Moving body control system

Abstract

To more appropriately calculate an actuator command value when switching a low-order application in conjunction with switching of a high-order application.SOLUTION: A moving body control system includes: a high-order ECU that calculates a required physical quantity according to each of switchable first and second high-order applications; a low-order ECU that receives the required physical quantity and calculates an actuator command value for causing a detected physical quantity to follow the required physical quantity according to the first or second low-order application while performing switching between the first low-order application and the second low-order application in conjunction with switching of the high-order applications; and an actuator. The first low-order application and the second low-order application implement control in which the followability of the detected physical quantity to the required physical quantity is different from each other. The low-order ECU executes amount-of-charge restriction processing that moderates a change from a previous value to a current value of the required physical quantity, and substitutes the detected physical quantity for the previous value of the amount-of-charge restriction processing in accordance with the switching between the first high-order application and the second high-order application.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a mobile object control system. [Background technology]

[0002] Patent Document 1 discloses a steering control device for a vehicle. The steering control device is configured to be able to switch between assist control, which generates an assist torque according to the steering torque of a driver, and tracking control, which causes a detected value of a physical quantity related to steering to follow a target value of the physical quantity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-069990 Summary of the Invention [Problem to be solved by the invention]

[0004] A mobile object control system including a host ECU that calculates a required physical quantity of a mobile object (e.g., a required steering angle of a vehicle) in accordance with a plurality of switchable host applications, and a lower ECU that receives the required physical quantity from the host electronic control unit and calculates an actuator command value for making a detected physical quantity (e.g., a detected steering angle) follow the required physical quantity while switching a plurality of lower applications in conjunction with switching of the plurality of host applications, has the following problem: If a timing discrepancy occurs between switching of the host application and switching of the lower application, the lower electronic control unit may not be able to properly calculate the actuator command value.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to enable more appropriate calculation of actuator command values when switching lower-level applications in conjunction with switching upper-level applications. [Means for solving the problem]

[0006] A mobile object control system according to a first aspect of the present disclosure includes a host electronic control unit, a lower electronic control unit, and an actuator. The host electronic control unit calculates a required physical quantity, which is a required value of a physical quantity related to driving operation of the mobile object, in accordance with each of first and second switchable host applications. The lower electronic control unit receives the required physical quantity from the host electronic control unit, and calculates an actuator command value for causing a detected physical quantity, which is a detected value of the physical quantity, to follow the required physical quantity in accordance with the first or second lower application while switching between the first and second lower application in conjunction with switching between the first and second higher application. The actuator is controlled in accordance with the actuator command value. The first and second lower application realize control in which the detected physical quantity has different trackability to the required physical quantity. The lower-level electronic control unit executes a change amount suppression process that makes the change from the previous value to the current value of the required physical quantity more gradual than when the required physical quantity is changed in a stepwise manner from the previous value to the current value, and substitutes the detected physical quantity for the previous value of the change amount suppression process in response to switching between the first upper-level application and the second upper-level application.

[0007] The mobile object control systems according to the second and third aspects of the present disclosure differ from the mobile object control system according to the first aspect in the following respects: In the second aspect, the lower-level electronic control unit substitutes an estimated physical quantity, which is an estimate of a physical quantity based on one or more parameters indicating the behavior of the mobile object, for the previous value of the change amount suppression process in response to switching between the first upper-level application and the second upper-level application; and In the third aspect, the lower-level electronic control unit substitutes zero for the previous value of the change amount suppression process in response to switching between the first upper-level application and the second upper-level application. [Effects of the Invention]

[0008] According to each of the first to third aspects of the present disclosure, when switching a lower-level application in conjunction with switching a higher-level application, it becomes possible to more appropriately calculate an actuator command value. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of the configuration of a vehicle steering system according to an embodiment; [Figure 2] FIG. 2 is a block diagram showing a functional configuration of steering control according to the embodiment. [Figure 3] FIG. 10 is a diagram for specifically explaining a problem that occurs when the relationship between a higher-level application and a lower-level application does not match. [Figure 4] 6 is a flowchart showing a process related to a first control example according to the embodiment. [Figure 5] 5A and 5B are diagrams for explaining the operation of a comparative example of steering control and a first control example. [Figure 6] 10 is a flowchart showing a process related to a second control example according to the embodiment. [Figure 7] 10 is a flowchart showing a process related to a third control example according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1. Vehicle Steering System Configuration FIG. 1 is a diagram showing an example of the configuration of a vehicle steering system 100 according to an embodiment. The vehicle steering system 100 is applied to a vehicle 1 (for example, a four-wheel vehicle). The vehicle steering system 100 includes a steering device 10, sensors 20, a host electronic control unit (host ECU) 30, and a lower electronic control unit (lower ECU) 40. The vehicle 1 may be an autonomous vehicle. The vehicle steering system 100 corresponds to an example of a "mobile body control system" according to the present disclosure.

