Management method and management system for control mapping

Abstract

When vibration damping control is performed using a control map indicating a correspondence relationship between a position and a parameter associated with an up-and-down movement of a reference point based on two or more wheel positions of a vehicle, a left-and-right wheel inverting input and a left-and-right wheel in-phase input are appropriately reflected in the vibration damping control. A first parameter map and a second parameter map used in vibration damping control of a vehicle are generated or updated. In the generation or update of a first parameter map, left and right wheel in-phase inputs of a first wheel and a second wheel are calculated as a first parameter associated with the vertical movement of a reference point. The generation or update of the second parameter map is performed for the same location as the location at which the generation or update of the first parameter map is performed. In the generation or update of a second parameter map, left and right wheel inverting inputs of the first wheel and the second wheel are calculated as a second parameter associated with the vertical movement of the reference point.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a technology of managing a control map used in damping control of a vehicle. BACKGROUND

[0002] Patent Literature 1 discloses a road surface displacement map that represents a correspondence relationship between a road surface displacement (road surface unevenness) and a position. Damping control is performed by using such a road surface displacement map. Specifically, from the road surface displacement map, a road surface displacement at a prescribed position ahead of the vehicle is identified in advance. A control amount of an active suspension is calculated in advance in accordance with the road surface displacement identified in advance. Then, by controlling the active suspension at the timing when the wheel passes the prescribed position, vibration of the vehicle is effectively suppressed. PRIOR ART DOCUMENTS PATENT LITERATURE

[0003] Patent Literature 1: U.S. Patent Application Publication No. 2018 / 0154723 Specification SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] In Patent Literature 1, when the road surface displacement map is created, a filter processing of cutting off frequencies that are substantially lower than a body frequency and frequencies that are substantially higher than the body frequency from road surface state data is performed. Here, the road surface state data can be said to be data of a parameter associated with a road surface displacement. Also, the data of the parameter associated with the road surface displacement can be said to be data of a parameter associated with up-and-down movement of a wheel that contacts a road surface.

[0005] In the present disclosure, a control map that represents a correspondence relationship between a position and a parameter associated with up-and-down movement based on a reference point of positions of 2 or more wheels possessed by a vehicle is created. Such a control map can be created, for example, using time-series data of a parameter associated with up-and-down movement of each wheel. However, in the parameter associated with up-and-down movement of each wheel, there is included an extremely low frequency component that originates from a change in elevation or the like. Thus, when the control map is created, it is desirable to perform a filter processing using a high-pass filter to cut off the extremely low frequency component from the parameter associated with up-and-down movement of each wheel. However, if a too strong high-pass filter is used, left-right wheel anti-phase input that originates from different up-and-down displacements of left and right wheels is also cut off.

[0006] In the case where the damping control is performed using the control map made from the time-series data in which the left and right wheel anti-phase inputs are cut off, the left and right wheel anti-phase inputs are not reflected in the damping control, and the control effect is degraded. In this regard, if a weaker high-pass filter is used in the filtering process, the problem is eliminated. However, in this case, the left and right wheel in-phase inputs, which are prone to be affected by the elevation change, are left as they are, which are derived from the same up-and-down displacement of the left and right wheels. Thus, in the damping control using the control map, the control amount to cancel the left and right wheel in-phase inputs, which is too large, can degrade the control effect.

[0007] An object of the present disclosure is to provide a technology that, in the case where the damping control is performed using a control map that represents a correspondence between a position and a parameter associated with up-and-down motion of a reference point based on positions of two or more wheels of a vehicle, can appropriately reflect left and right wheel anti-phase inputs and left and right wheel in-phase inputs in the damping control. Technical means for solving the problem

[0008] A first aspect of the present disclosure is a method of managing a control map used in damping control of a vehicle, which is executed by a computer, and has the following features. The control map includes a first parameter map and a second parameter map. The first parameter map and the second parameter map each represent a correspondence between a position and a parameter associated with up-and-down motion of a reference point based on 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 for the same position as the position for which the generation or update of the first parameter map is performed. The generation or update of the first parameter map includes calculating, as a first parameter associated with up-and-down motion of the reference point, a left and right wheel in-phase input derived from the same up-and-down displacement of a first wheel and a second wheel of the vehicle, based on time-series data of a parameter associated with up-and-down motion of the first wheel and time-series data of a parameter associated with up-and-down motion of the second wheel that constitutes left and right wheels with the first wheel. The generation or update of the second parameter map includes calculating, as a second parameter associated with up-and-down motion of the reference point, a left and right wheel anti-phase input derived from different up-and-down displacement of the first wheel and the second wheel, based on time-series data of a parameter associated with up-and-down motion of the first wheel and time-series data of a parameter associated with up-and-down motion of the second wheel.

[0009] A second aspect of the present disclosure has the following features based on the first aspect. The generating or updating of the first parameter map includes filtering processing of the left-right wheel in-phase input using a first high-pass filter. The generating or updating of the second parameter map includes filtering processing of the left-right wheel anti-phase input using a second high-pass filter. The second high-pass filter is weaker than the first high-pass filter.

