, the forward road surface sensor value is acquired. Specifically, the rear road surface sensor value acquisition unit 32 acquires the detection value of the second road surface sensor 12. Then, the process proceeds to step S3.

[0092] In step S3, the vehicle movement amount is acquired. Specifically, the vehicle movement amount acquisition unit 33 acquires the movement amount of vehicle V in the driving direction. Then, proceed to step S4.

[0093] In step S4, the road surface height is calculated. Specifically, the road surface height calculation unit 34 calculates the road surface height based on the detection value of the first road surface sensor 11 obtained by the front road surface sensor value acquisition unit 31, the detection value of the second road surface sensor 12 obtained by the rear road surface sensor value acquisition unit 32, and the movement of the vehicle V in the driving direction obtained by the vehicle movement amount acquisition unit 33, using the aforementioned calculation logic. Then, the process proceeds to step S5.

[0094] In step S5, the electromagnetic damper 2 is controlled. Specifically, the damper control unit 35 controls the motor element 23 of the electromagnetic damper 2 based on the road surface height calculated in step S4. This concludes the process.

[0095] According to this embodiment, the following effects are achieved.

[0096] According to the suspension system 1 of the vehicle V in this embodiment, the road surface height is calculated based on the detection values ​​of the first road surface sensor 11 (serving as a front road surface sensor) and the second road surface sensor 12 (serving as a rear road surface sensor), along with the amount of movement of the vehicle V in the driving direction. The vehicle body B's sway, which is included in the detection values ​​of each road surface sensor, can be subtracted, thereby accurately and precisely calculating the road surface height. Furthermore, the motor element 23 of the electromagnetic shock absorber 2 can be controlled based on the accurately and precisely calculated road surface height, thus further improving the ride comfort of the vehicle V.

[0097] Next, variations of the above-described embodiments will be described.

[0098] In the above embodiment, the following structure is adopted: two road surface sensors are set at different positions in the forward and backward directions of the vehicle V to detect the same road surface twice, and the displacement of the vehicle body B and the road surface height are calculated based on the difference between the detection values ​​and the amount of movement of the vehicle V. This structure is effective when the vehicle V is traveling straight. On the other hand, when the vehicle V is turning, the two different road surface sensors may not pass through the same road surface. Therefore, there is still room for improvement in order to calculate the road surface height accurately and with good precision.

[0099] Here, Figure 6 This is a plan view of vehicle V according to the above-described implementation method when traveling straight. (Example) Figure 6 As shown, when vehicle V is traveling straight, the passing position of the first road surface sensor 11, which is the front road surface sensor, and the passing position of the second road surface sensor 12, which is the rear road surface sensor, are on the same road surface.

[0100] Figure 7 It is a diagram showing the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 when the vehicle is traveling in a fixed position without acceleration, deceleration, or turning. Figure 8 It is Figure 7 The graph shows the time axis of the detection values ​​from each road surface sensor combined. (Examples are provided.) Figure 7 and Figure 8 As shown, when driving in a fixed position without acceleration, deceleration, or turning, the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 are only offset in time. When the time axes are combined, the waveforms are almost identical and overlap.

[0101] Figure 9 It is a graph showing the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 during deceleration. Figure 10 It is Figure 9 The graph shows the time axis of the detection values ​​from each road surface sensor combined. (Examples are provided.) Figure 9 and Figure 10 As shown, during deceleration, the detection values ​​of the first road surface sensor 11 and the second road surface sensor 12 are not only detected at different times, but also have different waveforms due to the pitch P of the vehicle V. Therefore, even if the time axes are combined, they will not overlap. In this respect, in the above embodiment, as described above, by subtracting the vehicle body B sway included in the detection values ​​of each road surface sensor, the road surface height can be calculated accurately and with good precision.

[0102] In contrast, Figure 11 This is a plan view of vehicle V according to the above-described embodiment when turning. (Example) Figure 11 As shown, when the vehicle V turns, the passing position of the first road surface sensor 11, which is the front road surface sensor, and the passing position of the second road surface sensor 12, which is the rear road surface sensor, are not on the same road surface.

[0103] Therefore, in this modified example, a structure is adopted in which multiple rear road surface sensors are set in the vehicle width direction. Figure 12 This is a plan view of vehicle V in this modified example when traveling straight. For example... Figure 12 As shown, the rear road surface sensor of this modified example has a second road surface sensor 12 as a rear central road surface sensor, a third road surface sensor 13 as a rear inner road surface sensor, and a fourth road surface sensor 14 as a rear outer road surface sensor.

