WO2020195174A1 - Steering characteristics setting device, steering characteristics setting method, and steering characteristics setting program - Google Patents

Steering characteristics setting device, steering characteristics setting method, and steering characteristics setting program Download PDF

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Publication number
WO2020195174A1
WO2020195174A1 PCT/JP2020/004012 JP2020004012W WO2020195174A1 WO 2020195174 A1 WO2020195174 A1 WO 2020195174A1 JP 2020004012 W JP2020004012 W JP 2020004012W WO 2020195174 A1 WO2020195174 A1 WO 2020195174A1
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WO
WIPO (PCT)
Prior art keywords
steering
vehicle
setting
assist
characteristic
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PCT/JP2020/004012
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French (fr)
Japanese (ja)
Inventor
山口　雄一
メリクシャ ユークセル
Original Assignee
ダイムラー・アクチェンゲゼルシャフト
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Publication of WO2020195174A1 publication Critical patent/WO2020195174A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits

Definitions

  • the present disclosure relates to a device, a method, and a program for setting the steering characteristics of the electric power steering provided in the vehicle.
  • the steering characteristics can be changed, for example, by the driver editing the steering characteristics at the timing when the mounted object is changed.
  • the technique described in Patent Document 1 has room for improvement in improving the steering performance of the vehicle.
  • This disclosure was devised in view of the above-mentioned problems, and one of the purposes is to improve the steering performance of the vehicle.
  • the steering characteristic setting device is a steering characteristic setting device for electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. It includes an acquisition unit and a setting unit that sets the characteristics of the assist force based on the information acquired by the acquisition unit.
  • the information includes the height of the center of gravity of the vehicle, and the setting unit has the characteristic that the larger the height of the center of gravity, the smaller the assist force. May be set. In this case, the higher the height of the center of gravity, the more the sharp turning (sudden steering) of the vehicle is suppressed, so that the posture of the vehicle becomes more stable.
  • the information includes the front axle weight of the vehicle, and the setting unit has the characteristics so that the larger the front axle weight, the larger the assist force. May be set. In this case, even if the front axle weight is large, it becomes easy to steer the vehicle.
  • the steering characteristic setting device includes a storage unit that stores a plurality of maps in which the characteristics are defined, and the setting unit stores the storage unit based on the information acquired by the acquisition unit.
  • One of the maps stored in the unit may be selected, and the characteristics specified in the selected map may be set. In this case, the control configuration is easily simplified.
  • the vehicle may be a truck. In this case, even if the bodywork as the load is changed in the truck, the characteristics of the assist force suitable for the load can be easily set.
  • the vehicle may be a bus. In this case, even if the number, arrangement, etc. of the occupants and luggage as the load are changed on the bus, the characteristics of the assist force suitable for the load can be easily set.
  • the steering characteristic setting method according to the present application example is a steering characteristic setting method of electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. It includes an acquisition step and a setting step for setting the characteristics of the assist force based on the information acquired in the acquisition step.
  • a steering characteristic setting method of electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. It includes an acquisition step and a setting step for setting the characteristics of the assist force based on the information acquired in the acquisition step.
  • the information includes the height of the center of gravity of the vehicle, and in the setting step, the characteristic is such that the larger the height of the center of gravity, the smaller the assist force. May be set. In this case, the higher the height of the center of gravity, the more the sharp turning (sudden steering) of the vehicle is suppressed, so that the posture of the vehicle becomes more stable.
  • the information includes the front axle weight of the vehicle, and in the setting step, the characteristic so that the larger the front axle weight, the larger the assist force. May be set. In this case, even if the front axle weight is large, it becomes easy to steer the vehicle.
  • the steering characteristic setting method includes a storage step of storing a plurality of maps in which the characteristic is defined before the implementation of the setting step, and is acquired in the acquisition step in the setting step. Based on the above information, one may be selected from the maps stored in the storage process, and the characteristics specified in the selected map may be set. In this case, the control configuration is easily simplified.
  • the steering characteristic setting program according to the present application example is a steering characteristic setting program of electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle.
  • the computer is made to execute the acquisition step and the setting step of setting the characteristics of the assist force based on the information acquired in the acquisition step.
  • the steering performance of the vehicle can be improved.
  • FIG. (A) to (c) are all map examples stored in the storage unit of the steering characteristic setting device of FIG. This is a map example for selecting one from the maps stored in the storage unit.
  • FIG. (A) to (c) is a map example for selecting one from the maps stored in the storage unit.
  • the steering characteristic setting device the steering characteristic setting method, and the steering characteristic setting program (hereinafter, simply referred to as "setting device”, “setting method”, and “setting program") will be described with reference to the drawings.
  • the embodiments shown below are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in the following embodiments.
  • Each configuration of the following embodiments can be variously modified and implemented without departing from the gist thereof.
  • it can be selected as needed, or can be combined as appropriate.
  • the setting device, the setting method, and the setting program according to the present embodiment set the steering characteristics of the electric power steering 2 provided in the vehicle 1 shown in FIG.
  • the vehicle 1 is a truck having a loading platform (pedestal portion) 11 is illustrated.
  • the vehicle 1 is an electric vehicle that travels by driving a traveling motor with the electric power of a battery (not shown).
  • the vehicle 1 can mount various loads (bodywork) 3 on the loading platform 11, and depending on the type of loader 3 to be mounted (bodywork), for example, a crane truck, a dump truck, a tank truck, a mixer truck, etc. Used as a wrecker truck, packer truck, van, etc.
  • the shape, size, weight, etc. of the load 3 differ depending on the type of the load 3.
  • the vehicle 1 is mechanically connected to a steering wheel 21 operated by a driver, a steering mechanism 22 that changes the steering angle of the front wheels 16 according to the steering angle of the steering wheel 21, and a steering wheel 21 and a steering mechanism 22.
  • a steering shaft 23 and a column 24 that rotatably supports the steering shaft 23 are provided. These devices 21 to 24 constitute the steering system of the vehicle 1.
  • the electric power steering (EPS) 2 is a device that gives an assist force to the steering system of the vehicle 1.
  • the electric power steering 2 of the present embodiment includes an electric steering motor 2A that generates an assist torque Ta as an assist force, and a steering ECU 2B (see FIG. 2) that controls the operation of the steering motor 2A.
  • the electric power steering 2 in which the steering motor 2A is a rack assist type or a pinion assist type provided in the steering mechanism 22 is illustrated.
  • a column assist type electric power steering in which the steering motor 2A is provided in the column 24 may be applied. Further, although FIG.
  • FIG. 1 illustrates a structure in which the steering mechanism 22 is connected to the lower end portion of the steering shaft 23, the structure of the steering system is not limited to this, and for example, between the steering shaft 23 and the steering mechanism 22
  • An intermediate shaft (not shown) connected to the lower end of the steering shaft 23 via a bevel gear (bevel gear) may be provided.
  • the vehicle 1 is provided with a VCU (Vehicle Control Unit) 4 for controlling the traveling motor and a setting ECU 5 as the setting device described above.
  • VCU Vehicle Control Unit
  • Each of these ECUs 2B, 4 and 5 is an electronic control device (computer) configured as an LSI device or an embedded electronic device in which a microprocessor, ROM, RAM, etc. are integrated, and is connected to a communication line of an in-vehicle network. Has been done.
  • the setting ECU 5 of this embodiment can communicate with both the steering ECU 2B and the VCU 4.
  • the vehicle 1 is provided with various sensors 12 to 15.
  • the height sensor 12 is attached to, for example, the vehicle body frame (not shown) of the vehicle 1, and is located on the front side of the vehicle 1 based on the distance (relative position) between the front axle (not shown) supporting the front wheels 16 and the vehicle body frame. Detects vehicle height Hf.
  • the acceleration sensor 13 detects the acceleration of the vehicle 1 in the front-rear direction. Specifically, the acceleration sensor 13 detects the acceleration ⁇ in the forward direction while the vehicle 1 is accelerating, and detects the acceleration (deceleration) ⁇ B in the rear direction while the vehicle 1 is decelerating.
  • acceleration ⁇ in the forward direction is simply referred to as “acceleration ⁇ ”
  • acceleration ⁇ B in the rear direction is referred to as “deceleration ⁇ B ”.
  • the height sensor 12 and the acceleration sensor 13 transmit the detected information to the setting ECU 5.
  • the speed sensor 14 detects the traveling speed V of the vehicle 1.
  • the steering torque sensor 15 detects the steering torque Ts input from the driver to the steering wheels 21.
  • the speed sensor 14 and the steering torque sensor 15 transmit the detected information to the steering ECU 2B.
  • the setting control is a control for setting the steering characteristics of the electric power steering 2.
  • the steering characteristic referred to here is the characteristic of the assist torque Ta described above, and is defined as, for example, the property of the assist torque Ta with respect to the steering torque Ts and the traveling speed V.
  • the steering characteristics are also referred to as "assist characteristics”.
  • the load 3 changes according to the application and usage conditions, even if the base vehicle body structure (structure other than the load 3) is the same, if the load 3 is different, the optimum assist characteristics are also different. there is a possibility.
  • the assist characteristic that exerts a larger assist torque Ta is preferable as compared with the case where the weight of the load 3 is relatively small.
  • the height Hc of the center of gravity of the vehicle 1 also changes according to the load 3.
  • the optimum assist characteristics change. For example, when the height Hc of the center of gravity is relatively high, the posture of the vehicle 1 is less stable than when the height Hc of the center of gravity is relatively low, so that sudden steering (sudden turning of the vehicle 1) is suppressed.
  • an assist characteristic that exerts a smaller assist torque Ta is preferable.
  • the assist characteristic is set based on the parameter that changes according to the load 3.
  • the height Hc of the center of gravity and the weight of the front axle (load applied to the front axle of the vehicle 1) Wf are exemplified as the above-mentioned parameters.
  • the height of the center of gravity Hc and the weight of the front axle Wf are both values that change according to the load 3.
  • the setting ECU 5 includes a storage unit 5A, an acquisition unit 5B, and a setting unit 5C as elements for executing setting control.
  • a storage unit 5A for executing setting control.
  • all of these elements 5A, 5B, and 5C are realized by software.
  • these elements 5A, 5B, and 5C may be realized by hardware (electronic circuit), or may be realized by using software and hardware in combination.
  • the storage unit 5A, the acquisition unit 5B, and the setting unit 5C are provided as the functions of the computer program (setting program) 7. Therefore, the setting ECU 5 executes the setting control by executing the computer program 7.
  • the computer program 7 may be provided so that it can be executed by the setting ECU 5, and is stored in a storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive) in the setting ECU 5, for example. It may be recorded in a medium that can be read by the setting ECU 5 or in an online storage on a network to which the setting ECU 5 can be connected.
  • the storage unit 5A stores a plurality of maps in which assist characteristics are defined.
  • each of these maps will be referred to as an "assist map".
  • the assist characteristics defined in the plurality of assist maps are different from each other.
  • each assist map of the present embodiment defines the steering torque Ts and the assist torque Ta with respect to the traveling speed V.
  • the vertical axis is the assist torque Ta and the horizontal axis is the steering torque Ts, and the lines showing the relationship between the assist torque Ta and the steering torque Ts are for each of the plurality of traveling speeds V.
  • the assist torque Ta is defined to increase as the steering torque Ts increases and as the traveling speed V increases.
