JP7063136B2 - Controls, vehicle steering, control methods and programs - Google Patents

Description

The present invention relates to a control device, a vehicle steering device, a control method and a program.

There is a vehicle steering device in which the steering wheel and the steering mechanism are not mechanically connected. For example, Patent Document 1 describes a steering device capable of independently steering left and right. A steering mechanism is provided for each of the left and right steering wheels, and each steering mechanism includes a steering actuator powered by an electric motor. Each steering mechanism can independently steer the steering wheel at different steering angles. Further, the steering device includes a fail-safe mechanism that mechanically transmits the driving force of one steering actuator to the other steering actuator when an abnormality occurs in the steering actuator. In the fail-safe mechanism described in Patent Document 1, the two shafts are engaged by the driver inserting a pin into the engaging portion of the two shafts connected to each of the two steering actuators. Then, the two steering actuators are connected so as to be able to transmit the driving force via the two shafts. That is, the left and right steering wheels are mechanically connected by the two shafts.

Japanese Unexamined Patent Publication No. 2011-131777

Here, in a steering device in which the left and right steering mechanisms are connected to each other by engaging the two shafts as in Patent Document 1, an abnormality such as a failure occurs in one of the steering mechanisms. However, the steering wheel connected to the steering mechanism in which the abnormality has occurred is unlikely to fall out of control. The failure of the steering mechanism or the steering wheel means that the steering angle control by the steering mechanism or the steering angle control for the steering wheel cannot be normally performed. On the other hand, for the purpose of weight reduction and cost reduction, a steering device in which the left and right steering mechanisms are not connected to each other is being studied. It is conceivable that the steering wheel connected to the steering mechanism in which the abnormality has occurred may become uncontrollable. As a result, when the vehicle turns, it may not be possible to control the running of the vehicle.

Therefore, according to the present invention, in a vehicle steering device in which the left and right steering mechanisms are not connected to each other, a control device for stabilizing the turning running of the vehicle and a vehicle steering device when an abnormality occurs in one of the steering mechanisms. , Control methods and programs.

The control device according to one aspect of the present invention is a control device for a vehicle steering device having left and right steering mechanisms that are not mechanically connected to each other and that individually steers the left and right steering wheels. A determination unit that acquires turning information that is information on turning and determines a vehicle speed limit value corresponding to the acquired turning information, and a vehicle control device that determines the determined vehicle speed limit value as a control device for the vehicle. When an abnormality occurs in one of the left and right steering mechanisms, the determination unit determines a limit value of the vehicle speed smaller than that in the normal state.

The vehicle steering device according to one aspect of the present invention includes the control device according to one aspect of the present invention, the left steering mechanism and the right steering mechanism, and the left steering mechanism is the same. The right steering mechanism has a left actuator that generates a driving force for individually steering the left steering wheel, and the right steering mechanism generates a driving force for individually steering the right steering wheel. Has an actuator.

The control method according to one aspect of the present invention is a control method for a vehicle steering device having left and right steering mechanisms that are not mechanically connected to each other and individually steering the left and right steering wheels. The turning information, which is information related to turning, is acquired, it is detected whether or not an abnormality has occurred in the left and right steering mechanisms, and the vehicle speed limit value corresponding to the acquired turning information is set to the left and right steering mechanisms. It is determined according to whether or not an abnormality has occurred, and the determined limit value of the vehicle speed is output to the vehicle control device which is the control device of the vehicle, and one of the left and right steering mechanisms has an abnormality. The limit value of the vehicle speed when the above occurs is smaller than the limit value of the vehicle speed when both the left and right steering mechanisms are normal.

The program according to one aspect of the present invention acquires turning information, which is information related to turning of the vehicle, detects whether or not an abnormality has occurred in the left and right steering mechanisms that are not mechanically connected to each other, and is acquired. The vehicle speed limit value corresponding to the turning information is determined according to whether or not an abnormality has occurred in the left and right steering mechanisms, and the determined vehicle speed limit value is the control device of the vehicle. The limit value of the vehicle speed when output to the vehicle control device and an abnormality occurs in one of the left and right steering mechanisms is the limit value of the vehicle speed when both the left and right steering mechanisms are normal. Let the computer do less than.

According to the control device or the like according to the present invention, when an abnormality occurs in one of the left and right steering mechanisms that are not connected to each other, it is possible to stabilize the turning running of the vehicle.

It is a figure which shows an example of the overall structure of the steering device for a vehicle which concerns on Embodiment 1. It is a block diagram which shows an example of the functional structure of the upper ECU of FIG. It is a block diagram which shows an example of the functional structure of the left steering ECU of FIG. It is a block diagram which shows an example of the functional structure of the right steering ECU of FIG. It is a figure which shows an example of the relationship between the steering angle and the limit value of a vehicle speed in a normal state of a steering mechanism and a failure state of a left steering mechanism. It is a figure which shows an example of the relationship between the steering angle and the limit value of a vehicle speed in a normal state of a steering mechanism and a failure state of a right steering mechanism. It is a flowchart which shows an example of the operation flow of the steering device for a vehicle which concerns on Embodiment 1. FIG. It is a block diagram which shows an example of the functional structure of the upper ECU of the vehicle steering apparatus which concerns on Embodiment 2. FIG. It is a schematic plan view which shows an example of the target locus of the vehicle which concerns on Embodiment 2. FIG. It is a figure which shows an example of the relationship between the curvature of the target locus of a vehicle, and the limit value of a vehicle speed in a normal state of a steering mechanism and a failure state of a left steering mechanism. It is a figure which shows an example of the relationship between the curvature of the target locus of a vehicle, and the limit value of a vehicle speed in a normal state of a steering mechanism and a failure state of a right steering mechanism. It is a block diagram which shows an example of the functional structure of the upper ECU of the vehicle steering apparatus which concerns on Embodiment 3. FIG.

Hereinafter, the vehicle steering device and the like according to the embodiment will be described with reference to the drawings. The embodiments described below are comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps (processes), order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. .. Further, among the components in the following embodiments, the components not described in the independent claim indicating the highest level concept are described as arbitrary components. Further, each figure is a schematic view and is not necessarily exactly shown. Further, in each figure, substantially the same components are designated by the same reference numerals, and duplicate description may be omitted or simplified.

[Embodiment 1]
First, the overall configuration of the vehicle steering device 100 according to the first embodiment of the present invention will be described. FIG. 1 shows a block diagram of an example of a functional configuration of the vehicle steering device 100 according to the first embodiment. As shown in FIG. 1, the vehicle steering device 100 is mounted on the vehicle 1 and has a steering-by-wire system configuration in which a left-right independent steering system is adopted. The vehicle steering device 100 includes a steering wheel 2 as a steering member operated by the driver for steering, a left steering mechanism 4L for individually steering the left steering wheel 3L, and a left steering mechanism 4L. It is not mechanically connected to and is provided with a right steering mechanism 4R for individually steering the right steering wheel 3R. The left steering wheel 3L constitutes the left front wheel of the front wheels arranged on the front side of the vehicle 1, and the right steering wheel 3R constitutes the right front wheel of the front wheels of the vehicle 1. The left steering mechanism 4L steers the left steering wheel 3L in response to the rotation operation of the steering wheel 2. The right-hand steering mechanism 4R steers the right-hand steering wheel 3R in response to the rotation operation of the steering wheel 2.

The left steering mechanism 4L and the right steering mechanism 4R each include a left steering actuator 5L and a right steering actuator 5R that are driven in response to a rotational operation of the steering wheel 2. An example of the left steering actuator 5L and the right steering actuator 5R is an electric motor. Further, the left steering mechanism 4L individually steers the left steering wheel 3L by the rotational driving force generated by the left steering actuator 5L. The right-hand steering mechanism 4R individually steers the right-hand steering wheel 3R by the rotational driving force generated by the right-hand steering actuator 5R. There is no mechanical coupling between the steering wheel 2 and the left steering mechanism 4L and the right steering mechanism 4R to mechanically transmit the steering torque applied to the steering wheel 2. The left steering actuator 5L steers only the left steering wheel 3L, and the right steering actuator 5R steers only the right steering wheel 3R. Here, the left steering actuator 5L is an example of a left actuator, and the right steering actuator 5R is an example of a right actuator.