[0012] Steering device 10 is a device that steers wheels 2 of vehicle 1. Steering device 10 includes steering wheel 11, steering shaft 12, and steering unit 13. Steering wheel 11 is operated by the driver of vehicle 1. Steering unit 13 steers wheels 2. Steering unit 13 includes steering actuator 14, steering shaft (rack shaft) 15, and tie rod 16. Steering actuator 14 is, for example, an electric motor, and generates torque to steer wheels 2. Wheels (steerable wheels) 2 are connected to steering shaft 15 via tie rod 16. Steering actuator 14 linearly moves steering shaft 15 in its axial direction, thereby changing the steering angle (steering angle) θ of wheels 2 via tie rod 16. Steering angle θ corresponds to an example of a "physical quantity related to driving operation (steering) of a mobile object" according to the present disclosure. Steering actuator 14 is used as an electric power steering (EPS) device that assists steering by the driver. The steering device 10 may be of a steer-by-wire type in which the steering wheel 11 is mechanically separated from the wheels (steered wheels) 2.

[0013] The sensors 20 include, for example, a recognition sensor, a steering angle sensor, a yaw rate sensor, a vehicle speed sensor, and a longitudinal acceleration sensor. The recognition sensor recognizes (detects) the surrounding conditions of the vehicle 1. The recognition sensor includes, for example, a camera C. Alternatively, the recognition sensor may include, instead of or in addition to the camera C, at least one of a millimeter-wave radar and a LIDAR (Laser Imaging Detection and Ranging). The steering angle sensor is attached to the steering actuator 14 and detects the steering angle θ (detected steering angle θd) of the wheels 2. The yaw rate sensor, the vehicle speed sensor, and the longitudinal acceleration sensor detect the yaw rate, vehicle speed, and longitudinal acceleration of the vehicle 1, respectively.

[0014] The upper ECU 30 and the lower ECU 40 can communicate with each other. For example, the upper ECU 30 and the lower ECU 40 are mounted on the vehicle 1, and the upper ECU 30 is connected to the lower ECU 40 via a communication line 3. Note that the upper ECU 30 does not necessarily have to be mounted on the vehicle 1. In other words, the upper ECU 30 may be provided outside the vehicle 1 and configured to communicate with the lower ECU 40 via a wireless communication network.

[0015] As will be described in detail later, the host ECU 30 cooperates with the subordinate ECU 40 to execute steering control of the vehicle 1. The host ECU 30 includes a processing circuit 31 and a memory 32. The processing circuit 31 executes various processes including calculation of a required steering angle θr based on information from the camera C. The required steering angle θr is a required value for the steering angle θ of the wheels 2. The memory 32 stores various information required for processing by the processing circuit 31. The processing circuit 31 executes a computer program, thereby realizing various processes by the host ECU 30. The computer program is stored in the memory 32. Alternatively, the computer program may be recorded on a computer-readable recording medium.

[0016] Lower-level ECU 40 includes a processing circuit 41 and a memory 42. Processing circuit 41 executes various processes including calculation of a torque command value Tc according to the difference (steering angle difference Δθ) between requested steering angle θr received from higher-level ECU 30 and detected steering angle θd (in other words, actual steering angle). Torque command value Tc is an actuator command value that is issued to steering actuator 14 to make detected steering angle θd follow requested steering angle θr. Memory 42 stores various information required for processing by processing circuit 41. Various processes by lower-level ECU 40 are realized by processing circuit 41 executing a computer program. The computer program is stored in memory 42. Alternatively, the computer program may be recorded on a computer-readable recording medium.

[0017] 2. Steering control 2 is a block diagram showing the functional configuration of the steering control according to the embodiment. As described above, the steering control is executed by cooperation between the host ECU 30 and the subordinate ECU 40. As shown in FIG. 2, the host ECU 30 includes a required steering angle calculation unit 33 and an application switching unit 34.

