Control map management method and management system

Abstract

When performing vibration damping control using a control map that represents the correspondence between position and parameters related to the vertical movement of reference points based on the positions of two or more wheels of the vehicle, the left and right wheel out-of-phase inputs and left and right wheel in-phase inputs are appropriately reflected in this vibration damping control. [Solution] First and second parameter maps used for vibration control of the vehicle are generated or updated. In the generation or update of the first parameter map, the in-phase inputs of the left and right wheels of the first and second wheels are calculated as the first parameter related to the vertical motion of the reference point. The generation or update of the second parameter map is performed at the same position where the generation or update of the first parameter map is performed. In the generation or update of the second parameter map, the out-of-phase inputs of the left and right wheels of the first and second wheels are calculated as the second parameter related to the vertical motion of the reference point.

Description

Technical Field

[0001] The present disclosure relates to a technique for managing a control map used for vibration control of a vehicle.

Background Art

[0002] Patent Document 1 discloses a road surface displacement map representing the correspondence between road surface displacement (road surface unevenness) and position. By using such a road surface displacement map, vibration control is performed. Specifically, the road surface displacement at a predetermined position in front of the vehicle is recognized in advance from the road surface displacement map. The control amount of the active suspension is calculated in advance according to the pre-recognized road surface displacement. Then, by controlling the active suspension at the timing when the wheel passes through the predetermined position, the vibration of the vehicle is effectively suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, when creating the road surface displacement map, filtering processing is performed to cut off frequencies significantly lower than the vehicle body frequency and frequencies significantly higher than the vehicle body frequency from the road surface state data. Here, the road surface state data can be said to be data of parameters related to road surface displacement. Also, the data of parameters related to road surface displacement can also be said to be data of parameters related to the vertical movement of the wheel in contact with the road surface.

[0005] This disclosure considers the creation of a control map that represents the correspondence between position and parameters related to the vertical motion of a reference point based on the positions of two or more wheels of a vehicle. Such a control map can be created, for example, using time-series data of parameters related to the vertical motion of each wheel. However, the parameters related to the vertical motion of each wheel include extremely low-frequency components originating from altitude changes, etc. Therefore, when creating the control map, it is desirable to perform filtering using a high-pass filter to cut out the extremely low-frequency components from the parameters related to the vertical motion of each wheel. However, if an excessively strong high-pass filter is used, the out-of-phase inputs of the left and right wheels, which originate from the different vertical displacements of the left and right wheels, will also be cut out.

[0006] When vibration damping control is performed using a control map created from time-series data from which the left and right wheel inverse phase inputs have been cut, these left and right wheel inverse phase inputs are not reflected in the vibration damping control, resulting in a decrease in the control effect. This problem can be solved by using a weak high-pass filter in the filtering process. However, in this case, the left and right wheel in-phase inputs, which originate from the same vertical displacement of the left and right wheels that are susceptible to changes in altitude, remain. Consequently, in vibration damping control using a control map, an excessive amount of control to try to cancel out the left and right wheel in-phase inputs may reduce the control effect.

[0007] One object of this disclosure is to provide a technology that can appropriately reflect left and right wheel out-of-phase inputs and left and right wheel in-phase inputs in vibration damping control when performing vibration damping control using a control map that represents the correspondence between position and parameters related to the vertical movement of reference points based on the positions of two or more wheels of a vehicle. [Means for solving the problem]

[0008] The first aspect of this disclosure is a method for managing control maps used for vibration control of a vehicle, which is performed by a computer and has the following features: The control map includes first and second parameter maps. The first and second parameter maps represent, respectively, the correspondence between position and parameters related to the vertical movement of a reference point based on the positions of two or more wheels of the vehicle. The method includes generating or updating the first parameter map, and generating or updating the second parameter map at the same location where the first parameter map is generated or updated. Generating or updating the first parameter map includes calculating a left-right wheel in-phase input derived from the same vertical displacement of the first and second wheels as a first parameter related to the vertical motion of the reference point, based on time-series data of parameters related to the vertical motion of the first wheel of the vehicle and time-series data of parameters related to the vertical motion of the second wheels of the vehicle which constitute the left and right wheels together with the first wheel. Generating or updating the second parameter map includes calculating left and right wheel out-of-phase inputs derived from the different vertical displacements of the first and second wheels as time-series data of the second parameter related to the vertical motion of the reference point, based on time-series data of the parameter related to the vertical motion of the first wheel and time-series data of the parameter related to the vertical motion of the second wheel.

[0009] The second aspect of this disclosure has the following characteristics in the first aspect: Generating or updating the first parameter map includes filtering the left and right wheel in-phase inputs using a first high-pass filter. Generating or updating the second parameter map further includes filtering the left and right wheel out-of-phase inputs using a second high-pass filter. The second high-pass filter is weaker than the first high-pass filter.

[0010] The third aspect of this disclosure is a system for managing control maps used for vibration control of a vehicle, and has the following features: The system comprises one or more processors and one or more storage devices for storing the control map. The control map includes first and second parameter maps. The first and second parameter maps represent, respectively, the correspondence between position and parameters related to the vertical movement of a reference point based on the positions of two or more wheels of the vehicle. The one or more processors are configured to perform the following: generating or updating the first parameter map; and generating or updating the second parameter map at the same location where the first parameter map is generated or updated. The process of generating or updating the first parameter map includes a process of calculating a left-right wheel in-phase input derived from the same vertical displacement of the first wheel and the second wheel as a first parameter related to the vertical movement of the reference point, based on time-series data of parameters related to the vertical movement of the first wheel of the vehicle and time-series data of parameters related to the vertical movement of the second wheel of the vehicle which constitutes the left and right wheels together with the first wheel. The process of generating or updating the second parameter map includes a process of calculating left and right wheel out-of-phase inputs derived from the different vertical displacements of the first and second wheels as time-series data of the second parameter related to the vertical movement of the reference point, based on time-series data of the parameter related to the vertical movement of the first wheel and time-series data of the parameter related to the vertical movement of the second wheel.

