Input / output device, vehicle manufacturing method, and program

Abstract

An input / output device according to the present disclosure comprises: a control constant holding unit that holds a first control constant corresponding to a first vehicle state value; a target characteristic setting unit that sets a second target characteristic, which is a target value for a control characteristic of steering, in a second vehicle state value different from the first vehicle state value; and a control constant calculation unit that calculates a second control constant corresponding to the second vehicle state value on the basis of the first control constant and the second target characteristic, and that outputs the second control constant to a steering control device.

Description

[Technical Field]

[0001] The present disclosure relates to an input / output device, a vehicle manufacturing method, and a program. [Background technology]

[0002] Patent Document 1 discloses a technology for setting multiple control parameters for vehicle steering to suit individual users. Specifically, the technology predicts and presents good control parameters based on an evaluation value given by the user to the control results. Patent Document 2 discloses a technology for controlling vehicle steering using a plurality of controllers (phase lead compensator, phase lag compensator, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-210291 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-29433 Summary of the Invention [Problem to be solved by the invention]

[0004] In a steering control device, it is necessary to set a control constant according to a vehicle state value such as vehicle speed. If an appropriate control parameter (control constant) according to the vehicle state value is not set, there is a possibility that the control characteristics will deteriorate as the vehicle state value transitions. The disclosure of Patent Document 1 does not take into account the transition of the vehicle state value. Furthermore, as shown in Patent Document 2, steering control is performed by a plurality of controllers. In other words, it is necessary to set an appropriate control constant for each controller, taking into account the transition of the vehicle state value. Conventionally, such setting has been performed by an operator, which has resulted in the problem of increasing the man-hours required for the setting work.

[0005] In view of the above circumstances, the present disclosure aims to provide an input / output device, a vehicle manufacturing method, and a program that can reduce the amount of work required to set control constants that take into account transitions in vehicle state values. [Means for solving the problem]

[0006] One aspect of the present disclosure is an input / output device for setting control constants corresponding to multiple vehicle state values ​​for a steering control device that controls steering mounted on a vehicle, the input / output device comprising: a control constant holding unit that holds a first control constant corresponding to a first vehicle state value; a target characteristic setting unit that sets a second target characteristic that is a target value of the steering control characteristic for a second vehicle state value that is different from the first vehicle state value; and a control constant calculation unit that calculates a second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic, and outputs the second control constant to the steering control device.

[0007] One aspect of the present disclosure is a method for manufacturing a vehicle, comprising the step of inputting the second control constant to the steering control device using the input / output device.

[0008] One aspect of the present disclosure is a program that causes a computer to execute the steps of: retaining a first control constant corresponding to a first vehicle state value; setting a second target characteristic that is a target value of the steering control characteristic at a second vehicle state value different from the first vehicle state value; calculating a second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic; and outputting the second control constant. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide an input / output device, a vehicle manufacturing method, and a program that can reduce the number of steps required to set control constants that take into account transitions in vehicle state values. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an example of a usage state of the input / output device according to the first embodiment. FIG. [Figure 2] 2 is a block diagram showing an example of the configuration of an input / output device and a steering control device shown in FIG. 1. FIG. [Figure 3] 3 is a control constant matrix according to the first embodiment. [Figure 4] 10 is a display example of a target characteristic in a table format according to the first embodiment. [Figure 5] FIG. 1 is a Bode diagram illustrating a problem to be solved by the present disclosure. [Figure 6] 3 is a block diagram showing an example of the configuration of a target characteristic setting unit according to the first embodiment. FIG. [Figure 7] 4 is a display example of a target characteristic in a map format according to the first embodiment. [Figure 8] 8 is a display example of a target characteristic according to the modified example of FIG. 7. [Figure 9] 10 is a control constant matrix according to a modification of the first embodiment. [Figure 10] FIG. 10 is a block diagram showing a configuration example of an input / output device according to a second embodiment. [Figure 11] FIG. 10 is a block diagram showing an example of the configuration of a target characteristic setting unit according to a second embodiment. [Figure 12] 10 is a control constant matrix according to the third embodiment. [Figure 13] 13 is a control constant matrix according to a modification of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments and can be modified as desired within the scope of the technical concept of the present disclosure.

[0012] Embodiment 1 FIG. 1 is a schematic diagram showing an example of a usage state of the input / output device 3 in the first embodiment. As shown in FIG. 1, the input / output device 3 is connected to an electric power steering device 50. The input / output device 3 and the electric power steering device 50 may be connected by wire or wirelessly. The connection between the input / output device 3 and the electric power steering device 50 may be made, for example, via an in-vehicle communication network mounted on the vehicle. The in-vehicle communication network may be, for example, CAN (Controller Area Network) (registered trademark), FlexRay (registered trademark), Ethernet (registered trademark), etc.