[0018] To calculate the required steering angle θr, the required steering angle calculation unit 33 uses multiple upper level applications (hereinafter abbreviated as "upper level applications"). The multiple upper level applications are included in the computer program stored in the memory 32. More specifically, the upper level applications are steering assist applications that assist the driver in steering. In the example shown in FIG. 2, two upper level applications A and B correspond to an example of the multiple upper level applications referred to here. Note that the number of multiple upper level applications may be three or more.

[0019] Specifically, the upper application A is an application that provides, for example, a function of calculating a required steering angle θra so as to avoid an obstacle that is detected by the camera C and exists in the driving lane ahead of the vehicle 1. The upper application B is an application that provides, for example, a function of calculating a required steering angle θrb so that the vehicle 1 travels while following the driving lane based on vehicle surrounding information from the camera C. The required steering angle calculation unit 33 calculates the required steering angles θra and θrb of the upper applications A and B in parallel at a predetermined control period (calculation period).

[0020] (Application switching unit 34) The application switching unit 34 switches between the upper application A and the upper application B by alternatively selecting either the upper application A or B. This switching is performed, for example, as follows. That is, the application switching unit 34 basically selects the upper application B for causing the vehicle 1 to travel while following the driving lane. Then, when an obstacle present in the driving lane is detected by the camera C, the application switching unit 34 selects the upper application A, that is, switches from the upper application B to the upper application A. Then, when it is determined from the peripheral information from the camera C that the vehicle 1 has completed avoiding the obstacle, the application switching unit 34 selects the upper application B, that is, switches from the upper application A to the upper application B. According to this switching, the requested steering angle θr output from the application switching unit 34 is switched in a stepwise manner between the requested steering angle θra and the requested steering angle θrb.

[0021] The upper ECU 30 transmits the calculated required steering angle θr (more specifically, the required steering angle θra or θrb calculated by the upper application A or B selected by the application switching unit 34) to the lower ECU 40 via the communication line 3. In addition to the required steering angle θr, the upper ECU 30 also transmits "application switching information" to the lower ECU 40. The application switching information is, for example, ID (Identification) information that identifies the upper application A or B currently selected by the application switching unit 34.

[0022] On the other hand, as shown in FIG. 2, the lower ECU 40 includes a change amount suppression unit 43, a subtraction unit 44, an application switching unit 45, and a torque calculation unit 46. To calculate the torque command value Tc, the torque calculation unit 46 uses multiple lower applications (hereinafter, abbreviated as "lower applications"). The multiple lower applications are included in the computer program stored in the memory 42. More specifically, the lower applications are also steering assistance applications that assist the driver in steering. Each lower application is paired with one of the multiple upper applications. In the example shown in FIG. 2, upper application A is paired with lower application A, and upper application B is paired with lower application B.

[0023] To suppress abrupt changes in the required steering angle θr, the change amount suppression unit 43 executes a change amount suppression process (in other words, a smoothing process). The change amount suppression process is a process for gradually changing the required steering angle θr from the previous value θr(n-1) to the current value θr(n) compared to a case where the required steering angle θr is changed stepwise from the previous value θr(n-1) to the current value θr(n). More specifically, the change amount suppression process is a process for limiting the change amount Δθr from the previous value θr(n-1) to the current value θr(n) to a predetermined upper limit value or less. The change amount suppression unit 43 outputs the required steering angle θrs after the change amount suppression process to the subtraction unit 44. In addition, the change amount suppression process may also include a filtering process for applying a low-pass filter (LPF) to time-series data of the required steering angle θr. The change amount suppression process of the required steering angle θr may also be performed on the host ECU 30 side.

[0024] The subtraction unit 44 calculates the steering angle difference Δθ by subtracting the detected steering angle (current actual steering angle) θd from the requested steering angle θrs output from the change amount suppression unit 43, and transmits the calculated steering angle difference Δθ to the application switching unit 45. Note that, to calculate the steering angle difference Δθ, an estimated steering angle θe, which will be described later, may be used instead of the detected steering angle θd.