[0010] A third aspect of the present disclosure is a system that manages a control map used in damping control of a vehicle, and has the following features. The system includes one or more processors and one or more storage devices that store the control map. The control map includes a first parameter map and a second parameter map. The first parameter map and the second parameter map respectively represent a correspondence between a position and a parameter associated with up-down movement of a reference point based on positions of two or more wheels of the vehicle. The one or more processors are configured to perform: processing of generating or updating the first parameter map; and processing of generating or updating the second parameter map for the same position as the position for which the generating or updating of the first parameter map is performed. The processing of generating or updating the first parameter map includes processing of calculating, as a first parameter associated with up-down movement of the reference point, left-right wheel in-phase input resulting from the same up-down displacement of a first wheel and a second wheel of the vehicle, based on time-series data of a parameter associated with up-down movement of the first wheel and time-series data of a parameter associated with up-down movement of the second wheel that constitutes left-right wheels with the first wheel. The processing of generating or updating the second parameter map includes processing of calculating, as a second parameter associated with up-down movement of the reference point, left-right wheel anti-phase input resulting from different up-down displacements of the first wheel and the second wheel, based on time-series data of a parameter associated with up-down movement of the first wheel and time-series data of a parameter associated with up-down movement of the second wheel.

[0011] A fourth aspect of the present disclosure is based on the third aspect and has the following features. The processing of generating or updating the first parameter map further includes filtering processing of the left-right wheel in-phase input of the first wheel and the second wheel using a first high-pass filter. The processing of generating or updating the second parameter map further includes filtering processing of the left-right wheel anti-phase input of the first wheel and the second wheel using a second high-pass filter. The second high-pass filter is weaker than the first high-pass filter. Inventive Effects

[0012] According to the first or third viewpoint, generation or update of the first parameter map and the second parameter map used in the damping control of the vehicle is performed. In the generation or update of the first parameter map, the in-phase input of the left and right wheels of the first and second wheels is calculated as the first parameter associated with the up-and-down motion of the reference point. The generation or update of the second parameter map is performed for the same position as the position at which the generation or update of the first parameter map is performed. In the generation or update of the second parameter map, the anti-phase input of the left and right wheels of the first and second wheels is calculated as the second parameter associated with the up-and-down motion of the reference point. Thus, in the damping control using the first parameter map and the second parameter map, the in-phase input of the left and right wheels as the first parameter and the anti-phase input of the left and right wheels as the second parameter can be appropriately reflected in the damping control.

[0013] According to the second or fourth viewpoint, a first high-pass filter is used in the generation or update of the first parameter map, and a second high-pass filter weaker than the first high-pass filter is used in the generation or update of the second parameter map. Thus, the first parameter map in which an extremely low frequency component originating from a change in elevation or the like is cut off can be generated or updated, and the second parameter map in which the anti-phase input of the left and right wheels is retained can be generated or updated. Therefore, the effects based on the first or third viewpoint can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram showing a configuration example of a vehicle related to the embodiment. Figure 2 is a conceptual diagram showing a configuration example of a suspension related to the embodiment. Figure 3 is a flowchart showing an example of a sprung displacement calculation process. Figure 4 is a block diagram showing a configuration example of a vehicle control system related to the embodiment. Figure 5 is a block diagram showing an example of driving environment information related to the embodiment. Figure 6 is a block diagram showing a configuration example of a map management system related to the embodiment. Figure 7 is a conceptual diagram for explaining a sprung displacement map related to the embodiment. Figure 8 is a flowchart showing a map generation / update process related to the embodiment. Figure 9 is a conceptual diagram showing an example of a sprung displacement map related to the embodiment. Figure 10is a conceptual diagram showing another example of the sprung displacement map involved in the embodiment. Figure 11 is a conceptual diagram for explaining preview control that utilizes the sprung displacement map involved in the embodiment. Figure 12 is a flowchart showing the preview control that utilizes the sprung displacement map involved in the embodiment. DETAILED DESCRIPTION

[0015] An embodiment of the present disclosure will be described with reference to the drawings.

[0016] 1. Suspension and up-and-down movement parameters Figure 1 is a schematic diagram showing a configuration example of a vehicle 1 involved in the embodiment. The vehicle 1 is provided with wheels 2 and suspensions 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 constitute left and right wheels on the front axle side, and the left rear wheel 2RL and the right rear wheel 2RR constitute left and right wheels on the rear axle side. The suspensions 3FL, 3FR, 3RL, and 3RR are provided for the left front wheel 2FL, the right front wheel 2FR, the left rear wheel 2RL, and the right rear wheel 2RR, respectively. In the following description, each wheel will be referred to as the wheel 2, and each suspension will be referred to as the suspension 3, in cases where no particular distinction is required.