[0013] The electric power steering device 50 includes a rotating machine 1, a steering control device 2, a torque detector 22, a rotation detector 23, a steering wheel 51, a steering shaft 53, a rack and pinion gear 54, wheels 55, a tie rod 56, and a knuckle arm 57. The electric power steering device 50 is mounted on a vehicle.

[0014] The steering shaft 53 has an input shaft 53a and an output shaft 53b. The input shaft 53a is connected to the steering wheel 51. The output shaft 53b is connected to a rack and pinion gear 54. The input shaft 53a and the output shaft 53b are connected to each other by a torsion bar (not shown). The torsion bar is disposed within the torque detector 22 and passes through the torque detector 22 in the axial direction. Hereinafter, the steering wheel 51, the steering shaft 53, and the torsion bar may be collectively referred to as "steering."

[0015] When the driver turns the steering wheel 51, a steering torque is applied to the input shaft 53a. A torsion approximately proportional to the steering torque is generated in the torsion bar. The torque detector 22 detects the torsion angle (the direction and amount of torsion) applied to the torsion bar. The torque detector 22 converts the detected torsion angle into a steering torque signal Ts. The rotation detector 23 is attached to the rotating shaft of the rotating machine 1. The rotation detector 23 detects the rotation speed of the rotating shaft and outputs a rotation speed signal ωm.

[0016] The rotating machine 1 generates a driving force (steering assist force) for steering and assists the driver in steering. The steering control device 2 controls the rotating machine 1. FIG. 2 shows an example of the configuration of the steering control device 2 and the input / output device 3. The steering control device 2 has a setting unit 24 and a power supply unit 25. The setting unit 24 sets a control constant to be used for calculations in the power supply unit 25 based on the vehicle state value and the control constant transmitted from the input / output device 3.

[0017] A "vehicle state value" is a parameter related to the operation of the vehicle. An example of the vehicle state value is vehicle speed. The vehicle state value is input to the steering control device 2 from various detectors equipped in the vehicle. For example, when the vehicle state value is vehicle speed, information related to the vehicle speed is input to the steering control device 2 from a detector that detects the vehicle speed.

[0018] The rotation speed (rotation speed signal ωm) of the rotating machine 1 detected by the rotation detector 23 is input to the power supply unit 25. The steering torque (steering torque signal Ts) detected by the torque detector 22 is also input to the power supply unit 25. The power supply unit 25 generates a voltage to be applied to the rotating machine 1 based on the control constants set by the setting unit 24, the rotation speed signal ωm, the steering torque signal Ts, etc.

[0019] The input / output device 3 has a target characteristic setting unit 4, a control constant holding unit 5, and a control constant calculation unit 6. Examples of hardware that constitutes the input / output device 3 include a tablet computer and a notebook PC. The target characteristic setting unit 4 sets a target characteristic of the steering in accordance with the vehicle state value. The "target characteristic" is a target value of the steering control characteristic for the vehicle state value.

[0020] The target characteristic may be related to, for example, a transfer characteristic that indicates the magnitude of the driving force of the rotating machine 1 relative to the output of the various detectors. The target characteristic may be related to the performance of suppressing noise or detection error contained in the various detectors. The target characteristic may be related to the performance of suppressing disturbance vibrations transmitted to the driver via the steering. The target characteristic may be related to the responsiveness of the steering to the steering operation of the driver. The target characteristic may be related to the stability of the various performances described above. The target characteristic may be related to the characteristics of the feedback control performed by the power supply unit 25. The target characteristic may be related to one or more of the above examples, or may be related to other characteristics.

[0021] (Definition of terms) Here, definitions of terms used in the following description will be given. The "first control constant" is a control constant corresponding to the first vehicle state value. In this embodiment, the first control constant is a preset value and is held by the control constant holding unit 5. The "first vehicle state value" is a vehicle state value for which a corresponding control constant (first control constant) has already been determined. The "first target characteristic" is a target characteristic at a first vehicle state value. The "second vehicle state value" is a vehicle state value that is different from the first vehicle state value. The "second control constant" is a control constant corresponding to a second vehicle state value. The "second target characteristic" is a target characteristic at a second vehicle state value. An "intermediate vehicle condition value" is a vehicle condition value between the first vehicle condition value and the second vehicle condition value. The "intermediate control constant" is a control constant that corresponds to an intermediate vehicle state value. The "intermediate target characteristic" is a target characteristic at an intermediate vehicle state value.