  • three assist maps A1, A2, and B1 are illustrated in FIGS. 3A to 3C, nine assist maps (A1 to A3, B1 to B1 to be described later) are shown in the storage unit 5A of the present embodiment. B3, C1 to C3) are stored. These assist maps are created based on the results of tests and simulations carried out in advance so that the steering performance of the vehicle 1 is ensured.
  • the acquisition unit 5B acquires a parameter (information according to the load 3) that changes according to the load 3.
  • the height Hc of the center of gravity of the vehicle 1 and the weight Wf of the front axle are acquired as parameters.
  • the acquisition unit 5B uses the respective values Hf, ⁇ , ⁇ B detected by the height sensor 12 and the acceleration sensor 13 while the vehicle 1 is traveling, and the motor current value I transmitted from the VCU 4.
  • the height Hc of the center of gravity and the weight Wf of the front axle are calculated.
  • the center-of-gravity height Hc is calculated by the following equation (1) when the vehicle 1 is decelerating (when the acceleration sensor 13 detects the deceleration ⁇ B ).
  • Hc ⁇ W ⁇ L / ( ⁇ B ⁇ W) ⁇ ⁇ ⁇ (1)
  • ⁇ W in the equation (1) is the amount of load (load movement amount) that moves from the rear to the front of the vehicle 1 when the vehicle 1 is decelerated.
  • the load transfer amount ⁇ W is calculated based on, for example, the amount of change in the vehicle height Hf detected by the height sensor 12.
  • the load transfer amount ⁇ W may be calculated based on the information detected by the 3-axis acceleration sensor.
  • L in the formula (1) is the wheelbase (distance between the front axle and the rear axle) of the vehicle 1. Since the wheelbase L is a value unique to the vehicle 1, for example, it is measured or set when the production of the vehicle 1 is completed, and is stored (stored) in the setting ECU 5.
  • T in the formula (2) is the drive torque of the traveling motor, and is calculated based on the motor current value I transmitted from the VCU 4.
  • the motor current value I may be a control value instructed by the VCU 4 to the traveling motor, or may be a detection value detected by a sensor provided in the electric circuit of the traveling motor.
  • R in the formula (2) is the radius of the tire of the vehicle 1 (tire radius). The tire radius r is, for example, measured or set when the production of the vehicle 1 is completed, and is stored (stored) in the setting ECU 5.
  • the acquisition unit 5B first calculates a drive torque T based on the motor current value I transmitted from the VCU 4, the drive torque T, the acceleration ⁇ detected by the acceleration sensor 13, and the tire radius r stored in advance. By applying and to the equation (2), the vehicle weight W is calculated. Further, the acquisition unit 5B calculates the load transfer amount ⁇ W based on the vehicle height Hf detected by the height sensor 12, and detects the load transfer amount ⁇ W, the wheelbase L stored in advance, and the acceleration sensor 13. The height of the center of gravity Hc is calculated by applying the deceleration ⁇ B and the vehicle weight W calculated from the equation (2) to the equation (1).
  • the front axle weight Wf is calculated based on, for example, the vehicle height Hf detected by the height sensor 12. Specifically, the front axle weight Wf is the difference between the vehicle height (reference value) when the load 3 is not mounted and the vehicle height Hf when the load 3 is mounted, and the front wheels. It is calculated based on the spring constant of the suspension device (front suspension) provided in 16. As the above-mentioned reference value and spring constant, for example, those measured or set at the completion of manufacturing of the vehicle 1 and stored (stored) in the setting ECU 5 can be applied.
  • the front axle weight Wf may be calculated based on the information transmitted from the steering ECU 2B.
  • the front axle weight Wf is the assist torque Ta (default value) in the stationary state transmitted from the steering ECU 2B when the loading object 3 is not mounted, and the steering ECU 2B when the mounting object 3 is mounted. It may be calculated based on the difference from the assist torque Ta in the stationary state transmitted from.
  • the above-mentioned default value may be acquired in advance when the production of the vehicle 1 is completed and stored (stored) in the setting ECU 5.
  • the setting unit 5C sets the assist characteristic of the electric power steering 2 based on the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B.
  • the setting unit 5C of the present embodiment selects one from a plurality of assist maps stored in the storage unit 5A based on the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B. Then, the setting unit 5C transmits the selected assist map to the steering ECU 2B to set the assist characteristics defined in the assist map for the electric power steering 2.
  • the setting unit 5C applies the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B to the selection map 6 illustrated in FIG. 4, so that the center of gravity height Hc at that time is applied. And select the assist map according to the front axle weight Wf.
  • nine assist maps stored in the storage unit 5A are defined in association with the center of gravity height Hc and the front axle weight Wf.
  • the vertical axis is the center of gravity height Hc and the horizontal axis is the front axle load Wf, and the vertical axis and the horizontal axis are each divided into three ranges (small, medium, and large). Has been done.
  • the above-mentioned nine assist maps (A1 to A3, B1 to B3, C1 to C3) are assigned to a total of nine categories.
  • the assist map is assigned so that the assist map having the smaller assist torque Ta is selected as the height Hc of the center of gravity is larger.
  • three assist maps A1 to A3 selected when the front axle weight Wf is "small" will be described as an example. As shown in FIGS. 3A and 3B, it is selected when the center of gravity height Hc is “medium” with respect to the assist map A1 selected when the center of gravity height Hc is “small”.
  • the assist map A2 defines a smaller assist torque Ta. That is, when the assist torque Ta for the same steering torque Ts and the traveling speed V is compared, the assist torque Ta is smaller in the assist map A2 than in the assist map A1.
  • a smaller assist torque Ta is defined in the assist map A3 (not shown) selected when the center of gravity height Hc is "large” with respect to the assist map A2.
  • the height Hc of the center of gravity is large in the assist maps B1 to B3 when the front axle weight Wf is “medium” and the assist maps C1 to C3 when the front axle weight Wf is “large”. The smaller the assist torque Ta is specified.
  • the assist map is assigned so that the assist map having a larger assist torque Ta is selected as the front axle weight Wf is larger.
  • three assist maps A1, B1, and C1 when the height Hc of the center of gravity is “small” will be described as an example.
  • a larger assist torque Ta is defined in the assist map B1. That is, when the assist torque Ta for the same steering torque Ts and the traveling speed V is compared, the assist torque Ta becomes larger in the assist map B1 than in the assist map A1.
  • a larger assist torque Ta is specified in the assist map C1 (not shown) selected when the front axle weight Wf is "large” with respect to the assist map B1.
  • the assist maps A2, B2, C2 when the center of gravity height Hc is “medium” and in the assist maps A3, B3, C3 when the center of gravity height Hc is "large” the front axle The larger the weight Wf, the larger the assist torque Ta is specified.
  • the assist characteristic is set so that the larger the center of gravity height Hc is, the smaller the assist torque Ta is, and the larger the front axle weight Wf is, the more the assist torque is set.
  • the selection map 6 shown in FIG. 4 is an example.
  • the number of assist maps defined in the selection map 6 is appropriately defined according to the number of assist maps stored in the storage unit 5A, the assumed center of gravity height Hc, and the range of the front axle load Wf.
  • the steering ECU 2B determines the assist torque Ta given from the steering motor 2A to the steering mechanism 22 by using the assist map set by the setting unit 5C (transmitted from the setting unit 5C). Specifically, the steering ECU 2B applies the traveling speed V transmitted from the speed sensor 14 and the steering torque Ts transmitted from the steering torque sensor 15 to the assist map set by the setting unit 5C. Determine the assist torque Ta. Then, the steering ECU 2B controls the steering motor 2A so that the determined assist torque Ta is applied to the steering mechanism 22.
  • FIG. 5 is a flowchart showing the above-mentioned setting control procedure (setting method). As shown in FIG. 5, in the setting control, first, the above-mentioned nine assist maps are stored (step S1). Step S1 is a process (storage step) performed by the storage unit 5A before the vehicle 1 is used (for example, when the vehicle 1 is manufactured).
  • steps S2 to S5 after step S1 are processes performed while the vehicle 1 is traveling in the present embodiment. If the load 3 does not change (or is expected to change) while the vehicle 1 is running, these steps S2 to S5 are performed only once during the running of the vehicle 1 (for example, at the start of running). Just do it. Alternatively, these steps S2 to S5 may be repeatedly performed in a predetermined cycle while the vehicle 1 is traveling. Here, it is assumed that steps S2 to S5 are performed only once while the vehicle 1 is traveling.
  • step S2 various information is input from the VCU 4, the height sensor 12, and the acceleration sensor 13.
  • step S3 the height Hc of the center of gravity and the weight Wf of the front axle are acquired (calculated) using the information input in step S2, various values stored in advance, and the like.
  • the processes of steps S2 and S3 are processes (acquisition steps) performed by the acquisition unit 5B.
  • step S4 one is selected from the assist maps stored in step S1 based on the center of gravity height Hc and the front axle weight Wf acquired in step S3.
  • step S4 the assist map selected in step S4 is transmitted to the steering ECU 2B, so that the assist characteristics defined in the assist map are set in the electric power steering 2 (step S5).
  • steps S4 and S5 are processes (setting steps) performed by the setting unit 5C. Then, the setting control ends.
  • the electric power is based on the information corresponding to the mounted object 3 (parameters of the center of gravity height Hc and the front axle weight Wf in this embodiment).
  • the assist characteristic of the steering 2 is set. Therefore, when the mounted objects 3 are different, it is possible to set the assist characteristic suitable for the mounted objects 3 in any of the different mounted objects 3.
  • the vehicle 1 is a crane truck (the load 3 is a crane mechanism) and the vehicle 1 is a mixer truck (the load 3 is composed of a drum or the like)
  • the height of the center of gravity Hc and The front axle weight Wf is different, and the optimum assist characteristics of the electric power steering 2 are also different. Therefore, for example, when the assist characteristic is fixed regardless of the load 3 as in the case where hydraulic power steering is applied, the steering performance of the vehicle 1 deteriorates due to the change of the load 3. There is a risk.
  • the assist characteristic is set based on the information according to the load 3, so that the vehicle 1 is a crane truck and the mixer truck. In each of the cases, it is possible to set the assist characteristic suitable for the mounted object 3. Therefore, the steering performance of the vehicle 1 can be improved.
  • the vehicle 1 can be easily steered by setting the assist characteristic so that the assist torque Ta increases as the front axle weight Wf as the above-mentioned parameter increases. Therefore, the steering performance of the vehicle 1 can be further improved.
  • the vehicle 1 described above is a truck
  • the load 3 as a bodywork is diverse and may be frequently changed according to the use of the vehicle 1, but the setting ECU 5 and the setting method described above may be used. And, by applying the computer program 7, the steering performance of the vehicle 1 can be easily improved as described above even when the load 3 is frequently changed.
  • the load 3 may be mounted on the vehicle 1, and the type thereof is not particularly limited. Further, the vehicle 1 is not limited to the truck as described above, and may be, for example, a bus. In this case, examples of the load 3 mounted on the bus include passengers, luggage, and the like. Generally, in a bus, even if the base body structure is the same, the number of occupants and the amount and position of luggage change depending on the situation, so that the optimum assist characteristics may also change. On the other hand, if the setting ECU 5, the setting method, and the computer program 7 described above are applied, as described above, even if the mounted object 3 is changed, the assist characteristic suitable for the mounted object 3 can be set. Therefore, the steering performance can be improved as in the above-described embodiment.
  • the information (parameters described above) according to the load 3 is not limited to the height Hc of the center of gravity and the weight Wf of the front axle described above. This information may include, for example, only one of the center of gravity height Hc and the front axle weight Wf, or may include other than the center of gravity height Hc and the front axle weight Wf.