The left steering mechanism 4L and the right steering mechanism 4R are rotation axes that rotate by the driving force of the left steering actuator 5L and the right steering actuator 5R and steer the left steering wheel 3L and the right steering wheel 3R, respectively. It has a steering shaft 6L and a right steering shaft 6R. The left steering shaft 6L and the right steering shaft 6R are supported by the front suspension of the vehicle 1. The front suspension that supports the left steering shaft 6L and the right steering shaft 6R may be any type of suspension such as a strut type, a double wishbone type, and a multi-link type.

Further, the vehicle steering device 100 includes a steering angle sensor 10 that detects the steering angle of the steering wheel 2. In the present embodiment, the steering angle sensor 10 detects the rotation angle of the rotation shaft of the steering wheel 2. Further, the vehicle steering device 100 includes a left steering angle sensor 11L for detecting the steering angle of the left steering wheel 3L and a right steering angle sensor 11R for detecting the steering angle of the right steering wheel 3R.

Further, the vehicle steering device 100 includes an upper ECU (Electronic Control Unit) 20 and a storage unit 21. The storage unit 21 may be arranged separately from the upper ECU 20 and may be connected to the upper ECU 20 or may be included in the upper ECU 20. The left steering mechanism 4L includes a left steering ECU 30L which is one of the lower ECUs, and the right steering mechanism 4R includes a right steering ECU 30R which is one of the lower ECUs. The upper ECU 20 is connected to the left steering ECU 30L, the right steering ECU 30R, and the steering angle sensor 10. Further, the upper ECU 20 is provided in the vehicle 1 and is connected to a vehicle speed sensor 12 that detects the speed of the vehicle 1. The left steering ECU 30L is connected to the upper ECU 20, the left steering angle sensor 11L, the left steering actuator 5L, and the right steering ECU 30R. The right steering ECU 30R is connected to the upper ECU 20, the right steering angle sensor 11R, the right steering actuator 5R, and the left steering ECU 30L. Here, the upper ECU 20, the left steering ECU 30L, and the right steering ECU 30R constitute the control device 90 of the vehicle steering device 100.

The upper ECU 20 determines the steering angles of the left steering wheel 3L and the right steering wheel 3R (“target turning”) based on the information acquired from the steering angle sensor 10, the vehicle speed sensor 12, the left steering ECU 30L, the right steering ECU 30R, and the storage unit 21. It is also called "rudder angle") and is output to the left steering wheel ECU 30L and the right steering wheel ECU 30R.

The left steering ECU 30L outputs the steering angle (also referred to as “detected steering angle” or “actual steering angle”) detected by the left steering angle sensor 11L to the upper ECU 20, and receives from the upper ECU 20 the target steering angle. The left steering actuator 5L is operated based on the above. The right steering ECU 30R outputs the actual steering angle detected by the right steering angle sensor 11R to the upper ECU 20, and operates the right steering actuator 5R based on the target steering angle received from the upper ECU 20.

The storage unit 21 enables storage and retrieval of various information. The storage unit 21 is realized by, for example, a storage device such as a ROM (Read-Only Memory), a RAM (Random Access Memory), a semiconductor memory such as a flash memory, a hard disk drive, or an SSD (Solid State Disk). The storage unit 21 stores the relationship between the steering angle and the vehicle speed for calculating the target steering angle in the form of a control map, a mathematical formula, or the like. Further, the storage unit 21 stores the first control information indicating the relationship between the steering angle and the limit value of the vehicle speed in the form of a control map, a mathematical formula, or the like. The storage unit 21 has the first control information when the left steering mechanism 4L and the right steering mechanism 4R are normal, and one of the left steering mechanism 4L and the right steering mechanism 4R is abnormal, that is, it has failed. Stores the first control information when there is. The details of the first control information will be described later.

The upper ECU 20 is also connected to another ECU mounted on the vehicle 1. For example, the upper ECU 20 is connected to the first ECU 50, the second ECU 60, the third ECU 70, the fourth ECU 80, and the like. The first ECU 50 is an ECU that controls the operation of the power device 51 of the vehicle 1. Examples of the power unit 51 are an engine and a motor. The second ECU 60 is an ECU that controls the operation of the brake device 61 of the vehicle 1. The third ECU 70 is an ECU that controls the operation of the IVI (In-Vehicle Infotainment) device 71 mounted on the vehicle 1. The IVI device 71 has functions such as a navigation function and a multimedia reproduction function for music and moving images. The fourth ECU 80 is an ECU that controls the operation of the measuring device 81 mounted on the vehicle 1. Examples of the measuring device 81 are a camera that captures the surroundings of the vehicle 1 such as the front of the vehicle 1, a sensor that scans the surroundings of the vehicle 1, and the like. Examples of sensors are laser light sensors, LIDAR (Light Detection and Ranging), magnetic sensors, ultrasonic sensors, and the like. Here, the first ECU 50 and the second ECU 60 are examples of the vehicle control device.

The upper ECU 20 receives information and commands, and transmits information and commands to the first ECU 50, the second ECU 60, the third ECU 70, and the fourth ECU 80. In this embodiment, the higher-level ECU 20 does not have to send / receive information and commands to the third ECU 70 and the fourth ECU 80. Upper ECU 20, left steering ECU 30L, right steering ECU 30R, left steering actuator 5L, right steering actuator 5R, ECU 50, 60, 70 and 80, and communication between each sensor is CAN (Controller Area Network) or the like. Communication may be performed via an in-vehicle network.

The upper ECU 20, the left steering ECU 30L, the right steering ECU 30R, and the ECUs 50, 60, 70, and 80 are composed of a microcomputer including a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor) and a memory. May be good. The memory may be a volatile memory such as RAM, a non-volatile memory such as ROM, or a storage unit 21. For the functions of the upper ECU 20, the left steering ECU 30L, the right steering ECU 30R, and some or all of the ECUs 50, 60, 70, and 80, the CPU executes a program recorded in the ROM using the RAM as a working memory. It may be achieved by doing.

Next, the details of the upper ECU 20, the left steering ECU 30L, and the right steering ECU 30R will be described. FIG. 2 is a block diagram showing an example of the functional configuration of the upper ECU 20 of FIG. FIG. 3 is a block diagram showing an example of the functional configuration of the left steering ECU 30L of FIG. FIG. 4 is a block diagram showing an example of the functional configuration of the right-hand steering ECU 30R of FIG. As shown in FIG. 2, the upper ECU 20 includes an acquisition unit 20a, a steering angle determination unit 20b, a limit value determination unit 20c, and an output unit 20d. Here, the limit value determination unit 20c is an example of the determination unit.

The acquisition unit 20a acquires the steering angle detected by the steering angle sensor 10 and the speed of the vehicle 1 detected by the vehicle speed sensor 12. Further, the acquisition unit 20a acquires first control information and the like indicating the relationship between the vehicle speed and the steering angle stored in the storage unit 21 from the storage unit 21. The acquisition unit 20a acquires the rotation angle of the rotation shaft of the steering wheel 2 by acquiring the steering angle from the steering angle sensor 10. Further, the acquisition unit 20a acquires failure information, which is information on whether or not the left steering mechanism 4L and the right steering mechanism 4R have failed, from the left steering ECU 30L and the right steering ECU 30R. The acquisition unit 20a acquires the actual steering angles of the left steering wheel 3L and the right steering wheel 3R from the left steering ECU 30L and the right steering ECU 30R.

The steering angle determination unit 20b determines a target steering angle according to the steering angle or the like acquired by the acquisition unit 20a for each of the left steering wheel 3L and the right steering wheel 3R. For example, the steering angle determining unit 20b calculates the target steering angles of the left steering wheel 3L and the right steering wheel 3R by using the steering angle information of the steering angle sensor 10 and the vehicle speed information of the vehicle speed sensor 12. The steering angle determination unit 20b calculates the target steering angle of the actual steering angles of the left steering wheel 3L and the right steering wheel 3R detected by the steering angle sensors 11L and 11R of the left steering wheel 3L and the right steering wheel 3R. The calculated target steering angle may be corrected by feeding back to.