[0022] Hereinafter, a case where the vehicle state value is the vehicle speed will be described as an example. That is, the "first vehicle speed," the "second vehicle speed," and the "intermediate vehicle speed" correspond to the "first vehicle state value," the "second vehicle state value," and the "intermediate vehicle state value," respectively.

[0023] The control constant storage unit 5 stores the first control constant. The control constant calculation unit 6 calculates the second control constant based on the first control constant and the second target characteristic set by the target characteristic setting unit 4.

[0024] Here, the input / output device 3 sets the above-mentioned second control constant so that the control performance of the steering control device 2 does not deteriorate even when the vehicle speed changes. The second control constant is input to a setting unit 24 of the steering control device 2. The setting unit 24 may receive the second control constant output by the input / output device 3 via an in-vehicle communication network of the vehicle. Alternatively, the second control constant may be displayed on a monitor or the like, and a user of the input / output device 3 may manually input the displayed second control constant to the setting unit 24. The monitor or the like that displays the second control constant may be provided in the input / output device 3. Alternatively, the second control constant may be displayed on a terminal (such as a notebook PC) connected to the input / output device 3.

[0025] Next, the operation of the electric power steering device 50 will be described. In FIG. 1, the steering torque applied by the driver to the steering wheel 51 is transmitted to the torsion bar in the torque detector 22 via the input shaft 53a. The steering torque is further transmitted to the rack-and-pinion gear 54. A rack included in the rack-and-pinion gear 54 is connected to the wheels 55 via a tie rod 56 and a knuckle arm 57. When the driver operates the steering wheel 51, the tie rod 56 pushes the knuckle arm 57 of the wheels 55 on one side, and the tie rod 56 pulls the knuckle arm 57 of the wheels 55 on the opposite side. This causes the wheels 55 to turn.

[0026] The output torque of the rotating machine 1 is transmitted to the steering shaft 53. The output torque of the rotating machine 1 can reduce the driver's burden associated with steering. The rotating machine 1 may be, for example, an AC motor such as a permanent magnet synchronous motor or an induction motor, or a DC motor.

[0027] Power supply unit 25 calculates a current command corresponding to the output torque of rotating machine 1 based on steering torque signal Ts and rotational speed signal ωm. Based on the current command, power supply unit 25 generates a voltage command for controlling the current flowing through rotating machine 1. Furthermore, power supply unit 25 applies a voltage to rotating machine 1 using a drive circuit (not shown) in accordance with the voltage command. In this manner, rotating machine 1 is driven.

[0028] The power supply unit 25 has multiple controllers (not shown) for calculating the current command described above. These controllers are configured to satisfy various requirements, such as steering feel, control stability, and noise and disturbance resistance. More specifically, the control constants of each controller are appropriately set to satisfy the performance requirements described above. Each controller in the power supply unit 25 performs feedback control based on information detected by various detectors. The "various detectors" may include a vehicle speed detector, a yaw rate detector, and the like, in addition to the torque detector 22 and the rotation detector 23. For example, the configuration disclosed in Japanese Patent Application Laid-Open No. 2002-29433 can be used as such a controller. Alternatively, the power supply unit 25 may calculate the current command using a controller that performs viscosity compensation.

[0029] 3 and 4, an example of the operation of the target characteristic setting unit 4, the control constant holding unit 5, and the control constant calculation unit 6 will be described below. In this embodiment, each control constant is set for each vehicle speed, as in the control constant matrix shown in FIG. 3. A "control constant matrix" is a table showing the relationship between control constants and vehicle state values. In the example of FIG. 3, a2 to d2 have already been determined as specific values ​​of each control constant A to D at a vehicle speed of 8 km / h. That is, a vehicle speed of 8 km / h is the "first vehicle speed," and a2 to d2 are the "first control constants." Furthermore, the values ​​of each control constant A to D at a vehicle speed of 0 km / h (i.e., a1 to d1) are newly calculated by the control constant calculation unit 6. That is, a vehicle speed of 0 km / h is the "second vehicle speed," and a1 to d1 are the "second control constants."

[0030] In FIG. 3, a vehicle speed greater than 0 km / h and less than 8 km / h is an "intermediate vehicle speed." For example, 1 km / h corresponds to an intermediate vehicle speed. The control constant corresponding to the intermediate vehicle speed (intermediate control constant) is not defined in the control constant matrix of FIG. 3. The intermediate control constant is calculated by interpolation based on the first control constant and the second control constant. A specific interpolation method may be linear interpolation or curve interpolation such as spline interpolation.

[0031] The first vehicle speed and the second vehicle speed in Fig. 3 are merely examples and may be changed. Also, a plurality of first vehicle speeds may be set. Similarly, a plurality of second vehicle speeds and a plurality of intermediate vehicle speeds may be set.