  • the method of acquiring information according to the load 3 is not limited to the above-mentioned method.
  • the driver or the operator may manually input the information corresponding to the mounted object 3 into the setting ECU 5 by using an appropriate input device.
  • the acquisition unit 5B may acquire information (for example, the above-mentioned parameters) corresponding to the mounted object 3 from the input device.
  • the process of storing the assist map in the storage unit 5A storage step
  • the maps shown in FIGS. 3 (a) to 3 (c) and FIG. 4 are all examples.
  • the above-mentioned assist map may be appropriately set according to the configuration of the vehicle 1, the characteristics of the electric power steering 2, and the like.
  • the steering angular velocity of the steering wheel 21 may be used instead of the steering torque Ts.
  • the setting ECU 5 may be provided as an element of the electric power steering 2. Specifically, the function of the setting ECU 5 and the function of the steering ECU 2B described above may be combined into one ECU. Further, the vehicle 1 does not have to be an electric vehicle, and may be, for example, a hybrid vehicle in which an engine and an electric motor are combined, a fuel cell vehicle, an engine vehicle, or the like.

Abstract

[Problem] To improve steering performance of a vehicle. [Solution] A steering characteristics setting device 5 is applied to electrically-powered power steering 2 that imparts assist power to a steering system of a vehicle, and comprises an acquisition unit 5B and a setting unit 5C. The acquisition unit 5B acquires information in accordance with a load on the vehicle. The setting unit 5C sets characteristics of assist power on the basis of the information acquired by the acquisition unit 5B. Accordingly, when there are different loads for the vehicle, it is possible to set, for each of the different loads, characteristics that are appropriate for the load.

Description

操舵特性設定装置、操舵特性設定方法、及び操舵特性設定プログラムSteering characteristic setting device, steering characteristic setting method, and steering characteristic setting program
　本開示は、車両に設けられた電動パワーステアリングの操舵特性を設定する装置、方法、及びプログラムに関する。 The present disclosure relates to a device, a method, and a program for setting the steering characteristics of the electric power steering provided in the vehicle.
　従来、車両のドライバの操舵力をアシストするパワーステアリングが知られている。パワーステアリングのアシスト力が適切に設定されれば、車両の操舵性能やドライバの操舵フィーリングが向上する。これに関し、電動のモータでアシスト力を与える電動パワーステアリング（ＥＰＳ；Electric Power Steering）の操舵特性（アシスト力の特性）を、ドライバ自身が編集できるようにすることが提案されている（例えば特許文献１参照）。 Conventionally, power steering that assists the steering force of a vehicle driver is known. If the assist force of the power steering is set appropriately, the steering performance of the vehicle and the steering feeling of the driver are improved. In this regard, it has been proposed that the steering characteristics (characteristics of assisting force) of electric power steering (EPS) that gives assisting force by an electric motor can be edited by the driver himself (for example, Patent Documents). 1).
特開2002-293257号公報JP-A-2002-293257
　ところで、例えばトラックでは、その用途や使用状況に応じて、荷台に架装される架装物が多岐にわたる。ベース車両が同一でも架装物が異なる場合、最適な操舵特性も異なる可能性がある。このため、操舵特性が固定された電動パワーステアリングや、操舵特性を変更できない油圧式のパワーステアリングでは、トラックの架装物が変更された場合に、操舵性能の低下を招く虞がある。なお、これはトラックに限らず、トラック以外の車両において、この車両に搭載される搭載物が変更された場合も同様である。 By the way, for example, in a truck, there are a wide variety of bodywork to be mounted on the loading platform depending on its use and usage conditions. If the base vehicle is the same but the bodywork is different, the optimum steering characteristics may also be different. Therefore, in the case of electric power steering in which the steering characteristics are fixed or hydraulic power steering in which the steering characteristics cannot be changed, there is a possibility that the steering performance may be deteriorated when the bodywork of the truck is changed. It should be noted that this is not limited to trucks, but the same applies to vehicles other than trucks when the load mounted on the vehicle is changed.
　これに対し、特許文献１に記載されているようにドライバが操舵特性を編集できる場合は、例えば搭載物が変更されたタイミングでドライバが操舵特性を編集することにより、操舵特性を変更できる。しかしながら、この場合、操舵特性をドライバの嗜好に合ったものには変更できたとしても、搭載物に適合したものとすることは困難である。したがって、特許文献１に記載された技術には、車両の操舵性能を向上させるうえで改善の余地がある。 On the other hand, when the driver can edit the steering characteristics as described in Patent Document 1, the steering characteristics can be changed, for example, by the driver editing the steering characteristics at the timing when the mounted object is changed. However, in this case, even if the steering characteristics can be changed to suit the driver's taste, it is difficult to make the steering characteristics suitable for the mounted object. Therefore, the technique described in Patent Document 1 has room for improvement in improving the steering performance of the vehicle.
　本開示は、上述したような課題に鑑み創案されたものであり、車両の操舵性能を向上させることを目的の一つとする。 This disclosure was devised in view of the above-mentioned problems, and one of the purposes is to improve the steering performance of the vehicle.
　本開示は上述した課題の少なくとも一部を解決するためになされたものであり、以下の態様又は適用例として実現することができる。
　（１）本適用例に係る操舵特性設定装置は、車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定装置であって、前記車両に搭載される搭載物に応じた情報を取得する取得部と、前記取得部で取得された前記情報に基づき、前記アシスト力の特性を設定する設定部と、を備えている。これにより、例えば同一のベース車両に対して搭載物が異なる場合に、異なる搭載物のいずれにおいても、搭載物に適合したアシスト力の特性が設定可能となる。 The present disclosure has been made to solve at least a part of the above-mentioned problems, and can be realized as the following aspects or application examples.
(1) The steering characteristic setting device according to the present application example is a steering characteristic setting device for electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. It includes an acquisition unit and a setting unit that sets the characteristics of the assist force based on the information acquired by the acquisition unit. As a result, for example, when the mounted objects are different for the same base vehicle, it is possible to set the characteristics of the assist force suitable for the mounted objects in any of the different loaded vehicles.
　（２）本適用例に係る操舵特性設定装置において、前記情報には前記車両の重心高さが含まれ、前記設定部は、前記重心高さが大きいほど前記アシスト力が小さくなるように前記特性を設定してもよい。この場合、重心高さが大きいほど車両の急旋回（急操舵）が抑制されるため、車両の姿勢が安定しやすくなる。 (2) In the steering characteristic setting device according to the present application example, the information includes the height of the center of gravity of the vehicle, and the setting unit has the characteristic that the larger the height of the center of gravity, the smaller the assist force. May be set. In this case, the higher the height of the center of gravity, the more the sharp turning (sudden steering) of the vehicle is suppressed, so that the posture of the vehicle becomes more stable.
　（３）本適用例に係る操舵特性設定装置において、前記情報には前記車両の前軸重量が含まれ、前記設定部は、前記前軸重量が大きいほど前記アシスト力が大きくなるように前記特性を設定してもよい。この場合、前軸重量が大きくても、車両を操舵しやすくなる。 (3) In the steering characteristic setting device according to the present application example, the information includes the front axle weight of the vehicle, and the setting unit has the characteristics so that the larger the front axle weight, the larger the assist force. May be set. In this case, even if the front axle weight is large, it becomes easy to steer the vehicle.
　（４）本適用例に係る操舵特性設定装置は、前記特性が規定された複数のマップを記憶する記憶部を備え、前記設定部は、前記取得部で取得された前記情報に基づき、前記記憶部に記憶された前記マップの中から一つを選択し、選択した前記マップに規定された前記特性を設定してもよい。この場合、制御構成が簡素化されやすくなる。 (4) The steering characteristic setting device according to the present application example includes a storage unit that stores a plurality of maps in which the characteristics are defined, and the setting unit stores the storage unit based on the information acquired by the acquisition unit. One of the maps stored in the unit may be selected, and the characteristics specified in the selected map may be set. In this case, the control configuration is easily simplified.
　（５）本適用例に係る操舵特性設定装置において、前記車両がトラックであってもよい。この場合、トラックにおいて、搭載物としての架装物が変更されたとしても、搭載物に適合したアシスト力の特性が容易に設定可能となる。
　（６）本適用例に係る操舵特性設定装置において、前記車両がバスであってもよい。この場合、バスにおいて、搭載物としての乗員や荷物の数、配置等が変更されたとしても、搭載物に適合したアシスト力の特性が容易に設定可能となる。 (5) In the steering characteristic setting device according to this application example, the vehicle may be a truck. In this case, even if the bodywork as the load is changed in the truck, the characteristics of the assist force suitable for the load can be easily set.
(6) In the steering characteristic setting device according to this application example, the vehicle may be a bus. In this case, even if the number, arrangement, etc. of the occupants and luggage as the load are changed on the bus, the characteristics of the assist force suitable for the load can be easily set.
　（７）本適用例に係る操舵特性設定方法は、車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定方法であって、前記車両に搭載される搭載物に応じた情報を取得する取得工程と、前記取得工程で取得された前記情報に基づき、前記アシスト力の特性を設定する設定工程と、を備えている。これにより、例えば同一のベース車両に対して搭載物が異なる場合に、異なる搭載物のいずれにおいても、その搭載物に適合したアシスト力の特性が設定可能となる。 (7) The steering characteristic setting method according to the present application example is a steering characteristic setting method of electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. It includes an acquisition step and a setting step for setting the characteristics of the assist force based on the information acquired in the acquisition step. As a result, for example, when the mounted objects are different for the same base vehicle, it is possible to set the characteristics of the assist force suitable for the mounted objects in any of the different loaded vehicles.
　（８）本適用例に係る操舵特性設定方法において、前記情報には前記車両の重心高さが含まれ、前記設定工程では、前記重心高さが大きいほど前記アシスト力が小さくなるように前記特性を設定してもよい。この場合、重心高さが大きいほど車両の急旋回（急操舵）が抑制されるため、車両の姿勢が安定しやすくなる。 (8) In the steering characteristic setting method according to the present application example, the information includes the height of the center of gravity of the vehicle, and in the setting step, the characteristic is such that the larger the height of the center of gravity, the smaller the assist force. May be set. In this case, the higher the height of the center of gravity, the more the sharp turning (sudden steering) of the vehicle is suppressed, so that the posture of the vehicle becomes more stable.
　（９）本適用例に係る操舵特性設定方法において、前記情報には前記車両の前軸重量が含まれ、前記設定工程では、前記前軸重量が大きいほど前記アシスト力が大きくなるように前記特性を設定してもよい。この場合、前軸重量が大きくても、車両を操舵しやすくなる。 (9) In the steering characteristic setting method according to the present application example, the information includes the front axle weight of the vehicle, and in the setting step, the characteristic so that the larger the front axle weight, the larger the assist force. May be set. In this case, even if the front axle weight is large, it becomes easy to steer the vehicle.
　（１０）本適用例に係る操舵特性設定方法は、前記設定工程の実施前に、前記特性が規定された複数のマップを記憶する記憶工程を備え、前記設定工程では、前記取得工程で取得された前記情報に基づき、前記記憶工程で記憶された前記マップの中から一つを選択し、選択した前記マップに規定された前記特性を設定してもよい。この場合、制御構成が簡素化されやすくなる。 (10) The steering characteristic setting method according to the present application example includes a storage step of storing a plurality of maps in which the characteristic is defined before the implementation of the setting step, and is acquired in the acquisition step in the setting step. Based on the above information, one may be selected from the maps stored in the storage process, and the characteristics specified in the selected map may be set. In this case, the control configuration is easily simplified.