[0025] The application switching information transmitted from the upper ECU 30 to the lower ECU 40 is input to the application switching unit 45. Based on the application switching information (i.e., an application switching request), the application switching unit 45 switches the lower application in conjunction with the switching of the upper application by the application switching unit 34. Specifically, the application switching unit 45 alternatively selects either the lower application A or B in conjunction with the switching of the upper application, thereby switching the lower application used in the torque calculation unit 46 between the lower application A and the lower application B. More specifically, the output destination of the steering angle difference Δθ received from the subtraction unit 44 is switched in a stepwise manner between the lower application A and the lower application B.

[0026] The lower application A is an application that provides a function of calculating a torque command value Tc according to a steering angle difference Δθ based on a required steering angle θra of the upper application A. Similarly, the lower application B is an application that provides a function of calculating a torque command value Tc according to a steering angle difference Δθ based on a required steering angle θrb of the upper application B.

[0027] As shown in Fig. 2, the relationship of the torque command value Tc to the steering angle difference Δθ (referred to as "torque gain") differs between the lower application A and the lower application B. Specifically, the lower application A and the lower application B have in common the fact that the torque command value Tc (absolute value) increases as the steering angle difference Δθ (absolute value) increases. Furthermore, the magnitude of the torque command value Tc for the same steering angle difference Δθ is determined to be larger in the lower application A than in the lower application B. In other words, the torque gain is determined to be larger in the lower application A than in the lower application B.

[0028] Therefore, when the lower application A is selected, control is realized in which the detected steering angle (actual steering angle) θd has high tracking ability with respect to the requested steering angle (target steering angle) θr. As a result, as shown in FIG. 3 described later, the steering angle difference Δθ during selection of the lower application A becomes small. As a result, when the upper application A calculates the requested steering angle θra to avoid an obstacle, for example, the detected steering angle (actual steering angle) θd can be quickly brought close to the requested steering angle θra. On the other hand, when the lower application B is selected, control is realized in which the detected steering angle θd has low tracking ability with respect to the requested steering angle θr compared to when the lower application A is selected. As a result, as shown in FIG. 3, the steering angle difference Δθ during selection of the lower application B becomes large.

[0029] The relationship between steering angle difference Δθ and torque command value Tc as shown in Fig. 2 is stored as a map in memory 42 for each lower application. When lower application A is selected by application switching unit 45, torque calculation unit 46 calculates torque command value Tc corresponding to steering angle difference Δθ from the map corresponding to lower application A. Similarly, when lower application B is selected, torque calculation unit 46 calculates torque command value Tc corresponding to steering angle difference Δθ from the map corresponding to lower application B. Steering actuator 14 is controlled in accordance with torque command value Tc, and generates torque corresponding to torque command value Tc.

[0030] Next, a problem of the vehicle steering system 100 according to the embodiment will be described. When the lower application is switched in conjunction with the switching of the upper application as described above, if there is a timing discrepancy between the switching of the upper application and the switching of the lower application, the lower ECU 40 may not be able to properly calculate the torque command value Tc.

[0031] Specifically, when there is a difference in tracking ability between the controls realized by the lower application A and the lower application B as described above (in other words, when there is a difference in torque gain), the following problem occurs. That is, when the lower application is switched at the same time as the switching of the upper application, the lower ECU 40 can appropriately calculate the torque command value Tc according to the lower application A corresponding to the switched upper application A (or the lower application B corresponding to the switched upper application B). On the other hand, due to the above-described change amount suppression process or a communication delay between the upper ECU 30 and the lower ECU 40, a mismatch may occur between the upper application that calculates the requested steering angle θr and the lower application that calculates the torque command value Tc when the upper application is switched. When the relationship between the upper application and the lower application is thus mismatched, the lower ECU 40 cannot appropriately calculate the torque command value Tc in response to the application switching request from the upper ECU 30, as illustrated in FIG. 3 . In addition, when the change amount suppression process is being executed, when switching between upper level applications, the upper level application that calculated the current value θr(n) and the upper level application that calculated the previous value θr(n-1) will temporarily be different.

[0032] FIG. 3 is a diagram specifically illustrating the problem that occurs when the relationship between the upper application and the lower application does not match. FIG. 3 shows an example in which a switch from the upper application A to the upper application B occurs around time t1, and then a switch from the upper application B to the upper application A occurs around time t2. FIG. 3 shows that while the lower application A, which has a large torque gain, is selected (before time t1 and after time t2), the detected steering angle θd closely follows the requested steering angle θr (θra). In addition, in this example, a large steering angle difference Δθ occurs between the requested steering angle θrb of the upper application B and the detected steering angle θd around times t1 and t2 when the upper application is switched.