[0011] The fourth aspect of this disclosure has the following characteristics in the third aspect: The process of generating or updating the first parameter map further includes filtering the in-phase inputs of the left and right wheels of the first and second wheels using a first high-pass filter. The process of generating or updating the second parameter map further includes filtering the out-of-phase inputs of the left and right wheels of the first and second wheels using a second high-pass filter. The second high-pass filter is weaker than the first high-pass filter. [Effects of the Invention]

[0012] According to the first or third viewpoint, first and second parameter maps used for vibration damping control of the vehicle are generated or updated. In the generation or update of the first parameter map, the in-phase inputs of the left and right wheels of the first and second wheels are calculated as the first parameter related to the vertical motion of the reference point. The generation or update of the second parameter map is performed at the same position where the generation or update of the first parameter map is performed. In the generation or update of the second parameter map, the out-of-phase inputs of the left and right wheels of the first and second wheels are calculated as the second parameter related to the vertical motion of the reference point. Therefore, in vibration damping control using the first and second parameter maps, it is possible to appropriately reflect the in-phase inputs of the left and right wheels as the first parameter and the out-of-phase inputs of the left and right wheels as the second parameter in the vibration damping control.

[0013] According to the second or fourth viewpoint, a first high-pass filter is used to generate or update the first parameter map, and a second high-pass filter weaker than the first is used to generate or update the second parameter map. As a result, it is possible to generate or update a first parameter map from which extremely low-frequency components originating from altitude changes, etc., are cut out, and to generate or update a second parameter map from which the left and right wheel out-of-phase inputs remain. Thus, it is possible to enhance the effects according to the first or third viewpoint. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing an example of the vehicle configuration according to the embodiment. [Figure 2] This is a conceptual diagram showing an example of the suspension configuration according to the embodiment. [Figure 3] This is a flowchart showing an example of the process for calculating unsprung displacement. [Figure 4] This is a block diagram showing an example configuration of a vehicle control system according to an embodiment. [Figure 5] This block diagram shows an example of driving environment information according to the embodiment. [Figure 6] This block diagram shows an example configuration of a map management system according to an embodiment. [Figure 7] It is a conceptual diagram for explaining the under-spring displacement map according to an embodiment. [Figure 8] It is a flowchart showing the map generation / update process according to an embodiment. [Figure 9] It is a conceptual diagram showing an example of the under-spring displacement map according to an embodiment. [Figure 10] It is a conceptual diagram showing another example of the under-spring displacement map according to an embodiment. <了 [Figure 11] It is a conceptual diagram for explaining preview control using the under-spring displacement map according to an embodiment. [Figure 12] It is a flowchart showing preview control using the under-spring displacement map according to an embodiment.

Mode for Carrying Out the Invention

[0015] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0016] 1. Suspension and vertical motion parameters FIG. 1 is a schematic diagram showing a configuration example of a vehicle 1 according to an embodiment. The vehicle 1 includes wheels 2 and a suspension 3. The wheels 2 include a left front wheel 2FL, a right front wheel 2FR, a left rear wheel 2RL, and a right rear wheel 2RR. The left front wheel 2FL and the right front wheel 2FR form left and right wheels on the front wheel axle side, and the left rear wheel 2RL and the right rear wheel 2RR form left and right wheels on the rear wheel axle side. Suspensions 3FL, 3FR, 3RL, and 3RR are provided for each of the left front wheel 2FL, the right front wheel 2FR, the left rear wheel 2RL, and the right rear wheel 2RR. In the following description, when there is no particular need for distinction, each wheel will be referred to as the wheel 2 and each suspension will be referred to as the suspension 3.

[0017] Figure 2 is a conceptual diagram showing an example configuration of the suspension 3. The suspension 3 is provided to connect the unsprung structure 4 and the sprung structure 5 of the vehicle 1. The unsprung structure 4 includes the wheels 2. The suspension 3 includes a spring 3S, a damper (shock absorber) 3D, and an actuator 3A. The spring 3S, damper 3D, and actuator 3A are provided in parallel between the unsprung structure 4 and the sprung structure 5. The spring constant of the spring 3S is K. The damping coefficient of the damper 3D is C. The damping force of the damper 3D may be variable. The actuator 3A applies a vertical control force Fc between the unsprung structure 4 and the sprung structure 5.

[0018] Here, we define the terms. "Road surface displacement Zr" is the vertical displacement of the road surface RS. "Unsprung displacement Zu" is the vertical displacement of the unsprung structure 4. "Sprung displacement Zs" is the vertical displacement of the sprung structure 5. "Unsprung velocity Zu'" is the vertical velocity of the unsprung structure 4. "Sprung velocity Zs'" is the vertical velocity of the sprung structure 5. "Unsprung acceleration Zu''" is the vertical acceleration of the unsprung structure 4. "Sprung acceleration Zs''" is the vertical acceleration of the sprung structure 5. Note that the sign of each parameter is positive when it is upward and negative when it is downward.

[0019] Wheel 2 moves on the road surface RS. As Wheel 2 moves on the road surface RS, the road surface displacement Zr causes the "reference point Pr" of Vehicle 1 to move up and down. The reference point Pr is set at an arbitrary position on Vehicle 1 based on the positions of two or more wheels on Vehicle 1. Examples of reference point Pr include the front wheel tread position (midpoint between the left front wheel 2FL and the right front wheel 2FR), the rear wheel tread position (midpoint between the left rear wheel 2RL and the right rear wheel 2RR), and the center position of Vehicle 1. The reference point Pr may be set separately on the front axle side and the rear axle side of Vehicle 1. In this case, the front wheel tread position is exemplified as reference point Pr1 on the front axle side, and the rear wheel tread position is exemplified as reference point Pr2 on the rear axle side. In this embodiment, an example in which reference points Pr1 and Pr2 are set at the front wheel tread position and the rear wheel tread position is described.