The limit value determination unit 20c determines the limit value of the vehicle speed, which is the upper limit value of the speed of the vehicle 1 at the target steering angle, by using the failure information, the target steering angle, and the first control information. Here, the target turning angle is an example of turning information. Details of the processing of the limit value determination unit 20c will be described later.

The output unit 20d outputs a travel command for commanding travel at the vehicle speed limit value determined by the limit value determination unit 20c to at least one of the first ECU 50 and the second ECU 60. As a result, the first ECU 50 adjusts the rotation speed, output, and the like of the power device 51 so that the speed of the vehicle 1 becomes equal to or less than the limit value of the vehicle speed. The second ECU 60 operates the brake device 61 as necessary so that the speed of the vehicle 1 becomes equal to or less than the limit value of the vehicle speed.

As shown in FIG. 3, the left steering ECU 30L includes a left steering control unit 31L, a drive circuit 32L, and a current detection unit 33L. The left steering control unit 31L controls the operation of the left steering actuator 5L via the drive circuit 32L. The drive circuit 32L is controlled by the left steering control unit 31L to supply electric power to the left steering actuator 5L. The drive circuit 32L is composed of an inverter circuit. The current detection unit 33L detects the magnitude of the current flowing through the left steering actuator 5L. The current detection unit 33L is composed of a circuit or the like for measuring the current.

The left steering control unit 31L acquires the left actual steering angle δ _LR from the left steering angle sensor 11L, acquires the left target steering angle δ _LT from the upper ECU 20, and the left actual steering angle δ _LR is the left target. The drive circuit 32L is controlled so as to be equal to the steering angle δ _LT . The left steering control unit 31L functions as a plurality of processing function units, and is a steering angle deviation calculation unit 41L, a steering angle PI (Proportional Integral) control unit 42L, an angular velocity calculation unit 43L, and an angular velocity deviation calculation unit 44L. It includes an angular velocity PI control unit 45L, a current deviation calculation unit 46L, a current PI control unit 47L, a PWM (Pulse Width Modulation) control unit 48L, and a left failure detection unit 49L.

The steering angle deviation calculation unit 41L calculates the deviation Δδ _L between the left target steering angle δ _LT and the left actual steering angle δ _LR , and outputs the deviation to the steering angle PI control unit 42L. The deviation Δδ _L = δ _LT − δ _LR . The steering angle PI control unit 42L calculates the left target steering angle velocity ω _LT , which is the target value of the left steering angle velocity, by performing the PI calculation for the deviation Δδ _L , and outputs the calculation to the angular velocity deviation calculation unit 44L. The angular velocity calculation unit 43L calculates the left actual turning angle velocity ω _LR , which is the angular velocity of the left actual turning angle δ _LR , by time-differentiating the left actual turning angle δ _LR , and outputs the angular velocity deviation calculation unit 44L. ..

The angular velocity deviation calculation unit 44L calculates the deviation Δω L between the left target turning angle velocity ω _LT and the left actual turning angle velocity ω _LR , and outputs the deviation Δω _L to the angular velocity PI control unit 45L. The deviation Δω _L = ω _LT −ω _LR . The angular velocity PI control unit 45L calculates the left target current value _ILT , which is the target value of the current to be passed through the left steering actuator 5L, by performing the PI calculation for the deviation Δω _L , and outputs the calculation to the current deviation calculation unit 46L. .. The current deviation calculation unit 46L calculates the deviation ΔIL between the left target current value _ILT and the actual current value _ILR of the left steering actuator 5L detected by the current detection unit 33L, and outputs the deviation to the current PI control unit _47L . do. The deviation ΔI _L = I _LT -I _LR .

The current PI control unit _47L performs a PI calculation on the deviation ΔIL to drive the left steering actuator 5L to guide the actual current value _ILR flowing through the left steering actuator 5L to the left target current value _ILT . A value is generated and output to the PWM control unit 48L. The PWM control unit 48L generates a left PWM control signal having a duty ratio corresponding to the drive command value, and outputs the signal to the drive circuit 32L. As a result, the drive circuit 32L supplies the electric power corresponding to the drive command value to the left steering actuator 5L.

The left failure detection unit 49L determines whether or not the left steering mechanism 4L has failed, and transmits the first failure information indicating the determination result to the upper ECU 20. The failure of the left steering mechanism 4L means that the steering angle control for the left steering wheel 3L cannot be normally performed. For example, when the state in which the steering angle deviation Δδ _L is equal to or greater than the first threshold value continues for the first predetermined time or longer, the left failure detection unit _49L states that the current deviation ΔIL is equal to or greater than the second threshold value. It may be determined that the left steering mechanism 4L has failed when it continues for a certain period of time or more. The former case may correspond to a case where an abnormality such as sticking occurs in the physical structure for rotating the left steering shaft 6L. The latter case may correspond to a case where an abnormality such as a disconnection occurs in the electric structure for driving the left steering actuator 5L or the left steering actuator 5L. The upper ECU 20 may determine that the left steering mechanism 4L has failed when the state in which communication with the left steering ECU 30L continues for a third predetermined time or longer.

Further, as shown in FIG. 4, the right steering ECU 30R has the same configuration as the left steering ECU 30L except for the difference between the left and right steering. The right-hand steering ECU 30R also includes a right-hand steering control unit 31R, a drive circuit 32R, and a current detection unit 33R. The right steering control unit 31R functions as a plurality of processing function units, and includes a steering angle deviation calculation unit 41R, a steering angle PI control unit 42R, an angular velocity calculation unit 43R, an angular velocity deviation calculation unit 44R, and an angular velocity PI. It includes a control unit 45R, a current deviation calculation unit 46R, a current PI control unit 47R, a PWM control unit 48R, and a right failure detection unit 49R. Since the components of the right steering ECU 30R and the right steering control unit 31R are the same as those of the left steering ECU 30L and the left steering control unit 31L, detailed description thereof will be omitted.

Further, the drive circuit 32R is controlled by the right steering control unit 31R to supply electric power to the right steering actuator 5R. The current detection unit 33R detects the magnitude of the current flowing through the right-hand steering actuator 5R. The right steering control unit 31R controls the drive circuit 32R so that the left actual steering angle δ _RR detected by the right steering angle sensor 11R becomes equal to the right target steering angle δ _RT given by the upper ECU 20. do.

The steering angle deviation calculation unit 41R calculates the deviation Δδ _R (Δδ _R = δ _RT −δ _RR ) between the right target steering angle δ _RT and the right actual steering angle δ _RR . The steering angle PI control unit 42R calculates the right target steering angular velocity ω _RT . The angular velocity calculation unit 43R calculates the right actual turning angle velocity ω _RR of the right actual turning angle δ _RR . The angular velocity deviation calculation unit 44R calculates the deviation Δω _R (Δω _R = ω _RT −ω _RR ) between the right target turning angular velocity ω _RT and the right actual turning angular velocity ω _RR . The angular velocity PI control unit _45R calculates the right target current value IRT of the right steering actuator 5R. The current deviation calculation unit 46R calculates the deviation _ΔIR ( _ΔIR = _IRT - _IRR ) between the right target current value _IRT and the actual current value _IRR of the right steering actuator 5R. The current PI control unit _47R generates a drive command value of the right steering actuator 5R for guiding the actual current value IRR flowing through the right steering actuator 5R to the right target current value _IRT . The PWM control unit 48R generates a right PWM control signal corresponding to the drive command value and outputs it to the drive circuit 32R, and the drive circuit 32R supplies electric power corresponding to the drive command value to the right steering actuator 5R.