　（１１）本適用例に係る操舵特性設定プログラムは、車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定プログラムであって、前記車両に搭載される搭載物に応じた情報を取得する取得工程と、前記取得工程で取得された前記情報に基づき、前記アシスト力の特性を設定する設定工程と、をコンピュータに実行させる。これにより、例えば同一のベース車両に対して搭載物が異なる場合に、異なる搭載物のいずれにおいても、その搭載物に適合したアシスト力の特性が設定可能となる。 (11) The steering characteristic setting program according to the present application example is a steering characteristic setting program of electric power steering that gives an assist force to the steering system of the vehicle, and acquires information according to the mounted object mounted on the vehicle. The computer is made to execute the acquisition step and the setting step of setting the characteristics of the assist force based on the information acquired in the acquisition step. As a result, for example, when the mounted objects are different for the same base vehicle, it is possible to set the characteristics of the assist force suitable for the mounted objects in any of the different loaded vehicles.
　本開示によれば、車両の操舵性能を向上させることができる。 According to the present disclosure, the steering performance of the vehicle can be improved.
実施形態としての操舵特性設定装置が適用された車両を搭載物の例と共に示す側面図である。It is a side view which shows the vehicle to which the steering characteristic setting device as an embodiment is applied, together with the example of a load. 図１の車両の制御構成を示すブロック図である。It is a block diagram which shows the control structure of the vehicle of FIG. （ａ）～（ｃ）はいずれも、図１の操舵特性設定装置の記憶部に記憶されたマップ例である。(A) to (c) are all map examples stored in the storage unit of the steering characteristic setting device of FIG. 記憶部に記憶されたマップの中から一つを選択するためのマップ例である。This is a map example for selecting one from the maps stored in the storage unit. 図１の操舵特性設定装置で実施される設定制御の手順を例示するフローチャートである。It is a flowchart which illustrates the procedure of the setting control performed by the steering characteristic setting apparatus of FIG.
　図面を参照して、実施形態としての操舵特性設定装置、操舵特性設定方法、及び操舵特性設定プログラム（以下、単に「設定装置」、「設定方法」、及び「設定プログラム」という）について説明する。以下に示す実施形態はあくまでも例示に過ぎず、以下の実施形態で明示しない種々の変形や技術の適用を排除する意図はない。以下の実施形態の各構成は、それらの趣旨を逸脱しない範囲で種々変形して実施することができる。また、必要に応じて取捨選択することができ、あるいは適宜組み合わせることができる。 The steering characteristic setting device, the steering characteristic setting method, and the steering characteristic setting program (hereinafter, simply referred to as "setting device", "setting method", and "setting program") will be described with reference to the drawings. The embodiments shown below are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in the following embodiments. Each configuration of the following embodiments can be variously modified and implemented without departing from the gist thereof. In addition, it can be selected as needed, or can be combined as appropriate.
［１．全体構成］
　本実施形態に係る設定装置、設定方法、及び設定プログラムは、図１に示す車両１に設けられた電動パワーステアリング２の操舵特性を設定するものである。本実施形態では、車両１が荷台（台座部）１１を有するトラックである場合を例示する。車両１は、図示しないバッテリの電力で走行用モータを駆動することにより走行する電動車両である。 [1. overall structure]
The setting device, the setting method, and the setting program according to the present embodiment set the steering characteristics of the electric power steering 2 provided in the vehicle 1 shown in FIG. In this embodiment, the case where the vehicle 1 is a truck having a loading platform (pedestal portion) 11 is illustrated. The vehicle 1 is an electric vehicle that travels by driving a traveling motor with the electric power of a battery (not shown).
　車両１は、様々な搭載物（架装物）３を荷台１１に搭載可能であり、搭載（架装）する搭載物３の種類に応じて、例えば、クレーン車、ダンプカー、タンクローリー、ミキサー車、レッカー車、パッカー車、バン等として使用される。なお、搭載物３の形状、大きさ、重量等は、搭載物３の種類に応じて異なる。 The vehicle 1 can mount various loads (bodywork) 3 on the loading platform 11, and depending on the type of loader 3 to be mounted (bodywork), for example, a crane truck, a dump truck, a tank truck, a mixer truck, etc. Used as a wrecker truck, packer truck, van, etc. The shape, size, weight, etc. of the load 3 differ depending on the type of the load 3.
　車両１には、ドライバにより操作される操舵輪２１と、操舵輪２１の操舵角に応じて前輪１６の舵角を変更する操舵機構２２と、操舵輪２１及び操舵機構２２を機械的に接続する操舵軸２３と、操舵軸２３を回転自在に支持するコラム２４とが設けられている。これらの装置２１～２４は、車両１の操舵系を構成する。 The vehicle 1 is mechanically connected to a steering wheel 21 operated by a driver, a steering mechanism 22 that changes the steering angle of the front wheels 16 according to the steering angle of the steering wheel 21, and a steering wheel 21 and a steering mechanism 22. A steering shaft 23 and a column 24 that rotatably supports the steering shaft 23 are provided. These devices 21 to 24 constitute the steering system of the vehicle 1.
　電動パワーステアリング（ＥＰＳ；Electric Power Steering）２は、車両１の操舵系にアシスト力を与える装置である。本実施形態の電動パワーステアリング２は、アシスト力としてのアシストトルクＴaを発生させる電動の操舵モータ２Ａと、操舵モータ２Ａの動作を制御する操舵ＥＣＵ２Ｂ（図２参照）とを有する。本実施形態では、操舵モータ２Ａが操舵機構２２に設けられたラックアシスト式又はピニオンアシスト式である電動パワーステアリング２を例示する。なお、これに代えて、操舵モータ２Ａがコラム２４に設けられたコラムアシスト式の電動パワーステアリングが適用されてもよい。また、図１では操舵機構２２が操舵軸２３の下端部に連結された構造を例示するが、操舵系の構造はこれに限定されず、例えば、操舵軸２３と操舵機構２２との間に、操舵軸２３の下端部とかさ歯車（ベベルギヤ）を介して連結された中間軸（図示略）が設けられてもよい。 The electric power steering (EPS) 2 is a device that gives an assist force to the steering system of the vehicle 1. The electric power steering 2 of the present embodiment includes an electric steering motor 2A that generates an assist torque Ta as an assist force, and a steering ECU 2B (see FIG. 2) that controls the operation of the steering motor 2A. In the present embodiment, the electric power steering 2 in which the steering motor 2A is a rack assist type or a pinion assist type provided in the steering mechanism 22 is illustrated. Instead of this, a column assist type electric power steering in which the steering motor 2A is provided in the column 24 may be applied. Further, although FIG. 1 illustrates a structure in which the steering mechanism 22 is connected to the lower end portion of the steering shaft 23, the structure of the steering system is not limited to this, and for example, between the steering shaft 23 and the steering mechanism 22 An intermediate shaft (not shown) connected to the lower end of the steering shaft 23 via a bevel gear (bevel gear) may be provided.
　図２に示すように、車両１には、上述した操舵ＥＣＵ２Ｂのほかに、走行用モータを制御するＶＣＵ（Vehicle Control Unit）４と、上述した設定装置としての設定ＥＣＵ５とが設けられている。これらのＥＣＵ２Ｂ、４、５はいずれも、例えばマイクロプロセッサやＲＯＭ、ＲＡＭ等を集積したＬＳＩデバイスや組み込み電子デバイスとして構成された電子制御装置（コンピュータ）であって、車載ネットワーク網の通信ラインに接続されている。本実施形態の設定ＥＣＵ５は、操舵ＥＣＵ２Ｂ及びＶＣＵ４の双方と通信可能である。 As shown in FIG. 2, in addition to the steering ECU 2B described above, the vehicle 1 is provided with a VCU (Vehicle Control Unit) 4 for controlling the traveling motor and a setting ECU 5 as the setting device described above. Each of these ECUs 2B, 4 and 5 is an electronic control device (computer) configured as an LSI device or an embedded electronic device in which a microprocessor, ROM, RAM, etc. are integrated, and is connected to a communication line of an in-vehicle network. Has been done. The setting ECU 5 of this embodiment can communicate with both the steering ECU 2B and the VCU 4.
　また、車両１には、様々なセンサ１２～１５が設けられる。ハイトセンサ１２は、例えば車両１の車体フレーム（図示略）に取り付けられ、前輪１６を支持する前車軸（図示略）とこの車体フレームとの距離（相対位置）に基づいて、車両１の前側の車高Ｈfを検出する。加速度センサ１３は、車両１の前後方向の加速度を検出する。具体的には、加速度センサ１３は、車両１の加速中に前方向の加速度αを検出し、車両１の減速中に後方向の加速度（減速度）αBを検出する。以下、前方向の加速度αを単に「加速度α」といい、後方向の加速度αBを「減速度αB」という。ハイトセンサ１２及び加速度センサ１３は、検出した情報を設定ＥＣＵ５に伝達する。 Further, the vehicle 1 is provided with various sensors 12 to 15. The height sensor 12 is attached to, for example, the vehicle body frame (not shown) of the vehicle 1, and is located on the front side of the vehicle 1 based on the distance (relative position) between the front axle (not shown) supporting the front wheels 16 and the vehicle body frame. Detects vehicle height Hf. The acceleration sensor 13 detects the acceleration of the vehicle 1 in the front-rear direction. Specifically, the acceleration sensor 13 detects the acceleration α in the forward direction while the vehicle 1 is accelerating, and detects the acceleration (deceleration) α B in the rear direction while the vehicle 1 is decelerating. Hereinafter, the acceleration α in the forward direction is simply referred to as “acceleration α”, and the acceleration α B in the rear direction is referred to as “deceleration α B ”. The height sensor 12 and the acceleration sensor 13 transmit the detected information to the setting ECU 5.
　速度センサ１４は、車両１の走行速度Ｖを検出する。操舵トルクセンサ１５は、ドライバから操舵輪２１に入力される操舵トルクＴsを検出する。速度センサ１４及び操舵トルクセンサ１５は、検出した情報を操舵ＥＣＵ２Ｂに伝達する。 The speed sensor 14 detects the traveling speed V of the vehicle 1. The steering torque sensor 15 detects the steering torque Ts input from the driver to the steering wheels 21. The speed sensor 14 and the steering torque sensor 15 transmit the detected information to the steering ECU 2B.
［２．制御構成］
　本実施形態では、設定ＥＣＵ５によって実施される設定制御について説明する。設定制御は、電動パワーステアリング２の操舵特性を設定する制御である。ここでいう操舵特性とは、上述したアシストトルクＴaの特性であって、例えば、操舵トルクＴs及び走行速度Ｖに対するアシストトルクＴaの性質として規定される。以下、操舵特性を「アシスト特性」ともいう。 [2. Control configuration]
In this embodiment, the setting control performed by the setting ECU 5 will be described. The setting control is a control for setting the steering characteristics of the electric power steering 2. The steering characteristic referred to here is the characteristic of the assist torque Ta described above, and is defined as, for example, the property of the assist torque Ta with respect to the steering torque Ts and the traveling speed V. Hereinafter, the steering characteristics are also referred to as "assist characteristics".