[0020] In the following explanation, parameters related to the vertical motion of reference points Pr1 and Pr2 are referred to as "vertical motion parameters." Examples of vertical motion parameters include the road surface displacement Zr, unsprung displacement Zu, unsprung velocity Zu', unsprung acceleration Zu'', sprung displacement Zs, sprung velocity Zs', sprung acceleration Zs'', etc. It can also be said that the vertical motion parameters are "road surface displacement parameters" related to the road surface displacement Zr.

[0021] As an example, the following explanation considers the case where the vertical motion parameters of reference points Pr1 and Pr2 are the unsprung displacement Zu. When generalizing, replace "unsprung displacement" with "vertical motion parameters" in the following explanation.

[0022] Figure 3 is a flowchart showing an example of the process for calculating unsprung displacement.

[0023] In step S11, the sprung mass acceleration Zs'' is detected by the sprung mass acceleration sensor 22 installed on the sprung mass structure 5. In step S12, the sprung mass displacement Zs is calculated by performing a second integral of the sprung mass acceleration Zs''.

[0024] In step S13, the stroke ST (=Zs-Zu), which is the relative displacement between the sprung mass structure 5 and the unsprung mass structure 4, is obtained. For example, the stroke ST is detected by a stroke sensor installed on the suspension 3. As another example, the stroke ST may be estimated based on the sprung mass acceleration Zs'' by an observer configured based on a single-wheel two-degree-of-freedom model.

[0025] In step S14, the difference between the sprung displacement Zs and the stroke ST is calculated as the unsprung displacement Zu.

[0026] As another example, the unsprung acceleration Zu'' may be detected by an unsprung acceleration sensor, and the unsprung displacement Zu may be calculated from the unsprung acceleration Zu''.

[0027] 2. Vehicle control system 2-1. Example Configuration Figure 4 is a block diagram showing an example configuration of a vehicle control system 10 according to an embodiment. The vehicle control system 10 is mounted on a vehicle 1 and controls the vehicle 1. The vehicle control system 10 includes a vehicle state sensor 20, a recognition sensor 30, a position sensor 40, a communication device 50, a driving device 60, and a control device 70.

[0028] The vehicle state sensor 20 detects the state of vehicle 1. The vehicle state sensor 20 includes a vehicle speed sensor (wheel speed sensor) 21 for detecting the vehicle speed V of vehicle 1, a sprung mass acceleration sensor 22 for detecting the sprung mass acceleration Zs'', etc. The vehicle state sensor 20 may also include a stroke sensor 23 for detecting the stroke ST. The vehicle state sensor 20 may also include an unsprung mass acceleration sensor. In addition, the vehicle state sensor 20 may include a lateral acceleration sensor, a yaw rate sensor, a steering angle sensor, etc.

[0029] The recognition sensor 30 recognizes (detects) the surrounding environment of the vehicle 1. Examples of recognition sensors include cameras, LIDAR (Laser Imaging Detection and Ranging), radar, etc.

[0030] The position sensor 40 detects the position and orientation of vehicle 1. For example, the position sensor 40 includes a GNSS (Global Navigation Satellite System).

[0031] The communication device 50 communicates with the outside of the vehicle 1.

[0032] The running gear 60 includes a steering gear 61, a drive gear 62, a braking gear 63, and a suspension 3 (see Figure 2). The steering gear 61 steers the wheels 2. For example, the steering gear 61 includes an electric power steering (EPS) system. The drive gear 62 is a power source that generates driving force. Examples of the drive gear 62 include an engine, an electric motor, an in-wheel motor, etc. The braking gear 63 generates braking force.

[0033] The control device 70 is a computer that controls the vehicle 1. The control device 70 includes one or more processors 71 (hereinafter simply referred to as processor 71) and one or more storage devices 72 (hereinafter simply referred to as storage devices 72). The processor 71 performs various processes. For example, the processor 71 includes a CPU (Central Processing Unit). The storage devices 72 store various information necessary for processing by the processor 71. Examples of storage devices 72 include volatile memory, non-volatile memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The control device 70 may also include one or more ECUs (Electronic Control Units).

[0034] The vehicle control program 80 is a computer program for controlling vehicle 1 and is executed by the processor 71. The vehicle control program 80 is stored in the storage device 72. Alternatively, the vehicle control program 80 may be recorded on a computer-readable recording medium. The processor 71 executes the vehicle control program 80, thereby realizing the functions of the control device 70.

[0035] 2-2. Driving Environment Information Figure 5 is a block diagram showing an example of driving environment information 90 indicating the driving environment of vehicle 1. The driving environment information 90 is stored in the storage device 72. The driving environment information 90 includes map information 91, vehicle status information 92, surrounding conditions information 93, and location information 94.

[0036] Map information 91 includes a general navigation map. Map information 91 may show lane layouts, road shapes, etc. Map information 91 may also include location information such as white lines, traffic lights, signs, and landmarks. Map information 91 is obtained from a map database. The map database may be installed in the vehicle 1 or stored on an external management server. In the latter case, the control device 70 communicates with the management server to obtain the necessary map information 91.

[0037] Map information 91 further includes an "unsprung displacement map 200". The unsprung displacement map 200 is associated with reference points Pr1 and Pr2, respectively. Details of the unsprung displacement map 200 will be described later.