The right failure detection unit 49R determines whether or not the right steering mechanism 4R has failed, and transmits the second failure information indicating the determination result to the upper ECU 20. When the right steering mechanism 4R fails, it means that the steering angle control for the right steering wheel 3R cannot be performed normally. For example, when the steering angle deviation Δδ _R is equal to or more than the first threshold value for the first predetermined time or longer, the right failure detection unit 49R is in the second predetermined state where the current deviation _ΔIR is equal to or greater than the second threshold value. It may be determined that the right steering mechanism 4R has failed when it continues for a certain period of time or more. The upper ECU 20 may determine that the right steering mechanism 4R has failed when the state in which communication with the right steering ECU 30R continues for a third predetermined time or longer.

Next, with reference to FIG. 2, the details of the processing of the limit value determination unit 20c of the upper ECU 20 will be described. The limit value determination unit 20c determines the limit value of the vehicle speed with respect to the target turning angle. The limit value determination unit 20c has a normal state in which the left steering mechanism 4L and the right steering mechanism 4R have not failed, and an abnormal state in which one of the left steering mechanism 4L and the right steering mechanism 4R has failed. Determine different vehicle speed limits between. Specifically, when an abnormality occurs in one of the left steering mechanism 4L and the right steering mechanism 4R, the limit value determination unit 20c determines a limit value for a vehicle speed smaller than that in the normal state.

When the left steering mechanism 4L fails, the upper ECU 20 controls the steering angle of the normal right steering mechanism 4R on the opposite side to drive the vehicle 1. Further, when the right steering mechanism 4R fails, the upper ECU 20 controls the steering angle of the normal left steering mechanism 4L to drive the vehicle 1. Further, when both the left steering mechanism 4L and the right steering mechanism 4R fail, the upper ECU 20 issues a command to stop the vehicle 1 or issues information prompting the driver to stop the vehicle 1.

When the left steering mechanism 4L fails, the limit value determining unit 20c reduces the limit value of the vehicle speed in the right turn rather than the left turn if the left and right target steering angles are the same size. Similarly, when the right steering mechanism 4R fails, the limit value determining unit 20c sets the limit value of the vehicle speed in the left turn rather than the right turn if the left and right target steering angles are the same size. Make it smaller.

Specifically, the limit value determining unit 20c sets the normal state of the steering mechanisms 4L and 4R and the steering mechanism 4L according to the relationship between the target steering angle and the vehicle speed limiting value as shown in FIGS. 5A and 5B. In one of the failure states of 4R and 4R, the limit value of the vehicle speed is determined and output to the output unit 20d.

FIG. 5A is a diagram showing an example of the relationship between the steering angle and the vehicle speed limit value in the normal state of the steering mechanisms 4L and 4R and in the failed state of the left steering mechanism 4L. FIG. 5B is a diagram showing an example of the relationship between the steering angle and the vehicle speed limit value in the normal state of the steering mechanisms 4L and 4R and in the failed state of the right steering mechanism 4R. In FIGS. 5A and 5B, the horizontal axis indicates the vehicle speed (unit: km / h). The vertical axis shows the left turning angle, which is the turning angle of the left turn with respect to the neutral position of the left and right turning, and the right turning angle, which is the turning angle of the right turning with respect to the neutral position. The neutral position corresponds to "0" on the vertical axis.

In FIGS. 5A and 5B, the normal limit line LAN shows the relationship between the steering angle in the normal state and the vehicle speed limit value, and the failure limit line LAF limits the steering angle and the vehicle speed in the failure state. Shows the relationship with the value. As shown in FIGS. 5A and 5B, the failure limit line LAF is formed so that the limit value of the vehicle speed is smaller than that of the normal limit line LAN for the same steering angle. In other words, the failure limit line LAF is formed so that the steering angle is smaller than that of the normal limit line LAN with respect to the limit value of the same vehicle speed.

Further, as shown in FIG. 5A, in the collapsed state of the left steering mechanism 4L, in the collapse limiting line LAF, the vehicle speed limit value in the right turn is left turning with respect to the steering angle of the same size. It is formed so as to be smaller than the limit value of the vehicle speed of. Similarly, as shown in FIG. 5B, in the collapsed state of the right steering mechanism 4R, the collapse limiting line LAF has the vehicle speed limit value of right turning when turning left with respect to the steering angle of the same size. It is formed so as to be smaller than the limit value of the vehicle speed of the times.

Further, the normal limit line LAN and the failure limit line LAF are formed so as to draw different linearities depending on the speed range. Specifically, in the speed region of vehicle speed 0 or more and V1 or less corresponding to the low speed region, the normal limiting line LAN and the failure limiting line LAF are not set. That is, in the low speed range, the vehicle speed limit value is not set. In the speed range of the vehicle speed V1 or more and V2 or less corresponding to the medium speed range, the ratio of the decrease in the vehicle speed limit value to the increase in the steering angle is set to be relatively small. At vehicle speeds above V2 and V3, which correspond to the high-speed range, the ratio of the decrease in the vehicle speed limit value to the increase in the steering angle is set to be significantly larger than in the medium-speed range. Further, in the speed region of the vehicle speed V3 or higher corresponding to the ultra-high speed region, the normal restriction line LAN and the failure restriction line LAF are not set, but they may be set in the same manner as in the high speed region. In the ultra-high speed range, the first ECU 50 and / or the second ECU 60 may reduce the speed of the vehicle 1 to the vehicle speed V3 or less. An example of vehicle speed V1 is 40 km / h, an example of vehicle speed V2 is 60 km / h, and an example of vehicle speed V3 is 80 km / h, but the present invention is not limited thereto.

The relationship shown in FIGS. 5A and 5B is set in advance as the first control information of the vehicle 1 at the time of manufacturing the vehicle 1 or before the sale, and is stored in the storage unit 21. The first control information may be stored in the storage unit 21 as a map as shown by FIGS. 5A and 5B, and is stored in the storage unit 21 as a function indicating the normal restriction line LAN and the failure restriction line LAF. You may. The first control information can be set according to the characteristics of the vehicle such as the shape of the vehicle, the suspension type and performance, the drive system, and the traveling performance. Such first control information may be set based on the measurement result obtained in the traveling experiment in which the vehicle is actually driven, or may be set based on the measurement result obtained in the virtual experiment such as simulation.

The limit value determination unit 20c limits the vehicle speed by collating the acquired failure information of the left steering mechanism 4L and the right steering mechanism 4R with the target steering angle with the first control information of the storage unit 21. Determine the value. For example, when the limit value determination unit 20c acquires the information that the steering mechanism is in the normal state and the right target steering angle “Aa”, the limit value determination unit 20c refers to the normal restriction line LAN as shown in FIGS. 5A and 5B. Determines the vehicle speed limit value "Va" corresponding to the right target steering angle "Aa". When the limit value determination unit 20c acquires the information that the left steering mechanism 4L is in the collapsed state and the right target steering angle “Aa”, the limit value determining unit 20c refers to the collapse limiting line LAF as shown in FIG. 5A. , The limit value "Va1" of the vehicle speed corresponding to the right target turning angle "Aa" and smaller than "Va" is determined. When the limit value determination unit 20c acquires the information that the right steering mechanism 4R is in the collapsed state and the left target steering angle “Aa”, the limit value determining unit 20c refers to the collapse limiting line LAF as shown in FIG. 5B. , The limit value "Va2" of the vehicle speed corresponding to the left target turning angle "Aa" and smaller than "Va" is determined.

When the size of the target turning angle is smaller than the size of the turning angle indicated by the normal limit line LAN and the failure limit line LAF at the vehicle speed V3, the limit value determining unit 20c does not determine the limit value of the vehicle speed. You may decide well. For example, when determining, the limit value determination unit 20c may determine the limit value of the vehicle speed to "V3".

Next, the operation of the vehicle steering device 100 according to the first embodiment will be described with reference to FIG. Specifically, the operation of the vehicle steering device 100 when a failure occurs in the steering mechanism will be described. FIG. 6 is a flowchart of an example of the operation flow of the vehicle steering device 100 according to the first embodiment.