　車両１では、用途や使用状況に応じて搭載物３が変化することから、ベースとなる車体構造（搭載物３以外の構造）が同一でも、搭載物３が異なる場合は最適なアシスト特性も異なる可能性がある。例えば、車両１において、搭載物３の重量が比較的大きい場合は、搭載物３の重量が比較的小さい場合と比べて、より大きなアシストトルクＴaを発揮するアシスト特性が好適となる。 In the vehicle 1, since the load 3 changes according to the application and usage conditions, even if the base vehicle body structure (structure other than the load 3) is the same, if the load 3 is different, the optimum assist characteristics are also different. there is a possibility. For example, in the vehicle 1, when the weight of the load 3 is relatively large, the assist characteristic that exerts a larger assist torque Ta is preferable as compared with the case where the weight of the load 3 is relatively small.
　また、搭載物３の形状及び重量は様々であるため、車両１では重心高さＨcも搭載物３に応じて変化する。重心高さＨcが変化すると、最適なアシスト特性が変わる。例えば、重心高さＨcが比較的高い場合は、重心高さＨcが比較的低い場合と比べて、車両１の姿勢が安定しにくくなるため、急操舵（車両１の急旋回）を抑制するために、より小さなアシストトルクＴaを発揮するアシスト特性が好適となる。 Further, since the shape and weight of the load 3 are various, the height Hc of the center of gravity of the vehicle 1 also changes according to the load 3. When the height Hc of the center of gravity changes, the optimum assist characteristics change. For example, when the height Hc of the center of gravity is relatively high, the posture of the vehicle 1 is less stable than when the height Hc of the center of gravity is relatively low, so that sudden steering (sudden turning of the vehicle 1) is suppressed. In addition, an assist characteristic that exerts a smaller assist torque Ta is preferable.
　そこで、設定制御では、搭載物３に応じて変化するパラメータに基づいてアシスト特性を設定する。これにより、搭載物３が変更される場合であっても、その時点で搭載されている（あるいは、これから搭載される予定の）搭載物３に適合したアシスト特性を設定することが可能となるため、操舵性能が向上する。本実施形態では、上述したパラメータとして、重心高さＨcと前軸重量（車両１の前車軸にかかる荷重）Ｗfとを例示する。重心高さＨc及び前軸重量Ｗfはいずれも、搭載物３に応じて変化する値である。 Therefore, in the setting control, the assist characteristic is set based on the parameter that changes according to the load 3. As a result, even if the load 3 is changed, it is possible to set the assist characteristic suitable for the load 3 that is currently mounted (or will be mounted) at that time. , Steering performance is improved. In the present embodiment, the height Hc of the center of gravity and the weight of the front axle (load applied to the front axle of the vehicle 1) Wf are exemplified as the above-mentioned parameters. The height of the center of gravity Hc and the weight of the front axle Wf are both values that change according to the load 3.
　本実施形態に係る設定ＥＣＵ５は、設定制御を実施するための要素として、記憶部５Ａ、取得部５Ｂ、及び設定部５Ｃを備えている。ここでは、これらの要素５Ａ、５Ｂ、５Ｃがいずれもソフトウェアで実現されるものとする。ただし、これらの要素５Ａ、５Ｂ、５Ｃは、ハードウェア（電子回路）で実現されてもよいし、ソフトウェアとハードウェアとが併用されて実現されてもよい。 The setting ECU 5 according to the present embodiment includes a storage unit 5A, an acquisition unit 5B, and a setting unit 5C as elements for executing setting control. Here, it is assumed that all of these elements 5A, 5B, and 5C are realized by software. However, these elements 5A, 5B, and 5C may be realized by hardware (electronic circuit), or may be realized by using software and hardware in combination.
　本実施形態では、記憶部５Ａ、取得部５Ｂ、及び設定部５Ｃがコンピュータプログラム（設定プログラム）７の機能として設けられている。したがって、設定ＥＣＵ５は、コンピュータプログラム７を実行することによって設定制御を実施する。なお、コンピュータプログラム７は、設定ＥＣＵ５で実行可能となるように設けられていればよく、例えば、設定ＥＣＵ５内のＨＤＤ（Hard Disk Drive）やＳＳＤ（Solid State Drive）等の記憶装置に格納されていてもよいし、設定ＥＣＵ５で読み取り可能な媒体や設定ＥＣＵ５が接続可能なネットワーク上のオンラインストレージに記録されていてもよい。 In this embodiment, the storage unit 5A, the acquisition unit 5B, and the setting unit 5C are provided as the functions of the computer program (setting program) 7. Therefore, the setting ECU 5 executes the setting control by executing the computer program 7. The computer program 7 may be provided so that it can be executed by the setting ECU 5, and is stored in a storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive) in the setting ECU 5, for example. It may be recorded in a medium that can be read by the setting ECU 5 or in an online storage on a network to which the setting ECU 5 can be connected.
　記憶部５Ａは、アシスト特性が規定された複数のマップを記憶する。以下、これらのマップのそれぞれを「アシストマップ」という。複数のアシストマップに規定されたアシスト特性は、互いに異なる。図３（ａ）～（ｃ）に例示するように、本実施形態の各アシストマップには、操舵トルクＴs及び走行速度Ｖに対するアシストトルクＴaが規定されている。図３（ａ）～（ｃ）には、縦軸がアシストトルクＴaであるとともに横軸が操舵トルクＴsであり、アシストトルクＴaと操舵トルクＴsとの関係を示す線が複数の走行速度Ｖごとに規定されたアシストマップを例示する。 The storage unit 5A stores a plurality of maps in which assist characteristics are defined. Hereinafter, each of these maps will be referred to as an "assist map". The assist characteristics defined in the plurality of assist maps are different from each other. As illustrated in FIGS. 3A to 3C, each assist map of the present embodiment defines the steering torque Ts and the assist torque Ta with respect to the traveling speed V. In FIGS. 3A to 3C, the vertical axis is the assist torque Ta and the horizontal axis is the steering torque Ts, and the lines showing the relationship between the assist torque Ta and the steering torque Ts are for each of the plurality of traveling speeds V. An example of the assist map specified in.
　本実施形態の各アシストマップにおいて、アシストトルクＴaは、操舵トルクＴsが大きいほど大きくなるとともに、走行速度Ｖが高いほど大きくなるように規定されている。なお、図３（ａ）～（ｃ）には三つのアシストマップＡ１、Ａ２、Ｂ１を例示するが、本実施形態の記憶部５Ａには、後述する九つのアシストマップ（Ａ１～Ａ３、Ｂ１～Ｂ３、Ｃ１～Ｃ３）が記憶されている。これらのアシストマップは、車両１の操舵性能が確保されるように、予め実施された試験やシミュレーションの結果に基づいて作成される。 In each assist map of the present embodiment, the assist torque Ta is defined to increase as the steering torque Ts increases and as the traveling speed V increases. Although three assist maps A1, A2, and B1 are illustrated in FIGS. 3A to 3C, nine assist maps (A1 to A3, B1 to B1 to be described later) are shown in the storage unit 5A of the present embodiment. B3, C1 to C3) are stored. These assist maps are created based on the results of tests and simulations carried out in advance so that the steering performance of the vehicle 1 is ensured.
　取得部５Ｂは、搭載物３に応じて変化するパラメータ（搭載物３に応じた情報）を取得する。上述したように、本実施形態では、パラメータとして、車両１の重心高さＨc及び前軸重量Ｗfが取得される。取得部５Ｂは、具体的には、車両１の走行中にハイトセンサ１２及び加速度センサ１３で検出される各値Ｈf、α、αBとＶＣＵ４から伝達されるモータ電流値Ｉとを用いて、重心高さＨc及び前軸重量Ｗfを算出する。 The acquisition unit 5B acquires a parameter (information according to the load 3) that changes according to the load 3. As described above, in the present embodiment, the height Hc of the center of gravity of the vehicle 1 and the weight Wf of the front axle are acquired as parameters. Specifically, the acquisition unit 5B uses the respective values Hf, α, α B detected by the height sensor 12 and the acceleration sensor 13 while the vehicle 1 is traveling, and the motor current value I transmitted from the VCU 4. The height Hc of the center of gravity and the weight Wf of the front axle are calculated.
　まず、重心高さＨcの算出（取得）方法について説明する。重心高さＨcは、車両１の減速時（加速度センサ１３が減速度αBを検出する場合）に、下記の式（１）で算出される。
　　Ｈc＝ΔＷ・Ｌ／（αB・Ｗ）　・・・（１） First, a method of calculating (acquiring) the height Hc of the center of gravity will be described. The center-of-gravity height Hc is calculated by the following equation (1) when the vehicle 1 is decelerating (when the acceleration sensor 13 detects the deceleration α B ).
Hc = ΔW ・ L / (α B・ W) ・ ・ ・ (1)
　式（１）中のΔＷは、車両１の減速時に車両１の後方から前方へ移動する荷重の量（荷重移動量）である。荷重移動量ΔＷは、例えば、ハイトセンサ１２で検出される車高Ｈfの変化量に基づいて算出される。なお、車両１に３軸加速度センサが設けられる場合には、この３軸加速度センサで検出された情報に基づいて荷重移動量ΔＷが算出されてもよい。 ΔW in the equation (1) is the amount of load (load movement amount) that moves from the rear to the front of the vehicle 1 when the vehicle 1 is decelerated. The load transfer amount ΔW is calculated based on, for example, the amount of change in the vehicle height Hf detected by the height sensor 12. When the vehicle 1 is provided with a 3-axis acceleration sensor, the load transfer amount ΔW may be calculated based on the information detected by the 3-axis acceleration sensor.
　式（１）中のＬは、車両１のホイールベース（前車軸と後車軸との距離）である。ホイールベースＬは、車両１に固有の値であるため、例えば、車両１の製造完了時に測定又は設定され、設定ＥＣＵ５内に記憶（保存）されている。式（１）中のＷは、車両１の重量（車両重量）である。車両重量Ｗは、車両１の加速中（加速度センサ１３が加速度αを検出する場合）に、下記の式（２）で算出される。
　　Ｗ＝Ｔ／（α・r）　・・・（２） L in the formula (1) is the wheelbase (distance between the front axle and the rear axle) of the vehicle 1. Since the wheelbase L is a value unique to the vehicle 1, for example, it is measured or set when the production of the vehicle 1 is completed, and is stored (stored) in the setting ECU 5. W in the formula (1) is the weight of the vehicle 1 (vehicle weight). The vehicle weight W is calculated by the following equation (2) while the vehicle 1 is accelerating (when the acceleration sensor 13 detects the acceleration α).
W = T / (α ・ r) ・ ・ ・ (2)
　式（２）中のＴは、走行用モータの駆動トルクであって、ＶＣＵ４から伝達されるモータ電流値Ｉに基づいて算出される。なお、モータ電流値Ｉは、ＶＣＵ４から走行用モータに指示される制御値であってもよいし、走行用モータの電気回路に設けられたセンサで検出される検出値であってもよい。式（２）中のｒは、車両１のタイヤの半径（タイヤ半径）である。タイヤ半径ｒは、例えば、車両１の製造完了時に測定又は設定され、設定ＥＣＵ５内に記憶（保存）されている。 T in the formula (2) is the drive torque of the traveling motor, and is calculated based on the motor current value I transmitted from the VCU 4. The motor current value I may be a control value instructed by the VCU 4 to the traveling motor, or may be a detection value detected by a sensor provided in the electric circuit of the traveling motor. R in the formula (2) is the radius of the tire of the vehicle 1 (tire radius). The tire radius r is, for example, measured or set when the production of the vehicle 1 is completed, and is stored (stored) in the setting ECU 5.