[0017] Figure 2 is a conceptual diagram showing a configuration example of the suspension 3. The suspension 3 is provided in a manner of linking between a sprung structure 4 and an un-sprung structure 5 of the vehicle 1. The sprung structure 4 includes the wheel 2. The suspension 3 includes a spring 3S, a shock absorber 3D, and an actuator 3A. The spring 3S, the shock absorber 3D, and the actuator 3A are provided in parallel between the sprung structure 4 and the un-sprung structure 5. A spring constant of the spring 3S is K. A damping coefficient of the shock absorber 3D is C. The damping force of the shock absorber 3D can also be variable. The actuator 3A applies a control force Fc in the up-and-down direction between the sprung structure 4 and the un-sprung structure 5.

[0018] Here, definitions of terms are made. A road surface displacement Zr is a displacement in the up-and-down direction of the road surface RS. A sprung displacement Zu is a displacement in the up-and-down direction of the sprung structure 4. An un-sprung displacement Zs is a displacement in the up-and-down direction of the un-sprung structure 5. A sprung velocity Zu' is a velocity in the up-and-down direction of the sprung structure 4. An un-sprung velocity Zs' is a velocity in the up-and-down direction of the un-sprung structure 5. A sprung acceleration Zu" is an acceleration in the up-and-down direction of the sprung structure 4. An un-sprung acceleration Zs" is an acceleration in the up-and-down direction of the un-sprung structure 5. Furthermore, the sign of each parameter is positive in the case of upward and negative in the case of downward.

[0019] The wheel 2 moves on the road surface RS. When the wheel 2 moves on the road surface RS, the "reference point Pr" of the vehicle 1 moves up and down due to the road surface displacement Zr. The reference point Pr is set to an arbitrary position of the vehicle 1 based on the positions of 2 or more wheels possessed by the vehicle 1. As the reference point Pr, the front wheel tire surface position (the middle point of the left front wheel 2FL and the right front wheel 2FR), the rear wheel tire surface position (the middle point of the left rear wheel 2RL and the right rear wheel 2RR), the center position of the vehicle 1, and the like are exemplified. The reference points Pr can also be set on the front wheel shaft side and the rear wheel shaft side of the vehicle 1, respectively. In this case, the front wheel tire surface position is exemplified as the reference point Prl on the front wheel shaft side, and the rear wheel tire surface position is exemplified as the reference point Pr2 on the rear wheel shaft side. Further, in the embodiment, an example in which the reference points Prl and Pr2 are set to the front wheel tire surface position and the rear wheel tire surface position is described.

[0020] In the following description, a parameter associated with the vertical motion of the reference points Prl and Pr2 is referred to as a "vertical motion parameter". As the vertical motion parameter, the road surface displacement Zr, the unsprung displacement Zu, the unsprung velocity Zu', the unsprung acceleration Zu", the sprung displacement Zs, the sprung velocity Zs', the sprung acceleration Zs", and the like described above are exemplified. The vertical motion parameter can also be said to be a "road surface displacement parameter" associated with the road surface displacement Zr.

[0021] As an example, in the following description, a case in which the vertical motion parameter of the reference points Prl and Pr2 is the unsprung displacement Zu is considered. In general, the "unsprung displacement" in the following description is replaced with the "vertical motion parameter".

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

[0023] In step Sll, the sprung acceleration Zs" is detected by the sprung acceleration sensor 22 provided to the sprung structure 5. In step S12, the sprung displacement Zs is calculated by performing a second-order integration on the sprung acceleration Zs".

[0024] In step S13, the stroke ST (= Zs - Zu) which is the relative displacement between the sprung structure 5 and the unsprung structure 4 is acquired. For example, the stroke ST is detected by a stroke sensor provided to the suspension 3. As another example, the stroke ST can also be estimated based on the sprung acceleration Zs" by an observer configured based on a single-wheel 2-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” can also be detected by the unsprung acceleration sensor, and the unsprung displacement Zu can be calculated from the unsprung acceleration Zu”.

[0027] 2. Vehicle control system 2-1. Example of composition Figure 4 This is a block diagram illustrating 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 status sensor 20, an identification sensor 30, a position sensor 40, a communication device 50, a driving device 60, and a control device 70.

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

[0029] The identification sensor 30 identifies (detects) the conditions around the vehicle 1. Examples of identification sensors include cameras, LIDAR (Laser Imaging Detection and Ranging), and radar.

[0030] Position sensor 40 detects the position and orientation of vehicle 1. For example, position sensor 40 includes 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 unit 62, a braking unit 63, and a suspension 3 (see reference). Figure 2 The steering device 61 steers the wheels 2. For example, the steering device 61 includes an electric power steering (EPS) device. The drive unit 62 is the power source that generates driving force. Examples of drive units 62 include an engine, an electric motor, a hub motor, etc. The braking device 63 generates braking force.

[0033] The control unit 70 is a computer that controls the vehicle 1. The control unit 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 device 72 stores various information required 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 unit 70 may also include one or more ECUs (Electronic Control Units).

[0034] The vehicle control program 80 is a computer program used to control vehicle 1, and is executed by processor 71. The vehicle control program 80 is stored in storage device 72. Alternatively, the vehicle control program 80 may also be recorded on a computer-readable recording medium. The functions of the control device 70 are realized by executing the vehicle control program 80 through processor 71.