First, in step S001, when the vehicle 1 is traveling, the acquisition unit 20a of the upper ECU 20 acquires various information. Specifically, the acquisition unit 20a acquires the steering angle detected by the steering angle sensor 10 and the speed of the vehicle 1 detected by the vehicle speed sensor 12. Further, the acquisition unit 20a receives information on whether or not the left steering mechanism 4L and the right steering mechanism 4R have failed from the left steering ECU 30L and the right steering ECU 30R, and the left steering angle sensor 11L. And the actual steering angle of the left steering wheel 3L and the right steering wheel 3R detected by the right steering angle sensor 11R is acquired.

Next, in step S002, the steering angle determination unit 20b of the upper ECU 20 determines the left or right target steering angle using the steering angle acquired by the acquisition unit 20a and the speed of the vehicle 1.

Next, in step S003, the limit value determination unit 20c of the upper ECU 20 determines whether or not the left steering mechanism 4L has failed based on the failure information acquired from the left steering ECU 30L. Further, the limit value determining unit 20c determines that the left steering mechanism 4L has failed even when the left steering ECU 30L cannot communicate with the left steering ECU 30L for the third predetermined time or more. The limit value determination unit 20c proceeds to step S004 when the left steering mechanism 4L has not failed (No in step S003), and when the left steering mechanism 4L has failed (Yes in step S003). Proceed to step S005.

In step S004, the limit value determination unit 20c determines whether or not the right steering mechanism 4R has failed based on the failure information acquired from the right steering ECU 30R. Further, the limit value determining unit 20c determines that the right steering mechanism 4R has failed even when communication with the right steering ECU 30R cannot be performed for the third predetermined time or more. The limit value determination unit 20c proceeds to step S006 when the right steering mechanism 4R has not failed (No in step S004), and when the right steering mechanism 4R has failed (Yes in step S004). Proceed to step S007.

In step S005, the limit value determination unit 20c determines whether or not the right steering mechanism 4R has failed, as in step S004. The limit value determination unit 20c proceeds to step S008 when the right steering mechanism 4R has not failed (No in step S005), and when the right steering mechanism 4R has failed (Yes in step S005). The process proceeds to step S010.

In step S006, the limit value determination unit 20c determines the limit value of the vehicle speed in the normal state and outputs the limit value to the output unit 20d. Specifically, the limit value determination unit 20c refers to the normal limit line LAN for left turn or right turn as shown in FIGS. 5A and 5B showing the relationship between the turning angle and the limit value of the vehicle speed in the storage unit 21. Then, the limit value of the vehicle speed corresponding to the target turning angle of the left or right is determined.

In step S007, the limit value determination unit 20c determines the limit value of the vehicle speed in the failed state of the right steering mechanism 4R, and outputs the limit value to the output unit 20d. Specifically, the limit value determination unit 20c refers to the left turn or right turn failure limit line LAF as shown in FIG. 5B, which shows the relationship between the steering angle and the vehicle speed limit value, in the storage unit 21. Determine the vehicle speed limit corresponding to the left or right target steering angle.

In step S008, the limit value determination unit 20c determines the limit value of the vehicle speed in the failed state of the left steering mechanism 4L and outputs the limit value to the output unit 20d. Specifically, the limit value determination unit 20c refers to the left turn or right turn failure limit line LAF in the storage unit 21 as shown in FIG. 5A, and has a vehicle speed corresponding to the left or right target steering angle. Determine the limit value.

In step S009, the output unit 20d outputs a command to drive the vehicle 1 at a speed equal to or lower than the determined vehicle speed limit value to at least one of the first ECU 50 and the second ECU 60. At least one of the first ECU 50 and the second ECU 60 controls the power device 51 and the brake device 61 so that the vehicle speed is equal to or less than the limit value.

In step S010, the upper ECU 20 outputs a command for displaying information prompting the driver to stop the vehicle 1 or a command for operating the brake or the like to stop the vehicle 1 to the first ECU 50, the second ECU 60, and the like.

As described above, the control device 90 of the vehicle steering device 100 according to the first embodiment includes left and right steering mechanisms 4L and 4R that are not mechanically connected to each other, and the left and right steering wheels 3L and 3R are individually provided. It is a control device of the steering device 100 for a vehicle to steer. The control device 90 acquires the turning information which is the information about the turning of the vehicle 1 and determines the limit value of the vehicle speed corresponding to the acquired turning information. The limit value determining unit 20c and the determined vehicle speed limit value are set to the vehicle. It is provided with an output unit 20d that outputs to the vehicle control device which is the control device of 1. When an abnormality occurs in one of the left and right steering mechanisms 4L and 4R, the limit value determination unit 20c determines a limit value for a vehicle speed smaller than that in the normal state.

According to the above configuration, when an abnormality occurs in one of the steering mechanisms 4L and 4R, the vehicle steering device 100 controls the steering mechanism 4L or 4R in which no abnormality has occurred and travels on the vehicle 1. Can be made to. In this case, even if the actual steering angle of the steering mechanism 4L or 4R in which the abnormality has not occurred is the same before and after the occurrence of the abnormality, the turning radius of the vehicle 1 becomes large and the turning performance of the vehicle 1 deteriorates. The control device 90 sets the limit value of the vehicle speed corresponding to the turning information regarding the turning of the vehicle 1 to be smaller in the abnormal time of the steering mechanism 4L or 4R than in the normal time. Therefore, the turning speed of the vehicle 1 at the time of such an abnormality can be suppressed. Therefore, the vehicle steering device 100 can stabilize the turning running of the vehicle 1 when an abnormality occurs in one of the left and right steering mechanisms 4L and 4R that are not connected to each other.

Further, in the control device 90 of the vehicle steering device 100 according to the first embodiment, the limit value determining unit 20c acquires the steering angles of the steering wheels 3L and 3R in the steering mechanisms 4L and 4R as turning information. Moreover, the limit value of the vehicle speed corresponding to the acquired steering angle is determined. For example, the turning speed possible for the vehicle 1 decreases as the steering angle increases. In the above configuration, since the vehicle speed limit value is determined according to the steering angle, it is possible to stabilize the turning running of the vehicle 1. For example, if the limit value of the vehicle speed is determined to be smaller as the steering angle becomes larger, the turning running of the vehicle 1 can be effectively stabilized.

Further, in the control device 90 of the vehicle steering device 100 according to the first embodiment, when an abnormality occurs in the left steering mechanism 4L, the limit value determining unit 20c limits the vehicle speed in a right turn rather than a left turn. If the value is reduced and an abnormality occurs in the right steering mechanism 4R, the limit value of the vehicle speed in the left turn is made smaller than that in the right turn. For example, when an abnormality occurs in the left steering mechanism 4L, the ability of the vehicle 1 to turn right, that is, to turn in the opposite direction to the left steering mechanism 4L, is to turn left, that is, to turn in the same direction as the left steering mechanism 4L. Is lower than the ability of. When an abnormality occurs in the right steering mechanism 4R, the ability of the vehicle 1 to turn left, that is, to turn in the opposite direction to the right steering mechanism 4R, is to turn right, that is, to turn in the same direction as the right steering mechanism 4R. Will be lower than. Since the vehicle speed limit value determined as described above is smaller in turning in the opposite direction than in turning in the same direction as the steering mechanism in which the abnormality has occurred, it is possible to effectively stabilize the turning running of the vehicle 1. become.

Further, the vehicle steering device 100 according to the first embodiment includes a control device 90, a left steering mechanism 4L and a right steering mechanism 4R, and the left steering mechanism 4L individually turns the left steering wheel 3L. The left steering actuator 5L for generating a driving force for steering, and the right steering mechanism 4R has a right steering actuator 5R for generating a driving force for individually steering the right steering wheel 3R. The vehicle steering device 100 as described above can exert the same effect as the control device 90 according to the first embodiment.

[Embodiment 2]
The vehicle steering device according to the second embodiment will be described. In the vehicle steering device according to the second embodiment, the limit value determining unit 220c of the upper ECU 20 determines the vehicle speed limit value based on the relationship between the target locus of the vehicle 1 and the vehicle speed limit value. Hereinafter, the points different from those of the first embodiment will be mainly described.