[0038] Vehicle status information 92 is information indicating the state of vehicle 1. The control device 70 acquires vehicle status information 92 from the vehicle status sensor 20. For example, vehicle status information 92 includes vehicle speed V, sprung mass acceleration Zs'', stroke ST, lateral acceleration, yaw rate, steering angle, etc. Vehicle speed V may be calculated from the vehicle position detected by the position sensor 40. The control device 70 may also calculate the unsprung mass displacement Zu using the method shown in Figure 3. In that case, vehicle status information 92 also includes the unsprung mass displacement Zu calculated by the control device 70.

[0039] The surrounding situation information 93 is information that indicates the conditions around the vehicle 1. The control device 70 recognizes the conditions around the vehicle 1 using the recognition sensor 30 and acquires the surrounding situation information 93. For example, the surrounding situation information 93 includes image information captured by a camera. As another example, the surrounding situation information 93 includes point cloud information obtained by a LIDAR.

[0040] The surrounding environment information 93 further includes "object information" concerning objects around vehicle 1. Examples of objects include pedestrians, bicycles, other vehicles (preceding vehicles, parked vehicles, etc.), road configurations (white lines, curbs, guardrails, walls, median strips, roadside structures, etc.), signs, poles, obstacles, etc. The object information indicates the relative position and relative velocity of the object with respect to vehicle 1. For example, by analyzing image information obtained by a camera, an object can be identified and its relative position can be calculated. Alternatively, an object can be identified and its relative position and relative velocity can be obtained based on point cloud information obtained by LIDAR.

[0041] The location information 94 is information indicating the position and orientation of vehicle 1. The control device 70 acquires the location information 94 from the detection results of the position sensor 40. Alternatively, the control device 70 may acquire highly accurate location information 94 by using a well-known self-position estimation process (localization) that utilizes object information and map information 91.

[0042] 2-3. Vehicle Control The control device 70 performs vehicle driving control to control the movement of the vehicle 1. Vehicle driving control includes steering control, drive control, and braking control. The control device 70 performs vehicle driving control by controlling the driving devices 60 (steering device 61, drive device 62, and braking device 63). The control device 70 may also perform driving assistance control to assist the driving of the vehicle 1 based on driving environment information 90. Examples of driving assistance control include lane keeping control, collision avoidance control, and automatic driving control.

[0043] Furthermore, the control device 70 controls the suspension 3. Typically, the control device 70 controls the suspension 3 to perform vibration damping control to suppress vibrations of the vehicle 1. For example, the control device 70 controls the actuator 3A to generate a vertical control force Fc between the unsprung mass structure 4 and the sprung mass structure 5 (see Figure 2). In another example, the control device 70 may variably control the damping force of the damper 3D. The vibration damping control includes "preview control," which will be described later.

[0044] 3. Map Management System 3-1. Example Configuration Figure 6 is a block diagram showing an example configuration of a map management system 100 according to an embodiment. The map management system 100 is a computer that manages various types of map information. The management of map information includes the generation, updating, provision, and distribution of map information. Typically, the map management system 100 is a management server on the cloud. The map management system 100 may also be a distributed system in which multiple servers perform distributed processing.

[0045] The map management system 100 includes a communication device 110. The communication device 110 is connected to a communication network NET. For example, the communication device 110 communicates with a number of vehicles 1 via the communication network NET.

[0046] The map management system 100 further includes one or more processors 120 (hereinafter simply referred to as processor 120) and one or more storage devices 130 (hereinafter simply referred to as storage devices 130). The processor 120 performs various information processing. For example, the processor 120 includes a CPU. The storage devices 130 store various map information. The storage devices 130 also store various information necessary for processing by the processor 120. Examples of storage devices 130 include volatile memory, non-volatile memory, HDD, SSD, etc.

[0047] The map management program 140 is a computer program for map management and is executed by the processor 120. The map management program 140 is stored in the storage device 130. Alternatively, the map management program 140 may be recorded on a computer-readable recording medium. The execution of the map management program 140 by the processor 120 realizes the functions of the map management system 100.

[0048] The processor 120 communicates with the vehicle control system 10 of the vehicle 1 via the communication device 110. The processor 120 collects various information from the vehicle control system 10 and generates and updates map information based on the collected information. The processor 120 also distributes the map information to the vehicle control system 10. Furthermore, the processor 120 provides map information in response to requests from the vehicle control system 10.

[0049] 3-2. Unsprung Displacement Map One of the map information managed by the map management system 100 is the "unsprung displacement map (vertical motion parameter map) 200". The unsprung displacement map 200 is a map relating to the unsprung displacement Zu (vertical motion parameter). The unsprung displacement map 200 is stored in the memory device 130.

[0050] Figure 7 is a conceptual diagram illustrating the unsprung displacement map 200. The absolute coordinate system in the horizontal plane is defined, for example, by the latitude and longitude directions. The position in the horizontal plane is defined, for example, by latitude LAT and longitude LON. The unsprung displacement map 200 represents the correspondence between position (LAT, LON) and unsprung displacement Zu. In other words, the unsprung displacement map 200 expresses the unsprung displacement Zu as a function of position (LAT, LON).

[0051] The road area is divided into a mesh-like structure on a horizontal plane, for example. In other words, the road area is divided into multiple unit areas M on a horizontal plane. A unit area M is, for example, a square. The length of one side of the square is, for example, 10 cm. The unsprung displacement map 200 represents the correspondence between the position of a unit area M and the unsprung displacement Zu. The position of a unit area M may be defined by a representative position of that unit area M (e.g., the center position), or by the range of that unit area M (latitude range, longitude range). The unsprung displacement Zu of a unit area M is, for example, the average value of the unsprung displacement Zu obtained within that unit area M. The smaller the unit area M, the higher the resolution of the unsprung displacement map 200.