　取得部５Ｂは、まずＶＣＵ４から伝達されたモータ電流値Ｉに基づいて駆動トルクＴを算出し、この駆動トルクＴと、加速度センサ１３で検出された加速度αと、予め記憶されているタイヤ半径ｒとを式（２）に適用することで、車両重量Ｗを算出する。また、取得部５Ｂは、ハイトセンサ１２で検出された車高Ｈfに基づいて荷重移動量ΔＷを算出し、この荷重移動量ΔＷと、予め記憶されているホイールベースＬと、加速度センサ１３で検出された減速度αBと、式（２）から算出した車両重量Ｗとを式（１）に適用することで、重心高さＨcを算出する。 The acquisition unit 5B first calculates a drive torque T based on the motor current value I transmitted from the VCU 4, the drive torque T, the acceleration α detected by the acceleration sensor 13, and the tire radius r stored in advance. By applying and to the equation (2), the vehicle weight W is calculated. Further, the acquisition unit 5B calculates the load transfer amount ΔW based on the vehicle height Hf detected by the height sensor 12, and detects the load transfer amount ΔW, the wheelbase L stored in advance, and the acceleration sensor 13. The height of the center of gravity Hc is calculated by applying the deceleration α B and the vehicle weight W calculated from the equation (2) to the equation (1).
　次に、前軸重量Ｗfの算出（取得）方法について説明する。前軸重量Ｗfは、例えば、ハイトセンサ１２で検出される車高Ｈfに基づいて算出される。具体的には、前軸重量Ｗfは、搭載物３が搭載されていない状態での車高（基準値）と、搭載物３が搭載された状態での車高Ｈfとの差、及び、前輪１６に設けられる懸架装置（フロントサスペンション）のバネ定数に基づいて算出される。なお、上述した基準値とバネ定数としては、例えば、車両１の製造完了時に測定又は設定され、設定ＥＣＵ５内に記憶（保存）されたものを適用できる。 Next, the method of calculating (acquiring) the front axle weight Wf will be described. The front axle weight Wf is calculated based on, for example, the vehicle height Hf detected by the height sensor 12. Specifically, the front axle weight Wf is the difference between the vehicle height (reference value) when the load 3 is not mounted and the vehicle height Hf when the load 3 is mounted, and the front wheels. It is calculated based on the spring constant of the suspension device (front suspension) provided in 16. As the above-mentioned reference value and spring constant, for example, those measured or set at the completion of manufacturing of the vehicle 1 and stored (stored) in the setting ECU 5 can be applied.
　あるいは、前軸重量Ｗfは、操舵ＥＣＵ２Ｂから伝達される情報に基づいて算出されてもよい。例えば、前軸重量Ｗfは、搭載物３が搭載されていない場合に操舵ＥＣＵ２Ｂから伝達される据え切り状態でのアシストトルクＴa（デフォルト値）と、搭載物３が搭載されている場合に操舵ＥＣＵ２Ｂから伝達される据え切り状態でのアシストトルクＴaとの差に基づいて算出されてもよい。なお、上述したデフォルト値は、例えば、車両１の製造完了時に予め取得され、設定ＥＣＵ５内に記憶（保存）しておけばよい。 Alternatively, the front axle weight Wf may be calculated based on the information transmitted from the steering ECU 2B. For example, the front axle weight Wf is the assist torque Ta (default value) in the stationary state transmitted from the steering ECU 2B when the loading object 3 is not mounted, and the steering ECU 2B when the mounting object 3 is mounted. It may be calculated based on the difference from the assist torque Ta in the stationary state transmitted from. The above-mentioned default value may be acquired in advance when the production of the vehicle 1 is completed and stored (stored) in the setting ECU 5.
　設定部５Ｃは、取得部５Ｂで取得された重心高さＨc及び前軸重量Ｗfに基づき、電動パワーステアリング２のアシスト特性を設定する。本実施形態の設定部５Ｃは、取得部５Ｂで取得された重心高さＨc及び前軸重量Ｗfに基づいて、記憶部５Ａに記憶された複数のアシストマップの中から一つを選択する。そして、設定部５Ｃは、選択したアシストマップを操舵ＥＣＵ２Ｂに送信することで、このアシストマップに規定されたアシスト特性を電動パワーステアリング２に対して設定する。 The setting unit 5C sets the assist characteristic of the electric power steering 2 based on the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B. The setting unit 5C of the present embodiment selects one from a plurality of assist maps stored in the storage unit 5A based on the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B. Then, the setting unit 5C transmits the selected assist map to the steering ECU 2B to set the assist characteristics defined in the assist map for the electric power steering 2.
　設定部５Ｃは、具体的には、取得部５Ｂで取得された重心高さＨcと前軸重量Ｗfとを図４に例示する選択マップ６に適用することで、その時点での重心高さＨc及び前軸重量Ｗfに応じたアシストマップを選択する。選択マップ６には、記憶部５Ａに記憶された九つのアシストマップが、重心高さＨc及び前軸重量Ｗfに関連付けられて規定されている。本実施形態の選択マップ６では、縦軸が重心高さＨcであるとともに横軸が前軸荷重Ｗfであり、縦軸と横軸とのそれぞれが三つの範囲（小・中・大）に区分されている。そして、選択マップ６では、合計九つの区分に対して、上述した九つのアシストマップ（Ａ１～Ａ３、Ｂ１～Ｂ３、Ｃ１～Ｃ３）がそれぞれ割り当てられている。 Specifically, the setting unit 5C applies the center of gravity height Hc and the front axle weight Wf acquired by the acquisition unit 5B to the selection map 6 illustrated in FIG. 4, so that the center of gravity height Hc at that time is applied. And select the assist map according to the front axle weight Wf. In the selection map 6, nine assist maps stored in the storage unit 5A are defined in association with the center of gravity height Hc and the front axle weight Wf. In the selection map 6 of the present embodiment, the vertical axis is the center of gravity height Hc and the horizontal axis is the front axle load Wf, and the vertical axis and the horizontal axis are each divided into three ranges (small, medium, and large). Has been done. Then, in the selection map 6, the above-mentioned nine assist maps (A1 to A3, B1 to B3, C1 to C3) are assigned to a total of nine categories.
　本実施形態の選択マップ６では、重心高さＨcが大きいほどアシストトルクＴaの小さいアシストマップが選択されるように、アシストマップが割り当てられている。ここで、前軸重量Ｗfが「小」である場合に選択される三つのアシストマップＡ１～Ａ３を例に挙げて説明する。図３（ａ），（ｂ）に示すように、重心高さＨcが「小」である場合に選択されるアシストマップＡ１に対し、重心高さＨcが「中」である場合に選択されるアシストマップＡ２には、より小さいアシストトルクＴaが規定されている。すなわち、同一の操舵トルクＴs及び走行速度Ｖに対するアシストトルクＴaを比較すると、アシストマップＡ１よりもアシストマップＡ２でアシストトルクＴaが小さくなる。　 In the selection map 6 of the present embodiment, the assist map is assigned so that the assist map having the smaller assist torque Ta is selected as the height Hc of the center of gravity is larger. Here, three assist maps A1 to A3 selected when the front axle weight Wf is "small" will be described as an example. As shown in FIGS. 3A and 3B, it is selected when the center of gravity height Hc is “medium” with respect to the assist map A1 selected when the center of gravity height Hc is “small”. The assist map A2 defines a smaller assist torque Ta. That is, when the assist torque Ta for the same steering torque Ts and the traveling speed V is compared, the assist torque Ta is smaller in the assist map A2 than in the assist map A1.
　同様に、アシストマップＡ２に対し、重心高さＨcが「大」である場合に選択されるアシストマップＡ３（図示略）には、より小さいアシストトルクＴaが規定されている。なお、前軸重量Ｗfが「中」である場合のアシストマップＢ１～Ｂ３、及び、前軸重量Ｗfが「大」である場合のアシストマップＣ１～Ｃ３においても同様に、重心高さＨcが大きいほど、小さいアシストトルクＴaが規定されている。 Similarly, a smaller assist torque Ta is defined in the assist map A3 (not shown) selected when the center of gravity height Hc is "large" with respect to the assist map A2. Similarly, the height Hc of the center of gravity is large in the assist maps B1 to B3 when the front axle weight Wf is "medium" and the assist maps C1 to C3 when the front axle weight Wf is "large". The smaller the assist torque Ta is specified.
　また、本実施形態の選択マップ６では、前軸重量Ｗfが大きいほどアシストトルクＴaの大きいアシストマップが選択されるように、アシストマップが割り当てられている。ここで、重心高さＨcが「小」である場合の三つのアシストマップＡ１、Ｂ１、Ｃ１を例に挙げて説明する。図３（ａ），（ｃ）に示すように、前軸重量Ｗfが「小」である場合に選択されるアシストマップＡ１に対し、前軸重量Ｗfが「中」である場合に選択されるアシストマップＢ１には、より大きいアシストトルクＴaが規定されている。すなわち、同一の操舵トルクＴs及び走行速度Ｖに対するアシストトルクＴaを比較すると、アシストマップＡ１よりもアシストマップＢ１でアシストトルクＴaが大きくなる。 Further, in the selection map 6 of the present embodiment, the assist map is assigned so that the assist map having a larger assist torque Ta is selected as the front axle weight Wf is larger. Here, three assist maps A1, B1, and C1 when the height Hc of the center of gravity is “small” will be described as an example. As shown in FIGS. 3A and 3C, it is selected when the front axle weight Wf is “medium” with respect to the assist map A1 selected when the front axle weight Wf is “small”. A larger assist torque Ta is defined in the assist map B1. That is, when the assist torque Ta for the same steering torque Ts and the traveling speed V is compared, the assist torque Ta becomes larger in the assist map B1 than in the assist map A1.
　同様に、アシストマップＢ１に対し、前軸重量Ｗfが「大」である場合に選択されるアシストマップＣ１（図示略）には、より大きいアシストトルクＴaが規定されている。なお、重心高さＨcが「中」である場合のアシストマップＡ２、Ｂ２、Ｃ２、及び、重心高さＨcが「大」である場合のアシストマップＡ３、Ｂ３、Ｃ３においても同様に、前軸重量Ｗfが大きいほど、大きいアシストトルクＴaが規定されている。 Similarly, a larger assist torque Ta is specified in the assist map C1 (not shown) selected when the front axle weight Wf is "large" with respect to the assist map B1. Similarly, in the assist maps A2, B2, C2 when the center of gravity height Hc is "medium", and in the assist maps A3, B3, C3 when the center of gravity height Hc is "large", the front axle The larger the weight Wf, the larger the assist torque Ta is specified.
　本実施形態の設定部５Ｃは、上述した選択マップ６を用いることから、重心高さＨcが大きいほどアシストトルクＴaが小さくなるようにアシスト特性を設定するとともに、前軸重量Ｗfが大きいほどアシストトルクＴaが大きくなるようにアシスト特性を設定する。なお、図４に示した選択マップ６は一例である。選択マップ６に規定されるアシストマップの個数は、記憶部５Ａに記憶されたアシストマップの数や、想定される重心高さＨc及び前軸荷重Ｗfの範囲に応じて適宜規定される。 Since the setting unit 5C of the present embodiment uses the selection map 6 described above, the assist characteristic is set so that the larger the center of gravity height Hc is, the smaller the assist torque Ta is, and the larger the front axle weight Wf is, the more the assist torque is set. Set the assist characteristics so that Ta becomes large. The selection map 6 shown in FIG. 4 is an example. The number of assist maps defined in the selection map 6 is appropriately defined according to the number of assist maps stored in the storage unit 5A, the assumed center of gravity height Hc, and the range of the front axle load Wf.