As shown in FIG. 7, the upper ECU 20 of the vehicle steering device according to the second embodiment includes an acquisition unit 220a, a steering angle determination unit 20b, a limit value determination unit 220c, and an output unit 20d. The steering angle determination unit 20b and the output unit 20d are the same as those in the first embodiment. Note that FIG. 7 is a block diagram showing an example of the functional configuration of the upper ECU 20 of the vehicle steering device according to the second embodiment.

The acquisition unit 220a acquires the same information as the acquisition unit 20a of the first embodiment. Further, the acquisition unit 220a acquires information on the target locus, which is the travel locus targeted by the vehicle 1. Specifically, even if the acquisition unit 220a acquires the target trajectory information based on the navigation information generated by the IVI device 71 (see FIG. 1) or the road information acquired by the IVI device 71 from the third ECU 70. good. Alternatively, the acquisition unit 220a may acquire information on the target locus based on the information acquired by the measuring device 81 (see FIG. 1) from the fourth ECU 80.

The navigation information generated by the IVI device 71 is information using a GPS (Global Positioning System) system. The navigation information may include map information, the position of the vehicle 1 on the map, and the planned travel route of the vehicle 1 on the map. The limit value determination unit 220c, which will be described later, may calculate the target locus of the vehicle 1 from the above information. Alternatively, the IVI device 71 or the third ECU 70 may calculate the target locus of the vehicle 1 and output it to the acquisition unit 220a as information on the target locus.

The road information acquired by the IVI device 71 may be road information acquired from the road administrator or other information providing service organization via wireless communication. Such road information may include information such as the alignment of the road on which the vehicle 1 is traveling or is scheduled to travel. The limit value determination unit 220c, which will be described later, may calculate the target locus of the vehicle 1 from the road information. Alternatively, the acquired road information may include the target locus of the vehicle 1. Alternatively, the IVI device 71 or the third ECU 70 may calculate the target locus of the vehicle 1 from the road information and output it to the acquisition unit 220a.

The information acquired by the measuring device 81 may be an image of a camera that captures the front of the vehicle 1. The limit value determination unit 220c, which will be described later, may calculate the target trajectory of the vehicle 1 by extracting the road on which the vehicle 1 travels from the image of the camera and calculating the alignment of the road. Alternatively, the fourth ECU 80 may calculate the target locus of the vehicle 1 by calculating the alignment of the road on which the vehicle 1 travels from the image of the camera, and output it to the acquisition unit 220a. A technique for extracting a road from an image of a camera and a technique for calculating the alignment of a road in an image are disclosed in, for example, Japanese Patent Application Laid-Open No. 9-319872. Since such a technique is a known technique, a detailed description thereof will be omitted.

In the present embodiment, as shown in FIG. 8, the target locus of the vehicle 1 is represented by at least one of the turning radius R and the curvature 1 / R of the target locus line TL, which is the locus that the vehicle 1 is going to travel. To. The target locus of the vehicle 1 is not limited to the turning radius and curvature of the target locus, but includes the turning angle at each turning radius included in the target locus, the locus length at each turning radius included in the target locus, and the like. But it may be. Alternatively, the target locus may be represented by a function indicating a locus using coordinates on the map, coordinates with respect to the vehicle 1, and the like. Note that FIG. 8 is a schematic plan view showing an example of the target locus of the vehicle 1 according to the second embodiment.

The storage unit 21 stores the second control information indicating the relationship between the target locus of the vehicle 1 and the limit value of the vehicle speed in the form of a control map, a mathematical formula, or the like. As shown in FIGS. 9A and 9B, in the present embodiment, the second control information shows the relationship between the curvature of the target locus of the vehicle 1 and the limit value of the vehicle speed, but is not limited to this, and the target locus of the target locus. It suffices as long as it shows the relationship between the information and the limit value of the vehicle speed. Note that FIG. 9A is a diagram showing an example of the relationship between the curvature of the target locus of the vehicle 1 and the limit value of the vehicle speed in the normal state of the steering mechanisms 4L and 4R and the collapsed state of the left steering mechanism 4L. FIG. 9B is a diagram showing an example of the relationship between the curvature of the target locus of the vehicle 1 and the limit value of the vehicle speed in the normal state of the steering mechanisms 4L and 4R and the collapsed state of the right steering mechanism 4R.

The limit value determination unit 220c acquires the failure information of the left steering mechanism 4L and the right steering mechanism 4R and the target locus of the vehicle 1. The limit value determination unit 220c determines the limit value of the vehicle speed corresponding to the failure information and the target locus by collating the acquired failure information and the target locus with the second control information of the storage unit 21. Output to the output unit 20d. Here, the target locus is an example of turning information.

In FIGS. 9A and 9B, the horizontal axis indicates the vehicle speed (unit: km / h). The vertical axis shows the curvature of the target locus of turning left and turning right. On the vertical axis, the upper region shows the curvature of the left turn and the lower region shows the curvature of the right turn with respect to the central position where the curvature is the minimum, that is, 0. The curvature of the left turn increases upward, and the curvature of the right turn increases downward.

In FIGS. 9A and 9B, the normal limit line LCN and the failure limit line LCF are formed corresponding to the left turn and the right turn. The normal limit line LCN shows the relationship between the curvature of the target locus and the limit value of the vehicle speed in the normal state, and the failure limit line LCF is the failure state of either the left steering mechanism 4L or the right steering mechanism 4R. The relationship between the curvature of the target locus and the limit value of the vehicle speed is shown. The failure limit line LCF is formed so that the limit value of the vehicle speed is smaller than that of the normal limit line LCN for the same curvature. In other words, the failure limit line LCF is formed so that the curvature is smaller than that of the normal limit line LCN with respect to the limit value of the same vehicle speed.

Further, as shown in FIG. 9A, in the collapsed state of the left steering mechanism 4L, the collapse limiting line LCF has the same magnitude of curvature, and the vehicle speed limit value for right turning is the vehicle speed for turning left. It is formed so as to be smaller than the limit value of. Similarly, as shown in FIG. 9B, in the collapsed state of the right steering mechanism 4R, the collapse limiting line LCF has a curvature of the same magnitude, but the vehicle speed limit value in the left turn is the right turn. It is formed so as to be smaller than the limit value of the vehicle speed.

Further, the normal limit line LCN and the failure limit line LCF are formed so as to draw different linearities depending on the speed range. Specifically, in the speed region of vehicle speed 0 or more and V1 or less corresponding to the low speed region, the normal limit line LCN and the failure limit line LCF are not set. In the speed region of the vehicle speed V1 or more and V2 or less corresponding to the medium speed range, the ratio of the decrease of the vehicle speed limit value to the increase of the curvature is set to be relatively small. At vehicle speeds above V2 and V3, which correspond to the high-speed range, the ratio of the decrease in the vehicle speed limit value to the increase in curvature is set to be significantly larger than in the medium-speed range. Further, in the speed range of the vehicle speed V3 or higher corresponding to the ultra-high speed range, the normal limit line LCN and the failure limit line LCF are not set, but they may be set in the same manner as in the high speed range. In the ultra-high speed range, the first ECU 50 and / or the second ECU 60 may reduce the speed of the vehicle 1 to the vehicle speed V3 or less.

The relationship shown in FIGS. 9A and 9B is set in advance as the second control information at the time of manufacturing or before the sale of the vehicle 1, and is stored in the storage unit 21. The second control information may be stored in the storage unit 21 as a map as shown by FIGS. 9A and 9B, and is stored in the storage unit 21 as a function indicating the normal restriction line LCN and the failure restriction line LCF. You may. The second control information, like the first control information, can be set according to the characteristics of the vehicle. Such second control information may be set based on the measurement result obtained in the traveling experiment in which the vehicle is actually driven, or may be set based on the measurement result obtained in the virtual experiment such as simulation.

