Combination vehicle estimation device, combination vehicle control device, combination vehicle estimation method, and combination vehicle estimation program

Abstract

To provide a combination vehicle estimation device capable of estimating a value of a model variable of a combination vehicle.SOLUTION: When a trailer is in a towing state and a combination vehicle is stopped (S22: YES), a PU reads values stored in a storage device among model variables of the combination vehicles (S24). The PU estimates the values of the model variables to be estimated using an equation of equilibrium that links the read model variables and the model variables to be estimated (S26).SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an articulated vehicle estimation device, an articulated vehicle control device, an articulated vehicle estimation method, and an articulated vehicle estimation program. [Background technology]

[0002] The following Patent Document 1 describes that trajectory control of articulated vehicles is performed based on the weight of the cargo on the articulated vehicles estimated at a loading center. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2020361492 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the above technology, the place where cargo can be loaded onto articulated vehicles is limited to a loading center. [Means for solving the problem]

[0005] The means for solving the above problems and their effects will be described below. 1. A combination vehicle estimation device for a combination vehicle that is applied to a combination vehicle that includes a tractor and a trailer towed by the tractor, the combination vehicle control device comprising an execution device configured to execute an acquisition process and a calculation process, wherein the acquisition process is a process of acquiring at least one of two values: the value of a prescribed model variable and the value of an operation variable of the combination vehicle, based on input from outside the control device, the model variable is a variable that defines a model of the combination vehicle, and the operation variable is a variable that indicates a physical quantity that quantifies the operation of the combination vehicle, and the calculation process is a process of calculating the value of the model variable to be estimated, based on the values ​​of the variables acquired by the acquisition process as input variables, when the combination vehicle is in a prescribed state.

[0006] When a model of an articulated vehicle is used, it is possible to derive equations of static balance and equations of motion using the values ​​of model variables that define the model. Therefore, by using the values ​​of specific variables that appear in these equations of balance and equations of motion as calculation targets, it is possible to estimate the values ​​of the actual variables. Incidentally, the equations of motion include physical quantities that quantify the movement of the articulated vehicle. Furthermore, the equations of balance may include variables that are not included in the basic specification information of the articulated vehicle.

[0007] Therefore, in the above configuration, the acquisition process acquires at least one of the values ​​of the predetermined model variables and the values ​​of the behavior variables, thereby making it possible to obtain the values ​​of the variables required to derive the values ​​of the model variables to be estimated.

[0008] 2. An estimation device for articulated vehicles as described in 1 above, wherein the predetermined variables include at least one of three: a trailer center of gravity variable, a cornering coefficient of the trailer, and a vertical moment of inertia of the trailer, and the trailer center of gravity variable is a variable indicating the center of gravity of the trailer.

[0009] 3. An articulated vehicle estimation device as set forth in claim 1 or 2 above, comprising a storage device in which data indicating the mass of the trailer, data indicating the value of a tractor centre of gravity variable, and data indicating the mass of the tractor, wherein the predetermined state is a state in which the articulated vehicle is stopped, and the calculation process includes processing for calculating the value of the predetermined variable based on an equation for balance of the moment of the articulated vehicle using the value of the tractor centre of gravity variable, the mass of the tractor, and the mass of the trailer when the articulated vehicle is stopped, wherein the tractor centre of gravity variable is a variable indicating the centre of gravity of the tractor, the predetermined variables include a trailer centre of gravity variable, and the trailer centre of gravity variable is a variable indicating the centre of gravity of the trailer.

[0010] Information on the trailer center of gravity is difficult to obtain from trailer specifications, etc. However, the trailer center of gravity, tractor center of gravity, tractor mass, and trailer mass can be linked by a balance equation. Therefore, the trailer center of gravity can be estimated using the balance equation.

[0011] 4. An articulated vehicle estimation device as defined in any one of claims 1 to 3, comprising the execution device in the estimation device for an articulated vehicle as defined in claim 1, wherein the execution device is configured to execute open-loop manipulated variable calculation processing, operation processing, and correction processing, wherein the open-loop manipulated variable calculation processing is processing to calculate an open-loop manipulated variable, the open-loop manipulated variable is an open-loop control manipulated variable in which a physical variable that determines the traveling state of the articulated vehicle is a controlled variable, the operation processing is processing to operate actuators of the articulated vehicles in accordance with the open-loop manipulated variable, and the correction processing includes processing to correct the open-loop manipulated variable in accordance with the value of the model variable calculated by the calculation processing.

[0012] The equation of motion, which includes the trailer yaw rate, can be related to the vehicle speed and cornering coefficient. Therefore, the cornering coefficient can be estimated by using the equation of motion.

[0013] 5. An articulated vehicle estimation device according to any one of 1 to 4 above, wherein the predetermined state is a turning driving state of the articulated vehicle, the operating variables include the vehicle speed of the articulated vehicle and the yaw rate of the trailer, and the calculation process includes a process of calculating the value of the predetermined variable based on an equation of motion using the vehicle speed of the articulated vehicle and the yaw rate of the trailer, and the predetermined variable includes the vertical moment of inertia of the trailer.

[0014] The equation of motion, which includes the trailer's vertical moment of inertia, can be related to the vehicle speed and yaw rate, so the moment of inertia can be estimated by using this equation of motion.

[0015] 6. A control device for combined vehicles comprising the execution device in the estimation device for combined vehicles set forth in any one of 1 to 5 above, wherein the execution device is configured to execute open-loop manipulated variable calculation processing, operation processing, and correction processing, wherein the open-loop manipulated variable calculation processing is processing to calculate an open-loop manipulated variable that is a manipulated variable for open-loop control in which a physical quantity that defines the traveling state of the combined vehicles is a control variable, the operation processing is processing to operate actuators of the combined vehicles in accordance with the open-loop manipulated variable, and the correction processing includes processing to correct the open-loop manipulated variable in accordance with the value of the model variable calculated by the calculation processing.

[0016] The open-loop manipulated variable calculation process is designed based on the assumed specifications and state of the combined vehicles. Therefore, if the assumed specifications, etc. deviate from the actual specifications, etc., the controllability of the control variable calculated by the open-loop manipulated variable decreases. However, the actual specification information, etc. is reflected in the values ​​of the model variables. Therefore, in the above configuration, the open-loop manipulated variable can be set to a more appropriate value by correcting the open-loop manipulated variable in accordance with the calculated values ​​of the model variables.

[0017] 7. A control device for articulated vehicles comprising the execution device of the estimation device for articulated vehicles described in 4 above, wherein the execution device is configured to execute an abnormality detection process and a notification process, the abnormality detection process being a process of detecting an abnormality in the tires of the trailer based on the cornering coefficient of the trailer as an input variable, and the notification process being a process of notifying a user if an abnormality in the tire is detected.

[0018] As tires deteriorate, their cornering coefficient decreases. Therefore, in the above configuration, tire abnormalities are detected based on the cornering coefficient. If an abnormality is detected, the user can be notified of the abnormality through notification processing.

[0019] 8. A control device for articulated vehicles comprising the execution device in the estimation device for articulated vehicles described in 5 above, wherein the execution device is configured to execute an abnormality detection process and a notification process, wherein the abnormality detection process is a process of detecting an abnormality in the cargo of the trailer based on the vertical moment of inertia of the trailer as an input variable, and the notification process is a process of notifying a user of the detection of an abnormality in the cargo of the trailer.

[0020] The condition of the cargo is reflected in the moment of inertia. Therefore, in the above configuration, cargo abnormalities are detected based on the state of the cargo ascertained using the moment of inertia. If an abnormality is detected in the cargo, a notification process can be performed to notify the user of this.