[0052] 3-3. Map generation / update process The processor 120 collects information from multiple vehicles 1 via the communication device 110. Based on the information collected from the multiple vehicles 1, the processor 120 generates and updates the unsprung displacement map 200. An example of the map generation / update process will be described in more detail below.

[0053] The positions in the unsprung displacement map 200 are the positions that reference points Pr1 and Pr2 pass through, respectively. Reference points Pr1 and Pr2 are calculated based on the position information 94 described above. Specifically, the relative positional relationship between the position of each wheel 2 and the reference position of the vehicle 1 for the position information 94 is known information. Also, the relative positional relationship between the position of each wheel 2 and reference points Pr1 and Pr2 is known information. Based on these relative positional relationships and the vehicle reference position indicated by the position information 94, the positions of reference points Pr1 and Pr2 can be calculated.

[0054] The unsprung displacement Zu is calculated using the method shown in Figure 3. Specifically, the sprung displacement Zs and stroke ST are obtained using the vehicle state sensor 20 mounted on the vehicle 1. For convenience, these sprung displacement Zs and stroke ST are referred to as "sensor-based information." The unsprung displacement Zu is calculated based on this sensor-based information.

[0055] For example, the control device 70 of the vehicle control system 10 associates the position of wheel 2 at the same time with sensor-based information. The control device 70 then transmits a set of time-series data of the position of wheel 2 and time-series data of sensor-based information to the map management system 100. The processor 120 of the map management system 100 calculates the unsprung displacement Zu based on the received sensor-based information. Furthermore, the processor 120 generates and updates the unsprung displacement map 200 based on the time-series data of the position of wheel 2 and the time-series data of the unsprung displacement Zu.

[0056] Furthermore, when calculating the unsprung displacement Zu in the map management system 100, there are no processing time constraints, so filtering can be performed using a zero-phase filter. By using a zero-phase filter, "phase shift" can be prevented.

[0057] Figure 8 is a flowchart showing the map generation / update process according to the embodiment.

[0058] In step S21, the processor 120 of the map management system 100 acquires "map update information" from the vehicle 1 (vehicle control system 10) via the communication device 110. The map update information includes time-series data of the position of the wheel 2. The map update information also includes time-series data of sensor-based information (e.g., sprung displacement Zs and stroke ST) necessary for calculating the unsprung displacement Zu. Alternatively, the map update information may include time-series data of the unsprung displacement Zu calculated by the control device 70 of the vehicle control system 10.

[0059] In step S22, the processor 120 of the map management system 100 decomposes the unsprung displacement Zu into left and right wheel in-phase inputs Zuin and left and right wheel out-of-phase inputs Zuan. When reference points Pr1 and Pr2 are set at the front wheel tread position and rear wheel tread position, the left and right wheel in-phase inputs Zufin and left and right wheel out-of-phase inputs Zufan on the front axle side are expressed by the following equations (1) and (2), and the left and right wheel in-phase inputs Zurin and left and right wheel out-of-phase inputs Zuran on the rear axle side are expressed by the following equations (3) and (4).

[0060]

number

[0061] In equations (1)-(4), Zufl represents the unsprung displacement Zu of the left front wheel 2FL, and Zufr represents the unsprung displacement Zu of the right front wheel 2FR, which together with the left front wheel 2FL constitute the front wheel. Zurl represents the unsprung displacement Zu of the left rear wheel 2RL, and Zurr represents the unsprung displacement Zu of the right rear wheel 2RR, which together with the left rear wheel 2RL constitute the rear wheel.

[0062] In another example, the processor 120 of the map management system 100 further decomposes the left and right wheel in-phase input Zuin into a front and rear wheel in-phase input (heave) Zuin derived from the same vertical displacement of the front and rear wheels of the vehicle 1, and a front and rear wheel out-of-phase input (pitch) Zuan derived from the different vertical displacements of the front and rear wheels. Here, the front and rear wheels refer to the combination of the left front wheel 2FL and the right front wheel 2FR, and the left rear wheel 2RL and the right rear wheel 2RR. In this case, the decomposed front and rear wheel in-phase input Zuin, i.e., the left and right wheel in-phase and front and rear wheel in-phase input Zuin-in, is expressed by the following equation (5). Also, the decomposed front and rear wheel out-of-phase input Zuan, i.e., the left and right wheel in-phase and front and rear wheel out-of-phase input Zuin-an, is expressed by the following equation (6).

[0063]

number

[0064] In step S23, filtering is performed on the left and right wheel in-phase input Zuin and the left and right wheel out-of-phase input Zuan. A first high-pass filter is applied to the left and right wheel in-phase input Zuin to cut out extremely low frequency components (e.g., components below 0.5 Hz) that originate from altitude changes, etc. On the other hand, a second high-pass filter is applied to the left and right wheel out-of-phase input Zuan to leave in extremely low frequency components (e.g., components above 0.2 Hz). In other words, the first high-pass filter applied to the left and right wheel in-phase input Zuin is a stronger high-pass filter than the second high-pass filter applied to the left and right wheel out-of-phase input Zuan. Here, "strong high-pass filter" means a high cutoff frequency (low frequency side), a high filter order, or a large number of filter stages.

[0065] The unsprung displacement Zu includes extremely low-frequency components (e.g., components below 0.5 Hz) originating from altitude changes, etc. However, these extremely low-frequency components also include the out-of-phase inputs of the left and right wheels. In this regard, in step S23, a relatively strong first high-pass filter is applied to the filtering process for the in-phase input Zuin of the left and right wheels. This cuts out the extremely low-frequency components originating from altitude changes, etc., from the in-phase input Zuin of the left and right wheels. On the other hand, a relatively weak second high-pass filter is applied to the filtering process for the out-of-phase input Zuan of the left and right wheels. This prevents the extremely low-frequency components from being cut out by the filtering process for the out-of-phase input Zuan of the left and right wheels.