[0033] First, a description will be given of switching from the upper application A to the upper application B around time t1. When the upper application and the lower application are switched simultaneously without causing a mismatch between the upper application and the lower application, the torque command value Tc is appropriately calculated as shown in the waveform labeled "simultaneous switching." On the other hand, when a mismatch occurs in which the lower application A is switched to the lower application B before the upper application A is switched to the upper application B, the lower ECU 40 calculates the torque command value Tc for reducing the steering angle difference Δθ corresponding to the requested steering angle θra based on the upper application A according to the lower application B, which has a small torque gain. As a result, the torque command value Tc decreases compared to the case of simultaneous switching in which the lower application A is used. Furthermore, when a mismatch occurs in which the upper application A is switched to the upper application B before the lower application A is switched to the lower application B, the lower ECU 40 calculates the torque command value Tc for reducing the large steering angle difference Δθ (see FIG. 3 ) corresponding to the requested steering angle θrb based on the upper application B according to the lower application A, which has a large torque gain. As a result, the torque command value Tc increases compared to the simultaneous switching case, as shown in the waveform labeled "torque increase (torque switching delay)" in Figure 3. This may lead to unnecessary torque being applied to the driver via the steering wheel 11.

[0034] Next, a description will be given of switching from the upper application B to the upper application A around time t2. In this example, too, the torque command value Tc is calculated appropriately in the case of "simultaneous switching." On the other hand, if a mismatch occurs in which the switching from the upper application B to the upper application A occurs before the switching from the lower application B to the lower application A, the lower ECU 40 calculates the torque command value Tc for reducing the steering angle difference Δθ corresponding to the requested steering angle θra based on the upper application A according to the lower application B, which has a small torque gain. As a result, the torque command value Tc decreases compared to the case of simultaneous switching in which the lower application A is used. Also, if a mismatch occurs in which the switching from the lower application B to the lower application A occurs before the switching from the upper application B to the upper application A, the lower ECU 40 calculates the torque command value Tc for reducing the large steering angle difference Δθ (see FIG. 3 ) corresponding to the requested steering angle θrb based on the upper application B according to the lower application A, which has a large torque gain. As a result, the torque command value Tc increases compared to the case of simultaneous switching, as shown in the waveform labeled "torque increase (torque switching advance)" in FIG. 3. This may also result in unnecessary torque being applied to the driver via the steering wheel 11.

[0035] 2-1. First control example In view of the above-mentioned problems, in a first control example according to the present embodiment, the lower ECU 40 uses the detected steering angle θd instead of the previous value θr(n-1) of the requested steering angle θr as the previous value for the change amount suppression process in response to switching of the upper application. More specifically, for example, the current value θd(n) of the detected steering angle θd is used.

[0036] 4 is a flowchart showing a process relating to a first control example according to the embodiment. The process of this flowchart is executed by the subordinate ECU 40 at a predetermined control cycle.

[0037] In step S100, the slave ECU 40 acquires the required steering angle θr (θra or θrb) and application switching information from the slave ECU 30, and also acquires the detected steering angle θd from the sensors 20 (steering angle sensor).

[0038] Next, in step S102, the subordinate ECU 40 determines whether or not the upper application has been switched based on the application switching information. For example, if the ID information of the upper application included in the currently acquired application switching information is different from the ID information acquired previously, the subordinate ECU 40 determines that the upper application has been switched. If the upper application has been switched, the process proceeds to step S104.

[0039] In step S104, the lower-level ECU 40 (change amount suppression unit 43) substitutes the current value θd(n) of the detected steering angle θd acquired in step S100 for the previous value θr(n-1) of the requested steering angle θr in the change amount suppression process described above. In other words, the previous value θr(n-1) is replaced by the current value θd(n).

[0040] After step S104, the process proceeds to step S106. If the upper application has not been switched (step S102; No), the process proceeds to step S106 without replacing the previous value θr(n−1) with the current value θd(n).

[0041] In step S106, the subordinate ECU 40 executes the change amount suppression process. As a result, the required steering angle (current value) θrs(n) after the change amount suppression is calculated. Next, in step S108, the subordinate ECU 40 updates the previous value θr(n-1) of the change amount suppression process with the current value θrs(n). The updated previous value θr(n-1) is used in the next control cycle.