[0021] 9. A method for estimating an articulated vehicle, comprising executing each of the processes in the articulated vehicle estimation device described in any one of 1 to 5 above. 10. An articulated vehicle estimation program that causes a computer to execute the processes in the articulated vehicle estimation device described in any one of 1 to 5 above. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view showing the configuration of an articulated vehicle according to a first embodiment. [Figure 2] 2 is a diagram showing the configuration of a control system provided in the articulated vehicle shown in FIG. 1. FIG. [Figure 3] 3 is a block diagram showing a process executed by a control device included in the control system shown in FIG. 2. FIG. [Figure 4] FIG. 2 is a diagram showing a model of an articulated vehicle according to the embodiment. [Figure 5] 3 is a flowchart showing the procedure of a process executed by a control device provided in the control system shown in FIG. 2. [Figure 6] 3 is a flowchart showing the procedure of a process executed by a control device provided in the control system shown in FIG. 2. [Figure 7] FIG. 2 is a diagram showing a model of an articulated vehicle according to the embodiment. [Figure 8] 3 is a flowchart showing the procedure of a process executed by a control device provided in the control system shown in FIG. 2. [Figure 9] 10 is a flowchart showing a procedure of a process executed by a control device according to a second embodiment. [Figure 10] 10 is a flowchart showing a procedure of a process executed by a control device according to a third embodiment. [Figure 11] 10 is a flowchart showing a procedure of a process executed by a control device according to a fourth embodiment. [Figure 12] FIG. 10 is a diagram illustrating a configuration of a control system according to a fifth embodiment. [Figure 13] 13 is a block diagram showing the processing executed by a control device provided in the control system shown in FIG. 12. FIG. [Figure 14] FIG. 13 is a block diagram showing a process executed by a control device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] First Embodiment The first embodiment will be described below with reference to the drawings. "Configuration of articulated vehicles" As shown in FIG. 1, the articulated vehicle 10 includes a tractor 20 and a trailer 30. The tractor 20 includes front wheels 22 and rear wheels 24. The front wheels 22 include two wheels, a right front wheel and a left front wheel, and the rear wheels 24 include two wheels, a right rear wheel and a left rear wheel. FIG. 1 also shows an example of a box-shaped trailer as the trailer 30. The trailer 30 has wheels 32. The wheels 32 include two wheels, a right wheel and a left wheel. Note that the trailer 30 may have left and right front wheels and left and right rear wheels, so that the total number of wheels on the trailer 30 may be four.

[0024] The trailer 30 is connected to the rear of the tractor 20 via a ball joint 40. The ball joint 40 is a member that connects the trailer 30 to the tractor 20 so that the trailer 30 can rotate about an axis 42. The axis 42 extends along the height direction of the tractor 20.

[0025] FIG. 2 shows some of the members provided on the articulated vehicle 10. As shown in Fig. 2, the tractor 20 includes a steering system 50. The steering system 50 includes a steering wheel 52 and the front wheels 22 as steered wheels. A reaction force is applied to the steering wheel 52 by a reaction motor 54. The reaction force is a torque with an opposite sign to the torque applied to the steering wheel 52 by the driver. The output voltage of an inverter 56 is applied to the terminals of the reaction motor 54.

[0026] On the other hand, the front wheels 22 are supplied with power from a front wheel steering motor 60. The output voltage of an inverter 62 is applied to the terminals of the front wheel steering motor 60. The steering control device 70 includes a PU 72 and a storage device 74. The PU 72 is a processing unit that executes software processing. The PU 72 may be, for example, a CPU, a GPU, or the like. The PU 72 controls the control target of the steering control device 70 by executing a program stored in the storage device 74.

[0027] The control object of the steering control device 70 is the steering wheel 52. Here, the control amount of the control object is the reaction force. The steering control device 70 operates the inverter 56 to control the reaction force. The control object of the steering control device 70 is the front wheels 22. Here, the control amount of the control object is the steering angle of the front wheels 22. The steering angle is the turning angle of the tires. The steering control device 70 operates the inverter 62 to control the steering angle of the front wheels 22.

[0028] To control the control amount, the steering control device 70 refers to the steering torque Th detected by the torque sensor 80. The steering torque Th is the torque input to the steering wheel 52. To control the control amount, the steering control device 70 also refers to the rotation angle θmh of the reaction force motor 54 detected by the rotation angle sensor 82. To control the control amount, the steering control device 70 also refers to the rotation angle θmf of the front wheel steering motor 60 detected by the rotation angle sensor 84.

[0029] The tractor 20 is equipped with a drivetrain 86. The drivetrain 86 includes at least one of an internal combustion engine and a rotating electric machine as a thrust generating device for the vehicle. The tractor 20 is equipped with a braking system 90. The braking system 90 includes a braking control device 91 and a brake actuator 96. The brake actuator 96 is configured to apply braking force to the front wheels 22 and rear wheels 24 of the tractor 20. The braking control device 91 includes a PU 92 and a memory device 94. The PU 92 is a processing unit that executes software processing. The PU 92 may be, for example, a CPU, a GPU, or the like. The PU 92 controls the controlled object of the braking control device 91 by executing a program stored in the memory device 94.

[0030] The control targets of the braking control device 91 are the front wheels 22 and the rear wheels 24. The braking control device 91 operates a brake actuator 96 to control the control amount of the control targets. The brake actuator 96 includes at least one of a device that decelerates the rotation of the wheels by frictional force, and a device that decelerates the rotation of the wheels by converting the power of the wheels into electrical energy. Note that the device that decelerates the rotation of the wheels by converting into electrical energy may be shared with the rotating electric machine of the drivetrain 86.

[0031] The tractor 20 is equipped with an ADASECU 100. The ADASECU 100 is equipped with a PU 102, a storage device 104, and a communication device 106. The PU 102 is a processing unit that executes software processing. The PU 102 may be, for example, a CPU, a GPU, or the like. The PU 92 controls the control target of the ADASECU 100 by executing a program stored in the storage device 104. The control target of the ADASECU 100 is the articulated vehicle 10. Here, the control amount is a variable that indicates the behavior of the vehicle. The ADASECU 100 operates the steering system 50, the drive system 86, and the braking system 90 to control the control amount.

[0032] The drive system 86 may include a drive control device that controls the internal combustion engine and the rotating electric machine. In this case, "the ADASECU100 operates the drive system 86" means that the ADASECU100 outputs a command signal to the drive control device. Furthermore, "the ADASECU100 operates the braking system 90" means that the ADASECU100 outputs a command signal to the braking control device 91. Furthermore, "the ADASECU100 operates the steering system 50" means that the ADASECU100 outputs a command signal to the steering control device 70.

[0033] The articulated vehicle 10 is equipped with a global positioning system (GPS 110). The articulated vehicle 10 is equipped with a vehicle speed sensor 112 that detects vehicle speed V. The articulated vehicle 10 is equipped with a tractor-side yaw rate sensor 114 that detects tractor yaw rate γ. The articulated vehicle 10 is equipped with a trailer-side yaw rate sensor 116 that detects trailer yaw rate γt. The articulated vehicle 10 is equipped with a hitch angle sensor 118 that detects hitch angle θhi. The hitch angle θhi is the angle formed between the fore-and-aft direction of the tractor 20 and the fore-and-aft direction of the trailer 30. Note that, depending on the specifications, the hitch angle θhi may be estimated by providing hitch angle estimation means, without using the hitch angle sensor 118.

[0034] "Control of steering control device" Fig. 3 shows the processing executed by the steering control device 70. The processing shown in Fig. 3 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at a predetermined interval.