[0066] In another example of step S22, in step S23, a second high-pass filter is applied to the left and right wheel in-phase input Zuan. Meanwhile, a third high-pass filter (first sub-high-pass filter) is applied to the left and right wheel in-phase and front and rear wheel in-phase input Zuin-in, which is generated by decomposing the left and right wheel in-phase input Zuin, to cut out extremely low frequency components (e.g., components below 0.5 Hz) originating from altitude changes, etc. Meanwhile, a fourth high-pass filter (second sub-high-pass filter) is applied to the left and right wheel in-phase and front and rear wheel in-phase input Zuin-an to retain extremely low frequency components (e.g., components above 0.4 Hz). In other words, the third high-pass filter applied to the left and right wheel in-phase and front and rear wheel in-phase input Zuin-in is a stronger high-pass filter than the fourth high-pass filter applied to the left and right wheel in-phase and front and rear wheel in-phase input Zuin-an. The fourth high-pass filter applied to the Zuin-an input, which is in phase with the left and right wheels and out of phase with the front and rear wheels, is a stronger high-pass filter than the second high-pass filter applied to the Zuin-an input, which is out of phase with the left and right wheels.

[0067] The reason why a third high-pass filter, which is relatively strong in filtering inputs Zuin-in (where both left and right wheels are in phase and front and rear wheels are in phase), is applied, and why a fourth high-pass filter, which is relatively weak in filtering inputs Zuin-an (where both left and right wheels are in phase and front and rear wheels are out of phase), is applied, is the same reason as the reason for using the first and second high-pass filters differently.

[0068] In step S24, the processor 120 of the map management system 100 synchronizes the position information and the sensor base information. For example, the processor 120 associates the position of wheel 2 with the sensor base information at the same timing, taking into account the delay in the position information, the delay in the sensor base information, and the difference in the sampling period. The processor 120 may either supplement the sensor base information with a longer sampling period to match the sensor base information with a shorter sampling period, or it may perform resampling. If the association and other processing have already been performed by the vehicle control system 10, the processing by the processor 120 is omitted. Then, the processor 120 calculates the positions of reference points Pr1 and Pr2 from the position of each wheel 2, and associates the positions of reference points Pr1 and Pr2 at the same timing with the left and right wheel in-phase input Zuin and left and right wheel out-of-phase input Zuan after filtering.

[0069] In step S25, the processor 120 of the map management system 100 searches for the mesh division closest to the positions of reference points Pr1 and Pr2 and generates / updates the unsprung displacement Zu (i.e., the left and right wheel in-phase input Zuin and left and right wheel out-of-phase input Zuan shown in equations (1)-(4)). The update of the unsprung displacement Zu is performed, for example, using the following equation (7).

[0070]

number

[0071] In equation (7), Zold is the unsprung displacement Zu originally included in the mesh section, Nold is the counter value for this mesh section, Znow is the current unsprung displacement Zu, and Znew is the updated unsprung displacement Zu.

[0072] Figure 9 is a conceptual diagram showing an example of an unsprung displacement map 200. In the example shown in Figure 9, the unsprung displacement map 200 includes a first unsprung displacement map (first parameter map) 210 and a second unsprung displacement map (second parameter map) 220. The first unsprung displacement map 210 is an unsprung displacement map that represents the correspondence between position (LAT, LON) and the left and right wheel in-phase input Zuin. The second unsprung displacement map 220 is an unsprung displacement map that represents the correspondence between position (LAT, LON) and the left and right wheel out-of-phase input Zuan.

[0073] Even when wheel 2 passes over the same location (LAT, LON) on the road, the calculated unsprung displacement Zu may differ depending on the direction of travel of vehicle 1. For example, consider the case where there are ruts on the road. The unsprung displacement Zu may differ depending on whether wheel 2 moves along the rut or crosses the rut. Therefore, the direction of travel φ of vehicle 1 may be obtained from position information 94, and the first unsprung displacement map 210 and the second unsprung displacement map 220 may be created and updated separately for each direction of travel φ. Alternatively, the first unsprung displacement map 210 and the second unsprung displacement map 220 may be created separately according to the tread width. Furthermore, these separate creations may be performed only for the second unsprung displacement map 220, which is susceptible to the influence of the direction of travel φ and tread width, and is based on the left and right wheel inverse phase input Zuan.

[0074] Figure 10 is a conceptual diagram showing another example of the unsprung displacement map 200. Figure 10 corresponds to another example of step S22. In the example shown in Figure 10, the unsprung displacement map 200 includes a first unsprung displacement map (first parameter map) 210 and a second unsprung displacement map (second parameter map) 220. Up to this point, it is the same as the example described in Figure 9. In the other example of step S22, the decomposition of the left and right wheel in-phase input Zuin is performed, so in the example shown in Figure 10, the first unsprung displacement map 210 includes two types of unsprung displacement maps. The two types of unsprung displacement maps are, specifically, a third unsprung displacement map (first subparameter map) 230 representing the correspondence between position (LAT, LON) and the in-phase input Zuin-in of the left and right wheels and the in-phase input Zuin-in of the front and rear wheels, and a fourth unsprung displacement map (second subparameter map) 240 representing the correspondence between position (LAT, LON) and the in-phase input Zuin-an of the left and right wheels and the out-of-phase input Zuin-an of the front and rear wheels.

[0075] Returning to Figure 8, in step S26, the processor 120 of the map management system 100 updates the counter values ​​of the mesh divisions that were generated / updated in step S25 using the following equation (8).