[0032] The target characteristic setting unit 4 sets a target characteristic at a second vehicle speed (second target characteristic) and a target characteristic at an intermediate vehicle speed (intermediate target characteristic). Specific examples of the "target characteristic" are as described above. The second target characteristic may be the same as or different from the target characteristic at the first vehicle speed (first target characteristic). The intermediate target characteristic may be the same as or different from the first target characteristic. The control constant calculation unit 6 calculates the second control constant so as to realize the second target characteristic and the intermediate target characteristic.

[0033] FIG. 4 shows an example of target characteristics set by target characteristic setting unit 4. In the example of FIG. 4, a target value (target characteristic) is set for the transfer characteristic of the torque controller. The torque controller is part of power supply unit 25 and controls the steering assist force generated by rotating machine 1. The "target value" in FIG. 4 is a gain that represents the ratio of the output (steering assist force) to the input (steering torque). In the example of FIG. 4, target values ​​in predetermined frequency bands (from frequency range 1 to frequency range 2) are set for each of the second vehicle speed and the intermediate vehicle speed.

[0034] For example, the target (1) for the second vehicle speed is set to a gain target value of 27 to 39 dB in the frequency band of 1 Hz to 3 Hz. In the example of FIG. 3, the second vehicle speed is 0 km / h, so the intermediate vehicle speed is higher than the second vehicle speed. The higher the vehicle speed, the smaller the steering force required for steering tends to be. Therefore, by reducing the steering assist force (i.e., gain) relative to the steering torque as the vehicle speed increases, the user's steering feeling is less likely to change depending on the vehicle speed. Therefore, in the example of FIG. 4, when compared in the same frequency band, the gain target value for the intermediate vehicle speed is set smaller than the gain target value for the second vehicle speed. Note that FIG. 4 is merely an example, and the set "target characteristic" may be external vibration suppression performance, stability, etc.

[0035] Next, the control constant storage unit 5 will be described. In the example shown in FIG. 3, the values ​​of the first control constants (a2 to d2) corresponding to a first vehicle speed (8 km / h) are predetermined and stored by the control constant storage unit 5. Here, the values ​​of the first control constants may be determined so that the first target characteristic is satisfied by performing a test steering operation at the first vehicle speed. Alternatively, the first control constants so that the first target characteristic is satisfied may be derived in advance by other methods. The control constant storage unit 5 outputs the values ​​of the first control constants to the control constant calculation unit 6.

[0036] Next, the control constant calculation unit 6 will be described. As mentioned above, the power supply unit 25 has multiple controllers. These controllers have a high degree of freedom, and there are many control constants that need to be set. Therefore, the control constant calculation unit 6 calculates the control constants that achieve the desired target characteristics through optimization calculation. As an optimization calculation method, the steepest descent method, genetic algorithm, etc. can be used. For example, by using PSO (Particle Swarm Optimization), which is a type of genetic algorithm, it is possible to arrive at global optimization.

[0037] As described above, the control constants at the intermediate vehicle speeds are calculated by interpolation. However, the control characteristics obtained using the control constants at the intermediate vehicle speeds are not necessarily the result of interpolating the control characteristics at the first vehicle speed and the control characteristics at the second vehicle speed. In other words, even if desired control characteristics are obtained at the first vehicle speed and the second vehicle speed, the desired control characteristics may not be obtained at the intermediate vehicle speed. An example of this is shown in FIG. 5.

[0038] FIG. 5 is a Bode diagram showing the open-loop transfer characteristics calculated from the characteristics of the torque controller and the mechanical characteristics of the steering. More specifically, this is an example in which the second control constant is determined so as to satisfy the target characteristics of the second vehicle speed without considering the control characteristics of the intermediate vehicle speed and the control constant for the first vehicle speed. Furthermore, the control constant for the intermediate vehicle speed is determined by interpolating the first control constant and the second control constant. In FIG. 5, the gain margin at the first vehicle speed and the gain margin at the second vehicle speed are sufficiently secured. However, the gain margin at the intermediate vehicle speed is smaller than that at the first vehicle speed and the second vehicle speed.

[0039] In other words, in FIG. 5, the gain margin at the intermediate vehicle speed is not the result of interpolating the gain margins at the first vehicle speed and the second vehicle speed. A small gain margin means that control stability is reduced. Reduced control stability may lead to, for example, a deterioration in steering feel. In the example of FIG. 5, the steering feel at the intermediate vehicle speed may be worse than the steering feel at the first vehicle speed and the second vehicle speed.

[0040] Therefore, in this embodiment, the second control constant is determined by optimization search so that the target characteristics are obtained at both the second vehicle speed and an intermediate vehicle speed for which the control constant is calculated by interpolation, thereby preventing a decrease in control performance due to changes in vehicle speed.