[0035] The target front wheel steering angle setting process M10 is a process for setting a target front wheel steering angle δf*0, which is a target value for the steering angle of the front wheels 22 of the tractor 20, based on the steering angle θh and the vehicle speed V as input variables. The steering angle θh is the rotation angle of the steering wheel 52. The steering angle θh is calculated by the PU 72 based on the rotation angle θmh as an input variable.

[0036] The target yaw rate setting process M20 is a process for setting a target tractor yaw rate γ*, which is a target value for the tractor yaw rate γ, based on the input variables of the steering angle θh and the vehicle speed V. As an example, the target tractor yaw rate γ* is set to a yaw rate that is expected to occur in the tractor 20 when the tractor 20 is not towing the trailer 30. This setting is intended to assist the combination vehicle 10 in changing lanes, etc.

[0037] The open-loop manipulated variable calculation process M22 is a process for calculating an open-loop manipulated variable Mff, which is a manipulated variable for open-loop control in which the tractor yaw rate γ is the controlled variable, based on the target tractor yaw rate γ* as an input variable. The open-loop manipulated variable Mff is a correction amount for the target front wheel steering angle δf*0 required to bring the yaw rate of the tractor 20 closer to the target tractor yaw rate γ*. In more detail, the open-loop manipulated variable calculation process M22 is a process for calculating the open-loop manipulated variable Mff using model variables that define the model of the combination vehicle 10 shown in FIG. 4.

[0038] The model shown in Figure 4 has one front wheel C0 corresponding to the pair of front wheels 22 of the tractor 20, and one rear wheel B0 corresponding to the pair of rear wheels 24 of the tractor 20. In other words, a two-wheel model is used for the tractor 20. Also, there is one wheel B1 corresponding to the pair of wheels 32 of the trailer 30. The hitch point C1 corresponds to the axle 42 in Figure 1.

[0039] The tractor center-of-gravity front wheel distance lf is the distance between the front wheels C0 of the tractor 20 and the center of gravity of the tractor 20. The tractor center-of-gravity rear wheel distance lr is the distance between the rear wheels B0 of the tractor 20 and the center of gravity of the tractor 20. The tractor center-of-gravity hitch point distance lh is the distance between the center of gravity of the tractor 20 and the hitch point C1. The trailer center-of-gravity hitch point distance lft is the distance between the center of gravity of the trailer 30 and the hitch point C1. The hitch point C1 corresponds to the axle 42 in Figure 1. The trailer center-of-gravity wheel distance lrt is the distance between the center of gravity of the trailer 30 and the wheel B1. The tractor front wheel lateral force Sf is the lateral force acting on the front wheel C0. The tractor rear wheel lateral force Sr is the lateral force acting on the rear wheel B0. In addition, in this model, the steering angle of the front wheel C0 is set to the front wheel steering angle δf. The turning angle of the rear wheels B0 is set to a rear wheel steering angle δr. However, in this embodiment, the rear wheel steering angle δr is always considered to be 0. Also, in this model, the longitudinal movement speed of the center of gravity of the tractor 20 is considered to be the vehicle speed V of the articulated vehicle 10. The tractor lateral speed vy indicates the lateral speed of the center of gravity of the tractor 20. The trailer lateral speed vyt indicates the lateral speed of the center of gravity of the trailer 30. The tractor lateral wind force W indicates the force applied by the lateral wind to the tractor 20. The trailer lateral wind force Wt indicates the force applied by the lateral wind to the trailer 30.

[0040] The open-loop operation amount calculation process M22 is a process for calculating the target tractor yaw rate γ* based on the following equation of motion for the model shown in FIG. m·V·(dβ / dt+γ)=Sf+Sr-F+W …(c1) Iz·dγ / dt=lf·Sf-lr·Sr+lh·F+lw·W+Mz …(c2) mt·V·(dβt / dt+γt)=Sfr+Ft+Wt …(c3) Izt·dγt / dt=lft·Ft-lrt·Srt+lwt·Wt+Mzt …(c4) Sf=Cf·{δf-(vy+lf·γ) / V} …(c5) Sγ=Cr·{δr-(vy-lr·γ) / V} …(c6) Srt=-Crt·(vyt-lrt·γt) / V …(c7) where the sideslip angle β is the sideslip angle of the tractor 20. The sideslip angle βt is the sideslip angle of the trailer 30. The tractor hitch force F is the force applied to the tractor 20 at the hitch point C1. The trailer hitch force Ft is the force applied to the trailer 30 at the hitch point C1. The tractor moment of inertia Iz is the moment of inertia of the tractor 20 in the vertical direction. Here, the vertical direction is the direction perpendicular to both the front-to-rear and left-to-right directions of the tractor 20. The trailer moment of inertia Izt is the moment of inertia of the trailer 30 in the vertical direction. The tractor braking moment Mz is the moment generated in the tractor 20 by the brake actuator 96. The trailer braking moment Mzt is the moment applied to the trailer 30 when the trailer 30 is equipped with a brake actuator. However, in this embodiment, the trailer braking moment Mzt is zero. The tractor wind force center-to-center-of-gravity distance lw is the distance between the center at which a crosswind is applied to the tractor 20 and the center of gravity of the tractor 20. The trailer wind force center-to-center-of-gravity distance lwt is the distance between the center at which a crosswind is applied to the trailer 30 and the center of gravity of the trailer 30. The tractor front wheel cornering coefficient Cf is the cornering coefficient of the front wheels C0 of the tractor 20. The tractor rear wheel cornering coefficient Cr is the cornering coefficient of the rear wheels B0 of the tractor 20. The trailer cornering coefficient Crt is the cornering coefficient of the trailer wheel B1.

[0041] The above equation (c1) represents the lateral movement of the tractor 20. The above equation (c2) represents the rotational movement of the tractor 20. The above equation (c3) represents the lateral movement of the trailer 30. The above equation (c4) represents the rotational movement of the trailer 30.

[0042] The open-loop manipulated variable calculation process M22 includes a process of substituting the target tractor yaw rate γ* for the tractor yaw rate γ. The open-loop manipulated variable calculation process M22 includes a process of substituting the open-loop manipulated variable Mff with the value obtained by subtracting the target front wheel steering angle δf*0 from the front wheel steering angle δf calculated by algebraically solving the simultaneous equations of the above expressions (c1) to (c7). The unknowns in the simultaneous equations are the tractor hitch force F, the trailer hitch force Ft, the sideslip angles β and βt, the tractor front wheel lateral force Sf, the tractor rear wheel lateral force Sr, and the front wheel steering angle δf. Meanwhile, the tractor center-of-gravity-to-rear wheel distance lr, the tractor center-of-gravity-to-hitch point distance lh, the trailer center-of-gravity-to-hitch point distance lft, and the trailer center-of-gravity-to-wheel distance lrt are stored in advance in the storage device 74. The tractor moment of inertia Iz and the trailer moment of inertia Izt are stored in the storage device 74. The PU 72 uses the detected value as the trailer yaw rate γt in the simultaneous equations (c1) to (c7) above. The PU 72 also calculates the trailer weight mt, the tractor weight m, the tractor lateral velocity vy, and the trailer lateral velocity vyt based on the vehicle speed V, the slip angles β and βt, etc. The PU 72 also estimates the tractor cross wind force W, the trailer cross wind force Wt, the tractor-to-wind force center-of-gravity distance lw, and the trailer-to-wind force center-of-gravity distance lwt by processing similar to the processing of S38 described below.