　操舵ＥＣＵ２Ｂは、設定部５Ｃで設定された（設定部５Ｃから送信された）アシストマップを用いて、操舵モータ２Ａから操舵機構２２に与えるアシストトルクＴaを決定する。具体的には、操舵ＥＣＵ２Ｂは、速度センサ１４から伝達された走行速度Ｖと、操舵トルクセンサ１５から伝達された操舵トルクＴsとを、設定部５Ｃで設定されたアシストマップに適用することで、アシストトルクＴaを決定する。そして、操舵ＥＣＵ２Ｂは、決定したアシストトルクＴaが操舵機構２２に付与されるように、操舵モータ２Ａを制御する。 The steering ECU 2B determines the assist torque Ta given from the steering motor 2A to the steering mechanism 22 by using the assist map set by the setting unit 5C (transmitted from the setting unit 5C). Specifically, the steering ECU 2B applies the traveling speed V transmitted from the speed sensor 14 and the steering torque Ts transmitted from the steering torque sensor 15 to the assist map set by the setting unit 5C. Determine the assist torque Ta. Then, the steering ECU 2B controls the steering motor 2A so that the determined assist torque Ta is applied to the steering mechanism 22.
［３．フローチャート］
　図５は、上述した設定制御の手順（設定方法）を示すフローチャートである。図５に示すように、設定制御では、まず、上述した九つのアシストマップが記憶される（ステップＳ１）。ステップＳ１は、車両１が使用される前（例えば車両１の製造時）に、記憶部５Ａで実施される処理（記憶工程）である。 [3. flowchart]
FIG. 5 is a flowchart showing the above-mentioned setting control procedure (setting method). As shown in FIG. 5, in the setting control, first, the above-mentioned nine assist maps are stored (step S1). Step S1 is a process (storage step) performed by the storage unit 5A before the vehicle 1 is used (for example, when the vehicle 1 is manufactured).
　一方、ステップＳ１以降のステップＳ２～Ｓ５は、本実施形態では、車両１の走行中に実施される処理である。これらのステップＳ２～Ｓ５は、車両１の走行中に搭載物３が変わらない（あるいは、変わらないことが予想される）場合は、車両１の走行中に一度だけ（例えば走行開始時に）実施されればよい。あるいは、これらのステップＳ２～Ｓ５は、車両１の走行中に所定の周期で繰り返し実施されてもよい。ここではステップＳ２～Ｓ５が車両１の走行中に一度だけ実施されるものとする。 On the other hand, steps S2 to S5 after step S1 are processes performed while the vehicle 1 is traveling in the present embodiment. If the load 3 does not change (or is expected to change) while the vehicle 1 is running, these steps S2 to S5 are performed only once during the running of the vehicle 1 (for example, at the start of running). Just do it. Alternatively, these steps S2 to S5 may be repeatedly performed in a predetermined cycle while the vehicle 1 is traveling. Here, it is assumed that steps S2 to S5 are performed only once while the vehicle 1 is traveling.
　ステップＳ２では、ＶＣＵ４、ハイトセンサ１２、及び加速度センサ１３から各種情報が入力される。続くステップＳ３では、ステップＳ２で入力された情報や予め記憶された各種の値等を用いて、重心高さＨc及び前軸重量Ｗfが取得（算出）される。ステップＳ２、Ｓ３の処理は、取得部５Ｂで実施される処理（取得工程）である。 In step S2, various information is input from the VCU 4, the height sensor 12, and the acceleration sensor 13. In the following step S3, the height Hc of the center of gravity and the weight Wf of the front axle are acquired (calculated) using the information input in step S2, various values stored in advance, and the like. The processes of steps S2 and S3 are processes (acquisition steps) performed by the acquisition unit 5B.
　続くステップＳ４では、ステップＳ３で取得された重心高さＨc及び前軸重量Ｗfに基づいて、ステップＳ１で記憶されたアシストマップの中から一つが選択される。次いで、ステップＳ４で選択されたアシストマップが操舵ＥＣＵ２Ｂに送信されることで、このアシストマップに規定されたアシスト特性が、電動パワーステアリング２において設定される（ステップＳ５）。ステップＳ４、Ｓ５の処理は、設定部５Ｃにおいて実施される処理（設定工程）である。そして、設定制御が終了する。 In the following step S4, one is selected from the assist maps stored in step S1 based on the center of gravity height Hc and the front axle weight Wf acquired in step S3. Next, the assist map selected in step S4 is transmitted to the steering ECU 2B, so that the assist characteristics defined in the assist map are set in the electric power steering 2 (step S5). The processes of steps S4 and S5 are processes (setting steps) performed by the setting unit 5C. Then, the setting control ends.
［４．効果］
　（１）上述した設定ＥＣＵ５、設定方法、及びコンピュータプログラム７によれば、搭載物３に応じた情報（本実施形態では重心高さＨc及び前軸重量Ｗfであるパラメータ）に基づいて、電動パワーステアリング２のアシスト特性が設定される。このため、搭載物３が異なる場合に、異なる搭載物３のいずれにおいても、その搭載物３に適合したアシスト特性を設定することができる。 [4. effect]
(1) According to the setting ECU 5, the setting method, and the computer program 7 described above, the electric power is based on the information corresponding to the mounted object 3 (parameters of the center of gravity height Hc and the front axle weight Wf in this embodiment). The assist characteristic of the steering 2 is set. Therefore, when the mounted objects 3 are different, it is possible to set the assist characteristic suitable for the mounted objects 3 in any of the different mounted objects 3.
　例えば、車両１がクレーン車である（搭載物３がクレーン機構である）場合と、車両１がミキサー車である（搭載物３がドラム等で構成される）場合とでは、重心高さＨc及び前軸重量Ｗfが異なるとともに、電動パワーステアリング２の最適なアシスト特性も異なる。このため、例えば油圧式のパワーステアリングが適用される場合のように、アシスト特性が搭載物３によらず固定されている場合には、搭載物３の変更に伴い車両１の操舵性能が低下する虞がある。 For example, in the case where the vehicle 1 is a crane truck (the load 3 is a crane mechanism) and the vehicle 1 is a mixer truck (the load 3 is composed of a drum or the like), the height of the center of gravity Hc and The front axle weight Wf is different, and the optimum assist characteristics of the electric power steering 2 are also different. Therefore, for example, when the assist characteristic is fixed regardless of the load 3 as in the case where hydraulic power steering is applied, the steering performance of the vehicle 1 deteriorates due to the change of the load 3. There is a risk.
　これに対し、上述した設定ＥＣＵ５、設定方法、及びコンピュータプログラム７によれば、搭載物３に応じた情報に基づいてアシスト特性が設定されるため、車両１がクレーン車である場合とミキサー車である場合とのそれぞれにおいて、搭載物３に適合したアシスト特性を設定することができる。よって、車両１の操舵性能を向上させることができる。 On the other hand, according to the setting ECU 5, the setting method, and the computer program 7 described above, the assist characteristic is set based on the information according to the load 3, so that the vehicle 1 is a crane truck and the mixer truck. In each of the cases, it is possible to set the assist characteristic suitable for the mounted object 3. Therefore, the steering performance of the vehicle 1 can be improved.
　（２）一般に、車両は、重心高さが大きいほど旋回時の姿勢が安定しにくくなる。このため、上述したパラメータとしての重心高さＨcが大きいほどアシストトルクＴaが小さくなるようにアシスト特性を設定することで、車両１の急旋回（ドライバによる急操舵）を抑制して、車両１の姿勢を安定しやすくすることができる。よって、車両１の操舵性能をより向上させることができる。 (2) In general, the larger the height of the center of gravity of a vehicle, the more difficult it is for the posture to stabilize when turning. Therefore, by setting the assist characteristic so that the assist torque Ta becomes smaller as the height Hc of the center of gravity as the above-mentioned parameter becomes larger, the sudden turning of the vehicle 1 (sudden steering by the driver) is suppressed, and the vehicle 1 The posture can be easily stabilized. Therefore, the steering performance of the vehicle 1 can be further improved.
　（３）一般に、車両では、前軸重量が大きいほど旋回時に要する操舵力（操舵トルク）が大きくなる。このため、上述したパラメータとしての前軸重量Ｗfが大きいほどアシストトルクＴaが大きくなるようにアシスト特性を設定することで、車両１を操舵しやすくすることができる。よって、車両１の操舵性能をより向上させることができる。 (3) Generally, in a vehicle, the heavier the front axle weight, the greater the steering force (steering torque) required when turning. Therefore, the vehicle 1 can be easily steered by setting the assist characteristic so that the assist torque Ta increases as the front axle weight Wf as the above-mentioned parameter increases. Therefore, the steering performance of the vehicle 1 can be further improved.
　（４）アシスト特性が規定された複数のアシストマップを記憶しておき、これらのアシストマップの中から一つを選択することでアシスト特性を設定する構成とすれば、複雑な演算をしなくても、搭載物３に適合したアシスト特性を設定することができる。よって、制御構成の簡素化を図ることができる。特に、本実施形態では、複数のアシストマップとパラメータとの関係が規定された選択マップ６を参照するため、搭載物３に適合したアシスト特性を容易に選択、設定することができる。したがって、制御構成をより簡素化することができる。 (4) If a plurality of assist maps in which assist characteristics are defined are stored and the assist characteristics are set by selecting one of these assist maps, complicated calculations are not required. Also, the assist characteristic suitable for the mounted object 3 can be set. Therefore, the control configuration can be simplified. In particular, in the present embodiment, since the selection map 6 in which the relationship between the plurality of assist maps and the parameters is defined is referred to, the assist characteristics suitable for the load 3 can be easily selected and set. Therefore, the control configuration can be further simplified.
　（５）上述した車両１はトラックであるため、架装物としての搭載物３が多岐にわたるとともに車両１の用途に応じて頻繁に変更される可能性があるが、上述した設定ＥＣＵ５、設定方法、及びコンピュータプログラム７を適用すれば、搭載物３が頻繁に変更される場合であっても、上述したように車両１の操舵性能を容易に向上させることができる。 (5) Since the vehicle 1 described above is a truck, the load 3 as a bodywork is diverse and may be frequently changed according to the use of the vehicle 1, but the setting ECU 5 and the setting method described above may be used. And, by applying the computer program 7, the steering performance of the vehicle 1 can be easily improved as described above even when the load 3 is frequently changed.
　（６）車両１の走行中に取得される各種の値（加速度αや減速度αB等）を用いてパラメータを算出（取得）する構成とすれば、搭載物３が変更された場合であっても、ドライバが車両１を走行させるだけで、その時点での搭載物３に適合したアシスト特性を自動で設定することができる。よって、利便性を高めることができる。 (6) If the parameters are calculated (acquired) using various values (acceleration α, deceleration α B, etc.) acquired while the vehicle 1 is running, it is a case where the mounted object 3 is changed. However, the driver can automatically set the assist characteristic suitable for the mounted object 3 at that time only by driving the vehicle 1. Therefore, convenience can be enhanced.