[0041] As shown in FIG. 6, the target characteristic setting unit 4 may have a target characteristic input unit 7. The target characteristic input unit 7 is an interface that allows an operator to input information related to the target characteristics. Specific examples of such an interface include a touch panel display, a keyboard, and a mouse. In the example of FIG. 4, the target characteristics are displayed in the interface (target characteristic input unit 7) in the form of a table. For example, the user may select a cell shown in this table and edit the value of that cell. This facilitates tuning of the target characteristics. The target characteristics set via the target characteristic input unit 7 are output to the control constant calculation unit 6, as shown in FIG. 2.

[0042] A modified example of FIG. 4 is shown in FIG. 7. FIG. 7 shows an example of displaying the target characteristics in the form of a map with the horizontal axis representing frequency and the vertical axis representing gain. The map format allows the operator to grasp the target characteristics more visually. For example, the input / output device 3 may be provided with a display that displays a map such as that shown in FIG. 7. The input / output device 3 may be configured to allow the operator to operate the cursor position or numerical values ​​on the map using a target characteristics input unit 7 that serves as an interface.

[0043] FIG. 8 shows a modified example of FIG. 7. As described above, in this embodiment, target characteristics are set for the second vehicle speed and the intermediate vehicle speed. The control constant calculation unit 6 calculates the control constant for the second vehicle speed by optimization calculation so as to satisfy the set target characteristics. The input / output device 3 calculates the control characteristics for the second vehicle speed and the intermediate vehicle speed using the second control constant obtained in this manner and the control constant for the intermediate vehicle speed obtained by interpolation. The calculated control characteristics may be displayed on a display together with the target characteristics, as shown in FIG. 8. This allows the operator to visually confirm whether the target characteristics are satisfied for each vehicle speed.

[0044] In the present embodiment, the vehicle state value is the vehicle speed. However, the vehicle state value does not have to be the vehicle speed. As a specific example, the vehicle state value may be a parameter indicating the lateral behavior of the vehicle (such as lateral acceleration, steering speed, or yaw rate). In the example of FIG. 9, the values ​​of the control constants A to D are set for each yaw rate value. For example, a yaw rate of 0 rad / s may be the first vehicle state value, a yaw rate of 2 rad / s may be the second vehicle state value, and a yaw rate of 1 rad / s may be the intermediate vehicle state value.

[0045] In this case, the values ​​of the control constants a1 to d1 at a yaw rate of 0 rad / s are the default "first control constants" and are stored in the control constant storage unit 5. Then, the second control constants (a3 to d3) are calculated so that the target characteristics are obtained at both a yaw rate of 2 rad / s (second vehicle state value) and a yaw rate of 1 rad / s (intermediate vehicle state value). The control constants (a2 to d2) at the intermediate vehicle state value are calculated by interpolating the first control constants and the second control constants, as described above.

[0046] Although the present embodiment has been described taking an example of an electric power steering that assists steering force, the present disclosure can also be applied to control in the case of generating a steering reaction force to give the driver a steering feeling, such as in SBW (Steer by Wire).

[0047] As described above, the input / output device 3 according to this embodiment sets control constants (first control constant, second control constant, intermediate control constant) corresponding to a plurality of vehicle state values ​​(first vehicle state value, second vehicle state value, intermediate vehicle state value) for the steering control device 2 that controls the steering mounted on the vehicle. The input / output device 3 includes a control constant holding unit 5 that holds a first control constant corresponding to the first vehicle state value, a target characteristic setting unit 4 that sets a second target characteristic that is a target value of the steering control characteristic for a second vehicle state value that is different from the first vehicle state value, and a control constant calculation unit 6 that calculates a second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic and outputs the second control constant to the steering control device 2.

[0048] According to this input / output device 3, the second control constant calculated so as to satisfy the second target characteristic is output to the steering control device 2. Therefore, unlike the conventional technique, the work of adjusting the second control constant by trial and error by an operator is no longer necessary. This provides the effect of reducing the number of steps required to set the control constant taking into consideration the transition of the vehicle state value.

[0049] Furthermore, the target characteristic setting unit 4 may set an intermediate target characteristic corresponding to a vehicle state value intermediate between the first vehicle state value and the second vehicle state value. With this configuration, the second control constant can be set so as to satisfy the target characteristic even for an intermediate vehicle state value. Therefore, it is possible to obtain an effect of avoiding a deterioration in control performance accompanying a transition of the vehicle state value.