[0042] In step S110 following step S108, the lower-level ECU 40 calculates the difference between the requested steering angle θrs(n) after the change amount is suppressed and the current value θd(n) of the detected steering angle as the steering angle difference Δθ. Next, in step S112, the lower-level ECU 40 calculates a torque command value Tc corresponding to the calculated steering angle difference Δθ using the same lower-level application as the currently selected upper-level application based on the current (latest) application switching information.

[0043] FIG. 5 is a diagram for explaining the operation of a comparative example (A) of steering control and a first control example (B).

[0044] The comparative example corresponds to an example in which the detected steering angle (current value) θd(n) is not replaced with the previous value θr(n-1) when the host application is switched. Specifically, as shown in Fig. 5(A), in response to switching from the host application B to the host application A around time t2, the requested steering angle θr is switched in a stepped manner from the previous value θr(0), which is the requested steering angle θrb based on the host application B, to the current value θr(1), which is the requested steering angle θra based on the host application A. In addition, in Fig. 5(A), the detected steering angle θd is located between the requested steering angles θra and θrb of the host applications A and B before and after the switching.

[0045] In the change amount suppression process according to the comparative example, a requested steering angle θrs(1) is calculated by suppressing the change in the requested steering angle θr due to this stepwise switching. In the calculation cycle following this calculation cycle, the change amount suppression process is executed using the requested steering angle θrs(1) as the previous value and the requested steering angle (current value) θr(2) based on the upper application A as the current value. As a result, the requested steering angle θrs(2) after the change amount suppression is calculated. This also applies to subsequent calculation cycles. In the example shown in FIG. 5(A), the requested steering angle θrs after the change amount suppression then converges to the requested steering angle θra of the upper application A after switching.

[0046] According to the change amount suppression process of the comparative example, the requested steering angle θrs (θrs(1) and θrs(2)) after the change amount suppression immediately after switching the application is positioned farther from the detected steering angle θd relative to the requested steering angle θra after switching. As a result, the torque command value Tc calculated by the lower ECU 40 based on the steering angle difference Δθ between the requested steering angle θrs after the change amount suppression and the detected steering angle (actual steering angle) θd changes in the opposite direction (upward in the paper of FIG. 5(A)) from the target of the higher-level application A after switching. As a result, the detected steering angle (actual steering angle) θd changes in the opposite direction to the requested steering angle θra. Thus, according to the comparative example, an unnecessary torque change may occur when switching the application. More specifically, since the torque command value Tc after switching is calculated according to the lower-level application A, which has a large torque gain, the unnecessary torque change may become large.

[0047] In contrast, according to the change amount suppression process of the first control example, as shown in FIG. 5B, the previous value θr(0) is replaced with the detected steering angle (current value) θd(1). As a result, the requested steering angle θrs (θrs(1), etc.) after the change amount suppression immediately after switching the application is positioned closer to the requested steering angle θra after switching than the detected steering angle θd. As a result, the torque command value Tc calculated by the lower ECU 40 changes to the target direction (downward in the paper of FIG. 5B) of the higher-level application A after switching. Therefore, the detected steering angle (actual steering angle) θd can be changed to approach the requested steering angle θra. In this way, according to the first control example, unnecessary torque changes caused by switching the application can be suppressed. This leads to suppression of unnecessary torque being applied to the driver.

[0048] As described above, according to the first control example, when a lower application is switched in conjunction with switching of a higher-level application, it is possible to more appropriately calculate the torque command value Tc (actuator command value). More specifically, the torque command value Tc of the steering actuator 14 is determined based on the steering angle difference Δθ as described above, that is, it is determined based on the detected steering angle (actual steering angle) θd. For this reason, the detected steering angle θd is suitable as the previous value for the process of suppressing the amount of change when switching higher-level applications in which the required steering angle θr changes stepwise.

[0049] 2-2. Second control example In the second control example, the lower ECU 40 uses the estimated steering angle θe instead of the previous value θr(n-1) of the requested steering angle θr as the previous value for the change amount suppression process in response to switching of the upper application. More specifically, for example, the current value θe(n) of the estimated steering angle θe is used. The estimated steering angle θe is calculated based on one or more parameters indicating the vehicle behavior. The one or more parameters are, for example, the vehicle speed and the yaw rate.