[0035] 2-2. Driving Environment Information Figure 5 This is a block diagram illustrating an example of driving environment information 90 representing the driving environment of vehicle 1. The driving environment information 90 is stored in 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 can show lane configurations, road shapes, etc. Map information 91 may also include location information for white lines, traffic lights, signs, road markers, etc. Map information 91 is obtained from a map database. Furthermore, the map database can be installed in vehicle 1 or stored on an external management server. In the latter case, control device 70 communicates with the management server to obtain the required map information 91.

[0037] Map information 91 also includes "Unsprung Displacement Map 200". Unsprung displacement map 200 is associated with reference points Pr1 and Pr2 respectively. Details regarding unsprung displacement map 200 will be discussed later.

[0038] Vehicle status information 92 indicates the status of vehicle 1. Control device 70 obtains vehicle status information 92 from vehicle status sensor 20. For example, vehicle status information 92 includes vehicle speed V, sprung acceleration Zs", travel ST, lateral acceleration, yaw rate, steering angle, etc. Vehicle speed V can also be calculated based on the vehicle position detected by position sensor 40. Control device 70 can also utilize... Figure 3 The unsprung displacement Zu is calculated using the method shown in the diagram. In this case, the vehicle status information 92 also includes the unsprung displacement Zu calculated by the control device 70.

[0039] Surrounding conditions information 93 is information showing the conditions around vehicle 1. Control device 70 uses recognition sensor 30 to recognize the conditions around vehicle 1 and obtain surrounding conditions information 93. For example, surrounding conditions information 93 includes image information captured by a camera. As another example, surrounding conditions information 93 includes point cloud information obtained by LIDAR.

[0040] The surrounding environment information 93 also includes "object information" related to objects around vehicle 1. Examples of objects include pedestrians, bicycles, other vehicles (moving vehicles, parked vehicles, etc.), road structures (white lines, curbs, guardrails, walls, median strips, roadside structures, etc.), signs, traffic cones, obstacles, etc. The object information shows the relative position and relative speed of the object relative to vehicle 1. For example, by analyzing image information obtained from a camera, objects can be identified and their relative positions calculated. Alternatively, based on point cloud information obtained from LIDAR, objects can also be identified and their relative positions and relative speeds obtained.

[0041] Location information 94 indicates the position and orientation of vehicle 1. Control device 70 obtains location information 94 from the detection results obtained by position sensor 40. Alternatively, control device 70 can also obtain high-precision location information 94 by utilizing object information and map information 91 through well-known self-position estimation (Localization) processing.

[0042] 2-3. Vehicle Control The control unit 70 performs vehicle driving control, which controls the movement of the vehicle 1. Vehicle driving control includes steering control, drive control, and braking control. The control unit 70 performs vehicle driving control by controlling the driving devices 60 (steering device 61, drive device 62, and braking device 63). The control unit 70 can also perform driver assistance control based on driving environment information 90 to assist the driving of the vehicle 1. Examples of driver assistance controls 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 performs damping control to suppress vibrations of the vehicle 1 by controlling the suspension 3. For example, the control device 70 controls the actuator 3A to generate a vertical control force Fc between the unsprung structure 4 and the sprung structure 5 (see reference). Figure 2 As another example, the control device 70 can also provide variable control over the damping force of the damper 3D. The damping control includes "predictive control" as described later.

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

[0045] The mapping 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 multiple vehicles 1 via the communication network NET.

[0046] The mapping management system 100 also 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 device 130). The processor 120 performs various information processing tasks. For example, the processor 120 includes a CPU. The storage device 130 stores various map information. Additionally, the storage device 130 stores various information required for processing by the processor 120. Examples of storage devices 130 include volatile memory, non-volatile memory, HDD, SSD, etc.

[0047] Mapping management program 140 is a computer program for mapping management, executed by processor 120. Mapping management program 140 is stored in storage device 130. Alternatively, mapping management program 140 may also be recorded on a computer-readable recording medium. The functions of mapping management system 100 are implemented by executing mapping management program 140 through processor 120.

[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. Additionally, the processor 120 publishes 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 mapping One of the map information managed by the mapping management system 100 is "Unsprung Displacement Mapping (Up-Down Motion Parameter Mapping) 200". Unsprung displacement mapping 200 is a map related to unsprung displacement Zu (up-down motion parameter). Unsprung displacement mapping 200 is stored in storage device 130.

[0050] Figure 7 This is a conceptual diagram used to illustrate the unsprung displacement map 200. The absolute coordinate system on the horizontal plane is defined, for example, by latitude and longitude. Position on 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 represents the unsprung displacement (Zu) as a function of position (LAT, LON).

[0051] The road area is divided into a grid pattern on a horizontal plane. That is, 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 the unit area M and the unsprung displacement Zu. The position of the unit area M can be defined by its representative position (e.g., the center position) or by its range (latitude range, longitude range). The unsprung displacement Zu of the 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. Mapping Generation / Update Processing Processor 120 collects information from multiple vehicles 1 via communication device 110. Then, based on the information collected from the multiple vehicles 1, processor 120 generates and updates the unsprung displacement mapping 200. An example of the mapping generation / update process will be described in more detail below.