[0043] The deviation calculation process M24 calculates the deviation Δγ, which is the value obtained by subtracting the tractor yaw rate γ from the target tractor yaw rate γ*. The closed-loop operation amount calculation process M26 calculates the closed-loop operation amount Mfb, which is the operation amount of closed-loop control in which the tractor yaw rate γ is the control amount and the target tractor yaw rate γ* is the target value of the control amount, based on the deviation Δγ as an input variable.

[0044] The manipulated variable calculation process M28 is a process of substituting the sum of the open-loop manipulated variable Mff and the closed-loop manipulated variable Mfb into the correction variable Δf. The steering angle correction process M30 is a process of adding the correction amount Δf to the target front wheel steering angle δf*0 and substituting the result for the target front wheel steering angle δf*.

[0045] The operation signal generation process M32 is a process for generating an operation signal MSf for the inverter 62 based on the target front wheel steering angle δf* as an input variable. The operation signal MSf controls the torque of the front wheel steering motor 60 so that the front wheel steering angle δf approaches the target front wheel steering angle δf*.

[0046] "About obtaining model variables" The driver can freely change the trailer 30 towed by the tractor 20. Therefore, the specifications of the trailer 30 are subject to change. Therefore, in this embodiment, some of the model variables that define the model of the trailer 30 are obtained as inputs from outside the combination vehicle 10.

[0047] Fig. 5 shows the procedure for the process of acquiring the model variables of the trailer 30. The series of processes shown in Fig. 5 is realized by the PU 102 repeatedly executing a program stored in the storage device 104 of the ADASECU 100, for example, at a predetermined interval. Note that, below, the step number of each process is represented by a number preceded by "S."

[0048] In the series of processes shown in Fig. 5, the PU 102 first determines whether values ​​of model variables defining the trailer 30 have been input by an input operation to the user interface 130 shown in Fig. 2 (S10). In the process of S10, as an example, the model variables are the trailer weight mt and the hitch point wheel distance lt. The hitch point wheel distance lt is the distance between the wheels B1 and the hitch point C1 of the trailer 30.

[0049] When the PU 102 determines that the values ​​of the model variables have been input (S10: YES), it stores the trailer weight mt and the hitch point wheel-to-wheel distance lt in the storage device 104 (S12). 5 when the processing of S12 is completed or when a negative determination is made in the processing of S10. When the processing of S12 is being performed, the PU 72 acquires the trailer weight mt and the hitch point wheel distance lt stored in the storage device 104 from the ADASECU 100 and stores them in the storage device 74. On the other hand, when the processing of S12 is not completed, the open-loop operation amount calculation processing M22 includes a process of reading out default values ​​stored in advance in the storage device 74 as the trailer weight mt and the hitch point wheel distance lt.

[0050] "Estimation of Model Variables: Statics Estimation" In this embodiment, the values ​​of some of the model variables that define the model of the trailer 30 are estimated, but which cannot be obtained by the processing in Fig. 5. Below, we will first explain the estimation processing based on static considerations when the articulated vehicle 10 is stopped.

[0051] The procedure for the estimation process based on the statics consideration is shown in Fig. 6. The process shown in Fig. 6 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at predetermined intervals.

[0052] 6, the PU 72 first determines whether the tractor 20 is in a state of towing the trailer 30 (S20). In other words, the PU 72 determines whether the trailer 30 is coupled to the rear of the tractor 20 via the ball joint 40. The processing of S20 may be, for example, processing in which the PU 72 determines whether there is a history in the storage device 74 of information that the driver has input, via an input operation on the user interface 130, that the trailer 30 has been coupled to the tractor 20. Alternatively, for example, the processing of S20 may be processing executed using an image captured by a camera provided at the rear of the tractor 20.

[0053] If the PU 72 determines that the trailer 30 is being towed (S20: YES), it determines whether the combination vehicle 10 is stopped or not (S22). If the PU 72 determines that the combination vehicle 10 is stopped (S22: YES), it reads out the tractor weight m, trailer weight mt, distance lf between the front wheels of the tractor center of gravity, and distance lh between the hitch point and the center of gravity of the tractor, which are stored in a predetermined area of ​​the storage device 74 (S24).

[0054] The PU 72 then estimates the trailer center-to-wheel distance lrt and the trailer center-to-hitch point distance lft based on the equations of balance (S26). The equations of balance are the following equations (c8) to (c12). Figure 7 shows a model of the articulated vehicle 10 when formulating the equations of balance.

[0055] Szr·(lf+lr)+(-m·g)·lf+(-Fz)·(lf+lh)=0 …(c8) Szf·(lf+lr)+(-m·g)·lr+Fz·(lh-lr)=0 …(c9) Fzt·lt+lrt·(-mt·g)=0 …(c10) Fz+mg=Szf+Szr …(c11) lrt=lt-lft …(c12) The above equation uses the force Szr applied to the rear wheel B0 of the tractor 20, the force Fz applied to the tractor 20 via the hitch point, and the acceleration of gravity g. The above equation also uses the force Szf applied to the front wheel C0 of the tractor 20 and the force Fzt applied to the trailer via the hitch point. The above equation (c8) is an equation for balancing the moment around the front wheel C0 of the tractor 20. The above equation (c9) is an equation for balancing the moment around the rear wheel B0 of the tractor 20. The above equation (c10) is an equation for balancing the moment around the wheel B1 of the trailer 30.

[0056] The unknowns in the above equations (c8) to (c12) are the trailer center-to-wheel distance lrt, the trailer center-to-hitch point distance lft, and the forces Szr, Szf, Fz, and Fzt, where Fz = Fzt. The PU 72 algebraically solves the simultaneous equations of the above equations (c8) to (c12) to determine the trailer center-to-wheel distance lrt and the trailer center-to-hitch point distance lft.

[0057] When the processing of S26 is completed, the PU 72 updates the trailer center-of-gravity-wheel distance lrt and the trailer center-of-gravity-hitch point distance lft stored in the storage device 74 (S28). The PU 72 temporarily terminates the series of processes shown in FIG. 6 when the process of S28 is completed or when a negative determination is made in the processes of S20 and S22.

[0058] "Estimation of Model Variables: Dynamic Estimation" The open-loop operation amount calculation process M22 includes a process of calculating the open-loop operation amount Mff using a default value stored in advance in the storage device 74 as the trailer cornering coefficient Crt. The trailer cornering coefficient Crt changes not only depending on the specifications of the trailer 30 but also due to aging of the wheels 32 of the trailer 30. Therefore, in this embodiment, the trailer cornering coefficient Crt used in the open-loop operation amount calculation process M22 is updated by estimating the trailer cornering coefficient Crt based on dynamic considerations.

[0059] The processing procedure for updating the trailer cornering coefficient Crt is shown in Figure 8. The series of processing shown in Figure 8 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at predetermined intervals.

[0060] In the series of processes shown in Fig. 8, the PU 72 first determines whether the tractor 20 is in a state towing the trailer 30 (S30). If the PU 72 determines that the tractor 20 is in a towing state (S30: YES), it determines whether the combination vehicle 10 is turning (S32). If the PU 72 determines that the combination vehicle 10 is traveling (S32: YES), it reads out the tractor weight m, the distance lf between the tractor center of gravity and the front wheels, the distance lr between the tractor center of gravity and the rear wheels, and the distance lh between the tractor center of gravity and the hitch points from the storage device 74 (S34). The PU 72 also reads out the trailer weight mt, the distance lft between the trailer center of gravity and the hitch points, the distance lrt between the trailer center of gravity and the wheels, and the trailer moment of inertia Izt from the storage device 74.