[0050] 6 is a flowchart showing a process relating to a second control example according to the embodiment. The process of this flowchart differs from the flowchart shown in FIG. 4 in that the process of step S200 is executed instead of step S104.

[0051] In FIG. 6, if there is a switch in the upper application, the process proceeds to step S200. In step S200, the lower ECU 40 (change amount suppression unit 43) calculates the estimated steering angle θe based on the vehicle speed and yaw rate acquired using the sensors 20. The calculation of the estimated steering angle θe may be performed by another ECU, such as the upper ECU 30. Then, the lower ECU 40 substitutes the calculated estimated steering angle (current value) θe(n) for the previous value θr(n-1) of the requested steering angle θr in the change amount suppression process. In other words, the previous value θr(n-1) is replaced by the current value θe(n).

[0052] The second control example also makes it possible to more appropriately calculate the torque command value Tc (actuator command value) when switching a lower application in conjunction with switching a higher application. More specifically, the estimated steering angle θe basically takes a value close to the detected steering angle θd. Therefore, like the detected steering angle θd, the estimated steering angle θe is also suitable as the previous value for the change amount suppression process when switching a higher application, in which the required steering angle θr changes stepwise. Furthermore, in the above-mentioned steer-by-wire steering device, a situation may arise in which the vehicle behavior and the detected steering angle (actual steering angle) θd do not match. In such a situation, the estimated steering angle θe is more suitable than the detected steering angle θd as the previous value for the change amount suppression process when switching a higher application.

[0053] 2-3.Third control example In the third control example, the subordinate ECU 40 uses zero instead of the previous value θr(n−1) of the requested steering angle θr as the previous value for the change amount suppression process in response to switching of the superior application.

[0054] 7 is a flowchart showing a process relating to a third control example according to the embodiment. The process of this flowchart differs from the flowchart shown in FIG. 4 in that the process of step S300 is executed instead of step S104.

[0055] 7, if there is a switch in the upper application, the process proceeds to step S300. In step S300, the lower ECU 40 (change amount suppression unit 43) substitutes zero for the previous value θr(n-1) of the requested steering angle θr in the change amount suppression process. In other words, the previous value θr(n-1) is replaced with zero.

[0056] The third control example also makes it possible to more appropriately calculate the torque command value Tc (actuator command value) when switching the lower application in conjunction with switching the upper application. More specifically, using the zero point of the steering angle θ as the previous value of the change amount suppression process is suitable for preventing the steering angle difference Δθ calculated at the time of switching from becoming excessive in a situation where the requested steering angles θr of the two upper applications before and after the switching have different signs, as in the example shown in Fig. 5(A).

[0057] 3. Other examples of mobile control systems The "mobile body" according to the present disclosure is not limited to a vehicle such as an automobile, but may be, for example, a construction machine, a robot, an aircraft, or a ship. The "mobile body control system" according to the present disclosure is not limited to the vehicle steering system 100 that executes the above-described steering control, as long as it includes the "host ECU," "subordinate ECU," and "actuator" according to the present disclosure.

[0058] Specifically, the vehicle control system may include, for example, an actuator capable of driving an accelerator pedal as the "actuator" according to the present disclosure. In this actuator example, the "physical quantity related to driving operation (acceleration / deceleration)" may be, for example, longitudinal acceleration or vehicle speed. The upper-level application may include, for example, a first upper-level application that calculates a required longitudinal acceleration or required vehicle speed for acceleration, and a second upper-level application that calculates a required longitudinal acceleration or required vehicle speed for deceleration.

[0059] Furthermore, the "actuator" according to the present disclosure may be, for example, an actuator capable of driving a brake pedal. In this example of an actuator, the "physical quantity related to driving operation (braking)" may be, for example, longitudinal acceleration or vehicle speed. The upper-level application may include, for example, a first upper-level application that calculates a required longitudinal acceleration or required vehicle speed for braking based on the first information, and a second upper-level application that calculates a required longitudinal acceleration or required vehicle speed for braking based on the second information.

[0060] Furthermore, the "actuator" according to the present disclosure may be, for example, a powertrain (at least one of an internal combustion engine and an electric motor for vehicle operation). In this example of an actuator, the "required physical quantity related to driving operation (e.g., acceleration / deceleration)" may be, for example, longitudinal acceleration or vehicle speed. An example of a host application is the same as the host application in the example of the actuator capable of driving the accelerator pedal.