[0053] The positions in the unsprung displacement mapping 200 are the positions through which reference points Pr1 and Pr2 pass, 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 used for the position information 94 is known information. In addition, 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 shown by the position information 94, the positions of reference points Pr1 and Pr2 can be calculated.

[0054] Unsprung displacement Zu passes through, as Figure 3The method shown is used to calculate the unsprung displacement Zs and the travel ST. That is, by using the vehicle state sensor 20 mounted on vehicle 1, the sprung displacement Zs and travel ST can be obtained. For convenience, these sprung displacements Zs and travel 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 unit 70 of the vehicle control system 10 associates the position of the wheel 2 at the same time with sensor-based information. Then, the control unit 70 sends the time-series data of the wheel 2's position and the time-series data of the sensor-based information to the mapping management system 100. The processor 120 of the mapping 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 mapping 200 based on the time-series data of the wheel 2's position and the time-series data of the unsprung displacement Zu.

[0056] Furthermore, when the unsprung displacement Zu is calculated in the mapping management system 100, since there is no processing time constraint, a zero-phase filter can be used for filtering. By utilizing the zero-phase filter, "phase shift" can be prevented.

[0057] Figure 8 This is a flowchart illustrating the mapping generation / update process involved in the implementation method.

[0058] In step S21, the processor 120 of the mapping management system 100 obtains "mapping update information" from the vehicle 1 (vehicle control system 10) via the communication device 110. The mapping update information includes timing data of the position of the wheel 2. In addition, the mapping update information includes timing data of sensor-based information (e.g., sprung displacement Zs and travel ST) required to calculate the unsprung displacement Zu. Alternatively, the mapping update information may also include timing 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 mapping management system 100 decomposes the unsprung displacement Zu into left and right wheel in-phase input Zuin and left and right wheel out-of-phase input Zuan. With reference points Pr1 and Pr2 set for the front tire surface position and the rear tire surface position, the left and right wheel in-phase input Zufin and left and right wheel out-of-phase input Zufan on the front wheel axle side are represented by the following equations (1) and (2), and the left and right wheel in-phase input Zurin and left and right wheel out-of-phase input Zuran on the rear wheel axle side are represented by the following equations (3) and (4).

[0060] [Mathematical Expression 1]

[0061] In equations (1)-(4), Zufl represents the unsprung displacement Zu of the left front wheel 2FL, Zufr represents the unsprung displacement Zu of the right front wheel 2FR which together with the left front wheel 2FL forms the front wheel, Zuurl 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 forms the rear wheel.

[0062] In another example, the processor 120 of the mapping management system 100 further decomposes the left and right wheel phase input Zuin into front and rear wheel phase input (heave) Zuin, which originates from the same vertical displacement of the front and rear wheels of the vehicle 1, and front and rear wheel phase input (pitch) Zuan, which originates from different vertical displacements of the front and rear wheels. The front and rear wheels referred to here are the combination of the left front wheel 2FL and the right front wheel 2FR with the left rear wheel 2RL and the right rear wheel 2RR. In this case, the decomposed front and rear wheel phase input Zuin, that is, the left and right wheel phase input Zuin-in, is represented by the following equation (5). In addition, the decomposed front and rear wheel phase input Zuan, that is, the left and right wheel phase input Zuin-an, is represented by the following equation (6).

[0063] [Mathematical Expression 2]

[0064] In step S23, the left and right wheel in-phase inputs Zuin and Zuan in-phase inputs are filtered. A first high-pass filter is applied to the left and right wheel in-phase inputs Zuin to cut off extremely low frequency components (e.g., components below 0.5 Hz) originating from elevation changes, etc. On the other hand, a second high-pass filter is applied to the left and right wheel in-phase inputs Zuan to retain 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 inputs Zuin is a stronger high-pass filter than the second high-pass filter applied to the left and right wheel in-phase inputs Zuan. Here, "stronger high-pass filter" means a high cutoff frequency (low-frequency side), a large filter order, or a large number of filter stages.

[0065] The unsprung displacement Zu contains extremely low frequency components (e.g., components below 0.5 Hz) originating from elevation changes, etc. However, these extremely low frequency components also include the out-of-phase inputs of the left and right wheels. Regarding this, in step S23, a relatively strong first high-pass filter is applied in the filtering process for the in-phase input Zuin of the left and right wheels. This truncates the extremely low frequency components originating from elevation 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 in the filtering process for the out-of-phase input Zuan of the left and right wheels. This avoids truncation of the extremely low frequency components through 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 inverted input Zuan. On the other hand, 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, generated by decomposing the left and right wheel in-phase input Zuin, to cut off extremely low frequency components (e.g., components below 0.5 Hz) originating from elevation changes, etc. On the other hand, 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 inverted input Zuin-an to retain extremely low frequency components (e.g., components above 0.4 Hz). That is, 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 inverted input Zuin-an. The fourth high-pass filter applied to the left and right wheel in-phase and front and rear wheel inverted input Zuin-an is also a stronger high-pass filter than the second high-pass filter applied to the left and right wheel inverted input Zuan.