[0061] The PU 72 also acquires the vehicle speed V, hitch angle θhi, tractor yaw rate γ, trailer yaw rate γt, front wheel steering angle δf, and crosswind speed vw (S36). Here, the front wheel steering angle δf is calculated by the PU 102 based on the rotation angle θmf as an input variable. The crosswind speed vw is estimated by the PU 72 based on weather information and map information. The weather information is acquired, for example, via the communication device 106 of the ADASECU 100 shown in FIG. 1.

[0062] Next, the PU 72 estimates the tractor crosswind force W, the tractor wind force center-to-center distance lw, the trailer wind force center-to-center distance lwt, and the trailer crosswind force Wt (S38). The PU 72 estimates the tractor crosswind force W and the trailer crosswind force Wt based on the crosswind speed vw. The PU 72 also estimates the tractor wind force center-to-center distance lw and the trailer wind force center-to-center distance lwt based on the wind direction indicated by the weather information.

[0063] Next, the PU 72 calculates the trailer cornering coefficient Crt based on the above equations (c1) to (c7) (S40). In the processing of S40, the slip angles β and βt, the tractor front wheel cornering coefficient Cf, the tractor rear wheel cornering coefficient Cr, the trailer cornering coefficient Crt, the tractor hitch force F, and the trailer hitch force Ft are unknown quantities. The PU 72 finds the trailer cornering coefficient Crt by algebraically solving the simultaneous equations of the above equations (c1) to (c7).

[0064] When the processing of S40 is completed, the PU 72 updates the trailer cornering coefficient Crt stored in the storage device 74 to the value calculated by the processing of S40 (S42). The PU 72 temporarily terminates the series of processes shown in FIG. 8 when it completes the process of S42 or when it makes a negative determination in the processes of S30 and S32.

[0065] "Actions and Effects of the Present Embodiment" The PU 72 sets the target tractor yaw rate γ* to the value of the yaw rate of the tractor 20 that is expected when the trailer 30 is not coupled to the tractor 20, according to the steering angle θh and the vehicle speed V. This allows the driver to change lanes of the combination vehicle 10 with the same ease as driving a normal vehicle. Here, the PU 72 calculates the open-loop control input Mff using the value of the model variable based on the target tractor yaw rate γ*. Therefore, if the value of the model variable deviates from the actual value, the controllability of the tractor yaw rate γ using the open-loop control input Mff decreases.

[0066] On the other hand, because the user of the tractor 20 can relatively freely select the trailer 30, the values ​​of the model variables that define the model of the trailer 30 are prone to change. For example, the trailer weight mt, the trailer center-to-wheel distance lrt, and the trailer center-to-hitch point distance lft vary depending on the specifications of the trailer 30. In addition, the trailer cornering coefficient Crt varies depending on the specifications of the wheels 32 of the trailer 30 and their deterioration over time.

[0067] Therefore, the PU 72 obtains specification information about the trailer 30 from the user using the process shown in Figure 5. However, it may be difficult for the user to obtain the trailer center-of-gravity wheel-to-wheel distance lrt, the trailer center-of-gravity hitch point distance lft, and the trailer cornering coefficient Crt. Therefore, the PU 72 estimates the trailer center-of-gravity wheel-to-wheel distance lrt and the trailer center-of-gravity hitch point distance lft based on a balance equation using model variables when the articulated vehicle 10 is stopped. In addition, the PU 72 estimates the trailer cornering coefficient Crt based on a motion equation using model variables when the articulated vehicle 10 is turning.

[0068] Therefore, by estimating the trailer center-to-wheel distance lrt, the trailer center-to-hitch point distance lft, and the trailer cornering coefficient Crt, it is possible to calculate an appropriate value for the open-loop operation amount Mff.

[0069] <Second embodiment> The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

[0070] In the first embodiment, the updated model variable values ​​were used in the open-loop manipulated variable calculation process M22. In contrast, in this embodiment, the updated model variable values ​​are also used to detect abnormalities in the combination vehicle 10.

[0071] "Tire abnormality" Fig. 9 shows a procedure for processing related to detection of an abnormality in the wheels 32 of the trailer 30. The processing shown in Fig. 9 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at a predetermined interval.

[0072] In the series of processes shown in FIG. 9 , the PU 72 first acquires the trailer cornering coefficient Crt (S50). Next, the PU 72 determines whether the trailer cornering coefficient Crt is equal to or less than the threshold value Crtth (S52). If the PU 72 determines that the trailer cornering coefficient Crt is equal to or less than the threshold value Crtth (S52: YES), the PU 72 determines that there is an abnormality in the wheels 32 of the trailer 30 (S54). Then, the PU 72 notifies the driver that there is an abnormality in the wheels 32 of the trailer 30 by operating the user interface 130 (S56). For example, if the user interface 130 includes a speaker, the PU 72 may notify the driver that there is an abnormality in the wheels 32 of the trailer 30 by audio information. Alternatively, if the user interface 130 includes a display, the PU 72 may display visual information on the display that there is an abnormality in the wheels 32 of the trailer 30.

[0073] The PU 72 temporarily terminates the series of processes shown in FIG. 9 when the process of S56 is completed or when a negative determination is made in the process of S52. <Third embodiment> The third embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

[0074] In this embodiment, the model variable to be dynamically estimated is set to the trailer moment of inertia Izt. Figure 10 shows the processing steps related to updating the trailer moment of inertia Izt. The series of processes shown in Figure 10 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at a predetermined interval. For convenience, the processes in Figure 10 that correspond to those shown in Figure 8 are denoted by the same reference numerals.

[0075] 10, when the PU 72 completes the processing of S32, it reads out the tractor weight m, the distance lf between the tractor's center of gravity and the front wheels, the distance lr between the tractor's center of gravity and the rear wheels, and the distance lh between the tractor's center of gravity and the hitch points from the storage device 74 (S34a). The PU 72 also reads out the trailer weight mt, the distance lft between the trailer's center of gravity and the hitch points, the distance lrt between the trailer's center of gravity and the wheels, and the trailer cornering coefficient Crt from the storage device 74. In this embodiment, it is assumed that the trailer cornering coefficient Crt is acquired in advance in accordance with the specifications of the wheels 32 of the trailer 30, etc.

[0076] The PU 72 further executes the processes of S36 and S38, and then estimates the trailer moment of inertia Izt (S40a). In the process of S40a, the slip angles β and βt, the tractor front wheel cornering coefficient Cf, the tractor rear wheel cornering coefficient Cr, the trailer moment of inertia Izt, the tractor hitch force F, and the trailer hitch force Ft are unknown quantities. The PU 72 determines the trailer moment of inertia Izt by algebraically solving the simultaneous equations (c1) to (c7) above.

[0077] When the processing of S40a is completed, the PU 72 updates the trailer moment of inertia Izt stored in the storage device 74 to the value calculated by the processing of S40a (S42a).

[0078] The PU 72 temporarily terminates the series of processes shown in FIG. 11 when the process of S42a is completed or when a negative determination is made in the processes of S30 and S32. <Fourth embodiment> The fourth embodiment will be described below with reference to the drawings, focusing on the differences from the third embodiment.

[0079] In the third embodiment, the values ​​of the model variables updated in the open-loop manipulated variable calculation process M22 are used. In contrast to this, in this embodiment, the values ​​of the updated model variables are also used to detect abnormalities in the combination vehicle 10.

[0080] Fig. 11 shows a procedure for processing related to detection of an abnormality in the state of the cargo on the trailer 30. The processing shown in Fig. 11 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at a predetermined interval.