[0104] The second road surface sensor 12, serving as a rear center road surface sensor, is configured to overlap with the first road surface sensor 11, serving as a front road surface sensor, in the vehicle width direction. Specifically, the centers of the first road surface sensor 11 and the second road surface sensor 12 are on the same straight line in the vehicle's longitudinal direction. This is the same configuration and structure as in the embodiment described above.

[0105] The third road surface sensor 13, which serves as the rear inner road surface sensor, is located inside the second road surface sensor 12, which serves as the rear center road surface sensor, in the vehicle width direction. The detection signal from the third road surface sensor 13 is sent to the aforementioned rear road surface sensor value acquisition unit 32.

[0106] The fourth road surface sensor 14, which serves as the rear outer road surface sensor, is positioned outside the second road surface sensor 12, which serves as the rear center road surface sensor, in the vehicle width direction. The detection signal from the fourth road surface sensor 14 is sent to the aforementioned rear road surface sensor value acquisition unit 32.

[0107] Furthermore, the second road surface sensor 12, the third road surface sensor 13, and the fourth road surface sensor 14 are preferably arranged at equal intervals in the vehicle width direction. However, this is not a limitation; these three rear road surface sensors can be arranged in any way they are arranged in the vehicle width direction, and there is no restriction on the spacing between them.

[0108] Figure 13 This is a plan view of vehicle V in this modified example when turning. Additionally, Figure 14 yes Figure 13 The magnified view of the road surface sensor is a diagram showing the movement trajectory L of the first road surface sensor 11 during a turn. As these... Figure 13 and Figure 14 As shown, when the vehicle turns V, the passing position of the first road surface sensor 11, which acts as the front road surface sensor, does not overlap with any of the three rear road surface sensors (the second road surface sensor 12, the third road surface sensor 13, and the fourth road surface sensor 14). That is, it can be seen that none of the three rear road surface sensors will detect the same road surface as the first road surface sensor 11, which acts as the front road surface sensor.

[0109] Therefore, in this modified example, the road height calculation unit 34 uses the detection values ​​of three rear road surface sensors and interpolation processing to calculate the road height between the three rear road surface sensors at the position where the first road surface sensor 11, the front road surface sensor, passes. Specifically, as... Figure 14 The trajectory L of the first road surface sensor 11 is shown in the diagram. Assume the first road surface sensor 11 passes between the second road surface sensor 12 and the third road surface sensor 13. Now, let the detection value of the second road surface sensor 12 be x. 12The detection value of the third road surface sensor 13 is x 13 If the distance between the passing position of the first road surface sensor 11 and the center of the second road surface sensor 12 in the vehicle width direction is D1, and the distance between the passing position of the first road surface sensor 11 and the center of the third road surface sensor 13 in the vehicle width direction is D2, then by interpolation processing and using the following mathematical formula (18), the detection value x of the road surface sensor behind the position through which the first road surface sensor 11 passes can be estimated.

[0110] x = x 12 ×D1 / (D1+D2)+x 13 ×D2 / (D1+D2)…Mathematical expression (18)

[0111] Here, Figure 15 This is a graph showing the detection values ​​of the second road surface sensor 12 and the third road surface sensor 13. Figure 16 This is a diagram illustrating the estimated value of the road surface sensor behind the position traversed by the first road surface sensor 11, which was estimated by interpolation using the detection values ​​of the second road surface sensor 12 and the third road surface sensor 13 as described above. Additionally, Figure 17 This is a graph showing the estimated value of the road surface sensor behind the position through which the first road surface sensor 11 has passed, as determined by interpolation, and the detection value of the first road surface sensor 11. Thus, by using the detection value of the first road surface sensor 11 (which serves as the front road surface sensor) and the estimated value of the road surface sensor behind the position through which the first road surface sensor 11 has passed, as determined by interpolation, the road surface height is calculated by the road surface height calculation unit 34 in the same manner as in the above embodiment, allowing for a more accurate and precise calculation of the road surface height.

[0112] Furthermore, for example, the passing position of the first road surface sensor 11 can be estimated based on the steering wheel angle detected by the steering angle sensor (not shown). Alternatively, the passing position of the first road surface sensor 11 can be estimated based on the vehicle speed detected by the vehicle speed sensor (not shown).

[0113] According to this modified example, since the rear road surface sensor has a second road surface sensor 12 as the rear center road surface sensor, a third road surface sensor 13 as the rear inner road surface sensor, and a fourth road surface sensor 14 as the rear outer road surface sensor arranged in the vehicle width direction, even when the vehicle is turning in V, the detection values ​​of multiple rear road surface sensors can be used to interpolate and calculate the road surface height at the position where the front road surface sensor (first road surface sensor 11) between multiple rear road surface sensors passes, thereby accurately and precisely calculating the road surface height.