[0067] The reasons for applying a relatively strong third high-pass filter in the filtering process where the left and right wheels are in phase and the front and rear wheels are in phase with the input Zuin-in, and for applying a relatively weak fourth high-pass filter in the filtering process where the left and right wheels are in phase and the front and rear wheels are out of phase with the input Zuin-an, are the same as the reasons for using the first high-pass filter and the second high-pass filter separately.

[0068] In step S24, the processor 120 of the mapping management system 100 synchronizes the position information with the sensor-based information. For example, the processor 120 considers the delay of the position information, the delay of the sensor-based information, and the difference in sampling periods, and establishes a correlation between the positions of the wheels 2 at the same time and the sensor-based information. The processor 120 can either supplement the sensor-based information with a longer sampling period to match the sensor-based information with a shorter sampling period, or it can resample. If the processing of establishing the correlation has been completed in the vehicle control system 10, the processing performed by the processor 120 is omitted. Then, the processor 120 calculates the positions of reference points Pr1 and Pr2 based on the positions of each wheel 2, and establishes a correlation between the positions of reference points Pr1 and Pr2 at the same time and the filtered left and right wheel in-phase input Zuin and left and right wheel out-of-phase input Zuan.

[0069] In step S25, the processor 120 of the mapping management system 100 explores the grid partitions closest to the positions of reference points Pr1 and Pr2 and generates / updates the unsprung displacement Zu (that is, the left and right wheel in-phase input Zuin and the left and right wheel out-of-phase input Zuan shown in equations (1)-(4)). The unsprung displacement Zu is updated, for example, using the following equation (7).

[0070] [Mathematical Expression 3] Znew=(Znow+Zold*Nold) / (1+Nold)…(7)

[0071] In equation (7), Zold is the unsprung displacement Zu that originally entered the grid partition, Nold is the count value of the grid partition, Znow is the current unsprung displacement Zu, and Znew is the updated unsprung displacement Zu.

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

[0073] Even when wheel 2 passes through the same position (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. Depending on whether wheel 2 moves along or across the ruts, the unsprung displacement Zu may differ. Therefore, the direction of travel φ of vehicle 1 can be obtained from position information 94, and a first unsprung displacement map 210 and a second unsprung displacement map 220 can be created and generated / updated separately for each direction of travel φ. Alternatively, the first unsprung displacement map 210 and the second unsprung displacement map 220 can be created separately based on the tire tread width. Furthermore, these separate creations can be performed only for the second unsprung displacement map 220, which is easily affected by the opposite phase input Zuan of the left and right wheels caused by the direction of travel φ and the tire tread width.

[0074] Figure 10 This is a conceptual diagram illustrating another example of unsprung displacement mapping 200. Figure 10 Another example corresponding to step S22. Figure 10 In the example shown, the unsprung displacement mapping 200 includes a first unsprung displacement mapping (first parameter mapping) 210 and a second unsprung displacement mapping (second parameter mapping) 220. Up to this point, with... Figure 9 The example described is the same. In another example of step S22, the decomposition of the left and right wheel in-phase input Zuin is performed, so in Figure 10In the example shown, the first unsprung displacement mapping 210 includes two types of unsprung displacement mappings. Specifically, the two types of unsprung displacement mappings are a third unsprung displacement mapping (first sub-parameter mapping) 230, which represents the correspondence between the position (LAT, LON) and the input Zuin-in, which is in phase with the left and right wheels and in phase with the front and rear wheels, and a fourth unsprung displacement mapping (second sub-parameter mapping) 240, which represents the correspondence between the position (LAT, LON) and the input Zuin-an, which is in phase with the left and right wheels and in phase with the front and rear wheels.

[0075] return Figure 8 In step S26, the processor 120 of the mapping management system 100 uses the following formula (8) to update the count value of the grid partition that became the object to be generated / updated in step S25.

[0076] [Mathematical Expression 4] Nnew=1+Nold…(8)

[0077] In equation (8), Nold is the count value of the current grid partition, and Nnew is the count value after generation / update.

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

[0079] 4. Predictive control utilizing unsprung displacement mapping. The control unit 70 of the vehicle control system 10 communicates with the mapping management system 100 via the communication device 50. The control unit 70 obtains the unsprung displacement mapping 200 of the region containing the current position of the vehicle 1 from the mapping management system 100. The unsprung displacement mapping 200 is stored in the storage device 72. Then, based on the unsprung displacement mapping 200, the control unit 70 performs "predictive control" as a type of vibration damping control.

[0080] Figure 11 This is a conceptual diagram used to illustrate predictive control. Figure 12 This is a flowchart illustrating predictive control. (Refer to...) Figure 11 and Figure 12 This section explains the concept of predictive control.