[0061] In addition, in an example in which not only two or more upper level applications in which the "requested physical quantity" is switched stepwise, such as switching of the requested steering angle θr by the application switching unit 34 (see FIG. 2), but also two or more upper level applications in which the "requested physical quantity" is switched continuously, the mobile object control system may be configured as follows: That is, in order to provide more versatile mobile object control, the mobile object control system may be configured to switch whether or not to use the "detected physical quantity" (the same applies to the examples of the "estimated physical quantity" and zero) as the previous value of the requested physical quantity in the change amount suppression process, depending on the combination of upper level applications to be switched. [Explanation of symbols]

[0062] 1 vehicle, 2 wheels, 3 communication line, 10 steering device, 14 steering actuator, 20 sensors, 30 upper ECU, 40 lower ECU, 100 vehicle steering system

Claims

1. a host electronic control unit that calculates a required physical quantity, which is a required value of a physical quantity related to a driving operation of a moving object, in accordance with each of first and second host applications that can be switched; a lower-level electronic control unit that receives the required physical quantity from the higher-level electronic control unit, and calculates an actuator command value for causing a detected physical quantity, which is a detection value of the physical quantity, to follow the required physical quantity in accordance with the first or second lower-level application while switching between a first lower-level application and a second lower-level application in conjunction with switching between the first higher-level application and the second higher-level application; an actuator controlled in accordance with the actuator command value; Equipped with the first lower-level application and the second lower-level application realize controls in which the detected physical quantity has different trackability to the requested physical quantity, and The lower level electronic control unit executes a change amount suppression process to make the change from the previous value to the current value more gradual than when the required physical quantity is changed in a stepwise manner from the previous value to the current value; Substituting the detected physical quantity for the previous value of the change amount suppression process in response to the switching between the first upper level application and the second upper level application. Mobile control system.

2. a host electronic control unit that calculates a required physical quantity, which is a required value of a physical quantity related to a driving operation of a moving object, in accordance with each of first and second host applications that can be switched; a lower-level electronic control unit that receives the required physical quantity from the higher-level electronic control unit, and calculates an actuator command value for causing a detected physical quantity, which is a detection value of the physical quantity, to follow the required physical quantity in accordance with the first or second lower-level application while switching between a first lower-level application and a second lower-level application in conjunction with switching between the first higher-level application and the second higher-level application; an actuator controlled in accordance with the actuator command value; Equipped with the first lower-level application and the second lower-level application realize controls in which the detected physical quantity has different trackability to the requested physical quantity, and The lower level electronic control unit executes a change amount suppression process to make the change from the previous value to the current value more gradual than when the required physical quantity is changed in a stepwise manner from the previous value to the current value; In response to the switching between the first upper level application and the second upper level application, an estimated physical quantity, which is an estimated value of the physical quantity based on one or more parameters indicating a behavior of the moving object, is substituted for the previous value of the change amount suppression process. Mobile control system.

3. a host electronic control unit that calculates a required physical quantity, which is a required value of a physical quantity related to a driving operation of a moving object, in accordance with each of first and second host applications that can be switched; a lower-level electronic control unit that receives the required physical quantity from the higher-level electronic control unit, and calculates an actuator command value for causing a detected physical quantity, which is a detection value of the physical quantity, to follow the required physical quantity in accordance with the first or second lower-level application while switching between a first lower-level application and a second lower-level application in conjunction with switching between the first higher-level application and the second higher-level application; an actuator controlled in accordance with the actuator command value; Equipped with the first lower-level application and the second lower-level application realize controls in which the detected physical quantity has different trackability to the requested physical quantity, and The lower level electronic control unit executes a change amount suppression process to make the change from the previous value to the current value more gradual than when the required physical quantity is changed in a stepwise manner from the previous value to the current value; Substituting zero for the previous value of the variation suppression process in response to the switching between the first upper level application and the second upper level application. Mobile control system.

4. A mobile object control system according to any one of claims 1 to 3, the moving body is a vehicle, the physical quantity is a steering angle of a wheel of the vehicle, the actuator is an electric motor that generates torque that changes the steering angle; The actuator command value is a torque command value for making the detected steering angle, which is the detected physical quantity, follow the requested steering angle, which is the requested physical quantity. Mobile control system.

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