For example, when the limit value determination unit 220c acquires the information that the steering mechanism is in the normal state and the curvature “Cb” of the target locus of the right turn, the limit value determination unit 220c obtains the normal limit line LCN as shown in FIGS. 9A and 9B. By reference, the limit value "Vb" of the vehicle speed corresponding to the curvature "Cb" is determined. When the limit value determination unit 220c acquires the information that the left steering mechanism 4L is in the collapsed state and the curvature “Cb” of the target locus of the right turn, the limit value determining unit 220c refers to the collapse limit line LCF as shown in FIG. 9A. By doing so, the limit value "Vb1" of the vehicle speed corresponding to the curvature "Cb" and smaller than "Vb" is determined. When the limit value determination unit 220c acquires the information that the right steering mechanism 4R is in the collapsed state and the curvature “Cb” of the target locus of the left turn, the limit value determining unit 220c refers to the collapse limit line LCF as shown in FIG. 9B. Thereby, the limit value "Vb2" of the vehicle speed corresponding to the curvature "Cb" and smaller than "Vb" is determined.

When the curvature of the target locus is smaller than the magnitude of the curvature indicated by the normal limit line LCN and the failure limit line LCF at the vehicle speed V3, the limit value determination unit 220c does not have to determine the limit value of the vehicle speed. You may. For example, when determining, the limit value determination unit 220c may determine the limit value of the vehicle speed to "V3".

According to the vehicle steering device according to the second embodiment as described above, the same effect as that of the first embodiment can be obtained. Further, in the control device 90 of the vehicle steering device according to the second embodiment, the limit value determining unit 220c acquires and acquires information on the target locus, which is the travel locus targeted by the vehicle 1, as turning information. Determine the limit value of the vehicle speed corresponding to the target trajectory. For example, the turning speed possible for the vehicle 1 becomes lower as the turning radius of the target locus becomes smaller, that is, the curvature becomes larger. In the above configuration, since the vehicle speed limit value is determined according to the target trajectory, it is possible to stabilize the turning running of the vehicle 1. For example, if the limit value of the vehicle speed is determined to be smaller as the turning radius of the target locus becomes smaller, that is, the curvature becomes larger, the turning traveling of the vehicle 1 can be effectively stabilized. Further, the limit value of the vehicle speed based on the target locus can reflect the traveling state of the vehicle 1 traveling along the target locus, which is effective for stabilizing the turning traveling of the vehicle 1.

[Embodiment 3]
The vehicle steering device according to the third embodiment will be described. In the vehicle steering device according to the third embodiment, the limit value determining unit 320c of the upper ECU 20 determines the relationship between the target turning angle of the vehicle 1 and the limit value of the vehicle speed, and the target locus of the vehicle 1 and the limit value of the vehicle speed. Determine the vehicle speed limit based on the relationship. Hereinafter, the differences from the first and second embodiments will be mainly described.

As shown in FIG. 10, the upper ECU 20 of the vehicle steering device according to the third embodiment includes an acquisition unit 220a, a steering angle determination unit 20b, a limit value determination unit 320c, and an output unit 20d. The acquisition unit 220a is the same as that of the second embodiment, and the steering angle determination unit 20b and the output unit 20d are the same as those of the first embodiment. Note that FIG. 10 is a block diagram showing an example of the functional configuration of the upper ECU 20 of the vehicle steering device according to the third embodiment.

The storage unit 21 stores the first control information similar to that of the first embodiment and the second control information similar to that of the second embodiment in the form of a control map, a mathematical formula, or the like. The first control information shows the relationship between the target turning angle of the vehicle 1 and the limit value of the vehicle speed as shown in FIGS. 5A and 5B, and the second control information is as shown in FIGS. 9A and 9B. The relationship between the target trajectory of the vehicle 1 and the limit value of the vehicle speed is shown.

The limit value determination unit 320c acquires the failure information of the left steering mechanism 4L and the right steering mechanism 4R, the target steering angle of the vehicle 1, and the target trajectory of the vehicle 1. The limit value determination unit 320c uses the acquired target steering angle and target locus together to determine the vehicle speed limit value based on the target steering angle, the target locus, and the failure information. Specifically, in the present embodiment, the limit value determination unit 320c uses the target locus when both the target steering angle and the target locus of the vehicle 1 are acquired. Then, the limit value determination unit 320c determines the vehicle speed limit value by collating the acquired failure information and the target locus with the second control information of the storage unit 21. When the limit value determining unit 320c cannot acquire the target locus of the vehicle 1 and acquires only the target turning angle, the acquired failure information and the target turning angle are collated with the first control information of the storage unit 21. By doing so, the limit value of the vehicle speed is determined. The limit value determination unit 320c outputs the determined vehicle speed limit value to the output unit 20d.

According to the vehicle steering device according to the third embodiment as described above, the same effects as those of the first and second embodiments can be obtained. Further, in the control device 90 of the vehicle steering device according to the third embodiment, the limit value determination unit 320c uses the steering wheels 3L and 3R in the steering mechanisms 4L and 4R as turning information, and the vehicle 1 is used. Information on the target locus, which is the target travel locus, is acquired, and the acquired steering angle and the target locus are used in combination to determine the limit value of the vehicle speed. According to the above configuration, since the limit value determination unit 320c determines the vehicle speed limit value by using the steering angle and the target locus together, it is possible to determine the vehicle speed limit value that further stabilizes the turning running of the vehicle 1. can.

Further, in the control device 90 of the vehicle steering device according to the third embodiment, the limit value determining unit 320c may use the target locus with a higher priority than the turning angle to determine the limit value of the vehicle speed. .. Since the steering angle can change according to the change in the steering angle of the steering wheel 2, the limit value of the vehicle speed determined in response to the steering angle can also change in the same manner as the steering angle. The frequency of change of the vehicle speed limit value determined in response to the target trajectory is less than the vehicle speed limit value determined in response to the steering angle. Therefore, the traveling of the vehicle 1 based on the vehicle speed limit value determined in response to the target locus can be more stable than the traveling based on the vehicle speed limit value determined in response to the steering angle. Therefore, it is possible to effectively stabilize the turning running of the vehicle 1.

[others]
Although the vehicle steering device and the like according to one or more aspects of the present invention have been described above based on the embodiments, the present invention is not limited to the embodiments. As long as it does not deviate from the gist of the present invention, a form in which various modifications conceived by those skilled in the art are applied to the present embodiment or a form constructed by combining components in different embodiments is also one or more aspects of the present invention. It may be included in the range of.

For example, in the vehicle steering device according to the third embodiment, when the limit value determination unit 320c of the upper ECU 20 acquires both the target steering angle and the target trajectory of the vehicle 1, the limit value of the vehicle speed is determined. The target trajectory was used, but it is not limited to this. For example, the limit value determination unit 320c may use both the target steering angle and the target trajectory. Specifically, the limit value determining unit 320c calculates the vehicle speed limit value based on the target turning angle by collating the target turning angle and the failure information with the first control information of the storage unit 21. , The limit value of the vehicle speed based on the target locus may be calculated by collating the target locus and the failure information with the second control information of the storage unit 21. Then, the limit value determination unit 320c may determine a smaller limit value as the vehicle speed limit value among the vehicle speed limit value based on the target turning angle and the vehicle speed limit value based on the target trajectory. This enables safe and stable running of the vehicle 1.

Further, in the vehicle steering device according to the first to third embodiments, the upper ECU 20 sets the target steering angle and the target trajectory of the vehicle 1 at least one of the target steering angles and the target trajectories of the vehicle 1 even when the steering mechanisms 4L and 4R of the vehicle 1 are normal. The vehicle speed limit was determined based on, but is not limited to this. When the steering mechanisms 4L and 4R of the vehicle 1 are normal, the upper ECU 20 does not have to set a limit value for the vehicle speed.

Further, in the vehicle steering device according to the first to third embodiments, the vehicle speed limit value is determined by the upper ECU 20, but is not limited thereto. For example, the vehicle speed limit value may be determined by at least one of the left steering ECU 30L and the right steering ECU 30R, and is other than the upper ECU 20 such as the first ECU 50 and the second ECU 60, the left steering ECU 30L and the right steering ECU 30R. It may be determined by the ECU.