[0081] 11, the PU 72 first acquires the trailer moment of inertia Izt (S60). Next, the PU 72 evaluates the center of gravity of the cargo based on the trailer moment of inertia Izt as an input variable (S62). For example, if the trailer moment of inertia Izt is excessively large, the PU 72 evaluates that the cargo is biased toward the edge of the trailer 30.

[0082] The PU 72 determines whether or not there is an abnormality in the cargo position based on the evaluation result of S62 (S64). If the PU 72 determines that there is an abnormality in the cargo position (S64: YES), it notifies the driver of this by operating the user interface 130 (S66). For example, if the user interface 130 includes a speaker, the PU 72 may notify the driver of the abnormality in the cargo position by audio information. Alternatively, if the user interface 130 includes a display, the PU 72 may display visual information on the display indicating that there is an abnormality in the cargo position.

[0083] When the process of S66 is completed or when a negative determination is made in the process of S64, the PU 72 temporarily terminates the series of processes shown in Fig. 11. Incidentally, the process shown in Fig. 11 is particularly effective when the trailer 30 consists only of a bed and does not have a roof or the like.

[0084] <Fifth embodiment> The fifth embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

[0085] Figure 12 shows some of the members provided in the articulated vehicle 10 according to this embodiment. For convenience, the same reference numerals are used in Figure 12 to refer to members corresponding to those shown in Figure 2.

[0086] As shown in Figure 12, in this embodiment, power can be transmitted between the steering wheel 52 and the front wheels 22 via the steering shaft 53. Torque from the assist motor 64 is applied to the steering shaft 53. The output voltage of the inverter 66 is applied to the terminals of the assist motor 64. The rear wheels 24 can be steered by the torque of the rear wheel steering motor 120. The output voltage of the inverter 122 is applied to the terminals of the rear wheel steering motor 120. The steering control device 70 refers to the rotation angle θmf of the assist motor 64 detected by the rotation angle sensor 124. The steering control device 70 refers to the rotation angle θmr of the rear wheel steering motor 120 detected by the rotation angle sensor 126.

[0087] The control targets of the steering control device 70 include the steering shaft 53 and the rear wheels 24. The steering control device 70 operates the inverter 66 to apply an assist torque, which assists the steering of the driver as a control variable, to the steering shaft 53. The steering control device 70 operates the inverter 122 to control the rear wheel steering angle δr, which is the steering angle of the rear wheels 24 as a control variable.

[0088] Figure 13 shows the processing executed by the steering control device 70. The processing shown in Figure 13 is realized by the PU 72 repeatedly executing a program stored in the storage device 74, for example, at a predetermined interval. Note that in Figure 13, processing corresponding to the processing shown in Figure 3 is denoted by the same reference numerals for convenience.

[0089] The open-loop manipulated variable calculation process M22a is a process for calculating an open-loop manipulated variable Mff, which is a manipulated variable for open-loop control, based on the target tractor yaw rate γ* as an input variable. The open-loop manipulated variable Mff is the rear wheel steering angle δr, which is the steering angle of the rear wheels 24 required to bring the yaw rate of the tractor 20 closer to the target tractor yaw rate γ*. More specifically, the open-loop manipulated variable calculation process M22a is a process for calculating the open-loop manipulated variable Mff using model variables that define the model of the articulated vehicle 10 shown in FIG. 4. The open-loop manipulated variable calculation process M22a is a process for substituting an actual value for the front wheel steering angle δf in the simultaneous equations of the above expressions (c1) to (c7), and substituting a value obtained by algebraically solving the equations with the rear wheel steering angle δr as an unknown into the open-loop manipulated variable Mff. The actual front wheel steering angle δf is calculated by the PU 72 based on the rotation angle θmf.

[0090] The closed-loop manipulated variable Mfb calculated by the closed-loop manipulated variable calculation process M26a is a correction amount for the open-loop manipulated variable Mff as a manipulated variable of closed-loop control in which the tractor yaw rate γ is the controlled variable.

[0091] The operation amount calculation process M28a is a process of substituting the sum of the open-loop operation amount Mff and the closed-loop operation amount Mfb into the target rear wheel steering angle δr*. The operation signal generation process M32a is a process for generating an operation signal MSr for the inverter 122 based on the target rear wheel steering angle δr* as an input variable.

[0092] As described above, in this embodiment, the manipulated variable of the control in which the tractor yaw rate γ is the controlled variable is the target rear wheel steering angle δr*. The open-loop manipulated variable Mff is calculated using a model based on the target tractor yaw rate γ* as an input variable. The model variables of the trailer 30 used to calculate the open-loop manipulated variable Mff are updated sequentially.

[0093] Sixth Embodiment The sixth embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment.

[0094] Fig. 14 shows the processing executed by the braking control device 91. The processing shown in Fig. 14 is realized by the PU 92 repeatedly executing a program stored in the storage device 94, for example, at a predetermined interval. In Fig. 14, the processing corresponding to the processing shown in Fig. 3 is denoted by the same reference numerals for convenience.

[0095] The open-loop manipulated variable calculation process M22b is a process for calculating an open-loop manipulated variable Mff, which is a vertical moment required to bring the yaw rate of the tractor 20 closer to the target tractor yaw rate γ*, based on the target tractor yaw rate γ* as an input variable. More specifically, the open-loop manipulated variable calculation process M22b is a process for calculating the open-loop manipulated variable Mff using model variables that define the model of the articulated vehicle 10 shown in FIG. 4. The open-loop manipulated variable calculation process M22b includes a process for substituting an actual value for the front wheel steering angle δf in the simultaneous equations of the above equations (c1) to (c7) and for algebraically solving the equations with the tractor braking moment Mz as an unknown. The open-loop manipulated variable calculation process M22b includes a process for substituting the calculated tractor braking moment Mz into the open-loop manipulated variable Mff.

[0096] The closed-loop operation amount calculation process M26b is a process for calculating a closed-loop operation amount Mfb as a correction amount for the tractor brake moment Mz. The operation amount calculation process M28b is a process of substituting the sum of the open-loop operation amount Mff and the closed-loop operation amount Mfb into the target brake moment Mz*.

[0097] The operation signal generation process M32b is a process for generating an operation signal MSb for the brake actuator 96 based on the target brake moment Mz* as an input variable. As described above, in this embodiment, the manipulated variable of the control in which the tractor yaw rate γ is the controlled variable is the target brake moment Mz*. The open-loop manipulated variable Mff is calculated using a model based on the target tractor yaw rate γ* as an input variable. The model variables of the trailer 30 used to calculate the open-loop manipulated variable Mff are updated sequentially.

[0098] <Correspondence> The correspondence between the matters in the above embodiment and the matters described in the "Means for Solving the Problem" column is as follows. Below, the correspondence is shown for each number of the means for solving the problem described in the "Means for Solving the Problem" column. [1, 9, 10] The acquisition process corresponds to the processes of S10 and S12 in FIG. 5 and the process of S36 in FIG. 8. The calculation process corresponds to the process of S26 in FIG. 6 and the process of S40 in FIG. 8. The predetermined variables correspond to the trailer center-of-gravity hitch point distance lft and the trailer center-of-gravity wheel distance lrt in FIG. 6. The predetermined variable also corresponds to the trailer cornering coefficient Crt in FIG. 8. [2] The trailer center-of-gravity variable corresponds to the trailer center-of-gravity hitch point distance lft and the trailer center-of-gravity wheel distance lrt. [3] The calculation process corresponds to the process of S16 in FIG. 6. [4] The calculation process corresponds to the process of S40 in FIG. 8. [5] The calculation process corresponds to the process of S40a in Fig. 10. [6] The open-loop manipulated variable calculation process corresponds to the open-loop manipulated variable calculation processes M22, M22a, and M22b. The operation process corresponds to the operation signal generation processes M32, M32a, and M32b. The correction process corresponds to the process of S28 in Fig. 6 and the process of S42 in Fig. 8. [7] The abnormality detection process corresponds to the processes of S52 and S54. The notification process corresponds to the process of S56. [8] The abnormality detection process corresponds to the processes of S62 and S64. The notification process corresponds to the process of S66.