［５．変形例］
　搭載物３は、車両１に搭載されるものであればよく、その種類は特に限定されない。また、車両１は、上述したようなトラックに限られず、例えばバスであってもよい。この場合、バスに搭載される搭載物３としては、乗員や荷物等が挙げられる。一般に、バスでは、ベースとなる車体構造が同一であっても、状況に応じて乗員の人数や荷物の量及び位置が変わることから、最適なアシスト特性も変化する可能性がある。これに対し、上述した設定ＥＣＵ５、設定方法、コンピュータプログラム７を適用すれば、上述したように、搭載物３が変更されたとしても、搭載物３に適合したアシスト特性を設定することができる。よって、上述した実施形態と同様に、操舵性能を向上させることができる。 [5. Modification example]
The load 3 may be mounted on the vehicle 1, and the type thereof is not particularly limited. Further, the vehicle 1 is not limited to the truck as described above, and may be, for example, a bus. In this case, examples of the load 3 mounted on the bus include passengers, luggage, and the like. Generally, in a bus, even if the base body structure is the same, the number of occupants and the amount and position of luggage change depending on the situation, so that the optimum assist characteristics may also change. On the other hand, if the setting ECU 5, the setting method, and the computer program 7 described above are applied, as described above, even if the mounted object 3 is changed, the assist characteristic suitable for the mounted object 3 can be set. Therefore, the steering performance can be improved as in the above-described embodiment.
　搭載物３に応じた情報（上述したパラメータ）は、上述した重心高さＨc及び前軸重量Ｗfに限定されない。この情報には、例えば、重心高さＨc及び前軸重量Ｗfのいずれか一方のみが含まれていてもよいし、重心高さＨc及び前軸重量Ｗf以外のものが含まれていてもよい。 The information (parameters described above) according to the load 3 is not limited to the height Hc of the center of gravity and the weight Wf of the front axle described above. This information may include, for example, only one of the center of gravity height Hc and the front axle weight Wf, or may include other than the center of gravity height Hc and the front axle weight Wf.
　また、搭載物３に応じた情報の取得方法も上述した方法に限定されない。例えば、ドライバやオペレータが、適宜の入力装置を用いて、搭載物３に応じた情報を設定ＥＣＵ５に手動で入力する構成としてもよい。この場合、取得部５Ｂは、搭載物３に応じた情報（例えば上述したパラメータ）を入力装置から取得すればよい。このような構成であれば、車両１が走行しなくても（車両１が走行する前から）、搭載物３に適合したアシスト特性を設定することができる。なお、この場合には、記憶部５Ａにアシストマップを記憶する処理（記憶工程）が、搭載物３に応じた情報を取得する処理（取得工程）の後に実施されてもよい。 Further, the method of acquiring information according to the load 3 is not limited to the above-mentioned method. For example, the driver or the operator may manually input the information corresponding to the mounted object 3 into the setting ECU 5 by using an appropriate input device. In this case, the acquisition unit 5B may acquire information (for example, the above-mentioned parameters) corresponding to the mounted object 3 from the input device. With such a configuration, even if the vehicle 1 does not travel (before the vehicle 1 travels), the assist characteristic suitable for the mounted object 3 can be set. In this case, the process of storing the assist map in the storage unit 5A (storage step) may be performed after the process of acquiring the information corresponding to the load 3 (acquisition step).
　図３（ａ）～（ｃ）及び図４に示したマップはいずれも一例である。上述したアシストマップは、車両１の構成や電動パワーステアリング２の特性等に応じて適宜設定されればよい。なお、各アシストマップでは、操舵トルクＴsに代えて、操舵輪２１の操舵角速度が用いられてもよい。 The maps shown in FIGS. 3 (a) to 3 (c) and FIG. 4 are all examples. The above-mentioned assist map may be appropriately set according to the configuration of the vehicle 1, the characteristics of the electric power steering 2, and the like. In each assist map, the steering angular velocity of the steering wheel 21 may be used instead of the steering torque Ts.
　設定ＥＣＵ５は、電動パワーステアリング２の一要素として設けられてもよい。具体的には、設定ＥＣＵ５の機能と、上述した操舵ＥＣＵ２Ｂの機能とが、一つのＥＣＵにまとめられてもよい。また、車両１は、電動車両でなくてもよく、例えば、エンジンと電動モータとを組み合わせたハイブリッド車両や燃料電池車両やエンジン車両などでもよい。 The setting ECU 5 may be provided as an element of the electric power steering 2. Specifically, the function of the setting ECU 5 and the function of the steering ECU 2B described above may be combined into one ECU. Further, the vehicle 1 does not have to be an electric vehicle, and may be, for example, a hybrid vehicle in which an engine and an electric motor are combined, a fuel cell vehicle, an engine vehicle, or the like.
　１　　車両
　２　　電動パワーステアリング
　３　　搭載物
　５　　設定ＥＣＵ（操舵特性設定装置）
　５Ａ　記憶部
　５Ｂ　取得部
　５Ｃ　設定部
　７　　コンピュータプログラム（操舵特性設定プログラム）
　Ｈc　 重心高さ（情報）
　Ｔa　 アシストトルク（アシスト力）
　Ｗf　 前軸重量（情報） 1 Vehicle 2 Electric power steering 3 On-board equipment 5 Setting ECU (steering characteristic setting device)
5A storage unit 5B acquisition unit 5C setting unit 7 computer program (steering characteristic setting program)
Hc Center of gravity height (information)
Ta assist torque (assist force)
Wf front axle weight (information)

Claims (11)

  1. 　車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定装置であって、
    　前記車両に搭載される搭載物に応じた情報を取得する取得部と、
    　前記取得部で取得された前記情報に基づき、前記アシスト力の特性を設定する設定部と、を備えている
    ことを特徴とする、操舵特性設定装置。     It is a steering characteristic setting device for electric power steering that gives assist force to the steering system of the vehicle.
    An acquisition unit that acquires information according to the load mounted on the vehicle, and
    A steering characteristic setting device including a setting unit for setting the characteristics of the assist force based on the information acquired by the acquisition unit.
  2. 　前記情報には前記車両の重心高さが含まれ、
    　前記設定部は、前記重心高さが大きいほど前記アシスト力が小さくなるように前記特性を設定する
    ことを特徴とする、請求項１に記載の操舵特性設定装置。     The information includes the height of the center of gravity of the vehicle.
    The steering characteristic setting device according to claim 1, wherein the setting unit sets the characteristic so that the assist force becomes smaller as the height of the center of gravity increases.
  3. 　前記情報には前記車両の前軸重量が含まれ、
    　前記設定部は、前記前軸重量が大きいほど前記アシスト力が大きくなるように前記特性を設定する
    ことを特徴とする、請求項１又は２に記載の操舵特性設定装置。     The information includes the front axle weight of the vehicle.
    The steering characteristic setting device according to claim 1 or 2, wherein the setting unit sets the characteristic so that the assist force increases as the weight of the front axle increases.
  4. 　前記特性が規定された複数のマップを記憶する記憶部を備え、
    　前記設定部は、前記取得部で取得された前記情報に基づき、前記記憶部に記憶された前記マップの中から一つを選択し、選択した前記マップに規定された前記特性を設定する
    ことを特徴とする、請求項１～３のいずれか一項に記載の操舵特性設定装置。     A storage unit for storing a plurality of maps in which the characteristics are defined is provided.
    Based on the information acquired by the acquisition unit, the setting unit selects one from the maps stored in the storage unit and sets the characteristics defined in the selected map. The steering characteristic setting device according to any one of claims 1 to 3, which is characterized.
  5. 　前記車両がトラックである
    ことを特徴とする、請求項１～４のいずれか一項に記載の操舵特性設定装置。     The steering characteristic setting device according to any one of claims 1 to 4, wherein the vehicle is a truck.
  6. 　前記車両がバスである
    ことを特徴とする、請求項１～４のいずれか一項に記載の操舵特性設定装置。     The steering characteristic setting device according to any one of claims 1 to 4, wherein the vehicle is a bus.
  7. 　車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定方法であって、
    　前記車両に搭載される搭載物に応じた情報を取得する取得工程と、
    　前記取得工程で取得された前記情報に基づき、前記アシスト力の特性を設定する設定工程と、を備えている
    ことを特徴とする、操舵特性設定方法。     It is a method of setting the steering characteristics of electric power steering that gives assist force to the steering system of the vehicle.
    An acquisition process for acquiring information according to the load mounted on the vehicle, and
    A steering characteristic setting method comprising a setting step of setting the characteristic of the assist force based on the information acquired in the acquisition step.
  8. 　前記情報には前記車両の重心高さが含まれ、
    　前記設定工程では、前記重心高さが大きいほど前記アシスト力が小さくなるように前記特性を設定する
    ことを特徴とする、請求項７に記載の操舵特性設定方法。     The information includes the height of the center of gravity of the vehicle.
    The steering characteristic setting method according to claim 7, wherein in the setting step, the characteristic is set so that the assist force becomes smaller as the height of the center of gravity increases.
  9. 　前記情報には前記車両の前軸重量が含まれ、
    　前記設定工程では、前記前軸重量が大きいほど前記アシスト力が大きくなるように前記特性を設定する
    ことを特徴とする、請求項７又は８に記載の操舵特性設定方法。     The information includes the front axle weight of the vehicle.
    The steering characteristic setting method according to claim 7 or 8, wherein in the setting step, the characteristic is set so that the assist force increases as the weight of the front axle increases.
  10. 　前記設定工程の実施前に、前記特性が規定された複数のマップを記憶する記憶工程を備え、
    　前記設定工程では、前記取得工程で取得された前記情報に基づき、前記記憶工程で記憶された前記マップの中から一つを選択し、選択した前記マップに規定された前記特性を設定する
    ことを特徴とする、請求項７～９のいずれか一項に記載の操舵特性設定方法。     A storage step of storing a plurality of maps in which the characteristics are defined is provided before the setting step is performed.
    In the setting step, based on the information acquired in the acquisition step, one is selected from the maps stored in the storage step, and the characteristics defined in the selected map are set. The steering characteristic setting method according to any one of claims 7 to 9, which is characterized.
  11. 　車両の操舵系にアシスト力を与える電動パワーステアリングの操舵特性設定プログラムであって、
    　前記車両に搭載される搭載物に応じた情報を取得する取得工程と、
    　前記取得工程で取得された前記情報に基づき、前記アシスト力の特性を設定する設定工程と、をコンピュータに実行させる
    ことを特徴とする、操舵特性設定プログラム。     It is a steering characteristic setting program of electric power steering that gives assist force to the steering system of the vehicle.
    An acquisition process for acquiring information according to the load mounted on the vehicle, and
    A steering characteristic setting program comprising causing a computer to execute a setting step of setting the characteristic of the assist force based on the information acquired in the acquisition step.
PCT/JP2020/004012 2019-03-28 2020-02-04 Steering characteristics setting device, steering characteristics setting method, and steering characteristics setting program WO2020195174A1 (en)

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JP2020199354A (en) * 2020-09-22 2020-12-17 株式会社三洋物産 Game machine
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5072803A (en) * 1989-07-08 1991-12-17 Daimler-Benz Ag Method of setting an assisting force in power-assisted steering
JPH04191172A (en) * 1990-11-27 1992-07-09 Suzuki Motor Corp Motor driven power steering device
JP2000292316A (en) * 1999-04-12 2000-10-20 Hino Motors Ltd Estimation arithmetic device of center-of-gravity height of vehicle
JP2011051409A (en) * 2009-08-31 2011-03-17 Nsk Ltd Electric power steering device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5072803A (en) * 1989-07-08 1991-12-17 Daimler-Benz Ag Method of setting an assisting force in power-assisted steering
JPH04191172A (en) * 1990-11-27 1992-07-09 Suzuki Motor Corp Motor driven power steering device
JP2000292316A (en) * 1999-04-12 2000-10-20 Hino Motors Ltd Estimation arithmetic device of center-of-gravity height of vehicle
JP2011051409A (en) * 2009-08-31 2011-03-17 Nsk Ltd Electric power steering device

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