[0114] Furthermore, this disclosure is not limited to the above-described forms, and variations and improvements within the scope of achieving the purpose of this disclosure are included in this disclosure.

[0115] In a variation of the above embodiment, multiple rear road surface sensors are provided in the vehicle width direction, but this is not a limitation. For example, multiple front road surface sensors can be provided in the vehicle width direction, or multiple front road surface sensors and rear road surface sensors can be provided in the vehicle width direction.

[0116] In a variation of the above embodiment, three rear road surface sensors are provided in the vehicle width direction, but this is not a limitation; more than three sensors may be provided. Similarly, if multiple front road surface sensors are provided in the vehicle width direction, the number is not limited to three; more than three sensors may be provided.

[0117] Figure Labels

[0118] 1: Vehicle suspension system

[0119] 11: First road surface sensor (front road surface sensor)

[0120] 12: Second road surface sensor (rear road surface sensor, rear center road surface sensor)

[0121] 13: Third road surface sensor (rear road surface sensor, rear inner road surface sensor)

[0122] 14: Fourth road surface sensor (rear road surface sensor, rear outer road surface sensor)

[0123] 2: Electromagnetic shock absorber (vibration damper)

[0124] 21: Elements of a shock absorber

[0125] 22: Spring Elements

[0126] 23: Motor Element (Actuator)

[0127] 3: ECU (Electronic Control Unit)

[0128] 31: Forward Road Surface Sensor Value Acquisition Unit

[0129] 32: Rear Road Surface Sensor Value Acquisition Unit

[0130] 33: Vehicle Mobility Acquisition Department

[0131] 34: Road Surface Height Calculation Department

[0132] 35: Shock absorber control unit

[0133] V: Vehicle

[0134] B: Body

[0135] Fw: Front wheel

[0136] T: Tire

[0137] P: Pitch

[0138] R: Road surface

[0139] S: Step difference

[0140] L: Trajectory

[0141] E b Spring-loaded components (body)

[0142] E t : Lower spring component (wheel)

[0143] M b Mass on the spring

[0144] M t : lower mass of the spring

[0145] Ks: Spring coefficient of the spring element

[0146] Kt: Tire spring rate

[0147] Cs: Viscous damping coefficient of the shock absorber element

[0148] Ct: Tire viscosity decay coefficient

[0149] x b Vehicle displacement

[0150] x 11 : Front road sensor value

[0151] x 12 Rear road surface sensor value

[0152] x r Road surface height

Claims

1. A vehicle suspension system, comprising: The road surface sensor is located on the part of the vehicle body further forward than the front wheels to detect the unevenness of the road surface; A shock absorber, disposed between the upper spring component of the vehicle (i.e., the body) and the lower spring component (i.e., the wheel), applies damping force and propulsive force along the stroke direction to the aforementioned body and the aforementioned wheel via an actuator; and, The control device controls the actuator based on the detection values ​​from the aforementioned road surface sensors; and, The aforementioned road surface sensor has the following characteristics: Forward road surface sensor; and, The rear road surface sensor overlaps with the aforementioned front road surface sensor in the vehicle width direction, and is positioned further rearward than the aforementioned front road surface sensor; furthermore, The aforementioned control device includes: The vehicle movement acquisition unit acquires the movement of the aforementioned vehicles; The road surface height calculation unit calculates the road surface height based on the detection values ​​from the aforementioned road surface sensors and the vehicle movement amount acquired by the aforementioned vehicle movement amount acquisition unit; and, The shock absorber control unit controls the aforementioned actuator based on the road surface height calculated by the aforementioned road surface height calculation unit, wherein... At least one of the aforementioned front road surface sensor and the aforementioned rear road surface sensor has the following characteristics: The central road surface sensor overlaps with another sensor in the vehicle width direction. The inner road surface sensor is located inside the aforementioned central road surface sensor in the vehicle width direction; and, The outer road surface sensor is located outside the aforementioned central road surface sensor in the vehicle width direction.

2. The vehicle suspension system according to claim 1, wherein, The aforementioned rear road surface sensor has the following features: The rear center road surface sensor overlaps with the aforementioned front road surface sensor in the vehicle width direction. The rear inner road surface sensor is located inside the aforementioned rear central road surface sensor in the vehicle width direction; and, The rear outer road surface sensor is located outside the aforementioned rear central road surface sensor in the vehicle width direction; and, The aforementioned road height calculation unit uses the detection values ​​of multiple aforementioned rear road surface sensors to calculate the road height at the position where the aforementioned front road surface sensor passes between the multiple aforementioned rear road surface sensors by interpolation.

Images