[0076]

number

[0077] In equation (8), Nold is the counter value for the current mesh division, and Nnew is the counter value after generation / update.

[0078] 3-4. Variations The vehicle control system 10 of vehicle 1 may maintain a database of unsprung displacement maps 200 and generate / update its own unsprung displacement maps 200. In other words, the map management system 100 may be included in the vehicle control system 10.

[0079] 4. Preview control using unsprung displacement map The control device 70 of the vehicle control system 10 communicates with the map management system 100 via the communication device 50. The control device 70 obtains an unsprung displacement map 200 of the area including the current position of the vehicle 1 from the map management system 100. The unsprung displacement map 200 is stored in the memory device 72. Then, the control device 70 performs "preview control," a type of vibration damping control, based on the unsprung displacement map 200.

[0080] Figure 11 is a conceptual diagram illustrating the preview control. Figure 12 is a flowchart illustrating the preview control. The preview control will be explained with reference to Figures 11 and 12.

[0081] In step S31, the control device 70 obtains the current position P0 of the reference point Pr. The relative positional relationship between the position of each wheel 2 and the reference position of the vehicle 1 for the position information 94 is known information. The relative positional relationship between the position of each wheel 2 and the reference points Pr1 and Pr2 is also known information. Based on these relative positional relationships and the vehicle reference position indicated by the position information 94, the current positions P0 of the reference points Pr1 and Pr2 are calculated, respectively.

[0082] In step S32, the control device 70 calculates the predicted passing position Pf of the reference point Pr after the preview time tp. The preview time tp is set to be longer than, for example, the time required for the calculation and communication processing necessary to activate the actuator 3A of the suspension 3. The preview time tp may be fixed or variable depending on the situation. The preview distance Lp is given by the product of the preview time tp and the vehicle speed V. The predicted passing position Pf is a position forward of the preview distance Lp from the current position P0. As an alternative, the control device 70 may calculate a predicted driving route based on the vehicle speed V and the steering angle of the wheels 2, and calculate the predicted passing position Pf based on the predicted driving route. If different unsprung displacement maps 200 are created according to the direction of travel φ, the predicted direction of travel of the vehicle 1 is also calculated in addition to the predicted passing position Pf.

[0083] In step S33, the control device 70 reads the unsprung displacement Zu at the predicted passing position Pf from the unsprung displacement map 200. Specifically, the unsprung displacement Zu read from the unsprung displacement map 200 is the in-phase input Zuin and out-of-phase input Zuan of the left and right wheels for reference point Pr1, and the in-phase input Zuin and out-of-phase input Zuan of the left and right wheels for reference point Pr2. If the unsprung displacement map 200 is created separately according to the direction of travel φ, the unsprung displacement Zu is read from the unsprung displacement map 200 based on the combination of the predicted direction of travel and the predicted passing position Pf.

[0084] In step S34, the control device 70 calculates the target control force Fc_t of the actuator 3A of the suspension 3 based on the unsprung displacement Zu at the predicted passing position Pf. The target control force Fc_t is calculated, for example, using the following equations (9)-(12).

[0085]

number

[0086] In equations (9)-(12), αfin is the in-phase input gain of the left and right wheels on the front axle side, αfan is the out-of-phase input gain of the left and right wheels on the front axle side, αrin is the in-phase input gain of the left and right wheels on the rear axle side, and αran is the out-of-phase input gain of the left and right wheels on the rear axle side.

[0087] If the left and right wheel common-phase input Zuin is decomposed, replace "left and right wheel common-phase input Zufin" in equations (9)-(10) with "left and right wheel common-phase and front and rear wheel common-phase input Zuin-in", replace "left and right wheel out-of-phase input Zufan" with "left and right wheel common-phase and front and rear wheel out-of-phase input Zuin-an", replace "left and right wheel common-phase input gain αfin" with "left and right wheel common-phase and front and rear wheel common-phase input gain αfrin", and replace "left and right wheel out-of-phase input gain αfan" with "left and right wheel common-phase and front and rear wheel out-of-phase input gain αfran". Furthermore, in equations (11)-(12), replace "left and right wheel in-phase input Zurin" with "left and right wheel in-phase and front and rear wheel in-phase input Zuin-in", replace "left and right wheel out-of-phase input Zuran" with "left and right wheel in-phase and front and rear wheel out-of-phase input Zurran", replace "left and right wheel in-phase input gain αrin" with "left and right wheel in-phase and front and rear wheel in-phase input gain αfrin", and replace "left and right wheel out-of-phase input gain αran" with "left and right wheel in-phase and front and rear wheel out-of-phase input gain αfran".

[0088] In step S35, the control device 70 controls the actuator 3A to generate a target control force Fc_t at the timing when the reference point Pr passes through the predicted passing position Pf. The timing when the reference point Pr passes through the predicted passing position Pf can be determined from the preview time tp.

[0089] By using the unsprung displacement map 200 described above for preview control, it becomes possible to effectively suppress vibrations of the vehicle 1 (supersprung structure 5). In particular, by configuring the unsprung displacement map 200 to include a first unsprung displacement map 210 representing the correspondence between position (LAT, LON) and the left and right wheel in-phase input Zuin, and a second unsprung displacement map 220 representing the correspondence between position (LAT, LON) and the left and right wheel out-of-phase input Zuan, it becomes possible to appropriately reflect the left and right wheel in-phase input Zuin and the left and right wheel out-of-phase input Zuan in vibration damping control. [Explanation of symbols]

[0090] 1…Vehicle 2...wheels 3…Suspension 3A… Actuator 10…Vehicle control system 20... Vehicle condition sensor 30…Recognition sensor 40…Position sensor 50…Communication device 60... Running gear 70...Control device 80... Vehicle control program 90…Driving environment information 93... Surrounding Area Information 94…location information 100... Map Management System 110...Communication device 120… Processor 130...Storage device 140... Map management program 200...Unsprung displacement map 210...First unsprung displacement map 220...Second unsprung displacement map 230... Third unsprung displacement map 240...Fourth unsprung displacement map Zu...Unsprung displacement Zuin...Same-phase input for left and right wheels Zuan... Left and right wheels in reverse phase input Zuin-in… Inputs that are in phase with both the left and right wheels and the front and rear wheels. Zuin-an…Left and right wheels in phase, front and rear wheels in opposite phase inputs.