[0099] <Other embodiments> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0100] "About the calculation process" (a) Calculation process taking into account static characteristics The calculation process taking into account the static characteristics is not limited to the process using the simultaneous equations (c8) to (c12) above. For example, the following equations may be used in addition to the above equations (c8) to (c12):

[0101] mfint·g=-kf·xfint …(c14) mrint·g=-kr·xrint …(c15) mf·g=-kf·xf …(c16) mr·g=-kr·xr …(c17) Szf=mf·g …(c18) Szr=mr·g …(c19) Here, the front wheel spring multiplier kf, rear wheel spring multiplier kr, front wheel displacement when not towing xfint, front wheel displacement xf, rear wheel displacement when not towing xrint, and rear wheel displacement xr are used. Also, the above equations use front wheel mass mf, front wheel mass when not towing mfint, rear wheel mass mr, and rear wheel mass when not towing mrint. Here, the front wheel spring multiplier kf is the elastic constant of the front wheel 22 side, including the suspension, etc. Also, the rear wheel spring multiplier kr is the elastic constant of the rear wheel 24 side, including the suspension, etc. Also, the front wheel displacement xf is the displacement of the rotation axis of the front wheel 22. And the rear wheel displacement xr is the displacement of the rotation axis of the rear wheel 24. The front wheel displacement amount xfint when not towing and the rear wheel displacement amount xrint when not towing are the front wheel displacement amount xf and the rear wheel displacement amount xr, respectively, when the tractor 20 is not connected to the trailer 30. The front wheel mass mf, the rear wheel mass mr, the front wheel mass mfint when not towing, and the rear wheel mass mrint when not towing are defined by the above equations (c18) and (c19).

[0102] In the above equations, the front wheel spring multiplier kf, the rear wheel spring multiplier kr, the front wheel displacement amount when not towing xfint, and the rear wheel displacement amount when not towing xrint are stored in the storage device 74. Meanwhile, the front wheel displacement amount xf and the rear wheel displacement amount xr are variables that can vary depending on the trailer 30 connected to the tractor 20. If the front wheel displacement amount xf and the rear wheel displacement amount xr can be measured, the force Szf applied to the front wheel C0 and the force Szr applied to the rear wheel B0 can be calculated. The front wheel displacement amount xf and the rear wheel displacement amount xr can be calculated based on the detection results of the pitch angle of the tractor 20. The pitch angle of the tractor 20 can be detected, for example, based on an image capturing the tractor 20 and the road surface around it.

[0103] The calculation process that takes static characteristics into consideration is not limited to the process of algebraically solving simultaneous equations. For example, a statistical method may be used. For example, the PU 72 calculates the front wheel displacement amount xf and the rear wheel displacement amount xr by substituting the trailer center-of-gravity wheel distance lrt, the trailer center-of-gravity hitch point distance lft, and various values ​​of the forces Szr, Szf, Fz, and Fzt into the above (c8) to (c19). Next, the PU 72 calculates the pitch angle from the front wheel displacement amount xf and the rear wheel displacement amount xr. The PU 72 then adopts the set of substituted values ​​when the difference between the calculated pitch angle and the detected pitch angle becomes small as an estimated value.

[0104] For example, the trailer weight mt may be included in the calculation target in the calculation process that takes into account static characteristics, such as using (c8) to (c19) above. In this case, the trailer weight mt may be a weight that takes into account the weight of the load, rather than a value determined by specifications. Note that, in addition to the trailer weight mt, quantities that vary depending on the load include the trailer center-to-wheel distance lrt, the trailer center-to-hitch point distance lft, and the trailer moment of inertia Izt. The condition of the load can be evaluated using some of these values. For example, if the trailer moment of inertia Izt is large compared to the trailer weight mt, the PU 72 can estimate that the load is biased toward the edge of the trailer 30. Therefore, the PU 72 can notify the user of this fact.

[0105] (b) Calculation process taking into account dynamic characteristics The calculation process taking dynamic characteristics into consideration is not limited to algebraically solving simultaneous equations. For example, statistical methods may be used. Specifically, for example, the PU 72 sets one of the available sensor detection values ​​in the above equations (c1) to (c7) as an estimated value estimated from the simultaneous equations without substituting it into the simultaneous equations. Then, when various values ​​are set for the original unknowns, the value of the unknown that minimizes the difference between the estimated value and the actual sensor value is set to a value to be calculated. In this process, the number of unknowns may be greater than the number of simultaneous equations. Therefore, for example, instead of the process of FIG. 8, the trailer cornering coefficient Crt and the trailer moment of inertia Izt may be estimated. Furthermore, for example, the trailer weight mt may also be included in the estimation. Here, the trailer weight mt is the weight of the trailer 30, including the weight of the cargo.

[0106] "About control amount" The physical quantity that defines the traveling state of the combination vehicle 10 as the control variable for open-loop control and the control variable for closed-loop control is not limited to the tractor yaw rate γ. The physical quantity may be, for example, the trailer yaw rate γt. Also, for example, the physical quantity may be the hitch angle θhi. Note that it is not necessary for there to be only one physical quantity. For example, the physical quantity may be the tractor yaw rate γ and the trailer yaw rate γt.

[0107] "Open-loop operation amount calculation process" It is not essential that the open-loop operation amount calculation process calculates the target tractor yaw rate γ* using the above equations (c1) to (c7). For example, the open-loop operation amount calculation process may calculate the target tractor yaw rate γ* using equations (c1) to (c7) obtained by deleting the terms including the tractor crosswind force W and the trailer crosswind force Wt.

[0108] The open-loop manipulated variable calculation process does not necessarily have to be a process of calculating the open-loop manipulated variable Mff by algebraically solving the simultaneous equations (c1) to (c7) above. The open-loop manipulated variable calculation process may include a process of setting one of the values ​​detected by a sensor, such as the trailer yaw rate γt, as the object to be estimated and substituting various values ​​for variables that were unknown when the algebraic solution was performed. In this case, the open-loop manipulated variable calculation process includes a process of searching for the value of the unknown variable so that the value of the variable set as the object to be estimated is closest to the sensor value.

[0109] The open-loop manipulated variable calculation process does not necessarily have to be a process of calculating the open-loop manipulated variable by calculation using the values ​​of the model variables that are to be corrected by the correction process. For example, the open-loop manipulated variable calculation process may be a process of map-calculating the open-loop manipulated variable by the PU with map data stored in a storage device. Here, the map data is data whose output variables are the open-loop manipulated variables.

[0110] About Corrective Actions The values ​​of the model variables to be corrected by the correction process are not limited to the values ​​of the variables exemplified in the above embodiment. The value of the model variable to be corrected by the correction process may be, for example, the vertical moment of inertia of the trailer 30. The value of the model variable to be corrected by the correction process is also not limited to the value of the model variable that defines the model of the trailer 30. The value of the model variable to be corrected by the correction process may be, for example, the value of the model variable that defines the model of the tractor 20.