[0081] In step S31, the control device 70 obtains the current position P0 of the reference point Pr. The relative positional relationship between the positions of each wheel 2 and the reference position of the vehicle 1 used for position information 94 is known information. In addition, the relative positional relationship between the positions 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 shown 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 prediction time tp. The prediction time tp is, for example, set to be more than the time required for calculation and communication processing until the actuator 3A of the suspension 3 is activated. The prediction time tp can be fixed or variable depending on the situation. The prediction distance Lp is given by the product of the prediction time tp and the vehicle speed V. The predicted passing position Pf is the position ahead of the current position P0 by a prediction distance Lp. As a variation, the control device 70 can also calculate the expected driving path based on the vehicle speed V and the steering angle of the wheel 2, and calculate the predicted passing position Pf based on the expected driving path. When the unsprung displacement mapping 200 is made separately according to the direction of travel φ, the predicted direction of travel of the vehicle 1 is 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 left and right wheel in-phase input Zuin and the left and right wheel out-of-phase input Zuan about the reference point Pr1, and the left and right wheel in-phase input Zuin and the left and right wheel out-of-phase input Zuan about the reference point Pr2. When the unsprung displacement map 200 is made separately according to the travel direction φ, the unsprung displacement Zu is read from the unsprung displacement map 200 based on the combination of the predicted travel direction 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 predicted unsprung displacement Zu at the passing position Pf. The target control force Fc_t is calculated, for example, using the following equations (9)-(12).

[0085] [Mathematical Expression 5] Ffl=Zufin·αfin+Zufan·αfan…(9) Ffr=Zufin·αfin-Zufan·αfan…(10) Frl=Zurin·αrin+Zuran·αran…(11) Frr=Zurin·αrin-Zuran·αran…(12)

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

[0087] In the case of decomposing the left and right wheel in-phase input Zuin, replace “left and right wheel in-phase input Zufin” in equations (9)-(10) 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 Zufan” with “left and right wheel in-phase and front and rear wheel out-of-phase input Zuin-an”, replace “left and right wheel in-phase input gain αfin” 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 αfan” with “left and right wheel in-phase and front and rear wheel out-of-phase input gain αfran”. In addition, replace “Zurin, the input of left and right wheels in phase” in equations (11)-(12) with “Zuin-in, the input of left and right wheels in phase and front and rear wheels in phase”, replace “Zuran, the input of left and right wheels in opposite phase” with “Zurran, the input of left and right wheels in phase and front and rear wheels in opposite phase”, replace “αrin, the input gain of left and right wheels in phase and front and rear wheels in phase” with “αfrin, the input gain of left and right wheels in opposite phase”, and replace “αran, the input gain of left and right wheels in opposite phase and front and rear wheels in opposite phase” with “αfran, the input gain of left and right wheels in phase and front and rear wheels in opposite phase”.

[0088] In step S35, the control device 70 controls the actuator 3A in such a way that a target control force Fc_t is generated at the moment when the reference point Pr passes through the predicted position Pf. The moment when the reference point Pr passes through the predicted position Pf is known from the prediction time tp.

[0089] By utilizing the predictive control of the unsprung displacement map 200 as described above, the vibration of the vehicle 1 (sprung structure 5) can be effectively suppressed. In particular, by configuring the unsprung displacement map 200 with a first unsprung displacement map 210 that represents the correspondence between the position (LAT, LON) and the in-phase input Zuin of the left and right wheels, and a second unsprung displacement map 220 that represents the correspondence between the position (LAT, LON) and the out-of-phase input Zuan of the left and right wheels, the in-phase input Zuin and the out-of-phase input Zuan of the left and right wheels can be appropriately reflected in the vibration reduction control. Explanation of reference numerals in the attached figures

[0090] 1…vehicles 2…wheels 3…Suspension 3A…Actuator 10…Vehicle Control System 20…Vehicle Status Sensors 30…Identification Sensor 40… Position Sensor 50…communication device 60…Travel device 70…Control device 80…Vehicle Control Program 90… Driving Environment Information 93…Surrounding conditions information 94…Location Information 100…Mapping Management System 110…communication device 120… processor 130… storage device 140…Mapping Management Program 200…Unsprung displacement mapping 210…First Unsprung Displacement Mapping 220…Second Unsprung Displacement Mapping 230…Third Unsprung Displacement Mapping 240… Fourth Unsprung Displacement Mapping Zu…Unsprung displacement Zuin…Same phase input for left and right wheels Zuan… Left and right wheel reverse phase input Zuin-in… Input: Left and right wheels in phase and front and rear wheels in phase. Zuin-an… Input where left and right wheels are in phase and front and rear wheels are in opposite phases