[0050] Furthermore, the target characteristic setting unit 4 may have a target characteristic input unit 7 for inputting the target characteristic from outside the input / output device 3. With this configuration, for example, an operator can manually input the target characteristic. Therefore, it becomes possible to easily set the target characteristic for a specific vehicle state value, and the adjustment man-hours can be reduced. Note that "outside the input / output device 3" also includes, for example, a management device connected to the input / output device 3 by wire or wirelessly. In other words, a configuration may be adopted in which the target characteristic is input to the target characteristic input unit 7 by the management device.

[0051] The vehicle state value may be the vehicle speed. In this case, the number of steps required to adjust the control constant for each vehicle speed can be reduced. Alternatively, the deterioration of control performance due to changes in vehicle speed can be avoided.

[0052] Embodiment 2 Next, an input / output device according to a second embodiment will be described. The basic configuration of the input / output device according to this embodiment is similar to that of the first embodiment, so differences will be mainly described. The target characteristic setting unit 4 according to this embodiment sets an intermediate target characteristic by interpolation based on the second target characteristic and the control characteristic corresponding to the first vehicle state value.

[0053] FIG. 10 is a schematic diagram showing the configuration of an input / output device 3 according to the second embodiment. As shown in FIG. 10, a control constant holding unit 5 in this embodiment inputs a first control constant to a target characteristic setting unit 4. The target characteristic setting unit 4 sets a second target characteristic. The second target characteristic may be determined in advance based on the vehicle model, know-how, etc. Furthermore, the target characteristic setting unit 4 calculates the control characteristic obtained from the first control constant as the "first control characteristic."

[0054] Here, the target characteristic setting unit 4 calculates the target characteristic of the intermediate vehicle state value (intermediate target characteristic) by interpolation using the "first control characteristic" and the "second target characteristic." A specific interpolation method may be linear interpolation or curved interpolation such as spline interpolation. The "intermediate vehicle state value" may be any value between the first vehicle state value and the second vehicle state value. For example, the average of the first vehicle state value and the second vehicle state value may be set as the intermediate vehicle state value. Furthermore, there may be multiple intermediate vehicle state values.

[0055] 11, the target characteristic setting unit 4 may have a target characteristic interpolation unit 8 in addition to the above-mentioned target characteristic input unit 7. In this case, the target characteristic interpolation unit 8 calculates an intermediate target characteristic by interpolating the second target characteristic input to the target characteristic input unit 7 and the first control characteristic.

[0056] As a modification of the second embodiment, the first target characteristic may be determined in advance before the first control constant is determined. In this case, the first control constant may be determined so as to satisfy the first target characteristic. Furthermore, the target characteristic setting unit 4 may calculate an intermediate target characteristic by interpolation using the "first target characteristic" and the "second target characteristic." In this case, in FIG. 11 , the target characteristic interpolation unit 8 calculates the target characteristic at the intermediate vehicle state value by interpolating the second target characteristic and the first target characteristic input to the target characteristic input unit 7.

[0057] In this embodiment, the vehicle state value may be the vehicle speed, as in the first embodiment, or may be a parameter related to the lateral behavior of the vehicle (such as lateral acceleration, steering speed, or yaw rate).

[0058] As described above, in this embodiment, the target characteristic setting unit 4 sets the intermediate target characteristic by interpolating between the second target characteristic and the control characteristic corresponding to the first vehicle state value. Alternatively, the target characteristic setting unit 4 sets the intermediate target characteristic by interpolating between the second target characteristic and the first target characteristic.

[0059] According to this configuration, the intermediate target characteristics are set by interpolation, which reduces the number of steps required by the operator. Furthermore, it is possible to prevent the control performance at the intermediate vehicle state values ​​from deteriorating due to the transition of the vehicle state values.

[0060] Embodiment 3 Next, an input / output device according to a third embodiment will be described. The basic configuration of the input / output device according to this embodiment is similar to that of the first embodiment, so differences will be mainly described. In this embodiment, an example will be described in which the vehicle state values ​​in the control constant matrix calculated by the control constant calculation unit 6 are set more finely. The step size of the vehicle state values ​​in the control constant matrix may be the same as the resolution detectable by a detector for the vehicle state value. For example, consider a case in which the vehicle state value is vehicle speed and the resolution detectable by the vehicle speed detector is 1 km / h. In this case, the control constants may be set in the control constant matrix for every 1 km / h of vehicle speed. A specific example of such a control constant matrix is ​​shown in FIG. 12.

[0061] In the example of FIG. 12, the "first vehicle speed" is 7 km / h and the "second vehicle speed" is 0 km / h. That is, the values ​​of the control constants a8 to d8 at a vehicle speed of 7 km / h are determined in advance and stored by the control constant storage unit 5. The control constants a1 to d1 (second control constants) at 0 km / h are calculated by the control constant calculation unit 6. The control constants at the "intermediate vehicle speeds" of 1 to 6 km / h are obtained by interpolation. The second control constants are optimized and calculated so that the target characteristics are satisfied at both the second vehicle speed and the intermediate vehicle speed.