Claims

1. A method for managing control maps used for vibration damping control of a vehicle, which are executed by a computer, The control map includes a first and a second parameter map, The first and second parameter maps represent, respectively, the correspondence between position and parameters related to the vertical movement of a reference point based on the positions of two or more wheels of the vehicle. The method described above is Generating or updating the first parameter map, This includes generating or updating the second parameter map at the same location where the first parameter map is generated or updated, Generating or updating the first parameter map includes calculating a left-right wheel in-phase input derived from the same vertical displacement of the first wheel and the second wheel as a first parameter related to the vertical movement of the reference point, based on time-series data of parameters related to the vertical movement of the first wheel of the vehicle and time-series data of parameters related to the vertical movement of the second wheel of the vehicle which constitutes the left and right wheels together with the first wheel, Generating or updating the second parameter map includes calculating left and right wheel out-of-phase inputs derived from the different vertical displacements of the first and second wheels as time-series data of the second parameter related to the vertical movement of the reference point, based on time-series data of the parameter related to the vertical movement of the first wheel and time-series data of the parameter related to the vertical movement of the second wheel. A method for managing control maps, characterized by the following features.

2. The method according to claim 1, Generating or updating the first parameter map further includes filtering the left and right wheel in-phase inputs using a first high-pass filter, Generating or updating the second parameter map further includes filtering the left and right wheel out-of-phase inputs using a second high-pass filter, The second high-pass filter is weaker than the first high-pass filter. A method for managing control maps, characterized by the following features.

3. A method according to claim 1 or 2, The first parameter map includes first and second sub-parameter maps, Generating or updating the first parameter map further includes generating or updating the first and second subparameters, Generating or updating the first and second sub-parameter maps is Based on time-series data of parameters related to the vertical movement of the first and second wheels and the third and fourth wheels of the vehicle that constitute the front and rear wheels, the following are calculated: a left and right wheel in-phase input derived from the same vertical displacement of the third and fourth wheels, and a left and right wheel out-of-phase input derived from the different vertical displacements of the third and fourth wheels, respectively. Based on the in-phase inputs of the left and right wheels of the first and second wheels, and the in-phase inputs of the left and right wheels of the third and fourth wheels, a first sub-parameter related to the vertical motion of the reference point is calculated, which is the in-phase input of the left and right wheels and the front and rear wheels derived from the same vertical displacement of the first and second wheels and the same vertical displacement of the first and second wheels and the third and fourth wheels. Based on the in-phase inputs of the left and right wheels of the first and second wheels, and the out-of-phase inputs of the left and right wheels of the third and fourth wheels, the method includes calculating a second sub-parameter related to the vertical motion of the reference point, which is an in-phase input of the left and right wheels and an out-of-phase input of the front and rear wheels derived from the same vertical displacement of the first and second wheels, and different vertical displacements of the first and second wheels and the third and fourth wheels. A method for managing control maps, characterized by the following features.

4. The method according to claim 3, The generation or updating of the first and second sub-parameter maps is further, The filtering process for the in-phase inputs of the left and right wheels and the front and rear wheels is performed using a first sub-high-pass filter, This includes performing filtering processing on the left and right wheels' in-phase and front and rear wheels' out-of-phase inputs using a second sub-high-pass filter, The second sub-high-pass filter is weaker than the first sub-high-pass filter. A method for managing parameter maps, characterized by the following features.

5. The method according to claim 4, The second sub-high-pass filter is stronger than the second high-pass filter. A method for managing control maps, characterized by the following features.

6. A system for managing control maps used for vibration control of vehicles, One or more processors, The system includes one or more storage devices for storing the control map, The control map includes a first and a second parameter map, The first and second parameter maps represent, respectively, the correspondence between position and parameters related to the vertical movement of a reference point based on the positions of two or more wheels of the vehicle. The one or more processors described above are: The process of generating or updating the first parameter map, A process for generating or updating the second parameter map at the same location where the first parameter map is generated or updated, It is configured to do the following: The process for generating or updating the first parameter map includes a process for calculating a first parameter related to the vertical movement of the reference point, which is derived from the same vertical displacement of the first and second wheels, based on time-series data of parameters related to the vertical movement of the first wheel of the vehicle and time-series data of parameters related to the vertical movement of the second wheels of the vehicle that constitute the left and right wheels together with the first wheel, and the left and right wheels. The process of generating or updating the second parameter map includes a process of calculating left and right wheel out-of-phase inputs derived from the different vertical displacements of the first and second wheels as time-series data of the second parameter related to the vertical movement of the reference point, based on time-series data of the parameter related to the vertical movement of the first wheel and time-series data of the parameter related to the vertical movement of the second wheel. A control map management system characterized by the following features.

7. The system according to claim 6, The process of generating or updating the first parameter map further includes filtering the in-phase inputs of the left and right wheels of the first and second wheels using a first high-pass filter, The process of generating or updating the second parameter map further includes filtering the out-of-phase inputs of the left and right wheels of the first and second wheels using a second high-pass filter, The second high-pass filter is weaker than the first high-pass filter. A control map management system characterized by the following features.

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