Further, in the vehicle steering device according to the first and third embodiments, the upper ECU 20 has determined the limit value of the vehicle speed of the vehicle 1 by using the target steering angle, but the present invention is not limited to this. The upper ECU 20 may determine the limit value of the vehicle speed by using the actual steering angles of the steering wheels 3L and 3R. For example, the upper ECU 20 determines a vehicle speed limit value using the actual steering angle of the right steering wheel 3R when the left steering mechanism 4L fails, and turns left when the right steering mechanism 4R fails. The limit value of the vehicle speed may be determined by using the actual steering angle of the steering wheel 3L.

Further, in the vehicle steering device according to the first to third embodiments, the upper ECU 20 outputs a traveling command for commanding traveling at a vehicle speed limit value to at least one of the first ECU 50 and the second ECU 60, and the vehicle 1 The control was performed to maintain the speed of the vehicle below the limit value of the vehicle speed, but the speed is not limited to this. The upper ECU 20 may notify the driver of the limit value of the vehicle speed. For example, the host ECU 20 may issue a warning to the driver by visual, auditory and / or vibration when the vehicle speed reaches the limit value. The host ECU 20 may output a visual and / auditory warning to the IVI device 71 via the third ECU 70. The upper ECU 20 may issue a warning due to vibration by vibrating the steering wheel 2 via another ECU.

Further, the vehicle steering device according to the first to third embodiments may be mounted on a vehicle having no automatic driving function, or may be mounted on a vehicle having an automatic driving function. The automatic driving function may be any automatic driving level from the automatic driving level 1 corresponding to the driving support to the automatic driving level 5 corresponding to the fully automatic driving.

Further, in the first to third embodiments, the vehicle 1 controls the power device 51 and / or the brake device 61 in order to control the speed of the vehicle 1 to the limit value or less, but the present invention is not limited to this. For example, when the vehicle 1 is provided with a regenerative motor, the vehicle 1 may control the vehicle speed by increasing the load of the regenerative motor.

Further, as described above, the technique of the present invention may be realized by a recording medium such as a system, an apparatus, a method, an integrated circuit, a computer program or a computer-readable recording disk, and the system, the apparatus, the method, the integrated circuit. , Computer programs and any combination of recording media. Computer-readable recording media include non-volatile recording media such as CD-ROMs.

For example, each processing unit included in the above embodiment is typically realized as an LSI (Large Scale Integration) which is an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip so as to include a part or all of them.

Further, the integrated circuit is not limited to the LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection and settings of the circuit cells inside the LSI may be used.

In the above embodiment, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a processor such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

Further, a part or all of the above components may be composed of a removable IC (Integrated Circuit) card or a single module. An IC card or module is a computer system composed of a microprocessor, ROM, RAM, and the like. The IC card or module may include the above LSI or system LSI. When the microprocessor operates according to a computer program, the IC card or module achieves its function. These IC cards and modules may have tamper resistance.

The control method of the present invention is, for example, a control method for a vehicle steering device having left and right steering mechanisms that are not mechanically connected to each other and individually steering the left and right steering wheels, and is related to turning of the vehicle. The turning information, which is information, is acquired, it is detected whether or not an abnormality has occurred in the left and right steering mechanisms, and the vehicle speed limit value corresponding to the acquired turning information is abnormally applied to the left and right steering mechanisms. Is determined and the determined limit value of the vehicle speed is output to the vehicle control device which is the control device of the vehicle, and an abnormality occurs in one of the left and right steering mechanisms. The limit value of the vehicle speed is smaller than the limit value of the vehicle speed when both the left and right steering mechanisms are normal. Such a control method may be realized by a processor such as an MPU (Micro Processing Unit) and a CPU, a circuit such as an LSI, an IC card, a single module, or the like.

Further, the technique of the present invention may be realized by a software program or a digital signal consisting of the software program, or may be a non-temporary computer-readable recording medium in which the program is recorded. For example, such a program acquires turning information, which is information related to the turning of the vehicle, detects whether or not an abnormality has occurred in the left and right steering mechanisms that are not mechanically connected to each other, and obtains the above-mentioned program. The vehicle speed limit value corresponding to the turning information is determined according to whether or not an abnormality has occurred in the left and right steering mechanisms, and the determined vehicle speed limit value is determined by the vehicle control which is the control device of the vehicle. The limit value of the vehicle speed when an abnormality occurs in one of the left and right steering mechanisms output to the device is larger than the limit value of the vehicle speed when both the left and right steering mechanisms are normal. Let the computer do the little things.

The technique according to the present invention is useful for a vehicle steering device in which a mechanism for steering each steering wheel is independent.

1 vehicle, 3L left steering wheel, 3R right steering wheel, 4L left steering mechanism, 4R right steering mechanism, 5L left steering actuator (left actuator), 5R right steering actuator (right actuator), 20 upper ECU, 20c , 220c, 320c Limit value determination unit (determination unit), 20d output unit, 50 1st ECU (vehicle control device), 60 2nd ECU (vehicle control device), 90 control device, 100 vehicle steering device.

Claims (9)

It is a control device for a vehicle steering device that has left and right steering mechanisms that are not mechanically connected to each other and that individually steers the left and right steering wheels.
A determination unit that acquires turning information, which is information related to the turning of the vehicle, and determines a limit value of the vehicle speed corresponding to the acquired turning information.
It is provided with an output unit that outputs the determined limit value of the vehicle speed to the vehicle control device which is the control device of the vehicle.
The determination unit is a control device that determines a limit value of the vehicle speed smaller than that in the normal state when an abnormality occurs in one of the left and right steering mechanisms. The first aspect of claim 1, wherein the determination unit acquires the steering angle of the steering wheel in the steering mechanism as the turning information, and determines the limit value of the vehicle speed corresponding to the acquired steering angle. Control device. The first aspect of the present invention, wherein the determination unit acquires information on a target locus, which is a travel locus targeted by the vehicle, as the turning information, and determines a limit value of the vehicle speed corresponding to the acquired target locus. Control device. The determination unit acquires the steering angle of the steering wheel in the steering mechanism and the information of the target locus, which is the traveling locus targeted by the vehicle, as the turning information, and the acquired steering angle. The control device according to claim 1, wherein the target locus is used in combination to determine a limit value for the vehicle speed. The control device according to claim 4, wherein the determination unit uses the target locus with a higher priority than the turning angle in determining the limit value of the vehicle speed. The decision-making part
If an abnormality occurs in the left steering mechanism, the limit value of the vehicle speed in the right turn is made smaller than that in the left turn.
The control device according to any one of claims 1 to 5, wherein when an abnormality occurs in the right steering mechanism, the limit value of the vehicle speed in the left turn is smaller than that in the right turn. The control device according to any one of claims 1 to 6.
The left steering mechanism and the right steering mechanism are provided.
The left steering mechanism has a left actuator that generates a driving force for individually steering the left steering wheel.
The right steering mechanism is a vehicle steering device having a right actuator that generates a driving force for individually steering the right steering wheel. It is a control method for a vehicle steering device that has left and right steering mechanisms that are not mechanically connected to each other and that individually steers the left and right steering wheels.
Acquire turning information, which is information about turning of the vehicle,
Detecting whether or not an abnormality has occurred in the left and right steering mechanisms,
The vehicle speed limit value corresponding to the acquired turning information is determined according to whether or not an abnormality has occurred in the left and right steering mechanisms.
The determined limit value of the vehicle speed is output to the vehicle control device which is the control device of the vehicle, and the limit value is output.
A control method in which the vehicle speed limit value when an abnormality occurs in one of the left and right steering mechanisms is smaller than the vehicle speed limit value when both the left and right steering mechanisms are normal. Acquire turning information, which is information about turning of the vehicle,
Detects whether or not an abnormality has occurred in the left and right steering mechanisms that are not mechanically connected to each other.
The vehicle speed limit value corresponding to the acquired turning information is determined according to whether or not an abnormality has occurred in the left and right steering mechanisms.
The determined limit value of the vehicle speed is output to the vehicle control device which is the control device of the vehicle, and the limit value is output.
The computer is informed that the vehicle speed limit value when one of the left and right steering mechanisms is abnormal is smaller than the vehicle speed limit value when both the left and right steering mechanisms are normal. The program to be executed.

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