[0062] Here, "target characteristics are satisfied" means that the control characteristics of the entire control system, which combines multiple controllers, are desirable. However, when focusing on individual controllers, the characteristics may change significantly depending on the vehicle state value. For example, in Figure 12, even if the target characteristics are satisfied at both vehicle speeds of 2 km / h and 3 km / h, the control constants a3 and a4 may be significantly different. When the change gradient of the control constants is large, abrupt fluctuations may occur in the output of a single controller as the vehicle state value transitions, potentially resulting in a deterioration in control performance. In particular, the more detailed the vehicle state values ​​are set in the control constant matrix, the more likely this problem is to occur.

[0063] Therefore, in this embodiment, when calculating the second control constant, the optimization calculation conditions are set so that the second control constant does not vary significantly from the first control constant. For example, in FIG. 12, a case will be described in which the second vehicle speed control constant a1 is calculated based on the first vehicle speed control constant a8. In this case, the following conditional formula (1) is set when performing the optimization calculation. In conditional formula (1), X1 is a lower fluctuation limit value and X2 is an upper fluctuation limit value. Both X1 and X2 are positive numbers. a8-X1 <a1<a8+X2 …(1)

[0064] Alternatively, when performing optimization calculations, the following conditional expression (2) may be set. In conditional expression (2), X3 is a lower fluctuation limiting magnification, and X4 is an upper fluctuation limiting magnification. Both X3 and X4 are positive numbers. a8×X3 <a1<a8×X4 …(2)

[0065] Alternatively, instead of using conditional expressions (1) and (2), a method of optimization calculation may be used in which a small difference between a1 and a8 is set as one of the target values. As described above, by calculating the second control constant so that it does not deviate significantly from the first control constant, it is possible to suppress deterioration in control performance that accompanies transitions in the vehicle state value.

[0066] A control constant matrix according to a modified example of this embodiment is shown in Fig. 13. In the example of Fig. 13, the step size of the vehicle state value in the control constant matrix changes according to the magnitude of the vehicle state value. Specifically, when the vehicle speed is in the range of 0 km / h to 5 km / h, the step size of the vehicle speed is 1 km / h. When the vehicle speed is in the range of more than 5 km / h, the step size increases as the vehicle speed increases.

[0067] In the example of FIG. 13, the vehicle speed step size is small in the range of 0 km / h to 5 km / h, so that the control performance is likely to deteriorate with the transition of the vehicle state value. Therefore, in the range of 0 km / h to 5 km / h, it is possible to "calculate the second control constant so that it does not deviate significantly from the first control constant." Furthermore, in the range where the vehicle speed exceeds 5 km / h, it is not necessary to "calculate the second control constant so that it does not deviate significantly from the first control constant." This configuration can ease the conditions for obtaining the second control constant through optimization calculation. Therefore, it is possible to reduce the calculation load on the input / output device 3.

[0068] In addition, in this embodiment, the vehicle speed has been described as the vehicle state value, but the vehicle state value may be a parameter relating to the lateral behavior of the vehicle, as described in the first embodiment.

[0069] Embodiment 4 In this embodiment, a vehicle manufacturing method and a program related to the input / output devices described in the first to third embodiments will be described.

[0070] The input / output device 3 described in the first to third embodiments can be used, for example, in a vehicle production line. When manufacturing vehicles, setting items common to all vehicles are set, and then different setting items may be set depending on the destination. The "setting items" include the various control constants described above. The "destination" includes the country or region to which the vehicle is shipped, or the use of the vehicle (general use, commercial use, sports use, etc.). The steering feel desired by the driver may differ depending on the destination. Furthermore, differences in the control constants result in differences in the steering feel. Therefore, by varying the control constants depending on the destination, it is possible to provide a good steering feel to more drivers.

[0071] As described in the first to third embodiments, the control constant calculation unit 6 calculates the second control constant so that the target characteristics are obtained for both the second vehicle state value and the intermediate vehicle state value. By setting different target characteristics depending on the destination, an appropriate second control constant according to the destination is calculated.

[0072] Therefore, the manufacturing method of a vehicle according to this embodiment includes a step of inputting the second control constant into the vehicle steering control device 2 using the input / output device 3 described in the first to third embodiments. This manufacturing method makes it possible to realize an appropriate steering feeling according to the destination. Furthermore, it eliminates the need for an operator to adjust the second control constant through trial and error. In other words, it is possible to obtain the effect of achieving both appropriate adjustment according to the destination of the vehicle and a reduction in the adjustment man-hours.