[0111] The correction process does not necessarily have to be a process of correcting the values ​​of the model variables used in the open-loop manipulated variable calculation process. For example, as described in the above section "Regarding the open-loop manipulated variable calculation process," in cases where the open-loop manipulated variable is calculated by map calculation, the correction process may be, for example, the following process. That is, the correction process may be a process of calculating a correction value for the result of the map calculation based on the update amount of the value of the model variable.

[0112] "About operation processing" The actuator that is the object of operation based on the manipulated variable of open-loop control is not limited to any one of the actuator that steers the front wheels of the tractor 20, the actuator that steers the rear wheels of the tractor 20, and the brake actuator. For example, it may be both the actuator that steers the front wheels of the tractor 20 and the actuator that steers the rear wheels of the tractor 20. The actuator that is the object of operation based on the manipulated variable of open-loop control is not limited to some of the three, the actuator that steers the front wheels of the tractor 20, the actuator that steers the rear wheels of the tractor 20, and the brake actuator. For example, if the thrust generating device of the tractor 20 includes an in-wheel motor, the actuator that is the object of operation based on the manipulated variable of open-loop control may be the thrust generating device.

[0113] "Application of open loop control variable Mff" In the above embodiment, the open-loop manipulated variable Mff is used for assistance processing to enable the driver to easily change lanes, etc., but this is not limited to this. For example, the open-loop manipulated variable Mff based on the values ​​of model variables that are successively updated may be used to control the behavior of the articulated vehicle 10 regarding parking. Here, the control regarding parking is not limited to control by the driver, but may also be automatic driving.

[0114] Uses of estimated model variable values It is not essential that the estimated model variable values ​​be reflected in the open-loop manipulated variable Mff. For example, the estimated model variable values ​​may be used for anomaly detection as shown in Figure 9, but may not be reflected in the open-loop manipulated variable Mff.

[0115] "About the estimation device and control device for articulated vehicles" In the first embodiment, the steering control device 70 executes the processes in Figures 6 and 8, but this is not limiting. For example, the ADASECU 100 may execute the processes in Figures 6 and 8.

[0116] In the second embodiment, the steering control device 70 executes the processing in Fig. 9, but the present invention is not limited to this. For example, the ADASECU 100 may execute the processing in Fig. 9. In the sixth embodiment, the braking control device 91 executes the correction process, but the present invention is not limited to this. For example, the ADASECU 100 may execute the correction process.

[0117] The estimation device and control device for articulated vehicles are not limited to those equipped with a PU and a storage device and executing software processing. For example, they may be equipped with dedicated hardware circuits, such as ASICs, that execute at least some of the various processes executed in the above embodiments. That is, the estimation device and control device may be equipped with any of the following processing circuits (a) to (c): (a) A processing circuit that includes a processing device that executes all of the above processes in accordance with a program, and a program storage device, such as a storage device, that stores the program. (b) A processing circuit that includes a processing device and program storage device that executes some of the above processes in accordance with a program, and a dedicated hardware circuit that executes the remaining processes. (c) A processing circuit that includes a dedicated hardware circuit that executes all of the above processes. Here, there may be multiple software execution devices equipped with a processing device and program storage device, and multiple dedicated hardware circuits.

[0118] "About the entity that will carry out the estimation method and control method for articulated vehicles" It is not essential that all of the processes in the above-described embodiment and modifications thereof be executed by processing circuits mounted on the combination vehicle 10. [Explanation of symbols]

[0119] 10...Articulated vehicle 20...Tractor 30...Trailer 50...Steering system 52...Steering wheel 53...Steering shaft 54...Reaction motor 56...Inverter 60...Front wheel steering motor 62...Inverter 64...Assist motor 66...Inverter 70...Steering control device 91...Brake control device

Claims

1. A control device for a combination vehicle that is applied to a combination vehicle that includes a tractor and a trailer towed by the tractor, an execution unit configured to execute the acquisition process and the calculation process; the acquisition process is a process of acquiring at least one of two values ​​of a predetermined model variable and a value of an operation variable of the combination vehicle based on an input from outside the control device, the model variables are variables that define a model of the articulated vehicles, the operation variable is a variable indicating a physical quantity that quantifies the operation of the combination vehicle, an estimation device for articulated vehicles, wherein the calculation process is a process of calculating the value of the model variable to be estimated based on the value of the variable acquired by the acquisition process as an input variable in a predetermined state of the articulated vehicles.

2. the predetermined variables include at least one of three: a trailer center of gravity variable, a cornering coefficient of the trailer, and a vertical moment of inertia of the trailer; 2. The vehicle articulation estimation device according to claim 1, wherein the trailer center of gravity variable is a variable indicating the center of gravity of the trailer.

3. a storage device storing data indicating the mass of the trailer, data indicating the value of a tractor center of gravity variable, and data indicating the mass of the tractor; the predetermined state is a stopped state of the combination vehicles, the calculation process includes a process of calculating, while the combination vehicle is stopped, the value of the predetermined variable based on an equation for balance of moments of the combination vehicle using the value of the tractor center of gravity variable, the mass of the tractor, and the mass of the trailer; the tractor center of gravity variable is a variable indicating the center of gravity of the tractor, the predetermined variables include a trailer center of gravity variable; 2. The vehicle articulation estimation device according to claim 1, wherein the trailer center of gravity variable is a variable indicating the center of gravity of the trailer.

4. the predetermined state is a turning operation state of the combination vehicle, the operational variables include a vehicle speed of the combination vehicle and a yaw rate of the trailer; the calculation process includes a process of calculating the value of the predetermined variable based on an equation of motion using the vehicle speed of the combination vehicle and the yaw rate of the trailer, 2. The vehicle articulation estimation apparatus according to claim 1, wherein said predetermined variables include a cornering coefficient of said trailer.

5. the predetermined state is a turning operation state of the combination vehicle, the operational variables include a vehicle speed of the combination vehicle and a yaw rate of the trailer; the calculation process includes a process of calculating the value of the predetermined variable based on an equation of motion using the vehicle speed of the combination vehicle and the yaw rate of the trailer, 2. The apparatus for estimating a vehicle combination according to claim 1, wherein said predetermined variable includes a vertical moment of inertia of said trailer.

6. The estimation device for an articulated vehicle according to claim 1 is provided with the execution device, the execution device is configured to execute an open-loop manipulated variable calculation process, an operation process, and a correction process; the open-loop manipulated variable calculation process is a process for calculating an open-loop manipulated variable, the open-loop manipulated variable is a manipulated variable of open-loop control in which a physical variable that defines the traveling state of the combined vehicles is a controlled variable, the operation processing is processing for operating actuators of the combination vehicles in accordance with the open-loop operation amount, The control device for articulated vehicles, wherein the correction process includes a process of correcting the open-loop manipulated variable in accordance with the value of the model variable calculated by the calculation process.

7. The estimation device for an articulated vehicle according to claim 4 is provided with the execution device, the execution device is configured to execute an abnormality detection process and a notification process; the abnormality detection process is a process of detecting an abnormality in a tire of the trailer based on a cornering coefficient of the trailer as an input variable, The notification process is a process of notifying a user of an abnormality detected in a tire.

8. The estimation device for an articulated vehicle according to claim 5 is provided with the execution device, the execution device is configured to execute an abnormality detection process and a notification process; the abnormality detection process is a process for detecting an abnormality in a load of the trailer based on a vertical moment of inertia of the trailer as an input variable, The notification process is a process for notifying a user of an abnormality in the load of the trailer when the abnormality is detected.

9. A method for estimating an articulated vehicle, comprising executing each of the processes in the articulated vehicle estimation device according to claim 1.

10. 2. An articulated vehicle estimation program that causes a computer to execute each of the processes in the articulated vehicle estimation device according to claim 1.

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