Claims

1. A management method of control map, which is a method of managing a control map used in damping control of a vehicle, executed by a computer, characterized by, the control map including a first parameter map and a second parameter map, the first parameter map and the second parameter map each representing a correspondence between a position and a parameter associated with up-and-down movement of a reference point based on positions of two or more wheels of the vehicle, the method including: generating or updating the first parameter map; and generating or updating the second parameter map for a position identical to a position for which the generation or the update of the first parameter map is performed, the generation or the update of the first parameter map including calculating, as a first parameter associated with up-and-down movement of the reference point, in-phase input of left and right wheels resulting from identical up-and-down displacements of a first wheel and a second wheel of the vehicle based on time-series data of a parameter associated with up-and-down movement of the first wheel and time-series data of a parameter associated with up-and-down movement of the second wheel which constitutes left and right wheels with the first wheel, the generation or the update of the second parameter map including calculating, as a second parameter associated with up-and-down movement of the reference point, anti-phase input of left and right wheels resulting from different up-and-down displacements of the first wheel and the second wheel based on the time-series data of the parameter associated with up-and-down movement of the first wheel and the time-series data of the parameter associated with up-and-down movement of the second wheel.

2. The management method of control map according to claim 1, characterized in that, the generation or the update of the first parameter map further includes filter processing of the in-phase input of left and right wheels using a first high-pass filter, the generation or the update of the second parameter map further includes filter processing of the anti-phase input of left and right wheels using a second high-pass filter, the second high-pass filter is weaker than the first high-pass filter.

3. The management method of control map according to claim 1 or 2, characterized in that, the first parameter map includes a first sub-parameter map and a second sub-parameter map, the generation or the update of the first parameter map further includes generating or updating the first sub-parameter map and the second sub-parameter map, the generation or the update of the first sub-parameter map and the second sub-parameter map includes: calculating, as in-phase input of left and right wheels resulting from identical up-and-down displacements of a third wheel and a fourth wheel of the vehicle and anti-phase input of left and right wheels resulting from different up-and-down displacements of the third wheel and the fourth wheel, respectively, based on time-series data of parameters associated with up-and-down movement of the third wheel and the fourth wheel which constitute front and rear wheels with the first wheel and the second wheel. ​ calculating, as a first sub-parameter associated with the up-and-down motion of the reference point, left-and-right wheel in-phase and front-and-rear wheel in-phase input that is derived from the same up-and-down displacement of the first and second wheels and the same up-and-down displacement of the first and second wheels and the third and fourth wheels, based on the left-and-right wheel in-phase input of the first and second wheels and the left-and-right wheel in-phase input of the third and fourth wheels; and calculating, as a second sub-parameter associated with the up-and-down motion of the reference point, left-and-right wheel in-phase and front-and-rear wheel reverse input that is derived from the same up-and-down displacement of the first and second wheels and different up-and-down displacement of the first and second wheels and the third and fourth wheels, based on the left-and-right wheel in-phase input of the first and second wheels and the left-and-right wheel reverse input of the third and fourth wheels.

4. The management method of control mapping according to claim 3, wherein the generating or updating the first sub-parameter mapping and the second sub-parameter mapping further includes: filtering processing of the left-and-right wheel in-phase and front-and-rear wheel in-phase input using a first sub-high-pass filter; and filtering processing of the left-and-right wheel in-phase and front-and-rear wheel reverse input using a second sub-high-pass filter, the second sub-high-pass filter is weaker than the first sub-high-pass filter.

5. The management method of control mapping according to claim 4, wherein the second sub-high-pass filter is stronger than the second high-pass filter.

6. A control mapping management system, which manages control mappings used in vehicle vibration damping control, characterized in that, comprises: one or more processors; and one or more storage devices that hold the control mapping, the control mapping includes a first parameter mapping and a second parameter mapping, the first parameter mapping and the second parameter mapping respectively represent a correspondence between a position and a parameter associated with an up-and-down motion of a reference point based on positions of two or more wheels of a vehicle, the one or more processors are configured to: a process of generating or updating the first parameter mapping; and a process of generating or updating the second parameter mapping for the same position as the position for which the generation or update of the first parameter mapping is performed, the process of generating or updating the first parameter mapping includes a process of calculating, as a first parameter associated with the up-and-down motion of the reference point, left-and-right wheel in-phase input that is derived from the same up-and-down displacement of a first wheel and a second wheel of the vehicle based on time-series data of a parameter associated with an up-and-down motion of the first wheel and time-series data of a parameter associated with an up-and-down motion of the second wheel that constitutes left-and-right wheels with the first wheel, the process of generating or updating the second parameter mapping includes a process of calculating, as a second parameter associated with the up-and-down motion of the reference point, left-and-right wheel reverse input that is derived from different up-and-down displacement of the first wheel and the second wheel based on the time-series data of the parameter associated with the up-and-down motion of the first wheel and the time-series data of the parameter associated with the up-and-down motion of the second wheel. ​ ​ 7. The management system of control mapping according to claim 6, characterized in that, the process of generating or updating the first parameter mapping further comprises filtering processing of left and right wheel in-phase input of the first wheel and the second wheel using a first high-pass filter, the process of generating or updating the second parameter mapping further comprises filtering processing of left and right wheel anti-phase input of the first wheel and the second wheel using a second high-pass filter, the second high-pass filter is weaker than the first high-pass filter.

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