[0073] The input / output device 3 according to the first to third embodiments can be used not only during vehicle manufacturing but also, for example, during vehicle maintenance. That is, when a vehicle undergoes maintenance, the control constants may be set using the input / output device 3. The maintenance may be performed by bringing the vehicle into a maintenance shop. Alternatively, the maintenance may be performed in response to a user request while the vehicle is stopped. In this case, it is preferable to connect the vehicle and the input / output device 3 via wireless communication and update the control constants.

[0074] The above-described functions of the steering control device 2 and the input / output device 3 are realized by a processor such as a CPU (Central Processing Unit) executing a program stored in a program memory. Some or all of these functions may be realized by hardware such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array), or may be realized by a combination of software and hardware.

[0075] The programs for realizing the functions of the steering control device 2 and the input / output device 3 described above are recorded, for example, on a computer-readable recording medium. The programs recorded on this recording medium may then be read into a computer and executed to perform the processing of the steering control device 2 and the input / output device 3 described above. Here, "reading the programs recorded on a recording medium into a computer and executing them" includes installing the programs on a computer. The term "computer" here includes hardware such as an OS and peripheral devices.

[0076] Furthermore, a "computer" may include multiple computer devices connected via a network, including the Internet or communication lines such as a WAN, LAN, or dedicated line. Furthermore, a "computer-readable recording medium" refers to portable media such as a flexible disk, optical magnetic disk, ROM, or CD-ROM, as well as storage devices such as a hard disk built into a computer. Thus, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

[0077] The recording medium also includes an internal or external recording medium accessible from a distribution server for distributing the program. The program may be divided into multiple parts, downloaded at different times, and then combined in the steering control device 2 and the input / output device 3. Each divided program may be distributed by a different distribution server.

[0078] The term "computer-readable recording medium" includes a medium that stores a program for a certain period of time, such as volatile memory (RAM) inside a computer that acts as a server or client when the program is transmitted over a network. The program may also be a program that realizes part of the functions described above. Furthermore, the program may be a so-called differential file (differential program). A differential program realizes the functions described above in combination with a program already stored on the computer.

[0079] A program according to the present embodiment causes a computer to execute the steps of: retaining a first control constant corresponding to a first vehicle state value; setting a second target characteristic that is a target value for the steering control characteristic for a second vehicle state value different from the first vehicle state value; calculating the second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic; and outputting the second control constant. This program provides the effect of achieving both appropriate adjustment according to the destination of the vehicle and a reduction in the amount of adjustment work required.

[0080] The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. The above-described embodiments and modifications may be combined as appropriate. [Explanation of symbols]

[0081] 2...Steering control device 3...Input / output device 4...Target characteristic setting section 5...Control constant holding section 6...Control constant calculation section 7...Target characteristic input section

Claims

1. An input / output device for setting a control constant corresponding to a plurality of vehicle state values ​​for a steering control device that controls a steering mounted on a vehicle, a control constant storage unit that stores a first control constant corresponding to a first vehicle state value; a target characteristic setting unit that sets a second target characteristic, which is a target value of the steering control characteristic, for a second vehicle state value that is different from the first vehicle state value; a control constant calculation unit that calculates a second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic, and outputs the second control constant to the steering control device.

2. The input / output device according to claim 1 , wherein the target characteristic setting unit sets an intermediate target characteristic corresponding to a vehicle state value intermediate between the first vehicle state value and the second vehicle state value.

3. 3. The input / output device according to claim 2, wherein the target characteristic setting unit sets the intermediate target characteristic by interpolating the second target characteristic and a control characteristic corresponding to the first vehicle state value.

4. 3. The input / output device according to claim 2, wherein the target characteristic setting unit sets the intermediate target characteristic by interpolating the second target characteristic and the first target characteristic at the first vehicle state value.

5. The input / output device according to claim 1 , wherein the target characteristic setting unit has a target characteristic input unit for inputting the target characteristic from outside the input / output device.

6. The input / output device according to claim 1 , wherein the vehicle state value is a vehicle speed.

7. The input / output device according to claim 1 , wherein the vehicle state value is a parameter related to a lateral behavior of the vehicle.

8. A method for manufacturing a vehicle, comprising the step of inputting the second control constant to the steering control device using the input / output device according to any one of claims 1 to 4.

9. On the computer, maintaining a first control constant corresponding to a first vehicle state value; setting a second target characteristic that is a target value of the steering control characteristic for a second vehicle state value that is different from the first vehicle state value; calculating a second control constant corresponding to the second vehicle state value based on the first control constant and the second target characteristic; outputting the second control constant; A program that executes.

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